Submerged injectors for axial fuel staging with internal cooling

Abstract

A submerged axial fuel staging (AFS) injector (180) includes an injector body (188) configured to be positioned in a hot gas path within a header (160). The injector body (188) includes an outer wall (190) defining a hollow interior (192) and having film cooling holes (194) extending from the hollow interior (192) to an outer side of the outer wall (190), and an inner wall (196) spaced from an inner side of the outer wall (190) along at least a portion of a length of the outer wall (190), the inner wall (196) defining an air chamber (200) therein. Impingement cooling holes (194) in fluid communication with the air chamber (200) extend through the inner wall (196) along at least a portion of the inner wall (196) and the outer wall (190).A fuel channel (210) extends at least partially along the hollow interior (192) of the outer wall (190), and fuel nozzles (220) in fluid communication with the fuel channel (210) extend to the outside of the outer wall (190).

Description

TECHNICAL FIELDThe disclosure relates generally to turbomachine combustors, and more particularly to submerged injectors for axially fuel staging with internal cooling.BACKGROUNDGas turbine systems include a combustion section that includes a plurality of combustors in which fuel is burned to generate a flow of burned gas that is converted to kinetic energy in a downstream turbine. Submerged axial fuel staging (AFS) injectors extend radially into a combustor liner to combust fuel in a secondary combustion zone downstream of a primary combustion zone. The submerged AFS injectors are used to supply higher energy combustion gases to the turbine and provide a more efficient combustor.BRIEF DESCRIPTIONAll of the aspects, examples and features mentioned below can be combined in any technically possible manner.One aspect of the disclosure includes an immersed axial fuel staging (AFS) injector comprising: an injector body configured to be disposed in a hot gas path within a combustor liner, the injector including: an outer wall defining a hollow interior and having a plurality of film cooling holes extending from the hollow interior to an exterior of the outer wall; an inner wall spaced from an interior of the outer wall along at least a portion of a length of the outer wall, the inner wall defining an air chamber therein, a first plurality of impingement cooling holes extending through the inner wall along at least a first portion of the inner wall, the first plurality of impingement cooling holes in fluid communication with the air chamber; a fuel passage extending at least partially along the hollow interior of the outer wall; a plurality of fuel nozzles extending through at least one of the inner wall and the outer wall to the exterior of the outer wall, each fuel nozzle in fluid communication with the fuel passage.Another aspect of the disclosure includes any of the foregoing aspects, and further comprises a coupler at a first end of the injector body, the coupler configured to couple the injector body in an opening of the combustor can.Another aspect of the disclosure includes any of the above aspects, and the air chamber includes a plurality of air chambers.Another aspect of the disclosure includes any of the foregoing aspects, and further comprises an intermediate wall extending from an inner side of the outer wall to an outer surface of the inner wall along at least a second portion of the inner wall and the outer wall, wherein the intermediate wall defines an air passage between the intermediate wall and the outer surface of the inner wall and a near-wall cooling passage between the intermediate wall and the inner side of the outer wall, wherein the intermediate wall includes a second plurality of impingement cooling holes fluidly coupling the air passage and the near-wall cooling passage defined by the intermediate wall, and wherein the air passage is in fluid communication with an outlet of an upstream one of the first plurality of impingement cooling holes and the second plurality of impingement cooling holes.Another aspect of the disclosure includes any of the foregoing aspects, and the intermediate wall includes a plurality of intermediate walls spaced along a respective plurality of second portions of the inner wall and the outer wall.Another aspect of the disclosure includes any of the foregoing aspects, and the air chamber is in fluid communication with a compressed air supply chamber extending along an exterior of the combustor can.Another aspect of the disclosure includes a combustor for a gas turbine system, the combustor comprising: a combustor liner; a plurality of submerged axial fuel staging (AFS) injectors extending radially into the combustor liner, each submerged AFS injector including an injector body including: an outer wall defining a hollow interior space and having a plurality of film cooling holes extending from the hollow interior space to an exterior of the outer wall; an inner wall spaced from an interior of the outer wall along at least a portion of a length of the outer wall, the inner wall defining an air chamber therein; a first plurality of impingement cooling holes extending through the inner wall along at least a first portion of the inner wall, the first plurality of impingement cooling holes being in fluid communication with the air chamber; a fuel passage extending at least partially along the hollow interior of the outer wall; and a plurality of fuel nozzles extending through at least one of the inner wall and the outer wall to the exterior of the outer wall, each fuel nozzle in fluid communication with the fuel passage.Another aspect of the disclosure includes any of the foregoing aspects, and further comprises a coupler at a first end of the injector body, the coupler configured to couple the injector body in an opening of the combustor can.Another aspect of the disclosure includes any of the above aspects, and the air chamber includes a plurality of air chambers.Another aspect of the disclosure includes any of the foregoing aspects, and further comprises an intermediate wall extending from an inner side of the outer wall to an outer surface of the inner wall along at least a second portion of the inner wall and the outer wall, wherein the intermediate wall defines an air passage between the intermediate wall and the outer surface of the inner wall and a near-wall cooling passage between the intermediate wall and the inner side of the outer wall, wherein the intermediate wall includes a second plurality of impingement cooling holes fluidly coupling the air passage and the near-wall cooling passage defined by the intermediate wall, and wherein the air passage is in fluid communication with an outlet of an upstream one of the first plurality of impingement cooling holes and the second plurality of impingement cooling holes.Another aspect of the disclosure includes any of the foregoing aspects, and the intermediate wall includes a plurality of intermediate walls spaced along a respective plurality of second portions of the inner wall and the outer wall.Another aspect of the disclosure includes any of the foregoing aspects, and the air chamber is in fluid communication with a compressed air supply chamber extending along an exterior of the combustor can.Another aspect of the disclosure includes any of the foregoing aspects and further comprises a head end fuel nozzle assembly coupled to a forward end of the combustor liner to supply a combustible fuel-air mixture to the combustor liner.Another aspect of the disclosure includes a gas turbine (GT) system comprising: a compressor section; a combustion section operatively connected to the compressor section; and a turbine section operatively connected to the combustion section, the combustion section including at least one combustor including a combustor liner and a plurality of submerged axial fuel staging (AFS) injectors extending radially into the combustor liner, each submerged AFS injector including an injector body including: an outer wall defining a hollow interior and having a plurality of film cooling holes extending from the hollow interior to an exterior of the outer wall; an inner wall spaced from an interior of the outer wall along at least a portion of a length of the outer wall, the inner wall defining an air chamber therein; a first plurality of impingement cooling holes extending through the inner wall along at least a first portion of the inner wall, the first plurality of impingement cooling holes being in fluid communication with the plenum chamber; a fuel passage extending at least partially along the hollow interior of the outer wall; and a plurality of fuel nozzles extending through at least one of