Seal flow circuits in the outlet region of a turbomachine compressor

Abstract

The turbomachine compressor includes a final stage of vanes having tip shrouds within circumferential grooves in the inner casing. Each tip shroud defines a downstream opening with the aft wall of the groove. Below each tip shroud, an outlet channel extends to a high-pressure packing seal (HPPS) cavity to reduce fluid leakage from downstream to an upstream region of the final stage of vanes. A first seal within the circumferential groove diverts compressed gas entering the downstream opening into the HPPS cavity. The outlet channels can extend axially or radially, and a second seal may be included between the outlet channel and the downstream opening for the radial outlet channel.

Description

[Technical Field]

[0001] The present disclosure relates generally to seal flow management for gas turbine compressors and flow circuits therefor. More particularly, the present disclosure relates to a flow circuit for use with a seal arrangement for vanes in the outlet region of a turbomachine compressor, such as last stage stator vanes. [Background technology]

[0002] Pressure losses at various locations within a turbomachine, particularly through seals on components within the flowpath through the turbomachine, can lead to reduced operating efficiency. For example, a turbomachine with a cold gas path can include a compressor with vanes in an outlet region, such as a last-stage stator, and the compressor can have a tip shroud that resides in a circumferential groove in the turbomachine's inner casing and can be attached to the vanes via mounting hardware, such as bolts, bushings, and the like. Tolerances and clearances of the tip shroud and the circumferential groove can provide a path through which leakage can occur during operation through a forward-aft opening defined by the forward-aft end of the tip shroud and the forward-aft end of the circumferential groove, as well as a gap between the mounting hardware and the bottom wall of the circumferential groove. To reduce leakage, previous arrangements have placed brush seals between the bottom wall of the circumferential groove and the tip shroud. While previous arrangements including brush seals have sufficiently reduced leakage through the circumferential groove below the tip shroud, modifications to the circumferential groove, the tip shroud, and / or the mounting hardware can reduce the effectiveness of such seals. As a result, turbomachines with such modified components may experience more pressure loss than desired as compressed gas passes through the brush seals under the vane bases. This can undesirably result in leaked compressed gas being reintroduced into the main flowpath before the vanes, which can cause aerodynamic problems for the turbomachine during operation. Additionally, compressor efficiency is adversely affected. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2016 / 0177762 Summary of the Invention

[0004] All aspects, examples, and features described below can be combined in any way technically possible.

[0005] One aspect of the present disclosure provides a turbomachine rotor assembly comprising: a circumferential groove in an inner casing of a turbomachine, the circumferential groove extending generally radially inward from an outer surface of the inner casing and having a bottom wall, a forward wall, and an aft wall; an HPPS cavity defined by the inner casing and a rotor of the turbomachine, the HPPS cavity including an HPPS inlet between a forward portion of the inner casing and an aft end of a compressor portion of the rotor of the turbomachine; a vane attached to an outer casing of the turbomachine and extending to the inner casing, the vane having a tip disposed in the circumferential groove; and a vane extending from the tip and extending to the inner casing. a vane tip shroud having an outer surface generally flush with the outer surface of the vane and an inner surface disposed within a circumferential groove, the tip shroud and a forward wall of the circumferential groove defining an upstream opening, and the tip shroud and an aft wall of the circumferential groove defining a downstream opening; a first seal mounted within the circumferential groove, extending toward the vane tip shroud and having a first clearance therewith; and an outlet channel extending from the circumferential groove through the inner casing to the HPPS cavity.

[0006] Another aspect of the present disclosure includes any of the above aspects, wherein the first seal is attached to a bottom wall of the circumferential groove.

[0007] Another aspect of the present disclosure includes the aforementioned aspect, wherein the outlet channel extends from a forward wall of the circumferential groove to a forward portion of the inner casing generally parallel to the axis of rotation of the turbomachine.

[0008] Another aspect of the present disclosure includes any of the preceding aspects, wherein the outlet channel is circumferentially oriented and angled to induce swirl in the gas within the HPPS cavity.

