High efficiency hydrogen fueled high altitude thermodynamic fuel cell system and aircraft using same

Patent metadata

Field	Value
Publication number	US-11752899-B2
Application number	US-202217973539-A
Country	US
Kind code	B2
Filing date	Oct 26, 2022
Priority date	Jun 15, 2020
Publication date	Sep 12, 2023
Grant date	Sep 12, 2023

Abstract

A high efficiency hydrogen fuel system for an aircraft at high altitude which utilizes compressors to compress air to a sufficiently high pressure for the fuel cell. Liquid hydrogen is compressed and then utilized in heat exchangers to cool the compressed air, maintaining the air at a temperature low enough for the fuel cell. The hydrogen is also used to cool the fuel cell as it is also depressurized prior to its entry in the fuel cell cycle. A water condensation system allows for water removal from the airstream to reduce impacts to the atmosphere. The hydrogen fuel system may be used with VTOL aircraft, which may allow them to fly at higher elevations. The hydrogen fuel system may be used with other subsonic and supersonic aircraft, such as with asymmetric wing aircraft.

First claim

What is claimed is:

1. A high efficiency hydrogen fueled thermodynamic fuel cell system for a high altitude aircraft, said system comprising:
an air inlet;
a first air compressor fluidically coupled to said air inlet, said first compressor adapted to compress inletted air into a fuel cell air pathway;
a second air compressor fluidically coupled to said first air compressor downstream from said first air compressor;
a third air compressor fluidically coupled to said second air compressor downstream from said second air compressor;
a liquid hydrogen reservoir;
a liquid hydrogen pump coupled to said liquid hydrogen reservoir, said pump adapted to pressurize liquid hydrogen through a hydrogen pathway;
a first heat exchanger adapted to cool air downstream of said first air compressor with inletted air;
a second heat exchanger adapted to cool air downstream of said first compressor with hydrogen from said pump;
a third heat exchanger adapted to cool air downstream of said second air compressor with inletted air;
a fourth heat exchanger adapted to cool air downstream of said second compressor with hydrogen from said pump downstream along said hydrogen pathway from said second heat exchanger;
a hydrogen expander along said hydrogen pathway downstream from said fourth heat exchanger, and
a fuel cell, said fuel cell fluidically coupled to said hydrogen pathway downstream of said hydrogen expander, said fuel cell fluidically coupled to said fuel cell air pathway downstream of said third compressor;
a closed loop cooling system adapted to cool said fuel cell, said closed loop cooling system comprising a cooling fluid and a pump; and
an eighth heat exchanger thermally coupled to said cooling fluid and with inletted air downstream from said air inlet.

2. The high efficiency hydrogen fueled thermodynamic fuel cell system for a high altitude aircraft of claim 1 further comprising:
a sixth heat exchanger thermally coupled to an exhaust conduit routing exhaust from said fuel cell;
a seventh heat exchanger thermally coupled to said exhaust conduit downstream from said sixth heat exchanger; and
a water separator coupled to said exhaust conduit downstream from seventh heat exchanger.

3. The high efficiency hydrogen fueled thermodynamic fuel cell system for a high altitude aircraft of claim 2 further comprising:
a water reservoir fluidically coupled to said water separator via a water pathway;
a water pump fluidically coupled to said water reservoir; and
a water sprayer adapted to spray water into the inletted air downstream of said fan and upstream of said eighth heat exchanger.

4. The high efficiency hydrogen fueled thermodynamic fuel cell system for a high altitude aircraft of claim 3 further comprising:
a burner, said burner fluidically coupled to said hydrogen pathway downstream from said hydrogen expander, said burner fluidically coupled to said fuel cell air pathway downstream from said third compressor.

5. The high efficiency hydrogen fueled thermodynamic fuel cell system for a high altitude aircraft of claim 4 wherein the heated output of said burner is routed to a fifth heat exchanger which heats dried fuel cell exhaust from the water separator.

6. The high efficiency hydrogen fueled thermodynamic fuel cell system for a high altitude aircraft of claim 5 wherein the heated dried fuel cell exhaust from said fifth heat exchanger is routed to a third turbo charger adapted to power said third compressor.

