Turbomachine cooling and alternative fuel delivery

Abstract

To provide an improved system and method for supplying alternative fuel to a turbomachine while cooling the turbomachine.SOLUTION: A method of operating a turbomachine (10) includes directing a flow of ammonia vapor to one or more hot gas path components (300) of the turbomachine (10). As a result, heat is transferred from the one or more hot gas path components (300) to the ammonia vapor. The method also includes generating hydrogen gas and nitrogen gas by decomposing the ammonia vapor with heat from the one or more hot gas path components (300). The method further includes flowing the hydrogen gas generated by the decomposition of the ammonia vapor to a combustor (24) of the turbomachine (10).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The subject matter disclosed herein relates generally to turbomachines, and more particularly to methods and systems for operating turbomachines. [Background technology]

[0002] Turbomachines are utilized in various industries and applications for energy transfer. Turbomachines, such as gas turbine engines and aero-derivative aircraft, typically include, in serial flow order, a compressor, a combustion section, and a turbine (i.e., an expansion turbine). The compressor section gradually increases the pressure of a working fluid entering the gas turbine engine and supplies the compressed working fluid to the combustion section. The compressed working fluid and fuel (e.g., natural gas) are mixed in the combustion section and combusted in a combustion chamber to generate high-pressure and high-temperature combustion gases. The combustion gases flow from the combustion section to the turbine section, where they expand to produce work. For example, the expansion of the combustion gases in the turbine section can rotate a rotor shaft connected to, for example, a generator, to generate electricity. The combustion gases then exit the gas turbine through an exhaust section.

[0003] Combustion of natural gas in the combustion section can produce by-products such as carbon monoxide (CO), nitrogen oxides (NOx), and other pollutants, which may be emitted by the exhaust section, often after costly treatment to remove or reduce the levels of undesirable components. Regulatory requirements for reducing emissions from gas turbines are becoming increasingly stringent, and environmental agencies worldwide are now requiring even lower emissions of CO, NOx, and other pollutants from both new and existing gas turbines. Alternative fuels, such as ammonia (NH3) and / or hydrogen (H2), can be used as substitutes for natural gas to reduce emissions in the combustor. However, providing or generating such alternative fuels typically increases the complexity and operating costs of the turbomachinery. For example, some systems include dedicated heaters or heat exchangers for cracking ammonia (e.g., by pyrolysis) to produce hydrogen, which can then be used as an alternative fuel.

[0004] Turbomachines generally include multiple components that receive or are otherwise exposed to hot combustion gases. Such components are located along the flow path of the hot combustion gases and are sometimes referred to as "hot gas path" components. Various cooling features may be provided to limit the temperature of the hot gas path components during operation of the turbomachine; for example, cooling gas may be flowed to and / or through at least a portion of the hot gas path components. For example, the hot gas path components may include stationary vanes (also referred to as "nozzles") and rotor blades in the turbine section of the turbomachine.

[0005] Therefore, improved systems and methods for supplying alternative fuels to turbomachines while cooling the turbomachines would be useful and desirable in the art. Summary of the Invention

[0006] Aspects and advantages of the systems and methods according to the present disclosure will be set forth in part in the description that follows, or may be obvious from the description, or may be learned by practice of the techniques.

[0007] According to one embodiment, a method of operating a turbomachine is provided. The method includes directing a flow of ammonia vapor to one or more hot gas path components of the turbomachine, such that heat is transferred from the one or more hot gas path components to the ammonia vapor. The method also includes generating hydrogen gas and nitrogen gas by decomposing the ammonia vapor with heat from the one or more hot gas path components. The method further includes flowing the hydrogen gas generated by decomposing the ammonia vapor to a combustor of the turbomachine.

[0008] According to another embodiment, a turbomachine is provided. The turbomachine includes one or more hot gas path components, a combustor, and a controller. The controller is configured to direct a flow of ammonia vapor to the one or more hot gas path components of the turbomachine. As a result, heat is transferred from the one or more hot gas path components to the ammonia vapor. The ammonia vapor may be decomposed by the heat from the one or more hot gas path components, thereby generating hydrogen gas and nitrogen gas. The controller is further configured to flow the hydrogen gas generated by decomposing the ammonia vapor to the combustor of the turbomachine.

