Gas Turbine Inlet Air Cooling System

Presented by

Bob Omidvar

75

80

85

90

95

100

105

110

0 5 10 15 20 25 30 35 40 45GT Inlet Temp (deg C)

Heat rate kJkWh Power output MW Exhaust flow th Exhaust temperature degC

Heavy Duty GT - Effects of Ambient Temp

60

70

80

90

100

110

120

0 5 10 15 20 25 30 35 40 45

GT Inlet Temp (deg C)

Exhaust temperature C Heat rate kJkWh Power output MW Exhaust flow th

Aero-Derivative GT - Effects of Ambient Temp

Gas Turbine Performance Design BasisWhat Does ISO Condition Mean

Dry bulb 15degC

Relative humidity 60

Wet bulb temperature 72degC

Atmospheric pressure 1 bar (sea level)

Most of the gas turbine installations are not in ISO standard locations they are in the real world

Ambient Air and Gas Turbine Performance

1 Air density is inversely related to the dry bulb temperature

2 Gas turbine output depends on mass flow and not the volume of air

3 Ambient temperature affects the following points drastically

Air flow

Output

Heat rate

Exhaust temperature

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Water Tank

CombustionAir

WettedMedia

Schematic of Evaporative Air Coolingshown with Optional Water Treatment

Exhaust GasBlow down

WaterTreatment

MakeUp

AirFilter

Evaporative CoolerApplications Areas where RH and wet bulb temperature is rather low

Advantage Lowest capital cost

Lowest OampM cost

Can operate on raw water

Quick delivery and installation time

Operates as an air washer and cleans the inlet air

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

DemineralisedWater Tank

CombustionAir

FogSpray

System

Schematic of Fog Inlet Air Cooling SystemUtilizing Demineralised Water

DemineralisedWater Treatment

Plant

RawWater

Exhaust Gas

AirFilter

Fog Systems

Demineralised Water Quality For Fog System Inlet Air Cooling

Total dissolved solids

pH

Na + K

5 PPM maximum

6-8

01 PPM maximum

Silica (SiO2)

Chlorides

Sulphate

01 PPM maximum

05 PPM maximum

05 PPM maximum

0123456789

10

0 25 50 75 100 125 150 175 200 225 250

Gas Turbine Output MW

th

Fogging System Demin Water ConsumptionInlet air 36degC DB 25degC WB

Chilled air temp 255degC DB 25degC WB 96RH

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

75

80

85

90

95

100

105

110

0 5 10 15 20 25 30 35 40 45GT Inlet Temp (deg C)

Heat rate kJkWh Power output MW Exhaust flow th Exhaust temperature degC

Heavy Duty GT - Effects of Ambient Temp

60

70

80

90

100

110

120

0 5 10 15 20 25 30 35 40 45

GT Inlet Temp (deg C)

Exhaust temperature C Heat rate kJkWh Power output MW Exhaust flow th

Aero-Derivative GT - Effects of Ambient Temp

Gas Turbine Performance Design BasisWhat Does ISO Condition Mean

Dry bulb 15degC

Relative humidity 60

Wet bulb temperature 72degC

Atmospheric pressure 1 bar (sea level)

Most of the gas turbine installations are not in ISO standard locations they are in the real world

Ambient Air and Gas Turbine Performance

1 Air density is inversely related to the dry bulb temperature

2 Gas turbine output depends on mass flow and not the volume of air

3 Ambient temperature affects the following points drastically

Air flow

Output

Heat rate

Exhaust temperature

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Water Tank

CombustionAir

WettedMedia

Schematic of Evaporative Air Coolingshown with Optional Water Treatment

Exhaust GasBlow down

WaterTreatment

MakeUp

AirFilter

Evaporative CoolerApplications Areas where RH and wet bulb temperature is rather low

Advantage Lowest capital cost

Lowest OampM cost

Can operate on raw water

Quick delivery and installation time

Operates as an air washer and cleans the inlet air

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

DemineralisedWater Tank

CombustionAir

FogSpray

System

Schematic of Fog Inlet Air Cooling SystemUtilizing Demineralised Water

DemineralisedWater Treatment

Plant

RawWater

Exhaust Gas

AirFilter

Fog Systems

Demineralised Water Quality For Fog System Inlet Air Cooling

Total dissolved solids

pH

Na + K

5 PPM maximum

6-8

01 PPM maximum

Silica (SiO2)

