EP3087323A1

EP3087323A1 - Burner, gas turbine having such a burner, and fuel nozzle

Info

Publication number: EP3087323A1
Application number: EP15741750.2A
Authority: EP
Inventors: Christian Beck; Stefan Dederichs; Olga Deiss; Berthold Köstlin
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2014-04-03
Filing date: 2015-03-20
Publication date: 2016-11-02
Anticipated expiration: 2035-03-20
Also published as: CN106164592A; WO2015150114A1; US10125993B2; US20170108224A1; CN106164592B; EP3087323B1

Abstract

The invention relates to a burner (2) having a plurality of pre-mixing chambers (6) each having a fuel nozzle (10) for two fuels, wherein the fuel nozzle (10) has a fuel lance (14) that extends in a flow direction (S), in which fuel lance a number of first outlet openings (18) for a first fuel is introduced, and the fuel lance (14) is surrounded by an outer pipe (16) having at least one second outlet opening (20) for a second fuel, wherein the first outlet openings (18) are oriented radially and the second outlet opening (20) is oriented axially, wherein a flow cross-section (Q) is formed between the fuel lance (14) and the inside of the pre-mixing chamber (6) and wherein a number of vortex generators (22) is arranged on the fuel lance (14), which vortex generators reduce the flow cross-section (Q) oriented transversely to the flow direction (S), wherein at least one vortex generator (22) is arranged upstream of the first outlet openings (18) and downstream of the second outlet opening (20) and the pre-mixing chamber (6) has a cross-section (50) and an end (52) and the distance of the first outlet openings (18) from the end (52) of the pre-mixing chamber (6) is at least three times as large as the cross-section (50) of the pre-mixing chamber (6). The invention further relates to a gas turbine (4) having such a burner (2). The invention further relates to a fuel nozzle (10).

Description

description

Burner, gas turbine with such a burner and fuel ^¬ nozzle

The invention relates to a burner with a premixing chamber and with a fuel nozzle for two fuels. The width ^¬ ren the invention relates to a gas turbine having such a burner. Furthermore, the invention relates to a fuel nozzle for two fuels.

In gas turbines, a burner is typically provided with a pre-mixing chamber in which a particular gaseous fuel is mixed with air to subsequently burn the resulting mixture. The efficiency of Gasturbi ^¬ ne and the formation of unwanted emission products, in particular nitrogen oxides are significantly dependent on the mixing of the fuel with the air. In particular, in a natural gas-powered gas turbine, the natural gas is often injected in the radial direction, that is perpendicular to the flow direction of the air (so-called jet-in-cross-flow method). As a result, a suitable mixing of natural gas and air can be achieved.

For mixing, for example, from DE 44 26 351 AI so-called vortex generators are known. There, a combustion chamber is disclosed, which essentially consists of a first and a downstream in the flow direction second stage. In this case, the first stage on the head side ei ^¬ nen mixer to form a fuel / air mixture and on the outflow side of the mixer vortex generators are available. These are used in particular for swirling hot air which subsequently research in a premixing zone for Vermi- is then passed into a combustion zone ^¬ the second stage with fuel and. In addition, it is known to operate gas turbines with multiple fuels, such as natural gas and water ^¬ material. The operation can take place either simultaneously with meh ^¬ reren fuels or only with one of the fuels. As a result, in particular, the flexibility of the gas turbine is increased, since fuels can be ^¬ depending on availability set. However, due to the different operating modes, additional requirements are imposed on the gas turbine and its burners.

When using or adding hydrogen, however, there is an increased risk of flashback and auto-ignition compared to the mere use of natural gas. For Ver ^¬ ringerung this risk, it is possible, the hydrogen is a less reactive gas to add to the formation of a hydrogen-containing fuel gas, which is often, however, adversely has a lower energy density than natural gas. As a result, it is particularly necessary to use different volume flows for the different fuels in a suitable injection concept.

