Thermal DEM-CFD modeling and simulation of heat transfer through packed bed

摘要

Heat transfer between particles takes place in a variety of industrial applications, but because of the stress and contact heterogeneities inherent to these applications, it is poorly understood, even in simple cases. Although particle-particle heat transfer is relatively weak compared with particle-fluid convection heat transfer, it may become very important in applications such as packed beds, where the fluid flow can be neglected or where fluid/particle stagnation areas can be observed. During our previous studies, CFD-DEM models and numerical simulations were developed to account for momentum and heat transfer between the fluid and the solid particles. The predictions of the simulations were validated with experimental data. In the present study, particle-particle and particle-wall heat transfer models were developed and integrated into our in-house unsteady three-dimensional discrete element method (DEM) software. Heat transfer simulations for predicting the effective thermal conductivity (ETC) of particulate beds under compression were conducted to validate these models with published experimental data. The results showed good agreement with the experimental data, and it was found that heat conduction through the bed's pores cannot be neglected even when particle thermal conductivity is much larger than that of the air. The influence of particle roughness on heat transfer through packed bed was examined. It was found that heat conduction through the packed bed pores cannot be neglected for rough particles.