U.S. patent application number 15/599519 was filed with the patent office on 2017-12-14 for combustion chamber.
This patent application is currently assigned to ROLLS-ROYCE plc. The applicant listed for this patent is ROLLS-ROYCE plc. Invention is credited to Imon-Kalyan BAGCHI, Thulasiram EZHILAN, Neil R GATER, Marek MACHEJ.
Application Number | 20170356653 15/599519 |
Document ID | / |
Family ID | 56894812 |
Filed Date | 2017-12-14 |
United States Patent
Application |
20170356653 |
Kind Code |
A1 |
BAGCHI; Imon-Kalyan ; et
al. |
December 14, 2017 |
COMBUSTION CHAMBER
Abstract
A combustion chamber arrangement includes an annular outer and
inner walls including at least one row of tiles. Each tile in the
row of tiles has a rail extending towards and sealing with the
outer wall and lip extending in a downstream direction from the row
of tiles. The outer wall has a row of apertures to direct coolant
onto the lips of the row of tiles. Each tile has a fastener
positioned upstream of the rail and the fastener extends through a
corresponding mounting aperture to secure the tile to the outer
wall. The rail of each tile defines a plurality of slots with the
outer wall and the slots are arranged in a region downstream of the
corresponding fastener. None of the apertures in the row of
apertures are in a region downstream of the tiles fastener. The
arrangement reduces crack generation and propagation in the outer
wall.
Inventors: |
BAGCHI; Imon-Kalyan; (Derby,
GB) ; GATER; Neil R; (Derby, GB) ; EZHILAN;
Thulasiram; (Ashby-de-la-Zouch, GB) ; MACHEJ;
Marek; (Derby, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ROLLS-ROYCE plc |
London |
|
GB |
|
|
Assignee: |
ROLLS-ROYCE plc
London
GB
|
Family ID: |
56894812 |
Appl. No.: |
15/599519 |
Filed: |
May 19, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F23R 2900/03044
20130101; F23R 3/50 20130101; F23R 3/22 20130101; F23R 3/007
20130101; F23R 3/02 20130101; F23R 2900/00005 20130101; F23R 3/002
20130101; F23R 2900/03042 20130101; F23R 3/06 20130101; F23R 3/26
20130101 |
International
Class: |
F23R 3/00 20060101
F23R003/00; F23R 3/02 20060101 F23R003/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 10, 2016 |
GB |
1610122.2 |
Claims
1. A combustion chamber arrangement comprising an annular outer
wall and an annular inner wall spaced from the annular outer wall,
the annular inner wall comprising at least one row of tiles, each
row of tiles comprising a plurality of circumferentially arranged
tiles, the downstream end of each tile in the at least one row of
tiles having a rail extending from the downstream end of the tile
towards and sealing with an inner surface of the annular outer wall
and a lip extending in a downstream direction from the downstream
end of the tile, the lips at the downstream ends of the tiles in
the at least one row of tiles have outer surfaces, the annular
outer wall having at least one row of apertures to direct coolant
onto the outer surfaces of the lips at the downstream ends of the
tiles in the at least one row of tiles, the annular outer wall
having a plurality of mounting apertures, each tile in the at least
one row of tiles having at least one fastener positioned upstream
of the rail, the at least one fastener of each tile in the at least
one row of tiles extending from the tile and through a
corresponding mounting aperture in the annular outer wall to secure
the tile to the annular outer wall, the rail of at least one tile
defining at least one slot with the inner surface of the annular
outer wall, the at least one slot of the at least one tile being
arranged in a region downstream of the at least one fastener and
none of the apertures in the at least one row of apertures in the
annular outer wall being arranged in the region downstream of the
at least one fastener of the at least one tile.
2. A combustion chamber arrangement as claimed in claim 1 wherein
the rail of the at least one tile defining a plurality of slots
with the inner surface of the annular outer wall and the plurality
of slots of the at least one tile being arranged in the region
downstream of the at least one fastener.
3. A combustion chamber arrangement as claimed in claim 1 wherein
the rail of each tile defining at least one slot with the inner
surface of the annular outer wall, the at least one slot of each
tile being arranged in a region downstream of the at least one
fastener and none of the apertures in the at least one row of
apertures being arranged in the region downstream of the at least
one fastener of each tile.
4. A combustion chamber arrangement as claimed in claim 3 wherein
the rail of each tile defining a plurality of slots with the inner
surface of the annular outer wall and the plurality of slots of
each tile being arranged in the region downstream of the at least
one fastener.
5. A combustion chamber arrangement as claimed in claim 1 wherein
each tile in the at least one row of tiles having a plurality of
fasteners positioned upstream of the rail, each fastener extending
from the tile and through a corresponding mounting aperture in the
annular outer wall to secure the tile to the annular outer
wall.
6. A combustion chamber arrangement as claimed in claim 1 wherein
the rail of each tile in the at least one row of tiles defining a
plurality of slots with the inner surface of the annular outer
wall, at least one slot of each tile being arranged in a region
downstream of each fastener and none of the apertures in the at
least one row of apertures in the annular outer wall being arranged
in the region downstream of each fastener of each tile.
7. A combustion chamber arrangement as claimed in claim 6 wherein a
plurality of slots of each tile being arranged in a region
downstream of each fastener.
8. A combustion chamber arrangement as claimed in claim 1 wherein
the annular inner wall comprising an upstream row of tiles and a
downstream row of tiles, the downstream end of each tile in the
upstream row of tiles having a lip extending in a downstream
direction towards but spaced from the upstream ends of the tiles in
the downstream row of tiles, the annular outer wall having at least
one row of apertures to direct coolant onto the outer surfaces of
the lips at the downstream ends of the tiles in the upstream row of
tiles, each tile in the upstream row of tiles having at least one
fastener positioned upstream of the rail, the at least one fastener
of each tile in the upstream row of tiles extending from the tile
and through a corresponding mounting aperture in the annular outer
wall to secure the tile to the annular outer wall, the rail of at
least one tile defining at least one slot with the inner surface of
the annular outer wall, the at least one slot of the at least one
tile being arranged in a region downstream of the at least one
fastener and none of the apertures in the at least one row of
apertures in the annular outer wall being arranged in the region
downstream of the at least one fastener of the at least one
tile.
