Presentacion air inlet cooling system
Content
Gas Turbine Inlet Air Cooling System
The 3rd Annual Australian Gas Turbine Conference
6th – 7th December 2001 Melbourne Australia Presented by
Bob Omidvar Manager, Power Engineering PB Power Australia
PB Power
Heavy Duty GT - Effects of Ambient Temp
110% 105% 100% 95% 90% 85% 80% 75% 0 5 10 15 20 25 30 35 40 45
GT Inlet Temp (deg C)
Heat rate kJ/kWh Power output MW Exhaust flow t/h Exhaust temperature °C
PB Power
Aero-Derivative GT - Effects of Ambient Temp
120% 110% 100% 90% 80% 70% 60% 0 5 10 15 20 25 30 35 40 45
GT Inlet Temp (deg C)
Exhaust temperature C Heat rate kJ/kWh Power output MW Exhaust flow t/h
PB Power
Gas Turbine Performance Design Basis
What Does ISO Condition Mean?
! ! ! !
Dry bulb 15°C Relative humidity 60% Wet bulb temperature 7.2°C Atmospheric pressure 1 bar (sea level)
Most of the gas turbine installations are not in ISO standard locations, they are in the real world
PB Power
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
PB Power
Gas Turbine Inlet Air Cooling
Available Technologies
1. Evaporative cooler 2. Fogging system 3. Mechanical refrigeration system (direct type) 4. Mechanical refrigeration system (indirect type) 5. Mechanical refrigeration with ice storage 6. Mechanical refrigeration system with chilled water storage 7. Single stage Lithium Bromide Absorption chiller 8. Two stage Lithium Bromide Absorption chiller
PB Power
Gas Turbine Inlet Air Cooling
Available Technologies
1. Evaporative cooler 2. Fogging system 3. Mechanical refrigeration system (direct type) 4. Mechanical refrigeration system (indirect type) 5. Mechanical refrigeration with ice storage 6. Mechanical refrigeration system with chilled water storage 7. Single stage Lithium Bromide Absorption chiller 8. Two stage Lithium Bromide Absorption chiller
PB Power
Schematic of Evaporative Air Cooling shown with Optional Water Treatment
Combustion Air Air Filter Water Treatment Make Up Blow down Wetted Media
Water Tank
Exhaust Gas
Fuel
Combustion Turbine
PB Power
Evaporative Cooler
Applications: Areas where RH and wet bulb temperature is rather low
Advantage
# # # #
Disadvantage
#
Lowest capital cost Lowest O&M cost Can operate on raw water Quick delivery and installation time Operates as an air washer and cleans the inlet air
Limitation on capacity improvement Highly influenced by the site wet bulb
#
#
PB Power
Gas Turbine Inlet Air Cooling
Available Technologies
1. Evaporative cooler 2. Fogging system 3. Mechanical refrigeration system (direct type) 4. Mechanical refrigeration system (indirect type) 5. Mechanical refrigeration with ice storage 6. Mechanical refrigeration system with chilled water storage 7. Single stage Lithium Bromide Absorption chiller 8. Two stage Lithium Bromide Absorption chiller
PB Power
Schematic of Fog Inlet Air Cooling System Utilizing Demineralised Water
Raw Water Demineralised Water Treatment Plant Demineralised Water Tank
Combustion Air Air Filter Fog Spray System
Exhaust Gas
Fuel
Combustion Turbine
PB Power
Fog Systems
PB Power
Demineralised Water Quality For Fog System Inlet Air Cooling
Total dissolved solids pH Na + K Silica (SiO2) Chlorides Sulphate 5 PPM maximum 6-8 0.1 PPM maximum 0.1 PPM maximum 0.5 PPM maximum 0.5 PPM maximum
PB Power
Fogging System Demin. Water Consumption Inlet air 36°C DB, 25°C WB Chilled air temp 25.5°C DB 25°C WB, 96%RH
10 9 8 7 6 5 4 3 2 1 0 0 25 50 75 100 125 150 175 200 225 250
t/h
Gas Turbine Output MW
PB Power
Fogging System
Applications: Areas where RH and wet bulb temperature is rather low
Advantage
# # #
Disadvantage
#
Low capital cost Low O&M cost Can increase gas turbine performance better than evaporative cooling Quick delivery and installation time
Limitation on capacity improvement Highly influenced by the site wet bulb
#
#
PB Power
