Stall prevention system with fuel cell

Abstract

A stall prevention system for an aircraft can be provided, where the aircraft includes a propulsion system including a fuel cell assembly and a combustion engine including a compressor section having a compressor. The stall prevention system can include at least one sensor configured to sense data indicative of at least one operating parameter indicative of a compressor stall condition of the compressor; and a controller including a processor and a memory storing instructions that, when executed by the processor, cause the controller to determine that the at least one operating parameter has reached a compressor stall condition threshold, and in response to determining that the at least one operating parameter has reached the compressor stall condition threshold, perform a stall prevention action. The stall prevention action can be configured to adjust at least one fuel cell parameter.

Description

Technical Field

[0001] This disclosure relates to anti-stall systems for propulsion systems including fuel cells and methods of operation thereof. Background Technology

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

[0003] During operation, air is compressed in the compressor and mixed with fuel in the combustion section and ignited to generate combustion gases, which flow downwards through the turbine section. The turbine section extracts energy from the combustion gases to rotate the compressor section and fan assembly, thereby powering the gas turbine engine and propelling the aircraft containing this gas turbine engine during flight.

[0004] Rotating airfoils in the compressor section may stall during operation. Stall can occur when the angle of attack of these airfoils exceeds the critical angle of attack, disrupting the flow to subsequent downstream airfoils in the compressor section. Compressor stall events can lead to engine inefficiency and damage. Effective and efficient prevention of compressor stall should be provided. Attached Figure Description

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

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

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

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

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

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

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

[0012] Figure 7 This is a schematic diagram of an anti-stall system for a gas turbine engine according to an exemplary aspect of this disclosure.

[0013] Figure 8 This is a schematic diagram of an anti-stall system for a gas turbine engine according to another exemplary aspect of this disclosure.

[0014] Figure 9 This is a schematic diagram of an anti-stall system for a gas turbine engine according to yet another exemplary aspect of this disclosure.

[0015] Figure 10 This is a schematic diagram illustrating the operability of exemplary aspects of this disclosure.

[0016] Figure 11 This is a flowchart of an operation method for an anti-stall system of a gas turbine engine according to an 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 specification 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 "combustion engine" refers to a turbomachinery component used to generate torque output through the force applied by the combustion reaction. Combustion engines can be described independently of other propulsion or power generation components, such as electric or fuel cell components.

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

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

[0035] A system and method for operating a propulsion system of an aircraft are provided. The propulsion system includes a fuel cell assembly comprising a fuel cell, the fuel cell defining an outlet positioned to remove output products from the fuel cell. The propulsion system further includes a combustion engine, such as a turbine, the turbine including a combustion section configured to receive an aviation fuel flow from an aircraft fuel supply unit of the aircraft, and further configured to receive output products from the fuel cell. The system and method are generally configured to determine whether at least one operating parameter has reached, for example, a compressor stall condition threshold indicating potential or near-stall of the compressor. If it is determined that the compressor stall condition threshold has been reached, the system and method are configured to perform anti-stall actions. The anti-stall actions are configured to adjust at least one fuel cell parameter.

[0036] The systems and methods according to this disclosure generally enable efficient and effective management of potential compressor stall conditions by adjusting at least one fuel cell parameter to take advantage of the operational effects of the fuel cell assembly integrated into the burner assembly. Using the fuel cell assembly to at least partially facilitate anti-stall systems and methods allows advantageous use of the exhaust flow from the compressor section, thereby limiting energy losses during compressor emissions.

[0037] 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.

[0038] Referring now to the accompanying drawings, where the same numbers indicate the same elements throughout all the drawings. Figure 1 A schematic cross-sectional view of an engine according to an exemplary embodiment of the present disclosure is provided. The engine can be integrated into a vehicle. For example, the engine can be an aircraft engine integrated into an aircraft. However, alternatively, the engine can be any other suitable type of engine for any other suitable vehicle.

[0039] 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). Generally, the turbofan engine 100 includes a fan section 102 and a turbine 104 disposed downstream of the fan section 102.

[0040] 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.

[0041] For 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. Further, 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.

[0042] 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.

[0043] 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. Additionally, 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).

[0044] 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. The 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.

[0045] 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. Further, although Figure 1 The exemplary gas turbine engine depicted herein is schematically shown as a direct-drive fixed-pitch turbofan engine; however, 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. Further, 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. Further, 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.

[0046] Now for reference Figure 2 The illustration schematically shows a portion of a combustion section 114 according to an embodiment of the present disclosure, which includes... Figure 1 Gas turbine engine 100 (above about Figure 1 It is described as part of the integrated fuel cell and burner assembly 200 used in the turbofan engine 100.

[0047] 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.

[0048] 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 housing 220 and the outer liner 210 define an outer passage 226 therebetween. The inner housing 222, the housing 220, and the dome assembly 212 together at least partially define the combustion chamber 228 of the combustor 206. A purge gas inlet 225 may be provided for the inner passage 224, as will be described in more detail below.

[0049] 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 One or more fuel delivery pipelines 150 are described.

[0050] 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.

[0051] 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).

[0052] 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. In some exemplary embodiments, the integrated fuel cell and combustor assembly 200 may additionally include a dedicated fuel cell igniter 233 (depicted in dashed lines). Specifically, for Figure 2 In one embodiment, a dedicated fuel cell igniter 233 is positioned downstream of at least a portion of the fuel cell, and particularly downstream of at least a portion of the fuel cell stack (described below). In this way, the dedicated fuel cell igniter 233 can more efficiently combust the fuel cell's output products.

[0053] 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 with an outer liner 210, and the second fuel cell stack 234 is constructed 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. Also described in more detail below, a purge gas inlet 225 may be provided, which is in fluid communication with one or more of the first fuel cell stack 232 and the second fuel cell stack 234, for example, providing an airflow directly to at least one of the first fuel cell stack 232 and the second fuel cell stack 234.

[0054] 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 particularly 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.

[0055] 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).

[0056] 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).

[0057] 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.

[0058] 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.

[0059] 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.

[0060] The following will explain this in more detail; please refer to [reference needed]. Figure 5 In 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 a centerline axis 101 into combustion chamber 228. Integrated fuel cell and burner 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.

[0061] 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.

[0062] 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.

[0063] 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).

[0064] 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.

