Power supply for an aircraft

Abstract

An aircraft electrical system comprising: a first DC power bus and a fuel cell assembly, the fuel cell assembly comprising a first fuel cell stack, wherein the first fuel cell stack is directly electrically coupled to the first DC power bus without a voltage converter to provide a first power output to the first DC power bus.

Description

Technical Field

[0001] An aircraft electrical system includes a first DC power bus and a fuel cell assembly. The fuel cell assembly includes a first fuel cell stack. The first fuel cell stack is directly electrically connected to the first DC power bus without a voltage converter to provide a first power output to the first DC power bus. Background Technology

[0002] Electricity on jet aircraft is provided, regulated, and distributed by the aircraft's electrical system. Electricity on jet aircraft is typically provided by generators on gas turbine engines and batteries, and in some cases by auxiliary power units (APUs), or by ram air turbines (RATs) during power outages when all other power sources fail. A mixture of aerodynamic, hydraulic, and electrical power is provided by generators, hydraulic pumps, and compressors within the gas turbine engine or APU system.

[0003] In conventional aircraft, the output of electric, hydraulic, and aerodynamic power all depends on the efficiency and capability of the jet turbine engine and APU system. Utilizing other forms of electrical, hydraulic, and aerodynamic energy can improve the overall system efficiency within the aircraft.

[0004] Proton exchange membrane fuel cells (PEMFCs) and solid oxide fuel cells (SOFCs) provide direct current (DC) power from chemical processes. SOFC-GT is a hybrid of SOFC and gas turbine engine, in which unreacted byproducts from the SOFC (such as oxygen and hydrogen) can be used to regulate the air used by the SOFC and increase the efficiency of the entire system electrically connected to it.

[0005] Much of aircraft systems have been electrified, leading to an increased proportion of electrically driven loads replacing traditional pneumatic or hydraulic loads. Traditionally, engine-driven motors have been the primary power source in aircraft. Modern aircraft, with their increased electrical loads in both the engine nacelle and fuselage, require more distributed power sources to provide greater efficiency, reliability, and operational flexibility. Attached Figure Description

[0006] 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:

[0007] Figure 1 This is a cross-sectional view of a gas turbine engine according to an exemplary aspect of this disclosure.

[0008] Figure 2 This is a perspective view of the integrated fuel cell and burner assembly according to this disclosure.

[0009] Figure 3yes Figure 2 A schematic axial view of an exemplary integrated fuel cell and burner assembly.

[0010] 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.

[0011] 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.

[0012] Figure 6 This is a schematic diagram of a vehicle and propulsion system according to an exemplary aspect of this disclosure.

[0013] Figure 7 This is a schematic diagram of an aircraft electrical system according to an exemplary aspect of this disclosure.

[0014] Figure 8 This is a schematic diagram of an aircraft electrical system according to another exemplary aspect of this disclosure.

[0015] Figure 9 This is a schematic diagram of an aircraft electrical system according to another exemplary aspect of this disclosure.

[0016] Figure 10 This is a schematic diagram of an aircraft electrical system according to another exemplary aspect of this disclosure. Detailed Implementation

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] Unless the context clearly indicates otherwise, the singular forms “a,” “a,” and “the” include plural references.

[0025] 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.

[0026] As used throughout the specification and claims, approximate language is applied to modify any quantitative expression that allows 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.

[0027] 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.

[0028] 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).

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] An aircraft electrical system is provided. The aircraft electrical system includes a first DC power bus and a fuel cell assembly. The fuel cell assembly includes a first fuel cell stack. The first fuel cell stack is directly electrically connected to the first DC power bus without a voltage converter to provide a first power output to the first DC power bus.

[0035] A power source is provided for a propulsion system of an aircraft with an engine (such as a gas turbine engine) having one or more accessory systems. The power source includes a power bus defining a designed electrical load and a fuel cell assembly configured to be integrated into the engine. The power bus, when integrated into the engine, is electrically coupled to one or more accessory systems for providing power to those systems. The fuel cell assembly includes a fuel cell stack electrically coupled to the power bus and configured to provide a power output. The power output is within the operability limits of the designed electrical load.

[0036] A power source is provided for a propulsion system of an aircraft having an engine, such as a gas turbine engine. The power source includes a first power bus; a second power bus; and a fuel cell assembly configured to be integrated into the engine. The fuel cell assembly includes a first fuel cell stack; and a second fuel cell stack. During at least a first operating condition of the power source, the fuel cell assembly is configured to provide a first power bus output from the first fuel cell stack, the second fuel cell stack, or both to the first power bus, and is further configured to provide a second power bus output to the second power bus, the second power bus output being different from the first power bus output. In this way, the first and second fuel cell stacks can supply power to different power sinks requiring different electrical forces and / or types of power. For example, such a fuel cell assembly can allow power to be supplied to a gas turbine engine using the power output designed for an accessory system of a gas turbine engine, and allows power to be supplied to the aircraft using the power output designed for an accessory system of an aircraft. This could result in a more efficient system, requiring less hardware for power conversion, etc.

[0037] In another exemplary aspect of this disclosure, an aircraft power assembly is provided. The power assembly includes a gas turbine engine and a power source, the gas turbine engine including one or more accessory systems. The power source includes a power bus integrated into the gas turbine engine and defining a designed electrical load, and a fuel cell assembly integrated into the gas turbine engine. The power bus is electrically coupled to the one or more accessory systems for providing power to the one or more accessory systems. The fuel cell assembly includes a fuel cell stack electrically coupled to the power bus and configured to provide a power output, wherein the power output is within the operability range of the designed electrical load.

