US20160298647A1

US20160298647A1 - Compressor stator assembly and method of installing

Info

Publication number: US20160298647A1
Application number: US15/188,124
Authority: US
Inventors: Michael Thomas Hudson; Ryan Wesley Murphy
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 2012-07-24
Filing date: 2016-06-21
Publication date: 2016-10-13

Abstract

A compressor stator assembly includes a stator casing having a plurality of stator casing slots and a set of stator portions insertable into the stator casing slots. The stator casing and the set of stator portions are configured such that the set of stator portions only assembles to the stator casing in a single stage of the stator casing, or in a single configuration. The set of stator portions includes a plurality of stator vanes, and the stator vanes have a stator vane characteristic that varies for each stage in the stator casing. The stator vane characteristic is at least one of, a radial height of a forward sidewall, a radial height of an aft sidewall or an axial length.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part application of U.S. application Ser. No. 13/556,296, filed Jul. 24, 2012, currently pending.

BACKGROUND OF THE INVENTION

The present invention relates generally to turbomachinery, and more particularly relates to a compressor stator assembly and a method of installing the assembly.
A conventional gas turbine generally operates on the principle of compressing air within a compressor, and then delivering the compressed air to a combustion chamber where fuel is added to the air and ignited. Afterwards, the resulting combustion mixture is delivered to the turbine section of the engine, where a portion of the energy generated by the combustion process is extracted by a turbine to drive the compressor via a shaft.
In multi-stage compressor sections, stators vanes are placed at the entrance and exit of the compressor section, as well as between each compressor stage, for purposes of properly directing the airflow to each successive compressor stage. As a result, stator vanes are able to enhance engine performance by appropriately influencing air flow and pressure within the compressor section.
Each stator stage generally consists of an annular array of airfoils, or vanes. A stator stage is typically formed in segments as stator vane units consisting of one or more airfoils supported by the base. These stator vane units are then individually mounted to the compressor casing to form an annular array, so that the airfoils project radially between an adjacent pair of rotor stages.
Stator vanes in an industrial gas turbine compressor are loaded and unloaded during start-stop cycles. In addition, the vanes are subject to small pressure fluctuations during operation. These result in relative motion between the vane base and the casing in which the vanes are assembled. The relative motion results in wear of both the vane base and casing, which, in turn, results in loose vanes. The loose vanes become more susceptible to relative motion and begin to chatter. Repair or replacement of the vanes may be required. Similar problems exist between stator ring segments, which hold a plurality of stator vanes, the stator ring segments being mounted in slots of the compressor casing.
FIG. 1 illustrates a known compressor section or compressor stator assembly 10 showing a portion of an open casing 15 of a compressor showing five exemplary stages (rows) 20 a-20 e of stator vanes 25. In the embodiment shown, the casing section 15 is semicircular. The casing 15 has a mounting surface 30 that may be secured to a corresponding mounting surface on another casing section with fasteners extending through a plurality of holes 35. For a complete compressor, two of the semicircular casing sections would be fitted together around a rotor (not shown).
Each stator vane 25 has an airfoil 40 that extends upwards from a base 45 and radially inward towards the shaft of the compressor rotor (not shown). The airfoil 40, and stator vanes 25, are interposed between the rotor blades (not shown). Certain stator stages of a compressor may mount stator vanes directly in a slot in the casing. Other stator stages mount stator vanes in ring segments, which are then mounted in slots of the casing.
FIG. 2 illustrates individual stator vanes 25. Airfoil 40 extends vertically from a base or platform 45. The base 45 has two opposing retaining faces 50. The base 45 has a pair of projections 55, one on each of the retaining faces. The projections 55 are to be received by a correspondingly shaped groove in a slot of the casing. The grooves retain the stator vane 25 in place in the slot of the casing. The other two opposing faces of the base 45 are the engaging faces 60. The engaging faces 60 of base 45 butt against the bases 45 of adjacent stator vane units when the units are installed in a casing slot. The retaining faces 50 and projections 55 are the same shape and size on both sides of the stator vane 25. In this arrangement, the stator vanes 25 can be rotated 180 degrees and inserted within a casing slot (or ring segment).
FIG. 3 illustrates an enlarged side view of the casing showing a stage in which individual stator vanes are assembled in a slot of the compressor casing. For this type of installation, a plurality of the stator vanes 25 are assembled in the casing to form the stator vane stage. The casing 15 has a plurality of slots 70 for receiving the stator vane units 25. The slot 70 has a pair of side edges 75, which each has a groove or dovetail-shaped recess 80. The square base dovetail 80 holds the vanes 25 in place. The side edges 75 and dovetails 80 are mirror images of each other on each side of the slot. As mentioned previously, this allows the stator vanes 25 to be rotated 180 degrees and inserted within a casing slot (or ring segment), with the potential for inserting a stator vane backwards. The term “backwards” is defined as the airfoil being oriented 180 degrees from a desired orientation. Each vane unit 25 is allowed to slide into place with the base 45 received in the slot 70 and the projections 55 received in the grooves/dovetails 80. The casing 15 in the particular example shown has an air extraction cavity 85 that underlies the stage and is formed by the slot 70 and the stator vanes 25.