Chlorides

Sulphate

01 PPM maximum

05 PPM maximum

05 PPM maximum

0123456789

10

0 25 50 75 100 125 150 175 200 225 250

Gas Turbine Output MW

th

Fogging System Demin Water ConsumptionInlet air 36degC DB 25degC WB

Chilled air temp 255degC DB 25degC WB 96RH

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

60

70

80

90

100

110

120

0 5 10 15 20 25 30 35 40 45

GT Inlet Temp (deg C)

Exhaust temperature C Heat rate kJkWh Power output MW Exhaust flow th

Aero-Derivative GT - Effects of Ambient Temp

Gas Turbine Performance Design BasisWhat Does ISO Condition Mean

Dry bulb 15degC

Relative humidity 60

Wet bulb temperature 72degC

Atmospheric pressure 1 bar (sea level)

Most of the gas turbine installations are not in ISO standard locations they are in the real world

Ambient Air and Gas Turbine Performance

1 Air density is inversely related to the dry bulb temperature

2 Gas turbine output depends on mass flow and not the volume of air

3 Ambient temperature affects the following points drastically

Air flow

Output

Heat rate

Exhaust temperature

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Water Tank

CombustionAir

WettedMedia

Schematic of Evaporative Air Coolingshown with Optional Water Treatment

Exhaust GasBlow down

WaterTreatment

MakeUp

AirFilter

Evaporative CoolerApplications Areas where RH and wet bulb temperature is rather low

Advantage Lowest capital cost

Lowest OampM cost

Can operate on raw water

Quick delivery and installation time

Operates as an air washer and cleans the inlet air

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

DemineralisedWater Tank

CombustionAir

FogSpray

System

Schematic of Fog Inlet Air Cooling SystemUtilizing Demineralised Water

DemineralisedWater Treatment

Plant

RawWater

Exhaust Gas

AirFilter

Fog Systems

Demineralised Water Quality For Fog System Inlet Air Cooling

Total dissolved solids

pH

Na + K

5 PPM maximum

6-8

01 PPM maximum

Silica (SiO2)

Chlorides

Sulphate

01 PPM maximum

05 PPM maximum

05 PPM maximum

0123456789

10

0 25 50 75 100 125 150 175 200 225 250

Gas Turbine Output MW

th

Fogging System Demin Water ConsumptionInlet air 36degC DB 25degC WB

Chilled air temp 255degC DB 25degC WB 96RH

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Gas Turbine Performance Design BasisWhat Does ISO Condition Mean

Dry bulb 15degC

Relative humidity 60

Wet bulb temperature 72degC

Atmospheric pressure 1 bar (sea level)

Most of the gas turbine installations are not in ISO standard locations they are in the real world

Ambient Air and Gas Turbine Performance

1 Air density is inversely related to the dry bulb temperature

2 Gas turbine output depends on mass flow and not the volume of air

3 Ambient temperature affects the following points drastically

Air flow

Output

Heat rate

Exhaust temperature

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Water Tank

CombustionAir

WettedMedia

Schematic of Evaporative Air Coolingshown with Optional Water Treatment

Exhaust GasBlow down

WaterTreatment

MakeUp

AirFilter

Evaporative CoolerApplications Areas where RH and wet bulb temperature is rather low

Advantage Lowest capital cost

Lowest OampM cost

Can operate on raw water

Quick delivery and installation time

Operates as an air washer and cleans the inlet air

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

DemineralisedWater Tank

CombustionAir

FogSpray

System

Schematic of Fog Inlet Air Cooling SystemUtilizing Demineralised Water

DemineralisedWater Treatment

Plant

RawWater

Exhaust Gas

AirFilter

Fog Systems

Demineralised Water Quality For Fog System Inlet Air Cooling

Total dissolved solids

pH

Na + K

5 PPM maximum

6-8

01 PPM maximum

Silica (SiO2)

