AN INVESTIGATION OF HEAT-TRANSFER PROCESS IN A CHEMICALLY REACTING PACKED-BED

In the present work a numerical simulation of the natural convection p rocess in a chemically reacting packed bed has been carried out. The s imulation has been based on a Galerkin method of finite element formul ation. An investigation of the transient as well as steady state resul ts is presented. The heat source term is represented by an Arrenhius-t ype source term, which typically represents several zero-order chemica l reactions in practice. The ensuing transient process of natural conv ection in the cavity is investigated, and the effect of the temperatur e of the hot boundary on the heat removal capacity is also presented. The critical boundary temperature that will result in the thermal runa way inside the cavity was investigated, and the effect of the boundary temperature on the thermal explosion in the cavity was also analyzed. It was found that the flow field was symmetrical about the vertical c enterline and the temperatures continued increasing away from the hori zontal walls of the cavity, thus giving hot spots in regions removed f rom the horizontal boundaries of the cavity. The transient results pro vided some valuable information in terms of the times required for the evolution of the natural convection process in the cavity.