Aircraft thrust management using fuel cells

Abstract

Systems and methods of aircraft thrust management are provided. For example, a propulsion system for an aircraft includes a fuel cell assembly including a fuel cell, a turbine, and a controller including a memory and one or more processors. The memory stores instructions that, when executed by the one or more processors, cause the propulsion system to perform operations including receiving data indicative of a propulsion system thrust discrepancy and modifying an output of the fuel cell in response to receiving the data indicative of the propulsion system thrust discrepancy. Modifying the fuel cell output can include modifying an output product, an electrical output, or both, of the fuel cell to balance thrust provided by the propulsion system.

Description

Technical Field

[0001] This disclosure relates to thrust management of aircraft, such as thrust management via an aircraft propulsion system including a fuel cell. Background Technology

[0002] A gas turbine engine generally consists of a turbine and a rotor assembly. Gas turbine engines (such as turbofan engines) can be used for aircraft propulsion. In the case of a turbofan engine, the turbine includes a compressor section, a combustion section, and a turbine section in a sequential flow sequence, and the rotor assembly is configured as a fan assembly.

[0003] During operation, air is compressed in the compressor and mixed with fuel in the combustion section and ignited to produce combustion gases, which flow downwards through the turbine section. The turbine section extracts energy from the combustion gases to at least rotate the compressor section to power the gas turbine engine. Typically, the blades in the turbine section are mechanically coupled to a fan assembly via one or more shafts, such that the rotational energy extracted in the turbine section also rotates the fan assembly to propel the aircraft containing this gas turbine engine during flight.

[0004] The turbine can also drive a generator to produce electricity that can be used to generate propulsive thrust, and other electrical loads can also be placed on the turbine. At least some aircraft may include multiple turbines and motors, one or more electric thrusters, or both. Systems and methods for providing a balance of thrust generation from these multiple thrust sources will be welcomed in the art. Attached Figure Description

[0005] The complete and feasible disclosure of this disclosure, including its best mode, is set forth in the specification with reference to the accompanying drawings, for those skilled in the art, wherein:

[0006] Figure 1 This is a cross-sectional view of a gas turbine engine according to an exemplary aspect of this disclosure.

[0007] Figure 2 This is a perspective view of the integrated fuel cell and burner assembly according to this disclosure.

[0008] Figure 3 yes Figure 2 A schematic axial view of an exemplary integrated fuel cell and burner assembly.

[0009] Figure 4 This is a schematic diagram of a fuel cell assembly according to an exemplary aspect of the present disclosure, the fuel cell being incorporated into... Figure 2 An exemplary integrated fuel cell and burner assembly.

[0010] Figure 5 This is a schematic diagram of a gas turbine engine including an integrated fuel cell and burner assembly, according to an exemplary aspect of this disclosure.

[0011] Figure 6 This is a schematic diagram of a vehicle and propulsion system according to an exemplary aspect of this disclosure.

[0012] Figure 7 This is a schematic diagram of a propulsion system according to an exemplary aspect of this disclosure.

[0013] Figure 7A This is a schematic diagram of thrust management via a gas / thermal connection between a fuel cell and a turbine, according to an exemplary aspect of this disclosure.

[0014] Figure 7B This is a schematic diagram of thrust management via an electrical connection between a fuel cell and a propulsion component, according to an exemplary aspect of this disclosure.

[0015] Figure 8 This is a schematic diagram of a propulsion system according to another exemplary aspect of this disclosure.

[0016] Figure 9 This is a flowchart of a method for operating a propulsion system for an aircraft according to another exemplary aspect of this disclosure.

[0017] Figure 10 This is a flowchart of a method for operating a propulsion system for an aircraft according to another exemplary aspect of this disclosure. Detailed Implementation

[0018] Reference will now be made in detail to the present embodiments of this disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerals and letter reference numerals to denote features in the drawings. Similar or analogous reference numerals in the drawings and description have been used to denote similar or analogous portions of this disclosure.

[0019] The term "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 superior or better than other implementations. Furthermore, unless explicitly stated otherwise, all embodiments described herein should be considered exemplary.

[0020] For the purposes described below, the terms “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” “lateral,” “longitudinal,” and their derivatives should be associated with the embodiments in which they are oriented in the accompanying drawings. However, it should be understood that various alternative variations may be assumed in the embodiments unless explicitly stated otherwise. It should also be understood that the specific devices shown in the drawings and described in the following description are merely exemplary embodiments of this disclosure. Therefore, the specific dimensions and other physical characteristics associated with the embodiments disclosed herein should not be considered limiting.

[0021] As used herein, the terms “first,” “second,” and “third” are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of the individual components.

[0022] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle, and specifically to the normal operating posture of the gas turbine engine or vehicle. For example, in the case of a gas turbine engine, "front" refers to the position closer to the engine inlet, while "rear" refers to the position closer to the engine nozzle or exhaust port.

[0023] The terms "upstream" and "downstream" refer to the relative directions of fluid flow within a fluid path. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction from which the fluid flows.

[0024] Unless otherwise specified herein, the terms “connection,” “fixed,” “attached to,” etc., refer to both direct connection, fixation, or attachment, and indirect connection, fixation, or attachment via one or more intermediate components or features.

[0025] Unless the context clearly indicates otherwise, the singular forms “a,” “a,” and “the” include plural references.

[0026] In the context of, for example, “at least one of A, B and C” or “at least one of A, B or C”, the term “at least one” means only A, only B, only C, or any combination of A, B and C.

[0027] As used herein throughout the specification and claims, approximate language is applied to modify any quantitative expression that may allow for variation without altering its underlying function. Therefore, values ​​modified by terms such as “about,” “approximate,” and “substantially” are not limited to specified exact values. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the component and / or system. For example, approximate language may refer to margins of 1%, 2%, 4%, 10%, 15%, or 20%. These approximate margins may apply to a single value, to either end of a range defining a numerical value, or to margins between two ends, and / or between the ends.

[0028] Throughout this specification and claims, scope limitations are combined and interchanged, and unless the context or language otherwise indicates otherwise, such scopes are identified and include all subscopes contained herein. For example, all scopes disclosed herein include endpoints, and endpoints may be combined independently of each other.

[0029] As used herein, "third stream" refers to a non-mainstream flow that can increase fluid energy to generate a small amount of total propulsion thrust. The pressure ratio of the third stream can be higher than that of the main propulsion flow (e.g., bypass or propeller-driven propulsion flow). Thrust can be generated through dedicated nozzles or by mixing the airflow through the third stream with the main propulsion flow or core flow (e.g., mixing it into a common nozzle).

[0030] In some exemplary embodiments, the operating temperature of the airflow through the third flow can be below the engine's maximum compressor discharge temperature, and more specifically, below 350 degrees Fahrenheit (e.g., below 300 degrees Fahrenheit, below 250 degrees Fahrenheit, below 200 degrees Fahrenheit, and at least as high as ambient temperature). In some exemplary embodiments, these operating temperatures can facilitate heat transfer to or from the airflow through the third flow and the separate fluid flow. Furthermore, in some exemplary embodiments, under takeoff conditions, or more specifically, under operating conditions of sea-level rated takeoff power, static flight speed, and an ambient temperature of 86 degrees Fahrenheit, the airflow through the third flow can contribute less than 50% (and at least, for example, 2%) of the total engine thrust.

[0031] Furthermore, in some exemplary embodiments, the aforementioned exemplary percentage contribution of the third flow's airflow aspects (e.g., airflow, mixing, or exhaust properties) to the total thrust can be passively adjusted during engine operation or purposefully modified by using engine control features (such as fuel flow, motor power, variable stator, variable inlet guide vanes, valves, variable exhaust geometry, or fluid characteristics) to adjust or optimize overall system performance under a wide range of potential operating conditions.

[0032] The term “turbine” or “turbomachinery” refers to a machine that includes one or more compressors, a heating section (e.g., a combustion section), and one or more turbines that together generate torque output.

[0033] The term "gas turbine engine" refers to an engine that has a turbine as its power source, in whole or in part. Examples of gas turbine engines include turbofan engines, turboprop engines, turbojet engines, turboshaft engines, and hybrid electric versions of one or more of these engines.

[0034] When used with compressors, turbines, shafts, or spool components, unless otherwise specified, the terms “low” and “high,” or their respective comparatives (e.g., “lower” and “higher,” where applicable), refer to relative speeds within the engine. For example, “low-speed turbine” or “low-turbine” defines a component constructed to operate at a rotational speed (such as the maximum permissible rotational speed) lower than that of a “high-speed turbine” or “high-turbine” at the engine.

[0035] As mentioned above, at least some gas turbine engines include a turbine configured to drive an electric motor during operation as part of the propulsion system. This can be referred to as a hybrid-electric gas turbine engine. Due to rapid changes in electrical load, such as during rapid drops in electrical load or motor torque loss, the propulsion system may experience a torque imbalance between the engine's torque output and the torque load (or the torque load expected from the engine) placed on the engine by the electrical system. Torque imbalance can cause speed deviations in the engine and generator, potentially leading to overspeed problems; poor power quality; and / or increased engine temperature, which may affect engine life, potentially causing undesirable aircraft handling problems, and / or thrust asymmetry. In particular, for propulsion systems that include a hybrid-electric gas turbine engine as a first thruster and a second thruster (e.g., a second hybrid-electric gas turbine engine, an electric thruster, etc.), such torque imbalance can result in one of the thrusters producing a higher proportion of thrust relative to balanced operation, thus generating thrust imbalance. Therefore, thrust management must be provided to mitigate or avoid such problems.

[0036] A propulsion system for an aircraft and a method for operating the propulsion system for the aircraft to provide such thrust management are provided. The propulsion system includes a fuel cell assembly having a fuel cell; a turbine; an electric motor; and a controller. The turbine, electric motor, or both are configured to contribute to propulsion system thrust generation during operation of the propulsion system. The controller includes a memory and one or more processors, and the memory stores instructions that, when executed by the one or more processors, cause the propulsion system to operate, including receiving data indicating changes in electrical load on the turbine and modifying the fuel cell output in response to receiving data indicating changes in electrical load on the turbine, receiving data indicating propulsion system thrust differentials, and modifying the fuel cell output in response to receiving data indicating propulsion system thrust differentials. For example, in some embodiments, the fuel cell output may be an output product supplied from the fuel cell to the combustion section of the turbine to increase or decrease the amount of power generated by the turbine and reduce propulsion system thrust differentials. Additionally or alternatively, in other embodiments, the fuel cell output may be an electrical output supplied to, for example, an electric motor or a separate propulsion assembly to reduce propulsion system thrust differentials.

[0037] Furthermore, in some exemplary embodiments, the propulsion system may include a first propulsion assembly having a turbine and an electric motor, and a second propulsion assembly. The first and second propulsion assemblies may be configured to be positioned on opposite sides of the aircraft, and the thrust difference in the propulsion system may be a thrust imbalance. With this configuration, the output of the fuel cell may again be supplied from the fuel cell to the combustion section of the turbine to increase or decrease the amount of power generated by the turbine, thereby increasing or decreasing the thrust generated by the first propulsion assembly relative to the second propulsion assembly to reduce the output products of the thrust imbalance. Additionally or alternatively, in other embodiments, the output of the fuel cell may again be an electrical output supplied to, for example, the electric motor or the second propulsion assembly to reduce the thrust imbalance.

[0038] In one or more of these configurations, fuel cell components may be able to address propulsion system thrust discrepancies (such as thrust imbalances) relatively quickly, and potentially without requiring major modifications to turbine operation.

[0039] As will be discussed in more detail below, a fuel cell is an electrochemical device that converts the chemical energy of a fuel (e.g., hydrogen) into electrical energy through an electrochemical reaction between the fuel and an oxidant (e.g., oxygen contained in the atmosphere). Fuel cell systems can be advantageously used as energy supply systems because they can be considered environmentally friendly and efficient compared to at least some existing systems. To improve system efficiency and fuel utilization and reduce external water consumption, fuel cell systems may include an anode recirculation loop. Since a single fuel cell can only produce about 1V of voltage, multiple fuel cells can be stacked together (which may be called a fuel cell stack) to produce the desired voltage. Fuel cells may include solid oxide fuel cells (SOFC), molten carbonate fuel cells (MCFC), phosphoric acid fuel cells (PAFC), and proton exchange membrane fuel cells (PEMFC), which are generally named after their respective electrolytes.

[0040] Referring now to the accompanying drawings, where the same numbers indicate the same elements throughout all the drawings. Figure 1 A schematic cross-sectional view of an engine according to an exemplary embodiment of the present disclosure is provided. The engine can be integrated into a vehicle. For example, the engine can be an aircraft engine integrated into an aircraft. However, alternatively, the engine can be any other suitable type of engine for any other suitable vehicle.

[0041] In the depicted embodiment, the engine is configured as a high-bypass turbofan engine 100. As... Figure 1 As shown, the turbofan engine 100 defines an axial direction A (extending parallel to the centerline axis 101 provided for reference), a radial direction R, and a circumferential direction (extending around the axial direction A; not shown in the diagram). Figure 1 (As shown in the figure). Typically, the turbofan engine 100 includes a fan section 102 and a turbine 104 disposed downstream of the fan section 102.

[0042] The depicted exemplary turbine 104 generally includes a substantially tubular housing 106 defining an annular inlet 108. The housing 106 surrounds, in a series flow relationship: a compressor section including a boost or low-pressure (LP) compressor 110 and a high-pressure (HP) compressor 112; a combustion section 114; a turbine section including a high-pressure (HP) turbine 116 and a low-pressure (LP) turbine 118; and an exhaust nozzle section 120. The compressor section, combustion section 114, and turbine section together at least partially define a core airflow path 121 extending from the annular inlet 108 to the exhaust nozzle section 120. The turbofan engine further includes one or more drive shafts. More specifically, the turbofan engine includes a high-pressure (HP) shaft or spool 122 drivingly connecting the HP turbine 116 to the HP compressor 112, and a low-pressure (LP) shaft or spool 124 drivingly connecting the LP turbine 118 to the LP compressor 110.

