Thermal power plant

A PRACTICAL TRAINING SEMINAR ON SURATGARH SUPER THERMAL POWER STATION SUBMITTED TO :Er. DAVENDRA YADAV

BLOCK DIAGRAM OF THERMAL POWER PLANT

PlSHRHRHFSH

Eco

PSH

147Kg/cm25400C

Generator TransformerGeneratorTurbineBoilerCoal BunkersPrimary Air Fans

Coal Mills

Raw Coal FdrChimneyFlue Gas DuctInduced Draft Fan

Coal ConveyerSECL Coal BunkerCSEB Crusher House

400/220 KV15.75KV

CondenserCoal Handling Plant

BoilerDrum

3000 rpm

210MWPlant Layout

ESP

AH

Working in Thermal Power Plant

OPERATION MECHANISMThe coal is brought and crushed to powder. This is fed to boiler for producing heat. In Boiler the water is converted to steam.In super heater the moisture content is removed from the steam and that steam is called super heated steam.The superheated steam rotates the shaft of the High pressure turbine. The exhausted steam is sent to preheater and the steam then rotates the intermediate pressure (IP) turbine . The steam from the IP Turbine is then feed to low pressure turbine.The turbine shaft is connected to the Generator, which produces electric Power. The power generated is then transmitted .

Coal Handling Plant Feed Water Plant Fuel and Ash Plant Steam Generating PlantElectrical EquipmentsCooling Water PlantDivisions of a thermal power plant

Coal handling plant

It contains many components:Coal UnloadingWagon tripplerCoal HopperCrusherMagnetic SeparatorCoal Mill/PulveriserStorageGeneral Layout of CHP

Coal unloading systemWagon Trippler :- Unload the coal from wagon to hopper.Hopper allows to pass coal pieces 300mmFrom hopper coal fall goes to Crusher house through conv. belts.

Crushing systemCRUSHER HOUSE:- Its main function to crush the coal to 6 mm Two types :-Primary crusherSecondary crusher

Conveying systemBelt are used to convey coal from coal handling plant to furnance.Specification:-Belt width : 1400mmSpeed : 2.2m/secCapacity : 1350/750 ton/hr

Coal hopper

Coal bunker

Coal millsPulveriser Layout

Steam generating equipment

BoilerIt is a closed vessel in which water under pressure is convert into steam.Steam is used to transfer heat to a process.A boiler is always designed to absorb max amount of heat released in process of combustion.Furnace :- It is primary part of boiler where the fuel is burnt to liberate the heat energy.

Chemical Energy of fuelThermal Energy by combustion

Aux Air + FUELCoal + Fuel +AirConcentric Firing System (CFS)

(Furnace Plan View)Fuel Streams( Coal+PA+Air)

EconomizerFlue 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

Super heater and ReheatersSuper heater is acomponent of a steam-generating unit in which steam, after it has left the boiler drum, is heated above its saturation temperature

Reheater :Some of the heat of superheated steam is used to rotate the turbine where it loses some of its energy

Air preheaters & DeAERATORAIR PREHEATER : After flue gases leave economizer, some further heat can be extracted from them and used to heat incoming heat. Cooling of flue gases by 20 degree centigrade increases the plant efficiency by 1%.

DEAERATOR : It is used to remove air which is entrapped in the water molecules. It is very important part because the entrapped air affects boiler drum badly and leads to corrosion.

turbinesA steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into mechanical energy.It is used as prime mover to generator.Three types of turbine are used : 1.HP turbine 2.IP turbine 3.LP turbine

Kinetic EnergyMechanical power

Steam Turbine

20

Turbine Blades and Rotor

condenserIt condenses steam at exhaust of turbine.It creates very low pressure at the exhaust of turbine which helps in converting heat energy of steam into mechanical energy in prime mover.The condensed steam can be used as feed water to the boiler.

Steam after rotating steam turbine comes to condenser. Condenser refers here to the shell and tube heat exchanger (or surface condenser) installed at the outlet of every steam turbine in Thermal power stations of utility companies generally.

COOLING TOWER Remove heat from the water discharged from the condenser so that the water can be discharged to the river or re circulated and reused.Air can be circulated in the cooling towers through natural draft and mechanical draft.

Ash handling plantIt can be done in 3 ways :Manual handling : 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 handling : 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.Electrostatic precipitator : From air preheater this flue gases (mixed with ash) goes to ESP. The ESP has plate banks (A-F) which are insulated from each other between which the flue gases are made to pass. The dust particles are ionized and attracted by charged electrodes. Hammering is done to the plates so that fly ash comes down and collect at the bottom.

UTILISATION OF SECONDARY RAW MATERIAL (ASH)Construction of embankments and fills.Construction of road in sub-base.Manufacture of cement.Manufacture of bricks/blocks.Agriculture as soil amendment/source of essential plant nutrients.

Electrical equipments

Basic Principle : Electro Magnetic InductionThe Synchronous Generator is used to Generate power by connecting the shaft of the Turbine to the shaft of the generator which cuts the magnetic flux producing Emf.The Generated Voltage will generally 11KV to 20 KV max.GENERATORGENERATORMECHANICAL ENERGYELECTRICAL ENERGY

Bus Duct

Generator Transformer20KV to 400KV

SYNCHRONOUSGENERATOR

UAT20Kv to 6.KV

Transformer & Switchyard

A switchyard is a part of an electrical generation, transmission system. Switchyard transform voltage from high to low or the reverse, or perform any of several other important functions.The Generated Voltage is stepped up by connecting Step up transformer and is transmitted and is also used for Auxiliary purposes.Unit Auxiliary Transformer: This transformer is used to step down the produced voltage and use for Auxiliary purpose.