Studies on gas loss of air cushion surge chamber based on gas seepage theory

Air cushion surge chamber (ACSC) is a kind of structure with its good performance on water hammer and surge controlling, it can effectively solve the problem between hydro-development and ecological environment protection to a great extent, and has tremendous social economic, environmental benefits, and the practicality, application value as well. Aiming to the gas leakage of ACSC, a new gas seepage model of ACSC was established, and the gas seepage distribution and losses under different cases of surrounding rock permeability, concrete lining were analyzed. The results indicate that the gas losses meet the need when the surrounding rock permeability is less than 10^-16m², and the rock is fresh and integrated. The concrete lining has good anti seepage effect, but it is easy to occurring local penetrated crack or other default, so using concrete lining is not recommended. Research findings provide important guide for the design of ACSC and the selection of inflator.