the inner wall and the outer wall to the exterior of the outer wall, each fuel nozzle being in fluid communication with the fuel passage.Another aspect of the disclosure includes any of the foregoing aspects, and further comprises a coupler at a first end of the injector body, the coupler configured to couple the injector body in an opening of the combustor can.Another aspect of the disclosure includes any of the above aspects, and the air chamber includes a plurality of air chambers.Another aspect of the disclosure includes any of the foregoing aspects, and further comprises an intermediate wall extending from an inner side of the outer wall to an outer surface of the inner wall along at least a second portion of the inner wall and the outer wall, wherein the intermediate wall defines an air passage between the intermediate wall and the outer surface of the inner wall and a near-wall cooling passage between the intermediate wall and the inner side of the outer wall, wherein the intermediate wall includes a second plurality of impingement cooling holes fluidly coupling the air passage and the near-wall cooling passage defined by the intermediate wall, and wherein the air passage is in fluid communication with an outlet of an upstream one of the first plurality of impingement cooling holes and the second plurality of impingement cooling holes.Another aspect of the disclosure includes any of the foregoing aspects, and the intermediate wall includes a plurality of intermediate walls spaced along a respective plurality of second portions of the inner wall and the outer wall.Another aspect of the disclosure includes any of the foregoing aspects, and the air chamber is in fluid communication with a compressed air supply chamber extending along an exterior of the combustor can.Another aspect of the disclosure includes any of the foregoing aspects and further comprises a head end fuel nozzle assembly coupled to a forward end of the combustor liner to supply a combustible fuel-air mixture to the combustor liner.Two or more aspects described in this disclosure, including those described in this summary section, may be combined to form implementations not specifically described herein. That is, all embodiments described herein may be combined with each other.The details of one or more implementations are set forth in the accompanying drawings and the description below. Further features, objects and advantages result from the description and the drawings and from the claims.BRIEF DESCRIPTION OF THE DRAWINGSThese and other features of this disclosure will be more fully 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 disclosure, in which: FIG. 1 shows a functional block diagram of an illustrative gas turbine system that may be used with a combustor with an immersed axial fuel staging (AFS) injector according to various embodiments of the disclosure; FIG. 2 shows a cross-sectional view of a portion of a combustor with an immersed AFS injector, in accordance with embodiments of the disclosure; FIG. 3 shows an end view of a plurality of submerged AFS injectors in a combustor can, in accordance with embodiments of the disclosure; FIG. 4 shows a cross-sectional view of an immersed AFS injector taken along a line of sight A-A in FIG. 3, in accordance with embodiments of the disclosure; FIG. 5 shows a cross-sectional view of an immersed AFS injector taken along a line of sight A-A in FIG. 3, in accordance with other embodiments of the disclosure; FIG. 6 shows a cross-sectional view of an immersed AFS injector taken along a line of sight A-A in FIG. 3, in accordance with still other embodiments of the disclosure; FIG. 7 shows a schematic view of a radially inner end of an AFS injector according to an alternative embodiment of the disclosure; FIG. 8 shows a perspective view of an immersed AFS injector from a radially outer end, according to embodiments of the disclosure; FIG. 9 is a perspective view of a radially outer end of an immersed AFS injector according to other embodiments of the disclosure; FIG. 10 shows a perspective view of a radially outer end of an immersed AFS injector according to other embodiments of the disclosure; FIG. 11 is a perspective view of a radially outer end of an immersed AFS injector according to still other embodiments of the disclosure; FIG. 12 shows a perspective view of a radially outer end of a submerged AFS injector according to additional embodiments of the disclosure; FIG. 13 shows a cross-sectional view of a plurality of parallel sintered metal layers of a combustor body according to embodiments of the disclosure; FIG. 14 shows a cross-sectional view of a plurality of parallel sintered metal layers of an immersed AFS injector according to embodiments of the disclosure; and FIG. 15 shows a schematic block diagram of an illustrative additive manufacturing system for additive manufacturing of a combustor body or submerged AFS injector according to various embodiments of the disclosure.It should be noted that the drawings of the disclosure are not necessarily to scale. The drawings are intended to represent only typical aspects of the disclosure and should therefore not be considered as limiting the scope of the disclosure. In the drawings, like numbering corresponds to like elements between the drawings.DETAILED DESCRIPTIONIn order to clearly describe the present disclosure, it will be necessary in the introduction to select certain terminology when referring to and describing relevant machine components within an exemplary application of a turbomachine. As such, terms common in the industry are used and used in a manner that matches accepted meaning, where possible. Unless otherwise indicated, such terminology should be given a broad interpretation consistent with the context of the present application and the scope of the appended claims. Those of ordinary skill in the art will appreciate that a particular component may often be referred to using multiple different or overlapping terms. What may be described herein as a single part may include multiple components and may be referred to as consisting of them in a different context. Alternatively, what may be described herein as including multiple components may be referred to elsewhere as a single part.In addition, several descriptive terms may be used regularly herein and it should prove helpful 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 fluid, such as the working fluid through a combustor of the turbomachine or, for example, the flow of air through the combustor or the coolant through one of the component systems of the turbomachine. The term "downstream" corresponds to the direction of flow of the fluid, and the term "upstream" refers to the direction opposite to the flow. The terms "forward" and "aft" refer to directions without further specification, where "forward" refers to the forward or compressor end of the turbomachine and "aft" refers to the aft or turbine end of the turbomachine.The term "axial" refers to movement or position parallel to an axis, e.g., an axis of a combustor or turbomachine. The term "radial" refers to movement or position perpendicular to an axis, e.g., an axis of a combustor or turbomachine. In such cases, when a first component is closer to the axis than a second component, the first component is stated herein to be "radially inward" or "inboard" to the second component. On the other hand, if the first component is further from the axis than the second component, it may be indicated herein that the first component is "radially outward" or "outward" from the second component. Finally, the term "circumferential" refers to movement or position about an axis, e.g., a circumferential inner surface of a combustor liner or a circumferential inner side of a housing extending around a combustion chamber. As noted above, and depending on the context, it should be understood that such terms may be applied with respect to the axis of the combustor or the axis of the turbomachine.In addition, a plurality of descriptive terms may be used herein on a regular basis, as described below. The terms "first", "second", and "third" may be used interchangeably to distinguish one component from another and are not intended to identify the location or importance of the individual components.The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an", and "the / s" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. "Optional" or "optionally" means that the event described below may but need not occur, or that the feature described below may but need not be present, and that the description includes cases in which the event occurs or the feature is present and cases in which the event does not occur or the feature is not present.When an element or layer