To further reduce the risk of flashback and auto-ignition, it is known to inject the hydrogen-containing fuel gas in the coaxial direction, that is to say in the direction of flow of the air. As a result, in particular an air-side pressure loss is reduced, which is greater when using hydrogen-containing fuel gas due to the larger volume flow than when using natural gas. From EP 2604919 Al a Brennstoffdü- example se for two fuels known, with an inner tube with ra dial ^¬ oriented exit openings for a first

Fuel and with an inner tube surrounding the outer tube with axially aligned outlet openings for a second fuel. By means of such a nozzle, it is possible, for example, to inject a hydrogen-containing fuel gas in the flow direction of the air via the axial outlet openings. To improve the mixing of the fuel gas with the air In addition, a so-called Lobe mixer is provided. The second fuel, for example natural gas is then injected via the radial outlet openings. The disadvantage here is that no further optimization options with respect to the mixing in particular of the natural gas and the air be ^¬ stands.

The object of the invention is to specify an improved burner which is suitable in particular for operation with a plurality of fuels. Furthermore, a mixture formation in the burner should be improved. Furthermore, a gas turbine to be specified with such a burner. In addition, an improved fuel nozzle is to be specified, which is particularly suitable for multiple fuels.

The object is achieved by a burner with the features of claim 1, a gas turbine with the features of claim 10 and a fuel nozzle with the features of claim 11. Advantageous embodiments, developments and variants are the subject of the dependent claims.

For this purpose, it is provided that a burner comprises a plurality of premix chambers each having a fuel nozzle for two fuels, the fuel nozzle having a fuel ^lance extending in a flow direction into which a number of first outlet openings for a first fuel are introduced fuel ^¬ lance surrounded by an outer tube, wherein between the internal ^¬ material lance and the inside of the premixing chamber, a flow ^¬ cross-section is formed with at least one second outlet opening for a second fuel, the first outlet openings radially and the second from ^¬ opening are axially aligned and wherein a number of vortex generators are arranged on the fuel lance, which reduce a flow cross-section oriented in the flow direction, wherein at least one vortex generator upstream of the first outlet openings and downstream of the second outlet Is arranged opening and the premixing chamber has a cross section and an end and the distance of the first Aus ^¬ outlet openings from the end of the premixing chamber is at least three times as large as the cross section of the premixing chamber. In particular, the premixing chamber has an air inflow channel in which the fuel nozzle is arranged. Advantageously ^¬ example flows in a flow direction of air, for mixing with the first and / or second fuel. The air, the first fuel and the second fuel ^¬ hereinafter referred to generally as gases. The application is in principle but not limited to gaseous media. Furthermore, the application is not limited to the following gases, namely natural gas, hydrogen and air.

The fuel lance is advantageously used for the injection of natural gas, which is provided by means of the radial outlet openings for mixing. Under radially here- is understood in that the fuel lance extends in flow ^¬ direction, that is axially and in addition a Man ^¬ telfläche radially, are inserted into the appropriate, such as circular openings. As a result, in particular a so-called jet-in-crossflow mixture is realized, in which the fuel is flowed substantially perpendicular to the air.

The outlet openings are preferably on a ge ^¬ common position in the axial direction and uniformly in the fuel lance environmental circumferential direction distributed. Alternatively, however, another suitable arrangement is chosen. ^{Beispielswei ¬} se outlet openings are arranged at several positions in the axial direction one behind the other. Also in the flow direction, ie in the axial direction extends the outer tube surrounding the fuel lance. The outer tube surrounds the fuel lance in the axial direction preferably only partially, that is, the fuel The substance lance projects in the flow direction. This makes it possible, in particular, to arrange the radial outlet openings outside a region of the fuel lance covered by the outer tube, which in particular improves the mixing with air. Alternatively, the radial From ^¬ outlet openings, however, are covered by the outer tube or they are both covered as not covered Austrittsöffnun ^¬ gen present. The outer tube is preferably used for axial injection of the second fuel, for example hydrogen or a hydrogen-containing fuel gas. Due to the axial injection, it is in particular possible to inject a fuel by means of a larger volume flow compared to natural gas. Advantageously, furthermore, an air-side pressure loss, as may possibly occur in the case of radial injection, can be reduced or avoided altogether.

To improve a mixing of two or all of the gases with one another, at least one vortex generator is provided, that is to say arranged in the burner. By means of the vortex generator, the mixing can be achieved, in particular, by reducing a flow cross-section of at least one of the gases at at least one position along the flow direction.

