Study on the chemical reaction mechanism and influencing factors of gas explosion in confined space

Abstract As an important associated resource of coal, mine gas is mainly composed of methane (CH 4 ), which is an unconventional natural gas formed in the process of coalification and stored in the coal seam and its adjacent strata. Its calorific value is up to 37, 618kJ/m 3 which is 2-5 times that of general coal, and almost no waste gas is generated after combustion. It is a clean and efficient energy. However, gas will pose a serious threat to underground workers in the process of coal mining. In order to prevent and control underground gas disasters scientifically, the chemical reaction mechanism of gas explosion is discussed in this paper. The research content covers the detailed mechanism of the methane combustion reaction, the role of free radicals, and the chain reaction mode. Through the simulation analysis of CHEMKIN software, the reaction characteristics of gas explosion under different conditions (such as initial pressure, CO, and H 2 concentration) were further studied. The results show that H, O, and OH radicals are the main activation centers of the reaction. CO will prolong the ignition delay time of methane-premixed gas, while H 2 will promote the formation of active radicals H and OH, and accelerate the reaction process. In addition, through sensitivity analysis, this paper also identified the key reactions that affect the overall response. These research results are of great significance for in-depth understanding and control of gas explosion accidents and help to ensure the safety of coal mine production.