EP3179169B1 - Method for mounting a combustion chamber of a gas turbine engine - Google Patents

Description

The invention relates to a method for assembling a combustion chamber of a gas turbine engine according to the features of the preamble of claim 1.

In particular, the invention relates to a method in which a combustion chamber, in particular an annular combustion chamber of a gas turbine engine is mounted. In this case, an outer and an inner annular combustion chamber wall are manufactured in the usual way, for example, from sheet materials. The outer and the inner combustion chamber wall can be formed single-walled. However, it is also possible to form these double-walled and to provide on the respective inside with shingles or similar components.

A combustion chamber of a gas turbine engine has a likewise annular top plate, which is provided with recesses through which burners are performed. The top plate is connected to the outer and inner combustion chamber walls so as to mount the basic elements of the combustion chamber. Subsequently, a combustion chamber head is attached to the top plate, the outer combustion chamber wall or the inner combustion chamber wall.

The prior art shows this for different design variants. These are for example in the US patents US Pat. No. 6,449,952 B1 and 7,765,809 B2 explained. US Pat. No. 6,449,952 B1 discloses a method of assembling a combustor of a gas turbine engine according to the preamble of claim 1. As in Figs Fig. 2 to 5 As shown in the prior art, the assembly is such that first an outer annular combustion chamber wall 29 and an inner, annular combustion chamber wall 30 are provided, these are formed as sheet metal parts. At the inflow end of a preferably also made of sheet metal top plate 31 is arranged.

The outer combustion chamber wall 29 has an outer flange 41, while the inner combustion wall 30 is provided with an inner flange 42. The flanges are arranged at an angle to the longitudinal extent of the outer and the inner combustion chamber wall 29, 30, to be aligned parallel to the engine axis 1. According to the invention, the angle between the outer flange 41 and the outer combustion wall 29 or the inner flange 42 and the inner combustion chamber 30 is not required.

The Fig. 3 shows a plan view of a portion of a fully assembled combustion chamber according to the prior art. In Fig. 2 is a sectional view according to section A shown. It can be seen that the top plate 31 is provided with an outer flange 43 and an inner flange 44. These two flanges 43 and 44 extend in the assembled state parallel to the flanges 41 and 42 of the outer and the inner combustion chamber wall.

Furthermore, the shows Fig. 2 a combustor head 32, preferably formed of a sheet metal material, which is provided with an outer flange 45 and an inner flange 46. These flanges are aligned in the mounted state parallel to the flanges 41 to 44 and are bolted by means of bolts 34 and nuts 35 together with the flanges of the outer combustion chamber wall 29 and the inner combustion chamber wall 30 and the top plate 31. The screwing takes place so that the central axes of the bolts extend in a radial plane, which is aligned radially to the engine axis 1. Thus, the flanges 41 to 46 each form cylindrical surfaces to allow easy installation and to avoid leakage through small tolerances.

As in the Fig. 2 . 4 and 5 shown, 31 heat shields 38 are mounted on the side facing the interior of the combustion chamber side of the top plate. The number of heat shields is usually identical to the number of fuel nozzles (not shown). The screwing of the heat shields 38 by means of threaded bolts 39 and nuts 40. The heat shields are screwed prior to assembly of the top plate 31 with this.

The Fig. 2 thus shows according to section A of Fig. 3 a fully assembled state with a plurality of circumferentially arranged bolts 34 and nuts 35. The screwing of the nuts 35 is effected by not shown mounting openings of the combustion chamber head 32nd

The Fig. 3 shows a plan view in which a portion of the outer combustion chamber wall 29 is shown. In the mounted state, a view of the outer flange 45 of the combustion chamber head 32 results in the plan view.

As in the section B according to Fig. 3 shows, the flange 45 of the combustion chamber head 32 distributed on the circumference recesses 47. These are for assembly, as in the following in connection with the 4 and 5 is described.

