U.S. patent application number 11/691668 was filed with the patent office on 2009-03-12 for mounting system for impingement cooling manifold.
This patent application is currently assigned to General Electric Company. Invention is credited to Dean Erickson, Mitch Orza, Hua Zhang.
Application Number | 20090068007 11/691668 |
Document ID | / |
Family ID | 38904848 |
Filed Date | 2009-03-12 |
United States Patent
Application |
20090068007 |
Kind Code |
A1 |
Erickson; Dean ; et
al. |
March 12, 2009 |
Mounting System for Impingement Cooling Manifold
Abstract
A manifold mounting system for mounting an impingement cooling
manifold to a casing of a turbine including a mounting pin affixed
to a shroud pin of the turbine wherein the mounting pin extends
through the impingement cooling manifold wherein the mounting pin
comprises a securing device operable for securing the mounting pin
to the impingement cooling manifold, and a leveling support leg
affixed to the impingement cooling manifold wherein the mounting
pin, securing device, and leveling support leg are operable for
adjusting the gap distance between the impingement cooling manifold
and the casing of the turbine.
Inventors: |
Erickson; Dean;
(Simpsonville, SC) ; Zhang; Hua; (Greer, SC)
; Orza; Mitch; (Roswell, GA) |
Correspondence
Address: |
SUTHERLAND ASBILL & BRENNAN LLP
999 PEACHTREE STREET, N.E.
ATLANTA
GA
30309
US
|
Assignee: |
General Electric Company
Schenectady
NY
|
Family ID: |
38904848 |
Appl. No.: |
11/691668 |
Filed: |
March 27, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11548791 |
Oct 12, 2006 |
|
|
|
11691668 |
|
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Current U.S.
Class: |
415/213.1 |
Current CPC
Class: |
F01D 11/24 20130101;
Y02T 50/676 20130101; F01D 25/14 20130101; Y02T 50/60 20130101;
F05D 2260/201 20130101 |
Class at
Publication: |
415/213.1 |
International
Class: |
F01D 25/28 20060101
F01D025/28 |
Claims
1. A manifold mounting system for mounting an impingement cooling
manifold to a casing of a turbine comprising: a mounting pin
affixed to a shroud pin of the turbine wherein the mounting pin
extends through the impingement cooling manifold wherein the
mounting pin comprises a securing device operable for securing the
mounting pin to the impingement cooling manifold; and a leveling
support leg affixed to the impingement cooling manifold wherein the
mounting pin, securing device, and leveling support leg are
operable for adjusting the gap distance between the impingement
cooling manifold and the casing of the turbine.
2. The system of claim 1 wherein the securing device comprises a
setting nut to adjust the gap distance between the impingement
cooling manifold and the casing of the turbine.
3. The system of claim 1 wherein the leveling support leg comprises
a leveling screw and a leveling nut.
4. The system of claim 1 wherein the leveling support leg is
affixed to a flange of the impingement cooling manifold.
5. The system of claim 1 comprising a plurality of mounting pins
and a plurality of leveling support legs.
6. A mounting system for an impingement cooling manifold cooling
system for heavy duty turbines comprising: an impingement cooling
manifold affixed to a casing of the turbine, wherein the
impingement cooling manifold comprises a plurality of impingement
holes in the surface of the impingement cooling manifold; a blower
that provides air flow across the plurality of impingement holes of
the impingement cooling manifold to cool the casing of the
heavy-duty turbine to control the clearance between a tip of a
turbine blade and a shroud of the heavy-duty turbine; a mounting
pin affixed to a shroud pin of the turbine wherein the mounting pin
extends through the impingement cooling manifold wherein the
mounting pin comprises a securing device operable for securing the
mounting pin to the impingement cooling manifold; and a leveling
support leg affixed to the impingement cooling manifold wherein the
mounting pin, securing device, and leveling support leg are
operable for adjusting the gap distance between the impingement
cooling manifold and the casing of the turbine.
7. A method for mounting an impingement cooling manifold system to
a casing of a turbine comprising: affixing a mounting pin to an
existing shroud pin of the turbine wherein the mounting pin extends
through the impingement cooling manifold; securing the impingement
cooling manifold to the mounting pin wherein the mounting pin
comprises a securing device operable to adjust a gap distance
between the impingement cooling manifold and the casing of the
turbine; and affixing a leveling support leg to the impingement
cooling manifold operable to adjust the gap distance between the
impingement cooling manifold and the casing of the turbine.
8. The method of claim 7 further comprising: adjusting the gap
distance between the impingement cooling manifold and the casing of
the turbine using the mounting pin, securing device of the mounting
pin, and/or the leveling support legs.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation-in-part of U.S. application Ser. No.
