EP2770260A2 - Impact effusion cooled shingle of a gas turbine combustion chamber with elongated effusion bore holes - Google Patents

Abstract

The chamber (15) has a combustion chamber wall that includes a tile carrier. The wall tiles are mounted on the tile carrier at a distance to form an impingement cooling gap, where the tile carrier has impingement cooling holes. The tile is provided with effusion holes, where tile has a surface structure on side of tile that faces the tile carrier, and the surface structure raise from the surface of the tile, and extends in the direction of the tile carrier. An inlet opening is located on a raised portion of the surface structure.

Description

The invention relates to a gas turbine combustor according to the preamble of claim 1.

In particular, the invention relates to a gas turbine combustor having a combustor wall. On the combustion chamber wall or on a shingle support provided thereon a plurality of shingles are mounted. For cooling the shingles and the combustion chamber wall of the shingle support is provided with impingement cooling holes through which cooling air is passed, which impinges on the arranged at a distance from the shingle support wall or surface of the shingle. The air is then passed through effusion holes of the shingle to effect cooling of the surface of the shingle.

The prior art shows different cooling concepts for cooling the shingles of the combustion chamber. In detail, the state of the art exemplifies the following solutions:

The WO 92/16798 A1 describes the construction of a gas turbine combustor by stud bolts attached metallic shingles, which leads by the combination of impingement and effusion cooling to a quite effective cooling effect and thus allows the reduction of the cooling air consumption. However, the pressure loss, which exists over the wall, distributed to two throttle points, the shingle support and the shingle itself. To avoid edge leakage is usually the greater proportion of the pressure loss generated on the shingle support, so that the cooling air has less cause, at the Pass the effusion shingles.

The GB 2 087 065 A discloses an impingement cooling configuration with a clipped shingle, wherein each individual impingement cooling jet is protected from upstream flow by an upstream fin on the shingle. Furthermore, the pins or ribs increase the area available for heat transfer.

The GB 2 360 086 A shows a baffle cooling configuration with hexagonal ribs and partly additional prisms centrally located within the hexagonal ribs to increase the heat transfer.

The WO 95/25932 A1 discloses a combustion chamber wall in which ribs are provided on the cooling air side into which the effusion bores are introduced at a shallow angle.

The US 6,408,620 A describes a combustion chamber wall, which is equipped with donated shingles, in the additional effusion holes are introduced at a low angle to the surface.

The US 5,000,005 A shows a heat shield for a combustion chamber, which identifies cooling holes, which are designed at a shallow angle to the surface and expanding in the flow direction.

The WO 92/16798 A1 uses only a flat surface as the target of impingement cooling. An attachment of ribs would bring little except the simple increase in the area, since the ribs, such as in GB 2 360 086 A are shown to require an overflow to take effect. Due to the congruence of impingement cooling air supply and removal of the air through the effusion bores, however, there is no appreciable speed in the upper flow of the ribs. In part, the pressure difference across the shingle is reduced by the torch swirl so that no effective flow through the effusion holes takes place more or even threatens hot gas burglary in the impingement cooling chamber of the shingle.

Film cooling is the most effective way to lower the wall temperature because the component is protected by the insulating cooling film from the transfer of heat from the hot gas, instead of removing already coupled heat by other methods afterwards. GB 2 087 065 A and GB 360 086 A contain no technical teaching on the renewal of the cooling film on the hot gas side within the Extension of the shingle. The shingle must be made so short in the flow direction that the cooling film generated by the upstream shingle over the entire length of the shingle carries. This forces a multitude of shingles along the combustion chamber wall and does not allow to cover this distance with a single shingle.

In the GB 2 087 065 A the air flows as a stratified flow along a continuous straight channel, which makes the boundary layer grow quickly and thus rapidly reduces the heat transfer despite the expense.

A technical teaching for the removal of the spent air is in the GB 2 360 086 A not given. Thus, this arrangement is only suitable for small shingles. For larger shingles, the cross flow would be too strong and the effect of impingement cooling would be reduced by the deflection of the impingement cooling jet.

