Q2Power Generation Sources
Question
Q.2. Define working principle of thermal power plant.
Answer
A thermal power plant converts the chemical energy of fuel into heat (by combustion), the heat converts water into high-pressure steam in a boiler, and the steam expands through a turbine coupled to an alternator, converting thermal energy into mechanical and then electrical energy.
The working principle follows the Rankine cycle: fuel (coal) is burnt in a boiler furnace to convert feed water into high-pressure, high-temperature steam; this steam is expanded in a steam turbine, converting thermal energy into mechanical rotational energy; the turbine shaft is coupled to an alternator which converts mechanical energy into electrical energy by electromagnetic induction; the exhaust steam is condensed back to water in a condenser and pumped back to the boiler, completing a closed feed-water cycle.