U.S. patent application number 14/140610 was filed with the patent office on 2014-08-07 for combustor liner for a can-annular gas turbine engine and a method for constructing such a liner.
The applicant listed for this patent is Weidong Cai, Krishna C. Miduturi, David M. Ritland. Invention is credited to Weidong Cai, Krishna C. Miduturi, David M. Ritland.
Application Number | 20140216043 14/140610 |
Document ID | / |
Family ID | 51258080 |
Filed Date | 2014-08-07 |
United States Patent
Application |
20140216043 |
Kind Code |
A1 |
Cai; Weidong ; et
al. |
August 7, 2014 |
COMBUSTOR LINER FOR A CAN-ANNULAR GAS TURBINE ENGINE AND A METHOD
FOR CONSTRUCTING SUCH A LINER
Abstract
A combustor liner (30) for a can-annular gas turbine engine (10)
and a method for constructing such a liner are provided. The
combustor liner includes an annular wall member (32) A cooling
channel (34, 42, 50, 54, 56, 58) is formed through the wall member
and extends from an inlet end of the liner to an outlet end of the
liner A property of the cooling channel may be varied along a
length of the cooling channel. The cooling channel may be formed
through the combustor liner using an electro-chemical machining
(ECM) process or a three dimensional printing process (3DP).
Inventors: |
Cai; Weidong; (Oviedo,
FL) ; Miduturi; Krishna C.; (Orlando, FL) ;
Ritland; David M.; (Winter Park, FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cai; Weidong
Miduturi; Krishna C.
Ritland; David M. |
Oviedo
Orlando
Winter Park |
FL
FL
FL |
US
US
US |
|
|
Family ID: |
51258080 |
Appl. No.: |
14/140610 |
Filed: |
December 26, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61761367 |
Feb 6, 2013 |
|
|
|
Current U.S.
Class: |
60/755 ;
29/888 |
Current CPC
Class: |
F23R 3/002 20130101;
F23R 2900/03045 20130101; F23R 3/005 20130101; Y10T 29/49229
20150115; F23R 2900/03043 20130101 |
Class at
Publication: |
60/755 ;
29/888 |
International
Class: |
F23R 3/00 20060101
F23R003/00 |
Claims
1. A combustor liner for a can-annular gas turbine engine
comprising. an annular wall member; and a cooling channel formed
through the wall member and extending from an inlet end of the
liner to an outlet end of the liner, wherein a property of the
cooling channel varies along a length of the cooling channel.
2. The combustor liner of claim 1, wherein a circumferential
position of the cooling channel varies along a longitudinal axis of
the liner
3. The combustor liner of claim 2, wherein the cooling channel
defines a curved shape
4. The combustor liner of claim 2, wherein the cooling channel
defines a helix shape.
5. The combustor liner of claim 1, wherein a diameter of the
cooling channel is not constant along its length.
6. The combustor liner of claim 1, wherein a surface finish of the
cooling channel is not constant along its length
7. The combustor liner of claim 1, wherein a cross-sectional shape
of the cooling channel is not constant along its length.
8. The combustor liner of claim 1, wherein a cross-sectional shape
of the cooling channel comprises a multi-lobe shape.
9. A combustor comprising the combustor liner of claim 1.
10. A method for constructing a combustor liner for a can-annular
gas turbine engine, the method comprising: establishing expected
thermal transfer demands along the combustor liner; forming a
cooling channel through the combustor liner using a process for
forming a structure; and controlling the forming process to vary a
cooling channel property along a length of the cooling channel
based on the expected thermal transfer demands.
11. The method of claim 10, wherein the forming process comprises
an electro-chemical machining process.
12. The method of claim 10, wherein the forming process comprises a
three-dimensional printing process
13. The method of claim 10, further comprising varying a
circumferential position of the cooling channel along a
longitudinal axis of the liner.
14. The method of claim 13, wherein the cooling channel defines a
helix shape
15. The method of claim 10, further comprising controlling the
forming process such that a diameter of the cooling channel is not
constant along its length.
16. The method of claim 10, further comprising controlling the
forming process such that a surface finish of the cooling channel
is not constant along its length.
17. The method of claim 10, further comprising controlling the
forming process such that a cross-sectional shape of the cooling
channel is not constant along its length
18. The method of claim 10, further comprising controlling the
forming process such that a cross-sectional shape of the cooling
channel comprises a multi-lobe shape
19. A combustor liner for a can-annular gas turbine engine
comprising. an annular wall member, and a cooling channel formed
through the wall member and extending from an inlet end of the
liner to an outlet end of the liner, wherein a property of the
cooling channel varies along a length of the cooling channel, and
wherein the cooling channel is formed by a process selected from
the group consisting of an electro-chemical machining process and a
three-dimensional printing process.