[0009] These and other features, aspects, and advantages of the present systems and methods will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present technology and, together with the description, serve to explain the principles of the technology.

[0010] A full and enabling disclosure of the present systems and methods, including the best mode directed to one of ordinary skill in the art of making and using the same, is set forth in this specification, which makes reference to the accompanying figures. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a functional block diagram of an exemplary turbomachine that may incorporate various embodiments of the present technique; [Figure 2] FIG. 2 is a schematic block diagram of components of the turbomachine shown in FIG. 1, including an exemplary embodiment of a cooling and alternative fuel system according to one or more embodiments of the present disclosure. [Figure 3] 2 is a schematic diagram of exemplary hot gas path components of a turbomachine, such as the exemplary turbomachine of FIG. 1. [Figure 4] FIG. 1 is a flowchart diagram of an exemplary method of operating a turbomachine in accordance with one or more embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] Reference will now be made in detail to the present system and method embodiments, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the present technology, not as a limitation of the technology. Indeed, it will be apparent to those skilled in the art that modifications and variations can be made in the present technology without departing from the scope or spirit of the claimed technology. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield yet a further embodiment. Accordingly, the present disclosure is intended to cover such modifications and variations as come within the scope of the appended claims and their equivalents.

[0013] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. Moreover, unless specifically specified otherwise, all embodiments described herein should be considered exemplary.

[0014] The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description are used to refer to like or similar parts of the technology. As used herein, the terms "first," "second," and "third" may be used interchangeably to distinguish one component from another and are not intended to denote the location or importance of the individual components.

[0015] The term "fluid" may be a gas or a liquid. The term "fluid communication" means that a fluid is capable of making a connection between specified areas.

[0016] As used herein, the terms "upstream" (or "forward") and "downstream" (or "aft") refer to relative directions with respect to fluid flow in a fluid pathway. For example, "upstream" refers to the direction from which fluid flows, and "downstream" refers to the direction to which fluid flows. However, as used herein, the terms "upstream" and "downstream" can also refer to electrical flow. The term "radially" refers to relative directions that are substantially perpendicular to the axial centerline of a particular component, the term "axially" refers to relative directions that are substantially parallel to and / or coaxially aligned with the axial centerline of a particular component, and the term "circumferentially" refers to relative directions that extend around the axial centerline of a particular component.

[0017] Approximate terms such as "about," "approximately," "generally," and "substantially" are not limited to the exact value stated. In at least some cases, approximate language may correspond to the precision of an instrument for measuring a value or the precision of a method or machine for constructing or manufacturing a component and / or system. For example, approximate language may refer to within a margin of 1, 2, 4, 5, 10, 15, or 20% for a particular value, a range of values, and / or any of the endpoints defining the range of values. When used in the context of angles or directions, such terms include a range of plus or minus 10 degrees of the stated angle or direction. For example, "approximately vertical" includes directions within 10 degrees of any direction, e.g., clockwise or counterclockwise, from vertical.

[0018] Terms such as "coupled," "fixed," and "attached," unless expressly stated otherwise herein, refer to both direct coupling, fixing, or attachment, as well as indirect coupling, fixing, or attachment via one or more intermediate components or features. As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that includes a list of features is not necessarily limited to only those features but may include other features not expressly listed or that are inherent to such process, method, article, or apparatus. Furthermore, unless expressly stated to the contrary, "and / or" includes any and all combinations of one or more listed items. For example, conditions A and / or B are satisfied by any one of the following: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); and both A and B are true (or exist).

[0019] Here, and throughout the specification and claims, range limitations are combinable and interchangeable, and unless the context or language dictates otherwise, such ranges are identified and include all subranges subsumed therein. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other.

