Pressure pulsation characteristics of axial-flow pump under multiple working conditions
WU Donglei1, ZHENG Yuan1*, XUE Haipeng2, DAI Qingyun2, ZHANG Yuquan1, LIU Weidong1
1. School of Energy and Electrical Engineering, Hohai University, Nanjing, Jiangsu 210098, China; 2. Qinhuai River Water Conservancy Project Management Office, Nanjing, Jiangsu 210001, China
Abstract：In order to study the pressure pulsation characteristics of axial extensional pump under different flow conditions, the numerical method was used to calculate the flow field within the internal pump under different flow conditions, and the characteristics of pressure pulsation under different flow conditions were revealed. The reliability of the numerical calculation method was verified by the pressure pulsation test of the real machine. The results shown that the pressure pulsation on each monitoring surface of the unit has a certain periodicity, and the peak and trough of the pressure pulsation at the runner were related to the number of the runner blades, and the main frequency of pressure pulsation was the blade frequency. The main frequency of pressure pulsation at the inlet section of the guide blade was the frequency of revolution. Under the condition of small flow, the flow was disordered and the pressure pulsation jitter was obvious. At the outlet section of the runner, due to the influence of rotor-stator interference, the flow was disordered, especially under the condition of small flow, the peak pressure pulsation reaches 12 times as high as the design condition. Low frequency signals induced by impact and backflow appears in the pressure pulsation frequency domain at the guide blade inlet and the monitoring point at the guide blade outlet. The low frequency frequency spectrum is complex and obvious jitter occurs.
