EP1048898B1 - Burner - Google Patents

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Publication number
EP1048898B1
EP1048898B1 EP98811145A EP98811145A EP1048898B1 EP 1048898 B1 EP1048898 B1 EP 1048898B1 EP 98811145 A EP98811145 A EP 98811145A EP 98811145 A EP98811145 A EP 98811145A EP 1048898 B1 EP1048898 B1 EP 1048898B1
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EP
European Patent Office
Prior art keywords
burner
built
components
flow
air
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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EP98811145A
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German (de)
French (fr)
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EP1048898A1 (en
Inventor
Ephraim Prof. Dr. Gutmark
Christian Oliver Dr. Paschereit
Wolfgang Weisenstein
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General Electric Switzerland GmbH
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Alstom Schweiz AG
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Publication date
Application filed by Alstom Schweiz AG filed Critical Alstom Schweiz AG
Priority to DE59810606T priority Critical patent/DE59810606D1/en
Priority to EP98811145A priority patent/EP1048898B1/en
Priority to US09/434,448 priority patent/US6196835B1/en
Priority to DE10022969A priority patent/DE10022969A1/en
Publication of EP1048898A1 publication Critical patent/EP1048898A1/en
Application granted granted Critical
Publication of EP1048898B1 publication Critical patent/EP1048898B1/en
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23CMETHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C7/00Combustion apparatus characterised by arrangements for air supply
    • F23C7/002Combustion apparatus characterised by arrangements for air supply the air being submitted to a rotary or spinning motion
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23CMETHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C2900/00Special features of, or arrangements for combustion apparatus using fluid fuels or solid fuels suspended in air; Combustion processes therefor
    • F23C2900/07002Premix burners with air inlet slots obtained between offset curved wall surfaces, e.g. double cone burners
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23DBURNERS
    • F23D2210/00Noise abatement

