Additively manufactured combustor with air re-use from aft frame to axial fuel stage injector

Abstract

To provide an additively manufactured combustor with air re-use from an aft frame to an axial fuel stage injector.SOLUTION: A one-piece member includes a combustion liner (52) including a cylindrical portion 53 and a tapered transition portion 54, and at least one axial fuel stage (AFS) injector 56 directed to the combustion liner 52. The member also includes an aft frame 70 at an aft end of the tapered transition portion 54, the aft frame including a first cooling passage 72 therein with an inlet 74 and an outlet 76 with the inlet 74 in fluid communication with an air coolant source 80. A flow sleeve 82 is spaced from an exterior surface 84 of the tapered transition portion 54 and defines a second, annular cooling passage 86 therebetween. The second cooling passage 86 extends from the outlet 76 of the first cooling passage 72 to an air inlet 88 of AFS injector(s) 56.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates generally to turbomachine combustors, and more specifically to an additively manufactured combustor body including a flow sleeve for directing air recycling from an aft frame to one or more axial fuel stage injectors. [Background technology]

[0002] A gas turbine system includes a combustion section containing multiple combustors in which fuel is combusted to create a flow of combustion gases that is converted to kinetic energy in a downstream turbine section (e.g., an expansion turbine). Modern combustors include many components that must be cooled efficiently. For example, a combustor may include a cylindrical portion of a combustion liner concentrically disposed inside a flow sleeve. Cooling air from a compressor discharge plenum is channeled into an annulus defined between the cylindrical portion of the combustion liner and the flow sleeve to cool the cylindrical portion. A tapered transition portion of the combustion liner is coupled to the aft end of the cylindrical portion, transitioning the hot gas path from the circular cross-section of the cylindrical portion to a more arcuate, polygonal cross-section at the turbine inlet. The flow sleeve may also direct cooling air along or against a portion of the tapered transition portion. Air from the compressor discharge plenum may pass through impingement openings to enter the annulus between the transition portion and the downstream flow sleeve. Alternatively, air can enter the annulus through a gap between the downstream flow sleeve and an aft frame connected to the aft end of the transition section. Air from the annulus can be directed to axial fuel stage (AFS) injectors located near the junction of the cylindrical section and the tapered section, through which air and fuel are introduced into the secondary combustion zone.

[0003] The aft frame joins the tapered transition section to the turbine inlet. Current combustors direct cooling air into the aft frame, where it is used for convection or impingement cooling of the aft frame. This cooling air is then discharged into the first stage nozzle of the turbine, which is not an efficient use of the cooling air. Summary of the Invention

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

[0005] One aspect of the disclosure includes a combustor for a gas turbine system, the combustor including an additively manufactured (AM) combustor body including a one-piece member. The one-piece member includes a combustion liner including a cylindrical portion and a tapered transition portion, at least one axial fuel stage (AFS) injector directed into the combustion liner, an aft frame at an aft end of the tapered transition portion, the aft frame including a first cooling passage therein with an inlet and an outlet, the inlet in fluid communication with an air coolant source, and a first flow sleeve spaced from an exterior surface of the tapered transition portion to define a second annular cooling passage between the first flow sleeve and the tapered transition portion. portion and defining a second,annular cooling passage between the first flow sleeve and the tapered transition portion, the second, annular cooling passage extending from the outlet of the first cooling passage in the aft frame to an air inlet of the at least one AFS injector, and the AM combustor body further includes a plurality of parallel, sintered metal layers.

[0006] Another aspect of the disclosure includes any of the preceding aspects, wherein the first flow sleeve includes a first portion spaced from and parallel to the exterior surface of the tapered transition portion, and a second portion extending in an outwardly convex manner over the air inlet of the at least one AFS injector.

[0007] Another aspect of the disclosure includes any of the preceding aspects, wherein the at least one AFS injector includes at least two AFS injectors circumferentially spaced along at least one of the cylindrical portion and the tapered transition portion, and the second portion of the first flow sleeve extends at least partially circumferentially around the tapered transition portion to fluidly connect the air inlets of the at least two AFS injectors.

[0008] Another aspect of the disclosure includes any of the preceding aspects, wherein the first flow sleeve includes a plurality of openings therethrough and in fluid communication with the air coolant source.

[0009] Another aspect of the disclosure includes any of the preceding aspects, and further includes a divider between the first flow sleeve and the exterior surface of the tapered transition portion, the divider defining a third cooling passage adjacent and fluidly separated from the second cooling passage, and the third cooling passage extending from the plurality of openings to the air inlet of the at least one AFS injector.

[0010] Another aspect of the disclosure includes any of the preceding aspects, wherein the first cooling passage in the aft frame has a non-linear flow path in the aft frame.

[0011] Another aspect of the disclosure includes any of the preceding aspects, and further includes a second flow sleeve spaced along at least a portion of an exterior surface of the cylindrical portion and defining a third cooling passage having an inlet adjacent the at least one AFS injector and extending to a head end fuel nozzle assembly coupled to a forward end of the AM combustor body.

[0012] Another aspect of the disclosure includes any of the preceding aspects, wherein the inlet to the third cooling passage is between an aft end of the second flow sleeve and a forward end of the first flow sleeve.

[0013] Another aspect of the disclosure includes any of the preceding aspects, wherein the first flow sleeve extends forwardly on opposing circumferential sides of the at least one AFS injector.

[0014] Another aspect of the disclosure includes a gas turbine (GT) system, the GT system including a compressor section, a combustion section operatively coupled to the compressor section, and a turbine section operatively coupled to the combustion section, the combustion section including at least one combustor, the combustion section including an additively manufactured (AM) combustor body including a one-piece member, the one-piece member including a combustion liner including a cylindrical portion and a tapered transition portion, and at least one axial fuel stage (AFS) injector directed into the combustion liner. an aft frame at an aft end of the tapered transition portion, the aft frame including a first cooling passage therein with an inlet and an outlet, the first cooling passage having an inlet and an outlet in fluid communication with an air coolant source;the inlet in fluid communication with an air coolant source; and a first flow sleeve spaced from an exterior surface of the tapered transition portion, the first flow sleeve defining a second, annular cooling passage between the first flow sleeve and the tapered transition portion, the second, annular cooling passage extending from the outlet of the first cooling passage in the aft frame to an air inlet of the at least one AFS injector, and the AM combustor body includes a plurality of parallel, sintered metal layers.

