Predictive Modeling of Gas-Phase Ignition of Products of the Thermal Decomposition of Coal

A predictive mathematical model for estimating the fire hazard presented by the interaction of a mixture of the products of the thermal decomposition of coal with atmospheric air at relatively low (up to 500 K) temperatures is developed. Heat and mass transfer processes are described by the differential equations of thermal conductivity and diffusion as well as by the balance equation of the concentrations of the components of the gas mixture. Exothermic reaction in the zone of the oxidation reaction is described by the Arrhenius equation. The limiting temperature of the medium formed by the oxidizing agent and the ignition delay time corresponding to these temperatures are established as a result of a numerical investigation of the integral characteristics of “low-temperature” ignition of the gaseous products of thermal decomposition of a single particle of coal of low dimensions (50–500 μm). Recommendations for reducing the number of uncontrolled ignitions of coal in the interaction with “low-temperature” flows of air under the conditions of industrial production are formulated.