抽水蓄能电站甩负荷主进水阀动水关闭过程内部流场仿真

The Internal Flow Field Simulation of Main Inlet Valve in Dynamic Water Closing Process of Pumped Storage Power Station under Load Rejections

为探究抽水蓄能电站机组甩负荷时主进水阀在导叶拒动和导叶协同关闭两种情况下的内部三维瞬变流动过程与特性。对某抽水蓄能电站主进水阀建立三维仿真模型,确定了流场仿真的边界条件,选用Realizable k-ε湍流模型,模拟了两种关阀方式下主进水阀内部三维瞬变流动过程,计算得到阀前压力变化曲线并与一维数值仿真计算结果进行了对比,分析了两种关阀方式下的内部流场演化过程。结果表明:甩负荷过渡过程中,两种关阀方式下主进水阀内部三维瞬变流动过程的CFD仿真结果具有较高的精度;主进水阀关闭过程中其内部流场复杂,形成的涡流会改变内部流向,造成压力损失;在阀腔处有较大的压力变化,为机组安全运行带来隐患;两种关阀方式下阀腔中的压力最大值均出现在枢轴处,且协联关闭方式下的压力最大值相对较小。

For the load rejection transient process of pumped storage power station,the three-dimensional internal flow field and characteristics of the main inlet valve under the conditions of guide vane operation rejection and guide vane-main inlet valve linkage operation are studied in this paper.Firstly,a three-dimensional simulation model for the main inlet valve is established,and the boundary conditions for the flow field simulation are determined.Then,by using the Realizable k-εturbulence model,the three-dimensional transient flow processes inside the main inlet valve under two closing modes are simulated.Finally,the three-dimensional simulation results are compared with the one-dimensional simulation results and the evolution processes of the internal flow field under the two closing modes are analyzed.The results show that the CFD simulation results of three-dimensional transient flow in the main inlet valve under load rejection are highly precise.The internal flow field in the main inlet valve is complex during the dynamic water closing process.The eddy changes the internal flow direction and then causes the pressure loss.Great pressure variation in valve chamber is a hidden danger for the safe operation of units.The maximum pressure in the valve chamber appears at the pivot under two closing modes,which is relatively small under the linkage operation mode.