Research on the Setting Condition of Tailrace Surge Chambers for Seawater Pumped-Storage Power Stations with Long Tailrace Tunnels

Seawater pumped-storage power station (SPPS), as an efficient large-scale energy storage facility for marine renewable energies, has been incorporated into the key research tasks in the “13th Five-Year Plan” of hydropower development in China. The tailrace surge chamber is very important for the operation safety of the SPPS with a long tailrace tunnel. To determine the conditions under which a SPPS requires a tailrace surge chamber and to account for the time sequence superposition of water hammer vacuum, velocity head vacuum and head loss vacuum, a new setting criterion using the rigid water hammer theory was derived. Then, comparisons among several setting criteria of tailrace surge chambers are conducted. Ultimately, the new setting criterion is investigated and validated by 1D numerical simulation of the hydraulic transient process for a certain pumped-storage power station. The discriminant result obtained by the new setting criterion is consistent with the actual setting condition, and it can be applied as a preliminary setting criterion of tailrace surge chambers for SPPSs and can provide guidance for preliminary engineering design.