Mathematical modeling of wood-coal pellet ignition in combined heating

The article presents the results of mathematical modeling of the ignition process of fuel pellets based on coal and biomass under high-temperature combined radiation-convective-microwave heating in an oxidizing environment. A new mathematical model of the ignition process of a composite fuel particle is presented, which differs from the known ones by a complete description of the entire complex of thermophysical, physicochemical and electrophysical processes occurring during ignition of wood-coal pellets under conditions of radiation-convective and microwave heating. The mathematical model was tested by comparative analysis of theoretical and experimental values of ignition delay times. According to the results of numerical modeling, it was found that the ignition process of fuel (composite fuels based on coal and biomass) pellets occurs in the gas phase (in the near-wall zone of the fuel pellet). At the same time, oxygen released during thermal decomposition of coal is not enough for stable ignition in the pore space of the fuel particle. For the first time, the prospects of using microwave energy for the purpose of illuminating the main fuel torch have been substantiated based on the results of theoretical studies.