导叶不同开度下抽水蓄能机组水轮机工况内流特性分析

Research on Internal Flow Characteristics of Pump-turbine in Turbine Plate under Different Guide Vane Openings

为了解抽蓄机组水轮机工况下活动导叶不同开度下的内流特性,以某抽水蓄能电站水泵水轮机为研究对象,基于SST k-ω湍流模型,进行活动导叶不同开度下全流道三维非定常数值模拟和分析,探讨活动导叶开度对过流部件内部流场的影响。结果表明:随着导叶开度的增加,水泵水轮机的流量增大,转轮力矩增大但增幅降低,效率先增大后降低。蜗壳整体上的压力沿周向分布比较均匀,从蜗壳进口到蜗壳出口均匀降低,水力损失较小;固定导叶形状及安放角与活动导叶搭配影响较大,小开度和大开度工况下活动导叶和固定导叶进口处水力损失大;压力变化线与进出口是否平行影响转轮内部流态,中开度转轮叶片做功最好;小开度工况下易产生偏心涡带,降低机组效率,不利于尾水管能量的回收,中开度工况下尾水管流态最好。研究结论对抽水蓄能机组运行提供了理论参考。

To understand guide vane pump storage unit turbine condition activities under different opening of internal flow characteristics of pump turbine in a pumped storage power station as the research object,based on the SST k-ωturbulence model,with different activity guide vane opening under full port three-dimensional unsteady numerical simulation and analysis,to explore activities guide vane opening across the influence of the internal flow field flow components.The results show that with the increase of guide vane opening,the flow rate of pump turbine increases,the runner torque increases but the increase rate decreases,and the efficiency increases first and then decreases.The pressure of the volute as a whole is evenly distributed along the circumferential direction,and decreases evenly from the volute inlet to the volute outlet,and the hydraulic loss is small.The shape and placement Angle of the fixed guide vane have great influence on the collocation of the movable guide vane,and the hydraulic loss at the inlet of the movable guide vane and the fixed guide vane is great under the condition of small and large opening.Whether the pressure variation line is parallel to the inlet and outlet of the runner affects the flow state inside the runner.Under the condition of small opening,it is easy to produce eccentric vortex belt,which reduces unit efficiency and is not conducive to the recovery of the tailpipe energy.Under the condition of medium opening,the flow pattern of the tailpipe is the best.The conclusion provides theoretical reference for pumped storage unit operation.