In Thermal Power Station, The heart of combustion of fossil fuels (like coal, oil and gas) is utilize by the boiler to get steam at high pressure and temperature.
thermal power station produce the steam and drive it to the steam turbines or sometime steam engines coupled to generators and thus electrical energy is generate.
Steam power plants are install either to generate electricity only or to generate steam. But for the industries like paper mills, textile mills, sugar mill etc.
The steam for process purpose is extract from certain section of turbine. And the remaining steam is allow to expand in the turbine. Alternatively the exhaust steam can be use for the process purposes.
Types of Steam Power Plant
- Condensing Power Plant: In this type of power plant, the exhaust steam is discharge into condenser. After which it creates a suction at very low pressure. This allows the expansion of steam in the turbine to a very low pressure and thus increases the efficiency.
- Non Condensing Power Plant: In such type the steam exhaust from the turbine is discharge at atmospheric pressure. A continuous supply of fresh feed water is require. In condensing type power plant steam condensed into the water in the condenser. It then recirculated to the boilers with the help of pumps. This point becomes very important at places where there is a shortage of water.
According to use such power plants are classified into two types
- Industrial Power Plants: The industries requiring steam for process purposes may use steam turbines for generation of electrical energy also for its won use. Moreover, The steam for process purpose may be tape from extraction bleeding if the turbines at a pressure of 1.4-7kg/cm2. Such power plant are usually non condensing. These types of power plants are usually of small capacity (like up to 10MW).
- Central Power Plants: steam power plants are mainly use as central power plants to generate the electrical energy for the supply to various consumers. Like industries, Agricultural, Commercial and domestic etc.
Such power plants are usually condensing type.steam power plant is prefer where large amount of power is required to generate and financial climatic and geographical conditions do not permit the installation of hydro power plant and coal is available in plenty.the size of generating sets may be from 10-500MW.