DE102009038848A1 - Burner, in particular for gas turbines - Google Patents

Abstract

The invention relates to a burner with a central fuel supply arrangement (27), an annular air duct (17) surrounding the central fuel supply arrangement (27) for supplying combustion air and swirl vanes (19) arranged in the annular air duct (17) which have first fuel nozzles (21) for injecting an essentially gaseous fuel into the combustion air and second fuel nozzles (23) for injecting an essentially gaseous fuel into the combustion air, the first fuel nozzles (21) being fed by a fuel distributor supply in the fuel supply arrangement (27) and the second fuel nozzles (23) ) are fed from a fuel distribution channel (31) in the fuel supply arrangement (27), wherein the fuel distribution supply comprises a supply pipe (55) which is connected downstream to the swirl vane (19) and a ring attachment (60), the supply pipe (55) being upstream connected to the ring attachment (60) n, the ring attachment (60) being connected upstream of the fuel distributor duct (31) as seen in the direction of flow. The invention also relates to a gas turbine with such a burner.

Description

The present invention relates to a burner, and more particularly to a gas turbine combustor having a central fuel supply arrangement. In addition, the invention relates to a gas turbine.

In view of the global efforts to reduce pollutant emissions from firing systems, particularly in gas turbines, burners have been developed in recent years that have particularly low emissions of nitrogen oxides (NOx). It is often emphasized that such burners are not only with a fuel, but possibly with different fuels, such as oil and natural gas, either selectively or in combination operable to increase the security of supply and flexibility of operation. Such burners are for example in the EP 0 276 696 B1 described.

The in EP 0 276 696 B1 described burner is a hybrid burner for Vormischbetrieb with gas and / or oil, as it is used in particular for gas turbine plants. The burner comprises a central fuel supply arrangement, in which also a pilot burner system is integrated, which is operable with gas and / or oil as a so-called diffusion burner or as a separate premix burner. In addition, the possibility for feeding in inert materials is provided. The central fuel supply assembly is surrounded by a main burner system having an air supply annular channel system with therein a swirl blading with a plurality of blades and nozzle pipes arranged upstream of the blades for premixing with gas. In addition, in the fuel supply arrangement there are inlet nozzles for oil in the area of the swirl blading, which allow premixing of the main air flow with oil.

Instead of like in EP 0 276 696 B1 By means of nozzle pipes located upstream of the swirl vanes, the fuel gas can also be injected into the air duct through nozzle openings arranged in the swirl vanes itself, as described, for example, in US Pat EP 0 580 683 B1 is described.

In order to increase the control of emissions and combustion stability in the future, in addition to a fuel injection through the blade as in EP 0 580 683 B1 another fuel injection can be used by the blade. This additional fuel injection should be controllable separately from the main gas stage, ie, in addition to the previously existing gas and oil channels, an additional, second gas channel must be introduced into the central fuel supply device of the burner. A difficulty now is that the additional gas channel meets the necessary strength criteria, while having a long life.

The object of the present invention is therefore to provide a burner, in particular a gas turbine burner, with two fuel passages which has a long service life. It is a second object of the present invention to provide an advantageous gas turbine.

The first object is achieved by the disclosure of a burner according to claim 1 or 2, the second object by a gas turbine according to claim 10. The dependent claims contain advantageous embodiments of the invention.

In this case, a burner has a central fuel supply arrangement and an annular air channel surrounding the central fuel supply arrangement for supplying combustion air. In the annular air duct swirl vanes are arranged, which have first fuel nozzles for injecting a substantially gaseous fuel into the combustion air and second fuel nozzles for injecting a substantially gaseous fuel into the combustion air. In this case, the first fuel nozzles are fed by a fuel distributor supply in the fuel supply arrangement and the second fuel nozzles by a fuel distributor channel in the fuel supply arrangement. In operation, the burner has a fuel flow direction.

According to the invention it has now been recognized that for this double Schaufeleindüsung therefore a realization is difficult because no sufficient life for the gas distributor, that is, the fuel supply arrangement is present and thus no safe use can be guaranteed. Furthermore, it was recognized that high temperature gradients between the individual fuel passages lead to high thermal stresses, which severely limit the service life.

