Working principle of the surge chamber of a hydropower station

What is a surge tank in a hydropower system?

Hydropower system with a surge tank Task 1: It enables the flow in the long upstream penstock to be gradually slowed down by absorbing and transforming the kinetic energy in the flow into the potential energy of water in the surge tank , when the turbines are shut down or the load is reduced.

Why do hydropower plants have surge tanks?

Nowadays, hydropower plants with long headrace or tailrace tunnels are normally equipped with surge tanks to control the water hammer pressure of the spiral case or draft tube [24–25]. Basically, surge tanks with large cross-sectional area helps to regulate the quality of energy production of hydropower plants after load disturbance .

What are the different types of surge tanks used in hydropower stations?

Different forms of surge tanks used in hydropower stations; for other forms of the surge tank see Chaudhry (2014), Giesecke and Mosonyi (2009), for instance a surge tank with inlet resistance, b surge tank with a lower chamber, c surge tank with an upper chamber

Why is a surge tank used in a water hammer pump?

The turbines to the reservoir is practically interrupted by the surge tank to prevent the pressure wave due to the water hammer at the free water surface and to free the pressure tunnel from excessive pressures. The surge provides protection to the penstock against damage of water hammer.

What happens when a surge chamber is opened?

The water surface in the surge chamber will be raised to above static level. In case of rapid opening, the flow in the tunnel is smaller than the turbine demand to supply water to the turbine. The water surface in the chamber will start to drop to below of the steady-state level.

Why is a surge tank placed near a power house?

The surge tank is placed near the power house to reduce the length of the penstock pipe. Temporary supply of water when the load on the turbine is suddenly increased (starting up the is phase). Under normal operating conditions, the flow through the pipeline is uniform and the pressure gradient is normal.