Convective and radiative heat loss impact on CO2 emission, O2 depletion and thermal stability in a reactive slab of variable thermal conductivity

Abstract

The impact of convective and radiative heat loss on CO2 emission, O2 depletion and thermal stability in a reactive stockpile of combustible materials is investigated. A rectangular slab of variable thermal conductivity is applied to study the reaction taking place in a stockpile. It is assumed that the slab's surface temperature is uniform throughout. Runge-Kutta-Fehlberg (RKF45) method coupled with shooting technique is applied to solve numerically derived governing equations for heat and mass transfer problem. Nusselt and Sherwood numbers at the material surface are obtained from numerical expressions for temperature fields. Graphical expressions for O2 emission, O2 depletion and temperature behavior are obtained to study and discuss quantitatively the effects of various thermo-physical parameters on CO2, O2 and thermal stability. Thermo-physical parameters that help to reduce CO2 emission and hence O2 preservation, are identified, including those which help spontaneous combustion processes from explosions.