Patent ID: 11959593
Assignee: GAZTRANSPORT ET TECHNIGAZ
Field: Measurement (Instruments)
Classification: CPC F  G | IPC F  G

Claim 0:
1. A detection method for detecting a leak from a sealed, thermally insulating tank for liquid gas, said tank comprising a sealing membrane surrounding the liquid gas, the sealing membrane being surrounded by an insulation space which separates the sealing membrane from a sealed support wall, the insulation space being filled with solid, thermally insulating materials and an inert gas, the insulation space having at least one injection duct arranged to inject the inert gas and at least one extraction duct arranged to extract the inert gas, the detection method comprising the following steps:
injecting inert gas into the insulation space;
removing inert gas from the insulation space;
determining a first variation of mass of inert gas between a first moment and a second moment, the first variation corresponding to the resultant of the total masses of inert gas added by the injection duct and removed by the extraction duct, between the first moment and the second moment;
determining a first mass of inert gas in the insulation space at the first moment and second mass of inert gas in the insulation space at the second moment by means for measuring the pressure and temperature in a free volume of the insulation space;
calculating a second variation of mass of inert gas between the first moment and the second moment, corresponding to the difference between the second mass and the first mass of inert gas; and
comparing the first variation of mass of inert gas with the second variation of mass of inert gas, and triggering an alarm if a difference between the first variation and the second variation of mass of inert gas is greater than a first threshold.