Numerical Simulation of Wood Chip Combustion

Wood combustion is a complex physicochemical process which involves moisture evaporation, solid pyrolysis, component transportation, gas combustion, radiation feedback and turbulent flow. In this work, the combustion of wood was modeled by means of large eddy simulation (LES), considering all the processes mentioned above. The wood mass loss rate and surface temperature of calculation agreed well with experimental data. The influences of moisture, wood slice thickness, activation energy and the size of grid on the simulation performance were investigated in this work. The results show that the increasing of the wood moisture fraction and activation energy could result in serious delay of ignition time. The wood slice thickness has no effect on the wood combustion model, which implies that this model has a good performance in predicting wood combustion. The grid size affects the numerical results seriously at the moment of ignition, while after ignition, coarse grid seems enough.