[0043] In the depicted embodiment, fan section 102 includes a fan 126 having a plurality of fan blades 128 spaced apart and coupled to disk 130. The plurality of fan blades 128 and disk 130 are rotatable together about a centerline axis 101 via LP shaft 124. Disk 130 is covered by a rotatable front hub 132, which is aerodynamically shaped to facilitate airflow through the plurality of fan blades 128. Furthermore, an annular fan housing or outer nacelle 134 is configured to circumferentially surround at least a portion of fan 126 and / or turbine 104. Nacelle 134 is supported relative to turbine 104 by a plurality of circumferentially spaced outlet guide vanes 136. A downstream section 138 of nacelle 134 extends over the outer portion of turbine 104 to define a bypass airflow passage 140 therebetween.

[0044] In this way, it will be understood that the turbofan engine 100 generally includes a first flow (e.g., a core airflow path 121) and a second flow extending parallel to the first flow (e.g., a bypass airflow passage 140). In some exemplary embodiments, the turbofan engine 100 may further define a third flow, for example, extending from the LP compressor 110 to the bypass airflow passage 140 or to the environment. With this configuration, the LP compressor 110 may generally include a first compressor stage configured as a ducted intermediate fan and a downstream compressor stage. The inlet of the third flow may be located between the first compressor stage and the downstream compressor stage.

[0045] Still referencing Figure 1 The turbofan engine 100 further includes an accessory gearbox 142 and a fuel delivery system 146. In the illustrated embodiment, the accessory gearbox 142 is located within the shroud / casing 106 of the turbine 104. Furthermore, it will be understood that for... Figure 1In the schematically depicted embodiment, accessory gearbox 142 is mechanically coupled to one or more shafts or spools of turbine 104 and is rotatable with one or more shafts or spools of turbine 104. For example, in the depicted exemplary embodiment, accessory gearbox 142 is mechanically coupled to HP shaft 122 via a suitable gear train 144 and is rotatable with HP shaft 122. Accessory gearbox 142 can provide power to one or more suitable accessory systems of turbofan engine 100 during at least some operations and can further provide power back to turbofan engine 100 during other operations. For example, in the illustrated embodiment, accessory gearbox 142 is coupled to starter motor / generator 152. Starter motor / generator can be configured to draw power from accessory gearbox 142 and turbofan engine 100 to generate electricity during some operations and can provide power back to accessory gearbox 142 and turbofan engine 100 (e.g., to HP shaft 122) during other operations to add mechanical work back to turbofan engine 100 (e.g., for starting turbofan engine 100).

[0046] Furthermore, the fuel delivery system 146 generally includes a fuel source 148 (such as a fuel tank) and one or more fuel delivery lines 150. One or more fuel delivery lines 150 supply fuel flow through the fuel delivery system 146 to the combustion section 114 of the turbine 104 of the turbofan engine 100. As will be discussed in more detail below, the combustion section 114 includes an integrated fuel cell and combustor assembly 200. In the described embodiment, one or more fuel delivery lines 150 supply fuel flow to the integrated fuel cell and combustor assembly 200.

[0047] However, what will be understood is that Figure 1 The exemplary turbofan engine 100 depicted is provided by way of example only. In other exemplary embodiments, any other suitable gas turbine engine may be used in conjunction with aspects of this disclosure. For example, in other embodiments, the turbofan engine may be any other suitable gas turbine engine, such as a turboshaft engine, a turboprop engine, a turbojet engine, etc. In this way, it will be further understood that in other embodiments, the gas turbine engine may have any other suitable construction, such as any other suitable number or arrangement of shafts, compressors, turbines, fans, etc. Furthermore, although Figure 1The exemplary gas turbine engine depicted herein is schematically shown as a direct-drive fixed-pitch turbofan engine, but in other embodiments, the gas turbine engine of this disclosure may be a geared gas turbine engine (i.e., including a gearbox between a fan 126 and a shaft (such as LP shaft 124) driving the fan), a variable-pitch gas turbine engine (i.e., including a fan 126 having a plurality of fan blades 128 capable of rotating about their respective pitch axes), etc. Furthermore, although the exemplary turbofan engine 100 includes a ducted fan 126, in other exemplary aspects, the turbofan engine 100 may include a non-ducted fan 126 (or an open rotor fan) without a nacelle 134. Moreover, although not depicted herein, in other embodiments, the gas turbine engine may be any other suitable type of gas turbine engine, such as a marine gas turbine engine.

[0048] Now for reference Figure 2 , Figure 2 A portion of a combustion section 114 according to an embodiment of the present disclosure is schematically shown, which includes Figure 1 The gas turbine engine 100 (as mentioned above) Figure 1 Described as part of the integrated fuel cell and burner assembly 200 used in the turbofan engine 100.

[0049] It will be understood that the combustion section 114 includes a compressor diffuser nozzle 202 and extends generally along the axial direction A between an upstream end and a downstream end. The combustion section 114 is fluidly connected via the compressor diffuser nozzle 202 to the compressor section at the upstream end and to the turbine section at the downstream end.

[0050] The integrated fuel cell and burner assembly 200 generally includes fuel cell assembly 204. Figure 2 Only a partial description is provided; see also Figures 3 to 5 The combustor 206 includes an inner liner 208, an outer liner 210, a dome assembly 212, a shroud assembly 214, a swirler assembly 216, and a fuel flow line 218. The combustion section 114 generally includes a housing 220 radially outward of the combustor 206 to surround it, and an inner housing 222 radially inward of the combustor 206. The inner housing 222 and the inner liner 208 define an inner passage 224 therebetween, while the housing 220 and the outer liner 210 define an outer passage 226 therebetween. The inner housing 222, the housing 220, and the dome assembly 212 together at least partially define the combustion chamber 228 of the combustor 206.

[0051] The dome assembly 212 is positioned near the upstream end of the combustion section 114 (i.e., closer to the upstream end than the downstream end) and includes an opening (not labeled) for receiving and retaining the swirler assembly 216. The swirler assembly 216 also includes an opening for receiving and retaining the fuel flow line 218. The fuel flow line 218 is further coupled to a fuel source 148 disposed radially R outside the housing 220 (see [link to fuel source 148]). Figure 1 It is configured to receive fuel from fuel source 148. In this way, fuel flow line 218 can be fluidly connected to the above reference. Figure 1 Describes one or more fuel delivery pipelines 150.

[0052] The swirler assembly 216 may include a plurality of swirlers (not shown) configured to swirl the compressed fluid before it is injected into the combustion chamber 228 to generate combustion gases. In the illustrated embodiment, the shroud assembly 214 is configured to hold the inner liner 208, the outer liner 210, the swirler assembly 216, and the dome assembly 212 together.

[0053] During operation, the compressor diffuser nozzle 202 is configured to direct compressed fluid 230 from the compressor section to the combustor 206, wherein the compressed fluid 230 is configured to mix with fuel within the cyclone assembly 216 and burn within the combustion chamber 228 to generate combustion gases. The combustion gases are supplied to the turbine section to drive one or more turbines of the turbine section (e.g., high-pressure turbine 116 and low-pressure turbine 118).

[0054] During operation of the gas turbine engine 100, which includes an integrated fuel cell and combustor assembly 200, the flame within the combustion chamber 228 is maintained by a continuous flow of fuel and air. To provide ignition of the fuel and air, for example during start-up of the gas turbine engine 100, the integrated fuel cell and combustor assembly 200 further includes an igniter 231. The igniter 231 can provide a spark or initial flame to ignite the fuel and air mixture within the combustion chamber 228.

[0055] As mentioned above and Figure 2The diagram schematically depicts an integrated fuel cell and burner assembly 200, which further includes a fuel cell assembly 204. The depicted exemplary fuel cell assembly 204 includes a first fuel cell stack 232 and a second fuel cell stack 234. More specifically, the first fuel cell stack 232 is constructed together with an outer liner 210, and the second fuel cell stack 234 is constructed together with an inner liner 208. Even more specifically, the first fuel cell stack 232 is integrated with the outer liner 210, and the second fuel cell stack 234 is integrated with the inner liner 208. The operation of the fuel cell assembly 204, and more specifically, the operation of the fuel cell stacks (e.g., the first fuel cell stack 232 or the second fuel cell stack 234) of the fuel cell assembly 204, will be described in more detail below.

[0056] In the described embodiments, fuel cell assembly 204 is configured as a solid oxide fuel cell (“SOFC”) assembly, wherein a first fuel cell stack 232 is configured as a first SOFC fuel cell stack, and a second fuel cell stack 234 is configured as a second SOFC fuel cell stack (each having multiple SOFCs). It will be understood that an SOFC is generally an electrochemical conversion device that generates electricity directly by oxidizing fuel. Generally, fuel cell assemblies, and especially fuel cells, are characterized by the electrolyte material used. The SOFCs of this disclosure generally may include solid oxide or ceramic electrolytes. Such fuel cells generally exhibit high overall thermoelectric efficiency, long-term stability, fuel flexibility, and low emissions.

[0057] Furthermore, the exemplary fuel cell assembly 204 further includes a first power converter 236 and a second power converter 238. The first fuel cell stack 232 is electrically connected to the first power converter 236 via a first plurality of power cables (unlabeled), and the second fuel cell stack 234 is electrically connected to the second power converter 238 via a second plurality of power cables (unlabeled).

[0058] The first power converter 236 controls the current drawn from the corresponding first fuel cell stack 232 and can convert direct current (“DC”) power to DC power or alternating current (“AC”) power at another voltage level. Similarly, the second power converter 238 controls the current drawn from the second fuel cell stack 234 and can convert DC power to DC power or AC power at another voltage level. The first power converter 236, the second power converter 238, or both can be electrically connected to an electrical bus (such as electrical bus 326 described below).

[0059] The integrated fuel cell and burner assembly 200 further includes a fuel cell controller 240, which is operatively communicable with a first power converter 236 and a second power converter 238 to send and receive communications and signals, for example, between the two. For example, the fuel cell controller 240 can send current or power setpoint signals to the first power converter 236 and the second power converter 238, and can receive voltage or current feedback signals, for example, from the first power converter 236 and the second power converter 238. The fuel cell controller 240 can be configured in accordance with the following references. Figure 5 The controller 240 described is constructed in the same manner.

[0060] It will be understood that, in at least some exemplary embodiments, the first fuel cell stack 232, the second fuel cell stack 234, or both may extend substantially 360 degrees in the circumferential direction C of the gas turbine engine (i.e., the direction in which it extends about the centerline axis 101 of the gas turbine engine 100). For example, now referring to... Figure 3 A simplified cross-sectional view of an integrated fuel cell and burner assembly 200 is depicted according to an exemplary embodiment of this disclosure. Although for simplicity... Figure 3 Only the first fuel cell stack 232 is depicted, but the second fuel cell stack 234 can be constructed in a similar manner.

[0061] As shown in the figure, the first fuel cell stack 232 extends around the combustion chamber 228 in the circumferential direction C, and in the illustrated embodiment, completely surrounds the combustion chamber 228 around the central axis 101. More specifically, the first fuel cell stack 232 includes a plurality of fuel cells 242 arranged in the circumferential direction C. Figure 3 The fuel cell 242 visible in the image can be a single ring of fuel cell 242, wherein fuel cells 242 are stacked together along the axial direction A (see [link]). Figure 2 ( ), to form a first fuel cell stack 232. In another example, multiple additional rings of fuel cell 242 may be placed on top of each other to form a first fuel cell stack 232 extending along the centerline axis 101.

[0062] The following will explain this in more detail; please refer to [reference needed]. Figure 5In the first fuel cell stack 232, fuel cell 242 is positioned to receive exhaust air 244 from, for example, a compressor section and fuel 246 from a fuel delivery system 146. Fuel cell 242 uses the air 244 and at least some of the fuel 246 to generate an electric current and guides partially oxidized fuel 246 and unused portion of air 248 radially toward the centerline axis 101 into combustion chamber 228. Integrated fuel cell and combustor assembly 200 combusts the partially oxidized fuel 246 and air 248 in combustion chamber 228 into combustion gases, which are then guided downstream into a turbine section to drive or assist in driving one or more turbines therein.

[0063] In addition, now refer to Figure 4 Provided as Figure 2 A schematic perspective view of the first fuel cell stack 232 of the integrated fuel cell and burner assembly 200. The second fuel cell stack 234 can be formed in a similar manner.

[0064] The depicted first fuel cell stack 232 includes a casing 250 having a combustion outlet side 252 and a side 254 opposite to the combustion outlet side 252, a fuel and air inlet side 256 and a side 588 opposite to the fuel and air inlet side 256, and sides 260 and 262. Sides 260, 258, and 254 are... Figure 4 It is not visible in the 3D image.

[0065] It will be understood that the first fuel cell stack 232 may include, for example, multiple fuel cells “stacked” side-by-side from one end of the first fuel cell stack 232 (e.g., fuel and air inlet side 256) to the other end of the first fuel cell stack 232 (e.g., side 258). Therefore, it will be further understood that the combustion outlet side 252 includes multiple combustion outlets 264, each combustion outlet originating from a fuel cell within the first fuel cell stack 232. During operation, combustion gases 266 (also referred to herein as “output products”) are directed from the combustion outlets 264 out of the housing 250. As described herein, the combustion gases 266 are generated using fuel and air not consumed by the fuel cells within the housing 250 of the first fuel cell stack 232. The combustion gases 266 are supplied to the combustion chamber 228 and combusted during operation to generate combustion gases used to generate thrust for the gas turbine engine 100 (and vehicles / aircraft in conjunction with the gas turbine engine 100).

[0066] The fuel and air inlet side 256 includes one or more fuel inlets 268 and one or more air inlets 270. Optionally, one or more of the inlets 268, 270 may be located on the other side of the housing 250. Each of the one or more fuel inlets 268 is fluidly connected to a fuel source (such as hydrogen gas or one or more pressurized containers of a fuel processing unit further described below) for the first fuel cell stack 232. Each of the one or more air inlets 270 is fluidly connected to an air source (such as air discharged from the compressor section and / or the air processing unit also further described below) for the fuel cell. The one or more inlets 268, 270 separately receive fuel and air from external fuel and air sources and separately direct the fuel and air into the fuel cell.

