Abstract: A device (HS) is provided with a refrigeration cycle unit (R) and a liquid hydrogen generation unit (P) for generating liquid hydrogen by cooling high-pressure raw material hydrogen by means of the refrigeration cycle unit (R) and by adiabatically expanding said raw material hydrogen by means of a Joule-Thomson valve (12). A first and second heat exchanger (E1, E2) are disposed along the refrigeration cycle unit (R) and the liquid hydrogen generation unit (P). The device (HS) is provided with a mechanism for generating liquid hydrogen by re-liquefying the boil-off gas generated in a liquid hydrogen storage tank. The boil-off gas is introduced into a hydrogen circulation path (1) at a section at which circulating hydrogen having an extremely low temperature flows, and the excessive circulating hydrogen generated therefrom is discharged to a raw material hydrogen path (11) from a section at which the circulating hydrogen is at room temperature.

Abstract: The boil-off gas discharged from a liquid hydrogen storage tank on a liquid hydrogen transport vessel (16) is introduced into the liquid hydrogen stored within liquid hydrogen storage tanks (19, 20) disposed on the ground by passing through a boil-off gas introduction path (17). At least a portion of the boil-off gas is re-liquefied by means of the cold temperature of the liquid hydrogen. The boil-off gas that was not re-liquefied and the gasified hydrogen generated as a consequence of the liquid hydrogen within the liquid hydrogen storage tanks (19, 20) gasifying are mixed with raw material hydrogen by being supplied to the raw material hydrogen path (11) of a liquid hydrogen production device (HS) by passing through a gasified hydrogen discharge path (21). The boil-off gas and the gasified hydrogen are re-liquefied by means of the liquid hydrogen production device (HS).