[0020] Each example is provided to explain the present technology, but not to limit it. Indeed, it will be apparent to those skilled in the art that modifications and variations can be made in the present disclosure without departing from the scope or spirit of the disclosure. For example, features illustrated or described as part of one embodiment may be used in another embodiment to yield a still further embodiment. Accordingly, the present technology is intended to cover such modifications and variations as come within the scope of the appended claims and their equivalents. While the exemplary embodiments are generally described in the context of a turbomachinery cooling and alternative fuel supply system for a land-based gas turbine for illustrative purposes, those skilled in the art will readily recognize that embodiments of the present technology may be applied to any air intake system for any type of turbomachine, and are not limited to land-based gas turbines unless specifically recited in the claims.

[0021] Referring now to the drawings, wherein like numbers refer to like components throughout the views, in Figure 1 , a functional block diagram of an exemplary turbomachine that may incorporate various embodiments of the present technique is provided, which in the illustrated exemplary embodiment is a gas turbine 10. As shown, the gas turbine 10 generally includes an air intake system 12 that may include a series of filters, cooling coils, water separators, and / or other devices for purifying and otherwise conditioning air 14 or other working fluid entering the gas turbine 10. The air 14 flows from the air intake system 12 to a compressor section where a compressor 16 progressively imparts kinetic energy to the air 14 to generate compressed air 18.

[0022] Compressed air 18 is mixed with fuel 20 from a fuel supply system 22 to form a combustible mixture in one or more combustors 24. Combustion of the combustible mixture generates combustion gases 26 at high temperature, pressure, and velocity. The combustion gases 26 flow through a turbine 28 (i.e., an expansion turbine) in a turbine section to produce work. For example, the turbine 28 may be connected to a shaft 30 such that rotation of the turbine 28 drives the compressor 16 to generate the compressed air 18. Alternatively, or additionally, the shaft 30 may connect the turbine 28 to a generator (not shown) for generating electricity. Exhaust gases 32 from the turbine 28 flow through an exhaust section 34 that connects the turbine 28 to an exhaust stack 36 downstream of the turbine 28. The exhaust section 34 may include, for example, a heat recovery steam generator (not shown) to clean and further extract heat from the exhaust gases 32 prior to release to the environment.

[0023] In at least some embodiments, the turbomachine, e.g., gas turbine 10, may further include, or be in operative communication with, a processing device or controller 100, which may be generally configured to facilitate operation of the turbomachine. In this regard, the controller 100 may communicate with various pumps, valves, user input devices, sensors, and other control elements of the gas turbine 10 to receive control inputs from user input devices and sensors and otherwise regulate operation of the gas turbine 10. For example, signals generated by the controller 100 may operate the gas turbine 10, including any or all system components, subsystems, or interconnected devices, in response to positions of user input devices and other control commands. The user input devices, sensors, and other components of the gas turbine 10 (e.g., pumps, valves, etc.) may communicate with the controller 100 via, for example, one or more signal lines or a shared communication bus. In this manner, input / output (“I / O”) signals may be routed between the controller 100 and the various operating components of the gas turbine 10. This communication may be wired or wireless.

[0024] As used herein, terms such as “processing device,” “computing device,” and “controller” may generally refer to any suitable processing device, such as a general-purpose or special-purpose microprocessor, microcontroller, integrated circuit, application-specific integrated circuit (ASIC), digital signal processor (DSP), field-programmable gate array (FPGA), logic device, one or more central processing units (CPUs), graphics processing units (GPUs), other specialized computational processing units, semiconductor devices, etc. Furthermore, these “controllers” are not necessarily limited to a single element, but may include any suitable number, type, and configuration of processing devices integrated in any suitable manner to facilitate operation of the turbomachine. Alternatively, the controller 100 may be configured without a microprocessor, for example, using a combination of discrete analog and / or digital logic circuits (e.g., switches, amplifiers, integrators, comparators, flip-flops, AND / OR gates, etc.) to perform control functions independent of software.

