An experimental and kinetic modeling study on the laminar burning velocity of NH3+N2O+air flames
(2021) In Combustion and Flame 228. p.13-28- Abstract
In the present work, the laminar burning velocities of the NH3+N2O+air flames were measured using the heat flux method at 1 atm and 298 K, with varied equivalence ratios and N2O mixing ratios. For the mixing ratio N2O/(N2O+air) = 0.5, a full range of equivalence ratios was covered. Moreover, at three equivalence ratios an extended range of mixing ratios was investigated. The laminar burning velocity has an approximately linear relationship against the fraction of nitrous oxide in the oxidizer mixture, regardless of the tested equivalence ratios. Several recently published NH3 mechanisms were compared with these new experimental data; among them the models of Nakamura et al. and... (More)
In the present work, the laminar burning velocities of the NH3+N2O+air flames were measured using the heat flux method at 1 atm and 298 K, with varied equivalence ratios and N2O mixing ratios. For the mixing ratio N2O/(N2O+air) = 0.5, a full range of equivalence ratios was covered. Moreover, at three equivalence ratios an extended range of mixing ratios was investigated. The laminar burning velocity has an approximately linear relationship against the fraction of nitrous oxide in the oxidizer mixture, regardless of the tested equivalence ratios. Several recently published NH3 mechanisms were compared with these new experimental data; among them the models of Nakamura et al. and Stagni et al. show the best performance for NH3+N2O+air flames over the entire range of the mixing ratios. The H/N/O kinetic mechanism of the authors was analyzed and updated focusing on the rate constants of reactions most sensitive in ammonia flame propagation and self-ignition of NH3+O2 and H2+N2O mixtures. The choice of the new rate constants is outlined, however, no modification (adjustment or tuning) of the rate parameters to accommodate experimental results was attempted. The updated mechanism demonstrates significantly improved agreement with all measurements used for the model development and with other experimental data from the literature for ammonia flames and self-ignition. A comparative reaction path analysis for NH3+N2O+air and NH3+air flames revealed that an almost linear increase of the laminar burning velocity with an increased fraction of N2O in the oxidizer originates from the rate controlling reaction N2O+H = N2+OH, which produces OH radicals dominating ammonia oxidation.
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- author
- Han, Xinlu LU ; Lavadera, Lubrano LU and Konnov, Alexander A. LU
- organization
- publishing date
- 2021
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Ammonia, Kinetic mechanism, Laminar burning velocity, Nitrous oxide
- in
- Combustion and Flame
- volume
- 228
- pages
- 16 pages
- publisher
- Elsevier
- external identifiers
-
- scopus:85100172805
- ISSN
- 0010-2180
- DOI
- 10.1016/j.combustflame.2021.01.027
- language
- English
- LU publication?
- yes
- id
- d8ac7fb5-34aa-4a3c-bc5d-993c17b6f049
- date added to LUP
- 2021-02-11 09:01:48
- date last changed
- 2022-04-27 00:11:51
@article{d8ac7fb5-34aa-4a3c-bc5d-993c17b6f049,
abstract = {{<p>In the present work, the laminar burning velocities of the NH<sub>3</sub>+N<sub>2</sub>O+air flames were measured using the heat flux method at 1 atm and 298 K, with varied equivalence ratios and N<sub>2</sub>O mixing ratios. For the mixing ratio N<sub>2</sub>O/(N<sub>2</sub>O+air) = 0.5, a full range of equivalence ratios was covered. Moreover, at three equivalence ratios an extended range of mixing ratios was investigated. The laminar burning velocity has an approximately linear relationship against the fraction of nitrous oxide in the oxidizer mixture, regardless of the tested equivalence ratios. Several recently published NH3 mechanisms were compared with these new experimental data; among them the models of Nakamura et al. and Stagni et al. show the best performance for NH<sub>3</sub>+N<sub>2</sub>O+air flames over the entire range of the mixing ratios. The H/N/O kinetic mechanism of the authors was analyzed and updated focusing on the rate constants of reactions most sensitive in ammonia flame propagation and self-ignition of NH<sub>3</sub>+O<sub>2</sub> and H<sub>2</sub>+N<sub>2</sub>O mixtures. The choice of the new rate constants is outlined, however, no modification (adjustment or tuning) of the rate parameters to accommodate experimental results was attempted. The updated mechanism demonstrates significantly improved agreement with all measurements used for the model development and with other experimental data from the literature for ammonia flames and self-ignition. A comparative reaction path analysis for NH<sub>3</sub>+N<sub>2</sub>O+air and NH<sub>3</sub>+air flames revealed that an almost linear increase of the laminar burning velocity with an increased fraction of N<sub>2</sub>O in the oxidizer originates from the rate controlling reaction N<sub>2</sub>O+H = N<sub>2</sub>+OH, which produces OH radicals dominating ammonia oxidation.</p>}},
author = {{Han, Xinlu and Lavadera, Lubrano and Konnov, Alexander A.}},
issn = {{0010-2180}},
keywords = {{Ammonia; Kinetic mechanism; Laminar burning velocity; Nitrous oxide}},
language = {{eng}},
pages = {{13--28}},
publisher = {{Elsevier}},
series = {{Combustion and Flame}},
title = {{An experimental and kinetic modeling study on the laminar burning velocity of NH<sub>3</sub>+N<sub>2</sub>O+air flames}},
url = {{http://dx.doi.org/10.1016/j.combustflame.2021.01.027}},
doi = {{10.1016/j.combustflame.2021.01.027}},
volume = {{228}},
year = {{2021}},
}