is referred to as being "on," "engaged to," "connected to," "coupled to," or "mounted to" another element or layer, it may be directly on, engaged to, connected to, coupled to, or mounted to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "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 "couple" and "mount" may be used interchangeably herein.Embodiments of the disclosure provide an immersed axial fuel staging (AFS) injector that includes an injector body configured to be disposed in a hot gas path within a combustor can. The injector body includes an outer wall defining a hollow interior space and having film cooling holes extending from the hollow interior space to an exterior of the outer wall, and an inner wall spaced from an interior of the outer wall along at least a portion of a length of the outer wall, the inner wall defining an air chamber therein. Impingement cooling holes in fluid communication with the air chamber extend through the inner wall along at least a portion of the inner wall and the outer wall. A fuel channel extends at least partially along the hollow interior of the outer wall, and fuel nozzles in fluid communication with the fuel channel extend to the exterior of the outer wall. The submerged AFS injector may be additively manufactured. The submerged AFS injector provides robust internal cooling, e.g., wall-mounted cooling and impingement cooling, while allowing the cooling air to be reused for combustion in the combustor liner.FIG. 1 shows a functional block diagram of an illustrative GT system 102 that may incorporate various embodiments of a combustor 100 of the present disclosure; FIG. 2 shows a cross-sectional view of combustor 100 according to embodiments of the disclosure. As shown in FIG. 1, GT system 102 generally includes an inlet section 110, which may include a series of filters, cooling coils, moisture separators, and / or other devices for cleaning and otherwise conditioning a working fluid (e.g., air) 112 entering GT system 102. Working fluid 112 flows to a compressor section where a compressor 114 progressively imparts kinetic energy to working fluid 112 to produce pressurized air 116 (hereinafter "pressurized air 116" or "air 116") in a high energy state. Pressurized air 116 is mixed with, among other things, a fuel 118 from a fuel supply 120 to form a combustible mixture within one or more combustors 100.As shown in FIG. 2, combustor 100 is at least partially surrounded by an outer casing 130, such as a compressor output casing and / or a turbine casing. An interior of the outer housing 130 is in fluid communication with a compressor outlet 132 of the compressor 114 and generates a compressed air supply 134. That is, compressed air supply 134 includes compressed air 116 from compressor outlet 132 of compressor 114. However, compressed air supply 134 may be any of compressed air supply 116 capable of flowing into various types of openings or flow channels in combustion chamber 100 to cool and / or burn parts.Referring to FIG. 1, combustion gases 140 flow through a turbine 142 (e.g., an expansion turbine) of a turbine section to generate work. For example, turbine 142 may be connected to a shaft 146 such that rotation of turbine 142 drives compressor 114 of the compressor section to generate compressed air 116. Alternatively or additionally, shaft 146 may connect turbine 142 to a generator 148 for power generation. Exhaust gases 150 from turbine 142 flow through an exhaust section 152 connecting turbine 142 to an exhaust stack 154 downstream of turbine 142. For example, exhaust section 152 may include a heat recovery steam generator (not shown) for purifying and extracting additional heat from exhaust gases 150 prior to release to the environment.In one embodiment, GT system 102 may include a commercially available gas turbine engine from GE Vernova of Cambridge, MA. The present disclosure is not limited to a particular GT system and may be used in conjunction with other engines, such as the GE Vernova HA, F, B, LM, GT, TM, and E class engine models, as well as other enterprise engine models. Moreover, the present disclosure is not limited to a particular turbomachine and may be applicable to, for example, steam turbines, jet engines, compressors, turbofans, etc.As shown in FIG. 2, combustors 100 include a combustor body 158 including a combustor liner 160 that contains combustion gases 140 and directs them to a turbine section including a turbine 142. As described herein, combustor can 160 may extend between a head end fuel nozzle assembly 166 and a rear frame 168. Combustor 160 includes a primary combustion zone 162 and a secondary combustion zone 164. Specifically, combustor 160 defines a combustion chamber in which combustion occurs in a primary combustion zone 162 and a secondary combustion zone 164. A combustible mixture of fuel and air is burned to produce high temperature, high pressure combustion gases 140. Combustor can 160 may include a cylindrical portion 172 and a conical transition portion 174 that is integral with the cylindrical portion 172, i.e., forms a common body structure (or "unibody structure"). According to embodiments of the disclosure, combustor liner 160 and / or combustor body 158 may be additively manufactured.Combustor 100 may include a head end fuel nozzle assembly 166 (hereinafter "head end assembly 166") connected to a forward end 167 of combustor liner 160 for supplying a combustible fuel-air mixture to primary combustion zone 162. Head end fuel nozzle assembly 166 may include any presently known or later developed fuel nozzle assembly for supplying fuel 118 from axially extending fuel nozzles 176 to primary combustion zone 162. Head end assembly 166 generally includes at least one axially extending fuel nozzle 176 extending downstream from end cap 170, and a cap assembly 178 extending radially and axially within combustor liner 160 downstream from end cap 170 and defining the upstream boundary of the combustion chamber.Combustor 100 also includes a plurality of submerged axial fuel staging (AFS) injectors 180 that extend radially into combustor liner 160, e.g., secondary combustion zone 164. FIG. 3 shows an end view of the submerged AFS injectors 180 in the combustor can 160. Referring to FIGS. 2 and 3, each submerged AFS injector 180 extends through an opening 182 in the combustor can 160. The injectors are referred to as "submerged" because they extend into the secondary combustion zone 164 and the combustion gases 140 contained therein. Therefore, they are immersed in the secondary combustion zone 164 and the combustion gases 140 contained therein. As will be further described, each submerged AFS injector 180 may be additively manufactured, e.g., with combustor body 158 or as a separate part coupled to the combustor body 158.Each submerged AFS injector 180 may include an injector body 188. FIGS. 4 to 6 show cross-sectional views along the line of sight A-A in FIG. 3 according to various embodiments of the disclosure. As shown in FIGS. 4-6, injector body 188 may include an outer wall 190 defining a hollow interior 192 and having a plurality of film cooling holes 194 extending from the hollow interior 192 to an exterior of the outer wall 190. The exterior of the outer wall 190 includes a secondary combustion zone 164 within the combustor can 160 (FIGS. 2-3 ). As will be further described, air 116 flows from the interior of the injector body 188 through film cooling holes 194 to provide film cooling to the exterior of the outer wall 190 and subsequently promote combustion in the secondary combustion zone 164. In a non-limiting example, the outer wall 190 may have a thickness in the range of 1.78 to 2.79 millimeters (mm) (0.07 to 0.11 inches). Film cooling holes 194 may have any required size, number, location, and arrangement to provide the desired film cooling flow characteristics and / or combustion characteristics for a particular combustor 100. Film cooling holes 194 may be disposed at a non-perpendicular angle with respect to the outer side (outer surface) of the outer wall 190 to direct, e.g., air 116 in a flow direction of the combustion gases 140 (arrows in FIGS. 4-6 ) in the combustor can 160 (FIGS. 2-3 ). It should be noted, however, that film cooling holes 194 may have different angles to the outside of the outer wall 190 depending on their position in the outer wall 190.Injector body 188 may also include an inner wall 196 spaced from an inner side 198 of outer wall 190 along at least a portion of a length of outer wall 190, i.e., into and out of the side of FIGS. 4-6. Inner wall 196 defines therein an air chamber 200. Air chamber 200 may include one or more air chambers that may include any form of air passages or cavities defined within inner wall 