[0067] In some exemplary embodiments, Figures 2 to 4 The first fuel cell stack 232 may be constructed in a manner similar to one or more of the exemplary fuel cell systems (labeled 100) described, for example, in U.S. Patent Application Publication No. 2020 / 0194799A1, filed December 17, 2018, the entire contents of which are incorporated herein by reference. It will be further understood that... Figure 2 The second fuel cell stack 234 can be constructed in a similar manner to the first fuel cell stack 232, or alternatively, it can be constructed in any other suitable manner.

[0068] It should be understood that the fuel cell assembly 204 of this disclosure is divided into multiple fuel cell stacks, each capable of producing discrete power output. As used herein, when referring to a fuel cell stack of a fuel cell assembly, the term "stack" means multiple fuel cells engaged in a manner that allows power to be output separately from any other fuel cell in the fuel cell assembly during at least some operation. For example, in Figure 2 In some embodiments, the first fuel cell stack 232 may be a first fuel cell array, and the second fuel cell stack 234 may be a second fuel cell array. However, alternatively, the fuel cell assembly 204 may include a plurality of fuel cell arrays arranged along the length of the outer liner 210 in the axial direction A, a plurality of fuel cell arrays arranged circumferentially along the outer liner 210 in the circumferential direction C, or a combination thereof. A separate power cable may be provided for each fuel cell array.

[0069] Furthermore, it should be understood that, despite Figures 2 to 4An exemplary fuel cell assembly 204 typically includes a fuel cell (e.g., a fuel cell of a first fuel cell stack 232 and a second fuel cell stack 234) arranged along and integrated with the outer liner 210 and inner liner 208 of the burner 206. However, in other embodiments, the fuel cell assembly 204 may be constructed in any other suitable manner at any other suitable location (e.g., axially in front of the burner 206, spaced outwards of the burner 206 in the radial direction R, etc.). Furthermore, in other embodiments, the fuel cell assembly 204 may use a chemical substance other than a solid oxide chemical substance.

[0070] Now for reference Figure 5 The operation of the integrated fuel cell and burner assembly 200 according to exemplary embodiments of the present disclosure will be described. More specifically, Figure 5 A schematic diagram of a gas turbine engine 100 and an integrated fuel cell and combustor assembly 200 according to embodiments of the present disclosure is provided. In some exemplary embodiments, the gas turbine engine 100 and the integrated fuel cell and combustor assembly 200 can be coupled with… Figures 1 to 4 One or more exemplary embodiments are constructed in a similar manner to those described above.

[0071] Therefore, it will be understood that the gas turbine engine 100 generally includes a fan section 102 with a fan 126, an LP compressor 110, an HP compressor 112, a combustion section 114, an HP turbine 116, and an LP turbine 118. The combustion section 114 generally includes an integrated fuel cell and combustor assembly 200 with a combustor 206 and a fuel cell assembly 204.

[0072] The propulsion system including the gas turbine engine 100 further includes a fuel delivery system 146. The fuel delivery system 146 generally includes a fuel source 148 and one or more fuel delivery lines 150. The fuel source 148 may include a supply section for fuel (e.g., hydrocarbon fuel, including, for example, carbon-neutral fuel or synthetic hydrocarbons) for the gas turbine engine 100. Furthermore, it will be understood that the fuel delivery system 146 also includes a fuel pump 272 and a distributor 274, and the one or more fuel delivery lines 150 include a first fuel delivery line 150A, a second fuel delivery line 150B, and a third fuel delivery line 15C. Diverter 274 divides the fuel flow from fuel source 148 and fuel pump 272 into a first fuel flow through a first fuel delivery line 150A to fuel cell assembly 204, a second fuel flow through a second fuel delivery line 150B also to fuel cell assembly 204 (and particularly to the air handling unit described below), and a third fuel flow through a third fuel delivery line 150C to burner 206. Diverter 274 may include a series of valves (not shown) to facilitate this diversion of the fuel flow from fuel source 148, or alternatively, may have a fixed geometry. Furthermore, for the illustrated embodiment, fuel delivery system 146 includes a first fuel valve 151A associated with the first fuel delivery line 150A (e.g., for controlling the first fuel flow), a second fuel valve 151B associated with the second fuel delivery line 150B (e.g., for controlling the second fuel flow), and a third fuel valve 151C associated with the third fuel delivery line 150C (e.g., for controlling the third fuel flow).

[0073] The gas turbine engine 100 further includes a compressor exhaust system and an airflow delivery system. More specifically, the compressor exhaust system includes an LP bleed air duct 276 and an associated LP bleed air valve 278, an HP bleed air duct 280 and an associated HP bleed air valve 282, and an HP outlet air duct 284 and an associated HP outlet air valve 286.

[0074] The gas turbine engine 100 further includes an air supply duct 288 (in airflow communication with the air supply unit 290) and an associated air valve 292, which is also in airflow communication with the air delivery system, for providing compressed airflow to the fuel cell assembly 204 of the integrated fuel cell and combustor assembly 200. The air supply unit may be, for example, a second gas turbine engine configured to provide cross-bleed air, an auxiliary power unit (APU) configured to provide bleed air, a ram air turbine (RAT), etc. If the compressor air source is insufficient or unavailable, the air supply unit may supplement the compressor exhaust system.

[0075] The compressor discharge system (and air supply duct 288) is in airflow communication with the airflow delivery system for supplying compressed airflow to the fuel cell assembly 204, as will be explained in more detail below.

[0076] Still referencing Figure 5 The fuel cell assembly 204, which integrates the fuel cell and burner assembly 200, includes a fuel cell stack 294, which can be constructed in a manner similar to, for example, the first fuel cell stack 232 described above. The fuel cell stack 294 is schematically depicted as a single fuel cell having a cathode side 296, an anode side 298, and an electrolyte 300 positioned between them. Generally, it will be understood that the electrolyte 300 can conduct negative oxygen ions from the cathode side 296 to the anode side 298 during operation to generate current and electricity.

[0077] In short, it will be understood that the fuel cell assembly 204 also includes a fuel cell sensor 302, which is configured to sense data indicating operating parameters of the fuel cell assembly, such as the temperature of the fuel cell stack 294 (e.g., the temperature of the cathode side 296 or anode side 298 of the fuel cell) and the pressure within the fuel cell stack 294 (e.g., the pressure within the cathode side 296 or anode side 298 of the fuel cell).

[0078] The anode side 298 can support an electrochemical reaction that generates electricity. Fuel can be oxidized in the anode side 298 via diffusion through the electrolyte 300, utilizing oxygen ions received from the cathode side 296. This reaction can generate heat, vapor, and electricity in the form of free electrons in the anode side 298, which can be used to power energy-consuming devices (such as one or more additional electrical devices 328 described below). Oxygen ions can be generated using electrons returning from the energy-consuming device to the cathode side 296 via oxygen reduction of the cathode oxidant.

[0079] The cathode side 296 can be coupled to a cathode oxidant source, such as atmospheric oxygen. The cathode oxidant is defined as the oxidant supplied to the cathode side 296, which is used by the fuel cell system to generate electricity. The cathode side 296 can be permeable to oxygen ions received from the cathode oxidant.

[0080] Electrolyte 300 can be connected to both the anode side 298 and the cathode side 296. Electrolyte 300 allows oxygen ions to pass from the cathode side 296 to the anode side 298, and can have very low conductivity or no conductivity to prevent free electrons from passing from the cathode side 296 to the anode side 298.

[0081] The anode side of a solid oxide fuel cell (such as fuel cell stack 294) can be constructed of nickel / yttrium oxide-stabilized zirconium oxide (Ni / YSZ) cermet. Nickel in the anode side serves as a catalyst for fuel oxidation and a current conductor. During normal operation of fuel cell stack 294, the operating temperature can be greater than or equal to approximately 700°C, and the nickel (Ni) in the anode retains its reduced form due to the continuous supply of primarily hydrogen fuel gas. Other configurations are also conceivable.

[0082] The fuel cell stack 294 is located downstream of the LP compressor 110, the HP compressor 112, or both. Furthermore, from the above regarding... Figure 2 As will be understood from the description, fuel cell stack 294 may be coupled to or otherwise integrated with the bushings (e.g., inner liner 208 or outer liner 210) of burner 206. In this way, fuel cell stack 294 may also be arranged upstream of combustion chamber 228, which integrates fuel cell and burner assembly 200, and further upstream of HP turbine 116 and LP turbine 118.

[0083] like Figure 5 As shown, the fuel cell assembly 204 also includes a fuel processing unit 304 and an air processing unit 306. The fuel processing unit 304 can be any suitable structure for generating a hydrogen-rich fuel stream. For example, the fuel processing unit 304 may include a fuel reformer or a catalytic partial oxidation converter (CPOx) for generating a hydrogen-rich fuel stream for the fuel cell stack 294. The air processing unit 306 can be any suitable structure for raising the temperature of the air supplied thereto to a temperature sufficiently high to achieve fuel cell temperature control (e.g., about 600°C to about 800°C). For example, in the described embodiment, the air processing unit includes a pre-burner system that operates based on the fuel stream via a second fuel delivery line 150B and is configured to raise the air temperature by combustion, for example, during transient conditions such as start-up, shutdown, and abnormal situations.

[0084] In the exemplary embodiment depicted, the fuel processing unit 304 and the air processing unit 306 are manifolded together within the housing 308 to provide conditioned air and fuel to the fuel cell stack 294.

[0085] However, it should be understood that the fuel processing unit 304 may additionally or alternatively include any suitable type of fuel reformer, such as an automatic thermal reformer and a steam reformer, which may require an additional steam inlet stream with a higher hydrogen composition at the reformer outlet stream. Additionally or alternatively, the fuel processing unit 304 may also include a reformer integrated with the fuel cell stack 294. Similarly, it should be understood that... Figure 5The air handling unit 306 may alternatively be a heat exchanger or another device for raising the temperature of the air supplied thereto to a temperature high enough to achieve fuel cell temperature control (e.g., about 600°C to about 800°C).

[0086] As described above, the compressor discharge system (and air supply duct 288) is in airflow communication with the airflow delivery system for providing compressed airflow to the fuel cell assembly 204. The airflow delivery system includes an anode airflow duct 310 and associated anode airflow valve 312 for providing airflow to the fuel processing unit 304, a cathode airflow duct 314 and associated cathode airflow valve 316 for providing airflow to the air processing unit 306, and a cathode bypass air duct 318 and associated cathode bypass air valve 320 for providing airflow directly to the fuel cell stack 294 (or more precisely, to the cathode side 296 of the fuel cell). The fuel delivery system 146 is configured to provide a first fuel flow to the fuel processing unit 304 via a first fuel delivery line 150A and a second fuel flow to the air processing unit 306 via a second fuel delivery line 150B (e.g., as fuel for the pre-combustor system, if provided).

[0087] The fuel cell stack 294 outputs electricity as the fuel cell power output 322. In addition, the fuel cell stack 294 directs cathode air emissions and anode fuel emissions (not labeled for clarity) into the combustion chamber 228 of the burner 206.

[0088] In operation, the air handling unit 306 is configured to heat / cool a portion of the compressed air entering through the cathode airflow duct 314 to generate processed air to be directed into the fuel cell stack 294, thereby facilitating the operation of the fuel cell stack 294. The air handling unit 306 receives a second fuel flow from the second fuel delivery line 150B and can, for example, combust this second fuel flow to heat the received air to a desired temperature (e.g., about 600°C to about 800°C), thereby facilitating the operation of the fuel cell stack 294. The air processed by the air handling unit 306 is directed into the fuel cell stack 294. In embodiments of this disclosure, as shown, the cathode bypass air duct 318 and the air processed by the air handling unit 306 can be combined into a combined airflow to be delivered to the cathode side 296 of the fuel cell stack 294.

[0089] In addition, such as Figure 5As shown in the embodiment, a first fuel flow via a first fuel delivery line 150A is directed to a fuel processing unit 304 for generating a hydrogen-rich fuel flow (e.g., optimizing the hydrogen content of the fuel flow), which is also fed into the fuel cell stack 294. It will be understood, and discussed below, that the air (processing air and bypass air) flow to the fuel cell stack 294 (e.g., cathode side 296) and the fuel from the fuel processing unit 304 to the fuel cell stack 294 (e.g., anode side 298) can facilitate power generation.

[0090] Since the inlet air to the fuel cell stack 294 may originate solely from the upstream compressor section without any other separately controlled air source, it will be understood that the inlet air to the fuel cell stack 294 discharged from the compressor section will be affected by air temperature variations occurring at different stages of flight. As an illustrative example only, the air in a specific location within the compressor section of the gas turbine engine 100 may operate at 200°C during idling, 600°C during takeoff, 268°C during cruise, and so on. This type of temperature variation in the inlet air directed to the fuel cell stack 294 can cause significant thermal transient problems (or even thermal shock) to the ceramic material of the fuel cell stack 294, potentially ranging from cracking to failure.

[0091] Therefore, by fluidly connecting the air handling unit 306 between the compressor section and the fuel cell stack 294, the air handling unit 306 can serve as a control device or system to maintain the air processed by the air handling unit 306 and directed into the fuel cell stack 294 within a desired operating temperature range (e.g., ±100°C, or preferably ±50°C, or ±20°C). During operation, the temperature of the air supplied to the fuel cell stack 294 (relative to the temperature of the air discharged from the compressor section) can be controlled by controlling the fuel flow to the air handling unit 306. Increasing the fuel flow to the air handling unit 306 can raise the temperature of the airflow to the fuel cell stack 294. Decreasing the fuel flow to the air handling unit 306 can lower the temperature of the airflow to the fuel cell stack 294. Optionally, fuel cannot be supplied to the air handling unit 306 to prevent the air handling unit 306 from raising and / or lowering the temperature of the air discharged from the compressor section and directed into the air handling unit 306.

