Research On Partial Mechanical Characteristics And Stress Concentration Factors Of Pressure Vessels With Special Opening Nozzle

Pressure Vessel is the equipment used extensively in industrial production such as chemical and petroleum, chemical industry, nuclear industry, light industry, power plants and pharmaceutical industry. Owing to all kinds of requirements on processes and structures, we have to open and install the nozzle in pressure vessel. Due to the change of geometric shape and size, The partial scope near the shell subjected to pressure and nozzle’s junction will produce higher discontinuous stress, leading to stress concentration near the region of opening and causing local high stress in the vessel,then it will influence the overall carrying capacity of vessel. The region is likely to be the source of the equipment damage. Therefore, the detailed research on partial mechanical characteristics and stress concentration factors in the opening nozzle is the indispensable content which ensures the safe operation of the pressure vessel.The pressure vessel with opening nozzle is studied in this article, the actual structure of it is more complicated, so it should be simplified. The structure of the power characteristic, restriction characteristic and geometrical symmetry are considered adequately, partial structure is selected as the calculative model. The model in this article is partial cylindrical shell of the flatting nozzle with the internal pressure.According to the simplified model, the geometrical parameters are confirmed. The parametric common calculation model which is applicable to different size in opening nozzle is compiled by APDL, avoiding the artificial repeat modeling. Then the automatic computer model is achieved and computer-aided engineering problems are analyzed. The efficiency of the finite element analysis is improvedFinite element numerical simulation method is applied and using ANSYS software tool to build the model with the cylinder axis and the nozzle axis in the same plane or not. The model is analysed for the three-dimensional elastic finite element. The SINT clouds are obtained and it studies various factors affecting the stress intensity. Then the maximum SINT and its stress concentration factor are solved. Fitting curves are plotted based on the stress concentration factor data. A swift and effective reference calculation method and calculation figure tools about the structure design and engineering practice of pressure vessel with opening nozzle are provided for the engineers and researchers.