According to the invention, the fuel distributor supply now comprises a supply pipe, which is connected downstream with the swirl blade, and a ring attachment, wherein the supply pipe is connected upstream with the ring attachment and wherein the ring attachment is seen upstream of the fuel distribution channel. This causes a spatial separation of the two fuel passages, that is, the supply pipe with the ring attachment and the original fuel distribution channel are spatially separated. Thus, the original fuel distribution channel is more or less parallel to the supply pipe. The ring attachment acts to remove the high stresses from the component, that is, pull out the fuel supply assembly and distribute it evenly over the component. This results in a defusing of the installation space due to lower voltages. Thus, the life of the fuel supply assembly is significantly extended. Due to the ring attachment, the original aero design is not or only insignificantly influenced. Also already manufactured machines can be easily provided with such a ring attachment and such a feed tube due to the now easier production and now easier installation.

The ring attachment preferably comprises a separate pipe connection. This supplies the feed pipe with fuel.

In a preferred embodiment, a plurality of swirl vanes are provided, each of these swirl vanes having a separate feed tube, wherein each of the separate feed tubes is connected to the one ring attachment.

Preferably, the first fuel injection is fed by a first manifold and the second fuel injection is fed by a second manifold, the manifold being integrated in the swirl vane, and wherein the swirl vane between the first and second manifolds is split into two vane halves. Thus, the distribution pipes and the respective nozzles are supplied separately with fuel. As a result, a controlled control of the fuel flow is possible.

Both blade halves preferably have a locating pin downstream and a sliding seat upstream. By the dowel pin and the sliding seat, the two blade halves are now thermally separately expandable, which also stresses are reduced.

In a preferred embodiment, the fuel distribution channel and the supply pipe are separated by a web, wherein the web is made flexible. As a result, occurring stresses in the web and in the fuel supply arrangement can be reduced. The web can be made of an elastic material and / or also act by a corresponding geometric design elastic and thus compensate for stress. This can be z. B. caused by a curved or corrugated web.

Preferably, such a burner is provided in a gas turbine.

Further features, properties and advantages of the present invention will become apparent from the following description of embodiments with reference to the accompanying figures.

Show in it

1 a burner in a very schematized schematic diagram,

2 a schematic representation of a swirl blade with two integrated gas levels,

3 a schematic diagram of a combustion chamber hub with two integrated gas stages and an oil channel,

4 a cross section of a combustion chamber hub according to the invention with ring attachment and swirl blade,

5 a plan view of a ring attachment with swirl vanes.

Hereinafter, with reference to 1 , which shows a burner in a highly schematic schematic diagram, the concept underlying the burner.

The burner, which may optionally be used in conjunction with a plurality of similar burners, for example in the combustion chamber of a gas turbine plant, comprises an inner pilot burner system and a main burner system concentrically surrounding the pilot burner system. Both the pilot burner system and the main burner system may optionally be operated with gaseous and / or liquid fuels, such as natural gas or fuel oil.

The pilot burner system includes an internal oil supply passage 1 that of an inner annular gas supply channel 3 can be surrounded concentrically. This can in turn of an inner air supply channel or Inertstoffzufuhrkanal 5 be surrounded concentrically. In addition, a suitable ignition system may be arranged in or on this air supply channel (not shown in the figure). The pilot burner system has a combustion chamber 7 facing outlet opening 9 in whose area a swirl blading 11 can be arranged in the air supply channel. By means of nozzle openings 13 can gas from the inner gas supply channel 3 in the area of the swirl blading or upstream of the swirl blading in the air supply channel 5 be injected. Oil from the oil supply channel can be oiled 15 Be injected downstream of the swirl blading in the supplied air or the supplied inert material.

The pilot burner system can in known manner with oil and / or gas as Diffusion burner can be operated in which the fuel is injected directly into the flame. However, it is also possible to operate the pilot burner system as a premix burner, in which the fuel is thoroughly mixed with air before the mixture is fed to the flame.

The main burner system surrounding the pilot burner system includes a radial outer air supply passage 17 , also called annular air duct, through the swirl blades 19 a twist blading extend. These swirl vanes 19 have first fuel nozzles 21 and second fuel nozzles 23 through, through the fuel gas in through the radial air supply duct 17 inflowing air can be injected. Into the through the air supply channel 17 flowing air can by means of oil nozzles 25 In addition, oil is injected. Although in the present embodiment of oil and oil nozzles, the speech, but this should only be representative of suitable liquid fuels and corresponding nozzles.

