Hydrogen liquefaction device and hydrogen liquefaction method

A hydrogen liquefaction device, comprising:

• a hydrogen pipe for connecting a hydrogen supply unit in which gaseous hydrogen is stored and a storage container in which liquid hydrogen liquefied in a liquid state is stored;
• and
• a heat exchange unit that cools hydrogen by a plurality of heat exchangers installed on the hydrogen pipe at predetermined intervals and having lower cooling temperatures from front to rear based on a flow direction of hydrogen so that hydrogen being introduced from the hydrogen supply unit and flowing through the hydrogen pipe toward the storage container can be cooled and liquefied in multiple stages in a process of passing through the hydrogen pipe and be discharged to the storage container as liquid hydrogen;
• wherein the heat exchanger includes:
• a cryocooler;
• a heat transfer unit configured to be in thermal contact with the cryocooler;
• and
• a heat exchange unit configured to be in thermal contact with the heat transfer unit and including a micro-channel formed therein through which hydrogen can flow to perform heat exchange between the cryocooler and hydrogen through the heat transfer unit;
• wherein the heat transfer unit includes one of a heat pipe formed in a pipe shape elongated in a vertical direction so that one end thereof can be in thermal contact with the cryocooler;
• and
• a heat conductor formed in a pillar shape elongated in a vertical direction so that one end thereof can be in thermal contact with the cryocooler,
• wherein the heat exchange unit is formed to surround the heat pipe, which is formed in a pipe shape, in an annular shape, and is formed with a micro-channel through which hydrogen can flow such that heat exchange between the cryocooler and hydrogen can be performed by heat convection of the refrigerant, or is formed as the micro-channel, which is formed to penetrate a surface of the heat conductor or an inside of the heat conductor so as to expand a heat transfer area of the heat conductor, such that heat exchange between the cryocooler and hydrogen can be performed by heat conduction of the heat conductor.

A hydrogen liquefaction method, comprising:

• (a) introducing hydrogen into a hydrogen pipe in a gaseous state from a hydrogen supply unit at room temperature in which hydrogen is stored;
• (b) cooling and liquefying hydrogen in a process of passing through the hydrogen pipe by at least one or more heat exchangers installed on the hydrogen pipe;
• and
• (c) discharging liquid hydrogen liquefied in a liquid state from the hydrogen pipe and storing it in a storage container;
• wherein (b) includes:
• (b-1) cooling the heat transfer unit by a cryocooler that is formed to be in thermal contact with the heat transfer unit of the heat exchanger;
• (b-2) cooling hydrogen by heat exchange between the cryocooler and the heat exchange unit of the heat exchanger, which is configured to be in thermal contact with the heat transfer unit and includes a micro-channel formed therein through which hydrogen flows, via an intermediary of the heat transfer unit.