叶轮时序位置对多级离心泵性能影响的数值研究

Numerical Simulation for the Effect of Clocking Position of Impeller in a Multistage Centrifugal Pump

时序位置会对多级离心泵的性能产生影响,本文采用数值模拟方法分析了不同首级和次级叶轮时序位置下外特性的变化规律,以及时序位置变化对蜗壳和次级叶轮内部流场的影响机理。结果表明:时序位置改变主要影响次级叶轮和蜗壳的性能,使得次级叶轮内涡量下降,高涡量区面积减小,出口径向速度明显增大;并且能够抑制蜗壳隔舌位置出现的漩涡,蜗壳内低速区面积和湍动能明显下降,流动损失减少,扬程和效率上升,当次级叶轮叶片的周向位置位于首级叶轮流道中间时,最大上升幅度分别达到了2.9%和1.78%;此外时序位置不会改变径向力主频,但是能够降低径向力的幅值,最大下降幅度达到了9.7%。研究结果能够为多级离心泵优化设计提供理论支撑。

The performance of the multistage centrifugal pump is affected by the clocking position of impeller.The head and efficiency under different clocking position was analyzed by the numerical simulation,and the effect mechanism of clocking position on flow field in the second impeller and volute was explored.The results show that only the performance of the second impeller and volute shows obvious changes.The vorticity in the second impeller decreases,and the area of the high-vorticity region decreases remarkable.The radial velocity in the impeller outlet increases.Appropriate clocking position can suppress the vortex in the volute tongue.The area of the low-velocity region and turbulence kinetic energy decrease significantly.The flow loss shows reduction trend.The head and efficiency increase,and the maximum range are 2.9%and 1.78%respectively.In addition,the frequency of radial force is not changed at different clocking positions,but the maximum decrease of amplitude reaches 9.7%.The research results provide theoretical support for the operation and optimal design of multistage centrifugal pump.