[0009] Another aspect of the present disclosure includes any of the aforementioned aspects, wherein the outlet channel is one of a plurality of outlet channels, each outlet channel of the plurality of outlet channels having a respective outlet hole, and the first seal is a labyrinth seal including two teeth having a clearance of about 0.254 millimeters (mm) to about 4 mm, and a diameter of each outlet hole is about 2.54 mm to about 25.4 mm.

[0010] Another aspect of the present disclosure includes any of the preceding aspects, wherein the vane is one of a plurality of circumferentially arranged vanes each having a respective tip shroud within the circumferential groove; and wherein the total area of ​​all of the plurality of outlet channels is at least 23 cm. 2 is.

[0011] Another aspect of the present disclosure includes any of the aforementioned aspects, wherein the outlet channel is one of a plurality of outlet channels, each outlet channel of the plurality of outlet channels having a respective outlet hole, the first seal is a labyrinth seal including two teeth with a clearance of about 4 mm, and a diameter of each outlet hole is about 10 mm to about 13 mm.

[0012] Another aspect of the present disclosure includes any of the above aspects, further including a second seal disposed between the first seal and the downstream opening.

[0013] Another aspect of the present disclosure includes any of the preceding aspects, wherein the outlet channel extends generally radially from a bottom wall of the circumferential groove to the HPPS cavity.

[0014] Another aspect of the present disclosure includes any of the preceding aspects, wherein the outlet channel extends from a location within the circumferential groove between the first seal and the downstream opening.

[0015] Another embodiment of the present disclosure includes any of the preceding embodiments, further including a second seal between the outlet channel and the downstream opening.

[0016] Another aspect of the present disclosure includes any of the preceding aspects, wherein the first seal is a labyrinth seal having one tooth and the second seal is a labyrinth seal having two teeth.

[0017] Another aspect of the present disclosure provides a seal apparatus for a turbomachine, the apparatus including: a first seal extending between a tip shroud of a vane of the turbomachine and a wall of a circumferential groove of an inner casing of the turbomachine, the first seal being disposed between a mount of the tip shroud and a forward wall of the circumferential groove; and an outlet channel extending from the circumferential groove to an HPPS cavity defined by a rotor and inner casing of the turbomachine, whereby during operation of the turbomachine, fluid entering a downstream opening of the circumferential groove is directed through the outlet channel to the HPPS cavity.

[0018] Another aspect of the present disclosure includes any of the aforementioned aspects, wherein the outlet channel extends generally parallel to the axis of rotation of the turbomachine from the circumferential groove to a forward portion of the inner casing that is perpendicular to the axis of rotation of the turbomachine.

[0019] Another aspect of the present disclosure includes any of the aspects described above, and further includes an outlet hole of the outlet channel formed in the forward portion of the inner casing and an inlet hole formed in the forward wall of the circumferential groove.

[0020] Another aspect of the present disclosure includes any of the above aspects, wherein the first seal is a labyrinth seal including two teeth.

[0021] Another aspect of the present disclosure includes any of the aforementioned aspects, further including a second seal disposed between the first seal and the downstream opening defined by the circumferential groove and the tip shroud.

[0022] Another aspect of the present disclosure includes any of the above aspects, wherein the outlet channel extends generally radially from the circumferential groove to the HPPS cavity.

[0023] Another aspect of the present disclosure includes any of the preceding aspects, wherein the outlet channel extends from a location within the circumferential groove between the first seal and the downstream opening.

[0024] Another aspect of the present disclosure includes any of the preceding aspects, wherein the first seal is a labyrinth seal having one tooth and the second seal is a labyrinth seal having two teeth.

[0025] Two or more aspects described in this disclosure, including those described in this Summary section, may be combined to form an embodiment not specifically described herein.

[0026] The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will become apparent from the description and drawings, and from the claims.