The 4 and 5 each show sections B according to Fig. 3 , It is in Fig. 4 the combustion chamber head 32 is not yet mounted. The Fig. 4 shows that the assembly is carried out by first at the periphery in the areas in which the outer flange 45 and the inner flange 46 of the combustion chamber head are provided with the recess 47, threaded bolts 48 and nuts 49 are used to the flanges 41 and 42 of the outer 29 and the inner 30 combustion chamber wall to connect with each other. This connection is made to align the combustion chamber walls 29 and 30 and the top plate 31 to each other and to be able to position. At the periphery, some of the recesses 47 are provided on the combustion head 32. According to the number of recesses 47, the number of threaded bolts 48 or nuts 49 to be used results.

The following will, as in Fig. 5 shown, the combustion chamber head 32 is slid, wherein the recesses 47 are positioned so that they coincide with the threaded bolt 48 and the nuts 49. In this case, it is necessary that the combustion chamber head 32 must be manufactured very precisely and positioned during assembly in order to prevent collisions with the threaded bolts 48.

Subsequently, a screwing of the outer and inner flanges 45, 46 of the combustion chamber head 32 with the flanges 41 to 44 of the combustion chamber walls 29, 30 and the top plate 31.

This results in a very labor-intensive assembly, which must be carried out with high precision. Another major disadvantage is that it is necessary to provide on the flanges 45 and 46 of the combustion chamber head 32 around the circumference a plurality of recesses 47 provided. This leads to a production engineering effort, which is associated with costs. US 2013/0192262 A1 discloses a combustor of a gas turbine engine in which the combustor walls, top plate, and combustor head are connected with either rivets or screws. The invention has for its object to provide a method of the type mentioned, which allows a simple construction and simple, cost-effective feasibility reliable assembly of the combustion chamber.

According to the invention the object is achieved by the combination of features of claim 1, the dependent claims show further advantageous embodiments of the invention. According to the invention it is thus provided that the head plate by means of distributed around the circumference arranged rivets with the outer combustion chamber wall and the inner combustion chamber wall is connected. The rivets thus serve to ensure a preliminary assembly in a simple and fast way. It is not necessary, as required in the prior art, additional fittings that need to be mounted and secured. Rather, the rivets themselves are sufficient to ensure a pre-assembly of the outer and inner combustion chamber wall and the combustion chamber head. After the pre-assembly and the connection by means of the rivets of the combustion chamber head is brought into position and connected in the usual way by means of bolts and nuts with the pre-assembled arrangement of outer combustion chamber wall, inner combustion chamber wall and top plate. Here, a conventional screw can be used, which serves to reliably clamp the individual flanges of the combustion chamber walls, the top plate and the combustion chamber head. This can be done in the usual way by mounting holes in the combustion chamber head.

According to the invention, it is thus not necessary to provide recesses or recesses on the combustion chamber head or its flanges, which, as in the prior art, serve to eliminate or circumvent the bolt connections with which the combustion chamber walls and the top plate were preassembled in advance.

Thus, according to the present invention, it is possible to accurately and effectively mount the four main groups of components of a combustor of a gas turbine engine, namely, an outer and an inner combustion chamber wall, a top plate, and a combustion head. Here, a pre-assembly of the top plate and the inner and outer combustion chamber walls by means of rivets. As a result, before the screwing of the combustion chamber head to the preassembled module before a stable arrangement. By providing the rivet connection between the inner and outer combustion chamber wall and the top plate, a precise connection can be achieved, wherein in particular no thermal stress on the components takes place, which occurs, for example, in welding processes. Furthermore, a rivet connection is simpler and more durable than a screw connection, which can also contain errors with regard to the torque to be applied and, incidentally, also increases a total weight of the combustion chamber. In contrast to a welded joint, the provision of a riveted joint results in a permanent bond without affecting the metallurgical environment, as would be the case in a welding process. Also, the rivet connection allows the avoidance of thermal distortion of the components, as may occur in a welded joint. Thus, according to the invention, a simple and inexpensive mountable combustion chamber can be made available in a targeted manner by the combination of the provision of rivet connections for a preassembled subassembly and the final screwing operation of the combustion chamber head Weight optimization allows, as the riveted joints have a significantly lower weight than screw connections. Manufacturing technology also results in advantages through the rivet connections.