[0015] Another aspect of the disclosure includes any of the preceding aspects, wherein the first flow sleeve includes a first portion spaced from and parallel to the exterior surface of the tapered transition portion, and a second portion extending in an outwardly convex manner over the air inlet of the at least one AFS injector.

[0016] Another aspect of the disclosure includes any of the preceding aspects, wherein the at least one AFS injector includes at least two AFS injectors circumferentially spaced along at least one of the cylindrical portion and the tapered transition portion, and the second portion of the first flow sleeve extends at least partially circumferentially around the tapered transition portion to fluidly connect the air inlets of the at least two AFS injectors.

[0017] Another aspect of the disclosure includes any of the preceding aspects, wherein the first flow sleeve includes a plurality of openings therethrough and in fluid communication with the air coolant source.

[0018] Another aspect of the disclosure includes any of the preceding aspects, and further includes a divider between the first flow sleeve and at least a portion of the exterior surface of the tapered transition portion, the divider defining a third cooling passage adjacent to and fluidly separated from the second cooling passage, and the third cooling passage extending from the plurality of openings to the air inlet of the at least one AFS injector.

[0019] Another aspect of the disclosure includes any of the preceding aspects, wherein the first cooling passage in the aft frame has a non-linear flow path in the aft frame.

[0020] Another aspect of the disclosure includes any of the preceding aspects, and further includes a second flow sleeve spaced along at least a portion of an exterior surface of the cylindrical portion, the second flow sleeve defining a third cooling passage having an inlet adjacent the at least one AFS injector and extending to a head end fuel nozzle assembly coupled to a forward end of the AM combustor body.

[0021] Another aspect of the disclosure includes any of the preceding aspects, wherein the inlet to the third cooling passage is between an aft end of the second flow sleeve and a forward end of the first flow sleeve.

[0022] Another aspect of the disclosure includes any of the preceding aspects, wherein the first flow sleeve extends forwardly on opposing circumferential sides of the at least one AFS injector.

[0023] Two or more aspects described in this disclosure may be combined to form implementations not specifically described herein, including those described in this Summary section, i.e., all embodiments described herein can be combined with each other.

[0024] The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. [Brief explanation of the drawings]

[0025] These and other features of the present disclosure will be more readily understood from the following detailed description of various aspects of the disclosure taken in conjunction with the accompanying drawings, which depict various embodiments of the disclosure. [Figure 1] FIG. 1 illustrates a functional block diagram of an exemplary gas turbine system that may be used with a combustor and combustor body according to disclosed embodiments. [Figure 2] 1 illustrates a cross-sectional side view of a portion of a combustor having an additively manufactured combustor body according to a disclosed embodiment. [Figure 3] 1 illustrates a perspective end view of a combustor body according to a disclosed embodiment; [Figure 4] 1 is a cross-sectional perspective view of a combustor body according to a disclosed embodiment; [Figure 5] 2 illustrates a cross-sectional view of a metal layer of a combustor body according to a disclosed embodiment. [Figure 6] FIG. 6A shows a cross-sectional view of a first flow sleeve and tapered transition portion of a combustor body according to a disclosed embodiment along line A-A in FIG. 3, and FIG. 6B shows a cross-sectional view of a first flow sleeve and tapered transition portion of a combustor body according to another disclosed embodiment along line A-A in FIG. 3. [Figure 7] 2 illustrates an enlarged cross-sectional side view of a cooling passage within an aft frame of a combustor body according to a disclosed embodiment. [Figure 8] 2 illustrates a schematic end view of a combustor body aft frame according to a disclosed embodiment; [Figure 9]FIG. 1 illustrates a schematic block diagram of an exemplary additive manufacturing system for additively manufacturing a combustor body in accordance with disclosed embodiments.

[0026] It should be noted that the drawings of the disclosure are not necessarily to scale. The drawings are intended to depict only typical aspects of the disclosure and should not be considered as limiting the scope of the disclosure. In the drawings, like numbering represents similar elements between the drawings. DETAILED DESCRIPTION OF THE INVENTION

[0027] As an initial matter, clearly describing the subject matter of the present disclosure requires the selection of specific terminology when referring to and describing relevant machine components within the exemplary application of a turbomachine. In doing so, where possible, common industry terminology will be used in a manner consistent with its accepted meaning. Unless otherwise noted, such terms should be given a broad interpretation consistent with the context of this application and the scope of the appended claims. Those skilled in the art will understand that a particular component may often be referred to using several different or overlapping terms. What may be described herein as a single component may include and be referred to in another context as consisting of multiple components. Alternatively, what may be described herein as comprising multiple components may be referred to elsewhere as a single component.

[0028] Additionally, several descriptive terms may be used periodically herein, and it should prove helpful to define these terms at the beginning of this section. The terms and their definitions are as follows, unless otherwise specified: As used herein, "downstream" and "upstream" are terms that indicate a direction relative to the flow of a fluid, e.g., a working fluid through a combustor of a turbomachine, or the flow of air through a combustor or 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 direction opposite to the flow. The terms "forward" and "aft" refer to directions without further specificity, with "forward" referring to the front or compressor end of the turbomachine and "aft" referring to the aft or turbine end of the turbomachine.

[0029] The term "axial" refers to movement or position parallel to an axis, such as the axis of a combustor or turbomachine. The term "axial" refers to movement or position perpendicular to an axis, such as the axis of a combustor or turbomachine. In such cases, if a first component is closer to the axis than the second component, the first component may be described herein as being "radially inward" or "inside" the second component. Conversely, if a first component is located farther from the axis than the second component, the first component may be described herein as being "radially outward" or "outside" the second component. Finally, the term "circumferential" refers to movement or position around an axis, such as the circumferential inner surface of a combustion liner or the circumferential interior of a casing extending around a combustor. As noted above, and depending on the context, it is understood that such terms may be applied in relation to the axis of a combustor or the axis of a turbomachine.

[0030] Additionally, as explained below, certain descriptive terms may be used periodically herein: the terms "first," "second," and "third" may be used interchangeably to distinguish one component from another, and are not intended to denote the location or importance of the individual components.

