EP1064498B1 - Burner for a gas turbine - Google Patents

Burner for a gas turbine Download PDF

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Publication number
EP1064498B1
EP1064498B1 EP99917770A EP99917770A EP1064498B1 EP 1064498 B1 EP1064498 B1 EP 1064498B1 EP 99917770 A EP99917770 A EP 99917770A EP 99917770 A EP99917770 A EP 99917770A EP 1064498 B1 EP1064498 B1 EP 1064498B1
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EP
European Patent Office
Prior art keywords
swirl
burner
flow
combustion
combustion air
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EP99917770A
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German (de)
French (fr)
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EP1064498A1 (en
Inventor
Manfred Ziegner
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Siemens AG
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Siemens AG
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C7/00—Combustion apparatus characterised by arrangements for air supply
    • F23C7/002—Combustion apparatus characterised by arrangements for air supply the air being submitted to a rotary or spinning motion
    • F23C7/004—Combustion apparatus characterised by arrangements for air supply the air being submitted to a rotary or spinning motion using vanes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D23/00—Assemblies of two or more burners
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2206/00—Burners for specific applications
    • F23D2206/10—Turbines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2210/00—Noise abatement

Definitions

  • the invention relates to a gas turbine burner according to the Preamble of claim 1.
  • combustion vibrations When operating a burner of a gas turbine, it can Training of combustion vibrations come. It is also known under the terms “combustion chamber hum”, “combustion chamber vibrations”, “combustion-induced pressure pulsations”, “swinging burns”.
  • the combustion vibrations are based on an interaction of the supplied per unit time Amount of the combustion air / fuel mixture flowing in the flow channel of the burner, which after an entry is ignited in a combustion chamber and in a flame burns with the current combustion turnover in the Flame. With combustion turnover, the per unit of time is at an amount of combustion air / fuel mixture converted in a flame designated.
  • By a change of the combustion turnover can lead to pressure fluctuations in the combustion chamber come to the formation of a stable Can cause pressure vibration.
  • the combustion vibrations cause increased noise in addition to increased mechanical and thermal stress from Combustion chamber walls and other combustion system belonging parts.
  • a hybrid burner for a gas turbine is known from the EP-0 580 683 B1.
  • a hybrid burner has both a diffusion burner, as well as a premix burner. It is therefore both in diffusion mode and in premix mode operated.
  • the premix burner of the hybrid burner has one Ring channel for supplying combustion air or from one Combustion air / fuel mixture.
  • a swirl device for embossing a swirl on a flow that is the supplied combustion air / fuel mixture or the combustion air in the Ring channel forms. This swirl device is also called a swirl grid designated.
  • the diffusion burner of the hybrid burner is arranged coaxially in the ring channel of the premix burner.
  • the Diffusion burner has an annular channel Combustion air supply channel in which a fuel supply channel coaxially is arranged.
  • the channels of the diffusion burner flow into a nozzle.
  • a pilot burner in its combustion air supply duct which is only for the operation of the premix burner is required.
  • the Ring channel of the premix burner a combustion air / fuel mixture fed, which is a flow in the ring channel forms which flow a swirl with the help of the swirl grid is imprinted.
  • the swirling flow occurs Combustion from the premix burner.
  • the combustion will stabilized with the flame of the pilot burner.
  • at Diffusion operation of the hybrid burner is via the Combustion air and the fuel supply channel of the Diffusion burner combustion air or fuel to a mixture in the area of the diffusion burner nozzles fed.
  • the combustion air / fuel mixture formed during the mixture occurs to a combustion from the Diffusion burner.
  • the object of the invention is to provide a gas turbine burner a lower tendency to form combustion vibrations specify.
  • the gas turbine burner is directed Problem solved by the features of claim 1.
  • Advantageous embodiments are the subject of this back-related subclaims.
  • the invention is based on the knowledge that when such a burner is operated, a flow of combustion air forms in the flow channel and is mixed with fuel to form a combustion air / fuel mixture via fuel inlets.
  • the fuel is preferably fed into a flow of combustion air that is uniform over the cross section of the flow channel. This has the advantage that the local mixing ratio between combustion air and fuel is essentially uniform over the cross section. With a uniform mixture, the NO x content of the exhaust gas, which arises during the combustion of the combustion air / fuel mixture formed in the mixture, can be influenced.
  • a swirl is preferably applied to the flow in the flow channel using a swirl device in order to stabilize the combustion.
  • This swirl is usually uniform over the circumference of the flow channel so as not to impair the uniformity of the flow.
  • Studies have shown that the more uniform the flow of a combustion air / fuel mixture supplied for combustion with a burner, the greater the likelihood that combustion vibrations can form when the burner is operated in a combustion system.
