Abstract

In this paper, the transient heating in a stockpile of combustible material due to an exothermic reaction in the presence of convective heat loss to the ambient is analyzed. The transient heating in a slab due to an exothermic chemical reaction with the possibility of heat loss to the ambient is considered. The chemistry involved in the problem is simplified by assuming a one-step finite-rate irreversible Arrhenius kinetics. By introducing dimensionless variables into the equations, the governing nonlinear partial differential equations are solved numerically by method of lines (MOL), with finite difference schemes used for the discretisation of the spatial derivatives. Graphical results are presented and discussed quantitatively with respect to various embedded parameters controlling the systems. The results reveal that among others, the slab temperature increases gradually with time for a given set of parameters value until the steady state is achieved. The slab temperature is highest during bimolecular reaction in comparison to Arrhenius and sensitized types of chemical reaction. Moreover, an increase in the heat loss to the ambient enhances thermal stability of the system.

Key words: Transient heating, Arrhenius kinetics, variables.