WO2019147219A1

WO2019147219A1 - Slide on shroud cover segments for gas turbine compressor stator vanes

Info

Publication number: WO2019147219A1
Application number: PCT/US2018/014797
Authority: WO
Inventors: Krishna VELURU; Grzegorz Blaszczak; Amit K. PASPULATI
Original assignee: Siemens Aktiengesellschaft
Priority date: 2018-01-23
Filing date: 2018-01-23
Publication date: 2019-08-01

Abstract

Apparatus and method embodying slide on shroud cover segments for gas turbine compressor stator vanes are provided. The apparatus may include a first shroud cover segment (12) including a respective circumferential groove (14). A gas turbine compressor stator vane (10) has a respective base anchoring joint (16) configured for slide on insertion in the respective circumferential groove (14). A stop (18) at a first end (20) of the respective circumferential groove (14). The first end of the respective circumferential groove located opposite a second end (22) of the respective circumferential groove, the second end of the respective circumferential groove may be an open end. A group of gas turbine compressor stator vanes (10a) may be disposed between the stop and the open end of the first shroud cover segment. Disclosed embodiments in a cost-effective and reliable manner, eliminate the need for any bolted or welded assemblies, which is conducive to user-friendly and efficient replacement of individual stator vanes during servicing.

Description

SLIDE ON SHROUD COVER SEGMENTS FOR GAS TURBINE COMPRESSOR STATOR VANES

[0001] BACKGROUND

[0002] 1. Field

[0003] Disclosed embodiments are generally related to turbomachinery, such as gas turbine engines and, more particularly, to slide on shroud cover segments for gas turbine compressor stator vanes.

[0004] 2. Description of the Related Art

[0005] A gas turbine engine generally includes a compressor section, a combustor section, and a turbine section. In operation, the compressor section

(hereinafter referred to as“compressor”) ingests ambient air and compresses it The compressed air from the compressor enters one or more combustors in the combustor section. The compressed air is mixed with fuel in the combustors, and an air-fuel mixture is combusted in the combustors to form a hot working gas. The hot working gas is routed to the turbine section where it is expanded through alternating row's of stationary airfoils and rotating airfoils and used to generate pow_'er that can drive a rotor. The expanded gas exiting the turbine section may then be exhausted from the engine via an exhaust section.

[0006] A plurality of fixed stator vanes is often shrouded at the outlet guide vane (OGV) stage in the compressor to define a desired flow' path for the compressed air and avoid leakage from the flow path. Aero-engines and industrial gas turbine compressor stator shrouds are commonly welded, bolted or cast to the stator vanes. [0007] Welding typical gas turbine compressor components may involve pre-heat treatment, post-heat treatment, and final machining of the assembly to, for example, correct heat-induced distortion. Accordingly, fabrication of a typical welded shroud assembly may be burdensome and costly as well as subject to increased risk of weld cracking.

[0008] Bolting techniques may involve extra parts in the assembly, such as bolts, washers, bushings, etc. Moreover, a bolted assembly can be over-torqued and the bolt can be subject to high preloading, potentially leading to buckling, fretting failures. In certain applications, casting can also be used but this technique can be expensive, and, often, longtime intervals may be required to develop the casting molds.

[0009] Disclosed embodiments offer improvements relating to a new design solution for assembling shroud cover segments to gas turbine compressor stator vanes. See patent application publications US2007/0107218 and US2007/0122274 for examples involving the installation of shrouds on stator vanes.