Definitions

  • the invention relates to a burner for operating a unit for generation a hot gas.
  • the cooling air flowing into the combustion chamber has a sound-absorbing effect and thus contributes to damping thermoacoustic vibrations.
  • an increasing proportion of the air is passed through the burners themselves in modern gas turbines and the cooling air flow is reduced.
  • the problems mentioned at the outset occur increasingly in modern combustion chambers.
  • One way of soundproofing is to connect Helmholtz dampers in the combustion chamber hood or in the area of the cooling air supply. Where space is limited, as is the case for modern, compact combustion chambers however, such dampers can be difficult to accommodate prepare and is associated with great design effort.
  • thermoacoustic Vibrations through active acoustic excitation.
  • the the shear layer forming in the area of the burner is acoustically excited. With a suitable phase position between the thermoacoustic vibrations and the excitation can thereby dampen the combustion chamber vibrations to reach.
  • such a solution requires the addition of additional ones Elements in the combustion chamber area.
  • US 5433596 describes a premix burner for stabilizing the lean Combustion, especially for the operation of a gas turbine with medium or low calorific fuels is suitable. For the purpose of improvement the mixing of the fuel with the combustion air and thus Avoiding local recirculation areas will create vortex elements in the entry gap the combustion air in the premix zone.
  • the invention as characterized in the claims, is the object to create a device that provides effective suppression enables thermoacoustic vibrations and with the least possible constructive Effort is connected.
  • This object is achieved according to the invention solved a burner of the type mentioned in the independent claim.
  • advantageous Execution types reflect the dependent claims.
  • the invention is based on the knowledge that the flow instabilities in the burner mostly have a dominant mode.
  • the damping of this dominant mode is a priority for the suppression of thermoacoustic vibrations.
  • the relevant frequencies are between a few 10 Hz and a few kHz.
  • the convection speed depends on the burner and is typically a few 10 m / s, for example 30 m / s.
  • a burner according to the invention for operating an aggregate for generation a hot gas consists essentially of at least two hollow, in Direction of the flow nested partial bodies, their central axes run offset from each other, such that adjacent walls the partial body at the burner slots tangential air inlet channels for the Influx of combustion air into one specified by the partial bodies Form interior.
  • the burner has a plurality of internals projecting into the flow, wherein According to the invention, the distances between adjacent installation elements are smaller or approximately equal to half the wavelength of a dominant mode of thermoacoustic Are vibrations.
  • the internals are at the burner outlet arranged. It has also proven to be particularly advantageous if the internals arranged both at the burner outlet and along the burner slots are.
  • any conceivable shape is possible for the internals. They can be both flat be, as well as have a distinctive three-dimensional structure. With advantage they become roughly in a sawtooth structure, sinusoidal or rectangular educated. It is particularly advantageous if the internals are in the form of vortex generators are designed. There is a device with "vortex generator” referred to, which introduces axial vortex strength into a flow without a recirculation zone to produce in a trailing area.
  • Figure 1 shows a known premix burner, which consists of two half hollow Partial cone bodies 1, 2, which are arranged offset to one another.
  • the Offset of the respective central axis of the partial cone bodies 1, 2 to one another creates a tangential on both sides in a mirror-image arrangement Air inlet duct 5, 6 at the burner slots 5a, 6a through which the Combustion air 7 flows into the interior 8 of the burner.
  • the partial cone bodies 1, 2 have cylindrical starting parts 9, 10, which have a fuel nozzle 11 include through which liquid fuel 12 is injected.
  • the Partial cone body 1, 2 as required each have a fuel line 13, 14 with Openings 15 are provided, through which gaseous fuel 16 the combustion air 7 flowing through the tangential air inlet ducts 5, 6 is admixed.
  • the burner has a collar-shaped, as anchoring for the partial cone body 1, 2 serving front plate 18 with a number of holes 19, through which, if necessary, dilution air or cooling air 20 front part of the combustion chamber or its wall can be supplied.
  • the fuel injection can be an air-assisted nozzle or is a nozzle that works according to the pressure atomization principle.
  • the conical spray pattern is created by the tangentially flowing combustion air flows 7 enclosed.
  • the concentration of fuel injected 12 is continuously in the direction of flow 30 through the combustion air flows 7 dismantled.
  • a liquid Fuel 12 is in the area of vortex bursting, that is in the area of Backflow zone 24 at the end of the premix burner the optimal, homogeneous Fuel concentration reached across the cross section.
  • the ignition of the Fuel / combustion air mixture begins at the top of the backflow zone 24. Only at this point can a stable flame front 25 arise.
  • each partial cone body had 1.2 at the burner outlet ten triangular internals 32 attached, the total of a sawtooth structure formed (Fig. 2).
  • the dimensions of the structure depended on it according to the wavelength the dominant mode of the flow instability to be suppressed, whose frequency in the exemplary embodiment was in the kHz range.
  • the experimental determination of the pressure fluctuations of Fig. 5 shows that the amplitude of the thermoacoustic fluctuations due to the internals ("Sawtooth internals", open circles) compared to a conventional burner ("unchanged", full squares) reduced by one to two orders of magnitude become.
  • Figure 6 shows the results of an experimental Determination of pressure fluctuations in the 100 Hz range when in use of conventional burners ("unchanged”, full squares) and of Burners according to the previous embodiment of the invention ("sawtooth internals", open circles) as a function of the air ratio ⁇ .
  • the air number ⁇ is included a measure of the ratio of those introduced into the combustion chamber to that theoretically required amount of air for complete combustion.
  • Fig. 6 shows, by the present invention, the amplitude of the pressure vibrations in the particularly relevant range 1.8 ⁇ ⁇ ⁇ 2.2 also in the 100 Hz range still significantly reduced.
  • Vortex generators 34 instead of geometrically simple internals, Vortex generators 34 used as internals.
  • Figures 4a-b show two embodiments for vortex generators 34, each at the edge 36 of a partial cone body are attached.
  • the reference symbol 40 denotes the local flow direction of the working fluid.
  • the through the vortex generators 34 generated vortex structures 42 are each shown schematically.
  • the vortex generator of Fig. 4a generates a pair of vertebrae that face inwards rotates, similar to a delta wing.
  • the vortex generator shown in Fig. 4b creates an outward rotating pair of vertebrae.
  • each vortex generator 34 was used in the Burner installed. As in Fig. 2, ten of the vortex generators were at the burner outlet attached along the circumference of the partial cone body 1,2. Each five more vortex generators were shown along the burner slots as shown in FIG. 3 5a, 6a attached. 3 shows only one of the two burner slots.
  • FIG. 7 shows the results of an experimental determination of the pressure fluctuations in the 100 Hz range depending on the air ratio ⁇ when used a conventional burner ("unchanged”, full squares) and a burner with the described arrangement of vortex generators ("Vortex generators", open circles).
  • the pressure fluctuations are over one wide range ⁇ ⁇ 2.2 significantly reduced compared to an unchanged burner.

Description

Die Erfindung betrifft einen Brenner zum Betrieb eines Aggregats zur Erzeugung eines Heißgases.The invention relates to a burner for operating a unit for generation a hot gas.

Stand der TechnikState of the art

Thermoakustische Schwingungen stellen eine Gefahr für jede Art von Verbrennungsanwendungen dar. Sie führen zu Druckschwankungen hoher Amplitude, zu einer Einschränkung des Betriebsbereiches und können die mit der Verbrennung verbundenen Emissionen erhöhen. Diese Probleme treten besonders in Verbrennungssystemen mit geringer akustischer Dämpfung, wie sie moderne Gasturbinen oft darstellen, auf. Thermoacoustic vibrations pose a threat to any type of combustion application They lead to high amplitude pressure fluctuations, to a limitation of the operating area and can with the Increase combustion related emissions. These problems occur particularly in combustion systems with low acoustic damping, as they do often represent modern gas turbines.

