Mathematical modelling of low-temperature ignition of small-sized coal particles

Physical and predictive mathematical models of small-sized coal particles ignition in the conditions of rather low temperatures (less than 500 K) were developed. The model considers the interconnected processes of heat transfer in a particle and surrounding gas area, thermal decomposition of coal, diffusion of coal decomposition products (volatile components) and its oxidation reaction, warming of coke part (carbon) and its heterogeneous ignition. Mechanisms of volatile components gas-phase ignition and coke part of a coal particle heterogeneous ignition were investigated. The limit conditions for possible ignition of coal dust particles at rather low temperatures were determined according to the results of the executed numerical modeling. Approximating mathematical expressions for forecasting of low-temperature ignition characteristics of coal particles at the objects of industrial power engineering were formulated.