Hydraulic characteristics of reverse power generation of axial-flow pump
HUANG Jiacheng1, ZHENG Yuan1, KAN Kan1*, XU Zhe2, HUANG Congbing3,ZHOU Guangxin3, DU Yizhao1
1. College of Energy and Electrical Engineering, Hohai University, Nanjing, Jiangsu 211000, China; 2. College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, Jiangsu 210098, China; 3. Jiangsu Aerospace Hydraulic Equipment Corporation, Yangzhou, Jiangsu 225600, China
Abstract:In order to investigate the hydraulic characteristics of reverse power generation of axial-flow pump device in a pumping station, the full flow channel numerical simulation analysis of reverse power generation of the axial-flow pump device was carried out. The results show that when the axial-flow pump device generates reverse power at rated speed, the head and flow are increased by 43% and 38% respectively compared with the pump mode. At the same time, with the increase of rotating speed, the flow-efficiency curve tends to shift to the direction of large flow, and the width of high efficiency zone increases gradually. The pressure fluctuation at the inlet and outlet of guide vane and runner is periodic. The pressure fluctuation at the guide vane inlet and the inlet and outlet of runner is periodic, and the pressure pulsation at the in and outlet of runner is more significantly affected by the rotation of the runner. The amplitude of pressure fluctuation coefficient increases gradually from hub to rim along the radial direction, the pressure fluctuation amplitude of runner outlet is the largest, which is nearly two times of that at the runner inlet. In the frequency domain, the main frequency of pressure fluctuation is the blade frequency, the secondary frequency is 2 times blade frequency. The amplitude of the pressure fluctuation coefficient corresponding to the main frequency at the inlet and outlet of runner increases gradually from the hub to the rim along the radial direction. In small flow condition, with the decrease of the flow rate of the reverse power generation of the axial-flow pump, the more chaotic the streamline of the outlet passage is, and the more obvious the vortex zone presented. The paper provides theoretical support and engineering operation reference for reverse power generation of axial-flow pump in pump station.