EP2362142A1 - Burner assembly - Google Patents

Abstract

The burner arrangement has two fuel nozzles (29) individually provided with a support side section with a contact surface on a support (27) side. The fuel nozzle rests on a supporting surface of the support. Two fuel nozzle tips are formed in one piece running from the support-side section in the direction of flow. The gas feed system includes one gas feed line and a lead-through through the support. The lead-through is embodied as a fit. An independent claim is also included for a gas turbine.

Description

The present invention relates to a burner assembly and a gas turbine having such a burner assembly.

A gas turbine comprises as essential components a compressor, a turbine with moving blades and at least one combustion chamber. The blades of the turbine are arranged as blade rings on a shaft extending mostly through the entire gas turbine, which is coupled to a consumer, such as a generator for power generation. The shaft provided with the blades is also called turbine runner or rotor. Between the blade rings are vanes, which serve as nozzles for guiding the working fluid through the turbine.

During operation of the gas turbine, the combustion chamber is supplied with compressed air from the compressor. The compressed air is mixed with a fuel, such as oil or gas, and the mixture burned in the combustion chamber. The hot combustion exhaust gases are finally supplied as a working medium via a combustion chamber outlet of the turbine, where they transmit momentum to the blades under relaxation and cooling and thus do work. The vanes serve to optimize the momentum transfer.

A typical burner assembly for gas turbines, as shown in US 6,082,111 is described and how it is used in particular in so-called tube combustion chambers, usually has an annular support with uniformly distributed around the circumference of the ring number of fuel nozzles. In these fuel nozzles fuel nozzle openings are arranged, with which fuel can be injected into an air supply channel. The fuel nozzles represent a main stage of the burner, which is used to generate a premix flame, ie a flame, in which the air and the fuel before the Ignition can be mixed, serves. In order to minimize the formation of NO _x in the flame, premix burners are operated with lean air-fuel mixtures, ie with mixtures which contain relatively little fuel.

Through the center of the annular fuel distributor ring typically extends a pilot burner, which is designed as a diffusion burner, i. it produces a flame in which the fuel is injected directly into the flame without first being mixed with air. The pilot burner, in addition to starting the gas turbine, also serves to stabilize the premix flame which, to minimize emissions, is often operated in a range of air to fuel mixing ratio which could lead to flame instabilities without assistive pilot flame.

A burner assembly, such as the burner assembly described, typically includes a number of fuel nozzles machined from a block of metal and welded to the carrier to supply fuel to the combustion chamber. The carrier distributes the fuel to the individual nozzles through incorporated fuel passages (distribution channels).

To be able to provide sufficient space for the machine incorporation of the fuel passages, the carrier blank and thus the subsequent carrier must have a certain minimum thickness. This increases the weight of the burner assembly and the material costs. In addition, machine incorporation is laborious.

During operation, the carrier also heats up, but the fuel-carrying lines remain cold. This results in thermal stresses and the carrier does not meet the requirement for a long service life.

It is therefore an object of the present invention to provide an advantageous burner arrangement available, in particular an advantageous burner assembly for gas turbines, which meets the required life. It is a further object to provide an advantageous gas turbine with such a burner arrangement available.

This object is achieved by a burner assembly according to claim 1. The object related to the gas turbine is solved by specifying a gas turbine according to claim 10. The dependent claims contain advantageous embodiments of the invention.

The burner assembly according to the invention comprises a carrier and a number of fuel nozzles, which are mounted in the flow direction on the carrier. It has been recognized that when used as a fuel distributor, the carrier has a minimum height, i. must have a certain thickness. Since the carrier designed as a fuel distributor is exposed directly to the hot gas in the combustion chamber, it must be made of high-temperature-resistant material, e.g. consist of a superalloy. These are very expensive.

According to the invention, therefore, a burner arrangement has a carrier and at least two fuel nozzles with fuel nozzle tips fixed to the carrier in the flow direction. In this case, each fuel nozzle comprises a carrier-side portion, which carrier side has a contact surface, with which it bears against a bearing surface of the carrier, wherein emanating from the carrier-side portion at least two integrally formed fuel nozzle tips in the flow direction. In addition, the burner assembly according to the invention has a gas supply supply system extending through the carrier to the fuel nozzle tips. According to the invention, the gas supply supply system comprises at least one gas supply line and its passage through the carrier. According to the invention, the implementation is now carried out as a fit. This may in particular be a dimensional or transitional fit.

