原型水泵水轮机在泵工况驼峰特性研究

An Investigation of the Hump Characteristic of a Prototype Pump-turbine at Pump Modes

为了研究水泵水轮机驼峰区的流态变化,在活动导叶为15°开度下,采用SST k-ω模型对原型水泵水轮机在泵工况下的三维定常湍流进行数值模拟。结合实验数据,分析了驼峰区内不同流道位置随着流量的减小,水泵水轮机流场的变化规律。结果表明,机组在驼峰区运行时,隔舌附近活动导叶压力面与固定导叶吸力面之间的流道会有漩涡生成,随着流量的减小,涡的运动区域不断向整个双列叶栅流道扩散,当进入小流量低负荷区时,漩涡主要集中在叶轮出口和活动导叶进口的流道。通过对旋度场的观察与分析,发现在驼峰极小值工况处,强旋度区主要集中在整个双列叶栅,在小流量低负荷区,强旋度区主要集中在叶轮出口和活动导叶进口。

To investigate the fluid properties change of the hump region of a prototype pump-turbine,3 D steady numerical simulations are conducted for a given guide vane opening of 15 degrees by using the shear-stress transport（ SST） k-ω turbulence model. Based on the experiment data,the change law of the flow field in pump-turbines is analyzed with the decrease of flow in the different flow paths of the hump region. The results show that： the vortex is generated in the flow paths between the pressure surface of the guide blade and the suction surface of the stay blade when the unit is operated in the hump region.With the decrease of the flow,vortex motion regions spread to the whole tandem cascade.When emtering the low load zone,the vortex mainly focuses on the flow path between the outlet of the impeller and the inlet of the guide blade. Through the observation and analysis of swirling,it shows that strong swirling area mainly concentrates in the whole tandem cascade in the hump minimum and between the outlet of the impeller and the inlet of the guide blade when entering the low load zone.