[0031] The terms used herein are for the purpose of describing particular embodiments and are not intended to limit the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural unless the context clearly dictates otherwise. Furthermore, as used in this specification, the terms "comprise" and / or "comprising" are understood to specify the presence of stated features, integers, steps, operations, elements, and / or components, but not to 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 may or may not occur, or the subsequently described feature may or may not be present, and that the description includes instances in which the event occurs, instances in which the feature is present, instances in which the event does not occur, or instances in which the feature is absent.

[0032] When an element or layer is referred to as being "placed," "engaged," "connected," "coupled," or "mounted" to another element or layer, it may be directly placed, engaged, connected, coupled, or attached to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly connected," "directly involved," "directly connected to," or "directly coupled" to another element or layer, there are no intervening elements or layers. Other words used to describe relationships between elements should be interpreted in a similar manner (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. The verb forms of "engage" and "mounted" may be used interchangeably herein.

[0033] The disclosed embodiment provides a combustor for a gas turbine system. The combustor includes an additively manufactured (AM) combustor body including a one-piece member. The one-piece member includes a combustion liner including a cylindrical portion and a tapered transition section, and at least one axial fuel stage (AFS) injector directed toward the combustion liner. The one-piece member also includes an aft frame at an aft end of the tapered transition section. The aft frame includes a first cooling passage therein with an inlet and an outlet with an inlet in fluid communication with an air coolant source. A flow sleeve is spaced from an outer surface of the tapered transition section and defines a second annular cooling passage between the first flow sleeve and the tapered transition section. The second annular cooling passage extends from an outlet of the first cooling passage in the aft frame to an air inlet of the at least one AFS injector. The AM combustor body includes a plurality of parallel sintered metal layers.

[0034] The AM combustor body improves efficiency by using air for aft frame cooling and reusing it for tapered transition cooling and combustion in the AFS injectors rather than venting it to the first-stage nozzle. As a result, approximately 40% of the AFS injector air is also used for tapered transition and / or aft frame cooling. Additive manufacturing allows the AM combustor body to be formed as a single body, reducing the cost of the combustor body by eliminating many of the multiple parts and required assembly steps. The AM combustor body also improves durability compared to conventional versions by improving cooling, eliminating welding, and providing the ability to design stress-raising shapes, such as high-stress welds between the aft section of the tapered transition and the aft frame.

[0035] FIG. 1 illustrates a functional block diagram of an exemplary gas turbine (GT) system 10 that may incorporate various embodiments of a combustor 40 of the present disclosure. As illustrated, the GT system 10 generally may include an inlet section 12 that may include a series of filters, cooling coils, moisture separators, and / or other devices for purifying and otherwise conditioning a working fluid (e.g., air) 14 entering the GT system 10. The working fluid 14 flows into a compressor 16 within a compressor section 17, which progressively imparts kinetic energy to the working fluid 14 to produce compressed air 18 (hereinafter “air 18” or “compressed air 18”) in an energized state. The compressed air 18 is mixed with fuel 20 from a fuel supply 22 to form a combustible mixture within at least one combustor 40 within a combustion section 23 operably coupled to the compressor section 17. The combustible mixture is combusted to produce high-temperature, high-pressure combustion gases 26. The combustion gases 26 flow through a turbine 28 (e.g., an expansion turbine) of a turbine section 29, operatively coupled to the combustion section 23 to produce work. For example, the turbine 28 may be connected to a shaft 30 such that rotation of the turbine 28 drives the compressor 16 to generate compressed air 18. Alternatively, or in addition, the shaft 30 may connect the turbine 28 to a generator 32 to generate electricity. Exhaust gases 34 from the turbine 28 flow through an exhaust section 36 that connects the turbine 28 to an exhaust stack 37 downstream from the turbine 28. The exhaust section 36 may include, for example, a heat recovery steam generator (not shown) to scrub and extract additional heat from the exhaust gases 34 before they are released to the ambient environment. If multiple combustors 40 are used, they may be circumferentially spaced about a turbine inlet 38 of the turbine 28.

[0036] In one embodiment, the GT system 10 may include a commercially available engine model from GE Vernova, Inc. of Cambridge, Massachusetts. The present disclosure is not limited to any particular GT system and may be implemented in connection with engines including, for example, any of GE Vernova's HA, F, B, LM, GT, TM, and E-Class engine models, as well as engine models from other manufacturers. Furthermore, the present disclosure is not limited to any particular turbomachine and may be applied to, for example, steam turbines, jet engines, compressors, turbofans, etc.

[0037] Figure 2 shows a cross-sectional side view of the combustor 40 disposed within the GT system 10. Figure 3 shows an end perspective view of the combustor body 44, and Figure 4 shows a cross-sectional perspective view of the AM combustor body 44. As shown in Figure 2, the combustor 40 is at least partially surrounded by an outer casing 46, such as a compressor discharge casing and / or a turbine casing. The interior of the outer casing 46 is in fluid communication with the compressor 16.

[0038] The combustor 40 for the GT system 10 includes an AM combustor body 44 that includes a one-piece member 50. The one-piece member 50 includes a combustion liner 52 including a cylindrical portion 53 and a tapered transition portion 54 at an aft end (right side as shown in FIGS. 2 and 4) of the cylindrical portion 53, and at least one axial fuel stage (AFS) injector 56 directed into the combustion liner 52. The combustion liner 52, also referred to as a hot gas path (HGP) duct or unibody liner, extends downstream from a separate head-end fuel nozzle assembly 58 (hereinafter “head-end assembly 58”) and a cap assembly 62 that is coupled to the forward end 60 of the AM combustor body 44. That is, the combustor 40 may include a separate head-end assembly 58 that is coupled to the forward end 60 of the AM combustor body 44. The head-end assembly 58 generally includes at least one axially extending fuel nozzle 64 that extends downstream from an end cover 65 and the cap assembly 62 that extends radially and axially within the outer casing 46 downstream from the end cover 65. The cap assembly 62 defines an upstream boundary of the combustion chamber.

