Hydraulic fluctuations during the pump power-off runaway transient process of a pump turbine with consideration of cavitation effects  

作　　者：Xiao-long Fu De-you Li Hong-jie Wang Yong-guang Cheng Xian-zhu Wei 

机构地区：[1]State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China [2]School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150001,China [3]State Key Laboratory of Hydro-Power Equipment,Harbin Institute of Large Electrical Machinery Harbin 150001,China

出　　处：《Journal of Hydrodynamics》2021年第6期1162-1175,共14页水动力学研究与进展B辑（英文版）

基　　金：Projects supported by the National Natural Science Foundation of China(Grant No.52079034).

摘　　要：A runaway transition after the pump power interruption and the simultaneous guide vane servomotor failure is one of the most dangerous and complex transitions for a pumped storage power system(PSPS).This paper analyzes the fluctuation behavior and mechanism of a PSPS during a runaway transition caused by the pump power interruption.The transient cavitation flow in the PSPS is simulated by using a one-dimensional and three-dimensional coupling flow simulation method for the runaway transition.Subsequently,the effects of the transient fluctuation of the radial hydraulic thrust on the runner and transient pressures are analyzed using the short-time Fourier transform method.Finally,the mechanisms are analyzed based on the analysis of the internal flow field.This study suggests that the extreme fluctuation generally occurs near the critical transformation points between the two operation modes.In addition,the extreme fluctuation behavior is primarily related to the local backflow near the runner inlet and the unstable cavitation phenomena in the runner and the draft tube.This finding helps for optimizing the runner design to resolve the instability problems of a PSPS.

关 键 词：Pumped storage power system pump power-off runaway transient fluctuation behavior local backflow CAVITATION 

分 类 号：TV13[水利工程—水力学及河流动力学]