U.S. patent application number 13/246000 was filed with the patent office on 2012-01-19 for turbine blade having material block and related method.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Alan Richard DeMania, Alan Donn Maddaus, Steven Russell Pock.
Application Number | 20120014803 13/246000 |
Document ID | / |
Family ID | 41666666 |
Filed Date | 2012-01-19 |
United States Patent
Application |
20120014803 |
Kind Code |
A1 |
DeMania; Alan Richard ; et
al. |
January 19, 2012 |
TURBINE BLADE HAVING MATERIAL BLOCK AND RELATED METHOD
Abstract
A turbine blade including a root section at an end of the
turbine blade, a first airfoil section adjacent to the root
section, and a tip section adjacent to the airfoil section and
including a material block that is incongruous with the airfoil
section. A midspan section may also include a material block. Each
material block can be selectively machined to customize the length
of the turbine blade and the position of a tip shroud connection or
midspan connection. The turbine blade can be sized for retrofitting
last stage blades of older turbines. A radial position of the root
mounts for the turbine blade may also be adjusted to provide
further customization.
Inventors: |
DeMania; Alan Richard;
(Niskayuna, NY) ; Maddaus; Alan Donn; (Rexford,
NY) ; Pock; Steven Russell; (Windham, ME) |
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
41666666 |
Appl. No.: |
13/246000 |
Filed: |
September 27, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12366688 |
Feb 6, 2009 |
8056227 |
|
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13246000 |
|
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Current U.S.
Class: |
416/235 |
Current CPC
Class: |
F05D 2230/80 20130101;
Y10T 29/49321 20150115; F05B 2240/33 20130101; B23P 6/005 20130101;
F05D 2230/10 20130101; F01D 5/141 20130101; F05D 2220/31 20130101;
Y10T 29/49336 20150115; Y10T 29/49325 20150115 |
Class at
Publication: |
416/235 |
International
Class: |
F01D 5/14 20060101
F01D005/14 |
Claims
1. A turbine blade form comprising: a root section at an end of the
turbine blade form; a first airfoil section adjacent to the root
section; a midspan section adjacent to the first airfoil section
and including a first material block; a second airfoil section
adjacent to the midspan section; and a tip section adjacent to the
second airfoil section and including a second material block,
wherein the first and second material block are incongruous with
any adjacent airfoil section, and wherein the first and second
material block constitute approximately 15 to 25 percent of a
length of the turbine blade form.
2. The turbine blade form of claim 1, wherein the first material
block is machinable to include a third airfoil section that is
congruous with the first and second airfoil sections.
3. The turbine blade form of claim 2, wherein the first material
block is machinable to include a midspan connection for mating
connection with an adjacent turbine blade at a selected position
along the length of the first material block.
4. The turbine blade form of claim 1, wherein the second material
block is machinable to include a third airfoil section that is
congruous with the second airfoil section.
5. The turbine blade form of claim 4, wherein the second material
block is machinable to include a tip shroud connection for mating
connection with an adjacent turbine blade at a selected position
along the length of the second material block.
6. The turbine blade form of claim 1, wherein the second material
block is machinable to selectively define a length of the turbine
blade form.
7. The turbine blade form of claim 1, wherein the root section
includes a connection for mating with a root mount coupled to a
rotating shaft of a multiple stage turbine.
8. The turbine blade form of claim 7, wherein the root mount has a
radial position relative to the rotating shaft that is one of less
than, greater than, and equal to an adjacent root mount for an
adjacent stage of the multiple stage turbine.
9. The turbine blade form of claim 1, wherein the first and second
material blocks each have a substantially polyhedron shape except
where at least one of the first and second airfoil sections connect
to a respective material block.
10. The turbine blade form of claim 1, wherein the turbine blade
form is a freestanding blade.
11. A turbine blade form comprising: a root section at an end of
the turbine blade form; a first airfoil section adjacent to the
root section; and a tip section adjacent to the first airfoil
section and including a first material block, wherein the first
material block is incongruous with the first airfoil section, and
wherein the first material block is substantially polyhedron in
shape.