Description
[0001] This application claims benefit of the 6 Feb. 2013 filing
date of U.S. provisional patent application No. 61/761,367 which is
incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention is generally related to gas turbine
engines and, more particularly, to a combustor liner for a gas
turbine engine, and a method for constructing such a liner
BACKGROUND OF THE INVENTION
[0003] Power generation systems, such as can-annular gas turbine
engines, include sophisticated combustion components and processes
for improving combustion efficiency. Market trends push for longer
lifetime for components of the engine, reduced emissions of
nitrogen oxides (NOx) and higher firing temperatures. Known
combustor liners for can-annular gas turbine engines typically
involve a pair of concentric rings, such as a plate with grooves
and a sleeve which cooperate to direct cooling air to maintain
appropriate liner temperatures at the combustor exhaust zone. These
grooves are constructed using traditional machining techniques,
and, consequently are not suited for structural refinements which
would allow to more efficiently meeting thermal transfer demands
along the combustor liner Thus, there continues to be a need for an
improved combustor liner for a can-annular gas turbine engine, and
a method for constructing such a liner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The invention is explained in the following description in
view of the drawings that show.
[0005] FIG. 1 is a simplified schematic of a can-annular turbine
engine, which may benefit from aspects of the present
invention.
[0006] FIG. 2 is a cross-sectional view of one example embodiment
of a combustor liner embodying aspects of the present
invention.
[0007] FIG. 3 is an isometric view of a combustor liner, such as
shown in FIG. 2.
[0008] FIG. 4 is a cross-sectional view of another example
embodiment of a combustor liner embodying aspects of the present
invention.
[0009] FIG. 5 is an isometric view of a combustor liner, such as
shown in FIG. 4
[0010] FIG. 6 illustrates respective side views of example cooling
channels embodying aspects of the invention.
[0011] FIGS. 7 and 8 illustrate respective cross-sectional shapes
of cooling channels embodying other aspects of the present
invention.
[0012] FIG. 9 illustrates further examples of cross-sectional
shapes of cooling channels embodying aspects of the present
invention
[0013] FIG. 10 is a flow chart of a method embodying aspects of the
present invention for constructing a combustor liner for a
can-annular gas turbine engine.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present inventors have innovatively recognized certain
limitations in connection with known combustor liners for
can-annular gas turbine engines. For example, structural
limitations of known combustor liners may impede the ability to
vary one or more properties of the cooling channel along a length
of the cooling channel This ability would allow tailoring the
cooling channel to more efficiently meet expected thermal transfer
demands along the combustor liner In view of such recognition, the
present inventors propose an innovative combustor liner for a
can-annular gas turbine engine, and a method for constructing such
a liner, where a cooling channel may be formed through the
combustor liner using a process for forming a structure, such as
may involve complex geometries and/or tightly-controlled tolerances
In one non-limiting embodiment, the forming process may be based on
subtraction of material, such as an electro-chemical machining
(ECM) process In another non-limiting embodiment, the forming
process may be based on addition of material, such as a three
dimensional printing (3DP) process, also referred to as additive
manufacturing
[0015] In the following detailed description, various specific
details are set forth in order to provide a thorough understanding
of such embodiments. However, those skilled in the art will
understand that embodiments of the present invention may be
practiced without these specific details, that the present
invention is not limited to the depicted embodiments, and that the
present invention may be practiced in a variety of alternative
embodiments. In other instances, methods, procedures, and
components, which would be well-understood by one skilled in the
art have not been described in detail to avoid unnecessary and
burdensome explanation.
[0016] Furthermore, various operations may be described as multiple
discrete steps performed in a manner that is helpful for
understanding embodiments of the present invention However, the
order of description should not be construed as to imply that these
operations need be performed in the order they are presented, nor
that they are even order dependent unless otherwise so described.
Moreover, repeated usage of the phrase "in one embodiment" does not
necessarily refer to the same embodiment, although it may. Lastly,
the terms "comprising", "including", "having", and the like, as
used in the present application, are intended to be synonymous
unless otherwise indicated.
[0017] FIG. 1 is a simplified schematic of a gas turbine engine,
such as a can-annular gas turbine engine 10. As will be appreciated
by those skilled in the art, turbine engine 10 includes a
compressor 12 for compressing air, a combustor 14 for mixing the
compressed air with fuel and igniting the mixture. In practice, the
turbine engine includes a plurality of annularly arranged
combustors, which may be referred to in the art as combustor cans
but just one combustor is shown in FIG. 1 for simplicity of
illustration. FIG. 1 further illustrates a turbine section 16 where
energy is extracted to turn a shaft 18, which may power the
compressor 12 and auxiliary equipment, such as an electrical
generator (not shown). Combustor 14 produces a hot-temperature flow
(e.g., gases flowing at approximately 1700.degree. C. or more),
which passes from combustor 14 through a transition 15 and into
turbine section 16.