For example, the air flows in the flow direction at a first position, a first surface, which is oriented transversely, that is substantially perpendicular to the flow direction. The first surface corresponds to the flow cross section at the first position. For example, a vortex generator is now arranged at ei ^¬ ner second position downstream of the first position, which opposes the air an additional Blo ^¬ ckierungsfläche, whereby the flowed through by the air at the second position second surface is smaller than the first surface. In other words, the flow area is smaller at the second position than at the first position. By way of example, the vortex generator is a surface which is set in relation to the flow direction. It points the vortex generator suitably on a contour, preferably ^¬ at least one edge, for the generation of turbulence. These are used especially for mixing of the now verwirbel ^¬ th gas with a second gas. Conveniently, this improves the mixing of the first and / or the second fuel with the air and / or the mixing of the fuels with one another. Overall, therefore, an efficient mixing of the gases is through the Anord ^¬ voltage of the vortex generators in a multi-fuel fuel nozzle achieved in operation due to the turbulence generated, regardless of the respective operating mode, so that current gas as fuel is ^¬ is set.

In the burner according to the invention, at least one turbulizer is mounted on the fuel lance. Particularly when using the vortex generator for swirling of the injected by the fuel lance primary fuel of the vortex generators is part way legally adapted to the requirements of this fuel before ^¬. When replacing the first fuel and thus possibly changed requirements for mixing with air, it is thereby possible in particular to replace the turbulizer by exchanging the fuel lance at the same time. Furthermore, in the burner according to the invention, at least one vortex generator is arranged upstream of the radial outlet openings and downstream of the axial outlet opening. In this way, in particular, turbulence of the air and / or of the second fuel can be achieved without the vortex generator directly influencing the flow of the first fuel. It is understood by direct influence that the respective vortex generator is affected by the gas influenced by this. Finally, the pre-mixing chamber of the burner according to the invention has a cross-section and an end, wherein in the Hin ^¬ view of a good mixing of fuel and air, the distance of the first outlet openings from the end of the premix chamber is at least three times as large as the cross section of the premixing chamber. This ensures that the length of the route, on which fuel and air can mix, is sufficiently large.

In a preferred embodiment, the fuel lance and the outer tube are arranged concentrically. In particular, the fuel lance and the outer tube are designed substantially cylindrical and have a common longitudinal axis. The outer tube is preferably formed as a tube with an annular profile transverse to the longitudinal axis. Suitably ^¬ ßigerweise the longitudinal axis extends in the flow Rich ^¬ processing. In particular, the second fuel and the air flow in each case in the flow direction. In other words, the air and the second fuel are flowed in or injected axially. In contrast, the first fuel is preferably injected radially.

In a suitable embodiment, at least one vortex generator is wedge-shaped. Is understood to wedge-shaped ^¬ that the vortex generator has a surface which extends obliquely to the axial direction and in particular obliquely to the flow direction. For example, the surface is rectangular. Alternatively, the surface is triangular, with one side of the triangle extending transversely to the flow direction. The two remaining sides either run in or against the flow direction to a tip of the triangle. In particular, keilför ^¬ mig is also understood tetrahedral.

Instead of a wedge-shaped configuration, other geometric shapes are still suitable. Also, the Wirbelerzeu ^¬ ger may be composed as a solid body or of different surface elements or even multi-part forms. It is essential that is setting by means of the bar ^¬ Wirbelerzeu ^¬ gers the flow cross section in the flow direction, to generate turbulence in the flow and in particular to the course of the vortex generator inflowing gas. It will Under adjustable in particular understood that the exact design and orientation of the Wirbelträgers is determined during its manufacture and assembly. In an advantageous embodiment, at least one turbulizer is attached to the outer tube. In this case, the vortex generator is either externally mounted on the outer tube, in particular for turbulence of the air flowing there suitably along it, or on the inside in the outer tube, for turbulence of the second fuel, which preferably flows along there.

In a further advantageous embodiment, the premixing chamber comprises an inner wall, on which at least one vortex generator is mounted. As a result, in particular one of the fuel nozzle substantially independent

To achieve turbulence.

In a further advantageous embodiment, at least one vortex generator is arranged downstream of the radial outlet openings. In other words, at least one vortex generator is arranged downstream of any outlet openings, as a result of which this vortex generator influences in particular each of the inflowing gases, that is, in particular, swirls.

Several or all of the above-mentioned embodiments relating to the positioning of the vortex generators are combined in a further advantageous embodiment. As a result, in particular, the corresponding advantages are also combined. For example, at least one vortex generator downstream of the axial outlet opening and upstream of the radial outlet openings and on the fuel lance angeord ^¬ net. Alternatively or additionally, for example, a plurality of vortex generators are arranged in the axial direction at different positions on the fuel lance.

