TY - JOUR
T1 - Probing the kinetic sensitization effect of NO2 on ethylene oxidation
AU - Sun, Wuchuan
AU - Hong, Congjie
AU - Zhao, Qian
AU - Tian, Zemin
AU - Yan, Yingwen
AU - Deng, Yuanhao
AU - Zhang, Yingjia
AU - Huang, Zuohua
N1 - Publisher Copyright:
© 2023
PY - 2024/1
Y1 - 2024/1
N2 - Exhaust gas recirculation (EGR) has been widely equipped in modern engines for pollutant emission abatement. NOx present in EGR can greatly influence fuel combustion properties in engine operation. Ethylene (C2H4) is well-known a critical intermediate formed via β-scission reactions of alkyl radicals in the pyrolysis and oxidation of hydrocarbons, thus investigating the mutual effects of C2H4 and NOx is beneficial to engine design as well as hierarchically developed strategy of the chemical kinetic model. This study investigated the auto-ignition behavior of C2H4/air mixtures containing different levels of NO2 (0 ppm, 200 ppm, 500 ppm, 3000 ppm) in a high-pressure shock tube at pressures of 1 atm and 24 atm, temperatures of 820–1300 K and different equivalence ratios of 0.5, 1.0 and 2.0. The results showed that the addition of NO2 significantly promoted auto-ignition at high pressure, while only limited effects at low pressure. A detailed kinetic mechanism was proposed based on a hierarchically developed strategy, and it successfully reproduced the experimental data over the entire test conditions. Flux and sensitivity analyses were implemented to explore the sensitization effect of NO2 addition on the ignition kinetics of C2H4. The analysis revealed that NO2 mainly affects the reaction pathway of ĊH2CHO radical, leading to the formation of HONO. The additional generation of ȮH radicals through HONO = NO + ȮH and NO + HȮ2 = NO2 + ȮH accelerate the auto-ignition of C2H4. At low pressure, the decrease in the rate constant of HONO decomposition weakens the role of NO2.
AB - Exhaust gas recirculation (EGR) has been widely equipped in modern engines for pollutant emission abatement. NOx present in EGR can greatly influence fuel combustion properties in engine operation. Ethylene (C2H4) is well-known a critical intermediate formed via β-scission reactions of alkyl radicals in the pyrolysis and oxidation of hydrocarbons, thus investigating the mutual effects of C2H4 and NOx is beneficial to engine design as well as hierarchically developed strategy of the chemical kinetic model. This study investigated the auto-ignition behavior of C2H4/air mixtures containing different levels of NO2 (0 ppm, 200 ppm, 500 ppm, 3000 ppm) in a high-pressure shock tube at pressures of 1 atm and 24 atm, temperatures of 820–1300 K and different equivalence ratios of 0.5, 1.0 and 2.0. The results showed that the addition of NO2 significantly promoted auto-ignition at high pressure, while only limited effects at low pressure. A detailed kinetic mechanism was proposed based on a hierarchically developed strategy, and it successfully reproduced the experimental data over the entire test conditions. Flux and sensitivity analyses were implemented to explore the sensitization effect of NO2 addition on the ignition kinetics of C2H4. The analysis revealed that NO2 mainly affects the reaction pathway of ĊH2CHO radical, leading to the formation of HONO. The additional generation of ȮH radicals through HONO = NO + ȮH and NO + HȮ2 = NO2 + ȮH accelerate the auto-ignition of C2H4. At low pressure, the decrease in the rate constant of HONO decomposition weakens the role of NO2.
KW - Auto-ignition
KW - CH
KW - Kinetic modeling
KW - NO
KW - Sensitization effect
UR - https://www.scopus.com/pages/publications/85174462225
U2 - 10.1016/j.combustflame.2023.113122
DO - 10.1016/j.combustflame.2023.113122
M3 - 文章
AN - SCOPUS:85174462225
SN - 0010-2180
VL - 259
JO - Combustion and Flame
JF - Combustion and Flame
M1 - 113122
ER -