Temperature Distribution in a Counterflow Moving Bed Under a Thermal Nonequilibrium Condition

Abstract

This work investigates the influence of physical properties on heat transfer between solid and fluid phases in a moving porous bed, in which the working fluid flows in the opposite direction with respect to the permeable medium. A two-energy equation model is applied in addition to a macroscopic mechanical model for laminar flow. Transport equations are discretized using the control-volume method and the system of algebraic equations is relaxed via the SIMPLE algorithm. The effects on inter-phase heat transfer due to variation of Reynolds number, solid-to-fluid velocity ratio, solid-to-fluid thermal capacity ratio, permeability, porosity, and solid-to-fluid thermal conductivity ratio are analyzed. Results for a counterflow moving bed indicate that motion of solid material, contrary to the direction of the fluid, enhances heat transfer between phases. The same effect was observed for smaller Darcy numbers and porosity, as well as for higher solid-to-fluid thermal capacity and thermal conductivity ratios.