多机系统水力振动与能量损失分析

Research on Hydraulic Vibration and Energy Loss of Multi-turbine System in Hydropower Station

针对多机系统的机组振动差异问题,采用RANS-LES数值计算方法,模拟一管双机组内部流场,利用监测点压力脉动信息分析过流部件的振动强度,计算能量损失与机组效率。结果表明,部分开度下,岔管的水流分配不平衡导致两机组流场存在差异,影响过流部件压力脉动与振动强度。数据对比发现2号机组尾水管涡带极不稳定,振动更强,导致能量损失更多,效率下降更严重。

Aiming at the problem of vibration difference between units,the RANS-LES numerical calculation method is adopted to simulate the internal flow field of the one-penstock two-turbine system.The pressure pulsation information of monitoring points is used to analyze the vibration intensity of flow parts,and then the energy loss and unit efficiency are calculated.The results show that the flow field of two units is different due to the unbalanced flow discharge distribution after the bifurcated penstock under partial opening,which affects the pressure pulsation and vibration intensity in the flow parts.The comparison of data shows that the vortex zone in the draft tube of unit 2 is extremely unstable,which causes stronger vibration,more energy loss and serious efficiency decreasing.