多级离心泵的单级增效研究

Research on Single-stage Efficiency of Multistage Centrifugal Pump

为提高D46-50X4型多级离心泵的单级运行效率,使用CFX流体分析软件,选取k-ε湍流模型,对其内部流场进行数值模拟,得出减损其效率的主要原因,设计新的导叶及叶轮,并对离心泵原始模型与改进模型的流场进行数值模拟与分析。结果表明:离心泵的原始模型中叶轮流道进口与导叶扩散段进口均存在明显漩涡,严重降低该型泵的效率;通过减小叶轮外径和调整叶轮流道型线,改进原始模型中的圆盘摩擦损失及叶轮流道内漩涡堵塞;标准工况下,与原始模型相比,改进模型单级扬程提高4.4 m,单级效率提高6.4%,达到了国家标准。

In order to improve the single-stage efficiency of D46-50X4 multistage centrifugal pump, the k- εturbulence model was employed, and with CFX fluid analysis software the numerical simulation of the internalflow field was carried on to find out the main reason of efficiency loss. Then new guide vane and impeller weredesigned, the flow fields of the original model and improved model were simulated and analyzed. The resultsindicate that in the original model of centrifugal pump, the entrances of the impeller and the diffuser section ofguide vane have obvious vortex, which seriously reduces the efficiency of the pump. By decreasing the impellerdiameter and adjusting the shape line of impeller, the disk friction loss and vortex in impeller flow passage ofthe original model are improved. Under standard operating conditions, compared with the original model, thesingle-stage head of the improved model is increased by 4.4 m, and the efficiency is increased by 6.4%, whichmeets the national standard.