Working of Simple Steam Power plant

 High Pressure, high - temperature super-heated steam leaving the steam generator or boiler does work in the turbine which drives the electric generator to produce electricity. The low-pressure steam enters the condenser, where heat is transferred from the steam to the cooling water circulating through the tubes. Steam is condensed to the water which is then pumped back to the boiler.

A fossil fuel ( coal, fuel oil or natural gas) is used to release heat by combustion, and the products of combustion or flue gases heat water to generate steam and then super heat it. The exhaust gases, before leaving through stack or chimney, heat the feedwater in heat exchanger called economizer before the feedwater enters the steam drum and then heats the air for combustion in another heat exchanger called air preheater. The exhaust gases leaving the stack have a considerable amount greenhouse gases (CO2) and cause Thermal pollution and global warming. A large power plant has many other pieces of equipment, some of which will be considered later. 

In a Nuclear power plant, the nuclear reactor replaces the furnace of a conventional power plant. The Turbine, condenser and pump are the three other basic components. Safety considerations and the disposal of the radioactive wastes are important in the design and operation of the Nuclear Plant.