Development of Simulation Model for Predicting the ... presentation_SEE2006... · 1 Development of...

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Development of Simulation Model for Predicting Development of Simulation Model for Predicting the Performance of a Hybrid the Performance of a Hybrid Photovoltaic/ThermalPhotovoltaic/Thermal

(PV/T) Air Heating System for Regenerating (PV/T) Air Heating System for Regenerating Silica Gel in the Air Conditioning RoomSilica Gel in the Air Conditioning Room

Presented byPresented by

Mr.YodMr.Yod SukamongkolSukamongkolDr. Dr. SupachartSupachart ChungpaibulpatanaChungpaibulpatanaDr. Dr. BunditBundit LimmeechokchaiLimmeechokchaiDr. Dr. PatamapornPatamaporn SripadungthamSripadungthamDr. Dr. LalitaLalita TantimurathaTantimuratha

SirindhornSirindhorn International Institute of TechnologyInternational Institute of TechnologyThammasatThammasat University, ThailandUniversity, Thailand

22

Organization of TalkOrganization of Talk

IntroductionIntroductionSimulation ModelSimulation ModelConfiguration of Simulation Configuration of Simulation SystemSystemResults and DiscussionResults and DiscussionConclusionConclusion

33

To develop a mathematical simulation To develop a mathematical simulation model for predicting the performance of model for predicting the performance of a PV/T air heating collector for a PV/T air heating collector for regenerating silica gel in airregenerating silica gel in air--condition condition system system

ObjectiveObjective

44

IntroductionIntroduction

For a small house, the air conditioner For a small house, the air conditioner consumes over 70% of the total electrical consumes over 70% of the total electrical energy used which is applied to remove the energy used which is applied to remove the sensible and latent heat to maintain the sensible and latent heat to maintain the comfort zone in the living space.comfort zone in the living space.

Desiccant can adsorb moisture in the air, Desiccant can adsorb moisture in the air, thus, the latent heat decreases resulted in thus, the latent heat decreases resulted in the decrement of electrical power demand the decrement of electrical power demand in the air conditioner. in the air conditioner.

55

IntroductionIntroductionAfter desiccant saturates, it needs to After desiccant saturates, it needs to regenerate or removeregenerate or remove waterwater by heating with by heating with the unsaturated air stream.the unsaturated air stream.

The hot air stream can be generated by The hot air stream can be generated by PV/T air heating collector and condenser of PV/T air heating collector and condenser of A/C system.A/C system.

The whole system of this study is called a The whole system of this study is called a hybrid PV/T air heating collector for hybrid PV/T air heating collector for regenerating silica gel in airregenerating silica gel in air--condition condition system.system.

66

A hybrid PV/T air heating collector for A hybrid PV/T air heating collector for regenerating silica gel in airregenerating silica gel in air--condition systemcondition system

1

4

3 2

(1) PV/T Collector(1) PV/T Collector(2) Silica gel(2) Silica gelDehumidification Unit,Dehumidification Unit,(3) Living space,(3) Living space,(4) Air(4) Air--conditioning conditioning systemsystem

77



88

Glass Cover (g)CH 1 (f1)Air (in)

PV/T AbsorberPlate (p)

CH 2 (f2)Air (out)

Back Plate (b)

Insulator

Qin,g Qrad,g-a Qconv,g-a

Qconv,g-f1Qin,p Qconv,g-f1Qrad,p-g

Qrad,p-b Qconv,g-f2

Qconv,b-f2

Qcond,b-a

Qelec

Qth

Simulation ModelSimulation Model

PV/T Air Heating CollectorPV/T Air Heating Collector

99

PV/T Air Heating Collector ModelPV/T Air Heating Collector Model

..

…

..

.

.

.

.

...

Glass CoverGlass Cover

, , , , 1 ,store g in g rad g a conv g a conv,g f rad p gQ Q Q Q Q Q→ → → →= − − − +

4 4

1 1

( ) ( )

( ) ( )

gg g g g g gs g g s s g cga g a

g cgf g f g rpg p g

dTm C GA A F T T A h T T

dtA h T T A h T T

α σ ε ε= − − − −

− − + −

1010


..

…

..

.

.

.

.

...

Air Flow Air Flow CH1CH1

, 1 1 1 1store f cov,g f cov,p f uQ Q Q Q→ →= + −

11 1 1 1 1 1 1 1 1( ) ( ) ( )f

f f g cgf g f g cpf p f f f out f in

dTm C A h T T A h T T mC T T

dt= − + − − −&

1111


..

…

..

.

.

.

.

...

