Chapter 4 Fossil Fuel Energies

Chapter 4 Fossil Fuel Energies Chapter 4 Fossil Fuel Energies Boosting Power Plant Efficient (Boosting Power Plant Efficient ( 提昇發電效提昇發電效率率 ))

Low Emission Boiler Systems—LEBS (Low Emission Boiler Systems—LEBS ( 低排放低排放鍋爐系統鍋爐系統 ))

Pressurized Fluidized Bed Combustion—PFBC Pressurized Fluidized Bed Combustion—PFBC (( 高壓流體化床燃燒技術高壓流體化床燃燒技術 ))

Integrated Gasification Combined Cycle—IGCCIntegrated Gasification Combined Cycle—IGCC (( 氣化複循環發電技術氣化複循環發電技術 ))

Indirectly Fired Cycle—IFC (Indirectly Fired Cycle—IFC ( 間接燃燒循環發間接燃燒循環發電技術電技術 ))

Advanced Turbine Systems—ATS (Advanced Turbine Systems—ATS ( 先進渦輪先進渦輪機系統機系統 ))

4-1 Boosting Power Plant Efficient 4-1 Boosting Power Plant Efficient

Less fuel will be consumed to generate the same Less fuel will be consumed to generate the same amount of electricity. amount of electricity.

↓ ↓

sharply reduce emissions of COsharply reduce emissions of CO22


Coal-Fired Power PlantsCoal-Fired Power Plants1.1. Efficiency ~ 33-38 %Efficiency ~ 33-38 %

2.2. Retrieve waste heatRetrieve waste heat

3.3. Simple cycle:heat from the burning coal boils water tSimple cycle:heat from the burning coal boils water to create steam which spins a steam turbine-generatoro create steam which spins a steam turbine-generator

↓ ↓

combined two or more power generation cyclescombined two or more power generation cycles



Low Emission Boiler System—Low Emission Boiler System—

“ “supercritical steam cycle”supercritical steam cycle”

a conventional power plant boiler releases steam a conventional power plant boiler releases steam at p~2400 psi (160 bar) & T~1050 at p~2400 psi (160 bar) & T~1050 ooF (570 F (570 ooC)C)

↓ ↓

p~3400-5500 psi (230-370 bar) & T~1100 p~3400-5500 psi (230-370 bar) & T~1100 ooF F

(590 (590 ooC)C)


Conventional combined cycle—Conventional combined cycle— burn natural gas or petroleum products, using thburn natural gas or petroleum products, using th

e hot combustion gases to power a combustion ge hot combustion gases to power a combustion gas turbine-generator, then channelling the waste as turbine-generator, then channelling the waste heat to drive a steam turbine-generator.heat to drive a steam turbine-generator.

↓ ↓ Pressurized Fluidized Bed Combustion & IntegrPressurized Fluidized Bed Combustion & Integr

ated Gasification Combined Cycle (DOE for “coated Gasification Combined Cycle (DOE for “combined cycle” operation to coal-burning power mbined cycle” operation to coal-burning power plants)plants)


Pressurized Fluidized Bed Combustion systemPressurized Fluidized Bed Combustion system——

coal is burned at elevated pressures (6-16 bars) coal is burned at elevated pressures (6-16 bars) to produce a high-p exhaust gas stream. →spin a to produce a high-p exhaust gas stream. →spin a gas turbine-generator. Simultaneously, the boiler gas turbine-generator. Simultaneously, the boiler also heats water to produce steam (steam cycle)also heats water to produce steam (steam cycle)


Integrated Gasification Combined Cycle systemIntegrated Gasification Combined Cycle system——

coal is converted into a combustible gas coal is converted into a combustible gas (typically a mixture of CO and H(typically a mixture of CO and H22) )

↓ ↓

The gas is burned in the combustor for a gas The gas is burned in the combustor for a gas turbine-generator. Simultaneously, exhaust turbine-generator. Simultaneously, exhaust gases from the gas turbine heats water to gases from the gas turbine heats water to produce steam (steam cycle)produce steam (steam cycle)



In the future, may combine with high-T fuel cell In the future, may combine with high-T fuel cell

↓ ↓

A hybrid system combining coal gasification, A hybrid system combining coal gasification, high-T fuel cells, and high efficiency gas turbine high-T fuel cells, and high efficiency gas turbine cycles→ efficiency up to 60% & COcycles→ efficiency up to 60% & CO22 release cut release cut

to half of conventional one.to half of conventional one.



