Surge Tank – Definition & Detailed Explanation – Hydroelectric Power Glossary Terms

I. What is a Surge Tank?

A surge tank, also known as a surge chamber or a surge drum, is a water storage reservoir used in hydroelectric power plants to regulate the flow of water in the system. It is typically located at the downstream end of the penstock, which is the pipe that carries water from the reservoir to the turbine. The surge tank helps to maintain a constant pressure in the system by absorbing sudden changes in water flow and preventing water hammer, which is a sudden increase in pressure that can damage the turbine and other components of the power plant.

II. Why is a Surge Tank used in Hydroelectric Power Plants?

A surge tank is used in hydroelectric power plants to prevent damage to the turbine and other components of the system caused by sudden changes in water flow. When the flow of water in the penstock changes rapidly, it can create water hammer, which can cause the turbine to vibrate or even break. The surge tank acts as a buffer, absorbing the excess water and maintaining a constant pressure in the system. This helps to protect the turbine and other equipment from damage, ensuring the smooth and efficient operation of the power plant.

III. How does a Surge Tank work?

A surge tank works by storing excess water when the flow in the penstock increases suddenly. When the flow decreases, the water in the surge tank is released back into the system to maintain a constant pressure. The surge tank is typically equipped with a control valve that regulates the flow of water in and out of the tank. This valve opens when the flow in the penstock increases, allowing water to enter the surge tank, and closes when the flow decreases, preventing water from flowing back into the penstock. This process helps to stabilize the pressure in the system and prevent water hammer.

IV. What are the components of a Surge Tank?

The main components of a surge tank include the tank itself, which is usually a large cylindrical or rectangular structure made of concrete or steel, and a control valve that regulates the flow of water in and out of the tank. The tank is typically connected to the penstock through a pipe, which allows water to flow in and out of the tank. Some surge tanks also have a surge shaft, which is a vertical pipe that connects the tank to the penstock and helps to dissipate excess pressure.

V. What are the benefits of using a Surge Tank in Hydroelectric Power generation?

Using a surge tank in hydroelectric power generation offers several benefits. First and foremost, it helps to protect the turbine and other components of the power plant from damage caused by water hammer. By absorbing sudden changes in water flow, the surge tank ensures the smooth and efficient operation of the system. Additionally, the surge tank helps to maintain a constant pressure in the system, which improves the overall performance of the power plant and reduces the risk of equipment failure. Overall, the use of a surge tank in hydroelectric power generation helps to increase the reliability and efficiency of the system.

VI. How is the Surge Tank maintained in a Hydroelectric Power Plant?

Maintaining a surge tank in a hydroelectric power plant is essential to ensure its proper functioning and longevity. Regular inspections should be conducted to check for any signs of damage or wear and tear. The control valve should be inspected and tested regularly to ensure that it is functioning properly. The tank itself should be cleaned and inspected for any cracks or leaks. In some cases, repairs or upgrades may be necessary to keep the surge tank in good working condition. By following a regular maintenance schedule, hydroelectric power plant operators can ensure that their surge tank continues to protect their equipment and maintain the efficiency of their system.