PV/T PV/T Absorber Absorber

PlatePlate

, , , 1 2 ,store p in p rad p g conv,p f conv,p f rad p b elecQ Q Q Q Q Q Q→ → → →= − − − − −

1 1

1 2

( ) ( )

( ) ( )

pp p S g p p rpg p g p cpf p f

p cpf p f p rpb p b S S g p

dTm C GA A h T T A h T T

dtA h T T A h T T GA

α τ

η α τ

= − − − −

− − − − −

1212


Air Flow Air Flow CH2CH2

, 2 2 2 2store f cov,p f cov,b f uQ Q Q Q→ →= + −

22 2 2 2 2 1 2 2 2( ) ( ) ( )f

f f p cpf p f b cbf p f f f out f in

dTm C A h T T A h T T mC T T

dt= − + − − −&

1313


Back Back PlatePlate

, , 2 ,store b rad p b conv,b f cond b aQ Q Q Q→ → →= − −

2 2( ) ( ) ( )bb b p rpb p b b cbf b f b ba b a

dTm c A h T T A h T T A U T Tdt

= − − − − −

1414

PV/T EfficiencyPV/T Efficiency

Thermal EfficiencyThermal Efficiency

Solar Cell EfficiencySolar Cell Efficiency

PV/T EfficiencyPV/T Efficiency

thth

c

Q dtTotal thermal energy outputTotal incident radiation A Gdt

η = = ∫∫

eleccell

c

Q dtTotal electrical energy outputTotal incident radiation A Gdt

η = = ∫∫

/

=

PV T

rem elec

c

Total thermal energy + Total electrical energyTotal incident radiation

Q dt Q dt

A Gdt

η =

+∫ ∫∫

1515


1

4

3 2


1616

Desiccant Cycle ProcessDesiccant Cycle Process

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Desiccant ModelDesiccant Model

,Y aρ

,Y dρ

, ,( )d m d W d W aR h A ρ ρ= −Mass Transfer:Mass Transfer:

, ,

, ,

W a W dm dd

W a W d

P Ph ARR T T

⎛ ⎞= −⎜ ⎟⎜ ⎟

⎝ ⎠Applying Idea Gas Law:Applying Idea Gas Law:

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Desiccant Operation ModelDesiccant Operation Model

Conservation of EnergyConservation of Energy::d s aQ Q Q= +

Where Where QdQd = heat gain during the sorption process (W),= heat gain during the sorption process (W),

QsQs = heat gain at desiccant (W), and = heat gain at desiccant (W), and

QaQa = heat gain at air stream (W).= heat gain at air stream (W).

,( )d d p W wb sQ R C T h= +

( )s d d wdTQ m C XCdt

= +

, 1 2 1( ( ) )( )va a p a w a a

dhQ m C C T TdT

ω= + + −&

1919


1

4

3 2


2020

Living Space Living Space (Load Calculation)(Load Calculation)

2121

Cooling Load CalculationCooling Load Calculation

Total Heat GainTotal Heat Gain::Total w inf intQ Q Q Q= + +

Where Where QQww = heat gain through walls and roof (W),= heat gain through walls and roof (W),

QQinfinf = heat gain due to infiltration (W)= heat gain due to infiltration (W)

QQintint = heat gain due to internal sources (W).= heat gain due to internal sources (W).

( )w eo roomQ UA T T= −

0.33 ( )0.8 ( )

si o room

la o room

Q nV T TQ nV g g

= −

= −

Human: Qsi = 90 W, Qla = 70 W

Appliances: Qsi is close to energy consumption

2222

Air Conditioning SystemAir Conditioning System

2323

Air Conditioning System ModelAir Conditioning System Model

For Compressor:For Compressor:

For Condenser:For Condenser:

For Evaporator: For Evaporator:

For COP:For COP:

)( 12 hhmW rcom −=••

)( 32 hhmQ rcon −=••

)( 41 hhmQ revap −=••

evap

com

QCOP

W

•

•=

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2525

Case StudyCase StudyTwo Two occupantsoccupants

Four 36W Four 36W Fluorescent Fluorescent lamps & a TVlamps & a TVTTroomroom = 25= 25ooC C RH = 50%RH = 50%3.6 m

4.8 m

2.5 m

2 m

15 o

N

3.6 m

Configuration of Simulation SystemConfiguration of Simulation System

2626

Configuration of Simulation SystemConfiguration of Simulation System

The The PVPV//T T solarsolar airair heatingheating collectorcollector consistingconsisting ofof a a 22--mm22 singlesingle--glassglass collectorcollector,, twotwo airair flowflow channelschannels andandthreethree 4242--WpWp amorphousamorphous--siliconsilicon..

HourlyHourly totaltotal solarsolar irradiancesirradiances simulatingsimulating fromfrom thetheExellExell’’ss solarsolar radiationradiation modelmodel areare usedused inin thethesimulationsimulation..

