Hydrodynamic characteristics in the full-loop circulating fluidized bed under load regulation. Part 2: Simulation

The key to improving the load regulation ability of circulating fluidized bed (CFB) units lies in the profound understanding of the hydrodynamic characteristics in the circulation loop. However, most experimental investigations are confined to the pressure and solid volume fraction measurements. To gain insight in the mass balance of the circulation loop under load regulation, the computational particle fluid dynamics (CPFD) method was applied to simulate the dynamic behavior of a CFB test rig at different ‘load’ change rates. After verifying the numerical model with the related experimental data, the transient profile of the solid inventory and solid mass flow rate was investigated. The results showed that the change in the solid inventory mainly happened in the riser and standpipe. In addition, the solid mass flow rate at different axial elevations showed distinct change patterns after an initial period of simultaneously increasing or decreasing.