The stator vanes 25 for an individual stage are sequentially placed in the slot 70 of the casing 15 until the full circumferential run of the slot has been filled with a designated number of stator vanes. Other stages of stator vanes may be attached to the casing using ring segment assemblies. The ring segment assembly includes a ring segment and one or more stator vanes. Ring segments typically hold a plurality of stator vanes. After the ring segments have been loaded with stator vanes, the ring segments are slid into circumferential slots in the turbine/compressor casing and are butted against each other to sequentially fill the circumferential slots. Blades that are larger and have more forces placed on them may be assembled using this vane and ring segment assembly to provide a stiffer base mount.
FIG. 4 illustrates a ring segment assembly 400 that is slid out and away from the casing 15. The ring segment 90 receives a plurality of stator vanes 25. A base 45 of the stator vane 25 slides (in a generally axial direction with respect to the compressor) into the ring segment 90. The base 45 of the stator vane 25 includes a dovetail 95 fitting into and being retained by a corresponding dovetail-shaped slot 100 in the ring segment 90.
The ring segment 90 slides into the circumferential slot 70 of the casing 15. The sidewalls 105 of the ring segment 90 are supported axially by the sidewalls 110 of the slot 70 when the ring segment 90 is within the slot 70. The square base dovetail 115 of the ring segment 90 fits into the grooves 120 of the circumferential slot 70, thereby retaining the ring segments 90 in the circumferential slot 70. Ring segments 90 are sequentially placed in the slot 70 of casing 15 until the slot 70 is filled with the desired number of ring segment assemblies.
During initial assembly of turbomachine components, or subsequent repair and replacement of turbomachine components, a large number of components must be installed in specific locations of the turbomachine. For example, a stage one stator vane must be installed in the correct position in a stage one stator slot. A typical turbomachine may have many stages with many corresponding components, so a high probability exists that a component for a specific stage may get installed in an incorrect stage (e.g., a stage five stator vane might get installed in a stage six stator slot). The negative implications of this event lead to machine malfunction or inefficiency and increase outage or construction time due to the need to remove and correctly install the specific components.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of the present invention, a compressor stator assembly includes a stator casing having a plurality of stator casing slots and a set of stator portions insertable into the stator casing slots. The stator casing and the set of stator portions are configured such that the set of stator portions only assembles to the stator casing in a single stage of the stator casing, or in a single configuration. The set of stator portions includes a plurality of stator vanes, and the stator vanes have a stator vane characteristic that varies for each stage in the stator casing. The stator vane characteristic is at least one of, a radial height of a forward sidewall, a radial height of an aft sidewall or an axial length.
According to another aspect of the present invention, a compressor stator assembly has an upper half and a lower half. The upper half has one or more upper half locker segments and a plurality of upper half pack segments. The plurality of upper half pack segments are located circumferentially between the one or more upper half locker segments. The lower half has one or more lower half locker segments and a plurality of lower half pack segments. The plurality of lower half pack segments are located circumferentially between the one or more lower half locker segments. At least one characteristic of the upper half is different than at least one characteristic of the lower half. The at least one characteristic of both the upper half and the lower half are chosen from at least one of, a number of pack segments, a pack segment span angle, and a pack segment arc length. Each of the upper half and the lower half have a stator casing having a plurality of stator casing slots. A set of stator portions are insertable in the stator casing slots, and the stator casing and the set of stator portions are configured such that the set of stator portions only assembles to the stator casing in a single stage of the stator casing, or in a single configuration.
According to yet another aspect of the present invention, a method of insuring proper installation of stator portions in a compressor stator assembly includes a step of inserting a set of stator portions into a stator casing slot of a stator casing. The stator portions are configured such that each of the stator portions only assembles to the compressor stator assembly in a single configuration or in a single stage of the stator casing. The inserting a set of stator portions step also includes inserting a plurality of stator vanes into a ring segment. The stator vanes have a stator vane characteristic that varies for each stage in the stator casing, and the stator vane characteristic is at least one of, a radial height of a forward sidewall, a radial height of an aft sidewall or an axial length. The inserting a set of stator portions step also includes inserting a plurality of ring segments into the stator casing slot. The ring segments have a ring segment characteristic that varies for each stage of the stator casing, and the ring segment characteristic is at least one of, a radial height of a forward ring segment surface, a radial height of an aft ring segment surface, a radial height of a forward ring segment projection, a radial height of an aft ring segment projection or a ring segment axial length. The stator casing slots have a casing slot characteristic that varies for each stage in the stator casing, and the casing slot characteristic is at least one of, a radial height of a forward casing slot sidewall, a radial height of an aft casing slot sidewall, a radial height of a forward casing slot groove, a radial height of an aft casing slot groove or a casing slot axial length. The stator vane characteristic and the ring segment characteristic are chosen so that stator vanes and the ring segments have asymmetrical profiles from an axial or radial/circumferential perspective. The asymmetrical profiles only allow the stator vanes and the ring segments to be assembled in a single direction.
These and other features and improvements of the present invention should become apparent to one of ordinary skill in the art upon review of the following detailed description when taken in conjunction with the several drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a compressor section including a portion of an open compressor casing showing five exemplary stages of stator vanes;

