超低比转速离心泵关阀启动瞬态特性分析  

Transient characteristic analysis of ultra-low specific-speed centrifugal pumps during startup period under shut-off condition

作　　者：王勇[1] 陈杰[1] 刘厚林[1] 邵昌[1] 张翔[2] 

机构地区：[1]江苏大学国家水泵及系统工程技术研究中心,镇江212013 [2]西华大学流体及动力机械教育部重点实验室,成都610039

出　　处：《农业工程学报》2017年第11期68-74,F0003,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：江苏省产学研联合创新资金-前瞻性联合研究项目(BY2015064-10);江苏省"六大人才高峰"高层次人才项目(GBZB-017);江苏高校优势学科建设工程资助项目;流体及动力机械教育部重点实验室(西华大学)开放课题(szjj2016-068)

摘　　要：为探究超低比转速离心泵关阀启动瞬态特性,该文以一台比转速为25的超低比转速离心泵为研究对象,在关死点工况下对稳态和关阀启动瞬态过程进行数值模拟,并与试验结果进行对比,研究表明:在关死点稳态工况下性能曲线与试验测得结果变化趋势相同,最大偏差小于5%,验证了数值模拟的准确性;关阀启动过程,不同启动加速度下启动过程的末期均出现一个冲击扬程;在相同转速时,稳态过程中间截面的静压分布、相对速度流线分布和进口管路内相对速度与关阀启动瞬态过程分布趋势存在差异。关阀启动瞬态过程内部流场的发展总体上滞后于关死点稳态过程内部流场。研究结果可为进一步研究超低比转速离心泵启动的瞬态过程特性提供参考。In order to explore the characteristics of the ultra-low specific-speed centrifugal pump during startup period under shut-off condition,an ultra-low specific-speed centrifugal pump with the specific-speed of 25 was chosen as the research object.Unsteady numerical calculation under shut-off condition and transient condition was conducted for the ultra-low specific-speed centrifugal pump.The accuracy of numerical simulation was verified by experimental contrast.Based on the numerical results,the influence of different starting acceleration on the transient impact head,the difference between steady state and transient impact head,and the internal flow field were analyzed.The results showed that：The variation tendency of performance curve on shut-off condition under steady state condition was similar with the experiment,and along with the increase of rotational speed,the head under shut-off condition increased gradually.When the start was completed,the transient head was 8.32%,6.13% and 4.19% higher than the steady state head,respectively,at 3 different starting accelerations,which indicated that the valve head change during the startup process had a significant transient effect.There was a significantly higher impact head at the end of startup processes with 3 different start accelerations,and with the increase of start acceleration,the impact head was also increased.With the rotation of the impeller acting fluid,the static pressure increased gradually with the increase of the radius.In addition to the impeller flow close to the tongue,the pressure distribution in the other channels was uniform,and the pressure gradient of the tongue was larger,which indicated that the volute tongue structure had an important influence on the distribution of the static pressure in the pump.With the increase of rotation speed,the static pressure increased gradually,and the pressure difference between the inlet and outlet of the pump increased gradually.When the time was 0.4 s,a high pressure concentration area occurred at impeller

关 键 词：离心泵 计算机仿真 试验 关死点工况 稳态特性 瞬态特性 

分 类 号：TH311[机械工程—机械制造及自动化]