Online-CPD-Coupled Large-Eddy Simulation of Pulverized-Coal Pyrolysis in a Hot Turbulent Nitrogen Jet

The pyrolysis characteristics of pulverized-coal particles in a hot turbulent nitrogen jet were investigated using large-eddy simulation (LES). In the present study an advanced pyrolysis model, the chemical percolation devolatilization (CPD) model, has been incorporated into LES in real time. The simulation results of the developed online-CPD-coupled LES were used to calibrate the kinetic parameters of the conventional single first-order reaction model (SFOM). Through the comparison between the CPD-coupled LES and the LES using the SFOM model, the CPD-coupled LES approach is found to be able to give a better prediction on particle pyrolysis in the high-temperature turbulent flow. Finally, the effects of important parameters, including the particle diameter, coal type, coal-feeding rate, carrier-phase velocity, and pyrolysis temperature, on the pulverized-coal pyrolysis process were investigated through parametric studies using the online-CPD-coupled LES method.