A thermal power plant converts heat energy into electrical energy by burning fossil fuels (coal, natural gas, or oil) or using nuclear reactions. The basic layout consists of several key components:
1. Fuel Handling & Storage
– Coal/Gas/Oil Storage: Fuel is stored before being fed into the boiler.
– Fuel Preparation (for coal): Crushing, pulverizing, and drying to improve combustion efficiency.
2. Boiler (Steam Generator)
– Furnace: Where fuel is burned to produce high-temperature flue gases.
– Water Walls & Tubes: Water circulates and absorbs heat to form steam.
– Superheater: Increases steam temperature beyond saturation point for higher efficiency.
3. Turbine Section
– High-Pressure (HP) Turbine: Steam expands here first, losing pressure but gaining velocity.
– Intermediate-Pressure (IP) Turbine & Low-Pressure (LP) Turbine: Further expansion to extract maximum energy.
– Condenser: Converts exhaust steam back into water by cooling.
4. Generator
– Connected to the turbine shaft, it converts mechanical energy into electrical energy via electromagnetic induction.
5. Cooling System
– Cooling Tower or Water Source (River/Sea): Removes waste heat from the condenser.
– Circulating Water Pumps: Maintain water flow for cooling.
6. Ash Handling System (For Coal Plants)
– Collects and disposes of ash residues from combustion.
7. Air & Flue Gas System
– Forced Draft (FD) Fan: Supplies air for combustion.
– Induced Draft (ID) Fan: Removes exhaust gases and maintains furnace pressure.
– Electrostatic Precipitator (ESP)/Scrubber: Removes particulate matter and pollutants before emission.
8. Feedwater & Condensate System
– Deaerator removes dissolved gases from feedwater.
– Feedwater pumps return condensed water to the boiler.
9. Electrical Switchyard
– Steps up voltage via transformers for transmission to the grid.
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Simplified Process Flow:
1. Fuel → Combustion in Boiler → Steam Generation
2. Steam → Turbine Rotation → Generator → Electricity
3. Exhaust Steam → Condenser → Cooling → Reused as Feedwater