[0038] For example, the power supply for aircraft disclosed herein can provide additional power to generate electricity for aircraft and offers increased flexibility in selecting the power supply for aircraft operation. The power supply disclosed herein can enhance previously used power supplies. Furthermore, the power supply itself can be configured to provide power output redundancy. As described in more detail below, depending on the needs of aircraft and gas turbine engine operation, the power supply of the present invention can include multiple discrete fuel cell stacks, and each fuel cell stack provides a power output that can be selectively coupled to more than one power bus. Therefore, based on need or based on the failure of one of the fuel cell stacks, many aircraft systems can rely on more than one fuel cell stack. Essentially, fuel cell stacks can be configured as backups for each other and for other aircraft power supplies.

[0039] Furthermore, the power supply of this disclosure can be configured to match the power output to the required load. Therefore, the power supply of this disclosure can provide a DC power output with the required voltage to the load, potentially eliminating the need for a power converter. This results in increased efficiency in terms of wiring and weight.

[0040] Furthermore, the power bus defines the design power load for one or more accessory systems connected to it. The design power load is the combined load required by one or more accessory systems under the operating conditions of the gas turbine engine. The design power load can depend on the current requirements of the gas turbine engine at different times during operation. For example, the design power load during engine startup will differ from the design power load during flight or engine shutdown. The design power load can also depend on the specific accessory system in use and its usage characteristics at a particular time. In summary, the design power load defined by the bus can have an operable range.

[0041] The operability range of the designed electrical load can be the range of electrical loads expected during the operation of the gas turbine engine. For example, the operability range of the designed electrical load can span from the expected minimum design load to the expected maximum design load. Furthermore, the operability range of the designed electrical load can span from a low value below the minimum expected design electrical load to twice the expected maximum design load to allow for additional loads during abnormal engine operation.

[0042] As will be discussed in more detail below, a fuel cell is an electrochemical device that converts the chemical energy from a fuel (such as hydrogen) into electrical energy through an electrochemical reaction between the fuel and an oxidant (such as oxygen contained in the atmosphere). Fuel cell systems can be advantageously used as energy supply systems because they can be considered environmentally superior 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 generate about 1V of voltage, multiple fuel cells can be stacked together (which may be called a fuel cell stack) to generate a desired voltage. Fuel cells can 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.

[0043] Referring now to the accompanying drawings, where the same numbers indicate the same elements throughout all the drawings. Figure 1A 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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 1 In 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).

[0049] 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.

[0050] However, it will be understood that, Figure 1The 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 1 The 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.

[0051] 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.

[0052] 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.

[0053] 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 5The 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 outer housing 220 and the outer liner 210 define an outer passage 226 therebetween. The inner housing 222, the outer housing 220, and the dome assembly 212 together at least partially define the combustion chamber 228 of the combustor 206.

[0054] 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.

[0055] 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.

[0056] 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).

[0057] 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.

[0058] As mentioned above and Figure 2 The 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.

[0059] 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.

[0060] 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).

[0061] 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).

[0062] 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.

[0063] 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.

[0064] 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.

[0065] The following will explain this in more detail; please refer to [reference]. 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.

[0066] 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.

[0067] 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.

[0068] 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).

[0069] 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.

[0070] 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.

[0071] It will be understood that the fuel cell assembly 204 of this disclosure is divided into multiple fuel cell stacks, each capable of producing discrete power outputs. As used herein, the term "stack" when referring to a fuel cell stack of a fuel cell assembly means multiple fuel cells engaged in a manner that allows multiple fuel cells to output power separately from any other fuel cells 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.

[0072] Furthermore, it will be understood that, despite Figures 2 to 4An exemplary fuel cell assembly 204 generally comprises fuel cells arranged and integrated with the outer liner 210 and inner liner 208 of a burner 206, such as fuel cells of a first fuel cell stack 232 and a second fuel cell stack 234. 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 forward of the burner 206, radially spaced outward of the burner 206, etc.). Furthermore, in other embodiments, the fuel cell assembly 204 may use chemicals other than solid oxide chemicals.

[0073] 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.

[0074] 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.

[0075] 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).

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] Simply put, it will be understood that the fuel cell assembly 204 further includes a fuel cell sensor 302 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 cathode side 296 or anode side 298 of the fuel cell) and the pressure within the fuel cell stack 294 (e.g., within the cathode side 296 or anode side 298 of the fuel cell).

[0081] 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.

[0082] 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.

[0083] 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.

[0084] The anode side of a solid oxide fuel cell (such as fuel cell stack 294) can be made 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.

[0085] 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.

[0086] 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 (CPO). x An air handling unit 306 is used to generate a hydrogen-rich fuel stream for the fuel cell stack 294. The air handling unit 306 can be any suitable structure for raising the temperature of the air supplied to it to a temperature sufficiently high to achieve fuel cell temperature control (e.g., about 600°C to about 800°C). For example, in the depicted embodiment, the air handling 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, for example, during transient conditions such as start-up, shutdown, and abnormal situations, through combustion.

[0087] 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.

[0088] 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).

[0089] 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).

[0090] The fuel cell stack 294 outputs electricity generated by 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.