Gasification-based power system produce a Gasification-based power system produce a concentrated COconcentrated CO22 gas stream→ carbon gas stream→ carbon

sequestrationsequestration

↓ ↓

cf. conventional coal-burning tech. release COcf. conventional coal-burning tech. release CO22

in a diluted, high-volume mixture with nitrogen in a diluted, high-volume mixture with nitrogen (from the combustion(from the combustion


Natural Gas Power PlantsNatural Gas Power Plants

– Worldwide, 16% of fuel consumed for electricity Worldwide, 16% of fuel consumed for electricity generation in 1995→23% in 2015generation in 1995→23% in 2015

– Emits only ½ COEmits only ½ CO2 2 than coal for the same energy than coal for the same energy

produced.produced.

4-1 Boosting Power Plant Efficient 4-1 Boosting Power Plant Efficient Natural Gas Power PlantsNatural Gas Power Plants

4-1 Boosting Power Plant Efficient 4-1 Boosting Power Plant Efficient Natural Gas TurbinesNatural Gas Turbines 40 years ago, η~20% for a simple cycle system.40 years ago, η~20% for a simple cycle system. Today, η~30% for a simple cycle system & η~mid-50% Today, η~30% for a simple cycle system & η~mid-50%

for a combined cycle system .for a combined cycle system . Thermal efficiency of a gas turbine depends on T of the Thermal efficiency of a gas turbine depends on T of the

gas entering the turbine blades.~2300 gas entering the turbine blades.~2300 ooF (1260 F (1260 ooC) for C) for modern turbines (temperature barrier)modern turbines (temperature barrier)

↓ ↓ Reaching the limits of current materials → new materialReaching the limits of current materials → new material

s or better ways to cool the bladess or better ways to cool the blades DOE is developing new tech. to push TDOE is developing new tech. to push Tinlet inlet to 2600 to 2600 ooF (1F (1

430 430 ooC) → η~60% for a combined cycle system C) → η~60% for a combined cycle system

4-1 Boosting Power Plant Efficient 4-1 Boosting Power Plant Efficient Fuel Cell Power Plants—another way to use Fuel Cell Power Plants—another way to use

natural gas, η> 50% natural gas, η> 50% – Using an electrochemical reaction of HUsing an electrochemical reaction of H22 (fuel) and O (fuel) and O22

(from air) to produce electricity, water and heat.(from air) to produce electricity, water and heat.

– Generate the least amount of COGenerate the least amount of CO22 in the fuel in the fuel

processing stage. processing stage.

4-1 Boosting Power Plant Efficient 4-1 Boosting Power Plant Efficient 「一度電」的定義就是「一度電」的定義就是 1kWh1kWh 也就是一千瓦也就是一千瓦

小時小時「一度電」就是「一度電」就是 1000(W)1000(W) 瓦耗電的用電器具，瓦耗電的用電器具，

使用一小時所消耗的電量使用一小時所消耗的電量例如你點亮一個例如你點亮一個 100100 瓦的燈泡瓦的燈泡 1010 小時，也就小時，也就

是是 1000Whr1000Whr ，也就耗掉「一度電」了，也就耗掉「一度電」了一度電一度電 = = 一千瓦一千瓦 x3600x3600 秒秒 = 3,600,000= 3,600,000 焦耳焦耳


BTUBTU (British thermal unit):a unit of (British thermal unit):a unit of energyenergy used in the used in the United StatesUnited States. In most other areas, it has been replaced . In most other areas, it has been replaced by the by the SISI unit of energy, the unit of energy, the joulejoule (J). (J).