In herkömmlichen Brennkammern wirkt die in die Brennkammer einströmende Kühlluft schalldämpfend und trägt damit zur Dämpfung von thermoakustischen Schwingungen bei. Um niedrige NOx-Emissionen zu erzielen, wird in modernen Gasturbinen ein zunehmender Anteil der Luft durch die Brenner selbst geleitet und der Kühlluftstrom reduziert. Durch die damit einhergehende geringere Schalldämpfung treten die eingangs angesprochenen Probleme in modernen Brennkammern demnach verstärkt auf.In conventional combustion chambers, the cooling air flowing into the combustion chamber has a sound-absorbing effect and thus contributes to damping thermoacoustic vibrations. In order to achieve low NO x emissions, an increasing proportion of the air is passed through the burners themselves in modern gas turbines and the cooling air flow is reduced. As a result of the associated lower sound absorption, the problems mentioned at the outset occur increasingly in modern combustion chambers.

Eine Möglichkeit der Schalldämpfung besteht im Ankoppeln von Helmholtz-Dämpfern in der Brennkammerhaube oder im Bereich der Kühlluftzuführung. Bei engen Platzverhältnissen, wie sie für moderne, kompakt gebaute Brennkammern typisch sind, kann die Unterbringung solcher Dämpfer jedoch Schwierigkeiten bereiten und ist mit großem konstruktiven Aufwand verbunden.One way of soundproofing is to connect Helmholtz dampers in the combustion chamber hood or in the area of the cooling air supply. Where space is limited, as is the case for modern, compact combustion chambers however, such dampers can be difficult to accommodate prepare and is associated with great design effort.

Nach einem alternativen Vorschlag zur Schallminderung in mager betriebenen Verbrennungssystemen gemäss US 5487274 führen voneinander beabstandete, sich radial über den gesamten Strömungsquerschnitt erstreckende Einbauten ausgangs der Vormischzone zu einer Störung der sich ausbildenden Wirbelstrukturen und in der Folge zu einer Verminderung der verbrennungsgetriebenen Druckoszillationen in der Brennkammer.According to an alternative proposal for noise reduction in lean operated Combustion systems according to US 5487274 lead spaced, internals extending radially over the entire flow cross-section out of the premix zone to a disturbance of the developing Vortex structures and consequently a reduction in the combustion-driven Pressure oscillations in the combustion chamber.

Eine weitere Möglichkeit der Schalldämpfung besteht in einer Kontrolle thermoakustischer Schwingungen durch aktive akustische Anregung. Dabei wird die sich im Bereich des Brenners ausbildende Scherschicht akustisch angeregt. Bei geeigneter Phasenlage zwischen den thermoakustischer Schwingungen und der Anregung läßt sich dadurch eine Dämpfung der Brennkammerschwingungen erreichen. Eine solche Lösung erfordert allerdings den Anbau zusätzlicher Elemente im Bereich der Brennkammer.Another possibility of sound attenuation is to control thermoacoustic Vibrations through active acoustic excitation. The the shear layer forming in the area of the burner is acoustically excited. With a suitable phase position between the thermoacoustic vibrations and the excitation can thereby dampen the combustion chamber vibrations to reach. However, such a solution requires the addition of additional ones Elements in the combustion chamber area.

US 5433596 beschreibt einen Vormischbrenner zur Stabilisierung der mageren Verbrennung, der insbesondere für den Betrieb einer Gasturbine mit mitteloder niederkalorischen Brennstoffen geeignet ist. Zum Zwecke der Verbesserung der Durchmischung des Brennstoffs mit der Verbrennungsluft und damit der Vermeidung lokaler Rezirkulationsgebiete werden Wirbelelemente im Eintrittsspalt der Verbrennungsluft in die Vormischzone angeordnet.US 5433596 describes a premix burner for stabilizing the lean Combustion, especially for the operation of a gas turbine with medium or low calorific fuels is suitable. For the purpose of improvement the mixing of the fuel with the combustion air and thus Avoiding local recirculation areas will create vortex elements in the entry gap the combustion air in the premix zone.

Darstellung der ErfindungPresentation of the invention

Der Erfindung, wie sie in den Ansprüchen gekennzeichnet ist, liegt die Aufgabe zugrunde, eine Vorrichtung zu schaffen, die eine wirkungsvolle Unterdrückung thermoakustischer Schwingungen ermöglicht und mit möglichst geringem konstruktiven Aufwand verbunden ist. Diese Aufgabe wird erfindungsgemäß durch einen Brenner der im unabhängigen Anspruch genannten Art gelöst. Vorteilhafte Ausführungsarten geben die abhängigen Ansprüche wieder.The invention, as characterized in the claims, is the object to create a device that provides effective suppression enables thermoacoustic vibrations and with the least possible constructive Effort is connected. This object is achieved according to the invention solved a burner of the type mentioned in the independent claim. advantageous Execution types reflect the dependent claims.

