大型离心泵空化性能与驼峰不稳定特性相关性分析  

Correlation Analysis of Cavitation Performance and Hump Instability Characteristic of Large Centrifugal Pump

作　　者：郑阳 薛鹏[1,2] 孟龙 田娅娟 王鑫[1,2] 张驰也 彭忠年[1,2] ZHENG Yang;XUE Peng;MENG Long;TIAN YA-juan;WANG Xin;ZHANG Chi-ye;PENG Zhong-nian(China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Beijing IWHR Technology Co.,Ltd,Beijing 100038,China)

机构地区：[1]中国水利水电科学研究院,北京100038 [2]北京中水科水电科技开发有限公司,北京100038

出　　处：《中国农村水利水电》2024年第5期17-22,共6页China Rural Water and Hydropower

基　　金：“中国水科院基本科研业务费项目基金”(HM0145B012021)。

摘　　要：空化现象和驼峰不稳定特性是影响离心泵机组安全稳定运行的主要因素。基于某大型离心泵两种叶轮方案的数值计算和模型试验结果对空化性能和驼峰不稳定特性进行比较分析,以探究两者之间的相关性,同时,分析了驼峰产生机理及空化性能在其中发挥的作用。数值结果表明,由于空化特性的影响,在数值计算结果中离心泵H-Q性能曲线上出现了驼峰不稳定现象。此外,在小流量区域叶片表面压力分布均匀,最低压力分布合理的空化性能优异叶轮,其驼峰不稳定特性得到显著改善。模型试验结果表明,在泵站正常运行条件下,提升小流量区域装置空化系数与初生空化系数的比值,在叶轮空化性能提升时驼峰裕度增加。研究结果表明,离心泵空化性能与驼峰不稳定特性存在正向相关关系,小流量区域叶轮空化性能提升后可以降低空化现象的发生程度,叶轮流道内部流态改善,整体水力效率提高,相应的驼峰不稳定特性得到提升。研究成果将对大型离心泵机组安全稳定运行提供设计参考。Cavitation phenomenon and hump instability characteristics are the main factors affecting the safe and stable operation of the centrifugal pump unit.In this paper,based on the numerical calculation and model test results of two impeller schemes of a large centrifugal pump unit,the cavitation performance and hump instability characteristics were comparatively analyzed to explore the correlation between the two.At the same time,the hump generation mechanism and the role that cavitation performance played in it were analyzed.The numerical results show that due to cavitation,a hump instability phenomenon appears on the H-Q performance curve in the numerical results.In addition,the impeller with excellent cavitation performance has a uniform pressure distribution on the blade surface in the small flow area and a reasonable minimum pressure distribution,and its hump instability characteristics are significantly improved.The model test results show that under normal operating conditions of the pumping station,by increasing the ratio of plant cavitation coefficientσ_(p)to incipient cavitation coefficientσ_(i),the hump margin increases when the impeller cavitation performance is improved.The results show that there is a positive correlation between cavitation performance and hump instability characteristics.The improvement of impeller cavitation performance in the small flow zone reduces the degree of cavitation,the flow in the impeller passage can be improved,hydraulic efficiency can be increased and hump instability characteristics can be improved.The study results provide design reference for the safe operation of large centrifugal pump.

关 键 词：离心泵 空化 驼峰特性 数值模拟 模型试验 

分 类 号：TH311[机械工程—机械制造及自动化]