The ones in the swirl blades 19 located first fuel nozzles 21 and second fuel nozzles 23 as well as the oil nozzles 25 be via a radially inner fuel supply assembly, the so-called hub 27 fueled. The swirl shovel 19 and the hub 27 have a fuel flow direction. In this are first and second annular fuel distributor channels 29 and 31 arranged the fuel nozzles 21 respectively. 23 supply with gas. Furthermore, in the hub 27 an annular oil distribution channel 33 arranged the oil nozzles 25 supplied with oil. The fuel distribution channels 29 . 31 and the oil distribution channel 33 be via fuel supply channels 35 . 37 or via an oil supply channel 39 supplied with the appropriate fuel. The fuel supply channels 35 . 37 supply the fuel distribution channels 29 . 31 with fuel. For the oil supply channel 39 lies its own oil supply pipe 43 in front.

2 shows a schematic diagram of a swirl blade 19 with two integrated gas levels B and D.

The swirl shovel 19 has two independent fuel distribution channels 29 and 31 on. The one fuel distribution channel 29 with the outlet nozzles 21 For example, for injecting a different medium D than the second fuel distribution channels 31 over the outlet nozzles 23 (Medium B) can be used. Preferably both are through the fuel distribution channels 29 and 31 the swirl blade 19 be injected media gaseous, z. As the one natural gas and the other coal gas. Likewise can over these outlet nozzles 21 and or 23 If necessary, an inert material such as water vapor can be injected.

3 shows a fuel hub 27 with the fuel distribution channel 29 and 31 with openings which feed the fuel into the blade 19 leads. The two fuel distribution channels 29 and 31 are arranged substantially parallel and through a bridge 50 separated.

According to the invention it has now been recognized that for this double Schaufeleindüsung therefore a realization is difficult because no sufficient life for the gas distributor, that is, the hub 27 is present and thus no safe use can be guaranteed. Furthermore, it was recognized that high temperature gradients between the individual fuel passages lead to high thermal stresses, which severely limit the service life.

According to the invention, at least one of the fuel distributor channels will now be used 29 (or alternatively 31 ) as a feed pipe 55 educated ( 4 ). The feed pipe 55 flows downstream into a manifold 65 (or alternatively 70 ). Upstream is the feed tube 55 with the ring attachment 60 ( 5 ) connected. Here is the ring attachment 60 seen in the flow direction of the fuel distribution channel 31 (or alternatively 29 ) upstream. Thus, virtually the original fuel distribution channel 31 (or alternatively 29 ) parallel to the feed tube 55 , The ring attachment 60 comes with a separate pipe connection 75 provided. The original fuel distribution channel 31 (or alternatively 29 ) will be with another channel 80 provided. Thus, the two leading gas passages, namely the supply pipe 55 with the ring attachment 60 and the original fuel distribution channel 31 (or alternatively 29 ) According to the invention spatially decoupled. The ring attachment 60 works to the effect that it releases the high voltages from the hub 27 pull it out and distribute it evenly over the component. This results in a defusing of the installation space due to lower voltages. Thus, the life of the burner hub 27 significantly extended. Through the ring attachment 60 the original aero design is not or only insignificantly influenced. Also already manufactured machines can easily with such a ring attachment 60 and such a supply pipe 55 due to the now easier production and the now easier installation are provided.

Such a burner hub according to the invention is preferred 27 in connection with a split swirl blade 19 used. This includes the first fuel injection 21 coming from a first manifold 65 is fed, as well as the second fuel injection 23 , which from a second manifold 70 is fed. Here is the manifold 65 . 70 in the swirl bucket 19 integrated. The split swirl vane 19 is now between the first and second manifold 65 and 70 divided into two blade halves 19a . 19b executed. This can still improve the voltage from the hub 27 be pulled, and evenly distributed over the component. The blade halves 19a . 19b also have downstream of a mating pin 90a . 90b and a sliding seat upstream 85a . 85b up, in the hub, so to speak 27 itself is attached. By the passport 90a . 90b and the sliding seat 85a . 85b are the two blade halves 19a . 19b now thermally separately expandable, which also reduces stress.

