低比转速离心泵临界空化特性研究  

Research on characteristics of critical cavitation in low specific speed centrifugal pump

作　　者：赵奇峰 刘德民 赵林[1] 王钊宁 ZHAO Qifeng;LIU Demin;ZHAO Lin;WANG Zhaoning(School of Engineering,Ocean University of China,Qingdao 266100,China;Dongfang Electric Machinery Co.,Ltd.,Deyang 618000,China)

机构地区：[1]中国海洋大学工程学院,山东青岛266100 [2]东方电机有限公司,四川德阳618000

出　　处：《流体机械》2025年第2期50-57,共8页Fluid Machinery

基　　金：四川省科技计划资助项目(2022ZDZX0041)。

摘　　要：为研究低比转速离心泵空化初生时内流场情况及诱发压力脉动现象,并确定合理的临界空化判定指标,开展了空化性能模型试验和基于RNG k-ε湍流模型及Rayleigh-Plesset空化模型的稳态及瞬态仿真模拟,效率和扬程误差均在3%以内。分别在未空化和不同空化程度工况下进行了性能、流场、脉动分析,结果表明,空化致效率下降1%工况下,叶轮内流态整体稳定,由局部空泡输运及溃灭造成湍流耗散并诱发低频压力脉动;空化致扬程下降3%工况下,叶轮内流态紊乱、形成漩涡,能量损失较大,并诱发宽频带压力脉动,易造成泵体振动及噪声危害。在进行该类型离心泵设计时,建议将临界汽蚀余量设为效率下降1%时的装置汽蚀余量及以上,以确保泵的稳定运行。研究结果可为低比转速离心泵的优化设计提供参考。In order to study the internal flow field and induced pressure pulsation phenomena at the inception of cavitation and to determine a reasonable critical cavitation criterion,this paper conducted cavitation experiment on a low specific speed centrifugal pump and carried out steady and unsteady CFD simulations based on the RNG k-εturbulence model and Rayleigh-Plesset cavitation model.The errors of efficiency and head are within 3%.Energy performance,flow field,and pulsation analyses were conducted under both non-cavitating conditions and different degrees of cavitation.The results indicate that the overall flow state is stable,and that the transport and collapse of local bubbles cause turbulent dissipation,leading to low-frequency pressure pulsation when cavitation triggers a 1%efficiency drop.When the head drops by 3%,the flow state in the pump is disturbed with vortex and large energy loss,and the wide band pressure pulsation which is easy to cause the vibration and noise of the pump body is induced.In the design of low-specific-speed centrifugal pump,it is recommended to set the critical cavitation margin to the device cavitation margin and above when the efficiency is reduced by 1%to ensure the stable operation of the pump.The research results can provide reference for the optimization design of low specific speed centrifugal pumps.

关 键 词：空化 离心泵 数值模拟 压力脉动 流场分析 

分 类 号：TH3[机械工程—机械制造及自动化]