[0010] BRIEF DESCRIPTION

[0011] One disclosed embodiment is directed to apparatus embodying slide on

shroud cover segments for gas turbine compressor stator vanes. The apparatus may include a first shroud cover segment (12) having a respective

circumferential groove (14). A gas turbine compressor stator vane (10) has a respective base anchoring joint (16) configured for slide on insertion in the respective circumferential groove (14). A stop (18) at a first end (20) of the respective circumferential groove (14). The first end of the respective circumferential groove located opposite a second end (22) of the respective circumferential groove, the second end of the respective circumferential groove may be an open end. A group of gas turbine compressor stator vanes (lOa) may be disposed between the stop and the open end of the first shroud cover segment. This apparatus eliminates the need for any bolted or welded assemblies. [0012] Another disclosed embodiment is directed to methodology for assembling one or more shroud cover segments to gas turbine compressor stator vanes. This may involve forming in the one or more shroud cover segments a respective circumferential groove. Forming in each gas turbine compressor stator vane a base anchoring joint for slide on insertion in the respective circumferential groove in the one or more shroud cover segments. Disposing a stop at a first end of the respective circumferential groove in the one or more shroud cover segments, the first end of the respective circumferential groove located opposite a second end of the respective circumferential groove, the second end of the respective circumferential groove constituting an open end.

Successively inserting each respective base anchoring joint of a group of gas turbine compressor stator vanes through the open end of the respective circumferential groove of a first shroud cover segment of the one or more shroud cover segments. The group of gas turbine compressor stator vanes disposed between the stop and the open end of the first shroud cover segment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 shorvs an isometric view of one disclosed embodiment of a slide on shroud cover segment for gas turbine compressor stator vanes.

[0014] FIG. 2 shows an isometric view of an assembly of a compressor stator vane segment and a group of compressor stator vanes.

[0015] FIG 3 shows generally a top view of a pair of circumferentially adjoining

shroud cover segments without groups of compressor stator vanes attached to such adjoining shroud cover segment.

[0016] FIG. 4 shows generally an elevational view of an assembly of a pair of

circumferentially adjoining shroud cover segments and respective groups of compressor stator vanes.

[0017] FIG. 5 show's a zoomed-in view of an end of a shroud cover segment including structural details in a base anchoring joint of a compressor stator vane located at such an end of the shroud cover segment.

[0018] FIG. 6 shows an isometric view of an assembly of a compressor stator vane segment and a group of compressor stator vanes at the outlet guide vane (QGV) stage. [0019] FIG. 7 shows generally an elevational view of an alternative disclosed embodiment of an assembly of a shroud cover segment and a respective group of compressor stator vanes.

[0020] DETAILED DESCRIPTION

[0021] The inventors of the present invention have recognized certain practical

limitations regarding known apparatuses involving gas turbine compressor stator shrouds and techniques for assembling gas turbine compressor stator shrouds to stator vanes. For example, such techniques may involve welding, bolting or casting, for assembling gas turbine compressor stator shrouds to stator vanes. For example, the stator vanes are typically frequently replaced over the life of the engine. In addition to cumbersome and time-consuming removal operations due to the presence of bolted assemblies, or assemblies involving tenon/weld components, several technical issues (e.g., preload relax, creep and fretting) may be associated with such known apparatuses and techniques.

[0022] In view of such recognition, the present inventors propose an innovative

design solution embodying slide on shroud cover segments for gas turbine compressor stator vanes. Disclosed embodiments, in a cost-effective and reliable manner, eliminate the need for any bolted or welded assemblies, which, without limitation, is conducive to user-friendly and time-efficient replacement of individual stator vanes during servicing operations.

[0023] in the following detailed description, various specific details are set forth in order to provide a thorough understanding of such embodiments. However, those skilled in the art will understand that disclosed embodiments may be practiced without these specific details that the aspects of the present invention are not limited to the disclosed embodiments, and that aspects of the present invention may be practiced in a variety of alternative embodiments. In other instances, methods, procedures, and components, which would be well- understood by one skilled in the art have not been described in detail to avoid unnecessary and burdensome explanation. [0024] Furthermore, various operations may be described as multiple discrete steps performed in a manner that is helpful for understanding embodiments of the present invention. However, the order of description should not be construed as to imply that these operations need be performed in the order they are presented, nor that they are even order dependent, unless otherwise indicated. Moreover, repeated usage of the phrase“in one embodiment” does not necessarily refer to the same embodiment, although it may. It is noted that disclosed embodiments need not be construed as mutually exclusive embodiments, since aspects of such disclosed embodiments may be

appropriately combined by one skilled in the art depending on the needs of a given application.