To obtain an additional voltage reduction, the bridge can 50 through which the fuel distribution channel 31 (respectively. 29 ) and the feed tube 55 are separated, flexible executed. The jetty 50 can be made of an elastic material. Additionally or alternatively, the bridge 50 but also act elastically by a corresponding geometry and thus compensate for stresses. This can be z. B. by a curved or corrugated web 50 be effected.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0276696 B1 [0002, 0003, 0004]
• EP 0580683 B1 [0004, 0005]

Claims (10)

Burner with a central fuel supply arrangement ( 27 ), the central fuel supply assembly ( 27 ) surrounding annular air channel ( 17 ) for the supply of combustion air and in the annular air channel ( 17 ) arranged swirl vanes ( 19 ), which first fuel nozzles ( 21 ) for injecting a substantially gaseous fuel into the combustion air and second fuel nozzles ( 23 ) for injecting a substantially gaseous fuel into the combustion air, wherein the first fuel nozzles ( 21 ) from a fuel rail feed in the fuel supply assembly ( 27 ) and the second fuel nozzles ( 23 ) from a fuel distribution channel ( 31 ) in the fuel supply assembly ( 27 ), wherein the burner in operation has a fuel flow direction, characterized in that the fuel distributor supply a supply pipe ( 55 ), which downstream with the swirl blade ( 19 ) and a ring attachment ( 60 ), wherein the feed tube ( 55 ) upstream with the ring attachment ( 60 ), the ring attachment ( 60 ) seen in the flow direction of the fuel distribution channel ( 31 ) is connected upstream. Burner with a central fuel supply arrangement ( 27 ), the central fuel supply assembly ( 27 ) surrounding annular air channel ( 17 ) for the supply of combustion air and in the annular air channel ( 17 ) arranged swirl vanes ( 19 ), which first fuel nozzles ( 21 ) for injecting a gaseous fuel into the combustion air and second fuel nozzles ( 23 ) for injecting a gaseous fuel into the combustion air, wherein the first fuel nozzles ( 21 ) from a fuel distribution channel ( 29 ) in the fuel supply assembly ( 27 ) and the fuel nozzles ( 23 ) from a fuel rail supply in the fuel supply assembly ( 27 ), wherein the burner in operation has a fuel flow direction, characterized in that the fuel distributor supply a supply pipe ( 55 ), which downstream with the swirl blade ( 19 ) and a ring attachment ( 60 ), wherein the feed tube ( 55 ) upstream with the ring attachment ( 60 ), the ring attachment ( 60 ) seen in the flow direction of the fuel distribution channel ( 29 ) is connected upstream. Burner according to claim 1 or 2, characterized in that the ring attachment ( 60 ) a separate pipe connection ( 75 ). Burner according to one of the preceding claims, characterized in that a plurality of swirl vanes ( 19 ), and each one of these swirl vanes ( 19 ) a separate feed tube ( 55 ), each of the separate supply pipes ( 55 ) with the one ring attachment ( 60 ) connected is. Burner according to one of the preceding claims, characterized in that the first fuel injection ( 21 ) from a first manifold ( 65 ) and the second fuel injection ( 23 ) from a second manifold ( 70 ), wherein the manifold ( 65 . 70 ) is integrated in the swirl blade and wherein the swirl blade ( 19 ) between the first and second distribution pipes ( 65 ) and ( 70 ) divided into two blade halves ( 19a . 19b ) is executed. Burner according to claim 5, characterized in that both blade halves ( 19a . 19b ) downstream of a passport ( 90a . 90b ) exhibit. Burner according to claim 6, characterized in that both blade halves ( 19a . 19b ) upstream a sliding seat ( 85a . 85b ) exhibit. Burner according to Claim 1, characterized in that the fuel distributor channel ( 31 ) and the feed tube ( 55 ) by a bridge ( 50 ) are separated, wherein the web ( 50 ) is flexible, whereby occurring stresses in the web ( 50 ) are reducible. Burner according to claim 2, characterized in that the fuel distributor channel ( 29 ) and the feed tube ( 55 ) by a bridge ( 50 ) are separated, wherein the web ( 50 ) is flexible, whereby occurring stresses in the web ( 50 ) are reducible. Gas turbine with at least one burner according to one of the preceding claims.

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