It is particularly favorable if the outer combustion chamber wall, the inner combustion chamber wall and the top plate are provided with a multiplicity of rivet recesses which are distributed around the circumference and are aligned with one another in the assembled state prior to assembly. These rivet recesses may be formed slightly different than the recesses for the implementation of the threaded bolt. Thus, it is possible, for example, to provide the rivet recesses with a smaller diameter, since the rivets required for pre-assembly need not have the same diameter as the threaded bolts.

The rivet recesses can be formed according to the invention as a circular holes or as slots. This makes it possible in a simple manner, make an assignment, pre-assembly and / or adjustment of the outer combustion chamber wall, the inner combustion chamber wall and the top plate. The rivet recesses may, for example, be provided with a countersink to introduce countersunk rivets whose heads do not protrude on the outer peripheral surface of the flanges of the combustion chamber walls and / or the top plate.

In a particularly favorable embodiment of the invention, it is provided that a riveting for the purpose of pre-assembly takes place only on some of the circumference provided Nietausnehmungen. For example, it is possible to provide only three rivets, which are distributed uniformly around the circumference, for example at a distance of 120 °. The other rivet recesses remain unused. This has the advantage that in case of a possible disassembly, the rivets used for pre-assembly can be drilled in order to allow the disassembly of the outer and the inner combustion chamber wall and the top plate. For a new assembly and associated riveting then some of the remaining Nietausnehmungen can be used. According to the invention, riveting is thus carried out at least three points on the circumference for pre-assembly. The number of rivets also depends on the stability of the outer and inner combustion chamber wall and the top plate and the dimensioning of the combustion chamber.

The inventively provided Nietausnehmungen are thus introduced according to the inventive method in addition to the recesses, by means of which in the assembled state, the combustion chamber head is screwed. It can be particularly advantageous if these Schraubausnehmungen and the Nietausnehmungen be mounted alternately.

The combustion chamber head according to the invention is preferably provided with a plurality of Schraubausnehmungen which are arranged on the outer and the inner flange of the combustion chamber head. These Schraubausnehmungen are arranged and dimensioned so that they are aligned with Schraubausnehmungen the combustion chamber walls and the top plate, so that the usual screwing can be done with deferred combustion chamber head.

Fig. 1

eine schematische Darstellung eines Gasturbinentriebwerks gemäß der vorliegenden Erfindung,

Fig. 2

eine vereinfachte Schnittansicht eines vorderen Bereichs einer fertig montierten Brennkammer gemäß dem Stand der Technik,

Fig. 3

eine Draufsicht auf die Anordnung gemäß Fig. 2, welche dem Schnitt A entspricht,

Fig. 4

eine vereinfachte Schnittansicht gemäß Schnitt B von Fig. 3 im vormontierten Zustand gemäß dem Stand der Technik,

Fig. 5

eine Schnittansicht im fertig montierten Zustand gemäß Schnitt B von Fig. 3 gemäß dem Stand der Technik,

Fig. 6

eine vereinfachte Schnittansicht, analog Fig. 5, eines erfindungsgemäßen Ausführungsbeispiels gemäß Schnitt A von Fig. 7,

Fig. 7

eine Unteransicht des Flanschbereiches der Anordnung gemäß Fig. 6,

Fig. 8

eine Schnittansicht gemäß Schnitt B von Fig. 7, und

Fig. 9

eine Schnittansicht gemäß Schnitt C von Fig. 7.