[0025] The terms‘‘comprising’,“including”,“having”, and the like, as used in the present application, are intended to be synonymous unless otherwise indicated. Lastly, as used herein, the phrases“configured to” or“arranged to” embrace the concept that the feature preceding the phrases“configured to” or“arranged to” is intentionally and specifically designed or made to act or function in a specific way and should not be construed to mean that the feature just has a capability or suitability to act or function in the specified way, unless so indicated.

[0026] FIG 1 shows an isometric view of one non-limiting example of a compressor stator vane 10 being assembled in a shroud cover segment 12, (e.g., as may constitute part of an inner annular shroud cover) as may be used in the context of disclosed embodiments involving slide on shroud cover segments for gas turbine compressor stator vanes. [0027] In one non-limiting embodiment, one may form in the one or more shroud cover segments 12 a respective circumferential groove 14. That is, a circumferentially-extending groove. In one non-limiting embodiment, one may form in each gas turbine compressor stator vane a base anchoring joint 16 for slide on insertion in the respective circumferential groove 14. That is, sliding relative movement between base anchoring joint 16 and cover segment 12 can be effective for inserting base anchoring joint 16 in the respective circumferential groove 14.

[0028] In one non-limiting embodiment, one may dispose a stop 18 at a first end 20 of the respective circumferential groove 14. It will be appreciated that in certain embodiments, stop 18 may be formed as a discrete stop. That is, a structure separate from shroud cover segment 12, such as a pin, rivet, etc. Alternatively, stop 18 may be formed as an integral stop. That is, a structure integrally constructed with shroud cover segment 12.

[0029] As may be appreciated in the zoomed-in view shown in FIG. 5, base

anchoring joint 16 of compressor stator vane 10 located at first end 20 of the shroud cover segment may include a protrusion 27 shaped to complementary engage a cutout 29 in stop 18. It will be readily appreciated that alternatively the protrusion could be formed in stop 18 and the cutout could be formed in base anchoring joint 16.

[0030] First end 20 of the respective circumferential groove may be located opposite a second end 22 of the respective circumferential groove 14. In one non limiting embodiment, second end 22 of the respective circumferential groove 14 may constitute an open end. [0031] In one non-limiting embodiment, one may successively insert each respective base anchoring joint 16 of a group of gas turbine compressor stator vanes 10 through open end 22 of the respective circumferential groove 14 of a first shroud cover segment 12. As can be appreciated in FIG. 2, in this embodiment, the group of gas turbine compressor stator vanes 10 would be disposed between the stop at the first end 20 and the open end 22 of first shroud cover segment 12.

[0032] FIG. 3 shows generally a top view of a pair of circumferentially adjoining

shroud cover segments l2a and l2b. For the sake of simplicity of illustration,

FIG. 3 does not illustrate the respective groups of gas turbine compressor stator vanes assembled onto adjoining shroud cover segments l2a and l2b. An assembly of the respective groups lOa and lOb of gas turbine compressor stator vanes with adjoining shroud cover segments l2a and l2b is illustrated in FIG. 4.

[0033] In this example, as shown in FIG. 3, the respective open ends 22 of the

respective circumferential grooves 14 of the adjoining shroud cover segments l2a and l2b are arranged to be mutually adjacent to one another. In one non- limiting embodiment, to accommodate thermal growth one may arrange a gap

25 between the respective mutually adjacent open ends 22 of the respective circumferential grooves 14 of the first and second shroud cover segments l2a and l2b.

