Thermal Power Station typical view

8/17/2019 Thermal Power Station typical view

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Thermal power station

From Wikipedia, the free encyclopedia

Republika Power Plant, a thermal power station in Pernik , Bulgaria

Mohave Generating tation, a !,"#$ MW thermal power station near %aughlin, &evada

fuelled by coal

' thermal power station in Richemont, France(

http://en.wikipedia.org/wiki/Republika_Power_Planthttp://en.wikipedia.org/wiki/Pernikhttp://en.wikipedia.org/wiki/Pernikhttp://en.wikipedia.org/wiki/Bulgariahttp://en.wikipedia.org/wiki/Mohave_Generating_Stationhttp://en.wikipedia.org/wiki/Laughlin,_Nevadahttp://en.wikipedia.org/wiki/Richemont,_Mosellehttp://en.wikipedia.org/wiki/File:NesjavellirPowerPlant_edit2.jpghttp://en.wikipedia.org/wiki/File:Thermal_power_station_%28Richemont,_France%29.jpghttp://en.wikipedia.org/wiki/File:Mohave_Generating_Station_1.jpghttp://en.wikipedia.org/wiki/File:TermoElectricaBulgaria.jpghttp://en.wikipedia.org/wiki/Republika_Power_Planthttp://en.wikipedia.org/wiki/Pernikhttp://en.wikipedia.org/wiki/Bulgariahttp://en.wikipedia.org/wiki/Mohave_Generating_Stationhttp://en.wikipedia.org/wiki/Laughlin,_Nevadahttp://en.wikipedia.org/wiki/Richemont,_Moselle


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Geothermal power station in )celand

' thermal power station is a power plant in which the prime mover is steam driven(

Water is heated, turns into steam and spins a steam turbine which drives an electricalgenerator ( 'fter it passes through the turbine, the steam is condensed in a condenser and

recycled to where it was heated* this is known as a Rankine cycle( +he greatest variationin the design of thermal power stations is due to the different fuel sources( ome prefer to

use the term energy center because such facilities convert forms of heat energy intoelectricity!-( ome thermal power plants also deliver heat energy for industrial purposes,

for district heating, or for desalination of water as well as delivering electrical power( '

large part of human ./0 emissions comes from fossil fueled thermal power plants* effortsto reduce these outputs are various and widespread(

