多级离心泵作液力透平空化流动特性研究  

Study on cavitation flow characteristics of multistage centrifugal pump as hydraulic turbine

作　　者：苗森春 刘剑 浦海燕 MIAO Sen-chun;LIU Jian;PU Hai-yan(College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Jiangsu Shuangda Pump Industry Co.Ltd.,Jingjiang 214500,China)

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]江苏双达泵业股份有限公司,江苏靖江214500

出　　处：《兰州理工大学学报》2025年第2期51-59,共9页Journal of Lanzhou University of Technology

基　　金：国家自然科学基金(52169019);甘肃省自然科学基金(20JR10RA203)。

摘　　要：为了研究空化对多级离心泵作液力透平内部流动的影响规律,以三级离心泵作液力透平为研究对象,基于Zwart空化模型和RNG k-ε湍流模型,在额定流量工况下进行不同空化数的三维数值模拟,分析主要过流部件的内部流动规律,并提出减小空化的建议.结果表明:空化初生后产生了少量空泡,改变了末级叶轮进、出口环量,使压头上升约2%,轴功率增大约3%;末级叶轮存在翼型空化和漩涡空化,叶片尾部扭曲过大可诱发翼型空化,进口来流相对液流角过大造成漩涡空化;尾水室出口最先发生空化,来流流量不均匀影响着腔体流态,腔体流动左侧混乱而右侧规整.该研究为多级离心泵作液力透平抑制空化发生和提高运行稳定性提供了参考.In order to study the influence of cavitation on the internal flow of hydraulic turbine in a multistage centrifugal pump,a three-stage centrifugal pump was selected as the research object.Based on Zwart cavitation model and KNG k-ε turbulence model,three-dimensional numerical simulation of different cavitation numbers was carried out under rated flow conditions turbulence model.The internal flow law of the main flow components was analyzed,and suggestions for reducing cavitation were put forward.The results show that a small amount of cavitation is generated after cavitation inception,which changes the inlet and outlet circulation of the last stage impeller,resulting in a 2%increase in head and a 3% increase in shaft power.There are airfoil cavitation and vortex cavitation in the last stage impeller.Excessive distortion at the blade tail can induce airfoil cavitation,and excessive inlet flow relative to the flow angle causes vortex cavitation.Cavitation occurs first at the outlet of the tailrace chamber,and the flow state inside the chamber is affected by the uneven flow rate.The flow on the left side of the chamber is more chaotic,while the right side is more regular.This study provides a reference for inhibiting the cavitation phenomenon of multistage centrifugal pumps as hydraulic turbines and improving the stability of turbine operation.

关 键 词：多级离心泵作液力透平 翼型空化 漩涡空化 液流角 数值模拟 

分 类 号：TH311[机械工程—机械制造及自动化]