Axial fuel staging injector with axially elongated mixing chamber, and combustor and

Abstract

An axial fuel staging (AFS) injector includes a mixing member including an axially elongated mixing chamber in fluid communication with a combustion liner of a combustor, and fuel injectors located in opposing sidewalls of the mixing chamber. A high pressure (HP) air injection member defines a set of HP air nozzles spaced from the inlet of each mixing chamber. A fuel plenum in the mixing member delivers fuel from a fuel source to each set of fuel injectors. In some embodiments, each set of HP air nozzles directs HP air from an HP air source, and in some embodiments, low pressure (LP) air from an LP air source is drawn to direct LP air along with the HP air into an inlet of a respective mixing chamber at which fuel is injected. An axially elongated mixing chamber directs an air-fuel mixture into the combustion liner for combustion in a secondary combustion zone.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to turbine combustors, and more particularly to axial fuel staging (AFS) injectors having axially elongated mixing chambers, and combustors and gas turbine systems including the same. BACKGROUND

[0002] Gas turbine systems include a combustion section that includes a plurality of combustors in which fuel is burned to form a combustion gas flow that is converted to kinetic energy in a downstream turbine section. Current combustors include a head end fuel nozzle assembly for burning fuel in a primary combustion zone and an axial fuel staging (AFS) injector for burning fuel in a secondary combustion zone downstream of the primary combustion zone. Portions of an air supply from a compressor discharge casing are delivered in various flow passages to the head end fuel nozzle assembly and the AFS injector, for example. Current AFS injectors present challenges with respect to adequately mixing high reactivity fuels, such as hydrogen, with air and achieving desirable low exhaust emissions and desirable flame holding capability. SUMMARY

[0003] All aspects, examples, and features mentioned below can be combined in any technically possible manner.

[0004] A first aspect of the present disclosure includes an axial fuel staging (AFS) injector for a combustor of a gas turbine (GT) system, the AFS injector comprising: a mixing member comprising: a plurality of axially elongated mixing chambers defined in the mixing member, each axially elongated mixing chamber comprising an inlet and an outlet, wherein each outlet is configured to be in fluid communication with a combustion chamber of the combustor; and a set of fuel injectors defined in opposite side walls of each axially elongated mixing chamber; a high pressure (HP) air injection member defining a set of HP air injection ports spaced apart from the inlet of each axially elongated mixing chamber; and a fuel plenum defined in the mixing member, the fuel plenum configured to deliver fuel from a fuel source to each set of fuel injectors, wherein each set of HP air injection ports is configured to direct HP air from a HP air source into the inlet of the corresponding mixing chamber where the fuel is injected by the set of fuel injectors.

[0005] Another aspect of the present disclosure includes any of the preceding aspects, and the plurality of axially elongated mixing chambers includes a first axially elongated mixing chamber, a second axially elongated mixing chamber, and a third axially elongated mixing chamber between the first axially elongated mixing chamber and the second axially elongated mixing chamber.

[0006] Another aspect of the present disclosure includes any of the preceding aspects, and the third axially elongated mixing chamber extends radially at a perpendicular angle relative to a circumference of the combustion liner, and the first and second axially elongated mixing chambers are angled relative to the third axially elongated mixing chamber in opposite circumferential directions.

[0007] Another aspect of the present disclosure includes any of the preceding aspects, and the set of HP air jets spaced apart from the inlet of each mixing member is configured to direct HP air into the respective axially elongated mixing chamber at the same angle as the angle of the respective axially elongated mixing chamber.

[0008] Another aspect of the present disclosure includes any of the preceding aspects, and the set of HP air jets spaced apart from the inlet of the third axially elongated mixing chamber includes a pair of axially offset rows of HP air jets.

[0009] Another aspect of the present disclosure includes any of the preceding aspects, and the sets of HP air jets spaced apart from the inlets of the first and second axially elongated mixing chambers each include a collar extending radially inward, a first side of the collar being radially further from the mixing member than a second side opposite the first side.

[0010] Another aspect of the present disclosure includes any of the preceding aspects, and the first side of the collar of the sets of HP air jets spaced apart from the inlets of the first and second axially elongated mixing chambers each include an opening defined therein.

[0011] Another aspect of the present disclosure includes any of the preceding aspects, and the sets of HP air jets spaced apart from the inlets of the first and second axially elongated mixing chambers each have a fewer number of HP air jets than the set of HP air jets spaced apart from the inlet of the third axially elongated mixing chamber.

[0012] Another aspect of the present disclosure includes any of the preceding aspects, and the sets of HP air jets each include a flared inlet having an outer radius, and the flared inlet of the HP air jets for the first and second axially elongated mixing chambers has a first outer radius that is greater than a second outer radius of the flared inlet of the HP air jets of the third axially elongated mixing chamber.

[0013] Another aspect of the present disclosure includes any of the preceding aspects, and the arrangement of the sets of HP air jets spaced apart from the inlets of the first and second axially elongated mixing chambers is the same, and the arrangement of the set of HP air jets spaced apart from the inlet of the third axially elongated mixing chamber is different than the arrangement of the sets of HP air jets spaced apart from the inlets of the first and second axially elongated mixing chambers.

[0014] Another aspect of the present disclosure includes any of the preceding aspects, and the fuel plenum extends within an upstream side wall of each of the plurality of axially elongated mixing chambers, and wherein each set of fuel injectors is closer to the inlet than to the outlet of the respective axially elongated mixing chamber of the plurality of axially elongated mixing chambers.

[0015] Another aspect of the present disclosure includes any of the preceding aspects, and the opposing side walls of the first and second axially elongated mixing chambers include a first side wall and an opposing second side wall, and wherein for each of the first and second axially elongated mixing chambers, the set of fuel injectors defined in the first side wall is arranged differently than the set of fuel injectors defined in the second side wall.

[0016] Another aspect of the present disclosure includes any of the preceding aspects, and the set of fuel injectors in the side walls of the first and second axially elongated mixing chambers are arranged differently in the first side wall of the axially elongated mixing chamber than in the opposing second side wall of the axially elongated mixing chamber.

[0017] Another aspect of the present disclosure includes any of the preceding aspects, and each axially elongated mixing chamber has a semi-circular opposing end.

[0018] Another aspect of the present disclosure includes any of the preceding aspects, and the mixing member includes a filter member upstream of the set of HP air injection ports.

[0019] Another aspect of the present disclosure includes any of the preceding aspects, and the mixing member and the HP air injection member each include at least one mounting element configured to receive a fastener to couple the mixing member and the HP air injection member to a flow sleeve at least partially surrounding a combustion liner defining a combustion chamber.

[0020] Another aspect of the present disclosure includes any of the preceding aspects, and each set of HP air injection ports is configured to draw low pressure (LP) air from a source of LP air to direct the LP air with the HP air into the inlet of each respective mixing chamber; the source of HP air is in direct fluid communication with a compressor discharge of the GT system, and the source of LP air is in fluid communication with a cooling passage defined along at least a portion of the combustion liner, wherein the cooling passage is downstream of an impingement cooling member in direct fluid communication with the compressor discharge of the GT system.

[0021] Another aspect of the present disclosure includes a combustor for a gas turbine system, the combustor comprising: a combustor body comprising a combustion liner; and a plurality of axial fuel staging (AFS) injectors directed into the combustion liner, each AFS injector comprising: a mixing member comprising: a plurality of axially elongated mixing chambers defined in the mixing member, each axially elongated mixing chamber comprising an inlet and an outlet, wherein each outlet is configured to be in fluid communication with a combustion chamber of the combustor; and a fuel injector set defined in opposite side walls of each axially elongated mixing chamber; a high pressure (HP) air injection member defining a set of HP air injection ports spaced apart from the inlet of each axially elongated mixing chamber; and a fuel plenum defined in the mixing member, the fuel plenum configured to deliver fuel from a fuel source to each set of fuel injectors, wherein each set of HP air injection ports is configured to direct HP air from a HP air source into the inlet of a respective mixing chamber where the fuel is injected by the set of fuel injectors.

[0022] Another aspect of the present disclosure includes any of the preceding aspects, and the plurality of axially elongated mixing chambers comprises a first axially elongated mixing chamber, a second axially elongated mixing chamber, and a third axially elongated mixing chamber between the first axially elongated mixing chamber and the second axially elongated mixing chamber.

[0023] Another aspect of the present disclosure includes a gas turbine (GT) system, the GT system comprising: a compressor section; a combustion section operatively coupled to the compressor section; and a turbine section operatively coupled to the combustion section, wherein the combustion section comprises at least one combustor comprising: a combustor body comprising a combustion liner; a head end fuel nozzle assembly at a forward end of the combustor body; a plurality of axial fuel staging (AFS) injectors directed into the combustor body downstream of the head end fuel nozzle assembly, each AFS injector comprising: a mixing member comprising: a first axially elongated mixing chamber; a second axially elongated mixing chamber; and a third axially elongated mixing chamber between the first and second axially elongated mixing chambers, each axially elongated mixing chamber comprising an inlet and an outlet, wherein each outlet is configured to be in fluid communication with a combustion chamber of the combustor; and a fuel injector set defined in opposite sidewalls of each axially elongated mixing chamber; a high pressure (HP) air injection member defining a set of HP air injection ports spaced from the inlet of each axially elongated mixing chamber; and a fuel plenum defined in the mixing member, the fuel plenum configured to deliver fuel from a fuel source to each set of fuel injectors, wherein each set of HP air injection ports is configured to direct HP air from a HP air source into the inlet of the respective mixing chamber where fuel is injected by the set of fuel injectors.

[0024] Two or more aspects described in this disclosure, including those described in this Summary, can be combined to form implementations not specifically described herein. That is, all embodiments described herein can be combined with each other.