[0039] The head end assembly 58 may include any now known or later developed axially-extending fuel nozzles 64 for delivering fuel 20 from the axially-extending fuel nozzles 64 to a primary combustion zone 66. In certain embodiments, the axially-extending fuel nozzles 64 of the head end assembly 58 extend at least partially through the cap assembly 62 and provide a combustible mixture of fuel and compressed air 18 to the primary combustion zone 66. The AFS injectors 56 extend radially through the liner 52 downstream from the axially-extending fuel nozzles 64. As described herein, the compressed air 18 may be routed to the AFS injectors 56 to combine with the fuel 20 for combustion in a secondary combustion zone 68 downstream from the primary combustion zone 66.

[0040] A tapered transition 54 at the aft end of cylindrical portion 53 transitions the hot gas path (HGP) from the circular cross-section of the liner to a more arcuate, polygonal cross-section for coupling to turbine inlet 38 of turbine 28. Combustor 40 also includes an aft frame 70 at the aft end (right side in FIGS. 2 and 4 ) of tapered transition 54. As described further herein, aft frame 70 includes a first cooling passage 72 therein having an inlet 74 and an outlet 76. Inlet 74 is in fluid communication with an air coolant source 80, e.g., the interior of casing 46, which is filled with compressed air 18 from compressor 16 or other compressed air source 18. The combustor 40 also defines a first flowsleeve 82 spaced from an outer surface 84 of the tapered transition portion 54 and a second annular cooling passage 86 between (the interior of) the first flowsleeve 82 and (the outer surface 84 of) the tapered transition portion 54. The second annular cooling passage 86 extends circumferentially about the tapered transition portion 54. The second annular cooling passage 86 also extends from the outlet 76 of the first cooling passage 72 in the aft frame 70 to the air inlets 88 of the AFS injectors 56. In this manner, the first flowsleeve 82 with the tapered transition portion 54 can route at least a portion of the compressed air 18 to the one or more AFS injectors 56 extending radially from the coolant source 80 to combine with the fuel 20 for combustion in a secondary combustion zone 68 downstream of the primary combustion zone 66.

[0041] As a result of additive manufacturing, there are no mechanical connections between the various parts (i.e., they are all one piece). Figure 5 shows a cross-sectional view of any portion of an additively manufactured combustor body 44 (hereinafter "AM combustor body 44" or "combustor body 44"). As shown in Figure 5, the AM combustor body 44 includes multiple parallel sintered metal layers 90, i.e., additively manufactured.

[0042] The combustor 40, i.e., the combustor body 44, may include second flow sleeves 96 spaced along at least a portion of an outer surface 98 of the cylindrical portion 53 of the combustion liner 52. The second flow sleeves 96 have inlets 102 adjacent the AFS injectors 56 and define third cooling passages 100 extending to a head end assembly 58 coupled to the forward end 60 of the AM combustor body 44. The second flow sleeves 96 may define one or more third cooling passages 100 for routing compressed air 18 from the source 80 across (across) the outer surface of the cylindrical portion 53 of the combustion liner 52. The one or more second flow sleeves 96 at least partially (annularly) surround at least a portion of the combustion liner 52, e.g., at least a portion of the cylindrical portion 53. The second flowsleeve 96 delivers air along a third cooling passage 100 to cool the cylindrical portion 53 of the combustion liner 52, after which the air 18 may also be used in the head-end assembly 58. The second flowsleeve 96 may be spaced from the exterior surface of the combustion cylindrical portion 53 in any manner, such as by bosses, spacers, or internal cooling passage structures. As shown in FIG. 2 , in some embodiments, an inlet 102 to the third cooling passage 100 is defined between an aft end 104 of the second flowsleeve 96 and a forward end 106 of the first flowsleeve 82. In other embodiments, a portion of the second cooling passage 86 between the first flowsleeve 82 and the tapered transition section 54 may be in fluid communication with the third cooling passage 100, as described below.

[0043] The first flow sleeve 82 can take a variety of forms to direct air from the aft frame 700 to cool the tapered transition portion 54 and deliver air to the one or more AFS injectors 56. In one embodiment, as shown in FIG. 2 , the first flow sleeve 82 includes a first portion 110 spaced from and parallel to at least a portion of the exterior surface 84 of the tapered transition portion 54 and a second portion 112 extending in an outwardly convex manner over the air inlet 88 of the one or more AFS injectors 56. First portion 110 may have any shape that is generally parallel to that of tapered transition portion 54 through which it extends. First portion 110 may be spaced from outer surface 84 of tapered transition portion 54 in any manner that does not impede the flow of air 18 through second cooling passage 86, such as by a boss 114 ( FIG. 2 ), an interior cooling passage fin structure (not shown), or the like.

[0044] The second portion 112 may have any shape configured to collect air as part of the second cooling passage 86 and deliver it to the air inlets 88 of one or more AFS injectors 56, e.g., in a circumferential direction between the AFS injectors 56. In certain embodiments, as shown in FIG. 2, the second portion 112 may extend beyond the air inlets 88 of the AFS injectors 56. In other embodiments, as shown in FIG. 3, the first flow sleeve 82, i.e., its second portion 112, may extend forward on the opposing circumferential side 116 of the AFS injector 56, such that the air 18 therein may enter the air inlets 88 from the circumferential side of the AFS injector 56. In either case, the second portion 112 delivers air from the second cooling passage 86 to the air inlets 88 of the AFS injectors 56. The air inlets 88 may be on one or more of the circumferential side 116 ( FIG. 3 ) and / or radially outer surface of the AFS injector 56 ( FIG. 2 ).

[0045] 2 and 3 , when two or more AFS injectors 56 are present, they are typically spaced apart circumferentially along at least one of the cylindrical portion 53 and / or tapered transition portion 54, i.e., spaced apart around the outside of the cylindrical portion 53 and / or tapered transition portion 54. In this case, the second portion 112 of the first flowsleeve 82 extends at least partially around the tapered transition portion 54 to fluidly connect the air inlets 88 of the at least two AFS injectors 56. In this manner, the second portion 112 of the first flowsleeve 82 provides a plenum that supplies air 18 to each AFS injector 56.

