Numerical simulation of pulverized coal jet flame employing the TDP model

Abstract

The effect of the devolatilization model on the coal particle behavior is investigated in detail by performing numerical simulations of a simple pulverized coal jet flame formed by a small jet burner (0.5kg-coal/h) [S. Hwang et al., Energy & Fuels 2005;19:382–92]. As the devolatilization model, widely-used conventional devolatilization model, two competing reaction rate model and newly-proposed tabulated-devolatilization-process model (TDP model) [N. Hashimoto et al., Combust Flame 2012;159:353–366] are used. The results show that the coal particle velocities predicted by the TDP model are in better agreement with the experiments than those by the other models, with a slight increase in computation time. The difference in the mean axial particle velocity between the simulations is caused by the difference in the axial gas velocity, which is ultimately caused by the difference in the volatile matter evolution rate. It is also found that the devolatilization model has great influence on particle velocity prediction compared to the turbulence model, the gas-phase combustion model and the radiation model.