Facility and method for supplying liquefied hydrogen

1 . A facility for supplying liquefied hydrogen, comprising:

a source of gaseous hydrogen;

a liquefier configured to be fed with gaseous hydrogen by the source and to produce liquefied hydrogen;

a first liquefied hydrogen tank configured to receive liquefied hydrogen coming from the liquefier, via a first feed pipe, and being configured to store this liquefied hydrogen at a pressure which is below a first predetermined pressure;

at least one transfer line configured to allow liquefied hydrogen to be transferred from the first tank to a tank to be filled, the transfer line being connected to the first tank by at least one transfer pipe;

a second liquefied hydrogen tank configured to receive liquefied hydrogen coming from the first tank, via a second feed pipe, the second tank being configured to store this liquefied hydrogen;

a pressurization system configured to allow the second tank to be pressurized at a second predetermined pressure which is greater than the first predetermined pressure;

at least one vaporization pipe connecting the second tank and the pressurization system to the transfer line in order to allow gaseous hydrogen under pressure to be transferred from the second tank and from the pressurization system to the transfer line, for the purpose of an operation of purging and cleaning the transfer line; and

a vaporization system configured to heat the gaseous hydrogen flowing in the vaporization pipe.

2 . The facility according to claim 1 , further comprising a control unit configured to selectively transfer gaseous hydrogen under pressure from the second tank and from the pressurization system to the transfer line when the liquefier is stopped, for the purpose of an operation of purging and cleaning the transfer line.

3 . The facility according to claim 1 , further comprising a set of isolation valves configured to fluidically isolate the second tank from the first tank and to fluidically isolate the second tank from the transfer line, in order to allow the second tank to be pressurized.

4 . The facility according to claim 1 , wherein the pressurization system comprises a pressurization pipe which connects the lower and upper parts of the second tank and comprises an atmospheric heater for converting a portion of the liquefied hydrogen flowing in the pressurization pipe into gaseous hydrogen.

5 . The facility according to claim 1 , wherein the transfer line is configured to allow hydrogen vapour to be transferred from the tank to be filled to the liquefier, the transfer line being connected to the liquefier by at least one vapour collection pipe.

6 . The facility according to claim 1 , wherein the vaporization pipe is connected to the liquefier, via a purge pipe, in order to allow gaseous hydrogen under pressure to be transferred from a high-pressure cycle of the liquefier to the transfer line, for the purpose of an operation of purging and cleaning the transfer line.

7 . A method for supplying liquefied hydrogen using the facility as claimed in claim 1 , the method comprising the following steps:

a) transferring liquefied hydrogen from the first tank to the second tank;

b) pressurizing the second tank to the second predetermined pressure; and

c) transferring gaseous hydrogen under pressure from the second tank and from the pressurization system to the transfer line, thereby purging and cleaning the transfer line.

8 . The method according to claim 7 , wherein step b) is carried out before step c), step b) being carried out for a predetermined period of time which is configured to allow the pressure in the second tank to reach the second predetermined pressure.

9 . The method according to claim 7 , wherein steps a) and b) and c) are carried out only when the liquefier is stopped.

10 . The method according to claim 7 , further comprising the step d) of transferring gaseous hydrogen under pressure from the liquefier to the transfer line, for the purpose of an operation of purging and cleaning the transfer line.