U.S. patent application number 12/014298 was filed with the patent office on 2013-06-06 for airfoil seal system for gas turbine engine.
This patent application is currently assigned to SIEMENS POWER GENERATION, INC.. The applicant listed for this patent is Ihor S. Diakunchak. Invention is credited to Ihor S. Diakunchak.
Application Number | 20130142630 12/014298 |
Document ID | / |
Family ID | 48524131 |
Filed Date | 2013-06-06 |
United States Patent
Application |
20130142630 |
Kind Code |
A1 |
Diakunchak; Ihor S. |
June 6, 2013 |
AIRFOIL SEAL SYSTEM FOR GAS TURBINE ENGINE
Abstract
A turbine airfoil seal system of a turbine engine having a seal
base with a plurality of seal strips extending therefrom for
sealing gaps between rotational airfoils and adjacent stationary
components. The seal strips may overlap each other and may be
generally aligned with each other. The seal strips may flex during
operation to further reduce the gap between the rotational airfoils
and adjacent stationary components.
Inventors: |
Diakunchak; Ihor S.;
(Ontario, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Diakunchak; Ihor S. |
Ontario |
|
CA |
|
|
Assignee: |
SIEMENS POWER GENERATION,
INC.
Orlando
FL
|
Family ID: |
48524131 |
Appl. No.: |
12/014298 |
Filed: |
January 15, 2008 |
Current U.S.
Class: |
415/174.2 |
Current CPC
Class: |
F01D 11/001 20130101;
F16J 15/3292 20130101; F02C 7/28 20130101; F16J 15/0887
20130101 |
Class at
Publication: |
415/174.2 |
International
Class: |
F02C 7/28 20060101
F02C007/28 |
Goverment Interests
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0001] Development of this invention was supported in part by the
United States Department of Energy, Contract No. DE-FC26-05NT42644.
Accordingly, the United States Government may have certain rights
in this invention.
Claims
1. An airfoil seal system for airfoils of a gas turbine engine,
comprising: a seal base configured to be received within a channel
of a rotational airfoil proximate to a platform extending from the
airfoil, wherein the seal base is generally an arcuate segment and
wherein the seal base is configured to extend a length at least
substantially equal to a length along an intersection between a
rotational airfoil and an adjacent stationary component; a
plurality of seal strips generally aligned with each other and
overlapping each other, wherein the plurality of seal strips are
attached to the seal base and extend generally radially inward from
the seal base a length sufficient to seal a gap between the
platform of the rotational airfoil and the adjacent stationary
component; wherein the plurality of seal strips are flexible such
that the seal strips may be flexed during operation of the gas
turbine engine thereby sealing the gap between the platform of the
rotational airfoil and the adjacent stationary component.
2. The airfoil seal system for airfoils of a gas turbine engine of
claim 1, wherein the plurality of seal strips are formed from
alloys.
3. The airfoil seal system for airfoils of a gas turbine engine of
claim 1, wherein the plurality of seal strips are curved out of
plane from the seal base such that when the seal base is attached
to the channel of a rotational airfoil, ends of the plurality of
seal strips curve toward adjacent stationary components.
4. The airfoil seal system for airfoils of a gas turbine engine of
claim 3, wherein the plurality of seal strips are curved out of
plane from the seal base such that when the seal base is attached
to the channel of a rotational airfoil such that the seal base is
generally aligned with a longitudinal axis of the rotational
airfoil, ends of the plurality of seal strips curve toward adjacent
stationary components.
5. The airfoil seal system for airfoils of a gas turbine engine of
claim 1, wherein the seal base extends a length at least
substantially equal to a length along an intersection between at
least two rotational airfoils and adjacent stationary
components.
6. An airfoil seal system for airfoils of a gas turbine engine,
comprising: a rotational airfoil having at least one channel
proximate to a platform extending from an upstream side of the
airfoil; a seal base positioned within the channel of the
rotational airfoil, wherein the seal base is generally an arcuate
segment and wherein the seal base extends a length at least
substantially equal to a length along an intersection between the
rotational airfoil and an adjacent stationary component; a
plurality of seal strips generally aligned with each other and
overlapping each other, attached to the seal base and extending
generally radially inward from the seal base a length sufficient to
seal a gap between the platform of the rotational airfoil and the
adjacent stationary component; wherein the plurality of seal strips
are flexible such that the seal strips may be flexed during
operation of the gas turbine engine thereby sealing the gap between
the platform of the rotational airfoil and the adjacent stationary
component.
7. The airfoil seal system for airfoils of a gas turbine engine of
claim 6, wherein the plurality of seal strips are formed from
alloys.
8. The airfoil seal system for airfoils of a gas turbine engine of
claim 6, wherein the plurality of seal strips are curved out of
plane from the seal base such that ends of the plurality of seal
strips curve toward adjacent stationary components.