[0034] In this embodiment, one can successively insert each respective base anchoring joint 16 of a further group of gas turbine compressor stator vanes lOb through the open end of the respective circumferential groove of a second shroud cover segment (e.g., shroud cover segment l2b, presuming shroud cover segment l2a is conceptualized as the first shroud cover segment assembled with group of gas turbine compressor stator vanes lOa) of the one or more shroud cover segments. In this example, the further group of gas turbine compressor stator vanes would be affixed between the stop at the first end 20 and the open end 22 of second shroud cover segment l2b. Accordingly, the respective groups of gas turbine compressor stator vanes lOa and lOb would be disposed between the respective stops 18 of the first shroud cover segment l2a and the second shroud cover segment l2b.

[0035] In one non-limiting embodiment, the assembly shown in FIG. 4 of first shroud cover segment l2a with the group of gas turbine compressor stator vanes lOa and the adjoining second shroud cover segment l2b with the respective further group of gas turbine compressor stator vanes lOb constitutes a building block for forming a segmented annular shroud cover (e.g., an inner annular shroud cover) over a 360 degrees circumferential span.

[0036] FIG. 6 shows an isometric view of the assembly shown in FIG. 4 of first

shroud cover segment l2a with the group of gas turbine compressor stator vanes lOa and the adjoining second shroud cover segment l2b, where this assembly is installed at the outlet guide vane (OGV) stage. As can be appreciated in FIG. 6, each vane includes a tip anchoring joint 23 that can be installed in a circumferential groove 24 in a vane carrier structure 26 disposed radially outwardly relative to the one or more shroud cover segments l2a and l2b. That is, shroud cover segments l2a and l2b constitute a radially inwardly structure relative to vane carrier structure 26. [0037] In one non-limiting embodiment, as shown in FIG. 7, subsequent to forming the respective circumferential groove in the one or more shroud cover segments, one may dispose a biasing means 30, such as a clamp plate 30, in the circumferential groove. In this embodiment, subsequent to successively inserting each respective base anchoring joint 16 of the group of gas turbine compressor stator vanes through second end 22 (e.g., the open end) of the respective circumferential groove 14 of the first shroud cover segment, one can block such open end of the respective circumferential groove of the first shroud cover by bending an end segment 32 of clamp plate 30 to block the open end with the bent end segment. Alternatively, in lieu of bending the end segment 32 of clamp plate 30, one could insert a pin or rivet to block the open end of the circumferential groove 14.

[0038] In one non-limiting embodiment the assembly shown in FIG. 7 of first shroud cover segment 12 with the group of gas turbine compressor stator vanes constitutes a building block for forming a segmented annular shroud cover (e.g., the inner annular shroud cover) over a 360 degrees circumferential span. In this embodiment, the group of gas turbine compressor stator vanes 10 is disposed between the stop 18 of the first shroud cover segment and the blocked end 22 of the first shroud cover segment.

[0039] In operation, disclosed embodiments eliminate the need for any bolted or welded assemblies, which, without limitation, is conducive to user-friendly and time-efficient replacement of individual tor example stator vanes during servicing operations.

[0040] While embodiments of the present disclosure have been disclosed in

exemplary forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein without departing from the scope of the invention and its equivalents, as set forth in the following claims.

Claims

What is claimed is:

1. Apparatus in a gas turbine engine comprising:

a first shroud cover segment (12) having a respective circumferential groove

(14);

a gas turbine compressor stator vane (10) having a respective base anchoring joint (16) configured for slide on insertion in the respective circumferential groove (14);

a stop (18) at a first end (20) of the respective circumferential groove (14), the first end of the respective circumferential groove located opposite a second end (22) of the respective circumferential groove, the second end of the respective

circumferential groove constituting an open end; and

a group of gas turbine compressor stator vanes (lOa) disposed between the stop and the open end of the first shroud cover segment.

2. The apparatus of claim 1, further comprising a further group of gas turbine compressor stator vanes (lOb) disposed between a stop and an open end of a second shroud cover segment.

3. The apparatus of claim 2, wherein the first and second shroud cover segments (l2a, l2b) are arranged in circumferentially adjoining relationship so that the respective open ends of the respective circumferential grooves of the first and second shroud cover segments are mutually adjacent.

