U.S. patent application number 12/774262 was filed with the patent office on 2011-11-10 for diffuser for gas turbine system.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Gunnar Leif Siden.
Application Number | 20110271654 12/774262 |
Document ID | / |
Family ID | 44170533 |
Filed Date | 2011-11-10 |
United States Patent
Application |
20110271654 |
Kind Code |
A1 |
Siden; Gunnar Leif |
November 10, 2011 |
DIFFUSER FOR GAS TURBINE SYSTEM
Abstract
A diffuser for a gas turbine system having a longitudinal axis
is disclosed. The diffuser includes a plurality of diffuser ducts.
Each of the plurality of diffuser ducts is disposed annularly about
the longitudinal axis and has an inlet, an outlet, and a passage
extending between the inlet and the outlet. The outlet of each of
the plurality of diffuser ducts is tangentially offset from the
inlet of the respective diffuser duct. Each of the plurality of
diffuser ducts is configured to flow a gas flow therethrough,
reducing the gas flow velocity.
Inventors: |
Siden; Gunnar Leif;
(Greenville, SC) |
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
44170533 |
Appl. No.: |
12/774262 |
Filed: |
May 5, 2010 |
Current U.S.
Class: |
60/39.37 ;
415/208.2 |
Current CPC
Class: |
F04D 29/545 20130101;
F01D 9/02 20130101; F04D 29/541 20130101; F05D 2260/60 20130101;
F05D 2240/12 20130101 |
Class at
Publication: |
60/39.37 ;
415/208.2 |
International
Class: |
F01D 9/04 20060101
F01D009/04; F23R 3/46 20060101 F23R003/46 |
Claims
1. A diffuser for a gas turbine system having a longitudinal axis,
the diffuser comprising: a plurality of diffuser ducts, each of the
plurality of diffuser ducts disposed annularly about the
longitudinal axis and having an inlet, an outlet, and a passage
extending between the inlet and the outlet, wherein the outlet of
each of the plurality of diffuser ducts is tangentially offset from
the inlet of the respective diffuser duct, and wherein each of the
plurality of diffuser ducts is configured to flow a gas flow
therethrough, reducing the gas flow velocity.
2. The diffuser of claim 1, wherein the outlet of each of the
plurality of diffuser ducts is longitudinally offset from the inlet
of the respective diffuser duct.
3. The diffuser of claim 1, wherein the outlet of each of the
plurality of diffuser ducts is radially offset from the inlet of
the respective diffuser duct.
4. The diffuser of claim 1, wherein gas flow exits the diffuser
flowing in a generally tangential direction.
5. The diffuser of claim 1, wherein gas flow exits the diffuser
flowing in a generally longitudinal direction.
6. The diffuser of claim 1, wherein each of the passages includes a
guide portion disposed adjacent the inlet of the respective
diffuser duct, the guide portions configured to guide the gas flow
from a generally longitudinal flow direction to a generally
tangential flow direction.
7. The diffuser of claim 6, wherein the guide portions are further
configured to guide the gas flow to a generally radial flow
direction.
8. The diffuser of claim 6, wherein each of the passages extends in
a generally linear manner downstream of the guide portion with
respect to the gas flow.
9. The diffuser of claim 6, wherein each of the passages extends in
a generally curvilinear manner downstream of the guide portion with
respect to the gas flow.
10. The diffuser of claim 1, wherein each of the passages includes
a guide portion disposed adjacent the outlet of the respective
diffuser duct, the guide portions configured to guide the gas flow
from a generally tangential flow direction to a generally
longitudinal flow direction.
11. The diffuser of claim 10, wherein the guide portions are
further configured to guide the gas flow from a generally radial
flow direction.
12. The diffuser of claim 10, wherein each of the passages extends
in a generally linear manner upstream of the guide portion with
respect to the gas flow.
13. The diffuser of claim 10, wherein each of the passages extends
in a generally curvilinear manner upstream of the guide portion
with respect to the gas flow.
14. The diffuser of claim 1, wherein each of the passages is
generally conically shaped.
15. A gas turbine system having a longitudinal axis, the gas
turbine system comprising: a compressor section for compressing a
gas flow; a diffuser configured to reduce the velocity of the gas
flow, the diffuser comprising a plurality of diffuser ducts, each
of the plurality of diffuser ducts disposed annularly about the
longitudinal axis and having an inlet, an outlet, and a passage
extending between the inlet and the outlet, wherein the outlet of
each of the plurality of diffuser ducts is tangentially offset from
the inlet of the respective diffuser duct, and wherein each of the
plurality of diffuser ducts is configured to flow the gas flow
therethrough; and a combustor section configured to accept the gas
flow from the diffuser.