[0091] In operation, the air treatment unit 306 is configured to heat / cool a portion of the compressed air entering through the cathode airflow duct 314 to generate treated air to be directed into the fuel cell stack 294, thereby facilitating the operation of the fuel cell stack 294. The air treatment 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 treated by the air treatment 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 treated by the air treatment unit 306 can be combined into a combined airflow to be fed into the cathode 552 of the fuel cell stack 294.

[0092] 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.

[0093] 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, ranging from cracking to failure.

[0094] 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.

[0095] 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. Airflow 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.

[0096] 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. Electrical devices adapted to draw current from a power source (such as one or more electrical devices 328) can generally be referred to as electrical loads. 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.

[0097] Still referencing Figure 5The 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.

[0098] 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.

[0099] 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 discharge from the compressor section, and valves of the fuel delivery system 146 that guide the fuel flow within the gas turbine engine 100).

[0100] 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.

[0101] 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 perform operations. In some embodiments, instructions 332C may be executed by one or more processors 332A to cause one or more processors 332A to perform operations 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, 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.

[0102] 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.

[0103] 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.

[0104] 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 204, the fuel cell assembly 204 may not require the fuel processing unit 304.

[0105] 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.

[0106] Specifically, for the described exemplary embodiment, an aircraft 400 is provided, 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.).

[0107] 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.

[0108] 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.

[0109] 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. The 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. The energy storage unit 416 may be, for example, a battery pack for storing electrical energy.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] In one embodiment, each integrated fuel cell and burner assembly 200 (labeled 200A and 200B; see also) Figures 2 to 5 The fuel cell assembly 204 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, while 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. In addition, 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).

[0115] Now for reference Figure 7 A power source 111 is provided, which includes a first power bus 326A and a fuel cell assembly (not shown) associated with a gas turbine engine (not shown). The first power bus 326A is electrically coupled to one or more accessory systems 329 for providing power to the one or more accessory systems 329. The one or more accessory systems 329 may be integrated into the engine or may be located in any other part of the aircraft. The one or more accessory systems 329 may be adapted to draw current from the power source and are therefore referred to as electrical loads. In this embodiment, the one or more accessory systems are independently selected from the group consisting of an engine control unit, a de-icing system, a starter, a compressor, a pump, an electric motor, and combinations thereof.

[0116] Fuel cell components can be combined with Figures 2 to 5 The exemplary fuel cell assembly 204 is constructed in a similar manner, and the gas turbine engine can be used in conjunction with... Figure 1 The exemplary gas turbine engine 100 is constructed in a similar manner.

[0117] The fuel cell assembly includes a fuel cell stack 243A. The fuel cell stack 243A is electrically connected to a first power bus 326A and is configured to provide a first power output 322A. During operation of the power source 111, the first power bus 326A defines a design power load with an operability range based on the operating states of one or more accessory systems 329. The fuel cell assembly is configured to provide the first power output 322A within the operability range of the design power load.

[0118] In some embodiments of this disclosure, the first power bus 326A may be an AC power bus or a DC power bus, as needed. Furthermore, the fuel cell stack 243A may be directly electrically connected to the first power bus 326A (i.e., without a power converter), or may be electrically connected to the first power bus 326A using a DC / AC power converter or a DC / DC power converter (not shown). The converter 325 may be a full-power converter or a partial-power converter (as described in U.S. Patent No. 9,809,119, which is incorporated herein by reference).

[0119] However, in the depicted exemplary embodiment, the first power bus 326A is directly electrically connected to the DC power bus of the fuel cell stack 243A without a power converter, and the first power output 322A has a voltage whose magnitude is set to match the load required by the first power bus 326A without using a DC / DC power converter. In this way, it will be understood that, for the depicted exemplary embodiment, the fuel cell assembly 204 is configured to provide power (via the first power bus 326A) to one or more accessory systems 329 without allowing such power to flow through any intermediary power electronics configured to modify such power.

[0120] exist Figure 7 In some embodiments, the power supply 111 may further include a second power bus 326B electrically connected to the first power bus 326A, wherein the first power bus 326A provides a second power output 322B to the second power bus 326B. In some embodiments of this disclosure, the first power bus 326A may be an AC power bus or a DC power bus, and the second power bus 326B may be an AC power bus or a DC power bus, as needed. Furthermore, the second power bus 326B may be directly electrically connected to the first power bus 326A (i.e., without a power converter), or may be electrically connected to the first power bus 326A using a DC / AC power converter or a DC / DC power converter, as needed.

[0121] More specifically, in the depicted exemplary embodiment, the second power bus 326B is a DC power bus and the first power bus 326A is a DC power bus, and both buses are electrically connected to a DC / DC power converter 325. The second power bus 326B can also be electrically connected to one or more accessory systems (such as one or more gas turbine engine accessory systems). With this configuration, the first power bus 326A can be configured to supply power to one or more accessory systems 329 (e.g., accessory systems with electric pumps or compressors) that are allowed to receive larger power fluctuations, while the second power bus 326B can be configured to supply power to one or more accessory systems (e.g., controllers or other computing systems) that require more consistent power. This allows at least a portion of the first power output 322A to be supplied more efficiently to certain accessory systems.