In the United States, the term "BTU" is used to describe In the United States, the term "BTU" is used to describe the heat value (the heat value (energyenergy content) of fuels, and also to des content) of fuels, and also to describe the cribe the powerpower of heating and cooling systems, such as of heating and cooling systems, such as furnaces, stoves, barbecue grills and air conditioners. furnaces, stoves, barbecue grills and air conditioners.

When used as a unit of power, BTU When used as a unit of power, BTU per hourper hour is underst is understood, though this is often confusingly abbreviated to just ood, though this is often confusingly abbreviated to just "BTU". "BTU".


1 BTU ≡ the amount of heat required to raise T 1 BTU ≡ the amount of heat required to raise T of one of one poundpound of of waterwater by one degree by one degree FahrenheitFahrenheit. .

One BTU is approximately:One BTU is approximately:

1.054-1.060 1.054-1.060 kilojoulekilojoule

252–253 cal (252–253 cal (caloriescalories, small) , small)

0.252–0.253 kcal (kilocalories) 0.252–0.253 kcal (kilocalories)

778–782 ft·lbf (778–782 ft·lbf (foot-pounds-forcefoot-pounds-force) )

4-1 Boosting Power Plant Efficient 4-1 Boosting Power Plant Efficient 1 1 wattwatt is approximately 3.41 BTU/h is approximately 3.41 BTU/h 1000 BTU/h is approximately 293 W 1000 BTU/h is approximately 293 W 1 1 horsepowerhorsepower is approximately 2540 BTU/h is approximately 2540 BTU/h 1 "1 "tonton of cooling", a common unit in North American refrigerati of cooling", a common unit in North American refrigerati

on and air conditioning applications, is 12,000 BTU/h (~3.5kW). on and air conditioning applications, is 12,000 BTU/h (~3.5kW). It is the amount of power needed to melt one It is the amount of power needed to melt one short tonshort ton of ice in 2 of ice in 24 hours. 4 hours.

1 1 thermtherm is defined in the United States and European Union as 1 is defined in the United States and European Union as 100,000 BTU – but the U.S. uses the BTU59 °F whilst the EU use00,000 BTU – but the U.S. uses the BTU59 °F whilst the EU uses the BTUIT. s the BTUIT.

1 1 quadquad (short for (short for quadrillionquadrillion BTU) is defined as 1015 BTU, whic BTU) is defined as 1015 BTU, which is about one exajoule (1.055×1018 J). Quads are occasionally uh is about one exajoule (1.055×1018 J). Quads are occasionally used in the United States for representing the annual energy consused in the United States for representing the annual energy consumption of large economies: for example, the U.S. economy used mption of large economies: for example, the U.S. economy used about 94.2 quads/year in 1997. about 94.2 quads/year in 1997.

4-2 Low Emission Boiler System 4-2 Low Emission Boiler System B&W’s Advanced Coal-Fired Low Emission

Boiler System

4-2 Low Emission Boiler System 4-2 Low Emission Boiler System 1. Rankine cycle.

Simple Steam Rankine Cycle

4-2 Low Emission Boiler System 4-2 Low Emission Boiler System 1. Rankine cycle—coal, oil, and natural gas.






4-2 Low Emission Boiler System 4-2 Low Emission Boiler System 2. Bryton Cycle—oil or natural gas.

Basic Bryton Cycle

4-2 Low Emission Boiler System 4-2 Low Emission Boiler System 2. Bryton Cycle—oil or natural gas.