FIG. 2 illustrates individual stator vanes;

FIG. 3 illustrates a stator vane assembled in a slot of a turbine casing;

FIG. 4 illustrates a ring segment assembly slid out from the turbine casing slot;

FIG. 5 illustrates an axial compressor flow path, according to an aspect of the invention;

FIG. 6 illustrates a partial, cross-sectional view of a stator casing, according to an aspect of the invention;

FIG. 7 illustrates a perspective view of a plurality of stator vanes inserted in a ring segment, according to an aspect of the invention;

FIG. 8 illustrates a cross-sectional view of a stator vane, according to an aspect of the invention;

FIG. 9 illustrates a schematic representation of a stator or compressor stator assembly, according to an aspect of the invention; and

FIG. 10 is a flowchart of a method for insuring proper installation of stator portions in a compressor stator assembly, according to an aspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

One or more specific aspects/embodiments of the present invention will be described below. In an effort to provide a concise description of these aspects/embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with machine-related, system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments of the present invention, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Any examples of operating parameters and/or environmental conditions are not exclusive of other parameters/conditions of the disclosed embodiments. Additionally, it should be understood that references to “one aspect” or “an aspect” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments or aspects that also incorporate the recited features. A turbomachine is defined as a machine that transfers energy between a rotor and a fluid or vice-versa, including but not limited to gas turbines, steam turbines and compressors.
Referring now to the drawings, FIG. 5 illustrates an axial compressor flow path 500 of a compressor 501 that includes a plurality of compressor stages. The compressor 501 may be used in conjunction with, or as part of, a gas turbine. As one non-limiting example only, the compressor flow path 500 may comprise about eighteen rotor/stator stages. However, the exact number of rotor and stator stages is a choice of engineering design, and may be more or less than the illustrated eighteen stages. It is to be understood that any number of rotor and stator stages can be provided in the compressor, as embodied by the invention. The eighteen stages are merely exemplary of one turbine/compressor design, and are not intended to limit the invention in any manner.
The compressor rotor blades 502 impart kinetic energy to the airflow and therefore bring about a desired pressure rise. Directly following the rotor blades 502 is a stage of stator vanes 504. However, in some designs the stator vanes 504 may precede the rotor blades 502. Both the rotor blades 502 and stator vanes 504 turn the airflow, slow the airflow velocity (in the respective airfoil frame of reference), and yield a rise in the static pressure of the airflow. Typically, multiple rows of rotor/stator stages are arranged in axial flow compressors to achieve a desired discharge to inlet pressure ratio. Each rotor blade and stator vane includes an airfoil, and these airfoils can be secured to rotor wheels or a stator case by an appropriate attachment configuration, often known as a “root,” “base” or “dovetail”. In addition, compressors may also include inlet guide vanes (IGVs) 506, variable stator vanes (VSVs) 508 and exit or exhaust guide vanes (EGVs) 510. All of these blades and vanes have airfoils that act on the medium (e.g., air) passing through the compressor flow path 500.
Exemplary stages of the compressor 501 are illustrated in FIG. 5. One stage of the compressor 501 comprises a plurality of circumferentially spaced rotor blades 502 mounted on a rotor wheel 512 and a plurality of circumferentially spaced stator vanes 504 attached to a static compressor case 514. Each of the rotor wheels 512 may be attached to an aft drive shaft 516, which may be connected to the turbine section of the engine. The rotor blades and stator vanes lie in the flow path 500 of the compressor 501. The direction of airflow through the compressor flow path 500, as embodied by the invention, is indicated by the arrow 518 (FIG. 5), and flows generally from left to right in the illustration.
The rotor blades 502 and stator vanes 504 herein of the compressor 501 are merely exemplary of the stages of the compressor 502 within the scope of the invention. In addition, each inlet guide vane 506, rotor blade 502, stator vane 504, variable stator vane 508 and exit guide vane 510 may be considered an article of manufacture. Further, the article of manufacture may comprise a stator vane and/or a stator casing and/or a ring segment configured for use with a compressor.
Aspects of the present invention provide a collection of strategically defined geometric features incorporated in the compressor stator assembly and on the stator vanes, ring segments (also referred to as stator vane attachments), and casing slots for a unique configuration of the compressor stator assembly. This unique (or single) configuration prevents mis-assembly due to assembly errors. Assembly errors occur when a stator vane or ring segment is installed in the wrong stage or the wrong half of the casing. For example, a stator vane or ring segment may be designed for an upper half of the compressor, but assembly error leads to installation in the lower half of the compressor. Further, this unique configuration provides a physical method of mis-assembly proofing where the wrong method of installation may not be visually apparent. For example, it would be difficult to place a stage five stator vane in a stage thirteen stator slot, however, it would be very easy to interchange (and install incorrectly) a stage eleven stator vane with a stage twelve stator vane. Adjacent stages may have very similarly sized components, and even though these sizes may look visually the same, the improper installation of components can lead to severe machine damage and loss of efficiency.