  • the invention is therefore based on the idea of a gas turbine burner to be designed so that a flow of an educated Combustion air / fuel mixture before supply combustion by imprinting an uneven Swirl is so uneven that the excitation of combustion vibrations when operating the gas turbine burner in a combustion system at least significantly reduced is.
  • a flow channel Swirl device with swirl elements available, whereby Deflection surfaces of the swirl elements one at the outflow end Have outflow angle to the main flow direction, the for at least two directly adjacent swirl elements is different. This ensures that the flow after flowing through the swirl device in the circumferential direction emerges at at least two different angles, so that the imprinted swirl of the flow of the combustion air / fuel mixture a circumferentially in Circumferential direction is uneven.
  • each swirl element is designed as a swirl blade.
  • the burner can be designed, for example, as a hybrid burner of the gas turbine.
  • swirl device has at least one such swirl group. More preferred the swirl device is formed from several swirl groups, where neighboring swirl groups have different outflow angles exhibit.
  • the swirl device can for example be formed from six swirl groups, each Swirl group can have four swirl elements.
  • the burner In order to reduce the amount of NO x compounds formed during combustion, it is desirable to supply fuel into a uniform flow of combustion air to form combustion air / fuel mixture intended for combustion.
  • the burner preferably has a fuel inlet through which fuel can be fed into the flow channel upstream of the outflow end. As a result, the fuel is fed into a uniform flow of combustion air flowing in the supply duct in front of the swirl device.
  • the hybrid burner 1 shows a burner 1 designed as a hybrid burner 1 a gas turbine not shown.
  • the hybrid burner 1 has both a diffusion burner 2 and also a premix burner 3.
  • the premix burner 3 has an annular channel 4 with an outer wall 16, which for feeding of combustion air 5 or one Combustion air / fuel mixture 5 is used.
  • Located in the ring channel 4 a swirl device 6 with an outflow end 12, which serves to impress a swirl on a flow 7, which flow 7 the supplied combustion air / fuel mixture 5 or forms the combustion air 5 in the ring channel 4.
  • the swirl device 6 is also referred to below as a swirl grid 6 designated.
  • the swirl grid 6 has several swirl elements 15, each of which is designed as a swirl vane.
  • Fuel inlets 13 are arranged upstream of the outflow end 12, can be fed into the annular channel 4 via the fuel 14 and thus the combustion air 5 can be mixed.
  • the diffusion burner 2 of the hybrid burner 1 is coaxial in the ring channel 4 of the premix burner 3 arranged.
  • the diffusion burner 2 has a combustion air supply duct designed as an annular duct 8, in which a fuel supply channel 9 coaxially is arranged.
  • the channels 8 and 9 of the diffusion burner 2 open into a nozzle 10.
  • the diffusion burner has 2 in its combustion air supply duct 8 a pilot burner 11, which is for operation of the premix burner 3 is provided.
  • combustion air becomes 5 supplied via the ring channel 4, which deal with over the fuel inlets 13 supplied fuel 14 into one Combustion air / fuel mixture mixes.
  • the combustion air / fuel mixture 5 forms a flow 7 with a local main flow direction 14.
  • the swirl grille 6 becomes the flow 7 in Uneven twist impressed with which the Flow 7 leaves the swirl grille 6 at the outflow end 12 and subsequently emerges from the ring channel 4.
  • the combustion air / fuel mixture is ignited and burned 5. With the help of a flame from the pilot burner 11 combustion is stabilized.
  • An advantage of the described configuration of the hybrid burner 1 is that, due to the uneven swirl that the flow 7 of the combustion air / fuel mixture 5 supplied to the combustion has, the outflow from the burner itself is uneven, which at least reduces the build-up of combustion vibrations.
  • Another advantage is that the flow 7 has a swirl with which the combustion is stabilized.
  • the combustion air 5 upstream of the outflow end 12 forms a uniform flow 7.
  • the arrangement of the fuel inlets 13 allows the uniform flow 7 of the combustion air 5 to be fed and mixed upstream with fuel 14, as a result of which a uniform mixture between the combustion air 5 and the fuel 14 can be achieved. This makes it possible to reduce the amount of NO x compounds formed during the combustion.
  • FIG. 2 shows a view of the swirl elements 15 of the ring channel 4 of the premix burner 3 which are developed in the circumferential direction, the direction 17 shown in FIG. 1 perpendicular to the outer wall 16 of the ring channel 4 being selected as the viewing direction.
  • the swirl elements 15 each have a deflection surface 18.
  • the deflection surfaces 18 each form an outflow angle ⁇ with the local main flow direction 14 (see also FIG. 1).
  • the deflection surfaces 18 of two adjacent swirl elements 20 and 21 have different outflow angles ⁇ 1 and ⁇ 2 .
  • the flow 7 leaves the swirl grille 6 at the outflow end 12 with a swirl impressed unevenly in the circumferential direction.
  • the swirl elements 20 and the swirl elements 21 are each combined to form a swirl group which have the outflow angle ⁇ 1 and ⁇ 2 .
  • the invention is characterized by a burner in which in a flow of combustion air or a combustion air / fuel mixture a combustion is supplied, wherein the flow is an uneven swirl in the circumferential direction is imprinted.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Pre-Mixing And Non-Premixing Gas Burner (AREA)
  • Air Supply (AREA)

Description

Die Erfindung betrifft einen Gasturbinenbrenner gemäß dem Oberbegriff des Anspruchs 1.The invention relates to a gas turbine burner according to the Preamble of claim 1.

