Study On The Influence Of Ignition Source On N₂ Inert And Inhibit Methane Explosion

Mine methane explosion poses a serious threat to mine safety production and disaster relief,one of the major causes of the explosion is the fire source that can ignite methane,the research results of complex gas explosion in the mine are abundant at present.However The research of ignition source characteristics is mainly concerned with the influence of ignition energy,the related researches are conducted by using spark ignition source,and the ignition research of non-electric ignition source is less.Therefore,this paper adopts the ignition mode of hot reservoir,analyze the effect of nitrogen on the methane explosion by comparing the ignition of spark ignition.Paper first calculate the ignition energy of pulse ignition and the hot reservoir,two kind of ignition source is a surface area of about 10mm2 cylinder,the ignition duration is about 400ms.The ignition,mode of hot reservoir is to continuously heat the nickel chrome wire,and the ignition energy is 8.7J.The ignition mode of the electric ignition source is the electronic pulse ignition,and the ignition energy is 0.4J.It is found that,compared to electric ignition,the area of the first area of the methane explosion triangle decreases as a whole when hot reservoir is ignited.This is a direct reflection that is change of the explosion limit and the critical oxygen concentration.The critical oxygen concentration of hot reservoir moves to the upper-left.The corresponding N₂ concentration,asphyxia ratio and the risk of methane explosion is reduced.Therefore,the use of hot reservoir ignition will enhance the explosion suppression effect of N₂.When igniteing by th pulse ignition and the hot reservoir,The change trend of the maximum explosion pressure,maximum explosion pressure rise rate and Initial flame propagation rate of different concentrations CH₄-N₂ is the same,all of them increase and then decrease with the increase of CH₄ concentration.And there are obvious differences when the concentration of methane gets closer to the upper limit,The decline range of the maximum explosion pressure,maximum explosion pressure rise rate and Initial flame propagation rate increase by the hot reservoir.The time of maximum explosion pressure and maximum explosion pressure rise rate are also gradually extended.When the methane concentration of 10%or higher,compared to pulse ignition,hot reservoir,the ignition condition of nitrogen inerting the maximum explosion pressure of methane to early,the maximum explosion pressure rise rate and combustion flame propagation rate is bigger,the influence of the inhibition effect is more apparent.The increase of nitrogen concentration in the methane explosion experiment is only applied to the reactants.There is no obvious effect on the pulse ignition and the hot reservoir.When igniteing by th pulse ignition and the hot reservoir,The ignition lag of different concentrations of methane-nitrogen mixed gas at the ignition state of electric ignition is 0.8ms?4.2ms,The ignition lag of different concentrations of methane-nitrogen mixed gas at high temperature heat source is 13ms?77ms.The ignition lag of the ignition of hot reservoir is far greater than that of the ignition of pulse ignition.At the same time,there is a significant difference between the variation trend of ignition lag by the pulse ignition and the hot reservoir respectively.Under the ignition condition of pulse ignition,The ignition lag of pure methane decreases with the increase of methane concentration.Under the ignition condition of hot reservoir,The ignition lag increases significantly when the concentration of methane reaches its limit,the other concentrations don't change much.The variation trend of the ignition lag of two ignition sources is the maximum when the concentration of methane is close to the upper limit.Therefore,the experimental research on the explosion suppression of gas by ignition source,has certain academic value for the basic theory of mine gas explosion prevention and control.