The WO 95/25932 A1 describes a single-walled combustion chamber construction in which no impingement cooling takes place on the cooling air side, but only convection cooling.

The US 6,408,628 A shows a combustion chamber wall, in which the pressure difference across the shingle can be fully optimized neither for convective cooling, since they prefer a large pressure difference, nor for the Effusionkühlung, as they prefer a small pressure difference to improve the film cooling.

The US 5,000,005 A relates to a heat shield for a combustion chamber, which is provided with expanding in the flow direction cooling holes, without going into the geometric relationship of impingement cooling holes and diffusive effusion holes.

The invention has for its object to provide a gas turbine combustor and a combustion chamber shingles, which allow a simple design and simple, inexpensive to manufacture a highly efficient cooling.

According to the invention the object is achieved by the combination of features of claim 1, the dependent claims show further advantageous embodiments.

According to the invention, a construction is thus provided in which shingles are mounted at a distance on a shingle support. The shingles can be fixed, for example by means of threaded bolts or the like. The shingle support has impingement cooling holes, through which the cooling air is passed, in order to impinge on the side of the shingle facing away from the combustion chamber and facing the shingle support. This will cool the shingle. The shingles have effusion holes, through which the air can escape from the gap between the shingle support and the shingle (baffle cooling gap). The exiting through the effusion holes air is the film cooling of the shingle. In order to provide improved heat transfer in the region of the shingle, and to form the effusion holes with high efficiency, it is provided that the inlet openings of the effusion holes are formed on raised portions of a surface structure of the shingle. The shingle thus has a surface structure which may be rib-shaped. However, it is also possible to form the surface structure in the form of singular bumps or the like. It is important in the context of the invention that the inlet openings of the effusion holes have a distance from the surface of the shingle and are thus arranged closer to the surface of the shingle support. This leads to more favorable flow conditions and better heat transfer.

In a particularly favorable embodiment of the invention it is provided that the inlet opening has a distance from the surface of the shingle support, which is 0.5 to 1.5 of the diameter of the inlet opening. This leads to a particularly efficient air flow and inflow into the inlet opening of the respective effusion hole.

The central axis of the inlet openings and thus the central axis of the at least first region of the effusion hole is preferably arranged substantially perpendicular to the surface of the shingle carrier and / or preferably parallel oriented to the central axis of the baffle hole. This leads to an improved flow guidance.

Another measure to ensure the inflow into the inlet openings during operation with thermally induced distortion is to provide at least one spacer adjacent to the inlet opening. This prevents thermal distortion that the effusion hole can be closed by the shingle support. This spacer can also partially enclose the inlet opening. It can also be designed so that it is designed to form a twist of the air flowing into the inlet opening.

The effusion hole may be straight or curved or partly straight and partly curved. It can be provided with a constant or with an expanding cross-section.

Furthermore, it is possible to form the surface structure in the form of cells which are triangular, quadrangular or polygonal. The surface structure may also be provided in the form of a circular depression. As a result, the impingement cooling jets of air jets exiting the impingement cooling holes can be directed to the center of these cells or recesses to improve the flow conditions. For this purpose, it may also be provided to provide a prism or similar configuration within these cells in order to distribute the air evenly.

Fig. 1

eine schematische Darstellung eines Gasturbinentriebwerks gemäß der vorliegenden Erfindung.

Fig. 2

eine schematische Schnittansicht einer Gasturbinenbrennkammer gemäß dem Stand der Technik,

Fig. 3

eine vereinfachte Seiten-Schnittansicht einer Schindelträger-Schindel-Konstruktion gemäß dem Stand der Technik,

Fig. 4

eine vereinfachte Seiten-Schnittansicht einer Schindel gemäß dem Stand der Technik,

Fig. 5

eine Draufsicht auf eine Schindel gemäß dem Stand der Technik,

Fig. 6

eine Seitenansicht, analog Fig. 3, einer erfindungsgemäßen Ausgestaltung,

Fig. 7

eine Draufsicht auf ein Ausführungsbeispiel der Erfindung,

Fig. 8

eine weitere Draufsicht auf ein Ausführungsbeispiel einer Schindel, analog Fig. 7,

Fig. 9

eine Detail-Seitenansicht eines weiteren Ausführungsbeispiels einer Schindel, und

Fig. 10

eine schematische Darstellung eines weiteren Ausführungsbeispiels analog Fig. 9.

