基于高速摄影的水力机械空化空腔膨胀收缩特性试验研究  

Experimental Study on Expansion and Contraction Characteristics of Hydraulic Machinery Cavitation Cavity Based on High-speed Photography

作　　者：徐洪泉[1] 朱雷[1] 何磊 张海平[1] XU Hongquan;ZHU Lei;HE Lei;ZHANG Haiping(China Institute of Water Resources and Hydropower Research,Beijing 100038,China)

机构地区：[1]中国水利水电科学研究院,北京100038

出　　处：《水力发电》2023年第8期94-98,113,共6页Water Power

基　　金：中国水利水电科学研究院科研专项(HM0145B432016)。

摘　　要：水力机械水力不稳定是水电站、水泵站机组和厂房强烈振动、转轮叶片断裂、尾水管撕裂、压力及负荷振荡等稳定性问题的主要来源。空化空腔危害水力机械稳定性理论认为,空化空腔的膨胀收缩循环变化是引起强烈压力脉动及振动的主要根源,但该空化空腔的膨胀、收缩及溃灭并无试验资料证实。采用高速摄影对水力机械空化空腔膨胀收缩特性进行研究,证实了混流式水轮机叶道涡空化空腔、贯流式水轮机叶片两个端面间隙流空化空腔遇低压膨胀、遇高压收缩甚至溃灭的特性,发现贯流式水轮机叶片与转轮室之间间隙流是小尺寸多列漩涡流涡街。Hydraulic instability is particularly prominent in hydraulic machinery which is the main source of stability problems such as strong vibration of hydropower station,pump station unit and powerhouse,runner blade fracture,draft tube tear,pressure and load oscillation.The theory that the cavitation endangers the stability of hydraulic machinery holds that the change of cavitation cavity expansion and contraction cycle is the main contributor of strong pressure pulsation and vibration,but this expansion,contraction and collapse of cavitation cavity are not confirmed by experimental data.In this paper,the research is carried out by means of high-speed photography.The characteristics of the vortex cavitation cavity in the blade passage of Francis turbine and the flow cavitation cavity in the gap between the two end faces of tubular turbine blades are confirmed,which expand under low pressure,shrink under high pressure and even collapse.It is found that the gap flow between tubular turbine blades and runner chamber is a small-size multi row vortex flow vortex street.

关 键 词：水力机械 空化空腔 压力脉动 高速摄影 膨胀 收缩 溃灭 

分 类 号：TV743[水利工程—水利水电工程]