叶轮后密封环直径加大量对轴向力特性的影响

以300QJ230-40/2型潜水泵为研究对象,以清水为介质,采用标准k-ε湍流模型在多重参考系下对该泵全流道进行了定常不可压数值模拟,获得了外特性和轴向力预测值,并绘制了性能曲线和轴向力随扬程变化的关系曲线;采用机械法对该泵轴向力进行了试验测量,并将模拟值与试验值进行对比分析.结果表明:在0.8Q_sp~1.2Q_sp(对应扬程为46~36 m)的工作区域,泵性能和轴向力的数值计算结果与实测结果基本吻合.在叶轮前密封环直径、平衡孔直径及数量不变的条件下,在叶轮后密封环直径加大量Δr_m≠0时,对该潜水泵进行了全流道数值模拟和轴向力数值计算,绘制了不同后密封环直径下泵轴向力随扬程变化的关系曲线,结果表明了加大后密封环直径能有效地减小轴向力;绘制了轴向力系数与比面积关系的无因次曲线.

Influence of increments of back sealing ring diameter of impeller on characteristic of axial force

Reducing the axial force is an important way to improve the service life and efficiency as well as to get higher lift of submersible pumps. With water as the medium, standard k-ε turbulence model in multiple reference frames was used to simulate the whole flow field for unsteady incompre-ssible flow in the 300QJ230-40/2 submersible pump. The overall performance and axial force were numerically obtained, and the simulated performance curves as well as axial force against head were drawn. Mechanical metrical method for axial force was used in the test, and the simulated curves were compared with the test curves of both performance and axial force. The results show that these curves are close to each other under working conditions from 0.8 Q_sp to 1.2 Qsp(heads from 46 m to 36 m). With the front sealing ring diameter increment of Δr_m≠0, the diameter and number of balance holes of the impeller of constant, numerical calculations and analysis for both the whole flow filed and axial force were conducted, and the results show that the axial force could be effectively reduced by increa-sing the back sealing ring diameter of the impeller.In order to find the way of prediction and evaluation of axial force on similar-designed pumps, dimensionless curves of axial force coefficient and specific area were drawn.