ASSESSING THE INFLUENCE OF COOLING THE AIR IN · PDF file · 2013-06-17ASSESSING...

Gas Production and Handling Advances

XVIII Gas Convention, AVPG, Caracas, Venezuela, May 27 - 29 th, 2008

ASSESSING THE INFLUENCE OF COOLING THE AIR IN THE POWER OF THE

INCREASE GAS OF TURBINAS I PIGAP.

ABSTRACT The sites MUC-1 and MUC-3 Field Carito, associated with the project gas injection PIGAP I decline each an average of 20.7 kPa (3 Psi) per million barrels produced, therefore, a pressure drop Additional 896.3 kPa (130 psi), the deficit generated by gas injection due to lack of infrastructure in the short term to injection, cause a loss of 32 MMBN which remains in the reservoir as a reserve surplus that could not be retrieved, and to the extent that it reduces the pressure of the reservoir, the effects of flocculation of asphaltenes and the production of sand are intensified by limiting the potential for producing wells, causing significant losses in productivity to a condition of premature abandonment of the reservoir. Taking into account the increased efficiency of the turbines in the night hours when the temperature decreases were evaluated technically and economically the application of cooling air compressors axales entrance to the turbine to increase power output of the turbines, using systems type absorption cooling, evaporation and compression, to the environmental conditions of maximum dry bulb of 38.8 ° C and relative humidity for that temperature. This evaluation determined that the most favourable option for cooling the air entering the axial compressor of a gas turbine technology is evaporative cooling with cooling capacity from 38.8 ° C to 27.1 ° C and costs investment of $ 7.5 MM with a NPV of $ 2.3 MM and a TIR 100.34, with the application of this technology will get an increase in power to brake each turbine 2267 (3040) for a total of 11335 kW (15202 BHP), translated into higher management gas per train 707921 m3 / d (25 MMPCND) and a total of 3.5 MMm3 / d (125 MMPCND). Keywords: cooling, spraying, axial compressor, a gas turbine, increased power. PDVSA EXPLORATION AND PRODUCTION EDF PDVSA EXPLORATION AND PRODUCTION AV. ALIRIO UGARTE PELAYO MATURIN-MONAGAS [email protected] TL: 0291-660808 FAX: 02916608999 Author: Marilyn Aguilera .- PDVSA E & P Co-Authors: Luis Vasquez / Gustavo Lopez - PDVSA E & P / LK



BACKGROUND In February 2006, was initiated Project Integrated Asset Modeling the Sovereign of the Campo The Carito (MIAS), in order to display, describe and quantify the uncertainties associated with the basement, in addition to the activities required to optimize the Plan Exploitation current, maximising the recovery factor and the Net Present Value to the Nation. That project was evaluated different profiles oil production in the Campo The Carito. Among the strategies for increased production, is the injection of water and gas in areas North, Central, West and South, hoping for a maximum output of crude 310 2009-2010, in which Case was named Optimist MIAS P90 (percentiles 90). The installed capacity of the plant compression high pressure PIGAP I, is 24.4 GM MMm3 / d @ 62053 kPa (900 MMPCN @ 9000 psig), raised the need to increase the capacity of gas compression and injection in the The Carito Oilfield in the order of 600 MMPCND, in addition to the existing 900 MMPCND, with a total of 1500 MMPCND injection pressure discharge 62053 kPa (9000 psig), in what is called Plant Gas Injection to High Pressure PIGAP III, which is estimated to begin operations late 2011. However, the prediction of the behaviour of average reservoir pressure, made with the numerical simulation indicates a decrease of 896.3 kPa (130 psi), compared with the case MIAS3c-980 (injection of 980 and 1100 MMPCND) for MUC-1 reservoirs and MUC-3 to the Year 2009, (see Figure 1). This pressure drop is a significant effect on the reservoir, caused by the steady decline of factor replacement as a result of growth in production from the fields. So the current shortfall injection increase energy reservoir decline accelerating depletion of the same, resulting in the condition of abandoned wells.