[0025] The controller 100 may include or be associated with one or more memory elements or non-transitory computer-readable storage media, such as RAM, ROM, EEPROM, EPROM, flash memory devices, magnetic disks, or other suitable memory devices (including combinations thereof). These memory devices may be separate components from the processor or may be incorporated within the processor. Furthermore, these memory devices may store information and / or data accessible by one or more processors, including instructions executable by the one or more processors. It should be understood that the instructions may be software written in any suitable programming language or may be implemented in hardware. Additionally and / or alternatively, the instructions may be executed on one or more processors using logically and / or virtually separate threads.

[0026] For example, the controller 100 may be operable to execute programming instructions or microcontrol code associated with the operating cycle of the gas turbine 10. In this regard, instructions may be software or any set of instructions that, when executed by a processing device, cause the processing device to perform an operation, such as running one or more software applications, displaying a user interface, receiving user input, processing user input, etc. Furthermore, it should be noted that the controller 100 disclosed herein may be capable of and operable to perform any method, method step, or portion of a method disclosed herein. For example, in some embodiments, the methods disclosed herein may be embodied in programming instructions stored in memory and executed by the controller 100.

[0027] The memory device may also store data that can be retrieved, manipulated, created, or stored by one or more processors or portions of the controller 100. The data may include, for example, data that facilitates execution of the methods described herein. The data may be stored locally (e.g., on the controller 100) in one or more databases and / or may be partitioned so that the data is stored in multiple locations. Additionally or alternatively, the one or more databases may be connected to the controller 100 via any suitable network, such as a high-bandwidth local area network (LAN) or wide area network (WAN). In this regard, for example, the controller 100 may further include a communications module or interface that may be used to communicate with one or more other components of the gas turbine 10, the controller 100, an external controller, or any other suitable device, for example, over any suitable communications line or network and using any suitable communications protocol. The communications interface may include any suitable components for interfacing with one or more networks, including, for example, a transmitter, a receiver, a port, a controller, an antenna, or other suitable components.

[0028] FIG. 2 is a schematic diagram of a steam circulation system that may be incorporated into a turbomachine, such as the example gas turbine 10 described above. As illustrated in FIG. 2, the example steam circulation system may include a cooled cooling air (CCA) system 202 or a fuel preheating system (not shown), which may include a heat exchanger and receive a flow of liquid ammonia (NH) 200. The liquid ammonia 200 may be vaporized in the cooling air system 202 using heat from compressed air (18 in FIG. 1), or the liquid ammonia 200 may be vaporized in the fuel preheating system using heat from exhaust gases (32 in FIG. 1) or steam. This results in a flow of vaporized ammonia 204, which may flow to one or more hot gas path components, such as nozzle 300 of turbine 28 (see, e.g., FIG. 3), which may be located in the turbine section of the gas turbine. In some embodiments, the vaporized ammonia 204 may be entrained or otherwise combined with a flow of cooling air, or the vaporized ammonia may be the only cooling gas supplied to one or more hot gas path components. The cooling air system 202 may also receive a portion of the high pressure, high temperature air from the compressor 16, such as the flow of compressed air 212 shown in Figure 2. The cooled cooling air flow 214 may be used to cool portions of the combustor or turbine.

[0029] As described in more detail below with reference to Figure 3, a steam circulation system may extend through one or more hot gas path components. Thus, heat may be transferred from the hot gas path components to gases (e.g., vaporized ammonia) within the steam circulation system. As illustrated in Figure 2, the heat transfer may result in a stream of heated steam 206, including, for example, hot vaporized ammonia.

[0030] After flowing to, through, and / or around one or more hot gas path components, the ammonia may be at least partially decomposed, i.e., thermally decomposed into hydrogen (H2) and nitrogen (N2) molecules, by heat from the one or more hot gas path components. That is, as the vaporized ammonia travels more generally through the hot gas path and / or turbine section, the ammonia may be thermally decomposed by heat from the one or more hot gas path components, thereby resulting in a mixture of nitrogen, hydrogen, and residual undecomposed ammonia, if present.

