Prediction of Bearing Fault Effect on the Hydraulic Performances of a Centrifugal Water Pump

Background Bearing faults in centrifugal pumps usually result in periodically fluctuating torque, which leads to flow instabilities, pressure pulsation, excessive heating, and even pump failure. Purpose This paper presents a theoretical approach for modeling and analyzing the impact of some typical bearing faults on the dynamic characteristics of a monoblock centrifugal pump. Method The governing equations of the flow are solved by the method of characteristics, while the dynamic parameters of the asynchronous motor are predicted by adopting the d-q axes theory. Bearing faults are modeled as periodic square-wave pulses injected into the shaft of the pump. Result The studies of the simulation results show that bearing fault has no significant impact on the pump H-Q curve but it has a large negative effect on the efficiency curve. Additionally, bearing failure in centrifugal pumps can induce head oscillation and flow rate fluctuation. Conclusion In this work, the influence of bearing anomalies on the performance of centrifugal pumps was analyzed using a numerical method. The model analysis indicated that bearing faults in centrifugal pumps can lead to remarkable performance degradation, severe vibrations, and significant flow instabilities.