9. A combustion chamber arrangement as claimed in claim 8 wherein
each tile in the upstream row of tiles having a plurality of
fasteners positioned upstream of the rail, each fastener extending
from the tile and through a corresponding mounting aperture in the
annular outer wall to secure the tile to the annular outer
wall.
10. A combustion chamber arrangement as claimed in claim 8 wherein
the annular outer wall having a bend, the rail at the downstream
end of each tile in the upstream row of tiles being arranged
upstream of the bend in the annular outer wall.
11. A combustion chamber arrangement as claimed in claim 10 wherein
the at least one row of apertures in the annular outer wall being
arranged upstream of the bend in the annular outer wall and
downstream of the rail at the downstream end of each tile in the
upstream row of tiles.
12. A combustion chamber arrangement as claimed in claim 8 wherein
the upstream end of each tile in the downstream row of tiles having
a rail extending from the upstream end of the tile towards and
sealing with an inner surface of the annular outer wall.
13. A combustion chamber arrangement as claimed in claim 1 wherein
the annular outer wall having a bend, the rail at the downstream
end of each tile in the at least one row of tiles being arranged
upstream of the bend in the annular outer wall.
14. A combustion chamber arrangement as claimed in claim 13 wherein
the at least one row of apertures in the annular outer wall being
arranged upstream of the bend in the annular outer wall and
downstream of the rail at the downstream end of each tile in the at
least one row of tiles.
15. A combustion chamber arrangement as claimed in claim 1 wherein
a plurality of slots being arranged in a region downstream of the
at least one fastener, the region downstream of the at least one
fastener having a circumferential dimension of up to four times the
diameter of the at least one fastener.
16. A combustion chamber arrangement as claimed in claim 1 wherein
the annular outer wall not having any apertures arranged in a
region downstream of the at least one fastener, the region
downstream of the at least one fastener having a circumferential
dimension of up to four times the diameter of the at least one
fastener.
17. A combustion chamber arrangement as claimed in claim 16 wherein
the annular outer wall not having any apertures arranged in a
region downstream of the at least one fastener, the region
downstream of the at least one fastener having a circumferential
dimension of up to twice the diameter of the at least one
fastener.
18. A combustion chamber arrangement as claimed in claim 1 wherein
the combustion chamber is an annular combustion chamber, the
annular combustion chamber comprising a radially inner annular wall
structure, a radially outer annular wall structure and an upstream
end wall structure, the radially outer annular wall structure
comprising the annular inner wall and the annular outer wall and
the annular inner wall is spaced radially inwardly from the annular
outer wall.
19. A combustion chamber arrangement comprising an annular outer
wall and an annular inner wall spaced from the annular outer wall,
the annular inner wall comprising at least one row of tiles, each
row of tiles comprising a plurality of circumferentially arranged
tiles, the downstream end of each tile in the at least one row of
tiles having a rail extending from the downstream end of the tile
towards and sealing with an inner surface of the annular outer wall
and a lip extending in a downstream direction from the downstream
end of the tile, the lips at the downstream ends of the tiles in
the at least one row of tiles have outer surfaces, the annular
outer wall having at least one row of apertures to direct coolant
onto the outer surfaces of the lips at the downstream ends of the
tiles in the at least one row of tiles, the annular outer wall
having a plurality of mounting apertures, each tile in the at least
one row of tiles having at least one fastener positioned upstream
of the rail, the at least one fastener of each tile in the at least
one row of tiles extending from the tile and through a
corresponding mounting aperture in the annular outer wall to secure
the tile to the annular outer wall, the rail of at least one tile
defining a plurality of slots with the inner surface of the annular
outer wall, the plurality of slots of the at least one tile being
arranged in a region downstream of the at least one fastener of the
at least one tile, the annular outer wall not having any apertures
arranged in the region downstream of the at least one fastener of
the at least one tile and the region downstream of the at least one
fastener having a circumferential dimension of up to four times the
diameter of the at least one fastener.
20. A combustion chamber arrangement comprising an annular outer
wall and an annular inner wall spaced from the annular outer wall,
the annular outer wall having a bend and a plurality of mounting
apertures, the annular inner wall comprising at least one row of
tiles, each row of tiles comprising a plurality of
circumferentially arranged tiles, the downstream end of each tile
in the at least one row of tiles having a rail extending from the
downstream end of the tile towards and sealing with an inner
surface of the annular outer wall and a lip extending in a
downstream direction from the downstream end of the tile, the lips
at the downstream ends of the tiles in the at least one row of
tiles have outer surfaces, the rail at the downstream end of each
tile in the at least one row of tiles being arranged upstream of
the bend in the annular outer wall, the annular outer wall having
at least one row of apertures to direct coolant onto the outer
surfaces of the lips at the downstream ends of the tiles in the at
least one row of tiles, the at least one row of apertures in the
annular outer wall being arranged upstream of the bend in the
annular outer wall and downstream of the rail at the downstream end
of each tile in the at least one row of tiles, each tile in the at
least one row of tiles having at least one fastener positioned
upstream of the rail, the at least one fastener of each tile in the
at least one row of tiles extending from the tile and through a
corresponding mounting aperture in the annular outer wall to secure
the tile to the annular outer wall, the rail of at least one tile
defining a plurality of slots with the inner surface of the annular
outer wall, the plurality of slots of the at least one tile being
arranged in a region downstream of the at least one fastener of the
at least one tile, the annular outer wall being imperforate in the
region downstream of the at least one fastener of the at least one
tile, the annular outer wall not having any apertures arranged in
the region downstream of the at least one fastener of the at least
one tile and the region downstream of the at least one fastener
having a circumferential dimension of up to four times the diameter
of the at least one fastener.
Description
[0001] The present disclosure relates to a combustion chamber and
in particular to a gas turbine engine combustion chamber.
[0002] One known type of combustion chamber comprises one or more
walls each of which comprises a double, or dual, wall structure. A
dual wall structure comprises an annular outer wall and an annular
inner wall spaced radially from the annular outer wall by rails to
define a chamber. The annular outer wall has a plurality of
impingement apertures to supply coolant into the chamber and the
annular inner wall has a plurality of effusion apertures to supply
coolant from the chamber over an inner surface of the annular inner
wall to provide a film of coolant on the inner surface of the
annular inner wall.