[0031] The heating steam 206 may also flow from the turbine section to a catalyst 208, where heat transferred from hot gas path components to the heating steam 206 improves the efficiency of the catalyst 208. The catalyst 208 may include metallic materials such as nickel, iron, ruthenium, cobalt, other similar materials, and combinations of any one or more of such materials. The material of the catalyst 208 may be selected based on the expected operating temperature, and may include relatively available and inexpensive materials, such as nickel- or iron-based catalytic materials, provided that the temperature of the heating steam 206 is sufficiently high at the lower end of the operating temperature range, e.g., at least about 600°C to 700°C. The catalyst 208 reacts with ammonia in the heating steam 206 to further destroy, e.g., decompose, the residual ammonia into hydrogen and nitrogen.

[0032] Thus, the decomposition of ammonia may generate a flow of hydrogen (H)-containing fluid 210, which may flow to one or more combustors 24 of a turbomachine, such as a gas turbine 10, where it may be used as fuel, as shown in Figure 2. The hydrogen-containing fluid 210 (also referred to herein as "hydrogen fuel 210") may then be combusted in the combustors 24 to generate combustion gases 26, for example, as described above. Thus, the hydrogen fuel 210 may provide an alternative fuel to the combustors 24 to at least partially replace natural gas fuel, for example.

[0033] A pair of exemplary hot gas path components is illustrated in Figure 3. In some embodiments, the hot gas path component directing the ammonia vapor may be nozzles 300 of a turbine 28. Those skilled in the art will recognize that the nozzles 300 of a turbine 28 may be part of an annular array of fixed vane structures extending around the central axis of the turbine 28 (e.g., the shaft 30 may extend along or generally parallel to the central axis). The component illustrated in Figure 3 includes a section of such an annular array with two nozzles 300. The turbine 28 may include multiple stages, each with an annular array of nozzles (sometimes referred to as stators or stator vanes because they are fixed) that direct or guide the combustion gases 26 to and toward an annular array of rotor blades adjacent the nozzles of that stage. A subsequent stage, e.g., another set of nozzles, may be adjacent to and immediately downstream of the rotor blades of the previous stage. For example, the nozzle 300 illustrated in FIG. 3 may be a first stage nozzle and may be part of an annular array of nozzles at the inlet of a turbine section, such as the first set of nozzles that receive combustion gases 26 from the combustor 24.

[0034] An exemplary cooling gas flow path through each nozzle 300 is shown by dashed lines in FIG. 3 . Cooling gas may flow through the nozzles 300, for example, as described above. For example, the cooling gas flow path may include a cooling circuit 302 within each nozzle 300 and through each nozzle. As such, heat may be transferred from the exemplary hot gas path components, nozzles 300, to gases flowing through the cooling circuits 302 within each nozzle 300, etc. Such heat transfer, e.g., cooling of nozzles 300, may beneficially reduce thermal and / or mechanical loads on nozzles 300 during operation of the turbomachine. Additionally, heating of the gas may advantageously assist in the decomposition of vaporized ammonia in the cooling gas stream, i.e., the ammonia may be at least partially decomposed by heat from one or more hot gas path components.

[0035] 4, embodiments of the present disclosure also include methods of operating a turbomachine, such as the exemplary method 400 illustrated in FIGURE 4. Such methods may be used to operate any suitable turbomachine, such as, but not limited to, the exemplary gas turbine 10 described above.

[0036] 4 , an exemplary method 400 may include directing 410 a flow of ammonia vapor to one or more hot gas path components of a turbomachine. Such flow results in heat transfer from the one or more hot gas path components to the ammonia vapor. As described above, such heat transfer may advantageously increase the temperature of the ammonia vapor, e.g., to decompose or promote the decomposition of the ammonia, and may also advantageously decrease the temperature of the one or more hot gas path components.

[0037] Thus, a method such as method 400 may also include decomposing 420 the ammonia vapor with heat from one or more hot gas path components, such as at least partially pyrolyzing the ammonia vapor into hydrogen gas and nitrogen gas. Thus, decomposition of the ammonia vapor may generate a gas mixture of hydrogen gas and nitrogen gas. The hydrogen-containing gas mixture may then be used as fuel by flowing to a combustor, where it is burned to generate combustion gases that are provided to a turbine. For example, as shown at 430 in FIG. 4 , method 400 may include flowing the hydrogen gas generated by the decomposition of the ammonia vapor to a combustor of a turbomachine.