Die Erfindung beruht auf der Erkenntnis, dass die Strömungsinstabilitäten im Brenner zumeist eine dominante Mode aufweisen. Die Dämpfung dieser dominanten Mode ist für die Unterdrückung thermoakustischer Schwingungen vordringlich. Die Wellenlänge λ der dominante Mode der Instabilität ergibt sich aus ihrer Frequenz f und der Konvektionsgeschwindigkeit uc über λ = uc / f. Die relevanten Frequenzen liegen zwischen einigen 10 Hz und einigen kHz. Die Konvektionsgeschwindigkeit hängt vom Brenner ab und beträgt typischerweise einige 10 m/s, beispielsweise 30 m/s.The invention is based on the knowledge that the flow instabilities in the burner mostly have a dominant mode. The damping of this dominant mode is a priority for the suppression of thermoacoustic vibrations. The wavelength λ of the dominant mode of instability results from its frequency f and the convection speed u c via λ = u c / f. The relevant frequencies are between a few 10 Hz and a few kHz. The convection speed depends on the burner and is typically a few 10 m / s, for example 30 m / s.

Ein erfindungsgemäßer Brenner zum Betrieb eines Aggregats zur Erzeugung eines Heißgases, besteht im wesentlichen aus mindestens zwei hohlen, in Richtung der Strömung ineinandergeschachtelten Teilkörpern, deren Mittelachsen zueinander versetzt verlaufen, dergestalt, daß benachbarte Wandungen der Teilkörper an den Brennerschlitzen tangentiale Lufteintrittskanäle für die Einströmung von Verbrennungsluft in einen von den Teilkörpern vorgegebenen Innenraum bilden. Zum Einbringen axialer Wirbelstärke in die Strömung weist der Brenner eine Mehrzahl von in die Strömung ragender Einbauten auf, wobei erfindungsgemäß die Abstände benachbarter Einbauelemente kleiner oder etwa gleich der halben Wellenlänge einer dominanten Mode der thermoakustischen Schwingungen sind. A burner according to the invention for operating an aggregate for generation a hot gas, consists essentially of at least two hollow, in Direction of the flow nested partial bodies, their central axes run offset from each other, such that adjacent walls the partial body at the burner slots tangential air inlet channels for the Influx of combustion air into one specified by the partial bodies Form interior. To introduce axial vortex strength into the flow the burner has a plurality of internals projecting into the flow, wherein According to the invention, the distances between adjacent installation elements are smaller or approximately equal to half the wavelength of a dominant mode of thermoacoustic Are vibrations.

Dies gilt für den Abstand entlang des Brenneraustritts angebrachter Einbauten, wie für den Abstand entlang der Brennerschlitze angeordneter Elemente.This applies to the spacing of internals installed along the burner outlet, as for the distance of elements arranged along the burner slots.

In einer bevorzugten Ausführungsform sind die Einbauten am Brenneraustritt angeordnet. Als besonders vorteilhaft hat es sich auch erwiesen, wenn die Einbauten sowohl am Brenneraustritt, als auch entlang der Brennerschlitze angeordnet sind.In a preferred embodiment, the internals are at the burner outlet arranged. It has also proven to be particularly advantageous if the internals arranged both at the burner outlet and along the burner slots are.

Für die Einbauten ist jede denkbare Form möglich. Sie können sowohl flach sein, als auch eine ausgeprägte dreidimensionale Struktur aufweisen. Mit Vorteil werden sie etwa in einer Sägezahnstruktur, sinusförmig oder rechteckig ausgebildet. Besonders vorteilhaft ist es, wenn die Einbauten in Form von Wirbelgeneratoren gestaltet sind. Dabei ist mit "Wirbelgenerator" ein Vorrichtung bezeichnet, die axiale Wirbelstärke in eine Strömung einbringt, ohne eine Rezirkulationszone in einem Nachlaufgebiet zu erzeugen.Any conceivable shape is possible for the internals. They can be both flat be, as well as have a distinctive three-dimensional structure. With advantage they become roughly in a sawtooth structure, sinusoidal or rectangular educated. It is particularly advantageous if the internals are in the form of vortex generators are designed. There is a device with "vortex generator" referred to, which introduces axial vortex strength into a flow without a recirculation zone to produce in a trailing area.

Das erfindungsgemäße Einbringen von Wirbelstärke in axialer Richtung zur Störung kohärenter Wirbelstrukturen durch in die Strömung ragende Einbauten läßt sich nicht nur bei dem hier beschriebenen Doppelkegelbrenner, sondern ebenso bei anderen Brennertypen anwenden.The introduction of vortex strength according to the invention in the axial direction Disruption of coherent vortex structures due to internals protruding into the flow can not only in the double-cone burner described here, but also apply to other types of burners.