[0065] In some exemplary embodiments, Figures 2 to 4 The first fuel cell stack 232 can be constructed in a manner similar to one or more 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.

[0066] 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 5A 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.

[0067] 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.

[0068] 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 fuels 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 150C. The distributor 274 divides the fuel flow from the fuel source 148 and the fuel pump 272 into a first fuel flow through the first fuel delivery line 150A to the fuel cell assembly 204, a second fuel flow through the second fuel delivery line 150B also to the fuel cell assembly 204 (and particularly to the air handling unit described below), and a third fuel flow through the third fuel delivery line 150C to the combustor 206. Diverter 274 may include a series of valves (not shown) to facilitate such 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 a first fuel delivery line 150A (e.g., for controlling a first fuel flow), a second fuel valve 151B associated with a second fuel delivery line 150B (e.g., for controlling a second fuel flow), and a third fuel valve 151C associated with a third fuel delivery line 150C (e.g., for controlling a third fuel flow).

[0069] The gas turbine engine 100 further includes a compressor exhaust system and an air 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.

[0070] 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.

[0071] The compressor discharge system (and air supply duct 288) is in airflow communication with the air delivery system for supplying compressed airflow to the fuel cell assembly 204, as will be explained in more detail below.

[0072] 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.

[0073] In simple terms, 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), the pressure within the fuel cell stack 294 (e.g., within the cathode side 296 or anode side 298 of the fuel cell), and / or the composition (e.g., chemical composition) of the output products from the fuel cell assembly 204.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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). xAn 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 by combustion, for example, during transient conditions such as start-up, shutdown, and abnormal situations.

[0080] 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.

[0081] 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. Further additionally or alternatively, the fuel processing unit 304 may include a reformer integrated with the fuel cell stack 294. It should be understood that the fuel processing unit 304 can therefore use a fuel reformer as described herein to provide reformed fuel. Similarly, it should be understood that... Figure 5 The 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).

[0082] As described above, 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. The airflow delivery system includes an anode airflow duct 310 and associated anode airflow valve 312 for supplying airflow to the fuel processing unit 304, a cathode airflow duct 314 and associated cathode airflow valve 316 for supplying airflow to the air processing unit 306, and a cathode bypass air duct 318 and associated cathode bypass air valve 320 for supplying 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 supply 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 supplied).

[0083] The fuel cell stack 294 outputs electricity as generated by the fuel cell power output 322. Furthermore, 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.

[0084] 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.

[0085] In addition, such as Figure 5 As 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 then 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.

[0086] Since the inlet air to the fuel cell stack 294 may originate solely from the upstream compressor section without any other separately controlled air source, it will be understood that the inlet air to the fuel cell stack 294 discharged from the compressor section will be affected by air temperature variations occurring at different stages of flight. As an illustrative example only, the air in a specific location within the compressor section of the gas turbine engine 100 may operate at 200°C during idling, 600°C during takeoff, 268°C during cruise, and so on. This type of temperature variation in the inlet air directed to the fuel cell stack 294 can cause significant thermal transient problems (or even thermal shock) to the ceramic material of the fuel cell stack 294, potentially ranging from cracking to failure.

[0087] 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, ±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.

[0088] 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.

[0089] As briefly mentioned above, the fuel cell stack 294 converts the anode fuel stream from the fuel processing unit 304 and the air processed by the air processing unit 306 into electrical energy in the form of DC current, i.e., fuel cell power output 322. This fuel cell power output 322 is directed to a power converter 324 to convert the DC current into DC or AC current that can be efficiently utilized by one or more subsystems. Specifically, in the depicted embodiment, power is supplied from the power converter to an electrical bus 326. The electrical bus 326 may be an electrical bus dedicated to the gas turbine engine 100, an electrical bus of an aircraft in conjunction with the gas turbine engine 100, or a combination thereof. The electrical bus 326 is electrically connected to one or more auxiliary electrical devices 328, which may be adapted to draw current from the fuel cell stack 294 or apply an electrical load to the fuel cell stack 294. The one or more auxiliary electrical devices 328 may be a power source, a power sink, or both. For example, the auxiliary electrical device 328 may be an energy storage device (such as one or more batteries), an electric motor (generator, electric motor, or both), an electric propulsion device, etc. For example, one or more auxiliary electrical devices 328 may include a starter motor / generator of the gas turbine engine 100.

[0090] Still referencing Figure 5 The gas turbine engine 100 further includes a sensor 330. In the illustrated embodiment, the sensor 330 is configured to sense data indicating the flame within the combustion section 114 of the gas turbine engine 100. The sensor 330 may be, for example, 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.

[0091] 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.

[0092] 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).

[0093] 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.

[0094] One or more memory devices 332B may store information accessible by one or more processors 332A, including computer-readable instructions 332C executable by one or more processors 332A. Instructions 332C may be any set of instructions that, when executed by one or more processors 332A, cause one or more processors 332A to operate. In some embodiments, instructions 332C may be executed by one or more processors 332A to cause one or more processors 332A to operate, such as any operations and functions configured for the controller 240 and / or computing device 332, operations for operating the propulsion system as described herein (e.g., method 600), 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] Specifically, for the described exemplary embodiment, the aircraft 400 is provided as including a fuselage 402, a tail 404, a first wing 406, a second wing 408, and a propulsion system. The propulsion system generally includes a first gas turbine engine 100A coupled to or integrated with the first wing 406 and a second gas turbine engine 100B coupled to or integrated with the second wing 408. However, it will be understood that in other embodiments, any other suitable number and / or configuration of gas turbine engines 100 may be provided (e.g., mounted on the fuselage, mounted on the tail, etc.).

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] Turn now Figure 7 The diagram illustrates an anti-stall system 500. The depicted anti-stall system 500 includes a fuel cell assembly 504, a combustion engine 506, and a controller 540. The fuel cell assembly 504 and the combustion engine 506 can be configured... Figure 1 Different parts of the gas turbine engine 100. For example, the fuel cell assembly 504 can be operatively connected to the combustion engine 506 via the fuel cell combustion engine interface 517. (See above reference...) Figure 2-4 In more detail, the fuel cell assembly 504 and the combustion engine 506 can form an integrated component of the gas turbine engine 100, but can still be separately defined and controlled based on independent operating capabilities.

