基于数值模拟的多级双吸式离心泵性能预测

Performance prediction of multi-stage double-suction centrifugal pump based on numerical simulation

以北赵引黄工程谢村站用多级双吸式离心泵为研究对象，基于雷诺时均N—S方程，采用SSTk－ω湍流模型，压力速度耦合使用SIMPLEC计算，对泵内部流动进行了三维定常全流场湍流数值模拟，得到不同工况下该泵内部流动的速度矢量图等流场信息．在对其内部流动规律进行了定性分析的基础上，预测了泵的性能，并与现场测试结果进行了对比分析．分析结果表明：首级叶轮首级压水室以及次级叶轮次级压水室内流动较均匀；由于过渡流道的结构特点以及流动惯性，流体在首级压水室进入过渡流道时，在流道突然扩大区域形成了旋涡，旋涡区域大小与流量有关；预测扬程值与现场测试扬程吻合较好，预测扬程最大误差为2．7％，而预测的流量－水力效率曲线与现场测试流量一机组效率曲线变化趋势一致．水泵内部流动的数值模拟可为工程中泵设计阶段的性能预测和结构优化提供依据．

Based on the Reynolds time-averaged N - S equations, the SST k - ω turbulence model and the SIMPLEC algorithm, the 3D steady turbulent flow within a muhi-stage double-suction centrifugal pump, which was installed in Xiecun Pump Station of Beizhao Yellow River Diversion Project, was simulated. The velocity vector field and other information at different operation conditions were obtained, the pump performance was predicted and was compared with the field test data. The results show that the flow fields are uniform in both the suction chamber of the first-stage and the volute of the second-stage. Because of the complicated structure of crossover and fluid itself inertia, a vortex region is found in the abrupt expansion region of the crossover, and the size of the vortex region is related to flow rate. The predicted head is consistent with the field test data, and the maximum error between them is 2.7%. The hydraulic efficiency curve estimated against capacity resembles to the pump efficiency curve measured in the pump station as well. The simulation of flow within a pump can provide a reference for performance prediction and structure optimization during the pump design process in an engineering project.