水泵水轮机启动过程转轮叶片受力分析

为了研究水泵水轮机水轮机工况启动过程转轮区域流态对叶片载荷的影响,以某水泵水轮机模型为研究对象,采用Realizable k-ε湍流模型开展水泵水轮机全流道三维数值计算,运用UDF技术和动网格方式,控制启动过渡过程活动导叶的开启过程,分析机组启动过程中转轮的转速变化,并与试验结果进行对比。结果表明：数值计算与试验结果吻合度较高,该文数值计算准确可行;启动过程中,在0~5 s区间,转轮叶道中间分布明显沿周向规律分布的叶道涡,叶道涡随开度的增加及转轮叶片来流条件的优化逐渐变小然后消失;启动过程来流与转轮叶片工作面发生冲击并在此区域形成高压区,导致叶片工作面进口位置压力载荷集中、相同半径处叶片工作面背面压力差较大。启动过程中转轮叶片来流与叶片工作面发生冲击是叶片压力载荷集中以及叶道涡的主要诱因。

STRESS ANALYSIS OF RUNNER BLADES IN PUMP-TURBINE START-UP PROCESS

In order to study the influence of fluid flow on the blade load in the runner region during the startup process of the pump turbine, the reversible pump-turbine in a domestic pumped storage power station is studied. Based on Realizable k-ε turbulent model, the UDF in fluent is used to control the movement of the active guide vanes in the starting process. Based on the dynamic and sliding grid method and combined with the speed change of the iterative computer group in the internal flow field of the reversible pump-turbine in the start-up process, the unsteady flow of the whole passage of the pump-turbine is calculated. Results show that the results of the simulation calculation are in good agreement with the theoretical research. The simulation calculation method is accurate and feasible for startup process of the pump turbine. During the start-up process, in the 0-5 s time interval, vortices distributed along the circumferential direction are distributed in the flow channel. With the increase of the opening and the optimization of the flow conditions of the runner blade, the blade vortex gradually decreases and then disappears. During the start-up process, the incoming flow impacts with the runner blade working face and forms a high pressure zone, which causes concentrated pressure load at the inlet position of the blade, resulting in a large difference in pressure between the working face and the back of the blade. During the start-up process, the impact of the incoming fluid on the blade working face is the main cause of the blade pressure load concentration and the blade vortex.