6800

6900

7000

7100

7200

7300

7400

7500

Ene- 06 Jul-06 Ene-07 Jul- 07 Ene-08 Jul-08 Ene-09

Pre

sio

n E

stá

tica

(psi

)

CASO MIAS-3c

CASO MIAS-3 1100

INICIO INYECCIÓN 1100 MMPCN

MA XIMO DP = 130 lpc

Figure 1 Prediction of the Behavior of Pressure in the Deposit MUC-3 with Numerical Malingerer

With the information of the increase of the efficiency of the turbines to gas of PIGAP I, in the night hours and with the knowledge that the head offices(plants) with gas turbines diminish his(her,your) power when the temperature of the air increases, one determined that technologically it is possible to eliminate the incident of the temperature set on the decrease of the power and the efficiency, cooled the air that enters to the turbine.



The need to find a way in the short term to reduce the damage caused by the decrease in pressure in the fields Carito is a sufficient argument to assess the feasibility of implementing technologies for the cooling of the air entering the compressor of the axial gas turbines of PIGAP I agree with the theory and industrial applications will get an increase in the power output of the turbines, increasing the volume handled by the centrifugal compressors, which will inject greater volume of gas deposits, minimising the damage caused by deficits injection.

DESCRIPTION OF THE EXISTING FACILITIES

The plant at High Gas Injection Pressure is located in the Complex Muscar, south of the people of Punta de Mata of Monagas State. The plant consists of five trains Compression gas. The whom are shaped primarily by: - Gas Turbine Nuovo Pignone MS 5002C. - Centrifugal Compressor Nuovo Pignone BCL 406 / B. - Centrifugal Compressor Nuovo Pignone BCL 305 / C. - Centrifugal Compressor Nuovo Pignone BCL 305 / D. Each Rail Compression was designed to increase the gas pressure of 7584.3 kPa (1100 psig) to 62053 kPa (9000 psig) through a process interetapas with a volume of 180 to handle MMPCND. The compression process occurs once the gas flow from the dehydration system enters the suction head of the plant, the flow in turn is divided into five sections that go to different compression trains, passing through debugger suction of the first phase indicated in the Figure 2 as BCL406B gas is then led to the separator suction of the second stage. The download process condensate accumulated in the separator is similar to the suction of the first stage. From there, gas makes a journey counterpart to the previous one, with pressures at the end of each phase increasing as the years pass through compressors. Each stage of compression, loading a cooler type End-Fan and then passes through a debugger, with the exception of downloading the third phase which goes directly to the head of unloading and there until each of the six tillers injection.

Figura 2 Scheme of gas managing PIGAP I



ESQUEMA DE COMPRESIESQUEMA DE COMPRESIÓÓN DE PIGAPN DE PIGAP

VENTEO

SALIDA 9000 PSIG180 MMPCGD

BCL406B

3000 PSIG 6000 PSIG 9000 PSIG

BCL305C BCL305D

ESQUEMA DE COMPRESIESQUEMA DE COMPRESIÓÓN DE PIGAPN DE PIGAP

VENTEO

SALIDA 9000 PSIG180 MMPCGD

BCL406B

3000 PSIG 6000 PSIG 9000 PSIG

BCL305C BCL305D

Figura 3 Scheme of Gas compression PIGAP I

The machine used in driving PIGAP I to supply power to the compressors are gas turbines, which extracts energy from the gas flowing through it and transforms it into useful power. In it, the particles flow rapidly emerging from the nozzle suffer a change in the direction of motion, generating a variation in the amount of movement. In Figure 4, there is a block diagram of the turbine with two trees, with an influx of atmospheric air, absorbed by the compressor moves to the combustion chamber where fuel is under pressure, a spark ignites the high voltage Fuel-air mixture and the hot gases of combustion products spread first through the high pressure turbine then, in the low-pressure turbine and then expelled into the atmosphere.

Figure 4 Scheme of gas Turbine.



This paper assesses the technical and economic cooling technologies business application, to determine the most favourable option to install on computers turbochargers MS5002C of PIGAP I; technologies chosen are: cooling by evaporation, absorption cooling and refrigeration mechanical, taking into account weather conditions nearest the area under study. It is expected to determine the average power potential recoverable.

A) Injection system (INLET FOGGING) This is a cooling system, where it is converted into fine droplets demineralized water in the form of mist through special designs jet injection, operating between 35 and 207 bar (500-3000 psig), as the mist evaporates over the duct, the air cools, this technique can reach up to 100% effectiveness of evaporative cooling, depending on the wet bulb temperature. The efficiency of cooling by evaporation is given by.

