安全与环境学报

为探究乙烯掺混对甲烷爆炸特性的影响规律及CO₂的抑爆机制，在常温常压(T=298 K，p₀=0.1 MPa)条件下，利用20 L球形爆炸试验系统与Chemkin反应动力学模拟，系统研究了乙烯掺混比(R=0～1)及CO₂添加量(0～20%)对甲烷–乙烯–空气预混气体爆炸特性的影响。结果表明，乙烯掺混显著增强了甲烷的爆炸强度与反应速率：随着R从0增至1，最大爆炸压力p_max上升16.5%，最大爆炸压力上升速率(dp/dt)_max提升2.3倍，火焰传播速度由2.37 m/s增至5.47 m/s。CO₂对爆炸具有显著抑制效果，但在高乙烯比例下其抑制效能减弱，如R=0.4时，20% CO₂可使p_max下降50%，(dp/dt)_max下降91.9%，层流燃烧速度降低73.8%。动力学分析表明：乙烯通过引入反应R254(C₂H₄+OH=C₂H₃+H₂O)和R16(HO₂+H=2OH)等重构了反应网络，提升了·OH浓度与链分支反应R1(H+O₂=O+OH)的速率；CO₂则通过参与反应R31(CO₂+H=CO+OH)消耗H·来降低反应强度。研究揭示了乙烯与CO₂分别通过调控·OH与反应路径实现爆炸增强与抑制的动力学机制，为甲烷–乙烯共存工业环境的风险评估与抑爆设计提供了理论依据与工程指导。

This study investigates the influence of ethylene blending on methane explosion characteristics and the suppression mechanism of carbon dioxide (CO?). Experiments and simulations were conducted at ambient temperature and pressure (T=298 K， p₀=0.1 MPa) using a standardized 20 L spherical explosion vessel， complemented by Chemkin software employing the USC Mech II detailed reaction mechanism (111 species， 784 reactions). The effects of the ethylene blending ratio (R， ranging from 0 to 1) and CO? addition (0 to 20% by volume) on the explosion characteristics of methane-ethylene-air premixed mixtures were systematically examined， with the equivalence ratio maintained at unity across all tests. Experimental results demonstrate that ethylene blending significantly enhances the explosion intensity and reaction rate of methane. As R increased from 0 to 1， the maximum explosion pressure (p_max) rose by 16.5%， the maximum rate of pressure rise [(dp/dt)_max] increased by a factor of 2.3， and the flame propagation velocity accelerated from 2.37 m/s to 5.47 m/s. CO? exhibited a pronounced inhibitory effect on explosions; however， its suppression efficacy diminished at higher ethylene ratios. For instance， at R=0.4， the addition of 20% CO? resulted in a 50% reduction in p_max， a 91.9% decrease in (dp/dt)_max， and a 73.8% reduction in laminar burning velocity. Chemical kinetics analysis revealed that ethylene modifies the reaction network by introducing pathways such as R254 (C₂H₄+OH=C₂H₃+H₂O) and R16 (HO₂+H=2OH)， which collectively enhance the concentration of OH radicals and the rate of the crucial chain-branching reaction R1 (H+O₂=O+OH). Conversely， CO? participates in reaction R31 (CO₂+H =CO+OH)， consuming H radicals and thereby reducing overall reaction intensity. This research elucidates the kinetic mechanisms through which ethylene and CO? respectively enhance and suppress explosions by regulating OH radical concentration and key reaction pathways. The findings provide a theoretical foundation and engineering guidance for risk assessment and explosion suppression design in industrial environments where methane and ethylene coexist.