Thus it can be dispensed with a distribution channel in the carrier. As a result, the material thickness of the carrier can be reduced, whereby weight and cost can be saved. In addition, the requirements for the installation space of the burner assembly in the region of the side facing away from the fuel nozzles side of the carrier in comparison to the prior art are less stringent. Overall, the machining of the carrier is simplified.

The gas supply supply system comprises at least one gas supply line and its passage through the carrier. However, since the gas supply line remains largely cold during operation by the gas flowing through and the carrier is heated by the compressor air, this results in thermal stresses that do not guarantee a sufficient life. This is especially the case when the gas supply line to the carrier materially connected, e.g. is welded, for example, to cause a seal of the implementation. Also arises with additional attachment of the fuel nozzle to the support by screws a double fixation, which also have a life-shortening effect.

Now the bushing is designed as a fit instead of the weld. This may in particular be a dimensional or transitional fit.

As a fit while a connection of two interlocking parts is referred to, both parts have the same nominal size, but the position and size of the tolerance fields can be different. A fit always indicates a tolerance in which the actual dimensions of bore and shaft are allowed to move.

This results in the finished component either a clearance fit or an oversize. If the tolerances allow both a game and an excess, one speaks of a Transitional fit, which falls into one of the former groups depending on the dimensions produced in the production. The implementation of the gas supply line through the carrier is therefore carried out in particular as such fit and leaves so little additional flow (compressor air or gas escape) to. Due to the omission of the weld, the wearer can now stretch thermally freely. The life requirements can thus be met. In addition, a nondestructive release of the fuel nozzles is possible by the inventive fit.

Another problem of the prior art fuel nozzle is the fixation of the fuel nozzles to the carrier, because the burner nozzles must be arranged perpendicular to the carrier in the manufacturing process.

According to the invention, the fuel nozzles can now be centered on the gas supply line, so that here no increased effort is required.

Preferably, at least one distributor channel is provided on the carrier side, which supplies the gas supply line with gas. Since the distribution channels now lie on the downstream side of the carrier and are not directly in contact with hot gas, as was the case originally with the distribution channel, the distribution channels can now be made of less expensive material. This can significantly save costs. That is, the fuel is already distributed to the carrier before (seen in the direction of flow) and is not split after the carrier on the channels.

Preferably, a further fuel supply line for liquid fuel through the support, in particular oil line, is provided, which supplies the fuel nozzle on the carrier side with liquid fuel, in particular oil. Thus, the fuel nozzle is supplied with gas and oil.

In a preferred embodiment, at least one seal is present between the carrier-side contact surface and the carrier. Preferably, the seal is the carrier side in the region of the fit and gas supply line, so arranged the gas pipe. The at least one seal can be designed as a c-ring seal. In this case, the carrier can identify a bulge, in which the seal is arranged.

Due to the fit and the additional seal, in particular the sealing ring, tightness against air passage is ensured.

Preferably, the carrier-side contact surface of the fuel nozzle on at least one opening for attachment of the carrier-side contact surface on the support surface of the carrier. In a preferred embodiment, the opening is a bore and the attachment is a screw or a bolt connection. Preferably, six holes for screw or bolt connections are provided in the carrier-side contact surface, wherein the holes are distributed over the entire carrier-side contact surface of the fuel nozzle. Due to the distribution pattern of the holes on the entire contact surface, the fuel nozzle has high natural frequencies, which can be quickly damped. Thus, the fuel nozzle is stable against natural frequencies.

The gas turbine according to the invention comprises a compressor section, a combustion section, a combustion chamber, a burner, a turbine section, a rotor and such a burner arrangement. As a result, the gas turbine is particularly easy.

Figur 1

zeigt eine Gasturbine in einer stark schematisierten Darstellung.

Figur 2

zeigt eine Gasturbinenbrenneranordnung nach dem Stand der Technik in einer perspektivischen Darstellung.

