U.S. patent application number 10/649496 was filed with the patent office on 2005-03-03 for combustor of a gas turbine engine.
Invention is credited to Glezer, Boris, Moon, Hee Koo.
Application Number | 20050044857 10/649496 |
Document ID | / |
Family ID | 34216970 |
Filed Date | 2005-03-03 |
United States Patent
Application |
20050044857 |
Kind Code |
A1 |
Glezer, Boris ; et
al. |
March 3, 2005 |
Combustor of a gas turbine engine
Abstract
A combustor has a combustion zone and a liner bounding the
combustion zone. The liner has a first end portion and a second end
portion spaced a defined distance from the first end portion. The
combustor has a convector spaced apart from the liner. The
convector has a first end portion and a second end portion spaced a
defined distance of the first end portion. A plurality of passages
are located between the liner and the convector. One of the
passages has a length that is longer than at least one of the
defined distance of the liner and the defined distance of the
convector.
Inventors: |
Glezer, Boris; (San Diego,
CA) ; Moon, Hee Koo; (San Diego, CA) |
Correspondence
Address: |
CATERPILLAR INC.
100 N.E. ADAMS STREET
PATENT DEPT.
PEORIA
IL
616296490
|
Family ID: |
34216970 |
Appl. No.: |
10/649496 |
Filed: |
August 26, 2003 |
Current U.S.
Class: |
60/772 ;
60/752 |
Current CPC
Class: |
F23D 2214/00 20130101;
F23R 3/002 20130101; F23R 3/44 20130101 |
Class at
Publication: |
060/772 ;
060/752 |
International
Class: |
F23R 003/42 |
Claims
What is claimed is:
1. A combustor, comprising: a combustion zone; a first liner
bounding said combustion zone, said first liner having a first end
portion and a second end portion spaced a defined distance from
said first end portion; a first convector spaced apart from said
first liner, said first convector having a first end portion and a
second end portion spaced a defined distance from said first end
portion, said first liner being disposed between said combustion
zone and said first convector; and a plurality of passages
positioned between said first liner and said first convector, at
least one of said passages having a length that is greater than at
least one of said defined distance of said first liner and said
defined distance of said first convector.
2. The combustor of claim 1 wherein said plurality of passages are
spiral passages.
3. The combustor of claim 1 wherein said plurality of passages are
serpentine passages.
4. The combustor of claim 1 wherein said plurality of passages are
three passages.
5. The combustor of claim 1 wherein at least one of said plurality
of passages includes at least one cooling device positioned
therein.
6. The combustor of claim 5 wherein said at least one cooling
device is a dimple.
7. The combustor of claim 5 wherein said at least one cooling
device is at least one of a trip strip, a fin, and a pin.
8. The combustor of claim 1 including: a second liner bounding said
combustion zone, said second liner having a first end portion and a
second end portion spaced a defined distance from said first end
portion of said second liner; a second convector spaced apart from
said second liner, said second convector having a first end portion
and a second end portion spaced a defined distance from said first
end portion of said second convector, said second liner being
disposed between said combustion zone and said second convector;
and a second plurality of passages positioned between said second
liner and said second convector, at least one of said second
plurality of passages having a length that is greater than at least
one of said defined distance of said second liner and said defined
distance of said second convector.
9. A gas turbine engine, comprising: a compressor; a combustor in
fluid communication with said compressor, said combustor including:
a combustion zone, a first liner bounding said combustion zone,
said first liner having a first end portion and a second end
portion spaced a defined distance from said first end portion, a
first convector spaced apart from said first liner, said first
convector having a first end portion and a second end portion
spaced a defined distance from said first end portion, said first
liner being disposed between said combustion zone and said first
convector, and a plurality of passages positioned between said
first liner and said first convector, at least one of said passages
having a length that is greater than at least one of said defined
distance of said first liner and said defined distance of said
first convector; and a turbine in fluid communication with said
combustor.
10. The turbine engine of claim 9 wherein said plurality of
passages are spiral passages.
11. The turbine engine of claim 9 wherein said plurality of
passages are serpentine passages.