Bei einem Betrieb eines Brenners einer Gasturbine kann es zur Ausbildung von Verbrennungsschwingungen kommen. Dies ist auch bekannt unter den Begriffen "Brennkammerbrummen", "Brennkammerschwingungen", "verbrennungsinduzierte Druckpulsationen", "schwingende Verbrennungen". Die Verbrennungsschwingungen beruhen auf einer Wechselwirkung der pro Zeiteinheit zugeführten Menge des im Strömungskanal des Brenners strömenden Verbrennungsluft/Brennstoff-Gemischs, welches nach einem Eintritt in eine Brennkammer gezündet wird und in einer Flamme verbrennt, mit dem momentanen Verbrennungsumsatz in der Flamme. Mit Verbrennungsumsatz ist die pro Zeiteinheit bei einer Verbrennung in einer Flamme umgesetzte Menge von Verbrennungsluft/Brennstoff-Gemisch bezeichnet. Durch eine Änderung des Verbrennungsumsatzes kann es zu Druckschwankungen in der Brennkammer kommen, die zur Ausbildung einer stabilen Druckschwingung führen können. Die Verbrennungsschwingungen verursachen neben einer erhöhten Lärmentwicklung eine verstärkte mechanische und thermische Beanspruchung von zur Brennkammer zugehörigen Wänden und weiterer zum Verbrennungssystem gehörender Teile.When operating a burner of a gas turbine, it can Training of combustion vibrations come. It is also known under the terms "combustion chamber hum", "combustion chamber vibrations", "combustion-induced pressure pulsations", "swinging burns". The combustion vibrations are based on an interaction of the supplied per unit time Amount of the combustion air / fuel mixture flowing in the flow channel of the burner, which after an entry is ignited in a combustion chamber and in a flame burns with the current combustion turnover in the Flame. With combustion turnover, the per unit of time is at an amount of combustion air / fuel mixture converted in a flame designated. By a change of the combustion turnover can lead to pressure fluctuations in the combustion chamber come to the formation of a stable Can cause pressure vibration. The combustion vibrations cause increased noise in addition to increased mechanical and thermal stress from Combustion chamber walls and other combustion system belonging parts.

Ein Brenner mit einer Vorrichtung aus parallel zueinander angeordneten Drallelementen ist in US 5 415 114 offenbart.A burner with a device made of parallel to each other Swirl elements are disclosed in US 5,415,114.

Ein Hybridbrenner für eine Gasturbine ist bekannt aus der EP-0 580 683 B1. Ein Hybridbrenner weist sowohl einen Diffusionsbrenner, als auch einen Vormischbrenner auf. Er ist daher sowohl im Diffusionsbetrieb, als auch im Vormischbetrieb betreibbar. Der Vormischbrenner des Hybridbrenners weist einen Ringkanal zur Zuführung von Verbrennungsluft oder von einem Verbrennungsluft/Brennstoff-Gemisch auf. Im Ringkanal angeordnet befindet sich eine Drallvorrichtung zur Aufprägung eines Dralls auf eine Strömung, die das zugeführte Verbrennungsluft/Brennstoff-Gemisch oder die Verbrennungsluft im Ringkanal bildet. Diese Drallvorrichtung wird auch als Drallgitter bezeichnet. Der Diffusionsbrenner des Hybridbrenners ist koaxial im Ringkanal des Vormischbrenners angeordnet. Der Diffusionsbrenner weist einen als Ringkanal ausgebildeten Verbrennungsluftzufuhrkanal auf, in dem koaxial ein Brennstoffzufuhrkanal angeordnet ist. Die Kanäle des Diffusionsbrenners münden in einer Düse. Weiterhin weist der Diffusionsbrenner in seinem Verbrennungsluftzufuhrkanal einen Pilotbrenner auf, welcher nur für den Betrieb des Vormischbrenners erforderlich ist.A hybrid burner for a gas turbine is known from the EP-0 580 683 B1. A hybrid burner has both a diffusion burner, as well as a premix burner. It is therefore both in diffusion mode and in premix mode operated. The premix burner of the hybrid burner has one Ring channel for supplying combustion air or from one Combustion air / fuel mixture. Arranged in the ring channel there is a swirl device for embossing a swirl on a flow that is the supplied combustion air / fuel mixture or the combustion air in the Ring channel forms. This swirl device is also called a swirl grid designated. The diffusion burner of the hybrid burner is arranged coaxially in the ring channel of the premix burner. The Diffusion burner has an annular channel Combustion air supply channel in which a fuel supply channel coaxially is arranged. The channels of the diffusion burner flow into a nozzle. Furthermore, the diffusion burner a pilot burner in its combustion air supply duct which is only for the operation of the premix burner is required.