11/548,791, filed Oct. 12, 2006, entitled "Turbine Case Impingement
Cooling for Heavy Duty Gas Turbines" now pending. That application
is incorporated herein by reference.
TECHNICAL FIELD
[0002] This application relates generally to the field of
impingement cooling manifolds for heavy-duty turbines and more
particularly to mounting systems for impingement cooling manifolds
for heavy-duty turbines.
BACKGROUND OF THE INVENTION
[0003] Air impingement cooling has been used to manage the casing
temperature of small gas turbines and to reduce and maintain the
clearances between rotating blades and accompanying interior casing
surfaces. One problem for air impingement cooling systems on
heavy-duty gas turbines is the ability to achieve a uniform heat
transfer coefficient across large non-uniform non-standard casing
surfaces. On small gas turbines, small impingement holes and short
nozzle to surface distances are normally applied. These factors
produce the required higher heat transfer coefficients on the
casing. One detrimental impact of applying small of impingement
cooling holes is the need for operating with high differential
pressure drop across the holes. This results in the requirement for
undesirable high cooling air supply pressures which negatively
impacts net efficiency.
[0004] Impingement cooling has been applied to aircraft engines as
a method of turbine clearance control. However, the impingement
systems used on aircraft engines cannot be used in heavy-duty
turbine applications. The systems applied to aircraft engines
utilize air extracted from the compressor as the cooling medium. It
is not feasible to use compressor extraction air on heavy-duty gas
turbines because the design heat transfer coefficients require
cooler air temperatures. Heavy-duty gas turbines have a
significantly larger, non-uniform casing surface that requires an
intricate manifold design as compared to aircraft engines. Also,
the casing thickness and casing thickness variations are
considerably greater on heavy-duty gas turbines.
[0005] Accordingly, there is a need in the art for a mounting
system for impingement cooling manifolds on heavy-duty gas
turbines.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a cross-sectional view of a heavy duty gas turbine
according to the embodiment of the invention.
[0007] FIG. 2 is a close-up view of the turbine blade to shroud
clearance according to the embodiment of the invention.
[0008] FIG. 3 is an impingement cooling system according to the
embodiment of the invention.
[0009] FIG. 4 is a perspective view of a impingement cooling
manifold attached to a casing of a turbine according to the
embodiment of the invention.
[0010] FIG. 5 is a cross-sectional view of a impingement cooling
manifold attached to a casing of a turbine according to the
embodiment of the invention.
[0011] FIG. 6 is a perspective view of a plurality of shroud pins
and mounting pins according to the embodiment of the invention.
[0012] FIG. 7 is a side view of a mounting pin attached to a shroud
pin according to the embodiment of the invention.
[0013] FIG. 8 is a perspective view of a leveling support leg
according to the embodiment of the invention.
[0014] FIG. 9 is a perspective view of a mounting system attached
to an impingement cooling manifold according to the embodiment of
the invention.
[0015] FIG. 10 is a perspective view of an impingement cooling
manifold attached to a casing of a turbine using a mounting system
according to the embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The present invention now will be described more fully
hereinafter with reference to the accompanying drawings, in which
exemplary embodiments of the invention are shown. This invention
may, however, be embodied in many different forms and should not be
construed as being limited to the embodiments set forth herein;
rather, these embodiments are provided so that this disclosure will
be thorough and complete, and will convey the scope of the
invention to those skilled in the art.
[0017] FIG. 1 illustrates an exemplary embodiment of a heavy-duty
turbine 110. The heavy-duty turbine engine includes a compressor
section 112, combustor section 114, and a turbine section 116. The
turbine 110 also includes a compressor casing 118 and a turbine
casing 120. The turbine and compressor casings enclose major parts
of the heavy-duty turbine. The turbine section 116 includes a shaft
and a plurality of sets of rotating and stationary turbine
blades.
[0018] Referring to FIGS. 1 and 2, the turbine casing 120 may
include a shroud 126 affixed to the interior surface of the casing
120. The shroud 126 may be positioned proximate to blade tips 123
of the rotating turbine blades 122 to minimize air leakage past the
blade tip 123. The distance between the blade tip 123 and the
shroud 126 is referred to as the clearance 128. It is noted that
the clearances 128 of each turbine stage are not consistent due to
the different thermal growth characteristics of the blades and
casing.
[0019] A key contributor in the efficiency of heavy-duty gas
turbines is the amount of air/exhaust gas leakage through the blade
tip to casing clearance 128. Due to the different thermal growth
characteristics of the turbine blades 122 and turbine casing 120,
clearances 128 significantly change as the turbine transitions
through transients from ignition to a base-load steady state
condition. A clearance control system, including its operating
sequence may be implemented to address the specific clearance
characteristics during all operating conditions. Incorrect design
and/or sequencing of the control system may lead to excessive
rubbing of the turbine blade 123 tips with the casing shrouds 126,
which can result in increased clearances and reduced
performance.