12. The turbine engine of claim 9 wherein said plurality of
passages are three passages.
13. The turbine engine of claim 9 wherein at least one of said
plurality of passages includes at least one cooling device
positioned therein.
14. The turbine engine of claim 13 wherein said at least one
cooling device is a dimple.
15. The turbine engine of claim 13 wherein said at least one
cooling device is at least one of a trip strip, a fin, and a
pin.
16. The turbine engine of claim 9 wherein said engine includes a
serial cooling system.
17. The turbine engine of claim 9 wherein said combustor includes:
a second liner bounding said combustion zone, said second liner
having a first end portion and a second end portion spaced a
defined distance from said first end portion of said second liner;
a second convector spaced apart from said second liner, said second
convector having a first end portion and a second end portion
spaced a defined distance from said first end portion of said
second convector, said second liner being disposed between said
combustion zone and said second convector; and a second plurality
of passages positioned between said second liner and said second
convector, at least one of said second plurality of passages having
a length that is greater than at least one of said defined distance
of said second liner and said defined distance of said second
convector.
18. A method of cooling a liner of a combustor of a gas turbine
engine, comprising: directing a fluid between a first end portion
of a first liner of a combustor and a first end portion of a first
convector of a combustor, at least one of said first liner and said
first convector having a central axis; and causing said fluid to
move in a direction nonparallel to said central axis.
19. The method of claim 18 wherein said causing said fluid to move
in a direction nonparallel to said central axis includes causing
said fluid to rotate about said central axis.
20. The method of claim 18 wherein said causing said fluid to move
in a direction nonparallel to said central axis includes causing
said fluid to move in a spiral path.
21. The method of claim 18 wherein said causing said fluid to move
in a direction nonparallel to said central axis includes causing
said fluid to move in a serpentine path.
22. The method of claim 18 wherein said causing said fluid to move
in a direction nonparallel to said central axis is effectuated by a
plurality of passages located between said first liner and said
first convector.
23. A combustor, comprising: a combustion zone; a first liner
bounding said combustion zone; a first convector spaced apart from
said first liner, said first liner being disposed between said
combustion zone and said first convector, at least one of said
first liner and said first convector having a central axis; a fluid
disposed between said first liner and said first convector; and
means for causing said fluid to move in a direction nonparallel to
said central axis.
Description
TECHNICAL FIELD
[0001] This invention relates generally to a gas turbine engine and
more specifically to cooling of a liner of a combustor of a gas
turbine engine.
BACKGROUND
[0002] Current gas turbine engines continue to improve emissions
and engine efficiencies. Notwithstanding these improvements,
further increases in engine efficiencies will require more
effective use of a mass of compressed air exiting a compressor. Gas
turbine engines normally use the mass of compressed air for: 1)
combustion air, 2) dilution air, 3) combustor cooling air, and 4)
turbine component cooling air. Each use of the mass of compressed
air may vary according to a load on the gas turbine engine.
Generally each of these uses requires more of the mass of
compressed air as the load increases.
[0003] In particular, combustion air and combustor cooling air have
increased in importance with increasing regulations of NOx (an
uncertain mixture of oxides of nitrogen). The efficiencies of the
gas turbine engine usually improve with increased temperatures
entering a turbine. Unlike the efficiency of the gas turbine
engine, decreasing NOx production in gas turbine engines typically
involves reducing a flame temperature. Lean premixed combustion
attempts to decrease NOx production while maintaining gas turbine
engine efficiencies. A lean premixed combustor premixes a mass of
combustion air and a quantity of fuel upstream of a primary
combustion zone. Increasing the mass of combustion air reduces the
flame temperature by slowing a chemical reaction between the fuel
and the combustion air. By reducing the flame temperature, NOx
production also decreases. A lean premixed fuel injector assembly
is shown in U.S. Pat. No. 5,467,926 issued to Idleman et al. on 21
Nov. 1995.