16. The gas turbine system of claim 15, wherein the compressor
section is free from guide vanes.
17. The gas turbine system of claim 15, the combustor section
comprising a plurality of combustor cans, each of the combustor
cans configured to accept the gas flow from one of the plurality of
diffuser ducts.
18. The gas turbine system of claim 15, wherein the outlet of each
of the plurality of diffuser ducts is longitudinally offset from
the inlet of the respective diffuser duct.
19. The gas turbine system of claim 15, wherein the outlet of each
of the plurality of diffuser ducts is radially offset from the
inlet of the respective diffuser duct.
20. The gas turbine system of claim 15, wherein each of the
passages is generally conically shaped.
Description
FIELD OF THE INVENTION
[0001] The subject matter disclosed herein related generally to gas
turbine systems, and more particularly to diffusers in gas turbine
systems.
BACKGROUND OF THE INVENTION
[0002] Gas turbine systems are widely utilized in fields such as
power generation. A conventional gas turbine system includes a
compressor section, a combustor section, and at least one turbine
section. The compressor section is configured to compress air as
the air flows through the compressor section. The air is then
flowed from the compressor section to the combustor section, where
it is mixed with fuel and combusted, generating a hot gas flow. The
hot gas flow is provided to the turbine section, which utilizes the
hot gas flow by extracting energy from it to power the compressor,
an electrical generator, and other various loads.
[0003] In conventional gas turbine systems, the air flow compressed
in the compressor section is discharged from the compressor section
at a relatively high velocity. The velocity of this air flow
generally should be reduced to a velocity that is optimal for
entering the combustor section. Thus, typical known compressor
sections include an axial diffuser 19, as shown in FIG. 2, which
acts to reduce the velocity of the air flow exiting the compressor
section.
[0004] The utilization of typical known diffusers in gas turbine
systems can subject the gas turbine system to a variety of
problems. For example, known diffusers typically diffuse the air
flow as the air flow travels along a generally longitudinal axis 90
of the gas turbine system. However, the air flow exiting the
compressor section generally has an "exit swirl" component, meaning
that the air flow is traveling in a generally rotational direction,
with tangential and radial flow components, along with traveling in
a generally longitudinal direction. To reduce this exit swirl
before the air flow enters the axial diffuser 19, a guide vane or
guide vanes 28 are typically disposed upstream of the axial
diffuser 19 in the compressor section. The guide vanes 28 are
designed to reduce the exit swirl. However, significant air flow
pressure drops are associated with the use of guide vanes 28 to
reduce the exit swirl, which results in losses in the performance
and efficiency of the gas turbine system. Further, after the air
flow exits a typical axial diffuser 19, the air flow must change
direction multiple times as it flows to the combustor section, as
shown in FIG. 2. Further significant air flow pressure drops are
associated with each change in direction, thus resulting in further
losses in the performance and efficiency of the gas turbine
system.
[0005] Thus, a diffuser that reduces air flow pressure drops would
be desired in the art. Additionally, a diffuser that utilizes the
exit swirl associated with the air flow to guide the air flow to
the combustor section would be advantageous. Further, a diffuser
that eliminates the need for guide vanes in the compressor section
would be desired.
BRIEF DESCRIPTION OF THE INVENTION
[0006] Aspects and advantages of the invention will be set forth in
part in the following description, or may be obvious from the
description, or may be learned through practice of the
invention.
[0007] In one embodiment, a diffuser for a gas turbine system
having a longitudinal axis is disclosed. The diffuser includes a
plurality of diffuser ducts. Each of the plurality of diffuser
ducts is disposed annularly about the longitudinal axis and has an
inlet, an outlet, and a passage extending between the inlet and the
outlet. The outlet of each of the plurality of diffuser ducts is
tangentially offset from the inlet of the respective diffuser duct.
Each of the plurality of diffuser ducts is configured to flow a gas
flow therethrough, reducing the gas flow velocity.
[0008] These and other features, aspects and advantages of the
present invention will become better understood with reference to
the following description and appended claims. The accompanying
drawings, which are incorporated in and constitute a part of this
specification, illustrate embodiments of the invention and,
together with the description, serve to explain the principles of
the invention.