196, e.g., by any number of longitudinally extending walls 202 (shown in dashed lines in FIG. 4 and in solid lines in FIG. 6 ). FIGS. 4 and 6 show embodiments that include a plurality of air chambers 200. In FIG. 4, for example, up to four air chambers 200 (via three walls 202) are provided. FIG. 6 shows two air chambers 200 separated by a wall 202.In contrast, in FIG. 5, a large air chamber 200 is used. It is emphasized that any number and size of air chambers 200 may be used.As will be further described, each air chamber 200 is in fluid communication with the compressed air supply 134. In certain embodiments, as further described, air chamber(s) 200 may / may be open at an end (i.e., a radially outer end) of the injector body 188 that extends through combustor can 160 and is in fluid communication with compressed air supply 134. In an alternative embodiment shown in FIGS. 3 and 9, AFS injector 180 may also include at least one air chamber 200 in fluid communication with a compressed air supply chamber 208 extending along an exterior of combustor can 160. Compressed air supply chamber 208 is in fluid communication with air supply 134, e.g., via openings therein or any required conduit.Inner wall 196 may extend the entire length of injector body 188 and outer wall 190 (into and out of the sides of FIGS. 4-6 ). Alternatively, as shown in the schematic side view of a radially outer end of an injector body 188 in FIG. 7, inner wall 196 may extend only partially along a length of outer wall 190. In a non-limiting example, inner wall 196 may have an inner width W in a range of 12.70 to 19.05 millimeters (mm) (0.5 to 0.75 inches).Inner wall 196 also includes a plurality of impingement cooling holes 204 extending through inner wall 196 along at least a first portion of inner wall 196 to direct cooling air along a corresponding first portion of outer wall 190. Impingement cooling holes 204 are in fluid communication with plenum chamber 200 and thus direct pressurized air 116 against inner side 198 of outer wall 190 to cool outer wall 190. The number, size, position, and arrangement of the impingement holes 204 may be user-defined and may be based on, for example, the fuel used, the characteristics of the air 116, the size of the injector body 188 and / or the combustor 100, the operating temperatures, and the material of the injector body 188, among others.Injector body 188 also includes a fuel passage 210 that extends at least partially along hollow interior 192 of outer wall 190.Fuel passage / passages 210 in the injector body 188 are / are in fluid communication with fuel supply 120, e.g., through fuel line 286 (FIGS. 2-3 ) extending along an exterior of the combustor can 160 and / or fuel line 286 (FIGS. 2-3 ) integrated with combustor can 160. Each type of fuel 118 may be directed into fuel passages 210 in the injector body 188. In FIGS. 4-5, fuel passage 210 is shown as extending within hollow interior 192 and within inner wall 196. However, in other embodiments, as shown in FIG. 6, fuel passage 210 may be integrated into inner wall 196, i.e., formed within inner wall 196.Injector body 188 also includes a plurality of fuel nozzles 220 that extend through at least one of inner wall 196 and outer wall 190 to the exterior of outer wall 190, i.e., secondary combustion zone 164. Each fuel nozzle 220 is in fluid communication with the fuel passage / passages 210. Fuel nozzles 220 may be longitudinally arranged along the injector body in any manner, e.g., uniformly, in groups, non-uniformly, etc. Fuel nozzles 220 may be longitudinally arranged along a trailing edge 222 of the injector body 188 where it has a aerofoil cross-sectional shape. Fuel nozzles 220 may have any configuration to provide the desired fuel-air mixture and / or distribution.With continued reference to the first portion of the inner wall 196 and the outer wall 190 that includes impingement cooling holes 204, in FIG. 4, the first portions of the inner wall 196 and the outer wall 190 (not labeled) actually enclose the entire wall, except where fuel nozzles 220 protrude. In contrast, in other embodiments, as shown in FIGS. 5 and 6, first portions 206 of the inner wall 196 and the outer wall 190 include only a portion of each wall 196, 190. In the example of FIG. 5, the first portion 206 extends from about the 8 o'clock position to about the 1 o'clock position of the inner and outer walls 196, 190, and in the example of FIG. 6, the first portion 206 extends from about the 6 o'clock position to about the 12 o'clock position of the inner and outer walls 196, 190. In the example of FIG. 5, the first portion 206 encloses the leading edge of the injector body 188 where it has a aerofoil cross-sectional shape and includes a relatively small area on one side of the injector body 188 and a relatively longer area on the opposite side of the injector body 188. In the example of FIG. 6, the first portion 206 encloses the leading edge of the injector body 188 where it has a aerofoil cross-sectional shape and encloses a majority of the area on both sides of the injector body 188. As illustrated in the example of FIG. 6, the first portion 206 includes approximately the same area on each side of the injector body 188.As shown in FIGS. 5 and 6, injector body 188 also includes, outside first portion 206, one or more intermediate walls 226 that extend from inner side 198 of outer wall 190 to an outer surface 228 of inner wall 196 along at least a second portion 230 of inner wall 196 and outer wall 190. In certain embodiments, intermediate wall 226 may include a plurality of intermediate walls 226 spaced apart along a respective plurality of second portions 230 of inner wall 196 and outer wall 190. In FIG. 5, six second sections 230A to F are shown, each with a corresponding intermediate wall 226, and in FIG. 6, two second sections 230G to H are shown, each with a corresponding intermediate wall 226.Intermediate wall / baffles 226 may / may extend in a curved manner from the inner side 198 of the outer wall 190 to the outer surface 228 of the inner wall 196. As shown for clarity in FIGS. 5 and 6 only with respect to the second portion 230A or 230G, each intermediate wall 226 defines an air channel 232 between intermediate wall 226 and outer surface 228 of the inner wall 196 and a near-wall cooling channel 234 between intermediate wall 226 and inner side 198 of the outer wall 190. Intermediate wall / walls 226 may / may extend along walls 190, 196 for any desired length. Where an end 240 of the intermediate wall 226 meets an adjacent inner wall 196, the inner wall 196 may include a curved portion 242.Intermediate wall / baffles 226 include / include a second plurality of impingement cooling holes 244 defined in intermediate wall 226 that fluidly couple air passage 232 and near-wall cooling passage 234. Thus, each second portion 230 includes intermediate wall 226 to provide impingement cooling of inner side 198 of outer wall 190 and near-wall cooling of outer wall 190 using near-wall cooling passage 234. As illustrated, each air passage 232 is in fluid communication in a second portion 230 with an outlet of an upstream hole of the first plurality of impingement cooling holes 204 (in inner wall 196 adjacent to the respective air passage 232) or the second plurality of impingement cooling holes 244 (in intermediate wall 226 adjacent to the respective air passage 232). Thus, air 116 (also shown by arrows in FIGS. 4-6 ) flows from air chamber 200 through the first plurality of impingement cooling holes 204 in inner wall 196. A portion of the air 116 then flows through film cooling holes 194 in the outer wall to the secondary combustion zone 164, and a portion of the air 116 flows to an air duct 232 of a downstream second portion 230 of the inner wall 196 and the outer wall 190 that includes intermediate wall 226. The portion of air 116 in air passage 232 flows through second plurality of impingement cooling holes 244 in intermediate wall 226 to near wall cooling passage 234. The portion of the air 116 impinges on the inner side 198 of the outer wall 190 and / or flows along the outer wall 190 in the cooling channel 234 close to the wall. Air 116 then either exits fully into secondary combustion zone 164 through film cooling holes 194 in outer wall 190 or, if there is another (adjacent) downstream second portion 230, a portion of air 116 exits into secondary combustion zone 164 through film cooling holes 194 in outer wall 190 and another portion of air 116 enters adjacent downstream second portion 230 (e.g., from second portion 230A to adjacent second portion 230B, as shown in FIG. 5 ) via passage 298.FIG. 8 shows a perspective view of a radially outer end of the injector body 188 of the submerged AFS injector 