尾水洞出现明满流的水电站小波动稳定性分析

针对尾水位变幅较大的水电站尾水洞出口段常出现无压流或明满流等复杂流态,提出基于动态尾水边界的分析方法,即以始终保持有压流态的尾水洞中间特征断面的动态测压管水头作为尾水洞系统出口边界条件,结合数值模拟方法研究系统的小波动稳定性,并与传统的边界处理方法进行比较。结果表明采用试验数据和数值模拟相结合进行小波动稳定性分析,考虑了尾水洞无压流或明满流对系统稳定性和调节品质的影响,能够较准确地反映系统的动态特性。

Stability analysis of small fluctuation for hydropower stations with free-surface-pressurized flows in tail tunnels

For the hydropower stations with constantly free-surface-pressurized flows in outlet segment of a tail tunnel and wide range of tail water levels,the dynamic piezometric head at a specific mid-section of the tail tunnel with pressurized flows was used as the boundary conditions of the tail tunnel system.The small fluctuation stability was analyzed by means of numerical simulations,and it was compared with the traditional boundary treatment methods.The results indicate that the integration of experimental data and numerical analysis for the small fluctuation analysis considers the influences of open channel flows or free-surface-pressurized flows in the tail tunnel on the stability and regulation performance of the system,and it can correctly reveal the dynamic characteristics of the system.