[0108] It should be understood that Figure 7 The fuel cell assembly 504 schematically depicted herein may include any features described elsewhere with respect to other embodiments. References may be provided, for example... Figure 5 The various sensors described in fuel cell sensor 302. Figure 7 The embodiments depict a fuel cell assembly sensor 505, which may be disposed within the fuel cell assembly 504. For example, the fuel cell assembly sensor 505 may be disposed near but outside the first fuel cell stack (not shown), and / or near but outside the fuel cell assembly 504. The fuel cell assembly sensor 505 may be disposed, for example, outside the fuel cell assembly 504, for monitoring conditions of or around the fuel cell assembly 504. It should be understood that the depicted fuel cell sensor 505 may include multiple sensors disposed at various locations within or near the fuel cell assembly 504.

[0109] Figure 7A fuel cell load 544 is depicted, which is operatively connected to the fuel cell assembly 504 and can be connected via a fuel cell load control 545. The fuel cell load 544 can be any number of electrical or mechanical loads that draw energy from the fuel cell assembly 504. As described in more detail below, the fuel cell load control 545 can operate in conjunction with a controller 540, for example, to disconnect, connect, increase, or decrease the load on the fuel cell assembly 504.

[0110] A fuel cell controller 554 may also be provided. For example, the fuel cell controller 554 may be operable to control the fuel cell load control 545. The fuel cell controller 554 may also be provided to increase, decrease, turn on, or turn off the output of the fuel cell 504. The output of the fuel cell 504 can be determined by referring to the above. Figure 5 A more detailed description of the various mechanisms for control.

[0111] Turn now Figure 7 The depicted combustion engine 506 includes a fan 526, an LP compressor 510, an HP compressor 512, a combustion section 514, an HP turbine 516, and an LP turbine 518. Each of these components can be configured as shown in the reference above. Figure 5 A more detailed description is available. Various sensors can also be provided, such as reference sensors. Figure 5 As described in the gas turbine engine sensor 330. Figure 7 As shown, the combustion engine 506 includes a turbine sensor 511. The turbine sensor 511 can be configured to measure the turbine (see...). Figure 1 Various operating parameters of the turbine. For example, turbine sensor 511 can be configured to detect the rotational speed, temperature, gas concentration, or flow rate of one or more turbine mechanical components, or the rotational speed, temperature, gas concentration, or flow rate at one or more turbine mechanical components. In an embodiment, turbine sensor 511 is configured to measure the rotational speed of at least one engine shaft 513, for example, by referring to... Figure 5 The rotational speed of one or both of the HP shaft 122 or LP shaft 124 is described in more detail.

[0112] As described above, the anti-stall system 500 can be configured to detect and mitigate stall conditions affecting the LP compressor 510, HP compressor 512, or both. Anti-stall action may include controlling the air bypass from one or more sections of the LP compressor 510 and / or HP compressor 512. For example, in cases where the pressure ratio is incompatible with a given rotational speed of the combustion engine 506, controlled discharge may be operable to adjust the pressure ratio as needed. In various embodiments, the pressure ratio at a given location in the LP compressor 510 and / or HP compressor 512 can be increased by discharging a flow from a downstream location and decreased by discharging a flow from an upstream location.

[0113] As referenced above Figure 5 The fuel cell assembly 504 discussed is configured to perform useful work in the form of a fuel cell power output 322 from air and fuel inputs. Figure 7 The anti-stall system 500 described herein is configured to utilize exhaust air to provide available energy output from the fuel cell assembly 504, for example, to provide additional power to the fuel cell load 544. The airflow supplied to the fuel cell during anti-stall operation can be received via a fuel cell flow device 560. As used herein, the fuel cell flow device 560 is configured to receive exhaust flow from the compressor section of the combustion engine 506 and supply flow to the fuel cell 504. For example, Figure 7 The fuel cell flow unit 560 depicted is configured to receive flow from the LP compressor 510 via a first discharge flow path 576 regulated by a first discharge flow valve 578, and to receive flow from the HP compressor via a second discharge flow path 584 regulated by a second discharge flow valve 586. However, it should be understood that more or fewer discharge flow paths can be provided from various locations within the compressor section.

[0114] The fuel cell flow device 560 can be a simple continuation of one or more flow paths into the fuel cell assembly 504. The fuel cell flow device 560 can also be configured to manage, for example, a combined flow between a first discharge flow path 576 and a second discharge flow path 584. In this example, a relatively low-pressure flow from the first discharge flow path 576 of the LP compressor 510 can be combined with a relatively high-pressure flow from the second discharge flow path 584 of the HP compressor 512 to provide a flow with an intermediate pressure greater than that of the first discharge flow path 576 but less than that of the second discharge flow path 584. Reference will be made below. Figure 9 In more detail, the fuel cell flow device can be configured to use a relatively high-pressure flow to entrain a relatively low-pressure flow in order to provide a laminar flow with intermediate pressure to the fuel cell assembly 504.

[0115] As described above, the fuel cell flow device 560 can be configured to increase the pressure of at least one flow, for example, from the first exhaust flow path 576, before delivering it to the fuel cell assembly 504. As described in more detail below, the pressure can be further increased by mechanical input in a compressor embodiment of the fuel cell flow device 560. Thus, the fuel cell flow device 560 can be configured to increase the pressure beyond a threshold sufficient to supply flow to the fuel cell assembly 504. For example, the fuel cell flow device 560 can be configured to increase the pressure of at least one bypass flow to a level greater than the combustion chamber pressure or the pressure within the fuel cell assembly 504.

[0116] Still referencing Figure 7 For example, you can refer to the above. Figure 5 The described method provides a fuel delivery system 562. For example... Figure 7 As depicted, the fuel delivery system 562 includes a fuel delivery valve 564. Similar to the regulation of the fuel cell flow device 560 described above, it should be understood that regulating this fuel delivery system 562 can be used to adjust one or more fuel cell parameters affecting the operation of the fuel cell assembly 504.