7. The high efficiency hydrogen fueled thermodynamic fuel cell system for a high altitude aircraft of claim 6 wherein the heated dried fuel cell exhaust from said third turbocharger is routed to a second turbo charger adapted to power said second compressor.

8. The high efficiency hydrogen fueled thermodynamic fuel cell system for a high altitude aircraft of claim 7 wherein the heated dried fuel cell exhaust from said second turbo charger is routed to a first turbo charger adapted to power said first compressor.

9. The high efficiency hydrogen fueled thermodynamic fuel cell system for a high altitude aircraft of claim 8 further comprising:
a first electric motor mechanically coupled to said first compressor;
a second electric motor mechanically coupled to said second compressor; and
a third electric motor mechanically coupled to said third compressor.

10. A vertical take-off and landing aircraft comprising:
a main vehicle body;
a right side wing, said right side wing coupled a right side of said main vehicle body;
one or more right side rotor assemblies, said one or more right side rotor assemblies comprising a propeller and a motor, wherein said one or more right side wing rotors are attached to said right side wing;
a right side wingtip rotor assembly, said right side wingtip rotor assembly comprising a propeller and a motor, where said right side wingtip rotor assembly is attached to the outboard tip of said right side wing;
a left side wing, said left side wing coupled a left side of said main vehicle body;
one or more left side rotor assemblies, said one or more left side rotor assemblies comprising a propeller and a motor, wherein said one or more left side wing rotors are attached to said left side wing;
a left side wingtip rotor assembly, said left side wingtip rotor assembly comprising a propeller and a motor, where said left side wingtip rotor assembly is attached to the outboard tip of said left side wing, wherein said right side rotor assemblies, said right side wingtip rotor assembly, said left side rotor assemblies, and said left side wingtip rotor assembly are attached by a deployment mechanism adapted to deploy said assemblies from a forward facing horizontal flight configuration to a vertical take-off configuration; and
a high efficiency hydrogen fueled thermodynamic fuel cell system, said thermodynamic fuel cell system comprising:
an air inlet;
a first air compressor fluidically coupled to said air inlet, said first compressor adapted to compress inletted air into a fuel cell air pathway;
a second air compressor fluidically coupled to said first air compressor downstream from said first air compressor;
a third air compressor fluidically coupled to said second air compressor downstream from said second air compressor;
a liquid hydrogen reservoir;
a liquid hydrogen pump coupled to said liquid hydrogen reservoir, said pump adapted to pressurize liquid hydrogen through a hydrogen pathway;
a first heat exchanger adapted to cool air downstream of said first air compressor with inletted air;
a second heat exchanger adapted to cool air downstream of said first compressor with hydrogen from said pump;
a third heat exchanger adapted to cool air downstream of said second air compressor with inletted air;
a fourth heat exchanger adapted to cool air downstream of said second compressor with hydrogen from said pump downstream along said hydrogen pathway from said second heat exchanger;
a hydrogen expander along said hydrogen pathway downstream from said fourth heat exchanger, and
a fuel cell, said fuel cell fluidically coupled to said hydrogen pathway downstream of said hydrogen expander, said fuel cell fluidically coupled to said fuel cell air pathway downstream of said third compressor.

11. The vertical take-off and landing aircraft of claim 1 wherein high efficiency hydrogen fueled thermodynamic fuel cell system further comprises:
a closed loop cooling system adapted to cool said fuel cell, said closed loop cooling system comprising a cooling fluid and a pump; and
an eighth heat exchanger thermally coupled to said cooling fluid and with inletted air.

12. The vertical take-off and landing aircraft of claim 11 wh

Assignees

• Joby Aero Inc

Inventors

• Mikic Gregor Veble
• Bevirt Joeben
• Lynn Robert Gulliver
• Stoll Alex

Classifications

• B64D27/355

  using fuel cells · CPC title

• B64D27/31

  within, or attached to, wings · CPC title

• B64D27/30

  Aircraft characterised by electric power plants · CPC title

• B64D35/023

  of series-parallel type · CPC title

• B64D27/33

  Hybrid electric aircraft · CPC title