BRIEF DESCRIPTION OF THE DRAWING
[0009] A full and enabling disclosure of the present invention,
including the best mode thereof, directed to one of ordinary skill
in the art, is set forth in the specification, which makes
reference to the appended figures, in which:
[0010] FIG. 1 is a schematic view of a gas turbine system of the
present disclosure;
[0011] FIG. 2 is a cross-sectional view of a known gas turbine
system;
[0012] FIG. 3 is an exploded perspective view of one embodiment of
a diffuser of the present disclosure;
[0013] FIG. 4 is a perspective view of one embodiment of a diffuser
duct of the present disclosure;
[0014] FIG. 5 is a front view of one embodiment of a diffuser of
the present disclosure; and
[0015] FIG. 6 is a front view of another embodiment of a diffuser
of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Reference now will be made in detail to embodiments of the
invention, one or more examples of which are illustrated in the
drawings. Each example is provided by way of explanation of the
invention, not limitation of the invention. In fact, it will be
apparent to those skilled in the art that various modifications and
variations can be made in the present invention without departing
from the scope or spirit of the invention. For instance, features
illustrated or described as part of one embodiment can be used with
another embodiment to yield a still further embodiment. Thus, it is
intended that the present invention covers such modifications and
variations as come within the scope of the appended claims and
their equivalents.
[0017] FIG. 1 is a schematic diagram of a gas turbine system 10.
The system 10 may include a compressor section 12, a combustor
section 14, and a turbine section 16. Further, the system 10 may
include a plurality of compressor sections 12, combustor sections
14, and turbine sections 16. The compressor section 12 and turbine
section 16 may be coupled by a shaft 18. The shaft 18 may be a
single shaft or a plurality of shaft segments coupled together to
form shaft 18. The gas turbine system 10 may have a central
longitudinal axis 90. For example, the shaft 18 may be disposed
longitudinally along the axis 90.
[0018] The compressor section 12 may compress a gas flow 80 as the
gas flow 80 flows through the compressor section 12. The gas flow
80 may be, for example, air or any other suitable gas. The
compressor section 12 may then flow the gas flow 80 to the
combustor section 14, which may be configured to accept the gas
flow 80, as discussed below.
[0019] As the gas flow 80 flows through the compressor section 12
after being compressed, it may flow in a generally longitudinal
direction with respect to the longitudinal axis 90. However, the
gas flow 80 may generally further include other flow components.
For example, the gas flow 80 after being compressed may have flow
components known collectively in the art as an "exit swirl." Thus,
the gas flow 80 may flow in a generally tangential direction, and
may further flow in a generally radial direction.
[0020] In various embodiments, the compressor section 12 may
include at least one guide vane 28. The guide vane 28 may reduce
the exit swirl, thus reducing the tangential and radial flow
components of the gas flow 80. In exemplary embodiments of the
present disclosure, however, the compressor section 12 may be free
from guide vanes 28.
[0021] As shown in FIGS. 3 through 6, the compressor section 12 may
include a diffuser 20. The diffuser 20 may be configured to reduce
the velocity of the gas flow 80, as discussed below. The diffuser
20 may further generally flow the gas flow 80 to the combustor
section 14. For example, after being compressed in the compressor
section 12, gas flow 80 may flow through the diffuser 20 and be
provided to the combustor section 14. For example, in one
embodiment, the gas flow 80 may exit the diffuser 20 into a plenum
22. The gas flow 80 may then be provided from the plenum 22 to the
combustor section 14. Alternatively, the gas flow 80 may exit the
diffuser 20 directly into the combustor section 14. For example,
the combustor section 14 may include a plurality of combustor cans
24. Further, in one embodiment as discussed below, the diffuser 20
may comprise a plurality of diffuser ducts 30. Each of the diffuser
ducts 30 may be coupled with a combustor can 24. The combustor cans
24 may be configured to accept gas flow 80 from one of the
plurality of diffuser ducts 30. For example, each of the combustor
cans 24 may be fluidly connected to one of the diffuser ducts 30,
such that gas flow 80 exiting the diffuser ducts 30 immediately
enters the combustor cans 24, and thus the combustor section
14.
[0022] As mentioned above, the diffuser 20 of the present
disclosure includes a plurality of diffuser ducts 30. As shown in
FIGS. 3 through 6, each of the plurality of diffuser ducts 30 may
have an inlet 32, an outlet 36, and a passage extending between the
inlet 32 and the outlet 36. The diffuser ducts 30 may be configured
to flow a gas flow 80 therethrough, reducing the gas flow 80
velocity. For example, the inlet 32 of each of the plurality of
diffuser ducts 30 may have a cross-sectional area that is generally
smaller than the cross-sectional area of the outlet 36 of the
respective diffuser duct 30. The inlets 32 and outlets 36 may have
generally circular or oval cross-sections, rectangular
cross-sections, triangular cross-sections, or any other suitable
polygonal cross-sections. Further, it should be understood that the
inlet 32 and outlet 34 of a respective diffuser duct 30 need not
have similarly shaped cross-sections. For example, in one
embodiment, the inlet 32 may have a generally rectangular
cross-section, while the outlet 36 may have a generally circular
cross-section.