TBHTBS

TECTBSE

−

−=

EQUATION 1 Where: TBS: Dry-bulb temperature TBH: wet bulb temperature ECT: Temperature entrance to the compressor A typical cooling system by injecting haze, consists of a series of a high-pressure pumps reciprocantes downloading demineralized water to a settlement located downstream of the injector system filters air inlet, the high pressure water is required to form the drops, where the size of the same depend on the limits of the high pressure applied to the exponent "a", this varies between -0.5 and -0.1, depending on the type of injector geometry and using char liquid and definition of the diameter of the drop.

a

Gota LimPT = EQUATION 2

Where:

GotaT :: Size Drop

aLimP : Stop Pressure

The demineralized water is required to avoid deposits in the compressor blades and formation of hot spots, products of the minerals present in the untreated water. In Figure 5 shows a diagram of operation of an injection system by fog, indicating three different areas going through a drop of water from the discharge of the jets until the injection zone entry axial compressor. In Zone 1 located downstream of the inlet filter has a diameter of 90 microns drop of a velocity of the air flow of 2.5 m / s, a time of residence of a second (1) efficiency of evaporation 94.4% and a percentage of saturation of the air inlet 30%. In the area denotada as 2 and located downstream from the muffler, indicates a particle size of 19 microns of water, air velocity of 12.7 km / s, a residence time of 0.5 seconds, an efficiency of evaporation and a 94% share of air saturation of 40%



The third and final stage for the entrance to the axial compressor is a particle diameter of 19 microns, an air velocity of 12.7 km / s, residence times of 0.2 seconds and a percentage of saturation of the air 90% efficiency of evaporation has a value of 85.7%.

Figure 5 Scheme of functioning system evaporation

B) Absorption cooling with Lithium bromide It is a closed-cycle cooling, limited to evaporation temperature above the freezing, because the water is used as coolant.



Figure 6 Scheme of functioning system absorption

In Figure 6 shows the heat supplied to the generator causing boiling weak dissolution of the absorbent (diluted) on the outside of the tubes. The evaporated water condenses on the outside of the condenser tubes, the water that is used to cool in the condenser, typically cools in a tower (the condenser and the generator are located in the same container), an absolute pressure about 6 kPa. The water passes through a siphon for liquids and enters the evaporator. The coolant (water) evaporates on tubes and evaporator cooling water provided by the cooling load. The evaporated refrigerant not flowing to the recirculation pump to be sprayed on the evaporator tubing. The dissolution with a high moisture content that enters the generator increases its concentration as water evaporates. The dissolution highly absorbent resulting (with a low concentration of water) leaves the generator and goes to the heat exchanger, where the flow of water, with high concentrations, which flows into the generator cooled to the flow of dissolution with low concentration of water , which runs until the second container, where they are distributed on the absorber tubes (the absorber and the evaporator are located in the same container), so that the coolant tubes evaporated on the evaporator, is absorbed in the dissolution absorbent. The pressure in the second container during operation is 7 kPa (absolute). The heat absorption and dilution are eliminated through the water from the tower. The resulting dissolution, with a high concentration of water is pumped through heat exchangers to the generator, completing the cycle, this preheating increases system efficiency by reducing the amount of heat that must be provided to the dissolution of high concentrations of water before it begins to evaporate in the generator.

C) Refrigeration Mechanic The refrigeration systems is a closed loop consisting of mechanically forcing the movement of fluid in a closed circuit by creating areas of high and low pressure with the aim of the fluid absorbs heat in a place and dissipate in



the other. It is based on the physical property that the evaporation of a liquid or a gas dilated absorb heat and compression or condensation heat emerge. It is a machine designed to alter the temperature of the environment by applying the so-called refrigeration cycle.

Refrigeration Cycle This cycle is due to thermodynamic cycle ideal Carnot, in these machines becomes the highest possible thermal energy into mechanical work, but there are real em missed the cycle; In Figure 7 shows the outline of the cycle:

Figure 7 Cycle of Mechanical Refrigeration

The compressor refrigerant absorbs as a gas at low pressure and low temperature at the point shown in Figure 1 and 7 comprimiéndolo moves towards the area of high pressure point 2, where the coolant is a gas at high pressure and high temperature. In going through the condenser coolant heat is dissipated into the environment. The refrigerant is licúa and high pressure continues to point 2 to 3. Hence, it passes through the appliance pressure regulator or expander that separates areas of high pressure and low pressure through a reduction in cross sectional point 3 to 4. By lowering the pressure, the saturation temperature of the refrigerant low, allowing absorb heat. Already in the side of low pressure, the coolant reaches the evaporator where it absorbs heat from the atmosphere and evaporates 4 to 1 point. Then it changes again the compressor closing the cycle.