[0027] These and other features of the present disclosure will be more readily understood from the following detailed description of the various aspects of the disclosure, taken in conjunction with the accompanying drawings which illustrate various embodiments of the present disclosure. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a cross-sectional view of an exemplary turbomachine (e.g., a gas turbine engine) in which aspects of the embodiments disclosed herein may be deployed. [Figure 2] 2 is an enlarged cross-sectional view of a turbomachine (e.g., the gas turbine engine of FIG. 1 ) compressor outlet region in which a seal arrangement according to an embodiment of the present disclosure may be deployed. [Figure 3] FIG. 1 is an elevation view of a portion of a last stator stage of a turbomachine compressor, illustrating the circumferential arrangement of stator vanes on its inner casing, in which a seal arrangement according to an embodiment of the present disclosure may be deployed. [Figure 4] FIG. 2 is an enlarged cross-sectional view of the outlet area of ​​a turbomachine compressor illustrating possible leak paths that may occur with conventional seal arrangements and that can be mitigated using a seal arrangement according to an embodiment of the present disclosure. [Figure 5] FIG. 2 is an enlarged cross-sectional view of a vane tip region at the outlet area of ​​a turbomachine compressor with a seal arrangement deployed according to an embodiment of the present disclosure. [Figure 6] FIG. 2 is an enlarged cross-sectional view of a vane tip region at the outlet area of ​​a turbomachine compressor with a seal arrangement deployed according to an embodiment of the present disclosure. [Figure 7] FIG. 2 is an enlarged cross-sectional view of a vane tip region at the outlet area of ​​a turbomachine compressor with a seal arrangement deployed according to an embodiment of the present disclosure. [Figure 8] FIG. 2 is a rear view of the face of the inner casing of a turbomachine with a seal arrangement deployed according to an embodiment of the present disclosure, illustrating an arrangement of root outlet channels according to an embodiment of the present disclosure. [Figure 9] FIG. 2 is an enlarged cross-sectional view of a vane tip region at the outlet area of ​​a turbomachine compressor with a seal arrangement deployed according to an embodiment of the present disclosure. [Figure 10] 1 is an enlarged cross-sectional view of a vane root area in an outlet region of a turbomachine compressor, in which a seal arrangement according to an embodiment of the present disclosure is deployed and an alternative outlet channel arrangement is used. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0029] It should be noted that the drawings of the present disclosure are not necessarily to scale. The drawings are intended to depict only typical aspects of the present disclosure and therefore should not be considered limiting of the scope of the present disclosure. In the drawings, like reference numerals represent like elements between the drawings.

[0030] As an initial matter, in order to clearly explain the subject matter of the present disclosure, it becomes necessary to select specific terminology when describing compositions related to machine components within turbomachinery. Wherever possible, common industry terminology will be used and adopted consistent with its accepted meaning. Unless otherwise noted, such terminology should be given a broad interpretation consistent with the context of this application and the appended claims. Those skilled in the art will understand that particular components are often referred to using several different or overlapping terms. What may be described as a single component in this specification may be included and referenced as consisting of multiple components in other contexts. Alternatively, what may be described as including multiple components in this specification may be referenced as a single component elsewhere.

[0031] Additionally, several descriptive terms may be used regularly herein, and it will prove useful to define these terms at the beginning of this section. These terms and their definitions are as follows, unless otherwise stated: As used herein, "downstream" and "upstream" are terms that indicate a direction relative to the flow of a working fluid through a turbomachine, or a fluid, such as, for example, the flow of air through a combustor, or a coolant through one of the component systems of a turbomachine. The term "downstream" corresponds to the direction of fluid flow, and the term "upstream" refers to the opposite direction to the flow. It is recognized that in counterflow configurations, the directions of upstream and downstream may change depending on where in the turbomachine one is located. The terms "forward" and "aft," without other specification, refer to directions, with "forward" referring to the front end of the turbomachine and "aft" referring to the rear of the turbomachine.

