EP3250857B1 - Burner arrangement - Google Patents

Description

The invention relates to a burner arrangement for a combustion chamber, in particular a gas turbine combustion chamber, for burning fluid fuels.

The availability of gas turbines is mainly limited by problems in the combustion system. These problems are in particular the exceeding of emission limit values (NOx and CO) and the hum behavior, caused by thermoacoustic vibrations in the area of the combustion chamber. In order to keep the emissions below limit value ranges and to suppress the hum behavior of the machine, very good adjustment (tuning) of the changeable combustion parameters is required.

In the case of a burner with, for example, main premix burner and pilot premix burner, these are primarily the fuel mass flows of the main premix burner and of the pilot premix burner. Depending on the setting, approx. 90% -95% of the fuel mass flow goes through the main premix burner, the rest through the pilot premix burner. It is known that a change (already in the percentage range) of the pilot gas mass flow has a significant influence on emissions and on the hum behavior. However, such regulation is limited by a single fuel stage in the pilot premix burner.

So far, it has therefore been necessary to do extensive tuning prior to the smooth operation of the gas turbine in the commissioning phase. Due to the few setting options on the main and pilot burners, it is necessary to drive through narrow corridors that are limited by emissions and stability. Compromises between stable driving and low emissions often have to be made.

To remedy this, a second premixed fuel stage can be integrated into the pilot burner. This stage must then also be supplied via its own fuel supply and fuel channel.

With this design, both stages can be controlled independently of one another. For example, both pilot fuel stages can be integrated in pilot burner blades in order to allow good mixing of fuel and air for both stages. By cleverly selecting the bore pattern, the radial fuel distribution can be actively influenced during operation and thus influence emissions and combustion stability. This makes it possible to expand the corridors through which maneuvering is required when starting and stopping the machine, and the emission and stability behavior, especially in the part-load range, can be improved.

The WO 2014/114533 A1 discloses for example a burner arrangement with a diffusion gas passage lying on the axis of the burner arrangement. This passage could be used, for example, through a tube-in-tube construction for the fuel supply of a second stage in the pilot burner. However, due to the expected different thermal expansions of the components, the pipe-in-pipe construction would have to be relieved by a complex and therefore also comparatively expensive compensator.

Documents DE102010061626 and EP2354662 disclose burner assemblies for a combustion chamber, in particular a gas turbine combustion chamber, for firing fluid fuels.

The object of the invention is therefore to provide a burner arrangement of the type mentioned at the outset which enables a considerable improvement in terms of emissions and stability and which is at the same time simple and inexpensive to manufacture and assemble.

The invention solves this problem in that, in the case of such a burner arrangement for a combustion chamber, in particular a gas turbine combustion chamber, for firing fluidic fuels, with a main burner and one arranged centrally therein Pilot burner, which is used to ignite and / or to stabilize the combustion of the main burner, the main burner comprising a first ring air duct for supplying combustion air and first fuel nozzles for injecting fuel into the first ring air duct, the pilot burner comprising a second ring air duct for supplying combustion air and one Burner head with second fuel nozzles for injecting a fuel into the second ring air duct, the second fuel nozzles being provided as separately controllable first and second fuel stages, for supplying fuel to the first and second fuel stages, a burner carrier tube connected to the burner head with a tube wall, the Pipe wall has at least a first and a second deep hole running parallel to the longitudinal axis of the burner support tube for supplying the first and second fuel stages with fuel.

As a result, the emission and stability behavior of the burner arrangement is improved and the comparatively complex and expensive tube-in-tube construction with compensator can be dispensed with.

The first and second deep-hole bores are expediently arranged on different radii in relation to the longitudinal axis of the burner support tube in the tube wall, so that fuel can be fed directly to a respective fuel stage via straight bores. The production of such bores is comparatively inexpensive.

In an advantageous embodiment, the at least one first and one second deep-hole bore each lead into a fuel distribution channel of a fuel stage. For example, the number of deep hole bores can be smaller than the number of fuel nozzles per fuel level.

Furthermore, it can be advantageous if the burner carrier tube has a diffusion gas passage on its axis, which also opens into the burner head, so that diffusion operation is also possible.

In a further advantageous embodiment, the burner support tube is connected to a support plate in the flow direction of a fuel upstream of the burner head, the support plate having fuel ring distributors, from which the at least one first and a second deep-hole bore branch off.

It is expedient if the carrier plate has fuel connections which open into the fuel ring distributor.

With regard to limited space, it is advantageous if a fuel connection is made via a screw-in connector with a through hole and essentially radial openings in the external thread, the radial openings coming to lie at the level of a fuel ring distributor when screwed in. In this way, even with fuel ring distributors located comparatively close to the surface of the carrier plate, it is ensured that the screw-in connector can be screwed sufficiently deep into the carrier plate in order to establish a secure connection.

