EP2459934B1 - Gas turbine combustion chamber - Google Patents

Description

The invention relates to a gas turbine combustion chamber having a housing, a flame tube accommodated therein and a perforated plate surrounding this, which is fastened to the housing at a front end, and a gas turbine, in particular a stationary gas turbine, with such a gas turbine combustor.

In a gas turbine, a fluid, usually called air and therefore generalized hereinafter as combustion air, first compressed to a higher pressure level and burned as a combustion air-fuel mixture in a combustion chamber before in a turbine enthalpy of the exhaust gas is converted into mechanical energy and as useful power is available.

The combustion chamber experiences both high pressure and temperature loads due to the pressure level and the combustion. Therefore, it has hitherto been customary in the prior art to reinforce the housing of the combustion chamber by inner and / or outer stiffening ribs, to use highly heat-resistant materials and to provide a so-called flame tube in the housing, which limits the combustion zone and thus at least partially shields the housing against the combustion heat ,

In addition to ceramic temperature protection layers and a film cooling is, for example from the WO 2008/028621 A1 , an impingement cooling of the flame tube known. For this purpose, a perforated plate surrounding the flame tube is provided. Compressed combustion air hits through holes in the perforated plate from the outside to the flame tube and cools this before it is fed by a radial swirl generator the Flammrohrinnen- or combustion chamber and burned there.

The US 6,134,877 shows a gas turbine combustor having a housing, a flame tube accommodated therein and a conical cylinder surrounding it, having in a downstream region openings for impingement cooling a region of decreasing diameter of the flame tube and at one front end attached to the housing. By a folded region, an axial compliance of the cylinder is introduced to allow thermal expansion. The cylinder opens with its other front end in the turbine outlet.

The US 5,784,876 shows a generic gas turbine combustor. From the JP 58 210413 A and the DE 197 51 299 A1 In each case, combustors for gas turbine burners with various wall / housing structures are disclosed.

In particular, in stationary gas turbines with radially outer, freestanding combustion chambers, as they Fig. 1 shows the additional weight of the Fig. 1 shown stiffening ribs 110 is a problem because it complicates the handling of the separate combustion chambers and their connection to the housing of the turbine loaded by torques to be supported.

The object of the present invention is therefore to improve a gas turbine or its combustion chamber.

To achieve this object, a gas turbine combustion chamber according to the preamble of claim 1 is further developed by its characterizing features. Claim 9 provides a gas turbine with at least one gas turbine combustor according to the invention under protection, the dependent claims relate to advantageous developments.

The present invention is based on the idea to reduce or replace previously required stiffening ribs of the housing by integrating or integrating the perforated plate as a support structure on both sides into the housing structure and thus increasing the structural rigidity and / or strength of the housing.

For this purpose, a gas turbine combustor according to the invention comprises a housing with a flame tube received therein and a perforated plate surrounding it at least partially, which is fastened to the housing at an end face, wherein the perforated plate is likewise fastened to the housing at its other front end, wherein the housing is an outer casing of the combustion chamber and forms an annular chamber which is formed from a plurality of parts welded together sheets, wherein the gas turbine combustor at a End face has an annular plate of a swirl generator and at the other end a flange for attachment to a turbine housing and the perforated plate is integrally formed and is secured via welds on the one hand at both ends with an annular plate or the flange and on the other hand attached to the annular chamber, so that its two end-side end portions form integral parts of the outer housing and loads of the housing are received and transmitted by the perforated plate.

By the perforated plate in addition to the flow guide and cooling according to the invention also used for transmitting loads of the housing and this is connected on both sides of the housing, the strength and / or rigidity of the housing can be increased without increasing its weight by excessive inner or outer ribs.

In a preferred embodiment, the perforated plate, at least in a primary combustion region of the flame tube, has cooling openings, in particular bores and / or slot openings, for impingement cooling of the flame tube. Preferably, by suitable arrangement and / or dimensioning of the cooling holes, for example, an angular offset of axially adjacent cooling holes, so that the perforated plate has network structure, or axially aligned cooling holes, so that the perforated plate axially continuous webs, by slits in the axial and / or circumferential direction of the perforated plate and / or a limitation of the number and / or diameter of the cooling openings can be adjusted, in particular axial, rigidity and strength of the perforated plate.