[0025] 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 DESCRIPTION OF DRAWINGS

[0026] These and other features of the present disclosure will be more readily understood from the following detailed description, taken in conjunction with the drawings, in which:

[0027] Figure 1 A functional block diagram of an exemplary gas turbine system that can be used with a combustor comprising axial fuel staging (AFS) injectors is shown in accordance with an embodiment of the present disclosure;

[0028] Figure 2 A cross-sectional side view of a combustor comprising AFS injectors is shown in accordance with an embodiment of the present disclosure;

[0029] Figure 3 A perspective partial cross-sectional view of an AFS injector is shown in accordance with embodiments of the present disclosure;

[0030] Figure 4 A cross-sectional view of an AFS injector taken along line 4-4 is shown in accordance with embodiments of the present disclosure; Figure 3

[0031] Figure 5 A cross-sectional view of an AFS injector taken along line 5-5 is shown in accordance with embodiments of the present disclosure; Figure 3

[0032] Figure 6A A top-down view of a mixing member of an AFS injector is shown in accordance with various embodiments of the present disclosure;

[0033] Figure 6D A schematic view of opposing side walls of an outer mixing chamber of a mixing member of an AFS injector is shown in accordance with embodiments of the present disclosure;

[0034] Figure 6E A schematic view of opposing side walls of a central mixing chamber of a mixing member of an AFS injector is shown in accordance with embodiments of the present disclosure;

[0035] Figure 7 A top-down view of a high pressure air injection member of an AFS injector is shown in accordance with embodiments of the present disclosure;

[0036] Figure 8A An enlarged perspective view of a high pressure air jet group in a high pressure air injection member is shown in accordance with embodiments of the present disclosure;

[0037] Figure 8B An enlarged cross-sectional view of a high pressure air jet group in a high pressure air injection member is shown in accordance with embodiments of the present disclosure;

[0038] Figure 9 A cross-sectional view of multiple parallel sintered metal layers of a mixing member or a high pressure air injection member of an AFS injector is shown in accordance with embodiments of the present disclosure; and

[0039] Figure 10 A schematic block diagram of an exemplary additive manufacturing system for additive manufacturing a mixing member and / or a high pressure air injection member of an AFS injector in accordance with embodiments of the present disclosure is shown.

[0040] It should be noted that the drawings of the present disclosure are not necessarily drawn to scale. The drawings are intended to depict only typical aspects of the disclosure and therefore should not be considered as limiting the scope of the disclosure. In the drawings, like numbering represents similar elements between the drawings. DETAILED DESCRIPTION​​

[0041] First, in order to clearly describe the present technology, when referring to and describing relevant machine components within the exemplary application of a turbine combustor and axial fuel staging (AFS) injector, it will be necessary to select certain terminology. In doing so, where possible, generic industry terminology will be used and employed in a manner consistent with its accepted meaning. 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 number of different or overlapping terms can be used to reference a particular component. An object that can be described herein as a single part can comprise multiple components and be referenced elsewhere as being composed of multiple components. Alternatively, an object that can be described herein as comprising multiple components can be referred to elsewhere as a single part.

[0042] Further, several descriptive terms can be used regularly herein, and it can prove helpful to define these terms at the outset of this section. Unless otherwise indicated, these terms, and their definitions, are as follows. As used herein, "downstream" and "upstream" are terms indicating direction with respect to the direction of fluid flow, such as the working fluid through a combustor of a turbine, or the air flow through a combustor or AFS injector, or the coolant through one of the component systems of a turbine. The term "downstream" corresponds to the direction of fluid flow, and the term "upstream" refers to the direction opposite to the flow. Without any further particularity, the terms "forward" and "aft" refer to directions, with "forward" referring to the forward or compressor end of a turbine or combustor, and "aft" referring to the aft or turbine end of a turbine or combustor.

[0043] The term "axial" refers to movement or positioning parallel to an axis (e.g., the axis of a combustor, mixing chamber of an AFS injector, or turbine). The term "radial" refers to movement or positioning perpendicular to an axis (e.g., the axis of a combustor or turbine). In the case of such, if a first component resides closer to an axis than a second component, it will be stated herein that the first component is "radially inward" or "inboard" of the second component.

[0044] On the other hand, if a first component resides further from an axis than a second component, it can be stated herein that the first component is "radially outward" or "outboard" of the second component. Finally, the term "circumferential" refers to movement or positioning around an axis, e.g., a circumferential inner surface of a combustor body or a circumferential interior of a casing extending around a combustor. As noted above, and depending on the context, it will be understood that such terms can be applied with respect to the axis of a combustor or the axis of a turbine.

[0045] Furthermore, several descriptive terms are routinely used herein, as set forth below. The terms "first," "second," and "third" can be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components.

[0046] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a," "an" and "the" 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" mean that the subsequently described event or circumstance can or can not occur, or that the subsequently described feature can or can not be present, and that the description includes instances where the event occurs (or the feature is present) and instances where the event does not occur (or the feature is not present).

[0047] 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 can be directly on, engaged to, connected to, coupled to, or mounted to the other element or layer, or intervening elements or layers can be present. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to," "directly coupled to," or "directly mounted 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 like fashion (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 "coupled" and "connected," along with their derivatives, can be used interchangeably in this document to mean one or more of the following: logically coupled, physically coupled, communicatively coupled, electrically coupled, magnetically coupled, and / or otherwise coupled.

[0048] Embodiments of the present disclosure provide an axial fuel staging (AFS) injector for a combustor, a combustor, and a gas turbine (GT) system including the combustor. The AFS injector includes a mixing member including a plurality of axially elongated mixing chambers in fluid communication with a combustion liner of the combustor, and a set of fuel injectors defined in a sidewall of each axially elongated mixing chamber. A high pressure (HP) air injection member defines a set of HP air injection ports spaced from an inlet of each axially elongated mixing chamber. A fuel plenum is defined in the mixing member to deliver fuel from a fuel source to each set of fuel injectors. Each set of HP air injection ports is configured to direct HP air from a HP air source, and optionally, to draw low pressure (LP) air from a LP air source, to direct the LP air with the HP air into the inlet of the respective axially elongated mixing chamber where the fuel is injected by the set of fuel injectors. The axially elongated mixing chamber directs the air-fuel mixture into the combustion liner for combustion in a secondary combustion zone thereof. The AFS injector can be additively manufactured to include a plurality of parallel sintered metal layers.

[0049] In some embodiments, the AFS injector mixes two air sources, one being high pressure air, for example, from a compressor discharge, and the other being low pressure air, for example, impingement post-cooling air, to reduce overall system pressure loss and more effectively use air in the combustor. The AFS injector can rapidly premix the two air sources with, for example, a high reactivity fuel, such as hydrogen, to achieve low emissions of, for example, nitrogen oxides (NOx) and acceptable flame holding capability.

[0050] In each embodiment, the AFS injector achieves high mixing of fuel and air, minimizes flow pressure loss, and prevents fuel from entering any low velocity air flow regions. Additionally, the AFS injector is packaged in a relatively small geometry, allowing the AFS injector to be assembled onto a combustion liner of a combustor body, and the combustor body to be installed into a GT system through a relatively small opening in a compressor discharge casing.

[0051] Figure 1 A combustor 100 and an axial fuel staging (AFS) injector 150 (shown in FIG. 1) can incorporate the present disclosure. Figure 2A functional block diagram of an exemplary gas turbine (GT) system 90 in accordance with various embodiments of the present disclosure. As shown, the GT system 90 generally includes an inlet section 102, which can include a series of filters, cooling coils, moisture separators, and / or other devices to purify and otherwise condition a working fluid 106 (e.g., air) entering the GT system 90. The working fluid 106 (e.g., air) flows to a compressor 108 in a compressor section 110, which progressively imparts kinetic energy to the working fluid 106 to produce compressed high pressure (HP) air 112 (hereinafter referred to as “HP air 112” or “compressed air 112”) in a high-energy state. The HP air 112 is typically mixed with fuel 114A and / or 114B from a fuel source 116 to form a combustible mixture within at least one combustor 100 in a combustion section 120, which is operatively coupled to the compressor section 110. The combustible mixture is combusted to produce combustion gases 122 having high temperature and pressure.

[0052] The combustion gases 122 flow through a turbine 128 of a turbine section 130 to produce work, which is operatively coupled to the combustion section 120. For example, the turbine 128 can be connected to a shaft 132 such that rotation of the turbine 128 drives the compressor 108 to produce the HP air 112. Alternatively or additionally, the shaft 132 can connect the turbine 128 to another load, such as an electrical generator 134 for producing electrical power. Exhaust gases 136 from the turbine 128 flow through an exhaust section 138, which connects the turbine 128 to an exhaust stack 140 downstream of the turbine 128. The exhaust section 138 can include, for example, a heat recovery steam generator (not shown) for cleaning the exhaust gases 136 and extracting additional heat from the exhaust gases before the exhaust gases are released to the environment. In the event that more than one combustor 100 is used, these combustors can be spaced circumferentially around a turbine inlet 142 of the turbine 128.

[0053] In one embodiment, the GT system 90 can include an engine model commercially available from GE Vernova of Cambridge, MA. The present disclosure is not limited to operation with any one particular GT system and can be implemented in conjunction with other engines, including, for example, any of the HA, F, B, LM, GT, TM, and E-class engine models of GE Vernova, as well as engine models of other companies. Moreover, the present disclosure is not limited to implementation with any particular turbomachinery, and can be applicable, for example, to steam turbines, jet engines, compressors, turbofans, and the like.

[0054] A combustor 100 capable of use within the GT system 90 will now be described. Figure 2A cross-sectional side view of a combustor 100 positioned within a GT system 90 is shown. As will be further described herein, the combustor 100 can include one or more axial fuel staging (AFS) injectors 150 in accordance with embodiments of the present disclosure.

[0055] As Figure 2 shown, the combustor 100 is at least partially surrounded by an outer casing 152, such as a compressor discharge casing and / or a turbine casing. The interior of the outer casing 152 is in fluid communication with a compressor discharge 109 of the compressor 108 and forms a HP air source 154. That is, the HP air source 154 includes HP air 112 from the compressor discharge of the compressor 108. The HP source 154 is in direct fluid communication with the compressor discharge 109 of the GT system 90. However, the HP air source 154 can be any supply of HP air 112 that can flow into any kind of opening or flow passage in the combustor 100 to cool parts and / or for combustion (e.g., in the AFS injectors 150).

