Study On Inner Flow Influence Of Francis Turbine By Sealing Structure

With the vigorous development of hydropower in China, turbine unit capacity is increasing, the unit size is also gradually increasing.So,the impact of turbine runner internal flow and performance becomes more acute. Specifically, the internal flow effect on the stability of the turbine, we need to further understand the inner flow of the turbine.Domestic and foreign researchers have done a lot of research on the inner flow of the turbine, which is particularly prominent cavity vortex turbine draft tube and pressure pulsation prediction of inquiry and research to do more, and get a lot of research, it had made great contributions to solve the problem of unit stability. But,draft tube vortex within the cavity is not caused by turbine vibration. Therefore, the research of inner flow is still relatively lacking in some areas, particularly the study of the inner flow of turbine due to runner seal is also very small.In this paper, a domestic hydropower Francis turbine( ??135LJHLA473) for the study, the flow field analysis using ANSYS software and RNG turbulence model for numerical simulation analysis of different sealing structure Francis turbine seal internal flow,and at the same time to the full port flow profile of numerical simulation analysis.It is concluded the internal flow influence law of turbine units that runner seal were gap-type seal, labyrinth and deformation labyrinth such as structures. The law is the influence of different of Francis turbine runner sealing structure is mainly focused on the runner crown and band with the adjacent area and the draft tube inlet near has certain influence.Hence,it laid the foundation for research about stability of low head Francis turbine in the future.