Cryocooler suitable for gas liquefaction applications, gas liquefaction system and method comprising the same

A cryocooler for gas liquefaction applications, the cryocooler comprising:

• a coldhead with one or more refrigeration stages;
• a refrigerator compressor for distributing a compressed cryogen gas inside the coldhead, lowering the temperature of the one or more refrigeration stages, wherein said compressed cryogen gas is supplied to and returned from the coldhead through a gas circulation circuit comprising an input gas line and an output gas line, which connect the coldhead with the refrigerator compressor;
• at least one extraction orifice communicating the gas circulation circuit inside the coldhead with an external region of the one or more refrigeration stages, acting as a pass-through port which allows the gas inside the coldhead to flow to the exterior thereof;
• and
• an input gas source configured to supply cryogen gas to the refrigerator compressor through the gas circulation circuit, wherein the input gas source comprises a heat exchanging coil arranged around an external region of the coldhead and spaced from said external region such that the heat exchanging coil and the coldhead are at least partially thermally isolated from each other;
• wherein the heat exchanging coil is connected at a first end to the gas circulation circuit through the at least one extraction orifice, and at a second end to one return port connected to said gas circulation circuit, such that the compressed cryogen gas flows from the first end of the heat exchanging coil to the second end of the heat exchanging coil, and wherein said return port is arranged at the output gas line between the coldhead and the refrigerator compressor.