Contents

• ! )ntroductory overview

• 0 1istory• 2 3fficiency

• 4 .ost of electricity

• " 5iagram of a typical coal6fired thermal power station

• 7 Boiler and steam cycle

o 7(! Feed water heating and deaeration

o 7(0 Boiler operation

o 7(2 Boiler furnace and steam drum

o 7(4 uper heater

o 7(" team condensing

o 7(7 Re heater

o 7(8 'ir path

• 8 team turbine generator

• # tack gas path and cleanup

o #(! Fly ash collection

o #(0 Bottom ash collection and disposal

• 9 'u:iliary systems

o 9(! Boiler make6up water treatment plant and storage

o 9(0 Fuel preparation system

o 9(2 Barring gear

o 9(4 /il system

o

9(" Generator coolingo 9(7 Generator high voltage system

o 9(8 Monitoring and alarm system

o 9(# Battery supplied emergency lighting and communication

• !$ +ransport of coal fuel to site and to storage

• !! ee also

• !0 References

http://en.wikipedia.org/wiki/Geothermal_powerhttp://en.wikipedia.org/wiki/Power_planthttp://en.wikipedia.org/wiki/Power_planthttp://en.wiktionary.org/wiki/prime_moverhttp://en.wikipedia.org/wiki/Steamhttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Condensationhttp://en.wikipedia.org/wiki/Surface_condenserhttp://en.wikipedia.org/wiki/Rankine_cyclehttp://en.wikipedia.org/wiki/Heathttp://en.wikipedia.org/wiki/Energyhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#cite_note-0http://en.wikipedia.org/wiki/District_heatinghttp://en.wikipedia.org/wiki/Desalinationhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Introductory_overviewhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Historyhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Efficiencyhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Cost_of_electricityhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Diagram_of_a_typical_coal-fired_thermal_power_stationhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Boiler_and_steam_cyclehttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Feed_water_heating_and_deaerationhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Boiler_operationhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Boiler_furnace_and_steam_drumhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Super_heaterhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Steam_condensinghttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Re_heaterhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Air_pathhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Steam_turbine_generatorhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Stack_gas_path_and_cleanuphttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Fly_ash_collectionhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Bottom_ash_collection_and_disposalhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Auxiliary_systemshttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Boiler_make-up_water_treatment_plant_and_storagehttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Fuel_preparation_systemhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Barring_gearhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Oil_systemhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Generator_coolinghttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Generator_high_voltage_systemhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Monitoring_and_alarm_systemhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Battery_supplied_emergency_lighting_and_communicationhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Transport_of_coal_fuel_to_site_and_to_storagehttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#See_alsohttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Referenceshttp://en.wikipedia.org/wiki/Geothermal_powerhttp://en.wikipedia.org/wiki/Power_planthttp://en.wiktionary.org/wiki/prime_moverhttp://en.wikipedia.org/wiki/Steamhttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Condensationhttp://en.wikipedia.org/wiki/Surface_condenserhttp://en.wikipedia.org/wiki/Rankine_cyclehttp://en.wikipedia.org/wiki/Heathttp://en.wikipedia.org/wiki/Energyhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#cite_note-0http://en.wikipedia.org/wiki/District_heatinghttp://en.wikipedia.org/wiki/Desalinationhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Introductory_overviewhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Historyhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Efficiencyhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Cost_of_electricityhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Diagram_of_a_typical_coal-fired_thermal_power_stationhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Boiler_and_steam_cyclehttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Feed_water_heating_and_deaerationhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Boiler_operationhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Boiler_furnace_and_steam_drumhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Super_heaterhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Steam_condensinghttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Re_heaterhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Air_pathhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Steam_turbine_generatorhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Stack_gas_path_and_cleanuphttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Fly_ash_collectionhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Bottom_ash_collection_and_disposalhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Auxiliary_systemshttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Boiler_make-up_water_treatment_plant_and_storagehttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Fuel_preparation_systemhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Barring_gearhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Oil_systemhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Generator_coolinghttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Generator_high_voltage_systemhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Monitoring_and_alarm_systemhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Battery_supplied_emergency_lighting_and_communicationhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#Transport_of_coal_fuel_to_site_and_to_storagehttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#See_alsohttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#References


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• !2 3:ternal links

Introductory overview

'lmost all coal, nuclear , geothermal, solar thermal electric, and waste incineration plants,as well as many natural gas power plants are thermal( &atural gas is fre;uently

combusted in gas turbines as well as boilers( +he waste heat from a gas turbine can be

used to raise steam, in a combined cycle plant that improves overall efficiency( Power

plants burning coal, fuel oil, or natural gas are often called fossil-fuel power plants( ome biomass6fueled thermal power plants have appeared also( &on6nuclear thermal power

plants, particularly fossil6fueled plants, which do not use co6generation are sometimes

referred to as conventional power plants(

.ommercial electric utility power stations are usually constructed on a large scale anddesigned for continuous operation( 3lectric power plants typically use three6phase

electrical generators to produce alternating current


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completed in !9$! for the Manhattan 3levated Railway( 3ach of seventeen units weighed

about "$$ tons and was rated 7$$$ kilowatts* a contemporary turbine6set of similar rating

would have weighed about 0$D as much( 2-

Efficiency

+he energy efficiency of a conventional thermal power station, considered as salable

energy as a percent of the heating value of the fuel consumed, is typically 22D to 4#D(

