Simulation of the process of coal dust ignition in the presence of metal particles

A mathematical model was developed for the gas-phase ignition of a layer of the dust of typical 2B brown coal by a metal particle heated to high temperatures (above 1100 K) under ideal thermal contact conditions. This model took into account the heating and thermal decomposition of ground coal upon the cooling of a local source, the yield of volatile components, and the formation, heating, and ignition of the gas mixture. The effect of heat source parameters (shape and dimensions) on the fundamental process characteristic—the delay time of ignition—was found. A relationship of the ignition zone position near a hot particle with the heating intensity of a gas mixture of volatile substances and an oxidizing agent was revealed. The results of numerical studies are consistent with well-known experimental data on the conditions and characteristics of ground coal burning on local heating by sources of limited energy capacity.