FIG. 6 illustrates a partial, cross sectional view of a stator casing 600 that has a plurality of stator casing slots 604, according to an aspect of the present invention. In this example, a ring segment 700, shown in phantom, is positioned within the stator casing slot 604. The stator casing slot has an axial length 605 which may be the distance between the forward sidewall 606 and the aft sidewall 607. Alternatively, the axial length 610 may be measured from the forward surface and aft surface of the forward groove 612 and aft groove 613. The stator casing slot 604 also has two radial heights. The radial height 620 of the forward sidewall 606 may be measured from the bottom of slot 604 to the top of forward sidewall 606. The radial height 630 of the aft sidewall 607 may be measured from the bottom of slot 604 to the top of aft sidewall 607. According to an aspect of the present invention, the stator casing slots 604 may have one or more casing slot characteristics that vary for each stage in the stator casing 600. The casing slot characteristics include a radial height 620 of a forward casing slot sidewall 606, a radial height 630 of an aft casing slot sidewall 607, a radial height 614 of a forward casing slot groove 612, a radial height 615 of an aft casing slot groove 613 or a casing slot axial length 605, 610. The forward radial height 620 may be configured to be different from the aft radial height 630, and in the example shown the forward radial height 620 is smaller than the aft radial height 630. Further, the radial height 614 (and/or radial position) of the forward groove 612 may be different than the radial height 615 (and/or radial position) of the aft groove 613. The radial positioning of the forward and aft grooves may also be different.
It is to be understood that the invention is not to be limited to only the examples shown, and that the invention also includes embodiments where the aft groove has a smaller radial height than the forward radial groove, the forward and aft radial grooves have different axial depths, the forward and aft radial grooves have different geometrical cross-sectional shapes and/or the forward and aft radial grooves have different radial heights or are located at different radial heights. It is also to be understood that the invention also includes embodiments where the forward sidewall has a larger radial height than the aft sidewall.
FIG. 7 illustrates a perspective view of a plurality of stator vanes 800 inserted in or assembled to a ring segment 700, according to an aspect of the present invention. The ring segment 700 fits into (or assembles to) the stator casing slot 604, and the stator vanes 800 fit into (or assemble to) a ring segment 700. The ring segments 700 may have one or more ring segment characteristics that vary for each stage in the stator casing 600. The ring segment characteristics include a radial height 740 of a forward ring segment surface 732, a radial height 742 of an aft ring segment surface 734, a radial height 744 of a forward ring segment projection 736, a radial height 746 of an aft ring segment projection 738 or a ring segment axial length 730.
The ring segment's axial length 730 may be measured from the forward sidewall or forward surface 732 to the aft sidewall or aft surface 734, or the axial length 730 may be measured from the end of the forward projection 736 to the end of the aft projection 738. According to an aspect of the present invention, this axial length 730 may be configured so that it is different for each stage of the stator, for adjacent stages of the stator, or for nearby stages of the stator. This “single” configuration provides the advantage of eliminating the possibility of a ring segment designed for a specific stage from being installed in an adjacent or nearby stage of the stator. For example, the axial length 730 for a stage five ring segment may be 3 inches, and the axial length for a stage six ring segment may be 2.75 inches, so it would be impossible to insert the stage five ring segment into a stage six stator casing slot, because the stage six stator casing slot would be too small.
Ring segments may also be installed backwards when the cross-sectional profile of the ring segment is symmetrical. When this happens, machine efficiency is reduced and damage may occur. According to another aspect of the present invention, the ring segment 700 has a generally trapezoidal or quadrilateral cross-sectional profile. The radial height 740 of the forward sidewall/surface 732 is configured to be different than the radial height 742 of the aft sidewall/surface 734, and these heights may be measured from the base of the respective sidewalls or from the bottom surface of the ring segment. The radial height 740 is shown to be smaller than radial height 742, but it is to be understood that the radial height 740 could also be configured to be larger than radial height 742.
