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Coal based thermal power plant works on the principal of Modified Rankine Cycle.

The Rankine cycle is a model that is used to predict the performance of steam engines. The Rankine cycle is an idealised thermodynamic cycle of a heat engine that converts heat into mechanical work.

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Coal handling plant

Economiser

Air Pre heater

Re heater

Steam turbines

Condenser

Boiler

Cooling tower

Ash handling

Generator

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: In coal-fired power stations, the raw feed coal from the coal storage area is first crushed into small pieces and then conveyed to the coal feed hoppers at the boilers.

: they are used in order to remove the excess moisture from coal mainly wetted during transport.

: coal which is brought may contain iron particles. The iron particles may include bolts, nuts wire fish plates etc. so these are unwanted and so are removed with the help of magnetic separators.

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These are detect the presence of any ferrous and non-ferrous metal in the coal and sends a signal to a relay which closes to seize the movement of belt until the metal is removed. It basically consists of a transmitter and a receiver

To SSTPS from gudla via a single railway

track

Wagon tippler

hoppersCrusher house

bunkers

Raw coal feeders

Coal mills(pulverization)

Boiler furnace ( tangential firing of pulverized coal)

Boiler is a combustion chamber

where water is heated at such

a temperature to achieve high

pressure steam .

1) fire tube boiler

2) water tube boiler

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Flue gases coming out of the boiler carry lot of heat. An economizer extracts a part of this heat from flue gases and uses it for heating feed water. This use of economizer results in saving coal consumption and higher boiler efficiency

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The heat carried out with the flue gases coming out of economiser are further utilized for preheating the air before supplying to the combustion chamber. It is a necessary equipment for supply of hot air for drying the coal in pulverized fuel systems to facilitate grinding and satisfactory combustion of fuel in the furnace

Power plant furnaces may have a re-heater section containing tubes heated by hot flue gases outside the tubes. Exhaust steam from the high pressure turbine is rerouted to go inside the re-heater tubes to pickup more energy to go drive intermediate or lower pressure turbines.

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A steam turbine is a device that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft . Because the turbine generates rotary motion, it is particularly suited to be used to drive an electrical generator.

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HPT IPT LPT

RH

Steam

Steam

Shaft

Super

Heater

Condenser

GeneratorHPT IPT LPT

Generator or Alternator is the electrical end of a turbo-generator set. It is generally known as the piece of equipment that converts the mechanical energy of turbine into electricity. The generation of electricity is based on the principle of electromagnetic induction. Generally three phase synchronous generator is used

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The disposal of ash from a large capacity power station is of same importance as ash is produced in large quantities. Ash handling is a major problem.

While barrows are used for this. The ash is collected directly through the ash outlet door from the boiler into the container from manually.

Mechanical equipment is used for ash disposal, mainly bucket elevator, belt conveyer. Ash generated is 20% in the form of bottom ash and next 80% through flue gases, so called Fly ash and collected in ESP.

The dust particles are ionized and attracted by charged electrodes. The electrodes are maintained at 60KV.Hammering is done to the plates so that fly ash comes down and collect at the bottom.

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They can respond to rapidly changing loads without difficulty

A portion of the steam generated can be used as a process steam in different industries

Steam engines and turbines can work under 25 % of overload continuously

Fuel used is cheaper

Cheaper in production cost in comparison with that of diesel power stations

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Maintenance and operating costs are high

Long time required for erection and putting into action

A large quantity of water is required

Great difficulty experienced in coal handling

Presence of troubles due to smoke and heat in the plant

Unavailability of good quality coal

Maximum of heat energy lost

Problem of ash removing

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