Chlorides

Sulphate

01 PPM maximum

05 PPM maximum

05 PPM maximum

0123456789

10

0 25 50 75 100 125 150 175 200 225 250

Gas Turbine Output MW

th

Fogging System Demin Water ConsumptionInlet air 36degC DB 25degC WB

Chilled air temp 255degC DB 25degC WB 96RH

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Ambient Air and Gas Turbine Performance

1 Air density is inversely related to the dry bulb temperature

2 Gas turbine output depends on mass flow and not the volume of air

3 Ambient temperature affects the following points drastically

Air flow

Output

Heat rate

Exhaust temperature

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Water Tank

CombustionAir

WettedMedia

Schematic of Evaporative Air Coolingshown with Optional Water Treatment

Exhaust GasBlow down

WaterTreatment

MakeUp

AirFilter

Evaporative CoolerApplications Areas where RH and wet bulb temperature is rather low

Advantage Lowest capital cost

Lowest OampM cost

Can operate on raw water

Quick delivery and installation time

Operates as an air washer and cleans the inlet air

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

DemineralisedWater Tank

CombustionAir

FogSpray

System

Schematic of Fog Inlet Air Cooling SystemUtilizing Demineralised Water

DemineralisedWater Treatment

Plant

RawWater

Exhaust Gas

AirFilter

Fog Systems

Demineralised Water Quality For Fog System Inlet Air Cooling

Total dissolved solids

pH

Na + K

5 PPM maximum

6-8

01 PPM maximum

Silica (SiO2)

Chlorides

Sulphate

01 PPM maximum

05 PPM maximum

05 PPM maximum

0123456789

10

0 25 50 75 100 125 150 175 200 225 250

Gas Turbine Output MW

th

Fogging System Demin Water ConsumptionInlet air 36degC DB 25degC WB

Chilled air temp 255degC DB 25degC WB 96RH

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Water Tank

CombustionAir

WettedMedia

Schematic of Evaporative Air Coolingshown with Optional Water Treatment

Exhaust GasBlow down

WaterTreatment

MakeUp

AirFilter

Evaporative CoolerApplications Areas where RH and wet bulb temperature is rather low

Advantage Lowest capital cost

Lowest OampM cost

Can operate on raw water

Quick delivery and installation time

Operates as an air washer and cleans the inlet air

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

DemineralisedWater Tank

CombustionAir

FogSpray

System

Schematic of Fog Inlet Air Cooling SystemUtilizing Demineralised Water

DemineralisedWater Treatment

Plant

RawWater

Exhaust Gas

AirFilter

Fog Systems

Demineralised Water Quality For Fog System Inlet Air Cooling

Total dissolved solids

pH

Na + K

5 PPM maximum

6-8

01 PPM maximum

Silica (SiO2)

Chlorides

Sulphate

01 PPM maximum

05 PPM maximum

05 PPM maximum

0123456789

10

0 25 50 75 100 125 150 175 200 225 250

Gas Turbine Output MW

th

Fogging System Demin Water ConsumptionInlet air 36degC DB 25degC WB

Chilled air temp 255degC DB 25degC WB 96RH

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Water Tank

CombustionAir

WettedMedia

Schematic of Evaporative Air Coolingshown with Optional Water Treatment

Exhaust GasBlow down

WaterTreatment

MakeUp

AirFilter

Evaporative CoolerApplications Areas where RH and wet bulb temperature is rather low

Advantage Lowest capital cost

Lowest OampM cost

Can operate on raw water

Quick delivery and installation time

Operates as an air washer and cleans the inlet air

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

DemineralisedWater Tank

CombustionAir

FogSpray

System

Schematic of Fog Inlet Air Cooling SystemUtilizing Demineralised Water

DemineralisedWater Treatment

Plant

RawWater

Exhaust Gas

AirFilter

Fog Systems

Demineralised Water Quality For Fog System Inlet Air Cooling

Total dissolved solids

pH

Na + K

5 PPM maximum

6-8

01 PPM maximum

Silica (SiO2)