[0092] Furthermore, as depicted in dashed lines, fuel cell assembly 204 further includes an airflow bypass duct 321 extending around fuel cell 294 to allow part or all of the airflow regulated by air handling unit 306 (and combined with any bypass air passing through duct 318) to bypass the cathode side 296 of fuel cell 294 and enter directly into combustion chamber 228. The bypass duct 321 may be in thermal communication with fuel cell 294. Fuel cell assembly further includes a fuel bypass duct 323 extending around fuel cell 294 to allow part or all of reformed fuel from fuel handling unit 304 to bypass the anode side 298 of fuel cell 294 and enter directly into combustion chamber 228.

[0093] As briefly mentioned above, the fuel cell stack 294 converts the anode fuel stream from the fuel processing unit 304 and the air processed by the air processing unit 306 into electrical energy in the form of DC current, i.e., fuel cell power output 322. This fuel cell power output 322 is directed to a power converter 324 to convert the DC current into DC or AC current that can be efficiently utilized by one or more subsystems. Specifically, in the depicted embodiment, power is supplied from the power converter to an electrical bus 326. The electrical bus 326 may be an electrical bus dedicated to the gas turbine engine 100, an electrical bus of an aircraft in conjunction with the gas turbine engine 100, or a combination thereof. The electrical bus 326 is electrically connected to one or more auxiliary electrical devices 328, which may be adapted to draw current from the fuel cell stack 294 or apply an electrical load to the fuel cell stack 294. The one or more auxiliary electrical devices 328 may be a power source, a power sink, or both. For example, the auxiliary electrical device 328 may be an energy storage device (such as one or more batteries), an electric motor (generator, electric motor, or both), an electric propulsion device, etc. For example, one or more auxiliary electrical devices 328 may include a starter motor / generator of the gas turbine engine 100.

[0094] Still referencing Figure 5 The gas turbine engine 100 further includes a sensor 330. In the illustrated embodiment, the sensor 330 is configured to sense data indicating the flame within the combustion section 114 of the gas turbine engine 100. For example, the sensor 330 may be a temperature sensor configured to sense data indicating the outlet temperature of the combustion section 114, the inlet temperature of the turbine section, the exhaust temperature, or a combination thereof. Additionally or alternatively, the sensor 330 may be any other suitable sensor or any suitable combination of sensors configured to sense one or more gas turbine engine operating conditions or parameters, including data indicating the flame within the combustion section 114 of the gas turbine engine 100.

[0095] In addition, such as Figure 5 Further schematically depicted, the propulsion system, the aircraft including the propulsion system, or both include controller 240. For example, controller 240 may be a standalone controller, a gas turbine engine controller (e.g., a full authority digital engine controller or a FADEC controller), an aircraft controller, a supervisory controller for the propulsion system, or combinations thereof.

[0096] The controller 240 is operatively connected to various sensors, valves, etc., within at least one of the gas turbine engine 100 and the fuel delivery system 146. More specifically, for the exemplary aspects depicted, the controller 240 is operatively connected to valves (valve 278, 282, 286) of the compressor discharge system, valves (valve 312, 316, 320) of the gas flow delivery system, and valves (splitter 274, valves 151A, 151B, 151C) of the fuel delivery system 146, as well as sensors 330 of the gas turbine engine 100 and fuel cell sensor 302. It will be understood from the following description that the controller 240 can communicate wirelessly with these components, either wired or wirelessly. In this way, the controller 240 can receive data from various inputs (including gas turbine engine sensor 330 and fuel cell sensor 302), make control decisions, and provide data (e.g., instructions) to various outputs (including valves of the compressor discharge system that control the airflow discharge from the compressor section, valves of the airflow delivery system that guide the airflow discharged from the compressor section, and valves of the fuel delivery system 146 that guide the fuel flow within the gas turbine engine 100).

[0097] Referring specifically to the operation of controller 240, in at least some embodiments, controller 240 may include one or more computing devices 332. Computing device 332 may include one or more processors 332A and one or more memory devices 332B. The one or more processors 332A may include any suitable processing means, such as a microprocessor, microcontroller, integrated circuit, logic device, and / or other suitable processing means. The one or more memory devices 332B may include one or more computer-readable media, including but not limited to non-transitory computer-readable media, RAM, ROM, hard disk drives, flash drives, and / or other memory devices.

[0098] One or more memory devices 332B may store information accessible by one or more processors 332A, including computer-readable instructions 332C executable by one or more processors 332A. Instructions 332C may be any set of instructions that, when executed by one or more processors 332A, cause one or more processors 332A to operate. In some embodiments, instructions 332C may be executed by one or more processors 332A to cause one or more processors 332A to operate, such as any operations and functions configured for the controller 240 and / or computing device 332, operations for operating the propulsion system as described herein (e.g., method 900 and / or method 1000), and / or any other operations or functions of one or more computing devices 332. Instructions 332C may be software written in any suitable programming language or may be implemented in hardware. Additionally and / or alternatively, instructions 332C may be executed in logically and / or virtually decoupled threads on the processor 332A. Memory device 332B may further store data 332D accessible by processor 332A. For example, data 332D may include data indicating power flow, data indicating operating conditions of the gas turbine engine 100 / aircraft, and / or any other data and / or information described herein.

[0099] The computing device 332 also includes a network interface 332E, which is configured to communicate, for example, with other components of the gas turbine engine 100 (such as valves of the compressor exhaust system (valve 278, 282, 286), valves of the airflow delivery system (valve 312, 316, 320), and valves of the fuel delivery system 146 (splitter 274, valves 151A, 151B, 151C), as well as sensors 330 and fuel cell sensors 302 of the gas turbine engine 100), and with an aircraft associated with the gas turbine engine 100. The network interface 332E may include any suitable components for communication with one or more network interfaces, including, for example, transmitters, receivers, ports, controllers, antennas, and / or other suitable components. In this way, it will be understood that the network interface 332E can utilize any suitable combination of wired and wireless communication networks.

[0100] The techniques discussed in this paper refer to computer-based systems, actions taken by computer-based systems, and information sent to and from computer-based systems. It will be understood that the inherent flexibility of computer-based systems allows for a wide variety of possible configurations, combinations, and divisions of tasks and functionalities between and within components. For example, the processes discussed herein can be implemented using a single computing device or multiple computing devices working in combination. Databases, memory, instructions, and applications can be implemented on a single system or distributed across multiple systems. Distributed components can operate sequentially or in parallel.

[0101] It will be understood that the gas turbine engine 100, the exemplary fuel delivery system 146, the exemplary integrated fuel cell and combustor assembly 200, and the exemplary fuel cell assembly 204 are provided as examples only. In other embodiments, the integrated fuel cell and combustor assembly 200 and the fuel cell assembly 204 may have any other suitable configuration. For example, in other exemplary embodiments, the fuel cell assembly 204 may include any other suitable fuel processing unit 304. Additionally or alternatively, for example when the combustor of the gas turbine engine 100 is configured to burn hydrogen fuel, and the fuel delivery assembly 146 is configured to supply hydrogen fuel to the integrated fuel cell and combustor assembly 200, particularly to the fuel cell assembly 206, the fuel cell assembly 204 may not require the fuel processing unit 304.

[0102] As briefly described above, the fuel cell assembly 204 can be electrically connected to an electrical bus 326, which can be the electrical bus of the gas turbine engine 100, the electrical bus of an aircraft, or a combination thereof. Now, briefly refer to... Figure 6 The present disclosure provides a schematic diagram of an aircraft 400 according to an embodiment of the present disclosure, the aircraft 400 including one or more gas turbine engines 100 (designated 100A and 100B), each engine having an integrated fuel cell and combustor assembly 200 (designated 200A and 200B), and an aircraft electrical bus 326 electrically connected to the one or more gas turbine engines 100.

[0103] Specifically, for the described exemplary embodiment, the aircraft 400 is provided as including a fuselage 402, a tail 404, a first wing 406, a second wing 408, and a propulsion system. The propulsion system generally includes a first gas turbine engine 100A coupled to or integrated with the first wing 406 and a second gas turbine engine 100B coupled to or integrated with the second wing 408. However, it will be understood that in other embodiments, any other suitable number and / or configuration of gas turbine engines 100 may be provided (e.g., mounted on the fuselage, mounted on the tail, etc.).

[0104] The first gas turbine engine 100A generally includes a first integrated fuel cell and combustor assembly 200A and a first electric motor 410A. The first integrated fuel cell and combustor assembly 200A may generally include a first fuel cell assembly. The first electric motor 410A may be an embedded motor, an offset motor (e.g., capable of rotating with the gas turbine engine 100A via an accessory gearbox or suitable gear train), etc. For example, in some exemplary embodiments, the first electric motor 410A may be a starter motor / generator of the first gas turbine engine 100A.

[0105] Similarly, the second gas turbine engine 100B generally includes a second integrated fuel cell and combustor assembly 200B and a second electric motor 410B. The second integrated fuel cell and combustor assembly 200B may generally include a second fuel cell assembly. The second electric motor 410B may also be an embedded motor, an offset motor (e.g., capable of rotating with the gas turbine engine 100 via an accessory gearbox or suitable gear train), etc. For example, in some exemplary embodiments, the second electric motor 410B may be a starter motor / generator of the second gas turbine engine 100B.

[0106] exist Figure 6 In this embodiment, the aircraft 400 additionally includes an electrical bus 326 and a supervisory controller 412. Furthermore, it will be understood that the aircraft 400 and / or propulsion system include one or more electrical devices 414 and energy storage units 416, each electrically connected to the electrical bus 326. Electrical devices 414 may represent one or more aircraft power loads (e.g., avionics systems, control systems, electric thrusters, etc.), one or more power sources (e.g., auxiliary power units), etc. Energy storage units 416 may be, for example, battery packs for storing electrical energy.

[0107] The electrical bus 326 is further electrically connected to the first motor 410A and the first fuel cell assembly, and electrically connected to the second motor 410B and the second fuel cell assembly. The supervisory controller 412 can be connected to... Figure 5 The controller 240 is constructed in a similar manner, or it can communicate operationally with a first gas turbine engine controller dedicated to the first gas turbine engine 100A and a second gas turbine engine controller dedicated to the second gas turbine engine 100B.

[0108] In this way, it will be understood that the supervisory controller 412 can be configured to receive data from the gas turbine engine sensor 330A of the first gas turbine engine 100A and the gas turbine engine sensor 330B of the second gas turbine engine 100B, and can be further configured to send data (e.g., commands) to various control elements (such as valves) of the first and second gas turbine engines 100A, 100B.

[0109] Furthermore, it will be understood that, for the depicted embodiment, the aircraft 400 includes one or more aircraft sensors 418 configured to sense data indicative of various flight operations of the aircraft 400, including, for example, altitude, ambient temperature, ambient pressure, airflow speed, etc. A supervisory controller 412 is operatively connected to these aircraft sensors 418 to receive data from them.

[0110] In addition to receiving data from sensors 330A, 330B, and 418 and transmitting data to the control element, the supervisory controller 412 is also configured to control the power flow through the electrical bus 326. For example, the supervisory controller 412 may be configured to command and receive desired power extraction from one or more motors (e.g., first motor 410A and second motor 410B), one or more fuel cell assemblies (e.g., first fuel cell assembly and second fuel cell assembly), or both, and to provide all or part of the extracted power to another or both of the one or more motors (e.g., first motor 410A and second motor 410B) and one or more fuel cell assemblies (e.g., first fuel cell assembly and second fuel cell assembly). One or more of these actions may be performed according to the logic outlined below.

[0111] In one embodiment, each integrated fuel cell assembly 204 and burner assembly 200 (labeled 200A and 200B; see also) Figures 2 to 5 The combustion chamber 206 is divided into multiple fuel cell stacks, each producing a discrete power output. For example, a first fuel cell stack 232 can be configured as a first fuel cell stack with a first power output, and a second fuel cell stack 234 can be configured as a second fuel cell stack with a second power output. The first and second fuel cell stacks can be arranged on the outer liner 210 and inner liner 208 of the burner 206 (e.g., ...). Figure 2 The fuel cell assembly 204 may be arranged axially along one of the outer liner 210 or inner liner 208 of the burner 206, or circumferentially along one or both of the outer liner 210 or inner liner 208 of the burner 206, or in any other suitable manner. Furthermore, in other embodiments, the fuel cell assembly 204 may include more than two groups (e.g., 3, 4, 5 or more groups, such as up to 20 groups).

[0112] Turn now Figure 7 In the depicted embodiment, the propulsion system is propulsion system 10, which includes a first propulsion assembly 500 having a first turbine 502, a second propulsion assembly 504 having a second turbine 506, and a third propulsion assembly 508 electrically connected to a power grid 510. The power grid 510 may be an electrical bus 326, or the power grid 510 may be similar to the one described in the reference document. Figure 5 and Figure 6 The described electrical bus 326 configuration.

[0113] In some embodiments, the propulsion system 10 includes only the first propulsion assembly 500, such that the second propulsion assembly 504 and the third propulsion assembly 508 are omitted. In other embodiments, the third propulsion assembly 508 is omitted, such that the propulsion system 10 includes the first propulsion assembly 500 and the second propulsion assembly 504. In a further embodiment, the propulsion system 10 includes only one turbine (e.g., the first turbine 502 of the first propulsion assembly 500), but includes multiple propulsion assemblies (e.g., multiple propulsion assemblies constructed in a manner similar to the second propulsion assembly 504). For example, in Figure 8 In the diagram, the second turbine 506 and the third propulsion assembly 508 of the second propulsion assembly 504 are shown in dashed lines to indicate that in some embodiments these components are optional; however, it will be understood that the second propulsion assembly 504 is also optional, alternatively or additionally.

[0114] like Figure 7 and Figure 8 As shown in the embodiments, each of the first propulsion assembly 500, the second propulsion assembly 504, and the third propulsion assembly 508 includes a fan section similar to the fan section 102 of the turbofan engine 100 described herein. Similarly, each of the first turbine 502 and the second turbine 506 is configured as a turbine 104 similar to that of the turbofan engine 100. Thus, the fan section of the first propulsion assembly 500 and the first turbine 502 together can be... Figure 6 The first gas turbine engine 100A of the illustrated embodiment, and the fan section of the second propulsion assembly 504 together with the second turbine 506 can be Figure 6 The second gas turbine engine 100B of the embodiment shown.