12. The turbine blade form of claim 11, further comprising: a
midspan section intersecting the first airfoil section into two
adjacent airfoil sections, the midspan section including a second
material block, wherein the second material block is incongruous
with the two adjacent airfoil sections.
13. The turbine blade form of claim 12, wherein the second material
block is machinable to include another airfoil section that is
congruous with the two adjacent airfoil sections and a midspan
connection for mating connection with an adjacent turbine blade at
a selected position along the length of the first material
block.
14. The turbine blade form of claim 11, wherein the first material
block is machinable to include another airfoil section that is
congruous with the first airfoil section, and a tip shroud
connection for mating connection with an adjacent turbine blade at
a selected position along the length of the first material
block.
15. The turbine blade form of claim 11, wherein the first material
block is machinable to selectively define a length of the turbine
blade.
16. The turbine blade form of claim 12, wherein the first and
second material block constitute approximately 15 to 25 percent of
a length of the turbine blade form.
17. A turbine blade form capable of being machined into a final
operative turbine blade comprising: a root section at an end of the
turbine blade form; a first airfoil section adjacent to the root
section; a midspan section adjacent to the first airfoil section
and including a first material block; a second airfoil section
adjacent to the midspan section; and a tip section adjacent to the
second airfoil section and including a second material block,
wherein the first and second material block are incongruous with
any adjacent airfoil section, wherein the first and second material
block are substantially polyhedron in shape, and wherein the first
and second material block constitute approximately 15 to 25 percent
of a length of the turbine blade form.
18. The turbine blade form of claim 17, wherein the root section
includes a connection for mating with a root mount coupled to a
rotating shaft of a multiple stage turbine.
19. The turbine blade form of claim 18, wherein the root mount has
a radial position relative to the rotating shaft that is less than
an adjacent root mount for an adjacent stage of the multiple stage
turbine.
20. The turbine blade form of claim 17, wherein the midspan section
intersects the first airfoil section into two adjacent airfoil
sections, and wherein the first material block is incongruous with
the two adjacent airfoil sections.
Description
REFERENCE TO PRIOR APPLICATION
[0001] This application claims the benefit of co-pending U.S.
application Ser. No. 12/366,688 filed on Feb. 6, 2009 and is
incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates generally to turbine blade technology.
More particularly, the invention relates to a turbine blade having
material block(s) to allow for customization for retrofitting last
stage blades of older turbines and a related method.
[0003] In the turbine industry, turbines may be periodically
upgraded. One technique that is used to upgrade a turbine is to
replace old turbine blades with more efficient design.
BRIEF DESCRIPTION OF THE INVENTION
[0004] A first aspect of the disclosure provides a turbine blade
comprising: a root section at an end of the turbine blade; a first
airfoil section adjacent to the root section; a midspan section
adjacent to the first airfoil section and including a first
material block; a second airfoil section adjacent to the midspan
section; and a tip section adjacent to the second airfoil section
and including a second material block, wherein the first and second
material block are incongruous with any adjacent airfoil
section.
[0005] A second aspect of the disclosure provides a method
comprising: obtaining a turbine blade including: a root section at
an end of the turbine blade, a first airfoil section adjacent to
the root section, a midspan section adjacent to the first airfoil
section and including a first material block, a second airfoil
section adjacent to the midspan section, and a tip section adjacent
to the second airfoil section and including a second material
block, the first and second material block being incongruous with
any adjacent airfoil section; and selectively machining the second
material block to include a tip shroud at a selected length for the
turbine blade.
[0006] A third aspect of the invention is directed to a turbine
blade comprising: a root section at an end of the turbine blade; a
first airfoil section adjacent to the root section; and a tip
section adjacent to the first airfoil section and including a first
material block, wherein the first material block is incongruous
with the first airfoil section.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 shows a perspective partial cut-away illustration of
a steam turbine.
