导叶与隔舌相对位置对离心泵叶轮径向力的影响

Influence of Relative Installation Positions of Guide Vane and Volute Tongue on Radial Force in Centrifugal Pump

采用SST模型对不同导叶与隔舌相对位置下的离心泵进行非定常数值模拟,并通过试验验证,其试验与模拟的效率与扬程误差均在5%以内。分析表明:当导叶叶片与蜗壳隔舌安装角度α为25°时,在各个流量工况下,其扬程与效率均高于其他安装位置,当α为5°时,其效率与扬程最小;当流量Q为24、32 m3/h时,最大与最小效率差值分别为1%、1.4%,流量Q为40、48、56 m3/h时,其差值分别为2.2%、2.4%、4.5%;叶轮出口圆周速度随着时间步的不同而改变,导致作用于叶轮上径向力矢量呈现出较不规则的分布;导叶与隔舌不同相对位置对径向力的影响主要在于其对叶轮出口圆周方向静压的影响,从而导致出口静压不对称,进而影响叶轮径向力;当α为41°和25°时,叶轮出口圆周方向静压对称性明显好于其他相对位置,且其径向力小于α为5°和59°时径向力。

The unsteady numerical simulation of centrifugal pump using SST model was conducted under different relative installation positions of guide vane and tongue. The errors of efficiency and head between test and simulation were within 5%. Investigation results showed that when the guide vane and volute tongue installation angle α was 25°,the head and efficiency were higher than those at other installation positions under various operating conditions. The minimal efficiency and head were occurred at α of 5°. When the flow rate Q was 24 m3/ h and 32 m3/ h,the maximum and minimum efficiencies differences were 1% and 1. 4%,respectively; when Q was 40 m3/ h,48 m3/ h and 56 m3/ h,the differences of the maximum and minimum efficiencies were 2. 2%,2. 4% and 4. 5%,respectively. The velocity at impeller outlet changed with different time steps,which caused the radial force vectors acting on the impeller appeared much irregular distribution. The influence of different relative installation positions of guide vane and tongue on the radial force was mainly attributed to its influence on the static pressure at impeller outlet which led to asymmetric output of static pressure,and affected the impeller radial force. When α was 41° and 25°, the symmetry of the impeller outlet static pressure was significantly better than those of other relative positions,and the radial force was smaller than those at αof 5° and 59°. When volute tongue apart gradually closed to guide vane,the efficient and head of pump were lower. The highest efficient and head occurred when volute tongue was in middle of two vane,which can be a guidance to engineering practice.