[0032] It is often necessary to describe components at different radial locations relative to a central axis. The term "radial" refers to movement or position perpendicular to the axis. In such cases, if a first component is closer to the axis than a second component, the first component is said to be "radially inward" or "inside" the second component. Conversely, if a first component is farther from the axis than the second component, the first component may be said to be "radially outward" or "outside" the second component. The term "axial" refers to movement or position parallel to the axis. Finally, the term "circumferential" refers to movement or position about an axis. It will be understood that such terms may be applied with respect to the central axis of a turbomachinery system, e.g., the axis of its rotor.

[0033] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the disclosure. The terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another, but are not intended to denote the location or importance of the individual components. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and / or “comprising,” as used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. "Optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, or the subsequently described component or element may or may not be present, and that the description includes instances in which the event occurs or the element is present and instances in which the event does not occur or is not present.

[0034] When an element or layer is referred to as "on," "engaged," "connected," or "coupled" to another element or layer, it may be directly on, engaged, connected, or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as "directly on," "directly engaged," "directly connected," or "directly coupled" to another element or layer, there are no intervening elements or layers. Other terms used to describe relationships between elements should be interpreted similarly (e.g., "between" and "directly between," "adjacent" and "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0035] As seen in FIG. 1 , a turbomachine 10 (e.g., a gas turbine engine) may include an outer casing 11 that may house a compressor 12, a turbine 14, and a combustor 16 that combusts fuel to generate hot gases that can drive the turbine 14. The turbine 14 is mechanically connected to the compressor 12, such as by a rotor 20, such that the turbine 14, when driven by hot gases from the combustor 16, drives the compressor 12. The compressor 12 includes a plurality of blades 18 and vanes, including alternating rows of rotor blades attached to the rotor 20 and stator vanes attached to an inner casing 22 and extending into a working flowpath 21 of the compressor 12. Each set of blades and vanes is circumferentially distributed about the turbomachine's axis of rotation R. The alternating rotor blades and stator vanes may be arranged in a series of stages such that, during operation, air received through an inlet 13 is compressed to progressively higher pressures until, with further reference to FIG. 2 , the compressed air passes through a final stage of stator vanes 30 and enters the compressor outlet cavity 15. The compressed air may then be supplied to the combustor 16 , the cooling circuit, and other systems of the turbomachine 10 .

[0036] FIG. 3 illustrates an arrangement of vanes 30 that may employ sealing embodiments of the present disclosure. More specifically, the inner casing 22 of the turbomachine 10 may include a circumferential groove 31, with the vanes 30 extending from an attachment point (not shown), for example, in the outer casing 11, toward the circumferential groove 31. The vanes 30 may include tip shrouds 32 disposed within the circumferential groove 31 such that adjacent tip shrouds engage with one another to form a segmented ring. Each tip shroud 32 may be attached to the respective vane 30 by a mount 34, which may include hardware such as bushings, bolts, etc., as understood in the art. Additional aspects of FIG. 3 will be described after discussing FIG. 4.

[0037] Turning to FIG. 4 , a schematic illustrating a problem that may arise when using a conventional brush seal 60 and high-pressure packing seal (HPPS) circuit 50 with a vane 30 mounted with a novel mount 34 is shown. As shown, a tip shroud 32 of a vane 30, such as a stator vane, may be retained within a circumferential groove 31 in an inner casing 22 of a turbomachine 10 via the mount 34. The HPPS circuit 50 may be configured to direct fluid in an HPPS flowpath 52 from an inlet 54 upstream of the vane 30 through an HPPS cavity 24 defined by a forward portion 23 of the inner casing 22 ( FIG. 3 ) and a surface of the rotor 20 of the turbomachine 10 aft of the blades 18 of the compressor 12. Specifically, the HPPS cavity 24 includes an HPPS inlet between the forward portion 23 of the inner casing 22 and the aft end of the compressor portion of the rotor 20 of the turbomachine 10. The HPPS flowpath 52 may continue between the surface of the inner casing 22 and the surface of the rotor 20, across the HPPS 26, to a downstream cavity 28 of the turbomachine 10, such as a turbine wheel cavity. The downstream cavity 28 may be defined in part by the surface of the inner casing 22 and the surface of the rotor 20 aft of the HPPS 26.