Basic Bryton Cycle

4-2 Low Emission Boiler System 4-2 Low Emission Boiler System 3. Combined Cycle

4-3 Pressurized Fluidized Bed Combustion4-3 Pressurized Fluidized Bed Combustion Fluidized bed combustionFluidized bed combustion (FBC) is a (FBC) is a

combustion technology used in power plants. combustion technology used in power plants. FBC plants are more flexible than conventional FBC plants are more flexible than conventional plants in that they can be fired on plants in that they can be fired on coalcoal, , biomassbiomass, , among other fuels. These boilers operate at among other fuels. These boilers operate at atmospheric pressure atmospheric pressure

Fluidized bedsFluidized beds suspend solid fuels on upward- suspend solid fuels on upward-blowing jets of air during the combustion blowing jets of air during the combustion process. The result is a turbulent mixing of gas process. The result is a turbulent mixing of gas and solids. The tumbling action, much like a and solids. The tumbling action, much like a bubbling fluid, provides more effective chemical bubbling fluid, provides more effective chemical reactions and heat transfer.reactions and heat transfer.

4-3 Pressurized Fluidized Bed Combustion4-3 Pressurized Fluidized Bed Combustion

4-3 Pressurized Fluidized Bed Combustion4-3 Pressurized Fluidized Bed Combustion FBC reduces the amount of FBC reduces the amount of sulfursulfur emitted in the form o emitted in the form o

f f SOSOxx emissions. emissions. LimestoneLimestone is used to precipitate out sulfate during com is used to precipitate out sulfate during com

bustion, which also allows more efficient heat transfer fbustion, which also allows more efficient heat transfer from the boiler to the apparatus used to capture the heat rom the boiler to the apparatus used to capture the heat energy (usually water pipes). The heated precipitate coenergy (usually water pipes). The heated precipitate coming in direct contact with the pipes (heating by conduming in direct contact with the pipes (heating by conduction) increases the efficiency. Since this allows coal plction) increases the efficiency. Since this allows coal plants to burn at cooler temperatures, less ants to burn at cooler temperatures, less NONOxx is also em is also emitted. itted.

However, burning at low temperatures also causes increHowever, burning at low temperatures also causes increased ased carbon dioxidecarbon dioxide, , nitrous oxidenitrous oxide, and , and polycyclic aromatic hydrocarbonpolycyclic aromatic hydrocarbon emissions. FBC boiler emissions. FBC boilers can burn fuels other than coal, and the lower temperats can burn fuels other than coal, and the lower temperatures of combustion (800 °C) have other added benefits ures of combustion (800 °C) have other added benefits as well.as well.

4-3 Pressurized Fluidized Bed Combustion4-3 Pressurized Fluidized Bed Combustion FBC evolved from efforts to find a combustion process FBC evolved from efforts to find a combustion process

able to control pollutant emissions without external emiable to control pollutant emissions without external emission controls (such as scrubbers). ssion controls (such as scrubbers).

The technology burns fuel at temperatures of 1,400 to 1,The technology burns fuel at temperatures of 1,400 to 1,700 °F (760 to 930 °C), well below the threshold where 700 °F (760 to 930 °C), well below the threshold where nitrogen oxides form (at approximately 2,500 °F (1370 nitrogen oxides form (at approximately 2,500 °F (1370 °C)). °C)).

The mixing action of the fluidized bed results brings the The mixing action of the fluidized bed results brings the flue gases into contact with a flue gases into contact with a sulfursulfur-absorbing chemical,-absorbing chemical, such as such as limestonelimestone or or dolomitedolomite. (> 95% of the sulfur po. (> 95% of the sulfur pollutants in coal can be captured inside the boiler by the llutants in coal can be captured inside the boiler by the sorbentsorbent) )

Commercial FBC units operate at competitive efficienciCommercial FBC units operate at competitive efficiencies, cost less than today's units, and have NOx and SO2 es, cost less than today's units, and have NOx and SO2 emissions below levels mandated by Federal standards.emissions below levels mandated by Federal standards.