Furthermore, it is possible to arrange several vortex generators advantageously in groups, for example in series, in axia- ler direction one behind the other or offset; or in a plane, that is, in particular, both side by side ^(¬ example, in the circumferential direction) and one behind the other. It is also possible that several vortex generators advantageously have different geometries and / or dimensions.

Preferably, a plurality of vortex generators are arranged at approximately the same position in the axial direction and along a circumferential direction with respect to the longitudinal axis. For example, sev- eral vortex generators are on the circumference of the outer tube in such a ^¬ arranged that all distances lying in the circumferential direction between adjacent vortex generators are the same.

In particular, it is possible that pairs of the different gases swirling influences by a suitable combination of several, in particular different vortex generators advantageous to be ^¬. For example, a number of vortex generators are mounted on the outer tube for entangling the air and for improved mixing with it downstream of it axially

injected hydrogen. To continue the swirl of

To optimize natural gas with air, for example, additional vortex generators are mounted downstream of the radial outlet openings. In an advantageous development, the outer tube has an end region which is designed as a lobe mixer and comprises a number of lamellae. These extend in particular in the flow direction and as radially formed folds. As a result, a star-shaped cross-section (or also a star-shaped profile) results transversely to the longitudinal axis. In the circumferential direction while a gap is formed between each two fins, by the particular flow cross-section of the air downstream ^¬ is advantageous magnification ßert.

The lamellae each have a vertex in the radial direction, which extends substantially in the axial direction. This means in particular that the radial distance between vertex and longitudinal axis in the flow direction is substantially constant. In particular, the outer tube ei ^¬ nen outer sheath and the apex of the slats are substantially aligned with the outer sheath. It is possible that a slight inclination or slope is provided in the axial direction.

A mixing of the second fuel with air is achieved before ^¬ geous in that it follows a flow in the flow direction, which breaks off at the end of the end region.

In particular, the star-shaped cross section of the Endberei ^¬ Ches at the end of a relative to the outer tube extended (and correspondingly star-shaped) contour line. As a result, an edge which is larger in comparison to the circumference of the outer tube is advantageously provided for stalling.

In a suitable development, the end region is twisted or twisted in such a way that the lamellae and thus also the apices extend in a spiral around the longitudinal axis.

This makes it possible to additionally twist the air flowing along the lamellae and thus to achieve improved mixing.

In a further suitable development, a number of lamellae are additionally designed as vortex generators. For this purpose, these lamellae are in particular designed such that de ^¬ ren apex are formed as in the axial direction inclined flächen ^¬ chen. In other words, the distance from the apex of a lamella to the longitudinal axis changes in the direction of flow. Preferably, the distance in the flow ^¬ direction is continuously increased. As a result, in particular an employed surface is provided with an edge in such a way that by means of this a turbulence in the manner of a vortex ^¬ producer can be achieved.

In an advantageous development, at least one vortex generator is arranged in an intermediate space between two lamellae. The space mentioned here corresponds to the already mentioned above space between two adjacent in the direction of rotation of the outer tube fins. In particular, it is possible by this arrangement to produce vortex generators with comparatively large side surfaces, that is, in comparison to, for example, arranged on an annular tube without lobe mixer vortex generators. As a result, the turbulence can be advantageously influenced.

Conveniently, a combination of the above-mentioned vortex generator with one of the above concepts for the injection of the second fuel allows improved Mi ^¬ research of the gases involved. Advantageously, the Mi ^¬ research is improved in each case both at the same time the injection of the first and second fuel (e.g., natural gas and hydrogen) and in a single operation, that is during spraying only a fuel (e.g. natural gas or hydrogen).