EVALUATION OF TECHNOLOGIES FOR COOLING THE AIR The next survey was limited to the assessment of the following technologies: Option 1: evaporation cooling injection Mist INLET FOGGING Option 2: Absorption cooling with Lithium bromide Option 3: Mechanical Refrigeration System Through a literature review of technical reports were obtained information from existing technologies in the market, and a careful consideration of the volumes of air to be cooled, the pressure and temperature atmospheric air. Below are the choices as well as their main features of operation.



Operational condition and composition of food The conditions of entry are: � Fluid: Air atmospheric � Másico Flow: 123 kg / s � Pressure: 101.35 kPa (14.5 Psig) � maximum dry bulb temperature: 38.8 ° C Eligibility air quality food. Maximum input Temperature: 27 ° C, corresponding to the wet-bulb temperature of the area. Minimum Temperature of entry: 12 ° C (recommended by the manufacturer of the turbine Nuovo Pignone) COOLING SYSTEM BY NEBLINA Designing a system for cooling mist turbine plant PIGAP I A) Conditions of Design: Maximum dry bulb temperature: 38.8 ° C / Relative humidity 42% Wet Bulb temperature: 27.1 ° C Air mass flow: 123 kg / s to 28.3 MW ISO Conditions B) Calculation of the amount of cooling water To calculate the theoretical amount of cooling water, it requires a letter psychometric where geometrically determining the quantity of water entering the conditions of dry bulb temperature and relative humidity for that status, takes this condition moisture to the line of 100% relative humidity, the difference between the amount of water present in the air conditions dry bulb temperature and the amount of water to the maximum relative humidity, is the theoretical amount of water needed for cooling. In the figure shown in the lines and strokes points, entering the chart in terms of dry-bulb temperature of 38.8 ° C and relative humidity of 42%, there is an amount of water present in the air of 17 grms H2O / kg of dry air, bringing this point to the curve relative humidity of 100%, can be seen in the chart valued at 22 grms H2O / kg Air saturated, so the amount of water required is the difference between these values, ie 5 grms H2O / kg of dry air. The flow volume of water required for each turbine is: (5 grms H2O / kg of dry air) X (123 kg Air / s) = 0615 grms H2O / s. For the five turbines, it requires a lot of water: 0.615 grms H2O / s X 5 = 3.075 grms H2O / s. (3075 l / s), the water flow is required for the calculation of water treatment and water flow total required from the source.



Figure 8 Letter Psicométrica

C) Water Treatment System The characteristics of the water supply, indicate that there is a pH of 5.12 and total solids of 70 mg / L, which should be injected caustic soda prior to injection into the booth filters axial compressor. The manufacturers recommend fully demineralized water system in order to prevent deposits in the moving parts of the compressor which can produce corrosion or damage to the compressor, the quality of water cooling is indicated in Table 1

Cantidad de Agua de Enfriamiento: 38.8 ºC - 27.1 ºC = 11.2 ºC 0.017- 0.022 = 5 grms. H2O /Kg de Aire



Tabla 1 Characteristics needed for the water of cooling

Indicador de Calidad del agua. Valor

PH 6,5-7,5

Total Sólidos 5 ppm

Total de metales alcalinos y otros que produzcan

corrosión en caliente

0,5 ppm

conductividad 0,5-1 micro mho/cm

Fuente: GT2005-69144 ASME TURBO EXPO 2005

This design has the following treatment. Power Supply: Well water producer Flow of water supply required: (70186 1671) Temperature of food: 25 ° C Supply pressure: 13,79-344,74 kPa (2-50 Psig). Pre-treatment Injection Soda Cáustica (chemical adjustment of pH from 5 to 7) Filtration of suspended solids to a particle size of 1 micron. Reverse Osmosis System The system must be capable of removing dissolved solids from 70 ppm to 5 ppm. Desmineralizar water to 0.5 ppm carbonates. Measures of membranes for this requirement: Reverse Osmosis Membranes: with the inflow in GPD, corresponding to 70185.6 GPD, we choose a system of 12 commercial membranes 0.3 m diameter by 3700 mm in length, as shown in Table 2.