Weitere vorteilhafte Ausgestaltungen, Merkmale und Details der Erfindung ergeben sich aus den abhängigen Ansprüchen, der Beschreibung der Ausführungsbeispiele und der Zechnungen. Die Erfindung soll nachfolgend anhand eines Ausführungsbeispiels im Zusammenhang mit den Zeichnungen näher erläutert werden. Es sind jeweils nur die für das Verständnis der Erfindung wesentlichen Elemente dargestellt. Dabei zeigen

Fig. 1
einen Brenner nach dem Stand der Technik in perspektivischer Darstellung entsprechend aufgeschnitten;
Fig. 2
eine Vorderansicht eines Ausführungsbeispiels eines erfindungsgemäßen Brenners;
Fig. 3
eine schematische Seitenansicht eines erfindungsgemäßen Brenners;
Fig. 4a-b
Ausführungsbeispiele für Wirbelgeneratoren zum Einsatz in einem erfindungsgemäßen Brenner;
Fig. 5
eine logarithmische Auftragung der relativen Druckamplitude im kHz-Bereich gegen die Brennerleistung für einen unveränderten Brenner nach dem Stand der Technik und für einen erfindungsgemäßen Brenner mit sägezahnförmigen Einbauten;
Fig. 6
eine Auftragung der relativen Druckamplitude im 100 Hz-Bereich gegen die Luftzahl λ für einen unveränderten Brenner nach dem Stand der Technik und für einen erfindungsgemäßen Brenner mit sägezahnförmigen Einbauten;
Fig. 7
eine Auftragung der relativen Druckamplitude im 100 Hz-Bereich gegen die Luftzahl λ für einen unveränderten Brenner nach dem Stand der Technik und für einen erfindungsgemäßen Brenner mit Wirbelgeneratoren;
Further advantageous refinements, features and details of the invention result from the dependent claims, the description of the exemplary embodiments and the calculations. The invention will be explained in more detail below using an exemplary embodiment in conjunction with the drawings. Only the elements essential for understanding the invention are shown. Show
Fig. 1
a burner according to the prior art in a corresponding perspective cut open;
Fig. 2
a front view of an embodiment of a burner according to the invention;
Fig. 3
a schematic side view of a burner according to the invention;
4a-b
Embodiments of vortex generators for use in a burner according to the invention;
Fig. 5
a logarithmic plot of the relative pressure amplitude in the kHz range against the burner output for an unchanged burner according to the prior art and for a burner according to the invention with sawtooth-shaped internals;
Fig. 6
a plot of the relative pressure amplitude in the 100 Hz range against the air ratio λ for an unchanged burner according to the prior art and for a burner according to the invention with sawtooth-shaped internals;
Fig. 7
a plot of the relative pressure amplitude in the 100 Hz range against the air ratio λ for an unchanged burner according to the prior art and for a burner according to the invention with vortex generators;

Wege zur Ausführung der ErfindungWays of Carrying Out the Invention

Figur 1 zeigt einen bekannten Vormischbrenner, der aus zwei halben hohlen Teilkegelkörpern 1, 2, besteht, die versetzt zueinander angeordnet sind. Die Versetzung der jeweiligen Mittelachse der Teilkegelkörper 1, 2 zueinander schafft auf beiden Seiten in spiegelbildlicher Anordnung jeweils einen tangentialen Lufteintrittskanal 5, 6 an den Brennerschlitzen 5a, 6a, durch welchen die Verbrennungsluft 7 in den Innenraum 8 des Brenners strömt. Die Teilkegelkörper 1, 2 weisen zylindrische Anfangsteile 9, 10 auf, die eine Brennstoffdüse 11 beinhalten durch die flüssiger Brennstoff 12 eingedüst wird. Weiter weisen die Teilkegelkörper 1, 2 nach Bedarf je eine Brennstoffleitung 13, 14 auf, die mit Öffnungen 15 versehen sind, durch welche gasförmiger Brennstoff 16 der durch die tangentialen Lufteintrittskanäle 5, 6 strömenden Verbrennungsluft 7 zugemischt wird.Figure 1 shows a known premix burner, which consists of two half hollow Partial cone bodies 1, 2, which are arranged offset to one another. The Offset of the respective central axis of the partial cone bodies 1, 2 to one another creates a tangential on both sides in a mirror-image arrangement Air inlet duct 5, 6 at the burner slots 5a, 6a through which the Combustion air 7 flows into the interior 8 of the burner. The partial cone bodies 1, 2 have cylindrical starting parts 9, 10, which have a fuel nozzle 11 include through which liquid fuel 12 is injected. Further point the Partial cone body 1, 2 as required, each have a fuel line 13, 14 with Openings 15 are provided, through which gaseous fuel 16 the combustion air 7 flowing through the tangential air inlet ducts 5, 6 is admixed.

Brennraumseitig 17 weist der Brenner eine kragenförmige, als Verankerung für die Teilkegelkörper 1, 2 dienende Frontplatte 18 mit einer Anzahl von Bohrungen 19 auf, durch welche bei Bedarf Verdünnungsluft oder Kühlluft 20 dem vorderen Teil des Brennraumes bzw. dessen Wand zugeführt werden kann.Combustion chamber side 17, the burner has a collar-shaped, as anchoring for the partial cone body 1, 2 serving front plate 18 with a number of holes 19, through which, if necessary, dilution air or cooling air 20 front part of the combustion chamber or its wall can be supplied.