[0004] Even with the lower flame temperatures, a liner wall of the
combustor must be maintained at an operating temperature meeting a
durability requirement. A number of cooling schemes may be used to
cool the combustor liner including film cooling, convection
cooling, effusion cooling, and impingement cooling. However, one
problem shared by many different cooling schemes is an inability to
obtain the maximum cooling potential from the available mass of
cooling air while still maintaining low emissions. For example, one
potential problem with film cooling, a very effective cooling
method, is the formation of carbon monoxide at the periphery of the
combustor.
[0005] The combustor of the present invention solves one or more of
the problems set forth above.
SUMMARY OF THE INVENTION
[0006] An embodiment of a combustor has a combustion zone and a
first liner bounding the combustion zone. The first liner has a
first end portion and a second end portion spaced a defined
distance from the first end portion. The combustor has a first
convector spaced apart from the first liner. The convector has a
first end portion and a second end portion spaced a defined
distance from the first end portion. The combustor has a plurality
of passages positioned between the first liner and the first
combustor liner. At least one of the plurality of passages has a
length that is greater than at least one of the defined distance of
the first liner and the defined distance of the first
convector.
[0007] An embodiment of a gas turbine engine has a compressor, a
combustor, and a turbine. The combustor has a combustion zone and a
first liner bounding the combustion zone. The first liner has a
first end portion and a second end portion spaced a defined
distance from the first end portion. The combustor has a first
convector spaced apart from the first liner. The convector has a
first end portion and a second end portion spaced a defined
distance from the first end portion. The combustor has a plurality
of passages positioned between the first liner and the first
combustor liner. At least one of the plurality of passages has a
length that is greater than at least one of the defined distance of
the first liner and the defined distance of the first
convector.
[0008] In a further embodiment of the present invention, a method
of cooling a liner of a combustor of a gas turbine engine includes
directing a fluid between a first end portion of a first liner and
a first end portion of a first convector of a combustor. At least
one of the first liner and the first convector has a central axis.
The method further includes causing the fluid to move in a
direction nonparallel to the central axis.
[0009] In another embodiment of the present invention, a combustor
has a combustion zone and a first liner bounding the combustion
zone. The combustor has a first convector spaced apart from the
first liner. At least one of the first liner and the first
convector has a central axis. The combustor has a fluid disposed
between the first liner and the first convector. The combustor has
means for causing the fluid to move in a direction nonparallel to
the central axis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a cross-sectional view of a portion of a gas
turbine engine;
[0011] FIG. 2 is an enlarged cross-sectional view of a combustor of
the gas turbine engine of FIG. 1;
[0012] FIG. 3 is a perspective view of one embodiment of the
combustor of FIG. 2; and
[0013] FIG. 4 is a perspective view of an alternative embodiment of
the combustor of FIG. 2.
DETAILED DESCRIPTION
[0014] Referring to FIG. 1, an embodiment of a gas turbine engine
10 is shown having a compressor 12, a combustor 14, and a turbine
16. The combustor 14 is in fluid communication with the compressor
12, and the turbine 16 is in fluid communication with the combustor
14. The turbine 16 is connected to the compressor 12 via a
force-transmitting device 17, such as a shaft or gear system. The
combustor 14 defines a combustion zone 18 of the gas turbine engine
10. In the embodiment of FIG. 1, the combustor 14 of the gas
turbine engine 10 is an annular combustor and has a central axis
20. However, in other embodiments, the combustor 14 may be tubular
with a single can, tubular with multiple cans, tuboannular, or any
other configuration known in the art. In the embodiment of FIG. 1,
the combustor 14 is generally in the shape of a cylinder joined to
a conical frustum. However, the combustor 14 may approximate any
other shape or combination of shapes, such as a cylinder, an
elliptic cylinder, a barrel, a funnel or a conical frustum.
[0015] Referring to FIG. 2, a portion of the combustor 14 is shown.
The combustor 14 has a combustion zone 18 and a first liner 22
bounding the combustion zone 18. As used herein, the term
"bounding" shall mean "providing a limit to." The first liner 22
has a first end portion 24 and a second end portion 26 spaced a
defined distance 28 from the first end portion 24. In the
embodiment of FIG. 1, the first liner 22 has a central axis 29 that
is generally the same as the central axis 20 of the combustor 14.
