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EP-4737321-A1 - FUEL CELL SYSTEMS FOR AERONAUTICAL VEHICLES

EP4737321A1EP 4737321 A1EP4737321 A1EP 4737321A1EP-4737321-A1

Abstract

A propulsion system for an aircraft includes a fan section having a fan; a turbomachine including a compressor section, a combustion section, and a turbine section arranged in serial flow order; at least one electric machine; a fuel cell assembly configured to supply power to the electric machine; and a controller including a memory and one or more processors. One or both of the turbomachine and the at least one electric machine are configured to drive rotation of the fan of the fan section. The fuel cell assembly includes at least one fuel cell, a first fluid inlet for receiving a flow of pressurized air, and a second fluid inlet for receiving a flow of fuel.

Inventors

  • CANTAGALLI, Silvia
  • ERDMENGER, RODRIGO RODRIGUEZ
  • SPAGNOLO, Cosimo
  • OSAMA, MOHAMED

Assignees

  • GE Avio S.r.l.
  • General Electric Deutschland Holding GmbH

Dates

Publication Date
20260506
Application Date
20251015

Claims (15)

  1. A propulsion system (112) for an aircraft (100), comprising: a fan section (122) comprising a fan; a turbomachine (124) comprising a compressor section (128), a combustion section (130), and a turbine section (132) arranged in serial flow order; at least one electric machine (136) , wherein one or both of the turbomachine (124) and the at least one electric machine (136) are configured to drive rotation of the fan of the fan section (122); a fuel cell assembly (300) configured to supply power to the electric machine (136), the fuel cell assembly (300) including at least one fuel cell (305), a first fluid inlet (325) for receiving a flow of pressurized air (320), and a second fluid inlet (330) for receiving a flow of fuel (335); and a controller (340) comprising a memory (346) and one or more processors (344), the memory (346) storing instructions (350) that when executed by the one or more processors (344) cause the propulsion system (112) to perform a plurality of operations including: receiving data indicative of an altitude of the aircraft (100); and managing the flow of pressurized air (320) to the fuel cell assembly (300) in response to the received data indicative of the altitude of the aircraft (100).
  2. The propulsion system (112) of claim 1, wherein receiving data indicative of the altitude of the aircraft (100) comprises determining the altitude of the aircraft (100) and comparing the determined altitude to an altitude threshold.
  3. The propulsion system (112) of any preceding claim, wherein receiving data indicative of the altitude of the aircraft (100) comprises receiving data indicative of the altitude being less than or equal to an altitude threshold, and wherein managing the flow of pressurized air (320) to the fuel cell assembly (300) comprises: increasing the flow of pressurized air (320) to the fuel cell assembly (300) based on the altitude being less than or equal to the altitude threshold; and reducing the flow of pressurized air (320) to the fuel cell assembly (300) based on the altitude being greater than the altitude threshold.
  4. The propulsion system (112) of any preceding claim, wherein: the fuel cell assembly (300) comprises at least one compressor (310) and at least one bypass valve (315) in fluid communication with the compressor and the first fluid inlet (325); and the altitude of the aircraft (100) is greater than or equal to 0 feet and less than or equal to 25,000 feet.
  5. The propulsion system (112) of claim 4, wherein the controller (340) is operably coupled to the at least one bypass valve (315) and configured to activate the at least one bypass valve (315) based on the altitude being less than or equal to an altitude threshold and deactivate the at least one bypass valve (315) based on the altitude exceeding the altitude threshold.
  6. The propulsion system (112) of claim 5, further comprising a recirculation valve (360) downstream from the at least one bypass valve (315) and upstream of the at least one compressor (310).
  7. The propulsion system (112) of claim 4, wherein the fuel cell assembly (300) comprises a supercharger (505) or a turbocharger (503) in fluid communication with and upstream of the at least one compressor (310).
  8. The propulsion system (112) of claim 4, wherein the at least one electric machine (136) comprises a first electric machine (136), and wherein the fuel cell assembly (300) comprises a second electric machine (380) mechanically coupled to the at least one compressor (310) for driving rotation of the at least one compressor (310).
  9. The propulsion system (112) of any preceding claim, wherein the fuel cell assembly (300) comprises: an air management system (610) in fluid communication with the at least one fuel cell (305) and the compressor section (128), the air management system (610) downstream of the compressor section (128) and upstream of the at least one fuel cell (305); and a control valve (615) in fluid communication with the air management system (610) and the compressor section (128), the control valve (615) downstream of the compressor section (128) and upstream of the at least one fuel cell (305).
  10. The propulsion system (112) of claim 9, wherein: the air management system (610) further comprises a distribution manifold (623) in fluid communication with the control valve (615) and the at least one fuel cell (305), the distribution manifold (623) configured to distribute the flow of pressurized air (320) to the at least one fuel cell (305); and the controller (340) is operably coupled to the control valve (615) and configured to activate the at control valve (615) based on the altitude being less than or equal to an altitude threshold and deactivate the control valve (615) based on the altitude exceeding the altitude threshold.
  11. The propulsion system (112) of any preceding claim, wherein the fuel cell assembly (300) further comprises: an air management system (610) in fluid communication with the at least one fuel cell (305); and an air stream supply (702) in fluid communication with the air management system (610), the air stream supply (702) comprising: a fuel cell compressor (710) in fluid communication with the air management system (610), a fuel cell turbine (755) drivingly coupled to the fuel cell compressor (710), a guide vane assembly (715) having a plurality of inlet guide vanes disposed upstream of the fuel cell compressor (710), and an actuator (745) operable to vary a pitch angle of each of the plurality of inlet guide vanes; wherein the controller (340) is operably coupled to the actuator (745); and wherein the managing the flow of pressurized air (320) to the fuel cell assembly (300) comprises rotating one or more of the plurality of inlet guide vanes via the actuator (745).
  12. The propulsion system (112) of claim 11, wherein: the controller (340) is configured to rotate the plurality of inlet guide vanes to a first position based on the altitude being less than or equal to an altitude threshold; and the controller (340) is configured to rotate the plurality of inlet guide vanes to a second position based on the altitude exceeding the altitude threshold.
  13. The propulsion system (112) of claim 1, wherein the fuel cell assembly (300) comprises: an air management system (610) in fluid communication with the at least one fuel cell (305), the air management system (610) upstream of the at least one fuel cell (305); and an air stream supply (843) configured to supply the flow of pressurized air (320) to the fuel cell assembly (300).
  14. The propulsion system (112) of claim 13, wherein the air stream supply (702) comprises one or both of an air tank for storing the pressurized air (320) or an oxygen tank.
  15. The propulsion system of any preceding claim, wherein the at least one fuel cell (305) comprise Proton Exchange Membrane Fuel Cells (PEMFCs).

