Analysis And Optimum Design Of The Nitric Acid 4 In 1 Unit Foundation

The nitric acid 4 in 1 unit is a combination of the steam turbine, nitric oxide compressors, axial compressors and expanding machine. As the main support structure of the nitric acid 4 in 1 unit, the base is required with big structure size, and highly security performance. With the Using of the computer-aided engineering analysis (CAE) technology in the structural design process, it can analyse the static strength, stiffness and vibration of the base of the nitric acid 4 in 1 unit quickly and accurately, so as to facilitate the optimization of the structural design.The paper, by the study of the nitric acid 4 in 1 unit's base, with theory guidance of the finite element method, structural mechanics, dynamics and so on, by means of ANSYS software, builds a parametrical finite element model in accordance with the structural characteristics and the actual working conditions of the base. Then the static analysis and dynamic analysis including modal analysis and harmonic response analysis, are carried out on the model respectively. The static strength and stiffness values are known through the static analysis, while the natural frequencies and corresponding vibration mode are known through the modal analysis, furthermore, the harmonic response analysis is continued on this base. Through this process, we can get the displacement response of nodes under different frequency disturbances. Each analysis result is extracted in order to prepare for dynamic optimum design.Optimum design of the nitric acid 4 in 1 unit's base based on dynamic characteristic is accomplished by finite element analysis software ANSYS. With the total displacement of side plate nodes and high-low cover plate nodes as dynamic optimization objectives respectively, the thickness of the main plate of the top beam as variable, and the static strength as constraint, a dynamic optimization model of the base is set up. After optimization analysis, optimum design programs which have different optimization objectives are compared, in order to put forward a design program of the nitric acid 4 in 1 unit's base with lighter weight and high-performance static and dynamic characteristics.