Influences of runner blade shape on the transient behaviours of pump-turbines in load rejection
Influences of runner blade shape on the transient behaviours of pump-turbines in load rejection
复制标题
转轮叶片形状对甩负荷下水泵水轮机瞬态特性的影响
DOI：
10.1080/00221686.2020.1780503
复制
发表时间：
2020-10
影响因子：
2.3
通讯作者：
L. Xia;Chunze Zhang;Hu Li
中科院分区：
文献类型：
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作者：
L. Xia;Chunze Zhang;Hu Li
水泵水轮机甩负荷过程的瞬态特性非常复杂，转轮叶片形状的微小变化都会对其产生很大的影响，为了解其流动机理，采用三维数值模拟方法对两台比转速相同但转轮叶片进口形状不同的模型水泵水轮机甩负荷过程进行了研究。结果表明，转轮叶片前缘倾斜角对转轮进口回流的发展有重要影响。对于具有负倾斜角的转轮，回流首先出现在围带侧，对于没有倾斜角的转轮，回流首先出现在轮毂侧。而围带侧的回流使流道内的流动更加不平衡，无叶空间的压力脉动增大幅度更大。结果，在转轮叶片上形成更大的径向力波动。
The transient behaviour of the pump-turbine in load rejection is very complex, and slight changes in runner blade shape may have great influence on it. To understand the underlying flow mechanisms, the load rejection processes of two model pump-turbines with the same specific-speed but different in the runner blade inlet shape were investigated by a three-dimensional numerical simulation method. The results show that the lean angle of the runner blade leading edge impacts the evolution of backflows at the runner inlet. The backflows first emerge at the shroud side for the runner with a negative lean angle, and the backflows first emerge at the hub side for the runner with no lean angle. However, the backflows at the shroud side make more imbalanced flows in the runner passages and higher increase of pressure fluctuations in the vaneless space. As a consequence, greater radial force fluctuations on the runner blades are formed.