4-3 4-3 PressurizedPressurized Fluidized Bed Combustion Fluidized Bed Combustion(r2001_03_109.pdf,)(r2001_03_109.pdf,)

The first-generation PFBC system also uses a sorbent aThe first-generation PFBC system also uses a sorbent and jets of air to suspend the mixture of sorbent and burnnd jets of air to suspend the mixture of sorbent and burning coal during combustion. However, these systems oping coal during combustion. However, these systems operate erate at elevated pressuresat elevated pressures and produce a high-pressure and produce a high-pressure gas stream at temperatures that can drive a gas stream at temperatures that can drive a gas turbinegas turbine. . Steam generated from the heat in the fluidized bed is seSteam generated from the heat in the fluidized bed is sent to a nt to a steam turbinesteam turbine, creating a highly efficient , creating a highly efficient combined cyclecombined cycle system. system.

A 1-1/2 generation PFBC system increases the gas turbiA 1-1/2 generation PFBC system increases the gas turbine firing temperature by using natural gas in addition to ne firing temperature by using natural gas in addition to the vitiated air from the PFB combustor. This mixture ithe vitiated air from the PFB combustor. This mixture is burned in a topping combustor to provide higher inlet s burned in a topping combustor to provide higher inlet temperatures for greater combined cycle efficiency. Hotemperatures for greater combined cycle efficiency. However, this uses wever, this uses natural gasnatural gas, usually a higher priced fuel , usually a higher priced fuel than coal. than coal.

4-3 4-3 PressurizedPressurized Fluidized Bed Combustion Fluidized Bed Combustion

4-3 4-3 PressurizedPressurized Fluidized Bed Combustion Fluidized Bed Combustion(2_1a6.pdf)(2_1a6.pdf)

4-3 4-3 PressurizedPressurized Fluidized Bed Combustion Fluidized Bed Combustion(2_1a6.pdf)(2_1a6.pdf)

4-4 4-4 IntegratedIntegrated Gasification Combined Gasification Combined Cycle TechnologyCycle Technology

This power plant configuration relies on a This power plant configuration relies on a coal gasifiercoal gasifier rather than a boiler. rather than a boiler.

Combustible gases produced by the gasifier can be cleaCombustible gases produced by the gasifier can be cleaned to high purity levels (more than 99 percent sulfur rened to high purity levels (more than 99 percent sulfur removal) before being burned in a gas turbine. moval) before being burned in a gas turbine.

Exhaust heat can be used to drive a steam turbine. Exhaust heat can be used to drive a steam turbine. 11stst-generation systems now being readied for constructi-generation systems now being readied for constructi

on can achieve efficiencies up to 42%. 2on can achieve efficiencies up to 42%. 2ndnd-generation sy-generation systems could reach efficiencies of 45 % by the end of thistems could reach efficiencies of 45 % by the end of this decade, and more advanced systems envisioned are exs decade, and more advanced systems envisioned are expected to exceed 50 % efficiency levels. pected to exceed 50 % efficiency levels.

Sulfur dioxide and nitrogen oxides emissions are less thSulfur dioxide and nitrogen oxides emissions are less than one-tenth of the New Source Performance Standards. an one-tenth of the New Source Performance Standards.





IGCC AdvantageIGCC Advantage1.1. A Clean Environment—99% SOA Clean Environment—99% SO22 removed before co removed before co

mbustion, NOx reduced by over 90%, COmbustion, NOx reduced by over 90%, CO2 2 is cut by 3is cut by 35%.5%.

2.2. High Efficiency—42 – 52%High Efficiency—42 – 52%3.3. Low-Cost Electricity. Low-Cost Electricity. 4.4. Low-Capital CostsLow-Capital Costs5.5. Repowering of Existing Plants—components of IGCRepowering of Existing Plants—components of IGC

C can be integrated into an existing system in modulC can be integrated into an existing system in modular formar form

6.6. Modularity—allowed for staged additions in blocks rModularity—allowed for staged additions in blocks ranging in size from 100-450 MW.anging in size from 100-450 MW.


