隔河岩电站1号水轮机水力稳定性的若干问题研究

Prototype Research on Hydraulic Characteristics of Turbine No.1 of Geheyan Hydropower Station

根据原型实测动水压力、空化噪声、补气、大轴摆度及水轮机检查等成果,研究了水轮机水力稳定性。成果表明:在168～233MW负荷区,水轮机存在低频涡带空化,脉动压力、补气、噪声、摆度等大幅度增加,尤其在177MW附近脉动压力和大轴摆度已达到甚至超过厂商保证值;在所研究负荷范围内,水轮机都存在高频激波空化噪声,主要发生在转轮叶片及缝隙中,在满负荷时最为明显,研究发现已出现空蚀前兆。

Based on the data of measured fluctuating pressures, cavitation noise, air entrainment, main shaft runout of the turbine and dewatering inspection of it afterward, the hydraulic stability of the turbine No.1 was analysed. The results indicated: in the load range from 168 MW to 233 MW, the turbine presented lowfrequency vortexband cavitation; the amounts of fluctuation pressure, air entrainment, noise level and shaft runout were greatly increased, specially near 177 MW loading, the values of fluctuation pressure and shaft runout reached, or even exceeded the guaranteed limits of the manufactory. In all measuring loading conditions, highfrequency cavitation noise occurred in the runner blade and its interstices, most obviously at full load operation. The blade has presented warning signs of cavitation.