[0115] refer to Figure 7 and Figure 8 The fan section of the first propulsion assembly 500 includes a fan 512 having a plurality of fan blades 514 spaced apart and coupled to a disk 516. The fan blades 514 and the disk 516 are rotatable together about a central axis (not shown) of the first turbine 502, for example, via a low-pressure (LP) shaft 536. The disk 516 is covered by a rotatable front hub 518, which is aerodynamically shaped to facilitate airflow through the plurality of fan blades 514. In some embodiments, the fan section of the first propulsion assembly 500 is duct-type, wherein an annular fan housing or outer nacelle circumferentially surrounds at least a portion of the fan 512 and / or the first turbine 502, similar to... Figure 1The nacelle 134 is shown in the diagram. In other embodiments, the fan section of the first propulsion assembly 500 is non-ducted, without a fan housing or outer nacelle circumferentially surrounding the fan 512. Whether ducted or non-ducted, it will be understood that the fan section of the first propulsion assembly 500 is configured to generate thrust such that the first propulsion assembly 500 can be any suitable propulsion unit and does not need to include a fan assembly.

[0116] The first turbine 502 includes a compressor section 520, a combustion section 522, and a turbine section 524 arranged in a sequential flow order. The combustion section 522 of the first turbine 502 is configured to receive fuel from the aircraft fuel supply unit (e.g., fuel delivery system 146). Figure 1 The first turbine 502 receives a first aviation fuel stream F1. Compressor section 520 includes a booster or low-pressure (LP) compressor 526 and a high-pressure (HP) compressor 528. Turbine section 524 includes a high-pressure (HP) turbine 530 and a low-pressure (LP) turbine 532. The first turbine 502 also includes a high-pressure (HP) shaft or spool 534 drivingly connecting the HP turbine 530 to the HP compressor 528, and a low-pressure (LP) shaft or spool 536 drivingly connecting the LP turbine 532 to the LP compressor 526.

[0117] Similarly, the fan section of the second propulsion assembly 504 includes a fan 538 having a plurality of fan blades 540 spaced apart and coupled to a disk 542. The fan blades 540 and the disk 542 are rotatable together about a central axis (not shown) of the second turbine 506, for example, via a low-pressure (LP) shaft 562 of the second turbine 506. The disk 542 is covered by a rotatable front hub 544, which is aerodynamically shaped to facilitate airflow through the plurality of fan blades 540. In some embodiments, the fan section of the second propulsion assembly 504 is duct-type, wherein an annular fan housing or outer nacelle circumferentially surrounds at least a portion of the fan 538 and / or the second turbine 506, such as... Figure 1 The nacelle 134 is shown. In other embodiments, the fan section of the second propulsion assembly 504 is non-ducted, without a fan housing or outer nacelle circumferentially surrounding the fan 538. Whether ducted or non-ducted, it will be understood that the fan section of the second propulsion assembly 504 is configured to generate thrust such that the second propulsion assembly 504 can be any suitable thruster and does not need to be a fan assembly.

[0118] The second turbine 506 includes a compressor section 546, a combustion section 548, and a turbine section 550 arranged in a sequential flow order. The combustion section 548 of the second turbine 506 is configured to receive fuel from the aircraft fuel supply unit (e.g., fuel delivery system 146). Figure 1The second turbine receives a second aviation fuel stream F2. Compressor section 546 includes a booster or low-pressure (LP) compressor 552 and a high-pressure (HP) compressor 554. Turbine section 550 includes a high-pressure (HP) turbine 556 and a low-pressure (LP) turbine 558. The second turbine 506 also includes a high-pressure (HP) shaft or spool 560 drivingly connecting the HP turbine 556 to the HP compressor 552, and a low-pressure (LP) shaft or spool 562 drivingly connecting the LP turbine 558 to the LP compressor 552.

[0119] Furthermore, the third propulsion assembly 508 includes a fan 564 having a plurality of fan blades 566 spaced apart and coupled to a disk 568. The fan blades 566 and the disk 568 are rotatable together about an axis (not shown), for example, via a shaft 572 coupled to a motor 574. The disk 568 is covered by a rotatable front hub 570, which is aerodynamically shaped to facilitate airflow through the plurality of fan blades 566. In some embodiments, the third propulsion assembly 508 is duct-type, wherein an annular fan housing or outer nacelle circumferentially surrounds the fan 564, such as... Figure 1 The nacelle 134 is shown. In other embodiments, the third propulsion assembly 508 is non-ducted and has no fan housing or outer nacelle circumferentially surrounding the fan 564.

[0120] like Figure 7 and Figure 8 As shown, the propulsion system 10 includes at least one fuel cell assembly. For example, the propulsion system 10 has a first fuel cell assembly 576 including a first fuel cell 578, the first fuel cell 578 defining an outlet (e.g. Figure 4 As shown in the diagram, outlet 264 is positioned to remove output products (e.g., output product 266) from the first fuel cell 578. The first turbine 502 is configured to receive output products from the first fuel cell 578. Similarly, the propulsion system 10 has a second fuel cell assembly 580 including a second fuel cell 582, which defines an outlet (e.g., outlet 264). Figure 4 The outlet 264 shown is positioned to remove output products (e.g., output product 266) from the second fuel cell 582. The second turbine 506 is configured to receive the output products from the second fuel cell 582. It should be understood that in the case where the propulsion system 10 includes only one turbine (e.g., only the first turbine 502), the propulsion system may include only one fuel cell assembly, such as only the first fuel cell assembly 576. Furthermore, it should be understood that although... Figure 7 and Figure 8The fuel cell assembly shown is integrated with a corresponding turbine, but in other embodiments, the fuel cell assembly can be positioned at any other suitable location spaced apart from the turbine. However, it will be further understood that each fuel cell assembly can be as described above regarding, for example... Figure 2 The fuel cell assembly 204 depicted is constructed as described, and includes a first fuel cell stack 232 constructed together with the outer liner 210 of the burner assembly 200 of the respective turbines 502, 506, and a second fuel cell stack 234 constructed together with the inner liner 208 of the burner assembly 200 of the respective turbines 502, 506.

[0121] Still referencing Figure 7 and Figure 8 The power grid 510 is electrically connected to one or more electrical devices adapted to draw current from or apply an electrical load to the first turbine 502, the second turbine 506, the first fuel cell 578, and / or the second fuel cell 582. The one or more electrical devices can be a power source, a power dissipator, or both. For example, the electrical devices can be a first motor 584, a second motor 586, a third motor 588, and a fourth motor 590. Each motor 584, 586, 588, and 590 can be a generator, an electric motor, or both (which may be referred to as an electric generator). Additional electrical devices electrically connected to the power grid 510 may include one or more power storage devices (e.g., one or more batteries, supercapacitors, etc.); electric propulsion devices (e.g., a third propulsion assembly 508 with a fifth motor, also referred to herein as a motor 574 coupled to the shaft 572 of the third propulsion assembly 508), etc. The fifth motor 574 can be constructed as the first motor 584, the second motor 586, the third motor 588, and / or the fourth motor 590.

[0122] Each of the first motor 584, the second motor 586, the third motor 588, the fourth motor 590, and the fifth motor 574 may rotate with one of the first turbine 502 or the second turbine 506, and may be an embedded motor, an offset motor (e.g., rotating with the gas turbine engine 100 via an accessory gearbox or suitable gear train), etc. Furthermore, each motor 584, 586, 588, 590, and 574 does not need to be of the same type. For example, at least one of the first motor 584, the second motor 586, the third motor 588, the fourth motor 590, and / or the fifth motor 574 may be an embedded motor, while at least one of the first motor 584, the second motor 586, the third motor 588, the fourth motor 590, and / or the fifth motor 574 may be an offset motor. Furthermore, although... Figure 7Five motors are shown, but in at least some embodiments, the propulsion system 10 does not need to include each of the first motor 584, the second motor 586, the third motor 588, the fourth motor 590, and / or the fifth motor 574, for example, as shown in the figure. Figure 8 As shown.

[0123] In some exemplary embodiments, the first motor 584 may be a starter motor / generator connected to the HP shaft / spool 534 of the first turbine 502, and may be referred to as HP MG 584, such as Figure 7 As shown. The first motor 584 can rotate together with the HP compressor 528, HP turbine 530, or both of the first turbine 502. Furthermore, the second motor 586 can be a starter motor / generator connected to the LP shaft / spool 536 of the first turbine 502, and can be referred to as LP MG 586. The second motor 586 can rotate together with the LP compressor 526, LP turbine 532, or both of the first turbine 502. Similarly, the third motor 588 can be a starter motor / generator connected to the HP shaft / spool 560 of the second turbine 506, and can be referred to as HP MG 588. The third motor 588 can rotate together with the HP compressor 554, HP turbine 556, or both of the second turbine 506. Furthermore, the fourth motor 590 can be a starter motor / generator connected to the LP shaft / spool 562 of the second turbine 506, and can be referred to as LP MG 590. The fourth motor 590 can rotate together with the LP compressor 552, LP turbine 558, or both of the second turbine 506. Furthermore, the fifth motor 574 can be a starter motor / generator connected to the third propulsion assembly 508 as previously described, and can be referred to as PMG 574, such as... Figure 7 As shown.

[0124] As previously discussed, the propulsion system 10 includes at least one propulsion component (e.g., a first propulsion component 500, a second propulsion component 504, and / or a third propulsion component 508) and at least one turbine (e.g., a first turbine 502 and / or a second turbine 506). However, in various embodiments, different combinations of the number of propulsion components, the number of turbines, and the connections between at least one propulsion component and at least one turbine are possible. For example, in at least some embodiments of the propulsion system 10 including a first propulsion component 500, a second propulsion component 504, and turbines 502 / 506 (i.e., a first turbine 502 or a second turbine 506), one of the first propulsion component 500 and the second propulsion component 504 is mechanically coupled to the turbine 502 / 506, and the other of the first propulsion component 500 and the second propulsion component 504 is electrically coupled to the turbine 502 / 506. Furthermore, in this embodiment, the power grid 510 can be electrically connected to fuel cell assembly 576 / 580 (i.e., the first fuel cell assembly 576 or the second fuel cell assembly 580, depending on whether turbine 502 / 506 is the first turbine 502 or the second turbine 506), turbine 502 / 506, and at least one of the first propulsion assembly 500 and the second propulsion assembly 504. In this embodiment of the propulsion system 10, which also includes a third propulsion assembly 508, the third propulsion assembly 508 can be electrically connected to turbine 502 / 506 via the power grid 510.

[0125] As an example of the foregoing, in an embodiment of the propulsion system 10 including a first propulsion assembly 500, a second propulsion assembly 504, and a first turbine 502, the first propulsion assembly 500 is mechanically coupled to the first turbine 502, and the second propulsion assembly 504 is electrically coupled to the first turbine 502. Furthermore, a power grid 510 is electrically coupled to the first fuel cell assembly 576, the first turbine 502, and at least the second propulsion assembly 504; the power grid may also be electrically coupled to the first propulsion assembly 500. Additionally, when included, a third propulsion assembly 508 is electrically coupled to the first turbine 502 via the power grid 510.

[0126] As further shown in the figure, propulsion system 10, and aircraft including propulsion system 10 (e.g., Figure 6 The aircraft 400 shown (or both) includes a controller, for example, regarding Figure 5 The controller 240 is described. For example, controller 240 may be a stand-alone controller, a gas turbine engine controller (e.g., a full authority digital engine controller or a FADEC controller), an aircraft controller, or a supervisory controller for a propulsion system (e.g., regarding...). Figure 6 The described supervisory controller 412), and its combination, etc.

[0127] For example, this article is about Figure 5As described, in at least some embodiments, controller 240 may include one or more computing devices 332. Computing device 332 may include one or more processors 332A and one or more memory devices 332B. In at least some embodiments, the one or more memory devices 332B store instructions that, when executed by the one or more processors 332A, cause propulsion system 10 to operate, including receiving data indicating a propulsion system thrust differential and modifying the fuel cell output in response to receiving the data indicating the propulsion system thrust differential. The term "propulsion system thrust differential" generally refers to a difference between the actual thrust generated by propulsion system 10 and the desired or commanded thrust. For example, for a single turbine and a single propulsion assembly configuration, propulsion system thrust differential may refer to an actual thrust lower than the commanded thrust. For a propulsion system comprising multiple propeller assemblies, propulsion system thrust differential may refer to a thrust imbalance among the multiple propeller assemblies (e.g., more thrust from the starboard propulsion assembly relative to balanced operation relative to the port propulsion assembly, or vice versa).

[0128] In at least some exemplary aspects, the data indicating the thrust difference in the propulsion system can be actual sensor data or can be a change in the electrical load on the turbine (such as the first turbine 502 and / or the second turbine 506). The change in the electrical load on the turbine can refer to the electrical force extracted via a motor that can rotate with the turbine. The change in electrical load can be the result of an increase in power extraction from the accessory system, a decrease in power extraction from the accessory system, a fault event, etc.

[0129] In such an exemplary aspect, modifying the output of a fuel cell in response to receiving data indicating a difference in thrust of the propulsion system may include modifying the output products of a fuel cell (e.g., a first fuel cell 578 and / or a second fuel cell 582) in response to receiving data indicating a change in electrical load on a turbine.

