Optimization of a Reinforced-flat End Cap Through Analytical Study and Genetic Algorithm

An efficient design is a key factor in final expenditure of a certain construction. Pressure vessels are structures that play an indispensable role in different industries such as petroleum, power plants etc. Pressure vessels are receptacles often used to keep gases or liquids at a pressure typically different from what atmospheric pressure is. End caps which close the end of vessels can be formed in  different shapes. Thus, end cap design also has a significant role in the integrity of vessels to prevent fatal accidents that are frequent in the pressure vessel’s history. In this study, an extensive investigation of huge-flat end caps under external pressure was carried out to extract the most efficient geometrical layout. This kind of flat end cap is an essential part of the designed main duct in the Air Cooled Condenser (ACC) systems as a configuration that renders steam to condensed water inside a definite arrangement of finned tubes in a hybrid thermal power plant. To determine an optimized state of stresses considering weight limitation, a number of finite element models were simulated. The simulations were performed in a relatively wide domain of two geometrical variables, namely thickness and height of stiffeners. By constituting a comprehensive data library, an objective function was formed using the results of finite element. The procedure was followed through a genetic algorithm to find an optimized stress state. An analytical study was also accomplished to reach an optimized end cap resulting in the lowest stress level. The findings showed very similar results for the two methods. Furthermore, a profound observation of the influence of two geometrical parameters was conducted in different weight limits. Although this study is based on a particular actual-industrial problem in an implemented power plant, the proposed method and results are applicable to a great number of similar cases.