[0117] The anti-stall system 500 can also be configured to control the combustion engine 506, for example, to regulate one or more combustion engine parameters that affect the operation of the combustion engine 506. Figure 7 The combustion engine 506 depicted is connected to a combustion engine load 546. The combustion engine load 546 can generally include thrust or rotational resistance to the engine. Additionally, the combustion engine load 546 can include auxiliary loads, such as a generator. The combustion engine load 546 can be regulated, for example, using a combustion engine load control 547. This combustion engine load control 547 can include any number of electrical or mechanical devices to switch on, off, reduce, or increase the load on the combustion engine 506. Therefore, the control of the combustion engine 506 can include the control of various valves, actuators, etc., in the fuel delivery system, bleed air system, or variable geometry actuation system. Such control can be used to regulate the flow of fuel or air into or out of the combustion engine, the temperature of the combustion engine, and other variables. As described in more detail below, the combustion engine load control 547 can be operated via a controller 540. Although the combustion engine load 546 is depicted as being connected to an LP turbine, it should be understood that the combustion engine load 546 can draw energy from the combustion engine 506 at various other locations and from various other components.

[0118] Figure 7The combustion engine 506 also includes a combustion engine controller 556. The combustion engine controller 506 can be configured to operate the combustion engine load control 547 as described above. The combustion engine controller 556 can also be configured to regulate the output of the combustion engine 506, for example, by cutting off, turning on, increasing, or decreasing the output. Regulation of the output of the combustion engine 506 can be performed in various ways, such as regulating the airflow or fuel flow through the combustion engine 506. Although the combustion engine controller 556 is depicted as being connected to the combustion section 514, it should be understood that the combustion engine controller 556 can be operatively connected to various components of the combustion engine 506.

[0119] Figure 7 Another embodiment of controller 540 is also described. For example, controller 540 may be a stand-alone controller, a gas turbine engine controller (e.g., a full authority digital engine controller or a FADEC controller), an aircraft controller, a propulsion system supervisory controller, or a combination thereof. Controller 540 may be operatively connected to a variety of other controllers. For example, controller 540 may be operatively connected to fuel cell controller 554 and combustion engine controller 556. In various embodiments, controllers 540, 554, and 556 may be wirelessly connected or connected via wired electrical connection, or they may each be integrated into a single controller. It should be understood that fuel cell controller 554 and combustion engine controller 556 may also be configured to operate independently during normal operation or when disconnected from controller 540.

[0120] In the depicted anti-stall system 500, a controller 540 is operatively connected to various sensors, valves, etc., which are located within, connected to, or near the fuel cell assembly 504 and combustion engine 506. More specifically, for the depicted exemplary aspect, the controller 540 is operatively connected to fuel cell assembly sensor 505, combustion section sensor 515, and turbine sensor 511. As will be understood from the following description, the controller 540 can communicate with these components via wired or wireless communication. For example, the controller 540 can communicate with each of the various sensors via the fuel cell controller 554 and the combustion engine controller 556. In this way, controller 540 can receive data from various inputs (including fuel cell controller 554 and its associated sensors, and combustion engine controller 556 and its associated sensors), make control decisions, and provide data (e.g., instructions) to various outputs, such as energy output from combustion engine 506, energy output from fuel cell assembly 504, internal combustion engine load control 546, fuel cell load control 545, first exhaust valve 578, second exhaust valve 586, fuel delivery valves (further including additional or alternative valves of the compressor exhaust system to control airflow discharge from the compressor section, additional or alternative valves of the airflow delivery system to guide the airflow discharged from the compressor section, and additional or alternative valves of the fuel delivery system 146 to guide fuel flow within gas turbine engine 100, as referenced). Figure 5 (as described above). It should also be understood that the controller 540 can also be directly connected to one or more of the inputs and outputs of, for example, the fuel cell controller 554 and / or the combustion engine controller 556.

[0121] Referring specifically to the operation of controller 540, in at least some embodiments, controller 540 may include one or more computing devices 542. Computing device 542 may include one or more processors 542A and one or more memory devices 542B. The one or more processors 542A 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 542B 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.

[0122] One or more memory devices 542B may store information accessible to one or more processors 542A, including computer-readable instructions 542C executable by one or more processors 542A, as referenced above. Figure 5In a more detailed description, memory device 542B can further store data 542D, which can be accessed by processor 542A, also as described above.

[0123] The computing device 542 also includes a network interface 542E, which is configured to communicate, for example, with the fuel cell controller 554 and the combustion engine controller 556, as well as with other components of the gas turbine engine 100 (such as valves of the compressor exhaust system (valve 278, 282, 286, 578, 586), valves of the airflow delivery system (valve 312, 316, 320), and valves of the fuel delivery system 146 (diffuser 274, valve 151A, 151B, 151C, and valve 564), and sensors such as turbine sensor 511, combustion section sensor 515, and fuel cell assembly sensor 505), and / or the aircraft that incorporates the gas turbine engine 100.

[0124] Figure 7 The schematic representation of the fuel cell combustion engine interface 517 in the above reference can be seen in the above reference. Figure 5 The described integrated fuel cell and burner assembly 200. Although in Figure 7 Direct control communication between the fuel cell assembly 504 and the combustion engine 506 is not depicted, but it should be understood that control paths, as described in more detail below, can also traverse this fuel cell combustion engine interface 517. For example, communication from controller 540 can travel from its network interface 542E to combustion engine controller 556, which then relays the communication or transmits it to fuel cell controller 554 in response to communication from controller 540. Various wired or wireless network interfaces can also be constructed between controller 540, combustion engine controller 556, and / or fuel cell controller 554.

[0125] The various sensors described herein can be configured to detect data indicating stall conditions in the compressor section. As used herein, a stall condition can refer to an active stall or an imminent or potential stall. It should be understood that various data points can be used individually or in combination to determine stall conditions. For example, sensors can be located in at least one of the fuel injector, compressor discharge valve, compressor section, combustor section, fuel duct, and / or air inlet. It should be understood that, particularly in embodiments employing mathematical models to detect stall conditions, it is conceivable that any of the sensors described herein can be used to detect data indicating stall conditions.

[0126] Once data indicating a stall condition is sensed or detected, this data can be used to determine whether a compressor stall condition threshold has been reached. Therefore, individual or combined data can be used as operating parameters measured relative to the compressor stall condition threshold. For example, data indicating engine speed (e.g., collected by turbine sensor 511) can be compared with data related to pressure in at least a portion of the compressor section to determine a stall margin, or proximity to a condition leading to compressor stall. A minimum acceptable stall margin can correspond to the compressor stall condition threshold such that when the compressor stall condition threshold has been reached, the actual stall margin is less than the minimum acceptable stall margin. It should be understood that the minimum acceptable stall margin can be an adjustable value depending on usage, such as an adjustable value at least in part based on the potential effects of compressor stall.

