U.S. patent application number 12/706198 was filed with the patent office on 2011-08-18 for steam turbine nozzle segment having arcuate interface.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Steven Sebastian Burdgick, Jason Paul Mortzheim, Dominick Joseph Werther.
Application Number | 20110200430 12/706198 |
Document ID | / |
Family ID | 43639928 |
Filed Date | 2011-08-18 |
United States Patent
Application |
20110200430 |
Kind Code |
A1 |
Burdgick; Steven Sebastian ;
et al. |
August 18, 2011 |
STEAM TURBINE NOZZLE SEGMENT HAVING ARCUATE INTERFACE
Abstract
Steam turbine nozzle segments with conical interfaces are
disclosed. In one embodiment a steam turbine static nozzle blade
includes: an airfoil; an inner sidewall integral with a first side
of the airfoil; and an outer sidewall integral with a second side
of the airfoil; the inner sidewall and the outer sidewall each
including: a pressure side having an arcuate concave surface
extending substantially an entire length of the sidewall; and a
suction side having an arcuate convex surface extending
substantially the entire length of the sidewall.
Inventors: |
Burdgick; Steven Sebastian;
(Schenectady, NY) ; Mortzheim; Jason Paul;
(Gloversville, NY) ; Werther; Dominick Joseph;
(Albany, NY) |
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
43639928 |
Appl. No.: |
12/706198 |
Filed: |
February 16, 2010 |
Current U.S.
Class: |
415/209.3 ;
415/208.1 |
Current CPC
Class: |
F05D 2230/232 20130101;
F01D 9/044 20130101; F05D 2250/712 20130101; F05D 2250/711
20130101; F05D 2250/232 20130101; F05D 2220/31 20130101; F05D
2230/237 20130101; F01D 5/147 20130101; F01D 9/042 20130101 |
Class at
Publication: |
415/209.3 ;
415/208.1 |
International
Class: |
F01D 9/04 20060101
F01D009/04; F01D 9/02 20060101 F01D009/02 |
Claims
1. A steam turbine static nozzle blade comprising: an airfoil; an
inner sidewall integral with a first side of the airfoil; and an
outer sidewall integral with a second side of the airfoil; the
inner sidewall and the outer sidewall each including: a pressure
side having an arcuate concave surface extending substantially an
entire length of the sidewall; and a suction side having an arcuate
convex surface extending substantially the entire length of the
sidewall.
2. The static nozzle blade of claim 1, wherein the arcuate concave
surface of the inner sidewall and the arcuate convex surface of the
inner sidewall have a substantially equal arc radius.
3. The static nozzle blade of claim 2, wherein the arcuate concave
surface of the outer sidewall and the arcuate convex surface of the
outer sidewall have a substantially equal arc radius.
4. The static nozzle blade of claim 3, wherein the arcuate concave
surface of the inner sidewall and the arcuate concave surface of
the outer sidewall complement the arcuate convex surface of the
inner sidewall and the arcuate convex surface of the outer
sidewall, respectively.
5. The static nozzle blade of claim 1, wherein the arcuate concave
surface of the inner sidewall and the arcuate convex surface of the
inner sidewall have a substantially equal arc length.
6. The static nozzle blade of claim 1, wherein the arcuate concave
surface of the outer sidewall and the arcuate convex surface of the
outer sidewall have a substantially equal arc length.
7. A steam turbine diaphragm assembly comprising: an outer
diaphragm ring; an inner diaphragm ring; an annulus of static
nozzle blades between the inner diaphragm ring and the outer
diaphragm ring, each static nozzle blade comprising: an airfoil; an
inner sidewall integral with a first side of the airfoil; and an
outer sidewall integral with a second side of the airfoil; the
inner sidewall and the outer sidewall each including: a pressure
side having an arcuate concave surface extending substantially an
entire length of the sidewall; and a trailing surface having an
arcuate convex surface extending substantially the entire length of
the sidewall; wherein at least one of the static nozzle blades is
demountably attached to a second one of the static nozzle
blades.