9. The airfoil seal system for airfoils of a gas turbine engine of
claim 8, wherein the seal base is generally aligned with a
longitudinal axis of the rotational airfoil and wherein the
plurality of seal strips extend radially inward at an intersection
of the seal strips and the seal base and are curved out of plane
from the seal base such that ends of the plurality of seal strips
curve toward adjacent stationary components.
10. The airfoil seal system for airfoils of a gas turbine engine of
claim 6, wherein the seal base extends a length at least
substantially equal to a length along an intersection between at
least two rotational airfoils and adjacent stationary
components.
11. The airfoil seal system for airfoils of a gas turbine engine of
claim 6, wherein the rotational airfoil comprises at least one
channel proximate to a platform extending from the airfoil on an
upstream side of the airfoil and at least one channel proximate to
a platform extending from the airfoil on a downstream side of the
airfoil; further comprising a seal base positioned within the
channel of the downstream side of the rotational airfoil, wherein
the seal base is generally an arcuate segment and wherein the seal
base extends a length at least substantially equal to a length
along an intersection between the rotational airfoil and an
adjacent stationary component; a plurality of seal strips generally
aligned with each other and overlapping each other, attached to the
seal base and extending from the seal base a length sufficient to
seal a gap between the platform of the rotational airfoil and the
adjacent stationary component; wherein the plurality of seal strips
are flexible such that the seal strips may be flexed during
operation of the gas turbine engine thereby sealing the gap between
the platform of the rotational airfoil and the adjacent stationary
component.
12. An airfoil seal system for airfoils of a gas turbine engine,
comprising: a rotational airfoil having at least one channel
proximate to a platform extending from an upstream side of the
airfoil; a seal base positioned within the channel of the
rotational airfoil, wherein the seal base is generally an arcuate
segment and wherein the seal base extends generally radially inward
a length at least substantially equal to a length along an
intersection between the rotational airfoil and an adjacent
stationary component, wherein the seal base is generally aligned
with a longitudinal axis of the rotational airfoil; a plurality of
seal strips generally aligned with each other and overlapping each
other, attached to the seal base and extending from the seal base a
length sufficient to seal a gap between the platform of the
rotational airfoil and the adjacent stationary component, wherein
the plurality of seal strips extend radially inward at an
intersection of the seal strips and the seal base and are curved
out of plane from the seal base such that ends of the plurality of
seal strips curve toward adjacent stationary components; wherein
the plurality of seal strips are flexible such that the seal strips
may be flexed during operation of the gas turbine engine thereby
sealing the gap between the platform of the rotational airfoil and
the adjacent stationary component; and wherein the seal base
extends a length at least substantially equal to a length along an
intersection between at least two rotational airfoils and adjacent
stationary components.
13. The airfoil seal system for airfoils of a gas turbine engine of
claim 12, wherein the plurality of seal strips are formed from
alloys.
14. (canceled)
15. The airfoil seal system for airfoils of a gas turbine engine of
claim 12, wherein the rotational airfoil comprises at least one
channel proximate to a platform extending from the airfoil on an
upstream side of the airfoil and at least one channel proximate to
a platform extending from the airfoil on a downstream side of the
airfoil; further comprising a seal base positioned within the
channel of the downstream side of the rotational airfoil, wherein
the seal base is generally an arcuate segment and wherein the seal
base extends a length at least substantially equal to a length
along an intersection between the rotational airfoil and an
adjacent stationary component; a plurality of seal strips generally
aligned with each other and overlapping each other, attached to the
seal base and extending from the seal base a length sufficient to
seal a gap between the platform of the rotational airfoil and the
adjacent stationary component; wherein the plurality of seal strips
are flexible such that the seal strips may be flexed during
operation of the gas turbine engine thereby sealing the gap between
the platform of the rotational airfoil and the adjacent stationary
component.
Description
FIELD OF THE INVENTION
[0002] This invention is directed generally to airfoils, and more
particularly to cooling systems in hollow airfoils usable in gas
turbine engines.
BACKGROUND
[0003] Typically, gas turbine engines include a compressor for
compressing air, a combustor for mixing the compressed air with
fuel and igniting the mixture, and a turbine blade assembly for
producing power. Combustors often operate at high temperatures that
may exceed 2,500 degrees Fahrenheit. Typical turbine combustor
configurations expose turbine blade assemblies to these high
temperatures. As a result, turbine blades must be made of materials
capable of withstanding such high temperatures. In addition,
turbine blades often contain cooling systems for prolonging the
life of the blades and reducing the likelihood of failure as a
result of excessive temperatures.
