[article]
Titre : |
Instability control by premixed pilot flames |
Type de document : |
texte imprimé |
Auteurs : |
Peter Albrecht, Auteur ; Stefanie Bade, Auteur ; Arnaud Lacarelle, Auteur |
Année de publication : |
2010 |
Article en page(s) : |
08 p. |
Note générale : |
Génie Mécanique |
Langues : |
Anglais (eng) |
Mots-clés : |
Combustion Flames |
Index. décimale : |
620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux |
Résumé : |
Premixed flames of swirl-stabilized combustors (displaced half-cone) are susceptible to thermo-acoustic instabilities, which should be avoided under all operating conditions in order to guarantee a long service life for both stationary and aircraft gas turbines. The source of this unstable flame behavior can be found in a transition of the premix flame structure between two stationary conditions that can be easily excited by fuel fluctuations, coherent structures within the flow, and other mechanisms. Pilot flames can alleviate this issue either by improving the dynamic stability directly or by sustaining the main combustion process at operating points where instabilities are unlikely. In the present study, the impact of two different premixed pilot injections on the combustion stability is investigated. One of the pilot injector (pilot flame injector) was located upstream of the recirculation zone at the apex of the burner. The second one was a pilot ring placed at the burner outlet on the dump plane. A noticeable feature of the pilot injector was that an ignition device allowed for creating pilot premixed flames. The present investigation showed that these premixed pilot flames were able to suppress instabilities over a wider fuel/air ratio range than the conventional premixed pilot injection alone. Furthermore, it was possible to prevent instabilities and maintain the flame burning near the lean blowout when a percentage of the fuel was premixed with air and injected through the pilot ring. NOx emissions were significantly reduced. |
DEWEY : |
620.1 |
ISSN : |
0742-4795 |
En ligne : |
http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000004 [...] |
in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 4 (Avril 2010) . - 08 p.
[article] Instability control by premixed pilot flames [texte imprimé] / Peter Albrecht, Auteur ; Stefanie Bade, Auteur ; Arnaud Lacarelle, Auteur . - 2010 . - 08 p. Génie Mécanique Langues : Anglais ( eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 4 (Avril 2010) . - 08 p.
Mots-clés : |
Combustion Flames |
Index. décimale : |
620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux |
Résumé : |
Premixed flames of swirl-stabilized combustors (displaced half-cone) are susceptible to thermo-acoustic instabilities, which should be avoided under all operating conditions in order to guarantee a long service life for both stationary and aircraft gas turbines. The source of this unstable flame behavior can be found in a transition of the premix flame structure between two stationary conditions that can be easily excited by fuel fluctuations, coherent structures within the flow, and other mechanisms. Pilot flames can alleviate this issue either by improving the dynamic stability directly or by sustaining the main combustion process at operating points where instabilities are unlikely. In the present study, the impact of two different premixed pilot injections on the combustion stability is investigated. One of the pilot injector (pilot flame injector) was located upstream of the recirculation zone at the apex of the burner. The second one was a pilot ring placed at the burner outlet on the dump plane. A noticeable feature of the pilot injector was that an ignition device allowed for creating pilot premixed flames. The present investigation showed that these premixed pilot flames were able to suppress instabilities over a wider fuel/air ratio range than the conventional premixed pilot injection alone. Furthermore, it was possible to prevent instabilities and maintain the flame burning near the lean blowout when a percentage of the fuel was premixed with air and injected through the pilot ring. NOx emissions were significantly reduced. |
DEWEY : |
620.1 |
ISSN : |
0742-4795 |
En ligne : |
http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000004 [...] |
|