Statistical Characteristics of Suction Pressure Signals for a Centrifugal Pumpunder Cavitating Conditions  

作　　者：LI Xiaojun YU Benxu JI Yucheng LU Jiaxin YUAN Shouqi 

机构地区：[1]Key Laboratory of Fluid Transmission Technology of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou310018, China [2]Jiangsu Feixiang Pump Manufacturing Co., LTD, Taizhou, 214537, China [3]National Research Center of Pumps, Jiangsu University, Zhenjiang 212013, China

出　　处：《Journal of Thermal Science》2017年第1期47-53,共7页热科学学报（英文版）

基　　金：supported by National Natural Science Foundation of China(No.51409233);Natural Science Fund project of Jiangsu Province(No.BK20140585)

摘　　要：Centrifugal pumps are often used in operating conditions where they can be susceptible to premature failure. The cavitation phenomenon is a common fault in centrifugal pumps and is associated with undesired effects. Among the numerous cavitation detection methods, the measurement of suction pressure fluctuation is one of the most used methods to detect or diagnose the degree of cavitation in a centrifugal pump. In this paper, a closed loop was established to investigate the pump cavitation phenomenon, the statistical parameters for PDF (Probability Density Function), Variance and RMS (Root Mean Square) were used to analyze the relationship between the cavitation performance and the suction pressure signals during the development of cavitation. It is found that the statistical parameters used in this research are able to capture critical cavitation condition and cavitation breakdown condition, whereas difficult for the detection of incipient cavitation in the pump. At part-load conditions, the pressure fluctuations at the impeller inlet show more complexity than the best efficiency point (BEP). Amplitude of PDF values of suction pressure increased steeply when the flow rate dropped to 40 m3/h (the design flow rate was 60 m3/h). One possible reason is that the flow structure in the impeller channel promotes an increase of the cavitation intensity when the flow rate is reduced to a certain degree. This shows that it is necessary to find the relationship between the cavitation instabilities and flow instabilities when centrifugal pumps operate under part-load flow rates. © 2017, Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag Berlin Heidelberg.

关 键 词：Centrifugal pumps Electric load flow Flow rate IMPELLERS Probability density function 

分 类 号：TH311[机械工程—机械制造及自动化]