Leakage detection for pressurized fuel tanks

1. A fuel tank for storing a pressurized fuel, the fuel tank comprising:

a tank enclosure defining a tank volume, wherein the tank enclosure comprises:

an inner pressure vessel that comprises at least one reinforced layer made from multiple plies of a carbon fiber reinforced polymer structure;

an insulation sheathing that covers an outer side of the inner pressure vessel and comprises at least two reflective layers and at least one spacer layer between the at least two reflective layers;

an outer shell that comprises a layer made from multiple plies of a carbon fiber reinforced polymer structure; and

at least one leakage detection device comprising:

a fuel-sensing tracer configured to alter optical properties thereof in a presence of a predetermined fuel; and

a light-wave conducting component that is in optical contact with the fuel sensing tracer;

wherein light travelling within the light-wave conducting component is modifiable by altered optical properties of the fuel sensing tracer to produce modified light that is indicative of a presence of fuel at a location of the fuel sensing tracer;

wherein the at least one leakage detection device is arranged within at least one of the inner pressure vessel, the insulation sheathing, and the outer shell.

2. The fuel tank of claim 1 , wherein:

the fuel sensing tracer comprises at least a chemo-chromatic substance attached to a sensing base surface;

the chemo-chromatic substance is chemo-chromatic sensitive to the predetermined fuel; and

the chemo-chromatic substance is chemo-chromatic sensitive to hydrogen.

3. The fuel tank of claim 2 , wherein:

the chemo-chromatic substance is attached to at least one of:

a portion along the light-wave conducting component, wherein one end of the light-wave conducting component is configured for light to enter the light-wave conducting component and another end of the light-wave conducting component is configured for light to exit the light-wave conducting component; and

an end portion of the light-wave conducting component, wherein another end of the light-wave conducting component is configured for light to enter and exit the light-wave conducting component.

4. The fuel tank of claim 2 , wherein:

the chemo-chromatic substance is:

applied to an end of the light-wave conducting component; or

attached to a tape mounted on an end of the light-wave conducting component; and

another end of the light-wave conducting component is configured for light to enter and exit the light-wave conducting component.

5. The fuel tank of claim 1 , wherein:

the light-wave conducting component comprises at least one optical fiber—that comprises a first end and a second end; and

either:

the first end is configured for light to enter the light-wave conducting component and the second end is configured for light to exit the light-wave conducting component; or

the first end is configured for light to enter and exit the light-wave conducting component and a reverse of a light travelling direction is at the second end.

6. The fuel tank according to claim 1 , wherein the light-wave conducting component of the at least one leakage detection device is a multi-functional element within the tank enclosure fulfilling at least one of a group of: electrical insulating and structural supporting, addition to light-wave conducting.

7. The fuel tank according to claim 1 , wherein the light-wave conducting component of the at least one leakage detection device is a glass fiber of an existing glass fiber layer of at least one of a group of: the inner pressure vessel, the insulation sheathing, and the outer shell.

8. The fuel tank according to claim 1 , wherein the light-wave conducting component of the at least one leakage detection device is provided as at least one glass fiber added to at least one of a group of the inner pressure vessel, the insulation sheathing, and the outer shell.

9. The fuel tank according to claim 1 , wherein:

the fuel tank is a pressurized vessel comprising a primary extension direction along a longitudinal axis and a secondary extension transverse to the longitudinal axis, such that the pressurized vessel forms a cylinder; and

a majority of an extent of the light-wave conducting component extends along:

an axial direction of the cylinder;

a circumferential direction of the cylinder; and

a helical direction along the cylinder.

10. The fuel tank according to claim 1 , wherein the at least one leakage detection device is a plurality of leakage detection devices that are arranged in a sensor pattern across a vessel forming the fuel tank.

11. A leakage detection system for an aircraft, the leakage detection system comprising:

at least one fuel tank according to claim 1 ;

a light source in optical contact with the light-wave conducting component and configured to emit light into the light-wave conducting component;

a light detector in optical contact with the light-wave conducting component and configured to receive light from the light-wave conducting component;

a processor configured to:

receive data from the light detector representing the received light;

determine, based on the received light, a presence of the fuel within the tank enclosure indicating a leakage of the fuel tank; and

generate indicator data; and

a display configured to display the indicator data.

12. A method for manufacturing the leakage detection system according to claim 11 , the method comprising:

providing the fuel-sensing tracer;

providing the light-wave conducting component; and

arranging the fuel-sensing tracer and the light-wave conducting component such that the light-wave conducting component is in optical contact with the fuel sensing tracer;

wherein light travelling within the light-wave conducting component is modifiable by optical properties of the fuel sensing tracer to produce a modified light that is indicative of the presence of the predetermined fuel at a location of the fuel sensing tracer.

13. The method of claim 12 , wherein:

the fuel sensing tracer comprises at least a chemo-chromatic substance attached to a sensing base surface;

the chemo-chromatic substance e is chemo-chromatic sensitive to the predetermined fuel; and

the chemo-chromatic substance is chemo-chromatic sensitive to hydrogen.

14. The method of claim 13 , wherein:

the chemo-chromatic substance is attached to at least one of:

a portion along the light-wave conducting component, wherein one end of the light-wave conducting component is configured for light to enter the light-wave conducting component and another end of the light-wave conducting component is configured for light to exit the light-wave conducting component; and

an end portion of the light-wave conducting component, wherein another end of the light-wave conducting component is configured for light to enter and exit the light-wave conducting component.

15. The method of claim 13 , wherein:

the chemo-chromatic substance is:

applied to an end of the light-wave conducting component; or

attached to a tape mounted on an end of the light-wave conducting component; and

another end of the light-wave conducting component is configured for light to enter and exit the light-wave conducting component.

16. The method of claim 12 , wherein:

the light-wave conducting component comprises at least one optical fiber that comprises a first end and a second end; and

either:

the first end is configured for light to enter the light-wave conducting component and the second end is configured for light to exit the light-wave conducting component; or

the first end is configured for light to enter and exit the light-wave conducting component and a reverse of a light travelling direction is at the second end.

17. The method of claim 12 , wherein the fuel sensing tracer is a reversible sensor that can be brought back to an initial sensing state by at least one of a group of:

passing of a preset amount of time;

supplying of a resetting substance; and

supplying of a resetting amount of energy.

18. A method for detecting leakage of a pressurized fuel tank, the method comprising:

providing the pressurized fuel tank, which comprises a tank enclosure that defines a tank volume, which comprises:

an inner pressure vessel that comprises at least one reinforced layer made from multiple plies of a carbon fiber reinforced polymer structure;

an insulation sheathing that covers an outer side of the inner pressure vessel and comprises at least two reflective layers and at least one spacer layer between the at least two reflective layers;

an outer shell that comprises a layer made from multiple plies of a carbon fiber reinforced polymer structure; and

at least one leakage detection device comprising a fuel-sensing tracer and a light-wave conducting component;

generating light by a light source;

transmitting the light into the light-wave conducting component;

altering optical properties of the fuel-sensing tracer in a presence of a predetermined fuel, which modifies the light transmitted into and travelling within the light-wave conducting component to produce a modified light;

transmitting the modified light through the light-wave conducting component towards a light detector; and

detecting the modified light to determine the presence of the predetermined fuel to indicate leakage of the predetermined fuel from the pressurized fuel tank.