Energy transfer mechanism of coal dust explosion based on the reactivity of gaseous products

NIE Baisheng; MA Xinyu; ZHAO Dan; ZHANG Hao; YAN Hongwei; CHANG Li; LIU Xianfeng; HE Xueqiu

doi:10.13247/j.cnki.jcumt.20250505

Abstract：The typical complex multiphase flow disasters of coal dust explosions pose a persis-tent and significant threat to national energy stability and development.In-depth research on the chain reaction and energy transfer mechanism of coal dust explosions is crucial for maintai-ning the efficient operation of the energy supply chain and promoting the safe development of the coal industry.This study reviewed the current status of coal dust explosions and the char-acteristics of gaseous products,and clarified the early pyrolysis fracture sites of coal macro-molecules while quantifying bond energy distribution.From the perspective of chemical kinet-ics,the main reaction paths and key free radical evolution laws of volatile gas in coal dust ex-plosion were expounded.The energy transfer framework based on the axial partition and radial stratification of the explosion cavity was proposed,and the spatial non-uniformity mechanism of heat and mass transfer and energy accumulation in the multi-phase medium during the ex-plosion process was revealed.The macroscopic and microscopic full-chain system from molecu-lar bond fracture to system energy release was constructed,and the influence of chain reaction on the initiation,expansion and termination of the explosion was clarified.The results show that coal dust explosions originate from the instantaneous high-temperature pyrolysis of pul-verized coal particles,and its essence can be regarded as a composite reaction system driven by solid-phase pyrolysis and dominated by gas-phase explosion.Under the influence of an external heat source,the C—C bonds of the aliphatic side chains connecting aromatic clusters in the en-ergy-optimized coal macromolecular structure are the preferred initiation sites for pyrolysis breakage.The combustible gas film formed by the escape of volatile components and free radi-cals form a chain exothermic cycle by radiation heating adjacent unburned particles,which di-rectly drives the explosion reaction to diffuse rapidly from point to surface.The axial partition and radial stratification in the explosion cavity cause energy and matter to be concentrated and transported along preferential channels with low impedance or strong drive,resulting in the heat release and energy accumulation of chemical reaction highly concentrated in localized are-as,aggravating the instability of the system and intensifying the formation of destructive shock waves.This study provides theoretical support for the risk assessment of coal dust explosion and the formulation of prevention and control strategies.