Simulation And Analysis Of Internal Flow Field In Water Conveying Mechanism Of Turbine Turbine

There are lots of key factors to determine hydraulic performance of Francis hydraulic turbine. It includes geometry parameters, the ratio of the relative positional relationship of the double vanes, the adjacent match with the wheel and the volute and the corner of the guide vanes. Research has found the loss of vanes liquid field have a greater proportion of the total energy loss through turbine model established. The main factors which influence the loss are geometry parameters and the relative positional relationship of the double vanes.Guide vanes performance will directly affect the flow of imports into the wheel uniformity. It will affect the efficiency of the Turbine. There are three kinds of Vane airfoils about positive curvature, symmetrical curvature and negative curvature. Different leaf type have a different impact on the Turbine at the performance of pressure, efficiency and losses,etc. Circumferential relative position differences of Vanes and Guide Vanes also have an impact on the performance of water turbine components. Vanes wake affect activities in the area of Vanes field. Flow Conditions Guide vanes has an bigger impact on the hydraulic loss.In this paper, a power plant of HLA772C-LJ-178 turbine models is for the study in Laos. A computational domain is established at the Casing and Distributor. To minimum hydraulic loss of double cascades,the whole flow passage of francis turbine is simulated to analyze the flow field of guide vane and stay vane. Two main factors:the guide vane profile and double cascades circumferential position were detailed discussed. The results show that both of the factors have obviously effect on hydranlic efficiency. For this flow passage, the negative curvature of the guide vane is the best one to meet the requirements of the runner inflow conditions, the flow loss is lowest. And the circumferential relative position of different dual cascades showed that the loss is the smallest if little circumferential position differences between the dual cascades. The study of this paper can be used to improve hydranlic performance in optimization design.