Bei einem Vormischbetrieb des Hybridbrenners wird über den Ringkanal des Vormischbrenners ein Verbrennungsluft/Brennstoff-Gemisch zugeführt, welches im Ringkanal eine Strömung bildet, welcher Strömung mit Hilfe des Drallgitters ein Drall aufgeprägt wird. Die drallbehaftete Strömung tritt zu einer Verbrennung aus dem Vormischbrenner aus. Die Verbrennung wird mit Hilfe der Flamme des Pilotbrenners stabilisiert. Bei einem Diffusionsbetrieb des Hybridbrenners wird über den Verbrennungsluft- und den Brennstoffzufuhrkanal des Diffusionsbrenners jeweils Verbrennungsluft, bzw. Brennstoff zu einer Mischung im Bereich der Düsen des Diffusionsbrenners zugeführt. Das bei der Mischung gebildete Verbrennungsluft/Brennstoff-Gemisch tritt zu einer Verbrennung aus dem Diffusionsbrenner aus.When the hybrid burner is premixed, the Ring channel of the premix burner a combustion air / fuel mixture fed, which is a flow in the ring channel forms which flow a swirl with the help of the swirl grid is imprinted. The swirling flow occurs Combustion from the premix burner. The combustion will stabilized with the flame of the pilot burner. at Diffusion operation of the hybrid burner is via the Combustion air and the fuel supply channel of the Diffusion burner combustion air or fuel to a mixture in the area of the diffusion burner nozzles fed. The combustion air / fuel mixture formed during the mixture occurs to a combustion from the Diffusion burner.

Aufgabe der Erfindung ist es, einen Gasturbinenbrenner mit einer geringeren Neigung zur Ausbildung von Verbrennungsschwingungen anzugeben.The object of the invention is to provide a gas turbine burner a lower tendency to form combustion vibrations specify.

Erfindungsgemäß wird die auf den Gasturbinenbrenner gerichtete Aufgabe gelöst durch die Merkmale des Anspruchs 1. Vorteilhafte Ausgestaltungen sind Gegenstand der auf diesen rückbezogenen Unteransprüche. According to the invention, the gas turbine burner is directed Problem solved by the features of claim 1. Advantageous embodiments are the subject of this back-related subclaims.

Die Erfindung geht von der Erkenntnis aus, daß sich bei einem Betrieb eines derartigen Brenners im Strömungskanal eine Strömung von Verbrennungsluft bildet, der zur Bildung eines Verbrennungsluft/Brennstoff-Gemischs über Brennstoffeinlässe Brennstoff beigemischt wird. Die Zuführung von Brennstoff erfolgt vorzugsweise in eine über den Querschnitt des Strömungskanals gleichmäßige Strömung von Verbrennungsluft. Dies hat den Vorteil, daß das örtliche Mischungsverhältnis zwischen Verbrennungsluft und Brennstoff über den Querschnitt im wesentlichen gleichmäßig ist. Mit einer gleichmäßigen Mischung kann der NOx-Gehalt des Abgases, welches bei der Verbrennung des bei der Mischung gebildeten Verbrennungsluft/Brennstoff-Gemisches entsteht, beeinflußt werden. Bevor das Verbrennungsluft/Brennstoff-Gemisch der Verbrennung zugeführt wird, wird vorzugsweise mit einer Drallvorrichtung der Strömung im Strömungskanal ein Drall aufgeprägt, um die Verbrennung zu stabilisieren. Dieser Drall ist über den Umfang des Strömungskanals meist gleichmäßig, um die Gleichmäßigkeit der Strömung nicht zu beeinträchtigen. Untersuchungen haben ergeben: je gleichmäßiger die Strömung eines zur Verbrennung mit einem Brenner zugeführten Verbrennungsluft/Brennstoff-Gemisches ist, um so größer ist die Wahrscheinlichkeit, daß es bei einem Betrieb des Brenners in einem Verbrennungssystem zur Ausbildung von Verbrennungsschwingungen kommen kann.The invention is based on the knowledge that when such a burner is operated, a flow of combustion air forms in the flow channel and is mixed with fuel to form a combustion air / fuel mixture via fuel inlets. The fuel is preferably fed into a flow of combustion air that is uniform over the cross section of the flow channel. This has the advantage that the local mixing ratio between combustion air and fuel is essentially uniform over the cross section. With a uniform mixture, the NO x content of the exhaust gas, which arises during the combustion of the combustion air / fuel mixture formed in the mixture, can be influenced. Before the combustion air / fuel mixture is supplied to the combustion, a swirl is preferably applied to the flow in the flow channel using a swirl device in order to stabilize the combustion. This swirl is usually uniform over the circumference of the flow channel so as not to impair the uniformity of the flow. Studies have shown that the more uniform the flow of a combustion air / fuel mixture supplied for combustion with a burner, the greater the likelihood that combustion vibrations can form when the burner is operated in a combustion system.