In addition, the radial height 744 of the forward projection 736 may be configured to be smaller than the radial height 746 of the aft projection 738. As one example only, the radial height 744 of the forward projection 736 may be about 0.25 inches while the radial height 746 of the aft projection 738 may range between about 0.30 inches and about 0.50 inches. The purpose of the difference in radial heights (between forward and aft projections) is to ensure that the ring segment 700 is not installed backwards in the stator casing slot. Further, adjacent or nearby stages may have different radial heights for the aft projection (and/or different radial heights for the forward projection) to further error-proof installation. Both the ring segments 700 and the stator vanes 800 may have their characteristics and asymmetrical profiles (from an axial and/or radial/circumferential perspective) chosen so that both articles may only be installed (or assembled) in a single direction, or a single configuration. This asymmetrical profile aspect will prevent backwards installation of the ring segment 700 or stator vane 800. An asymmetrical profile example is the forward surface of the stator vane being lower (or higher) than the aft surface, as this requires the stator vane to be installed in only one direction. Another example is that the forward and aft projections (or grooves) have different radial heights and/or positions, and this also ensures that the stator components are installed in a single configuration.
FIG. 8 illustrates a cross-sectional view of a stator vane 800, according to an aspect of the present invention. The stator vane 800 may be configured to fit directly or assemble into a stator casing slot or into a ring segment, where the ring segment is configured to engage a stator casing slot. The stator vane 800 has an angled platform 810 that tapers up from a forward side 801 to an aft side 802. However, the platform could also be configured to taper downward from the forward side to the aft side of the stator vane. This taper ensures that the stator vane 800 can only be inserted in the designed direction on the ring segment or stator casing slot, and that backwards installation is impossible. In order to properly match the complementary surfaces of the ring segment or stator casing slot, the stator vane characteristics must cooperate with the complementary surfaces. The stator vane characteristics may include a radial height 821 of a forward sidewall 811, a radial height 822 of an aft sidewall 812 or an axial length 850. The forward surface or forward sidewall 811 is configured to have a smaller radial height 821 than the radial height 822 of the aft surface or aft sidewall 812. The lower dovetail 830 or tang portion 830 is configured to fit within the lower portion of the ring segment slot. The upper dovetail 840 is tapered to follow the contours of the platform 810 and to allow insertion into the ring segment or stator casing slot. The axial length 850 of the stator vane 800 may also be configured to be different for each stage or for adjacent or nearby stages to reduce or eliminate the possibility of installation in an undesired stage ring segment or stator casing slot.
It will be apparent that the set of stator portions (e.g., ring segment 700 and stator vane 800) are insertable in the stator casing slot 604. The stator casing slot 604, ring segment 700 and stator vane 800 may be configured so that the set of stator portions only assemble to the stator casing slot 604 in a single stage of the stator casing 600, and/or in a single configuration. For example, this arrangement prevents a stage 9 stator vane from being assembled in a stage 10 or stage 11 ring segment, and also prevents a stage 7 ring segment from being assembled in a stage 6 or stage 8 casing slot. A single configuration may be viewed as the part for a specific stage is installed in that stage (and not some other stage), and/or the part is installed in the correct orientation (i.e., not backwards from what is intended).
FIG. 9 illustrates a schematic representation of a stator, according to an aspect of the present invention. The stator 900 may be divided into many arcuate sections or segments. An upper half 901 may include an upper half left half locker segment 911, an upper half right half locker segment 912, and a plurality of pack segments 913-916. However, it is to be understood that more or less pack segments could be used as desired in the specific application. Each of the upper pack segments span an angle of θn and have a circumferential length or arc length of ARCn. θn may be referred to as the span angle. The upper half segments may be referred to collectively as the n-Pack.
A lower half 902 may include a lower half left half locker segment 921, a lower half right half locker segment 922, and a plurality of pack segments 923-929. However, it is to be understood that more or less pack segments could be used as desired in the specific application, as long as there are a different number of upper and lower pack segments. Each of the lower pack segments span an angle of Gm and have a circumferential length or arc length of ARCm. θm may be referred to as the span angle. The lower half m-segments may be referred to collectively as the m-Pack.
