Predicting cold gas-solid flow in a pilot-scale dual-circulating fluidized bed: Validation of computational particle fluid dynamics model

Abstract

This study uses the Eulerian-Lagrangian multiphase particle-in-cell (MP-PIC) approach, adopted in the computational particle fluid dynamics (CPFD) code, Barracuda VR®, to simulate a cold-flow dual-circulating fluidized bed. The hydrodynamics is simulated using a novel segregated approach, in which the experimental solids circulation rate is specified as an input parameter. CPFD predictions of pressures and particle concentration distributions are compared with experimental results for varying bed material circulation rate of 76–153 kg/m2s and superficial gas velocity in the reactor riser from 3.3 m/s to 6.4 m/s. Overall trends in these quantities are well captured by the model. Detailed sensitivity studies of the reactor riser are carried out using a riser-only approach with a fixed bed mass inventory. Apart from the drag model selection, the pressure constant Ps and the exponent β of the MP-PIC particle stress model are found to have the greatest influence on the fluidization behavior and on the predicted solids flux.