Chlorides

Sulphate

01 PPM maximum

05 PPM maximum

05 PPM maximum

0123456789

10

0 25 50 75 100 125 150 175 200 225 250

Gas Turbine Output MW

th

Fogging System Demin Water ConsumptionInlet air 36degC DB 25degC WB

Chilled air temp 255degC DB 25degC WB 96RH

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Fuel

Combustion Turbine

Water Tank

CombustionAir

WettedMedia

Schematic of Evaporative Air Coolingshown with Optional Water Treatment

Exhaust GasBlow down

WaterTreatment

MakeUp

AirFilter

Evaporative CoolerApplications Areas where RH and wet bulb temperature is rather low

Advantage Lowest capital cost

Lowest OampM cost

Can operate on raw water

Quick delivery and installation time

Operates as an air washer and cleans the inlet air

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

DemineralisedWater Tank

CombustionAir

FogSpray

System

Schematic of Fog Inlet Air Cooling SystemUtilizing Demineralised Water

DemineralisedWater Treatment

Plant

RawWater

Exhaust Gas

AirFilter

Fog Systems

Demineralised Water Quality For Fog System Inlet Air Cooling

Total dissolved solids

pH

Na + K

5 PPM maximum

6-8

01 PPM maximum

Silica (SiO2)

Chlorides

Sulphate

01 PPM maximum

05 PPM maximum

05 PPM maximum

0123456789

10

0 25 50 75 100 125 150 175 200 225 250

Gas Turbine Output MW

th

Fogging System Demin Water ConsumptionInlet air 36degC DB 25degC WB

Chilled air temp 255degC DB 25degC WB 96RH

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Evaporative CoolerApplications Areas where RH and wet bulb temperature is rather low

Advantage Lowest capital cost

Lowest OampM cost

Can operate on raw water

Quick delivery and installation time

Operates as an air washer and cleans the inlet air

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

DemineralisedWater Tank

CombustionAir

FogSpray

System

Schematic of Fog Inlet Air Cooling SystemUtilizing Demineralised Water

DemineralisedWater Treatment

Plant

RawWater

Exhaust Gas

AirFilter

Fog Systems

Demineralised Water Quality For Fog System Inlet Air Cooling

Total dissolved solids

pH

Na + K

5 PPM maximum

6-8

01 PPM maximum

Silica (SiO2)

Chlorides

Sulphate

01 PPM maximum

05 PPM maximum

05 PPM maximum

0123456789

10

0 25 50 75 100 125 150 175 200 225 250

Gas Turbine Output MW

th

Fogging System Demin Water ConsumptionInlet air 36degC DB 25degC WB

Chilled air temp 255degC DB 25degC WB 96RH

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

DemineralisedWater Tank

CombustionAir

FogSpray

System

Schematic of Fog Inlet Air Cooling SystemUtilizing Demineralised Water

DemineralisedWater Treatment

Plant

RawWater

Exhaust Gas

AirFilter

Fog Systems

Demineralised Water Quality For Fog System Inlet Air Cooling

Total dissolved solids

pH

Na + K

5 PPM maximum

6-8

01 PPM maximum

Silica (SiO2)

Chlorides

Sulphate

01 PPM maximum

05 PPM maximum

05 PPM maximum

0123456789

10

0 25 50 75 100 125 150 175 200 225 250

Gas Turbine Output MW

th

Fogging System Demin Water ConsumptionInlet air 36degC DB 25degC WB

Chilled air temp 255degC DB 25degC WB 96RH

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Fuel

Combustion Turbine

DemineralisedWater Tank

CombustionAir

FogSpray

System

Schematic of Fog Inlet Air Cooling SystemUtilizing Demineralised Water

DemineralisedWater Treatment

Plant

RawWater

Exhaust Gas

AirFilter

Fog Systems

Demineralised Water Quality For Fog System Inlet Air Cooling

Total dissolved solids

pH

Na + K

5 PPM maximum

6-8

01 PPM maximum

Silica (SiO2)

Chlorides

Sulphate

01 PPM maximum

05 PPM maximum

05 PPM maximum

0123456789

10

0 25 50 75 100 125 150 175 200 225 250

Gas Turbine Output MW

th

Fogging System Demin Water ConsumptionInlet air 36degC DB 25degC WB

Chilled air temp 255degC DB 25degC WB 96RH

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Fog Systems

Demineralised Water Quality For Fog System Inlet Air Cooling

Total dissolved solids

pH

Na + K

5 PPM maximum

6-8

01 PPM maximum

Silica (SiO2)