Der Erfindung liegt daher die Idee zugrunde, einen Gasturbinenbrenner so zu gestalten, daß eine Strömung eines gebildeten Verbrennungsluft/Brennstoff-Gemisch vor der Zuführung zu einer Verbrennung durch Aufprägung eines ungleichmäßigen Dralls so verungleichmäßigt wird, daß die Anregung von Verbrennungsschwingungen bei einem Betrieb des Gasturbinenbrenners in einem Verbrennungssystem zumindest deutlich reduziert ist. Dazu ist eine im Strömungskanal angeordnete Drallvorrichtung mit Drallelementen vorhanden, wobei Umlenkflächen der Drallelemente jeweils am Abströmende einen Abströmwinkel zur Hauptströmungsrichtung aufweisen, der für mindestens zwei direkt benachbarte Drallelemente unterschiedlich ist. Dadurch wird erreicht, daß die Strömung nach dem Durchströmen der Drallvorrichtung in Umfangsrichtung in zumindest zwei unterschiedlichen Winkeln austritt, so daß der aufgeprägte Drall der Strömung des Verbrennungsluft/Brennstoff-Gemisches ein in Umfangsrichtung in Umfangsrichtung ungleichmäßig ist.The invention is therefore based on the idea of a gas turbine burner to be designed so that a flow of an educated Combustion air / fuel mixture before supply combustion by imprinting an uneven Swirl is so uneven that the excitation of combustion vibrations when operating the gas turbine burner in a combustion system at least significantly reduced is. For this purpose, one is arranged in the flow channel Swirl device with swirl elements available, whereby Deflection surfaces of the swirl elements one at the outflow end Have outflow angle to the main flow direction, the for at least two directly adjacent swirl elements is different. This ensures that the flow after flowing through the swirl device in the circumferential direction emerges at at least two different angles, so that the imprinted swirl of the flow of the combustion air / fuel mixture a circumferentially in Circumferential direction is uneven.

Zwar ist es aus der US 5,388,536 bekannt, schaufelartige Umlenkelemente im Strömungskanal eines Brenners mit unterschiedlichen Anstellwinkeln bzw. in verschiedenen Abständen zueinander anzuordnen. Allerdings sollen dadurch bei Brennern für Dampferzeuger brennstoffarme und brennstoffreiche Strömungskanalbereiche geschaffen werden, um den NOx-Gehalt im Verbrennungsgas zu reduzieren.
Weiter bevorzugt ist jedes Drallelement als eine Drallschaufel ausgebildet. Der Brenner kann beispielsweise als Hybridbrenner der Gasturbine ausgebildet sein.It is known from US Pat. No. 5,388,536 to arrange blade-like deflection elements in the flow channel of a burner with different angles of attack or at different distances from one another. However, this should create low-fuel and fuel-rich flow channel areas in burners for steam generators in order to reduce the NO x content in the combustion gas.
More preferably, each swirl element is designed as a swirl blade. The burner can be designed, for example, as a hybrid burner of the gas turbine.

Bevorzugtermaßen bilden mehrere Drallelemente mit gleichen Abströmwinkeln eine Drallgruppe, und die Drallvorrichtung weist mindestens eine solche Drallgruppe auf. Weiter bevorzugt ist die Drallvorrichtung aus mehreren Drallgruppen gebildet, wobei benachbarte Drallgruppen unterschiedliche Abströmwinkel aufweisen. Die Drallvorrichtung kann hierbei beispielsweise aus sechs Drallgruppen gebildet sein, wobei jede Drallgruppe jeweils vier Drallelemente aufweisen kann.Preferably, several swirl elements form the same Outflow angles a swirl group, and the swirl device has at least one such swirl group. More preferred the swirl device is formed from several swirl groups, where neighboring swirl groups have different outflow angles exhibit. The swirl device can for example be formed from six swirl groups, each Swirl group can have four swirl elements.

