基于Hilbert-Huang变换的轴流泵流动诱导振动试验

Experiment on the flow induced vibration of an axial-flow pump basedon Hilbert-Huang transform

对不同叶片角度下轴流泵站机组正常运行和开机状态进行振动试验,对比分析振动信号特征,探寻叶片角度在正常运行和开机状态下对机组振动的影响规律,为保证机组安全稳定运行提供参考。得到以下结论:正常运行工况下,随叶片角度从-8°增大到+8°,外筒体和下机架的振动幅值整体表现出逐渐升高的趋势,主轴摆度的幅值基本不变,满足无限制长期运行要求;沿来流方向监测的振动信号主要频率成分包括2.5 Hz和10 Hz;垂直来流方向及轴向的振动信号主要频率成分包括2.5 Hz,10 Hz和20 Hz,与水泵的转频2.5 Hz成倍数关系;随着叶片角度从2°增大到8°,部分测点振动峰峰值逐渐超出50μm,进入C区域,说明水泵不宜在大角度下长期持续运行。

The influence of blade angle on the vibration of an axial-flow pump under normal operation and in starting state was studied by comparing the vibration signal characteristics of the pump station running under normal operation and in starting state at different blade angles.This could serve as a reference to ensure the safe and stable operation of the unit.The results show that under normal operating conditions,the general vibration amplitudes of the outer cylinder and the lower frame increase gradually as the blade angle increases from-8°to+8°.The amplitude of spindle slips is almost constant.The main frequency components of vibration signals in the flow direction include 2.5 Hz and 10Hz.And the main frequency components of vibration signals in the vertical flow direction and axial direction are 2.5 Hz,10 Hz and 20 Hz,presenting a multiple relationship with the rotational frequency of the pump(2.5 Hz).When the blade angle increases from 2°to 8°,part of the peak values of vibration gradually exceeds 50μm,entering into the C area,which indicates that the pump should not run continuously at large angle.