[0020] As illustrated in the exemplary embodiment of FIG. 3, an
impingement air-cooling system 200 may be used to reduce and
maintain the clearances between the turbine shroud 126 and the
accompanying blade tip 123. Referring to FIG. 3, the impingement
air-cooling system 200 may include a blower 130, a flow control
damper 132, interconnect piping 134, a distribution header 136,
flow metering valves or orifices 138 and into a series impingement
cooling manifolds 140. The impingement cooling manifold 140 is
affixed to the turbine casing 120. In the exemplary embodiment of
FIG. 3, a plurality of impingement manifolds 140 are affixed about
the circumference of the turbine casing 120. The impingement
cooling blower 130 takes suction from ambient air and blows the air
through the flow control damper 132, interconnect piping 134,
distribution header 136, flow metering valves or orifices 138 and
into the impingement cooling manifolds 140. The blower 130 may be
any blowing device including a fan or a jet. The impingement
cooling manifold 140 insures a uniform heat transfer coefficient is
delivered to the turbine casing 120. It should be appreciated that
the impingement air-cooling system is not limited to the components
disclosed herein but may include any components that enables air to
pass along the impingement cooling manifolds.
[0021] Referring to the exemplary embodiment illustrated in FIGS. 5
and 9, the impingement cooling manifolds 140 may be designed to the
contours of the target area of the turbine casing 120. Each
impingement cooling manifold 140 may include an upper plate 142
with feed pipe 144, a lower plate 146 with multiple impingement
holes 148, side pieces, leveling support legs 170 and mounting pins
150. The impingement holes 148 permit the air to flow from the
impingement cooling manifold to the turbine casing to selectively
cool the turbine casing.
[0022] The impingement holes 148 may be positioned in an array. In
an exemplary embodiment, the impingement holes 148 may be spaced in
the range from 1.25 to 2.5 inches. In an exemplary embodiment, the
individual impingement holes 148 may be sized between 0.12 and 0.2
inches. The varying hole sizes and spacing are required to
compensate for the non-uniformity of the turbine casing geometry.
The size and positioning of the impingement holes 148 on the lower
plate 146 produce a uniform heat transfer coefficient across the
casing targeted by the impingement air-cooling system. However, the
impingement holes are not limited to these sizes or spacings. The
distance between the upper 142 and lower plates 146 also may be
dimensioned to minimize internal pressure variations, which results
in uniform cooling hole pressure ratios.
[0023] The gap distance 147 between impingement cooling manifold
lower plates 146 and the turbine casing 120 effects the heat
transfer coefficient. Too large of a gap distance 147 can result in
a non-optimum heat transfer coefficient. Too little of a gap
distance 147 can result in both non-optimum and a non-uniform heat
transfer coefficient. In an exemplary embodiment, a gap of between
0.5 and 1.0 inch provides a suitable heat transfer coefficient.
However, the gap distance 147 in not limited to this range and may
be any distance that provides a suitable heat transfer
coefficient.
[0024] An exemplary embodiment may include a plurality of
impingement cooling manifolds 140. The plurality of impingement
cooling manifolds 140 may be affixed to the casing 120 of the
turbine directly above target cooling area. The impingement cooling
manifolds 140 may be positioned such that there is ample spacing
between their edges and any protrusions off of the casing. The
spacing provides a free path for the air passing through the
impingement holes 148 to exhaust from under the impingement cooling
manifold 140 to the environment. In an exemplary embodiment, the
spacing between two adjacent impingement cooling manifolds may be
between 1 to 30 inches and is dependent on casing protrusions and
flanged joints. The spacing are not limited to these dimensions and
may be at any suitable distance. The impingement cooling manifolds
140 also may provide impingement cooling to any of the axial
flanges, including a horizontal split joint.
Mounting the Manifolds
[0025] The manifold 140 may be mounted to the casing 120 of the
turbine without machining the casing 120. The manifold 140 should
maintain a substantially uniform distance from the casing 120
across the entire surface of the manifold 140 for the most
efficient and productive air flow across the casing 120. However,
turbine casings 120 from unit to unit have wide variations in
geometries. FIGS. 5-10 illustrate exemplary embodiments of the
mounting system to account for the variation in turbine geometries
without machining the turbine.
[0026] FIG. 5 is an exemplary embodiment of the mounting system
including at least one mounting pin and at least one leveling
support leg. The at least one mounting pin 150 may be used to mount
the manifold 140 to the casing 120 and modify the gap distance 147.