Zur Verminderung der Menge der bei einer Verbrennung gebildeten NOx-Verbindungen ist es wünschenswert, zur Bildung von zur Verbrennung bestimmtem Verbrennungsluft/Brennstoff-Gemisch Brennstoff in eine gleichmäßige Strömung von Verbrennungsluft zuzuführen. Vorzugsweise weist der Brenner dazu einen Brennstoffeinlaß auf, durch den Brennstoff in den Strömungskanal stromauf des Abströmendes zuführbar ist. Hierdurch wird der Brennstoff in eine vor der Drallvorrichtung gleichmäßige Strömung von im Zufuhrkanal strömender Verbrennungsluft zugeführt. In order to reduce the amount of NO x compounds formed during combustion, it is desirable to supply fuel into a uniform flow of combustion air to form combustion air / fuel mixture intended for combustion. For this purpose, the burner preferably has a fuel inlet through which fuel can be fed into the flow channel upstream of the outflow end. As a result, the fuel is fed into a uniform flow of combustion air flowing in the supply duct in front of the swirl device.

Anhand des in der Zeichnung dargestellten Ausführungsbeispiels wird die Drallvorrichtung zur Aufprägung des Dralls und das Verfahren zur Reduzierung von Verbrennungsschwingungen näher erläutert. Es zeigen schematisiert und teilweise nicht maßstäblich unter Darstellung der für die Erläuterung verwendeten konstruktiven und funktionellen Merkmale:

FIG 1
ein als Hybridbrenner ausgeführter Brenner für eine Gasturbine und
FIG 2
eine Ansicht der in Umfangsrichtung abgewickelten Drallelemente des Ringkanals des Vormischbrenners.
The swirl device for imparting the swirl and the method for reducing combustion vibrations are explained in more detail using the exemplary embodiment shown in the drawing. They show schematically and partly not to scale, showing the constructive and functional features used for the explanation:
FIG. 1
a burner designed as a hybrid burner for a gas turbine and
FIG 2
a view of the swirl elements of the ring channel of the premix burner developed in the circumferential direction.

Die Bezugszeichen sämtlicher Figuren haben jeweils die gleiche Bedeutung.The reference numerals of all figures have the same in each case Importance.

In FIG 1 ist ein als Hybridbrenner 1 ausgeführter Brenner 1 einer nicht näher dargestellten Gasturbine gezeigt. Der Hybridbrenner 1 weist sowohl einen Diffusionsbrenner 2, als auch einen Vormischbrenner 3 auf. Der Vormischbrenner 3 weist einen Ringkanal 4 mit einer Außenwand 16 auf, der zur Zuführung von Verbrennungsluft 5 oder von einem Verbrennungsluft/Brennstoff-Gemisch 5 dient. Im Ringkanal 4 angeordnet befindet sich eine Drallvorrichtung 6 mit einem Abströmende 12, die zur Aufprägung eines Dralls auf eine Strömung 7 dient, welche Strömung 7 das zugeführte Verbrennungsluft/Brennstoff-Gemisch 5 oder die Verbrennungsluft 5 im Ringkanal 4 bildet. Die Drallvorrichtung 6 wird im folgenden auch als Drallgitter 6 bezeichnet. Das Drallgitter 6 weist mehrere Drallelemente 15 auf, die jeweils als Drallschaufel ausgebildet sind. Stromauf des Abströmendes 12 sind Brennstoffeinlässe 13 angeordnet, über die Brennstoff 14 in den Ringkanal 4 zuführbar und somit der Verbrennungsluft 5 beimischbar ist. Der Diffusionsbrenner 2 des Hybridbrenners 1 ist koaxial im Ringkanal 4 des Vormischbrenners 3 angeordnet. Der Diffusionsbrenner 2 weist einen als Ringkanal ausgebildeten Verbrennungsluftzufuhrkanal 8 auf, in dem koaxial ein Brennstoffzufuhrkanal 9 angeordnet ist. Die Kanäle 8 und 9 des Diffusionsbrenners 2 münden in einer Düse 10. Weiterhin weist der Diffusionsbrenner 2 in seinem Verbrennungsluftzufuhrkanal 8 einen Pilotbrenner 11 auf, welcher für einen Betrieb des Vormischbrenners 3 vorgesehen ist.1 shows a burner 1 designed as a hybrid burner 1 a gas turbine not shown. The hybrid burner 1 has both a diffusion burner 2 and also a premix burner 3. The premix burner 3 has an annular channel 4 with an outer wall 16, which for feeding of combustion air 5 or one Combustion air / fuel mixture 5 is used. Located in the ring channel 4 a swirl device 6 with an outflow end 12, which serves to impress a swirl on a flow 7, which flow 7 the supplied combustion air / fuel mixture 5 or forms the combustion air 5 in the ring channel 4. The swirl device 6 is also referred to below as a swirl grid 6 designated. The swirl grid 6 has several swirl elements 15, each of which is designed as a swirl vane. Fuel inlets 13 are arranged upstream of the outflow end 12, can be fed into the annular channel 4 via the fuel 14 and thus the combustion air 5 can be mixed. The diffusion burner 2 of the hybrid burner 1 is coaxial in the ring channel 4 of the premix burner 3 arranged. The diffusion burner 2 has a combustion air supply duct designed as an annular duct 8, in which a fuel supply channel 9 coaxially is arranged. The channels 8 and 9 of the diffusion burner 2 open into a nozzle 10. Furthermore, the diffusion burner has 2 in its combustion air supply duct 8 a pilot burner 11, which is for operation of the premix burner 3 is provided.

