Numerical investigation of the effect of the heterogeneous reaction model on the thermal behavior of pulverized coal combustion

To achieve high efficiency in pulverized coal combustion furnace and burner, the detailed estimation of the burn-off time and thermal behavior of pulverized coal particles is important. The volume reaction and unreacted core models have been employed as solid-gas reaction model for a pulverized coal particle. Moreover, the possibility that the heat of reaction generated on the particle surface does not fully contribute as heating source to the coal particle should be considered. In this study, the heat and mass transfer around a single pulverized coal char particle exposed to a simplified heating environment are numerically analyzed to investigate the influence of the different coal ranks in their reactivity, coal char particle diameter, and reaction models for the burn-off time and thermal behavior of the pulverized coal particle. From the sensitivity analysis of the reaction models for the burn-off time, the importance of model selection when dealing the coal char particle with high reaction rates is indicated.