水泵水轮机“S”特性及其性能改善  

S-shaped characteristics of pump-turbine and improvement on its performance

作　　者：刘竹青[1] 孙卉[1] 肖若富[1] 刘伟超 

机构地区：[1]中国农业大学水利与土木工程学院,北京100083 [2]东方电机有限公司研试中心,四川德阳618000

出　　处：《水力发电学报》2013年第2期257-260,270,共5页Journal of Hydroelectric Engineering

基　　金：国家自然科学基金项目(50809073)

摘　　要：水泵水轮机在"S"特性区内会发生机组并网困难或者甩负荷过程中水压异常上升,使机组振动加剧。为了探究"S"特性发生的原因以及相应的改善措施,本文对水泵水轮机模型分别在同步导叶和不同预开启导叶条件下进行能量试验及全流道内流场的CFD数值计算,通过对试验结果与计算结果的研究表明:在小流量工况下,由于离心力以及转轮叶片进口冲角非常大,在活动导叶与转轮进口之间以及转轮内形成大范围的漩涡流动,这些漩涡对于对流动的阻滞是导致水泵水轮机"S"特性的重要原因;通过预开启部分导叶的方法,强制增大了过流量,使得转轮进口及转轮叶片之间的漩涡减少,水泵水轮机能够有效的避开"S"特性的影响。When a pump-turbine operates in the mode with S-shaped characteristics,its load rejection is difficult and its water pressure takes an unusual increase,causing an intensification of its mechanical vibrations.To explore the origin of such characteristics and corresponding improvement measures,this study conducted a CFD analysis of the full flow and an energy test for a pump-turbine under the conditions of synchronous guide vanes and pre-opening guide vanes.A comparison of the CFD results with experimental data shows that in the low flow conditions,centrifugal force and large incident angle cause the formation of large-scale vortex flows inside the runner and between the guide vanes and runner entrance,and that these vortices should be the major factors causing the S-shaped characteristics.Pre-opening of the guide vanes can increase the flow and reduce the vortices in these two flow regions,and thus it is an effective measure for pump-turbine to avoid the mode with S-shaped characteristics.

关 键 词：水力机械 可逆水泵水轮机 “S”特性 同步导叶 预开导叶 

分 类 号：TV136[水利工程—水力学及河流动力学]