[0038] The circumferential groove 31 and tip shroud 32 collectively define a downstream opening 38 to the compressor working flow passage 21 and an upstream opening 39 to the compressor working flow passage 21. FIG. 4 shows a conventional brush seal 60 in the circumferential groove 31 and illustrates the groove flow 36 that may result from several mounts 34 from the downstream opening 38 to the upstream opening 39 and into the working flow passage 21 upstream of the vane 30. It should be understood that the vane 30 is one of multiple vanes 30 circumferentially distributed on the inner casing 22, each having its own mount 34 and associated components. As a result, the illustrated downstream and upstream openings 38, 39 are part of the downstream and upstream circumferential gaps between the tip shroud 32 and the forward and aft walls of the circumferential groove 31, as seen in FIG. 3 .

[0039] 3 and 5-8 , a seal arrangement 100 according to an embodiment of the present disclosure may include a first seal 102 in a circumferential groove 31 beneath a vane 30. As seen particularly in FIG. 6 , the circumferential groove 31 may have a forward wall 311, a bottom wall 312, and an aft wall 313. In an embodiment, the bottom wall 312 may include a forward portion 314 and an aft portion 315 with a step 316 therebetween such that the forward portion 314 extends deeper into the inner casing 22 than the aft portion 315. Providing such a step 316 in the bottom wall 312 provides sufficient space in the forward portion 314 for the mount 34 and a portion of the tip shroud 32, while reducing the space between the tip shroud 32 and the aft portion 315, thereby reducing leakage through the circumferential groove 31 during operation of the turbomachine 10.

[0040] As indicated above, each tip shroud 32 having a circumferential groove 31 may define a downstream opening 38 to the working flow passage 21 at the downstream end of the respective vane 30 and an upstream opening 39 to the working flow passage 21 at the upstream end of the respective vane 30. More specifically, the downstream opening 38 may be defined by the tip shroud 32 and the aft wall 313, and the upstream opening 39 may be defined by the tip shroud 32 and the forward wall 311. The first seal 102 may extend radially between the tip shroud 32 and the inner casing 22, for example. Each outlet channel 110 may extend from the circumferential groove 31 to the HPPS cavity 24 to fluidly connect these regions, such that, during operation of the turbomachine 10, fluid entering the downstream opening 38 of the circumferential groove 31 is directed through the outlet channel 110 to the HPPS flow passage 52, effectively forming the modified HPPS flow passage 152 of the modified HPPS circuit 150. That is, the forward / upstream HPPS inward flow drawn into the HPPS inlet 54 by the modified HPPS circuit 150 may combine with the modified groove flow 136 to form a modified HPPS circuit flow within the modified HPPS flowpath 152 .

[0041] As seen in FIGS. 6 and 7 , the first seal 102 can include a base 104 having at least one tooth 106, 108 extending therefrom. In the particular example illustrated, two teeth 106, 108 are shown on the first seal 102, but other numbers of teeth can be used as desired and appropriate and / or depending on other factors of the arrangement 100. As seen in particular in FIGS. 5 and 7 , the first seal 102 can interact with a modified root cavity flow 136, an upstream root inward flow 120, an upstream root outward flow 122, and / or an axial root exit flow 124. The first seal 102 and root exit channel 110 can advantageously be tailored to minimize the upstream root outward flow 122, with the modified root cavity flow 136 and the upstream root inward flow 120 combining to form the root exit flow 124.

[0042] 8 , each outlet channel 110 can include an outlet hole 112 in the forward portion 23 of the inner casing 22. Each outlet channel 110 extends from a respective inlet hole 114 in the forward wall 311 of the circumferential groove 31 generally parallel to the axis of rotation R ( FIG. 1 ) of the turbomachine 10. In an embodiment, each outlet hole 112 can be circumferentially spaced from the respective inlet hole 114 such that the outlet channel 110 is circumferentially oriented and angled to induce swirl in the gases within the HPPS cavity 24 during operation of the turbomachine 10. For example, this spacing can result in an orientation or angle of the outlet channel 110 of between about 5° and about 90° relative to the plane of the forward portion 23 of the inner casing 22 or relative to a tangent plane.