+his efficiency is limited as all heat engines are governed by the laws of thermodynamics( +he rest of the energy must leave the plant in the form of heat( +his

waste heat can go through a condenser and be disposed of with cooling water or in

cooling towers( )f the waste heat is instead utili>ed for district heating, it is called co6generation( 'n important class of thermal power station are associated with desalination

facilities* these are typically found in desert countries with large supplies of natural gas

and in these plants, freshwater production and electricity are e;ually important co6 products(

' Rankine cycle with a two6stage steam turbine and a single feed water heater(

ince the efficiency of the plant is fundamentally limited by the ratio of the absolute

temperatures of the steam at turbine input and output, efficiency improvements re;uire

http://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#cite_note-2http://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#cite_note-2http://en.wikipedia.org/wiki/Heating_valuehttp://en.wikipedia.org/wiki/Thermodynamichttp://en.wikipedia.org/wiki/Waste_heathttp://en.wikipedia.org/wiki/Surface_condenserhttp://en.wikipedia.org/wiki/Cooling_waterhttp://en.wikipedia.org/wiki/Cooling_towerhttp://en.wikipedia.org/wiki/District_heatinghttp://en.wikipedia.org/wiki/Co-generationhttp://en.wikipedia.org/wiki/Co-generationhttp://en.wikipedia.org/wiki/Co-generationhttp://en.wikipedia.org/wiki/Desalinationhttp://en.wikipedia.org/wiki/Natural_gashttp://en.wikipedia.org/wiki/Rankine_cyclehttp://en.wikipedia.org/wiki/Rankine_cyclehttp://en.wikipedia.org/wiki/Rankine_cyclehttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Carnot_cyclehttp://en.wikipedia.org/wiki/File:Feedwater-heating.pnghttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#cite_note-2http://en.wikipedia.org/wiki/Heating_valuehttp://en.wikipedia.org/wiki/Thermodynamichttp://en.wikipedia.org/wiki/Waste_heathttp://en.wikipedia.org/wiki/Surface_condenserhttp://en.wikipedia.org/wiki/Cooling_waterhttp://en.wikipedia.org/wiki/Cooling_towerhttp://en.wikipedia.org/wiki/District_heatinghttp://en.wikipedia.org/wiki/Co-generationhttp://en.wikipedia.org/wiki/Co-generationhttp://en.wikipedia.org/wiki/Desalinationhttp://en.wikipedia.org/wiki/Natural_gashttp://en.wikipedia.org/wiki/Rankine_cyclehttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Carnot_cycle


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use of higher temperature, and therefore higher pressure, steam( 1istorically, other

working fluids such as mercury have been used in a mercury vapor turbine power plant,

since these can attain higher temperatures than water at lower working pressures(1owever, the obvious ha>ards of to:icity, high cost, and poor heat transfer properties,

have ruled out mercury as a working fluid(

'bove the critical point for water of 8$" EF


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Typical diagram of a coal-fired thermal power station

!( .ooling tower !$( team .ontrol valve !9( uperheater

0( .ooling water pump!!( 1igh pressure steamturbine

0$( Forced draught


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)n fossil6fueled power plants, steam generator refers to a furnace that burns the fossil fuel

to boil water to generate steam(

)n the nuclear plant field, steam generator refers to a specific type of large heate:changer used in a pressuri>ed water reactor ers produces water so pure that it coincidentally becomes an

electrical insulator , with conductivity in the range of $(2!($ microsiemens per centimeter( +he makeup water in a "$$ MWe plant amounts to perhaps 0$ J gallons per

