XIA Yuan zhi, MING Ting feng, SU Yong sheng, CAO Yu liang

 

(College of Power Engineering, Naval University of Engineering, Wuhan 430033, China)

 

 

Abstract: Aiming at the problem of identifying the centrifugal pump cavitation state, the vibration,inlet and outlet pressure, acoustic signals were investigated before and after the centrifugal pump cavitation. The texperiment operation was done through designing and constructing the comprehensive test platform of centrifugal pump. Signal detection and acquisition system was constructed, and the condition monitoring system was developed by using LabVIEW. Under the premise of keeping the constant flow of the centrifugal pump, the cavitation experiment was simulated through adjusting the opening degree of the inlet and outlet.Under three kinds of working conditions, the pump flow, rotating speed and pressure of inlet and outlet, etc., were measured. The cavitation allowance of the pump was calculated obtained and NPSHA discriminant curves were plotted. Finally, according to the structure feature and cavitation properties of centrifugal pump, the pressure of centrifugal pump,vibration and acoustic signal were analyzed detailedly for extracting the pump′s cavitation feature information .The results indicate that, before and after the cavitation, the pressure, vibration and acoustic signal can be used as the characteristic of cavitation monitoring, and the influence of the pressure of centrifugal pump on the inlet and outlet and vibration parameters is more obvious than that of the acoustic signal.

 

Key words: centrifugal pump; cavitation; cavitation allowance; condition monitoring