(172f) Particle Scale Modelling and Analysis of Fluid Flow and Heat Transfer in Fluidised Beds

Fluidised beds are widely used in industries due to their high heat transfer efficiency. To achieve optimal design and control of such a fluid bed reactor, it is important to understand the flow and heat transfer characteristics at different time and length scales. A lof of work has been done in the past. In recent years, particle scale simulation, based on the combined method of computatinal fluid dynamics (CFD) for fluid phase and discrete element method (DEM) for discrete particles, has been extended to study the fundamentals governing this complicated fluid flow and heat transfer system. With this approach, microscopic information such as particle-particle or particle-wall contact, local voidage and local gas-solid flow structure can be produced, and then different heat transfer mechanisms such as particle-fluid convection, particle-particle conduction, and particle radiation can be implemented. This talk will provide an overview of the work in this direction, covering the model development, validation, and application. The usefulness of this CFD-DEM approach will be demonstrated through a few representative case studies. The need for further studies is also discussed.