minute

http://en.wikipedia.org/wiki/Boiler_(steam_generator)http://en.wikipedia.org/wiki/Boiler_(steam_generator)http://en.wikipedia.org/wiki/Nuclear_powerhttp://en.wikipedia.org/wiki/Steam_generator_(nuclear_power)http://en.wikipedia.org/wiki/Steam_generator_(nuclear_power)http://en.wikipedia.org/wiki/Heat_exchangerhttp://en.wikipedia.org/wiki/Heat_exchangerhttp://en.wikipedia.org/wiki/Heat_exchangerhttp://en.wikipedia.org/wiki/Pressurized_water_reactorhttp://en.wikipedia.org/wiki/Boiling_water_reactorhttp://en.wikipedia.org/wiki/Geothermal_powerhttp://en.wikipedia.org/wiki/Economizerhttp://en.wikipedia.org/wiki/Steam_drumhttp://en.wikipedia.org/wiki/Furnacehttp://en.wikipedia.org/wiki/Furnacehttp://en.wikipedia.org/w/index.php?title=Super_heater&action=edit&redlink=1http://en.wikipedia.org/wiki/Safety_valvehttp://en.wikipedia.org/wiki/Flue_gashttp://en.wikipedia.org/wiki/Centrifugal_fanhttp://en.wikipedia.org/wiki/Centrifugal_fanhttp://en.wikipedia.org/w/index.php?title=Air_Preheater&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Air_Preheater&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Air_Preheater&action=edit&redlink=1http://en.wikipedia.org/wiki/Electrostatic_precipitatorhttp://en.wikipedia.org/wiki/Electrostatic_precipitatorhttp://en.wikipedia.org/wiki/Dust_collector#Fabric_filtershttp://en.wikipedia.org/wiki/Flue_gas_stackhttp://en.wikipedia.org/wiki/Flue_gas_stackhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#cite_note-3http://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#cite_note-Babcock-4http://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#cite_note-Elliott-5http://en.wikipedia.org/wiki/Steamhttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Corrosionhttp://en.wikipedia.org/wiki/Water_softenerhttp://en.wikipedia.org/wiki/Ion_exchangehttp://en.wikipedia.org/wiki/Ion_exchangehttp://en.wikipedia.org/wiki/Ion_exchangehttp://en.wikipedia.org/wiki/Electrical_insulationhttp://en.wikipedia.org/wiki/Electrical_insulationhttp://en.wikipedia.org/wiki/Electrical_conductivityhttp://en.wikipedia.org/wiki/Electrical_conductivityhttp://en.wikipedia.org/wiki/Siemens_(unit)#Definitionhttp://en.wikipedia.org/wiki/Surface_condenserhttp://en.wikipedia.org/wiki/Boiler_(steam_generator)http://en.wikipedia.org/wiki/Nuclear_powerhttp://en.wikipedia.org/wiki/Steam_generator_(nuclear_power)http://en.wikipedia.org/wiki/Heat_exchangerhttp://en.wikipedia.org/wiki/Heat_exchangerhttp://en.wikipedia.org/wiki/Pressurized_water_reactorhttp://en.wikipedia.org/wiki/Boiling_water_reactorhttp://en.wikipedia.org/wiki/Geothermal_powerhttp://en.wikipedia.org/wiki/Economizerhttp://en.wikipedia.org/wiki/Steam_drumhttp://en.wikipedia.org/wiki/Furnacehttp://en.wikipedia.org/w/index.php?title=Super_heater&action=edit&redlink=1http://en.wikipedia.org/wiki/Safety_valvehttp://en.wikipedia.org/wiki/Flue_gashttp://en.wikipedia.org/wiki/Centrifugal_fanhttp://en.wikipedia.org/w/index.php?title=Air_Preheater&action=edit&redlink=1http://en.wikipedia.org/wiki/Electrostatic_precipitatorhttp://en.wikipedia.org/wiki/Dust_collector#Fabric_filtershttp://en.wikipedia.org/wiki/Flue_gas_stackhttp://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#cite_note-3http://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#cite_note-Babcock-4http://en.wikipedia.org/w/index.php?title=Thermal_power_station&printable=yes#cite_note-Elliott-5http://en.wikipedia.org/wiki/Steamhttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Corrosionhttp://en.wikipedia.org/wiki/Water_softenerhttp://en.wikipedia.org/wiki/Ion_exchangehttp://en.wikipedia.org/wiki/Ion_exchangehttp://en.wikipedia.org/wiki/Electrical_insulationhttp://en.wikipedia.org/wiki/Electrical_conductivityhttp://en.wikipedia.org/wiki/Siemens_(unit)#Definitionhttp://en.wikipedia.org/wiki/Surface_condenser


