水泵水轮机导叶水力矩非定常特性研究

Unsteady Characteristics of Hydraulic Torque of Guide Vanes of a Pump Turbine

摘要: 活动导叶水力矩大小及机组运行过程中水力矩变化情况对导叶轴及导叶保护装置的设计十分重要。本文采用数值模拟的方法研究了水泵水轮机在正常发电工况下导叶的水力矩特性。分析了流场的非定常性对导叶水力矩的影响。采用快速傅里叶变换(FFT)的手段分析了导叶水力矩的频率成分及相邻导叶水力矩间的相位关系。结果表明，随着导叶开度的增大，导叶水力矩从正值变为负值，这使得导叶由自关趋势转向自开趋势。转轮对导叶的动静干涉使得导叶水力矩呈周期性变化。相邻导叶的水力矩变化存在相位差，这反映了转轮旋转引起的导叶水力矩的规律性变化。

Abstract: The magnitude of the hydraulic torque of the guide vane and the variation of the hydraulic torque during the operation of the unit are very important to the design of the guide vane shaft and the guide vane protection device. In this paper, the water torque characteristics of the guide vane of a pump turbine under normal generating conditions are studied by numerical simulation. The in-fluence of unsteady flow field on the water torque of guide vanes is analyzed. Fast Fourier Transform (FFT) is used to analyze the frequency component of the hydraulic torque of the guide vane and the phase relation between the hydraulic torques of the adjacent guide vanes. The results show that with the increase of the guide vane opening, the hydraulic torque of the guide vane changes from positive value to negative value, which makes the guide vane turn from auto-closing to auto-opening. The hydraulic torque of the guide vane varies periodically with the static and dynamic interference of the guide vane. There is phase difference in the variation of the water torque of the adjacent guide vane, which reflects the regular change of the hydraulic torque of the guide vane caused by the rotation of the runner.