Electricity is everywhere but most of the people does not know how it is produced. Let's introduce about the power generation factory “the thermal power plant”. Thermal power plant are designed to produce power in the form of voltage and current by using thermal energy. The power is generated by driving a large electrical generator (also called turbo-generator). This generator is driven by a shaft coupled turbine which rotates by using force of steam. Hence, in order to produce the electrical power, our primary concern is to produce steam from water by using thermal energy. This thermal energy is produced by burning fuel (mostly fossil fuels are used) to produce a sufficient amount of heat to generate steam from water. In thermal power plant, there are a number of process are done such as fuel firing, boiling of water, generation of steam, rotation of turbine, generation of voltage etc. These process need a number of parts, equipments and they are arranged in a definite manner.
Main Parts of a coal based thermal power plant :
Boiler - Boiler is the main part of the power plant. The purpose of the boiler is to boil water to produce steam. In actual, the boiler is made of several mechanical as well as electrical parts like boiler drum, deaerator, economizer, water wall tubes, furnace, super-heaters etc.
Water storage reservoir - Thermal power plant needs a huge amount of water per hour for steam generation and to full-fill the steam loss. Thus each plant must have at least one reservoir for storing water. Most of the power plant fill their reservoir by pumping water from any remote location water source like tunnel, river, lake water, ground water etc.
Water treatment plant – Water is treated to remove the mineral contents as these minerals are harmful for boiler parts because presence of minerals may lead to corrosion.
Coal handling plant - The coal is the main fuel in a coal fired thermal power plant. First of all the coal is kept ready in CHP(Coal handling plant) to send it before the boiler because it may content some impurities as per their grade.
Ash handling plant – Here the final ash coming out from ESP is collected. These ash can be used to make bricks, cement etc.
Cooling towers - The hot water coming out from the boiler are cooled naturally or by air force fans.
Chimney – The flue gas coming out from the plant side is thrown away by these giant pipe like design.
Control room – The control room is equipped with a number of computers with smart visual simulating software to control the whole power plant machines by giving commands.
Switchyard – It receives and controls the flow of power with various types of protective electrical devices. Some parts of switchyard are bus bar, circuit breaker, earth switch, lightning arrester, SCADA(Supervisory control & data acquisition system), Insulators, PLCC(Power Line Career Communication), transformers etc.
Turbine –The turbine is a rotating mechanical metallic part to generate mechanical torque to drive the heavy turbo generator by using pressure of steam.
Generator – This is a very important rotary electrical part where the plant output in the form of voltage and current are produced. The function of generator is to convert the mechanical energy of turbine to the electrical energy. Almost the generators are directly shaft coupled with the turbine.
Electro static precipitator - In order to save environment from harmonic micro particles as well as large dust particles, the dust in the form of fly ash are caught here and settled down. The ESP (Electro static precipitator) is an electrical device to produce high voltage corona effect to charge the dust particles.