密封口环磨损对离心泵外特性及内流场的影响  

Effects of wear-ring abrasion on hydraulic characteristic and internal flow field of centrifugal pump

作　　者：张景[1] 谈明高[1] 刘厚林[1] 吴贤芳[2] 何乃昌 

机构地区：[1]江苏大学国家水泵及系统工程技术研究中心,江苏镇江212013 [2]江苏大学能源与动力工程学院,江苏镇江212013

出　　处：《排灌机械工程学报》2017年第10期849-855,共7页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(51509109;51579117);江苏省工业支撑计划项目(BE2014879);江苏省成果转化项目(BA2015169);江苏省高校优势学科建设工程项目

摘　　要：以比转数为88的立式离心泵为研究对象,基于CFD研究不同口环间隙对能量性能及压力脉动的影响.研究分为5组方案,使间隙值f从0.13 mm增大到0.93 mm,Δf=0.2 mm.通过外特性试验结果对比,验证了计算方法的准确性,进一步研究口环间隙变化对性能及压力脉动的影响,结果表明:随着口环间隙的增大,模型泵扬程和效率均有所下降,下降值分别为4.00%和7.99%,前泵腔口环泄漏量增大约3.3倍;间隙变化对泵内流场的影响主要集中在前泵腔及间隙出口处,随着间隙的增大,泵腔低压区向蜗室方向扩大,间隙出口处高压区也有所扩大;绝对速度矢量涡由间隙出口附近向叶轮入口移动,导致入口处流体稳定性变差;隔舌及前泵腔处压力脉动幅值下降明显,下降值ΔCp分别为0.002 5和0.002 0;对比分析5组方案中扬程、效率及压力脉动幅值的变化趋势可知,设计工况下模型泵对前口环间隙变化的敏感范围在0.13~0.53 mm.In order to analyze the effect of different wear-ring clearances on hydraulic characteristic and internal flow field of the centrifugal pump, by applying CFD, a vertical centrifugal pump was cho- sen as the research object, with specific speed of 88. With Af=0.2 mm, 5 schemes were established between f = 0. 13 mm and f = 0.93 mm. In order to verify the accuracy of computational model and me- thod, the results of numerical simulation and experiment on performance were compared, which were the basis for researching the effects of wear-ring clearance modifications on performance and pressure pulsation, and the further results show that head and efficiency drop by 4.00% and 7.99% as the clearance widens, leakage flow in front chamber increases about 3.3 times. As the clearance widens, the low-pressure area tends to expand toward the volute while the high-pressure zone near the outlet of clearance has a tendency to expand; the absolute velocity vector vortex moves from clearance outlet area to impeller inlet, which leads to the results that the inlet flow regime becomes more and more in- stability; the amplitude of pressure pulsation in volute tongue and front chamber decrease obviously, which is 0. 002 5 and 0. 002 0, respectively. Finally, by comparing and analyzing the variation ten- dency of head, efficiency and the amplitude of pressure pulsation among 5 schemes, there is a conclu- sion that the sensitivity range of model pump related to front wear-ring clearance modifications in the design condition is between 0. 13 mm and 0. 53 mm.

关 键 词：离心泵 密封口环 间隙 泄漏量 压力脉动 

分 类 号：TH311[机械工程—机械制造及自动化] S277.9[农业科学—农业水土工程]