Gas Turbine Inlet Air Cooling
Available Technologies
1. Evaporative cooler 2. Fogging system 3. Mechanical refrigeration system (direct type) 4. Mechanical refrigeration system (indirect type) 5. Mechanical refrigeration with ice storage 6. Mechanical refrigeration system with chilled water storage 7. Single stage Lithium Bromide Absorption chiller 8. Two stage Lithium Bromide Absorption chiller
PB Power
Schematic of a Direct System Using an Ammonia Refrigeration Machine
Ammonia Suction Line
Mechanical Refrigeration Machine
Combustion Air Air Filter Condensate Drip Pan Ammonia Liquid Line
Exhaust Gas
Fuel
Combustion Turbine
PB Power
Mechanical Refrigeration System (Direct Type)
Applications: Areas where relative humidity is rather high
Advantage
#
Disadvantage
# # #
Can increase gas turbine performance better than evaporative cooling, and fog system
High initial capital cost High O&M cost Longer delivery and installation time Expertise is needed to operate and maintain the plant
#
PB Power
Gas Turbine Inlet Air Cooling
Available Technologies
1. Evaporative cooler 2. Fogging system 3. Mechanical refrigeration system (direct type) 4. Mechanical refrigeration system (indirect type) 5. Mechanical refrigeration with ice storage 6. Mechanical refrigeration system with chilled water storage 7. Single stage Lithium Bromide Absorption chiller 8. Two stage Lithium Bromide Absorption chiller
PB Power
Schematic of an Indirect System Using a Mechanical Chiller
Combustion Air Mechanical Chiller Air Filter Air Cooling Coil Condensate Drip Pan
Exhaust Gas
Fuel
Chilled Water Pump
Combustion Turbine
PB Power
Mechanical Refrigeration System (Indirect Type)
Applications: Areas where relative humidity is rather high
Advantage
#
Disadvantage
# # # #
#
Can increase gas turbine performance better than evaporative cooling, and fog system Not very sensitive to ambient air wet bulb temperature
# # #
PB Power
High initial capital cost High O&M 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 Cooling
Available Technologies
1. Evaporative cooler 2. Fogging system 3. Mechanical refrigeration system (direct type) 4. Mechanical refrigeration system (indirect type) 5. Mechanical refrigeration with ice storage 6. Mechanical refrigeration system with chilled water storage 7. Single stage Lithium Bromide Absorption chiller 8. Two stage Lithium Bromide Absorption chiller
PB Power
Inlet Air Cooling With Ice Storage, Chilled Water Storage System Schematic
Combustion Air Mechanical Chiller/ Ice Maker Ice Storage Tank Air Filter Air Cooling Coil Condensate Drip Pan
Exhaust Gas
Fuel
Chilled Water Pump
Combustion Turbine
PB Power
Inlet Air Cooling With Chilled Water Storage System Schematic
Mech. Chiller
Chilled Water Storage Tank
Combustion Air Air Filter Air Cooling Coil Condensate Drip Pan
Exhaust Gas
Fuel
Chilled Water Pump
Combustion Turbine
PB Power
Mechanical Refrigeration System With Ice Storage
Applications: Areas where RH is rather high,plus a wide variation in electricity tariff between peak and non peak hours
Advantage
#
Disadvantage
# # #
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
PB Power
High initial capital cost High O&M cost Longer delivery and installation time Higher expertise is needed to operate and maintain the plant
#
#
#
Chiller Electrical Load MW 36°C DB, 25°C WB, 10°C Chilled Air Temp
6
Chiller Electrical Load MW
5 4 3 2 1 0 0 25 50 75 100 125 150 175 200 225 250 275 300
Gas Turbine Output MW
PB Power
Gas Turbine Inlet Air Cooling
Available Technologies
1. Evaporative cooler 2. Fogging system 3. Mechanical refrigeration system (direct type) 4. Mechanical refrigeration system (indirect type) 5. Mechanical refrigeration with ice storage 6. Mechanical refrigeration system with chilled water storage 7. Single stage Lithium Bromide Absorption chiller 8. Two stage Lithium Bromide Absorption chiller