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

Fig. 1

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

Fig. 2

a schematic sectional view of a gas turbine combustor according to the prior art,

Fig. 3

a simplified side sectional view of a shingle carrier shingle construction according to the prior art,

Fig. 4

a simplified side sectional view of a shingle according to the prior art,

Fig. 5

a top view of a shingle according to the prior art,

Fig. 6

a side view, analog Fig. 3 , an inventive embodiment,

Fig. 7

a top view of an embodiment of the invention,

Fig. 8

a further plan view of an embodiment of a shingle, analog Fig. 7 .

Fig. 9

a detail side view of another embodiment of a shingle, and

Fig. 10

a schematic representation of another embodiment analog Fig. 9 ,

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 succession an air inlet 11, a fan 12 circulating in a housing, 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 solidifies a circumferentially extending arrangement stationary stator vanes 20, which are generally referred to as stator blades and which project radially inwardly from the engine housing 21 in an annular flow channel through the compressors 13, 14. 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 blades 24 projecting outwardly from a rotatable hub 27. The compressor drum or compressor disk 26 and the vanes 22 disposed thereon and the turbine rotor hub 27 and the turbine blades 24 disposed thereon rotate about the engine axis 1 during operation.

The Fig. 2 shows a schematic representation of a cross section of a gas turbine combustor according to the prior art. In this case, compressor outlet blades 101 and a combustion chamber outer housing 102 and a combustion chamber inner housing 103 are shown schematically. The reference numeral 104 denotes a burner with arm and head, the reference numeral 105 denotes a combustion chamber head, which is followed by a combustion chamber wall 106, through which the flow to turbine inlet blades 107 is passed.

The Fig. 3 shows the construction of a known from the prior art construction. In this case, a shingle support 109 is shown in sectional view, which may be identical to the combustion chamber wall 106 or may be formed as a separate component. The shingle support 109 is provided with a plurality of impingement cooling holes 108, the axes 133 of which are arranged perpendicular to the center plane or to the surfaces of the plate-shaped shingle support 109. Cooling air flows into an impingement cooling gap 114 through the impingement cooling holes 108. This is formed by the spaced arrangement of a shingle 110. The shingle 110 is by means of threaded bolts 115 and nuts 131 attached. The shingle 110 further has effusion holes 111, through which the cooling air for cooling the surface flows out by means of a cooling film. The reference numeral 112 denotes the cooling air flow, while the reference numeral 113 shows the hot gas flow.

The Fig. 4 shows a further illustration of a shingle according to the prior art. In this case, this has on its the shingle support side facing a surface structure 116 and 117, which may be in the form of ribs or singular elevations. In addition, prisms 119 are formed to distribute the exiting cooling air. The surface structure may also be formed by depressions 118.

The Fig. 5 shows a schematic plan view, analog Fig. 4 , It follows that the effusion holes 111 have an inlet opening 120, through which the cooling air flows. From the Fig. 5 It can be seen that the inlet openings are arranged in the prior art on the flanks of the prism 119 or in the region of the recess 118.

The Fig. 6 shows an embodiment of the invention. The shingle support 109 has, as in the prior art, a plurality of impingement cooling holes 108. These are arranged so that they preferably impinge on the tips 121 of the prisms 119. According to the invention, the inlet openings 120 of the effusion holes 111 are formed on the raised areas of the surface structure 116, 117. These raised areas may, as known from the prior art, be in the form of ribs or singular elevations.