Bei einem Vormischbetrieb des Hybridbrenners 1 wird Verbrennungsluft 5 über den Ringkanal 4 zugeführt, die sich mit über die Brennstoffeinlässe 13 zugeführten Brennstoff 14 zu einem Verbrennungsluft/Brennstoff-Gemisch mischt. Im Strömungskanal 2 bildet das Verbrennungsluft/Brennstoff-Gemisch 5 eine Strömung 7 mit einer lokalen Hauptströmungsrichtung 14. Beim Durchströmen des Drallgitters 6 wird der Strömung 7 ein in Umfangsrichtung ungleichmäßiger Drall aufgeprägt, mit dem die Strömung 7 das Drallgitter 6 an der Abströmende 12 verläßt und nachfolgend aus dem Ringkanal 4 austritt. Nach dem Austritt erfolgt eine Zündung und Verbrennung des Verbrennungsluft/Brennstoff-Gemisches 5. Mit Hilfe einer Flamme des Pilotbrenners 11 wird die Verbrennung stabilisiert.When the hybrid burner 1 is premixed, combustion air becomes 5 supplied via the ring channel 4, which deal with over the fuel inlets 13 supplied fuel 14 into one Combustion air / fuel mixture mixes. In the flow channel 2, the combustion air / fuel mixture 5 forms a flow 7 with a local main flow direction 14. At Flow through the swirl grille 6 becomes the flow 7 in Uneven twist impressed with which the Flow 7 leaves the swirl grille 6 at the outflow end 12 and subsequently emerges from the ring channel 4. After the exit the combustion air / fuel mixture is ignited and burned 5. With the help of a flame from the pilot burner 11 combustion is stabilized.

Vorteilhaft an der beschriebenen Ausgestaltung des Hybridbrenners 1 ist, daß aufgrund des ungleichmäßigen Dralls, den die Strömung 7 des der Verbrennung zugeführten Verbrennungsluft/Brennstoff-Gemischs 5 aufweist, die Abströmung aus dem Brenner selbst ungleichmäßig ist, wodurch eine Anfachung von Verbrennungsschwingungen zumindest reduziert ist. Weiterhin von Vorteil ist, daß die Strömung 7 einen Drall aufweist, mit dem die Verbrennung stabilisiert wird. Im Ringkanal 4 des Vormischbrenners bildet die Verbrennungsluft 5 stromauf des Abströmendes 12 eine gleichmäßige Strömung 7. Durch die Anordnung der Brennstoffeinlässe 13 kann der gleichmäßigen Strömung 7 der Verbrennungsluft 5 stromauf Brennstoff 14 zugeführt und beigemischt werden, wodurch eine gleichmäßige Mischung zwischen Verbrennungsluft 5 und Brennstoff 14 erreicht werden kann. Hierdurch ist eine Verkleinerung der bei der Verbrennung gebildeten Menge von NOx-Verbindungen möglich. An advantage of the described configuration of the hybrid burner 1 is that, due to the uneven swirl that the flow 7 of the combustion air / fuel mixture 5 supplied to the combustion has, the outflow from the burner itself is uneven, which at least reduces the build-up of combustion vibrations. Another advantage is that the flow 7 has a swirl with which the combustion is stabilized. In the annular channel 4 of the premix burner, the combustion air 5 upstream of the outflow end 12 forms a uniform flow 7. The arrangement of the fuel inlets 13 allows the uniform flow 7 of the combustion air 5 to be fed and mixed upstream with fuel 14, as a result of which a uniform mixture between the combustion air 5 and the fuel 14 can be achieved. This makes it possible to reduce the amount of NO x compounds formed during the combustion.

In Analogie zur Ausbildung des Drallgitters 6 des Vormischbrenners 3 kann ein im Verbrennungsluftzufuhrkanal 8 angeordnetes Drallgitter so ausgeführt sein, daß damit auf eine sich im Verbrennungsluftzufuhrkanal 8 ausbildende Strömung ein in Umfangsrichtung ungleichmäßiger Drall aufprägbar ist.In analogy to the formation of the swirl grille 6 of the premix burner 3 can be arranged in the combustion air supply duct 8 Swirl grille be designed so that it is on a in the combustion air supply duct 8 forming a flow in Uneven twist can be impressed on the circumferential direction.