8. The steam turbine diaphragm assembly of claim 7, wherein the
arcuate concave surface of the inner sidewall and the arcuate
convex surface of the inner sidewall have a substantially equal arc
radius.
9. The turbine diaphragm assembly of claim 8, wherein the arcuate
concave surface of the outer sidewall and the arcuate convex
surface of the outer sidewall have a substantially equal arc
radius.
10. The steam turbine diaphragm assembly of claim 9, wherein the
arcuate concave surface of the inner sidewall and the arcuate
concave surface of the outer sidewall of a first one of the static
nozzle blades complement the arcuate convex surface of the inner
sidewall and the arcuate convex surface of the outer sidewall,
respectively, of a second one of the static nozzle blades.
11. The steam turbine diaphragm assembly of claim 10, further
comprising a plurality of removable weld joints, each removable
weld joint substantially removably affixing one of the static
nozzle blades to one of the outer diaphragm ring or the inner
diaphragm ring.
12. The steam turbine diaphragm assembly of claim 11, wherein the
at least one of the static nozzle blades is demountably attached to
the second one of the static nozzle blades by at least one of the
removable weld joints.
13. The steam turbine diaphragm assembly of claim 12, wherein the
at least one of the removable weld joints demountably attaches the
at least one of the static nozzle blades to the second one of the
static nozzle blades in an axial direction.
14. A steam turbine diaphragm assembly comprising: an outer
diaphragm ring; an inner diaphragm ring; an annulus of static
nozzle blades between the inner diaphragm ring and the outer
diaphragm ring, each static nozzle blade comprising: an airfoil; an
inner sidewall integral with a first side of the airfoil; and an
outer sidewall integral with a second side of the airfoil; the
inner sidewall and the outer sidewall each including: a pressure
side having an arcuate concave surface extending substantially an
entire length of the sidewall; and a suction side having an arcuate
convex surface extending substantially the entire length of the
sidewall, wherein at least one of the static nozzle blades is
demountably attached to a second one of the static nozzle blades in
an axial direction; and a plurality of pairs of removable weld
joints, each pair of removable weld joints substantially removably
affixing one of the static nozzle blades to one of the outer
diaphragm ring or the inner diaphragm ring.
15. The steam turbine diaphragm assembly of claim 14, wherein the
arcuate concave surface of the inner sidewall and the arcuate
convex surface of the inner sidewall have a substantially equal arc
radius.
16. The steam turbine diaphragm assembly of claim 15, wherein the
arcuate concave surface of the outer sidewall and the arcuate
convex surface of the outer sidewall have a substantially equal arc
radius.
17. The steam turbine diaphragm assembly of claim 15, wherein the
arcuate concave surface of the inner sidewall and the arcuate
concave surface of the outer sidewall of a first one of the static
nozzle blades complement the arcuate convex surface of the inner
sidewall and the arcuate convex surface of the outer sidewall,
respectively, of a second one of the static nozzle blades.
18. The steam turbine diaphragm assembly of claim 14, wherein each
pair of removable weld joints substantially maintains an axial
position of the removably affixed static nozzle blade.
19. The steam turbine diaphragm assembly of claim 14, wherein the
arcuate concave surface of the inner sidewall and the arcuate
convex surface of the inner sidewall have a substantially equal arc
length; and wherein the arcuate concave surface of the outer
sidewall and the arcuate convex surface of the outer sidewall have
a substantially equal arc length.
20. The steam turbine diaphragm assembly of claim 14, wherein the
removably affixed static nozzle blade is substantially affixed to
the turbine diaphragm assembly by only the pair of removable weld
joints.
Description
BACKGROUND OF THE INVENTION
[0001] The subject matter disclosed herein relates to a steam
turbine nozzle assembly, or diaphragm stage. Specifically, the
subject matter disclosed herein relates to a steam turbine nozzle
assembly including a plurality of nozzle segments with arcuate or
"conical" (e.g., arced concave, arced convex) interfaces.
