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

Claim 17:
18. An installation for storage of liquid gas comprising a sealed, thermally insulating tank which comprises 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,
wherein the tank comprises at least one pressure sensor and a plurality of temperature sensors which are configured to determine the pressure and the temperature of the inert gas enclosed in a free volume of the insulation space,
wherein the installation comprises flow measurement devices to measure a flow of inert gas in the injection duct and in the extraction duct, and at least one leak detection device, the at least one leak detection device being configured to:
determine together with the flow measurement devices a first variation of mass of inert gas between a first moment and a second moment, with 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;
determine a first mass of the inert gas in the insulation space at the first moment and a second mass of inert gas in the insulation space at the second moment based on pressure and temperature measurements carried out by the at least one pressure sensor and the plurality of temperature sensors in a free volume of the insulation space;
calculate 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
compare the first variation of mass of inert gas with the second variation of mass of inert gas, and
trigger an alarm if a difference between the first variation and the second variation of mass of inert gas is greater than a first threshold.