A Parametric Study of the Insulation Thickness and the Emissivity of the Reflector during the Billet Transport

Abstract

An investigation of the effect of the insulation thickness and the emissivity of the stainless steel reflector of the covering material during the billet transport on the amount of saving energy is presented.  A mathematical model of the heat transfer from the billet through the covering material to the environment is developed.  The fully implicit scheme of finite difference equations is employed.  The numerical solution is obtained by using the linearization technique.  The results are presented in terms of a parametric study of the average temperature of the billet and the amount of saving energy.  The data from field measurement is used to verify the numerical result in case of the billet transport without the covering material.  A good agreement is observed between those two.  As the insulation thickness increases, the temperature drop of the billet during the transport decreases due to the lower heat loss to the environment.  This result leads to increasing of the amount of saving energy increases from 219.7 to 272.5 MJ as the insulation thickness increases from 12.5 to 50 mm.  As the emissivity of the stainless steel reflector increases, the temperature drop of the billet during the transport increases, corresponding to the decreasing amount of saving energy.  In case of the 12.5-mm insulation thickness, the effect of the emissivity on both temperature drop and the amount of saving energy is observed when the emissivity is lower than 0.3.  The effect of the emissivity on those two is less significant when the insulation thickness reaches 50 mm.  The amount of energy saving is approximately 273 MJ regardless of the emissivity of the stainless steel reflector.