双吸式离心泵叶频压力脉动及诱导振动实验研究

Experimental Research on the Pressure Fluctuation at Blade Passage Frequency and Induced Vibration in a Double-suction Centrifugal Pumps

离心泵的压力脉动是影响水泵机组稳定运行的主要因素之一。采用实验方法,测试了双吸式离心泵在不同运行工况下的压力脉动信号和振动信号,并进行了FFT变换和频谱分析,结果表明,叶频压力脉动受流量的影响明显,在Q<0.28 Qn和Q>1.14 Qn时,叶频脉动均较大;叶频脉动可向上下游传播,向上传播至进水管,叶频脉动随流量增大的变化趋势基本不变,叶频幅值均减小,且减小幅度基本均匀;叶频脉动对水泵传动端轴承座的径向垂直和径向水平方向振动都有影响,且径向水平方向振动受叶频脉动影响的程度大于径向垂直方向振动。本文研究可以拓展实验技术思路,同时可以为双吸式离心泵的设计、运行提供依据,具有一定理论意义和工程价值。

Pressure pulsation in a double-suction centrifugal pump is one of the main factors affecting stable operation. The pressure pulsation signals in the test points and vibration signals on the bearing chock of the drive end were obtained and recorded under various operation conditions. The signals were analyzed by the fast Fourier Transform Method. The results show： the pressure fluctuations at blade passage frequency were affected by the flow rates. When the flow rates were at Q〈0.28 Qn and Q〉 1.14 Qn, the pressure fluctuations at blade passage frequency were both greater. The pressure fluctuations at blade passage frequency propagated upstream and downstream, and the change trend of the pressure fluctuations at blade passage frequency at the top of the inlet pipe was similar to the one at the top of the volute basically, and the amplitudes were reduced uniformly. On the bearing chock of the test pump drive end, the pressure fluctuations at blade passage frequency could be represented in the vertical and horizontal vibration, and the horizontal vibration was affected more heavily by the pressure fluctuations at blade passage frequency than the vertical vibration. This research could expand the experimental technological approach, and provide reference for design and operating double-suction centrifugal pumps, which had theoretical significance and engineering value.