Study on Flow Characteristics of a Single Blade Breakage Fault in a Centrifugal Pump

Abstract

The precise identification of faults in centrifugal pumps is crucial for ensuring their safe and stable operation, given their significance as vital industrial equipment. This article aims to rigorously examine and analyze the flow characteristics of centrifugal pumps under two specific conditions: normal blade operation and a single blade breakage fault. Through systematic comparison and in-depth study, this article sheds light on distinguishing flow patterns exhibited by these pumps under both normal and fault scenarios. Utilizing validated numerical simulation methods, a thorough analysis is conducted to explore the flow condition and energy characteristics of the impeller channel following the breakage of a single blade. Additionally, the article investigates changes in the pressure pulsation characteristics of the pump volute as a result. The numerical simulation results reveal that the head of the centrifugal pump decreases at all flow points when a single blade breaks. However, there is no significant change in efficiency at small flow points. As the flow rate exceeds 0.9Qd, efficiency experiences a substantial decrease. Furthermore, the efficiency decline becomes even more pronounced as the flow rate continues to increase. At 1.5Qd, efficiency plummets by 14.33%. The flow pattern undergoes significant changes as well. The breakage of the blade induces noteworthy secondary flow in adjacent impeller channels, resulting in heightened turbulence dissipation. Additionally, it was observed that blade fracture causes alterations in the main frequency of pressure pulsation within the volute. This is characterized by an increase in shaft passing frequency and a decrease in blade passing frequency. Notably, near the tongue monitoring point, the shaft frequency escalates by over 20 times.