Visible chemiluminescence of ammonia premixed flames and its application for flame diagnostics
(2023) In Proceedings of the Combustion Institute 39(4). p.4327-4334- Abstract
We report a spatially resolved spectroscopic study of the visible chemiluminescence emission from different premixed ammonia-air-oxygen flames stabilized on a laminar flat flame burner, with equivalence ratio ranging from 0.7 to 1.35 and an O2/N2 ratio of 0.4. In the reaction zone of the observed flames, the visible emission was recognized to be the chemiluminescence of excited NH2* radicals, while in the post-flame zone, two types of chemiluminescence were observed: NO2* chemiluminescence dominated in the fuel-lean flames and NH2* chemiluminescence dominated in the fuel-rich flames. The high-resolution spectra of the NO2* and NH2* chemiluminescence in the... (More)
We report a spatially resolved spectroscopic study of the visible chemiluminescence emission from different premixed ammonia-air-oxygen flames stabilized on a laminar flat flame burner, with equivalence ratio ranging from 0.7 to 1.35 and an O2/N2 ratio of 0.4. In the reaction zone of the observed flames, the visible emission was recognized to be the chemiluminescence of excited NH2* radicals, while in the post-flame zone, two types of chemiluminescence were observed: NO2* chemiluminescence dominated in the fuel-lean flames and NH2* chemiluminescence dominated in the fuel-rich flames. The high-resolution spectra of the NO2* and NH2* chemiluminescence in the visible region (400-700 nm) were recorded. The intensity of both spectra increased gradually with wavelength. However, the NO2*-chemiluminescence spectrum appeared to be continuous and unstructured, while the NH2*-chemiluminescence spectrum consisted of groups of distinct emission lines. Based on the spectral feature, the ratios of the integrated chemiluminescence intensities over the 598-603 nm wavelength range to the intensities over the 586-592 nm range and 447-453 nm range were used to sense equivalence ratio. In addition, slightly different colors of the fuel-lean and fuel-rich flames were observed, due to the fact that NO2* chemiluminescence had a relatively stronger signal in the blue region than NH2* chemiluminescence. The difference was used to infer flame equivalence ratio using the flame images recorded by a RGB digital camera, where the ratio of the signal from the red channel to the signal from the blue channel was calculated.
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- author
- Weng, Wubin LU ; Aldén, Marcus LU and Li, Zhongshan LU
- organization
- publishing date
- 2023
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Amino radical, Ammonia, Chemiluminescence, Equivalence ratio, Nitrogen dioxide
- in
- Proceedings of the Combustion Institute
- volume
- 39
- issue
- 4
- pages
- 8 pages
- publisher
- Elsevier
- external identifiers
-
- scopus:85139439705
- ISSN
- 1540-7489
- DOI
- 10.1016/j.proci.2022.08.012
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2022 Elsevier Inc. All rights reserved.
- id
- 96673286-564c-4ab7-8502-e37fd5e6b718
- date added to LUP
- 2022-10-21 08:36:14
- date last changed
- 2023-11-21 17:07:40
@article{96673286-564c-4ab7-8502-e37fd5e6b718,
abstract = {{<p>We report a spatially resolved spectroscopic study of the visible chemiluminescence emission from different premixed ammonia-air-oxygen flames stabilized on a laminar flat flame burner, with equivalence ratio ranging from 0.7 to 1.35 and an O<sub>2</sub>/N<sub>2</sub> ratio of 0.4. In the reaction zone of the observed flames, the visible emission was recognized to be the chemiluminescence of excited NH<sub>2</sub>* radicals, while in the post-flame zone, two types of chemiluminescence were observed: NO<sub>2</sub>* chemiluminescence dominated in the fuel-lean flames and NH<sub>2</sub>* chemiluminescence dominated in the fuel-rich flames. The high-resolution spectra of the NO<sub>2</sub>* and NH<sub>2</sub>* chemiluminescence in the visible region (400-700 nm) were recorded. The intensity of both spectra increased gradually with wavelength. However, the NO<sub>2</sub>*-chemiluminescence spectrum appeared to be continuous and unstructured, while the NH<sub>2</sub>*-chemiluminescence spectrum consisted of groups of distinct emission lines. Based on the spectral feature, the ratios of the integrated chemiluminescence intensities over the 598-603 nm wavelength range to the intensities over the 586-592 nm range and 447-453 nm range were used to sense equivalence ratio. In addition, slightly different colors of the fuel-lean and fuel-rich flames were observed, due to the fact that NO<sub>2</sub>* chemiluminescence had a relatively stronger signal in the blue region than NH<sub>2</sub>* chemiluminescence. The difference was used to infer flame equivalence ratio using the flame images recorded by a RGB digital camera, where the ratio of the signal from the red channel to the signal from the blue channel was calculated.</p>}},
author = {{Weng, Wubin and Aldén, Marcus and Li, Zhongshan}},
issn = {{1540-7489}},
keywords = {{Amino radical; Ammonia; Chemiluminescence; Equivalence ratio; Nitrogen dioxide}},
language = {{eng}},
number = {{4}},
pages = {{4327--4334}},
publisher = {{Elsevier}},
series = {{Proceedings of the Combustion Institute}},
title = {{Visible chemiluminescence of ammonia premixed flames and its application for flame diagnostics}},
url = {{http://dx.doi.org/10.1016/j.proci.2022.08.012}},
doi = {{10.1016/j.proci.2022.08.012}},
volume = {{39}},
year = {{2023}},
}