水泵水轮机反水泵工况的特性研究

Characteristics Study of Pump-turbine at Reverse Pump Conditions

为了解水泵水轮机反水泵工况的水力性能,以某抽蓄电站为例构建了水力模型,采用SSTκ-ω模型和Presto差分格式模拟反水泵工况的内流场和外特性,并结合试验数据进行对比验证。结果表明,反水泵工况的扬程与流量关系曲线及特性曲线均呈抛物线分布;活动导叶开度越大,进入反水泵的转速越高,流量越大;反水泵工况存在大量的回流涡结构,反水泵的能量损失主要集中于活动导叶的入口和出口处;转轮内存在的脱流现象主要分布在叶片吸力面进口处和压力面出口处;流量越低,转轮流道大尺度涡结构越多,乃至充满整个流道。该结论为水泵水轮机"S"特性的研究提供了依据。

To study the hydraulic performance of pump-turbine at reverse pump conditions, a hydraulic model is es- tablished according to a pumped storage power station. SST κ-ω model and pressure staggering option （Presto） discretiza- tion are used to simulate the flow field and external characteristics at reverse pump conditions. Computational results are also compared with the experimental results. The results show that the relationship between the head and flow rate as well as characteristics of reverse pump conditions has parabolic distribution; with the opening of guide vanes increasing, larger flow rate and rotating speed are needed to run into reverse pump conditions; there are a lot of vortexes at reverse pump conditions and the energy loss mainly distributes in the inlet and outlet of guide vanes; in the impeller, the phenom- ena of flow separation mainly distributes in the inlet of suction side and the outlet of pressure side; all the passages are gradually filled with large-scale vortexes as the flow rate reduces. These conclusions can be used as a guide for the calcula- tion of pump-turoine S characteristics.