A propulsion system includes an electric fan propulsion motor with a plurality of propulsion motor windings. The propulsion system also includes a means for controlling a flow rate of a working fluid through a cryogenic working fluid flow control assembly to the propulsion motor windings. The propulsion system further includes a controller operable to control supplying a pre-cooling flow of the working fluid from a cryogenic liquid reservoir through the cryogenic working fluid flow control assembly to the propulsion motor windings.

A system for an aircraft includes an engine bleed source of a gas turbine engine. The system also includes a means for chilling an engine bleed air flow from the engine bleed source to produce a chilled working fluid. The system further includes a means for providing the chilled working fluid for an aircraft use.

A mobile liquefaction plant (7) for liquefying helium, includes a liquefaction device (8) that liquefies helium, an intermediate storage tank (9) for liquefied helium, a cleaning device (29) which removes non-helium components from the helium and is connected upstream of the liquefaction device, and an additional collecting device (25) that collects gaseous helium which evaporates when an application cryostat (4) is filled with liquid helium and that includes a container (26) with a flexible wall and which stores the collected gaseous helium approximately at atmospheric pressure. The container (26) has an available container volume of at least 5 m.sup.3. Systems provided with such a mobile liquefaction plant exhibit an improved recovery of helium from application cryostats in a simple and cost-effective manner.

A process for liquefying and simultaneously purifying natural gas from acidic compounds is provided. The process involves pre-cooling a natural gas flow in a cryogenic exchanger, pre-treating the pre-cooled natural gas flow inside a pre-treatment unit and obtaining a purified flow, heat recovering and obtaining a higher temperature flow, compressing the higher temperature flow and obtaining a first compressed recirculation flow, cooling the first compressed recirculation flow and obtaining a compressed and cooled flow, and separating from the compressed and cooled flow a recirculation flow portion of natural gas. One or more cooling steps are carried out by a flow of nitrogen circulating inside a closed nitrogen refrigeration cycle.

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.

Process and plant for the production of liquid hydrogen with a liquefier that has a variable cooling power dependent on the electrical power consumed. The liquefier is supplied with electricity by a first source of electricity at least one additional source of electricity that provides an intermittent or variable amount of electricity over time. Liquid hydrogen is produced at first thermodynamic conditions when the liquefier is supplied with a predetermined nominal electrical energy level and produced at subcooled conditions, with respect to the first thermodynamic conditions, when electricity supplied to the liquefier exceeds the nominal level.

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.

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.

A system for the production of liquefied natural gas from raw natural gas. The system includes a pre-treatment module to remove impurities from a raw natural gas input, a gas compression module to compress gas received from the pre-treatment module, an absorption chiller for providing gas equipment cooling in the compression module, and a gas liquefaction module including a gas pre-cooler configured to pre-cool gas received from the compression module using a closed-loop refrigeration cycle and a six-stream heat exchanger unit configured to cool gas received from the gas pre-cooler. A power module is provided that powers the pre-treatment module, gas compression module, and gas liquefaction module.

An LNG production plant is constructed from a plurality of containerised LNG liquefaction units. Each containerised LNG liquefaction unit can produce a predetermined quantity of LNG. For example, up to 0.3 MPTA. A manifold system enables connection between the plurality of containerised LNG liquefaction units, and at least a feed stream of natural gas, a source of electrical power, and an LNG storage facility. The production capacity of the plant is incrementally changed by connecting or disconnecting containerised LNG liquefaction units to or from the plant via the manifold system. Each unit contains its own liquefaction plant having a closed loop SMR circuit. Refrigerant within the SMR circuit is circulated solely by pressure differential generated by refrigerant compressors in the liquefaction plant.