IGCC AdvantageIGCC Advantage7.7. Fuel Flexibility—most gasifier systems can be easily Fuel Flexibility—most gasifier systems can be easily

adapted to different adapted to different 8.8. Phased Construction—1Phased Construction—1stst-phase include only a gas tu-phase include only a gas tu

rbine, operating as a simple natural-gas-fired cycle.(2rbine, operating as a simple natural-gas-fired cycle.(2/3 ultimate capacity) →2nd phase, a steam turbine cr/3 ultimate capacity) →2nd phase, a steam turbine create a combined cycle with full capacity. →3rd phaseate a combined cycle with full capacity. →3rd phase, integrate the gasifier and gas cleanup systems.e, integrate the gasifier and gas cleanup systems.

9.9. Low Water Use. ~50-70 % that of a PC plant with a fLow Water Use. ~50-70 % that of a PC plant with a flue gas desulfurization systemlue gas desulfurization system

10.10. Low COLow CO22 Emissions. high efficiency. More reduct∵ Emissions. high efficiency. More reduct∵ion when combined with fuel cell systems in the futuion when combined with fuel cell systems in the future.re.

11. Continuous Product Improvement11. Continuous Product Improvement


IGCC AdvantageIGCC Advantage12.12. Reusable SorbentsReusable Sorbents13.13. Marketable By-Products—Waste disposal is minimal:Marketable By-Products—Waste disposal is minimal:

sulfuric acid, element sulfur, Ash and any trace elem sulfuric acid, element sulfur, Ash and any trace elements are melted and when cooled become an environents are melted and when cooled become an environmentally safe, glass-like slag that can be used in the cmentally safe, glass-like slag that can be used in the construction or cement industries.onstruction or cement industries.

14.14. Co-Products—fuels in the form of methanol or gasolCo-Products—fuels in the form of methanol or gasoline, urea ine, urea (( 尿素尿素 )) for fertilizer, hot metal for steal m for fertilizer, hot metal for steal making and chemicals.aking and chemicals.

15.15. Demonstrated SuccessDemonstrated Success16.16. Public AcceptabilityPublic Acceptability


Improving Key ComponentsImproving Key Components1.1. Advanced Gasifier SystemsAdvanced Gasifier Systems

2.2. Hot Gas DesulfurizationHot Gas Desulfurization

3.3. Hot Gas Particulate RemovalHot Gas Particulate Removal

4.4. Advanced Turbine Systems (ATS)Advanced Turbine Systems (ATS)

4-5 4-5 IndirectlyIndirectly Fired Cycle Systems Fired Cycle Systems The combustion gases created by burning coal in The combustion gases created by burning coal in

this high performance power system are preventthis high performance power system are prevented from contacting a gas turbine. Instead, they ted from contacting a gas turbine. Instead, they transfer heat to an ransfer heat to an impurity free gasimpurity free gas, eg. air, that , eg. air, that powers the turbine. powers the turbine.

Currently, in the conceptual design phase, indireCurrently, in the conceptual design phase, indirectly fired cycle systems could offer a coal-based ctly fired cycle systems could offer a coal-based technology with efficiencies approaching 50 %, technology with efficiencies approaching 50 %, with sulfur dioxide, nitrogen oxides, and particulwith sulfur dioxide, nitrogen oxides, and particulates reduced to 1/4 of the New Source Performaates reduced to 1/4 of the New Source Performance Standards. nce Standards.

4-5 Indirectly Fired Cycle Systems4-5 Indirectly Fired Cycle Systems

4-5 4-5 IndirectlyIndirectly Fired Cycle Systems Fired Cycle Systems

4-5 Indirectly Fired Cycle Systems4-5 Indirectly Fired Cycle Systems

Ceramic Heat Exchanger Development (Key Ceramic Heat Exchanger Development (Key component)component)

1.1. Survive high operating temperatureSurvive high operating temperature

2.2. Resist corrosionResist corrosion

3.3. Withstand pressure differentialsWithstand pressure differentials

4.4. Avoid seal leakageAvoid seal leakage

5.5. Avoid catastrophic failureAvoid catastrophic failure

4-6 Advanced Turbine Systems4-6 Advanced Turbine Systems What is a What is a GasGas Turbine? (also called a Turbine? (also called a combustion combustion

turbineturbine))– A rotary A rotary engineengine that extracts energy from a flow of that extracts energy from a flow of

combustion gas. It has an upstream compressor coupled to a combustion gas. It has an upstream compressor coupled to a downstream turbine, and a combustion chamberdownstream turbine, and a combustion chamber in-between. in-between.