[0122] use Figure 7In some embodiments, power supply 111 may further include an alternative power supply 327 electrically connected to the first power bus 326A and providing a third power output 322C to the first power bus 326A. The alternative power supply 327 may be a permanent magnet generator, an auxiliary power unit, an energy storage system, an additional fuel cell, a power output from another power bus, or a combination thereof. In some embodiments of this disclosure, the first power bus 326A may be an AC power bus or a DC power bus, as needed. Furthermore, the alternative power supply 327 may provide an AC power output or a DC power output, and may be directly electrically connected to the first power bus 326A (i.e., without a power converter), or may be electrically connected to the first power bus 326A using a DC / AC power converter or a DC / DC power converter (not shown). However, in the depicted exemplary embodiments, the alternative power supply 327 provides a DC power output 322C, and the first power bus 326A is directly electrically connected to the DC power bus of the alternative power supply 327 without a power converter.

[0123] Now for reference Figure 8 and Figure 9 It provides a power supply 111 according to another exemplary embodiment of the present disclosure. Figure 8 and Figure 9 The power supply 111 can be connected with Figure 7 Constructed in a similar manner to an exemplary power supply. For example, Figure 8 and Figure 9 The power supply 111 includes a first power bus 326A and a first fuel cell stack 243A, the first fuel cell stack 243A being electrically connected to the first power bus 326A and providing a first power output 322A. The first power bus 326A is electrically connected to one or more first accessory systems 329A (e.g., electrical loads) for providing power to the one or more first accessory systems 329A. Figure 8 and Figure 9 In one embodiment, the power source 111 further includes a second power bus 326B and a second fuel cell stack 243B, the second fuel cell stack 243B being electrically connected to the second power bus 326B and providing a second power output 322B. The second power bus 326B is electrically connected to one or more second accessory systems 329B (e.g., electrical loads) for providing power to the one or more second accessory systems 329B. Figure 8 and Figure 9 In one embodiment, the first power bus 326A and the second power bus 326B are electrically connected to each other (discussed in more detail below). In this embodiment, one or more accessory systems 329A, 329B are independently selected from the group consisting of an engine control unit, a de-icing system, a starter, a compressor, a pump, an electric motor, and combinations thereof.

[0124] In some embodiments of this disclosure, the first power bus 326A may be an AC power bus or a DC power bus, as needed. Furthermore, the first fuel cell stack 243A may be directly electrically connected to the first power bus 326A (i.e., without a power converter), or may be electrically connected to the first power bus 326A using a DC / AC power converter or a DC / DC power converter 325, as needed.

[0125] Similarly, in some embodiments of this disclosure, the second power bus 326B may be an AC power bus or a DC power bus, as needed. Therefore, the second fuel cell stack 243B may be directly electrically connected to the second power bus 326B (i.e., without a power converter), or may be electrically connected to the second power bus 326B using a DC / AC power converter or a DC / DC power converter (not shown).

[0126] However, in the depicted exemplary embodiment, the first power bus 326A is directly electrically connected to the DC power bus of the first fuel cell stack 243A without a power converter, and the second power bus 326B is also directly electrically connected to the DC power bus of the second fuel cell stack 243B without a power converter. With this configuration, the first power output 322A has a voltage whose magnitude is set to match the load required by the first power bus 326A without a power converter, and the second power output 322B has a voltage whose magnitude is set to match the load required by the second power bus 326B without a power converter. This configuration is similar to that discussed above. Figure 7 Examples of implementations.

[0127] like Figure 8 As shown, the first power bus 326A and the second power bus 326B are more specifically selectively electrically connected. Therefore, during at least a first operating condition of the power supply 111 (when, for example, switch 333 is open), the power supply 111 is configured to provide a first power output 322A from the first fuel cell stack 243A to the first power bus 326A and a second power output 322B from the second fuel cell stack 243B to the second power bus 326B. Under this operating condition, the first power bus 326A supplies power only to the first accessory system 329A, and the second power bus 326B supplies power only to the second accessory system 329B; or in other words, the first power bus 326A and the second power bus 326B are electrically isolated from each other, such that they are not electrically connected.

[0128] It will be understood that during at least a second operating condition of power supply 111 (when, for example, switch 333 is closed), power supply 111 is configured to provide a first power output 322A from the first fuel cell stack 243A to the first power bus 326A, and a second power output 322B from the second fuel cell stack 243B to the second power bus 326B. Under this operating condition, the first power bus 326A can supply power to the second power bus 326B as needed, and the second power bus 326B can supply power to the first power bus 326A. This operating condition allows power transfer from one bus to another, depending on the design power load requirements of each power bus. Furthermore, for example, this operating condition allows one of the two fuel cell stacks 243A, 243B to supply power to both power buses 326A, 326B only if one of the fuel cell stacks is offline or otherwise unable to produce power output or desired power output.

[0129] like Figure 9 As shown, the first power bus 326A and the second power bus 326B can be electrically connected via a power converter 325. As discussed above, in some embodiments of this disclosure, the first power bus 326A may be an AC power bus or a DC power bus as needed, and the second power bus 326B may be an AC power bus or a DC power bus as needed, and the power converter 325 may be an AC / DC converter or a DC / DC converter as needed.