[0056] As Figure 2 shown, the combustor 100 for the GT system 90 includes a combustor body 160. The combustor body 160 can be formed using any now known or later developed technique. For example, the combustor body 160 can be additively manufactured. The combustor body 160 can include a combustion liner 164, which can include, for example, a cylindrical portion 166 and a conical transition portion 168. The combustion liner 164 can have an axis A, the direction of which can vary slightly depending on the axial position within the curved combustion liner 164. The conical transition portion 168 is located at a rear end (as Figure 2 shown, right side) of the cylindrical portion 166. As understood in the art, the conical transition portion 168 transitions the hot gas path (HGP) from a circular cross-section of the cylindrical portion 166 of the liner to a more curved cross-section for mating with a turbine inlet 142 of the turbine 128. The combustor 100 can also include a rear frame 170 at a rear end (right side in Figure 2 ) of the conical transition portion 168.

[0057] The combustion liner 164 can contain and convey the combustion gases 122 to the turbine section 130 Figure 1 ). More specifically, the combustion liner 164 defines a combustion chamber 172, i.e., within the hot gas path (HGP), within which combustion occurs. As in many conventional combustion systems, the combustion liner 164 can have a conical transition portion 168 separate from the cylindrical portion 166. Alternatively, as Figure 2As shown, the combustion bushing 164 may have an integral (or “monolithic”) construction, wherein the cylindrical portion 166 and the tapered transition portion 168 are integral with each other, i.e., as components of an additively manufactured monolithic component. Therefore, any discussion herein of the combustion bushing 164 is intended to cover both conventional combustion systems with separate cylindrical and tapered transition portions and those combustion systems with monolithic bushings.

[0058] The burner body 160 also includes an airflow passage 174 defined at least partially by a cylindrical portion 166 of the combustion bushing 164. As will be described herein, the airflow passage 174 is configured to deliver air (e.g., HP air 112A from HP air source 154) to the front end of the combustion bushing 164 of the burner 100. Figure 2 The head-end fuel nozzle assembly 176 (hereinafter referred to as "head-end assembly 176") is located at the left end of the burner 100. That is, its size, shape, and / or arrangement are configured to deliver air, such as HP air 112A from HP air source 154, to the head-end assembly 176 of the burner 100. The airflow passage 174 may be completely defined within the cylindrical portion 166, or the airflow passage 174 may be disposed between the cylindrical portion 166 and a flow sleeve 177 spaced apart along at least a portion of the outer surface of the cylindrical portion 166. The airflow passage 174 has an open end 178 or airflow opening near the head-end assembly 176 through which HP air 112A from HP air source 154 enters. Here, HP air 112A from HP air source 154 may be directly drawn from the compressor discharge; that is, the air has no other purpose than uniform convective cooling of the burner body 160.

[0059] An annular separator 179, positioned between the cylindrical portion 166 and the flow sleeve 177, separates the front portion of the airflow passage 174 from its rear portion. The annular separator 179 is axially aligned approximately with the cap assembly 198, as described below, such that the front portion of the airflow passage 174 is radially outside the head assembly 176 (rather than the combustion chamber 172), thus requiring less cooling. Behind the annular separator 179, the flow sleeve 177 may include a plurality of impact holes 192 (as shown in the outer sleeve 190) that allow HP air 112B to flow into the airflow passage 174. As a result of passing through the impact holes 192, the HP air 112B experiences a pressure drop and becomes LP air 182, which flows through the airflow passage 174 to and / or into the AFS injector 150, as discussed further herein.

[0060] The head end assembly 176 generally includes at least one axially extending fuel nozzle 194 extending downstream from an end cap 196, and a cap assembly 198 extending radially and axially within the outer casing 152 downstream of the end cap 196 and defining a forward boundary of the combustion chamber 172. The head end assembly 176 can include any now known or later developed axially extending fuel nozzle 194 for delivering the first fuel 114A from the axially extending fuel nozzle 194 to the main combustion zone 202. In certain embodiments, the axially extending fuel nozzle 194 of the head end assembly 176 extends at least partially through the cap assembly 198 to provide the main combustion zone 202 with a combustible mixture of fuel 114A and HP air 112A.

[0061] The combustor body 160 also includes an axial fuel staging (AFS) injector opening or standoff 180 directed into the combustion liner 164 downstream of the head end assembly 176. The opening or standoff 180 extends through a wall of the combustion liner 164. One or more AFS injector openings or standoffs 180 (hereinafter referred to as “openings 180”) can be provided and configured to have an AFS injector 150 mounted thereto and to receive HP air 112B from the HP air source 154, possibly along with other air flows as will be described herein. Each AFS injector opening 180 can include any necessary structure to allow the AFS injector 150 to be mounted thereto, such as threaded fasteners, bolt holes, weld areas, etc. As shown, the combustor 100 and combustor body 160 can include a plurality of circumferentially spaced apart AFS injector openings 180 and corresponding AFS injectors 150. Any number of AFS injectors 150 can be used.

[0062] As will be described, in some embodiments, the AFS injector 150 is also structured to receive (draw in) low pressure (LP) air 182 from a low pressure (LP) air source 184 (e.g., a cooling passage), and direct the low pressure air into the combustion liner 164 along with fuel 114B. The fuel 114B can be delivered from the fuel source 116 using any form of fuel line 188. The fuels 114A, 114B can be any now known or later developed combustor 100 fuel, such as but not limited to fuel oil, natural gas, hydrogen, and / or mixtures thereof. The fuels 114A, 114B can be the same or different.

[0063] In some embodiments, LP air 182 can be delivered from LP air source 184 to AFS injector 150 in various ways. In certain embodiments, LP air 182 originates from HP air source 154, but is used for cooling prior to use in AFS injector 150. In one example, combustor body 160 further includes a cooling passage 186 providing LP air source 184, which is at least partially defined by conical transition portion 168. Cooling passage 186 can also be in fluid communication with other cooling passages (not shown) in combustor 100 (e.g., in aft frame 170). In any event, LP air 182 of LP air source 184 can be used to cool one or more hot parts of combustor 100. More specifically, LP air 182 of LP air source 184 passes through cooling passage 186 after being tapped from compressor discharge 109, which as noted is at least partially defined by conical transition portion 168.

[0064] In one example, cooling passage 186 can be formed by or within flow sleeve 190 around conical transition portion 168. If desired, impingement cooling holes 192 can be provided in flow sleeve 190 around conical transition portion 168 to allow HP air 112 from HP air source 154 to enter and become LP air 182. In this regard, LP air source 184 includes cooling passage 186 defined along at least a portion of combustion liner 164 (e.g., conical transition portion 168). Moreover, cooling passage 186 can be downstream of an impingement cooling member (portion 168 having impingement cooling holes 192 in an outer sleeve thereof or sleeve 190 around portion 168 having holes 192 therein) that is in direct fluid communication with compressor discharge 109 (i.e., HP air source 154) of GT system 90. It should be noted that the hot part can include any part of combustor 100 that requires cooling, and LP air 182 can be directed into cooling passage 186 in any desired manner. That is, cooling passage 186 can be defined in (other) hot parts of combustor 100 (e.g., aft frame 170) other than conical transition portion 168 or along such hot parts. In any event, cooling passage 186 is located between AFS injector 150 and HP air source 154, which in some embodiments is configured to deliver LP air 182 of LP air source 184 to AFS injector 150. LP air 182 from LP air source 184 can also be referred to herein as "aft cooling" or "aft impingement air" as it is used to provide significant cooling of a part of combustor 100.

[0065] As mentioned, the combustor 100 includes at least one axial fuel stage (AFS) injector 150 directed into the combustor body 160 (i.e., combustion liner 164). As mentioned, the AFS injector 150 may include a plurality of AFS injectors 150 circumferentially spaced around the combustor body 160. Each AFS injector 150 extends radially through the combustion liner 164 downstream of the head assembly 176 (i.e., downstream of the axially extending fuel nozzle 194). As will be further described, the AFS injector 150 is configured to receive HP air 112B from HP air source 154 and optionally draw in LP air 182 from LP air source 184. In a specific embodiment, LP air 182 from LP air source 184 may be directed to the AFS injector 150, for example in a cooling passage 186, to combine with HP air 112B and second fuel 114B for combustion in a secondary combustion zone 204 downstream of the primary combustion zone 202.

[0066] Figures 3-5 Various views of an AFS injector 150 according to an embodiment of this disclosure are shown. Figure 3 A three-dimensional cross-sectional view of the AFS injector 150 is shown; Figure 4 It shows along Figure 3 A cross-sectional view taken from the midline of sight 4-4; Figure 5 It shows along Figure 3 A cross-sectional view taken from the midline of sight 5-5; the AFS injector 150 includes a mixing component 210 and a high-pressure (HP) air injection component 212. Figure 6A -C shows a top-to-bottom view of the hybrid component 210 according to various embodiments, and Figure 7 The image shows a top-to-bottom view of the HP air injection component 212 according to various embodiments.

[0067] The mixing component 210 and the HP air injection component 212 are joined together to form the AFS injector 150. More specifically, as Figures 3-5 As shown, the mixing component 210 and the HP air injection component 212 may each include a mounting element 213 configured to receive fasteners 215 (e.g., bolts, welds, or other fasteners) to attach the mixing component 210 and the HP air injection component 212 to the burner body 160, for example to an AFS injector mount 274 attached to the outer sleeve 190. Alternatively, the mixing component 210 and the HP air injection component 212 may be formed as a single integral piece, for example by additive manufacturing. Each AFS injector 150 is aligned with and mounted within a corresponding opening 180 in the combustion bushing 164. Hereinafter, for brevity, the HP air injection component 212 is sometimes referred to as "injection component 212".

