The device (100) for pre-cooling a flow (101) of a target gas to a temperature of less than or equal to 90 K comprises: a group (105) of at least two heat exchangers (106, 107, 108, 136) for exchanging heat between the target gas flow, a flow (102) of a first cooling fluid and at least one flow among a flow of a second cooling fluid and a flow of a third cooling fluid, closed circulation circuit (110) for a flow of a second cooling fluid, said fluid comprising at least methane, said circuit comprising: at least one compression stage (111, 112), at least one liquid-gas separation stage (115, 116) and at least one expansion stage (120, 121, 122) and a circulation circuit (125) for a flow of the third cooling fluid through at least one of said heat exchangers.

A helium management control system for controlling the helium refrigerant supply from a common manifold supplies cryogenic refrigerators with an appropriate helium supply. The system employs sensors to monitor and regulate the overall refrigerant supply to deliver an appropriate refrigerant supply to each of the cryogenic refrigerators depending on the computed aggregate cooling demand of all of the cryogenic refrigerators. An appropriate supply of helium is distributed to each cryopump by sensing excess and sparse helium and redistributing refrigerant accordingly. If the total refrigeration supply exceeds the demand, or consumption, excess refrigerant is directed to cryogenic refrigerators which can utilize the excess helium to complete a current cooling function more quickly. If the total refrigeration demand exceeds the total refrigeration supply, the refrigerant supply to some or all of the cryogenic refrigerators will be reduced accordingly so that detrimental or slowing effects are minimized based upon the current cooling function.

Apparatus and processes for liquefying process gases using multi-stage active magnetic regenerative refrigerators are disclosed. The apparatus and processes can be configured to liquefy process streams that liquefy below .sup.200 K, such as ethane, methane, argon, nitrogen, neon, hydrogen and/or helium process gases. Active magnetic regenerative liquefiers use multiple successive active magnetic regenerator stages, with each stage using a compositionally distinct magnetic refrigerant material having a distinct Curie temperature. In some aspects, the refrigerant material in each successive stage has a Curie temperature of about 20 K-40K different from that of neighboring stages. Heat transfer fluid flows are directed to improve system efficiency.

Cryogenic refrigeration device comprising a working circuit intended to cool a working fluid circulating in the said circuit, the working circuit comprising, arranged in series in a loop: a compression portion, a cooling portion, a portion with valve(s), an expansion portion and a reheating portion, in order to subject the working fluid to a recuperative working cycle comprising compression, then cooling, then expansion and then reheating to prepare for a new cycle, wherein the compression portion comprises at least one compressor having a linear piston driven by a linear motor, the expansion proportion comprises at least one expander with a linear piston, the portion with valve(s) comprises at least one regulating valve linearly actuated by a linear motor and controlled in order to supply or extract the working fluid from the at least one expansion piston.

An arrangement comprising at least one liquefaction plant for liquefying a gaseous medium to produce a liquefied medium; and at least one storage tank for storing the liquefied medium. A first transfer line is provided which is connected between the liquefaction plant and the storage tank, for transferring liquefied medium from the liquefaction plant into the storage tank. A second transfer line is connected between the liquefaction plant and the storage tank, for transferring gaseous medium from the storage tank into the liquefaction plant. The second transfer line, which used for transferring medium from the storage tank into the liquefaction plant, is arranged so that it is routed at least partially through the area of the storage tank in which the liquefied medium is stored in use.

An arrangement comprising at least one liquefaction plant for liquefying a gaseous medium to produce a liquefied medium; and at least one storage tank for storing the liquefied medium. At least one first transfer line is connected between the liquefaction plant and the storage tank, for transferring liquefied medium from the liquefaction plant into the storage tank. At least one second transfer line is connected between the liquefaction plant and the storage tank, for transferring gaseous medium from the storage tank into the liquefaction plant. At least one shut-off valve is provided in each transfer line. The apparatus further includes a bypass line

A system for recovering compression energy from a gas, the system comprising an organic Rankine cycle module and an adiabatic compressor, the organic Rankine cycle module comprising a heat transfer fluid and the adiabatic compressor comprising N adiabatic compression stages for the gas, N being greater than or equal to 2, and, downstream of each adiabatic compression stage, two heat exchangers, a first heat exchanger configured to extract heat from the gas leaving the adiabatic compression stage and to heat the heat transfer fluid passing through the first heat exchanger and a second heat exchanger configured to extract heat from the gas leaving the first heat exchanger to a cold source passing through the second heat exchanger. A liquefier comprising such a system and method for recovering compression energy from a gas.

The present invention relates to a cryocooler suitable for gas liquefaction applications, that comprises a coldhead with one or more refrigeration stages; further comprising: a refrigerator compressor for distributing compressed gas-phase cryogen inside the coldhead; a heat exchanging coil arranged at least partially around the external region of the coldhead; at least one extraction orifice communicating a gas circulation circuit inside the coldhead with the heat exchanging coil; acting said extraction orifice/s as pass-through port/s which allow the gas inside the coldhead to flow through the inside of the heat exchanger coil for exchanging heat with the exterior thereof, and wherein the heat exchanging coil is adapted to connect and redirect the gas to one return port connected to the gas circulation circuit. Another object of the invention relates to a cryogen-gas liquefaction system and a method for liquefaction of gases that comprises said system.

The present invention discloses a hydrogen or helium throttling liquefaction system using direct current (DC) flow from the cold and hot ends of the regenerative cryocoolers, which belongs to the technical field of refrigeration and cryogenics. It includes a regenerative cryocooler module, a hot-end DC flow module, a cold-end DC flow module, a throttling liquefaction module, and a gas-phase circulation module. The modules are interconnected to form a closed loop for the flow of hydrogen or helium working fluid. DC flow is introduced from the cold and hot ends of the regenerative cryocooler through the DC flow pipelines and DC flow valves. The hot-end DC flow exchanges heat with the reflowing low-temperature working fluid and is cooled down. After that, it mixes with the cold-end DC flow and enters the throttling liquefaction module to generate liquid phase through throttling and liquefaction. After the liquid phase has output cooling capacity, it flows through the gas-phase circulation module and then enters the back-pressure chamber of the compressor to complete the cycle. Compared with the existing small-scale hydrogen and helium liquefaction technology using regenerative cryocoolers, the present invention has the advantages of simple structure, easy installation, high heat transfer efficiency and liquefaction efficiency of the system.

The present invention relates to a refrigerant composition. According to the invention it is envisioned that the composition comprises comprising an inert gas selected from nitrogen, argon, neon and a mixture thereof, and a mixture of at least two C.sub.1-C.sub.5 hydrocarbons. The present invention further relates to the use of the refrigerant composition in a method for liquefying a gaseous substance, particularly hydrogen or helium.