叶轮进口边位置对自吸泵性能的影响分析

为研究自吸泵叶轮气液混合能力对自吸性能的影响,在叶轮原模型基础上,设计了叶片不同进口边位置的5种模型方案.采用VOF多相流模型对不同方案全流域进行三维定常数值计算,研究对自吸性能的影响规律.针对350WFB-1200-50型外混式无密封自吸泵,初始条件设定进水S型弯管中含一定体积的空气段,出口处设置含气率监测点.结果表明:针对中高比转速叶轮,进口边沿后盖板位置向出口前掠,使得叶轮进口边工作时对流体分时加载,可以有效提升叶轮的气液混合能力,从而缩短自吸泵的自吸时间;在一定前掠角度范围内改变进口边位置对自吸泵的扬程和效率影响不大,但是当叶片进口边向出口位置前掠超过一定范围时,会导致自吸泵扬程明显下降;当叶轮进口边前掠10°时,额定工况下自吸时间缩短25％,自吸性能明显得到提高.

Analysis of the influence of the position of the impeller inlet on the performance of the self-priming pump

In order to study the effect of the gas-liquid mixing capacity of the self-priming pump impeller on the self-priming performance, based on the original model of the impeller, five model schemes with different positions of the blade inlet edge are designed. The VOF multiphase flow model is used to calculate the three-dimensional constant value of the whole basin with different schemes, and the law of influence on the self-priming performance is studied. For the 350WFB-1200-50 external-mixing non-sealed self-priming pump, the initial conditions are set to include a certain volume of air section in the inlet S-shaped elbow, and a gas content monitoring point is set at the outlet. The results show that for the medium and high specific speed impeller, the position of the rear cover of the inlet edge is swept forward to the outlet, so that the fluid is loaded at the inlet side of the impeller, which can effectively improve the gas-liquid mixing capacity of the impeller and shorten the self-priming of the self-priming pump time. Changing the position of the inlet side within a certain forward sweep angle has little effect on the head and efficiency of the self-priming pump, but when the blade inlet side is swept forward to the outlet position beyond a certain range, the head of the self-priming pump will decrease significantly. When the inlet side of the impeller is swept forward by 10°, the self-priming time under rated conditions is shortened by 25%, and the self-priming performance is significantly improved.