A refrigerant management system controls the supply of refrigerant from two or more variable speed and fixed speed compressors to a plurality of cryogenic refrigerators. The system employs a plurality of sensors to monitor and regulate the overall refrigerant supply to deliver an appropriate refrigerant supply to each of the cryogenic refrigerators. The amount of refrigerant to supply is based on an aggregate demand for refrigerant from the plurality of cryogenic refrigerators and a refrigerant correction metric. An appropriate supply of refrigerant is distributed to each cryogenic refrigerator by adjusting the speed of the variable speed compressors or, alternatively, selectively turning the compressors on or off. The speed of the variable speed compressors is adjusted by determining an amount of refrigerant to supply to the plurality of cryogenic refrigerators. If the aggregate demand for refrigerant exceeds the capacity of the compressors, then the speed of a refrigerator within the plurality of refrigerators is adjusted.

Device and method for purifying a gas mixture to produce a concentrated gas, notably neon, starting from a mixture comprising neon, said device including, in a cold box housing a cryogenic purification circuit comprising, in series, at least one unit for purifying the mixture by cryogenic adsorption at a temperature between 65K and 100K and notably 65K, then a unit for cooling the mixture to a temperature between 25 and 65 K and then a unit for cryogenic distillation of the mixture to produce the concentrated liquid at the outlet of the cryogenic distillation unit, characterized in that the unit for cooling the mixture to a temperature between 25 and 65 K comprises at least one cryocooler that extracts thermal power from the mixture via a heat exchanger.

The invention relates to a method for adjusting a cryogenic refrigeration apparatus including a plurality of liquefiers/refrigerators arranged in parallel in order to cool a single device. The method includes a step of calculating in real time the dynamic mean value of at least one operating parameter for all the liquefiers/refrigerators. The apparatus controlling in real time the at least one valve for controlling the stream of working gas of at least one liquefier/refrigerator in accordance with the difference between the instantaneous values of the parameter relative to said dynamic converge toward said dynamic mean value.

The invention relates to a method for low-temperature cooling/liquefaction of a working fluid, in particular a working fluid including helium or consisting of pure helium by means of a refrigerator/liquefier that includes a working circuit provided with a compressor station and a cold box. The refrigerator/liquefier subjects the working gas within the working circuit to a cycle that includes, in series: compressing the working fluid within the compressor station, cooling and decompressing the working fluid in the cold box, and heating the working fluid with a view to the return thereof to the compressor station. The compressor station includes one or more compression levels, each one using one or more compressors mounted on landings. The method is characterized in that the refrigerator includes a device for injecting a seal gas that is separate from the working fluid on at least one landing of the compressor(s) so as to form a gas seal that guides the working fluid leaks, coming from the working circuit, to an area for recirculating and returning the fluid into the working circuit.

A system and a method for recovery and recycling of gases which are utilized in their liquid state as refrigerants in applications that require low temperatures, throughout various pressure ranges, from slightly above atmospheric pressures to pressures near the critical point for the particular gas. The system and method are based on closed-cycle cryocoolers and utilize the thermodynamic properties of the gas to achieve optimal liquefaction rates.

Embodiments of the present invention relate to a refrigeration method, during which a user is supplied with frigories by means of a working gas, such as helium, that is cooled by having the same flow into a cold box that comprises, in series, at least one first aluminum heat exchanger having brazed plates and flanges, one second heat exchanger having welded plates, and one third aluminum heat exchanger having brazed plates and flanges in such a way that the flow of said working gas is at least partially caused to pass, consecutively, through the first exchanger, then through the second exchanger, and finally through the third exchanger before said working gas flow is directed to the user in order to supply the user with frigories.

A device for refrigerating and/or liquefying a working gas comprising helium, the device comprising a looped working circuit for the working gas includes, in series, a compression station, a cold box, a heat exchange system exchanging heat between the cooled working gas and a user, the device further comprising an additional pre-cooling system comprising at least one tank of auxiliary cryogenic fluid, such as liquid nitrogen, the cold box comprising a first cooling stage of the working gas comprising a first exchanger disposed at the output of the compression station as well as a second heat exchanger and a third heat exchanger, the first heat exchanger being of the aluminum plate-fin type, the second heat exchanger being of the tube or welded plate type, characterized in that the second and third heat exchangers are connected both serially and in parallel on the working circuit downstream of the first heat exchanger.

Refrigeration device comprising a working circuit in a loop for the working gas and comprising, in series: a compression station, a cold box, a system for the exchange of heat between the cooled working gas and a point of use, a system for the additional pre-cooling of the working gas leaving the compression station comprising an auxiliary cryogenic fluid volume, the cold box comprising a first cooling stage for the working gas comprising a first and a second heat exchanger, these being connected both in series and in parallel to the working circuit at the outlet of the compression station, the first cooling stage also comprising a third heat exchanger selectively exchanging heat with the auxiliary fluid, characterized in that the third heat exchanger is connected both in series and in parallel to the first and to the second heat exchangers, the working circuit comprising a recuperation pipe fitted with at least one valve and which connects the outlet of the third heat exchanger to the second heat exchanger.

An active gas regenerative refrigerator includes a plurality of compressor-expander units, each having a hermetic cylinder with a drive piston configured to be driven reciprocally therein, and a quantity of working fluid in each end of the cylinder. A piston seal in a central portion of the cylinder prevents passage of the working fluid between ends of the cylinder. Movement of the piston to a first extreme results in radial compression of one of the quantities of working fluid in a cylindrical gap formed between one end of the piston and an inner surface of the cylinder, while the other quantity is expanded in the opposite end of the cylinder. The piston includes a plurality of magnets arranged in pairs, with magnets of each pair positioned with like-poles facing each other. A piston drive is configured to couple with transverse magnetic flux regions formed by the magnets.

A device for refrigerating and/or liquefying a working gas comprising helium, the device comprising a looped working circuit for the working gas includes, in series, a compression station, a cold box, a heat exchange system exchanging heat between the cooled working gas and a user, the device further comprising an additional pre-cooling system comprising at least one tank of auxiliary cryogenic fluid, such as liquid nitrogen, the cold box comprising a first cooling stage of the working gas comprising a first exchanger disposed at the output of the compression station as well as a second heat exchanger and a third heat exchanger, the first heat exchanger being of the aluminum plate-fin type, the second heat exchanger being of the tube or welded plate type, characterized in that the second and third heat exchangers are connected both serially and in parallel on the working circuit downstream of the first heat exchanger.