[0023] Further, the passage 34 may be generally tapered between the
inlet 32 and the outlet 36. For example, in an exemplary
embodiment, the passage 34 may be generally conically shaped.
Alternatively, however, the passage 34 may have a generally
rectangular cross-section, triangular cross-section, or any other
suitable polygonal cross-section. It should be understood that the
cross-sectional shape of the passage 34 may change throughout the
passage 34 as the passage 34 tapers from the relatively smaller
inlet 32 to the relatively larger outlet 36.
[0024] The diffuser ducts 30 may be disposed in an annular array
about the longitudinal axis 90. Thus, as gas flow 80 flows in a
generally longitudinal direction through the compressor section 12
and into the diffuser 20 after being compressed, the gas flow 80
may flow through the inlets 32 into the annular array of diffuser
ducts 30.
[0025] The outlet 36 of each of the plurality of diffuser ducts 30
may be offset from the inlet 32 of the respective diffuser duct 30.
The term "offset", as used herein, means spaced from along the
identified coordinate direction. For example, the outlet 36 of each
of the plurality of diffuser ducts 30 may be tangentially offset
from the inlet 32 of the respective diffuser duct 30, such as
offset along a tangential axis 92. Because the outlet 36 of each of
the plurality of diffuser ducts 30 is tangentially offset from the
inlet 32 of the respective diffuser duct 30, the diffuser ducts 30
may advantageously utilize the tangential component of the gas flow
80 exit swirl to flow the gas flow 80 through the diffuser duets
30. In exemplary embodiments, this utilization of the tangential
gas flow 80 component may eliminate the need for guide vanes 28 in
the compressor section 12. Further, the utilization of the
tangential gas flow 80 component may prevent gas flow 80 pressure
losses due to flow direction changes in typical prior art gas
turbine systems as the gas flow 80 flows from the compressor
section 12 through the diffuser 20 to the combustor section 14.
[0026] Additionally, in some exemplary embodiments, the outlet 36
of each of the plurality of diffuser ducts 30 may be longitudinally
offset from the inlet 32 of the respective diffuser duct 30, such
as offset along the longitudinal axis 90. Because the outlet 36 of
each of the plurality of diffuser ducts 30 is longitudinally offset
from the inlet 32 of the respective diffuser duct 30, the diffuser
ducts 30 may advantageously utilize the longitudinal component of
the gas flow 80 to flow the gas flow 80 through the diffuser ducts
30.
[0027] Further, in some exemplary embodiments, the outlet 36 of
each of the plurality of diffuser ducts 30 may be radially offset
from the inlet 32 of the respective diffuser duct 30, such as
offset along a radial axis 94. Because the outlet 36 of each of the
plurality of diffuser ducts 30 is radially offset from the inlet 32
of the respective diffuser duct 30, the diffuser ducts 30 may
advantageously utilize the radial component of the gas flow 80 exit
swirl to flow the gas flow 80 through the diffuser ducts 30.
[0028] It should be understood that the tangential axis 92 and the
radial axis 94 are defined individually for each diffuser duct 30
with respect to the circumference defined by the diffuser 20 and
diffuser ducts 30, as shown in FIGS. 5 and 6, and that the axes 92
and 94 vary for each diffuser duct 30 about the circumference of
the diffuser 20 based on the number of diffuser ducts 30 disposed
in an annular array about the longitudinal axis 90 of the diffuser
20.
[0029] Each of the passages 34 may include a first guide portion
40, as shown in FIG. 4. In exemplary embodiments, the first guide
portion 40 may be disposed adjacent the inlet 32 of the respective
diffuser duct 30. Alternatively, however, the first guide portion
40 may be any portion of the passage 34 of the diffuser duct 30.
The first guide portion 40 may be that portion of the passage 34
that redirects the general direction of gas flow 80 within a
diffuser duct 30. For example, the first guide portions 40 may be
configured to guide the gas flow 80 from a generally longitudinal
flow direction to a generally tangential flow direction.
Alternatively, the first guide portions 40 may be configured to
guide the gas flow 80 from a generally longitudinal flow direction
to a generally radial flow direction, a generally tangential and
radial flow direction, a generally tangential and longitudinal flow
direction, or to a generally tangential, radial, and longitudinal
flow direction. It should be understood that gas flow 80 in any
general direction, such as in a generally longitudinal direction,
may have other flow components, such as radial and tangential flow
components, and is not limited to flow strictly in the referenced
direction.