In the following the invention will be described by means of an embodiment in conjunction with the drawing. Showing:

Fig. 1

a schematic representation of a gas turbine engine according to the present invention,

Fig. 2

5 is a simplified sectional view of a front portion of a pre-assembled combustion chamber according to the prior art,

Fig. 3

a plan view of the arrangement according to Fig. 2 which corresponds to the section A,

Fig. 4

a simplified sectional view according to section B of Fig. 3 in the preassembled state according to the prior art,

Fig. 5

a sectional view in the assembled state according to section B of Fig. 3 according to the prior art,

Fig. 6

a simplified sectional view, analog Fig. 5 , An inventive embodiment according to section A of Fig. 7 .

Fig. 7

a bottom view of the flange portion of the arrangement according to Fig. 6 .

Fig. 8

a sectional view according to section B of Fig. 7 , and

Fig. 9

a sectional view according to section C of Fig. 7 ,

In the following embodiments, the same parts as in the Fig. 2 to 5 provided with the same reference numerals, so that can be dispensed with a repeated detailed description.

The gas turbine engine 10 according to Fig. 1 is a generalized example of a turbomachine, in which the invention can be applied. The engine 10 is formed in a conventional manner and comprises in the flow direction in succession an air inlet 11, a circulating in a housing fan 12, a medium pressure compressor 13, a high pressure compressor 14, a combustion chamber 15, a high pressure turbine 16, a medium pressure turbine 17 and a low pressure turbine 18 and a Exhaust nozzle 19, which are all arranged around a central engine axis 1.

The intermediate pressure compressor 13 and the high pressure compressor 14 each include a plurality of stages, each of which includes a circumferentially extending array of fixed stationary vanes 20, commonly referred to as stator vanes, that radially inwardly from the core engine housing 21 into an annular flow passage through the compressors 13, 14 protrude. The compressors further include an array of compressor blades 22 projecting radially outwardly from a rotatable drum or disc 26 coupled to hubs 27 of high pressure turbine 16 and mid pressure turbine 17, respectively.

The turbine sections 16, 17, 18 have similar stages, comprising an array of fixed vanes 23 projecting radially inward from the housing 21 into the annular flow passage through the turbines 16, 17, 18, and a downstream array of turbine rotor blades 24 projecting outwardly from a rotatable hub 27. The compressor drum or compressor disk 26 and the blades 22 disposed thereon and the turbine rotor hub 27 and the turbine rotor blades 24 disposed thereon rotate about the engine axis 1 during operation.

The Fig. 6 shows in the sectional view A according to Fig. 7 a fully assembled state in which the outer flange 45 and the inner flange 46 of the combustion chamber head 32 and the flanges 41 and 42 of the outer combustion chamber wall 29 and the inner combustion chamber wall 30 and the outer flange 43 and the inner flange 44 of the top plate 31 by means of Screw bolt 34 and the nuts 35 are screwed. In addition, the shows Fig. 6 in that the top plate 31 is screwed to at least one heat shield 38 by means of threaded bolts 39 and nuts 40.

In Fig. 8 is in the sectional view B of the assembled state according to Fig. 6 shown. The sectional view of Fig. 8 However, it is offset by the circumference. While the section A is laid through the center axes of the threaded bolts 34, the section according to Fig. 8 (Section B) through central axes of Nietausnehmungen 36 which, as in Fig. 7 is shown, are formed on the circumference alternately with Schraubausnehmungen 37. In the sectional view according to Fig. 8 It is shown that the Nietausnehmungen 36 through the Flange 41 of the outer combustion chamber wall 29 and the outer flange 43 of the top plate 31 and the inner flange 44 of the top plate 31 and the inner flange 42 of the inner combustion chamber 30 extend. These rivet recesses 36 are not occupied in the section shown, since, as mentioned above, only a small number of rivet connections are used for pre-assembly around the circumference, while the remaining rivet recesses 36 remain unused. The Fig. 8 shows that the outer flange 45 and the inner flange 46 of the combustion head 32 are slid over the flanges 41 and 42, respectively, to be bolted at locations circumferentially offset, as in Figs Fig. 6 shows.

