Fuel system and method

• US 8,904,669 B2
• Filed: 03/17/2011
• Issued: 12/09/2014
• Est. Priority Date: 03/23/2010
• Status: Active Grant

• Current Assignee: Airbus Operations Limited (Airbus SE)
• Original Assignee: Airbus Operations Limited (Airbus SE)
• Inventors: Tichborne, Franklin, Lam, Joseph K-W, Parmenter, David, Masters, Simon
• Primary Examiner(s): Gravini, Steve M
• Application Number:
  US13/634,449
• Publication Number:
  US 20130000142A1
• Time in Patent Office: 1,363 Days
• Field of Search: 343/80, 343/81, 344/13, 344/43, 34/60, 34/72, 34/80, 34/90, 341/04, 702/25, 73/310.1, 731/143.8, 951/83
• US Class Current: 34/443
• CPC Class Codes: B01D 2257/104 Oxygen
• CPC Class Codes: B01D 2259/4516 for fuel vapour recovery systems
• CPC Class Codes: B01D 2259/4575 in aeroplanes or space ships
• CPC Class Codes: B01D 53/265 by refrigeration (condensation)
• CPC Class Codes: B01D 53/8671 Removing components of defined structure not provided for in B01D53/8603 - B01D53/8668
• 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: B64D 37/34 Conditioning fuel, e.g. heating during filling B64D37/18
• CPC Class Codes: Y02T 50/40 Weight reduction

Abstract

A fuel system comprising a fuel tank, a vent tank having a duct open to the ambient atmosphere, a first vent line fluidically connecting the fuel tank ullage to the vent tank, a gas drying system including a pump and a dehumidifying device disposed within the vent tank, and a second vent line fluidically connecting a dry gas outlet of the dehumidifying device to the ullage, wherein the pump is operable to maintain a higher pressure within the ullage than in the vent tank so as to drive vapor rich gas from the ullage into the vent tank via the first vent line. Also, a method of operating the fuel system and a method of retro-fitting the gas drying system in an existing fuel system. The gas drying system may optionally be a gas drying/inerting system.

Claims

1. A fuel system comprising a fuel tank, a vent tank having a duct open to the ambient atmosphere, a first vent line fluidically connecting the fuel tank ullage to the vent tank, a gas drying system including a pump and a dehumidifying device disposed within the vent tank, and a second vent line fluidically connecting a dry gas outlet of the dehumidifying device to the ullage, wherein the pump is operable to maintain a higher pressure within the ullage than in the vent tank so as to drive vapour rich gas from the ullage into the vent tank via the first vent line.

2. A system according to claim 1, further comprising a catalyst disposed within the vent tank, wherein the catalyst is adapted to deplete one or more reactive components of the gas in the vent tank by catalytic reaction.

3. A system according to claim 2, wherein the reactive components include oxygen and/or fuel vapour.

4. A system according to claim 2, wherein the catalyst is disposed in series between the pump and the dehumidifying device to provide a combined gas drying/inerting system.

5. A system according to claim 1, wherein the dehumidifying device is of a refrigerative type having a refrigerating element in contact with gas flowing through the drying system.

6. A system according to claim 5, wherein the refrigerating element includes one or more condensing cold plates.

7. A system according to claim 5, wherein the refrigerating element is connected in a refrigeration cycle to a compressor.

8. A system according to claim 5, further comprising a discharge tube adapted to pass condensate from the refrigerating element to the ambient atmosphere.

9. An aircraft including a fuel system according to claim 1.

10. An aircraft according to claim 9, wherein the vent tank further includes a climb/dive valve.

11. A method for removing water from a fuel system, the fuel system comprising a fuel tank, a vent tank having a duct open to the ambient atmosphere, a first vent line fluidically connecting the fuel tank ullage to the vent tank, a drying system including a pump and a dehumidifying device disposed within the vent tank, and a second vent line fluidically connecting a dry gas outlet of the dehumidifying device to the ullage;

the method comprising operating the pump to provide a higher pressure within the ullage than in the vent tank so as to drive vapour rich gas from the ullage into the vent tank via the first vent line.

12. A method according to claim 11, wherein the fuel system further comprises a catalyst disposed within the vent tank;

the method further comprising bringing the gas in the vent tank into contact with the catalyst and operating the catalyst to deplete one or more reactive components of the gas in the vent tank by catalytic reaction.

13. A method according to claim 12, wherein the reactive components include oxygen and/or fuel vapour.

14. A method according to claim 12, wherein the catalyst is disposed in series between the pump and the dehumidifying device.

15. A method according to claim 12, further comprising heating waste water from the dehumidifying device using waste heat from the catalytic reaction.

16. A method according to claim 12, further comprising controlling the pump according to the temperature of the catalytic reaction, and/or the oxygen content of the gas downstream of the catalyst.

17. A method according to claim 11, further comprising jettisoning waste water from the dehumidifying device into the ambient atmosphere.

18. A method of retro-fitting a gas drying system in a fuel system, the fuel system comprising a fuel tank, a vent tank having a duct open to the ambient atmosphere, a first vent line fluidically connecting the fuel tank ullage to the vent tank, and a second vent line fluidically connecting the vent tank to the ullage;

the method comprising installing a gas drying system comprising a pump and a dehumidifying device within the vent tank, and connecting a dry outlet of the dehumidifying device to an inlet of the second vent line on the vent tank side.

19. A method according to claim 18, wherein the gas drying system forms part of a gas drying/inerting system that further comprises a catalyst for depleting one or more reactive components of gas in the vent tank by catalytic reaction.