The mounting pin 150 may be affixed to a shroud pin 155 located on
the casing 120. As illustrated in the exemplary embodiment of FIG.
6, the shroud pin 155 extends from the casing 120 of the turbine
outward. The mounting pin 150 provides extra length to the shroud
pin 155 to permit the manifold 140 to be mounted thereon. A
securing device 160 may affix the mounting pin 150 to the manifold
140. In an exemplary embodiment, the securing device includes a
setting nut 165 affixed towards the distal end of the mounting pin
150. FIG. 7 illustrates an exemplary embodiment of a mounting pin
150 affixed to a shroud pin 155. It should be appreciated that
affixation of the mounting pin to the shroud pin may include the
mounting pin being an extension of or incorporated into the shroud
pin.
[0027] As shown in the exemplary embodiment of FIG. 5, the mounting
pin 150 extends through a hole on the manifold 140 such that the
manifold 140 may rest upon the setting nut 165. The setting nut 165
may be tightened or loosened to adjust the gap distance 147 between
the manifold 140 and the casing 120 proximate to the mounting pin.
A securing nut 167 may be affixed to the proximate end of the
mounting pin 150 to secure the manifold 140 to the setting nut 165
of the mounting pin 150. One of ordinary skill in the art will
appreciate that the securing device is not limited to the use of
setting nuts and may include any means of adjusting the distance
between the manifold 140 and the casing 120 including but not
limited to setting pins, clips, or any other device.
[0028] The mounting system also may include at least one leveling
support leg 170 to adjust the manifold 140 to create a
substantially uniform gap distance 147 between the casing 120 and
the manifold 140. The leveling support leg 170 may be affixed to
the manifold 140 and positioned against the casing 120. The
leveling support leg 170 may be positioned at any location on the
manifold 140. In an exemplary embodiment, the at least one leveling
support leg 170 may be positioned near the perimeter of the
manifold 140. As shown in the exemplary embodiment of FIG. 8, the
leveling support leg 170 may include a leveling screw 172 and
leveling nut 174 that may affix the leveling support leg 170 to a
support flange 176 that may be attached to the manifold lower plate
146. The leveling screw 172 may be used to adjust the distance
between the manifold 140 and the casing 120 at the location of the
leveling support leg. One of ordinary skill in the art will
appreciate that the leveling support legs 170 are not limited to
the use of leveling screws 172 and leveling nuts 174 but may
implement any device that will assist in the adjusting of the gap
distance 147 between the manifold 140 and the casing 120 proximate
to the leveling support leg.
[0029] FIG. 9 illustrates an exemplary embodiment of the mounting
system attached to the manifold 140 prior to being affixed to the
casing 120. It should be appreciated that the mounting system does
not have to be attached to the manifold prior to affixation to the
casing. For example, the mounting pins 150 may be affixed to the
shroud pins 155 prior to attachment to the manifold 140.
[0030] FIG. 5 illustrates an exemplary embodiment of the mounting
pins 150 and the leveling support legs 170 of the mounting system
affixed to the casing 120 of the turbine. As shown in FIG. 5, the
casing 120 may not be uniform. Therefore, the gap distance 147 may
not be uniform across the surface of the manifold 140. To adjust
the gap distance 147, the mounting pin 150 and leveling support leg
170 may be independently adjusted to set the gap distance 147
between the manifold 140 and casing 120 proximate to each
respective mounting pin 150 or leveling support leg 170. In the
exemplary embodiment of FIG. 5 for example, the mounting pin
adjusts a middle portion of the manifold 140 and the plurality of
leveling support legs 170 adjusts a perimeter of the manifold
140.
[0031] A plurality of mounting pins 150 and a plurality of leveling
support legs 170 may be included to mount a manifold 140 and set
the gap distance 147. In the exemplary embodiment of FIG. 10 for
example, the mounting system includes two mounting pins 150
positioned in middle portions of the manifold 140 and four leveling
support legs 170 positioned at the perimeter of the manifold 140.
It should be appreciated that the mounting system may include any
number of mounting pins 150 and leveling support legs 170 and is
not limited to the embodiment illustrated in FIG. 10.
[0032] Many modifications and other embodiments of the invention
will come to mind to one skilled in the art to which this invention
pertains having the benefit of the teachings presented in the
foregoing descriptions and the associated drawings. Therefore, it
is to be understood that the invention is not to be limited to the
specific embodiments disclosed and that modifications and other
embodiments are intended to be included within the scope of the
appended claims. Although specific terms are employed herein, they
are used in generic and descriptive sense only and not for purposes
of limitation.
* * * * *