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为了研究乙烯中低温燃烧的点火特性,用公开报道的可用于乙烯燃烧的反应动力学机理,模拟了乙烯的点火延时,发现现有机理难于描述乙烯中低温点火延时.根据敏感度分析,找到了对全温度段乙烯点火起重要作用的C_2H_3+O_2=CH_2CHO+O和C_2H_3+O_2=CH_2O+HCO反应,以及对低温点火起关键作用的HO_2参与的反应.通过引入最新报道的关键反应的动力学参数和添加新的反应通道,修正了UCSD机理,使乙烯中低温燃烧的点火延时模拟值更接近实验值.用修正机理模拟点火延时时,出现了低温燃烧的一阶点火和中温燃烧的负温度效应,进一步采用敏感度分析和物质产率分析,解释了这些现象,指出C_2H_4+HO_2反应可以有效缩短低温点火延时,HO_2的生成和消耗是影响乙烯低温一阶点火的主要原因,C_2H_3消耗反应是出现负温度效应的重要原因.
In order to study the ignition characteristics of low-temperature combustion of ethylene, a publicly reported kinetic mechanism of reaction kinetics for ethylene combustion was used to simulate the ignition delay of ethylene, and it was found that the existing mechanism is difficult to describe the low-temperature ignition delay of ethylene.According to the sensitivity analysis, The reaction of C_2H_3 + O_2 = CH_2CHO + O and C_2H_3 + O_2 = CH_2O + HCO, which plays an important role in the ignition of ethylene at full temperature, and the participation of HO_2, which plays a key role in low temperature ignition, were found. By introducing the newly reported key reaction Kinetic parameters and adding a new reaction channel, the UCSD mechanism was modified to make the ignition delay simulation value of low-temperature combustion of ethylene closer to the experimental value.When the ignition delay was simulated by the modification mechanism, the first-order ignition and the middle temperature The negative temperature effect of combustion is further explained by sensitivity analysis and material yield analysis. It is pointed out that the reaction of C 2 H 4 + HO 2 can shorten the ignition delay at low temperature, and the generation and consumption of HO 2 are the main factors that affect the first-order ignition of ethylene at low temperature , C 2 H 3 depletion reaction is an important cause of negative temperature effect.