[0003] The annular inner wall comprises a plurality of rows of
circumferentially arranged tiles. These rows of tiles produce a
discontinuity, or a number of discontinuities, in the inner surface
of the annular inner wall that has a detrimental effect on the film
of coolant on the inner surface of the annular inner wall. The
downstream ends of the tiles have lips which extend axially towards
but are spaced from the upstream ends of the adjacent row of tiles
and the annular outer wall has one or more rows of apertures to
direct coolant onto the lips and then to assist in re-forming a
film of coolant over the inner surface of the upstream ends of the
adjacent row of tiles.
[0004] The row or rows of apertures in the annular outer wall which
direct coolant onto the lips of the tiles reduce the strength of
the annular outer wall and it is possible for cracks to initiate
and propagate circumferentially around the annular outer wall. The
problem is exacerbated by the rails at the downstream ends of the
tiles which are positioned close to the row of rows of apertures in
the annular outer wall because the rails conduct heat from the
tiles to the annular outer wall. At the points where the fasteners,
studs, used to secure the tiles to the annular outer wall are close
to the rails the clamping loads due to the fasteners produces
perfect conduction of heat from the tiles through the rails to the
annular outer wall and hence increasing the stress in the annular
outer wall adjacent the row or rows of apertures in the annular
outer wall which direct coolant onto the lips of the tiles. The
annular outer wall may have a bend and the bend may be subject to
significant thermal and vibrational stresses. If the bend is
positioned close to the row or rows of apertures in the annular
outer wall then this may further increase the stress in the annular
outer wall adjacent the row or rows of apertures in the annular
outer wall which direct coolant onto the lips of the tiles.
[0005] Hence, this may lead to a reduction in the working life of
the annular outer wall of the combustion chamber.
[0006] Accordingly the present disclosure seeks to provide a
combustion chamber which reduces, or overcomes, the above mentioned
problem.
[0007] According to a first aspect of the present disclosure there
is provided a combustion chamber arrangement comprising an annular
outer wall and an annular inner wall spaced from the annular outer
wall, the annular inner wall comprising at least one row of tiles,
each row of tiles comprising a plurality of circumferentially
arranged tiles, the downstream end of each tile in the at least one
row of tiles having a rail extending from the downstream end of the
tile towards and sealing with an inner surface of the annular outer
wall and a lip extending in a downstream direction from the
downstream end of the tile, the annular outer wall having at least
one row of apertures to direct coolant onto the outer surfaces of
the lips at the downstream ends of the tiles in the at least one
row of tiles, each tile in the at least one row of tiles having at
least one fastener positioned upstream of the rail, the at least
one fastener of each tile in the at least one row of tiles
extending from the tile and through a corresponding mounting
aperture in the annular outer wall to secure the tile to the
annular outer wall, the rail of at least one tile defining at least
one slot with the inner surface of the annular outer wall, the at
least one slot of the at least one tile being arranged in a region
downstream of the at least one fastener and none of the apertures
in the at least one row of apertures in the annular outer wall
being arranged in the region downstream of the at least one
fastener of the at least one tile.
[0008] The rail of the at least one tile may define a plurality of
slots with the inner surface of the annular outer wall and the
plurality of slots of the at least one tile being arranged in the
region downstream of the at least one fastener.
[0009] The rail of each tile may define at least one slot with the
inner surface of the annular outer wall, the at least one slot of
each tile being arranged in a region downstream of the at least one
fastener and none of the apertures in the at least one row of
apertures being arranged in the region downstream of the at least
one fastener of each tile.
[0010] The rail of each tile may define a plurality of slots with
the inner surface of the annular outer wall and the plurality of
slots of each tile being arranged in the region downstream of the
at least one fastener.
[0011] Each tile in the at least one row of tiles may have a
plurality of fasteners positioned upstream of the rail, each
fastener extending from the tile and through a corresponding
mounting aperture in the annular outer wall to secure the tile to
the annular outer wall.
[0012] The rail of each tile in the at least one row of tiles may
define a plurality of slots with the inner surface of the annular
outer wall, at least one slot of each tile being arranged in a
region downstream of each fastener and none of the apertures in the
at least one row of apertures in the annular outer wall being
arranged in the region downstream of each fastener of each
tile.
[0013] A plurality of slots of each tile may be arranged in a
region downstream of each fastener.
[0014] The annular inner wall may comprise an upstream row of tiles
and a downstream row of tiles, the downstream end of each tile in
the upstream row of tiles having a lip extending in a downstream
direction towards but spaced from the upstream ends of the tiles in
the downstream row of tiles, the annular outer wall having at least
one row of apertures to direct coolant onto the outer surfaces of
the lips at the downstream ends of the tiles in the upstream row of
tiles, each tile in the upstream row of tiles having at least one
fastener positioned upstream of the rail, the at least one fastener
of each tile in the upstream row of tiles extending from the tile
and through a corresponding mounting aperture in the annular outer
wall to secure the tile to the annular outer wall, the rail of at
least one tile defining at least one slot with the inner surface of
the annular outer wall, the at least one slot of the at least one
tile being arranged in a region downstream of the at least one
fastener and none of the apertures in the at least one row of
apertures in the annular outer wall being arranged in the region
downstream of the at least one fastener of the at least one
tile.
[0015] Each tile in the upstream row of tiles may have a plurality
of fasteners positioned upstream of the rail, each fastener
extending from the tile and through a corresponding mounting
aperture in the annular outer wall to secure the tile to the
annular outer wall.
[0016] The annular outer wall may have a bend, the rail at the
downstream end of each tile in the upstream row of tiles being
arranged upstream of the bend in the annular outer wall.
[0017] The at least one row of apertures in the annular outer wall
may be arranged upstream of the bend in the annular outer wall and
downstream of the rail at the downstream end of each tile in the
upstream row of tiles.
[0018] The at least one row of apertures in the annular outer wall
may be arranged downstream of the bend in the annular outer wall
and downstream of the rail at the downstream end of each tile in
the upstream row of tiles.
[0019] The upstream end of each tile in the downstream row of tiles
may have a rail extending from the upstream end of the tile towards
and sealing with an inner surface of the annular outer wall.
[0020] The rail at the upstream end of each tile in the downstream
row of tiles may extend in an upstream direction.
[0021] The rail at the upstream end of each tile in the downstream
row of tiles may be arranged downstream of the bend in the annular
outer wall.
[0022] The annular outer wall may have a bend, the rail at the
downstream end of each tile in the at least one row of tiles being
arranged upstream of the bend in the annular outer wall.
