离心泵叶轮磨损破坏程度下的振动特性分析

Vibration characteristics analysis for a centrifugal pump under different damage degrees of its impeller

为了研究离心泵叶片进口边不同破损程度下的振动特性,针对在同种破坏方式下不同破坏程度对泵振动的影响,通过信号处理方法分析多个工况下的振动信号的时域和频域特征。选用IS-50-160-00单级单吸离心泵为试验对象,研究了六个叶片离心泵分别破坏对称2、4、6个进口叶片离心泵进行试验,在离心泵上布置加速度传感器,采集泵不同运行工况下的径向、纵向、轴向和基座方向振动信号,并进行时域和频谱分析,分别把正常叶片、破损2、4、6个进口叶片对应的振动信号进行对比分析,从而获得叶轮破坏不同程度下的振动信号特征。试验结果表明:由时域图可知,2个叶片进口破坏的情况下泵轴向振动信号波动幅值最大,其不稳定性最差;在频谱中得出:叶片的破损导致离心泵转子旋转失衡并产生轴向伴随频率使振动能量增加,出现大量的高倍频;在统计方法中:振动能量随着流量的增加呈先降低后平稳的趋势,设计工况点处各个方向的振动能量趋于平稳。研究离心泵叶轮不同破坏程度下振动信号特征,可以为离心泵故障的监测分析提供借鉴和参考。

In order to study vibration characteristics of a centrifugal pump under different damage degrees of its blades at inlet edge,an IS-50-160-00 single-suction centrifugal pump was taken as the test object.To acquire influences of different damage degrees of impeller blades under the same damage mode on the pump vibration,6 centrifugal pumps were used to do tests.The symmetrical 2,4 and 6 inlet blades of these pumps were damaged.Acceleration sensors were arranged on these centrifugal pumps,vibration signals in radial,longitudinal,axial and pedestal directions under different operating conditions were collected,respectively.They were analyzed in time domain and in frequency domain,respectively.Vibration signals corresponding to cases of normal impeller blades and symmetrical 2,4 and 6 inlet blades damaged were compared and analyzed,respectively to obtain vibration signal characteristics under different damage degrees of impeller.The test results showed that in time domain figures,the amplitude fluctuation of the axial vibration of the pump with two damaged blades is the largest,so its stability is the worst;in the frequency domain figures,damaged blades cause the pump rotation to lose balance and generate axial accompanying frequencies to increase vibration energy and a lot of high frequency components appear;in the statistical method,vibration energy decreases at first and then keeps steady with increase in flow rate,and vibration energy in all directions tends to be steady at designed case points;to study vibration characteristics of the centrifugal pump under different damage degrees of its impeller can provide a reference for fault monitoring and diagnosis of centrifugal pumps.