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5iagram of boiler feed water deaerator ontal water storage section

+he water flows through a series of si: or seven intermediate feed water heaters, heatedup at each point with steam e:tracted from an appropriate duct on the turbines and

gaining temperature at each stage( +ypically, the condensate plus the makeup water then

flows through a deaerator8-#- that removes dissolved air from the water, further purifyingand reducing its corrosiveness( The water may be dosed following this point with

hydraine! a chemical that removes the remaining o"ygen in the water to below #

parts per billion $ppb%& It is also dosed with pH control agents such as ammonia or

morpholine to 'eep the residual acidity low and thus non-corrosive&

Boiler operation

+he boiler is a rectangular furnace about "$ feet

Pulveri>ed coal is air6blown into the furnace from fuel no>>les at the four corners and it

rapidly burns, forming a large fireball at the center( +he thermal radiation of the fireballheats the water that circulates through the boiler tubes near the boiler perimeter( +he

water circulation rate in the boiler is three to four times the throughput and is typically

driven by pumps( 's the water in the boiler circulates it absorbs heat and changes intosteam at 8$$ EF


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Plants designed for lignite ed coal and hot gas

mi:ture into the boiler(

Plants that use gas turbines to heat the water for conversion into steam use boilers known

as heat recovery steam generators ation or enthalpy is underway( +he boiler transfers energy to the water by the

chemical reaction of burning some type of fuel(

+he water enters the boiler through a section in the convection pass called theeconomi>er ( From the economi>er it passes to the steam drum( /nce the water enters the

steam drum it goes down to the lower inlet water wall headers( From the inlet headers the

water rises through the water walls and is eventually turned into steam due to the heat being generated by the burners located on the front and rear water walls


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e;uipment inside the steam drum, it is piped from the upper drum area into tubes inside

an area of the furnace known as the super heater , which has an elaborate set up of tubing

where the steam vapor picks up more energy from hot flue gases outside the tubing andits temperature is now superheated above the saturation temperature( +he superheated

steam is then piped through the main steam lines to the valves before the high pressure

turbine(

&uclear6powered steam plants do not have such sections but produce steam at essentiallysaturated conditions( 3:perimental nuclear plants were e;uipped with fossil6fired super

heaters in an attempt to improve overall plant operating cost(

(team condensing

+he condenser condenses the steam from the e:haust of the turbine into li;uid to allow it

to be pumped( )f the condenser can be made cooler, the pressure of the e:haust steam is

reduced and efficiency of the cycle increases(

5iagram of a typical water6cooled surface condenser("-7-9-!$-

+he surface condenser is a shell and tube heat e:changer in which cooling water is

circulated through the tubes("-9-!$-!!- +he e:haust steam from the low pressure turbineenters the shell where it is cooled and converted to condensate


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+ypically the cooling water causes the steam to condense at a temperature of about 2" E.


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'nother form of condensing system is the air6cooled condenser( +he process is similar to

that of a radiator and fan( 3:haust heat from the low pressure section of a steam turbine

runs through the condensing tubes, the tubes are usually finned and ambient air is pushedthrough the fins with the help of a large fan( +he steam condenses to water to be reused in

the water6steam cycle( 'ir6cooled condensers typically operate at a higher temperature

than water cooled versions( While saving water, the efficiency of the cycle is reducedles on the furnace wall(

+he induced draft fan assists the F5 fan by drawing out combustible gases from thefurnace, maintaining a slightly negative pressure in the furnace to avoid backfiring

through any opening(

(team turbine generator

Main articleH +urbo generator

Rotor of a modern steam turbine, used in a power station

http://en.wikipedia.org/wiki/Radiatorhttp://en.wikipedia.org/wiki/Condensate_pumphttp://en.wikipedia.org/wiki/Turbo_generatorhttp://en.wikipedia.org/wiki/File:Dampfturbine_Laeufer01.jpghttp://en.wikipedia.org/wiki/Radiatorhttp://en.wikipedia.org/wiki/Condensate_pumphttp://en.wikipedia.org/wiki/Turbo_generator