[0127] As described above, data can be combined in various ways to determine stall margin or whether a compressor stall condition threshold has been reached. For example, various physics-based models, statistical models, artificial intelligence models, or combinations thereof can be used. In embodiments, a hybrid model employing two or more of these model types is used to determine whether at least one operating parameter has reached a compressor stall condition threshold. It should be understood that the various statistical models used herein can include compressor pressure models, matched filter models, precursor models, or any combination thereof. Various physics-based models can include Moore-Greitzer compressor models, Fink compressor models, Botros compressor models, or any combination thereof.

[0128] Once it has been determined that at least one operating parameter has reached the compressor stall condition threshold... Figure 7 The anti-stall system 500 shown can perform one or more anti-stall actions. As described above, in response to this determination, the anti-stall system 500 advantageously adjusts at least one fuel cell parameter. Adjusting at least one fuel cell parameter may include regulating the fuel cell current and / or fuel utilization rate of the fuel cell assembly 504. At least one fuel cell parameter can be further adjusted by controlling the air / fuel ratio of the fuel cell assembly, for example by controlling the first exhaust valve 578, the second exhaust valve 586, and / or the fuel delivery valve 564. Additionally, the fuel cell load 544 can be regulated to increase or decrease the load on the fuel cell assembly 504.

[0129] It should be understood that adjusting at least one fuel cell parameter can be operable to mitigate stall conditions in various ways. For example, at least one fuel cell parameter can be adjusted to facilitate the processing of more flow from the first exhaust flow path 576 and / or the second exhaust flow path 584, thereby facilitating the useful work from the flow already compressed by the combustion engine 506 via the fuel cell assembly 504. Thus, the anti-stall system 500 can increase at least one bypass flow to the fuel cell assembly 504 to potentially maintain or increase stall margin. Additionally or alternatively, the fuel supply to the fuel cell assembly 504 (such as the fuel delivery system 562) can be increased or decreased, for example, via the fuel delivery valve 564. Furthermore, the fuel cell 504 can be additionally or alternatively operated to increase the output of the fuel cell assembly 504, for example, by driving an electric motor embodiment of the combustion engine load 546, thereby electrically supplying torque to the engine shaft 513. Furthermore, adjusting the fuel cell exhaust composition and / or enthalpy by modifying the current, fuel utilization rate, and / or air-fuel ratio of the fuel cell assembly can in turn affect compressor stall conditions.

[0130] Turn now Figure 8 This provides another embodiment of the anti-stall system 600. Figure 8 Implementation examples and Figure 7 The embodiments differ in that they further include embodiments of a fuel cell flow device 660, operable to compress the flow. In various embodiments, the fuel cell flow device 660 is configured to receive power from a propulsion system including a fuel cell assembly 504 and a combustion engine 506. For example, the fuel cell flow device 660 may be mechanically connected to the engine shaft 513, for example, via a flow device drive 661. Given a range of operating conditions for the engine shaft 513, the flow device drive 661 may have a fixed ratio, configured to provide appropriate torque and rotational speed to the flow device 660. Alternatively, the flow device drive 661 may be variable and adjustable to regulate the operation of the flow device 660. It should also be understood that the flow device 660 may be pneumatically, hydraulically, or electrically driven, for example, by an electric motor (not shown) driven by the fuel cell assembly 504 and / or the combustion engine 506.

[0131] Figure 8The fuel cell flow device 660 can be configured to increase the pressure of the flow entering the fuel cell assembly 504, for example, to ensure adequate operation of the fuel cell assembly 504, thereby mitigating the stall conditions described above. This embodiment of the fuel cell flow device 660 can be referred to as a secondary compressor. Therefore, the fuel cell flow device 660 can receive at least one bypass flow from at least one secondary compressor inlet (e.g., from the first discharge flow path 576, the second discharge flow path 584, etc.), increase the pressure of that flow, and connect the pressurized flow from the secondary compressor outlet 663 to the fuel cell assembly 504.

[0132] It is conceivable that, in this embodiment, the configuration of the fuel cell flow unit 660 may itself be prone to stall, as it may rely on fixed compressor blades (not shown) to handle variable airflow. In various embodiments, a recirculation flow path 688 may be provided to mitigate stall conditions of the fuel cell flow unit 660 and / or maintain preferred operating conditions. The recirculation flow path 688 may be controlled by a recirculation control device 690, which is, for example, configured to regulate the flow between the secondary compressor outlet 663 and the recirculation flow path 688. Thus, the recirculated flow can be diverted from downstream of the fuel cell flow unit 660 to upstream of the fuel cell flow unit 660, for example, to one or more secondary compressor inlets (shown herein as a first discharge flow path 576 and a second discharge flow path 584). Referring above... Figure 7 As should be understood, the recirculation control device 690 can provide further control to mitigate compressor stall conditions by improving and / or maintaining the function of the fuel cell flow device 660.

[0133] Turn now Figure 9 This provides another embodiment of the anti-stall system 700. Figure 9 Implementation examples and Figure 8 The difference in the embodiments lies in that they further include embodiments of a fuel cell flow device 760, which is operable to compress the flow using at least one mixing component 792. The at least one mixing component 792 may be as referenced above. Figure 7 The generally described use (describes fuel cell flow device 560 as a continuation of one or more flow paths into fuel cell assembly 504) utilizes a high-pressure flow entraining a low-pressure flow, or in conjunction with a reference Figure 8 The described combination of drive embodiments for the fuel cell flow device 760. For example... Figure 9The depicted mixing assembly 792 is configured to receive a flow downstream of the fuel cell flow unit 760 via a mixing path 794, which is regulated by a mixing control device 796, which may include at least one valve. The relatively high-pressure flow from the mixing path 794 can be used to entrain relatively low-pressure flows from the first discharge flow path 576 and / or the second discharge flow path 584, thereby providing a relatively smooth and usable intermediate pressure flow to the fuel cell flow unit 760 and / or the fuel cell assembly 504. In various embodiments, a recirculation flow path 788 may be provided to mitigate stall conditions of the fuel cell flow unit 760 and / or maintain preferred operating conditions. The recirculation flow path 788 may be controlled by a recirculation control device 790, which is, for example, a proportional valve configured to regulate the flow between the secondary compressor outlet 663 and the recirculation flow path 788.