180, according to embodiments of the disclosure. As mentioned, each air chamber 200 in the injector body 188 is in fluid communication with a pressurized air supply 134 supplied with pressurized air 116 from the compressor outlet 132 of the compressor 114. Pressurized air 116 may also be supplied to submerged AFS injectors 180 in any manner now known or later developed. In certain embodiments shown in FIG. 8, plenum(s) 200 may / may be open at an end 240 that extends through combustor can 160 and is in fluid communication with pressurized air supply 134. In an alternative embodiment shown in FIGS. 3 and 9, AFS injector 180 may also include air chamber(s) 200 in fluid communication with the air supply chamber defined by a sheathed member 208 extending along an exterior of combustor can 160. The sheathed member 208 defining the compressed air supply chamber fluidly couples the compressed air supply 134 to air chamber(s) 200 within each submerged AFS injector 180.Each submerged AFS injector 180 may also include a coupler 250 at a first end of the injector body 188 configured to couple the injector body within an opening 182 in the combustor can 160. FIG. 10 shows a perspective view of a radially outer end of a coupler 250 according to an embodiment of the disclosure. In certain embodiments, coupler 250 includes a sleeve 252 that extends radially from an outer portion 255 of combustor liner 160 at each opening 182 of combustor liner 160. Each sleeve 252 may have an inner surface 256 configured to conform to an outer surface 258 of a respective submerged AFS injector 180, i.e., having the same cross-sectional shape. Sleeve 252 may be coextensive with opening 182 in combustor can 160. Coupler 250 may further include a pin 260 extending through an opening 262 in sleeve 252 and an opening 263 in a radially outer end 264 of submerged AFS injector 180. In this manner, pin 260 secures the submerged AFS injector 180 in opening 182. That is, the submerged AFS injector 180 cannot move relative to the opening 182. Pin 260 may be any type of mechanical fastening mechanism, e.g., a threaded fastener, an interference fit pin, etc., capable of securing submerged AFS injector 180 in place in sleeve 252 and opening 182 in fire tube 160.Coupler 250 may also take other forms. FIG. 11 shows a perspective view of a radially outer end of a submerged AFS injector 180 with a coupler 250 according to another embodiment. In FIG. 11, coupler 250 includes a threaded connection 270 between each submerged AFS injector 180 and the respective aperture 182 in the combustor can 160, i.e., with mating threaded fasteners. In this case, the submerged AFS injector 180 may have a circular cross-section (e.g., at least at the radially outer end 264), and the radially outer end 264 (surface) may be provided with threads configured to mate with threads on an inner surface of the opening 182. Instead of the pin 260, a threaded arrangement with sleeve 252 may also be used in the embodiment of FIG. 10, i.e., where at least the radially outer end 264 of the injector body 188 has a circular cross-section. Threaded coupler 250 may have any required thread tolerance to prevent hot gas path (HGP) leakage within combustor 160. FIGS. 8, 9 and 12 show a perspective view of a coupler 250 according to another embodiment. In these embodiments, coupler 250 includes a tack weld 272 between the radially outer end 264 of each submerged AFS injector 180 and the outer portion 255 of the combustor can 160, i.e., at or about opening 182.The radially inner ends of the submerged AFS injector 180 may have any desired configuration, e.g., rounded, conical, etc. In FIGS. 4-6, the submerged AFS injector 180 has a symmetrical airfoil cross-sectional shape. Other cross-sectional shapes, for example circular, are also possible.Arrangements of impingement holes 204, 244, film cooling holes 194, baffles 226, plenum chambers 200, air passages 232, near wall cooling passages 234, fuel passages 210, and nozzles 220 may take a variety of alternative forms, among other structures, that are different from those illustrated, depending on a number of factors, such as, but not limited to: fuel properties (e.g., flow rate, combustibility, reactivity, pressure, temperature, etc.), other physical and operational properties of the combustor (e.g., volume of the combustion zone), and / or air properties (e.g., flow rate, pressure, temperature, etc.). Accordingly, it is emphasized that the arrangements shown herein are merely illustrative. While FIG. 3 further shows a circular fuel chamber 280 having radially extending passages 282 for supplying fuel 118 to fuel passages 210 in each injector body 188 of submerged AFS injectors 180, other arrangements are also possible. That is, fuel 118 may be supplied to fuel passages 210 in injector bodies 188 in any manner now known or later developed.Referring again to FIG. 2, combustor body 158 may also include an air flow passage 284 provided in combustor liner 160, or alternatively spaced apart from and surrounding a portion of combustor liner 160 by a flow sleeve (not shown). Air flow channel 284 at least partially surrounds cylindrical portion 172 of combustor liner 160. Air flow passage 284 directs pressurized air 116 over an outer surface of the combustor liner 160 (cylindrical portion 172 and / or conical transition portion 174). Additionally, air flow passage 284 may direct at least a portion of the compressed air 116 to one or more radially extending submerged AFS injectors 180 to combine it with fuel 118 for combustion in a secondary combustion zone 164 located downstream of the primary combustion zone 162. Additionally, as shown in FIG. 2, fuel lines 286 extending along or within combustor can 160 (or a fuel sleeve not shown) may direct fuel 118 from the fuel supply 120 to the submerged AFS injectors 180, i.e., to fuel channels 210 in injector bodies 188.Combustors 100 generally terminate at a point adjacent a first stage 288 of stationary nozzles 290 of turbine 142. The first stage 288 of the stationary nozzles 290 at least partially defines a turbine inlet 254 to the turbine 142. As mentioned, combustor 160 at least partially defines the HGP for directing the combustion gases 140 from the primary combustion zone 162 and the secondary combustion zone 164 to the turbine inlet 254 of the turbine 142 during operation of the GT system 102.In operation, compressed air 116 from the compressor 114 flows into an outer housing 130 surrounding the combustors 100, and is directed through fluid flow channel / channels (one) in each combustor 100. A portion of the pressurized air 116 is directed to the head end assembly 166 of the combustor 100, where it reverses direction and is directed through axially extending fuel nozzle(s) 176. Pressurized air 116 is mixed with fuel 118 to form a first combustible mixture that is injected into primary combustion zone 162. The first combustible mixture is burned to generate combustion gases 140. A second portion of the pressurized air 116 may be directed through the radially extending submerged AFS injectors 180 where it is mixed with fuel 118 supplied from fuel lines 286 and through (an) internal fuel passage / passages 210 to form a second combustible mixture. In either case, the second combustible mixture is injected into combustor can 160 and into the HGP. The second combustible mixture mixes at least partially with combustion gases 140 and is burned in the secondary combustion zone 164. As mentioned, combustor 160 defines the HGP for directing the combustion gases 140 from the primary combustion zone 162 and the secondary combustion zone 164 to the turbine inlet 254 of the turbine 142 during operation of the GT system 102.With respect to airflow 116 in the submerged AFS injectors 180, as shown by arrows of the air 116 in FIGS. 4-6, the second portion of the compressed air 116 enters (comes out of the side of FIGS. 4-6 ) air chamber(s) 200 and flows through a plurality of impingement cooling holes 204 defined by inner wall 196, i.e., into each first(s) portion(s) 206 in the injector body 188. More specifically, in the first portion(s) 206 of the inner wall 196 and the outer wall 190, air 116 impinges on the inner side 198 of the outer wall 190 to cool it, and then a first portion of the stream exits through the film cooling holes 194 into the secondary combustion zone 164 within the combustor can 160. Where a downstream second portion 230 is present (as in FIGS. 5 and 6 ), a second portion of the stream moves to the downstream second portion 230. The size of each portion of the flow may be controlled by, among other things, the size and number of film cooling holes 194 and the size of a passage 298 between the first and second portions 206 and 230 or between