泄洪洞有压出口渐变段及工作闸门室体型优化

针对黄金坪水电站1号泄洪洞原设计方案有压出口渐变段顶板存在负压，在工作闸门小开度运行时工作闸门室底板出现大范围负压，容易引起空蚀等问题，根据水力学模型试验，提出通过增加有压渐变段长度、改变工作闸门室底板连接形式，对有压出口渐变段及闸门室体型进行优化。试验实测结果表明，优化后的有压段出口项板及闸门室底板在各种运行工况下均没有出现负压，闸门室底板水流空化数显著增加，提高了泄洪洞安全运行的可靠性。

Shape optimization for pressure outlet transition section and working gate chamber of spillway tunnel

According to the original design scheme of No. 1 spillway tunnel of Huangjinping Hydropower Station, there were negative pressure on the roof of pressure outlet transition section and large region of negative pressure on the bottom plates of working gate chamber operating at small aperture, which might cause cavitation erosion. Based on hydraulic model tests, the shape of pressure outlet transition and working gate chamber was optimized by increasing the length of pressure transition and adjusting the connecting form of the bottom plates of working gate chamber. After the optimization, the negative pressure did not occur in any operation case, and the cavitation number of the water flow at the bottom plates of gate chamber increased obviously. The optimization scheme enhanced the reliability of safety operation of the spillway tunnel.