The Fig. 6 further shows that the effusion holes 111 may be formed straight or angled. The cross section can remain constant or expand. It is also possible to form the effusion holes 111 bent. The right half of the picture Fig. 6 shows an enlarged curved cross section 129, next to a constant curved cross section 128. The cross section 127 is formed in sections straight and enlarged. In contrast, the cross section 126 is straight trained and expanded in the second section. The cross section 125 is angled and each has a constant cross section. The cross section 124 is straight and has a constant cross section. The reference numeral 132 shows the central axis of the entrance opening 120 and the adjacent area of the effusion hole 111, respectively.

The FIGS. 7 and 8 each show plan views of design variants. It follows that the inlet openings 120 are respectively arranged on the raised areas of the surface structures 116, 117 or adjacent depressions 118. The reference numeral 122 shows a hexagonal structure or cell, the reference numeral 123 shows a prism.

The Fig. 9 and 10 each show enlarged side views of further embodiments, in which adjacent to the inlet opening 120 spacers 130 are provided. These can, as in particular in Fig. 10 shown to be provided for the formation of a twist.

The most important aspects of the present invention are again summarized below, this being done with reference to the exemplary embodiments, but not with regard to the exemplary embodiments:

1. a.) sich die Eintrittsöffnungen 120 der Effusionslöcher 111 auf dem erhabenen Teil der Oberflächenstruktur 116,117 befinden, der sich nahe am Schindelträger 109 befindet, somit die Eintrittsöffnung bis auf 0,5 bis 1,5 mal dem Durchmesser der Eintrittsöffnung 120 der Effusionsbohrung 111 an den Schindelträger 109 herangeführt sind, und
2. b.) die Achse der Eintrittsöffnung 120 der Effusionslöcher 111 im Wesentlichen parallel zur Richtung der Prallkühllöcher 109 ausgerichtet ist und damit im wesentlichen senkrecht zum Schindelträger 109, durch welchen die Prallkühllöcher 109 gebohrt sind, und
3. c.) zusätzlich Abstandhalter 130 so um die Eintrittsfläche 120 angeformt sind, so dass die Eintrittsöffnung auch bei betriebsbedingter Deformation nicht blockiert werden kann.

Impact-cooled shingles 110 are provided with a surface structure 116, 117, for example, by hexagonal ribs or other polygonal shapes or pins, the spent air being discharged through effusion holes 111 from the impingement cooling gap 114, where:

1. a.), the inlet openings 120 of the effusion holes 111 are on the raised portion of the surface structure 116,117, which is located close to the shingle support 109, thus the inlet opening to 0.5 to 1.5 times the diameter of the inlet opening 120 of the effusion bore 111 to the Shingle support 109 are introduced, and
2. b.) The axis of the inlet opening 120 of the effusion holes 111 substantially is aligned parallel to the direction of the impingement cooling holes 109 and thus substantially perpendicular to the shingle support 109, through which the impingement cooling holes 109 are drilled, and
3. c.) Additional spacers 130 are thus formed around the entrance surface 120, so that the inlet opening can not be blocked even during operational deformation.

The effusion holes 111 may have a constant 124, 125, 128, or a flow-increasing cross-section 126, 127, 129. The effusion holes may have a continuous straight axis 124, 126, a sectionally straight axis 125, 127 or an arcuate axis 28, 29. Preferably, the extended outlet cross section is performed at a smaller angle than 90 ° to the surface.

The spacers 130 are due to tolerances usually not in contact with the shingle support, otherwise they could be longer depending on the tolerance position than the shingle edge high, and thus they could provide an increase in edge leakage.

In addition, the spacers 130 may be configured to swirl the air flowing into the effusion hole 111 in front of the entrance port 120.

By the twisting of the air before entering the effusion hole 111, the heat transfer in the effusion hole 111 is increased.

The surface structure 116, 117 may be in the form of hexagonal ribs, these may be filled with a prism 119, 123 so that the tip 121 of the prism 119, 123 is at or above the level of the ribs.

The surface structure 116, 117 may be formed of triangular, four or other polygonal cells 122. The surface structure may also consist of circular depressions 118. Thus, the impact cooling jets meet substantially in the middle of the polygonal cell or at the lowest point of the circular recess on the shingle 110th

On the hot gas side facing the shingle 110 may have a thermal barrier coating of ceramic material.

