采空区遗煤氧化标志性伴生气体对瓦斯爆炸的影响

摘要

为了研究采空区遗煤氧化过程中标志性伴生气体对瓦斯爆炸的影响,通过对煤样进行试验测定,确定遗煤升温不同阶段的标志性伴生气体.基于动力学模型CHEMKIN中Senkin的GRI 3.0甲烷燃烧反应机理,在定容条件下设定加速、激烈氧化2个阶段瓦斯与标志性伴生气体体积分数,模拟计算瓦斯爆炸温度、压力、中间产物及关键反应步敏感性系数.结果表明:随着标志性伴生气体体积分数的增加,在加速氧化阶段,爆炸时间提前了约0.003 0s,爆炸压力及温度分别升高了约0.012MPa和30 K;在激烈氧化阶段,爆炸时间提前了约0.000 2 s,爆炸压力升高了约0.007 MPa,两阶段自由基OH体积分数均逐渐降低,促进甲烷生成的关键反应步敏感性系数降低幅度均较大,即促进了瓦斯爆炸.%In order to study the symbolic associated gas during the oxidization process of the left coal in the mine goaf affected to the gas explosion,with the experiment measurement conducted on the coal samples,the symbolic associated gas at the different temperature rising stage of the left coal was determined.Based on the GRI 3.0 methane combustion reaction mechanism of the Senkin in CHEMKIN,under the condition of the constant volume,the volume fractions of the gas and symbolic associated gas in the two stages of the acceleration and intense oxidation were set up and the gas explosion temperature,pressure,intermediates and key reaction step sensitivity coefficient were simulated and calculated.The results showed that with the volume fraction of the symbolic associated gas increased,at the acceleration oxidation stage,the explosion time was about 0.003 0 s in advance and the explosion pressure and temperature were increased by 0.012 MPa and 30 K individually.In the intense oxidation stage,the explosion time was about 0.000 2 s in advance and the explosion pressure was increased by 0.007 MPa.The free radical OH volume fractions were steadily reduced at the two stages,thus the sensitive coefficient of key reaction step was highly reduced and could promote the gas explosion.