A multi-fluid model for simulating turbulent gas–particle flow and pulverized coal combustion

Based on the pure two-fluid model for turbulent reacting gas–particle flows with combusting pulverized coal particles, a new comprehensive model for pulverized coal combustion was developed by incorporating a modified k–ϵ–kp model, a general model of pulverized coal devolatilization and a general model of char combustion. Both gas-phase and particle-phase conservation equations are described using Eulerian coordinates, and these equations are discretized and integrated in the computational cell. As the first stage of numerical modeling of pulverized coal combustion in the cyclone furnace, three-dimensional simulation of turbulent gas combustion and gas–particle flows has been made. The predicted results show that there is a near wall recirculating zone at the bottom of the cyclone furnace, and the recirculating zone enhances ignition and flame stabilization. The predicted tangential velocity distribution of both the gas phase and the particle phase similar to those of the Rankine vortex.