PB Power
Absorption Chiller Inlet Air Cooling System Schematic
Combustion Air Absorption Chiller Air Filter Return Condensate LP Steam Air Cooling Coil Condensate Drip Pan
Exhaust Gas
Chilled Water Pump
Fuel
Heat Recovery Steam Generator Combustion Turbine
PB Power
Flow Diagram
Pressure approx. 60 Torr 60 mm Hg 80 mbar 8 kPa Condenser tc 45°C 37°C Tower Water Out
Generator
Heat Medium In
Steam or Hot Water
70 °C
Heat Medium Out
95 °C
Pressure approx. 6,2 Torr 6,2 mm Hg 8,2 mbar 0,83 kPa
to 4°C 6°C Chilled Water
Evaporator
12°C
Absorber 32,5°C 27°C ta 35°C Chilled Water Tower Water Concentrated Solution (LiBr) Diluted Solution (LiBr) Steam or Hot Water Refrigerant (Water) 50°C Tower Water In
70°C
PB Power
Picture courtesy of York International
Absorption Chiller Steam Consumption 36°C DB, 25°C WB, 10°C Chilled Air Temp
80 70
Steam Consumption t/h
60 50 40 30 20 10 0
0
25
50
75
100
125
150
175
200
225
250
275
300 Single Stage Two Stage
Gas Turbine Output MW
PB Power
Single Stage Lithium Bromide Absorption Chiller
Applications: 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 steam
Advantage
#
Disadvantage
# # #
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
High initial capital cost High O&M 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
#
#
#
#
PB Power
Two Stage Lithium Bromide Absorption Chiller
Applications: 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 steam
Advantage
#
Disadvantage
# # #
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
PB Power
High initial capital cost High O&M 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
#
#
# #
#
Condensate Formation on the Chilled Water Coil t/h Based on 36°C DB, 25°C WB, 10°C Chilled Inlet Air Temperature
Condensate Formation t/h
20 15 10 5 0
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
PB Power
Performance Evaluation Of Different Inlet Air Cooling Systems
Base Condition
! ! !
35°C Dry bulb 25°C Dry bulb 44.7% Relative humidity
Real world condition
Increase in power output
Percent Change Gas turbine output before inlet air cooling Gas turbine output with mechanical refrigeration system and inlet air temperature of 10°C Gas turbine with evaporative cooler running at 85% RH Gas turbine with fog system running at 100% RH
PB Power
108.23 MW (net) 124.8 MW (net including chiller electrical load) 114.8 MW (net) 116.65 MW (net)
0%
15.3%
6% 7.69%
Capital Cost Comparisons of Inlet Cooling Systems
Options
Evaporative cooler Fog system (excluding water treatment plant) Single stage LiBr absorption chiller Two stage LiBr absorption chiller Ammonia mechanical refrigeration system
PB Power
Relative Costs 1 2 8 10 9.5
Major Contributors To The O&M Costs
Options
Evaporative cooler Fog system (excluding water treatment plant) Single stage LiBr absorption chiller
O&M Costs
# # # # # # # # # # # # # #
Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption 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
Two stage LiBr absorption chiller
Ammonia mechanical refrigeration system
PB Power
# #
Heavy Duty Gas Turbine NOx Emission kg/MWh
GT with Dry Low NOx burner
0.470
NOx Emission kg/MWh
0.460 0.450 0.440 0.430 0.420 0.410 0 5 10 15 20 25 30 35 40 45
Ambient Temperature deg C
PB Power
Heavy Duty Gas Turbine CO2 Emission kg/MWh
590 CO2 Emission kg/MWh 580 570 560 550 540 530 520 0 5 10 15 20 25 30 35 40 45 Ambient Temperature deg C
PB Power
Aero-Derivative Gas Turbine NOx Emission kg/MWh
GT with Dry Low NOx burner
0.43
NOx Emission kg/MWh
0.42 0.41 0.4 0.39 0.38 0.37
0
5
10
15
20
25
30
35
40
45
Ambient Temperature deg C
PB Power
Aero-Derivative Gas Turbine CO2 Emission kg/MWh
550
CO2 Emission kg/MWh
540 530 520 510 500 490 480 470 0 5 10 15 20 25 30 35 40 45
Ambient Temperature deg C
PB Power
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
PB Power
! !
