Thermal Power Station
A thermal power station is an energy source for producing electrical energy from coal, natural gas, or waste heat. There are many different kinds of power stations. Some use coal to generate electricity; some use natural gas. These power plants are also called coal-fired or natural gas-fired thermal power stations. The most common type of power station is the coal-fired thermal power station.
Coal-fired steam turbines
A thermal power station uses coal-fired steam turbines to generate electricity. The turbines use steam cycles to produce power and heat. They use thermodynamic and energy balance equations to describe the process. The steam passes through a high-pressure feedwater heater that desuperheating the steam. It is then condensed to heat feedwater, passing through the turbine.
Thermal power plants use coal as their primary fuel, which accounts for nearly half of the global electricity supply. The coal is burned in a furnace-like boiler, converting it into steam and heat. The high-pressure steam then turns the turbine blades attached to a shaft. The turbine then turns a generator that produces electricity.
Heat-only boilers
Heat-only boilers in thermal power stations produce hot water and steam without producing any liquid water. The steam then passes through a boiler and a turbine to drive an electrical generator. Afterward, the steam returns to the boiler through a condenser and is used as boiler-feed water.
To determine a boiler’s efficiency, it is important to calculate its net heat output. The British Standards measure heat output as a percentage of the available energy in the fuel. However, the German DIN 1942 standard recommends a lower calorific value, while the American ASME PTC-4.1 standard requires a higher one. To calculate boiler efficiency, there are two methods: direct and indirect. Direct methods divide the heat output by the fuel-power input, while indirect methods subtract major losses from unity.
The main goal of a boiler is to extract as much energy as possible from fuel. This involves burning all the fixed carbon and volatile matter in the fuel. To achieve this, the boiler must have a high temperature and burn the fuel continuously. In addition, the boiler must be designed to maximize heat transfer. Some thermal power stations use separate heat exchangers to increase efficiency.