[0068] As Figures 3-4 shown, the mixing member 210 includes a plurality of axially elongated mixing chambers 214 defined therein. The mixing member 210 can also be referred to as an injector body. In the example shown, the plurality of axially elongated mixing chambers 214 includes a first axially elongated mixing chamber 214A, a second axially elongated mixing chamber 214B, and a third axially elongated mixing chamber 214C between the first and second axially elongated mixing chambers 214A-B. Although the mixing member 210 is shown as having three axially elongated mixing chambers 214A-C, more than three axially elongated mixing chambers 214 can be provided. As Figures 3-5 shown, each axially elongated mixing chamber 214A-C includes an inlet 216 and an outlet 218. Each inlet 216 is radially inward of the HP air injection member 212, and the outlet 218 is configured to be in fluid communication with the combustion liner 164 of the combustor 100 Figure 2 ). More specifically, the outlet 218 can be positioned and secured in the opening 180 in the combustion liner 164.

[0069] The axially elongated mixing chambers 214 can take a variety of forms. In the example shown in the drawings, each of the plurality of axially elongated mixing chambers 214A-C has a slot shape. More specifically, as Figure 4 shown, each mixing chamber 214 has a generally elongated tubular chamber having opposing elongated sidewalls 220, 222 and opposing end portions 224 (best seen in Figure 6A -C). The mixing chamber 214 is referred to as "axially elongated" because its longitudinal length (e.g., the longitudinal length of the slot) can be generally aligned with the axis A of the combustion liner 164. As Figure 6A shown in the top view, the opposing end portions 224 can be substantially linear as they transition to the respective sidewalls 220, 222, or as Figure 6B -C shown, the opposing end portions 224 can be rounded or semi-circular as they transition to the respective sidewalls 220, 222. Although not shown, some curvature and / or narrowing from the inlet 216 to the outlet 118 can be provided in the axially extending mixing chamber 214 if desired.

[0070] Referring to Figure 4 , the third axially elongated mixing chamber 214C extends radially at a perpendicular angle relative to the circumference C of the combustion liner 164 (best seen in Figure 4(From right to left on the page). Therefore, the third axially elongated mixing chamber 214C extends radially from axis A of the combustion bushing 164, i.e., along the radial direction R. In contrast, the first axially elongated mixing chamber 214A and the second axially elongated mixing chamber 214B are angled relative to the third axially elongated mixing chamber 214C in opposite circumferential directions. More specifically, the first axially elongated mixing chamber 214A is angled relative to the third axially elongated mixing chamber 214C at a first angle α1, and the second axially elongated mixing chamber 214B is angled relative to the third axially elongated mixing chamber 214C at a second angle α2. The first angle α1 and the second angle α2 may be equal.

[0071] In the following text, for the sake of brevity, the first and second axially elongated mixing chambers 214A-B will be referred to as “mixing chambers” or “outer mixing chambers” 214A or 214B as needed, and the third axially elongated mixing chamber 214C may be referred to as “central mixing chamber 214C” herein. The mixing chambers may be collectively referred to as “mixing chamber 214”. The outer mixing chambers 214A-B can also be considered to be at an angle relative to the axis A of the combustion bushing 164 with respect to the radial direction R, i.e., in the circumferential plane (i.e.,... Figure 4 In the plane of the page. That is to say, the centerline of the outer mixing chambers 214A-B does not extend parallel to or collinear with the radius (R) of the axis A relative to the combustion liner 164. In this way, the outer mixing chambers 214A-B (extending into and out) Figure 4 The page (of the mixture) can be angled to guide the air-fuel mixture 250 exiting from it toward axis A of the combustion liner 164. It should be understood that the angle in the circumferential plane can vary depending on the number of mixing chambers 214 used.

[0072] The number and arrangement of mixing chambers 214 can vary, for example, based on the fuel 114B used, the size of the burner 100, and other factors. Figure 6A As shown in -B, the mixing chamber 214 can be arranged with three mixing chambers 214A-C. Figure 6C Another example is shown, comprising five mixing chambers 214A-E. It should be emphasized that the scope of this disclosure includes other arrangements not explicitly shown. Figure 6C The mixing chamber 214 may also include, as about Figure 4 The angle described is relative to the radial direction R.

[0073] The AFS injector 150 also includes a fuel plenum 230 defined in the mixing member 210. In alternative embodiments, although not shown, the fuel plenum 230 can be defined in the air injection member 212. The fuel plenum 230 can extend within an upstream portion of the side walls 220, 222 of each mixing chamber 214A-C, or at least an upstream portion of the side walls 220, 222 of any mixing chamber 214A-C necessary to supply fuel 114B to the desired mixing chamber 214. More specifically, the fuel plenum 230 can extend around each mixing chamber 214 to any degree necessary to deliver fuel 114B, with a set of fuel injectors 232 positioned at the fuel plenum. The AFS injector 150 can also include an inlet port 234 in fluid communication with the fuel plenum 230 and configured to receive fuel 114B from the fuel source 116 Figures 1-2 ). The inlet port 234 of each AFS injector 150 can be fluidly coupled to the fuel source 116 by, for example, a fuel line 188 Figure 2 ) and, optionally, a distribution plenum (not shown) around the combustion liner 164. In any case, the fuel plenum 230 is configured to deliver fuel 114B from the fuel source 116 to each set of fuel injectors 232. As noted, the fuel 114B can be any burner 100 fuel now known or hereafter developed, such as but not limited to fuel oil, natural gas, etc. Due to the advantages of the AFS injector 150, the fuel 114B can also include a highly reactive fuel, such as hydrogen. The fuel 114B can also include a mixture of fuels, such as natural gas and hydrogen.

[0074] The mixing member 210 also includes a set of fuel injectors 232 defined in the opposing side walls 220, 222 of each mixing chamber 214. Each fuel injector 232 is in fluid communication with the fuel plenum 230 such that fuel 114B can be introduced into the respective mixing chamber 214 from the fuel source 116, i.e., under pressure. The fuel injectors 232 can be arranged in any manner to achieve the desired air-fuel mixture 250. More specifically, the fuel injectors 232 in each set are configured to entrain fuel 114B in the HP air stream 244 from the injection member 212 to produce the desired air-fuel mixture 250 for combustion in the combustion liner 164. The type, number, spacing, and size of the fuel injectors 232 within a given set and overall can be selected according to, for example, a variety of characteristics of the burner 100, the HP air 112B, the LP air 182 (when used), and / or the fuel 114B. For example, with respect to the fuel 114B, characteristics can include, but are not limited to: gas type, level of reactivity, viscosity, desired flow rate or volume, pressure, temperature, etc. Similar characteristics of the air 112B, 182 can also be considered.

[0075] In certain embodiments, as Figure 3and Figure 4 and Figure 6D As shown in the schematic illustration, each set 236 of fuel injectors 232 may include a single row of fuel injectors 232 in each of opposite side walls 220, 222 of a respective mixing chamber 214. Opposite sets 236 of fuel injectors 232 for a particular mixing chamber 214 may have the same arrangement, but are more likely to be different in terms of fuel injector 232 spacing, size, quantity, etc. so that the fuel 114B( Figure 2 ) mixes better with the HP air stream 244. The fuel injectors 232 within a given set 236 and the different sets 236 of fuel injectors 232 need not be the same.

[0076] For example, as shown in the schematic illustration of Figure 6D , first and second axially elongated mixing chambers 214A, 214B may include a first side wall 220 and an opposite second side wall 222, and a set 236A of fuel injectors 232A defined in the first side wall 220 may be arranged in a different manner than a set 236B of fuel injectors 232B defined in the second side wall 222, for each outer mixing chamber 214A, 214B. For example, the quantity, size, orientation, and other physical characteristics of the fuel injectors 232 may be different in the different side walls 220, 222. In terms of the quantity of injectors, in one non - limiting example, a set 236A of fuel injectors 232A in one side wall 222 may include X fuel injectors 232; and a set 236B of fuel injectors 232B in the other side wall 220 may include Y fuel injectors 232. The quantity X of fuel injectors 232A in set 236A in side wall 220 is not equal to the quantity Y of fuel injectors 232B in set 236B in side wall 222. In the example shown, X < Y. In one non - limiting example, the fuel injectors 232 for the outer mixing chambers 214A - B may be non - uniformly spaced on one or both of the side walls 220, 222.

[0077] Conversely, as shown in the schematic illustration of Figure 6E , for the central mixing chamber 214C, opposite sets 236D and 236D of fuel injectors 232C and 232D may have different arrangements, but are more likely to be the same in terms of fuel injector 232 spacing, size, quantity, etc. For example, as Figure 6EAs shown in the schematic diagram, the central mixing chamber 214C may include a first sidewall 220 and an opposing second sidewall 222, and the fuel injector assembly 232C 236C defined in the first sidewall 220 may be arranged in the same or similar manner as the fuel injector assembly 232D 236D defined in the second sidewall 222. In this example, the same number of fuel injectors 232 are defined in the opposing sidewalls 220, 222 of the central mixing chamber 214C. In another non-limiting example, the fuel injectors 232 for the central mixing chamber 214C may be evenly spaced on the two sidewalls 220, 222.

[0078] In other implementation schemes, such as Figure 5 As shown, each group of fuel injectors 232 may include a first group 236E of fuel injectors 232E that are axially spaced (relative to the axis of the respective mixing chamber 214) from a second group 236F of fuel injectors 232F in a respective mixing chamber 214 of the plurality of mixing chambers. More specifically, the first group 236E of fuel injectors 232E may be spaced apart from the outlet 218 of the respective mixing chamber 214 by a first distance D1, and the second group 236F of fuel injectors 232F may be spaced apart from the outlet 218 in the respective mixing chamber 214 of the plurality of mixing chambers by a second distance D2 less than the distance D1. As shown, the first group 236E and the second group 236F form two rows. Figure 5 The multi-row fuel injector 232 shown can be used in any mixing chamber 214. Although one or two sets of axially spaced fuel injectors 232A-B are shown on each sidewall 220, 222, more than two sets of axially spaced fuel injectors are possible in other embodiments.