[0023] The at least one row of apertures in the annular outer wall
may be arranged upstream of the bend in the annular outer wall and
downstream of the rail at the downstream end of each tile in the at
least one row of tiles.
[0024] The at least one slot in the rail of the at least one tile
may be arranged perpendicular to the surface of the rail or at
angle to the surface of the rail.
[0025] A plurality of slots may be arranged in a region downstream
of the at least one fastener, the region downstream of the at least
one fastener having a circumferential dimension of up to four times
the diameter of the at least one fastener.
[0026] At least one slot may be arranged in a region downstream of
the at least one fastener, the region downstream of the at least
one fastener having a circumferential dimension of up to four times
the diameter of the at least one fastener.
[0027] The annular outer wall may not have any apertures arranged
in a region downstream of the at least one fastener, the region
downstream of the at least one fastener having a circumferential
dimension of up to four times the diameter of the at least one
fastener. The annular outer wall may be imperforate in the region
downstream of the at least one fastener, the region downstream of
the at least one fastener having a circumferential dimension of up
to four times the diameter of the at least one fastener.
[0028] The annular outer wall may not have any apertures arranged
in a region downstream of the at least one fastener, the region
downstream of the at least one fastener having a circumferential
dimension of up to twice the diameter of the at least one fastener.
The annular outer wall may be imperforate in the region downstream
of the at least one fastener, the region downstream of the at least
one fastener having a circumferential dimension of up to twice the
diameter of the at least one fastener.
[0029] The combustion chamber may be an annular combustion chamber,
the annular combustion chamber comprising a radially inner annular
wall structure, a radially outer annular wall structure and an
upstream end wall structure, the radially outer annular wall
structure comprising the annular inner wall and the annular outer
wall and the annular inner wall is spaced radially inwardly from
the annular outer wall.
[0030] The combustion chamber may be an annular combustion chamber,
the annular combustion chamber comprising a radially inner annular
wall structure, a radially outer annular wall structure and an
upstream end wall structure, the radially inner annular wall
structure comprising the annular inner wall and the annular outer
wall and the annular inner wall is spaced radially outwardly from
the annular outer wall.
[0031] The combustion chamber may be a tubular combustion chamber
and the annular inner wall is spaced radially inwardly from the
annular outer wall.
[0032] The combustion chamber may be a gas turbine engine
combustion chamber.
[0033] The skilled person will appreciate that except where
mutually exclusive, a feature described in relation to any one of
the above aspects of the invention may be applied mutatis mutandis
to any other aspect of the invention.
[0034] Embodiments of the invention will now be described by way of
example only, with reference to the Figures, in which:
[0035] FIG. 1 is a sectional side view of a turbofan gas turbine
engine having a combustion chamber arrangement according to the
present disclosure.
[0036] FIG. 2 is an enlarged cross-sectional view of a combustion
chamber arrangement according to the present disclosure.
[0037] FIG. 3 is a further enlarged cross-sectional view of a
portion of a combustion chamber arrangement according to the
present disclosure.
[0038] FIG. 4 is an enlarged perspective view of the portion of the
combustion chamber arrangement shown in FIG. 3.
[0039] FIG. 5 is a further enlarged perspective view of a portion
of the downstream end of a tile used in a combustion chamber
arrangement according to the present disclosure.
[0040] FIG. 6 is a plan view in the direction of arrow A in FIG. 3
showing a portion of the downstream end of a tile and the
surrounding outer wall used in a combustion chamber arrangement
according to the present disclosure.
[0041] With reference to FIG. 1, a turbofan gas turbine engine is
generally indicated at 10, having a principal and rotational axis
X. The engine 10 comprises, in axial flow series, an air intake 11,
a propulsive fan 12, an intermediate pressure compressor 13, a
high-pressure compressor 14, combustion equipment 15, a
high-pressure turbine 16, an intermediate pressure turbine 17, a
low-pressure turbine 18 and an exhaust nozzle 19. A nacelle 21
generally surrounds the engine 10 and defines the intake 11, a
bypass duct 22 and a bypass exhaust nozzle 23.
[0042] The gas turbine engine 10 works in the conventional manner
so that air entering the intake 11 is compressed by the fan 12 to
produce two air flows: a first air flow A into the intermediate
pressure compressor 13 and a second air flow B which passes through
a bypass duct 22 to provide propulsive thrust. The intermediate
pressure compressor 13 compresses the air flow directed into it
before delivering that air to the high pressure compressor 14 where
further compression takes place.
[0043] The compressed air exhausted from the high-pressure
compressor 14 is directed into the combustion equipment 15 where it
is mixed with fuel and the mixture combusted. The resultant hot
combustion products then expand through, and thereby drive the
high, intermediate and low-pressure turbines 16, 17, 18 before
being exhausted through the nozzle 19 to provide additional
propulsive thrust. The high 16, intermediate 17 and low 18 pressure
turbines drive respectively the high pressure compressor 14,
intermediate pressure compressor 13 and fan 12, each by suitable
interconnecting shaft 24, 25 and 26 respectively.
[0044] Combustion equipment 15 according to the present disclosure,
as shown more clearly in FIGS. 2 to 6, comprises an annular
combustion chamber arrangement and comprises a radially inner
annular wall structure 40, a radially outer annular wall structure
42 and an upstream end wall structure 44. The radially inner
annular wall structure 40 comprises a first annular wall 46 and a
second annular wall 48. The radially outer annular wall structure
42 comprises a third annular wall 50 and a fourth annular wall 52.
The second annular wall 48 is spaced radially from and is arranged
radially around the first annular wall 46 and the first annular
wall 46 supports the second annular wall 48. The fourth annular
wall 52 is spaced radially from and is arranged radially within the
third annular wall 50 and the third annular wall 50 supports the
fourth annular wall 52. The upstream end of the first annular wall
46 is secured to the upstream end wall structure 44 and the
upstream end of the third annular wall 50 is secured to the
upstream end wall structure 44. The upstream end wall structure 44
has a plurality of circumferentially spaced apertures 54 and each
aperture 54 has a respective one of a plurality of fuel injectors
56 located therein. The fuel injectors 56 are arranged to supply
fuel into the annular combustion chamber 15 during operation of the
gas turbine engine 10.