!
The 3rd Annual Australian Gas Turbine Conference
6th – 7th December 2001 Melbourne Australia Presented by
Bob Omidvar Manager, Power Engineering PB Power Australia
PB Power
Heavy Duty GT - Effects of Ambient Temp
110% 105% 100% 95% 90% 85% 80% 75% 0 5 10 15 20 25 30 35 40 45
GT Inlet Temp (deg C)
Heat rate kJ/kWh Power output MW Exhaust flow t/h Exhaust temperature °C
PB Power
Aero-Derivative GT - Effects of Ambient Temp
120% 110% 100% 90% 80% 70% 60% 0 5 10 15 20 25 30 35 40 45
GT Inlet Temp (deg C)
Exhaust temperature C Heat rate kJ/kWh Power output MW Exhaust flow t/h
PB Power
Gas Turbine Performance Design Basis
What Does ISO Condition Mean?
! ! ! !
Dry bulb 15°C Relative humidity 60% Wet bulb temperature 7.2°C Atmospheric pressure 1 bar (sea level)
Most of the gas turbine installations are not in ISO standard locations, they are in the real world
PB Power
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
PB Power
Gas Turbine Inlet Air Cooling
Available Technologies
1. Evaporative cooler 2. Fogging system 3. Mechanical refrigeration system (direct type) 4. Mechanical refrigeration system (indirect type) 5. Mechanical refrigeration with ice storage 6. Mechanical refrigeration system with chilled water storage 7. Single stage Lithium Bromide Absorption chiller 8. Two stage Lithium Bromide Absorption chiller
PB Power
Gas Turbine Inlet Air Cooling
Available Technologies
1. Evaporative cooler 2. Fogging system 3. Mechanical refrigeration system (direct type) 4. Mechanical refrigeration system (indirect type) 5. Mechanical refrigeration with ice storage 6. Mechanical refrigeration system with chilled water storage 7. Single stage Lithium Bromide Absorption chiller 8. Two stage Lithium Bromide Absorption chiller
PB Power
Schematic of Evaporative Air Cooling shown with Optional Water Treatment
Combustion Air Air Filter Water Treatment Make Up Blow down Wetted Media
Water Tank
Exhaust Gas
Fuel
Combustion Turbine
PB Power
Evaporative Cooler
Applications: Areas where RH and wet bulb temperature is rather low
Advantage
# # # #
Disadvantage
#
Lowest capital cost Lowest O&M cost Can operate on raw water Quick delivery and installation time Operates as an air washer and cleans the inlet air
Limitation on capacity improvement Highly influenced by the site wet bulb
#
#
PB Power
Gas Turbine Inlet Air Cooling
Available Technologies
1. Evaporative cooler 2. Fogging system 3. Mechanical refrigeration system (direct type) 4. Mechanical refrigeration system (indirect type) 5. Mechanical refrigeration with ice storage 6. Mechanical refrigeration system with chilled water storage 7. Single stage Lithium Bromide Absorption chiller 8. Two stage Lithium Bromide Absorption chiller
PB Power
Schematic of Fog Inlet Air Cooling System Utilizing Demineralised Water
Raw Water Demineralised Water Treatment Plant Demineralised Water Tank
Combustion Air Air Filter Fog Spray System
Exhaust Gas
Fuel
Combustion Turbine
PB Power
Fog Systems
PB Power
Demineralised Water Quality For Fog System Inlet Air Cooling
Total dissolved solids pH Na + K Silica (SiO2) Chlorides Sulphate 5 PPM maximum 6-8 0.1 PPM maximum 0.1 PPM maximum 0.5 PPM maximum 0.5 PPM maximum
PB Power
Fogging System Demin. Water Consumption Inlet air 36°C DB, 25°C WB Chilled air temp 25.5°C DB 25°C WB, 96%RH
10 9 8 7 6 5 4 3 2 1 0 0 25 50 75 100 125 150 175 200 225 250
t/h
Gas Turbine Output MW
PB Power
Fogging System
Applications: Areas where RH and wet bulb temperature is rather low
Advantage
# # #
Disadvantage
#
Low capital cost Low O&M cost Can increase gas turbine performance better than evaporative cooling Quick delivery and installation time
Limitation on capacity improvement Highly influenced by the site wet bulb
#
#
PB Power
Gas Turbine Inlet Air Cooling
Available Technologies
