Flow characteristic of guide vane region in turbine braking operation of pump-turbine
LI Qifei1,2, LIU Mengmeng1, ZHANG Jianxun1, LIU Qian1, ZHANG Zhen1
1.School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 2. Key Laboratory of Fluid Machinery and Systems, Gansu Province, Lanzhou, Gansu 730050, China
Abstract:To study the inner flow mechanism of pump turbine in the braking operation with vanes′ abnormal vibration, the numerical simulation was done with the SST k-ω turbulent model and SIMPLEC algorithm. The analyses of vane region′s flow and pressure fluctuation were done after comparing with the data from experiment which was finished before. The results show that there exists wake structure after the guide vanes and stay vanes. There will be a loss of energy in the transformation between them and it could cause hydraulic vibration. There also exists impact loss in the inlet of guide vanes which increases the instability of guide vanes region. The instability of the flow in the guide vanes is further verified by the pressure fluctuation monitoring in the guide vanes region. Through the analyses of time domain and frequency domain characteristics, they show that the relative amplitude has reached more than 3 times of normal working conditions of turbine mode and pump mode. The main frequency is theblade frequency with high amplitude. It is an intermediate frequency component which could cause resonance. The results can be used to guide the optimal design of the pump turbine.
李琪飞,,刘萌萌, 张建勋, 刘谦, 张震. 水泵水轮机制动工况导叶区流动特性分析[J]. 排灌机械工程学报, 2017, 35(6): 495-501.
LI Qifei,, LIU Mengmeng, ZHANG Jianxun, LIU Qian, ZHANG Zhen. Flow characteristic of guide vane region in turbine braking operation of pump-turbine. Journal of Drainage and Irrigation Machinery Engin, 2017, 35(6): 495-501.
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