Methods and systems for evaporative cooling infrared thermographic leak detection
AssigneeThe Boeing Company
InventorPaul van Staden
Life of this patent
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Abstract
A method for leak testing a vessel is described. The method includes providing an environment within the vessel that is at a lower humidity than the environment surrounding the vessel, and using a thermographic imaging system to identify any leaks associated with the vessel. The leaks are identified based on evaporative cooling that occurs when a portion of the lower humidity environment escapes from the vessel and mixes with the higher humidity environment surrounding the vessel.
Claims20
A method for leak testing a commercial aircraft fuel tank, said method comprising:
- providing an environment within the fuel tank that is at a lower humidity than the environment surrounding the fuel tank, and that is at a pressure less than about 4 psi greater than a pressure of the environment surrounding the fuel tank by at least forming a quasi-closed loop in which air is drawn from the fuel tank, routed to a dehumidifier, and pumped back into the fuel tank;
- and
- using a thermographic imaging system to identify any leaks associated with the fuel tank by detecting any areas of decreased temperature resulting from evaporative cooling that occurs when a portion of the lower humidity environment escapes from the fuel tank and mixes with the higher humidity environment surrounding the fuel tank.
A leak testing method comprising:
- pressurizing a commercial aircraft fuel tank to be leak tested to a pressure less than about 4 psi greater than a pressure of the environment surrounding the fuel tank with a gas having a humidity less than a gas surrounding the fuel tank by at least forming a quasi-closed loop in which air is drawn from the fuel tank, routed to a dehumidifier, and pumped back into the fuel tank;
- sensing any temperature drops proximate the fuel tank caused by localized evaporation of moisture from external gas using thermographic imaging;
- and
- identifying the temperature drops as leakages associated with the fuel tank.
A system for testing a commercial aircraft fuel tank for leakages, said system comprising:
- at least one device for providing a humidity differential between an inside of the fuel tank and the exterior of the fuel tank;
- a pump operable to provide a pressure differential of less than about 4 psi between the interior of the fuel tank and the exterior of the fuel tank;
- and
- a thermographic imaging system operable to identify any leaks associated with the fuel tank when the fuel tank is pressurized to less than about 4 psi, the leaks identifiable with said imaging system based on evaporative cooling that occurs when a portion of the lower humidity environment mixes with the higher humidity environment, wherein said at least one device, said pump, and said fuel tank are configured in a quasi-closed loop in which air is drawn from the fuel tank, routed to said at least one device, and pumped back into the fuel tank.
Dependencies are inferred from the claim text.