Numerical research of heat and mass transfer during low-temperature ignition of a coal particle

Abstract

Numerical researches have been carried out to study the influence of air flow temperature and a fossil fuel particle rate on sufficient conditions of ignition in a "coal particle - air" system. Developed mathematical model takes into account interconnected processes of heat transfer in a coal particle and gas area, thermal decomposition of organic material, diffusion and gas-phase oxidation of volatiles, heating of a coke (carbon) and its heterogeneous ignition. The effect of low-temperature (about 600 K) ignition for a single coal particle is impossible even at variation of its rate (radius) from 0.05 mm to 0.5 mm. Nevertheless this process is possible for group of particles (two, three, et al.) situated at close-range from each other. The physical aspects of the problem are discussed.