蜗壳面积变化规律对低比转数离心泵性能的影响  

Influences of volute cross-section area profile on performance of low-specific-speed centrifugal pump

作　　者：高波[1] 杜文强[1] 杨丽[1] 张宁[1] 王浩宇[1] 袁霄 

机构地区：[1]江苏大学能源与动力工程学院,江苏镇江212013 [2]江苏振华泵业股份有限公司,江苏泰州225500

出　　处：《排灌机械工程学报》2017年第9期749-754,共6页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(51576090);江苏高校优势学科建设工程项目

摘　　要：为研究不同蜗壳面积变化规律对离心泵性能的影响,以一台单级单吸离心泵为研究对象,在保证叶轮及其他几何参数不变的前提下,针对4种蜗壳断面面积变化规律(即上凸式、线性式、下凹式和S形),进行泵内非定常数值计算及分析.结果表明:蜗壳面积变化规律在设计工况下对离心泵水力性能的影响较小,上凸式、下凹式和S形蜗壳面积变化规律的泵扬程和效率与线性式之差分别在1.4%和0.4%以内,而在非设计工况下,差异较大;不同蜗壳断面内的速度分布差异较大,线性式、下凹式和S形的速度分布较上凸式更为均匀;在设计工况下,上凸式和S形面积变化规律的蜗壳能有效降低泵内的压力脉动水平,其中S形面积变化规律的蜗壳效果最佳,而下凹式则会使泵内的压力脉动幅值增大;蜗壳面积规律变化引起叶轮周围静压分布变化,致使叶轮所受径向力的大小改变,线性式面积规律的泵叶轮平均径向力最小,上凸式面积规律的泵叶轮所受平均径向力最大.研究成果可为低脉动水平离心泵的优化设计提供一定参考.In order to investigate effects of volute cross-section area profile on performance and pres- sure pulsation of centrifugal pump, a single stage centrifugal pump with a volute respectively in four different cross-section area profiles （convex up, linear, concave down and S-shaped） is involved in the present study. Unsteady turbulent flow field in the pump is simulated and analyzed. The results show that the area profile has a slight influence on the hydraulic performance at design point, the pump head and efficiency are changed by less than 1.4% and 0.4% , respectively, in comparison with the reference case-linear profile. However, at off-design points, the head and efficiency change considera- bly from one profile to another. Further, velocity distribution in the cross-section largely depends on cross-section area profile. The velocity field in the volute with linear, concave down and S-shaped area profiles is more uniform than that in the volute with convex up area profile. At design point, the volute with convex up and S-shaped area profiles can reduce pressure pulsation level obviously, in particular, the volute with S-shaped area profile results in the lowest pulsation level and is the best configuration. Furthermore, the volute with concave down area profile can intensify pressure pulsation amplitude. The static pressure around the impeller can be altered by volute cross-section area profile, as a result, the magnitude of radial thrust is changed. The average radial thrust on the impeller is the minimum for the linear area profile, and it is the maximum for the convex up area profile. The results can be significant for configuration optimization of volute in a centrifugal pump.

关 键 词：离心泵 蜗壳 面积变化规律 压力脉动 径向力 

分 类 号：S277.9[农业科学—农业水土工程] TH311[农业科学—农业工程]