Thermal Power Plant familarization

Introduction and some facts about large thermal power station.

Boiler is used for steam generation.

Ball Mill or Bowl mills are used for pulverisation of coal in powder form for efficient firing in boiler.

Raw Coal Feeders are used to supply coal to ball mills in controlled quantity.

PA Fan are used to transport and preheat pulverised coal to burners.

ID Fan are used to exhaust flue gases to chimeny and create vaccum in Furnace.

Electrostatic Precipitators are used to separate ash particles from flue gases to control pollution.Here collecting electrode,emmiting electrode and rapping mechanism used.

FD Fan used to provide air to boiler for help in firing.

Steam produced in boiler is further superheated in Superheaters.There are lot superheaters such as platen,pendent,convection and final superheaters.

Boiler drum used for separation of staem from water.

Boiler circulation pump used for forced circulation of water in water wall because at high pressure natural circulation is not possible.

Ash slurry pumps are used to flush ash with water.

Boiler Feed Pump used to provide water to boiler.

Deaerator used to separate dissolved air from water.

In Turbine heat energy of steam is converted into mechanical energy.

ESV which is called emergency stop valve used to stop supply of steam to turbine when unit trips.

Barring gear or shaft turning gear is used to ratate turbinr rotor at 3.15 rpm when turbine is not running to check bending of rotor due to its own weight.

LP Heaters and HP Heaters are used to heat condensate and feed water supplied to boiler to increase efficiency by steam bled from turbine extraction.

Economiser are used to heat feed water by flue gages to increase efficiency. Heat of waste flue gas is utilised here.

Air Heaters uses heat of waste flue gases to preheat primary and secondary air.There are two types of air heaters tubular and rotary.

Condenser used to condence steam exhausted from turbine.

Condensate Pump are used to supply water to Deaerator from condensers.

CW Pump used to cool steam in condensers.

Turbogenerator converts mechanical energy into electrical energy.

H2 Gas used in generators used for cooling of generators.

Seal Oil system used to seal hydrogen gas from escape from generator.


Stator Water Cooling system provides demineralised water into hollow stator conductor of generator for its cooling.

Generating Tansformer steps up volatage for transmission.

Water Treatment Plant is used to produce demineralised water for steam generation. Cation anion and degassifier tower used to separate mineral and gases from water.PAC or alum used to separate mud and silica from water.

Coal Handling Plant supplies Coal to Boiler.Merry go round system or wagon trippler used to unload coal into hoppers. Coal is crused in crusher to crush it in 25mm size.Magnetic separators used to separate metalic particles from coal.

ABCB,SF6,OCB,MOCB and VCB are circuit breakers used to make or break electricity contact at load.

Isolators are used to make or break contact at no loads.

ABT is availability based tarrif system to maintain grid discipline.

Purging is done to clean furnace from combustible gases by running IDF and FDF at atleast 30% load for 5 minutes.

Furnace explosion may be checked by timely purging and adjusting firing properly using right quantity primary and secondary air and timely oil support.

Flame scanners used to sence flame in boiler.

FSS is furnace safeguards supervisory system to safeguard boiler.

Clinker formation which caused by more ash content and mineral in poor quality coal may be checked by proper poking and using more water for flushing and use of clinker grinder.

Acoustic Instruments used to detect early boilker tube leakage to avoid secondary damage to pressure parts.






Thermal Power Plant Boiler Turbine Turbogenerator ESP
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