[0046] In some embodiments, the first flowsleeve 82 may have a solid exterior wall, as shown in FIG. 2. In other embodiments, the first flowsleeve 82 may include a plurality of openings 130 therethrough, i.e., through the wall, and in fluid communication with the air coolant source 80 and the second cooling passage 86, as shown in FIG. 3. In this case, the air 18 from the coolant source 80 may mix with the air 18 that has passed through the aft frame 70. FIG. 6A illustrates a cross-sectional view of the first flowsleeve 82 and tapered transition section 54 of the combustor body 44 according to another disclosed embodiment, taken along line AA in FIG. 3. In this embodiment, the second cooling passage 86 is completely annular, i.e., has no interruptions therethrough, around the tapered transition section 54, and within the flowsleeve 82. The plurality of openings 130 may be in fluid communication with a second cooling passage 86 through which air 18 passes directly from a coolant source 80 without passing through the aft frame 70, where the air 18 in the second cooling passage 86 is supplied from the aft frame 70 and the coolant source 80.

[0047] 6B illustrates a cross-sectional view of the first flow sleeve 82 and tapered transition section 54 of the combustor body 44 along view line AA in FIG. 3 according to additional embodiments of the disclosure. In these embodiments, the plurality of openings 130 are in fluid communication with another (fourth) cooling passage 132 (the adjacent second cooling passage 86), and the air 18 passes directly from the coolant source 80 without passing through the aft frame 70. That is, the fourth cooling passage 132 is not in fluid communication with the outlet 76 of the first cooling passage 72 in the aft frame 70, while the second cooling passage 86 between the tapered transition section 54 and the first flow sleeve 82 is in fluid communication with the outlet 76 of the first cooling passage 72. As shown in FIG. 6B , one or more dividers 134 may be positioned between the first flow sleeve 82 and at least a portion of the outer surface 84 of the tapered transition section 54 to define the second cooling passage 86 and the fourth cooling passage 132. The divider 134 may define a fourth cooling passage 132 adjacent to and fluidly separated from the second cooling passage 86 for a portion of the axial extent between the aft frame 70 and the AFS injector 56. The fourth cooling passage 132 extends from the plurality of openings 130 to the air inlet 88 of the AFS injector 56, i.e., the second portion 112 of the first flow sleeve 82, to cool the tapered transition portion 54 and may supply air from the coolant source 80 directly to the AFS injector 56, i.e., without passing through the aft frame 70.

[0048] Furthermore, with respect to the first cooling passages 72 in the rear frame 70, any number of first cooling passages 72 can extend through the rear frame 70, limited only by the amount of space available for their placement. The first cooling passages 72 can have any cross-sectional shape and / or dimensions. Furthermore, the first cooling passages 72 can take various paths through the rear frame 70, e.g., linear, non-linear, or both. FIG. 7 illustrates an enlarged cross-sectional side view of the first cooling passage 72 at the rear frame 70. As illustrated, the first cooling passages 72 can have non-linear paths, e.g., serpentine paths or other non-linear paths when viewed from the side. Alternatively, as shown in FIG. 2, the first cooling passages 72 can have a U-shaped cross section.

[0049] FIG. 8 shows a schematic end view of the aft frame 70 and illustrates some examples of possible alternative paths for the first cooling passages 72 in the aft frame 70 as viewed from that end. The vertical U-shaped path of FIG. 2 is shown in the upper right of FIG. 8 . However, the first cooling passages 72 can flow anywhere through the aft frame 70. For example, the first cooling passages 72 can make a horizontal U-shaped turn (center right example), pass around a corner 138 of the aft frame 70 (lower left example), pass within the side of the aft frame 70 (upper left example), or take a non-linear path through the aft frame 70 (lower right example). Each aft frame 70 can have a single form of the cooling passage 72 arrangement described above, or any variety of the cooling passage arrangements described above, to provide the desired cooling of the aft frame 70 and / or air supply to the AFS injectors 56.

[0050] 2 , the combustor 40 generally terminates at a point adjacent a first stage 140 of stationary nozzles 142 of the turbine 28. The first stage 140 of the stationary nozzles 142 at least partially define the turbine 28 from the turbine inlet 38. The liner 52 at least partially defines a hot gas path (HGP) for routing the combustion gases 26 from the primary combustion zone 66 and secondary combustion zone 68 to the turbine inlet 38 of the turbine 28 during operation of the GT system 10.

[0051] During operation, compressed air 18 flows from the compressor 16 and is routed through various fluid flow paths. A portion of the compressed air 18 is routed through the second flow sleeve 96 to the head end assembly 58 of the combustor 40, where it reverses direction and is directed through the axially extending fuel nozzles 64. The compressed air 18 is mixed with fuel to form a first combustible mixture that is then injected into the primary combustion zone 66. This may be the same fuel 20 as or a different fuel than the fuel 20 supplied from the fuel source 22 to the AFS injectors 56. The first combustible mixture is combusted to produce combustion gases 26. A second portion of the compressed air 18 is routed through the radially extending AFS injectors 56 and may be mixed with fuel 20 from a fuel passage 150 (e.g., a conduit from the fuel source 22 provided as an external tube (as shown) or the second flow sleeve 96) to form a second combustible mixture. The second combustible mixture is injected into the hot gas path (HGP) through liner 52. The second combustible mixture at least partially mixes with the combustion gases 26 and is combusted in the secondary combustion zone 68. The liner 52 at least partially defines the hot gas path (HGP) for routing the combustion gases 26 from the primary combustion zone 66 and the secondary combustion zone 68 to the turbine inlet 38 of the turbine 28 during operation of the GT system 10.

[0052] When the GT system 10 is operational, the compressed air 18 also enters the inlets 74 of the first cooling passages 72 in the aft frame 70 to cool the aft frame 70. The air 18 in the aft frame 70 then enters the second annular cooling passage 86 between the first flow sleeve 82 and the tapered transition section 54 and is directed to the inlets 88 of the AFS injectors 56, where it is used for combustion with fuel 20 in the secondary combustion zone 68. In certain embodiments, the air 18 can also be introduced into the cooling passages 86 via openings 130 ( FIG. 3 ). Recycling the air 18 from the aft frame 70 is more efficient than discarding it to the first stage 140 of the static nozzles 142, resulting in approximately 40% of the air 18 used by the AFS injectors 56 also being used to cool the tapered transition section 54, among other portions of the combustor body 44.

