水泵水轮机泵工况流动结构演变对驼峰特性的影响  

Influence of flow structures evolution on hump characteristics of a model pump-turbine in pump mode

作　　者：张春泽[1,2] 夏林生 刁伟[1,2] 

机构地区：[1]重庆交通大学西南水运工程科学研究所,重庆400016 [2]武汉大学水资源与水电科学国家重点实验室,湖北武汉430072 [3]中国舰船设计研究中心,湖北武汉430064

出　　处：《浙江大学学报（工学版）》2017年第11期2249-2258,共10页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(51579187);重庆市科委自然科学基金资助项目(cstc2016jcyjA1935);重庆市教委基金资助项目(KJ1600514);重庆交通大学内河航道整治技术交通行业重点实验室开放基金资助项目(NHHD-201505)

摘　　要：为了揭示水泵水轮机在泵工况流动结构演变对特性曲线驼峰特性的影响,采用SAS湍流模型对多个工况点的流态进行全流道数值模拟,得到两者之间的关联性.结果表明,当水轮机在40%~80%最优流量运行时,导叶内发生旋转失速;当流量低于40%最优流量时,转轮进口产生的回流涡结构在尾水管边壁侧产生螺旋回流阻碍过流,并改变转轮叶道在空间上的过流能力,进而改变转轮出流特性;转轮出口下环侧流速降低,使导叶所有叶道均产生剧烈流动分离,导致旋转失速消失,并产生回流流入转轮.转轮进口回流涡结构的出现,改变了水轮机内的流动分离特性,使水头损失突然增大,产生驼峰特性.The SAS turbulence model and unsteady RANS approach were adopted to simulate the internal flow in a mode pump-turbine under different flow rate in order to analyze the influence of flow structures evolution within pump-turbine on the hump characteristics.Results show that the rotating stall occurs within the guide vanes over a large range of part load operating conditions from 40% to 80% of best efficiency point（BEP）flow rate.When the flow rate decreases to less than 40% of BEP flow rate,the flow recirculation on shroud side at runner inlet appears and causes the helical backflow near the wall of draft tube.These reverse flow vortices at runner inlet change the spatial distribution of flow rate inside runner and the runner outflow.The decelerated outflow at shroud side cause severe separations in guide vanes.The irregular vortices occupy all flow passages with backward flow at shroud side and the regular rotating stall disappears.The reverse flow vortex structures at runner inlet make a sudden change of the internal flow features and increase of the flow losses,resulting the hump characteristics.

关 键 词：水泵水轮机 旋转失速 水泵工况 驼峰特性 

分 类 号：TV7[水利工程—水利水电工程]