[0079] Regardless of the implementation, each set of fuel injectors 232 may be closer to the inlet 216 than the outlet 218 of the corresponding mixing chamber 214 (e.g., 214C) of the plurality of mixing chambers. In any case, the fuel injectors 232 are arranged such that the HP airflow 244, the LP airflow 182 (when in use), and the fuel 114B ( Figure 2 Maximize the mixing of airflow. Other arrangements tailored to the characteristics of factors such as HP airflow 244, LP airflow 182 (when in use), fuel 114B, burner 100, and others are also possible.

[0080] The fuel injectors 232 can employ any now known or later developed opening form for delivering a particular type of fuel 114B to the respective mixing chamber 114. For example, the fuel injectors 232 can be cylindrical openings or have a narrowed nozzle cross-section to dispense the fuel 114B. Additionally, the fuel injectors 232 can introduce the fuel 114B into the respective mixing chamber 214 in any desired direction. For example, the fuel injectors 232 can introduce the fuel 114B into the respective mixing chamber 214 at a perpendicular angle relative to the axis of the respective mixing chamber 214 and / or its upstream sidewall 222; at a non-perpendicular angle relative to the upstream sidewall 222 to impart rotation to the fuel 114B; and / or at a non-perpendicular angle relative to the axis of the respective mixing chamber 214 radially outwardly or inwardly (i.e., toward or away from the combustion liner 164).

[0081] The dimensions of the mixing chambers 214 can be defined by the user based on, for example, the properties of the fuel 114B, the HP air 112B, the LP air 182 (when used), and / or the combustion liner 164. As shown, the length LI of each mixing chamber 214A-B from the inlet 216 to the outlet 218 (only shown in mixing chamber 214B for clarity) is generally the same, but the length L2 of the central mixing chamber 214C can be longer. The dimensions of any portion of the mixing member 210 (and the HP air injection member 212) of the AFS injector 150 can be tailored to produce a desired air-fuel mixture 250 while maintaining a low profile to facilitate installation of the combustor 100 within the respective opening in the outer casing 152. Figure 4 Figure 4 The length LI of each mixing chamber 214A-B from the inlet 216 to the outlet 218 (only shown in mixing chamber 214B for clarity) is generally the same, but the length L2 of the central mixing chamber 214C can be longer. The dimensions of any portion of the mixing member 210 (and the HP air injection member 212) of the AFS injector 150 can be tailored to produce a desired air-fuel mixture 250 while maintaining a low profile to facilitate installation of the combustor 100 within the respective opening in the outer casing 152.

[0082] Referring to Figures 3-5 and Figures 7-8B The HP air injection member 212 will now be described. It should be noted that the injection member 212 can also be referred to as a "top hat." The injection member 212 has a generally arcuate (e.g., C-shaped) cross-sectional profile that is configured to surround the radially outward portion of the mixing member 210. The perimeter of the injection member 212 can include a flanged edge 217 Figure 3 that contacts the outer sleeve 177, 190 when the AFS injector 150 is installed. The injection member 212 defines a set 240 of HP air injection ports 242 for each mixing chamber 214. When the AFS injector 150 is assembled, the outlets of the HP air injection ports 242 are spaced apart from the respective inlets 216 of each mixing chamber 214. The number of sets 240 of HP air injection ports 242 in the injection member 212 is the same as the number of mixing chambers 214 in a given mixing member 210. For example, as shown in FIG. 2, the injection member 212 defines two sets 240 of HP air injection ports 242 for each mixing chamber 214A-B, and three sets 240 of HP air injection ports 242 for the central mixing chamber 214C. Figure 7 ​As shown, three groups 240 of HP air jets 242, namely groups 240A, 240B, 240C, are shown, corresponding to the three mixing chambers 214A-C in FIG. 6. The injection member 212 is in fluid communication with the HP air source 154 such that HP air 112B enters and is directed through the groups 240 of HP air jets 242 into the AFS injector 150.

[0083] As will be described, in some embodiments, each group 240 of HP air jets 242 is configured to direct HP air 112B from the HP air source 154 and draw LP air 182 from the LP air source 184 to direct the LP air 182 with the HP air 112B into the inlet 216 of the respective mixing chamber 214. This collection of flows is referred to herein as a HP air flow 244 Figures 3-5 , see arrows extending toward the inlet 216 of the respective mixing chamber 214. Thus, the HP air flow 244 can include both HP air 112B and LP air 182. Note that, although mixed with LP air 182, the HP air flow 244 is referred to as a high pressure flow because it maintains a relatively high pressure, although not as high as the HP air 112B from the HP air source 154 (e.g., the compressor discharge 109 Figure 2 ).

[0084] As Figures 3-5 shown, the injection member 212 can optionally include a filter member 246 upstream of the groups of HP air jets 242. Note that the filter member 246 is not shown in FIG. 6 for clarity. The filter member 246 can include any now known or later developed filtering structure capable of preventing undesirable contaminants from the HP air source 154 from entering the AFS injector 150. Figure 7

[0085] Figure 8A An enlarged perspective view of the groups 240A-C of HP air jets 242 is shown, and Figure 8B a cross-sectional view of the HP air jets 242A-C of the injection member 212 is shown. As Figure 3 , Figure 7 and Figure 8A ​As shown, the arrangement of HP air nozzle groups 240A-B, spaced apart from the inlets 216 of the outer mixing chambers 214A-B, is the same for groups 240A and 240B, while the arrangement of HP air nozzle groups 242 240C, spaced apart from the inlet 116 of the central mixing chamber 214C, differs from that of HP air nozzle groups 240A-B, which are spaced apart from the inlets 116 of the mixing chambers 214A-B. This difference in arrangement can take any form, such as, but not limited to, the layout, size, shape, and / or number of HP air nozzles 242 in each group 240. Regarding the size of the individual air nozzles, the cross-sectional area of ​​the HP air nozzle groups 240A-B for the outer mixing chambers 214A-B is larger than that of the HP air nozzles for the central mixing chamber group 240C.

[0086] In terms of quantity, each group 240 of HP air nozzles 242 may include any number of HP air nozzles 242. For example, groups 240A-B of HP air nozzles 242 spaced apart from the inlets 216 of the outer mixing chambers 214A-B each have fewer HP air nozzles 242 than group 240C of HP air nozzles 242 spaced apart from the inlet 216 of the central mixing chamber 214C. A smaller number of HP air nozzles 242 on the outer mixing chambers 214A-B may be advantageous to reduce any obstruction to the flow of LP air 182 (when in use) into the mixing member 210. Figures 3-5 and Figure 7 In the example shown, each group 240A-B of the external mixing chambers 214A-B comprises six (6) HP air nozzles 242A-B in a single row. That is, each group 240A-B comprises six (6) HP air nozzles 242 in the corresponding row. Conversely, as Figure 7 As shown, the HP air nozzle 242 group 240C for the central mixing chamber 214C includes rows 248A-B of a pair of axially offset HP air nozzles 242. For example, group 240C may include a row 248B of eleven (11) HP air nozzles 242 and another row 248A of ten (10) HP air nozzles 242. Although a specific number of HP air nozzles 242 are shown in each group 240, any number of HP air nozzles 242 can be used in each group 240A-C. In the example shown, each HP air nozzle 242 may have an airfoil cross-sectional shape to allow LP air 182 to flow from the circumferentially outer side of the injection member 212 ( Figures 3-4 and Figure 8AThe left and right sides in -B lead to the mixing chambers 214, and in particular, to the central mixing chamber 214C. However, the HP air jets 242 can alternatively have a cross-sectional shape such as, but not limited to, an oval, an elongated opening or slot, or a narrowing longitudinal cross-section (a nozzle or venturi-like). While a particular arrangement of each group is shown in the drawings, other arrangements are possible.

[0087] As shown in Figure 8B , the HP air jet 242 groups 240A-B each include a flared inlet 251 having a first outer radius Rl, and the HP air jet 242 groups 240C each include a flared inlet 251 having a second outer radius R2. The first outer radius Rl is greater than the second outer radius R2. The different radii make it easier for the HP air 112B to flow into the HP air jets 242, and also reduce pressure loss, based on the desired volume and size of the HP air jets 242.

[0088] Further regarding the HP air jet 242 configuration, and as shown in Figure 3 , Figure 4 and Figure 8A -B, the HP air jet 242 groups 240A-B that are spaced apart from the inlets 116 of the mixing chambers 214A, 214B each include a collar 252 that extends radially inward. The collar 252 has an airfoil cross-sectional shape (similar to the HP air jet 242 as shown in Figure 7 ), with a first (leading) side 254 that is farther from the central mixing chamber 214C than a second, opposite (trailing) side 256. That is, the first side 254 is circumferentially farther from the central mixing chamber 214C than the second side 256, which can be radially (outwardly) on the side walls 220, 222 of the central mixing chamber 214C. In some embodiments, the first side 254 presents the leading edge of the airfoil cross-section of the collar 252 to the low pressure air 182 when the low pressure air encounters the collar 252, and thus functions to make the low pressure air 182 flow easily to at least the central mixing chamber 214C.

[0089] As shown in Figure 3 and Figure 8A , the first side 254 is radially farther from the mixing member 210 than the second side 256. More specifically, the first side 254 is radially farther from the radially outer surfaces of the side walls 220, 222 of the mixing chambers 214A, 214B, respectively, than the second side 256 is from the radially outer surfaces of the side walls 220, 222 of the central mixing member 214C. With this configuration, the collar 252 also directs the HP air flow 244 for the mixing chambers 214A-B more directly into the mixing chambers 214A-B to prevent it from impeding the flow of the LP air 182 toward the central mixing chamber 214C. In alternative embodiments, as shown in Figure 3 andFigure 8A As shown, the first side 254 of the collar 252 of the set 240A-B of HP air jets 242 can also each include an opening 258 defined therein (i.e., in the side 254 facing the flow of LP air 182). The opening 258 can have any desired size and shape, e.g., it can be circular, slot-like (shown), or other shape. In operation, the opening 258 slightly alters the path of the HP air 112B through the collar 252 toward the central mixing chamber 214C, which allows the LP air 182 to more easily enter the outer mixing chambers 214A, 214B without significant pressure loss. However, the HP air 112B in the collar 252 does not exit through the opening 258.