[0053] The combustor 40 and AM combustor body 44 may be additively manufactured using any now known or later developed technology capable of forming a large, integral body. FIG. 9 illustrates a schematic / block diagram of an exemplary computerized metal powder additive manufacturing system 210 (hereinafter “AM system 210”) for generating the AM combustor body 44, of which only one layer is shown. While described herein in the context of building the AM combustor body 44 using multiple melting beam sources 212, 214, 216, 218, it is emphasized and readily recognized that the AM system 210 is equally applicable to building the AM combustor body 44 using any number of melting beam sources. In this example, the AM system 210 is configured for direct metal laser melting (DMLM). It is understood that the general teachings of this disclosure are equally applicable to other forms of metal powder additive manufacturing, such as selective laser melting (SLM), and possibly other forms of additive manufacturing (i.e., other than metal powder applications). The layers of the AM combustor body 44 on the build platform 220 are illustrated in FIG. 9 as circular elements. However, it is understood that the additive manufacturing process can be readily adapted to produce arbitrarily shaped portions of the AM combustor body 44 on the build platform 220.

[0054] The AM system 210 generally includes an additive manufacturing control system 230 (“control system”) and an AM printer 232. As described below, the control system 230 executes a set of computer-executable instructions or code 234 to generate the combustor body 44 using multiple melt beam sources 212, 214, 216, and 218. In the illustrated example, the four melt beam sources may include four lasers. However, any melt beam source, e.g., electron beam, laser, etc., is applicable. The control system 230 is shown implemented as computer program code on a computer 236. To this extent, the computer 236 includes a memory 238 and / or storage system 240, a processor unit (PU) 244, an input / output (I / O) interface 246, and a bus 248. Additionally, the computer 236 is shown in communication with external I / O devices / resources 250. Generally, the processor unit (PU) 244 executes the computer program code 234 stored in the memory 238 and / or storage system 240. While executing computer program code 234, processor unit (PU) 244 can read and write data from memory 238, storage system 240, I / O devices 250, and / or AM printer 232. Bus 248 provides a communication link between each component of computer 236, and I / O devices 250 can include any device that allows a user to interact with computer 236 (e.g., a keyboard, a pointing device, a display, etc.).

[0055] Computer 236 is merely representative of various possible combinations of hardware and software. For example, processor unit (PU) 244 may include a single processing unit or may be distributed across one or more processing units on one or more locations, e.g., a client and a server. Similarly, memory 238 and / or storage system 240 may reside in one or more physical locations. Memory 238 and / or storage system 240 may include any combination of various types of non-transitory computer-readable storage media, including magnetic media, optical media, random access memory (RAM), read-only memory (ROM), etc. Computer 236 may include any type of computing device, such as an industrial controller, a network server, a desktop computer, a laptop, a handheld device, etc.

[0056] As previously mentioned, AM system 210, and particularly control system 230, executes code 234 to generate combustor body 44. Code 234 may include, among other things, a set of computer-executable instructions 234S (also referred to herein as “code 234S”) for operating AM printer 232 and a set of computer-executable instructions 234O (also referred to herein as “code 234O”) that define the AM combustor body 44 that is physically generated by AM printer 232. As described herein, the additive manufacturing process begins with a non-transitory computer-readable storage medium (e.g., memory 238, storage system 240, etc.) that stores code 234. The set of computer-executable instructions 234S for operating AM printer 232 may include any now known or later developed software code capable of operating AM printer 232.

[0057] The set of computer-executable instructions 234O defining the combustor body 44 may include a precisely defined 3D model of the combustor body 44 and may be generated from any of a wide variety of well-known computer-aided design (CAD) software systems, such as AutoCAD®, TurboCAD®, DesignCAD3DMax, etc. In this regard, the code 234O may include any currently known or later-developed file format. Additionally, the code 234O representing the combustor body 44 may be converted between different formats. For example, the code 234O may include a Standard Tessellation Language (STL) file created for the 3D Systems stereolithography CAD program or an Additive Manufacturing File (AMF), an American Society of Mechanical Engineers (ASME) standard that is an extensible markup language (XML)-based format designed to allow any CAD software to describe the shape and configuration of any three-dimensional object to be manufactured by any AM printer. The code 234O representing the combustor body 44 may be converted into a set of data signals for transmission, or may be received as a set of data signals, converted into code, stored, or the like, as needed. Code 234O can be configured to enable the formation of boundaries and interior sections in overlapping field regions according to embodiments of the present disclosure. In either case, code 234O can be input to AM system 210 and may come from a part designer, an intellectual property (IP) provider, a design firm, the operator or owner of AM system 210, or other source. In either case, control system 230 executes code 234S and 234O to divide combustor body 44 into a series of thin slices, which are then assembled into successive layers of material using AM printer 232.

[0058] The AM printer 232 may include a sealed process chamber 260 to provide a controlled atmosphere for printing the combustor body 44. The build platform 220, on which the combustor body 44 is constructed, is disposed within the process chamber 260. Multiple melt beam sources 212, 214, 216, 218 are configured to melt layers of metal powder on the build platform 220 to produce the combustor body 44. While four melt beam sources 212, 214, 216, 218 are illustrated, it is emphasized that the teachings of the disclosure are applicable to systems using any number of sources, e.g., one, two, three, or five or more. As will be understood in the field, each melt beam source 212, 214, 216, 218 may have a magnetic field that includes a non-overlapping magnetic field region, where the metal powder can be melted exclusively, and may also include at least one overlapping magnetic field region, where two or more magnetic field sources can melt the metal powder. In this regard, each melt beam source 212, 214, 216, 218 may generate a respective particle-fusing melt beam for each slice, as defined by code 234O. For example, FIG. 9 shows melt beam source 212 creating a layer of combustor body 44 in one region with melt beam 262, while melt beam source 214 creating a layer of combustor body 44 in another region with melt beam 262′. Each melt beam source 212, 214, 216, 218 is calibrated by any now known or later developed method. That is, each melt beam source 212, 214, 216, 218 correlates the expected position of its laser or electron beam with its actual position relative to build platform 220 to provide individual positional corrections (not shown) to ensure its individual accuracy. In one embodiment, each of the multiple melt beam sources 212, 214, 216, 218 may produce a melt beam, eg, 262, 262', having the same cross-sectional dimensions (eg, shape and size during operation), power, and scan speed.