[0002] Steam turbines include static nozzle (or "airfoil") segments
that direct flow of a working fluid into turbine buckets connected
to a rotating rotor. A complete assembly of nozzle segments is
commonly referred to as a diaphragm stage of the steam turbine. One
method of constructing the diaphragm stage is to weld (or
alternatively, braze) a plurality of single airfoils with
integrated sidewalls ("static nozzle blades", or "singlets") to
inner and outer rings. Each of these singlets have interfaces to
which adjacent singlets are welded or brazed (in the inner and
outer ring). These interfaces include an axial leading edge section
(or "pressure-side" section) oriented parallel to the steam
turbine's axis, and an angled trailing edge section (or
"suction-side" section). While the current singlet design including
angled interface sections allows for a tight fit between individual
segments, the angled interfaces make removal and repair of
individual segments nearly impossible.
BRIEF DESCRIPTION OF THE INVENTION
[0003] Steam turbine nozzle segments with conical interfaces are
disclosed. In one embodiment a steam turbine static nozzle blade
includes: an airfoil; an inner sidewall integral with a first side
of the airfoil; and an outer sidewall integral with a second side
of the airfoil; the inner sidewall and the outer sidewall each
including: a pressure side having an arcuate concave surface
extending substantially an entire length of the sidewall; and a
suction side having an arcuate convex surface extending
substantially the entire length of the sidewall.
[0004] A first aspect of the invention includes a steam turbine
static nozzle blade comprising: an airfoil; an inner sidewall
integral with a first side of the airfoil; and an outer sidewall
integral with a second side of the airfoil; the inner sidewall and
the outer sidewall each including: a pressure side having an
arcuate concave surface extending substantially an entire length of
the sidewall; and a suction side having an arcuate convex surface
extending substantially the entire length of the sidewall.
[0005] A second aspect of the invention includes a steam turbine
diaphragm assembly comprising: an outer diaphragm ring; an inner
diaphragm ring; and an annulus of static nozzle blades between the
inner diaphragm ring and the outer diaphragm ring, each static
nozzle blade comprising: an airfoil; an inner sidewall integral
with a first side of the airfoil; and an outer sidewall integral
with a second side of the airfoil; the inner sidewall and the outer
sidewall each including: a pressure side having an arcuate concave
surface extending substantially an entire length of the sidewall;
and a suction side having an arcuate convex surface extending
substantially the entire length of the sidewall; wherein at least
one of the static nozzle blades is demountably attached to a second
one of the static nozzle blades.
[0006] A third aspect of the invention includes a steam turbine
diaphragm assembly comprising: an outer diaphragm ring; an inner
diaphragm ring; and an annulus of static nozzle blades between the
inner diaphragm ring and the outer diaphragm ring, each static
nozzle blade comprising: an airfoil; an inner sidewall integral
with a first side of the airfoil; and an outer sidewall integral
with a second side of the airfoil; the inner sidewall and the outer
sidewall each including: a pressure side having an arcuate concave
surface extending substantially an entire length of the sidewall;
and a suction side having an arcuate convex surface extending
substantially the entire length of the sidewall, wherein at least
one of the static nozzle blades is demountably attached to a second
one of the static nozzle blades in an axial direction; and a
plurality of removable weld joints, each removable weld joint
substantially removably affixing one of the static nozzle blades to
one of the outer diaphragm ring or the inner diaphragm ring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and other features of this invention will be more
readily understood from the following detailed description of the
various aspects of the invention taken in conjunction with the
accompanying drawings that depict various embodiments of the
invention, in which:
[0008] FIG. 1 shows a plan view of a top of a steam turbine nozzle
assembly.
[0009] FIG. 2 shows a three-dimensional perspective views of a
steam turbine nozzle assembly.
[0010] FIG. 3 shows a partial three-dimensional perspective view of
a steam turbine diaphragm assembly.
[0011] FIG. 4 shows a three-dimensional perspective view of a steam
turbine static nozzle blade according to an embodiment.
