Electricity generation in coal-fired power plants involves the conversion of coal's chemical energy into electrical energy through a process called combustion. Here's a step-by-step explanation of how this process occurs:
Coal Storage: The coal is first delivered to the power plant and stored in coal bunkers or silos. This ensures a steady supply of coal to the power plant for continuous operation.
Pulverization: The coal is then crushed into a fine powder form to increase its surface area. This process is known as pulverization, and it makes the coal easier to burn efficiently.
Combustion: The pulverized coal is mixed with air and blown into the combustion chamber of the boiler. In the combustion chamber, the coal particles react with the oxygen in the air and undergo a chemical reaction, releasing heat. This process is known as combustion, and it generates a large amount of heat energy.
Boiler: The heat generated during combustion is used to convert water into steam. The boiler is a large vessel that contains water-filled tubes, and the hot gases from the combustion chamber pass over these tubes, heating the water inside.
Steam Turbine: The high-pressure steam from the boiler is directed into a steam turbine. The steam turbine is a mechanical device with blades that are turned by the high-velocity steam. As the steam flows over the turbine blades, it causes them to rotate.
Generator: The steam turbine is connected to an electric generator. As the turbine blades spin, they turn the generator's rotor, which is surrounded by a stationary coil. This motion induces a flow of electrons within the coil, generating an electric current.
Electricity Generation: The electric current produced by the generator is in the form of alternating current (AC). This electrical energy is then stepped up to high voltages using transformers, making it more efficient for long-distance transmission.
Transmission and Distribution: The high-voltage electricity is transmitted through power lines over long distances to reach homes, businesses, and industries. Substations step down the voltage for local distribution, and finally, the electricity is supplied to consumers for various uses.
It's essential to note that coal-fired power plants are considered a significant source of greenhouse gas emissions, contributing to climate change and environmental pollution. To address these concerns, many countries are transitioning towards cleaner and more sustainable energy sources, such as renewable energy (e.g., solar, wind, hydro, and geothermal power).