4. The apparatus of claim 3, further comprising a gap (25) arranged between the respective mutually adjacent open ends of the respective circumferential grooves of the first and second shroud cover segments.

5. The apparatus of claim 3, wherein the group and the further group of gas turbine compressor stator vanes (lOa, lOb) are disposed between the respective stops of the first shroud cover segment and the second shroud cover segment.

6. The apparatus of claim 3, wherein an assembly of the first shroud cover segment with the group of gas turbine compressor stator vanes and the adjoining second shroud cover segment with the respective further group of gas turbine compressor stator vanes constitutes a building block for forming a segmented annular shroud cover over a 360 degrees circumferential span.

7. The apparatus of claim 1, a biasing means (30) disposed in the circumferential groove (14).

8. The apparatus of claim 7, a blocking structure to block the open end of the respective circumferential groove of the first shroud cover segment, wherein the group of gas turbine compressor stator vanes is disposed between the stop of the first shroud cover segment and the blocked end of the first shroud cover segment.

9. The apparatus of claim 7, wherein the biasing means (30) comprises a clamp plate, and wherein the blocking structure comprises an end segment (32) of the clamp plate bent to block the open end.

10. The apparatus of claim 7, wherein the biasing means (30) comprises a clamp

plate, and wherein the blocking structure comprises a pin or rivet arranged to block the open end.

11. The apparatus of claim 7, wherein an assembly of the first shroud cover segment with the group of gas turbine compressor stator vanes constitutes a building block for forming a segmented shroud cover over a 360 degrees circumferential span.

12. The apparatus of claim 1, wherein the stop at the first end of the respective

circumferential groove comprises a discrete stop or an integral stop.

13. The apparatus of claim 1, wherein the base anchoring joint comprises a cutout (29) shaped to complementary engage a protrusion (27) in the stop.

14. The apparatus of claim 1, wherein the base anchoring joint comprises a protrusion (27) shaped to complementary engage a cutout (29) in the stop.

15. Method for assembling one or more shroud cover segments (12) to gas turbine compressor stator vanes (10), the method comprising:

forming in the one or more shroud cover segments (12) a respective circumferential groove (14);

forming in each gas turbine compressor stator vane (10) a base anchoring joint (16) for slide on insertion in the respective circumferential groove (14);

disposing a stop (18) at a first end (20) of the respective circumferential groove (14), the first end of the respective circumferential groove located opposite a second end (22) of the respective circumferential groove, the second end of the respective circumferential groove constituting an open end; and

successively inserting each respective base anchoring joint of a group of gas turbine compressor stator vanes through the open end of the respective circumferential groove of a first shroud cover segment of the one or more shroud cover segments, the group of gas turbine compressor stator vanes disposed between the stop and the open end of the first shroud cover segment.

16. The method of claim 15, further comprising successively inserting each

respective base anchoring joint of a further group of gas turbine compressor stator vanes (lOb) through the open end of the respective circumferential groove of a second shroud cover segment (l2b) of the one or more shroud cover segments, the further group of gas turbine compressor stator vanes affixed between the stop and the open end of the second shroud cover segment.

17. The method of claim 16, further comprising arranging in circumferentially adjoining relationship the first and second shroud cover segments (l2a, l2b) so that the respective open ends of the respective circumferential grooves of the first and second shroud cover segments are mutually adjacent.

18. The method of claim 17, wherein the arranging in circumferentially adjoining relationship of the first and second shroud cover segments comprises arranging a gap (25) between the respective mutually adjacent open ends of the respective circumferential grooves of the first and second shroud cover segments.

19. The method of claim 15, subsequent to forming the respective circumferential groove (14) in the one or more shroud cover segments, disposing a biasing means (30) in the circumferential groove (14).

20. The method of claim 19, subsequent to successively inserting each respective base anchoring joint (16) of the group of gas turbine compressor stator vanes through the open end of the respective circumferential groove of the first shroud cover segment of the one or more shroud cover segments, blocking the open end of the respective circumferential groove of the first shroud cover segment of the one or more shroud cover segments.