– Energy is released when air is mixed with fuel and ignited in Energy is released when air is mixed with fuel and ignited in the combustor. The resulting gasses are directed over the the combustor. The resulting gasses are directed over the turbine's blades, spinning the turbine and powering the turbine's blades, spinning the turbine and powering the compressor, and finally is passed through a nozzle, generating compressor, and finally is passed through a nozzle, generating additional thrust by accelerating the hot exhaust gases by additional thrust by accelerating the hot exhaust gases by expansion back to atmospheric pressure.expansion back to atmospheric pressure.

– Energy is extracted in the form of shaft power, compressed Energy is extracted in the form of shaft power, compressed air and thrust, in any combination, and used to power aircraft, air and thrust, in any combination, and used to power aircraft, trains, ships, generators, and even tankstrains, ships, generators, and even tanks

4-6 Advanced Turbine Systems4-6 Advanced Turbine Systems What is a Gas Turbine? What is a Gas Turbine?

This machine has a single-stage radial compressor and turbine, a recuperator, and foil bearings.

4-6 Advanced Turbine Systems4-6 Advanced Turbine Systems What is a Gas Turbine? What is a Gas Turbine?

– The power turbines in the largest industrial gas The power turbines in the largest industrial gas turbines operate at 3,000 or 3,600 rpm to match the turbines operate at 3,000 or 3,600 rpm to match the AC power grid frequency and to avoid the need for a AC power grid frequency and to avoid the need for a reduction gearbox. Such engines require a dedicated reduction gearbox. Such engines require a dedicated building.building.

– They can be particularly efficient — up to 60% — They can be particularly efficient — up to 60% — when waste heat from the gas turbine is recovered by when waste heat from the gas turbine is recovered by a conventional steam turbine in a combined cycle a conventional steam turbine in a combined cycle configuration. configuration.

4-6 Advanced Turbine Systems4-6 Advanced Turbine Systems What is a Gas Turbine?What is a Gas Turbine?

– They can also be run in a cogeneration configuration: the They can also be run in a cogeneration configuration: the exhaust is used for space or water heating, or drives an aexhaust is used for space or water heating, or drives an absorption chiller for cooling or refrigeration; cogeneratiobsorption chiller for cooling or refrigeration; cogeneration can be over 90% efficient.n can be over 90% efficient.

– Simple cycle gas turbines in the power industry require sSimple cycle gas turbines in the power industry require smaller capital investment than combined cycle gas, coal maller capital investment than combined cycle gas, coal or nuclear plants and can be designed to generate small oor nuclear plants and can be designed to generate small or large amounts of power. r large amounts of power.

– Also, the actual construction process can take as little as Also, the actual construction process can take as little as several weeks to a few months, compared to years for baseveral weeks to a few months, compared to years for baseload plants. Their other main advantage is the ability to seload plants. Their other main advantage is the ability to be turned on and off within minutes, supplying power dube turned on and off within minutes, supplying power during peak demand. Large simple cycle gas turbines may ring peak demand. Large simple cycle gas turbines may produce several hundred megawatts of power and approaproduce several hundred megawatts of power and approach 40% thermal efficiency.ch 40% thermal efficiency.

4-6 Advanced Turbine Systems4-6 Advanced Turbine Systems

GE H series power generation gas turbine. This 480-megawatt unit has a rated thermal efficiency of 60% in combined cycle configurations.







4-6 Advanced Turbine Systems (ngt.pdf)4-6 Advanced Turbine Systems (ngt.pdf)












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Chapter 4 Fossil Fuel Energies