水蒸气抑制甲烷燃烧和爆炸实验研究与数值计算

在爆炸激波管中对水蒸气抑制甲烷燃烧和爆炸进行较系统的实验研究,并对其抑燃、抑爆化学动力学作用机理进行数值计算分析。结果表明:加入一定量的水蒸气后,可以有效降低CH4-O2混合气体的燃烧速度和爆炸强度;当水蒸气量达到某临界值时,CH4-O2混合气体将不能被点燃。化学动力学数值计算结果表明:在混合气体中加入水蒸气后,增大了甲烷的点火延迟时间,降低了燃烧温度和H,O和OH等高活性自由基的浓度。水蒸气能有效抑制甲烷燃烧和爆炸,其作用效果源于其物理抑制和化学阻化的综合效应。

Experimental Investigation and Numerical Computation of Methane Combustion and Explosion Suppressed by Vapor

An experiment on methane combustion and explosion suppressed by vapor was conducted in an explosion shock tube, and corresponding numerical computations were made. The result indicates that the combustion velocity and explosion intensity of methane-oxygen mixture will decrease if a certain amount of vapor is added into the tube. When the amount of the vapor reaches critical value, the methane-oxygen mixture can not be ignited any more. Meanwhile, the chemical kinetics computational results indicate that the ignition delay time of methane is elongated, the combustion temperature is reduced and the concentrations of the free radicals of H, O and OH are reduced when the vapor is added in the mixture of methane-oxygen. It is concluded that the vapor can effectively restrain the combustion and explosion of methane, which owes to the combined effect of physical suppression and chemical inhibition.