水泵水轮机泵工况小流量波动特性

为了研究水泵在水轮机泵工况小流量下的流场特性,对某电站水泵水轮机进行建模.采用SIMPLEC算法和剪切压力传输模型（SST k-ω）模拟泵工况的流场特性,分析当泵工况活动导叶处于设计开度时在小流量下转轮、导叶的流场,结合实验对水泵水轮机的性能进行对比计算.结果显示,在导叶设计开度下当体积流量为设计流量的15%～53%时扬程曲线有小幅度波动；流量越小在导叶间的类似射流现象越明显,随着流量降低涡结构逐渐增多并且尺度逐渐变大,以至于充满整个活动导叶与固定导叶之间的流域；导叶的存在是小流量下扬程小幅度波动的主要原因.以上结论均可为水泵水轮机的优化设计提供依据.

Low flow's fluctuation characteristics in pump-turbine's pump mode

One power plant’s pump-turbine was modeled in order to analyze the field characteristic with low flow conditions in pump mode of pump turbine. The flow characteristic in pump mode was simulated by SIMPLEC algorithm and shear stress transmission (SST) k-ω mode. The flow of runner and vanes was analyzed when pump mode was at the condition of that guide vanes were in designed opening and low flow. The performance of pump-turbine was analyzed combined with experimental results. Results show that the head line is in the small amplitude fluctuations when the flow is 15%～53% of designed flow and vanes are in designed opening. The phenomenon like a jet between vanes is more obvious when lower flow. The number of vortex is gradually increasing with lower flow , and its scale becomes larger so that the field between stay vanes and guide vanes are filled with vortex. It is the vanes that make the head of pump-turbine fluctuate in small amplitude when the flow is low. Those results can be used to guide the pump-turbine’s optimal design．