Tabla 2 Characteristics of different equipments of inverse osmosis.

c) Requirement of power of pumping:

Pressure of Suction: 34,47 kPa (5 Psig) Pressure Comes out: 13790 kPa (2000 psig) Rate of Flow: 1161 Fluid GPD: demineralized Water

The power needed of pumping comes given by the equation η1714/PQPf ∆=

Equation 3

Para un Flujo Total de GPD = 70186



With a volume of 48,4GPM, one difference of pressure of 13755,09 kPa (1995 psi) and supposing an

efficiency of 75 %, it is had:

PF = 48,4 (1995)/1714 (0,75) = 75 HP = 55,93 kW Requirement of Power of the System of Total

Pumping: 75 HP.

d) Specifications of the System of Mist:

Pressure of Operation: 13790 kPa (2000 psig) Capacity of Cooling: 11,2 º C, for this capacity of cooling

and as every stage he must not be a minor to 1 º C, is had:

Stages of Cooling: 6 Stages (1,86 º C for Stage) I Number of tewels of injection: 210 (I date back to the

supplier) Type of recommended Tewel: Impaction-pin orifice.

e) Calculation of the Hours of Equivalent Cooling:

In the Figures 9 and Figures 10, they present the equivalent one to the hours(o'clock) of cooling total

and usable, monthly and accumulated annual of Monagas's North in the period In April 2005-Marzo 2006, in

agreement to the temperature of humid bulb and dry bulb of the zone.

Representación del Equivalente de Enfriamiento Grados Horas Periodo 2005-2006 Norte de Monagas

0

10000

20000

30000

40000

50000

60000

Abril Mayo Junio Julio Agosto Septiembre Octubre Noviembre Diciembre Enero Febrero Marzo

Meses

EC

DH

(ºC

.hr)

"

ECDH Acumulativo (ºC.hr)

ECDHTotales49838,8

Figura 9 ECDH Totales Anuales del Norte de Monagas Período 2005-2006.



Representación del Equivalente de Enfriamiento Grados Horas Periodo 2005-2006 Norte de Monagas

0

5000

10000

15000

20000

25000

30000

Abril Mayo Junio Julio Agosto Septiembre Octubre Noviembre Diciembre Enero Febrero Marzo

Meses

ECDH (ºC

.hr)"

ECDH Acumulativo (ºC.hr)

ECDH18450,683

Figura 10 ECDH Aprovechables Anuales del Norte de Monagas Período 2005-2006.

The quantity of usable hours of cooling refers to the quantity of hours that is estimated, operative this one the system of injection of mist, differs from the quantity of equivalent annual hours, due to the fact that the first one is reduced the hours of the winter time, where there takes as a premise a relative dampness of 100 %, for what the system cannot operate, nevertheless in this time the temperature of the air diminuye for the effect of the rains, increasing equally the power of exit of the turbines.

REFRIGERATION FOR ABSORPTION WITH BROMIDE OF LITHIUM

This system is limited to temperatures of Evaporation over that of freezing, due to the fact that the

water uses like cooling. In the Figure 11se it(he,she) shows the scheme of functioning.

a) Calculation of the capacity of needed(asked) refrigeration

Figure 11 11Esquema of Simulation in HYSYS, Calculation of the Capacity of Refrigeration

For the calculation of the capacity of needed(asked) refrigeration, there decides the heat that is necessary

to remove of the air, to take the temperature from 38,8 º C up to(even) 15 º C, using the package of simulation



HYSYS Version 3.1, a heat value decides to remove of 16,95 MMBtu/hr, correspondent to 1412,5 Tons of

Refrigeration.

With the value of the tons of refrigeration needed, there is chosen between a catalogue a sales team of a

system of refrigeration by bromide of lithium as(like) absorbent, since one shows in the Table 3, using the water

as(like) cooling.