[0090] With respect to the HP air 112B drawn from the HP air source 154, the set of HP air jets 242 is spaced apart from the inlet 216 of each mixing chamber 214 and is configured to direct a flow of HP air 244 (see arrows) including the HP air 112B from the HP air jets into the respective mixing chamber 214. As mentioned, the jet member 212 is in fluid communication with the HP air source 154 such that the HP air 112B enters the HP air jets 242. The set of HP air jets 242 is spaced apart from the inlet 216 of each mixing chamber 214 and is configured to direct the HP air 112B from the HP air jets, and in some embodiments, draw the LP air 182 in the HP air jets to form the flow of HP air 244. The HP jets 242 also direct the flow of HP air 244 into the respective mixing chamber 214. More specifically, the HP jets 242 can direct the flow of HP air 244 into the respective mixing chamber 214 at the same angle as the angle al, a2 of the respective mixing chamber 214 relative to the axis A of the combustion liner 164. Each HP jet 242 in a set does not necessarily have the angle of the respective mixing chamber 214, e.g., angle al or a2, but the HP air jets 242 of a given set 240 are each angled such that the flow of HP air 244 (including the HP air 112B and the LP air 182 (when used)) from the set of a given set has the same angle as the angle of the respective mixing chamber 214 relative to the axis A of the combustion liner 164 (not labeled for clarity). More specifically, as shown in FIG. 3, the flow of HP air 244 from the set 240A of HP air jets 242A has the angle al of the mixing chamber 214A; the flow of HP air 244 from the set 240B of HP air jets 242B has the angle a2 of the mixing chamber 214B; and the flow of HP air 244 from the set 240C of HP air jets 242C has the angle a3 of the mixing chamber 214C. Figure 4 As shown in FIG. 3, the flow of HP air 244 from the set 240A of HP air jets 242A has the angle al of the mixing chamber 214A; the flow of HP air 244 from the set 240B of HP air jets 242B has the angle a2 of the mixing chamber 214B; and the flow of HP air 244 from the set 240C of HP air jets 242C has the angle a3 of the mixing chamber 214C. Figure 7 ) has the angle a2 of the mixing chamber 214B; and the flow of HP air 244 from the set 240C of HP air jets 242C( Figure 7 ) has the angle a2 of the mixing chamber 214B; and the flow of HP air 244 from the set 240C of HP air jets 242C( Figure 7The HP airflow 244 has an angle of the mixing chamber 214C (perpendicular to the axis A of the combustion bushing 164). The collar 252 may also be angled at the same angle as the mixing chambers 214A-B.

[0091] In operation, such as Figures 3-5 As shown, mixing chamber 214 mixes HP airflow 244 with fuel 114B entering from fuel injector 232. As mentioned, each HP air nozzle 242 is configured to direct HP airflow 244 toward inlet 216 of the corresponding mixing chamber 214, the HP airflow including HP air 112B from HP air source 154. In some embodiments, HP air nozzle 242 draws LP air 182 from LP air source 184 into the space between HP air nozzle 242 and mixing member 210, i.e., creates an injection for LP air 182. HP airflow 244 impinges on inlet 216 of mixing chamber 214, or more precisely, on leading edge of mixing chamber 214, generating vortices and promoting in-plane mixing of HP air 112B, LP air 182, and fuel 114B (the plane of the upper surface of mixing member 210). In a non-limiting example, HP air 112B can account for 45% to 55% of the total airflow from HP air 112B and LP air 182, and LP air 182 can also account for 45% to 55% of the total airflow from HP air 112B and LP air 182. In this way, the AFS injector 150 using two air sources reduces the overall system pressure loss and utilizes the air in the burner 100 more efficiently.

[0092] The AFS injector 150, namely the mixing component 210 and the injection component 212, can be made of any now-known or hereafter developed fire-resistant and oxidation-resistant material. This material can be a metal and can be a pure metal or an alloy. The AFS injector 150 may include metals typically used in turbine components (such as turbine blades or nozzles) and having higher temperature resistance and higher oxidation resistance than materials typically used in combustion hardware. In this case, the material may include non-reactive metals, such as those made from non-explosive or non-conductive powders, such as, but not limited to: cobalt-chromium-molybdenum (CoCrMo) alloys; stainless steel; austenitic nickel-chromium based alloys, such as nickel-chromium-molybdenum-niobium alloys (NiCrMoNb) (e.g., Inconel 625 or Inconel 718); nickel-chromium-iron-molybdenum alloys (NiCrFeMo) (e.g., available from Haynes International, Inc.). X); or nickel-chromium-cobalt-molybdenum alloys (NiCrCoMo) (e.g., Haynes 233 or Haynes 282 available from Haynes International, Inc.), nickel-chromium-cobalt-titanium alloys (NiCrCoTi) (e.g., GTD 262 developed by General Electric Company). Other possibilities include, for example, Rene 108, CM 247, Mar M 247, and any precipitation hardenable (PH) nickel alloy.

[0093] In certain embodiments, the AFS injector 150 (i.e., the mixing member 210 and / or the injection member 212) can be additively manufactured using any now known or later developed technique capable of forming a unitary body. Thus, as shown, the mixing member 210 and / or the injection member 212 includes a plurality of parallel sintered metal layers 270. Figure 9 Figure 10 An exemplary computerized metal powder additive manufacturing system 310 (hereinafter "AM system 310") for generating the AFS injector 150, i.e., the mixing member 210 and / or the injection member 212, is shown in a schematic / block diagram, with only a single layer shown. The teachings of the present disclosure will be described with respect to building the mixing member 210 and / or the injection member 212 using a plurality of melting beam sources 312, 314, 316, 318, but it should be emphasized and will be readily appreciated that the teachings of the present disclosure are equally applicable to building the mixing member 210 and / or the injection member 212 using any number of melting beam sources. In this example, the AM system 310 is arranged for direct metal laser melting (DMLM). It should be understood that the general teachings of the present disclosure are equally applicable to other forms of metal powder additive manufacturing, such as but not limited to selective laser melting (SLM), and possibly other forms of additive manufacturing (i.e., in addition to metal powder applications). The layers of the mixing member 210 and / or the injection member 212 in the build platform 320 are shown in Figure 10 as circular elements; however, it should be understood that the additive manufacturing process can readily be adapted to manufacture any shape on the build platform 320.

[0094] ​The AM system 310 generally includes an additive manufacturing control system 330 ("control system") and an AM printer 332. As will be described, the control system 330 executes a set of computer executable instructions or code 334 to generate the hybrid build 210 and / or the spray build 212 using a plurality of fusing beam sources 312, 314, 316, 318. In the illustrated example, the four fusing beam sources can include four lasers. However, the teachings of the present disclosure are applicable to any fusing beam source, such as an electron beam, a laser, etc. The control system 330 is shown as implemented as computer program code on a computer 336. In this regard, the computer 336 is shown as 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, the computer 336 is shown as being in communication with external I / O devices / resources 350.

[0095] Generally, the processor unit (PU) 344 executes the computer program code 334 stored in the memory 338 and / or storage system 340. When executing the computer program code 334, the processor unit (PU) 344 can read from and / or write to the memory 338, the storage system 340, the I / O devices 350, and / or the AM printer 332. The bus 348 provides a communication link between each of the components in the computer 336, and the I / O devices 350 can include any devices that enable a user to interact with the computer 336 (e.g., keyboard, pointing devices, displays, etc.). The computer 336 represents only a variety of possible combinations of hardware and software. For example, the processor unit (PU) 344 can include a single processing unit, or one or more processing units distributed across one or more locations (e.g., on a client and server). Similarly, the memory 338 and / or storage system 340 can reside at one or more physical locations. The memory 338 and / or storage system 340 can 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. The computer 336 can include any type of computing device, such as an industrial controller, a network server, a desktop computer, a notebook computer, a handheld device, etc.

[0096] As noted, the AM system 310, and specifically the control system 330, executes code 334 to generate the hybrid member 210 and / or the ejection member 212. Among other things, the code 334 can include a set of computer executable instructions 334S (also referred to herein as "code 334S") for operating the AM printer 332, and a set of computer executable instructions 3340 (also referred to herein as "code 3340") that define the hybrid member 210 and / or the ejection member 212 to be physically generated by the AM printer 332. As described herein, the additive manufacturing process begins with the code 334 stored in a non-transitory computer readable storage medium, such as the memory 338, the storage system 340, etc. The set of computer executable instructions 334S for operating the AM printer 332 can include any now known or later developed software code capable of operating the AM printer 332.

[0097] The set of computer executable instructions 3340 that define the hybrid member 210 and / or the ejection member 212 can include a precisely defined 3D model of the hybrid member 210 and / or the ejection member 212, and can be generated by any of a variety of known computer aided design (CAD) software systems, such as DesignCAD 3D Max, etc. In this regard, the code 3340 can include any now known or later developed file format. Moreover, the code 3340 representing the hybrid member 210 and / or the ejection member 212 can be converted between different formats. For example, the code 3340 can include a standard tessellation language (STL) file created for a stereolithography CAD program for a 3D system or an additive manufacturing file (AMF) that is an Extensible Markup Language (XML) based format designed to allow any CAD software to describe the shape and composition of any three-dimensional object to be manufactured on any AM printer as an American Society of Mechanical Engineers (ASME) standard. The code 3340 representing the hybrid member 210 and / or the ejection member 212 can also be converted to a set of data signals as needed, and transmitted, received, and converted to code, stored, etc. as a set of data signals. The code 3340 can be configured to allow the formation of boundary and interior sections in the overlap field region in accordance with embodiments of the present disclosure, as will be described. In any case, the code 3340 can be input to the AM system 310 and can come from a part designer, an intellectual property (IP) provider, a design company, an operator or owner of the AM system 310, or from other sources. In any case, the control system 330 executes the code 334S and 3340, thereby dividing the hybrid member 210 and / or the ejection member 212 into a series of thin slices that are assembled using successive layers of material with the AM printer 332.