[0038] In some embodiments, method 400 may also include flowing the ammonia vapor over a catalyst. In such embodiments, the ammonia vapor may be decomposed by interaction with the catalyst and by heat from one or more hot gas path components. For example, the catalyst may be downstream of one or more hot gas path components such that the ammonia vapor is heated by the one or more hot gas path components before flowing over the catalyst. Heating the ammonia vapor before flowing over the catalyst may advantageously increase the reaction rate between the ammonia vapor and the catalyst, which may result in more complete decomposition of the ammonia and / or allow for the use of more readily available and economical catalyst materials.

[0039] In some embodiments, the method 400 may also include providing a flow of liquid ammonia to a cooling air system, such as a CCA system (e.g., described above with reference to FIG. 2 ), of the turbomachine. Such embodiments may further include generating a flow of ammonia vapor from the liquid ammonia in the cooling air system of the turbomachine. In some embodiments, the cooling air system, the turbine section of the turbomachine, and the combustor of the turbomachine may form a closed ammonia vapor circuit. For example, the vapor circulation system of FIG. 2 discussed above may include a closed circuit in which the vaporized ammonia flows such that the ammonia vapor is contained within the circuit, beginning with, for example, vaporization of the liquid ammonia in the cooling air system 202, through a complete cycle until the vaporized ammonia decomposes into a mixture of hydrogen gas and nitrogen gas. Thus, the vaporized ammonia is contained within the steam circulation system and is not exposed to or leaks into the ambient environment around the turbomachine.

[0040] In some embodiments, the method 400 may further include flowing nitrogen gas generated by the decomposition of the ammonia vapor to a combustor of the turbomachine; e.g., the hydrogen-containing fluid 210 may further contain nitrogen from the decomposition of ammonia, and the nitrogen gas may flow with the hydrogen gas. The nitrogen gas may be a power augmenting source for a gas turbine, such that the pressure of the nitrogen gas may help push combustion gases from the combustor into and through the turbine.

[0041] In some embodiments, directing 410 the flow of ammonia vapor to one or more hot gas path components of the turbomachine may include passing the ammonia vapor through a cooling circuit within at least one of the one or more hot gas path components of the turbomachine. For example, the cooling circuit may be a serpentine channel within one or more nozzles, such as illustrated in FIG. 3 and described above. For example, in some embodiments, the one or more hot gas path components of the turbomachine may be or include a nozzle in a turbine section of the turbomachine, such as a first stage nozzle.

[0042] This specification discloses the invention, including the best mode, and uses examples to enable any person skilled in the art to practice the invention, including making and using any device or system, and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are considered to be within the scope of the claims if they contain structural elements that do not differ from the literal language of the claims, or if they contain equivalent structural elements that do not differ insubstantial way from the literal language of the claims.

[0043] Further aspects of the present invention are provided by the subject matter of the following clauses.

[0044] 1. A method of operating a turbomachine, comprising: directing a flow of ammonia vapor to one or more hot gas path components of the turbomachine, whereby heat is transferred from the one or more hot gas path components to the ammonia vapor; decomposing the ammonia vapor with heat from the one or more hot gas path components, whereby hydrogen gas and nitrogen gas are generated; and flowing the hydrogen gas generated by the decomposition of the ammonia vapor to a combustor of the turbomachine.

[0045] 10. The method of claim 9, further comprising flowing ammonia vapor over a catalyst, wherein the ammonia vapor is decomposed by interaction with the catalyst and by heat from one or more hot gas path components.

[0046] 10. The method according to one or more of the preceding clauses, wherein the catalyst is downstream of the one or more hot gas path components, whereby the ammonia vapor is heated by the one or more hot gas path components before flowing over the catalyst.

