The Cushion Spiral Case Structure Analysis Of The Turbine And Cushion Layer Scheme Optimization Research

With the development of the hydroelectric industry in our country, the unit capacity of the power station under construction and building is larger and larger. As the important flow part of hydraulic turbine, the HD values of spiral case also increases quickly, and its structure gradually towards the direction of the development of the giant. Spiral case with cushion layer relative to the water filling pressurization and buried type two kind of forms, has simple construction, saving investment, construction period is relatively short and other advantages, and in the domestic large and medium-sized hydropower station have been widely applied in. This combination of a spiral case of hydropower station composite structure design data, the cushion layer range in size and the elastic modulus on the stress characteristics of spiral case combined structure the problem such as the influence, to the large-scale general finite element analysis software ANSYS as platform, mainly carried out the following work:(1) Systematically introduced the burying method, structure characteristics and research methods of spiral case, through comparative analysis, to determine the volute as the object of study, the finite element method as the means of research the basic technology course.(2) The basic theory of FEM and analysis steps were shown, and on the concrete, steel, steel spiral case and the seat ring of the simulation are introduced briefly.(3) The design data of a hydropower station was organized, to the spiral case cushion to pave range size for variables, established three different schemes, using linear elastic finite element analysis of spiral case combined structure stress, strain and displacement etc., choosed out the optimum scheme of cushion.(4) In view of the above selected optimum scheme, to cushion modulus for variables, established another plan, the concrete stress and bearing capacity of steel spiral case and a seat ring, stress, a seat ring and machine pier displacement sensitivity analysis is carried out.(5) According to the concrete of steel spiral case, and a seat ring stress, in the optimal solution based on the bedding plane, the laying of locally optimum analysis, optimization of the optimum scheme was obtained.