However, in other embodiments, such as a tubular combustor with
multiple cans, the central axis 29 of the first liner 22 may not be
generally the same as the central axis 20 of the combustor 14.
[0016] Referring to FIG. 2, the combustor 14 also has a first
convector 30 spaced apart from the first liner 22. The first
convector 30 has a first end portion 32 and a second end portion 34
spaced a defined distance 36 from the first end portion 32. The
first liner 22 is disposed between the combustion zone 18 and the
first convector 30. A defined volume 38 is disposed between the
first liner 22 and the first convector 30. The defined volume 38
has a first end portion 40 and a second end portion 42 spaced apart
from the first end portion 40. In the embodiment of FIG. 1, the
first convector 30 has a central axis 44 that is generally the same
as the central axis 20 of the combustor 14 and the central axis 29
of the first liner 22. However, in other embodiments, such as a
tubular combustor with multiple cans, the central axis 44 of the
first convector 30 may not be generally the same as the central
axis 20 of the combustor 14. Also, in other embodiments the central
axis 44 of the first convector 30 may not be generally the same as
the central axis 29 of the first liner 22.
[0017] In the embodiment of FIG. 2, the first end portion 24 of the
first liner 22 does not contact the first end portion 32 of the
first convector 30, such that the first end portion 40 of the
defined volume 38 is open. A fluid may pass into the defined volume
38 between the first end portion 24 of the first liner 22 and the
first end portion 32 of the first convector 30. In FIG. 2, the
second end portion 42 of the defined volume 38 is closed. In other
embodiments either or both of the first end portion 40 and the
second end portion 42 of the defined volume 38 may be open or
closed.
[0018] Referring to FIG. 3, the combustor 14 has at least one means
45 for causing a fluid positioned between the first liner 22 and
the first convector 30 to move in a direction nonparallel to at
least one of the central axis 29 of the first liner 22 and the
central axis 44 of the first convector 30. In the embodiment of
FIG. 3, the at least one means 45 is a plurality of passages 46
positioned between the first liner 22 and the first convector 30.
In the embodiment of FIG. 3, the plurality of passages 46 are
formed by a first surface 48 of the first liner 22, a first surface
50 of the first convector 30, and at least one wall 52 connected to
the first liner 22 and the first convector 30. However, in other
embodiments the at least one wall 52 may be connected to only one
of the first liner 22 and the first convector 30. In the embodiment
of FIG. 3, the at least one wall 52 is a continuous wall, but in
other embodiments the at least one wall 52 may be formed by a
plurality of wall portions. The plurality of wall portions may be
spaced apart. One ordinary skill in the art will recognize that
other structures may perform substantially the same function as the
at least one wall 52 and that any of such structures may be
substituted for the at least one wall 52.
[0019] Referring to FIG. 2, each of the plurality of passages 46
has a first end portion 54 proximate one or both of the first end
portion 24 of the first liner 22 and the first end portion 32 of
the first convector 30. Each of the plurality of passages 46 has a
second end portion 56 proximate one or both of the second end
portion 26 of the first liner 22 and the second end portion 34 of
the first convector 30. Referring to FIG. 3, each of the plurality
of passages 46 has a length defined as the length of a line 58 that
is positioned halfway between the at least one wall 52 defining the
passage 46 and that extends from the first end portion 54 of the
passage 46 to the second end portion 56 of the passage 46. The
length of at least one of the plurality of passages 46 is greater
than either one or both of the defined distance 28 of the first
liner 22 and the defined distance 36 of the first convector 30.
[0020] In the embodiment of FIG. 2 and FIG. 3, the plurality of
passages 46 are spiral passages, i.e. the at least one wall 52 of
the passages 46 rotates about at least one of the central axis 20
of the combustor 14, the central axis 29 of the first liner 22, and
the central axis 44 of the first convector 30. In the embodiment of
FIG. 4, the passages 46 are serpentine passages. Other passage
configurations are possible so long as the length of at least one
of the plurality of passages 46 is longer than either the defined
distance 28 of the first liner 22 or the defined distance 36 of the
first convector 30. In FIG. 3, the combustor 14 has three passages
46. However, one of ordinary skill in the art will recognize that
the combustor 14 may have other numbers of passages 46.