[0047] 10. The method according to one or more of the preceding clauses, further comprising providing a flow of liquid ammonia to a cooling air system of the turbomachine; and generating a flow of ammonia vapor from the liquid ammonia in the cooling air system of the turbomachine.

[0048] 10. The method according to one or more of the preceding clauses, wherein the cooling air system, the turbine section of the turbomachine, and the combustor of the turbomachine form a closed ammonia vapor circuit.

[0049] The method according to one or more of the preceding clauses, further comprising flowing nitrogen gas generated by decomposition of the ammonia vapor to a combustor of the turbomachine.

[0050] 10. The method according to one or more of the preceding clauses, wherein directing the flow of ammonia vapor to the one or more hot gas path components of the turbomachine includes passing the ammonia vapor through a cooling circuit within at least one of the one or more hot gas path components of the turbomachine.

[0051] The method according to one or more of the preceding clauses, wherein one or more hot gas path components of the turbomachine comprise a nozzle in a turbine section of the turbomachine.

[0052] The method according to one or more of the preceding clauses, wherein the nozzle is a first stage nozzle.

[0053] Further aspects of the present invention are provided by the subject matter of the following clauses.

[0054] A turbomachine comprising: one or more hot gas path components; a combustor; and a controller, wherein the controller is configured to: direct a flow of ammonia vapor to the one or more hot gas path components of the turbomachine, whereby heat is transferred from the one or more hot gas path components to the ammonia vapor; decompose the ammonia vapor with heat from the one or more hot gas path components, whereby hydrogen gas and nitrogen gas are generated; and flow the hydrogen gas generated by the decomposition of the ammonia vapor to the combustor of the turbomachine.

[0055] 10. The turbomachine of any preceding clause, further including a catalyst, wherein the controller is further configured to flow the ammonia vapor across the catalyst, the ammonia vapor being decomposed by interaction with the catalyst and by heat from the one or more hot gas path components.

[0056] 10. The turbomachine of claim 1, wherein the catalyst is downstream of the one or more hot gas path components, whereby the ammonia vapor is heated by the one or more hot gas path components before flowing over the catalyst.

[0057] 10. The turbomachine of one or more of the preceding clauses, further comprising a cooling air system, wherein the controller is further configured to provide a flow of liquid ammonia to the cooling air system of the turbomachine to generate a flow of ammonia vapor from the liquid ammonia in the cooling air system of the turbomachine.

[0058] The turbomachine of one or more of the preceding clauses, wherein the cooling air system, the turbine section of the turbomachine, and the combustor of the turbomachine form a closed ammonia vapor circuit.

[0059] The turbomachine of one or more of the preceding clauses, wherein the controller is further configured to channel nitrogen gas generated by decomposition of the ammonia vapor to a combustor of the turbomachine.

[0060] 10. The turbomachine of claim 1, further comprising a cooling circuit within at least one of the one or more hot gas path components, wherein directing the flow of ammonia vapor to the one or more hot gas paths comprises flowing the ammonia vapor through the cooling circuit.

[0061] The turbomachine of any one or more of the preceding clauses, wherein one or more hot gas path components of the turbomachine comprise a nozzle in a turbine section of the turbomachine.

[0062] The turbomachine of any one or more of the preceding clauses, wherein the nozzle is a first stage nozzle. [Explanation of symbols]

[0063] 10 Gas turbines and turbomachinery 12 Intake system 14 Air 16 Compressor 18 Compressed Air 20 fuel 22 Fuel supply system 24 Combustor 26 Combustion Gas 28 Turbine, turbine section 30 shaft 32 Exhaust gas 34 Exhaust section 36 Exhaust stack 100 Controllers 200 liquid ammonia 202 Chilled Cooled Air (CCA) System, Cooled Air System 204 Vaporized ammonia, ammonia vapor 206 Heating steam 208 Catalyst 210 Hydrogen-containing fluids, hydrogen fuel, hydrogen gas 212 Compressed Air 214 Cold cooling airflow 300 Hot gas path components, nozzles 302 Cooling circuit 400 ways 410 directing a flow of ammonia vapor to one or more hot gas path components of a turbomachine 420 Decomposing ammonia vapor with heat from one or more hot gas path components 430 Flow of hydrogen gas generated by decomposition of ammonia vapor into the combustor of a turbomachine

