A system for cooling a feed stream including hydrogen or helium with a mixed refrigerant includes a pre-cooling heat exchanger. A compression system has an inlet in fluid communication with the pre-cooling heat exchanger and receives and increases a pressure of a refrigerant vapor stream including hydrogen and/or helium mixed with at least one other refrigerant such that the molecular weight of the mixture is greater than 6 kg/kgmol. The compression system has an outlet in fluid communication with the pre-cooling heat exchanger. A first refrigerant separation device receives fluid from the pre-cooling heat exchanger and has a liquid outlet in fluid communication with the pre-cooling heat exchanger and a vapor outlet. A refrigerant purifier has a purifier inlet in fluid communication with the vapor outlet of the first refrigerant separation device and an outlet in fluid communication with the pre-cooling heat exchanger.

Disclosed are a method and a device for manufacturing liquid hydrogen by offshore off-grid superconducting wind turbine. The method comprises the following steps: electrolyzing seawater to obtain hydrogen based on electric energy output by an offshore off-grid superconducting wind turbine generator, liquefying the hydrogen into prepared liquid hydrogen, and outputting a part of the liquid hydrogen as the refrigerant of the offshore off-grid superconducting wind turbine generator. The device comprises a liquid preparation platform, an offshore off-grid superconducting wind turbine generator, a seawater electrolysis unit, a hydrogen liquefaction unit and a liquid hydrogen storage unit, wherein the power ends of the seawater electrolysis unit and the hydrogen liquefaction unit are connected with the output end of the offshore off-grid superconducting wind turbine generator, and the hydrogen liquefaction unit is connected with the coolant input end of the offshore off-grid superconducting wind turbine generator.

A hydrogen feed stream is introduced into a primary refrigeration system of a precooling system and cooling the hydrogen stream to a first precooling temperature. From there, the precooled hydrogen stream is then introduced to a secondary refrigeration system of the precooling system and cooling the precooled hydrogen stream to a second temperature. Next, the cooled hydrogen stream is then liquefied in the liquefaction system to produce liquid hydrogen.

An integrated industrial unit is provided, which can include: a nitrogen source configured to provide liquid nitrogen; a hydrogen source; a hydrogen liquefaction unit, wherein the hydrogen liquefaction unit comprises a precooling system, and a liquefaction system; and a liquid hydrogen storage tank, wherein the precooling system is configured to receive the gaseous hydrogen from the hydrogen source and cool the gaseous hydrogen to a temperature between 75 K and 100 K, wherein the precooling system comprises a primary refrigeration system and a secondary refrigeration system, wherein the liquefaction system is in fluid communication with the precooling system and is configured to liquefy the gaseous hydrogen received from the precooling system to produce liquid hydrogen, wherein the liquid hydrogen storage tank is in fluid communication with the liquefaction system and is configured to store the liquid hydrogen received from the liquefaction system.

A hydrogen feed stream is introduced into a primary refrigeration system of a precooling system and cooling the hydrogen stream to a first precooling temperature. From there, the precooled hydrogen stream is then introduced to a secondary refrigeration system of the precooling system and cooling the precooled hydrogen stream to a second temperature. Next, the cooled hydrogen stream is then liquefied in the liquefaction system to produce liquid hydrogen. The refrigeration is provided by expansion of a pressurized gaseous nitrogen stream and vaporization of a liquid nitrogen stream that is sourced from a nearby air separation unit.

Disclosed is a low-temperature refrigeration device comprising a working circuit that forms a loop and contains a working fluid the working circuit forming a cycle which includes, connected in series: a compression mechanism, a cooling mechanism, an expansion mechanism and a heating mechanism, the device further comprising a refrigeration heat exchanger for extracting heat from at least one member by exchanging heat with the working fluid flowing in the working circuit, the compression mechanism comprising two separate compressors, the mechanism for cooling the working fluid comprising two cooling heat exchangers which are arranged respectively at the outlet of the two compressors and ensure heat exchange between the working fluid and a cooling fluid, each cooling heat exchanger comprising a cooling fluid inlet and a cooling fluid outlet, characterized in that the cooling fluid outlet of one of the two cooling heat exchangers is connected to the cooling fluid inlet of the other cooling heat exchanger.

Disclosed is a refrigeration and/or liquefaction method using a system that includes a low-temperature refrigeration device comprising a working circuit which forms a loop and contains a working fluid, the working circuit forming a cycle comprising, connected in series: a compression mechanism, a cooling mechanism, an expansion mechanism and a heating mechanism the refrigeration device further comprising a cooling exchanger for extracting heat from the useful fluid stream by exchanging heat with the working fluid flowing in the working circuit, the system comprising a pipe through which the useful fluid stream flows in the cooling exchanger, the method comprising a cooling step in which the refrigeration device is in a first operating mode for cooling the cooling exchanger while a useful fluid stream flows in the cooling exchanger, the method comprising, after said cooling step, a step of cleaning impurities that have solidified in the cooling exchanger, characterized in that during the cleaning step, the refrigeration device is in a second operating mode in which the working gas flows in the working circuit but in which the cooling exchanger cools less intensely than in the first operating mode.

The invention relates to a method for cooling and/or liquefying a user fluid flow the method using a cooling and/or liquefying system comprising a low-temperature refrigeration device, the refrigeration device comprising a working circuit forming a loop and containing a working fluid, the refrigeration device comprising a cooling exchanger intended to extract heat from the user fluid flow by heat exchange with the working fluid circulating in the working circuit, the working circuit forming a cycle comprising, in a series: a compression mechanism a cooling mechanism, an expansion mechanism, and a reheating mechanism, the system comprising a pipe for circulation of the user fluid flow to be cooled in heat exchange with the cooling exchanger of the refrigeration device, the method comprising a step of cooling a user fluid flow in the cooling exchanger and after this cooling step, a step of cleaning impurities solidified in the cooling exchanger, the cleaning step comprising stopping of the refrigeration device and simultaneously, circulation of a user fluid flow in the cooling exchanger.

Systems and methods for liquefying a gaseous hydrogen that include a first refrigeration stage and a second refrigeration stage. The first refrigeration stage includes a first heat exchanger configured to flow a first refrigerant to pre-cool the gaseous hydrogen. The second refrigeration stage includes a second heat exchanger configured to flow a second refrigerant to liquefy and sub-cool the hydrogen. The second refrigerant is split into two streams that flow through two compressor-expanders and multiple passes through the second heat exchanger before being recombined to repeat the second refrigeration stage circuit.

Systems and methods for liquefying a gaseous hydrogen that include a first refrigeration stage and a second refrigeration stage. The first refrigeration stage includes a first heat exchanger configured to flow a first refrigerant to pre-cool the gaseous hydrogen. The second refrigeration stage includes a second heat exchanger configured to flow a second refrigerant to liquefy and sub-cool the hydrogen. The second refrigerant is split into two streams that flow through two compressor-expanders and multiple passes through the second heat exchanger before being recombined to repeat the second refrigeration stage circuit.