Particularly in such a primary combustion region, the annular chamber urges the perforated plate with combustion air, so as to preferably cool this thermally highly stressed axial portion of the flame tube. The annular chamber is preferably designed such that the entire supplied combustion air is supplied to the flame tube through cooling openings of the perforated plate and, for this purpose, may preferably extend substantially in the primary combustion region in the axial direction. The perforated plate can define or define the annular chamber radially from the inside and extend axially on one or both sides beyond the annular chamber adjoining it from outside. Form the axially over the annular chamber In addition, extending portions of the perforated plate part of an outer housing, the annular chamber can put on the outside of the perforated plate, which is thus structurally integrated as part of the outer housing in this. The perforated plate is permanently attached to both sides of welds on welds on the housing. As a result, structural loads can be transferred particularly favorably between housing and perforated plate. In a non-inventive embodiment, it is also possible to releasably attach the perforated plate at least one of its two front ends to the housing in order to improve the (de) mountability of the gas turbine combustor.

In particular, the perforated plate can have one or more sections which delimit a combustion air feed to the outside environment. Such sections may be formed with a section having cooling openings in one or more parts, in particular ur- or reshaped with each other.

In an advantageous embodiment, the housing, at least in the region of the perforated plate, be formed largely free of ribs.

According to a preferred embodiment, the swirl generator is a radial swirl generator. The inventive division of structural loads on housing and integrated perforated plate, the housing can be advantageously formed thinner walls. Preferably, one or more corresponding areas of the housing and the perforated plate have substantially the same wall thickness. In particular, regions at the same axial height of the combustion chamber are referred to as corresponding regions.

In a preferred embodiment, the flame tube is axially fixed at its upstream front end to the housing. Due to the connection on both sides of the perforated plate, the larger clearance or the larger thermal expansions can occur in an upstream head region of the combustion chamber occur, so that it may be advantageous to now provide the fixed storage of a fixed-mounted flame tube there.

Fig. 1:

eine Gasturbine nach dem Stand der Technik mit zwei außenliegenden Brennkammern; und

Fig. 2:

eine Gasturbinenbrennkammer nach einer Ausführung der vorliegenden Erfindung im Axial- bzw. Längsschnitt.

Preferably, the perforated plate is formed substantially circular cylindrical, so as to provide a higher structural rigidity or strength available. Further advantages and features emerge from the subclaims and the exemplary embodiments. This shows, partially schematized:

Fig. 1:

a gas turbine according to the prior art with two external combustion chambers; and

Fig. 2:

a gas turbine combustor according to an embodiment of the present invention in axial or longitudinal section.

In Fig. 1 is, as stated in the introduction, shown a gas turbine according to the prior art with two external combustion chambers, the housing 100 are reinforced with stiffening ribs 110 and thus complicate the handling by their higher weight and burden the underlying turbine housing to which they are attached.

Fig. 2 shows a gas turbine combustor according to an embodiment of the present invention in axial or longitudinal section to replace the in Fig. 1 shown combustion chambers.

In its interior, a flame tube 2 defines a combustion chamber. This is supplied by a radial swirl generator 5, a combustion air-fuel mixture B, burned substantially in a cylindrical primary combustion zone of the combustion or flame tube interior and the exhaust gas A from there to a turbine (not shown) supplied.

In order to cool the flame tube, in particular in the region of the primary combustion zone, it is surrounded by a cylindrical perforated plate 3 which has cooling openings 4. Through this, compressed combustion air L impinges on the flame tube 2 from the outside before it flows along the latter to the swirl generator 5, is swirled by the latter and mixed with fuel.

In order to supply the entire combustion air to the cylindrical perforated plate in the area of the primary combustion zone, the outer housing 1 of the combustion chamber forms an annular chamber 1 which is formed in several parts from sheet-metal parts welded together.

The one-piece perforated plate 3 is on welds 8 on the one hand at both ends with an annular plate 6 of the swirl generator 5 and a flange for attachment of the outer combustion chamber to a turbine housing (not shown) and on the other hand attached to the annular chamber 1, so that its two end-side end portions 3.1, 3.2 form integral parts of the outer housing. In a modification, not shown, the perforated plate is formed axially in several parts with a central part having the cooling holes 4 and the front side in each case to the annular chamber 1 or edge strips 3.1, 3.2 of the perforated plate is welded. The plate 6 of the swirl generator 5 and the flange, to which the perforated plate 3 forming part of the outer housing is welded, are connected via screw connections 7.1, 7.2 to a cover or turbine housing (not shown).

