不同径向间隙对双蜗壳泵径向力影响的数值模拟  

Numerical simulation of influence of radial gaps in a double-volute centrifugal pump on its radial hydraulic force

作　　者：刘宜[1,2] 蒋跃[1] 张人会[1] 韩正杰[1] 

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 [2]兰州理工大学温州泵阀工程研究院,浙江温州325105

出　　处：《兰州理工大学学报》2013年第3期43-47,共5页Journal of Lanzhou University of Technology

基　　金：国家自然科学基金(51109104);甘肃省自然科学基金(ZS022-A25-018)

摘　　要：通过改变蜗壳基圆直径改变叶轮与隔舌之间的间隙,采用CFD软件Fluent对5种蜗壳基圆直径的双蜗壳离心泵作全流场计算.计算采用雷诺时均方程和RNGk-ε湍流模型,压力和速度耦合采用SIMPLEC算法.通过离心泵径向力的数学计算模型获得不同基圆直径离心泵叶轮所受的径向力大小,并对其进行比较分析.结果表明:相比于单蜗壳泵,双蜗壳结构泵能有效地减小径向力,在设计点运行时径向力最小且不为0,偏离设计工况下径向力逐渐增大,但不同工况下径向力的变化不大,验证了双蜗壳能有效地平衡径向力;不同基圆直径工况下,随着基圆直径的增大,叶轮所受的径向力大小先减小后增大,说明适当增大蜗壳基圆直径能减小作用在叶轮上的径向力,起到降低振动和噪音的作用,并使效率有所提高.同时针对蜗壳基圆直径为397mm的泵进行性能试验,与数值模拟结果对比分析表明数值模拟的方法可行.By means of altering the gap between the impeller and pump tongue with alteration of base-cir- cle diameter of pump volute, and by using the software Fluent for CFD, the computation of full flow field was carried out for the double-volute centrifugal pump with five base-circle diameters of the double-volute casing Reynolds averaged equation and/e-e turbulence model were employed in the computation. The SIM- PLEC algorithm was used for coupling pressure and velocity. By using the mathematical model of pump radial force, the magnitude of radial force on the pump impeller with different base-circle diameters was obtained and then compared and analyzed. The result showed that, compared with single-volute pump, centrifugal pump with double volute could be used to reduce the radial force effectively. Near the design flow rate condition, the radial force would reach its minimum at off-design conditions, the radial force would increase gradually but with a little difference at different conditions, justifying that the radial force could effectively be balanced with the double volute. With different base circle diameters, the radial hy- draulic force would decrease at first and then increase with the increase of volute base circle diameters. By means of enlarging the base circle diameter, the radial force of impeller, vibration and noise could be re- duced, and the efficiency would be improved. For a centrifugal pump with 397 mm volute base circle diam- eter, its performance experiments and numeric simulations were conducted. It was found that the calcula- tion result agreed well With the measurement one.

关 键 词：离心泵 双蜗壳 基圆直径 径向力 数值模拟 

分 类 号：TH311[机械工程—机械制造及自动化]