[0134] Generally described, the hybrid assembly 792 is configured to receive a first bypass flow having a first pressure and a second bypass flow having a second pressure greater than the first pressure. Therefore, embodiments of the hybrid assembly 792 may include at least two inlets and at least one outlet. The second bypass flow is used to entrain the first bypass flow and a combined flow having a pressure greater than the first pressure but less than the second pressure is conveyed downstream toward the fuel cell assembly 504. It should be understood that embodiments of the hybrid assembly 792 can be applied to systems such as those described above. Figure 7 The described first discharge stream 576 and second discharge stream 584, and / or applied as referenced herein. Figure 9 The described method utilizes one or both of the first discharge stream 576 and the second discharge stream 584 entrained by the stream from the mixing path 794.

[0135] In some exemplary embodiments, the mixing component can be configured as an ejector. In this way, the mixing component can be configured to receive a relatively high-pressure airflow (e.g., an exhaust flow from a location downstream of the secondary compressor 760) and use this relatively high-pressure airflow to increase the pressure and / or flow rate of a relatively low-pressure airflow (e.g., an exhaust flow from a location upstream of the secondary compressor 760). In this way, it will be understood that the mixing component can conserve energy within the exhaust airflow.

[0136] Turn now Figure 10 Figure 800 is provided, which illustrates the structure and effects of this disclosure. (See above reference.) Figure 7-9 As discussed in the embodiments, various constructions and methods can be employed to increase stall margin and improve operability. Figure 10 Chart 800, which may be referred to as a compressor performance chart, indicates the operability of at least one compressor component. For example, Figure 10Chart 800 can indicate at least one level of operability for LP compressors 110, 510, HP compressors 112, 512, or both. Chart 800 plots pressure ratio 801 on its vertical axis, compared to mass flow rate 802 plotted on its horizontal axis. A surge line 803 (also known as a stall line) is provided to indicate the region in chart 800 where surge or stall conditions are expected. As can be seen in chart 800, generally as pressure ratio 801 increases, mass flow rate 802 must also increase to avoid crossing the surge or stall line 803 into compressor stall conditions.

[0137] Still referencing Figure 10 The diagram displays various constant velocity lines, representing a given engine speed measured, for example, at engine shaft 513 or at various other rotating parts as described elsewhere herein. The first constant velocity line 804 represents a relatively low operating speed, such as idle speed without load. The second constant velocity line 805 represents an intermediate operating speed, such as cruise speed. The third constant velocity line 806 represents a relatively high operating speed, such as maximum engine speed or takeoff speed. As can be seen from Figure 800, constant velocity lines 804, 805, and 806 can be used to represent the relationship between pressure ratio 801 and mass flow rate 802 while maintaining a constant speed.

[0138] Figure 10 A steady-state operating line 810 is also depicted, indicating the pressure ratio 801 and mass flow rate 802 maintained at a given constant speed without acceleration. On either side of the steady-state operating line 810 are a first positive acceleration line 811 and a first negative acceleration line 813, each representing the operability of the construction and methods of this disclosure. The first positive acceleration line 811 represents the pressure ratio 801 and mass flow rate 802 at a given speed during acceleration. The first negative acceleration line 813 represents the pressure ratio 801 and mass flow rate 802 at a given speed during deceleration. As can be seen from Figure 800, acceleration results in a reduced distance from the surge line 803. This distance from the surge line 803 is called the stall margin, and is represented as the first stall margin 815 at the second constant speed line 805.

[0139] A second stall margin 816 is provided according to the construction and method of this disclosure. The second stall margin 816 increases compared to the first stall margin 815, thereby increasing engine operability. The second stall margin 816 is derived from a second positive acceleration line 812 at the same exemplary second constant velocity line 805. According to the construction and method described herein, the second positive acceleration line 812 and the second negative acceleration line 814 represent beneficial changes to compressor function. For example, the mass flow rate 802 at the second constant velocity line 812 can be increased by controlling at least one fuel cell parameter (e.g., increasing the flow to the fuel cell assembly 504, increasing the output products or output enthalpy from the fuel cell assembly 504, etc.). The resulting second stall margin 816 represents an operational margin improvement leading to high operability or flexibility in engine operation. For increasing engine operability, additionally or alternatively, the construction and method of this disclosure can also be used to increase engine efficiency. For example, reducing fuel combustion may be possible because, for example, waste heat from the bleed air is used for power generation and / or engine thrust enhancement.

[0140] Turn now Figure 11 This provides a flowchart describing the operation of an aircraft's propulsion system, and more specifically, a flowchart of method 900 for operating the anti-stall systems 500, 600, and 700 of the aircraft and its propulsion system. See reference... Figure 7 As described, the anti-stall system 500 includes at least one sensor, such as the one mentioned above. Figure 7 Any sensor described or any conceivable sensor applicable to the sensing model described herein. For example... Figure 11 As shown in the first process 901, these sensors can be configured to determine data indicating at least one operating parameter of the propulsion system. It should be understood that the propulsion system referred to herein includes at least the combustion engine 506 and the fuel cell assembly 504 (see [link to documentation]). Figure 7 As described above, processors, such as processor 542A, fuel cell controller 554, or combustion engine controller 556, are configured to make determinations based on inputs from sensors (see [link to relevant documentation]). Figure 7 For example, processor 542A can be configured to determine in a second process 902 whether at least one operating parameter has reached a compressor stall condition threshold.

[0141] In the third process 903, if it is determined in the second process 902 that the operating parameters have reached the compressor stall condition threshold, then the processor or another processor continues to execute the anti-stall action. (See above for general reference.) Figure 7-10 The stall prevention action described includes adjusting at least one fuel cell parameter. It should also be understood that this stall prevention method can additionally adjust further parameters, such as the combustion engine parameters as described above.

[0142] In addition to executing the above reference in 903 Figure 7-10 In addition to the described anti-stall actions, the method may further transmit one or more messages to an operator, such as an aircraft pilot. Therefore, method 900 may further include transmitting a stall condition message to the pilot in response to determining that operating parameters have reached a compressor stall condition threshold. Finally, the method may continue to determine, for example, by repeating process 901, that operating parameters have not yet reached the compressor stall condition threshold. If it is determined that operating parameters have not reached the compressor stall condition threshold, the method may continue without performing anti-stall actions, or, if anti-stall actions have already been performed, by ceasing to perform anti-stall actions.

