TY - JOUR
T1 - Effect of C-N cross-reactions on combustion dynamics in ammonia binary blends
AU - Liu, Zechang
AU - He, Xu
AU - Feng, Guangyuan
AU - Zhao, Chengyuan
AU - Zhou, Xiaoran
AU - Wang, Zhi
AU - Chen, Qingchu
N1 - Publisher Copyright:
© 2024 Elsevier Ltd
PY - 2024/10/1
Y1 - 2024/10/1
N2 - The application of ammonia (NH3) in the transportation sector presents a practical approach to steer the automotive industry towards a more eco-friendly and sustainable trajectory. The study examined the effect of C-N cross-reactions on laminar flame speed (LFS), ignition delay time (IDT), and species concentrations in binary NH3 blends using methane/ammonia (CH4/NH3), toluene/ammonia (C7H8/NH3), dimethyl ether/ammonia (DME/NH3), and n-heptane/ammonia (NC7H16/NH3) fuel mixtures. The research indicates that although C-N cross-reactions have a minimal impact on LFS of most blends, they significantly reduce the predictive precision of models for mixtures of C7H8/NH3. Furthermore, the existence of C-N cross-reactions diminishes the anticipated IDT of the combinations, and this influence becomes more pronounced as the initial temperature (T0) decreases. Furthermore, although C-N cross-reactions have a negligible impact on fuel species concentrations, they exert an impact on the concentrations of nitroic oxide (NO) and nitrous oxide (N2O). The mechanism by which C-N cross-reactions affect IDT and species concentrations is similar, mainly attributed to methyl (CH3) related C-N cross-reactions, which can be illustrated as: (1) C-N cross-reaction effects the concentration of CH3, which subsequently affects the concentration of CH3O. CH3O plays a vital role as a reactant for hydroperoxyl radical (HO2) generation in the intermediate temperature range (CH3O + O2 = CH2O + HO2), consequently exerting an impact on IDT; (2) the reaction NO + HO2 = NO2 + OH denotes the principal consumption reaction of NO, which is affected by HO2, consequently affecting the concentration of NO. (3) The H-abstraction reaction between NH2 and fuel promoted the primarily oxidation of fuel. This study concludes that limiting the inclusion to nine categories of reactions in C-N cross-reactions results in a considerable reduction in the complexity of the mechanism. This reduction significantly improves the predictive capacity of the model regarding combustion characteristics.
AB - The application of ammonia (NH3) in the transportation sector presents a practical approach to steer the automotive industry towards a more eco-friendly and sustainable trajectory. The study examined the effect of C-N cross-reactions on laminar flame speed (LFS), ignition delay time (IDT), and species concentrations in binary NH3 blends using methane/ammonia (CH4/NH3), toluene/ammonia (C7H8/NH3), dimethyl ether/ammonia (DME/NH3), and n-heptane/ammonia (NC7H16/NH3) fuel mixtures. The research indicates that although C-N cross-reactions have a minimal impact on LFS of most blends, they significantly reduce the predictive precision of models for mixtures of C7H8/NH3. Furthermore, the existence of C-N cross-reactions diminishes the anticipated IDT of the combinations, and this influence becomes more pronounced as the initial temperature (T0) decreases. Furthermore, although C-N cross-reactions have a negligible impact on fuel species concentrations, they exert an impact on the concentrations of nitroic oxide (NO) and nitrous oxide (N2O). The mechanism by which C-N cross-reactions affect IDT and species concentrations is similar, mainly attributed to methyl (CH3) related C-N cross-reactions, which can be illustrated as: (1) C-N cross-reaction effects the concentration of CH3, which subsequently affects the concentration of CH3O. CH3O plays a vital role as a reactant for hydroperoxyl radical (HO2) generation in the intermediate temperature range (CH3O + O2 = CH2O + HO2), consequently exerting an impact on IDT; (2) the reaction NO + HO2 = NO2 + OH denotes the principal consumption reaction of NO, which is affected by HO2, consequently affecting the concentration of NO. (3) The H-abstraction reaction between NH2 and fuel promoted the primarily oxidation of fuel. This study concludes that limiting the inclusion to nine categories of reactions in C-N cross-reactions results in a considerable reduction in the complexity of the mechanism. This reduction significantly improves the predictive capacity of the model regarding combustion characteristics.
KW - C-N cross reactions
KW - Combustion characteristics
KW - TRF/NH
UR - http://www.scopus.com/inward/record.url?scp=85196490971&partnerID=8YFLogxK
U2 - 10.1016/j.fuel.2024.132061
DO - 10.1016/j.fuel.2024.132061
M3 - Article
AN - SCOPUS:85196490971
SN - 0016-2361
VL - 373
JO - Fuel
JF - Fuel
M1 - 132061
ER -