Computational analysis of heat transport and storage processes in large-volume isothermal heat flow calorimeter

Abstract

Isothermal heat flow calorimeters for large-volume applications are utilized for monitoring heat generation in highly inhomogeneous systems mostly. However, the time delay of measured data caused by internal heat inertia limits their effective use to slower processes. In this paper, a computational analysis of heat transport and storage processes in a large-volume isothermal heat flow calorimeter is presented. Using a three dimensional computational representation of the real device, thermal processes occurring in the calorimeter-sample system are simulated and the time delay between the generation of internal heat and its subsequent detection is identified. The computational model is calibrated at first, using four different constant heat power pulses, and then verified in an independent heat power scheme. The comparison of experimental and computational outputs shows a very high level of agreement, R2=0.9998, which gives the applied modeling approach good prerequisites for successful practical applications. Apparently, the computational model introduced in this paper is able to provide higher accuracy than common mathematical corrections of experimental outputs that have been used so far.