[0018] In one example embodiment, as may be appreciated in FIGS. 2
and 3, a combustor liner 30 for a can-annular gas turbine engine
comprises an annular wall member 32, which may be an integral
member One or more cooling channels 34 are formed through the wall
member 32 and may extend from an inlet end 36 of liner 30 to an
outlet end 38 of the liner. In one example embodiment, the
cross-sectional shape of a cooling channel 34 may be a generally
rounded shape, such as circular, elliptical, or other shapes free
of corners, and the channel may be aligned along a longitudinal
axis 40 of the liner 30. The use of ECM or 3DP provides the ability
to form cooling channels having a relatively large ratio of length
to maximum cross-section dimension (L/D) with tightly controlled
tolerances. For example, this provides the ability to form a
relatively larger number of smaller-sized cooling channels per unit
area, which is conducive to improve the heat transfer efficiency of
the liner. In one example embodiment, cooling channels having an
L/D ratio ranging from approximately 100 to approximately 200 may
be implemented.
[0019] In one example embodiment, the use of ECM or 3DP may further
provide the ability to vary a property of the cooling channel along
the length of the cooling channel. For example, as illustrated in
FIGS. 4 and 5, a circumferential position of a cooling channel 42
may vary along the longitudinal axis 40 of the liner 30 In one
example embodiment, the cooling channel 42 may be configured to
define a curve in the three-dimensional wall member, such as a
helix shape This configuration effectively increases the surface
area available per cooling channel compared to a cooling channel
which is aligned along the longitudinal axis of the liner.
[0020] Further examples of respective cooling channel properties
that may be varied along the length of the cooling channel through
the use of ECM or 3DP may be as conceptually illustrated in FIG. 6.
For example, a diameter of a cooling channel 50 is not constant
along its length. In another example, a surface finish of a cooling
channel 52 is not constant along its length For example, an inner
surface portion 54 of cooling channel may have a surface finish
comprising a relatively coarser surface finish compared to other
inner surface portions of the channel. As will be appreciated by
one skilled in the art, this type of structural features may
effectively provide along the length of the cooling channel,
turbulence zones having a locally-enhanced heat transfer
capability.
[0021] FIGS. 7 and 8 illustrate respective cross-sectional shapes
of cooling channels embodying further aspects of the present
invention. For example, the use of ECM or 3DP further provides the
ability to form cross-sectional shapes that may comprise respective
multi-lobe shapes, such as conceptually illustrated for cooling
channels 56, 58. This type of cross-sectional shape may be
effective to increase the wetted area and thus the available heat
transfer area per cooling channel compared to a cooling channel
with a discrete rounded shape Moreover, structural features of such
multi-lobe shapes need not be constant along the length of the
cooling channel. For example, the size of one or more of the lobes
may be adjusted along the length of the cooling channels depending
on the heat transfer demand at a given liner location.
[0022] FIG. 9 further illustrates further examples of
cross-sectional shapes that may be feasible for the cooling
channels through the use of ECM or 3DP. For example,
cross-sectional shapes having corners, such as square 60,
rectangular 62, triangular 64, polygonal shapes 66, etc may be
implemented.
[0023] FIG. 10 is a flow chart 100 of a method for constructing a
combustor liner for a can-annular gas turbine engine In one example
embodiment, subsequent to a start step 102, a step 104 allows
establishing expected thermal transfer demands along the combustor
liner. For example, the expected thermal transfer demands may be
obtained by collection of historical data, modeling,
experimentation or any suitable means for acquiring information
indicative of the expected thermal transfer demands along the
combustor liner. A step 106 allows forming a cooling channel
through the combustor liner using a process for forming a
structure, such as may involve complex geometries and/or
tightly-controlled tolerances. Non-limiting embodiments of the
forming process may be based on subtraction of material, such as an
electro-chemical machining (ECM) process; or, alternatively, the
forming process may be based on addition of material, such as a
three dimensional printing (3DP) process Prior to a return step
110, a step 108 allows controlling the forming process to vary a
cooling channel property along a length of the cooling channel
based on the expected thermal transfer demands For example, the
cooling channel property may be varied to meet a relatively higher
thermal transfer demand at a given location of the liner.
[0024] While various embodiments of the present invention have been
shown and described herein, it will be apparent that such
embodiments are provided by way of example only. Numerous
variations, changes and substitutions may be made without departing
from the invention herein. Accordingly, it is intended that the
invention be limited only by the spirit and scope of the appended
claims.
* * * * *