摘要
为了研究在大流量工况下离心泵的空化现象,以及该工况下的空化与压力脉动关系,通过实验测试,在蜗壳内建立监测点进行数值分析,研究了大流量工况下,不同空化阶段离心泵的压力脉动情况,并且对离心泵的非定常空化流动特性进行了分析。首先,通过搭建离心泵闭式管路实验台,对离心泵外特性及不同程度空化情况进行了测试;然后,应用RNG k-ε湍流模型和全空化模型,对一台单级单吸悬臂式离心泵进行了数值计算,得到了空化流场和蜗壳上监测点P1~P5的压力脉动时域和频域特征;最后,基于数值计算结果,分别对叶轮内不同空化状态下,蒸汽体积分数、中间截面速度矢量分布以及监测点的压力脉动进行了分析。研究结果表明:随着空化的加剧,叶片吸力面的空泡区域不断扩大,对流道进口的堵塞作用逐渐增强,而蜗壳上各压力脉动监测点的主频也随之发生显著变化;因此,对泵蜗壳上压力脉动的监测和分析可为空化现象的判断提供参考。
In order to study the cavitation phenomenon of centrifugal pump under large flow condition and the relationship between cavitation and pressure pulsation under the condition,through experimental test,the monitoring points were established in the volute for numerical analysis,the pressure pulsation of centrifugal pump in different cavitation stages under large flow condition was studied,and the unsteady cavitation flow characteristics of centrifugal pump were analyzed.Firstly,the external characteristics and different degrees of cavitation of centrifugal pump were tested by building a closed pipeline test-bed.Then,RNG k-εturbulence model and full cavitation model were used to calculate a single-stage single suction cantilever centrifugal pump,and the time-domain and frequency-domain characteristics of cavitation flow field and pressure pulsation at monitoring points P1~P5 on volute were obtained.Finally,based on the numerical results,the steam volume fraction,the velocity vector distribution of the middle section and the pressure pulse at the monitoring point under different cavitation conditions in the impeller were analyzed.The research results show that with the intensification of cavitation,the cavitation area on the suction surface of the blade continues to expand,the blocking effect on the inlet of the flow channel gradually increases,and the main frequency of each pressure pulsation monitoring point on the pump volute also changes significantly.Therefore,the monitoring and analysis for pressure fluctuations on the pump volute can provide reference for the assessment of cavitation phenomenon.
作者
于群
章宇
王阳
王涛
张伟华
YU Qun;ZHANG Yu;WANG Yang;WANG Tao;ZHANG Wei-hua(Architectural Engineering Institute,Qingdao Huanghai University,Qingdao 266555,China;Nanfang Pump Industry Co.,Ltd.,Hangzhou 311106,China;College of Metrology and Measurement Engineering,China Jiliang University,Hangzhou 310018,China)
出处
《机电工程》
CAS
北大核心
2022年第7期935-941,共7页
Journal of Mechanical & Electrical Engineering
基金
浙江省博士后科研项目择优资助项目(ZJ2021105)
浙江省属高校基本科研业务费专项资金资助项目(2021YW72)。
关键词
离心泵
空化程度
空化阶段
空化流动特性
湍流模型
全空化模型
压力脉动
动静干涉
centrifugal pump
cavitation degree
cavitation stage
cavitation flow characteristics
turbulence model
full cavitation model
pressure fluctuation
rotor-stator interaction
