Analysis of Thermal Diffusivity Evaluation under Transient Conditions for Powder Insulations

Abstract

When an insulated vessel at ambient temperature is filled with a cryogenic liquid, considerable time elapses before the rate of heat transfer to the liquid reaches a steady-state value. Thus, the design of such vessels requires an analysis of the cooldown characteristics of the insulation which are governed by the thermal diffusivity of the insulating material. Blanks and Timmerhaus [¹] have called attention to the fact that, although the steady-state heat leak can always be reduced by increasing the amount of insulation, the optimum design of a storage vessel for minimum liquid loss must consider the cooldown time because in many practical situations, e.g., transfer lines, the heat transfer process never reaches the steady-state condition.