摘要
以两个水泵水轮机模型转轮为研究对象,联合分析了单流道计算结果与模型试验结果,形成了不同转轮方案“驼峰”性能比较的CFD评判方法,对水力设计时“驼峰”性能的优化提供了理论指导,同时对转轮和活动导叶在压力系数“转折点”和“驼峰”谷点工况下进行了内部流态分析,对“驼峰”现象的产生原因有了更加深入的了解。结果表明:转轮对比时,压力系数“转折点”流量系数越小,模型试验得到的“驼峰”谷点流量系数越小,压力系数越高,“驼峰”裕度越大;活动导叶近顶盖区域的不稳定流动是单流道计算时压力系数曲线出现“转折点”的主要原因;转轮内部分流体从低压边近上冠侧向高压边近下环侧的流动导致活动导叶近底环区域产生复杂的紊流,严重堵塞了流道,导叶的过流能力下降,是水泵工况出现“驼峰”现象的内因。
Two pump-turbine model runners were taken as the research objects.The single-passage calculation results and model test results were jointly analyzed,and the CFD evaluation method for comparing the""hump"performance of different runner schemes was developed,providing theoretical guidance for optimizing,"hump",performance in hydraulic designs.In addition,internal flow regimes of the runner and movable guide vane under conditions of pressure coefficient"turning point"and,"hump"valley point were analyzed to enhance understanding of the causes of the,"hump"phenomenon.The results are as follows:Upon the comparison of runners,the smaller the discharge coefficient at the pressure coefficient"turning point"is,the smaller the discharge coefficient at the"hump"valley point obtained from the model test is,the higher the pressure coefficient is,and the larger the"hump"margin is the unsteady flow near the head cover area of movable guide vane is the main reason for the occurrence of"turning point"in the pressure coefficient curve during single-passage calculation;the flow of some fluid in the runner from the low-pressure side near the runner crown to the high-pressure side near the lower ring causes complex turbulence in the area near the bottom ring of the movable guide vane,seriously blocking the flow passage and reducing the discharge capacity of the guide vane.This is the internal cause of the"hump"phenomenon under pump conditions.
作者
何海平
张勇
杨光东
唐兆祥
郑津生
HE Hai-ping;ZHANG Yong;YANG Cuang-dong;TANG Zhao-xiang;ZHENG Jin-sheng(DEC Dongfeng Electric Machinery Co.,Ltd.,Deyang 618000,China;Yalong River Hydropower Development Company,Ltd.,Chengdu 610000,China)
出处
《水电站机电技术》
2024年第2期1-6,123,共7页
Mechanical & Electrical Technique of Hydropower Station