According to an aspect of the present invention, and to aid in fool proofing installation of stator components, the stator has a different number of n-pack segments than m-pack segments. As shown, there are fewer n-pack segments than m-pack, but this could be reversed to have more m-pack segments than n-pack segments as desired in the specific application. The angle of θn is also configured to be different than the angle θm, and in the example shown θn is greater than θm. However, it is to be understood that in some applications it may be desirable to have θm be greater than θn. The difference in angles also leads to a difference in segment arc length, as the arc length ARCn is greater than the arc length ARCm. However, it is to be understood that in some applications it may be desirable to have ARCm be greater than ARCn.
According to an aspect of the present invention, an article of manufacture configured for use with a turbomachine has a stator 900 having an upper half 901 and a lower half 902. The upper half 901 has one or more upper half locker segments 911, 912 and a plurality of upper half pack segments 913-916. The upper half pack segments 913-916 are located circumferentially between the one or more upper half locker segments 911, 912. The lower half 902 has one or more lower half locker segments 921, 922 and a plurality of lower half pack segments 923-929. The lower half pack segments 923-929 are located circumferentially between the lower half locker segments 921, 922. At least one characteristic of the upper half 901 is different than at least one characteristic of the lower half 902. The characteristics of both the upper half 901 and lower half 902 are chosen from one, all or a portion of, the number of pack segments, the pack segment span angle θn or θm, and pack segment arc length ARCn or ARCm.
The various features of the stator, according to an aspect of the present invention, are used to fool proof installation of stator components. It can be seen that by physically changing the stator segments so that the number of n-pack segments are different from the number of m-pack segments, configuring the angle θn to be different from the angle θm and by configuring the arc length ARCn to be different than the arc length ARCm, that it is now extremely difficult, if not impossible, to improperly install the stator components.
Aspects of the present invention provide, an article of manufacture comprising a first component (e.g., stator vane 800) configured for use with a stator of a turbomachine. The first component (e.g., stator vane 800) is configured for attachment to a second component (e.g., ring segment 700) also configured for use with the stator of the turbomachine. The first component (e.g., stator vane 800) is configured to substantially reduce the possibility of installation in an undesired stage of the stator by modification of at least one characteristic of the first component. The second component (e.g., ring segment 700) is configured to substantially reduce the possibility of installation in an undesired stage of the stator by modification of at least one characteristic of the second component.
The characteristic of the stator vane 800 may be chosen from one, all, or a portion of, the radial height 821 of a forward sidewall 811, the radial height 822 of an aft sidewall 812, and an axial length 850. The characteristic of the ring segment 700 may be chosen from one, all, or a portion of, the radial height 740 of a forward surface 732, the radial height 742 of an aft surface 734, the radial height 744 of a forward projection 736, the radial height 746 of an aft projection 738, and an axial length 730.
The article of manufacture may also include a third component (e.g., stator casing slot 604) configured for use with the stator of the turbomachine. The third component is also configured for attachment to the second component (e.g., ring segment 700). The third component (e.g., stator casing slot 604) is configured to substantially reduce the possibility of installation in an undesired stage of the stator by modification of at least one characteristic of the third component. The characteristic of the stator casing slot 604 may be chosen from one, all, or a portion of, the radial height 620 of a forward sidewall 606, a radial height 630 of an aft sidewall 607, a radial height of a forward groove 612, a radial height of an aft groove 613, and an axial length 605 or 610. The article(s) of manufacture, as herein described may also be referred to as a compressor stator assembly. The compressor stator assembly may include, some or all of, the stator casing 600, stator casing slots 604, ring segments 700 and stator vanes 800.
FIG. 10 is a flowchart of a method 1000 for insuring proper installation of stator portions in a compressor stator assembly, according to an aspect of the present invention. In inserting step 1010, a set of stator portions are inserted in a stator casing slot 604 or stator casing 600. The stator portions may include ring segments 700 and/or stator vanes 800. The inserting step 1020 may be viewed as part of step 1010, and includes inserting a plurality of stator vanes 800 into a ring segment 700. The inserting step 1030 may also be viewed as part of step 1010, and includes inserting a plurality of ring segments 700 into a stator casing slot 604. These steps may be repeated as often as desired, or until the compressor stator assembly is fully assembled. As mentioned previously, the stator vane characteristic and the ring segment characteristic are chosen so that stator vanes 800 and the ring segments 700 have asymmetrical profiles from an axial and/or radial or circumferential perspective. The asymmetrical profiles restrict or only allow the stator vanes and the ring segments to be assembled in a single direction, and this prevent backwards installation of the stator vanes 800 or ring segments 700.
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.