[0012] FIGS. 5-6 show three-dimensional perspective views of a
plurality of steam turbine static nozzle blades according to
embodiments.
[0013] FIG. 7 shows a partial three-dimensional perspective view of
a steam turbine diaphragm assembly according to an embodiment.
[0014] It is noted that the drawings of the invention are not to
scale. The drawings are intended to depict only typical aspects of
the invention, and therefore should not be considered as limiting
the scope of the invention. In the drawings, like numbering
represents like elements between the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0015] As indicated above, aspects of the invention provide for a
steam turbine nozzle segment having a conical interface.
Specifically, aspects of the invention provide for a steam turbine
nozzle assembly including a plurality of nozzle segments with
arcuate or "conical" (e.g., arced concave, arced convex)
interfaces. These arced interfaces may allow for removal and/or
repair of individual nozzle segments while substantially
maintaining the structural integrity of the nozzle assembly.
[0016] Referring to the drawings, FIGS. 1-2 show a nozzle assembly
100 for a steam turbine (not shown). FIG. 1 shows a plan view of
nozzle assembly 100, while FIG. 2 shows a three-dimensional
schematic of nozzle assembly 100. Nozzle assembly 100 includes a
static nozzle blade 10 including at least one airfoil 12 having an
inner sidewall 14 and an outer sidewall 16. Nozzle assembly 100
further includes an inner ring 18 and an outer ring 20. Inner and
outer, as used herein, refer to a radial position relative to a
rotor (not shown) to which an inner end of airfoil 12 is coupled
via inner ring 18. Inner ring 18 and inner sidewall 14 (and
similarly, outer ring 20 and outer sidewall 16) are coupled
together at an interface 80, which is understood to refer to the
entire area where the rings and sidewall are adjacent and coupled.
Inner ring 18 and inner sidewall 14 (and similarly, outer ring 20
and outer sidewall 16) are welded (or alternatively, brazed)
together at several points at interface 80 (FIG. 1). It is
understood that as described herein, brazing may be performed as an
alternative to welding. As is understood in the art, welding and
brazing may be used to join metals together. As is further
understood in the art, welding may be performed by melting and
fusing metals together, usually by adding a filler material.
Brazing, by contrast, usually does not involve melting the base
metals being joined, and is usually performed at lower temperatures
than welding. While metal joints are described herein as "weld
joints", it is understood that these metal joints may alternatively
be described as "braze joints."
[0017] Returning to FIG. 1, the multiple welded areas of interfaces
80, on both an entrance (front) side of airfoil 12 and an exit
(back) side of airfoil 12, that are welded together are shown
generally as weld joints 90 in FIGS. 1 and 2. Interfaces 80 between
rings 18, 20 and sidewalls 14, 16 may each include a mechanical
radial stop 19 which maintains airfoil 12 in the correct radial
position during welding and prevents weld shrinkage. Interfaces 80
each may further include a mechanical axial stop 17 which maintains
airfoil 12 in the correct axial position and controls the weld
length depth. These mechanical stops 17, 19 comprise an
interconnection of a series of male steps which engage in
corresponding female steps of the complementary part as described
in more detail herein.
[0018] Turning to FIG. 3, the nozzle assembly 100 of FIG. 2 is
shown, further including a plurality of static nozzle blades 10
arranged in a portion of a diaphragm assembly (full assembly
omitted for clarity). As shown, sidewalls 14, 16 of static nozzle
blades 10 may include angled interfaces 34 (e.g., a "dogleg"
interface including two surfaces oriented at obtuse angles). These
angled interfaces 34 may allow for a plurality of static nozzle
blades to be arranged substantially flush with one another in
nozzle assembly 100. As shown, the plurality of static nozzle
blades 10 are held within inner 18 and outer sidewalls 20 via the
plurality of welds 90.
