Uniqueness and similarity in flame propagation of pre-dissociated NH3 + air and NH3 + H2 + air mixtures : An experimental and modelling study
(2022) In Fuel 327.- Abstract
Ammonia (NH3) has attracted significant attention as a promising hydrogen carrier and a carbon-free alternative fuel. Partial dissociation could convert part of ammonia to H2 and N2 before injecting the fuel into a combustor, thus overcoming the low reactivity and high NOx emission problems during the NH3 combustion. The pre-dissociated NH3 + air mixture has unburnt species NH3, H2, O2, and N2, the same as more widely investigated NH3 + H2 + air flames, while similarities or differences between these two types of flames have not yet been investigated. In the present work, the laminar burning velocities of... (More)
Ammonia (NH3) has attracted significant attention as a promising hydrogen carrier and a carbon-free alternative fuel. Partial dissociation could convert part of ammonia to H2 and N2 before injecting the fuel into a combustor, thus overcoming the low reactivity and high NOx emission problems during the NH3 combustion. The pre-dissociated NH3 + air mixture has unburnt species NH3, H2, O2, and N2, the same as more widely investigated NH3 + H2 + air flames, while similarities or differences between these two types of flames have not yet been investigated. In the present work, the laminar burning velocities of pre-dissociated NH3 + air flames at 1 atm and an initial temperature of 298 K have been measured and compared to the scarce data from the literature. Experiments were carried out using the heat flux method at varied dissociation ratio γ and equivalence ratio ϕ. Kinetic simulations were also performed using six recently published or updated mechanisms, while none of the tested mechanisms can accurately reproduce the present results for the pre-dissociated NH3 + air flames over the whole range of the covered conditions, even for those predicting well the NH3 + H2 + air flames. To understand this deficiency, flame temperatures for the two fuel systems were examined, as well as in-depth sensitivity analyses were carried out. Similar conditions between the pre-dissociated NH3 + air and the NH3 + H2 + air flames were found, and a new approach to identifying inconsistent experimental data obtained using the same experimental setup was also suggested and discussed.
(Less)
- author
- Han, Xinlu ; Wang, Zhihua ; He, Yong ; Zhu, Yanqun ; Lin, Riyi and Konnov, Alexander A. LU
- organization
- publishing date
- 2022-11-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Ammonia, Hydrogen, Kinetic mechanism, Laminar burning velocity, Partial dissociation
- in
- Fuel
- volume
- 327
- article number
- 125159
- publisher
- Elsevier
- external identifiers
-
- scopus:85133429441
- ISSN
- 0016-2361
- DOI
- 10.1016/j.fuel.2022.125159
- language
- English
- LU publication?
- yes
- id
- d73eedbc-5fe6-4a9d-87e7-d820f6595d03
- date added to LUP
- 2022-09-15 13:53:28
- date last changed
- 2023-11-17 02:47:54
@article{d73eedbc-5fe6-4a9d-87e7-d820f6595d03,
abstract = {{<p>Ammonia (NH<sub>3</sub>) has attracted significant attention as a promising hydrogen carrier and a carbon-free alternative fuel. Partial dissociation could convert part of ammonia to H<sub>2</sub> and N<sub>2</sub> before injecting the fuel into a combustor, thus overcoming the low reactivity and high NO<sub>x</sub> emission problems during the NH<sub>3</sub> combustion. The pre-dissociated NH<sub>3</sub> + air mixture has unburnt species NH<sub>3</sub>, H<sub>2</sub>, O<sub>2</sub>, and N<sub>2</sub>, the same as more widely investigated NH<sub>3</sub> + H<sub>2</sub> + air flames, while similarities or differences between these two types of flames have not yet been investigated. In the present work, the laminar burning velocities of pre-dissociated NH<sub>3</sub> + air flames at 1 atm and an initial temperature of 298 K have been measured and compared to the scarce data from the literature. Experiments were carried out using the heat flux method at varied dissociation ratio γ and equivalence ratio ϕ. Kinetic simulations were also performed using six recently published or updated mechanisms, while none of the tested mechanisms can accurately reproduce the present results for the pre-dissociated NH<sub>3</sub> + air flames over the whole range of the covered conditions, even for those predicting well the NH<sub>3</sub> + H<sub>2</sub> + air flames. To understand this deficiency, flame temperatures for the two fuel systems were examined, as well as in-depth sensitivity analyses were carried out. Similar conditions between the pre-dissociated NH<sub>3</sub> + air and the NH<sub>3</sub> + H<sub>2</sub> + air flames were found, and a new approach to identifying inconsistent experimental data obtained using the same experimental setup was also suggested and discussed.</p>}},
author = {{Han, Xinlu and Wang, Zhihua and He, Yong and Zhu, Yanqun and Lin, Riyi and Konnov, Alexander A.}},
issn = {{0016-2361}},
keywords = {{Ammonia; Hydrogen; Kinetic mechanism; Laminar burning velocity; Partial dissociation}},
language = {{eng}},
month = {{11}},
publisher = {{Elsevier}},
series = {{Fuel}},
title = {{Uniqueness and similarity in flame propagation of pre-dissociated NH<sub>3</sub> + air and NH<sub>3</sub> + H<sub>2</sub> + air mixtures : An experimental and modelling study}},
url = {{http://dx.doi.org/10.1016/j.fuel.2022.125159}},
doi = {{10.1016/j.fuel.2022.125159}},
volume = {{327}},
year = {{2022}},
}