[0130] exist Figure 9In some embodiments, the first power output 322A is different from the second power output 322B. For example, depending on the requirements of the power supply 111, the first power output 322A may be at a different voltage than the second power output 322B, may be at a different current than the second power output 322B, or both. For example, in at least some exemplary embodiments, the first power output 322A and the second power output 322B may be at voltages with a difference of at least about 10% (e.g., calculated by the absolute value of (voltage of the first power output 322A - voltage of the second power output 322B) / voltage of the first power output 322A), such as at least about 20%, such as at least about 30%, such as at least about 40%, such as at least about 50%, such as at least about 100%, such as up to about 1000%. Additionally or alternatively, in at least some exemplary embodiments, the first power output 322A and the second power output 322B may be in a current with a difference of at least about 10% (e.g., calculated by the absolute value of: (current of the first power output 322A - current of the second power output 322B) / current of the first power output 322A), such as at least about 20%, such as at least about 30%, such as at least about 40%, such as at least about 50%, such as at least about 100%, such as up to about 1000%.

[0131] In other exemplary embodiments, the first power bus 326A is a DC power bus, and the second power bus 326B is a DC power bus, and the power converter 325 is a DC / DC power converter.

[0132] In at least some exemplary embodiments, the first fuel cell stack 243A and the second fuel cell stack 243B may be the same fuel cell stack (see [link]). Figure 2 The first fuel cell stack 243A and the second fuel cell stack 243B may each be part of a different fuel cell stack, and may be in different fuel cell assemblies (see [reference]). Figure 2-3 On the fuel cell assembly 204), it can even be a related different engine (see Figure 6 and Figure 10 Engines 100A and 100B; discussed in detail below. Figure 10 ).

[0133] In at least some exemplary embodiments, the first fuel cell stack 243A and the second fuel cell stack 243B can be configured to provide different power outputs. For example, the first fuel cell stack 243A and the second fuel cell stack 243B may include different total numbers of fuel cells connected in series (see [link to documentation]). Figure 4); can have different heights, widths, or both, so that the electrolyte layer of the fuel cell defines different total surface areas (see Figure 5 Layer 300; can be configured to receive different amounts of fuel, air or both; etc.

[0134] In this way, it will be understood that the first fuel cell stack 243A and the second fuel cell stack 243B can provide their respective power outputs 322A, 322B to dedicated power dissipators. For example, in the depicted embodiment, the first power bus 326A distributes power to the aircraft outside the engine compartment (see...). Figure 1 The engine compartment 134), and more specifically, one or more aircraft accessory systems 329 (e.g., electronic devices 414, see engine compartment 134) are distributed to the exterior of the gas turbine engine 100. Figure 6 (The aircraft's power bus.)

[0135] Now for reference Figure 10 The power source 111 is depicted as having four propulsion engines (100A-D). Specifically, engines 100A and 100C are gas turbine engines (e.g., similar to...). Figure 1 The exemplary gas turbine engine 100 is constructed as follows, and the engines 100B and 100D are electric propulsion engines (e.g., electric propulsion fans).

[0136] This embodiment can be considered as Figures 7 to 9 A more detailed description of an exemplary version of the embodiments. Figure 10 In one embodiment, the power source 111 includes a first power bus 326A and a second power bus 326B. A first fuel cell stack 243A is part of a fuel cell assembly (not shown) of engine 100A. A second fuel cell stack 243B is part of a fuel cell assembly (not shown) of engine 100B. The first fuel cell stack 243A is electrically connected to the first power bus 326A and provides a first power output 322A to the first power bus 326A. Similarly, the second fuel cell stack 243B is electrically connected to the second power bus 326B and provides a second power output 322B to the second power bus 326B. In an exemplary embodiment, the first and second fuel cell assemblies (not shown) are solid oxide fuel cell assemblies, and the gas turbine engines 100A, 100B include a combustion section, wherein the fuel cell includes an outlet positioned to provide output products from the fuel cell to the combustion section (see, for example...). Figures 2 to 5 ).

[0137] A first power bus 326A is electrically connected to one or more first accessory systems 329A for providing power to the one or more first accessory systems 329A. A second power bus 326B is electrically connected to one or more second accessory systems 329B for providing power to the one or more second accessory systems 329B.

[0138] exist Figure 10 In this embodiment, the power supply may further include a third power bus 326C and a fourth power bus 326D. The third power bus 326C may be electrically connected to a first power bus 326A, which provides a third power output 322C to the third power bus 326B. The fourth power bus 326D may be electrically connected to a second power bus 326B, which provides a fourth power output 322D to the fourth power bus 326D. The third power bus 326C is electrically connected to one or more third accessory systems 329C for providing power to the one or more third accessory systems 329C. The fourth power bus 326D is electrically connected to one or more fourth accessory systems 329D for providing power to one or more first accessory systems 329D. In this embodiment, the one or more accessory systems 329C, 329D are independently selected from the group consisting of an engine control unit, a de-icing system, a starter, a compressor, a pump, an electric motor, and combinations thereof.

[0139] In this embodiment, the power supply 111 further includes a first energy storage system 416A and a second energy storage system 416B. A first power bus 326A is also electrically connected to the first energy storage system 416A (such as a battery), and can provide power to or be recharged through the first power bus 326A as needed. A second power bus 326B is also electrically connected to the second energy storage system 416B (such as a battery), and can provide power to or be recharged through the second power bus 326B as needed.

[0140] Furthermore, in some exemplary embodiments, power supply 111 also includes one or more alternative power supplies 327, and more specifically, for the depicted embodiments, includes one or more motors electrically connected to a first power bus 326A or a second power bus 326B, as shown. For example, the depicted power supply 111 includes a first high-voltage motor (depicted as an alternative power supply 327 for engine 100A) connected to a high-voltage component of engine 100A, and a second low-voltage motor (depicted as another alternative power supply 327 for engine 100A) connected to a low-voltage component of engine 100A. In the described embodiments, both the high-voltage and low-voltage motors are electrically connected to the first power bus 326A (via a corresponding power converter 325, such as an AC / DC power converter). In the depicted embodiments, a similar motor is provided for engine 100C (also depicted as an alternative power supply 327).