[0030] After gas flow 80 passes through the first guide portion 40
of the passage 34 of a diffuser duct 30, the gas flow 80 may
continue to flow through the passage 34 towards the outlet 36. In
certain exemplary embodiments, the passages 34 may extend in a
generally linear manner downstream of the guide portion 40 with
respect to the gas flow 80, as shown in FIG. 6. Thus, the gas flow
80, after passing through the first guide portion 40 of the passage
34, may continue through the passage 34 in a generally linear
manner. In alternative exemplary embodiments, the passages 34 may
extend in a generally curvilinear manner downstream of the guide
portion 40 with respect to the gas flow 80, as shown in FIGS. 3
through 5. Thus, the gas flow 80, after passing through the first
guide portion 40 of the passage 34, may continue through the
passage 34 in a generally curvilinear manner.
[0031] Each of the passages 34 may further include a second guide
portion 42. In exemplary embodiments, the second guide portion 42
may be disposed adjacent the outlet 36 of the respective diffuser
duct 30. Alternatively, however, the second guide portion 42 may be
any portion of the passage 34 of the diffuser duct 30. The second
guide portion 42 may be another portion of the passage 34 that
further redirects the general direction of gas flow 80 within a
diffuser duct 30. For example, the second guide portions 42 may be
configured to guide the gas flow 80 from a generally tangential
flow direction to a generally longitudinal flow direction.
Alternatively, the second guide portions 42 may be configured to
guide the gas flow 80 from a generally radial flow direction, a
generally tangential and radial flow direction, a generally
tangential and longitudinal flow direction, or a generally
tangential, radial, and longitudinal flow direction to a generally
longitudinal flow direction. It should be understood that gas flow
80 in any general direction, such as in a generally longitudinal
direction, may have other flow components, such as radial and
tangential flow components, and is not limited to flow strictly in
the referenced direction.
[0032] It should be understood that before gas flow 80 passes
through the second guide portion 42 of the passage 34 of a diffuser
duct 30, the gas flow 80 may flow through the passage 34 towards
the guide portion 42 and the outlet 36. In certain exemplary
embodiments, the passages 34 may extend in a generally linear
manner upstream of the second guide portion 42 with respect to the
gas flow 80, as shown in FIG. 6. Thus, the gas flow 80, before
passing through the second guide portion 42 of the passage 34, may
travel through the passage 34 in a generally linear manner. In
alternative exemplary embodiments, the passages 34 may extend in a
generally curvilinear manner upstream of the second guide portion
42 with respect to the gas flow 80, as shown in FIGS. 3 through 5.
Thus, the gas flow 80, before passing through the second guide
portion 42 of the passage 34, may travel through the passage 34 in
a generally curvilinear manner.
[0033] After the gas flow 80 flows through the outlet 36 of a
diffuser duct 30 of the present disclosure, the gas flow 80 may
exit the diffuser 20. In some exemplary embodiments, the gas flow
80 may exit the diffuser 20 flowing in a generally tangential
direction. It should be understood, however, that the gas flow 80
may have radial and longitudinal flow components, and is not
limited to flow in a strictly tangential direction. Alternatively,
the gas flow 80 may exit the diffuser 20 flowing in a generally
longitudinal direction. It should be understood, however, that the
gas flow 80 may have tangential and radial flow components, and is
not limited to flow in a strictly longitudinal direction. Further,
the gas flow 80 may exit the diffuser 20 flowing in a generally
radial direction. It should be understood, however, that the gas
flow 80 may have tangential and longitudinal flow components, and
is not limited to flow in a strictly radial direction.
[0034] As discussed above, after the gas flow 80 exits the diffuser
20 and the compressor section 12, the gas flow 80 may enter a
plenum 22, or may directly enter the combustor section 14. For
example, each of the diffuser ducts 30 may be coupled to a
combustor can 24, and the gas flow 80 exiting each diffuser duct 30
may enter the combustor can 24 coupled with the diffuser duct 30.
Thus, in exemplary embodiments, the diffuser 20 may include a
number of diffuser ducts 20 equal to the number of combustor cans
24 in the combustor 14. For example, the diffuser 20, in various
embodiments, may include 8, 12, or 16 diffuser ducts 30, or any
other suitable number of diffuser ducts 30.
[0035] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they include structural elements that do not
differ from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal languages of the claims.
* * * * *