Thermal power plant || Operation, advantage

In a power system, there are different types of power plant like hydropower, wind, diesel etc in which one of them is thermal power plant. Here we are going to discuss about Thermal power plant || Electricity generation using thermal power plant.

Thermal power plant

Thermal power plant is the plant in  which liquid/gas/solid are used to heat the water and steam will obtained which is used to rotate the turbine to generate electricity by connecting turbine shaft with generator shaft. Here water is needed to be heated for that different source can be used like petroleum product, coal, LPG gas etc. and gas/steam turbine is used for converting kinetic energy of steam into rotational energy. It also means that this station utilizes calorific values of fuels as the source of energy and the conversion of such energy is carried out by turbo-generator which is run by steam turbines.

Operation of Thermal power plant

The steam is obtained from high pressure boiler where fuel is heated by fuel to heat water. The fuel is burnt in the boiler which can be solid (like coal), liquid (like petroleum) and gases (like natural gas, LPG gas). Conventionally, thermal  power generation means steam power 

plant using coal as fuel. The diagram of a Thermal Plant is shown below.

In the boiler, the fuel is burnt and heat the water so that it is converted into high pressure steam which is further superheated in a super heater.  There are many type of heat exchangers such as Economiser, Evaporator, Super Heater and so on. In Economiser, the feed water is heated to some specific amount by the flue and that superheated steam is passed in the turbine to rotate the turbine blades. Thus this system converts the heat energy to mechanical energy by using turbine. The steam after passing through the turbine, the pressure of it will decrease and volume will increase and that low pressure steam passes into condenser. In condenser, the condensed water is further supplied to low pressure water heater where the temperature of the low pressure feed water will increase and further process go on. 

Thermal power plant requires tremendous amount of water for steam generation as well as for cooling purpose in condenser. In actual, the turbine is the prime mover of the alternator which is used to generate electricity. Then, the alternator is connected to bus bar and grid with transformers and protection devices.

 

The efficiency of thermal power plant is very less as compared to hydropower plant. The overall efficiency of the thermal power plant by using coal as fuel is in the range of 20% to 26% depending upon the capacity of the plant which means higher the capacity, relatively higher will be the efficiency. This power generation plant covers a massive and greatest portion of total energy consumption of the world. As a result, environmental problems are being big issue. In these days, over 90% of greenhouse gas production is due to burning fossil fuels to meet the energy requirement of the today’s industrialized and commercialized world.

Advantages

• This is most economical plant for low initial cost as compared to other generating plant. 
• Maintenance for this plant is easier. 
• Generally, coal is used as fuel source which cost is quite cheap so generation cost is relatively low as compared to diesel power plant. 
• It can be installed in any location suitable according to load center.
• Land required for it is less as compared to hydropower plant. 

Disadvantages

• Overall efficiency of thermal power plant is low i.e. less 30%.
• The running cost for a thermal power station is comparatively high due to requirement of high amount of fuel, large number of maintenance etc. 
• Large amount of smoke or harmful gases is obtained which causes air pollution so that it is mainly responsible for Global warming. 
• The heated water that comes from the plant has an adverse effect on aquatic animals and disturbs the ecology.