The 4th International Symposium on Mine Safety Science and Engineering (ISMSSE2018)

326 / 2018-05-04 17:04:57

Micro Initiation Mechanism of Multiple Flammable Gas Explosion

gases explosion;,initiation mechanism;,main reaction path;,emission spectrum characteristics

Mine occupational health and environmental safety > Explosion-proof

To investigate the micromechanism of a multiple flammable gas explosion, CH4, CO, C2H6, C2H4 and H2 were selected to determine the thermodynamic and dynamic characteristics of the gas mixture explosion using Gaussian software. The initiation mechanism and primary initiation pathway of the coupling explosion of the five combustible gases were analysed. A spherical experimental device for gas/dust explosion combined with a spectrum measurement system was implemented to obtain emission spectra of the •H radical and CH2O during the gas mixture explosion process. It was the oxidation reaction of CH4 that initiated the chain reaction for the entire explosive reaction rather than the CO/C2H6/C2H4/H2 mixture at the ignition moment of the explosion. Nevertheless, the addition of the CO/C2H6/C2H4/H2 mixture had obvious effects on the chain-branching reactions of CH4 explosion. The •CH3 radicals produced during methane oxidation induced a hydrogen reaction, and •H radicals generated in the reaction of •CH3 and H2 triggered the involvement of other combustible gases in the explosion reaction, which considerably decreased the activation energy demand by multiple combustible gases to participate in the explosion reaction. The sequence of flammable gases involved in the explosion reaction was CH4, CO, C2H6, C2H4 and H2. Furthermore, the experimental results indicate that the •H radical appeared before CH2O during the explosion reaction process, which is consistent with the numerical simulation results.