[0059] Continuing with FIG. 9 , an applicator (or re-coater blade) 270 may create a thin layer of feedstock material 272 that is laid down as a blank canvas upon which each successive slice of the final combustor body 44 is created. Various parts of the AM printer 232 may move to accommodate the addition of each new layer, e.g., the build platform 220 may lower and / or the chamber 260 and / or the applicator 270 may raise after each layer. This process may use a different feedstock material in the form of a finely divided metal powder, the stock of which may be held in a chamber 268 accessible by the applicator 270. In that instant case, the combustor body 44 may be made of a metal that may include a pure metal or an alloy. In one example, the metal may include virtually any non-reactive metal powder, i.e., non-explosive or non-conductive, such as cobalt-chromium-molybdenum (CoCrMo) alloy, stainless steel, austenitic nickel-chromium-based alloys such as nickel-chromium-molybdenum-niobium alloy (NiCrMoNb) (e.g., Inconel 625 or Inconel 718), nickel-chromium-iron-molybdenum alloy (NiCrFeMo) (e.g., Hastelloy® X available from Haynes International, Inc.), or nickel-chromium-cobalt-molybdenum alloy (NiCrCoMo) (e.g., Haynes 282 available from Haynes International, Inc.). Other possibilities include, for example, Rene 52, CM247, MarM247, and any precipitation hardenable (PH) nickel alloy.

[0060] The process chamber 260 is filled with an inert gas, such as argon or nitrogen, and is controlled to minimize or eliminate oxygen. The control system 230 is configured to control the flow of a gas mixture 274 within the process chamber 260 from a source of inert gas 276. In this case, the control system 230 may control a pump 280 and / or a flow valve system 282 for the inert gas to control the content of the gas mixture 274. The flow valve system 282 may include one or more computer-controllable valves, flow sensors, temperature sensors, pressure sensors, etc., that can precisely control the flow of specific gases. The pump 280 can be provided with or without the valve system 282. If the pump 280 is omitted, the inert gas can simply be placed in a conduit or manifold prior to introduction into the process chamber 260. The source of the inert gas 276 can take the form of any conventional source for the material contained therein, e.g., a tank, reservoir, or other source. Any sensors (not shown) necessary to measure the gas mixture 274 may be provided. The gas mixture 274 may be filtered using a filter 286 in a conventional manner.

[0061] In operation, a build platform 220 loaded with metal powder is provided within the processing chamber 260, and a control system 230 controls the flow of a gas mixture 274 within the processing chamber 260 from a source of inert gas 276. The control system 230 also controls an AM printer 232, in particular an applicator 270 and melt beam sources 212, 214, 216, and 218 that sequentially melt layers of metal powder on the build platform 220 to produce a combustor body 44 according to embodiments of the present disclosure. While a particular AM system 210 is described herein, it is emphasized that the teachings of the disclosure are not limited to any particular additive manufacturing system or method.

[0062] Once the AM combustor body 44 is formed, it may be assembled with other portions of the combustor 40 and / or connected to the turbine inlet 38, as shown in FIG. 2 . For example, a head end assembly 58 may be coupled to a forward end 60 of the combustor body 44. The head end assembly 58 may be coupled by any now known or later developed method, such as welding or fasteners (with or without seals). Additionally, an aft frame 70 may be coupled to the turbine inlet 38 by any now known or later developed method, such as welding or fasteners (with or without seals).

[0063] The present disclosure provides various technical and commercial advantages, examples of which are discussed herein. As noted, the AM combustor body improves efficiency by using air to cool the aft frame, which in turn is used for the AFS injectors typically used for purging a first stage nozzle gap. As a result, approximately 40% of the AFS injector air is also used to cool the tapered transition section, among other parts of the combustor body. Additive manufacturing allows the AM combustor body to be formed as a single body, reducing the cost of the combustor body by eliminating many of the multiple parts and required assembly steps. The AM combustor body also improves durability compared to conventional versions by improving cooling, eliminating welding, and providing the ability to design stress-raising geometries, such as high-stress welds between the aft end of the tapered transition section and the aft frame.

[0064] Approximate language used throughout this specification and claims may be applied to modify any quantitative expression that can be permissibly varied without resulting in a change in the basic function to which it relates. Thus, values modified by terms such as "about," "approximately," "substantially," etc. 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. Herein and throughout the specification and claims, range limitations can be combined and / or interchanged. Such ranges are identified and include all subranges contained therein unless the context or language dictates otherwise. "Approximately" or "about" applied to a particular value in a range applies to both endpoints and may indicate + / - 10% of the stated value, unless otherwise dependent on the precision of the instrument used to measure the value.

[0065] Corresponding structure, material, acts, and equivalents of all means 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 other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or to limit the disclosure to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiments were chosen and described to best explain the principles of the disclosure and practical application, and to enable others skilled in the art to understand the disclosure of various embodiments with various modifications suited to the particular use contemplated. [Explanation of symbols]

[0066] 10: Gas turbine system / GT system 12: Inlet section 14; Working fluid / air 16: Compressor 17;Compressor section 18: Compressed air 20: Fuel 22: Fuel supply 23: Combustion section 26: Combustion gases 28: Turbine 29: Turbine section 30: Shaft 32: Generator 34: Exhaust gases 36: Exhaust section 37: Exhaust stack 38: Turbine inlet 40: Combustor 44: Additively manufactured combustor body / AM combustor body 46: Outer casing 50: Monolithic member 52: Combustion liner 53: Cylindrical section 54: Tapered transition 56: Axial fuel stage injector / AFS injector 58: Separate head end fuel nozzle assembly / head end assembly 60: Fore end 62: Cap assembly 64: Fuel nozzle 65: End cover 66: Primary combustion zone 68: Secondary combustion zone 70: Aft frame 72: First cooling passage 74: Inlet 76: Outlet 80: Air coolant source 82: First flow sleeve 84: Outer surface 86: Second cooling passage 88: Air inlet 90: Sintered metal layer 96: Second flow sleeve 98: Outer surface 100: Third cooling passage 102: Inlet 104: Aft end 106: Forward end 110: First section 112: Second section 114: Boss 116: Circumferential side 130: Opening 132: Fourth cooling passage 134: Divider 138: Corner 140: First stage 142: Stationary nozzle 150: Fuel passage 210: Computerized metal powder additive manufacturing system / AM system 212, 214, 216, 218: Melt beam source 213: Tapered transition 215: Aft end 217: Axial fuel stage injector / AFS injector 219: Aft frame 220: Build platform 222: Fuel passage 224: Cooling passage 230: Additive manufacturing control system 232: AM printer 234, 234O, 234S: Computer executable instructions or code / computer program code 236: Computer 238: Memory 240: Storage system 244: Processor unit (PU) 246: Input / output (I / O) interface 248: Bus 250: I / O device 260: Processing chamber 262, 262': Melt beam 268: Accessible chamber 270: Applicator / recoat blade 272: Raw material 274: Gas mixture 276: Inert gas 280: Pump 282: Flow valve system 286: Filter;