[0143] This written description uses examples to disclose this disclosure, including best practices, and also enables any person skilled in the art to practice this disclosure, including making and using any device or system and methods of making any combination. The patent scope of this disclosure is defined by the claims, but may include other examples that would occur to a person skilled in the art. Such other examples are intended to fall within the scope of the claims if they include structural elements that are not indistinguishable from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

[0144] Further aspects are provided by the subject matter of the following clauses:

[0145] An anti-stall system for an aircraft, the aircraft including a propulsion system including a fuel cell assembly and a combustion engine including a compressor section having a compressor, the anti-stall system including: at least one sensor configured to sense data indicating at least one operating parameter, the at least one operating parameter indicating a compressor stall condition of the compressor; and a controller including a processor and a memory storing instructions, the instructions, when executed by the processor, causing the controller to: determine that the at least one operating parameter has reached a compressor stall condition threshold; and in response to determining that the at least one operating parameter has reached the compressor stall condition threshold, perform an anti-stall action, wherein the anti-stall action is configured to adjust at least one fuel cell parameter.

[0146] According to the anti-stall system described in the foregoing clauses, the at least one fuel cell parameter includes: the current output of the fuel cell assembly; the fuel utilization rate of the fuel cell assembly; the air-to-fuel ratio of the fuel cell stack of the fuel cell assembly; the power ratio between the fuel cell assembly and the combustion engine; the power ratio between the fuel cell assembly and the electric motor driven by the combustion engine; or any combination thereof.

[0147] The anti-stall system according to any one of the foregoing clauses, wherein the combustion engine is configured as a turbine, the turbine including a combustion section having a burner, wherein the fuel cell assembly includes a fuel cell with a defined outlet, the outlet being positioned to remove output products from the fuel cell and to supply the output products to the burner, wherein the burner output power of the burner is controlled by adjusting the operating parameters of the fuel cell.

[0148] The anti-stall system according to any one of the foregoing clauses, wherein the combustion engine is configured as a turbine having a shaft and an electric motor capable of rotating with the shaft, wherein adjusting the at least one fuel cell parameter includes adjusting the fuel cell power output to the electric motor.

[0149] The anti-stall system according to any one of the foregoing clauses, wherein adjusting the at least one fuel cell parameter includes adjusting the motor based on the acceleration of the shaft.

[0150] The anti-stall system according to any one of the foregoing clauses, wherein adjusting the at least one fuel cell parameter includes increasing the pressure, flow rate, or both of at least one bypass flow from the compressor to the fuel cell assembly.

[0151] The anti-stall system according to any one of the foregoing clauses, wherein adjusting the at least one fuel cell parameter includes increasing the pressure of the at least one bypass flow to be greater than the combustion chamber pressure.

[0152] The anti-stall system according to any one of the foregoing clauses further includes: a secondary compressor configured to: receive the at least one bypass flow at a secondary compressor inlet; increase the pressure of the at least one bypass flow; and connect the at least one bypass flow to the fuel cell assembly via a secondary compressor outlet.

[0153] According to any one of the preceding clauses, the anti-stall system wherein the secondary compressor is further configured to receive torque input from the shaft of the combustion engine.

[0154] The anti-stall system according to any one of the foregoing clauses further includes a secondary compressor drive, wherein the secondary compressor drive is configured to control the rotational output speed of the secondary compressor.

[0155] The anti-stall system according to any one of the foregoing clauses, wherein the secondary compressor is configured to receive power from the motor.

[0156] The anti-stall system according to any one of the foregoing clauses, wherein the secondary compressor is further configured to receive power from the propulsion system.

[0157] The anti-stall system according to any one of the foregoing clauses, wherein the secondary compressor is configured to receive power from the fuel cell assembly.

[0158] The anti-stall system according to any one of the foregoing clauses further includes a recirculation flow configured to transfer at least a portion of the flow downstream of the secondary compressor outlet to the upstream of the secondary compressor inlet.

[0159] The anti-stall system according to any one of the foregoing clauses further includes a recirculation control device configured to control the proportion of the recirculation flow transferred upstream of the secondary compressor inlet.

[0160] The anti-stall system according to any one of the foregoing clauses further includes a mixing component configured to use at least a portion of the recirculation flow to entrain the at least one bypass flow upstream of the secondary compressor inlet.

[0161] The anti-stall system according to any one of the foregoing clauses, wherein the secondary compressor includes a mixing assembly configured to: receive a first bypass flow having a first pressure; receive a second bypass flow having a second pressure, wherein the second pressure is greater than the first pressure; entrain the first bypass flow with the second bypass flow; and connect to a combined bypass flow from the outlet of the secondary compressor having a third pressure, wherein the third pressure is greater than the first pressure and less than the second pressure.

[0162] A method for operating an anti-stall system of an aircraft, the aircraft including a propulsion system including a fuel cell assembly and a combustion engine, the method comprising: detecting at least one operating parameter indicating a compressor stall condition using at least one sensor; determining, using at least one controller, that the at least one operating parameter has reached a compressor stall condition threshold; and performing an anti-stall action using the at least one controller in response to the at least one operating parameter reaching the compressor stall condition threshold, wherein the anti-stall action includes adjusting at least one fuel cell parameter.

[0163] The method according to any one of the foregoing clauses, wherein adjusting the at least one fuel cell parameter includes controlling at least one bypass flow into the fuel cell assembly.

[0164] The method according to any one of the foregoing clauses, wherein adjusting the at least one fuel cell parameter includes controlling the fuel cell fuel supply unit.

[0165] The method according to any one of the foregoing clauses further includes transmitting a stall condition message to the pilot in response to the at least one operating parameter having reached the compressor stall condition threshold.

[0166] The method according to any one of the foregoing clauses, wherein the anti-stall action further includes adjusting at least one combustion engine parameter.

[0167] The method according to any one of the foregoing clauses further includes: using the at least one controller to determine that the at least one operating parameter has not yet reached the compressor stall condition threshold; and in response to the at least one operating parameter not reaching the compressor stall condition threshold, stopping the execution of the anti-stall action.

