叶轮口环间隙对井用潜水泵性能的影响

井用潜水泵的口环间隙大小对泵性能及流场具有较大影响,基于200QJ80-22井用潜水泵,通过CFD软件对泵全流场进行了数值计算,并与试验结果进行对比分析,研究了不同口环间隙大小对泵外特性和内部流场的影响.数值模拟结果表明,整泵的扬程和效率都随着间隙值的增大而减小,特别是口环间隙值增大到0.70 mm,减小更为明显,但功率变化较小.当间隙值达到1.00 mm时,效率从最高点的77.2%减小为68.7%,同时扬程也随之减小了约3.5 m.口环间隙为0.20 mm时,第一,二级叶轮前盖板腔体内以及叶轮出口与前盖板区域间产生回流,泄漏量较小,对叶轮进口流动和流场影响也较小,当口环间隙值增大至0.50 mm时,第一,二级叶轮前盖板腔体内以及叶轮出口与前盖板区域间回流逐渐消失,但更大的泄漏量冲击叶轮进口处,使叶轮进口过流面积减小,严重影响了泵的水力性能.

Influence on performance of submersible well pump changing clearance of wear-rings

The whole flow field of the submersible well pump 200QJ80-22 was numerically simulated with CFD. By comparing the calculation results with experimental results, the influence of clearance of wear-rings on the external characteristic and internal flow field was analyzed. The results of the nume-rical simulation shows that the head and efficiency of the pump decrease as the size of clearance increases. Especially, when the size of clearance reaches 0.7 mm, the decreasing becomes very obvious yet the pump power almost remains constant; when the size of the clearance reaches 1.00 mm, the efficiency decreases from the highest point of 77.2% to 68.7%, and the head of pump decreases by about 3.5 m; when the size of clearance is 0.2 mm, reverse-flow will appear in the front shroud cavity of the first stage impeller and second stage impeller and in the area between the impeller outlet and the front shroud, which has a small influence on the flow of the impeller inlet and flow field, because there is little leakage flow; reverse-flow gradually disappears when the size of clearance increases to 0.5 mm, but more leakage flow could impact on the impeller inlet, which results in the area of passage of impeller inlet decreasing, and thus seriously affecting the hydraulic performance of the pump.