second portions 230. With respect to all second portions of the inner wall 196 and the outer wall 190, e.g., 230A- F in FIG. 5, the second portion of the airflow 116 enters a respective air passage 232 between the intermediate wall 226 and the inner wall 196 in the respective second portion 230. Subsequently, air 116 flows through impingement cooling holes 244 in the respective intermediate wall 226 and cools inner side 198 of outer wall 190 in the respective second portion 230. Subsequently, the second portion of the airflow 116 is re-divided to either exit through film cooling holes 194 into the secondary combustion zone 164 within the combustor 160 or flow to a subsequent second portion, e.g., 230B or 230D-F in FIG. 5. For each subsequent or downstream second portion 230 of the inner and outer walls 190, 196, the process of impingement cooling the inner side 198 of the outer wall 190 or directing it to a subsequent air channel 232 repeats until all of the air 116 exits into the secondary combustion zone 164 to provide a film cooling layer around the submerged AFS injector 180 and participate in the second combustible mixture.Combustor body 158 and each injector body 188 of submerged AFS injector 180 may be additively manufactured using any presently known or later developed capable of forming large integrated bodies. In certain embodiments, as shown in FIG. 13, combustor body 158 includes a plurality of parallel sintered metal layers 294 of a first material, and as shown in FIG. 14, each submerged AFS injector 180 includes a plurality of parallel sintered metal layers 296 of a second material. The first material for combustor bodies 158 may include any currently known or later developed combustion tolerant and oxidation resistant material. The first material may include, but is not limited to, a nickel-chromium based austenite alloy such as a nickel-chromium-molybdenum-niobium alloy (NiCrMoMn) (e.g., Inconel 625 or Inconel 718), a nickel-chromium-iron-molybdenum alloy (NiCrFeMo) (e.g., Hastelloy® X available from Haynes International, Inc.), a nickel-chromium-cobalt-molybdenum alloy (NiCrCoMo) (e.g., Haynes 233 or Haynes 282 available from Haynes International, Inc.) or a nickel-chromium-cobalt-titanium alloy (NiCrCoTi) (e.g., GTD 262 developed by General Electric Company). Submerged AFS injectors 180, i.e., injector bodies 188, may include a metal that is typically used in a hot gas path (HGP) component, such as a turbine blade or nozzle 142, and that has a higher temperature and oxidation tolerance than the first material used for combustor bodies 158. The metal may be a pure metal or an alloy.The second material used for the combustor body 158 may include a non-reactive metal powder, i.e., of a non-explosive or non-conductive powder, such as, but not limited to: a cobalt chromium molybdenum alloy (CoCrMo), stainless steel, a nickel chromium based austenite alloy such as a nickel chromium molybdenum niobium alloy (NiCrMoMn) (e.g., Inconel 625 or Inconel 718), a nickel chromium iron molybdenum alloy (NiCrFeMo) (e.g., Hastelloy® X, available from Haynes International, Inc.) or a nickel-chromium-cobalt-molybdenum alloy (NiCrCoMo) (e.g., Haynes 282 available from Haynes International, Inc.). Further possibilities are, for example, René 108, CM 247, Mar M 247 and any curable (PH) nickel alloy.FIG. 15 shows a schematic / block diagram of an illustrative computer-aided additive metal powder manufacturing system 310 (hereinafter "AM system 310") for creating a combustor body 158 and / or submerged AFS injectors 180, only a single layer of which is shown. Combustor body 158 and submerged AFS injectors 180 may be manufactured separately or as an integrated unitary piece. The teachings of the disclosures are described with respect to forming a combustor body 158 and / or submerged AFS injectors 180 using multiple melt jet sources 312, 314, 316, 318, but it is emphasized and readily appreciated that the teachings of the disclosure are equally applicable to forming a combustor body 158 and / or submerged AFS injectors 180 using any number of melt jet sources.In this example, the AM system 310 is configured for direct metal laser melting (DMLM). It should be appreciated that the general teachings of the disclosure are also applicable to other forms of additive metal powder manufacturing, such as, but not limited to, selective laser melting (SLM), and possibly other forms of additive manufacturing (i.e., other than metal powder applications). The layer of the combustor body 158 and / or the submerged AFS injector 180 in the build plate 320 is illustrated in FIG. 15 as a circular element; however, it should be appreciated that the additive manufacturing process can be easily adapted to produce any shape parts of the combustor body 158 and / or the submerged AFS injector 180 on the build plate 320.AM system 310 generally includes an additive manufacturing ("control system") control system 330 and an AM printer 332. As will be described, control system 330 executes a set of computer-executable instructions or codes 334 to generate a combustor body 158 and / or submerged AFS injectors 180 using a plurality of melt jet sources 312, 314, 316, 318. In the example shown, four melt beam sources may include four lasers. However, the teachings of the disclosures are applicable to any melt beam source, e.g., an electron beam, laser, etc. Control system 330 is shown implemented on computer 336 as computer program code. As such, computer 336 is shown including a memory 338 and / or storage system 340, a processor unit (PU) 344, an input / output (I / O) interface 346, and a bus 348. Further, computer 336 is shown in communication with an external I / O device / resource 350.Generally, processor unit (PU) 344 executes computer program code 334 stored in memory 338 and / or storage system 340. During execution of computer program code 334, processor unit (PU) 344 may read and / or write data from memory 338, storage system 340, I / O device 350, and / or AM printer 332. Bus 348 establishes a communication link between each of the components in computer 336, and I / O device 350 may include any device that allows a user to interact with computer 336 (e.g., keyboard, pointing device, display, etc.).Computer 336 is representative only of various possible combinations of hardware and software. For example, processor unit (PU) 344 may comprise a single processing unit or be distributed to one or more processing units at one or more locations, e.g., on a client and server. Similarly, storage 338 and / or storage system 340 may be located in one or more physical locations. Memory 338 and / or storage system 340 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 336 may include any type of computing device, such as an industrial controller, a network server, a desktop computer, a laptop, a mobile device, etc.As mentioned, AM system 310, and more particularly control system 330, executes code 334 to generate combustor bodies 158 and / or submerged AFS injectors 180. Code 334 may include, among other things, a set of computer-executable instructions 334S (also referred to herein as "code 334S") for operating the AM printer 332 as a system and a set of computer-executable instructions 334O (also referred to herein as "code 334O") for defining respective objects, such as combustor bodies 158 and / or submerged AFS injectors 180, to be physically generated by the AM printer 332. As described herein, the additive manufacturing process begins with a non-transitory computer readable storage medium (e.g., memory 338, storage system 340, etc.) storing code 334. The set of computer-executable instructions 334S for servicing the AM printer 332 may include any currently known or later developed software code capable of servicing the AM printer 332.The set of computer executable instructions 334O defining the combustor body 158 and / or the submerged AFS injectors 180 may include a well-defined 3D model of the combustor body 158 and / or the submerged AFS injectors 180, and may be generated from a variety of known computer aided design (CAD) software systems such as AutoCAD® TurboCAD® DesignCAD 3D Max, etc. In this regard, code 334O may include any currently known or later developed file format. Additionally, code 334O representing combustor body 158 and / or submerged AFS injectors 180 may be translated between different formats. For example, code 334O may include files in standard tessellation language (STL) created for stereolithography CAD programs of 3D systems or additive manufacturing file (AMF), an American Society of Mechanical Engineers (ASME) standard, which is an extensible markup language (XML) format that allows each CAD software to describe the shape and composition of a