Claims

1. A combustor (40) for a gas turbine system (10), comprising: The combustor (40) includes an additively manufactured (AM) combustor body (44) including a one-piece member (50); The integral member is a combustion liner (52) including a cylindrical portion (53) and a tapered transition portion (54); at least one axial fuel stage (AFS) injector (56) directed toward the combustion liner (52); an aft frame (70) disposed at an aft end of the tapered transition section (54) and including a first cooling passage (72) having an inlet (74) and an outlet (76) in fluid communication with an air coolant source (80); a first flowsleeve (82) spaced apart from an outer surface (84) of the tapered transition portion (54) and defining a second annular cooling passage (86) between the first flowsleeve (82) and the tapered transition portion (54); Including, a second annular cooling passage (86) extending from an outlet (76) of the first cooling passage (72) in the aft frame (70) to an air inlet (88) of the at least one AFS injector (56); The AM combustor body (44) includes a plurality of parallel sintered metal layers (90); A combustor (40) including a head-end axial fuel nozzle assembly (58) at a forward end (60) of a combustion liner (52).

2. 2. The combustor (40) of claim 1, wherein the first flow sleeve (82) includes a first portion (110) spaced parallel from the outer surface (84) of the tapered transition (54) and a second portion (112) extending convexly outwardly over the air inlet (88) of the at least one AFS injector (56).

3. 3. The combustor (40) of claim 2, wherein the at least one AFS injector (56) includes at least two AFS injectors (56) circumferentially spaced along at least one of the cylindrical portion (53) and the tapered transition portion (54), and wherein the second portion (112) of the first flow sleeve (82) extends at least partially around the tapered transition portion (54) to fluidly connect the air inlets (88) of the at least two AFS injectors (56).

4. The combustor (40) of any preceding claim, wherein the first flow sleeve (82) includes a plurality of openings (130) therethrough in fluid communication with the air coolant source (80).

5. 5. The combustor of claim 4, further comprising a divider disposed between the first flow sleeve and the outer surface of the tapered transition portion, the divider defining a third cooling passage adjacent to and fluidly separated from the second cooling passage, the third cooling passage extending from the plurality of openings to the air inlet of the at least one AFS injector.

6. The combustor (40) of any preceding claim, wherein the first cooling passage (72) in the aft frame (70) has a non-linear flow path within the aft frame (70).

7. 2. The combustor of claim 1, further comprising: a second flow sleeve disposed at a spaced interval along at least a portion of an outer surface of the cylindrical portion, the second flow sleeve defining a third cooling passage having an inlet adjacent the at least one AFS injector, the second flow sleeve extending to a head end axial fuel nozzle assembly coupled to the forward end of the AM combustor body.

8. 8. The combustor of claim 7, wherein an inlet to the third cooling passage is between an aft end of the second flowsleeve and a forward end of the first flowsleeve.

9. The combustor (40) of any preceding claim, wherein the first flow sleeve (82) extends forwardly on opposite circumferential sides (116) of the at least one AFS injector (56).

10. A gas turbine (GT) system (10) comprising: a compressor section (17); a combustion section (23) operably coupled to the compressor section (17); a turbine section (29) operably coupled to the combustion section (23); Including, The combustion section (23) includes at least one combustor (40); At least one combustor (40) includes an additively manufactured (AM) combustor body (44) including a one-piece member (50); The integral member (50) comprises: a combustion liner (52) including a cylindrical portion (53) and a tapered transition portion (54); at least one axial fuel stage (AFS) injector (56) directed toward the combustion liner (52); an aft frame (70) at an aft end of the tapered transition section (54), the aft frame (70) including a first cooling passage (72) therein with an inlet (74) and an outlet (76) in fluid communication with an air coolant source (80); a first flowsleeve (82) spaced apart from an outer surface (84) of the tapered transition portion (54) and defining a second annular cooling passage (86) between the first flowsleeve (82) and the tapered transition portion (54), the second annular cooling passage (86) extending from an outlet (76) of the first cooling passage (72) in the aft frame (70) to an air inlet (88) of the at least one AFS injector (56); The AM combustor body (44) includes a plurality of parallel sintered metal layers (90); A GT system (10) including a head-end axial fuel nozzle assembly (580) at the forward end (60) of a combustion liner (52).

11. 11. The GT system of claim 10, wherein the first flow sleeve includes a first portion spaced parallel to and spaced apart from the outer surface of the tapered transition section, and a second portion extending convexly outwardly over the air inlet of the at least one AFS injector.

12. 12. The GT system of claim 11, wherein the at least one AFS injector includes at least two AFS injectors circumferentially spaced along at least one of the cylindrical portion and the tapered transition portion, and wherein the second portion of the first flow sleeve extends at least partially around the tapered transition portion to fluidly couple the air inlets of the at least two AFS injectors.

13. The GT system (10) of claim 10, wherein the first flow sleeve (82) includes a plurality of openings (130) therethrough in fluid communication with the air-cooled water source (80).

14. 14. The GT system of claim 13, further comprising a divider between at least a portion of the outer surface of the tapered transition portion and the first flow sleeve, the divider defining a third cooling passage adjacent to and fluidly separated from the second cooling passage, the third cooling passage extending from the plurality of openings to the air inlet of the at least one AFS injector.

15. The GT system (10) of claim 10, wherein the first cooling passage (72) in the aft frame (70) has a non-linear flow path within the aft frame (70).

Images