叶轮流道扩散度对超低比转速离心泵性能的影响  

Effect of impeller passage expansibility on performance of centrifugal pump with ultra-low specific speed

作　　者：杨从新[1] 崔宗辉 

机构地区：[1]兰州理工大学能源与动力工程学院,甘肃兰州730050

出　　处：《兰州理工大学学报》2015年第6期48-53,共6页Journal of Lanzhou University of Technology

基　　金：国家科技支撑计划(2013BAF01B02)

摘　　要：以超低比转速离心泵水力模型M23-12.5为研究对象,借助流体动力计算的数值模拟方法,采用RNGk-ε湍流模型封闭时均N-S方程组,在保证叶轮叶片数不变的前提下,通过改变影响叶轮流道扩散度的两个重要因素,即叶片包角和叶片出口排挤系数,来比较分析不同叶轮流道扩散度对超低比转速离心泵外特性参数和内部流场分布的影响.研究结果表明,叶片包角的增大和叶片出口排挤系数减小(叶片厚度变大)都会减小叶轮流道的扩散度,从而减小离心泵的轴功率,提高效率.过大的叶片包角会增大液体与叶片的接触面积,进而增大摩擦损失,使得轴功率增大,效率降低.该结论将为超低比转速离心泵的设计提供参考.Taking the hydraulic model M23-12.5of ultra-low specific speed centrifugal pump as research object,having the aid of the numeric simulation method for fluid dynamic computation,and employing the closed time-averaged Navier-Stokes equation set with RNGk-εturbulence mode the effect of the expansibility of impeller passage on the external characteristic parameters and internal flow field distribution of ultralow specific speed centrifugal pump is compared and analyzed by means of changing the two major factors influencing that expansibility,i.e.the blade wrap angle and outlet blade squeeze coefficient,in the case of constant numbers of blade.The investigation result indicates that the larger blade wrap angle and the smaller outlet blade squeeze coefficient（layer blade thickness）will make the expansibility of the impeller passage smaller,so that the shaft power of pump will reduce and the efficiency raise.However,excessive blade wrap angle will increase the contact area of the liquid with the blade so that the friction loss will increase,leading to a higher shaft power and lower the efficiency.These conclusions will be meaningful to the design of ultra-low specific speed centrifugal pump.

关 键 词：超低比转速离心泵 扩散度 数值模拟 性能预测 

分 类 号：TH312[机械工程—机械制造及自动化]