The Structure Strength Analyze Of Steam Turbine Switching Arrangement With Finite Element Methods

Steam turbine switching arrangement is one kind of marine auxiliaries, whose main function is to control the direction of high temperature and pressure steam flow by opening or closing the valves in it. It works in a terrible environment and especially the temperature fluctuation is important to the safety of the arrangement, so some specific analysis is necessary to calculate the equipment reliability.The structure strength is studied in the project for the steam turbine switching arrangement. Firstly, with the structural and dimensional data of the switching arrangement, 3-D model is created and assembled by the 3-D modeling software PRO/ENGINNER. Secondly, based on the models, the thermal-structure analysis is made by the Finite Element Analysis software ANSYS, and the structure strength of the arrangement is analyzed when the structure is under the conditions of high temperate, pressure and forces.The main contents are as following. The structure strength of the important parts is studied when the arrangement works under normal conditions. The influences which are caused by the boundary loads are made when the steam pipes expand because of suffering from heat to the structure strength. Because the data of fixed form and location on the steam pipes was absent, the analyses can't be done by common method. So a new method, which based on successive approximation and contained vector resolution, appraise formulae with weight coefficient, was applied to analyze the influence caused by thermal expansion force. With the FEM analysis, the data of the von-stress distribution and the deformation are obtained, which is used as available reference information in the arrangement structure design and pipe location design.