High-amplitude pressure fluctuations of a pump-turbine with large head variable ratio during the turbine load rejection process  

作　　者：FU XiaoLong LI DeYou SONG YeChen WANG HongJie WEI XianZhu 

机构地区：[1]School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150001,China [2]State Key Laboratory of Hydro-Power Equipment,Harbin Institute of Large Electrical Machinery,Harbin 150040,China

出　　处：《Science China(Technological Sciences)》2023年第9期2575-2585,共11页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.52209108 and 52079034);Sichuan Science and Technology Program(Grant No.2023YFQ0021);the Natural Science Foundation of Heilongjiang Province,China(Grant No.LH2023E058);China Postdoctoral Science Foundation(Grant No.2022M720948)。

摘　　要：Large-head variable-amplitude pump turbines(PTs) encounter serious transient hydraulic instability issues. To explore the evolution mechanisms of pressure fluctuations(PFs) and flow patterns inside large-head variable-amplitude PTs, the load rejection process(LRP) was investigated using a one-and three-dimensional coupled flow simulation approach. The temporal,spatial, and frequency characteristics of the fluctuating pressures were analyzed for four monitoring points using a combined time-frequency analysis approach. The results indicated that PFs during the LRP of large-head variable-amplitude PTs had a new fluctuation frequency component related to Dean vortices(DVs) in the volute, in addition to the common fluctuation frequency components related to rotor-stator interaction phenomena and local backflow vortices near the impeller inlet. The PF frequency component existed throughout the LRP and had a significant influence on the transient maximum pressure at the volute end. This study provides a useful theoretical guide for the design and optimization of large-head variable-amplitude PTs.

关 键 词：large-head variable-amplitude pump turbine load rejection process 1D-3D flow simulation pressure fluctuation flow pattern evolution 

分 类 号：TV734.1[水利工程—水利水电工程]