叶片数对离心泵内流诱导振动噪声的影响

Effects of number of blades on flow induced vibration and noise of centrifugal pumps

基于虚拟仪器数据采集系统和泵产品测试系统在离心泵闭式试验台上建立了泵空化诱导振动噪声试验测试系统,实现了泵能量性能参数和流动诱导振动噪声信号的同步采集.以一台比转数为93的5叶片单级单吸离心泵作为研究对象,在保证泵体和叶轮其他几何参数不变的情况下,将叶轮叶片数分别设计为4,6和7片.测量了不同叶片数下模型泵在全流量范围内的能量性能、振动强度和噪声信号,并对振动和噪声信号数据进行了处理.试验结果表明:模型泵内部流动诱导的振动对泵体的影响最大,5叶片时模型泵的振动强度最高;随着流量的增大各测点振动强度大致都呈现先基本不变后显著上升的趋势;泵的噪声信号主要集中在0～2 000 Hz的范围内;在小于设计流量时,随着叶片数的增大,轴频的峰值逐步增大.研究结果对于建立低振动低噪声离心泵水力设计方法具有重要的参考意义和指导作用.

The present state of research on flow induced vibration and noise of centrifugal pumps was introduced. Based on the virtual instrument data acquisition system and a routine pump test system, a closed-loop test rig was established for measurement of flow induced vibration and noise in centrifugal pumps. A synchronous acquisition was realized for pump performance parameters and flow induced vi- bration and noise signals. A single-stage, end-suction centrifugal pump with 5 blades, whose specific speed was 93, was chosen as the experimental model. The additional impellers respectively with 4, 6 and 7 were made and tested in the same volute. The performance of pumps with those four impellers were measured in the whole flow rate, the vibration and noise signals were recorded and processed as well. The experimental results show that the highest vibration intensity is observed in the pump with 5 blades. With increasing flow rate, the vibration intensity level keeps constant initially and then significantly rises. The frequency of noise issued from the pumps mainly was in the range of 0 - 2 000 Hz. With increasing number of blades, the peak shaft frequency augments gradually at small flow rates. Those outcomes will be instructive and helpful for establishing a hydraulic design method to ensure centrifugal pumps with a low level of flow induced vibration and noise.