3D full-loop simulation and experimental verification of gas–solid flow hydrodynamics in a dense circulating fluidized bed

Abstract

Because of their advantages of high efficiency and low cost, numerical research methods for large-scale circulating fluidized bed (CFB) apparatus are gaining ever more importance. This article presents a numerical study of gas–solid flow dynamics using the Eulerian granular multiphase model with a drag coefficient correction based on the energy-minimization multi-scale (EMMS) model. A three-dimensional, full-loop, time-dependent simulation of the hydrodynamics of a dense CFB apparatus is performed. The process parameters (e.g., operating and initial conditions) are provided in accordance with the real experiment to enhance the accuracy of the simulation. The axial profiles of the averaged solid volume fractions and the solids flux at the outlet of the cyclone are in reasonable agreement with experimental data, thereby verifying the applicability of the mathematical and physical models. As a result, the streamline in the riser and standpipe as well as the solids distribution contours at the cross sections is analyzed. Computational fluid dynamics (CFD) serves as a basis for CFB modeling to help resolve certain issues long in dispute but difficult to address experimentally. The results of this study provide the basis of a general approach to describing dynamic simulations of gas–solid flows.