Transient temperature evolution of pulverized coal cloud deflagration in a methane–oxygen atmosphere

Pulverized coal cloud deflagration in a methane–oxygen atmosphere is a fairly intricate process owing to transient turbulent combustion accompanied by gas–particle premix flow. We developed a comprehensive computational fluid dynamics model that considers gas–solid two-phase flow, interaction between gaseous and discrete coal particles, and homogeneous–heterogeneous reactions. Numerical results revealed nonconforming and random particle temperature at different instants. The temperature threshold and distribution of high-temperature particles were quantitatively and qualitatively analyzed using the simulation results. Particle accumulation and agglomeration reported for previous experiments was verified and interpreted using turbulence theory. In addition, we analyzed the coupling and heat-mass transfer between coal particles and gas. This investigation has yielded the detailed mechanism of heat transfer for a dust explosion and provided valuable information for prediction, precaution, and control of an explosion involving discrete particles.