[0008] FIGS. 2A-2C show perspective views of embodiments of a
turbine blade according to the invention.
[0009] FIG. 3 shows a perspective view of one embodiment of the
turbine blade of FIG. 2A after machining.
[0010] FIGS. 4-5 show cross-sectional views of a multiple stage
turbine illustrating embodiments of a method of using the turbine
blade of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
[0011] Referring to the drawings, FIG. 1 shows a perspective
partial cut-away illustration of a multiple stage, steam turbine
10. Turbine 10 includes a rotor 12 that includes a rotating shaft
14 and a plurality of axially spaced rotor wheels 18. A plurality
of rotating blades 20 are mechanically coupled to each rotor wheel
18. More specifically, blades 20 are arranged in rows that extend
circumferentially around each rotor wheel 18. A plurality of
stationary vanes 22 extends circumferentially around shaft 14, and
the vanes are axially positioned between adjacent rows of blades
20. Stationary vanes 22 cooperate with blades 20 to form a stage
and to define a portion of a steam flow path through turbine
10.
[0012] In operation, steam 24 enters an inlet 26 of turbine 10 and
is channeled through stationary vanes 22. Vanes 22 direct steam 24
downstream against blades 20. Steam 24 passes through the remaining
stages imparting a force on blades 20 causing shaft 14 to rotate.
At least one end of turbine 10 may extend axially away from
rotating shaft 12 and may be attached to a load or machinery (not
shown) such as, but not limited to, a generator, and/or another
turbine.
[0013] In one embodiment, turbine 10 may include five stages. The
five stages are referred to as L0, L1, L2, L3 and L4. Stage L4 is
the first stage and is the smallest (in a radial direction) of the
five stages. Stage L3 is the second stage and is the next stage in
an axial direction. Stage L2 is the third stage and is shown in the
middle of the five stages. Stage L1 is the fourth and next-to-last
stage. Stage L0 is the last stage and is the largest (in a radial
direction). It is to be understood that five stages are shown as
one example only, and each turbine may have more or less than five
stages. Also, as will be described herein, the teachings of the
invention do not require a multiple stage turbine.
[0014] FIGS. 2A-B show perspective views of a turbine blade 100
according to embodiments of the invention. As will be described,
turbine blade 100 is not an operative blade, but an intermediate
product capable of being machined into a final, operative turbine
blade 150 (FIG. 3) for customized replacement or retrofitting of
last stage turbine blades in multiple stage turbine 10. The
location of a tip shroud connection (and hence length of turbine
blade 100) and/or a midspan connection can be adjusted to
accommodate different applications. Turbine blade 100 is, in one
embodiment, formed by forging of an appropriate metal alloy for the
applications to which the turbine blade will be exposed. Some
post-forging machining or other material processing may be provided
in addition to the machining described herein.
[0015] Turbine blade 100 may include a root section 102 at a first
end 104 of the turbine blade. Root section 102 may include a block
of material for forming into complementary mating connection 106
for a root mount 108, or may include the complementary mating
surface 106 as forged. As understood, and as shown in FIG. 5, root
section 102 is connected to a root mount 108, which may be coupled
to, for example, rotating shaft 14, or rotor wheel 18 coupled to
rotating shaft 14, of multiple stage turbine 10 (FIG. 1). Root
section 102 may have a shape or configuration of either the
"inverted pine tree" shown in FIGS. 2A and 2B, or the "radial
finger type" shown in FIGS. 4 and 5. In either case, root section
102 and root mount 108 may include complementary mating surfaces
106 for attaining a firm connection. Root mount 108 is fixedly
positioned at a particular radial position relative to rotating
shaft 14, thus creating a root diameter annulus for turbine blades
within a particular stage.
[0016] Turbine blade 100 may also include a first airfoil section
110 adjacent to root section 102. First airfoil section 110 may
have any airfoil shape now known or later developed for imparting a
force to turbine blade 100 from steam 24 (FIG. 1), thus turning
rotating shaft 14.