[0021] Referring to FIG. 2, at least one of the plurality of
passages 46 has a first surface 60. In the embodiment of FIG. 2,
the first surface 60 is formed by the first surface 48 of the first
liner 22. At least one of the plurality of passages 46 may have at
least one cooling device 62 positioned therein. In the embodiment
of FIG. 2, the at least one cooling device 62 is connected to the
first surface 60 of the passage 46. In the embodiment of FIG. 2,
the at least one cooling device 62 is a dimple 64, such as the
dimple described in U.S. Pat. No. 6,098,397 issued to Glezer et al.
on 8 Aug. 2000. However, one of ordinary skill in the art will
recognize that other cooling devices 62 may be used, such as trip
strips, fins, or pins. Also, in other embodiments at least one
cooling device 62 may be connected to a second surface 66 of at
least one of the plurality of passages 46. Such second surface 66
may be formed by the first surface 50 of the first convector
30.
[0022] In the embodiment of FIGS. 1 and 2, the combustor 14 has a
second liner 68 bounding the combustion zone 18. The second liner
68 has a first end portion 70 and a second end portion 72 spaced a
defined distance 74 from the first end portion 70 of the second
liner 68. In the embodiment of FIG. 1, the second liner 68 has a
central axis 76 that is generally the same as the central axis 20
of the combustor 14. However, in other embodiments, such as a
tubular combustor with multiple cans, the central axis 76 of the
second liner 68 may not be generally the same as the central axis
20 of the combustor 14.
[0023] In the embodiments of FIGS. 1 and 2, the combustor 14 also
has a second convector 78 spaced apart from the second liner 68.
The second convector 78 has a first end portion 80 and a second end
portion 82 spaced a defined distance 84 from the first end portion
80. The second liner 68 is disposed between the combustion zone 18
and the second convector 78. A second defined volume 86 is disposed
between the second liner 68 and the second convector 78. The second
defined volume 86 has a first end portion 88 and a second end
portion 90 spaced apart from the first end portion 88. In the
embodiment of FIG. 1, the second convector 78 has a central axis 92
that is generally the same as the central axis 20 of the combustor
14 and the central axis 76 of the second liner 68. However, in
other embodiments, such as a tubular combustor with multiple cans,
the central axis 92 of the second convector 78 may not be generally
the same as the central axis 20 of the combustor 14. Also, in other
embodiments the central axis 92 of the second convector 78 may not
be generally the same as the central axis 76 of the second liner
68.
[0024] In the embodiment of FIG. 2, the combustor 14 has a second
plurality of passages 94 positioned between the second liner 68 and
the second convector 78. In FIG. 2, the second plurality of
passages 94 are formed by at least one wall 96. Other features of
the second liner 68, second convector 78, second plurality of
passages 94, and the at least one wall 96 forming the second
plurality of passages 94 are similar to those features set forth
above of the first liner 22, first convector 30, plurality of
passages 46 and at least one wall 52 forming the plurality of
passages 46.
[0025] Industrial Applicability
[0026] During operation of the gas turbine engine 10, a fluid,
typically air, enters the compressor 12 of the engine 10. The
compressor 12 compresses the fluid and delivers the compressed
fluid to the combustor 14. A portion of the compressed fluid is
delivered to the combustion zone 18 of the combustor 14 where it is
combusted with gas. This combustion process creates energy, a
portion of which is used to drive the turbine 16 of the gas turbine
engine 10. Another portion of the energy created by the combustion
process manifests itself as heat. This portion of energy increases
the temperature of the first liner 22 of the combustor 14.
