Heat transfer analysis of thermal barrier in high temperature fluid vessel

Abstract

High temperature fluid storage and handling vessels require to maintain large temperature gradient between the fluid surfaces to top of the vessel. This is achieved by the usage of baffle plates. High temperature failure modes such as ratcheting, creep and fatigue damage, mainly under thermal loadings, decide the vessel life. Tests are conducted in high temperature fluid test vessels on models of shells subjecting them to axially varying temperature gradients to simulate thermal ratcheting which affects the free level variations vessels facing high temperature fluid. Baffle plates are used to maintain the temperature on of the surface of the test vessel below 100 degrees centigrade. The transfer of heat through radiation is contained through the baffle plates. The heat transfer analysis of the baffle plates gives clues of the number of baffle plates required to maintain the top surface in the required temperature. The objective of the project is to design the thermal barrier using baffle plates. The initial calculation of required baffle plates is done using theoretical method available in literature. A computer program is developed to perform similar calculations for various calculations with different parameters of design. Theoretical analysis only considers radiation mode of heat transfer which is the predominant mode of heat transfer where high temperatures are present. But in reality both conduction and convection plays a role in heat transfer. At the same time multimode heat transfer is very complex for theoretical analysis. Hence, Finite element method is used to analyze to improve the design of the baffle plate arrangement.