[0130] For example, controller 240 is configured to control various components of propulsion system 10 to take corrective action in the event of a rapid electrical load change on the turbines (e.g., first turbine 502 and / or second turbine 506). A rapid electrical load change can be a load decrease or a load increase. In the case of a load decrease, one or more electrical components of propulsion system 10 may fail or otherwise be controlled to disconnect. For example, one or more electrical loads applying a torque load to first turbine 502 and / or second turbine 506 may stop requesting power or become electrically disconnected from the system. When this occurs, the electrical load on first turbine 502 and / or second turbine 506 decreases rapidly, or in other words, the torque resisting the rotation of the output shafts of first turbine 502 and / or second turbine 506 decreases rapidly, resulting in a torque imbalance between the torque output of first turbine 502 and / or second turbine 506 and the torque load applied to first turbine 502 and / or second turbine 506 by the electrical system. Under increased load conditions, the power required by a power-consuming device or load electrically connected to, for example, the power grid 510 cannot be supplied by one or more power generation devices (e.g., one or more motors described herein). That is, the required power exceeds the available power that can be generated by one or more power generation devices. Such rapid changes in electrical load can cause a number of problems, such as overspeed problems (e.g., speed deviation due to high power supply and low electrical load), poor power quality (e.g., system overvoltage), elevated turbine temperatures (which can affect turbine life), significant and unsafe aircraft handling problems, thrust asymmetry, etc.

[0131] Therefore, as previously described, in response to receiving data indicating a change in electrical load or demand on the turbine of propulsion system 10, controller 240 is configured to cause propulsion system 10 to modify the output of the associated fuel cell. (See reference...) Figure 7A , combined Figure 7 and Figure 8The output of the fuel cell is the output product or combustion gas 266 emitted from the fuel cell to the combustion section of the associated turbine, and the controller 240 is configured to cause the propulsion system 10 to modify the output product of the fuel cell flowing to the turbine. For example, in response to receiving data indicating an increase in electrical load on the first turbine 502, one or more processors 332A of the controller 240 execute instructions to cause the propulsion system 10 to modify the output product of the first fuel cell 578. By modifying the output product of the first fuel cell 578, the propulsion system 10 adjusts the exhaust gas (e.g., combustion gas 266) of the first fuel cell 578 to increase the work of the turbine section 524 of the first turbine 502. This increase in turbine work via the first fuel cell 578 increases the power output of the first turbine 502, helping to compensate for the increase in electrical load on the first turbine 502. Therefore, the effects of the increased electrical load can be minimized or avoided, which can prevent the aforementioned problems associated with changes in electrical load (e.g., overspeed, poor power quality, shortened engine life, aircraft handling problems, and thrust asymmetry). Compared to adding main fuel to the combustor to increase or enhance turbine output, using fuel cells can offer significant benefits by achieving the same turbine power increase without violating engine operability constraints (such as temperature limits). For example, the use of fuel cells can introduce desired gas components in a desired distribution within the combustor, resulting in lower turbine inlet temperatures and / or more uniform turbine temperature distribution, reduced emissions, and so on.

[0132] It should be understood that similar adjustments can be made to the output products of the second fuel cell 582 to minimize or eliminate the effects of electrical load changes on the second turbine 506. For example, in response to receiving data indicating an increase in electrical load on the second turbine 506, one or more processors 332A of the controller 240 execute instructions to cause the propulsion system 10 to modify the output products of the second fuel cell 582. By modifying the output products of the second fuel cell 582, the propulsion system 10 adjusts the exhaust gas (e.g., combustion gas 266) of the second fuel cell 582 to increase the work of the turbine section 550 of the second turbine 506. By increasing or adding turbine work via the second fuel cell 582, the power output of the second turbine 506 is increased to help compensate for the increase in electrical load on the second turbine 506, thereby minimizing or preventing problems associated with changes in electrical load on the second turbine 506 (such as those described above).

[0133] refer to Figure 7B , combined Figure 7 and Figure 8The output of the fuel cell is its electrical or current output, and the controller 240 is configured to cause the propulsion system 10 to modify the electrical output from the fuel cell to the corresponding propulsion assembly (e.g., the first propulsion assembly 500, the second propulsion assembly 504, and / or the third propulsion assembly 508). For example, in response to receiving data indicating an increase in electrical load on the first turbine 502, one or more processors 332A of the controller 240 execute instructions to cause the propulsion system 10 to modify the electrical output from the first fuel cell 578 to the first propulsion assembly 500. By modifying the electrical output of the first fuel cell 578, the propulsion system 10, for example, increases the electrical output from the first fuel cell 578 to the first propulsion assembly 500 to compensate for the increased electrical load on the first turbine 502, which can increase the torque output of the first turbine 502 driving the first propulsion assembly 500. Therefore, by providing power from the first fuel cell 578 to the first propulsion assembly 500, the effects of increased electrical load can be minimized or avoided, which can prevent the aforementioned problems associated with changes in electrical load (e.g., overspeed, poor power quality, shortened engine life, aircraft handling problems, and thrust asymmetry).

[0134] It should be understood that similar adjustments can be made to the electrical output of the second fuel cell 582 to minimize or eliminate the effects of electrical load changes on the second turbine 506. For example, in response to receiving data indicating a reduction in electrical load on the second turbine 506, one or more processors 332A of the controller 240 execute instructions to cause the propulsion system 10 to modify the electrical output from the second fuel cell 582 to the second propulsion assembly 504. By modifying the electrical output of the second fuel cell 582, the propulsion system 10, for example, increases the electrical output from the second fuel cell 582 to the second propulsion assembly 504 to compensate for the increased electrical load on the second turbine 506, which can reduce the torque output of the second turbine 506 driving the second propulsion assembly 504. The electrical output from the second fuel cell 582 to the second propulsion assembly 504 helps to compensate for the increased electrical load on the second turbine 506, thereby minimizing or preventing problems associated with changes in electrical load on the second turbine 506 (such as those described above).

[0135] It should be understood that, although the above description pertains to an increase in electrical load, controller 240 can also cause propulsion system 10 to modify the output (i.e., output product or electrical output) of the corresponding fuel cell in response to a decrease in electrical load on the corresponding turbine. Furthermore, in response to receiving data indicating a change in electrical load on two or more turbines of propulsion system 10, controller 240 can be configured to cause propulsion system 10 to modify the output of the fuel cell associated with each of the two or more turbines. Additionally or alternatively, in cases where the fuel cell assembly of an associated turbine comprises two or more fuel cells, controller 240 can be configured to execute instructions to cause propulsion system 10 to modify the output of one or more fuel cells associated with the corresponding turbine. For example, propulsion system 10 can modify the output product or electrical output of the fuel cell stack 232 of the first fuel cell assembly 576 and / or the second fuel cell assembly 580.

[0136] As an example, in addition to receiving data indicating a change in the first electrical load on the first turbine 502, the controller 240 may also receive data indicating a change in the second electrical load on the second turbine 506. As a result, the controller 240 can execute instructions to cause the propulsion system 10 to modify the output products of the first fuel cell 578 and the second fuel cell 582. In other embodiments, the controller 240 may execute instructions to cause the propulsion system 10 to modify the power output of the first fuel cell 578 and the second fuel cell 582. In other embodiments, the controller 240 may execute instructions to cause the propulsion system 10 to modify the power output from the first fuel cell 578 to the first propulsion system 500 and the second propulsion system 504, or to modify the power output from the second fuel cell 582 to the first propulsion system 500 and the second propulsion system 504.

[0137] In at least some embodiments, modifying the output products of a fuel cell (e.g., first fuel cell 578 and / or second fuel cell 582) in response to receiving data indicating a difference in propulsion system thrust includes modifying the composition of the output products. For example, instead of adding fuel or increasing the fuel flow to the turbine, which would increase turbine temperature, the composition of the output products from the fuel cell can be altered to increase turbine work. As an example, the gaseous composition of the fuel cell output products can be modified by reducing the power output of the fuel cell assembly. As a result, the fuel utilization rate of the fuel cell assembly will also decrease, leading to a higher percentage composition of, for example, hydrogen (H2) in the output products. Additionally or alternatively, the fuel cell assembly is operated to increase the temperature of the output products (e.g., by heating the gas flow to the cathode, by extracting the gas flow from the compressor section at a higher temperature, etc.), thereby increasing turbine work. Despite the reduced fuel utilization rate, the fuel flow to the anode of the fuel cell can be increased in conjunction with these operations to maintain the desired power output. Thus, the enthalpy of the exhaust gas from the fuel cell is altered, for example, rather than changing the power supplied by the fuel cell, to enhance turbine work.

[0138] Changes in electrical load that trigger modification of the fuel cell's output (output products or electrical output) can be determined in various ways. For example, the electrical load may exceed or fall below a threshold to be sufficient to warrant modification of the output products or electrical output of the fuel cell (e.g., first turbine 502 and / or second turbine 506) or turbine (e.g., first turbine 578 and / or second turbine 582). As another example, the electrical load may increase or decrease by a predetermined amount within a predetermined time interval, indicating a rapid increase or decrease in the electrical load. For example, if the electrical load changes a predetermined voltage within a predetermined number of milliseconds, the controller 240 may determine that it has received data indicating a change in the electrical load on the turbine, and therefore, data indicating a thrust difference in the propulsion system, such that the output products or electrical output of the associated fuel cell should be modified.

[0139] As described herein, the power grid 510 is configured to transmit electrical loads to, or from, each turbine included in the propulsion system 10 (e.g., a first turbine 502, a second turbine 506, or both) via one or more motors. In at least some embodiments, receiving data indicating a difference in propulsion system thrust includes determining that the electrical load has been removed from the power grid 510. For example, the electrical load may be provided by one or more motors coupled to the power grid 510 (e.g., a first motor 584, a second motor 586, a third motor 588, a fourth motor 590, and / or a fifth motor 574). In such embodiments, receiving data indicating a change in the electrical load on a turbine (e.g., a first turbine 502 and / or a second turbine 506) may include determining that at least one motor 584, 586, 588, 590, or 574 has stopped requesting power or has been electrically disconnected from the power grid 510, indicating that the electrical load has been removed from the power grid 510.

[0140] Although the foregoing has described changes in electrical load or power demand on propulsion system 10, it will be understood that thrust differentials in propulsion system 10 may also arise due to changes in one or more mechanical loads on propulsion system 10. For example, changes in the output from the hydraulic pump can increase or decrease the mechanical load on the first propulsion assembly 500 and / or the second propulsion assembly 504, resulting in a thrust imbalance between the first propulsion assembly 502 and the second propulsion assembly 504, and this thrust imbalance or thrust differential can be overcome by modifying the output of one or more fuel cells as described herein. It should be understood that various components, assemblies, and systems can contribute to the mechanical load on one or more of the propulsion assemblies 500, 504, 508 of propulsion system 10. Furthermore, changes in mechanical load, changes in electrical load, or combinations thereof can lead to thrust differentials in propulsion system 10.

[0141] In some embodiments, receiving data indicating thrust differences in the propulsion system includes receiving data on changes in the rotational speed of the shafts of at least one of the first propulsion assembly 500, the second propulsion assembly 504, and the third propulsion assembly 508. As described herein, the propulsion system 10 may include one or more sensors, such as a fuel cell sensor 302 configured to sense data indicating operating parameters of a fuel cell assembly and / or a gas turbine engine sensor 330 configured to sense one or more gas turbine engine operating conditions or parameters. Figure 7 and Figure 8In the embodiment of the propulsion system 10 shown, the propulsion system 10 includes one or more shaft sensors 592, each shaft sensor 592 being configured to sense the rotational speed of an associated shaft. For example, a first shaft sensor 592 may be disposed on the HP shaft / spindle 534 of the first turbine 502 to sense the rotational speed of the HP shaft / spindle 534; a second shaft sensor 592 may be disposed on the LP shaft / spindle 536 of the first turbine 502 to sense the rotational speed of the LP shaft / spindle 536; a third shaft sensor 592 may be disposed on the HP shaft / spindle 560 of the second turbine 506 to sense the rotational speed of the HP shaft / spindle 560; and a fourth shaft sensor 592 may be disposed on the LP shaft / spindle 562 of the second turbine 506 to sense the rotational speed of the LP shaft / spindle 562. The shaft sensors 592 may be, in addition to the fuel cell sensor 302 (… Figure 5 ) and / or gas turbine engine sensor 330 ( Figure 6 In addition to the above, one or more of the fuel cell sensor 302, gas turbine engine sensor 330, and shaft sensor 592 can be omitted from the propulsion system 10.

[0142] Therefore, thrust differentials in the propulsion system can be indicated by changes in the rotational speed of the turbine shaft / spindle. For example, a first shaft sensor 592 disposed on the HP shaft / spindle 534 can sense changes in the rotational speed of the HP shaft / spindle 534 sufficient to indicate a thrust imbalance that may be caused by one or more of the problems identified above that are associated with thrust imbalance (e.g., rapid and / or sharp increases or decreases in electrical load). As an example, the first shaft sensor 592 can sense that the rotational speed of the HP shaft / spindle 534 has increased or decreased below a threshold rotational speed, indicating a change in the mechanical or electrical load on the first turbine 502. As described herein, in some embodiments, when the controller 240 receives such data indicating thrust differentials in the propulsion system, the controller 240 executes instructions to cause the propulsion system 10 to modify, for example, the output products of the first fuel cell 578, thereby modifying the work of the first turbine 502 and the rotational speed of the HP shaft / spindle 534. In other embodiments, when the controller 240 receives such rotational speed data indicating a difference in thrust of the propulsion system, the controller 240 executes an instruction to cause the propulsion system 10 to modify the power output of the first fuel cell 578, and thereby modify, for example, the power supplied to one or more propulsion components (e.g., the first propulsion component 500, the second propulsion component 504, and / or the third propulsion component 508) via the power grid 510.

[0143] In at least some embodiments, in addition to modifying the output products or electrical output of one or more fuel cells, other parameters may be changed or modified to compensate for thrust differences in the propulsion system. For example, in response to receiving data indicating changes in electrical load on one or more turbines, instructions executed by controller 240 cause propulsion system 10 to further perform operations including modifying the electrical output of motors (e.g., first motor 584, second motor 586, third motor 588, fourth motor 590, and / or fifth motor 574). Thus, as described herein, at least one propulsion component (e.g., first propulsion component 500, second propulsion component 504, and / or third propulsion component 508) may be coupled to motors (e.g., first motor 584, second motor 586, third motor 588, fourth motor 590, and / or fifth motor 574), and modifying the electrical output of the motors includes modifying the electrical output from the motors to at least one propulsion component. One or more of the motors 584, 586, 588, and 590 can extract or inject power to slow down or accelerate the respective turbine shafts (e.g., HP shaft 534, LP shaft 536, HP shaft 560, and / or LP shaft 562), thereby affecting the thrust provided by the respective turbines 502 and 506.