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+he turbine generator consists of a series of steam turbines interconnected to each other

and a generator on a common shaft( +here is a high pressure turbine at one end, followed

by an intermediate pressure turbine, two low pressure turbines, and the generator( 'ssteam moves through the system and loses pressure and thermal energy it e:pands in

volume, re;uiring increasing diameter and longer blades at each succeeding stage to

e:tract the remaining energy( +he entire rotating mass may be over 0$$ metric tons and!$$ feet ed to the power grid(

+he rotor spins in a sealed chamber cooled with hydrogen gas, selected because it has thehighest known heat transfer coefficient of any gas and for its low viscosity which reduces

windage losses( +his system re;uires special handling during startup, with air in thechamber first displaced by carbon dio:ide before filling with hydrogen( +his ensures thatthe highly e:plosive hydrogen o:ygen environment is not created(

+he power grid fre;uency is 7$ 1> across &orth 'merica and "$ 1> in 3urope, /ceania,

'sia e the frictional resistance to the

rotation, the shaft has a number of bearings( +he bearing shells, in which the shaft rotates,

are lined with a low friction material like Babbitt metal( /il lubrication is provided tofurther reduce the friction between shaft and bearing surface and to limit the heat

generated(

http://en.wikipedia.org/wiki/Turbinehttp://en.wikipedia.org/wiki/Revolutions_per_minutehttp://en.wikipedia.org/wiki/Emergency_lightinghttp://en.wikipedia.org/wiki/Emergency_lightinghttp://en.wikipedia.org/wiki/Communicationhttp://en.wikipedia.org/wiki/Communicationhttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Pressurehttp://en.wikipedia.org/wiki/Pressurehttp://en.wikipedia.org/wiki/Statorhttp://en.wikipedia.org/wiki/Rotor_(electric)http://en.wikipedia.org/wiki/Copperhttp://en.wikipedia.org/wiki/Magnethttp://en.wikipedia.org/wiki/Magnethttp://en.wikipedia.org/wiki/Amperehttp://en.wikipedia.org/wiki/Amperehttp://en.wikipedia.org/wiki/Volthttp://en.wikipedia.org/wiki/Alternating_currenthttp://en.wikipedia.org/wiki/Revolutions_per_minutehttp://en.wikipedia.org/wiki/Revolutions_per_minutehttp://en.wikipedia.org/wiki/Power_gridhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Heat_transfer_coefficienthttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Windagehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Explosivehttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Utility_frequencyhttp://en.wikipedia.org/wiki/Hertzhttp://en.wikipedia.org/wiki/Hertzhttp://en.wikipedia.org/wiki/North_Americahttp://en.wikipedia.org/wiki/Europehttp://en.wikipedia.org/wiki/Europehttp://en.wikipedia.org/wiki/Oceaniahttp://en.wikipedia.org/wiki/Oceaniahttp://en.wikipedia.org/wiki/Asiahttp://en.wikipedia.org/wiki/Koreahttp://en.wikipedia.org/wiki/Koreahttp://en.wikipedia.org/wiki/Japanhttp://en.wikipedia.org/wiki/Japanhttp://en.wikipedia.org/wiki/Africahttp://en.wikipedia.org/wiki/Transformerhttp://en.wikipedia.org/wiki/Turbo_generatorhttp://en.wikipedia.org/wiki/Bearing_(mechanical)http://en.wikipedia.org/wiki/Bearing_(mechanical)http://en.wikipedia.org/wiki/Babbitt_metalhttp://en.wikipedia.org/wiki/Turbinehttp://en.wikipedia.org/wiki/Revolutions_per_minutehttp://en.wikipedia.org/wiki/Emergency_lightinghttp://en.wikipedia.org/wiki/Communicationhttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Pressurehttp://en.wikipedia.org/wiki/Statorhttp://en.wikipedia.org/wiki/Rotor_(electric)http://en.wikipedia.org/wiki/Copperhttp://en.wikipedia.org/wiki/Magnethttp://en.wikipedia.org/wiki/Amperehttp://en.wikipedia.org/wiki/Volthttp://en.wikipedia.org/wiki/Alternating_currenthttp://en.wikipedia.org/wiki/Revolutions_per_minutehttp://en.wikipedia.org/wiki/Power_gridhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Heat_transfer_coefficienthttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Windagehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Explosivehttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Utility_frequencyhttp://en.wikipedia.org/wiki/Hertzhttp://en.wikipedia.org/wiki/North_Americahttp://en.wikipedia.org/wiki/Europehttp://en.wikipedia.org/wiki/Oceaniahttp://en.wikipedia.org/wiki/Asiahttp://en.wikipedia.org/wiki/Koreahttp://en.wikipedia.org/wiki/Japanhttp://en.wikipedia.org/wiki/Africahttp://en.wikipedia.org/wiki/Transformerhttp://en.wikipedia.org/wiki/Turbo_generatorhttp://en.wikipedia.org/wiki/Bearing_(mechanical)http://en.wikipedia.org/wiki/Babbitt_metal


