Finite Element Analysis Of Rectangular Flue Gas Duct Based On ANSYS

Flue gas duct is the main components of flue gas system in power boiler. In the course of running the boiler, flue gas duct plays an important role in the transportation of air or flue gas. The flue gas duct bear various loads weight when boiler running, such as own weight, insulation weight, pressure, wind loads, etc. However, the flue gas duct panel is thin structure, it cannot bear those loads because of its weakly strength. Therefore, the reasonable choice of wall thickness of the flue gas duct and size of stiffener is essential for design and cost control of flue gas duct.Firstly, in this paper, theoretical knowledge about the existing methods of designing the flue gas duct panel has been introduced, such as the method for solving the problem of large deflection of thin plate, for solving the problem of bending and vibration of stiffener, and the method of designing the smoke duct wall in engineering, etc. Then the finite element theory of knowledge related to flue gas duct finite element calculations were introduced, According to an engineering drawing of flue gas duct, a solid model of rectangular flue duct, hot and cold air duct, using a 3D modeling software Pro/E, were established. Then those solid modes were imported into ANSYS. As well, the mechanical properties and load of components as well as its boundary conditions were given. According to the control conditions of the intensity, vibration and stability of the flue gas duct, the static, modal and buckling analysis were carried out on the flue gas duct. From the static analysis result, it is shown that all of the ducts meet the strength requirements. The lower modes and natural frequency are obtained by means of the mode analysis. Finally, the buckling internal pressure is obtained and the result indicates that all of the ducts are stable under the working pressure.In this paper, the optimization design of turning flue duct was carried out, and get the relationship between design variables and panel stress, as well as the deformation of channel. And obtained a design variable’s degree of influence on the objective function, which can lead us effectively optimize the design of flue. Through calculated the 500 design point, the optimum design point was obtained, it is showed that, under the optimum design point, the weight of flue is reduced by 13% compared to the initial design point, Obviously, it effectively reduce the manufacturing cost of the flue gas duct.Based on the actual situation of the project, the finite element analysis and optimization analysis for the smoke duct were carried out, and providing a reference design which has practical engineering significance.