[0141] In this embodiment, each of the four power buses 326A-D can be (individually) an AC power bus or a DC power bus. Furthermore, each power source (i.e., fuel cell stacks 243A, 243B, alternative power source 327, auxiliary power unit (“APU”), energy storage system 416) can be a DC power source or an AC power source (excluding fuel cell stacks 243A, 243B). Therefore, the electrical connection between a power source and a power bus, or between one power bus and another, can be direct (i.e., without a power converter). Alternatively, the electrical connection between a power source and a power bus, or between one power bus and another, can be achieved via a power converter 325 (i.e., an AC / DC power converter or a DC / DC power converter, as appropriate).

[0142] More specifically, in the depicted embodiment, the first power bus 326A and the second power bus 326B are each configured to receive unregulated power from the first fuel cell stack 243A and the second fuel cell stack 243B, respectively (e.g., directly, without using any power electronics to modify the received power). In this way, the first power bus 326A and the second power bus 326B are unregulated power buses. This allows the first power bus 326A and the second power bus 326B to directly provide and distribute this power to at least some accessory systems in a more efficient manner. Furthermore, for the depicted embodiment, it will be understood that engines 100B and 100D are electrically connected to the first power bus 326A and the second power bus 326B, respectively. In this way, they are configured to receive power from unregulated power buses, which again allows for more efficient power transmission.

[0143] In contrast, in the depicted embodiment, the third power bus 326C and the fourth power bus 326D receive power via corresponding converters 325, such that the power transmitted through the third power bus 326C and the fourth power bus 326D is at a desired power level (e.g., voltage and current). In this way, the third power bus 326C and the fourth power bus 326D can be referred to as regulated power buses (e.g., voltage-regulated DC power buses). Using this configuration, the first power bus 326A and the second power bus 326B can be configured to supply power to accessory systems capable of accepting power over a wider power range (e.g., a wider voltage and / or current range), while the third power bus 326C and the fourth power bus 326D can be configured to supply power to accessory systems capable of accepting power over a narrower power range (e.g., a narrower voltage and / or current range). The width of the power range that a particular accessory system can accept refers to the range of power that the accessory system can accept and still operate in the desired manner, can operate without significantly accelerating system degradation, or both.

[0144] In an embodiment, power supply 111 may include one or more controllers (not shown) electrically connected to power buses 326A-D, fuel cell stacks 243A, 243B, alternative power supply 327, energy storage unit 416, or a combination thereof, to control the distribution of power from power buses 326A-D, fuel cell stacks 243A, 243B, alternative power supply 327, and energy storage units 416A, 416B. The one or more controllers may be connected to... Figure 2 or Figure 5 The controller 240 is constructed in a similar manner. In this way, it will be further understood that one or more controllers can be configured to control the operating conditions of one or more fuel cells to modify the power output 322A-D in particular.

[0145] As will be further understood, the power system includes multiple switches 333A, 333B to allow selective electrical connection of the power buses. Specifically, one embodiment includes a first switch 333A that selectively connects a first power bus 326A to a second power bus 326B, and a second switch 333B that selectively connects a third power bus 326C to a fourth power bus 326D. In embodiments, additional switches (not shown) may be present to allow selective electrical connection between other power buses or between power buses 326A-D and one or more fuel cell stacks 243A, 243B, alternative power source 327, and energy storage system 416. A controller (not shown) may be operatively connected to one or more of these switches 333 to selectively electrically connect these components in response to, for example, various sensed data, control decisions, etc.

[0146] Further aspects are provided by the subject matter of the following clauses:

[0147] An aircraft electrical system includes: a first DC power bus; and a fuel cell assembly, the fuel cell assembly including a first fuel cell stack, wherein the first fuel cell stack is directly electrically connected to the first DC power bus without a voltage converter to provide a first power output to the first DC power bus.

[0148] The aircraft electrical system according to one or more of these provisions further includes a first electrical load, wherein the first DC power bus is electrically connected to the first electrical load and provides power to the first electrical load.

[0149] The aircraft electrical system according to one or more of these clauses, wherein the first electrical load is selected from the group consisting of an engine control unit, a de-icing system, a starter, a compressor, a pump, an electric motor, and combinations thereof.

[0150] The aircraft electrical system according to one or more of these provisions further includes an alternative power source that provides a second power output to the first DC power bus.

[0151] The aircraft electrical system described in one or more of these provisions, wherein the alternative power source is a permanent magnet generator, an auxiliary power unit, an energy storage system, an additional fuel cell, a power output from another power bus, or a combination thereof.

[0152] The aircraft electrical system according to one or more of these provisions further includes a voltage converter, wherein the voltage converter is electrically connected to the first DC power bus and configured to electrically connect the first DC power bus to a second electrical load such that the first DC power bus can provide power to the second electrical load, or is configured to electrically connect the first DC power bus to an alternative power source such that the alternative power source can provide power to the first DC power bus.

[0153] According to one or more of these provisions, the aircraft electrical system wherein the first DC power bus is electrically connected to the second electrical load or the alternative power source via a voltage-regulated DC power bus.

