导叶式混流泵汽蚀振动噪声试验研究

Experiment study of cavitation induced vibration and noise of guide vane mixed flow pump

混流泵汽蚀的产生将导致性能的下降,同时伴随着较大的振动和噪声.为分析导叶式混流泵的振动噪声特性并对汽蚀进行诊断预测,通过安装在导叶式混流泵机体不同监测点的加速度传感器以及泵入口段的水听器测试了混流泵的振动和噪声信号,利用1/3倍频谱信号分析手段对试验结果进行了进一步的分析,研究了混流泵内汽蚀时的振动噪声的特征和规律.试验结果表明,导叶式混流泵入口法兰位置及靠近入口的泵体位置处的振动信号对混流泵汽蚀较为敏感,可以用于监测混流泵汽蚀的发生;随着流量的增大,混流泵机体的振动信号可以用于监测其汽蚀特性的频段越来越宽;混流泵发生汽蚀时入口辐射噪声呈现出先增大,达到极值后又逐渐减小的趋势;泵入口处的低频段辐射噪声可以用于监测混流泵汽蚀的发生.

The cavitation of mixed flow pumps can cause the pump performance decline,and accompanies with violent vibration and noise.To analyze the vibration and noise characteristics of a mixed flow pump and detect the cavitation,the vibration and noise signals were obtained by acceleration sensors mounted on different positions and a hydrophone in pump inlet.The experimental data were further analyzed by a third times octave spectrum analysis method,and the characteristics of vibration and noise induced by cavitation were obtained.The results show that the vibration signals on pump inlet flange and on the case near pump inlet are more sensitive to pump cavitation,and it can be used for detecting cavitation;with the increasing of the flow rate,the frequency range of vibration signals for detecting the cavitation becames wider;the noise level induced by cavitation firstly gets higher with the frequency increasing,and the noise level reduces gradually when the frequence reaches the extreme value;the low frequency noise in pump inlet can be used to detect cavitation.