COMPUTATIONAL AND EXPERIMENTAL STUDY OF THE THERMAL PROCESS IN AN INDIVIDUAL CYLINDRICAL PARTICLE

Abstract

he paper proposes a one-dimensional mathematical model of thermal conductivity in a cylinder under conditions of convective heat exchange with an external gas medium based on the difference formulation of Fourier's law of thermal conductivity. Parametric identification was per-formed for the proposed model based on the use of known data and empirical regularities for the material constants of the process. The mentioned data made it possible to adapt a mathematical model to describe the process of heat treatment of granular fuel particles. The verification of the operability of the physical and mathematical model proposed in this way was performed by com-paring the calculated forecasts obtained with the data of a full-scale experiment. For a full-scale experiment fuel particles were prepared in such a way that thermocouple junctions were placed attwo points inside each of them. The presence of thermocouple junctions directly inside the particles made it possible to fix local temperature values of the material during its heat treatment. Particles with thermocouples were placed in the apparatus withthe active hydrodynamic regime of a heating gas medium. Thus, during the computational and experimental study, kinetic characteristics of heating thermally massive cylindrical bodies were obtained under three different hydrodynamic regimes. The calculatedforecasts and experimental data are in good agreement for engineering calculations, which indicates sufficient predictive effectiveness of the proposed physical and math-ematical model and makes it possible to consider it as a reliable basis for constructing computer methods for calculating heat transfer processes. The proposed mathematical model can also serve as an element for assembling more complex discrete models of heat and mass transfer processes in a single particle and/or models of the functioning of technological equipment for heat treat-ment of bulk media.