[0045] The first annular wall 46 has a plurality of mounting
apertures 58 extending there-though and the second annular wall 48
has a plurality of fasteners 60 extending radially there-from. Each
fastener 60 on the second annular wall 48 extends radially through
a corresponding mounting aperture 58 in the first annular wall 46.
A cooperating fastener 62 locates on each of the fasteners 60
extending through the mounting apertures 58 in the first annular
wall 46. A washer 64 is positioned between each fastener 60 on the
second annular wall 48 and the cooperating fastener 62. Each washer
64 has a first surface 66 abutting an outer surface of the first
annular wall 46 and a second surface 68 abutting a surface of the
cooperating fastener 62. The second annular wall 48 comprises a
plurality of segments, or tiles, 48A, 48B and 48C and the segments,
or tiles, 48A, 48B and 48C are arranged circumferentially and
axially around the first annular wall 46. The axially extending
edges of adjacent segments, or tiles, 48A, 48B and/or 48C may abut
each other or may overlap each other and the circumferentially
extending ends of adjacent segments, or tiles, 48A, 48B and 48C are
spaced from each other.
[0046] Similarly, the third annular wall 50 has a plurality of
mounting apertures 70 extending there-though and the fourth annular
wall 52 has a plurality of fasteners 72 extending radially
there-from. Each fastener 72 on the fourth annular wall 52 extends
radially through a corresponding mounting aperture 70 in the third
annular wall 50. A cooperating fastener 74 locates on each of the
fasteners 72 extending through the mounting apertures 70 in the
third annular wall 50. A washer 76 is positioned between each
fastener 72 on the fourth annular wall 52 and the cooperating
fastener 74. Each washer 76 has a first surface 78 abutting an
outer surface of the third annular wall 50 and a second surface 80
abutting a surface of the cooperating fastener 74. The fourth
annular wall 52 comprises a plurality of segments, or tiles, 52A,
52B and 52C and the segments, or tiles, 52A, 52B and 52C are
arranged circumferentially and axially adjacent to each other to
define the fourth annular wall 52. The axially extending edges of
adjacent segments, or tiles, 52A, 52B and/or 52C may abut each
other or may overlap each other and the circumferentially extending
ends of adjacent segments, or tiles, 52A, 52B and 52C are spaced
from each other.
[0047] The fasteners 60 and 72 on the second and fourth annular
walls 48 and 52 are threaded studs which are cast integrally with
the segments, or tiles, 48A, 48B, 48C, 52A 52B and 52C or may be
secured to the segments, or tiles, 48A, 48B, 48C, 52A, 52B and 52C
by welding, brazing etc. Alternatively, the fasteners, e.g.
threaded studs are formed by additive layer manufacturing
integrally with the segments, or tiles 48A, 48B, 48C, 52A 52B and
52C. The cooperating fasteners 62 and 74 are nuts.
[0048] The first and third annular walls 46 and 50 form outer walls
of the annular combustion chamber 15 and the second and fourth
annular walls 48 and 52 form inner walls of the annular combustion
chamber 15. The second annular wall 48 comprises at least one row
of circumferentially arranged tiles and in this example there are
three rows 48A, 48B and 48C of circumferentially arranged tiles and
the tiles 48A form an axially upstream row of circumferentially
arranged tiles, the tiles 48B form an axially intermediate row of
circumferentially arranged tiles and the tiles 48C form an axially
downstream row of circumferentially arranged tiles. Similarly, the
fourth annular wall 52 comprises at least one row of
circumferentially arranged tiles and in this example there are
three rows 52A, 52B and 52C of circumferentially arranged tiles and
the tiles 52A form an axially upstream row of circumferentially
arranged tiles, the tiles 52B form an axially intermediate row of
circumferentially arranged tiles and the tiles 52C form an axially
downstream row of circumferentially arranged tiles. The tiles 52A
are an upstream row of tiles with respect to the tiles 52B and
similarly the tiles 52B are a downstream row of tiles with respect
to the tiles 52A. The tiles 52B are an upstream row of tiles with
respect to the tiles 52C and similarly the tiles 52C are a
downstream row of tiles with respect to the tiles 52B. The second
annular wall 48 and/or the fourth annular wall 52 may comprise any
suitable number of rows of tiles.
[0049] The combustion chamber in this arrangement also comprises a
plurality of dilution ports 71 in the radially inner annular wall
structure 40 and a plurality of dilution ports 73 in the radially
outer annular wall structure 42. The dilution ports 73 in the
radially outer annular wall structure 42 comprise a plurality of
aligned apertures 79 and 81 in the annular outer wall 50 and the
tiles 52B of the annular inner wall 52. The dilution ports 71 in
the radially inner annular wall structure 40 comprise a plurality
of aligned apertures 75 and 77 in the annular outer wall 46 and the
tiles 48B of the annular inner wall 48. The dilution ports 71 and
73 supply dilution air H into the combustion chamber to control
emissions.
[0050] The annular outer wall 50 has a plurality of impingement
cooling apertures 67 extending there-through to direct coolant onto
the outer surface of the tiles 52A, 52B and 52C and the tiles 52A,
52B and 52C have effusion cooling apertures 69 extending
there-through to provide a film of coolant onto the inner surfaces
of the tiles 52A, 52B and 52C respectively. The impingement cooling
apertures 67 are generally arranged perpendicularly to the surfaces
of the annular outer wall 50 and the outer surfaces of the tiles
52A, 52B and 52C respectively. However, the impingement cooling
apertures 67 may be arranged at other suitable angles to the
surfaces of the annular outer wall 50 and the outer surfaces of the
tiles 52A, 52B and 52C respectively. The effusion cooling apertures
69 are generally arranged at an angle, for example 30.degree., to
the inner surfaces of the tiles 52A, 52B and 52C but other suitable
angles may be used. Some effusion cooling apertures 69 may be
arranged perpendicularly to the inner surfaces of the tiles 52A,
52B and 52C and some of the effusion cooling apertures 69 may be
arranged at an angle, for example 30.degree., to the inner surfaces
of the tiles 52A, 52B and 52C.
[0051] The downstream end of each tile 52A in the upstream row of
tiles 52A has a rail 53 which extends from the outer surface of the
tile 52A at the downstream end of the tile 52A towards and seals
with an inner surface of the annular outer wall 50 and a lip 63
extends in a downstream direction towards but is spaced from the
upstream ends of the tiles 52B in the downstream row of tiles 52B.
The lip 63 extends from the junction between the rail 53 at the
downstream end of the tile 52A and the main body of the tile 52A.