Once determined the system, the water volume is had to be handled by every equipment(team) in the process; In agreement to the description of the system of refrigeration for absorption, it is needed to extract heat of the condenser simulating this process there is had that the quantity of water steam needed to cool the air of entry of the turbine is of 7481 kg/h and the heat quantity that it is necessary to to extract from the steam in the condenser to be 4,5 MM kcal/h, since one shows in the Figure 12

Tabla 3 Typical Sales teams of refrigeration with Bromide of Lithium

Equipo ABTF-1500



Figura 12 Calculation heat quantity that it is necessary to to remove from the Generator.

For the extraction of the heat in the absorbedor and the condenser there is in use water of cooling that

normally comes from a tower of cooling, to the case in study the water of cooling goes of the tower for 29,44 ºC

(85 ºF) and enters(approaches) the same one to 36,11 ºC (97 ºF); The water needed of cooling for the given

conditions is of 1226 m3/h since(as,like) it is possible to observe in the table 4.3, additional a volume of losses

has po evaporation, dragging, reinstatement and lost by wind of 6,504 m3/h

The water quantity of cooling is of a total rate of 1232,5 m3/h.

With this flow and a temperature of humid bulb it(he,she) is of 27 °C and the environmental temperature

of a maximum of design of 40 °C; there calculates the quantity of ventilators necessary for the tower of cooling,

of agreement to the scheme showed in the Figure 13



Figura 13 Determination water quantity of cooling needed

To cool a water volume of 1232,5 m3/h, from a temperature of 36,11 °C up to(even) 30 °C, it is needed to

withdraw from the water a quantity of 7,6 MMkcal/h.

Mechanical refrigeration

The mechanical refrigeration is similar to the process of cooling that the system with bromide of

lithium, only that is in use a compressor in substitution of the generator - absorbedor, for the design decides the

dimensions of the heat interchanger propane angers-, using the propane as(like) cooling, that shows in the Figure

14

Figura 14 Schematic graph of the Simulation of the process of Mechanical Refrigeration



Of the Figure 14 is observed that, as soon as the gas happens(passes) for the compressor it is cooled up to saturation conditions, later it(he,she) goes on to the valve of expansion, where the pressure is reduced and for ende the temperature up to conditions of sub-cooled liquid, with these conditions it(he) is directed up to the heat interchanger to reduce the temperature of the air from 38,8 °C up to(even) 15 °C. In Table 4 show themselves the design parameters, dimensionamiento and power needed for every equipment(team).

Tabla 4 Design parameters equipments of mechanical refrigeration

Equipo/Device

Potencia/

Duty/UxA

Size/

Cv

Lost

pressure

Polytr

opica

Efficiency

Type

Compressor 4673,3 HP 79,6% Centrifugo

Condenser 24,33

MMBtu/hr

68,95

kPa

10 Psi

Valve of Expansion

137,4

GPM

1509,96

kPa

219 Psi

Interchanger /

evaporating

6,9exp4

Btu/°F-hr

2

pasos Tubo

34,47

kPa

5 Psi

TEMA E

In the Appendix 6, show themselves the results of every showed simulation.

Financial analysis of the Evaluated Technologies

Economic evaluation

To determine the most attractive option from the economic point of view there was used the

methodology of the options of minor cost using as economic indicator of comparison the present value, for what

it thinks that the best option is that of minor present value.

The options of minor cost constitute a useful tool of evaluation to compare alternatives related to not

generating projects of income, but of recovery or maintenance, since it is the case of the increase of power of the

turbines across the cooling.

Financial analysis of the Evaluated Technologies

In the Table 5se it(he,she) shows a summary of the present values related to the costs of investment

(capex), operative costs (opex) and the total costs (capex + opex) resultant of the economic evaluation (in an

economic horizon of 12 years) realized to the different alternatives to cool the air of entry to the axial

compressors of the turbines to gas of PIGAP I.



Table 5 Results economic evaluation VP (Costs)

Present value Costs MMBs. Evaporation Absorption Mechanical Refrigeration

CAPEX 1.502.186,28 6.373.450,16 4.427.525,59

OPEX 3.542.772,74 9.379.286,93 7.047.773,66

TOTAL VP 5.044.959,02 15.752.737.09 11.475.299,2

Fuente: propia

In the Figures 15 and Figure 16 represent graphically the results obtained of the internal rate of return

and present total value of each one of the options of cooling evaluated.

