摘要
为分析转轮叶片缺陷情况下的水轮机流道内水沙两相分布规律,该文根据HLA855a-LJ-250水轮机模型,对转轮叶片进行缺陷处理。分别建立了完整、空蚀凹坑及出水边磨蚀三种叶片模型,对应命名方案1、方案2和方案3,通过RNG k-?湍流模型和欧拉多相流模型进行模拟计算。转轮流域采用滑移网格,入口泥沙体积分数设置为0.35%,水轮机额定工况下工作5s,模拟结果显示:(1)方案3转轮叶片压力面与吸力面的泥沙压力与体积分数,均高于方案1和方案2转轮叶片对应面的泥沙压力与体积分数,说明不同缺陷形式的转轮叶片直接影响了转轮叶面泥沙分布规律;(2)转轮叶片缺陷形式不同,呈现在转轮上下游流道内的泥沙分布规律差异性显著;(3)当转轮叶片无缺陷时,机组运行过程中受泥沙磨蚀影响较小,但是当转轮叶片发生磨蚀破坏时,流道内的泥沙体积分数会升高,需要重点关注蜗壳鼻端、转轮叶片压力面及尾水管扩散段部位。
In order to analyze the water-sand two-phase flow law under the defective runner blade, in this paper, defective treatment on the runner blade according to the HLA855a-LJ-250 hydraulic turbine model is performed. The three scenarios of complete,cavitation pit and outflow side abrasion blade models are established respectively, corresponding to schemes 1, 2 and 3,the RNG k-?turbulence model and Eulerian multiphase flow model are used for simulations. The runner basin adopts slip grid, the inlet sediment volume fraction is set to 0.35%, and the hydraulic turbine works for 5 s under rated working condition, the simulation results show:(1) The sediment pressure and volume fraction of the pressure surface and suction surface of the runner blade of Scheme 3 is the highest among three schemes, showing that different defective forms of leaves directly affect the distribution pattern of sediment on the leaf surface;(2) The different forms of runner blade defects present significant differences in the distribution pattern of sediment in the upstream and downstream flow channels;(3) When the runner blade is intact, the unit is less affected by sediment abrasion during operation. But when damage occurs to the blades, sediment will silt up in the flow channel. Thus, the nose of the spiral shell,pressure surface of runner blade and the diffusion section of the tail pipe have to be focused.
作者
潘泓江
于凤荣
刘宇晨
曾云
丁文华
Pan Hongjiang;Yu Fengrong;Liu Yuchen;Zeng Yun;Ding Wenhua(Faculty of Metallurgy and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China;Yunnan Provincial University Hydraulic Machinery Intelligent Testing Engineering Research Center,Kunming 650041,China;Huaneng Lancang River Hydropower INC.Nuozhadu Power Plant,Puer 665000,China)
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2023年第5期766-773,共8页
Chinese Journal of Hydrodynamics
基金
云南省揭榜挂帅科技项目(202204BW050001)。
关键词
水轮机
转轮叶片
滑移网格
两相流
泥沙磨蚀
Hydraulic turbine
Runner blade
Slipping Mesh
Two-phase flow
Sand abrasion