The impingement cooling holes 108 may vary in diameter in the axial and / or circumferential direction, as well as the effusion holes 111 and the dimensions of the surface structure 116, 117.

The impingement cooling holes 108 are aligned substantially perpendicular to the impingement cooling surface and the main flow directions of cooling air 112 and hot gas 113.

The placement of the inlet opening 120 of the effusion holes 111 on the raised areas of the surface structure 116, 117 increases the length of the effusion holes 111 and thus their total surface area and also the amount of heat transferred.

If the sum of the effusion hole areas is chosen to be large compared to the sum of the impact-cooling inlet surfaces, a simple vertical hole is sufficient.

If the sum of the areas of the inlet openings 120 of the effusion holes 111 turns out to be smaller, the wall normal velocity of the outflowing air can be reduced by the curvature of the axis 132 or by the widening of the flow channel (or both) and, despite the small entrance surface 120 of the effusion hole 111 good film cooling effect.

The invention is not limited to the described combination between shingle support and shingle, but also relates to a combustion chamber shingle as such.

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

Engine casing

22

Compressor blades

23

vanes

24

turbine blades

26

Compressor drum or disc

27

Turbinenrotornabe

28

outlet cone

101

Kompressorauslassschaufel

102

Combustion chamber outer housing

103

Combustion chamber inner housing

104

Burner with arm and head

105

bulkhead

106

combustion chamber wall

107

Turbine inlet scoop

108

Impingement cooling hole

109

tile carrier

110

shingle

111

effusion

112

Cooling air flow

113

Hot gas stream

114

Impingement cooling gap

115

threaded bolt

116

surface structure

117

surface structure

118

deepening

119

prism

120

inlet opening

121

Tip of the prism

122

hexagonal structure / cell

123

prism

124

straight axis, constant cross section

125

sectionwise straight axis, constant cross section

126

magnifying cross section, straight axis

127

sectionwise straight axis, increasing cross section

128

constant cross section

129

enlarging cross-section

130

spacer

131

mother

132

Axle of the inlet opening 120th

133

Axis of the baffle hole 108

Claims (10)

A gas turbine combustor having a combustion chamber wall (106) comprising a shingle support (109) on which shingles (110) are mounted at a distance to form an impingement cooling gap (114), said shingle support (109) having impingement cooling holes (108) and said shingle (108) is provided with effusion holes (111), the shingle (110) being provided, on its side facing the shingle support (109), with a surface structure (116, 117) which rises from the surface of the shingle (110) in the direction of the shingle support (11). 109). Gas turbine combustor according to claim 1, characterized in that the inlet opening (120) is located on a raised part of the surface structure and / or at a distance from the surface of the shingle support (109) which is 0.5 to 1.5 times the diameter of the Inlet opening (120) is. Gas turbine combustor according to claim 1 or 2, characterized in that a central axis (132) of the inlet opening (120) is arranged substantially perpendicular to the surface of the shingle support (109). Gas turbine combustor according to one of claims 1 to 3, characterized in that a central axis (132) of the inlet opening (120) is arranged substantially parallel to the central axis (133) of the baffle cooling hole (108). Gas turbine combustor according to one of claims 1 to 4, characterized in that a partially enclosing spacer (130) is arranged around the inlet opening (120). Gas turbine combustor according to one of claims 1 to 5, characterized in that adjacent to the inlet opening (120), a spacer (130) is arranged. Gas turbine combustor according to one of claims 1 to 6, characterized in that the effusion hole (111) is straight or curved or partly straight or partly curved. Gas turbine combustor according to one of claims 1 to 7, characterized in that the effusion hole (111) has a constant or a widening diameter. Gas turbine combustor according to one of Claims 5 to 8, characterized in that the spacer (130) is designed to form a swirl of the air flowing into the inlet opening (120). Gas turbine combustor according to one of claims 1 to 9, characterized in that the surface structure (116, 117) is formed like a rib, in particular forming polygonal cells (122), in particular by arranging a prism (119, 123) within the cell (122). ,

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