Cooling system, preferably adapted for use in or including a refrigeration plant and/or liquefier plant, having a refrigeration circuit (1) configured to use a refrigerant including a mixture of helium and neon; wherein the refrigerant is based on a raw mixture, preferably is the raw mixture, including helium and neon, extracted from air by an air separation plant (2). Method for producing a refrigerant usable in a refrigeration circuit (1), comprising: extracting a raw mixture including helium and neon from air, wherein the raw mixture preferably further includes nitrogen and hydrogen; and using the raw mixture as the refrigerant or obtaining the refrigerant from the raw mixture.

The present invention relates to a refrigerant composition comprising neon and hydrogen. The present invention further relates to the use of the refrigerant composition in liquefying gaseous substances such as hydrogen or helium.

Closed-loop refrigeration cycles for liquid oxygen densification are disclosed. The disclosed refrigeration cycles may be turbine-based refrigeration cycles or a Joule-Thompson (JT) expansion valve based refrigeration cycles and include a refrigerant or working fluid comprising a mixture of neon or helium together with nitrogen and/or oxygen.

An expansion turbine configured such that even when pressure of process gas steeply changes, the amount of process gas leaking from a gap between an impeller and a cover is made small. The expansion turbine includes a gas supply passage which is connected to any one of a gas supply passage and a gas discharge passage and through which gas is supplied to a region located between a rotor member and a casing member.

Closed-loop refrigeration cycles for liquid oxygen densification are disclosed. The disclosed refrigeration cycles may be turbine-based refrigeration cycles or a Joule-Thompson (JT) expansion valve based refrigeration cycles and include a refrigerant or working fluid comprising a mixture of neon or helium together with nitrogen and/or oxygen.

Plant and process for the production of liquid methane from a feed gas stream comprising at least methane and carbon dioxide. A feed gas stream is injected into a CO.sub.2 crystallizer in countercurrent fashion against a stream of predominantly liquid methane, thereby crystallizing amounts of carbon dioxide from the feed gas stream. Gaseous methane recovered from the CO.sub.2 crystallizer is liquefied at a liquefaction exchanger.

The amount of consumption of gas is reduced when the gas is expanded to be cooled by using a plurality of expansion turbines. A high-pressure expansion turbine includes: a gas supply passage through which bearing gas is supplied to a bearing portion; and a gas discharge passage through which the bearing gas which has been supplied from the gas supply passage to the bearing portion is discharged from the bearing portion. A low-pressure expansion turbine includes: a gas supply passage through which the bearing gas is supplied to a bearing portion; and a gas discharge passage through which the bearing gas which has been supplied from the gas supply passage to the bearing portion is discharged from the bearing portion. The bearing gas discharged from the gas discharge passage of the high-pressure expansion turbine is supplied to the gas supply passage of the low-pressure expansion turbine.

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.

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.