离心泵部分负载下进口二次回流成因分析及验证  

Discussion and Verification on the Cause of Inlet Secondary Backflow Under Partial Load of Centrifugal Pumps

作　　者：王桃 周星丞 周敏 向茹 WANG Tao;ZHOU Xingcheng;ZHOU Min;XIANG Ru(Key Laboratory of Fluid and Power Machinery,Ministry of Education(Xihua University),Chengdu 610039 China;School of Energy and Power,Xihua University,Chengdu 610039 China)

机构地区：[1]流体及动力机械教育部重点实验室(西华大学),四川成都610039 [2]西华大学能源与动力工程学院,四川成都610039

出　　处：《西华大学学报（自然科学版）》2022年第1期104-110,共7页Journal of Xihua University:Natural Science Edition

基　　金：四川省教育厅重大培育项目(18CZ0016);流体及动力机械教育部重点实验室(西华大学)开放课题资助(LTDL2020-010);西华大学校人才引进项目(Z201081)。

摘　　要：为探讨离心叶轮在部分负载下进口回流的成因以及其对离心泵运行的影响,应用理论分析与实验方法对强制涡压力分布特点、叶轮入口二次回流产生的原因进行分析,采用数值模拟方案对一比转速为66的泵进行数值计算,探讨在不同流量下叶轮进口速度与压力分布规律,对比叶片进口切割前后的泵外特性,分析入口回流对泵外特性的影响。结果表明:强制涡中压力随着半径增大按抛物线规律上升;二次回流产生的原因在于部分工况下旋转叶轮形成叶轮入口黏性流体的强制涡产生不同半径上的压力差,回流对消除流量扬程曲线的驼峰有积极作用。本文对离心泵部分负载下进口回流成因的探讨以及深入认识离心泵流动原理提供了一定的参考。To discuss the cause of inlet secondary backflow of centrifugal impellers under partial load and its effect on centrifugal pump performance,the pressure distribution of forced vortex,the causes of inlet secondary backflow and the influence of impeller inlet backflow on the characteristics of the pump were analyzed by using theoretical and experimental methods.Numerical simulation and analysis of a pump with a specific speed of 66 was performed by using a verified computational fluid dynamics(CFD)technique.The pressure and velocity vector distribution of impeller inlet were analyzed at different flow rates.The external characteristic curves of two pumps with different blade leading edge were compared to analyze the influence of the inlet secondary backflow on the external characteristics of the pump.The results show that the pressure in the forced vortex rises along a parabolic trajectory as the radius increases.The cause of the secondary backflow is that the pressure differences on different radius caused by the rotation impeller form-ing a forced vortex of the viscous fluid at the entrance of the impeller under partial load.And the secondary backflow at the inlet of the impeller have certain effects on eliminating the hump of H-Q curve,which is a positive phenomenon.Therefore,it plays a certain role for the formation and mechanism of inlet backflow under partial loads of centrifugal pumps,and provides some reference for further research of centrifugal pump.

关 键 词：离心泵 部分负载 进口回流 强制涡 二次回流 

分 类 号：TH311[机械工程—机械制造及自动化]