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Influence of combustor geometry on swirl stabilized premixed methane-air flame

Tong, Yiheng LU ; Li, Mao LU and Klingmann, Jens LU (2016) ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition, GT 2016 In Proceedings of ASME 2016 Turbo Expo: Turbomachinery Technical Conference and Exposition 4B-2016.
Abstract

Flame structures, blowout limits and emissions of swirlstabilized premixed methane-air flames were studied experimentally in a small atmospheric combustor rig. Combustion sections with rectangular cross section (30mm by 40mm) and circular cross section (inner diameter = 39mm) were used to investigate effects of combustor geometry on the flame's performance. Flame structures and instabilities were obtained from CH chemiluminescence captured by a high speed intensified CMOS camera. Maps of flame blowout limits (ΦBO) versus total mass flow rates (m = 70∼130 standard liter per minute, SLPM) were obtained with the combustor inlet flow temperature (Tin) kept at Tin = 397 ± 5K and a flow swirl... (More)

Flame structures, blowout limits and emissions of swirlstabilized premixed methane-air flames were studied experimentally in a small atmospheric combustor rig. Combustion sections with rectangular cross section (30mm by 40mm) and circular cross section (inner diameter = 39mm) were used to investigate effects of combustor geometry on the flame's performance. Flame structures and instabilities were obtained from CH chemiluminescence captured by a high speed intensified CMOS camera. Maps of flame blowout limits (ΦBO) versus total mass flow rates (m = 70∼130 standard liter per minute, SLPM) were obtained with the combustor inlet flow temperature (Tin) kept at Tin = 397 ± 5K and a flow swirl number of S = 0.6. Emission data of mole fraction of CO in the exhaust gas versus equivalence ratio was obtained under the conditions of Tin= 293 ± 5K and S = 0.66. It is found that the flame became longer and more unstable with decreasing equivalence ratio or increasing total mass flow rates. A strong high-amplitude and low-frequency oscillation was found to be the reason for the flame blowout. A possible reason for flame instability and blowout is presented in the paper. Within the parameters investigated in this study, the equivalence ratio had the strongest impact on flame stabilities and CO emission. Both in the rectangular and circular combustors, when the flame length increased to a critical value (LIBO, which was approximately the same for these two combustors), flame could not be stabilized anymore and blowout occurred. Compared with the rectangular combustor, the circular one had lower blowout limits and was better in stabilizing the flame. Combustor geometry did not significantly affect CO emission in the current study.

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organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
in
Proceedings of ASME 2016 Turbo Expo: Turbomachinery Technical Conference and Exposition
volume
4B-2016
publisher
American Society Of Mechanical Engineers (ASME)
conference name
ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition, GT 2016
external identifiers
  • scopus:84991660271
ISBN
9780791849767
DOI
10.1115/GT2016-57165
language
English
LU publication?
yes
id
6dc9f0c3-6246-4064-978f-b89f71cf7664
date added to LUP
2016-11-27 10:32:54
date last changed
2017-11-05 05:10:04
@inproceedings{6dc9f0c3-6246-4064-978f-b89f71cf7664,
  abstract     = {<p>Flame structures, blowout limits and emissions of swirlstabilized premixed methane-air flames were studied experimentally in a small atmospheric combustor rig. Combustion sections with rectangular cross section (30mm by 40mm) and circular cross section (inner diameter = 39mm) were used to investigate effects of combustor geometry on the flame's performance. Flame structures and instabilities were obtained from CH<sup>∗</sup> chemiluminescence captured by a high speed intensified CMOS camera. Maps of flame blowout limits (Φ<sub>BO</sub>) versus total mass flow rates (m = 70∼130 standard liter per minute, SLPM) were obtained with the combustor inlet flow temperature (T<sub>in</sub>) kept at T<sub>in</sub> = 397 ± 5K and a flow swirl number of S = 0.6. Emission data of mole fraction of CO in the exhaust gas versus equivalence ratio was obtained under the conditions of T<sub>in</sub>= 293 ± 5K and S = 0.66. It is found that the flame became longer and more unstable with decreasing equivalence ratio or increasing total mass flow rates. A strong high-amplitude and low-frequency oscillation was found to be the reason for the flame blowout. A possible reason for flame instability and blowout is presented in the paper. Within the parameters investigated in this study, the equivalence ratio had the strongest impact on flame stabilities and CO emission. Both in the rectangular and circular combustors, when the flame length increased to a critical value (L<sub>IBO</sub>, which was approximately the same for these two combustors), flame could not be stabilized anymore and blowout occurred. Compared with the rectangular combustor, the circular one had lower blowout limits and was better in stabilizing the flame. Combustor geometry did not significantly affect CO emission in the current study.</p>},
  author       = {Tong, Yiheng and Li, Mao and Klingmann, Jens},
  booktitle    = {Proceedings of ASME 2016 Turbo Expo: Turbomachinery Technical Conference and Exposition},
  isbn         = {9780791849767},
  language     = {eng},
  publisher    = {American Society Of Mechanical Engineers (ASME)},
  title        = {Influence of combustor geometry on swirl stabilized premixed methane-air flame},
  url          = {http://dx.doi.org/10.1115/GT2016-57165},
  volume       = {4B-2016},
  year         = {2016},
}