In FIG 2 ist eine Ansicht der in Umfangsrichtung abgewickelten Drallelemente 15 des Ringkanals 4 des Vormischbrenners 3 dargestellt, wobei als Blickrichtung die in FIG 1 dargestellte Richtung 17 senkrecht zur Außenwand 16 des Ringkanals 4 gewählt ist. Die Drallelemente 15 weisen jeweils eine Umlenkfläche 18 auf. Die Umlenkflächen 18 bilden mit der lokalen Hauptströmungsrichtung 14 (siehe auch FIG 1) jeweils einen Abströmwinkel α. Die Umlenkflächen 18 zweier benachbarter Drallelemente 20 und 21 weisen unterschiedliche Abströmwinkel α1 und α2 auf. Hierdurch verläßt die Strömung 7 das Drallgitter 6 am Abströmende 12 mit einem in Umfangsrichtung ungleichmäßig aufgeprägten Drall. Die Drallelemente 20 und die Drallelemente 21 sind dabei jeweils zu einer Drallgruppe zusammengefaßt, die den Abströmwinkel α1 bzw. α2 aufweisen.FIG. 2 shows a view of the swirl elements 15 of the ring channel 4 of the premix burner 3 which are developed in the circumferential direction, the direction 17 shown in FIG. 1 perpendicular to the outer wall 16 of the ring channel 4 being selected as the viewing direction. The swirl elements 15 each have a deflection surface 18. The deflection surfaces 18 each form an outflow angle α with the local main flow direction 14 (see also FIG. 1). The deflection surfaces 18 of two adjacent swirl elements 20 and 21 have different outflow angles α 1 and α 2 . As a result, the flow 7 leaves the swirl grille 6 at the outflow end 12 with a swirl impressed unevenly in the circumferential direction. The swirl elements 20 and the swirl elements 21 are each combined to form a swirl group which have the outflow angle α 1 and α 2 .

Die Erfindung zeichnet sich aus durch einen Brenner, bei dem in einer Strömung Verbrennungsluft oder ein Verbrennungsluft/Brennstoff-Gemisch einer Verbrennung zugeführt wird, wobei der Strömung ein in Umfangsrichtung ungleichmäßiger Drall aufgeprägt wird.The invention is characterized by a burner in which in a flow of combustion air or a combustion air / fuel mixture a combustion is supplied, wherein the flow is an uneven swirl in the circumferential direction is imprinted.

Claims (4)

  1. Burner
    having a flow (7),
    having a swirl device (6) for imposing a swirl on the flow (7),
    the flow (7) being formed by a mixture of fuel and combustion air,
    the flow (7) being guided in a flow duct, and
    the swirl device being arranged in the flow duct (4), and
    the burner being a gas turbine burner, and
    the burner being a premixing burner (3), and
    each of a number of swirl elements (15) of the swirl device (6) having a deflection surface (18) with an outlet angle (α) relative to a main flow direction (14) at its output end (12),
    the outlet angle (α) of at least two adjacent swirl elements (15) being different,
    so that the swirl device (6) is configured for imposing on the flow (7) a swirl which is non-uniform over the periphery of the annular duct (4).
  2. Burner according to Claim 1, characterized in that the swirl device (6) is formed by a plurality of swirl groups (20, 21), each swirl group (20, 21) having a plurality of swirl elements (15) having the same outlet angle (α1 and α2, respectively), and the swirl elements (15) of adjacent swirl groups (20, 21) having different outlet angles (α1, α2).
  3. Burner according to Claim 1 or 2, characterized by its embodiment as a hybrid burner.
  4. Burner according to Claim 1, characterized in that each swirl element (15) is configured as a swirl vane.
EP99917770A 1998-03-20 1999-03-08 Burner for a gas turbine Expired - Lifetime EP1064498B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19812322 1998-03-20
DE19812322 1998-03-20
PCT/DE1999/000614 WO1999049264A1 (en) 1998-03-20 1999-03-08 Burner and method for reducing combustion humming during operation

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EP1064498A1 EP1064498A1 (en) 2001-01-03
EP1064498B1 true EP1064498B1 (en) 2002-11-13

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US (1) US6374593B1 (en)
EP (1) EP1064498B1 (en)
JP (1) JP2002507717A (en)
DE (1) DE59903398D1 (en)
WO (1) WO1999049264A1 (en)

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JP2002507717A (en) 2002-03-12
WO1999049264A1 (en) 1999-09-30
DE59903398D1 (en) 2002-12-19
US6374593B1 (en) 2002-04-23
EP1064498A1 (en) 2001-01-03

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