[0144] As an example of modifying the electrical output of the motors, in some embodiments, the propulsion system includes a first propulsion assembly 500, a first turbine 502, and a second propulsion assembly 504, wherein a second motor 586 is coupled to the first turbine 502, and a fourth motor 590 is coupled to the second propulsion assembly 504. In this embodiment, the electrical output of either or both of the second motor 586 and the fourth motor 590 can be adjusted or modified together with the output of the fuel cell of the propulsion system 10 so that the thrust of the propulsion system returns to equilibrium after a thrust disturbance that causes thrust asymmetry. For example, a disturbance to the propulsion system 10 may cause the thrust output of the first propulsion assembly 500 to exceed the thrust output of the second propulsion assembly 504; in this case, the thrust output of the first propulsion assembly 500 can be reduced or the thrust output of the second propulsion assembly 504 (or a combination thereof) can be increased to balance the thrust provided by the propulsion system 10. In some embodiments, controller 240 may reduce the power output of the second motor 586 and modify the output products of the first fuel cell 578 to reduce the exhaust enthalpy of the first fuel cell 578, thereby reducing the thrust output of the first propulsion assembly 500. In other embodiments, controller 240 may execute instructions to increase the power output of the first fuel cell 578, thereby reducing the work of the first turbine 502 to decrease the thrust output of the first propulsion assembly 500. Simultaneously, the increased power output of the first fuel cell 578 may be transmitted to a fourth motor 590, which, in "motor mode" (as opposed to "generator mode"), increases the speed / thrust provided by the second propulsion assembly 504. Therefore, in any embodiment (or a combination of these embodiments), by adjusting the fuel cell output along with the power output of one or more motors, the thrust imbalance between the first propulsion assembly 500 and the second propulsion assembly 504 can be overcome to make the thrust asymmetry zero. Therefore, it should be understood that propulsion system 10 may include motors and fuel cells that can work together to balance the thrust of propulsion system 10.

[0145] In addition to the output of the fuel cell, other parameters that can change in response to the thrust difference of the propulsion system 10 include the power output of one or more electrical devices, the fan blade pitch of the propulsion system fan, the variable geometry of the propulsion system, the auxiliary load on the turbine, the accessory load outside the turbine, and the aviation fuel flow to the combustion section of the turbine. For example, controller 240 may be configured such that instructions executed by one or more processors 332A cause propulsion system 10 to perform further operations including adjusting at least one of the following: (i) the power output of one or more electrical devices (e.g., one or more electrical storage devices), which may be separate devices or part of an energy storage system (ESS) 594, which may include one or more batteries (e.g., lithium-ion batteries), supercapacitors, etc., which may be charged at a first time A to store electrical / energy and then release the stored electrical / energy at a second time B; (ii) the fan blade pitch of a fan, such as the pitch of fan blade 514 of fan 512 of the first propulsion assembly 500, the pitch of fan blade 540 of fan 538 of the second propulsion assembly 504, and / or the pitch of fan 514 of fan 538 of the third propulsion assembly 508. The pitch of the fan blades 566 of the 64th fan; (iii) the variable geometry of the propulsion system 10, such as the position of the variable inlet guide vanes (IGV) and / or the variable outlet guide vanes (OGV), variable exhaust geometry, etc.; (iv) one or more auxiliary loads 596 on the turbine, such as one or more accessory systems (e.g., lubrication system, fuel pump, thermal management system, engine anti-icing unit, electronic control unit, etc.); (v) one or more electrical loads 598 outside the engine or turbine, such as those in the aircraft fuselage (connected to the main power distribution bus), which may include environmental control systems, anti-icing units, flight controls, landing gear, galleys, brakes, etc.; and (vi) aviation fuel flows to the combustion section of the turbine, such as a first aviation fuel flow F1 to the first turbine 502 and / or a second aviation fuel flow F2 to the second turbine 506. It will be understood that adjusting the geometry of the variable geometry component includes modifying the opening size of the opening in the component, changing the size and / or shape of the component, etc. Therefore, one or more parameters can be adjusted in conjunction with modifying the output of the fuel cell to bring the thrust provided by the propulsion system 10 back to equilibrium after a disruption of thrust balance. For example, thrust balance can be achieved by modifying the power consumption of some electrical loads or removing some electrical loads to provide additional power to the propulsion assembly, or by modifying the work of the turbine (e.g., by increasing or decreasing the fuel flow) to adjust the thrust output of the propulsion assembly.

[0146] Now for reference Figure 9 This topic also includes various methods for operating propulsion systems for aircraft. Figure 9A method 900 for operating the propulsion system 10 as described above is depicted. Figure 9 As shown, method 900 includes (902) receiving data indicating changes in thrust differentials in the propulsion system, such as actual sensor data or changes in electrical load on turbines (e.g., first turbine 502 and / or second turbine 506) as described herein. Figure 9 Further, method 900 includes (904) modifying the output products of one or more fuel cells in response to receiving data indicating a thrust difference in the propulsion system. As described above, modifying the output products of one or more fuel cells may include modifying the output products of a first fuel cell 578 and / or a second fuel cell 582, which may depend on whether the propulsion system 10 includes one or both of the first fuel cell 578 and the second fuel cell 582. Furthermore, as described herein, receiving data indicating a thrust difference in the propulsion system may include determining whether one or more electrical loads have been removed from the power grid 510, which can electrically connect one or more electrical loads to one or more turbines. Additionally, receiving data indicating a thrust difference in the propulsion system may include, for example, receiving data on changes in the rotational speed of one or more shafts of one or more turbines using one or more shaft sensors 592 as described above.

[0147] In at least some embodiments, modifying the output products of one or more fuel cells in response to receiving data indicating changes in one or more electrical loads on one or more turbines includes modifying the composition of the output products. For example, modifying the composition of the output products may include increasing or decreasing fuel utilization (e.g., increasing or decreasing the power supplied from the fuel cell assembly), increasing or decreasing the fuel flow to the fuel cell, increasing or decreasing the gas flow to the fuel cell, or a combination thereof.

[0148] In addition, such as Figure 9As shown, method 900 may optionally include (906) modifying the power output of one or more fuel cells in response to receiving data indicating a thrust difference in the propulsion system. For example, as described herein, propulsion system 10 may include at least one fuel cell, such as a first fuel cell 578 and / or a second fuel cell 582, which may be electrically connected, for example, directly or via a power grid 510, to a first turbine 502 and / or a second turbine 506. As an example, propulsion system 10 may include a fuel cell assembly, such as a first fuel cell assembly 576; a first propulsion assembly 500 including a first turbine 502 and an electric motor (e.g., a first electric motor 584 and / or a second electric motor 586); and a second propulsion assembly 504 electrically connected to the fuel cell assembly (e.g., the first fuel cell assembly 576). In such an embodiment, receiving data indicating a thrust difference in the propulsion system may include receiving data indicating a thrust imbalance between the first propulsion assembly 500 and the second propulsion assembly 504, such that modifying the power output of the fuel cells includes modifying the power output from the first fuel cell 578 to the second propulsion assembly 504.

[0149] like Figure 9 As further shown, method 900 may optionally include (908) adjusting at least one of the following: the electrical output of one or more electrical devices, the fan blade pitch of the propulsion system's fans, the variable geometry of the propulsion system, one or more auxiliary loads on the turbine, one or more accessory loads external to the turbine, and the aviation fuel flow to the combustion section of one or more turbines of the propulsion system 10. As described herein, the one or more electrical devices may be one or more electric motors and / or power storage devices, such as batteries, which may be part of an energy storage system (ESS). Furthermore, the fan blade pitch may be the pitch of fan blade 514 of fan 512 of the first propulsion assembly 500, the pitch of fan blade 540 of fan 538 of the second propulsion assembly 504, and / or the pitch of fan blade 566 of fan 564 of the third propulsion assembly 508. The variable geometry may include any variable geometry of the propulsion system, such as variable dimensions and / or shapes of components, and / or the relative positions of two or more elements (e.g., variable IGV and / or OGV) of a multi-piece component.

[0150] Still referencing Figure 9Method 900 optionally includes (910) generating electricity using fuel cells (e.g., first fuel cell 578 and / or second fuel cell 582) when the engine (e.g., first gas turbine engine 100A and / or second gas turbine engine 100B) incorporating the fuel cell is not in operation. As described herein, a first fuel cell assembly 576 including a first fuel cell 578 (which may be part of a first fuel cell stack) and a second fuel cell assembly 580 including a second fuel cell 582 (which may be part of a second fuel cell stack) are capable of generating electricity. This electricity can be used to start the engine and / or for other power needs when the engine is not in operation, such that the engine cannot generate electricity. Although shown as the last box in the flowchart of method 900, it will be understood that the use of fuel cells to generate electricity can occur at any point within method 900.

[0151] Now go to Figure 10 It provides a flowchart of another method for operating the propulsion system of an aircraft. Figure 10 A method 1000 for operating the propulsion system 10 as described above is depicted. For example... Figure 10 As shown, method 1000 includes (1002) receiving data indicating thrust differences in the propulsion system, such as actual sensor data or changes in electrical load on turbines (e.g., first turbine 502 and / or second turbine 506) as described herein. Figure 10 As further shown, method 1000 includes (1004) modifying the power output of one or more fuel cells in response to receiving data indicating a thrust difference in the propulsion system. As described above, modifying the power output of one or more fuel cells may include modifying the power output of a first fuel cell 578 and / or a second fuel cell 582, which may depend on whether the propulsion system 10 includes one or both of the first fuel cell 578 and the second fuel cell 582. Furthermore, as described herein, receiving data indicating a thrust difference in the propulsion system may include determining whether one or more electrical loads have been removed from the power grid 510, which can electrically connect one or more electrical loads to one or more turbines of the propulsion system 10. Additionally, receiving data indicating a thrust difference in the propulsion system may include, for example, receiving data on changes in the rotational speed of one or more shafts of one or more turbines using one or more shaft sensors 592 as described above.

[0152] In addition, such as Figure 10As shown, method 1000 may optionally include (1006) modifying the output products of one or more fuel cells in response to receiving data indicating a thrust difference in the propulsion system. For example, as described herein, propulsion system 10 may include at least one of a first fuel cell 578 and a second fuel cell 582, which may be coupled, for example, to a first turbine 502 and / or a second turbine 506 via an outlet from the respective fuel cell, the outlet being positioned to remove the output products from the respective fuel cell to the respective turbine, the respective turbine mechanism causing to receive the output products from the respective fuel cell. Thus, modifying the output products of one or more fuel cells may include changing the composition of the output products removed from the fuel cells and delivered to the turbine, for example, to increase or decrease the work of the turbine as described herein.

[0153] like Figure 10 As further shown, method 1000 may optionally include (1008) adjusting at least one of the following: the power output of one or more electrical devices, the fan blade pitch of the propulsion system's fan, the variable geometry of the propulsion system, one or more auxiliary loads on the turbine, one or more accessory loads external to the turbine, and the aviation fuel flow to the combustion section of one or more turbines of the propulsion system 10. As described herein, the one or more electrical devices may be one or more electric motors and / or power storage devices, such as batteries, which may be part of an energy storage system (ESS). Furthermore, the fan blade pitch may be the pitch of fan blade 514 of fan 512 of the first propulsion assembly 500, the pitch of fan blade 540 of fan 538 of the second propulsion assembly 504, and / or the pitch of fan blade 566 of fan 564 of the third propulsion assembly 508. The variable geometry may include any variable geometry of the propulsion system, such as variable dimensions and / or shapes of components, and / or the relative positions of two or more elements (e.g., variable IGV and / or OGV) of a multi-piece component.

[0154] Still referencing Figure 10Method 1000 may optionally include (1010) generating electricity using fuel cells (e.g., first fuel cell 578 and / or second fuel cell 582) when the engine (e.g., first gas turbine engine 100A and / or second gas turbine engine 100B) incorporating the fuel cell is not in operation. As described herein, a first fuel cell assembly 576 including a first fuel cell 578 (which may be part of a first fuel cell stack) and a second fuel cell assembly 580 including a second fuel cell 582 (which may be part of a second fuel cell stack) are capable of generating electricity. This electricity can be used to start the engine and / or for other power needs when the engine is not in operation, such that the engine cannot generate electricity. Although shown as the last box in the flowchart of method 1000, it will be understood that the use of fuel cells to generate electricity can occur at any point within method 1000.

[0155] It will be understood that method 900 and / or method 1000 may include, for example, as described above. Figure 7 and Figure 8 Other variations described herein. For example, the construction of the propulsion system 10 may differ (e.g., depending on the number of turbines, the number of propulsion components, the number of fuel cells, the number of electric motors and / or the connection of the respective electric motors to the components of the propulsion system 10, etc.), as described herein.

[0156] Further details are provided by the following topics:

[0157] A propulsion system for an aircraft includes: a fuel cell assembly including a fuel cell; a turbine; and a controller including a memory and one or more processors, the memory storing instructions that, when executed by the one or more processors, cause the propulsion system to operate, the operation including: receiving data indicating a thrust difference in the propulsion system, and modifying the output of the fuel cell in response to receiving the data indicating the thrust difference in the propulsion system.

[0158] The propulsion system according to any of the foregoing clauses, wherein the propulsion system further includes an electric motor capable of rotating with the turbine, wherein the turbine, the electric motor, or both are configured to contribute to the generation of thrust during operation of the propulsion system.

[0159] According to any of the preceding clauses, the propulsion system wherein the fuel cell defines an outlet positioned to remove output products from the fuel cell, wherein the turbine is configured to receive the output products from the fuel cell, and wherein the output of the fuel cell is the output product of the fuel cell.