Description

FIELD The present disclosure relates to fuel cell systems for aeronautical vehicles and methods of operating such fuel cell systems. BACKGROUND Aeronautical vehicles use a variety of power sources to drive one or more propulsors that may generate thrust for the vehicles. Many vehicles use gas turbine engines, having a turbomachine and a rotor assembly. For example, the turbomachine includes a compressor section, a combustion section, and a turbine section in serial flow order, and the rotor assembly is configured as a fan assembly. Fuel cells may be used as a source of power for the one or more propulsors. A compressor may be utilized for supplying air to the fuel cells. However, operation of the compressor may be limited by the altitude of the aeronautical vehicle. Accordingly, improved fuel cell systems designed for operating at a range of altitudes are desirable. BRIEF DESCRIPTION OF THE DRAWINGS A full and enabling disclosure of the present disclosure, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: FIG. 1 is a schematic diagram of an aeronautical vehicle in accordance with an aspect of the present disclosure.FIG. 2 is a schematic diagram of a propulsor in accordance with an aspect of the present disclosure.FIG. 3 is a schematic diagram of a propulsion system including a fuel cell assembly in accordance with an aspect of the present disclosure.FIG. 4 is a perspective view of a fuel cell of the fuel cell assembly of FIG. 3 in accordance with an exemplary aspect of the present disclosure.FIG. 5 is a schematic diagram of a propulsion system including a fuel cell assembly in accordance with an aspect of the present disclosure.FIG. 6 is a schematic diagram of a propulsion system in accordance with an aspect of the present disclosure.FIG. 7 is a schematic diagram of a propulsion system in accordance with an aspect of the present disclosure.FIG. 8 is a schematic diagram of a propulsion system in accordance with an aspect of the present disclosure.FIG. 9 is a flow diagram of a method of operating a propulsion system in accordance with an aspect of the present disclosure.FIG. 10 is a flow diagram of a method of operating a propulsion system in accordance with an aspect of the present disclosure. DETAILED DESCRIPTION Reference will now be made in detail to present embodiments of the disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the disclosure. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. Additionally, unless specifically identified otherwise, all embodiments described herein should be considered exemplary. The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. The term "at least one of" in the context of, e.g., "at least one of A, B, and C" refers to only A, only B, only C, or any combination of A, B, and C. The term "turbomachine" refers to a machine including one or more compressors, a heat generating section (e.g., a combustion section), and one or more turbines that together generate a torque output. The term "gas turbine engine" refers to an engine having a turbomachine as all or a portion of its power source. Example gas turbine engines include turbofan engines, turboprop engines, turbojet engines, turboshaft engines, etc., as well as hybrid-electric versions of one or more of these engines. The term "combustion section" refers to any heat addition system for a turbomachine. For example, the term combustion section may refer to a section including one or more of a deflagrative combustion assembly, a rotating detonation combustion assembly, a pulse detonation combustion assembly, or other appropriate heat addition assembly. In certain example embodiments, the combustion section may include an annular combustor, a can combustor, a cannular combustor, a trapped vortex combustor (TVC), or other appropriate combustion system, or combinations thereof. The terms "upstream" and "downstream" refer to the relative direction with respect to fluid flow in a fluid pathway. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction to which the fluid flows. The terms "coupled," "fixed," "attached to," and the like refer to both direct coupling, fixing, or attaching, as well as indirect coupling, fixing, or attaching through one or more intermediate components or features, unless otherwise specified herein. As used herein, the terms "first," "se