两级离心泵压力脉动与振动的相关特性分析

Correlation analysis of pressure fluctuation and vibration characteristics of two-stage centrifugal pump

该文以两级离心泵为研究对象,探究离心泵压力脉动与振动的相关特性。在离心泵泵体布置若干压力脉动测点,同时在泵体和水泵机组的机脚布置相应的振动测点,进行同步数据采集。对采集到的信号通过快速傅里叶变换(FFT)进行频谱特性分析;通过计算压力脉动信号与振动信号的相干函数,比较各测点的相干系数,分析压力脉动对振动的影响。结果表明:两级离心泵泵体一级导叶出口处与泵体二级导叶出口处的压力脉动均以叶频为主;泵体导叶处的压力脉动对水泵机组机脚在不同方向的振动影响存在差异,泵体导叶在叶频处压力脉动是垂直于安装面方向的机脚振动和平行于离心泵出口方向的机脚振动在叶频处产生振动分量的主要原因,泵体的一级导叶在轴频处的压力脉动是垂直于离心泵出口方向的机脚振动在轴频处产生振动分量的主要原因。

This article takes a two-stage centrifugal pump as the research object, the characteristics of the centrifugal pump pressure fluctuation and vibration is explored. Several pressure fluctuation measuring points are arranged in the pump body of the centrifugal pump, corresponding vibration measurement points are arranged on the pump body and the machine feet of the pump unit for simultaneous data collection. The frequency spectrum characteristics of the collected signals is analyzed by FFT;the coherence function of the pressure fluctuation and the vibration signal is calculated. Through comparing the coherence coefficients of the various measurement points, the impact of the pressure fluctuation on the vibration is analyzed. The experimental results show that the pressure fluctuation at the first guide vane outlet of the pump body and the second guide vane outlet of the pump body of the two-stage centrifugal pump is dominated by the blade passing frequency;the pressure fluctuation of the guide vane of the pump body has different influence on the vibration of the pump unit foot in different directions, the pressure fluctuation of the guide vane of the pump body at the blade frequency is the main reason that machine foot vibration perpendicular to the mounting surface and machine foot vibration parallel to the outlet direction of the centrifugal pump produce the vibration component at the blade frequency, the pressure fluctuation of the first guide vane of the pump body at the shaft frequency is the main reason that machine foot vibration perpendicular to the outlet direction of the centrifugal pump produces the vibration component at the shaft frequency.