Chlorides

Sulphate

01 PPM maximum

05 PPM maximum

05 PPM maximum

0123456789

10

0 25 50 75 100 125 150 175 200 225 250

Gas Turbine Output MW

th

Fogging System Demin Water ConsumptionInlet air 36degC DB 25degC WB

Chilled air temp 255degC DB 25degC WB 96RH

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Demineralised Water Quality For Fog System Inlet Air Cooling

Total dissolved solids

pH

Na + K

5 PPM maximum

6-8

01 PPM maximum

Silica (SiO2)

Chlorides

Sulphate

01 PPM maximum

05 PPM maximum

05 PPM maximum

0123456789

10

0 25 50 75 100 125 150 175 200 225 250

Gas Turbine Output MW

th

Fogging System Demin Water ConsumptionInlet air 36degC DB 25degC WB

Chilled air temp 255degC DB 25degC WB 96RH

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

0123456789

10

0 25 50 75 100 125 150 175 200 225 250

Gas Turbine Output MW

th

Fogging System Demin Water ConsumptionInlet air 36degC DB 25degC WB

Chilled air temp 255degC DB 25degC WB 96RH

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Fogging SystemApplications Areas where RH and wet bulb temperature is rather low

Advantage Low capital cost

Low OampM cost

Can increase gas turbine performance better than evaporative cooling

Quick delivery and installation time

Disadvantage Limitation on capacity

improvement

Highly influenced by the site wet bulb

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Fuel

Combustion Turbine

AmmoniaLiquid Line

MechanicalRefrigeration

Machine

CombustionAir

AmmoniaSuction Line

Schematic of a Direct SystemUsing an Ammonia Refrigeration Machine

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Mechanical Refrigeration System (Direct Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Disadvantage High initial capital cost

High OampM cost

Longer delivery and installation time

Expertise is needed to operate and maintain the plant

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical Chiller

CombustionAir

Air CoolingCoil

Schematic of an Indirect SystemUsing a Mechanical Chiller

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Mechanical Refrigeration System (Indirect Type)Applications Areas where relative humidity is rather high

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Disadvantage High initial capital cost High OampM cost Long delivery and installation

time Expertise is needed to

operate and maintain the plant

Requires extra chilled water cooling circuit

Higher parasitic load than direct type

Higher energy input compared to direct type chiller

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled

water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Fuel

Combustion Turbine

Chilled WaterPump

Mechanical ChillerIce Maker

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Ice StorageChilled Water Storage System Schematic

Ice Storage Tank

Exhaust Gas

AirFilter

CondensateDrip Pan

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Fuel

Combustion Turbine

Chilled WaterPump

ChilledWater

StorageTank

MechChiller

CombustionAir

Air CoolingCoil

Inlet Air Cooling With Chilled Water StorageSystem Schematic

Exhaust Gas

AirFilter

CondensateDrip Pan

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Mechanical Refrigeration SystemWith Ice Storage

Applications Areas where RH is rather highplus a wide variation in electricity tariff between peak and non peak hours

Advantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Can utilise low night time tariff to produce and store ice for peak hours operation

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time Higher expertise is needed

to operate and maintain the plant

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

0

1

2

3

4

5

6

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Chi

ller E

lect

rical

Loa

d M

WChiller Electrical Load MW

36degC DB 25degC WB 10degC Chilled Air Temp

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Gas Turbine Inlet Air CoolingAvailable Technologies

1 Evaporative cooler2 Fogging system3 Mechanical refrigeration system (direct type)4 Mechanical refrigeration system (indirect type)5 Mechanical refrigeration with ice storage6 Mechanical refrigeration system with chilled water storage7 Single stage Lithium Bromide Absorption chiller8 Two stage Lithium Bromide Absorption chiller