1. Evaporative cooler 2. Fogging system 3. Mechanical refrigeration system (direct type) 4. Mechanical refrigeration system (indirect type) 5. Mechanical refrigeration with ice storage 6. Mechanical refrigeration system with chilled water storage 7. Single stage Lithium Bromide Absorption chiller 8. Two stage Lithium Bromide Absorption chiller
PB Power
Schematic of a Direct System Using an Ammonia Refrigeration Machine
Ammonia Suction Line
Mechanical Refrigeration Machine
Combustion Air Air Filter Condensate Drip Pan Ammonia Liquid Line
Exhaust Gas
Fuel
Combustion Turbine
PB Power
Mechanical Refrigeration System (Direct Type)
Applications: Areas where relative humidity is rather high
Advantage
#
Disadvantage
# # #
Can increase gas turbine performance better than evaporative cooling, and fog system
High initial capital cost High O&M cost Longer delivery and installation time Expertise is needed to operate and maintain the plant
#
PB Power
Gas Turbine Inlet Air Cooling
Available Technologies
1. Evaporative cooler 2. Fogging system 3. Mechanical refrigeration system (direct type) 4. Mechanical refrigeration system (indirect type) 5. Mechanical refrigeration with ice storage 6. Mechanical refrigeration system with chilled water storage 7. Single stage Lithium Bromide Absorption chiller 8. Two stage Lithium Bromide Absorption chiller
PB Power
Schematic of an Indirect System Using a Mechanical Chiller
Combustion Air Mechanical Chiller Air Filter Air Cooling Coil Condensate Drip Pan
Exhaust Gas
Fuel
Chilled Water Pump
Combustion Turbine
PB Power
Mechanical Refrigeration System (Indirect Type)
Applications: Areas where relative humidity is rather high
Advantage
#
Disadvantage
# # # #
#
Can increase gas turbine performance better than evaporative cooling, and fog system Not very sensitive to ambient air wet bulb temperature
# # #
PB Power
High initial capital cost High O&M 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 Cooling
Available Technologies
1. Evaporative cooler 2. Fogging system 3. Mechanical refrigeration system (direct type) 4. Mechanical refrigeration system (indirect type) 5. Mechanical refrigeration with ice storage 6. Mechanical refrigeration system with chilled water storage 7. Single stage Lithium Bromide Absorption chiller 8. Two stage Lithium Bromide Absorption chiller
PB Power
Inlet Air Cooling With Ice Storage, Chilled Water Storage System Schematic
Combustion Air Mechanical Chiller/ Ice Maker Ice Storage Tank Air Filter Air Cooling Coil Condensate Drip Pan
Exhaust Gas
Fuel
Chilled Water Pump
Combustion Turbine
PB Power
Inlet Air Cooling With Chilled Water Storage System Schematic
Mech. Chiller
Chilled Water Storage Tank
Combustion Air Air Filter Air Cooling Coil Condensate Drip Pan
Exhaust Gas
Fuel
Chilled Water Pump
Combustion Turbine
PB Power
Mechanical Refrigeration System With Ice Storage
Applications: Areas where RH is rather high,plus a wide variation in electricity tariff between peak and non peak hours
Advantage
#
Disadvantage
# # #
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
PB Power
High initial capital cost High O&M cost Longer delivery and installation time Higher expertise is needed to operate and maintain the plant
#
#
#
Chiller Electrical Load MW 36°C DB, 25°C WB, 10°C Chilled Air Temp
6
Chiller Electrical Load MW
5 4 3 2 1 0 0 25 50 75 100 125 150 175 200 225 250 275 300
Gas Turbine Output MW
PB Power
Gas Turbine Inlet Air Cooling
Available Technologies
1. Evaporative cooler 2. Fogging system 3. Mechanical refrigeration system (direct type) 4. Mechanical refrigeration system (indirect type) 5. Mechanical refrigeration with ice storage 6. Mechanical refrigeration system with chilled water storage 7. Single stage Lithium Bromide Absorption chiller 8. Two stage Lithium Bromide Absorption chiller
PB Power
Absorption Chiller Inlet Air Cooling System Schematic