Figur 3

zeigt eine erfindungsgemäße Brenneranordnung von vorne.

Figur 4

zeigt einen Querschnitt durch einen Teil der erfindungsgemäßen Brenneranordnung.

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

FIG. 1

shows a gas turbine in a highly schematic representation.

FIG. 2

shows a gas turbine burner assembly of the prior art in a perspective view.

FIG. 3

shows a burner assembly according to the invention from the front.

FIG. 4

shows a cross section through a part of the burner assembly according to the invention.

The following is based on FIG. 1 showing a highly schematic sectional view of a gas turbine, explaining the structure and function of a gas turbine. The gas turbine 1 comprises a compressor section 3, a combustion section 4, which in the present embodiment comprises a plurality of tube combustion chambers 5 with burners 6 arranged thereon, but in principle may also comprise an annular combustion chamber, and a turbine section 7. A rotor 9, also called a runner, extends extending through all sections and carries in the compressor section 3 compressor blade rings 11 and the turbine section 7 turbine blade rings 13. Between adjacent compressor blade rings 11 and between adjacent turbine blade rings 13 are wreaths of compressor vanes 15 and wreaths of turbine vanes 17 arranged, extending from a housing 19 of the gas turbine 1 from extend radially in the direction of the rotor 9.

During operation of the gas turbine 1, air is sucked through an air inlet 21 into the compressor section 3. There, the air is compressed by the rotating compressor blades 11 and directed to the burners 6 in the combustion section 4. In the burners 6, the air is mixed with a gaseous or liquid fuel and the mixture is burned in the combustion chambers 5. The under high pressure hot combustion gases are then as working medium the Turbine section 7 supplied. On their way through the turbine section, the combustion exhaust gases impart a pulse to the turbine blades 13, relaxing and cooling. Finally, the expanded and cooled combustion exhaust gases exit the turbine section 7 through an exhaust 23. The transmitted pulse results in a rotational movement of the rotor that drives the compressor and a consumer, such as an electric current generator or a work machine. The rings of turbine vanes 17 serve as nozzles for conducting the working medium in order to optimize the momentum transfer to the turbine blades 13.

FIG. 2 shows a known from the prior art burner 6 of the combustion section 4 in a perspective view. As main components, the burner 6 comprises a fuel distributor ring 27, eight fuel nozzles 29 extending from the fuel distributor ring 27 and eight swirlers 31 arranged in the region of the tips of the fuel nozzles 29. The fuel distributor ring 27 and the fuel nozzles 29 together form a burner housing through which fuel lines extend to Eindüsöffnungen which are disposed within the swirl generator 31. The fuel nozzles 29 may be welded to the fuel distributor ring 27. Through a number of pipe sockets (not shown), the burner can be connected to fuel supply lines. By means of a flange 35, the burner 6 can be attached to a tube combustion chamber so that the fuel nozzles 29 point towards the interior of the combustion chamber.

Although the in FIG. 2 As shown burner 6 has eight fuel nozzles 29, it is also possible to equip it with a different number of fuel nozzles 29. The number of fuel nozzles 29 may be greater than or less than eight, for example, six fuel nozzles 29 or twelve fuel nozzles 29 may be present, each having its own swirl generator. Furthermore, a pilot fuel nozzle is usually arranged in the center of the burner. The pilot fuel nozzle is in for clarity FIG. 2 not shown.

During the combustion process, air from the compressor is passed through the swirl generators 31 where it is mixed with fuel. Subsequently, the air-fuel mixture is then burned in the combustion zone of the combustion chamber 5 to form the working medium.

The carrier 27 has the task of distributing the fuel to the fuel nozzles 29. It is internally provided with fuel channels, each of which supplies a number of nozzles 29 with fuel. On the carrier 27 there are 2 connections for fuel supply lines, which guide the fuel to the carrier 27, in which it is subsequently distributed to the fuel nozzles 29. These can also be different types of fuel. The fuel nozzles 29 have for this purpose at least one fuel opening at which the fuel can escape.