[0027] To cool the first liner 22, another portion of the
compressed fluid from the compressor 12, hereinafter referred to as
"the cooling portion of the compressed fluid," is directed into the
first end portion 54 of the plurality of passages 46 of the
combustor 14. The motion of the cooling portion of the compressed
fluid within the plurality of passages 46 will be described by
focusing on one of the plurality of passages 46. The cooling
portion of the compressed fluid enters the first end portion 54 of
the passage 46. The cooling portion of the compressed fluid
contacts the first surface 60 of the passage 46 and, thereby,
withdraws heat from the first liner 22 of the combustor 14. In
addition, the cooling portion of the compressed fluid contacts the
at least one wall 52 of the passage 46 causing the cooling portion
of the compressed fluid to move in a direction nonparallel to at
least one of the central axis 20 of the combustor 14, the central
axis 29 of the first liner 22, and the central axis 44 of the first
convector 30. As used herein, "a direction nonparallel to" one of
the central axes 20, 29, and 30 refers to the general direction of
the majority of the cooling portion of the compressed fluid, not
the particular movement of each individual fluid molecule. In
addition, "a direction nonparallel to" one of the central axes 20,
29, and 30 is not intended to describe movement in a direction
towards or away from one of the central axes 20, 29, and 30, e.g.
the movement of the cooling portion of the compressed fluid
typically caused by cooling devices 62, such as trip strips.
Rotation of the cooling portion of the compressed fluid about at
least one of the central axes 20, 29, and 30 is an example of
movement of the cooling portion of the compressed fluid in a
direction nonparallel to at least one of the central axes 20, 29,
and 30. If the passage 46 is a spiral passage, the cooling portion
of the compressed fluid is caused to move in a spiral path. If the
passage 46 is a serpentine passage, the cooling portion of the
compressed fluid is caused to move in a serpentine path. During its
movement through such a serpentine path, the cooling portion of the
compressed fluid may travel in a direction parallel to at least one
of the central axes 20, 29, and 30, but at other points in the
serpentine path the cooling portion of the compressed fluid will be
caused to move in a direction nonparallel to at least one of the
central axes 20, 29, and 30.
[0028] Extending the length of the passage 46 ensures utilization
of a greater cooling capacity of the cooling portion of the
compressed fluid between the first liner 22 and the first convector
30. In combustors 14 wherein the cooling portion of the compressed
fluid between the first liner 22 and the first convector 30 simply
travels either the defined distance 28 of the first liner 22 or the
defined distance 36 of the first convector 30, the cooling portion
of the compressed fluid may still have some cooling capacity
remaining when the fluid exits the defined volume 38 between the
first liner 22 and the first convector 30. If the passage 46 has
one or more cooling devices 62 connected to the first surface 60,
the cooling effect of the cooling portion of the compressed fluid
is increased. The cooling portion of the compressed fluid contacts
the cooling device 62, and the cooling device 62 introduces
turbulence into the flow of the cooling portion of the compressed
fluid. Therefore, a warmer segment of the cooling portion of the
compressed fluid that is near the first liner 22 is moved away from
the first liner 22 and a cooler segment of the cooling portion of
the compressed fluid that is near the first convector 30 moves
towards the first liner 22, where it can increase the cooling of
the first liner 22.
[0029] In the embodiments described herein, compressed fluid enters
the plurality of passages 46 via open first end portions 54 of the
passages 46. However, other means of entrance into the plurality of
passages 46 may be utilized, such as impingement jets or other
orifices. In an alternative embodiment not shown, in which the gas
turbine engine 10 has a serial cooling system, the cooling portion
of the compressed fluid may enter the plurality of passages 46
proximate the second end portion 56 of the passages 46 and exit
proximate the first end portion 54 of the passages 46.
[0030] The operation of the second liner 68, second convector 78,
second plurality of passages 94, and at least one wall 96 forming
the second plurality of passages 94, in embodiments having such
structures, is similar to the operation discussed above of the
first liner 22, first convector 30, plurality of passages 46, and
at least one wall 52 forming the plurality of passages 46.
[0031] Other aspects, objects, and advantages of this invention can
be obtained from a study of the drawings, the disclosure, and the
appended claims.
* * * * *