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Generation of Electricity from Coal. *. www.powerpointpresentationon.blogspot.com. In this Presentation. Basic of Power Generation Basic information on Coal/Fuel Oil Combustion Process Power Plant Cycle 4 Main Path come across in any thermal power plant Boilers and Turbines
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Generation of Electricity from Coal * www.powerpointpresentationon.blogspot.com
In this Presentation • Basic of Power Generation • Basic information on Coal/Fuel Oil • Combustion Process • Power Plant Cycle • 4 Main Path come across in any thermal power plant • Boilers and Turbines • Transmission of Power and Switching * *
A thermal power station is a power plant in which the Water is heated, turns into steam and spins a steam turbine and does some other work and produce electricity . • After 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
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Coal to Electricity ….. Basics Pollutants Super Heated Steam Alternating current in Stator Turbine Torque Coal Mech. Energy Loss Elet. Energy Loss Heat Loss ASH Heat Loss In Condenser Thermal Energy Kinetic Energy Electrical Energy Chemical Energy * *
Overview of Thermal Power Plant Simplified Diagram * *
For 1000 MW electricity Generation the consumption of raw material is as follows • Coal - 12000 Ton/day • Water – 98000 Cubic meter / day • Oil - 100 Cubic metre / day • Air - 50000 Tons/ day • This also result in the following • Ash - 4200 tons/ day • CO2 - 30000 tons/ day • So2 - 600 tons/ day • No2 - 80 tons/ day * *
Why Coal? Advantages of Coal Fuel • Abundantly available in India • Low cost • Technology for Power Generation well developed. • Easy to handle, transport, store and use Shortcomings of Coal • Low Calorific Value • Large quantity to be Handled • Produces pollutants, ash • Disposal of ash is Problematic • Reserves depleting fast Share of Coal in Power Generation • India’s Coal Reserves are estimated to be 206 billion tonnes. Present consumption is about 450 million tonnes. • Cost of coal for producing 1 unit of electricity (Cost of coal Rs 1000/MT) is Rs 0.75. • Cost of Gas for producing 1 unit of electricity (Cost of Gas Rs 6/SMC) is Rs 1.20. * * Nuclear RES 3% 5% Hydel 26% Coal 55% Diesel 1% Gas 10%
Knowing more about Coal Coal Properties • Calorific Value • Grade of Coal (UHV) • Proximate Analysis • Ultimate Analysis • Ash and Minerals • Grindability • Rank • Physical Characteristics Coal Transportation • Rail • Truck • Conveyor • Ship Coal Beneficiation (Coal cleaning and reduction in total volume of coal.) Coal production • Surface Mining • Underground Mining * *
Physical Characteristic - Hardness , Color, Weight, Volume * *
Combustion of coal • Carbon, hydrogen, sulfur are sources of heat on combustion • Surface moisture removed on heating during pulverization. • Inherent moisture and volatiles are released at higher temperature, making coal porous and leading to char/ coke formation. (Thermal preparation stage) *
Combustion Reactions (Carbon) • Main reactions 2C + O2 = 2CO + 3950 BTU/lb(Deficit air) C + O2 = CO2 +14093 BTU/lb Secondary reactions 2CO + O2 = 2CO2 + 4347BTU/lb C + CO2 = 2CO -7.25MJ/kg *
Combustion Reactions (Carbon) • Carbon reaction 2C + O2 =2CO [Eco =60kJ/mol] C + O2 =CO2 [Eco2 =140kJ/mol] reaction at 1200oC 4C + 3O2 =2CO + 2CO2 (Ratio 1:1) Reaction at 1700oC 3C + 2O2 = 2CO +CO2 (Ratio 2:1) It is desirable to supply combustion air at lower temperature regime in furnace *
Combustion Reaction (H2, S) • Hydrogen reaction 2H2 + O2 = 2H2O +61095 BTU/lb • Sulfur reaction S + O2 = SO2 + 3980 BTU/lb (undesirable) *
Coal for combustion • Anthracite • Semi-anthracite • Bituminous • Semi-Bituminous • Lignite • Peat • High CV, low VM • High CV, low VM • Medium CV, medium VM • Medium CV, medium VM • Low CV, high VM, high TM • Very low CV, high VM & TM *
Fuel Oil • liquid fuels used in power plants Light Diesel Oil (LDO) - Heavy Fuel Oil (HFO) - • Droplet formation on atomization (by steam/ compressed air/ mechanical pressurization) • Combustion initiation by High energy spark ignition *
The four main circuits one would come across in any thermal power plant layout are- Coal and Ash Circuit- Air and Gas Circuit- Feed Water and Steam Circuit- Cooling Water Circuit * *
Coal and Ash CircuitCoal Circuit Wagon Tripler Conveyer Belt Magnetic Separation Crusher (20-25 mm) Bunker Mill Burner * *
Coal and Ash Circuit Ash Circuit Bottom Ash Fly Ash (80%) (20%) Slurry Silo Ash Ponds * *
Air and Gas Circuit • Fuel gas Circuit Furnace Super heater Economiser APH ESP ID Fan Chimney Air Circuit FD Fan APH Wind Box Furnace * *
Water Cycle * *
Cooling Water Circuit Circulating Pump Condenser Cooling Tower * *
Boiler/ steam generator • Steam generating device for a specific purpose. • Capable to meet variation in load demand • Capable of generating steam in a range of operating pressure and temperature • For utility purpose, it should generate steam uninterruptedly at operating pressure and temperature for running steam turbines. * *
Boiler/ steam generator • Raw materials for design of boilers • Coal from mines • Ambient air • Water from natural resources • (river, ponds) • Generating heat energy • Air for combustion • Working fluid for steam • generation, possessing heat energy • A 500MW steam generator consumes about 8000 tonnes of coal every day • It will be considered good, if it requires about 200 cubic meter of DM water in a day • It will produce about 9500 tonnes of Carbon di Oxide every day * *
ARRANGEMENT OF MAIN BOILER (STEAM GENERATOR) • A STEAM GENERATOR IS A COMPLEX INTEGRATION OF THE FOLLOWING ACCESSORIES: * ECONOMISER * LTSH * BOILER DRUM * DIV PANEL * DOWN COMERS * PLATEN SH * CCW PUMPS * REHEATER * BOTTOM RING HEADER * BURNERS * WATER WALLS * APHs *
Type of Boilers used in Thermal Power Plant • Water Tube Boiler: Here the heat source is outside the tubes and the water to be heated is inside. Most high-pressure and large boilers are of this type. In the water-tube boiler, gases flow over water-filled tubes. These water-filled tubes are in turn connected to large containers called drums. *
Steam Flows from Boiler to turbine Bypass Turbine *
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Turbine are multistage The steam turbine is a form of heat engine that derives much of its improvement in thermodynamic efficiency from the use of multiple stages in the expansion of the steam *
Switchyard One line Diagram Transfer Bus 400 KV Main Bus II Main Bus I Bus Isolator CB CB CB Transfer Bus Bay GT 20.5/400KV * Gen Bay Feeder Bay
SF6 CB *