In the burner arrangements known today ( FIG. 2 ), the channels are typically milled by machine into a cylindrical carrier blank and then covered with welded-on elements. Likewise, the bushings for the pipelines are machined into the carrier blank. In order to provide sufficient space for the machine incorporation of the bushings and the gas passages, the carrier blank and thus the subsequent carrier must have a certain minimum thickness. This increases the weight of the burner assembly and the material costs. In addition, the machine incorporation is laborious and therefore associated with high costs. Another problem is the production of the fuel nozzles 29 to the carrier 27, because the burner nozzles 29 must be welded perpendicular to the carrier 27. This production is also very tedious and associated with increased effort and therefore costs. Also, the fuel nozzles are welded to the swirl generator 31. The carrier 27 is exposed to high temperatures such as Therefore, the carrier 27 and fuel nozzles 29 must be made of high temperature resistant material, such as corrosion-resistant nickel-based alloys. However, this material also drives up the costs greatly.

This is avoided using the invention thus ( FIG. 3 and FIG. 4 ). According to the invention, a burner arrangement is provided with a carrier 37 and at least two fuel nozzles 40 attached to the carrier 37 in the flow direction. In this case, each fuel nozzle 40 has a carrier-side section 45, which carrier side 100 has a bearing surface 60, with which it bears against a bearing surface 55 of the carrier 37. At least two integrally formed fuel nozzle tips 47a, 47b extend from the carrier-side section 45 in the flow direction, that is to say in the direction of the combustion chamber 5.

The fuel nozzle 40 has a gas supply supply system 120 extending through the carrier 37, which transports gas to the fuel nozzle tips 47a, 47b.

In this case, the gas supply supply system 120 comprises at least one gas supply line 70, one in the form of a gas tube 70 and its passage through the carrier 37. The feedthrough may be a bore.

In this case, the implementation, in particular the bore, designed as a fit 75.

The passage of the gas pipe 70 is therefore carried out according to the invention as a fit 75 and thus allows little flow, for example, compressor air inlet or gas outlet. This is especially a dimensional or transitional fit. As a result of the fit, the carrier 37 can thus freely expand during operation. Thermal stresses are thus eliminated or greatly reduced, resulting in an increase in life. According to the invention, the gas pipe 70 remains largely cold during operation, whereas the carrier 37 heats up. In this case, the carrier 37 expands. If, as in the prior art, the gas pipe 70 is welded to the carrier 37 for the purpose of sealing, then high stresses in the welding region can result from the thermal expansion. When welding, the service life requirements are therefore not met by the different extent of the carrier 37 and the gas pipe 70. If, in addition, the fuel nozzle 40 is still bolted to the carrier 37, the attachment of the fuel nozzle 40 to the carrier 37 is overdetermined by the welding and the screw connection, which likewise has a negative effect on the service life.

In order to prevent the fit 75 for the gas tube 70 from forming unwanted gas or compressor air passages of the turbine, at least one seal 80 is preferably present on the wearer 100 end of the fit 75, particularly in the region of the fit 75 and the gas tube 70. In this case, the carrier 37 can identify a bulge, in which the seal 80 is arranged. Such a seal 80 may in particular be designed as a c-ring seal. These are particularly well suited as seals due to their springback properties. In principle, however, other resilient seals such as o-ring seals are possible. Due to the elasticity of the seal, excessive restrictions on relative movements, which could occur, for example, due to the operational heating of the components, can be avoided.

Another problem of the prior art fuel nozzle is the manufacture of the fuel nozzles 40 to the carrier 37, because the fuel nozzles 40 must be arranged perpendicular to the carrier 37 in the manufacturing process. This production is also very tedious and associated with increased effort and therefore costs.

With the invention, however, can thus easily centering, in particular by the fit 75, make the fuel nozzle 40 via the gas pipe 70, so that now no increased effort is required.

In the carrier 37 further through holes (not shown separately) may be arranged through which in addition at least one oil passage is guided through the carrier 37 therethrough.

Trägerabseitig 101 is at least one distribution channel (not shown), but mostly two distribution channels each for oil and gas, provided which supply the gas supply pipe 70 and the at least one oil channel already carrier downstream 101 with the appropriate fuel. Since the distribution channels are not directly in contact with the hot gas in the combustion chamber, they can be made of a low-cost material.

