Working of Hydro Power Plant (Function of Different Components)
Q. What are the parts of a hydroelectric power plant?
Q. How does hydroelectric power plant operate draw diagram.
Q. How hydroelectric power plant works?
- Reservoir : It is required to store the water, which is used to run the turbine.
- Dam : It facilitates collection of water at suitable head, which can be used throughout the year by proper controls.
- Trash rack : It prevents entry of debris which might damage the wicket gates and turbine runners or may choke nozzles of Impulse turbines.
- Forebay : It serves as a regulating reservoir . In case of plants having forebay, no surge tank is required as the surge due to change in load will be absorbed by the forebay itself.
- Surge tank : This is a tank provided near the turbine. As the load on the turbine decreases suddenly, water flow to the turbine reduces suddenly. This causes a hammer effect on penstock. This effect is absorbed by the surge tank by providing space for the additional water.
- Penstock : It is a pipe line of cast iron for taking water from the intake work and forebay to the turbines.
- Power house : It is generally located at the foot of the dam and near the reservoir. It is located in such a way that the use of maximum possible head can be utilized at the turbines.
- Prime mover : Prime movers convert the kinetic energy of water into mechanical energy Commonly Pelton wheel, Francis, Kaplan and Propeller type turbines are used as prime movers.
- Spill way : This may be considered as a sort of safety valve for the dam. A spill way serves to discharge excess water in the reservoir beyond the full permissible level.
- Intake : Since water level in the reservoir is below the crest of the spill way, some inlet has to be provided to draw water from the reservoir as required. Level of intake is decided by the maximum drawdown of the reservoir, providing for the requirement that the intake should be sufficiently below the minimum reservoir level so as to prevent air being drawn in, it should be arranged as high as possible. With such cholce intake is less likely to be affected by floating trash. Also there will be less chance of interruption due to Ice. For locations where there will be wide fluctuations of water level, Intake towers are often used. Screens or trash racks are used to prevent debris passing into the water passage.
- Tail race : The tail race is a water way to lead water discharged from the turbine to the river. Water level of the tail race should be kept high enough so as to avoid cavitation near the runners when the Francis or Kaplan turbines are used.