Char Oxidation Model Validation in Detailed Coal Simulations

Abstract

Abstract The controlling mechanisms governing the amount of unburned carbon in fly ash from practical pulverized coal combustion systems have been studied by incorporating elements of the carbon burnout kinetic model (CBK) proposed by Hurt et al. in a computational fluid dynamics based combustion, cfd, simulator. An experimental data set from The International Flame Research Foundation are compared to evaluate mechanistic variations in the carbon burnout processes. Simulation results comparing total exit LOI (defined as the residual weight of carbon in the ash) and centerline carbon burnout indicates that use of a char oxidation submodel, including the effects of a statistical reactivity distribution, thermal annealing of active oxidation sites and a developing ash film resistance layer, is necessary to predict experimentally measured exit LOI and centerline burnout profiles.