Fuel system inerting

• US 8,828,344 B2
• Filed: 05/04/2012
• Issued: 09/09/2014
• Est. Priority Date: 05/06/2011
• Status: Active Grant

• Current Assignee: Airbus Operations Limited (Airbus SE)
• Original Assignee: Airbus Operations Limited (Airbus SE)
• Inventors: K-WLam, Joseph, Hylands, Gregory
• Primary Examiner(s): Smith, Duane
• Assistant Examiner(s): SHAO, PHILLIP Y
• Application Number:
  US13/464,043
• Publication Number:
  US 20120279395A1
• Time in Patent Office: 858 Days
• Field of Search: None
• US Class Current: 423/219
• CPC Class Codes: B64D 37/32 Safety measures not otherwise provided for, e.g. preventing explosive conditions extinguishing or preventing fires in aircraft A62C
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02T 50/40 Weight reduction

Abstract

A fuel system comprising a fuel tank, a catalytic inerting device for producing oxygen depleted air (ODA) by reaction of fuel vapor from the fuel tank with air, and a separator device for separating carbon dioxide from the ODA gas before feeding the carbon dioxide depleted ODA gas to the fuel tank so as to render the fuel tank ullage atmosphere inert. Also, a method of reducing the carbon dioxide content of oxygen depleted air (ODA) produced by a catalytic inerting device for inerting a fuel tank ullage atmosphere, the method comprising separating carbon dioxide from the ODA gas before feeding the carbon dioxide depleted ODA gas to the fuel tank. The system may be installed in an aircraft.

Claims

1. A fuel system comprising a fuel tank, a catalytic inerting device for producing oxygen depleted air (ODA) by reaction of fuel vapour from the fuel tank with air, and a separator device for separating carbon dioxide from the ODA gas before feeding the carbon dioxide depleted ODA gas to the fuel tank so as to render the fuel tank ullage atmosphere inert.

2. A fuel system according to claim 1, wherein the separator device includes a condenser comprising a water reservoir and a refrigerating element for cooling water in the reservoir, wherein the condenser is adapted to condense water vapour and scrub carbon dioxide gas from the ODA gas passing through the cooled water.

3. A fuel system according to claim 2, further comprising a conduit adapted to convey relatively warm, moist ODA gas from the catalytic inerting device into the bottom of the water reservoir.

4. A fuel system according to claim 3, wherein the conduit has a nozzle opening in the bottom of the water reservoir for forming fine gas bubbles.

5. A fuel system according to claim 2, wherein the condenser further includes a collection funnel over the water reservoir for collecting relatively cool, dry, carbon dioxide depleted ODA gas that has passed through the cooled water.

6. A fuel system according to claim 5, further comprising a conduit adapted to convey the relatively cool, dry, carbon dioxide depleted ODA to the fuel tank.

7. A fuel system according to claim 2, wherein the water reservoir includes a fluid overflow path.

8. A fuel system according to claim 2, wherein the refrigeration element is adapted to be cooled by recirculating fuel from the fuel tank.

9. A fuel system according to claim 2, wherein the refrigeration element forms part of a vapour-compression refrigeration system.

10. A fuel system according to claim 2, wherein the separator device further includes an evaporator comprising a water reservoir fluidically coupled to the condenser water reservoir, and a heating element for heating water in the reservoir, wherein the evaporator is adapted to liberate dissolved carbon dioxide gas from the water in the evaporator reservoir.

11. A fuel system according to claim 10, wherein the evaporator water reservoir includes a fluid outlet for ejection of liberated carbon dioxide gas and/or water vapour and/or excess water.

12. A fuel system according to claim 10, wherein the heating element is adapted to be heated by the heat of combustion generated by the catalytic inerting device.

13. A fuel system according to claim 10, wherein the bottom of the condenser water reservoir is situated higher than the bottom of the evaporator water reservoir.

14. A fuel system according to claim 10, wherein the evaporator water reservoir and the condenser water reservoir are two sections of a common reservoir.

15. A fuel system according to claim 14, wherein the common reservoir has an inclined roof to encourage outgas to flow towards to the evaporator side.

16. A fuel system according to claim 14, wherein the common reservoir has an inclined floor to encourage cool water to flow to the evaporator side.

17. A fuel system according to claim 14, wherein the common reservoir includes a baffle between the evaporator and condenser sections, and the baffle preferably includes thermally insulating material.

18. A fuel system according to claim 10, wherein the evaporator water reservoir and the condenser water reservoir are fluidically coupled by an upper conduit extending between the upper parts of the reservoirs and a lower conduit extending between the lower parts of the reservoirs.

19. An aircraft including the fuel system of claim 1.

20. A method of reducing the carbon dioxide content of oxygen depleted air (ODA) produced by a catalytic inerting device for inerting a fuel tank ullage atmosphere, the method comprising separating carbon dioxide from the ODA gas before feeding the carbon dioxide depleted ODA gas to the fuel tank.

21. A method according to claim 20, wherein the separating step includes passing the ODA gas through cooled water so as to condense water vapour and scrub carbon dioxide gas from the ODA gas.

22. A method according to claim 21, wherein the separating step further includes liberating the carbon dioxide by subsequently heating the water.

23. A method according to claim 20 performed onboard an aircraft.