Claims

1. A compressor stator assembly comprising:

a stator casing having a plurality of stator casing slots,

a set of stator portions being insertable in the stator casing slots, the stator casing and the set of stator portions being configured such that the set of stator portions only assembles to the stator casing in a single stage of the stator casing, or in a single configuration.

2. The compressor stator assembly of claim 1, wherein the set of stator portions includes a plurality of stator vanes, the stator vanes having a stator vane characteristic that varies for each stage in the stator casing, the stator vane characteristic comprising at least one of, a radial height of a forward sidewall, a radial height of an aft sidewall or an axial length.

3. The compressor stator assembly of claim 2, wherein the set of stator portions includes a plurality of ring segments configured to assemble to the stator casing slots, and the stator vanes are configured to assemble to the ring segments, the ring segments having a ring segment characteristic that varies for each stage of the stator casing, the ring segment characteristic comprising at least one of, a radial height of a forward ring segment surface, a radial height of an aft ring segment surface, a radial height of a forward ring segment projection, a radial height of an aft ring segment projection or a ring segment axial length.

4. The compressor stator assembly of claim 3, the stator casing slots have a casing slot characteristic that varies for each stage in the stator casing, the casing slot characteristic comprising at least one of, a radial height of a forward casing slot sidewall, a radial height of an aft casing slot sidewall, a radial height of a forward casing slot groove, a radial height of an aft casing slot groove or a casing slot axial length.

5. The compressor stator assembly of claim 4, wherein the stator vane characteristic and the ring segment characteristic are chosen so that the stator vanes and the ring segments have asymmetrical profiles from an axial or radial/circumferential perspective.

6. The compressor stator assembly of claim 5, wherein the asymmetrical profiles only allow the stator vanes and the ring segments to be assembled in a single direction.