In addition, the requirements on the installation space of the burner assembly in the region of the side facing away from the fuel nozzles 40 side of the carrier in comparison to the prior art are less stringent. Overall, the machining of the carrier is simplified.

The carrier-side contact surface 60 has holes for attachment of the fuel nozzles 40 on the carrier. The carrier 37 has corresponding openings or holes. Through these holes, the fuel nozzle 40 can be secured to the carrier 37 by means of a screw or a bolt connection. The holes are distributed over the entire carrier-side contact surface 60. By this distribution of the holes, the fuel nozzle 40 high natural frequencies that can be quickly damped. Thus, the fuel nozzle 40 is stable against natural frequencies. The screw or bolt connection secures the fuel nozzle 40 to the carrier 37 and thus takes over a large part of the pressure loads during operation.

The holes in the carrier-side abutment surface 60, as well as the corresponding holes / holes in the carrier 37 may be provided with large measurement tolerances, so that a quick and easy production is possible.

Due to the burner assembly according to the invention, it is possible to significantly increase the life of the burner assembly. This is due to the fact that the now possible free thermal deformations no longer build up disabling thermal stresses. The fuel nozzle 40 can be easily centered over the gas pipe 70.

The c-ring seal prevents unwanted leaks; An uncontrolled gas and / or compressor air entering or exiting can thus be avoided.

With the burner arrangement according to the invention, the individual fuel nozzles 40 can now be detached from the carrier easily and non-destructively, whereby the assembly / disassembly is in particular improved. This is of enormous benefit; especially when checking already manufactured and put into operation systems.

Due to the burner assembly according to the invention, it is possible to significantly reduce costs. This is due to the fact that the fuel distributor 37 now has a substantially small thickness than the fuel distributor 27 in the prior art. All holes or openings can be made quickly and easily, since no particularly accurate measurement tolerances required and adhered to.

Claims (10)

Burner arrangement with a carrier (37), at least two fuel nozzles (40) with fuel nozzle tips (47a, 47b) attached to the carrier (37) in the flow direction, - A gas supply supply system extending through the carrier (37) to the fuel nozzle tips (47a, 47b), characterized in that each fuel nozzle (40) comprises a carrier-side portion (45) having a support surface (60) on the carrier side (100) it abuts against a bearing surface (55) of the carrier (37), wherein from the carrier-side portion (45) at least two integrally formed fuel nozzle tips (47a, 47b) emanate in the flow direction wherein the gas supply supply system (120) at least one gas supply line (70) and its Carrying out by the carrier (37) comprises
wherein the passage is designed as a fit (75). Burner arrangement according to claim 1,
characterized in that the carrier downstream (101) at least one distribution channel is provided, which supplies the gas supply line (70) with gas. Burner arrangement according to one of the preceding claims,
characterized in that a further fuel supply line for liquid fuel through the support (37), in particular oil line, is provided, which supplies the fuel nozzle carrier side (100) with liquid fuel, in particular oil. Burner arrangement according to one of the preceding claims,
characterized in that between the carrier-side contact surface (60) of the fuel nozzle (40) and the carrier (37) at least one seal is present. Burner arrangement according to Claim 4,
characterized in that the seal (80) carrier side (100) in the region of the fitting (75) and gas supply line (70) is arranged. Burner arrangement according to Claim 4 or 5,
characterized in that the at least one seal (80) is a c-ring seal. Burner arrangement according to one of the preceding claims,
characterized in that the carrier-side contact surface (60) has at least one opening for attachment of the carrier-side contact surface (60) on the support surface (55) of the carrier (37). Burner arrangement according to claim 7,
characterized in that the opening is a bore and the attachment is a screw connection or a bolt connection. Burner assembly according to claim 8,
characterized in that six holes are provided in the carrier-side contact surface (60), wherein the holes over the entire carrier-side contact surface (60) are distributed. A gas turbine comprising a compressor section 3, a combustion section 4, a combustion chamber 5, a burner 6, a turbine section 7, a rotor 9 and a burner arrangement according to one of the preceding claims.

Images