Study on flow and pressure fluctuation characteristics of two-way pumping system with super low head and large flow rate

29th IAHR Symposium on Hydraulic Machinery and Systems

Jiao, Weixuan^1 ; Cheng, Li^1 ; Luo, Can^1 ; Zhang, Di^1

School of Hydraulic, Energy and Power Engineering Yangzhou University, Yangzhou, Jiangsu

225009, China^1

关键词: Blade passing frequency;    Flow charac-teristics;    Fluctuation amplitudes;    Hydraulic vibration;    Low Frequency Fluctuations;    Low-head pumping stations;    Periodic variation;    Pressure fluctuation;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/240/3/032011/pdf
DOI  :  10.1088/1755-1315/240/3/032011

来源: IOP

【 摘 要 】

The pumping station along the Yangtze River runs around the zero head all the year round, and the work flow rate deviates from the design condition, which is easy to cause hydraulic vibration, and seriously affects the safety of the unit. By using the CFD software, the numeric simulation of typical low head Two-way pumping system was made. The flow characteristics and pressure fluctuation characteristics of two-way flow channel with large flow rate are calculated and analysed. The calculated results are verified by model tests. The results show: Under the super low head condition, the flow pattern of the main flow area of the inlet and outlet channel is better, but the blind end of the inlet and outlet of the flow channel has larger reflux. The pressure fluctuation at the monitoring point of the impeller and guide vane has obvious periodic variation rule. Due to impeller rotation, the pressure fluctuation exists alternately in the impeller. Frequency domain graph display based on fast Fourier transform, the main frequency of each point at the outlet of the impeller are all blade passing frequency (BPF). The main frequency of impeller inlet and guide vane outlet was the multiples of BPF. The pressure fluctuation in the inlet and outlet channel is more complicated, the low frequency fluctuation dominates, and the fluctuation amplitude decreases greatly. The research results can provide reference for hydraulic vibration research of super low head pumping station along the Yangtze River.