14/19

(tac' gas path and cleanup

see Flue gas emissions from fossil fuel combustion and Flue gas desulfurization

for more details

's the combustion flue gas e:its the boiler it is routed through a rotating flat basket of metal mesh which picks up heat and returns it to incoming fresh air as the basket rotates,

+his is called the air preheater ( +he gas e:iting the boiler is laden with fly ash, which are

tiny spherical ash particles( +he flue gas contains nitrogen along with combustion products carbon dio:ide, sulfur dio:ide, and nitrogen o:ides( +he fly ash is removed by

fabric bag filters or electrostatic precipitators( /nce removed, the fly ash byproduct can

sometimes be used in the manufacturing of concrete( +his cleaning up of flue gases,however, only occurs in plants that are fitted with the appropriate technology( till, the

maIority of coal fired power plants in the world do not have these facilities( citation needed -

%egislation in 3urope has been efficient to reduce flue gas pollution( Aapan has beenusing flue gas cleaning technology for over 2$ years and the J has been doing the same

for over 0" years( .hina is now beginning to grapple with the pollution caused by coalfired power plants(

Where re;uired by law, the sulfur and nitrogen o:ide pollutants are removed by stack gasscrubbers which use a pulveri>ed limestone or other alkaline wet slurry to remove those

pollutants from the e:it stack gas( /ther devices use catalysts to remove &itrous /:ide

compounds from the flue gas stream( +he gas travelling up the flue gas stack may by thistime have dropped to about "$ E.


15/19

't the bottom of the furnace, there is a hopper for collection of bottom ash( +his hopper

is always filled with water to ;uench the ash and clinkers falling down from the furnace(

ome arrangement is included to crush the clinkers and for conveying the crushedclinkers and bottom ash to a storage site(

*u"iliary systems

Boiler ma'e-up water treatment plant and storage

ince there is continuous withdrawal of steam and continuous return of condensate to the

boiler, losses due to blowdown and leakages have to be made up to maintain a desired

water level in the boiler steam drum( For this, continuous make6up water is added to the boiler water system( )mpurities in the raw water input to the plant generally consist of

calcium and magnesium salts which impart hardness to the water( 1ardness in the make6

up water to the boiler will form deposits on the tube water surfaces which will lead tooverheating and failure of the tubes( +hus, the salts have to be removed from the water,

and that is done by a water demineralising treatment plant ers may be ball mills, rotating drum