Preferably, a gas turbine comprises a burner having one or more of the above features, thereby providing the above-mentioned advantages. Such a gas turbine is also particularly efficient and has front ^¬ geous enough, a lower pollutant emissions. Suitably, a fuel nozzle for two fuels has a fuel ^lance extending in a flow direction. In this a number of first Aus ^¬ outlet openings for a first fuel is introduced. The fuel lance is surrounded by an outer tube with at least one second outlet opening for a second fuel, wherein the first outlet openings are radially aligned and the second outlet opening axially, wherein a number of vortex generators on the fuel lance ange ^{¬ is} arranged. At least one vortex generator is arranged upstream of the first outlet openings and downstream of the second outlet opening. Embodiments of the invention will be explained in more detail with reference to a drawing. Show:

1 shows a side view of a burner with a

Fuel nozzle for two fuels and several attached to the fuel nozzle Wirbelerzeu ^¬ like,

2 shows the burner according to FIG 1 with an alternative

Fuel nozzle and a premixing chamber, to which internally several vortex generators are attached,

FIGS. 3 to 17 show further exemplary embodiments of the fuel ^nozzle according to FIG. 1, the fuel nozzle being shown in side views in FIGS. 3, 6, 9, 12 and 15, in FIGS. 4, 7, 10, 13 and 16, respectively in front view and in Figures 5, 8, 11, 14 and 17 respectively in a perspective view, and

Each show an embodiment of a vortex ^¬ generator in a perspective view.

A schematic representation of a burner 2, in particular for a gas turbine 4, respectively show the FIG 1 and 2. The burner 2 includes a premixing chamber 6, which is followed by a combustion chamber 8 in the flow direction S. In the exemplary embodiment shown here, two fuels and air are injected into the premixing chamber 6 during operation. For injecting the fuel is a fuel nozzle 10, which extends in the flow direction S. The air is flown in through a fuel inlet duct 12 surrounding the fuel nozzle 10 in the flow direction S. The fuel nozzle 10 comprises a fuel lance 14 and an outer tube 16 surrounding it, the fuel lance 14 projecting in the flow direction S and with respect to the outer tube 16. The fuel lance 14 and the outer tube 16 are in the embodiment shown here is designed substantially cylindrical, that is, these have transversely to the Strö ^¬ tion direction S a circular or annular cross-section. In particular, the fuel lance 14 and the outer tube 16 arranged concentrically and have a common longitudinal axis L corresponding to the ver ^¬ runs in the flow direction S.

The fuel lance 14 has a number of radial outlet openings 18. These are circular in the embodiment shown here and arranged on a common ^¬ position in the axial direction, ie in the flow direction S. In this case, the outlet openings 18 are distributed in a circumferential direction U and in particular uniformly. The radial outlet openings 18 are used in particular for the injection of the first fuel, for example natural gas.

The outer tube 16 has a larger diameter than the fuel lance 14, whereby in particular an annular, axial outlet opening 20 is realized in the axial direction. By means of this, the second fuel is injected into the pre-mixing chamber 6. That is, the second fuel to flow ^¬ especially the fuel lance 14. In FIG 1 is on the fuel lance 14, a number of ^¬ We belerzeugern 22 attached. These are arranged downstream of the axia ^¬ len outlet opening 20 and upstream of the radial outlet openings 18. In the exemplary embodiment shown here, the vortex generators 22 are of tetrahedral design (cf., in particular, also FIG.

FIG 1 also shows that the pre-mixing chamber 6 has a cross section 50 and one end 52 and the spacing of the ers ^¬ th exit openings 18 of the end 52 of the pre-mixing chamber 6 is at least three times as large as the cross-section 50 of the premixing chamber. 6 In an alternative or additional embodiment according to FIG. 2, the vortex generators 22 according to FIG. 1 are fastened to the premixing chamber 6 on the inside. In this case, the vortex generators 22 are arranged at a position downstream of the radial outlet openings.

In both exemplary embodiments illustrated in FIGS. 1 and 2, the vortex generators 22 each have a surface 24 which is set up with respect to the flow direction S, which is triangular here and counter to the flow direction S on the

Longitudinal axis L tapers. This arrangement is also referred to as forward directed. In an alternative, non ge here ^¬ embodiment shown, the vortex generators 22 are, however, directed backwards, that is rotated such that the surface 24 runs in the flow direction S to the longitudinal axis L to ^¬ 180 °.

