高水头大变幅混流式水轮机尾水管内部流动分析  

Analysis of Internal Flow in Draft Tube of Francis Hydro-turbine with Wide Range of High Water Head

作　　者：赵之洲 李洪[2] 宋文武 由丽华[2] 宿科 ZHAO Zhi-zhou;LI Hong;SONG Wen-wu;YOU Li-hua;SU Ke(School of Energy and Power Engineering,Xihua University,Chengdu 610039,China;Sichuan Province Zipingpu Development CO.,LTD.,Chengdu 610091,China)

机构地区：[1]西华大学能源与动力工程学院,四川成都610039 [2]四川省紫坪铺开发有限责任公司,四川成都610091

出　　处：《水电能源科学》2022年第1期176-179,共4页Water Resources and Power

基　　金：流体及动力机械教育部重点实验室开放基金项目(szjj2014-045);四川省科技厅项目(2016JY0187)。

摘　　要：为探究高水头大幅变化对混流式水轮机尾水管涡带的演化及对压力脉动的影响,以国内运行水头变幅最大的紫坪铺水电站水轮机为例,通过三维建模及定常和非定常条件的CFD分析,研究混流式水轮机在相同开度下最大水头、设计水头和最小水头三种工况的流动特点。结果表明,最小水头工况下尾水管内部流态较乱,尾水管中存在螺旋型空腔涡带,主要分布在直锥段。最大水头工况下尾水管的柱状涡带直径较大,且分布在直锥段和弯肘段,对机组振动和空化影响较大。研究结果阐明了非定常流动的特性,揭示了尾水管内压力脉动与涡带发展形态变化的规律,可为水轮机的安全可靠运行提供技术保障。For study of the impacts of large variation range of high water head on evolution of draft tube vortex strip and pressure fluctuation in Francis hydro-turbine,taking the hydro-turbine of Zipingpu hydropower station as an example,which has the largest water head variation in China,three-dimensional modeling and CFD analysis of steady and unsteady conditions are carried out in this paper.This numerical simulation is used to explore the flow characteristics of Francis hydro-turbine in three conditions:the maximum head,design head and the minimum head at the same opening of guide vanes.The results show that the internal flow pattern of the draft tube is chaotic under the minimum head condition,and the spiral-type vortex strip exists in the draft tube,which is mainly distributed in the straight cone section.Under the condition of maximum head,the diameter of the columnar vortex strip of the draft tube is larger than the condition of design head,and it is distributed in the straight cone section and elbow section,which will have a great impact on the vibration and cavitation of the unit.The research illustrates the characteristics of unsteady flow and reveals the development rules of pressure fluctuation and vortex strip in draft tube,which can provide technical support for safe and reliable operation of hydro-turbine.

关 键 词：大变幅水头 混流式水轮机 尾水管 非定常流动 压力脉动 

分 类 号：TK733[交通运输工程—轮机工程] TV734.1[动力工程及工程热物理—流体机械及工程]