TY - JOUR
T1 - Role of H2 doping in freely-propagating C2H2–O2 flames
T2 - Sensitivity and flame structure
AU - Li, Jianhang
AU - Wang, Chaoqing
AU - Xun, Xuelian
AU - Han, Wenhu
AU - Liang, Wenkai
N1 - Publisher Copyright:
© 2024
PY - 2024/7/4
Y1 - 2024/7/4
N2 - The effects of hydrogen (H2) addition on the freely-propagating acetylene-oxygen (C2H2–O2) flames in a doubly-infinite domain are investigated, considering separate and coupled chemical and transport phenomena. Results show that increasing proportions of H2 enhance the laminar flame speeds of C2H2–O2 mixtures. Moreover, H2 promotes the C2H2–O2 flame to contain both light (H, H2) and heavy (C2H2) species. Compared with the Soret diffusion and radiation effect, the unity Lewis number assumption can induce substantial inaccuracies. Sensitivity analysis indicates that the key elementary reaction H + O2[dbnd]O + OH exerts stronger influences on the laminar flame speed. Additionally, due to the effective enthalpy of C2H2 being greater than H2, adding H2 decreases both adiabatic flame temperature and enthalpy of C2H2–O2 flames. Notably, reactions C2H2 + O[dbnd]H + HCCO and C2H + H2[dbnd]H + C2H2 in the C2H2 sub-mechanism are identified as important exothermic- and endothermic-reactions respectively. Furthermore, it is demonstrated that dilution effects from CO2 have a larger impact compared to those from H2O and Ar. Finally, the effects of initial pressure and temperature on the laminar flame speeds are also discussed. The results of the present work provide guidance for the effective use of binary fuel and risk control as well as fire suppression.
AB - The effects of hydrogen (H2) addition on the freely-propagating acetylene-oxygen (C2H2–O2) flames in a doubly-infinite domain are investigated, considering separate and coupled chemical and transport phenomena. Results show that increasing proportions of H2 enhance the laminar flame speeds of C2H2–O2 mixtures. Moreover, H2 promotes the C2H2–O2 flame to contain both light (H, H2) and heavy (C2H2) species. Compared with the Soret diffusion and radiation effect, the unity Lewis number assumption can induce substantial inaccuracies. Sensitivity analysis indicates that the key elementary reaction H + O2[dbnd]O + OH exerts stronger influences on the laminar flame speed. Additionally, due to the effective enthalpy of C2H2 being greater than H2, adding H2 decreases both adiabatic flame temperature and enthalpy of C2H2–O2 flames. Notably, reactions C2H2 + O[dbnd]H + HCCO and C2H + H2[dbnd]H + C2H2 in the C2H2 sub-mechanism are identified as important exothermic- and endothermic-reactions respectively. Furthermore, it is demonstrated that dilution effects from CO2 have a larger impact compared to those from H2O and Ar. Finally, the effects of initial pressure and temperature on the laminar flame speeds are also discussed. The results of the present work provide guidance for the effective use of binary fuel and risk control as well as fire suppression.
KW - Acetylene
KW - Flame promote
KW - Hydrogen
KW - Kinetics
UR - http://www.scopus.com/inward/record.url?scp=85195569692&partnerID=8YFLogxK
U2 - 10.1016/j.ijhydene.2024.06.089
DO - 10.1016/j.ijhydene.2024.06.089
M3 - Review article
AN - SCOPUS:85195569692
SN - 0360-3199
VL - 73
SP - 673
EP - 680
JO - International Journal of Hydrogen Energy
JF - International Journal of Hydrogen Energy
ER -