TheThe dailydaily ambientambient temperaturetemperature variationvariation isis assumedassumedtoto bebe sinusoidalsinusoidal andand a a constantconstant windwind speedspeed ofof 11mm//s s isisusedused forfor thethe sakesake ofof simplicitysimplicity..

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2828

Meteorological InputMeteorological Input

0

100

200

300

400

500

600

700

800

900

1000

6:00 12:00 18:00 0:00 6:00 12:00 18:00 0:00 6:00

Time of Day (hours)

Glo

bal R

adia

tion (

W/m

2)

0

5

10

15

20

25

30

35

40

45

50

Tem

pera

ture

(oC

)

G

Ta

2929

0

10

20

30

40

50

60

70

80

90

100

6:00 12:00 18:00 0:00 6:00 12:00 18:00 0:00 6:00

Time

Tem

pera

ture

(oC

)

TP

TB

TG

TF2

TF1

Ta

Simulated ResultsSimulated Results

3030


3131

0

100

200

300

400

500

600

700

800

900

1000

1100

6:00 9:00 12:00 15:00 18:00 21:00 0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00 3:00 6:00

Time of Day (hours)

Glo

bal R

adia

tion

(W/m

2),

Hea

t Gai

n (W

)

.

0

10

20

30

40

50

60

70

80

90

100

110

Am

bien

t Tem

pera

ture

( o

C )

.

Q South

Q West

Q East

Q North

G

Ta


3232

Temperature and Relative Humidity in The room

0102030405060708090

100

6:00 9:00 12:00 15:00 18:00

Time

Tem

pera

ture

(oC

)

.

-1-0.8-0.6-0.4-0.200.20.40.60.81

Rel

ativ

e H

umid

ity

.

RH ambient

RH room

Ta

Troom


3333

ToTal Energy SavingSensible Latent Total A/C MJ Des. MJ Used in A/C %

A/C only 63.159 38.979 102.138 15.884 38.979 0.000 0.000 102.138 0.000A/C with 60.128 44.373 104.501 7.458 18.301 10.624 27.060 77.441 24.180

Dessicant

Q Gain (MJ) Water drain (Kg)


3434

The main objectives, which are The main objectives, which are constructing and developing the simulation constructing and developing the simulation model of a hybrid PV/T air heating system model of a hybrid PV/T air heating system for regenerating silica gel in the air for regenerating silica gel in the air conditioning room, are succeeded.conditioning room, are succeeded.

The PV/T air heating can be used to supply The PV/T air heating can be used to supply the hot air, which is about 50oC, for mixing the hot air, which is about 50oC, for mixing with those of condensing unit of air with those of condensing unit of air conditioning system to regenerate the conditioning system to regenerate the saturated desiccantsaturated desiccant

ConclusionsConclusions

3535


The generated electrical energy which is The generated electrical energy which is about 2about 2--3 MJ per day can be used to 3 MJ per day can be used to supply the electrical device in the system supply the electrical device in the system or sent to the grid line.or sent to the grid line.

The results show that the silica gel can be The results show that the silica gel can be used to dehumidify the moisture in the air used to dehumidify the moisture in the air which leads to about 24% energy saving which leads to about 24% energy saving for the air conditioning systemfor the air conditioning system

3636

Once the developed model is verified Once the developed model is verified by experimental results, it will be by experimental results, it will be useful for predicting the useful for predicting the performances and energy saving of performances and energy saving of the system to meet the load the system to meet the load requirements at any operating site requirements at any operating site location.location.


3737

Thank you

3838

Temperature and Relative Humidity of Air at the outlet of PV/T Collector

0

1020

3040

50

6070

8090

100

6:00

9:00

12:00

15:00

18:00

21:00 0:0

03:0

06:0

09:0

012

:0015

:0018

:0021

:00 0:00

3:00

6:00

Time

Tem

pera

ture

(oC

)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Rel

ativ

e H

umid

ity

RH ambient

RH out

T out

Ta


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PV/T Air Heating Collector PV/T Air Heating Collector Experimental SetupExperimental Setup

4040


4141


4242


4343


4444


4545


4646

Experimental RoomExperimental Room

4848

Experimental RoomExperimental Room

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Desiccant Operation Desiccant Operation

5050

Air Conditioning ProcessesAir Conditioning Processes

Dry air mass:Dry air mass:Water Mass:Water Mass:

Energy:Energy:

, ,a i a em m=∑ ∑& &

, , , , or w i w e a i i a e em m m mω ω= =∑ ∑ ∑ ∑& & & &

e e i iQ W m h m h− = −∑ ∑& & & &

5151

Air Conditioning SystemAir Conditioning System

..

…

..

.

.

.

.

...

con com evap

evapcom

Q W Q

QW

COP

= +

=

& &&

&&

Condenser

Compressor

Hot Air

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