[0160] According to any of the foregoing clauses, modifying the output products of the fuel cell in response to receiving data indicating thrust differences of the propulsion system includes modifying the composition of the output products.

[0161] The propulsion system according to any of the foregoing clauses further includes: a first propulsion assembly including the turbine and the motor; and a second propulsion assembly, wherein, when the propulsion assemblies are mounted on the aircraft, the first propulsion assembly and the second propulsion assembly are configured to be located on opposite sides of the aircraft, wherein receiving data indicating thrust difference of the propulsion system includes receiving data indicating thrust imbalance between the first propulsion assembly and the second propulsion assembly, and wherein modifying the output products of the fuel cell includes modifying the output products of the fuel cell to the turbine.

[0162] According to any of the preceding clauses, receiving data indicating thrust differences in the propulsion system includes receiving data indicating a higher proportion of thrust relative to the balancing operation from the second propulsion component, and modifying the output products of the fuel cell includes modifying the output products of the fuel cell to increase thrust generation of the first propulsion component.

[0163] According to any of the preceding clauses, the output of the fuel cell is the electrical output of the fuel cell.

[0164] The propulsion system according to any of the foregoing clauses further includes: a first propulsion assembly including the turbine and an electric motor rotatable with the turbine, wherein the turbine, the electric motor, or both are configured to contribute to propulsion system thrust generation during operation of the propulsion system; and a second propulsion assembly electrically connected to the fuel cell assembly, wherein receiving data indicating a thrust difference in the propulsion system includes receiving data indicating a thrust imbalance between the first propulsion assembly and the second propulsion assembly, wherein modifying the output of the fuel cell in response to receiving the data indicating a thrust difference in the propulsion system includes modifying the electrical output to the second propulsion assembly.

[0165] The propulsion system according to any of the foregoing clauses further includes: a power grid electrically connected to the fuel cell assembly and the motor, wherein receiving data indicating thrust differences in the propulsion system includes receiving data indicating changes in electrical load on the turbine.

[0166] According to any of the preceding clauses, the propulsion system wherein receiving data indicating changes in the electrical load on the turbine includes receiving sensor data indicating changes in the rotational speed of the shaft of at least one propulsion component.

[0167] According to any of the preceding clauses, receiving data indicating thrust differences in the propulsion system includes receiving data indicating a higher proportion of thrust relative to the balancing operation from the second propulsion component, and modifying the output of the fuel cell includes reducing the electrical output to the second propulsion component.

[0168] According to any of the foregoing clauses, modifying the output of the fuel cell in response to receiving data indicating a thrust difference in the propulsion system further includes modifying the output product of the fuel cell to increase the thrust generation of the first propulsion component.

[0169] The propulsion system according to any of the foregoing clauses further includes: a first propulsion assembly including the turbine, an electric motor rotatable with the turbine, and a variable-pitch fan; and a second propulsion assembly electrically connected to the fuel cell assembly, wherein the operation further includes adjusting the power output of the electric motor, the power output of the power storage device, the fan blade pitch of the variable-pitch fan, the variable geometry of the first propulsion assembly, auxiliary loads on the turbine, accessory loads external to the turbine, and aviation fuel flow to the combustion zone of the turbine, or combinations thereof.

[0170] The propulsion system according to any of the foregoing clauses, wherein the fuel cell is a fuel cell stack comprising a plurality of fuel cells.

[0171] The propulsion system according to any of the foregoing clauses further includes: a first propulsion assembly including the turbine, wherein the fuel cell assembly is integrated with the first propulsion assembly; a second propulsion assembly including a second turbine and a second motor rotatable with the second turbine, wherein the second turbine, the second motor, or both are configured to contribute to the generation of thrust during operation of the propulsion system; and a second fuel cell assembly including a fuel cell integrated with the second propulsion system, wherein modifying the output of the fuel cell in response to receiving data indicating a thrust difference in the propulsion system further includes modifying the output of the fuel cell of the second fuel cell assembly in response to receiving data indicating a thrust difference in the propulsion system.

[0172] A method of operating a propulsion system for an aircraft, the propulsion system including a fuel cell assembly comprising a fuel cell and a turbine, the method comprising: receiving data indicating a thrust difference in the propulsion system; and modifying the output of the fuel cell in response to receiving the data indicating the thrust difference in the propulsion system.

[0173] According to any of the foregoing clauses, the propulsion system further includes an electric motor capable of rotating with the turbine, wherein the turbine, the electric motor, or both are configured to contribute to the generation of propulsion thrust during operation of the propulsion system.

[0174] According to any of the foregoing clauses, the fuel cell defines an outlet positioned to remove output products from the fuel cell, wherein the turbine is configured to receive the output products from the fuel cell, wherein the output of the fuel cell is the output product of the fuel cell, and wherein modifying the output product of the fuel cell in response to receiving data indicating a thrust difference in the propulsion system includes modifying the composition of the output product.

[0175] According to any of the foregoing descriptions, modifying the output of the fuel cell in response to receiving data indicating thrust differences in the propulsion system includes modifying the power output of the fuel cell.

[0176] According to any of the foregoing provisions, the propulsion system further includes: a first propulsion assembly including the turbine; and a second propulsion assembly electrically connected to the fuel cell assembly, wherein receiving data indicating a thrust difference in the propulsion system includes receiving data indicating a thrust imbalance between the first propulsion assembly and the second propulsion assembly, and wherein modifying the output of the fuel cell in response to receiving the data indicating a thrust difference in the propulsion system includes modifying the power output to the second propulsion assembly.

[0177] According to any of the foregoing clauses, the fuel cell defines an outlet positioned to remove output products from the fuel cell, wherein the turbine is configured to receive the output products from the fuel cell, wherein the output of the fuel cell is the output product of the fuel cell, and wherein modifying the output of the fuel cell in response to receiving data indicating a thrust difference in the propulsion system further includes modifying the output product of the fuel cell to increase the thrust generation of the first propulsion assembly.

[0178] According to any of the foregoing clauses, the propulsion system further comprises: a first propulsion assembly including the turbine, an electric motor rotatable with the turbine, and a variable-pitch fan; and a second propulsion assembly electrically connected to the fuel cell assembly, wherein the method further comprises: adjusting the power output of the electric motor, the power output of the power storage device, the fan blade pitch of the variable-pitch fan, the variable geometry of the first propulsion assembly, auxiliary loads on the turbine, accessory loads external to the turbine, and aviation fuel flow to the combustion zone of the turbine, or combinations thereof.

[0179] The method according to any of the foregoing clauses further includes generating electricity using the fuel cell when the engine coupled with the fuel cell is not in operation.

[0180] A propulsion system for an aircraft, the propulsion system comprising: a fuel cell assembly including a fuel cell; a turbine; an electric motor rotatable with the turbine, wherein the turbine, the electric motor, or both are configured to contribute to propulsion system thrust generation during operation of the propulsion system; and a controller including a memory and one or more processors, the memory storing instructions that, when executed by the one or more processors, cause the propulsion system to operate, the operation including: receiving data indicating a thrust difference in the propulsion system, and modifying the output of the fuel cell in response to receiving the data indicating the thrust difference in the propulsion system.

[0181] This written description uses examples to disclose this disclosure, including best practices, and also enables any person skilled in the art to practice this disclosure, including making and using any device or system and methods of making any combination. The patent scope of this disclosure is defined by the claims, but may include other examples that would occur to a person skilled in the art. Such other examples are intended to fall within the scope of the claims if they include structural elements that are not indistinguishable from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

Claims

1. A propulsion system for an aircraft, characterized in that, The propulsion system includes: Fuel cell assembly, the fuel cell assembly including a fuel cell; Turbine; A controller, comprising a memory and one or more processors, the memory storing instructions that, when executed by the one or more processors, cause the propulsion system to operate, the operation including: Receive data indicating thrust difference in the propulsion system, and The output of the fuel cell is modified in response to receiving data indicating a thrust difference in the propulsion system; A first propulsion assembly, comprising the turbine and an electric motor rotatable with the turbine, wherein the turbine, the electric motor, or both are configured to contribute to thrust generation during operation of the propulsion system; and The second propulsion component is electrically connected to the fuel cell assembly. Receiving data indicating thrust difference in the propulsion system includes receiving data indicating thrust imbalance between the first propulsion component and the second propulsion component, wherein modifying the output of the fuel cell in response to receiving data indicating thrust difference in the propulsion system includes modifying the power output to the second propulsion component.

2. The propulsion system according to claim 1, characterized in that, in, The fuel cell defines an outlet positioned to remove output products from the fuel cell, wherein the turbine is configured to receive the output products from the fuel cell, and wherein the output of the fuel cell is the output product of the fuel cell.

3. The propulsion system according to claim 2, characterized in that, in, Modifying the output products of the fuel cell in response to receiving data indicating thrust differences in the propulsion system includes modifying the composition of the output products.

4. The propulsion system according to claim 2, characterized in that, Further includes: A first propulsion assembly includes the turbine and an electric motor capable of rotating with the turbine, wherein the turbine, the electric motor, or both are configured to contribute to the generation of thrust during operation of the propulsion system. as well as Second propulsion component, Wherein, when the propulsion assembly is mounted on the aircraft, the first propulsion assembly and the second propulsion assembly are configured to be located on opposite sides of the aircraft, wherein receiving data indicating thrust difference of the propulsion system includes receiving data indicating thrust imbalance between the first propulsion assembly and the second propulsion assembly, and wherein modifying the output product of the fuel cell includes modifying the output product of the fuel cell to the turbine.

5. The propulsion system according to claim 4, characterized in that, in, Receiving data indicating thrust differences in the propulsion system includes receiving data indicating a higher proportion of thrust relative to the balancing operation from the second propulsion component, and wherein modifying the output products of the fuel cell includes modifying the output products of the fuel cell to increase thrust generation of the first propulsion component.

6. The propulsion system according to claim 1, characterized in that, in, The output of the fuel cell is the electrical output of the fuel cell.

7. The propulsion system according to claim 1, characterized in that, Further includes: The power grid is electrically connected to the fuel cell assembly and the motor, wherein receiving data indicating thrust differences in the propulsion system includes receiving data indicating changes in electrical load on the turbine.

8. The propulsion system according to claim 7, characterized in that, in, Receiving data indicating changes in the electrical load on the turbine includes receiving sensor data indicating changes in the rotational speed of the shaft of at least one propulsion component.

9. The propulsion system according to claim 1, characterized in that, in, Receiving data indicating thrust differences in the propulsion system includes receiving data indicating a higher proportion of thrust relative to balancing operations from the second propulsion component, and wherein modifying the output of the fuel cell includes reducing the electrical output to the second propulsion component.

10. The propulsion system according to claim 1, characterized in that, in, Modifying the output of the fuel cell in response to receiving data indicating a thrust difference in the propulsion system further includes modifying the output product of the fuel cell to increase the thrust generation of the first propulsion assembly.

11. The propulsion system according to claim 1, characterized in that, Further includes: The first propulsion assembly includes a variable pitch fan; and The operation further includes adjusting the power output of the motor, the power output of the power storage device, the blade pitch of the variable pitch fan, the variable geometry of the first propulsion assembly, the auxiliary load on the turbine, the accessory load outside the turbine, the aviation fuel flow to the combustion section of the turbine, or a combination thereof.

12. The propulsion system according to claim 1, characterized in that, in, The fuel cell is a fuel cell stack comprising multiple fuel cells.

13. The propulsion system according to claim 1, characterized in that, Further includes: The fuel cell assembly is integrated with the first propulsion assembly; and The second propulsion assembly includes a second turbine and a second motor capable of rotating together with the second turbine, wherein the second turbine, the second motor, or both are configured to contribute to the generation of thrust in the propulsion system during operation of the propulsion system; as well as The second fuel cell assembly includes a fuel cell integrated with the second propulsion assembly. Modifying the output of the fuel cell in response to receiving data indicating a thrust difference in the propulsion system further includes modifying the output of the fuel cell in response to receiving data indicating a thrust difference in the propulsion system.

14. A method of operating a propulsion system for an aircraft, the propulsion system comprising a fuel cell assembly, the fuel cell assembly comprising a fuel cell and a turbine, characterized in that, The method includes: Receive data indicating thrust difference in the propulsion system; and The output of the fuel cell is modified in response to receiving data indicating a thrust difference in the propulsion system; The propulsion system further includes: A first propulsion assembly, the first propulsion assembly including the turbine; and The second propulsion component is electrically connected to the fuel cell assembly. Receiving data indicating thrust difference in the propulsion system includes receiving data indicating thrust imbalance between the first propulsion component and the second propulsion component, wherein modifying the output of the fuel cell in response to receiving data indicating thrust difference in the propulsion system includes modifying the power output to the second propulsion component.

15. The method according to claim 14, characterized in that, in, The fuel cell defines an outlet positioned to remove output products from the fuel cell, wherein the turbine is configured to receive the output products from the fuel cell, wherein the output of the fuel cell is the output product of the fuel cell, and wherein modifying the output product of the fuel cell in response to receiving data indicating a thrust difference in the propulsion system includes modifying the composition of the output product.

16. The method according to claim 14, characterized in that, Modifying the output of the fuel cell in response to receiving data indicating a thrust difference in the propulsion system includes modifying the power output of the fuel cell.

17. The method according to claim 14, characterized in that, in, The fuel cell defines an outlet positioned to remove output products from the fuel cell, wherein the turbine is configured to receive the output products from the fuel cell, wherein the output of the fuel cell is the output product of the fuel cell, and wherein modifying the output of the fuel cell in response to receiving data indicating a thrust difference in the propulsion system further includes modifying the output product of the fuel cell to increase thrust generation of the first propulsion assembly.

18. The method according to claim 14, characterized in that, in, The propulsion system further includes: The first propulsion assembly includes a variable pitch fan; and The method further includes: Adjusting the power output of the motor, the power output of the power storage device, the blade pitch of the variable pitch fan, the variable geometry of the first propulsion assembly, the auxiliary load on the turbine, the accessory load outside the turbine, the aviation fuel flow to the combustion section of the turbine, or a combination thereof.

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