The inner surface of the lip 63 forms a continuation of the inner
surface of the main body of the tile 52A. The annular outer wall 50
has at least one row of apertures 57 to direct coolant F onto the
outer surfaces of the lips 63 at the downstream ends of the tiles
52A in the upstream row of tiles 52A. The at least one row of
apertures 57 is arranged to supply the coolant F to a chamber, e.g.
an annular chamber, 65 defined between the inner surface of the
annular outer wall 50, the rails 53 at the downstream ends of the
tiles 52A and the lips 63 at the downstream ends of the tiles 52A
in the upstream row of tiles 52A. The upstream end of each tile 52A
in the upstream row of tiles 52A has a rail 51 which extends from
the upstream end of the tile 52A towards and seals with the inner
surface of the annular outer wall 50. Each tile 52A in the upstream
row of tiles 52A also has two rails 55, each rail 55 extends
axially along a respective one of the circumferentially spaced
edges and each rail 55 also extend towards and seal against the
inner surface of the annular outer wall 50. Thus, each tile 52A has
rails 51, 53 and 55 which extend around the periphery of the tile
52A to form a closed chamber between each tile 52A and the annular
outer wall 50.
[0052] The downstream end of each tile 52B in the intermediate row
of tiles 52B has a rail 53 which extends from the outer surface of
the tile 52B at the downstream end of the tile 52B towards and
seals with the inner surface of the annular outer wall 50 and a lip
63 extends in a downstream direction towards but is spaced from the
upstream ends of the tiles 52C in the downstream row of tiles 52C.
The lip 63 extends from the junction between the rail 53 at the
downstream end of the tile 52B and the main body of the tile 52B.
The inner surface of the lip 63 forms a continuation of the inner
surface of the main body of the tile 52B. The annular outer wall 50
has at least one row of apertures 57 to direct coolant onto the
outer surfaces of the lips 63 at the downstream ends of the tiles
52B in the intermediate row of tiles 52B. The at least one row of
apertures 57 is arranged to supply the coolant to a chamber, e.g.
an annular chamber, 65 defined between the inner surface of the
annular outer wall 50, the rails 53 at the downstream ends of the
tiles 52B and the lips 63 at the downstream ends of the tiles 52B
in the intermediate row of tiles 52B. The upstream end of each tile
52B in the intermediate row of tiles 52B has a rail 51 which
extends from the upstream end of the tile 52B towards and seals
with the inner surface of the annular outer wall 50. The rail 51 at
the upstream end of each tile 52B in the intermediate row of tiles
52B in this particular example also extends in an upstream
direction. Each tile 52B in the intermediate row of tiles 52B also
has two rails 55, each rail 55 extends axially along a respective
one of the circumferentially spaced edges and each rail 55 also
extend towards and seal against the inner surface of the annular
outer wall 50. Thus, each tile 52B has rails 51, 53 and 55 which
extend around the periphery of the tile 52B to form a closed
chamber between each tile 52B and the annular outer wall 50.
[0053] The downstream end of each tile 52C in the downstream row of
tiles 52C has a rail (not shown) which extends from the outer
surface of the tile 52C at the downstream end of the tile 52C
towards and seals with the inner surface of the annular outer wall
50. The upstream end of each tile 52C in the downstream row of
tiles 52C has a rail 51 which extends from the upstream end of the
tile 52C towards and seals with the inner surface of the annular
outer wall 50. The rail 51 at the upstream end of each tile 52C in
the downstream row of tiles 52C in this particular example also
extends in an upstream direction. Each tile 52C in the downstream
row of tiles 52C also has two rails 55, each rail 55 extends
axially along a respective one of the circumferentially spaced
edges and each rail 55 also extend towards and seal against the
inner surface of the annular outer wall 50. Thus, each tile 52C has
rails 51, 53 and 55 which extend around the periphery of the tile
52C to form a closed chamber between each tile 52C and the annular
outer wall 50. The tiles 52C in the downstream row of tiles 52C may
have dilution apertures or may not have dilution apertures.
Similarly, the tiles 52A in the upstream row of tiles 52A may have
dilution apertures or may not have dilution apertures.
Additionally, the tiles 52B in the intermediate row of tiles 52B
may not have dilution apertures.
[0054] It is to be noted that the annular outer wall 50 has a bend
82 and the rail 53 at the downstream end of each tile 52A is
upstream of the bend 82 in the annular outer wall 50 and the rail
51 at the upstream end of each tile 52B is downstream of the bend
82 in the annular outer wall 50. It is also to be noted that the
apertures 57 in the outer annular wall 50, which are arranged to
direct coolant onto the lip 63 at the downstream end of each tile
52A, are positioned upstream of the bend 82 in the annular outer
wall 50 and downstream of the rail 53 at the downstream end of each
tile 52A. Likewise, the annular outer wall 46 may have a bend and
the rail at the downstream end of each tile 48A is upstream of the
bend in the annular outer wall 46 and the rail at the upstream end
of each tile 48B is downstream of the bend in the annular outer
wall 46. It is also to be noted that the apertures in the outer
annular wall 46, which are arranged to direct coolant onto the lip
at the downstream end of each tile 48A, are positioned upstream of
the bend in the annular outer wall 46 and downstream of the rail at
the downstream end of each tile 48A. However, it may be equally
possible to provide the apertures 57 in the outer annular wall 50,
which are arranged to direct coolant onto the lip 63 at the
downstream end of each tile 52A, downstream of the bend 82 in the
annular outer wall 50 and downstream of the rail 53 at the
downstream end of each tile 52A. Similarly, it may be equally
possible to provide the apertures in the outer annular wall 46,
which are arranged to direct coolant onto the lip at the downstream
end of each tile 48A, downstream of the bend in the annular outer
wall 46 and downstream of the rail at the downstream end of each
tile 48A. The apertures in the row of apertures 57 in the outer
annular wall 50 may be arranged perpendicularly to the outer
surfaces of the lips 63 of the tiles 52A or may be arranged at
other suitable angles. The apertures in the row of apertures 57 in
the outer annular wall 46 may be arranged perpendicularly to the
outer surfaces of the lips of the tiles 48A or may be arranged at
other suitable angles.
