摘要
为了降低压力脉动对低比转速离心泵产生的不利影响,在固液两相流条件下,对离心泵内的压力脉动(尤其是隔舌处的压力脉动)以及径向力进行了研究。首先,以一台n_(s)为66的低比转速离心泵为研究对象,利用软件构建了离心泵三维仿真模型,并对模型进行了网格划分;然后,选用了Mixture多相流模型和RNG k-ε湍流模型作为计算模型,在离心泵叶片、蜗壳以及隔舌处设置了监测点,并设置了计算方案;最后,采用ANSYS CFX软件,通过数值模拟的方法,对低比转速离心泵内部各监测点的压力脉动和径向力规律进行了研究,以得到离心泵内颗粒粒径、颗粒浓度和离心泵流量对离心泵压力脉动特性的影响规律。研究结果表明:当d=1.0%时,随着颗粒粒径增大,各监测点的压力脉动幅值减小,叶轮处径向力总体下降,蜗壳处径向力总体上升;当d=0.5 mm时,随着液体浓度增加,离心泵内压力脉动幅值整体呈上升趋势,但隔舌处略有减小,叶轮处所受径向力不断增加,蜗壳处径向力减小;离心泵隔舌处监测点的压力脉动主要出现在叶频及其倍频处,叶片监测点处的压力脉动主要出现在小频率区间内,因此,适当减小离心泵内颗粒粒径,增加颗粒浓度及流量可以降低隔舌处的压力脉动。
In order to reduce the negative effect of pressure pulsation on low specific speed centrifugal pumps,pressure pulsation and radial forces in centrifugal pumps were investigated under solid-liquid two-phase flow conditions.Firstly,a centrifugal pump with specific speed of 66 was used as the research object.The simulation model was built and meshed by software.Then,the mixture multiphase flow model and RNG k-εturbulence model were used as the calculation model.Monitoring points were set at centrifugal pump blades,volutes and separators,and calculation schemes were set.Finally,the laws of pressure fluctuation and radial force at each monitoring point in the low specific speed centrifugal pump were numerically simulated by ANSYS CFX software,in order to obtain the influence law of particle size,particle concentration and centrifugal pump flow on the characteristics of centrifugal pump.The research results show that when d=1.0%,with the increase of particle size,the pressure fluctuation amplitude at each monitoring point decreases,the radial force at the impeller generally decreases,and the radial force at the volute generally increases.When d=0.5 mm,with the increase of liquid concentration,the pressure pulsation amplitude in the centrifugal pump shows an overall upward trend,but it decreases slightly at the tongue,the radial force at the impeller increases continuously,and the radial force at the volute decreases.The pressure pulsation at the monitoring point of the centrifugal pump diaphragm mainly occurs at the blade frequency and its multiple frequency,and the pressure pulsation at the blade monitoring point mainly occurs in the small frequency range.Therefore,properly reducing the particle size in the centrifugal pump and increasing the particle concentration and flow can stabilize the pressure pulsation at the diaphragm.
作者
任蔼琳
宋文武
周月
REN Ai-Lin;SONG Wen-Wu;ZHOU Yue(School of Energy and Power Engineering,Xihua University,Chengdu 610039,China;Key Laboratory of Fluid and Power Machinery of Ministry of Education,Xihua University,Chengdu 610039,China)
出处
《机电工程》
CAS
北大核心
2022年第12期1653-1661,共9页
Journal of Mechanical & Electrical Engineering
基金
四川省科技厅科技计划资助项目(2016JY0187)。
关键词
叶片式泵
固液两相
数值模拟
颗粒粒径
颗粒浓度
离心泵流量
径向力
vane pump
solid-liquid two-phase
numerical simulation
particle size
particle concentration
centrifugal pump flow
radial force