7. The compressor stator assembly of claim 4, further comprising:

an upper half and a lower half;

the upper half having one or more upper half locker segments and a plurality of upper half pack segments, the plurality of upper half pack segments located circumferentially between the one or more upper half locker segments;

the lower half having one or more lower half locker segments and a plurality of lower half pack segments, the plurality of lower half pack segments located circumferentially between the one or more lower half locker segments; and

wherein at least one characteristic of the upper half is different than at least one characteristic of the lower half, and the at least one characteristic of both the upper half and the lower half are chosen from at least one of, a number of pack segments, a pack segment span angle, and a pack segment arc length.

8. A compressor stator assembly comprising:

an upper half and a lower half;

the lower half having one or more lower half locker segments and a plurality of lower half pack segments, the plurality of lower half pack segments located circumferentially between the one or more lower half locker segments, wherein at least one characteristic of the upper half is different than at least one characteristic of the lower half, and the at least one characteristic of both the upper half and the lower half are chosen from at least one of, a number of pack segments, a pack segment span angle, and a pack segment arc length;

each of the upper half and the lower half having a stator casing having a plurality of stator casing slots; and

9. The compressor stator assembly of claim 8, wherein the set of stator portions includes a plurality of stator vanes, the stator vanes having a stator vane characteristic that varies for each stage in the stator casing, the stator vane characteristic comprising at least one of, a radial height of a forward sidewall, a radial height of an aft sidewall or an axial length.

10. The compressor stator assembly of claim 9, wherein the stator vane characteristic is chosen so that the stator vanes have asymmetrical profiles from an axial or radial/circumferential perspective.

11. The compressor stator assembly of claim 10, wherein the asymmetrical profiles only allow the stator vanes to be assembled in a single direction.

12. The compressor stator assembly of claim 8, wherein the set of stator portions includes a plurality of ring segments configured to assemble to the stator casing slots, and a plurality of stator vanes are configured to assemble to the ring segments, the ring segments having a ring segment characteristic that varies for each stage of the stator casing, the ring segment characteristic comprising at least one of, a radial height of a forward ring segment surface, a radial height of an aft ring segment surface, a radial height of a forward ring segment projection, a radial height of an aft ring segment projection or a ring segment axial length.

13. The compressor stator assembly of claim 12, wherein the ring segment characteristic is chosen so that the ring segments have asymmetrical profiles from an axial or radial/circumferential perspective.

14. The compressor stator assembly of claim 13, wherein the asymmetrical profiles only allow the ring segments to be assembled in a single direction.

15. The compressor stator assembly of claim 8, the stator casing slots having a casing slot characteristic that varies for each stage in the stator casing, the casing slot characteristic comprising at least one of, a radial height of a forward casing slot sidewall, a radial height of an aft casing slot sidewall, a radial height of a forward casing slot groove, a radial height of an aft casing slot groove or a casing slot axial length.

16. A method of insuring proper installation of stator portions in a compressor stator assembly, the method comprising:

inserting a set of stator portions into a stator casing slot of a stator casing; and

the stator portions being configured such that each of the stator portions only assembles to the compressor stator assembly in a single configuration or in a single stage of the stator casing.

17. The method of claim 16, the inserting a set of stator portions step further comprising:

inserting a plurality of stator vanes into a ring segment; and

wherein the stator vanes have a stator vane characteristic that varies for each stage in the stator casing, the stator vane characteristic comprising at least one of, a radial height of a forward sidewall, a radial height of an aft sidewall or an axial length.

18. The method of claim 17, the inserting a set of stator portions step further comprising:

inserting a plurality of ring segments into the stator casing slot; and

wherein the ring segments have a ring segment characteristic that varies for each stage of the stator casing, the ring segment characteristic comprising at least one of, a radial height of a forward ring segment surface, a radial height of an aft ring segment surface, a radial height of a forward ring segment projection, a radial height of an aft ring segment projection or a ring segment axial length.

19. The method of claim 18, wherein the stator casing slots have a casing slot characteristic that varies for each stage in the stator casing, the casing slot characteristic comprising at least one of, a radial height of a forward casing slot sidewall, a radial height of an aft casing slot sidewall, a radial height of a forward casing slot groove, a radial height of an aft casing slot groove or a casing slot axial length.

20. The method of claim 19, wherein the stator vane characteristic and the ring segment characteristic are chosen so that stator vanes and the ring segments have asymmetrical profiles from an axial or radial/circumferential perspective; and

wherein the asymmetrical profiles only allow the stator vanes and the ring segments to be assembled in a single direction.