The Fig. 9 shows a section C according to Fig. 7 , It can be seen that for pre-assembly of the outer flange 41 of the outer combustion chamber wall 29 and the outer flange 43 of the top plate 31 are connected by means of a rivet 33 for pre-assembly. Similarly, the inner flange 44 of the top plate 31 and the flange 42 of the inner combustion chamber wall 30 have been connected by means of a rivet 33 for pre-assembly. Below may be for final assembly, as in Fig. 9 shown, the combustion chamber head 32 with its annular flanges 45 and 46 are pushed over the rivets 33. Since the rivets 33 are designed as countersunk rivets, they do not interfere with the further assembly and in particular not with the pushing on of the flanges 45, 46 of the combustion chamber head 32.

LIST OF REFERENCE NUMBERS

1

Engine axis

10

Gas turbine engine / core engine

11

air intake

12

fan

13

Medium pressure compressor (compressor)

14

High pressure compressor

15

combustion chamber

16

High-pressure turbine

17

Intermediate pressure turbine

18

Low-pressure turbine

19

exhaust nozzle

20

vanes

21

Core engine casing

22

Compressor blades

23

vanes

24

Turbine rotor blades

25

Bypass duct

26

Compressor drum or disc

27

Turbinenrotornabe

28

outlet cone

29

Outer combustion chamber wall

30

Inner combustion chamber wall

31

headstock

32

bulkhead

33

rivet

34

bolt

35

mother

36

Nietausnehmung

37

Schraubausnehmung

38

heat shield

39

threaded bolt

40

mother

41

Outer flange

42

Inner flange

43

Outer flange

44

Inner flange

45

Outer flange

46

Inner flange

47

recess

48

threaded bolt

49

mother

Claims (10)

1. Method for mounting a combustion chamber (15) of a gas-turbine engine, wherein an annular outer combustion chamber wall (29) and an annular inner combustion chamber wall (30) are brought into position relative to one another and are connected to a head plate (31), and wherein subsequently a combustion chamber head (32) is mounted, characterized in that the head plate (31) is connected to the outer combustion chamber wall (29) and to the inner combustion chamber wall (30) by means of circumferentially distributed rivets (33) and that subsequently the combustion chamber head (32) is bought into position and bolted by means of threaded bolts (34) and nuts (35) to the arrangement of the head plate (31), the outer combustion chamber wall (29) and the inner combustion chamber wall (30), with said arrangement being premounted by means of the rivets (33).
2. Method in accordance with Claim 1, characterized in that, prior to mounting, the outer combustion chamber wall (29), the inner combustion chamber wall (30) and the head plate (31) are provided with a plurality of circumferentially distributed rivet recesses (36) that align with one another in the mounted state.
3. Method in accordance with Claim 2, characterized in that the rivet recesses (36) are designed as circular holes or as elongated holes.
4. Method in accordance with Claim 2 or 3, characterized in that the rivet connection is realized only at some of the rivet recesses (36).
5. Method in accordance with one of the Claims 1 to 4, characterized in that countersunk-head rivets are used as rivets (33).
6. Method in accordance with one of the Claims 1 to 5, characterized in that the rivets (33) are arranged evenly distributed around the circumference.
7. Method in accordance with one of the Claims 2 to 6, characterized in that the combustion chamber head (32) is provided with a plurality of screw recesses (37), which in the mounted state align with screw recesses of the outer combustion chamber wall (29), the inner combustion chamber wall (30) and the head plate (31).
8. Method in accordance with one of the Claims 1 to 7, characterized in that, prior to mounting the head plate (31), at least one heat shield (38) is attached to the latter by means of threaded bolts (39) and nuts (40).
9. Method in accordance with one of the Claims 1 to 8, characterized in that screw recesses (37) and rivet recesses (36) are arranged alternatingly around the circumference.
10. Method in accordance with one of the Claims 1 to 9, characterized in that the outer combustion chamber wall (29) and/ or the inner combustion chamber wall (30) and/ or the head plate (31) and/ or the combustion chamber head (32) are/ is made of a sheet metal material.

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