Study On The Performance Of 20L Inert Gas In A Sphere To Suppress The Premixed Explosion Of Methane-ethylene With Air

The spontaneous combustion of coal in goaf may produce ethylene and other gases,which seriously affects the concentration limit of gas explosion and easily induces gas explosion accidents,posing a great threat to the safety production of coal mines.In order to prevent and control methane/ethylene mixture explosion accidents,it is necessary to study the effects of carbon dioxide and nitrogen on methane/ethylene mixture explosion characteristics from the perspective of explosion prevention and explosion suppression safety.This paper use the methods of theoretical analysis,numerical simulation and experimental research,studies the different proportion and equivalent methane/ethane explosion properties,inert gas carbon/nitrogen mixture the different proportion and equivalent methane/ethylene explosion properties,inert gas carbon/nitrogen mixture the different proportion and equivalent methane/ethylene mixture explosion chemical reaction kinetics,The kinetic parameters such as reaction and sensitivity of key elements in gas combustion process were obtained.The main contents and achievements are as follows:Firstly,relevant explosion suppression experiments were carried out in the 20L explosive ball experimental system.The results show that the explosion time decreases with the increase of ethylene ratio in both lean fuel combustion and rich fuel combustion.For different combustible gas mixtures,the three parameters of explosion pressure time are minimum when the equivalent ratio is 1.2.For all tested mixtures,the amount of heat loss per unit area decreased as the ethylene volume ratio increased at each equivalent ratio.When the equivalent ratio is 1 and R is 0.1,the heat loss fraction of methane-ethylene mixture explosion is 40.5%,and when R is 0.9,the heat loss fraction is only 7.2%.At each equivalent ratio,the heat loss fraction decreases with the increase of the ethylene volume ratio.When the equivalent ratio is 1.2,the heat loss fraction of the combustible gas body is the smallest,and the use of ethylene rich methane combustion is more efficient.Adding inert gas nitrogen or carbon dioxide can effectively reduce the explosive intensity of methane/ethylene mixture.Under the same equivalent ratio,the increase of inert gas can significantly slow down the rapid combustion time and combustion duration in the explosion process,and the effect of adding equal volume of carbon dioxide is better than that of nitrogen.Secondly,the chemkin-Pro software was used to build the GRI 3.0 kinetic model and analyze the combustion process of methane/ethylene mixture under the same experimental conditions.The results showed that when the ethylene ratio increased from0.1 to 0.9,the maximum formation rate of OH group increased slightly by 5%,and the volume fraction of inert gas CO₂/N₂ increased,and the formation rate of OH group decreased significantly.When 25%CO₂ was added,the maximum formation rate of OH group decreased by 81.6%.When 25%N₂ was added,the maximum formation rate of OH group decreased by 81.6%.The maximum formation rate of OH group decreased by64.7%.Both nitrogen and carbon dioxide have physical inhibition effect,and CO₂molecule also participates in the chain reaction through the elemental reaction H+CO₂=OH+CO.Consumption of large amounts of hydrogen radicals,while producing carbon monoxide,leads to incomplete combustion of methane.It greatly reduces the reaction rate of H+O₂=OH+O,and inhibits the explosion from the perspective of chemical reaction.The sensitivity analysis shows that the reaction steps promoting the explosion process are R38,R112,R119,R164,R285 and R294.With the increase of the volume fraction of inert gas CO₂/N₂,the sensitivity coefficients of the promoting elemental reactions decrease.The accelerative sensitivity coefficient with the same volume fraction of carbon dioxide was smaller than that with nitrogen.When equivalent ratio is 1,the sensitivity coefficient of each reaction is the largest,and the sensitivity coefficient decreases less than when equivalent ratio is 0.8 and equivalent ratio is 1.2,indicating that it is the most difficult to suppress combustion.N₂/CO₂ does not change the reaction rate of the key element,and the inert inhibition effect is achieved by reducing the reaction rate of the key element.Figure[37]Table[14]Reference[112]...