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.

A method including, compressing a first hydrogen stream, and expanding a portion to produce a hydrogen refrigeration stream, cooling a second hydrogen stream thereby producing a cool hydrogen stream, wherein at least a portion of the refrigeration is provided by a nitrogen refrigeration stream, further cooling at least a portion of the cool hydrogen stream thereby producing a cold hydrogen stream, and a warm hydrogen refrigeration stream wherein at least a portion of the refrigeration is provided by the hydrogen refrigeration stream, compressing the warm hydrogen refrigeration stream, mixing the balance of the compressed first hydrogen stream with a high-pressure gaseous nitrogen stream to form an ammonia synthesis gas stream, and wherein the first hydrogen stream and the warm hydrogen refrigeration stream are compressed in the same compressor.

A method of liquefying hydrogen, including dividing a hydrogen stream into at least a first fraction and a second fraction, introducing the first fraction into a refrigeration cycle of a hydrogen liquefaction unit, thereby liquefying a product hydrogen stream, withdrawing one or more warm hydrogen stream(s) from the hydrogen liquefaction unit, and returning the one or more warm hydrogen stream to the hydrogen stream, wherein the second fraction is combined with a high-pressure nitrogen stream to form an ammonia synthesis gas stream.

The method for producing liquid hydrogen can include the steps of: introducing pressurized natural gas from a high pressure natural gas pipeline to a gas processing unit under conditions effective for producing a purified hydrogen stream; and introducing the purified hydrogen stream to a hydrogen liquefaction unit under conditions effective to produce a liquid hydrogen stream, wherein the hydrogen liquefaction unit provides a warm temperature cooling and a cold temperature cooling to the purified hydrogen stream, wherein the warm temperature cooling is provided by utilizing letdown energy of a pressurized stream selected from the group consisting of a nitrogen stream sourced from a nitrogen pipeline, a natural gas stream sourced from the high pressure natural gas pipeline, an air gas sourced from an air separation unit, and combinations thereof, wherein the cold temperature is provided by utilizing letdown energy of the purified hydrogen stream.

A raw material gas liquefying device includes a feed line which feeds a raw material gas, a refrigerant circulation line which circulates a refrigerant, the refrigerant circulation line including an expansion unit of a turbine type which expands the refrigerant to generate cryogenic energy, and an expansion unit entrance valve provided at an entrance side of the expansion unit, a heat exchanger which exchanges heat between the raw material gas and the refrigerant, a cooler which performs initial cooling of the raw material gas and the refrigerant by heat exchange with liquid nitrogen, and a controller which manipulates the opening rate of the expansion unit entrance value and performs a feedback control so that the rotation speed of the expansion unit reaches a predetermined target value, and outputs the opening rate command to the expansion unit entrance valve, at start-up and stop of the expansion unit.

The invention relates to an installation and a process for production of a cryogenic fluid, in particular of liquefied hydrogen, comprising, positioned in at least one cold box, a set of heat exchangers in thermal exchange with the circuit for hydrogen to be cooled, the installation comprising a device for pre-cooling, which is configured to pre-cool the circuit for gas to be cooled to a first determined temperature, and a device for cryogenic cooling which is configured to cool the circuit for gas to be cooled to a second determined temperature, lower than the first temperature, the cycle gas cooling unit and/or the cycle gas heating unit comprise(s) one or more first cycle heat exchangers distinct from the first part of the pre-cooling heat exchangers of the circuit for the gas to be cooled, these first cycle heat exchangers also being cooled by thermal exchange with the pre-cooling fluid circuit of the pre-cooling device.