Claims

1. An anti-stall system for aircraft, characterized in that, The anti-stall system includes: A propulsion system comprising a fuel cell assembly and a combustion engine, the combustion engine comprising a low-pressure compressor, a high-pressure compressor, and a combustor in series flow relationship, the combustor comprising an inner liner, an outer liner, and a combustion chamber defined therebetween, wherein the propulsion system further comprises a secondary compressor, wherein the secondary compressor is fluidly coupled to the low-pressure compressor via a first discharge flow path to receive a first discharge flow from the low-pressure compressor, wherein the secondary compressor is fluidly coupled to the high-pressure compressor via a second discharge flow path to receive a second discharge flow from the high-pressure compressor, wherein the secondary compressor is in gaseous communication with the fuel cell assembly to provide at least one of the first discharge flow or the second discharge flow to the fuel cell assembly; Sensors configured to sense data indicating operating parameters, the operating parameters indicating compressor stall conditions of at least one of the low-pressure compressor or the high-pressure compressor; and A controller electrically connected to the sensor, wherein the controller is configured to: Receive the data indicating the operating parameters indicating compressor stall conditions; and If the operating parameters have reached the compressor stall condition threshold, anti-stall action is performed in response to the data indicating the operating parameters indicating the compressor stall condition, wherein performing the anti-stall action includes adjusting at least one fuel cell parameter of the fuel cell assembly.

2. The anti-stall system according to claim 1, characterized in that, The at least one fuel cell parameter includes: The current output of the fuel cell assembly; Fuel utilization rate of the fuel cell assembly; The air-to-fuel ratio of the fuel cell stack in the fuel cell assembly; The power ratio between the fuel cell assembly and the combustion engine; The power ratio between the fuel cell assembly and the electric motor driven by the combustion engine; or Any combination thereof.

3. The anti-stall system according to claim 1, characterized in that, The combustion engine is configured as a turbine, and the fuel cell assembly includes a fuel cell with a defined outlet positioned to remove output products from the fuel cell and supply the output products to the burner, wherein the burner output power is controlled by adjusting at least one fuel cell parameter.

4. The anti-stall system according to claim 1, characterized in that, The combustion engine is configured as a turbine having a shaft and an electric motor capable of rotating with the shaft, wherein adjusting the at least one fuel cell parameter includes adjusting the fuel cell power output to the electric motor.

5. The anti-stall system according to claim 4, characterized in that, Receiving the data indicating the operating parameters includes receiving sensor data on changes in the rotational speed of the shaft, and adjusting the at least one fuel cell parameter includes adjusting the motor based on the acceleration of the shaft.

6. The anti-stall system according to claim 1, characterized in that, Adjusting the at least one fuel cell parameter includes increasing the pressure, flow rate, or both of the first or second discharge stream from the secondary compressor to the fuel cell assembly.

7. The anti-stall system according to claim 6, characterized in that, Adjusting the at least one fuel cell parameter includes increasing the pressure of at least one of the first or second exhaust streams to be greater than the combustion chamber pressure.

8. The anti-stall system according to claim 6, characterized in that, The secondary compressor is configured as follows: At least one of the first discharge stream or the second discharge stream is received at the secondary compressor inlet of the secondary compressor; Increase the pressure of at least one of the first discharge stream or the second discharge stream; and At least one of the first discharge stream or the second discharge stream is connected to the fuel cell assembly via the secondary compressor outlet of the secondary compressor.

9. The anti-stall system according to claim 8, characterized in that, The secondary compressor is further configured to receive power from the propulsion system.

10. The anti-stall system according to claim 8, characterized in that, The secondary compressor is configured to receive power from the fuel cell assembly.

11. The anti-stall system according to claim 8, characterized in that, It further includes a recirculation flow configured to divert at least a portion of at least one of the first or second discharge flow downstream of the secondary compressor outlet to the upstream of the secondary compressor inlet.

12. The anti-stall system according to claim 11, characterized in that, It further includes a recirculation control device configured to control the proportion of the recirculation flow transferred upstream of the secondary compressor inlet.

13. The anti-stall system according to claim 12, characterized in that, It further includes a mixing component configured to use at least a portion of the recirculated flow to entrain at least one of the first or second discharge flow upstream of the secondary compressor inlet.

14. The anti-stall system according to claim 8, characterized in that, The secondary compressor includes a mixing assembly configured to: Receive the first discharge stream at a first pressure; Receive the second discharge flow at a second pressure, wherein the second pressure is greater than the first pressure; The second discharge stream carries the first discharge stream; and A combined discharge stream from the outlet of the secondary compressor is connected, the combined discharge stream having a third pressure, wherein the third pressure is greater than the first pressure and less than the second pressure.

15. A method of operating an anti-stall system for an aircraft, the aircraft comprising a propulsion system including a fuel cell assembly and a combustion engine, the combustion engine including a low-pressure compressor, a high-pressure compressor, and a combustor in series flow relationship, the combustor including an inner liner, an outer liner, and a combustion chamber defined therebetween, wherein the propulsion system further includes a secondary compressor, wherein the secondary compressor is fluidly coupled to the low-pressure compressor via a first exhaust flow path to receive a first exhaust flow from the low-pressure compressor, wherein the secondary compressor is fluidly coupled to the high-pressure compressor via a second exhaust flow path to receive a second exhaust flow from the high-pressure compressor, wherein the secondary compressor is in airflow communication with the fuel cell assembly to provide at least one of the first exhaust flow or the second exhaust flow to the fuel cell assembly, characterized in that, The method includes: Using at least one sensor, detect operating parameters that indicate compressor stall conditions; and Using the at least one controller, in response to the operating parameters reaching the compressor stall condition threshold, an anti-stall action is performed, wherein the anti-stall action includes adjusting at least one fuel cell parameter.

16. The method according to claim 15, characterized in that, Adjusting the at least one fuel cell parameter includes controlling at least one of the first or second emission streams entering the fuel cell assembly.

17. The method according to claim 15, characterized in that, Adjusting the at least one fuel cell parameter includes controlling the fuel cell fuel supply unit.

18. The method according to claim 15, characterized in that, It further includes transmitting a stall condition message to the pilot in response to the operating parameters having reached the compressor stall condition threshold.

19. The method according to claim 15, characterized in that, The anti-stall action further includes adjusting at least one combustion engine parameter.

20. The method according to claim 15, characterized in that, Further includes: If the operating parameters are lower than the compressor stall condition threshold, the anti-stall action will be stopped.

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