Study On Explosion Suppression Characteristics Of Various Fire Extinguishing Agents In Gas Explosion

In order to explore the influence of various inhibitors on the flame spread of gas explosions,an active explosion suppression system capable of detecting flames and spraying inhibitors was designed.The system is mainly composed of five sub-systems:piping system,inflation system,ignition system,anti-explosion system and acquisition system.According to the requirements of experimental conditions,the system is designed to collect and record the pressure change process,flame propagation process and other relevant data involved in the experiment.After the methane explosion occurs in the pipeline,the active anti-explosion device is turned on,the inhibitor sprays out and forms a suppression extinguishing area,which forms a continuous suppression effect on the explosion flame and finally realizes the prevention of the explosion flame propagation.Different explosion flame propagation laws are obtained by changing the gas type,and then cooperate with ABC dry powder fire extinguishing agent to study the anti-explosion effect on gas explosion propagation.In addition,on the self-designed pipeline platform,by changing the amount of perfluorohexanone and the pressure of CO₂and N₂to study the synergistic effect of perfluorohexanone and CO₂and N₂on gas explosion flame suppression,and qualitatively and quantify this analyze.Through experiments,it is found that injecting pure methane gas,nitrogen,carbon dioxide and 9.5%premixed methane into the pipeline will reduce the speed of gas explosion flame,among which pure methane gas has the best inhibition effect,reducing the speed of explosion flame by 24.5%.The analysis of the explosion overpressure curve shows that pure methane gas has a stronger inhibitory effect on the explosion overpressure than carbon dioxide and nitrogen.Under the deceleration suppression effect of pure methane,the explosion flame can be extinguished with less ABC dry powder downstream,and it is easier to achieve explosion suppression.Through the analysis of the explosion suppression reaction mechanism of pure methane,it is found that pure methane not only strongly inhibits and blocks the free radicals produced by hydrocarbon fuel,but also inhibits the free radicals produced by oxygen,indicating that the injection of pure methane has a stronger explosion suppression effect than carbon dioxide.By studying the influence of perfluorohexanone and CO₂gas on the propagation process of gas explosions,it is found that CO₂and N₂cannot achieve explosion suppression alone,while C₆F₁₂O can achieve explosion suppression alone.Perfluorohexanone mixed with a certain pressure of CO₂or N₂to spray is conducive to the complete vaporization of perfluorohexanone and enhance its ability to inhibit explosion.When the pressure of CO₂gas is 1.1MPa,the perfluorohexanone required to extinguish the flame The dosage is 78.3%lower than that of using perfluorohexanone alone to extinguish the flame.At this time,the synergistic inhibitory effect of perfluorohexanone and CO₂gas on the explosion flame just achieves the best effect.The combination of perfluorohexanone and CO₂has a stronger effect on reducing the second peak of overpressure than the combination of N₂and perfluorohexanone.The chemical inhibition mechanism of perfluorohexanone is that it decomposes at high temperature to produce a large amount of CF₃,C₃F₇and F free radicals,which preferentially combine with the O,H,and OH free radicals generated by the premixed gas,thereby inhibiting and preventing the explosion reaction.