Liquid hydrogen is produced while reducing emission of carbon dioxide to the atmosphere. Provided is a liquid hydrogen production device including: a carbon dioxide cycle plant (2), which includes a turbine (23) using a carbon dioxide fluid as a driving fluid, and is configured to drive the turbine (23) to generate motive power with use of a carbon dioxide cycle in which the carbon dioxide fluid discharged from the turbine (23) is increased in pressure and heated and is then re-supplied to the turbine (23); and a liquefaction plant (4) configured to cool gaseous hydrogen by heat exchange with a refrigerant, to obtain liquid hydrogen. The motive power generated by driving of the turbine (23) is used as motive power to be consumed in the liquefaction plant (4).

Disclosed is a device for refrigerating or liquefying a fluid such as natural gas or hydrogen, comprising a fluid circuit that is to be cooled and has an upstream end for connection to a source of gaseous fluid as well as a downstream end for connection to a member for collecting the cooled or liquefied fluid, the device comprising a heat exchanger assembly in heat exchange with the fluid circuit to be cooled, the device comprising a refrigerator in heat exchange with at least a portion of the exchanger assembly, the refrigerator being of the type that has a cycle for refrigerating a cycle gas containing at least one of: helium, hydrogen, nitrogen or neon; said refrigerator comprising in series in a cycle circuit: a mechanism for compressing the cycle gas, at least one member for cooling the cycle gas, a mechanism for expanding the cycle gas, and at least one member for reheating the expanded cycle gas, wherein the compression mechanism comprises a plurality of compression stages in series composed of a centrifugal compressor assembly, the compression stages being mounted on a set of shafts that are rotationally driven by a motor assembly, the at least one member for cooling the cycle gas comprising at least one heat exchanger at the outlet of at least one compression stage in heat exchange with the cycle circuit, said heat exchanger being cooled by a heat transfer fluid, characterized in that the compression mechanism comprises at least two compression stages that are arranged successively in series and do not include any member for cooling the cycle gas such as a heat exchanger therebetween.

In an aspect, a system comprises a water stream in fluid communication with an electrolyzer; the electrolyzer comprising an anode and a cathode side chamber; a deep space oxygen radiator in fluid communication with the anode side chamber of the electrolyzer; a cryogenic heat exchanger comprising an oxygen storage tank in fluid communication with the deep space oxygen radiator; an electrochemical hydrogen compressor in fluid communication with the cathode side chamber; a hydrogen storage tank in fluid communication with the electrochemical hydrogen compressor via a cooled hydrogen stream; wherein at least a portion of the cooled hydrogen stream is in a first fluid communication with an expansion valve and the cryogenic heat exchanger; wherein the hydrogen storage tank is in a second fluid communication with the electrochemical hydrogen compressor via a warmed hydrogen stream; and wherein the cryogenic heat exchanger is in fluid communication with the warmed hydrogen stream.

Disclosed is a device for refrigerating or liquefying a fluid such as natural gas or hydrogen, comprising a circuit for fluid that is to be cooled and has an upstream end for connection to a source of gaseous fluid and a downstream end for connection to a member for collecting the cooled or liquefied fluid, the device comprising a heat exchanger assembly in heat exchange with the circuit of fluid to be cooled, the device comprising a refrigerator in heat exchange with at least a portion of the heat exchanger assembly, the refrigerator being of the type that has a cycle for refrigerating a cycle gas containing at least one of: helium, hydrogen, nitrogen or neon; said refrigerator comprising, arranged in series in a cycle circuit: a mechanism for compressing the cycle gas, at least one member for coding the cycle gas, a mechanism for expanding the cycle gas, and at least one member for reheating the expanded cycle gas, wherein the compression mechanism comprises a plurality of compression stages in series composed of a centrifugal compressor assembly, the compression stages being mounted on a set of shafts rotated by an assembly of one or more motors, the at least one member for cooling the cycle gas comprising at least one heat exchanger arranged at the outlet of at least one compression stage in heat exchange with the cycle circuit, said heat exchanger being cooled by a heat-transfer fluid, characterized in that the compression mechanism comprises at least two compression stages that are arranged successively in series and do not include any member for cooling the cycle gas such as a heat exchanger therebetween.