Bei der Brennstoffeindüsung kann es sich um eine luftunterstüzte Düse oder um eine nach dem Druckzerstäubungsprinzip arbeitende Düse handeln. Das kegelige Spraybild wird von den tangential einströmenden Verbrennungsluftströmen 7 umschlossen. Die Konzentration des eingedüsten Brennstoffs 12 wird in Richtung der Strömung 30 fortlaufend durch die Verbrennungsluftströme 7 abgebaut. Wird ein gasförmiger Brennstoff 16 im Bereich der tangentialen Lufteintrittskanäle 5, 6 eingebracht, beginnt die Gemischbildung mit der Verbrennungsluft 7 bereits in diesem Bereich. Beim Einsatz eines flüssigen Brennstoffs 12 wird im Bereich des Wirbelaufplatzens, also im Bereich der Rückströmzone 24 am Ende des Vormischbrenners die optimale, homogene Brennstoffkonzentration über den Querschnitt erreicht. Die Zündung des Brennstoff/Verbrennungsluft-Gemisches beginnt an der Spitze der Rückströmzone 24. Erst an dieser Stelle kann eine stabile Flammenfront 25 entstehen.The fuel injection can be an air-assisted nozzle or is a nozzle that works according to the pressure atomization principle. The conical spray pattern is created by the tangentially flowing combustion air flows 7 enclosed. The concentration of fuel injected 12 is continuously in the direction of flow 30 through the combustion air flows 7 dismantled. Becomes a gaseous fuel 16 in the area of the tangential Introduced air inlet channels 5, 6, the mixture formation begins with the Combustion air 7 already in this area. When using a liquid Fuel 12 is in the area of vortex bursting, that is in the area of Backflow zone 24 at the end of the premix burner the optimal, homogeneous Fuel concentration reached across the cross section. The ignition of the Fuel / combustion air mixture begins at the top of the backflow zone 24. Only at this point can a stable flame front 25 arise.

In einem Ausführungsbeispiel wurden an jedem Teilkegelkörper 1,2 am Brenneraustritt zehn dreieckige Einbauten 32 befestigt, die insgesamt eine Sägezahnstruktur bildeten (Fig. 2). Die Abmessungen der Struktur richtete sich dabei nach der Wellenlänge der dominante Mode der zu unterdrückenden Strömungsinstabilität, deren Frequenz im Ausführungsbeispiel im kHz-Bereich lag. Die experimentelle Bestimmung der Druckschwankungen von Fig. 5 zeigt, daß die Amplitude der thermoakustischen Schwankungen durch die Einbauten ("Sägezahneinbauten", offene Kreise) gegenüber einem konventionellen Brenner ("unverändert", volle Quadrate) um ein bis zwei Größenordnungen reduziert werden. In one exemplary embodiment, each partial cone body had 1.2 at the burner outlet ten triangular internals 32 attached, the total of a sawtooth structure formed (Fig. 2). The dimensions of the structure depended on it according to the wavelength the dominant mode of the flow instability to be suppressed, whose frequency in the exemplary embodiment was in the kHz range. The experimental determination of the pressure fluctuations of Fig. 5 shows that the amplitude of the thermoacoustic fluctuations due to the internals ("Sawtooth internals", open circles) compared to a conventional burner ("unchanged", full squares) reduced by one to two orders of magnitude become.

Obwohl die Abmessungen der Einbauten auf Schwingungen im kHz-Bereich ausgelegt waren, erstreckte sich die dämpfende Wirkung der Einbauten auf einen weiten Frequenzbereich. Figur 6 zeigt die Ergebnisse einer experimentellen Bestimmung der Druckschwankungen im 100 Hz-Bereich bei Verwendung von konventionellen Brennern ("unverändert", volle Quadrate) und von Brennern gemäß dem vorigen Auführungsbeispiels der Erfindung ("Sägezahneinbauten", offene Kreise) als Funktion der Luftzahl λ. Die Luftzahl λ ist dabei ein Maß für das Verhältnis der in den Verbrennungsraum eingeführten zu der zur vollständigen Verbrennung theoretisch benötigten Luftmenge. Wie Fig. 6 zeigt, wird durch die vorliegende Erfindung die Amplitude der Druckschwingungen im besonders relevanten Bereich 1,8 ≤ λ ≤ 2,2 auch im 100 Hz-Bereich noch deutlich reduziert.Although the dimensions of the internals on vibrations in the kHz range were designed, the damping effect of the internals extended a wide frequency range. Figure 6 shows the results of an experimental Determination of pressure fluctuations in the 100 Hz range when in use of conventional burners ("unchanged", full squares) and of Burners according to the previous embodiment of the invention ("sawtooth internals", open circles) as a function of the air ratio λ. The air number λ is included a measure of the ratio of those introduced into the combustion chamber to that theoretically required amount of air for complete combustion. Like Fig. 6 shows, by the present invention, the amplitude of the pressure vibrations in the particularly relevant range 1.8 ≤ λ ≤ 2.2 also in the 100 Hz range still significantly reduced.