In particular, in each case two edges 26 are formed by the surface 24, on which in particular a turbulence is generated during operation. In addition, in particular by the premixing chamber 6 and the elements arranged therein as well as transversely to the flow direction S, a flow cross-section Q defi ^¬ ned, which is changed by the vortex generators 22 in the flow direction S. For example, in FIG. 1, the flow cross-section Q is defined at a first position PI by the premixing chamber 6 and the fuel lance 14. At this first position PI, the flow cross section Q is particularly RESIZE ^¬ SSER than at a second position P2, the vortex generators 22 are disposed at the position shown here in the exemplary embodiment. Advantage of oats, it is possible to adjust the flow cross section Q through suitable From ^¬ design of the vortex generator 22 and thus to influence in particular the mixing of the gases suitable. The FIG 3 to 17 schematically show further Ausführungsbei ^¬ play a fuel nozzle 14. Here, Figs 3, 6, 9, 12 and 15 respectively, the fuel nozzle 14 in a Seitenan ^¬ view and to each of the gases clarified by arrows a Inlet direction 28, 30, 32. In this case, the first fuel in the inflow direction 28 is flowed in radially and the second fuel and the air are flowed axially in the inflow directions 30, 32. The axial inflow of the general flow direction ^¬ S is defined in the pre-mixing chamber 6 in particular, which follows also the first fuel at a sufficient distance to the radial outlet openings 18 substantially. The FIG 4, 7, 10, 13 and 16 respectively show the corresponding fuel lance 14 in front view, FIG 5, 8, 11, 14 and 17 respectively show the corresponding fuel lance 14 in ei ^¬ ner perspective view. The embodiment illustrated in FIGS. 3 to 5

Fuel nozzle 10 includes a number of forward orientier ^¬ th, tetrahedron shaped vortex generators 22, which are mounted downstream of the axial outlet opening 20 and upstream of the radial outlet openings 18 on the fuel lance fourteenth In this case, the vortex generators 22 each have a height H, which is selected here such that the Wirbelerzeu ^¬ ger 22 extends in the radial direction, as the outer tube 16. This is particularly clearly shown in FIG 4. Here ^¬ through it is possible in particular di- rectly 22 to flow through the vortex generator with air and to swirl them.

The Figures 6 to 8 show the fuel nozzle 10 mounted on the Au ^¬ ßenrohr 16 vortex generators 22. These are oriented forward and here are flowing from the flowed around the outer pipe 16 air. By contrast, the fuel lance 14 has no vortex generators 22.

FIGS. 9 to 11 show the fuel nozzle 10 with an end region 34 designed as a lobe mixer. For this purpose, a number of six lamellae 36 are formed in the end region 34.

These result in a star-shaped cross-section, as example ^¬ from FIG 10 is clear. FIG. 10 further shows that the lamellae 36 do not substantially project beyond the outer tube 16 in the radial direction.

The lamellae 36 each have a vertex 38 extending in the axial direction and, in particular, are evenly spaced in the circumferential direction U by intermediate spaces 40. At the end 42 of the outer tube 16, the lamellae 36 form a star-shaped contour 44, by which in particular a number of outlet channels 46 is realized. The axial outlet opening 20 therefore comprises six outlet channels 46 in the exemplary embodiment shown here.

As shown in FIGS. 10 and 11, the vortex generators 22 mounted downstream on the fuel lance 14 can either follow one of the outlet channels 46 in the flow direction S or be offset therefrom. Of the existing here four vortex generators 22, for example two Wirbelerzeu ^¬ ger 22A are arranged in an imaginary extension of the outlet channels 46 and two vortex generator disposed in an imaginary extension of gaps 40 22B. By means of a particularly arranged mixed arrangement, it is possible to use the respective vortex generator 22 either primarily for turbulence of the air flowing through a gap 40 or primarily for turbulence of the second fuel flowing through an outlet channel 46.

Figures 12 to 14 show an embodiment in which the outer tube 16 of the fuel nozzle 10 in the end region 34 has a number of four fins 36 here, which are designed as a vortex generator 22 at the same time. The respective vertex 38 of a lamella 36 is formed as an employee surface 24 and has two substantially triangular surface 24 be ^¬ bordering edges 26. These extend downstream of the longitudinal axis L away. The end region 34 has a number of outlet ^channels 46 corresponding to the number of vortex generators 22 for the second fuel. Furthermore, in the exemplary embodiment shown here, the radial outlet openings 18 are arranged substantially directly downstream of the outer tube 16. A respective radial From ^¬ opening 18 is arranged either in an imaginary extension of an intermediate space 40 or in an imaginary extension of an outlet duct 46th

An alternative embodiment with both vortex generators 22 and fins 36 in the end region 34 of the outer tube 16 is shown in Figures 15 to 17. There is one in each case