Figura 15 Results of economic evaluation (total VP)

2,3566562

1,00534949

1,82128745

0

0,5

1

1,5

2

2,5

3

Evaporación Adsorción Compresión

Tecnologías

Valo

r P

resen

te N

eto

MM

$



Figura 16 Results of Economic evaluation Appraises Hospitalizes of Return (TIR)

Is observed that for this project the most suitable option from the economic point of view is the represented one for the system of cooling across the Injection of Mist, (potential of cooling of 11,2 °C) which means that it is the " less costly " option for the cooling of the air of entry. The refrigeration for adsorption (potential of cooling of 23 °C), generates operative costs very raised beside needing high volumes of water for the process of cooling while the system of refrigeration for compression represents the second major cost of investment.

Selection of the Best Option for the Cooling of the Air

Since the most suitable option was demonstrated in the previous section from the economic point of view for the air volumes of cooling (123 (kg/s) it is constituted by the installation of a system of cooling for evaporation, nevertheless the economic considerations, though valid, they are insufficient to decide which is the most suitable option. For this reason there is realized a more wide evaluation, in which there is applied a counterfoil of analysis of options, which allows to compare three technologies of cooling applying criteria, both technical and economic, to evaluate the feasibility of the processes proposed in the cooling of the draught in the entry of the axial compressors of the turbines to gas It(He,She) Marks General Electric Model MS5002-C.

Three proposed technologies are submitted to comparison by means of the assignment of a scale considered from the 1 to 5 (poor person to very good respectively) assigning a respective value to which(whom) every option is evaluated with regard to the established criteria him(her) and then multiplying this value by the weight of the

100%

32,11%

8,72%

0%

20%

40%

60%

80%

100%

120%

Evaporación Adsorción CompresiónTecnologias

TIR



above mentioned criterion. The convenience of every option comes given by the total sumatoria of these products. The results 6 appear in the table.

Tabla 5 6Matriz of analysis of options for the suction of the axial compressors

Opciones A B C D E F G H I J Total

Evaporación 2/25 3/36 3/30,9 3,26,1 3/24,5 3/21,2 2/17,4 3/40,8 3/24,5 1/10,9 257,21

Absorción 3/37,5 1/12 1/10,9 1/8,7 1/8,2 2/14,1 2/17,4 1/13,6 1/13,6 2/21,8 159,89

Compresión 3/37,5 1/12 2/20,6 2/17,4 2/16,3 3/21,2 3/26,1 2/27,2 2/27,2 3/32,7 227,31

Peso 12,5 12 10,3 8,7 8,15 7,07 8,7 13,6. 8,15 10,9

Escala 1: Excelente 2: Bueno 3: Regular

Fuente: propia

Since it is possible to observe in the counterfoil of previous evaluation the best classified option (major puntaje) it is the option number one (1) for what the technology of cooling takes for evaporation as(like) most adapted from the technical point of view - economically to cool the air of entry to the axial compressor of the turbines to gas MS5002C of PIGAP I.

CONCLUSIONS

� The effective power of exit of the turbines in relation to the temperature of entry of the air to the axial

compressor is:

� Effective Power 27 °C (80°F) = 24873 KW (33817,9 HP)

� Effective Power 15 °C (60°F) = 27424 KW (37286 HP)

� The brake horsepower needed by every train of compressors is 32532 HP to handle 205 MMPCND,

33322 HP for 210 MMPCND

� The major volume that it is possible to handle in the centrifugal compressors, with the technology of

cooling for evaporation, is 210 MMPCND and corresponds(fits) to diminishing the temperature of

entry of the air from 38,8 ºC up to(even) 27 °C

� In case of the technologies of refrigeration for absorption and mechanical refrigeration, the major

volume of gas that it is possible to handle is 230 MMPCND, on having diminished the temperature of

entry of the air from 38 ºC up to(even) 15 °C.

� The technology of cooling for evaporation depends on the values of relative dampness of the area in

evaluation.



RECOMMENDATIONS

� To install a system of refrigeration for the air of entry to the turbina to gas of PIGAP I, MS5002C.

� To study the feasibility of using the system of cooling for absorption in the administrative adjacent

buildings to the area of location of turbines to gas, using the heat of unload of the turbines.

ASSESSING THE INFLUENCE OF COOLING THE AIR IN · PDF file · 2013-06-17ASSESSING...

Documents

Transcript of ASSESSING THE INFLUENCE OF COOLING THE AIR IN · PDF file · 2013-06-17ASSESSING...