01-11-2014, 03:58 PM
Abstracts: In the present era of super technology, demands of high pressure to ultra high pressure vessel are increasing. To sustain high pressure and high temperature, high strength vessels are required. With increasing of pressure, thickness of the vessel is also increasing, which ultimately lead to increasing weight of the vessel and creates problems related with it. The design of support for these types of vessels is very critical. Generally these vessels are supported with skirt. It is well recognized that a excessive temperature gradient from the junction of head to skirt in axial direction in a hot pressure vessel can cause unpredicted high thermal stress at the junction and/or in axial direction of a skirt. This thermal stress resulting from axial thermal gradient maybe a major cause of unsoundness of structural integrity. In case of cyclic operation of hot pressure vessels, the thermal stress becomes one of the primary design considerations because of the possibility of fracture .as a result of cyclic thermal fatigue and progressively incremental plastic deformation. To perform thermal stress analysis of the junction and cylindrical skirt of a vessel, or, at least, to inspect quantitatively the magnitude and effect of thermal stress, the temperature profile of the vessel and skirt must be known. This project is to study the temperature distribution and thermal stresses at the skirt to head junction using Finite Element Analysis method and Ansys as a software tool. No direct method or theoretical formula is available so as to predict the thermal stresses or the temperature distribution. Hence Finite Element Analysis method is adopted to study the affected zone. Effect of air pocket length and forming radius in enclosed space formed by the Vessel &Insulation (hotbox) is to be investigated so as to minimize the temperature gradient causing the thermal stress in axial direction.