three-dimensional object to be created on an AM printer. Code 334O representing combustor body 158 and / or submerged AFS injectors 180 may also be converted to and transmitted as a set of data signals, received as a set of data signals, and converted to code, stored, etc., as appropriate. Code 334O may be configured in accordance with embodiments of the disclosure to enable the formation of edge and interior portions in overlapping field regions, as will be described. In each event, code 334O may be input to AM system 310 and may originate from a part developer, a intellectual property (IP) service provider, a design company, the operator or owner of AM system 310, or other sources. In each event, control system 330 executes code 334S and 334O and splits combustor body 158 and / or submerged AFS injectors 180 into a series of thin slices that are assembled into successive layers of material using AM printer 332.AM printer 332 may include a processing chamber 360 sealed to provide a controlled atmosphere for the pressure of the combustor body 158 and / or the submerged AFS injectors 180. A fabrication panel 320 on which combustor bodies 158 and / or submerged AFS injectors 180 are built is disposed within the processing chamber 360. A number of melt jet sources 312, 314, 316, 318 are configured to melt layers of metal powder on fabrication panel 320 to produce combustor bodies 158 and / or submerged AFS injectors 180. Although four melt beam sources 312, 314, 316, 318 are illustrated, it is emphasized that the teachings of the disclosure are applicable to a system using any number of sources, e.g., 1, 2, 3, or 5 or more. As is known in the art, each melt jet source 312, 314, 316, 318 may have a field that includes a non-overlapping field region, respectively, in which it may melt solely metal powder, and may include at least one overlapping field region in which two or more sources may melt metal powder. In this regard, each melt jet source 312, 314, 316, 318 may each generate a melt jet that melts particles for each disk as defined by code 334O.For example, in FIG. 15, melt jet source 312 is shown producing a layer of combustor body 158 (or submerged AFS injector 180) in one region using melt jet 362, while melt jet source 314 produces a layer of combustor body 158 (or submerged AFS injector 180) in another region using melt jet 362'. Each melt jet source 312, 314, 316, 318 is calibrated in any manner now known or later developed. That is, each melt beam source 312, 314, 316, 318 had its expected position of the laser or electron beam relative to the fabrication plate 320 that correlates to its actual position to provide an individual position correction (not shown) to ensure its individual accuracy. In one embodiment, each of the plurality of melt beam sources 312, 314, 316, 318 may generate melt beams, e.g., 362, 362', having the same cross-sectional dimensions (e.g., shape and size during operation), power, and scan speed.Continuing with FIG. 15, an applicator (or post-coater blade) 370 may generate a thin layer of raw material 372 that is spread out as a blank working surface from which each subsequent slice of the final combustor body 158 and / or the submerged AFS injector 180 is generated. Various portions of AM printer 332 may move to accommodate the addition of each new layer, e.g., a fabrication tray 320 may be lowered and / or chamber 360 and / or applicator 370 may rise after each layer. The process may use different raw materials in the form of fine grain metal powder, a supply of which may be stored in a chamber or powder container 368 that may be accessed by the applicator 370.Processing chamber 360 is filled with an inert gas such as argon or nitrogen and is controlled to minimize or eliminate oxygen. Control system 330 is configured to control the flow of a gas mixture 374 from an inert gas source 376 within processing chamber 360. In this case, control system 330 may control a pump 380 and / or an inert gas flow valve system 382 to control the content of the gas mixture 374. Flow valve system 382 may include one or more computer controllable valves, flow sensors, temperature sensors, pressure sensors, etc., that may precisely control the flow of the respective gas. Pump 380 may be provided with or without valve system 382. If pump 380 is omitted, inert gas may simply enter a conduit or manifold prior to introduction into processing chamber 360. Inert gas source 376 may take the form of any conventional source of material contained therein, e.g., a container, tank, or other source. All sensors (not shown) required to measure the gas mixture 374 may be provided. Gas mixture 374 may be filtered using a filter 386 in a conventional manner.In operation, fabrication panel 320 with metal powder thereon is provided within processing chamber 360, and control system 330 controls the flow of gas mixture 374 within processing chamber 360 from inert gas source 376. Control system 330 also controls AM printers 332, and more particularly, applicators 370 and melt jet sources 312, 314, 316, 318, to sequentially melt layers of metal powder on fabrication panel 320 to produce combustor bodies 158 and / or submerged AFS injectors 180 according to embodiments of the disclosure. Although a particular AM system 310 has been described herein, it is emphasized that the teachings of the disclosure are not limited to a particular additive manufacturing system or method.Once formed as shown in FIG. 2, combustor bodies 158 and / or submerged AFS injectors 180 may be mounted to other portions of combustor 100 and / or turbine inlet 254. For example, head end assembly 166 may be coupled to a front end of combustor body 158. Head end assembly 166 may be coupled in any manner presently known or later developed, such as by welding or fasteners. Additionally, turbine inlet 254 may be coupled to rear frame 168. The rear frame 168 may be coupled to turbine inlet 254 in any manner presently known or later developed, such as by welding or fasteners. AFS injectors 180 may be coupled to couplers 190 as illustrated in FIGS. 8-12 and as discussed above such that AFS injectors 180 extend radially inward into the combustion chamber.The disclosure provides various technical and commercial advantages, examples of which are discussed herein. The additively manufactured combustor body reduces the cost of the combustor by no longer requiring as many parts to be manufactured and subsequently assembled. As a result, additive manufacturing results in a reduction of the parts within the final combustion chamber by up to 70%. Additive manufacturing also allows for the use of highly temperature and oxidation resistant hot gas path (HGP) materials for the submerged AFS injectors and lower cost combustor body materials. Moreover, the submerged AFS injector provides robust internal cooling, such as wall cooling and impingement cooling, while allowing the cooling air to be reused for combustion in the combustor liner. Such robust internal cooling can be achieved by cooling structures and flow paths that would be difficult to produce using conventional manufacturing methods such as casting and machining.Approximating language, as used throughout the specification and claims herein, may be applied to modify any quantitative representation that could vary permissibly without resulting in a change in the basic function to which it relates. Accordingly, a value modified by a term or terms such as "about", "approximately", and "substantial" is not to be limited to the exact value indicated. At least in some cases, the approximating language may correspond to the accuracy of an instrument for measuring the value. Here, and throughout the specification and claims, range constraints may be combined and / or interchanged; such ranges are identified and include all sub-ranges included therein unless context or phrase indicates otherwise. "About" or "about" relative to a particular value of a range applies to both final values and, unless otherwise indicated, may indicate + / - 10% of the stated values depending on the accuracy of the instrument that measures the value.The corresponding structures, materials, acts, and equivalents of all means or steps plus functional elements in the claims below are intended to include any structure, material, or act 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 limited to the disclosure in 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 in order to best explain the principles of the disclosure and its practical application of the technology, and to enable others of ordinary skill in the art to understand the present disclosure and the possibility of various modifications of the present embodiments that are suitable for the particular use contemplated.