[0004] Typically, turbine blades are formed from a root portion
having a platform at one end and an elongated portion forming a
blade that extends outwardly from the platform coupled to the root
portion. The blade is ordinarily composed of a tip opposite the
root section, a leading edge, and a trailing edge. The inner
aspects of most turbine blades typically contain an intricate maze
of cooling channels forming a cooling system. The cooling channels
in a blade receive air from the compressor of the turbine engine
and pass the air through the blade. Some of the cooling fluids are
passed through the root and into the cavity between adjacent
turbine blades to cool the platforms of the blades. The cooling
fluids may be exhausted through gaps between adjacent blades and
may create film cooling. Various seals have been used to limit the
flow of cooling fluids between the gap and to limit the influx of
hot combustion gases through the gap.
[0005] Cooling air and hot gas leakages have a detrimental impact
on performance of a gas turbine engine, NOx emissions and
mechanical integrity of components. Air leakage detracts from
turbine performance because energy is expended to compress air
without incurring any benefit in turbine airfoil cooling and hence
in metal temperature reduction. Excessive air leakage from disc
cavities may disrupt the flow in the turbine airfoil channels,
increase losses and decrease stage efficiency. Also, the more air
is extracted from the compressor and dumped into the gas path
downstream of the combustor, the higher the primary zone
temperature in the combustor has to be for the required engine
firing temperature. This results in increased NOx production. Hot
gas ingestion into the turbine disc cavities leads to higher disc
and blade root temperatures and may result in reduced service lives
and failures. In addition, hot gas leakage through the blade root
serrations and under the stator assemblies reduces turbine
performance. Such losses are exacerbated in engines with increased
firing temperatures and pressure ratios. For the same seal
clearance, the increase in leakage is directly proportional to the
increase in the pressure upstream of the seal. The pressure ratio
increase is further driven by gas turbine applications.
[0006] Depending on the turbine disc cavity configuration,
clearances at the disc rim and flow conditions in the gas path, the
disc will pump a specific amount of air flow. If the supplied disc
cooling air flow is not able to satisfy this amount, there will be
hot gas ingestion from the gas path. As previously set forth, the
air and hot gas leakages have a detrimental effect on the turbine
performance and the mechanical integrity of the affect parts.
SUMMARY OF THE INVENTION
[0007] This invention relates to an airfoil seal system for a gas
turbine engine that is configured to seal gaps between adjacent
stationary airfoils, such as turbine or compressor vanes or other
stationary components, and rotational airfoils, such as turbine or
compressor blades. The airfoil seal system may be formed from a
seal base having a plurality of seal strips extending therefrom and
configured such that during operation of the gas turbine engine,
the seal strips bend and reduce the opening between the seal strips
and the adjacent stationary components to prevent loss of cooling
fluids into the hot gas path and to prevent ingestion of hot gases
into the cooling chambers radially inboard of the rotational
airfoil.
[0008] The airfoil seal system includes a seal base configured to
be received within a channel of a rotational airfoil proximate to a
platform extending from the airfoil. The seal base may generally be
an arcuate segment. The seal base may be configured to extend a
length at least substantially equal to a length along an
intersection between a rotational airfoil and an adjacent
stationary airfoil. In another embodiment, the seal base may be
configured to extend a length at least substantially equal to a
length along an intersection between two rotational airfoils and
adjacent stationary airfoils.
[0009] A plurality of seal strips may be generally aligned with
each other and may overlap each other. The plurality of seal strips
may be attached to the seal base and extend from the seal base a
length sufficient to seal a gap between the platform of the
rotational airfoil and the adjacent stationary component. The seal
strips may be flexible such that the seal strips may be flexed
during operation of the gas turbine engine thereby sealing the gap
between the platform of the rotational airfoil and the adjacent
stationary component. The seal strips may be formed from alloys or
other appropriate materials. The plurality of seal strips may be
curved out of plane from the seal base such that when the seal base
is attached to the channel of a rotational airfoil, ends of the
plurality of seal strips curve toward adjacent stationary
components. In one embodiment, the plurality of seal strips may be
curved out of plane from the seal base such that when the seal base
is attached to the channel of a rotational airfoil such that the
seal base is generally aligned with a longitudinal axis of the
rotational airfoil, ends of the plurality of seal strips curve
toward adjacent stationary components. In at least one embodiment,
the rotational airfoil may include an upstream channel and a
downstream channel, wherein both channels house a seal base.
[0010] An advantage of this invention is that when a turbine engine
is operating, centrifugal forces bend the strips radially outward
resulting in a closure of the radial clearance between the seal
strips and the stationary seal lip extending inward from the
upstream and downstream stationary components.
[0011] Another advantage of this invention is that the airfoil seal
system creates a tortuous flow path that reduces the influx of hot
gases from the hot gas path.
[0012] Yet another advantage of this invention is that the airfoil
seal system may be used with turbine airfoils and compressor
airfoils alike.
