Characterization of Scaling Laws in Computational Fluid Dynamics Simulations of Spouted Fluidized Beds for Chemical Looping Combustion

摘要

Chemical-looping combustion (CLC) is a next generation combustion technology that has shown great promise in addressing the need for high-efficiency low-cost carbon capture from fossil fueled power plants to address rising carbon emissions. The spouted fluidized bed setup provides several advantages when solid coal is used as fuel for CLC. The Lagrangian particle tracking approach known as the discrete element method (DEM) coupled with a computational fluid dynamics (CFD) solution of the flow field provides an effective means of simulating the behavior of a spouted fluidized bed. However, given the high computing cost of CFD-DEM, it is necessary to develop a scaling methodology based on the principles of dynamic similarity that can be applied to a CFD-DEM simulation to expand the scope of this approach to larger CLC systems up to the industrial scale. In this article, a new scaling methodology based on the terminal velocity is proposed for spouted fluidized beds. Simulations of a laboratory-scale spouted fluidized bed are used to characterize the performance of the new scaling law in comparison with existing scaling laws in the literature. It is shown that the new model improves the accuracy of the simulation results compared to the other scaling methodologies while also providing the largest reduction in the number of particles and in turn in the computing cost of the CFD-DEM simulation.