[0043] It should be noted that the number of seals, the number of teeth within the seals, and the tooth clearance can be varied to tailor an embodiment to the aerodynamic requirements of the working flow path 21 in a given installation. In some embodiments, the teeth can have a clearance of about 0.25 millimeters (mm) to about 4 mm. In addition, the number and size of the outlet channels 110, inlet holes 114, and outlet holes 112 can also be varied to tailor an embodiment. For example, in some embodiments, there can be 20 to 50 outlet channels 110, and the diameter of the outlet holes 112 can be about 2.5 mm to about 25.4 mm in diameter. In other embodiments, the outlet holes 112 can have a diameter of about 20.3 mm or less.

[0044] In the example embodiment illustrated in Figures 5-7, the first seal 102 may be a labyrinth seal including two teeth 106, 108 with a clearance of about 0.40 mm to about 0.60 mm. In such an embodiment, 30 to 40 outlet channels 110 may be used, and the outlet holes 112 may be spaced apart such that the total area of ​​all outlet holes is at least 23 cm. 2The diameter of the circumferential groove 31 can be about 10 mm to about 13 mm so that the tooth clearance is about 0.50 mm, and as many as 40 outlet channels 110 with outlet holes 112 having a diameter of about 10.1 mm can be used to achieve good results. Using these criteria, the flow from the circumferential groove 31 through the upstream opening 39 and into the working flow passage 21 can be significantly reduced.

[0045] In other embodiments, the first seal 102 can be a labyrinth seal including two teeth 106, 108 with a tooth clearance of as much as about 4 mm, with 45 to 50 outlet channels 110 and an outlet hole 112 having a diameter of 10 mm to about 13 mm, e.g., about 12.7 mm. In such embodiments, and still referring to FIG. 9, the second seal 116 can be positioned between the first seal 102 and the downstream opening 38 of the circumferential groove 31. For example, the second seal 116 can be a labyrinth seal with one tooth 117.

[0046] Turning now to FIG. 10 , an alternative configuration of arrangement 100 is shown in which each outlet channel is a radial outlet channel 111 that can extend generally radially from circumferential groove 31 to HPPS cavity 24 between rotor 20 and inner casing 22. In such a configuration, each radial outlet channel 111 can extend through an inlet hole 114 formed in bottom wall 312 between first seal 102 and downstream opening 38. For example, inlet hole 114 can be formed in forward portion 314 of bottom wall 312, but could instead be formed in aft portion 315, if desired and / or appropriate. Additionally, similar to the example of FIG. 9 , arrangement 100 can further include a second seal 116 between radial outlet channel 111 and downstream opening 38 of circumferential groove 31.

[0047] In embodiments, the first seal 102 can be, for example, a labyrinth seal having one tooth 106, and the second seal 116 can be, for example, a labyrinth seal having two teeth 117, 118. Similar to the above-described embodiments, the first seal 102, the second seal 116, and / or the radial outlet channel 111 can be configured such that the upstream root inward flow 120 and the modified root cavity flow 136 combine to form a radial root outlet flow 125 to the HPPS cavity 24, forming a modified HPPS flow in the modified HPPS flow path 152. Furthermore, similar to the outlet channel 110, the radial outlet channel 111 can be angled to induce swirl in the radial root outlet flow 125, for example, angled circumferentially at an angle of about 5° to about 90°.

[0048] The use of the seal flow circuit or seal arrangement 100 described herein has the technical effect of significantly reducing the reintroduction of fluid into the region upstream of the vane 30, thereby improving the operating efficiency of the turbomachine 10. This is achieved, according to various embodiments presented herein, because the presence of the first seal 102 within the circumferential groove 31 causes fluid entering the circumferential groove 31 at the downstream opening 38 to be diverted into the HPPS cavity 24 via the outlet channel 110, or in embodiments, the radial outlet channel 111, where it can merge with the HPPS flow in the modified HPPS flow path 152, rather than allowing the fluid to enter the working flow path 21 upstream of the vane 30 through the upstream opening 39.