grinders, or other types of grinders(

ome power stations burn fuel oil rather than coal( +he oil must kept warm >les(

http://en.wikipedia.org/wiki/Bottom_ashhttp://en.wikipedia.org/wiki/Bottom_ashhttp://en.wikipedia.org/wiki/Condensationhttp://en.wikipedia.org/wiki/Calciumhttp://en.wikipedia.org/wiki/Magnesiumhttp://en.wikipedia.org/wiki/Water_hardnesshttp://en.wikipedia.org/wiki/Polyvinyl_chloridehttp://en.wikipedia.org/wiki/Surface_condenserhttp://en.wikipedia.org/wiki/Ejectorhttp://en.wikipedia.org/wiki/Pulverizershttp://en.wikipedia.org/wiki/Ball_millhttp://en.wikipedia.org/wiki/Grinder_(milling)http://en.wikipedia.org/wiki/Fuel_oilhttp://en.wikipedia.org/wiki/Pour_pointhttp://en.wikipedia.org/wiki/Bottom_ashhttp://en.wikipedia.org/wiki/Condensationhttp://en.wikipedia.org/wiki/Calciumhttp://en.wikipedia.org/wiki/Magnesiumhttp://en.wikipedia.org/wiki/Water_hardnesshttp://en.wikipedia.org/wiki/Polyvinyl_chloridehttp://en.wikipedia.org/wiki/Surface_condenserhttp://en.wikipedia.org/wiki/Ejectorhttp://en.wikipedia.org/wiki/Pulverizershttp://en.wikipedia.org/wiki/Ball_millhttp://en.wikipedia.org/wiki/Grinder_(milling)http://en.wikipedia.org/wiki/Fuel_oilhttp://en.wikipedia.org/wiki/Pour_point


16/19

Boilers in some power stations use processed natural gas as their main fuel( /ther power

stations may use processed natural gas as au:iliary fuel in the event that their main fuel

supply


17/19

+he generator also uses water cooling( ince the generator coils are at a potential of about

00 kC and water is conductive, an insulating barrier such as +eflon is used to interconnect

the water line and the generator high voltage windings( 5eminerali>ed water of lowconductivity is used(

,enerator high voltage system

+he generator voltage for modern utility6connected generators ranges from !! kC insmaller units to 00 kC in larger units( +he generator high voltage leads are normally large

aluminum channels because of their high current as compared to the cables used in

smaller machines( +hey are enclosed in well6grounded aluminum bus ducts and aresupported on suitable insulators( +he generator high voltage leads are connected to step6

up transformers for connecting to a high voltage electrical substation


18/19

sent by belt conveyors to a storage pile( &ormally, the crushed coal is compacted by

bulldo>ers, as compacting of highly volatile coal avoids spontaneous ignition(

+he crushed coal is conveyed from the storage pile to silos or hoppers at the boilers byanother belt conveyor system(

(ee also

• Boiler

• .ombined heat and power

• .ooling tower system

• Flue gas stacks

• Fossil fuel power plant

• Geothermal power

• &uclear power

• Power station

• Relative cost of electricity generated

by different sources

• %evelised energy cost

• Water6tube boiler

• )ntegrated Gasification .ombined

.ycle

)eferences

!( . 3lectricity

0( . httpHKKbooks(google(comKbooksQ

idSMw8'''')''A@pgP'!8"@d;centralTstationTsteamTengineTturbine@hlen@eiu>fU+OV93sOVn'fF0c&Bg@saV@oibookresult@ctresult@res

num7@ved$.3MU7'3wBUXvonepage@;centralD0$stationD0$steam

D0$engineD0$turbine@ffalse The early days of the power station industry,

.ambridge Jniversity Press 'rchive, pages !846!8"2( . Maury Olein, The Power Makers: Steam !lectricity and the Men "ho

#nvented Modern $merica Bloomsbury Publishing J', 0$$9 )B& !"979!788V4( . British 3lectricity )nternational

incorporating modern power system practice Pergamon( )B& $6$#6$4$"!$6V("( Y a b c Babcock @ Wilco: .o(


19/19

!!( . Robert +hurston Oent !ngineers+ 'andbook

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Thermal Power Station typical view

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