[0154] According to one or more of these provisions, the aircraft electrical system further includes a second fuel cell stack and a second DC power bus, wherein the second fuel cell stack is directly electrically connected to the second DC power bus without a voltage converter to provide a second power output to the second DC power bus.

[0155] The aircraft electrical system according to one or more of these provisions, wherein the first DC power bus is electrically connected to the second DC power bus via a voltage converter.

[0156] The aircraft electrical system described in one or more of these clauses, wherein the voltage converter is a DC / DC power converter.

[0157] According to one or more of these provisions, the aircraft electrical system wherein the first DC power bus is selectively and directly electrically connected to the second DC power bus without a voltage converter.

[0158] The aircraft electrical system according to one or more of these provisions further includes a controller electrically connected to the fuel cell assembly and the DC power bus to regulate the power distribution from the first fuel cell stack and the second fuel cell stack, as well as the first DC power bus and the second DC power bus.

[0159] The aircraft electrical system according to one or more of these terms, wherein the fuel cell assembly is located in the engine, or in the fuselage of the aircraft, or in any other location within the aircraft.

[0160] According to one or more of these provisions, the first fuel cell stack includes one or more fuel cells selected from the group consisting of solid oxide fuel cells, polymer electrolyte membrane fuel cells, direct methanol fuel cells, alkaline fuel cells, phosphoric acid fuel cells, molten carbonate fuel cells, reversible fuel cells, and combinations thereof.

[0161] A power source for an aircraft having an engine having one or more accessory systems, the power source comprising: a power bus defining a design electrical load, the power bus being configured to be electrically connected to the one or more accessory systems when integrated into the engine for providing power to the one or more accessory systems; and a fuel cell assembly configured to be integrated into the engine, the fuel cell assembly including a fuel cell stack electrically connected to the power bus and configured to provide a power output, wherein the power output is within the operability range of the design electrical load.

[0162] The power source is described in accordance with one or more of these terms, wherein the power bus is a DC power bus, and the fuel cell stack is directly electrically connected to the power bus without a power converter, and the power output has a voltage whose magnitude is set to match the load required by the power bus without the use of a DC / DC power converter.

[0163] The power source described in one or more of these terms, wherein the fuel cell assembly is a solid oxide fuel cell assembly.

[0164] The power source according to one or more of these provisions, wherein the engine is a gas turbine engine including a combustion section, wherein the fuel cell stack includes a fuel cell, wherein the fuel cell defines an outlet positioned to provide output products from the fuel cell to the combustion section.

[0165] The power supply described in one or more of these provisions further includes an alternative power supply electrically connected to the power bus and configured to provide a second power output.

[0166] The power source described in one or more of these clauses is a permanent magnet generator, an auxiliary power unit, an energy storage system, an additional fuel cell, a power output from another power bus, or a combination thereof.

[0167] The power source according to one or more of these terms, wherein the power bus is a first power bus, wherein the fuel cell stack is a first fuel cell stack, wherein the alternative power source is a power output from a second power bus electrically connected to the second fuel cell stack, and the second fuel cell stack is configured to provide power to the second power bus.

[0168] According to one or more of these terms, the power supply, wherein the first power bus and the second power bus are selectively in direct electrical connection without a power converter, and are selectively connected.

[0169] The power supply according to one or more of these terms, wherein the first power bus and the second power bus are selectively electrically connected to the power converter.

[0170] The power supply according to one or more of these terms, wherein the second power output is an AC power output, and the alternative power supply is electrically connected to the first power bus using an AC / DC power converter.

[0171] The power source described in one or more of these clauses, wherein the one or more accessory systems are independently selected from the group consisting of an engine control unit, a de-icing system, a starter, a compressor, a pump, an electric motor, and combinations thereof.

[0172] The power source according to one or more of these terms, wherein the power bus is a first power bus, wherein the fuel cell stack is a first fuel cell stack, and wherein the power source further includes a second power bus, wherein the second power bus is a regulated power bus electrically connected to the first power bus using a DC / DC power converter.

[0173] The power supply described in one or more of these provisions is configured to distribute less than about 40% of the total power supplied to the first power bus to the regulated power bus.

[0174] An aircraft power assembly includes: a gas turbine engine including one or more accessory systems; and a power source including: a power bus integrated into the gas turbine engine and defining a design electrical load, the power bus being electrically connected to the one or more accessory systems for providing power to the one or more accessory systems; and a fuel cell assembly integrated into the gas turbine engine, the fuel cell assembly including a fuel cell stack, the fuel cell stack being electrically connected to the power bus and configured to provide a power output, wherein the power output is within the operability range of the design electrical load.

[0175] The power source is described according to one or more of these terms, wherein the power bus is a DC power bus, and wherein the fuel cell stack is directly electrically connected to the power bus without a power converter, and the power output has a voltage whose magnitude is set to match the load required by the power bus without the use of a DC / DC power converter.

[0176] The power source described in one or more of these provisions, wherein the fuel cell assembly includes a fuel cell selected from the group consisting of solid oxide fuel cells, polymer electrolyte membrane fuel cells, direct methanol fuel cells, alkaline fuel cells, phosphoric acid fuel cells, molten carbonate fuel cells, reversible fuel cells, and combinations thereof.

[0177] The power supply described in one or more of these provisions further includes an alternative power supply electrically connected to the power bus and configured to provide a second power output.