[0098] The AM printer 332 can include a process chamber 360 that is sealed to provide a controlled atmosphere for mixing member 210 and / or jet member 212 printing. A build platform 320 on which the mixing member 210 and / or jet member 212 are built is positioned within the process chamber 360. A plurality of melt beam sources 312, 314, 316, 318 are configured to melt layers of metal powder on the build platform 320 to generate the mixing member 210 and / or jet member 212. While four melt beam sources 312, 314, 316, 318 are shown, it is emphasized that the teachings of the present disclosure are applicable to systems employing any number of sources (e.g., 1, 2, 3, or 5 or more). As is understood in the art, each melt beam source 312, 314, 316, 318 can respectively have a field that includes a non-overlapping field region in which the melt beam source can exclusively melt the metal powder, and the melt beam source can include at least one overlapping field region in which two or more sources can melt the metal powder. In this regard, each melt beam source 312, 314, 316, 318 can respectively generate a melt beam that is used to fuse the particles of each slice defined by the code 3340. For example, in Figure 10 the melt beam source 312 is shown forming a layer of the mixing member 210 and / or jet member 212 in one region using a melt beam 362, while the melt beam source 314 is shown forming a layer of the mixing member 210 and / or jet member 212 in another region using a melt beam 362'.

[0099] Each melt beam source 312, 314, 316, 318 is calibrated in any now known or later developed manner. That is, each melt beam source 312, 314, 316, 318 has its laser or electron beam relative to the build platform 320 with an expected position relative to the actual position of the laser or electron beam in order to provide individual position corrections (not shown) to ensure its individual accuracy. In one embodiment, each of the plurality of melt beam sources 312, 314, 316, 318 can form a melt beam, e.g., 362, 362', having the same cross-sectional size (e.g., shape and size in operation), power, and scan speed.

[0100] With continued reference to Figure 10The coater (or recoater blade) 370 can form a thin layer of the raw material 372 that spreads out as a blank canvas from which each successive slice of the final hybrid component 210 and / or injection component 212 is formed. Various parts of the AM printer 332 can move to accommodate the addition of each new layer, for example, after each layer, the build platform 320 can lower and / or the chamber 360 and / or the coater 370 can raise. The process can use different raw materials in the form of fine-grained metal powders, which can be held in powder reservoirs 368 accessible to the coater 370.

[0101] The process chamber 360 is filled with an inert gas such as argon or nitrogen and is controlled to minimize or eliminate oxygen. The control system 330 is configured to control the flow of the gas mixture 374 from the inert gas source 376 within the process chamber 360. In this case, the control system 330 can control a pump 380 and / or a flow valve system 382 for the inert gas to control the content of the gas mixture 374. The flow valve system 382 can include one or more computer-controllable valves, flow sensors, temperature sensors, pressure sensors, etc. that can precisely control the flow of a particular gas. The pump 380 can or can not be provided with the valve system 382. In the case of omitting the pump 380, the inert gas can simply enter a pipe or manifold before being introduced into the process chamber 360. The inert gas source 376 can take the form of any conventional source for the material contained therein, such as a tank, reservoir, or other source. Any sensors (not shown) needed to measure the gas mixture 374 can be provided. A filter 386 can be used to filter the gas mixture 374 in a conventional manner.

[0102] In operation, the build platform 320 with metal powder thereon is disposed within the process chamber 360, and the control system 330 controls the flow of the gas mixture 374 from the inert gas source 376 within the process chamber 360. In accordance with embodiments of the present disclosure, the control system 330 also controls the AM printer 332, particularly the coater 370 and the melt beam sources 312, 314, 316, 318, to sequentially melt layers of metal powder on the build platform 320 to generate the hybrid component 210 and / or the injection component 212. While particular AM systems 310 have been described herein, it should be emphasized that the teachings of the present disclosure are not limited to any particular additive manufacturing system or method.

[0103] Once the hybrid component 210 and the injection component 212 are formed, as shown in FIG. 3C, they can be assembled to form the AFS injector 150 with other components of the combustor 100. For example, as shown in FIG. 3D, the hybrid component 210 and / or the injection component 212 can be fastened to the AFS injector mount 274 on the combustion liner 164. Figure 2 Figures 3-5 The coater (or recoater blade) 370 can form a thin layer of the raw material 372 that spreads out as a blank canvas from which each successive slice of the final hybrid component 210 and / or injection component 212 is formed. Various parts of the AM printer 332 can move to accommodate the addition of each new layer, for example, after each layer, the build platform 320 can lower and / or the chamber 360 and / or the coater 370 can raise. The process can use different raw materials in the form of fine-grained metal powders, which can be held in powder reservoirs 368 accessible to the coater 370.

[0101] The process chamber 360 is filled with an inert gas such as argon or nitrogen and is controlled to minimize or eliminate oxygen. The control system 330 is configured to control the flow of the gas mixture 374 from the inert gas source 376 within the process chamber 360. In this case, the control system 330 can control a pump 380 and / or a flow valve system 382 for the inert gas to control the content of the gas mixture 374. The flow valve system 382 can include one or more computer-controllable valves, flow sensors, temperature sensors, pressure sensors, etc. that can precisely control the flow of a particular gas. The pump 380 can or can not be provided with the valve system 382. In the case of omitting the pump 380, the inert gas can simply enter a pipe or manifold before being introduced into the process chamber 360. The inert gas source 376 can take the form of any conventional source for the material contained therein, such as a tank, reservoir, or other source. Any sensors (not shown) needed to measure the gas mixture 374 can be provided. A filter 386 can be used to filter the gas mixture 374 in a conventional manner.

[0102] In operation, the build platform 320 with metal powder thereon is disposed within the process chamber 360, and the control system 330 controls the flow of the gas mixture 374 from the inert gas source 376 within the process chamber 360. In accordance with embodiments of the present disclosure, the control system 330 also controls the AM printer 332, particularly the coater 370 and the melt beam sources 312, 314, 316, 318, to sequentially melt layers of metal powder on the build platform 320 to generate the hybrid component 210 and / or the injection component 212. While particular AM systems 310 have been described herein, it should be emphasized that the teachings of the present disclosure are not limited to any particular additive manufacturing system or method.

[0103] Once the hybrid component 210 and the injection component 212 are formed, as shown in FIG. 3C, they can be assembled to form the AFS injector 150 with other components of the combustor 100. For example, as shown in FIG. 3D, the hybrid component 210 and / or the injection component 212 can be fastened to the AFS injector mount 274 on the combustion liner 164. Figure 2 Figures 3-5 The coater (or recoater blade) 370 can form a thin layer of the raw material 372 that spreads out as a blank canvas from which each successive slice of the final hybrid component 210 and / or injection component 212 is formed. Various parts of the AM printer 332 can move to accommodate the addition of each new layer, for example, after each layer, the build platform 320 can lower and / or the chamber 360 and / or the coater 370 can raise. The process can use different raw materials in the form of fine-grained metal powders, which can be held in powder reservoirs 368 accessible to the coater 370.

[0101] The process chamber 360 is filled with an inert gas such as argon or nitrogen and is controlled to minimize or eliminate oxygen. The control system 330 is configured to control the flow of the gas mixture 374 from the inert gas source 376 within the process chamber 360. In this case, the control system 330 can control a pump 380 and / or a flow valve system 382 for the inert gas to control the content of the gas mixture 374. The flow valve system 382 can include one or more computer-controllable valves, flow sensors, temperature sensors, pressure sensors, etc. that can precisely control the flow of a particular gas. The pump 380 can or can not be provided with the valve system 382. In the case of omitting the pump 380, the inert gas can simply enter a pipe or manifold before being introduced into the process chamber 360. The inert gas source 376 can take the form of any conventional source for the material contained therein, such as a tank, reservoir, or other source. Any sensors (not shown) needed to measure the gas mixture 374 can be provided. A filter 386 can be used to filter the gas mixture 374 in a conventional manner.

[0102] In operation, the build platform 320 with metal powder thereon is disposed within the process chamber 360, and the control system 330 controls the flow of the gas mixture 374 from the inert gas source 376 within the process chamber 360. In accordance with embodiments of the present disclosure, the control system 330 also controls the AM printer 332, particularly the coater 370 and the melt beam sources 312, 314, 316, 318, to sequentially melt layers of metal powder on the build platform 320 to generate the hybrid component 210 and / or the injection component 212. While particular AM systems 310 have been described herein, it should be emphasized that the teachings of the present disclosure are not limited to any particular additive manufacturing system or method.Figures 3-5 ). More specifically, as noted, the mixing member 210 and the HP air injection member 212 can each include at least one mounting element 213 configured to receive a fastener 215 (e.g., a bolt or a weld) to couple the mixing member 210 and the HP air injection member 212 to the combustion liner 164 defining the combustion chamber 172, i.e., to the AFS injector mount 274 of the combustion liner 164.

[0104] As shown in FIG. 2, the AFS injector 150 includes a mixing member 210 and a HP air injection member 212. The mixing member 210 and the HP air injection member 212 are coupled to the combustion liner 164 defining the combustion chamber 172. The mixing member 210 and the HP air injection member 212 are coupled to the combustion liner 164 by fasteners 215 (e.g., bolts or welds) received by mounting elements 213 of the mixing member 210 and the HP air injection member 212. The mixing member 210 and the HP air injection member 212 are coupled to the combustion liner 164 at the AFS injector mount 274 of the combustion liner 164. Figures 3-5 As shown, the perimeter of the HP injection member 212 rests on the outer surface of the front flow sleeve 177 or the rear flow sleeve 190, and the mixing member 210 extends outwardly from the combustion liner 164 within an opening in the flow sleeve 177, 190. A gap can be defined between the inner surface of the HP air injection member 212 and the mixing member 210, thereby allowing LP air 182 to flow from the opening into the interior of the AFS injector 150. In such embodiments, the LP air 182 is entrained with the HP air 112B flowing through the HP injection member 212.

