Oxygen-enriched combustion could rise the hazard of unexpected fire and explosion in industry. This study experimentally and numerically analyzed the combustion characteristic of H2 and CH4 in oxygen-enriched environment (Ω = 21%–100 %). For H2 at Φ = 1 and Ω = 100 %, the maximum explosion pressure and maximum pressure rise rate were about 3.89 MPa and 1259.2 MPa/s. For CH4, these values were about 4.77 MPa and 6279.4 MPa/s. The upper flammability limit of gases increased sharply with the increase of Ω, however, the lower flammability limit was almost unchanged. Besides, the increasing of Ω also could result in the rising of aforementioned combustion parameters. The sensitivity of burning velocity was also analyzed. For H2 flame at Φ = 0.8, R35 could slow down burning velocity when Ω = 21 %, but promote it when Ω = 30 % and 70 %. For CH4 flame at Φ = 1.4, the sensitivity coefficients of R11, R35, R43 and R84 changed from negative to positive when Ω increased from 21 % - 30 %–70 % - 100 %. It was concluded that the oxygen concentration not only affect the inert gas but also affect the reaction kinetic of flame.

中文翻译：

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富氧环境下 H2 和 CH4 燃烧特性的实验和数值研究


富氧燃烧可能会增加工业中意外火灾和爆炸的危险。本研究通过实验和数值分析了 H2 和 CH4 在富氧环境 （Ω = 21%–100 %） 下的燃烧特性。对于 Φ = 1 和 Ω = 100 % 时的 H2，最大爆炸压力和最大压力上升速率约为 3.89 MPa 和 1259.2 MPa/s。对于 CH4，这些值约为 4.77 MPa 和 6279.4 MPa/s。气体的可燃性上限随着Ω的增加而急剧增加，但可燃下限几乎没有变化。此外，Ω的增加也可能导致上述燃烧参数的升高。还分析了燃烧速度的敏感性。对于 Φ = 0.8 的 H2 火焰，当 Ω = 21 % 时，R35 会减慢燃烧速度，但当 Ω = 30 % 和 70 % 时，R35 会促进燃烧速度。对于 Φ = 1.4 的 CH4 火焰，当 R11、R35、R43 和 R84 的敏感性系数从 21 % - 30 %–70 % - 100 % 增加到 30 % 时，Ω 从负变为正。结果表明，氧浓度不仅影响惰性气体，还影响火焰的反应动力学。