[0013] These and other embodiments are described in more detail
below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings, which are incorporated in and
form a part of the specification, illustrate embodiments of the
presently disclosed invention and, together with the description,
disclose the principles of the invention.
[0015] FIG. 1 is a partial side view of a turbine engine with an
airfoil seal system attached to upstream and downstream sides of
the airfoil. FIG. 2 is an axial view of the airfoil seal
system.
DETAILED DESCRIPTION OF THE INVENTION
[0016] As shown in FIGS. 1-2, this invention is directed to an
airfoil seal system 10 for a gas turbine engine 12 that is
configured to seal gaps 14 between adjacent stationary airfoils 16,
such as turbine or compressor vanes or other stationary components,
and rotational airfoils 18, such as turbine or compressor blades.
The airfoil seal system 10 may be formed from a seal base 20 having
a plurality of seal strips 22 extending therefrom and configured
such that during operation of the gas turbine engine 12, the seal
strips 22 bend and reduce the opening 24 between the seal strips 22
and the adjacent stationary components 16 to prevent loss of
cooling fluids into the hot gas path 26 and to prevent ingestion of
hot gases into the cooling chambers radially inboard of the
rotational airfoil 18.
[0017] The airfoil seal system 10 may be formed from a seal base 20
configured to be received within a channel 30 of a rotational
airfoil 18 proximate to a platform 32 extending from the airfoil
18. The airfoil 18 may include channels 30 on upstream and
downstream sides 34, 36 of the airfoil 18. The channels 30 may
include openings 38 on radially inward sides 40 of the channels 30.
The channel 30 and the seal base 20 may form an interference fit.
In other embodiments, the seal base 20 may be attached to the
channel 30 in other manners.
[0018] The seal base 20 may be a generally flat, planar structure,
as shown in FIG. 1, and may be formed generally from an arcuate
segment, as shown in FIG. 2, when viewed axially. The seal base 20
may extend a length at least substantially equal to a length along
an intersection between a rotational airfoil 18 and an adjacent
stationary airfoil 16. In other embodiments, the seal base 20 may
extend a length at least substantially equal to a length along an
intersection between two or more rotational airfoils 18 and
adjacent stationary airfoils 16. Thus, the seal base 20 may extend
proximate to a plurality of rotational airfoils 18.
[0019] A plurality of seal strips 22 may be generally aligned with
each other and may overlap each other, as shown in FIG. 2. The
plurality of seal strips 22 may be flexible such that the seal
strips 22 may be flexed during operation of the gas turbine engine
thereby sealing the gap 14 between the platform 32 of the
rotational airfoil 18 and the adjacent stationary component 16. The
seal strips 22 may be formed from alloys, such as high temperature
alloys, which may include, but not limited to, PM 2000, Inconnel
738, 901 and other appropriate alloys. The seal strips 22 may be
formed from thin alloys, with thicknesses between about 0.005 inch
and about 0.045 inch.
[0020] The seal strips 22 may be attached to the seal base 20 and
may extend from the seal base 20 a length sufficient to seal the
gap 14 between the platform 32 of the rotational airfoil 18 and the
adjacent stationary component 16. The seal strips 22 may extend
radially inward from the seal base 20 at the intersection of the
seal strips 22 and the seal base 20. Remaining portions of the seal
strips 22 may be curved away from the radially inward direction and
out of plane from the seal base 20, as shown in FIG. 2, such that
ends 42 of the seal strips 22 curve toward adjacent stationary
components 16. Thus, the plurality of seal strips 22 may be curved
out of plane from the seal base 20 such that when the seal base 20
is attached to the channel 30 of a rotational airfoil 18 and the
seal base 20 is generally aligned with a longitudinal axis 44 of
the rotational airfoil 18, ends 42 of the plurality of seal strips
22 curve toward adjacent stationary components 18. The seal strips
22 may be bent into a curved position such that when static, the
seal strips 22 do not contact adjacent stationary airfoils 16 and
do not extend linearly from the seal base 20 in a radially inward
direction.
[0021] During operation, the airfoil seal system 10 limits the flow
of gases through the gap 14 between the stationary component 16 and
the rotational airfoil 18. Before turbine engine operation, the
seal strips 22 extend from the seal base 20 attached to the
rotational airfoil 18 toward the adjacent stationary component 16.
During operation, however, the seal strips 22 flex radially
outwards, thereby placing the ends 42 of the seal strips 22 in
close proximity to the adjacent stationary component 16, as shown
in FIG. 2, reducing the gap 14. The seal strips 22 may overlap a
sufficient distance such that where the seal strips are flexed,
gaps do not form between adjacent seal strips 22.
[0022] The foregoing is provided for purposes of illustrating,
explaining, and describing embodiments of this invention.
Modifications and adaptations to these embodiments will be apparent
to those skilled in the art and may be made without departing from
the scope or spirit of this invention.
* * * * *