叶片几何参数对管道泵径向力及振动的影响

Effects of blade geometry parameters on radial force and vibration of in-line circulator pump

为了解决一台比转数为221的管道泵振动问题,在保证能量特性具有较好一致性的前提下,通过优化叶片几何参数Z,β2,β1减小振动烈度.采用CFX数值计算软件分别对不同工况下优化前后的管道泵内部全流场进行非定常数值模拟,研究叶片几何参数Z,β2,β1对管道泵压力脉动、径向力及振动的影响.计算结果表明:叶轮A的压力脉动、径向力及径向力脉动强度均大于叶轮B,叶频及其谐波是压力脉动的主要激励频率.同时,为了进一步研究由叶片几何参数的改变引起的压力脉动及径向力的变化对振动的影响,通过振动试验测量了带有叶轮A,B的管道泵振动速度.结果表明:在不同工况下,叶轮A的振动强度大于叶轮B,叶频及其谐波是管道泵振动的主要激励频率.对比数值计算结果和试验结果可以看出,压力脉动较大、径向力及径向力脉动较为剧烈的叶轮A,其振动强度也较强;优化后的管道泵在0.4Qd到1.3Qd工作范围内,振动速度小于1.8 mm/s,满足振动标准.

To solve the vibration issue of one in-line circulator pump with specific speed of 221,on the premise of having similar energy characteristics,the blade geometry parameters Z,β 2,β 1 were optimized to lower the vibration amplitude.In order to investigate the effects of blade geometry parameters on pressure pulsation,radial force and vibration of an in-line circulator pump,by applying CFX,the full unsteady flow numerical simulations of in-line circulator pumps in different flow conditions were executed both on pre-optimized impeller A and post-optimized impeller B.The results indicate that the overall pressure pulsation,radial force and radial force fluctuation amplitude of impeller A are higher than those of impeller B;and blade passing frequency and its harmonics are the domain frequencies for pressure pulsation.Meanwhile,to get a deep understanding on the effect of radial force changing on vibration because of changing the blade geometry parameters,the experimental vibration tests were conducted to measure the vibration velocity of in-line circulator pumps with impeller A and impeller B.Result is that vibration amplitudes of impeller A are higher than impeller B under different flow conditions,and blade passing frequency and its harmonics are the domain frequencies for pump vibration.In addition,to further study the effect of the changes of pressure pulsation and radial forces caused by changing blade geometry parameters on vibration,vibration velocities of the in-line circulator pump with impeller A and impeller B respectively were measured.The vibration results show that,under different working conditions,the vibration amplitude of impeller A is stronger than impeller B.Blade frequency and its harmonics are the main incentives of the vibration of in-line circulator pumps.The comparison between computational and experimental results shows that impeller A has higher vibration amplitude because there are higher pressure pulsation,radial forces and radial force fluctuation amplitude it served.The vibration velocity of post-optimized pump is lower than 1.8 mm / s in the flow range from 0.4Q d to 1.3Q d,and satisfies the ISO 10816 standard.