In weiteren Ausführungsbeispielen wurden statt geometrisch einfacher Einbauten Wirbelgeneratoren 34 als Einbauten verwendet. Figuren 4a-b zeigen zwei Ausführungsformen für Wirbelgeneratoren 34, die jeweils am Rand 36 eines Teilkegelkörpers angebracht sind. Das Bezugszeichen 40 kennzeichnet die lokale Strömungsrichtung des Arbeitsmittels. Die durch die Wirbelgeneratoren 34 erzeugten Wirbelstrukturen 42 sind jeweils schematisch eingezeichnet. Der Wirbelgenerator von Fig. 4a erzeugt dabei ein Wirbelpaar, das nach innen rotiert, ähnlich wie bei einem Deltaflügel. Der in Fig. 4b gezeigte Wirbelgenerator erzeugt dagegen ein nach außen drehendes Wirbelpaar.In further exemplary embodiments, instead of geometrically simple internals Vortex generators 34 used as internals. Figures 4a-b show two embodiments for vortex generators 34, each at the edge 36 of a partial cone body are attached. The reference symbol 40 denotes the local flow direction of the working fluid. The through the vortex generators 34 generated vortex structures 42 are each shown schematically. The vortex generator of Fig. 4a generates a pair of vertebrae that face inwards rotates, similar to a delta wing. The vortex generator shown in Fig. 4b creates an outward rotating pair of vertebrae.

In einem Ausführungsbeispiel wurden zwanzig Wirbelgeneratoren 34 in den Brenner eingebaut. Zehn der Wirbelgeneratoren wurden wie in Fig. 2 am Brenneraustritt entlang des Umfangs der Teilkegelkörper 1,2 angebracht. Jeweils fünf weitere Wirbelgeneratoren wurden wie in Fig. 3 gezeigt entlang der Brennerschlitze 5a, 6a befestigt. Dabei zeigt der Schnitt von Fig. 3 lediglich einen der beiden Brennerschlitze.In one embodiment, twenty vortex generators 34 were used in the Burner installed. As in Fig. 2, ten of the vortex generators were at the burner outlet attached along the circumference of the partial cone body 1,2. Each five more vortex generators were shown along the burner slots as shown in FIG. 3 5a, 6a attached. 3 shows only one of the two burner slots.

Figur 7 zeigt die Ergebnisse einer experimentellen Bestimmung der Druckschwankungen im 100 Hz-Bereich in Abhängigkeit von der Luftzahl λ bei Verwendung eines konventionellen Brenners ("unverändert", volle Quadrate) und eines Brenners mit der beschriebenen Anordnung von Wirbelgeneratoren ("Wirbelgeneratoren", offene Kreise). Die Druckschwankungen sind über einen weiten Bereich λ <2,2 gegenüber einem unveränderten Brenner deutlich reduziert. FIG. 7 shows the results of an experimental determination of the pressure fluctuations in the 100 Hz range depending on the air ratio λ when used a conventional burner ("unchanged", full squares) and a burner with the described arrangement of vortex generators ("Vortex generators", open circles). The pressure fluctuations are over one wide range λ <2.2 significantly reduced compared to an unchanged burner.

BezugszeichenlisteLIST OF REFERENCE NUMBERS

1,21.2
TeilkegelkörperPartial conical bodies
5,65.6
LufteintrittskanalAir inlet channel
5a,6a5a, 6a
BrennerschlitzeBrenner slots
77
Verbrennungsluftcombustion air
88th
Innenrauminner space
9,109.10
zylindrische Anfangsteilecylindrical initial parts
1111
Brennstoffdüsefuel nozzle
1212
flüssiger Brennstoffliquid fuel
13,1413.14
Brennstoffleitungfuel line
1515
Öffnungenopenings
1616
gasförmiger Brennstoffgaseous fuel
1717
Brennraumcombustion chamber
1818
Frontplattefront panel
1919
Bohrungendrilling
2020
Kühlluftcooling air
2424
Rückströmzonebackflow
2525
Flammenfrontflame front
3030
Richtung der Strömung des Brennstoff/Luft-GemischsDirection of flow of the fuel / air mixture
3232
Einbautenfixtures
3434
Wirbelgeneratorvortex generator
3636
KegelköperrandCone body edge
4040
lokale Strömungsrichtunglocal flow direction
4242
Wirbelstrukturvortex structure

Claims (5)