Furthermore, with regard to a good mixing of fuel and air, it is advantageous if the first ring air duct has first swirl vanes and the first fuel nozzles are arranged in the first swirl vanes.

This also applies to the second ring air duct, which advantageously has second swirl vanes, the second fuel nozzles being arranged in the second swirl vanes.

Figur 1

eine Brenneranordnung,

Figur 2

einen bekannten Pilotbrenner,

Figur 3

ein stromabwärtiges Detail des Pilotbrenners aus Figur 2,

Figur 4

ein stromaufwärtiges Detail des Pilotbrenners aus Figur 2,

Figur 5

eine Schnittdarstellung der erfindungsgemäßen Brenneranordnung den Innenkanal zeigend,

Figur 6

eine Schnittdarstellung der erfindungsgemäßen Brenneranordnung den Außenkanal zeigend,

Figur 7

eine Seitenansicht auf das stromabwärtige Ende des Brennerträgerrohrs der Brenneranordnung,

Figur 8

einen Schnitt durch Trägerplatte und Außenkanal des Brennerträgerrohrs,

Figur 9

einen Schnitt durch Trägerplatte und Anschluss für den Außenkanal sowie durch den Innenkanal des Brennerträgerrohrs,

Figur 10

eine Seitenansicht auf einen Schnitt durch die Trägerplatte mit Anschluss für den Innenkanal,

Figur 11

einen Einschraubverbinder mit durchgehender Bohrung und radialen Öffnungen im Außengewinde in der Draufsicht,

Figur 12

einen Einschraubverbinder mit durchgehender Bohrung und radialen Öffnungen im Außengewinde im Schnitt,

Figur 13

eine Detailsicht auf den Brennerkopf mit Übergang zum Brennerträgerrohr und

Figur 14

eine Schrägansicht der stromaufwärtigen Seite des Brennerkopfes.

The invention is explained in more detail by way of example with reference to the drawings. They show schematically and not to scale:

Figure 1

a burner arrangement,

Figure 2

a well-known pilot burner,

Figure 3

a downstream detail of the pilot burner Figure 2 .

Figure 4

an upstream detail of the pilot burner Figure 2 .

Figure 5

3 shows a sectional illustration of the burner arrangement according to the invention, showing the inner channel

Figure 6

2 shows a sectional view of the burner arrangement according to the invention, showing the outer channel,

Figure 7

a side view of the downstream end of the burner support tube of the burner assembly,

Figure 8

a section through the support plate and outer channel of the burner support tube,

Figure 9

a section through the support plate and connection for the outer channel and through the inner channel of the burner support tube,

Figure 10

a side view of a section through the support plate with connection for the inner channel,

Figure 11

a screw connector with a through hole and radial openings in the external thread in plan view,

Figure 12

a screw-in connector with a through hole and radial openings in the external thread in section,

Figure 13

a detailed view of the burner head with transition to the burner support tube and

Figure 14

an oblique view of the upstream side of the burner head.

The Figure 1 shows schematically and by way of example a section through part of a burner arrangement 1 according to the invention. The burner arrangement 1 is essentially radially symmetrical about the longitudinal axis 13 and comprises a main burner 2 and a pilot burner 3 arranged therein, which serves to ignite and / or stabilize the combustion of the main burner 2.

The main burner 2 comprises a first ring air channel 4 for supplying combustion air and first fuel nozzles 5 for injecting a fuel into the first ring air channel 4. The pilot burner 3 comprises a second ring air channel 6 for supplying combustion air and second fuel nozzles 8 for injecting a fuel into the second ring air channel 6th

The second fuel nozzles 8 are provided as first and second fuel stages 9, 10, each fuel stage 9, 10 having its own fuel supply.

In the burner assembly 1 of Figure 1 the first ring air duct 4 has first swirl blades 30, in which the first fuel nozzles 5 are arranged.

Furthermore, in the burner arrangement 1 Figure 1 the second ring air duct 6 has second swirl blades 31. The second fuel nozzles 8 are arranged in the second swirl vanes 31 and, as already explained, are divided into a first and a second fuel stage 9, 10.

Figure 2 shows a known pilot burner 32 with a central diffusion gas passage 20, in which a tube 33 is arranged, an annular channel 36 for the between an inner wall 34 of the diffusion gas passage 20 and an outer tube wall 35 Fuel supply to the second fuel stage 10 is formed. This pipe-in-pipe construction is relieved by a compensator 37.

Figure 3 shows a downstream detail of the pilot burner 3 Figure 2 , in particular the pilot burner head 7 with the fuel supply for the first and second fuel stages 9, 10.

Figure 4 shows an upstream detail of the pilot burner 3 Figure 2 , in particular the compensator 37 of the tube-in-tube construction.