[0049] As used throughout this specification and claims, approximation language may be applied to modify any quantitative expression that may vary within acceptable limits without resulting in a change in the basic function involved. Thus, values ​​modified by terms such as "about," "approximately," and "substantially" are not limited to the exact value specified. In at least some instances, approximation language may correspond to the precision of the instrument used to measure the value. Throughout this specification and claims, range limitations are combinable and / or interchangeable, and unless the context or language dictates otherwise, such ranges are identified and include all subranges encompassed therein. As used herein, "about" and "approximately" refer to + / - 10% of the stated value, or, in the case of ranges, + / - 10% of the stated value(s).

[0050] The corresponding structure, material, acts, and equivalents of all means-plus-function or step-plus-function elements in the following claims are intended to include any structure, material, or acts for performing the function in combination with the elements recited in other claims that are specifically recited in the claims. The description of the present disclosure has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the disclosure to the form disclosed. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the disclosure. The embodiments were chosen and described to be suitable for the particular uses contemplated in order to best explain the principles of the disclosure and practical applications of such techniques, and to enable those skilled in the art to appreciate various embodiments of the disclosure and the potential for various modifications of the disclosed embodiments. [Explanation of symbols]

[0051] 10 Turbomachinery 11 Outer casing 12 Compressor 13 Entrance 14 Turbine 15 Exit cavity 16 Combustor 18 blades 20 rotors 21 Working flow path 22 Inner casing 23 Front part 24 HPPS cavities 26 HPPS 28 downstream cavity 30 vanes 31 Circumferential groove 32 Tip shroud 34 Mount 36 Mizoryu 38 Downstream opening 39 Upstream opening 50 HPPS circuits 52 HPPS flow path 54 HPPS Entrance 60 Brush seal 100 placement 102 First Seal 104 Base 106 teeth 108 teeth 110 Exit Channel 111 Radial Exit Channel 112 Exit hole 114 Entrance hole 116 Second Seal 117 teeth 118 teeth 120 Upstream inward flow at the base 122 Upstream outward flow 124 Axial root outlet flow 125 Radial root exit flow 136 Modified root cavity flow, modified groove flow 150 Modified HPPS Circuit 152 Modified HPPS flow path 311 Front Wall 312 Bottom wall 313 Back wall 314 Front part 315 Rear part 316 Step

Claims

1. A high pressure packing seal (HPPS) circuit arrangement for a turbomachine (10), comprising: a circumferential groove (31) in an inner casing (22) of the turbomachine (10), the circumferential groove (31) extending generally radially inward from an outer surface of the inner casing (22) and having a bottom wall (312), a forward wall (311), and an aft wall (313); an HPPS cavity (24) defined by the inner casing (22) and the rotor (20) of the turbomachine (10), the HPPS cavity including an HPPS inlet (54) between a forward portion (314) of the inner casing (22) and an aft end of a compressor (12) portion of the rotor (20) of the turbomachine (10); a vane (30) attached to an outer casing (11) of the turbomachine (10) and extending to the inner casing (22), the vane (30) having a tip disposed in the circumferential groove (31); a tip shroud (32) of the vane (30) extending from the tip and having an outer surface generally flush with the outer surface of the inner casing (22) and an inner surface disposed within the circumferential groove (31), wherein the tip shroud (32) and the forward wall (311) of the circumferential groove (31) define an upstream opening (39), and the tip shroud (32) and the aft wall (313) of the circumferential groove (31) define a downstream opening (38); a first seal (102) mounted in the circumferential groove (31) and extending toward the tip shroud (32) of the vane (30) and having a first clearance therewith; an outlet channel (110) extending from the circumferential groove (31) through the inner casing (22) to the HPPS cavity (24); An apparatus comprising:

2. The device of claim 1, wherein the first seal (102) is attached to the bottom wall (312) of the circumferential groove (31).