[0178] The power source according to one or more of these terms, wherein the power bus is a first power bus, wherein the fuel cell stack is a first fuel cell stack, wherein the alternative power source is a power output from a second power bus electrically connected to the second fuel cell stack, and the second fuel cell stack is configured to provide power to the second power bus.

[0179] According to one or more of these terms, the power supply, wherein the first power bus and the second power bus are selectively in direct electrical connection without a power converter, and are selectively connected.

[0180] The power supply according to one or more of these terms, wherein the first power bus and the second power bus are selectively electrically connected to the power converter.

Claims

1. An aircraft electrical system, characterized in that, include: A first DC power bus defines a design power load, wherein the first DC power bus is configured to provide power to one or more accessory systems of the gas turbine engine; and A fuel cell assembly configured to be integrated into the gas turbine engine, the fuel cell assembly including a first fuel cell stack, wherein the first fuel cell stack is directly electrically connected to a first DC power bus without a voltage converter to provide a first power output to the first DC power bus, wherein the first power output is within the operability range of the designed power load.

2. The aircraft electrical system according to claim 1, characterized in that, It further includes a first electrical load, wherein the first DC power bus is electrically connected to the first electrical load and provides power to the first electrical load.

3. The aircraft electrical system according to claim 2, characterized in that, The first electrical load is selected from the group consisting of an engine control unit, a de-icing system, a starter, a compressor, a pump, an electric motor, and combinations thereof.

4. The aircraft electrical system according to claim 1, characterized in that, It further includes an alternative power source that provides a second power output to the first DC power bus.

5. The aircraft electrical system according to claim 4, characterized in that, The alternative power source is a permanent magnet generator, an auxiliary power unit, an energy storage system, an additional fuel cell, power output from another power bus, or a combination thereof.

6. The aircraft electrical system according to claim 1, characterized in that, The device further includes a voltage converter, wherein the voltage converter is electrically connected to the first DC power bus and configured to electrically connect the first DC power bus to a second electrical load such that the first DC power bus can supply power to the second electrical load, or is configured to electrically connect the first DC power bus to an alternative power source such that the alternative power source can supply power to the first DC power bus.

7. The aircraft electrical system according to claim 6, characterized in that, The first DC power bus is electrically connected to the second electrical load or the alternative power source via a voltage-regulated DC power bus.

8. The aircraft electrical system according to claim 1, characterized in that, The fuel cell assembly further includes a second fuel cell stack and a second DC power bus, wherein the second fuel cell stack is directly electrically connected to the second DC power bus without a voltage converter to provide a second power output to the second DC power bus.

9. The aircraft electrical system according to claim 8, characterized in that, The first DC power bus is electrically connected to the second DC power bus via a voltage converter.

10. The aircraft electrical system according to claim 9, characterized in that, The voltage converter mentioned above is a DC / DC power converter.

11. The aircraft electrical system according to claim 8, characterized in that, The first DC power bus is selectively and directly electrically connected to the second DC power bus without a voltage converter.

12. The aircraft electrical system according to claim 8, characterized in that, It further includes a controller electrically connected to the fuel cell assembly, the first DC power bus, and the second DC power bus to regulate the power distribution from the first fuel cell stack and the second fuel cell stack, as well as the first DC power bus and the second DC power bus.

13. The aircraft electrical system according to claim 1, characterized in that, The first fuel cell stack includes one or more fuel cells, which are selected from the group consisting of solid oxide fuel cells, polymer electrolyte membrane fuel cells, direct methanol fuel cells, alkaline fuel cells, phosphoric acid fuel cells, molten carbonate fuel cells, reversible fuel cells, and combinations thereof.

14. An aircraft power supply assembly, characterized in that, include: A gas turbine engine, the gas turbine engine including one or more accessory systems; and The aircraft electrical system includes: A power bus, integrated into the gas turbine engine and defining the design power load, is electrically connected to the one or more accessory systems for providing power to the one or more accessory systems; and A fuel cell assembly integrated into the gas turbine engine, the fuel cell assembly comprising a fuel cell stack electrically connected to the power bus and configured to provide a power output, wherein the power output is within the operability range of the designed power load.

15. The aircraft power supply assembly according to claim 14, characterized in that, The power bus is a DC power bus, and the fuel cell stack is directly electrically connected to the DC power bus without a power converter, and the power output has a voltage whose magnitude is set to match the load required by the DC power bus without using a DC / DC power converter.

16. The aircraft power supply assembly according to claim 14, characterized in that, The fuel cell assembly includes a fuel cell, which is selected from the group consisting of solid oxide fuel cells, polymer electrolyte membrane fuel cells, direct methanol fuel cells, alkaline fuel cells, phosphoric acid fuel cells, molten carbonate fuel cells, reversible fuel cells, and combinations thereof.

17. The aircraft power supply assembly according to claim 14, characterized in that, It further includes an alternative power source electrically connected to the power bus and configured to provide a second power output.

18. The aircraft power supply assembly according to claim 17, characterized in that, The power bus is a first power bus, the fuel cell stack is a first fuel cell stack, and the alternative power source is a power output from a second power bus electrically connected to the second fuel cell stack, the second fuel cell stack being configured to provide power to the second power bus.

19. The aircraft power supply assembly according to claim 18, characterized in that, The first power bus and the second power bus are selectively in direct electrical connection and selectively connected in the absence of a power converter.

20. The aircraft power supply assembly according to claim 18, characterized in that, The first power bus and the second power bus are selectively electrically connected to the power converter.

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