Numerical study of heat and mass transfer during ignition of thermal decomposition products of a coal particle

Abstract

Abstract. A numerical research was executed for macroscopic regularities determination of heat and mass transfer processes under the conditions of phase transformation and chemical reaction at the ignition of vapour coming from fabrics impregnated by typical combustible liquid into oxidant area at the local power supply. Limit conditions of heterogeneous system "fabric -combustible liquid -oxidant" ignition at the heating of single metal particle was established. Dependences of ignition delay time on temperature and rates of local power source were obtained.The mathematical modeling of interrelated processes of heat and mass transfer and chemical reacting was carried out at ignition of single coal particles with different sizes from 0.05 mm to 0.5 mm in air flow heated to moderate temperatures (T<500 K).A physical model of ignition process describes the more common scheme of investigating phenomena (Figure 1). At the initial time moment (Figure 1) a spherically-shaped coal particle with the radius of r p was put into the oxidized area (air) with temperature higher that the initial temperature of the particle (T g >T 0 ). It was assumed that the heat supply to the solid fuel particle occurs due to the mechanism of radiative and conductive heat transfer on the particle boundary with the surrounding gas area. The a Corresponding author: dmitriyog@tpu.ru