[0105] In other embodiments (not shown), the use of LP air 182 can be omitted by blocking flow from the LP air source 184 to the AFS injector 150, such that the AFS injector 150 is not in fluid communication with the LP air source 184. In such embodiments, the mixing member 210 and / or the injection member 212 can include an axially extending wall extending between the mixing member 210 and the inner surface of the HP injection member 212. The wall prevents any LP air 282 from entering the mixing chamber 214. More specifically, the wall defines a sealed chamber between the mixing member 210 and the injection member 212, which prevents any additional (LP) air from entering the air-fuel mixture 250 exiting the HP air-fuel injector 232. The AFS injector 150 so configured uses only HP air 112B to mix with fuel and does not receive post-impingement air, like LP air 182.

[0106] Embodiments of the present disclosure can also include a combustor 100 for a GT system 90. The combustor 100 includes a combustor body 160 having a combustion liner 164. The combustor 100 can also include a plurality of AFS injectors 150 directed into the combustion liner 164, as described herein. Returning to FIG. 1, the GT system 90 includes a compressor 110, a combustor 100, and a turbine 120. The compressor 110, the combustor 100, and the turbine 120 are coupled to one another by a shaft 130. The GT system 90 also includes a controller 140 in communication with the compressor 110, the combustor 100, and the turbine 120. Figure 2The combustor 100 typically terminates at a point adjacent to the first stage 260 of the fixed nozzle 262 of the turbine 128. The first stage 260 of the fixed nozzle 262 at least partially defines the turbine inlet 142 of the turbine 128. The combustor body 160 (i.e., the combustion bushing 164) at least partially defines a hot gas path (HGP) for guiding combustion gases 122 from the primary combustion zone 202 and the secondary combustion zone 204 to the turbine inlet 142 of the turbine 128 during operation of the GT system 90. Due to the small size of the AFS injectors 150, they can be mounted onto the combustion bushing 164 of the combustor body 160. Figure 2 Furthermore, the burner body 160 can be mounted in the generally axial direction into the GT system 90 through a relatively small opening (not shown) in the compressor discharge housing (housing 152).

[0107] like Figure 1 As shown, embodiments of this disclosure may further include a GT system 90, which includes a compressor section 110, a combustion section 120 operatively coupled to the compressor section 110, and a turbine section 130 operatively coupled to the combustion section 120. As described herein, the combustion section 120 includes at least one combustor 100, which includes a combustor body 160 having a combustion bushing 164 and a head fuel nozzle assembly 176 at a front end of the combustor body 160. The combustor 100 may also include a plurality of AFS injectors 150, as described herein, which are directed into the combustion body 160, i.e., into the combustion bushing 164, downstream of the head fuel nozzle assembly 176.

[0108] This disclosure provides various technical and commercial advantages, examples of which are discussed herein. As described herein, the AFS injector can accept high-pressure air and optionally low-pressure air, such as post-impact cooling air, to reduce overall system pressure loss. The AFS injector can rapidly premix the air source with, for example, highly reactive fuels (such as hydrogen) to achieve low emissions (e.g., nitrous oxide (NOx)) and acceptable flame retention. The AFS injector provides high fuel-air mixing, minimizes flow pressure loss, and prevents fuel from entering any low-velocity airflow zone. Additionally, the AFS injector has a relatively small radial height from top to bottom, allowing the AFS injector to be mounted onto the combustion bushing of the combustor body, and the combustor body to be axially mounted into the GT system through a relatively small opening in the compressor exhaust housing.

[0109] As used throughout the specification and claims, approximate language can be used to modify any quantitative representation that can allow for variation, without resulting in a change in the basic function to which it is related. Accordingly, a value modified by one or more terms such as “about,” “approximately,” and “substantially” is not limited to the precise value specified. In at least some instances, the approximate language can correspond to the precision of an 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 the sub-ranges contained therein unless context or language indicates otherwise. “About” or “approximate” applied to any specified value of a range means + / - 10% of the stated value, unless otherwise dependent on the precision of the instrument measuring the value.

[0110] All means or step-plus-function elements in the claims that follow the designation of an element preceded by “means for” or “step for” are intended to function as open-ended claims over the specific devices or actions specified in such claims. 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 precise form disclosed. Many modifications and variations will be apparent to those skilled in the art. Embodiments were chosen and described in order to best explain the principles of the disclosure and its practical application, and to thereby enable others skilled in the art to best utilize the disclosure, as well as various alternatives and modifications thereof.

Claims

1. An axial fuel staging (AFS) injector (150) for a combustor (100) of a gas turbine (GT) system (90), the AFS injector (150) comprising: a mixing member (210) including: a plurality of axially elongated mixing chambers (214) defined in the mixing member (210), each axially elongated mixing chamber (214) including an inlet (216) and an outlet (218), wherein each outlet (218) is configured to be in fluid communication with a combustion chamber (172) of the combustor (100), and a set of fuel injectors (236) defined in opposite side walls (220, 222) of each axially elongated mixing chamber (214); a high pressure (HP) air injection member (212) defining a set of HP air injection ports (240) spaced apart from the inlets (216) of each axially elongated mixing chamber (214); and a fuel plenum (230) defined in the mixing member (210), the fuel plenum (230) configured to deliver fuel (114A, 114B) from a fuel source (116) to each set of fuel injectors (236), wherein each set of HP air injection ports (240) is configured to direct HP air (112) from a HP air source (154) into the inlet (216) of a respective mixing chamber (214) where fuel (114A, 114B) is injected by the set of fuel injectors (236).

2. The AFS injector (150) of claim 1, wherein, the plurality of axially elongated mixing chambers (214) includes a first axially elongated mixing chamber (214A), a second axially elongated mixing chamber (214B), and a third axially elongated mixing chamber (214C) between the first and second axially elongated mixing chambers (214A, 214B).

3. The AFS injector (150) of claim 2, wherein, the third axially elongated mixing chamber (214C) extends radially at a perpendicular angle relative to a circumference of the combustion liner (164), and the first and second axially elongated mixing chambers (214A, 214B) are angled in opposite circumferential directions relative to the third axially elongated mixing chamber (214C).

4. The AFS injector (150) of claim 3, wherein, the set of HP air injection ports (240) spaced apart from the inlets (216) of each mixing member (210) is configured to direct the HP air (112) into a respective axially elongated mixing chamber (214) at the same angle as the angle of the respective axially elongated mixing chamber (214).

5. The AFS injector (150) of claim 3, wherein, the set of HP air injection ports (240) spaced apart from the inlets (216) of the third axially elongated mixing chamber (214C) includes a pair of axially offset rows (248A-248B) of HP air injection ports (242).

6. The AFS injector (150) of claim 2, wherein, the set of HP air injection ports (240) spaced apart from the inlets (216) of the first and second axially elongated mixing chambers (214A, 214B) each include a collar (252) extending radially inward, a first side (254) of the collar being radially further from the mixing member (210) than a second side (256) of the first side opposite.

7. The AFS injector (150) of claim 6, wherein, The first side (254) of the collar (252) of the set of HP air jets (240) spaced apart from the inlets (216) of the first and second axially elongated mixing chambers (214A, 214B) each includes an opening (258) defined therein.

8. The AFS injector (150) of claim 2, wherein, The set of HP air jets (240) spaced apart from the inlets (216) of the first and second axially elongated mixing chambers (214A, 214B) each has a fewer number of HP air jets (242) than the set of HP air jets (242) spaced apart from the inlet (216) of the third axially elongated mixing chamber (214C).

9. The AFS injector (150) of claim 2, wherein, The set of HP air jets (240) each includes a flared inlet (251) having an outer radius, and the flared inlets (251) of the HP air jets (242) for the first and second axially elongated mixing chambers (214A, 214B) have a first outer radius that is greater than a second outer radius of the flared inlets (251) of the HP air jets (242) of the third axially elongated mixing chamber (214C).

10. The AFS injector (150) of claim 2, wherein, The arrangement of the set of HP air jets (240) spaced apart from the inlets (216) of the first and second axially elongated mixing chambers (214A, 214B) is the same, and the arrangement of the set of HP air jets (240) spaced apart from the inlet (216) of the third axially elongated mixing chamber (214C) is different than the set of HP air jets (240) spaced apart from the inlets (216) of the first and second axially elongated mixing chambers (214A, 214B).

11. The AFS injector (150) of claim 1, wherein, The fuel plenum (230) extends within an upstream side wall (222) of each of the plurality of axially elongated mixing chambers (214), and wherein each set of fuel injectors (236) is closer to the inlet (216) than the outlet (218) of the respective axially elongated mixing chamber (214) of the plurality of axially elongated mixing chambers (214).

12. The AFS injector (150) of claim 11, wherein, Opposing side walls of the first and second axially elongated mixing chambers (214A, 214B) include a first side wall (220) and an opposing second side wall (222), and wherein for each of the first and second axially elongated mixing chambers (214A, 214B), the set of fuel injectors (236) defined in the first side wall (220) is arranged differently than the set of fuel injectors (236) defined in the second side wall (222).

13. The AFS injector (150) of claim 12, wherein, The set of fuel injectors (236) in the side walls of the first and second axially elongated mixing chambers (214A, 214B) are arranged differently in a first side wall (220) of an axially elongated mixing chamber than in an opposing second side wall (222) of the axially elongated mixing chamber.

14. The AFS injector (150) of claim 1, wherein, Each axially elongated mixing chamber (214) has a semi-circular opposing end (224).

15. The AFS injector (150) of claim 1, wherein, The mixing member (210) includes a filter member (246) upstream of the set of HP air jets (240). The mixing member (210) includes a filter member (246) upstream of the set of HP air jets (240).

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