前伸式双叶片环保用泵的回归分析及优化设计

Numerical optimization and regression analysis of forward-extended double-blade sewage pump

以某典型前伸式双叶片环保用泵为研究对象,选择了其叶轮进口直径Dj、叶轮外径D2、叶片出口安放角β2b、叶片包角θ四个几何因素,第一阶段选用L9（34）正交表进行正交设计,设计出9副叶轮,对叶轮、蜗壳在内的前伸式双叶片环保用泵进行数值模拟,获得9组设计方案额定点的效率、扬程及功率,应用极差分析与多指标综合平衡法选出泵设计的最佳参数;第二阶段在正交试验确定的最佳条件附近安排二次回归通用旋转设计,得到30组设计方案,采用CFD进行计算,分析结果以建立效率与各因素的定量关系,再通过响应面法精确得出泵的最佳设计条件.结果发现：在给定范围内,对泵效率影响的顺序为β2b〉D2〉θ〉Dj;对于中高比转速的前伸式双叶片环保用泵,其叶片出口安放角应取β2b=15°~25°.

This research was focused on raising the efficiency of one forward-extended double-blade sewage pump.The experiment was designed with four factors including impeller inlet diameter Dj,impeller outside diameter D2,outlet angleβ2b,blade wrap angleθ.In the first stage,9impellers were designed using orthogonal table L9（34）,and then numerical simulation was conducted on the pumps with different impellers and the same volute so that 9groups data of efficiency,head and shaft power in the operating point were obtained.Then the optimum parameter of impeller could be chosen by range analysis and multi-index comprehensive balance method.In the second stage,near the optimum condition determined by orthogonal test,30 sets of design were obtained by quadratic regression general rotational design.After 30 sets of design were simulated by CFD,quantitative relationship between efficiency and the four factors were established and then the optimum design conditions of impeller could be obtained.It is found out that in agiven range,the most influential factor on pump efficiency isβ2b〉D2〉θ〉Dj.Furthermore,for double-blade pumps of medium and high specific speed,β2b=15°~25°is better.