Combustion Air Absorption Chiller Air Filter Return Condensate LP Steam Air Cooling Coil Condensate Drip Pan
Exhaust Gas
Chilled Water Pump
Fuel
Heat Recovery Steam Generator Combustion Turbine
PB Power
Flow Diagram
Pressure approx. 60 Torr 60 mm Hg 80 mbar 8 kPa Condenser tc 45°C 37°C Tower Water Out
Generator
Heat Medium In
Steam or Hot Water
70 °C
Heat Medium Out
95 °C
Pressure approx. 6,2 Torr 6,2 mm Hg 8,2 mbar 0,83 kPa
to 4°C 6°C Chilled Water
Evaporator
12°C
Absorber 32,5°C 27°C ta 35°C Chilled Water Tower Water Concentrated Solution (LiBr) Diluted Solution (LiBr) Steam or Hot Water Refrigerant (Water) 50°C Tower Water In
70°C
PB Power
Picture courtesy of York International
Absorption Chiller Steam Consumption 36°C DB, 25°C WB, 10°C Chilled Air Temp
80 70
Steam Consumption t/h
60 50 40 30 20 10 0
0
25
50
75
100
125
150
175
200
225
250
275
300 Single Stage Two Stage
Gas Turbine Output MW
PB Power
Single Stage Lithium Bromide Absorption Chiller
Applications: 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 steam
Advantage
#
Disadvantage
# # #
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
High initial capital cost High O&M 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
#
#
#
#
PB Power
Two Stage Lithium Bromide Absorption Chiller
Applications: 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 steam
Advantage
#
Disadvantage
# # #
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
PB Power
High initial capital cost High O&M 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
#
#
# #
#
Condensate Formation on the Chilled Water Coil t/h Based on 36°C DB, 25°C WB, 10°C Chilled Inlet Air Temperature
Condensate Formation t/h
20 15 10 5 0
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
PB Power
Performance Evaluation Of Different Inlet Air Cooling Systems
Base Condition
! ! !
35°C Dry bulb 25°C Dry bulb 44.7% Relative humidity
Real world condition
Increase in power output
Percent Change Gas turbine output before inlet air cooling Gas turbine output with mechanical refrigeration system and inlet air temperature of 10°C Gas turbine with evaporative cooler running at 85% RH Gas turbine with fog system running at 100% RH
PB Power
108.23 MW (net) 124.8 MW (net including chiller electrical load) 114.8 MW (net) 116.65 MW (net)
0%
15.3%
6% 7.69%
Capital Cost Comparisons of Inlet Cooling Systems
Options
Evaporative cooler Fog system (excluding water treatment plant) Single stage LiBr absorption chiller Two stage LiBr absorption chiller Ammonia mechanical refrigeration system
PB Power
Relative Costs 1 2 8 10 9.5
Major Contributors To The O&M Costs
Options
Evaporative cooler Fog system (excluding water treatment plant) Single stage LiBr absorption chiller
O&M Costs
# # # # # # # # # # # # # #
Make up water Water treatment (if applicable) Make up water Demineralised water treatment Injection pump power consumption 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
Two stage LiBr absorption chiller
Ammonia mechanical refrigeration system
PB Power
# #
Heavy Duty Gas Turbine NOx Emission kg/MWh
GT with Dry Low NOx burner
0.470
NOx Emission kg/MWh
0.460 0.450 0.440 0.430 0.420 0.410 0 5 10 15 20 25 30 35 40 45
Ambient Temperature deg C
PB Power
Heavy Duty Gas Turbine CO2 Emission kg/MWh
590 CO2 Emission kg/MWh 580 570 560 550 540 530 520 0 5 10 15 20 25 30 35 40 45 Ambient Temperature deg C
PB Power
Aero-Derivative Gas Turbine NOx Emission kg/MWh
GT with Dry Low NOx burner
0.43
NOx Emission kg/MWh
0.42 0.41 0.4 0.39 0.38 0.37
0
5
10
15
20
25
30
35
40
45
Ambient Temperature deg C
PB Power
Aero-Derivative Gas Turbine CO2 Emission kg/MWh
550
CO2 Emission kg/MWh
540 530 520 510 500 490 480 470 0 5 10 15 20 25 30 35 40 45
Ambient Temperature deg C
PB Power
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
PB Power
! !
!
