Based on the theory of fluid dynamics and combustion , the mathematical model of gas explosion in the pipe with diameter of 500 mm is established ,by Fluent ,numerical simulation study of the flame′s quenching process in inert gas is conducted by using the finite rate combustion model , and the characteristics of explosion field by injecting different flow rate of high pressure and low temperature CO2 are also investigated .T he experimental results show that ,w hen the CO2 injection is less than 12 kg/s ,it can not extinguish the flame in the pipe ;however ,when the CO2 injection is greater than 16 kg/s ,it can greatly reduce the temperature of the mixed gas ,and also dilute the methane and oxygen ,and eventually lead to the flame extinguished at the carbon dioxide entrance . The reducing process of the maximum reaction rate can be divided into three stages ,where two of the high-speed reducing stages satisfy the power-law model .When the CO2 injection is between 16 kg/s and 100 kg/s ,the extinction time reduces rapidly ,and then changes slowly ;the simulation results agree well with the experimental data .Research results can provide theoretical basis and reference for the explosion suppression in coal mine ,and also have practical significance to protect the safety of people′s lives during coal mine production .%基于流体动力学和燃烧理论，建立了管道直径为500 mm的瓦斯爆炸数学模型，借助Fluent流体力学软件，采用有限速率燃烧模型，对管道内甲烷预混气体爆炸后被惰性气体熄灭的过程进行了数值模拟研究，考察了瓦斯被点燃后，喷入不同流量高压、低温二氧化碳气体后管道内的燃烧流场特性。结果表明，二氧化碳喷入量低于12 kg/s不能使管内火焰熄灭；二氧化碳喷入量大于16 kg/s时，能大大降低管道内混合气体温度，同时降低甲烷和氧气浓度，导致火焰在二氧化碳喷入口所在管道截面处熄灭。此过程中管内最大反应速率降低过程可分为3个阶段，其中2个快速降低阶段均符合幂律模型。二氧化碳喷入量在16～100 kg/s时，火焰熄灭时间先迅速变短后变化缓慢；模拟结果与试验结果吻合较好。研究结果可为煤矿防爆抑爆研究工作提供理论依据和参考，同时对保障煤矿安全生产和人民生命安全也具有重要的现实意义。
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