  1. Burner for operating a unit for producing a hot gas with reduced thermoacoustic vibrations, the burner comprising essentially at least two hollow sectional bodies (1, 2) which are nested one inside the other in the direction of flow (30) of a fuel/air mixture and whose centre axes run offset from one another in such a way that adjacent walls of the sectional bodies (1, 2) form tangential air-inlet ducts (5, 6) at the burner slots (5a, 5b) for the inflow of combustion air (7) into an interior space (8) predetermined by the sectional bodies (1, 2), and the burner, for introducing axial vorticity into the flow (30), having a plurality of built-in components (32) projecting into the flow (30), characterized in that the distances between adjacent built-in components (32) is less than or approximately equal to half the wavelength of a dominant mode of the thermoacoustic vibrations.
  2. Burner according to Claim 1, in which the built-in components (32) are arranged at the burner outlet.
  3. Burner according to Claim 1, in which the built-in components (32) are arranged at the burner outlet and along the burner slots (5a, 6a).
  4. Burner according to one of the preceding claims, in which the built-in components (32) are designed in a saw tooth structure.
  5. Burner according to one of the preceding claims, in which the built-in components (32) are vortex generators (34).
EP98811145A 1998-11-18 1998-11-18 Burner Expired - Lifetime EP1048898B1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
DE59810606T DE59810606D1 (en) 1998-11-18 1998-11-18 burner
EP98811145A EP1048898B1 (en) 1998-11-18 1998-11-18 Burner
US09/434,448 US6196835B1 (en) 1998-11-18 1999-11-05 Burner
DE10022969A DE10022969A1 (en) 1998-11-18 2000-05-14 Burner for hot gas production plant e.g. for gas turbine, has offset interfitting hollow bodies provided with projections on their inside faces for providing axial flow turbulence

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP98811145A EP1048898B1 (en) 1998-11-18 1998-11-18 Burner
DE10022969A DE10022969A1 (en) 1998-11-18 2000-05-14 Burner for hot gas production plant e.g. for gas turbine, has offset interfitting hollow bodies provided with projections on their inside faces for providing axial flow turbulence

Publications (2)

Publication Number Publication Date
EP1048898A1 EP1048898A1 (en) 2000-11-02
EP1048898B1 true EP1048898B1 (en) 2004-01-14

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US (1) US6196835B1 (en)
EP (1) EP1048898B1 (en)
DE (1) DE10022969A1 (en)

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US6672862B2 (en) 2000-03-24 2004-01-06 North American Manufacturing Company Premix burner with integral mixers and supplementary burner system
EP1217295B1 (en) 2000-12-23 2006-08-23 ALSTOM Technology Ltd Burner for generating a hot gas
GB2375601A (en) * 2001-05-18 2002-11-20 Siemens Ag Burner apparatus for reducing combustion vibrations
EP1262714A1 (en) * 2001-06-01 2002-12-04 ALSTOM (Switzerland) Ltd Burner with exhausts recirculation
JP4508474B2 (en) * 2001-06-07 2010-07-21 三菱重工業株式会社 Combustor
US6889686B2 (en) 2001-12-05 2005-05-10 Thomas & Betts International, Inc. One shot heat exchanger burner
DE10205428A1 (en) * 2002-02-09 2003-09-11 Alstom Switzerland Ltd Pre-mixed gas burner for heating system has conical swirl generator with vanes leading into mixing pipe with nozzle incorporating teeth acting as swirl generators
US7494337B2 (en) 2004-04-22 2009-02-24 Thomas & Betts International, Inc. Apparatus and method for providing multiple stages of fuel
US7097448B2 (en) * 2004-05-07 2006-08-29 Peter Chesney Vortex type gas lamp
US7726386B2 (en) * 2005-01-14 2010-06-01 Thomas & Betts International, Inc. Burner port shield
CA2497378A1 (en) * 2005-02-16 2006-08-16 Alberta Welltest Incinerators Ltd. Gas phase thermal unit
CA2537685C (en) * 2006-02-24 2013-05-14 9131-9277 Quebec Inc. Fuel injector, burner and method of injecting fuel
EP1975506A1 (en) * 2007-03-30 2008-10-01 Siemens Aktiengesellschaft Combustion pre-chamber
US20090084292A1 (en) * 2007-09-27 2009-04-02 International Environmental Solutions Corporation Thermal Oxidizer With Enhanced Gas Mixing
WO2011085105A2 (en) 2010-01-06 2011-07-14 The Outdoor Greatroom Company Llp Fire container assembly
DE102014205201A1 (en) * 2014-03-20 2015-09-24 Kba-Metalprint Gmbh Device for thermal afterburning of exhaust air
DE102014205203B3 (en) * 2014-03-20 2015-05-21 Kba-Metalprint Gmbh Device for thermal afterburning of exhaust air
DE102014205198A1 (en) 2014-03-20 2015-09-24 Kba-Metalprint Gmbh Burner and device for thermal afterburning of exhaust air
DE102014205200B3 (en) 2014-03-20 2015-06-11 Kba-Metalprint Gmbh Device for thermal afterburning of exhaust air

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DE59402803D1 (en) * 1993-04-08 1997-06-26 Asea Brown Boveri Combustion chamber
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US5487274A (en) * 1993-05-03 1996-01-30 General Electric Company Screech suppressor for advanced low emissions gas turbine combustor
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JP4130475B2 (en) * 1996-09-09 2008-08-06 シーメンス アクチエンゲゼルシヤフト Apparatus and method for burning fuel in air

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US6196835B1 (en) 2001-03-06
EP1048898A1 (en) 2000-11-02

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