[0055] The fasteners 60 are generally provided at the corners of
the tiles 48A, 48B, 48C and the fasteners 72 are generally provided
at the corners of the tiles 52A, 52B and 52C. The row, or rows, of
apertures 57 in the annular outer wall 50 which direct coolant onto
the lips 63 of the tiles 52A reduce the strength of the annular
outer wall 50. The rails 53 at the downstream ends of the tiles 52A
are positioned close to the row, or rows, of apertures 57 in the
annular outer wall 50. The points where the fasteners 72 used to
secure the tiles 52A to the annular outer wall 50 are close to the
rails 53 at the downstream ends of the tiles 52A. The bend 82 in
the annular outer wall 50 is positioned close to the row or rows of
apertures 57 in the annular outer wall 50.
[0056] The rail 53 at the downstream end of each tile 52A is
provided with at least one groove 86 at its end remote from the
tile 52A and the at least one groove 86 defines at least one slot
with the inner surface of the annular outer wall 50. The at least
one groove 86 and hence the at least one slot is arranged in a
region 84 downstream of a fastener 72 at the downstream end of the
tile 52A. In this arrangement the rail 53 at the downstream end of
each tile 52A is provided with a plurality of grooves 86 at its end
remote from the tile 52A and each groove 86 defines a slot with the
inner surface of the annular outer wall 50. Each tile 52A has a
plurality of grooves 86, and hence a plurality of slots, are
arranged in the region 84 downstream of the fastener 72. As
mentioned above each tile 52A has a plurality of fasteners 72
positioned upstream of the rail 53 and the rail 53 of each tile 53A
has a plurality of grooves 86 which define a plurality of slots
with the inner surface of the annular outer wall 50. At least one
groove 86, and hence at least one slot, of each tile 52A is
arranged in a region 84 downstream of each fastener 72. In this
arrangement the rail 53 at the downstream end of each tile 52A is
provided with a plurality of grooves 86 at its end remote from the
tile 52A and each groove 86 defines a slot with the inner surface
of the annular outer wall 50 and a plurality of grooves 86, and
hence a plurality of slots, of each tile 52A are arranged in a
region 84 downstream of each fastener 72. There may for example be
five grooves 86 in each region 84 and each region 84 may have a
circumferential dimension of up to four times the diameter of a
fastener 72. There may be one groove 84 and hence one slot, or a
plurality of grooves 84 and hence a plurality of slots, arranged in
each region 84 and each region 84 downstream of a corresponding
fastener 72 may have a circumferential dimension of up to four
times the diameter of the corresponding fastener 72. The grooves 86
in this arrangement are arranged perpendicularly to the surfaces of
the rail 53, but the grooves 86 may be arranged at any suitable
angle to the surfaces of the rail 53. The number of grooves 86, the
depth of the grooves 86, the pitch of the grooves 86, and the
orientation, e.g. angle, of the grooves 86 may be optimised for a
particular geometry. The pitch of the apertures in the row of
apertures 57 may be optimised for a particular geometry.
[0057] The rails 55 along the axially extending edges of the tiles
52A may be provided with at least one groove 88 at its end remote
from the tile 52A and the at least one groove 88 defines at least
one slot with the inner surface of the annular outer wall 50. There
may be a plurality of grooves 88 in each of the rails of each tile
52A. The grooves 88 may be arranged perpendicular to the surfaces
of the rails 55 or at any other suitable angle to the surfaces of
the rails 55.
[0058] None of the apertures 57 in the at least one row of
apertures in the annular outer wall 50 are arranged in a region 90
downstream of the at least one fastener 72 of the at least one tile
52A and in particular none of the apertures 57 in the at least one
row of apertures in the annular outer wall 50 are arranged in a
region 90 downstream of each fastener 72 of the at least one tile
52A. Each region 90 may have a circumferential dimension of up to
four times the diameter of a fastener 72, but in this example each
region 90 has a circumferential dimension less than the
circumferential dimension of the corresponding region 84. Each
region 90 may have a circumferential dimension of up to twice the
diameter of the fastener 72. Thus, in the, or each, region 90
downstream of a fastener 72 the annular outer wall 50 is
imperforate. The region 90 may have the same circumferential
dimension as the corresponding region 84.
[0059] However, in some circumstances the region 84 may have a
circumferential dimension greater than four times the diameter of a
fastener 72 and/or the region 90 may have a circumferential
dimension greater than twice the diameter of the fastener 72 to
suit the need of a particular design.
[0060] The inner surface of the tiles 48A, 48B, 48C, 52A, 52B and
52C are provided with a thermal barrier coating 92 to further
protect the tiles from the heat in the combustion chamber 15.
[0061] In operation the coolant F is directed with high velocity
from the apertures 57 in the annular outer wall 50 to impinge upon
the lips 63 at the downstream ends of the tiles 52A. The coolant
flows from the lips 63 of the tiles 52A such that the coolant G
flows predominantly axially over and across the rails 51 at the
upstream ends of the tiles 52B and across and over the upstream
ends of the tiles 52B. This axial flow of coolant G reduces, or
prevents, the ingress of hot gases into the chamber 65 defined
between the rails 53 and lips 63 of the tiles 52A and the annular
outer wall 50. The axial flow of coolant G also enables an
effective film of coolant to be formed, or re-formed, on the inner
surfaces of the tiles 52B in the regions of the tiles 52B
immediately upstream of the dilution apertures 81 of the tiles 52B.
This reduces the temperature of the upstream ends of the tiles 52B
and the downstream ends of the tiles 52A and the temperature of the
annular outer wall 50 between the rails 53 of the tiles 52A and the
rails 51 of the tiles 52B.
[0062] As mentioned previously, coolant is directed to flow through
the impingement cooling apertures 67 onto the outer surface of the
tiles 52A, 52B and 52C and coolant is directed through the effusion
cooling apertures 69 to provide a film of coolant on the inner
surfaces of the tiles 52A, 52B and 52C respectively. Some of the
coolant supplied by the impingement cooling apertures 67 flows
around the fasteners 72 at the downstream ends of the tiles 52A,
through the grooves 86 into the chamber 65 to mix with and join the
flow of coolant F from the apertures 57.