[0019] Turning to FIG. 4, a steam turbine static nozzle blade 110
is shown according to an embodiment. Static nozzle blade 110 may
include an airfoil 112, an inner sidewall 114, and an outer
sidewall 116. As shown, inner sidewall 114 may be integral with a
first side of the airfoil 112 (e.g., via machining from a forging
or block, welding, casting, brazing, etc.), and outer sidewall 116
may be integral with a second side of the airfoil 112 (e.g., via
machining from a forging or block, welding, casting, brazing,
etc.). The inner sidewall 114 and the outer sidewall 116 may each
include a pressure side 124 and a suction side 126. The terms
"pressure side" and "suction side" correspond to the pressure side
and suction side of airfoil 112, respectively. As is known in the
art, the pressure side of airfoil 112 is the high-pressure side
designed to guide the flow of a working fluid through the static
nozzle blade 110. As is further known in the art, the suction side
of airfoil 112 is the lower-pressure side substantially opposing
the pressure side. Each pressure side 124 may have an arcuate
concave surface 134, and each suction side 126 may have an arcuate
convex surface 136. In one embodiment, the arcuate concave surface
134 may extend substantially an entire length L of the sidewall
114, 116, respectively, and the arcuate convex surface 136 may
extend substantially the entire length L of the sidewall 114, 116,
respectively. In one embodiment, the arcuate concave surface 134 of
the inner sidewall 114 has a substantially equal arc radius to the
arcuate convex surface 136 of the inner sidewall 114. Further, in
this embodiment, the arcuate concave surface 134 of the outer
sidewall 116 and the arcuate convex surface 136 of the outer
sidewall 116 may have a substantially equal arc radius.
Additionally, in this embodiment, the arcuate concave surfaces 134
of the inner sidewall 114 and outer sidewall 116, respectively, may
have substantially equal arc lengths as the arcuate convex surfaces
136 of the inner sidewall 114 and outer sidewall 116,
respectively.
[0020] With continuing reference to FIG. 4, in one embodiment, the
arcuate concave surface 134 of the inner sidewall 114 and the
arcuate concave surface 134 of the outer sidewall 116 complement
the arcuate convex surface 136 of the inner sidewall 114 and the
arcuate convex surface 136 of the outer sidewall 116, respectively.
That is, in an arrangement including more than one steam turbine
static nozzle blade 110 (FIGS. 5-7), the arcuate convex surface 136
of an inner sidewall 114 of a first steam turbine static nozzle
blade 110 complements the arcuate concave surface 134 of an inner
sidewall 114 on a second similar steam turbine static nozzle blade
110. Likewise, the arcuate convex surface 136 of an outer sidewall
116 of a first steam turbine static nozzle blade 110 complements
the arcuate concave surface 134 of an outer sidewall 116 on a
second similar steam turbine static nozzle blade 110. It is
understood that as used herein, the term "complement(s)" refers to
a relationship between surfaces in which portions of those surfaces
may be arranged substantially flush with one another. For example,
in one embodiment, pressure-side (arcuate concave) surfaces and
suction-side (arcuate convex) surfaces may be arranged in a steam
turbine diaphragm assembly (FIG. 7) such that each of the
respective (inner, outer) arcuate concave surfaces of a first steam
turbine static nozzle blade 110 are substantially flush with the
respective (inner, outer) arcuate convex surfaces of a second steam
turbine static nozzle blade 110. The relationship between
pressure-side surfaces and suction-side surfaces is further
explained with reference to FIGS. 5-7.
[0021] Turning to FIGS. 5 and 6, arrangements including a plurality
of substantially similar steam turbine static nozzle blades 110 are
shown. In these arrangements, steam turbine static nozzle blades
110 may be arranged such that their complementary surfaces (arcuate
concave surfaces 134 and arcuate convex surfaces 136, respectively)
are substantially flush with one another. This may allow for, among
other things, efficient feeding of steam across airfoils 112 and
mechanical stability. FIG. 5 shows an arrangement including the
plurality of steam turbine static nozzle blades 110 of FIG. 5,
along with additional substantially similar blades, forming part of
a steam turbine diaphragm assembly (diaphragm rings omitted). As
described with respect to FIG. 5, and shown more clearly in FIG. 6,
part of a steam turbine diaphragm assembly may be formed by
arranging complementary conical surfaces of steam turbine static
nozzle blades 110 flush with one another. As will be described with
reference to FIG. 7, in a more complete diaphragm assembly, the
plurality of steam turbine static nozzle blades 110 may be
demountably attached to one another in an axial direction (denoted
by "A"). This demountable attachment may allow for axial removal of
one or more steam turbine static nozzle blades 110 from the
assembly without substantially disturbing the structural integrity
(e.g., weld joints 190) of the remainder of the assembly.