Vortex generator 22 is arranged in the intermediate space 40 between two adjacent lamellae 36. The vortex generators 22 are formed in the embodiment shown here to the end 42 of the outer ^¬ pipe 16, that is, in particular, the vortex generators 22 are aligned in the radial direction with the end 42 of the outer tube 16. In contrast to the vortex generators shown in Figures 12 to 14 22, the vortex generators 22 shown in FIGS. 15 to 17 have no outlet channels 46 at the end. The Figures 18 to 23 each show an embodiment of a vortex generator 22. Here, the actual execution not be limited ^¬ to the embodiments shown herein. The Figures 18 and 19 respectively show a relation to a Strö ^¬ flow direction S employed triangular or right ^¬ shaped surface 24. The Figures 20 and 21 show similar ausgestal ^¬ preparing vortex generator 22, but these are here designed as a solid body and have respective side surfaces 48 on. In contrast, the vortex generator shown in Figures 22 and 23, 22 each comprise two, in particular separately manufactured Be ^¬ tenflächen 48, the flow direction S are employed respect. In FIGS. 18 to 23, the vortex generators 22 are respectively oriented forward with respect to the flow direction S. Alternatively, however, the vortex generators 22 are oriented backwards, that is, rotated by 180 ° with respect to the flow direction S (the arrow indicating the flow direction S in FIG FIGS 18 to 23 then has in the opposite Rich ^¬ tung).

Claims

claims

1 burner (2) having a plurality of premixing chambers (6) each having a fuel nozzle (10) for two fuels, wherein the fuel nozzle (10) in a flow ^¬ direction (S) extending fuel lance (14), in the a first number of first outlet openings (18) is introduced for a first fuel, and the fuel lance (14) is surrounded by an outer tube (16) having at least one second outlet opening (20) for a second fuel, the first outlet openings (18 ) radially and the second outlet opening (20) are aligned axially, where ^¬ between the fuel lance (14) and inside of the pre-mixing chamber (6) has a flow cross-section (Q) is formed and wherein a number of vortex generators (22) on the fuel lance ( 14) is arranged transversely to the flow direction ^¬ (S) oriented flow cross-section (Q) reduzie ^¬ reindeer,

characterized in that at least one vortex generator (22) upstream of the first outlets (18) and is arranged downstream of the second outlet opening (20) and the pre-mixing chamber (6) has a cross section (50) and an end (52) on ^¬ and the distance of the first outlet openings (18) from the end (52) of the premixing chamber (6) is at least three times as large as the cross-section (50) of the premixing chamber (6).

2. burner (2) according to claim 1,

characterized in that the fuel lance (14) and the outer tube (16) are arranged concentrically.

3. Burner (2) according to one of the preceding claims, characterized in that at least one vortex generator (22) is wedge-shaped.

4. burner (2) according to any one of the preceding claims, characterized in that at least one vortex generator (22) on the outer tube (16) is mounted.

5. burner (2) according to any one of the preceding claims, characterized in that at least one vortex generator (22) downstream of the radial outlet openings (18) is arranged.

6. burner (2) according to any one of the preceding claims, characterized in that at least one vortex generator (22) is attached to the premixing chamber (6) internally.

7. Burner (2) according to one of the preceding claims, characterized in that the outer tube (16) has an end ^¬ area (34) which is designed as a Lobe mixer and a number of lamellae (36).

8. burner (2) according to the preceding claim,

characterized in that a number of the fins (36) is designed as a vortex generator (22).

9. Burner (2) according to one of the two preceding claims,

characterized in that at least one vortex generator (22) in an intermediate space (40) between two blades (36) is arranged.

10. Gas turbine (4) with a burner (2) according to one of the preceding claims.

11 fuel nozzle (10) for two fuels, wherein the fuel nozzle (10) has a in a flow direction (S) extending fuel lance (14) into which an on ^¬ plurality of first outlet openings (18) is introduced for a first fuel, and the fuel lance (14) is surrounded by an outer tube (16) with at least one second outlet opening (20) for a second fuel, said first outlet openings (18) radially and the second from ^¬ opening (20) are axially aligned, wherein a number of vortex generators (22) is arranged on the fuel lance (14),

characterized in that at least one vortex generator (22) upstream of the first outlet openings (18) and downstream of the second outlet opening (20) is arranged.