Claims

1. A method (400) of operating a turbomachine (10), comprising: directing (410) a flow of ammonia vapor (204) to one or more hot gas path components (300) of the turbomachine (10), whereby heat is transferred from the one or more hot gas path components (300) to the ammonia vapor (204); decomposing (420) the ammonia vapor (204) with the heat from the one or more hot gas path components (300), thereby generating hydrogen gas (210) and nitrogen gas; flowing (430) the hydrogen gas (210) generated by decomposition of the ammonia vapor (204) into a combustor (24) of the turbomachine (10); A method (400) comprising:

2. 10. The method of claim 1, further comprising flowing the ammonia vapor over a catalyst, wherein the ammonia vapor is decomposed by interaction with the catalyst and by the heat from the one or more hot gas path components.

3. 3. The method of claim 2, wherein the ammonia vapor is heated by the heat from the one or more hot gas path components prior to flowing the ammonia vapor over the catalyst, the catalyst being downstream of the one or more hot gas path components.

4. 2. The method (400) of claim 1, further comprising providing a flow of liquid ammonia (200) to a cooling air system (202) of the turbomachine (10), and generating the flow of ammonia vapor (204) from the liquid ammonia (200) in the cooling air system (202) of the turbomachine (10).

5. The method (400) of claim 1, further comprising flowing the nitrogen gas generated by decomposition of the ammonia vapor (204) to the combustor (24) of the turbomachine (10).

6. 2. The method of claim 1, wherein directing the flow of the ammonia vapor to the one or more hot gas path components of the turbomachine comprises flowing the ammonia vapor through a cooling circuit in at least one of the one or more hot gas path components of the turbomachine, the one or more hot gas path components of the turbomachine comprising one or more nozzles in a turbine section of the turbomachine.

7. one or more hot gas path components (300); a combustor (24); A controller (100) 7. A turbomachine (10) comprising: a controller (100) configured to operate the turbomachine (10) according to a method (400) of any one of claims 1 to 6.

8. 8. The turbomachine of claim 7, further comprising a catalyst, and wherein the controller is further configured to flow the ammonia vapor across the catalyst, wherein the ammonia vapor is decomposed by interaction with the catalyst and by the heat from the one or more hot gas path components.

9. 10. The turbomachine (10) of claim 8, wherein the catalyst (208) is downstream of the one or more hot gas path components (300), whereby the ammonia vapor (204) is heated by the one or more hot gas path components (300) before flowing over the catalyst (208).

10. 8. The turbomachine (10) of claim 7, further comprising a cooling air system (202), and wherein the controller (100) is further configured to provide a flow of the liquid ammonia (200) to the cooling air system (202) of the turbomachine (10) to generate the flow of the ammonia vapor (204) from the liquid ammonia (200) in the cooling air system (202) of the turbomachine (10).

11. 11. The turbomachine (10) of claim 10, wherein the cooling air system (202), a turbine section (28) of the turbomachine (10), and the combustor (24) of the turbomachine (10) form a closed ammonia vapor circuit.

12. 8. The turbomachine (10) of claim 7, wherein the controller (100) is further configured to channel nitrogen gas generated by decomposition of the ammonia vapor (204) to the combustor (24) of the turbomachine (10).

13. 8. The turbomachine (10) of claim 7, further comprising a cooling circuit (302) in at least one of the one or more hot gas path components (300), and directing the flow of the ammonia vapor (204) to the one or more hot gas path components (300) comprises flowing the ammonia vapor (204) through the cooling circuit (302).

14. 8. The turbomachine (10) of claim 7, wherein the one or more hot gas path components (300) of the turbomachine (10) comprise one or more nozzles (300) in a turbine section (28) of the turbomachine (10).

15. The turbomachine (10) of claim 14, wherein the nozzle (300) is a first stage nozzle.

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