离心泵内部由叶轮-隔舌动静干涉作用诱发的压力脉动是激励离心泵振动噪声的重要因素,对泵的稳定、安全运行有重要影响。为了全面获得离心泵压力脉动特性,本文采用试验手段对一台低比转速离心泵进行压力脉动试验,在蜗壳周向均布20个高频压力脉动传感器对压力信号进行提取。结果表明:离心泵压力频谱呈现典型的离散特征,峰值信号出现在叶频及其高次谐波处,压力频谱中没有出现明显的轴频及其和叶频非线性干涉诱发的峰值信号。不同测量点处压力脉动幅值差异显著,在设计点及大流量工况,叶频处压力脉动幅值极大值点出现在隔舌后端区域范围内,而在隔舌前部区域内,压力脉动幅值较小;且随着角度的增加,叶频处压力脉动幅值呈现递减的趋势,而在小流量工况叶频处压力脉动幅值并没有出现在隔舌后端区域内。流量对叶频处压力脉动幅值影响显著,压力脉动幅值极小值点出现在0.9Qd附近,而偏离该工况时,压力脉动幅值迅速上升。
Pressure pulsations due to rotor-stator interaction are vital factors induced vibration and noise in centrifugal pumps, which have a great influence on the stable operating of the pumps. To have a comprehensive understanding of pressure spectrum characteristics of a low specific speed centrifugal pump, twenty pressure transduces are evenly mounted on the volute casing to obtain pressure pulsation signals. Results show that: pressure spectrum shows typical discrete characteristics, and evident peaks occur at the blade passing fl'equency fBPF and its higher harmonics. Components at tile shaft rotatin~ frequencyfR together with the non-linear peaks betweenfBpF and fa are not evident. At nominal and high flow rates, the maximum amplitude occurs at the point after the volute tongue, and at the point before the volute tongue, pressure amplitude is much smaller. This phenomenon is not observed at low flow rates. With the angle increasing, pressure amplitude shows a decreasing tendency. Minimum am- plitude occurs at 0.9 Q0, and pressure amplitude increases rapidly when flow rate deviating from 0.9Qd.