| In order to study the effect of metal explosion suppression materials on different flammable alkane gases,the inhibition mechanism of different explosion suppression materials on hydrocarbon explosions was analyzed.In the self-designed closed pipeline,the explosion experiments of different types of metal explosion suppression materials against premixed hydrocarbon gases are carried out.The pressure change law is tested by the transient pressure acquisition system,the explosion products are qualitatively and quantitatively analyzed by gas chromatography.The suppression mechanism of the metal explosion suppression materials to the alkane gas is derived by using the Chemkin-Pro software combined with the experimental parameters of the explosion to analyze the reaction of the key intermediate free radicals.It can be seen from the explosion experiment results that the suppression effect of magnetic iron wire and nickel wire is better than nonmagnetic copper wire,aluminum wire,and expanded aluminum material,which effectively reduces the rate of overpressure rise.Among them,the suppression effect of iron wire is the best,copper wire is better than aluminum material,aluminum wire and expanded aluminum material are relatively close.In contrast with alkanes,expanded aluminum material have no obvious suppression effect on ethylene gas,which is mainly due to the existence of carbon-carbon double bond of ethylene molecules resulting in the free radical reaction mechanism of gas explosion is very different from the alkanes.It can be seen from the analysis of the explosion products that after filling the explosion suppression materials,the content of carbon monoxide and carbon dioxide in the explosion product components was significantly reduced,and the inhibition effect of aluminum alloy was the strongest,followed by iron wire and aluminum wire.The iron wire promotes the generation of more hydrocarbon substances,especially the hydrocarbon products generated by the participation of methyl radicals,such as butane and isopentane with larger molecular weight,and at the same time promotes the generation of ethylene,ethane,proparyne,etc.Under the condition of expanded aluminum material,the types of hydrocarbon generation are obviously reduced.Expanded aluminum material inhibits the formation of methane more strongly,aluminum wire inhibits the formation of propylene more strongly,and promotes the formation of acetylene.It can be seen from the explosion reaction mechanism research that the Chemkin-Pro is used to simulate the reaction rate and sensitivity of the products and analyze theirs main reaction paths.Combined with the characteristics of explosion pressure and the composition of explosion products,it was consider that the filling of metal explosion suppression materials significantly promote the collision probability between free radicals and materials,accelerate their destruction,promote the wall effect to effectively inhibit the formation of ·H,·O,and ·OH,promote the formation of free radicals such as methyl and the gas phase destruction reaction,and finally lead to the decrease of exothermic reaction in the explosion elementary reaction.This positive feedback mechanism further increases the generation of hydrocarbon substances and reduce the heat generated by oxidation.Finally,the explosion reaction is terminated when the energy is insufficient to further trigger the requirement of the bond breaking ability of hydrocarbon substances.The results of mechanism study show that the ability of ferromagnetic metal to destruct ·H,·O,·OH and promote the chain termination reaction of methyl and ethyl is stronger than that of non-magnetic material.The inhibition of expanded aluminum material on chain initiation and chain transfer reaction is better than that of aluminum wire,mainly because it has the strongest ability to consume ·OH and promotes the formation of isopropyl. |
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