Differential pressure and surge analysis of differential surge tank with interconnecting holes

Based on the differential surge tank commonly used in long-distance diversion hydropower stations,in which interconnecting holes with rational cross sectional area were arranged at different elevations of breast wall between outer chamber and gate shaft used as a riser,a study was made on the influences of interconnecting holes on the differential performance and differential pressure of the surge tank,and further surge analysis was performed through a case study.The result shows that,with less effect on differential performance,surge amplitude,and decay rate of the surge tank,the arrangement of interconnecting holes at rational positions with proper sizes can effectively decrease the differential pressure on breast wall(from over 30?m down to 20?m below) and ensure the safe operation of the surge tank,and it is beneficial to gate control.Therefore,the differential surge tank with interconnecting holes arranged is rational and feasible.