In the Figures 5 and 6 the pilot burner 3 according to the invention is shown in different sectional planes. In Figure 5 the section runs through second deep-hole bores 15, which represent the inner channel 38, in FIG Figure 6 is the corresponding view with first deep hole 14 for the outer channel 39. It can be seen that the first and second deep hole 14, 15 are arranged on different radii 16, 17 in relation to the longitudinal axis 13 of the burner support tube 11 in the tube wall 12. Furthermore, the Figures 5 and 6 that the at least one first and a second deep hole 14, 15 each open into a fuel distribution channel 18, 19 of a fuel stage 9, 10.

Figure 7 shows a side view of the downstream end of the burner support tube 11 of the burner arrangement 1. The ends of the first and second deep hole bores 14, 15 of the inner and outer channels 38, 39 can be seen.

The Figures 8, 9 and 10 show sectional detailed views in the region of the carrier plate 21 of the pilot burner 3.

In particular, the Figure 8 a section through the support plate 21 with the first and second fuel ring manifold 22, 23 and the outer channel 39 formed by deep hole bores 14 in the tube wall 12 of the burner support tube 11th

The Figure 9 shows a section through the carrier plate 21 with the first and second fuel ring distributors 22, 23 and the inner channel 38 formed by deep-hole bores 15 in the tube wall 12 of the burner carrier tube 11 Figure 9 a section through the serious fuel connection 24 to the first fuel ring distributor 22 for the outer channel 39.

The Figure 10 finally shows a section through the carrier plate 21 with the second fuel connection 25 to the second fuel ring distributor 23 for the inner channel 38 Figure 10 recognizable that the second fuel ring distributor 23 for the inner channel 38 is comparatively close below the surface of the carrier plate 21. In order to ensure a mechanically reliable fuel supply, the fuel connection 25 is implemented via a screw connector 26 with a through bore 27 and essentially radial openings 28 in the external thread 29. The Figures 11 and 12 show such a screw connector 26 in plan view and in section.

Figure 13 shows a detailed view of the burner head 7 with transition to the burner support tube 11. The burner head 7, which in the Figure 14 shown in the oblique view is the same as in FIG Figure 3 , According to the invention, only the burner support tube 11 is changed.

Claims (9)

1. Burner arrangement (1) for a combustion chamber, especially a gas turbine combustion chamber, for firing fluid fuels, with a main burner (2) and a pilot burner (3), arranged centrally therein, which serves for igniting and/or for stabilizing the combustion of the main burner (2), the main burner (2) comprising a first annular air passage (4) for feeding combustion air and first fuel nozzles (5) for injecting a fuel into the first annular air passage (4), the pilot burner (3) comprising a second annular air passage (6) for feeding combustion air and a burner head (7) with second fuel nozzles (8) for injecting a fuel into the second annular air passage (6), wherein the second fuel nozzles (8) are provided as separately controllable first and second fuel stages (9, 10), characterized in that for feeding fuel to the first and second fuel stages (9, 10) a burner support tube (11), adjoining the burner head (7), with a tube wall (12) is provided, and in that the tube wall (12) has at least one first and at least one second gun-drilled hole (14, 15), parallel to the longitudinal axis (13) of the burner support tube (11), for supplying the first and second fuel stages (9, 10) with fuel.
2. Burner arrangement (1) according to Claim 1, wherein the first and second gun-drilled holes (14, 15) are arranged in the tube wall (12) on different radii (16, 17) with regard to the longitudinal axis (13) of the burner support tube (11).
3. Burner arrangement (1) according to either of the preceding claims, wherein the at least one first and at least one second gun-drilled hole (14, 15) each open into a fuel distributor passage (18, 19) of a fuel stage (9, 10).
4. Burner arrangement (1) according to one of the preceding claims, wherein the burner support tube (11) has a diffusion gas passage (20) on its axis (13) which also opens into the burner head (7).
5. Burner arrangement (1) according to one of the preceding claims, wherein the burner support tube (11) is connected to a support plate (21) upstream of the burner head (7) in the flow direction of a fuel, wherein the support plate (21) has annular fuel distributors (22, 23) from which branch the at least one first and at least one second gun-drilled hole (14, 15).
6. Burner arrangement (1) according to Claim 5, wherein the support plate (21) has fuel connections (24, 25) which open into the annular fuel distributors (22, 23).
7. Burner arrangement (1) according to Claim 6, wherein a fuel connection (25) is effected via a screw-in connector (26) with a through-hole (27) and basically radial openings (28) in the male thread (29), wherein in the screwed-in state the radial openings (28) come to lie level with an annular fuel distributor (23).
8. Burner arrangement (1) according to one of the preceding claims, wherein the first annular air passage (4) has first swirl vanes (30) and the first fuel nozzles (5) are arranged in said first swirl vanes (30).
9. Burner arrangement (1) according to one of the preceding claims, wherein the second annular air passage (6) has second swirl vanes (31) and the second fuel nozzles (8) are arranged in said second swirl vanes (31).

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