[0022] Turning to FIG. 7, a portion of a steam turbine diaphragm
assembly 200 is shown according to an embodiment. Portion of steam
turbine diaphragm assembly 200 may include a plurality of steam
turbine static nozzle blades 110 arranged with substantially flush
complementary surfaces as described with reference to FIGS. 5-6.
Further, portion of steam turbine diaphragm assembly 200 may
include an inner diaphragm ring 118 and an outer diaphragm ring
120, which may be substantially similar to those inner and outer
rings (18 and 20) shown and described with reference to FIGS. 1-3.
In a complete diaphragm assembly (not shown for purposes of
clarity), the plurality of steam turbine static nozzle blades 110
may form an annulus between the inner diaphragm ring 118 and the
outer diaphragm ring 120. In this arrangement, plurality of steam
turbine static nozzle blades 110 may be demountably attached to one
another. Further, the plurality of steam turbine static nozzle
blades 110 may be substantially removably affixed to at least one
of the inner diaphragm ring 118 and outer diaphragm ring 120 via
the plurality of removable weld joints 190. That is, where a steam
turbine static nozzle blade 110 is not affixed to at least one of
the inner diaphragm ring 118 and outer diaphragm ring 120, that
steam turbine static nozzle blade 110 may be removed from the steam
turbine diaphragm assembly 200 without removing weld joints 190 of
one or more adjacent steam turbine static nozzle blades 110.
[0023] In the nozzle assembly 100 of FIG. 3, when a complete
annulus of static nozzle blades 10 is assembled and welded (or
alternatively, brazed), individual static nozzle blades 10 cannot
be removed from the assembly 100 without removal of a plurality of
the nozzle blades 10 (and their corresponding weld joints 90, or
braze joints). This is because the angled interfaces 34 (FIG. 3) of
the plurality of blades 10 obstruct movement of adjacent blades 10,
even when a weld joint 90 is removed. Specifically, as shown in
FIG. 3, the angled interfaces 34 of the plurality of blades 10
obstruct movement of those blades in an axial direction ("A"). In
contrast, the plurality of steam turbine static nozzle blades 110
of an embodiment (e.g., FIG. 7) are demountably attached to one
another. That is, each steam turbine static nozzle blade 110 that
is not welded to one of the inner diaphragm ring 118 and outer
diaphragm ring 120 may be removed or inserted between two fixed
(e.g., welded) steam turbine static nozzle blades 110 in the axial
direction (A). Phrased differently, in the steam turbine diaphragm
assembly 200, each steam turbine static nozzle blade 110 may be
demountably attached to an adjacent steam turbine static nozzle
blade 110 in an axial direction. Further, in one embodiment each
steam turbine static nozzle blade 110 is substantially removably
affixed to at least one of the inner diaphragm ring 118 and outer
diaphragm ring 120 by only the plurality of removable weld joints
190 (or alternatively, braze joints).
[0024] The steam turbine static nozzle blades 110 including conical
(arcuate concave, arcuate convex) interfaces as described herein
may allow for removal of individual blades 110 from an assembly
(e.g., steam turbine diaphragm assembly 200) by removing (e.g., by
grinding, machining and/or heating) only those removable weld
joints 190 (or braze joints) associated with the individual blade
being removed. This may allow for, among other things, faster and
more efficient repair, replacement, and/or enhancement of
individual steam turbine static nozzle blades 110.
[0025] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the disclosure. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof.
[0026] 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 have 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.
* * * * *