叶轮进口几何参数对离心泵空化性能的影响  

Effect of impeller inlet geometry on centrifugal pump cavitation performance

作　　者：罗先武[1] 张瑶[1] 彭俊奇[1] 许洪元[1] 

机构地区：[1]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《清华大学学报（自然科学版）》2008年第5期836-839,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(50676044);北京市自然科学基金资助项目(3072008)

摘　　要：对一个低比转速(ns=86 m.m3.s-1.min-1)离心式锅炉给水泵进行了空化性能实验。为了与实验对比,在泵最佳效率点附近,基于标准k-ε模型和VOF空化模型进行了泵内全流道的三维空化湍流计算。结果表明数值模拟能较好地预测泵的平均空化性能。为改善锅炉给水泵内的空化性能,在实验泵已有叶轮的基础上,采用延长叶轮进口及加大叶片安放角的措施设计了5种新叶轮,并以这些新叶轮替代原叶轮进行了泵内全流道的空化流计算。结果表明,适当延伸叶轮叶片的进口位置及加大叶片进口角均可较明显地改善离心泵的空化性能。进一步的流场分析显示,保证叶轮进口的流动均匀性是离心泵空化性能得到改善的重要原因。Cavitation in a centrifugal boiler feed pump with a low specific speed of 86 m·ma·s^-1· min^-1 was analyzed experimentally and numerically. The three-dimensional turbulent cavitating flow was modeled using the k-ε turbulence model and the volume of fluid （VOF） cavitation model in the full pump flow passage near the peak efficiency point. Comparison with the experimental data showed that the simulations reasonably predicted the average pump cavitation performance. Five impellers were then designed based on the original impeller by extending the blade inlet toward the pump inlet or enlarging the blade inlet angle to reduce the cavitation in the boiler feed pump. The cavitating flow in the full flow passage of the pump with the newly designed impellers was also analyzed to show that the pump cavitation performance can be significantly improved by properly extending the blade inlet or enlarging the blade inlet angle. Further flow analyses show that the uniformity of the flow upstream of the impeller inlet is an important means for reducing cavitation in a pump.

关 键 词：离心泵 进口几何参数 叶轮进口流动 空化性能 

分 类 号：TH311[机械工程—机械制造及自动化]