3. 2. The apparatus of claim 1, wherein the outlet channel extends from the forward wall of the circumferential groove to the forward portion of the inner casing generally parallel to an axis of rotation of the turbomachine.

4. The apparatus of claim 3, wherein the outlet channel (110) is circumferentially angled to induce swirl in the gas within the HPPS cavity (24).

5. 4. The apparatus of claim 3, wherein the outlet channel (110) is one of a plurality of outlet channels (110), each outlet channel (110) of the plurality of outlet channels (110) having a respective outlet hole (112), and the first seal (102) is a labyrinth seal including two teeth (106, 108) having a clearance of about 0.25 millimeters (mm) to about 4 mm, and wherein a diameter of each outlet hole (112) is about 2.5 mm to about 25.4 mm.

6. The vane (30) is one of a plurality of circumferentially arranged vanes (30) each having a respective tip shroud (32) within the circumferential groove (31), and the total area of ​​all of the plurality of outlet channels (110) is at least 23 cm ２ 6. The device of claim 5, wherein:

7. 4. The apparatus of claim 3, wherein the outlet channel (110) is one of a plurality of outlet channels (110), each outlet channel (110) of the plurality of outlet channels (110) having a respective outlet hole (112), and the first seal (102) is a labyrinth seal including two teeth (106, 108) having a clearance of about 4 mm, and each outlet hole (112) has a diameter of about 10 mm to about 13 mm.

8. The apparatus of claim 7, further comprising a second seal (116) disposed between the first seal (102) and the downstream opening (38).

9. The apparatus of claim 1, wherein the outlet channel (110) extends generally radially from the bottom wall (312) of the circumferential groove (31) to the HPPS cavity (24).

10. 10. The apparatus of claim 9, wherein the outlet channel (110) extends from a location within the circumferential groove (31) between the first seal (102) and the downstream opening (38).

11. The apparatus of claim 9, further comprising a second seal (116) between the outlet channel (110) and the downstream opening (38).

12. 12. The apparatus of claim 11, wherein the first seal (102) is a labyrinth seal having one tooth (106) and the second seal (116) is a labyrinth seal having two teeth (117, 118).

13. A sealing apparatus for a turbomachine (10), the apparatus comprising: a first seal (102) extending between a tip shroud (32) of a vane (30) of the turbomachine (10) and a wall of a circumferential groove (31) of an inner casing (22) of the turbomachine (10), the first seal (102) being disposed between a mount of the tip shroud (32) and a forward wall (311) of the circumferential groove (31); an outlet channel (110) extending from the circumferential groove (31) to an HPPS cavity (24) defined by the rotor (20) and the inner casing (22) of the turbomachine (10), whereby, during operation of the turbomachine (10), fluid entering a downstream opening (38) of the circumferential groove (31) is directed through the outlet channel (110) to the HPPS cavity (24); An apparatus comprising:

14. 14. The apparatus of claim 13, wherein the outlet channel extends substantially parallel to the rotational axis of the turbomachine from the circumferential groove to a forward portion of the inner casing that is perpendicular to the rotational axis of the turbomachine.

15. 15. The apparatus of claim 14, further comprising an outlet hole (112) of the outlet channel (110) formed in the forward portion (314) of the inner casing (22) and an inlet hole (114) formed in a forward wall (311) of the circumferential groove (31).

16. The apparatus of claim 14, wherein the first seal (102) is a labyrinth seal including two teeth (106, 108).

17. 14. The apparatus of claim 13, further comprising a second seal (116) disposed between the first seal (102) and a downstream opening (38) defined in the circumferential groove (31) and the tip shroud (32).

18. 18. The apparatus of claim 17, wherein the outlet channel (110) extends generally radially from the circumferential groove (31) to the HPPS cavity (24).

19. 19. The apparatus of claim 18, wherein the outlet channel (110) extends from a location within the circumferential groove (31) between the first seal (102) and the downstream opening (38).

20. 20. The apparatus of claim 18, wherein the first seal (102) is a labyrinth seal having one tooth (106) and the second seal (116) is a labyrinth seal having two teeth (117, 118).

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