Claims

An immersed axial fuel staged (AFS) injector (180) comprising: an injector body (188) configured to be positioned in a hot gas path within a combustor liner (160), the injector body (188) including: an outer wall (190) defining a hollow interior space (192) and having a plurality of film cooling holes (194) extending from the hollow interior space (192) to an exterior of the outer wall (190); an inner wall (196) spaced apart from an interior side (198) of the outer wall (190) along at least a portion of a length of the outer wall (190), the inner wall (196) defining an air chamber (200) therein; a first plurality of impingement cooling holes (204) extending through the inner wall (196) along at least a first portion (206) of the inner wall (196), the first plurality of impingement cooling holes (204) in fluid communication with the air chamber (200); a fuel passage (210) extending at least partially along the hollow interior space (192) of the outer wall (190); and a plurality of fuel nozzles (220) extending through at least one of the inner wall (196) and the outer wall (190) to the exterior of the outer wall (190), each fuel nozzle (220) in fluid communication with the fuel passage (210).The submerged AFS injector (180) of claim 1, further comprising a coupler (250) at a first end of the injector body (188), the coupler (250) configured to couple the injector body (188) in an opening (182) of the combustor can (160).The submerged AFS injector (180) of claim 1, wherein the air chamber (200) includes a plurality of air chambers.The submerged AFS injector (180) of claim 1, further comprising an intermediate wall (226) extending from an inner side (198) of the outer wall (190) to an outer surface (228) of the inner wall (196) along at least a second portion (230) of the inner wall (196) and the outer wall (190), the intermediate wall (226) defining an air channel (232) between the intermediate wall (226) and the outer surface (228) of the inner wall (196) and a near-wall cooling channel (234) between the intermediate wall (226) and the inner side (198) of the outer wall (190), the intermediate wall (226) including a second plurality of impingement cooling holes (244) fluidly coupling the air channel (232) and the near-wall cooling channel (234) defined by the intermediate wall (226), and wherein the air duct (232) is in fluid communication with an outlet of an upstream hole of the first plurality of impingement cooling holes (204) and the second plurality of impingement cooling holes (244).The submerged AFS injector (180) of claim 4, wherein the intermediate wall (226) includes a plurality of intermediate walls spaced along a respective plurality of second portions (230) of the inner wall (196) and the outer wall (190).The submerged AFS injector (180) of claim 1, wherein the air chamber (200) is in fluid communication with a compressed air supply chamber (208) extending along an exterior of the combustor can (160).A combustor (100) for a gas turbine system (102), the combustor (100) comprising: a combustor liner (160); a plurality of submerged axial fuel staging (AFS) injectors (180) extending radially into the combustor liner (160), each submerged AFS injector (180) including an injector (188) including: an outer wall (190) defining a hollow interior space (192) and having a plurality of film cooling holes (194) extending from the hollow interior space (192) to an exterior of the outer wall (190); an inner wall (196) spaced from an interior side (198) of the outer wall (190) along at least a portion of a length of the outer wall (190), the inner wall (196) defining an air chamber (200) therein; a first plurality of impingement cooling holes (204) extending through the inner wall (196) along at least a first portion (206) of the inner wall (196), the first plurality of impingement cooling holes (204) in fluid communication with the air chamber (200); a fuel passage (210) extending at least partially along the hollow interior space (192) of the outer wall (190); and a plurality of fuel nozzles (220) extending through at least one of the inner wall (196) and the outer wall (190) to the exterior of the outer wall (190), each fuel nozzle (220) in fluid communication with the fuel passage (210).The combustor (100) of claim 7, further comprising a coupler (250) at a first end of the injector body (188), wherein the coupler (250) is configured to couple the injector body (188) in an opening (182) of the combustor can (160).The combustor (100) of claim 7, wherein the air chamber (200) includes a plurality of air chambers.The combustor (100) of claim 7, further comprising an intermediate wall (226) extending from an inner side (198) of the outer wall (190) to an outer surface (228) of the inner wall (196) along at least a second portion (230) of the inner wall (196) and the outer wall (190), the intermediate wall (226) defining an air channel (232) between the intermediate wall (226) and the outer surface (228) of the inner wall (196) and a near wall cooling channel (234) between the intermediate wall (226) and the inner side (198) of the outer wall (190), the intermediate wall (226) including a second plurality of impingement cooling holes (244) fluidly coupling the air channel (232) and the near wall cooling channel (234) defined by the intermediate wall (226), wherein the air duct (232) is in fluid communication with an outlet of an upstream hole of the first plurality of impingement cooling holes (204) and the second plurality of impingement cooling holes (244).The combustor (100) of claim 10, wherein the intermediate wall (226) includes a plurality of intermediate walls spaced apart along a respective plurality of second portions (230) of the inner wall (196) and the outer wall (190).The combustor (100) of claim 7, wherein the air chamber (200) is in fluid communication with a compressed air supply chamber (208) extending along an exterior of the combustor can (160).The combustor (100) of claim 7, further comprising a fuel nozzle assembly (166) coupled to a forward end (167) of the combustor liner (160) for supplying a combustible fuel-air mixture to the combustor liner (160).A gas turbine (GT) system (102) comprising: a compressor section (114); a combustion section operatively connected to the compressor section (114); and a turbine section (142) operatively connected to the combustion section, the combustion section including at least one combustor (100) including a combustor liner (160) and a plurality of submerged axial fuel staging injectors (180) extending radially into the combustor liner (160), each submerged AFS injector (180) including an injector body (188) including: an outer wall (190) defining a hollow interior space (192) and having a plurality of film cooling holes (194) extending from the hollow interior space (192) to an exterior of the outer wall (190); an inner wall (196) spaced apart from an inner side of the outer wall (190) along at least a portion of a length of the outer wall (190), the inner wall (196) defining an air chamber (200) therein; a first plurality of impingement cooling holes (204) extending through the inner wall (196) along at least a first portion (206) of the inner wall (196), the first plurality of impingement cooling holes (204) in fluid communication with the air chamber (200); a fuel channel (210) extending at least partially along the hollow interior space (192) of the outer wall (190); and a plurality of fuel nozzles (220) extending through at least one of the inner wall (196) and the outer wall (190) to the outer side of the outer wall (190), each fuel nozzle (220) in fluid communication with the fuel channel (210).The GT system (102) of claim 14, further comprising a coupler (250) at a first end (167) of the injector body (188), the coupler (250) configured to couple the injector body (188) in an opening (182) of the combustor can (160).

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