[0017] In one embodiment, as shown in FIG. 2A, a midspan section
120 may be adjacent to first airfoil section 110 and includes a
first material block 122. The term "midspan" should not be
interpreted to require any exactness of position along the length
of turbine blade 100, only general positioning somewhat away from
ends 104, 134 of turbine blade 100. A second airfoil section 126
may be adjacent to midspan section 120. Second airfoil section 126
may have any airfoil shape now known or later developed for
imparting a force to turbine blade 100 from steam 24 (FIG. 1), thus
turning rotating shaft 14 (FIG. 1). In one embodiment, second
airfoil section 126 has an airfoil shape that can be made congruous
with first airfoil section 110 by machining of first material block
122, as will be described in greater detail herein.
[0018] Turbine blade 100 also may include a tip section 130
adjacent to second airfoil section 126 and including a second
material block 132. Tip section 130 constitutes a second end 134 of
turbine blade 100. Although a remainder of the disclosure describes
embodiments of the invention in terms of the FIG. 2A embodiment, in
alternative embodiments shown in FIGS. 2B-2C, midspan section 120
(FIG. 2A) may be omitted or tip section 130 (FIG. 2A) may be
omitted, respectively. In terms of the FIG. 2B embodiment, second
airfoil section 126 (FIG. 2A) is made as one congruous airfoil
section 140 with first airfoil section 110 (FIG. 2A). Also, in this
embodiment, either no midspan connection 154 (FIG. 3) is provided
or its position is not adjustable.
[0019] With further reference to first and second material blocks
122, 132, in one embodiment, the blocks are incongruous with any
adjacent airfoil section. That is, the surface of any adjacent
airfoil section 110, 126 does not continue along a typical path
that would allow for proper functioning of turbine blade 100 where
it meets a material block. In one embodiment, both blocks 122, 132
have a substantially polyhedron shape except where first and second
airfoil sections 110, 126 connect to a respective material block.
However, material blocks 122, 132 may have any shape that supplies
a sufficient amount of material for machining of material blocks
122, 132 to form a final turbine blade 150, an example of which is
shown in FIG. 3. That is, as shown in FIG. 3, first material block
122 may be machined, e.g., via grinding, to include a third airfoil
section 152 that is congruous with first and second airfoil
sections 110, 126 to form an operative airfoil. In addition, in one
embodiment, first material block 122 may also be machined to
include a midspan connection 152 for mating connection (e.g.,
male/female mating parts) with an adjacent turbine blade (FIG. 1)
at a selected position along the length L1 of first material block
122.
[0020] As also shown in FIG. 3, second material block 132 may be
machined, e.g., via grinding, to include a fourth airfoil section
160 that is congruous with second airfoil section 126 to form an
operative airfoil. Furthermore, second material block 132 may be
machined to selectively define a length L3 of final turbine blade
150. In an alternative embodiment, second material block 132 may be
machined to include a tip shroud connection 162 (i.e., an integral
cover) for mating connection with an adjacent turbine blade (FIG.
1) at a selected position along the length L2 of second material
block 132. In a second alternative embodiment, not shown, material
block 120 may be machined to include a midspan connection 154, but
in the absence of tip section 130 without any tip shroud connection
162.
[0021] In a third alternative embodiment, material block 122, 132
may be machined to be devoid of any midspan connection 154 or tip
shroud connection 162 such that turbine blade 150 is a freestanding
blade (see FIG. 1).
[0022] In one embodiment, first and second material block 122, 132
constitute approximately 15 to 25 percent of a length of turbine
blade 100, each. However, other dimensions may also be
employed.