In particular, axial forces exerted on a high pressure level combustion air V in the annular chamber 1 on the outer housing are partially absorbed and transmitted from the perforated plate due to the inventive integration of the perforated plate 3 as a support in the housing structure. Due to the annular bilateral connection of the cylindrical perforated plate 3 in the surrounding annular chamber 1, this is reinforced and stiffened in the radial direction.

By forming the perforated plate 3 for transmitting loads of the housing 1 and for this purpose at its front ends 3.1, 3.2 attached to the housing, it can in addition to its function, combustion air V to be directed to the flame tube 2 and to the swirl generator lead to reinforce the housing. This can therefore, at least in the reinforced by the tethered perforated plate area, largely free of ribs and thus easier to be formed.

Due to the substantially same wall thicknesses of perforated plate 3 and housing 1, the perforated plate can also be advantageous, especially in low-load areas 3.1, 3.2, directly form the outer housing, which makes the construction of the combustion chamber advantageously more compact and manufacturing technology cheaper. Since the perforated plate defines the annular chamber radially from the inside and subsequently defines the combustion air supply to the swirl generator in the regions 3.1, 3.2 as the outer housing, the entire combustion air serves to cool the flame tube in a structurally advantageous manner. At the same time by placing the annular chamber 1 outside of the axially projecting beyond the perforated plate. 3 this perforated plate, the front-side edge portions 3.1, 3.2 act as part of the outer housing, integrated in a structurally advantageous manner.

LIST OF REFERENCE NUMBERS

1

(Ring chamber of the) (outer) housing (s)

2

flame tube

3

perforated sheet

3.1, 3.2

front sides

4

cooling apertures

5

swirl generator

6

plate

7.1, 7.2

screw

8th

Weld

A

exhaust

B

Combustion air-fuel mixture

L

combustion air

Claims (10)

1. A gas turbine combustion chamber with a housing (1), a flame tube (2) received therein and a perforated plate (3) which at least partly surrounds the same, which at a face end (3.1) is fastened to the housing (1),
   wherein the perforated plate (3) on its other face end (3.2) is likewise fastened to the housing (1),
   wherein the housing (1) is an outer housing (1) of the combustion chamber and forms an annular chamber (1), which is formed in multiple parts from plates that have been welded together,
   wherein the gas turbine combustion chamber at a face end (3.2) comprises a flange for fastening to a turbine housing,
   characterized in that
   the gas turbine combustion chamber at the other face end (3.1) comprises an annular plate (6) of a swirl generator (5) and the perforated plate (3) is formed in one piece and fastened via weld seams (8) on the one hand at both face ends (3.2, 3.2) with the annular plate (6) and the flange respectively and on the other hand fastened to the annular chamber (1) so that its two face end regions (3.1, 3.2) form integral parts of the outer housing and loads of the housing (1) are absorbed and transmitted by the perforated plate (3).
2. The gas turbine combustion chamber according to any one of the preceding claims, characterized in that the perforated plate, at least in a primary combustion region of the flame tube, comprises cooling openings (4) for the impingement cooling of the flame tube (2).
3. The gas turbine combustion chamber according to any one of the preceding claims, characterized in that the housing is formed free of ribs at least in the region of the perforated plate.
4. The gas turbine combustion chamber according any one of the preceding claims, characterized in that the swirl generator (5) is a radial swirl generator.
5. The gas turbine combustion chamber according to any one of the preceding claims, characterized in that at least one corresponding region of the housing and of the perforated plate substantially has the same wall thickness.
6. The gas turbine combustion chamber according to any one of the preceding claims, characterized in that the flame tube (2) at its upstream face end is axially fixed to the housing.
7. The gas turbine combustion chamber according to any one of the preceding claims, characterized in that the perforated plate (3) is substantially circular-cylindrical in shape.
8. The gas turbine combustion chamber according to any one of the preceding claims, characterized in that the annular chamber (1) admits combustion air (L) to the perforated plate.
9. A gas turbine, in particular stationary gas turbine, with at least one gas turbine combustion chamber according to any one of the preceding claims.
10. The gas turbine according to Claim 9, characterized in that the gas turbine combustion chamber located outside is connected to a cover and/or a basic housing via screw connections (7.1, 7.2).

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