Optimum insulation models for one dimensional steady state heating

Abstract

Theoretical analysis of parameters related to the critical and optimum insulation models were carried out. Analytical and computational models were developed for one-dimensional steady state heat transfer units to be used in industries. Finite horizontal air plate element is idealized for the heating section and basic heat transfer analysis is applied in the rectangular and radial heating units. Critical and optimum insulation thicknesses were modeled for plane walls and radial systems. Graphics analysis showed the hyperbolic response of insulation thickness with heat loss and the infinite heat loss as the insulation decreased. The critical and optimum models developed for plane walls and cylinders show critical insulation thickness of heat transfer surfaces as a function of the convective heat transfer coefficient of fluid surrounding the external walls of insulation (ambient air) and the thermal conductivity of insulating material. While the optimum insulation thickness is a function of thermal conductivity of insulating material, the convective heat transfer coefficient of out side air as well as the thermal gradient ratio, dependent on the temperature difference between the walls of the insulation and the temperature gradient between the outer walls of insulation and the external air. Insulation models were developed for fiberglass and asbestos and the predictions of the models compared favourably with analytically derived data.