[0023] Referring to FIGS. 4-5, based on the above-described
machining, turbine blade 100 is customizable for retrofit into a
variety of different turbines 10 (FIG. 1). The teachings of the
embodiments of the invention are particularly applicable to the
last stage of the turbine where an increased exit flow area may be
accomplished by increasing the airfoil length relative to the
original, thereby reducing the loss associated with flow that
leaves the turbine. In one embodiment, turbine blade 100 is
obtained and at least second material block 132 selectively
machined to a selected length L3 for turbine blade 150, and perhaps
to include a tip shroud connection 160. In this fashion, as shown
in FIG. 4, an old last stage turbine blade 180 having a length L4
may be removed from a root mount 182 of rotating shaft 14 (or rotor
wheel 18) of a turbine. As shown in FIG. 5, a radial position of a
(new) root mount 108 may be adjusted, inwardly or outwardly. Root
mount 108 may be adjusted radially by, for example, creating a new
rotor wheel 18 to provide the selected root diameter. Rotor wheel
18 can be machined, for example: into the existing rotation shaft
14, as an entire new rotor wheel forging if the low pressure
rotating shaft is to be replaced, or as a separate wheel and stub
shaft which will then be fine lined welded to the existing rotating
shaft 14 after machining off the original last stage rotor wheel
18. In the example shown, a radial position of root mount 108
relative to rotating shaft 14 has been adjusted to be less than an
adjacent root mount 170 for an adjacent stage of the multiple stage
turbine 10 (FIG. 1). Where circumferential space limitations
require, the adjusting of the radial position of root mount 108 may
include removing at least one other root mount (not shown) within a
stage to which the root mount 108 belongs. Similarly, root mount
108 may have a radial position greater than an adjacent root mount
170, similar to that shown in FIG. 4, and radial mounts 108 added
if circumferential space allows. In any event, the selected length
L3 is chosen to be compatible with the adjusted radial position of
root mount 108, and any turbine casing or other structural
requirements. The last stage turbine blade 180 (FIG. 4) may then be
replaced with turbine blade 150 (FIG. 5).
[0024] It is also understood that conventional analysis techniques
may be carried out to ensure proper functioning of turbine blade
150. For example, analysis may be completed to ensure that: exhaust
loss reduction objectives are met, new tip shroud connection 162
and midspan connection 154 relative to change in pitch or spacing
at these locations are properly accommodated, the new connections
154, 162 meet life requirements, vibration frequencies of the new
blade and wheel construction are appropriate, and/or the flow path
from the original preceding stage (L-1) blade exit to the last
stage bucket entrance and corresponding nozzle diaphragm are
suitable for the retrofit application. An overall aeromechanical
and aerodynamic/performance analysis of turbine blade 150 (and/or
stage L0 and/or turbine 10) may also be performed, as
necessary.
[0025] The terms "first," "second," and the like, herein do not
denote any order, quantity, or importance, but rather are used to
distinguish one element from another, and the terms "a" and "an"
herein do not denote a limitation of quantity, but rather denote
the presence of at least one of the referenced item. The modifier
"about" used in connection with a quantity is inclusive of the
stated value and has the meaning dictated by the context, (e.g.,
includes the degree of error associated with measurement of the
particular quantity). The suffix "(s)" as used herein is intended
to include both the singular and the plural of the term that it
modifies, thereby including one or more of that term (e.g., the
metal(s) includes one or more metals). Ranges disclosed herein are
inclusive and independently combinable (e.g., ranges of "up to
about 25 wt %, or, more specifically, about 5 wt % to about 20 wt
%", is inclusive of the endpoints and all intermediate values of
the ranges of "about 5 wt % to about 25 wt %," etc).
[0026] While various embodiments are described herein, it will be
appreciated from the specification that various combinations of
elements, variations or improvements therein may be made by those
skilled in the art, and are within the scope of the invention. In
addition, many modifications may be made to adapt a particular
situation or material to the teachings of the invention without
departing from essential scope thereof. Therefore, it is intended
that the invention not be limited to the particular embodiment
disclosed as the best mode contemplated for carrying out this
invention, but that the invention will include all embodiments
falling within the scope of the appended claims.
* * * * *