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Fuel

Combustion Turbine

Chilled WaterPump

Absorption Chiller

CombustionAir

Air CoolingCoil

Absorption Chiller Inlet Air CoolingSystem Schematic

Heat RecoverySteam Generator

Exhaust Gas

AirFilter

CondensateDrip Pan

LP S

team

Ret

urn

Con

dens

ate

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

6degC

12degC

Chilled Water

Tower Water In

Tower Water Out

Heat Medium Out

Heat Medium In Steam or Hot Water

tc 45degC

95degC

70degC

to 4degC

Condenser

Generator

Pressure approx60 Torr60 mm Hg80 mbar8 kPa

Pressure approx62 Torr62 mm Hg82 mbar083 kPa

ta 35degC

Evaporator

Absorber

50degC

70degC

27degC

325degC

37degC

Refrigerant (Water)Steam or Hot WaterDiluted Solution (LiBr)Concentrated Solution (LiBr)Tower WaterChilled Water

Flow Diagram

Picture courtesy of York International

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

0

10

20

30

40

50

60

70

80

0 25 50 75 100 125 150 175 200 225 250 275 300

Gas Turbine Output MW

Stea

m C

onsu

mpt

ion

th

Single StageTwo Stage

Absorption Chiller Steam Consumption36degC DB 25degC WB 10degC Chilled Air Temp

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Single Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Two Stage Lithium Bromide Absorption ChillerApplications Areas where relative humidity is rather high and the plant is going to operate in a combined cycle or cogeneration mode and has

access to low pressure steamAdvantage Can increase gas turbine

performance better than evaporative cooling and fog system

Not very sensitive to ambient air wet bulb temperature

Low electrical parasitic load Requires less steam per unit

of refrigeration than single stage chiller

Disadvantage High initial capital cost High OampM cost Longer delivery and

installation time High expertise is needed to

operate and maintain the plant

In case of a steam operated chiller cannot be applied in an open cycle gas turbine plant

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

0

5

10

15

20

25 35 45 55 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 215 225 235 245 255 265

Gas Turbine Output MW

Con

dens

ate

Form

atio

n th

Condensate Formation on the Chilled Water Coil thBased on 36degC DB 25degC WB 10degC Chilled Inlet Air

Temperature

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Performance EvaluationOf Different Inlet Air Cooling Systems

Base Condition 35degC Dry bulb 25degC Dry bulb Real world condition 447 Relative humidity

Increase in power output

Gas turbine output before inlet air cooling

Gas turbine output with mechanical refrigeration system and inlet air

temperature of 10degC

Gas turbine with evaporative cooler running at 85 RH

Gas turbine with fog system running at 100 RH

010823 MW (net)

Percent Change

1531248 MW (net including chiller electrical load)

61148 MW (net)

76911665 MW (net)

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Capital Cost Comparisons ofInlet Cooling Systems

Options

Evaporative cooler

Fog system (excluding water treatment plant)

Relative Costs

1

2Single stage LiBrabsorption chillerTwo stage LiBrabsorption chillerAmmonia mechanical refrigeration system

8

10

95

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Major Contributors To The OampM CostsOptionsEvaporative cooler

Fog system (excluding water treatment plant)

OampM Costs Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption

Single stage LiBrabsorption chiller

Two stage LiBr absorption chiller

Ammonia mechanical refrigeration system

Steam Cooling tower chemical treatment Chiller maintenance Electric power consumption Steam Cooling tower chemical treatment and

make up water Chiller maintenance Electric power consumption Electric power consumption Cooling tower chemical treatment and

make up water Chiller maintenance

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Heavy Duty Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

0410

0420

0430

0440

0450

0460

0470

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Heavy Duty Gas Turbine CO2 Emission kgMWh

520530

540550560570

580590

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Aero-Derivative Gas Turbine NOx Emission kgMWhGT with Dry Low NOx burner

037

038

039

04

041

042

043

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

NO

xEm

issi

on k

gM

Wh

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

Aero-Derivative Gas Turbine CO2 Emission kgMWh

470

480

490

500

510

520

530

540

550

0 5 10 15 20 25 30 35 40 45

Ambient Temperature deg C

CO

2Em

issi

on k

gM

Wh

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam

In Selecting Inlet Air Cooling As A Retrofit To An Existing Plant

Points to watch Check the generator capacity in order not to overload the

generator

Quality of raw water for the evaporative cooler

When using an existing demineralised water treatment plant be careful about the capacity and quality of available demineralised water

With an existing heat recovery steam generator inlet air cooling will change the behaviour of the existing HRSG leading to a drop in steam production at high pressure and increase in intermediate and low pressure steam