The research of gas-solid fluidized bed bubbling behavior based on CFD-DEM coupled simulation

Abstract

Fluidized bed is an efficient reactor. For fluidized beds, the changes and bubbling behavior of the bed are important indicators of fluidization quality. Different operating conditions can affect the bed state and bubbling behavior. Moreover, the generation and rupture laws of bubbles under different operating conditions have not been thoroughly studied. Based on the CFD-DEM method, this paper investigates the bubbling behavior and bed state of fluidized beds with different boiler shapes. The simulation results indicate that the inclined fluidized bed has the most significant range of variation and the largest cross-sectional area of bubbles, with a maximum area of 231.76 mm2. The bubbling interface area of the conical fluidized bed without corners is only 83.76 mm2. Smaller bubbles tend to have a larger aspect ratio and a form factor closer to 1. In addition, the merging phenomenon in the early stage of bubble formation makes it more difficult to track the rupture. These results will help improve the contact between gas and solid phases, providing a theoretical basis for improving the performance of fluidized beds.