[0063] The grooves 86 in the rail 53 in the region 84 downstream of
each fastener 72 reduce the conduction of heat from the tile 52A
into the annular outer wall 50 by reducing the area of contact
between the rail 53 and the annular outer wall 50 in the region 84
downstream of the fastener 72. The grooves 86 allow a flow of
coolant I over the inner surface of the annular wall 50 in the
region 84 downstream of each fastener 72. The grooves 86 also
enhance the flow of coolant around the fasteners 72 to cool the
fasteners 72 and hence reduce the temperature of the tiles 52A in
the region of the fasteners 72 and in particular the base of the
fasteners 72. This reduces the potential for cracks to initiate and
propagate in the annular outer wall 50 by reducing the temperature
of the annular outer wall 50 and removing the stress concentration
features. The cooling of the fasteners 72 reduces creep of the
fasteners 72 and maintains the clamping load of the fastener 72 and
tile 52A onto the annular outer wall 50.
[0064] The at least one row of apertures 57 in the annular outer
wall 50 is arranged such that there are no apertures in each region
90 downstream of a fastener 72 of each tile 52A, each region 90
downstream of a fastener 72 of the annular outer wall 50 is
imperforate. These regions 90 are arranged to arrest crack
propagation should any crack be initiated and propagated in the
annular outer wall 50.
[0065] The provision of the grooves 86 in the regions 84 of the
rails 53 provides a flow of coolant over the inner surface of the
annular outer wall 50 and the outer surfaces of the lips 63 of the
tiles 52A which compensates for the regions 90 of the annular wall
50 where there are no apertures 57 to direct coolant through the
annular outer wall 50 and onto the outer surfaces of the lips 63 of
the tiles 52A.
[0066] The tiles 52B and 52C of the radially outer annular wall
structure 42 may be arranged in a similar manner to the tiles 52A.
Thus, the rails at the downstream ends of the tiles 52B may be
provided with grooves 86 downstream of at least one fastener 72 and
the row of apertures 57 arranged to direct coolant onto the lips 63
may be provided with a region without apertures and/or the rails at
the downstream ends of the tiles 52C may be provided with grooves
86 downstream of at least one fastener 72 and the row of apertures
57 arranged to direct coolant onto the lips 63 may be provided with
a region without apertures.
[0067] The tiles 48A, 48B and 48C of the radially inner annular
wall structure 40 may be arranged in a similar manner to the tiles
52A. Thus, the rails at the downstream ends of the tiles 48A may be
provided with grooves downstream of at least one fastener 60 and
the row of apertures arranged to direct coolant onto the lips may
be provided with a region without apertures and/or the rails at the
downstream ends of the tiles 48B may be provided with grooves
downstream of at least one fastener 60 and the row of apertures
arranged to direct coolant onto the lips may be provided with a
region without apertures and/or the rails at the downstream ends of
the tiles 48C may be provided with grooves downstream of at least
one fastener 60 and the row of apertures arranged to direct coolant
onto the lips may be provided with a region without apertures.
[0068] Each of the tiles 48A, 48B and 48C and each of the tiles
52A, 52B and 52C is parallelogram in shape in a plan view and in
particular each of the tiles 48A, 48B and 48C and each of the tiles
52A, 52B and 52C is rectangular in a plan view. Each of the tiles
48A, 48B and 48C and each of the tiles 52A, 52B and 52C has
longitudinally, axially, spaced ends and laterally,
circumferentially, spaced edges. Each of the tiles 48A, 48B and 48C
and each of the tiles 52A, 52B and 52C is arcuate and in particular
is curved between its laterally spaced edges. Each of the tiles
48A, 48B and 48C has a rail extending around the periphery of a
first surface, a radially inner surface, and the first surface is
concave between its laterally spaced edges. Each of the tiles 52A,
52B and 52C has a rail extending around the periphery of a first
surface, a radially outer surface, and the first surface is convex
between its laterally spaced edges.
[0069] An advantage of the present disclosure is that the row or
rows of apertures in the annular outer wall which direct coolant
onto the lips of the tiles are provided with circumferential
regions where there are no apertures to increase the strength of
the annular outer wall and to arrest the propagation of any cracks
circumferentially around the annular outer wall. The rails at the
downstream ends of the tiles which are positioned close to the row
of rows of apertures in the annular outer wall are provided with
grooves at their ends remote from the tiles to reduce the
conduction of heat from the tiles to the annular outer wall and
hence reduce the stress in the annular outer wall adjacent the row
or rows of apertures in the annular outer wall which direct coolant
onto the lips of the tiles. The mechanical integrity of the annular
outer wall and the fasteners of the tiles are improved by reducing
the possibility of crack initiation and increasing the possibility
of preventing the propagation of cracks around the annular outer
wall whilst preserving cooling effectiveness. The arrangement
reduces the loss of clamping load of the tiles.
[0070] Although the present disclosure has referred to the use of
studs and nuts to secure the tiles to the particular supporting
annular wall it may be possible to use bolts which are inserted
through apertures in the tiles and respective apertures in the
supporting annular wall and threaded into associated nuts or it may
be possible to use threaded bosses on the tiles and bolts which are
inserted through apertures in the supporting annular wall and into
threaded into the respective bosses.
[0071] The combustion chamber may be an annular combustion chamber
and the annular inner wall is spaced radially inwardly from the
annular outer wall.
[0072] The combustion chamber may be an annular combustion chamber
and the annular inner wall is spaced radially outwardly from the
annular outer wall.
[0073] Although the present disclosure has referred to an annular
combustion chamber is equally applicable to a tubular combustion
chamber in which the annular inner wall is spaced radially inwardly
from the annular outer wall.
[0074] The combustion chamber is a gas turbine engine combustion
chamber.
[0075] Although the present disclosure has been described with
reference to a turbofan gas turbine engine it is equally applicable
to a turbojet gas turbine engine, a turbo-shaft gas turbine engine
and a turbo-propeller gas turbine engine.
[0076] Although the present disclosure has been described with
reference to an aero gas turbine engine it is equally applicable to
a marine gas turbine engine, an automotive gas turbine engine and
an industrial gas turbine engine.
[0077] The tiles may be made by casting or by additive layer
manufacturing, e.g. direct laser deposition (DLD) or powder bed
laser deposition. The tiles may comprise a nickel based superalloy,
a cobalt based superalloy or an iron based superalloy.
[0078] It will be understood that the invention is not limited to
the embodiments above-described and various modifications and
improvements can be made without departing from the concepts
described herein. Except where mutually exclusive, any of the
features may be employed separately or in combination with any
other features and the disclosure extends to and includes all
combinations and sub-combinations of one or more features described
herein.
* * * * *