A gas supply system for a high-pressure gas consuming appliance and a low-pressure gas consuming appliance of a floating structure including a tank containing the gas is disclosed. The supply system includes: a first supply circuit and a second supply circuit; a gas return line; and a first heat exchanger and a second heat exchanger configured to carry out a heat exchange between the gas of the first supply circuit and the gas circulating in the return line. The first supply circuit includes an additional pump.

A liquid nitrogen energy storage (LNES) system that includes a liquid charging mode and a power generating mode is provided. The disclosed liquid nitrogen energy storage system comprises a nitrogen liquefier designed to cool or liquefy a first portion of the gaseous nitrogen and a cold recovery heat exchanger designed to cool or liquefy a second portion of the gaseous nitrogen during a liquid charging mode and to warm a liquid nitrogen energy stream during a power generating mode. The liquid nitrogen energy storage system also includes a cold store configured to provide refrigeration for liquefaction of the second portion of the gaseous nitrogen in the cold recovery heat exchanger during the liquid charging mode and to warm a portion of the liquid nitrogen taken as a liquid nitrogen energy stream in the cold recovery heat exchanger during the power generating mode.

Disclosed is a re-liquefying device using a boil-off gas as a cooling fluid so as to re-liquefy the boil-off gas generated from a liquefied gas storage tank provided in a ship. A boil-off gas re-liquefying device for a ship comprises: a multi-stage compression unit for compressing boil-off gas generated from a liquefied gas storage tank; a heat exchanger in which the boil-off gas generated from the storage tank and the boil-off gas compressed exchange heat; a vaporizer for heat exchanging the boil-off gas cooled by the heat exchanger and a separate liquefied gas supplied to a fuel demand source of a ship, and thus cooling the boil-off gas; an intermediate cooler for cooling the boil-off gas that has been cooled by the heat exchanger; and an expansion means for branching a part of the boil-off gas, which is supplied to the intermediate cooler, and expanding the same.

The system for treating a gas deriving from the evaporation of a cryogenic liquid and supplying pressurized gas to a gas engine according to the invention comprises, on the one hand, from upstream to downstream, a reliquefaction unit (10) with compression means (11, 12, 13), a first heat exchanger (17) and expansion means (30), and, on the other hand, a pressurized gas supply line comprising, from upstream to downstream, a pump (48) for pressurizing the liquid and high-pressure vaporization means (61). The pressurized gas supply line has, upstream of the vaporization means (61), a bypass (57) for supplying a second heat exchanger (60) between, on the one hand, pressurized liquid of the supply line (56) and, on the other hand, a line (22) of the reliquefaction unit (10) downstream of the first exchanger and upstream of the expansion means (30).

A process for liquefying a natural gas feed stream including cooling a feed gas stream to obtain a liquefied natural gas stream; introducing the liquefied natural gas stream into a deazotization column to produce a liquefied natural gas stream and a nitrogen-enriched vapor stream; at least partially condensing at least part of the nitrogen-enriched vapor stream to produce a two-phase stream; introducing the two-phase stream into a phase-separating vessel to produce a first liquid stream and a first nitrogen-enriched gas stream; introducing at least part of the nitrogen-enriched gas stream into a distillation column thereby producing a second nitrogen-enriched stream containing less than 1 mol % of methane and a second liquid stream containing less than 10 mol % of nitrogen; wherein at least part of the liquefied natural gas stream is used to cool the at least part of the nitrogen-enriched vapor stream in said heat exchanger.

A booster system includes: a cooling temperature regulating unit configured to regulate a temperature of an intermediate supercritical pressure liquid cooled and generated by a main cooling unit on upstream of a pump unit according to a flow rate of a supplied cooling medium; and a pressure detection unit configured to detect inlet pressure of the intermediate supercritical pressure liquid on an inlet side of the pump unit and detect outlet pressure of a target supercritical fluid on an outlet side of the pump unit. The cooling temperature regulating unit controls the flow rate of the cooling medium based on a pressure difference between the inlet pressure and the outlet pressure or a pressure ratio between the inlet pressure and the outlet pressure.

A thermodynamic system containing a working fluid is disclosed. The thermodynamic system comprises at least a working fluid collection vessel (11) adapted to contain a liquid phase and a gaseous phase of the working fluid in thermodynamic equilibrium. A chilling arrangement (51) is functionally coupled to the fluid collection vessel (11) and adapted to remove heat from the working fluid collected in the working fluid collection vessel (11) and thereby reduce pressure in said thermodynamic system. Also disclosed are methods for depressurizing a thermodynamic system containing a working fluid in liquid/gas equilibrium.

Provided is a reliquefaction device with which a gas gasified from a liquid can be efficiently reliquefied. A plurality of flow passages include: a mixing flow passage which is connected to the downstream end section of one among a liquid flow passage and a gas flow passage and allows a fluid mixture to flow so that a reliquefaction promoting liquid flowing through the liquid flow passage and a reliquefaction target gas flowing through the gas flow passage are mixed and the reliquefaction of the reliquefaction target gas is promoted by direct heat exchange; and a gas cooling flow passage which allows a coolant to flow and cool the reliquefaction target gas by means of indirect heat exchange with the reliquefaction target gas through a separation wall, thereby suppressing the gasification of the reliquefaction promoting liquid when the reliquefaction target gas is mixed with the reliquefaction promoting liquid flowing through the liquid flow passage.

A method and apparatus for producing liquefied natural gas. A portion of a natural gas stream is cooled in a heat exchanger and combined with the natural gas stream. Heavy hydrocarbons are removed from the combined natural gas stream, and the resulting separated natural gas stream is partially condensed in the first heat exchanger, with a liquid stream separated therefrom. The natural gas stream is warmed in the first heat exchanger and then is compressed and cooled. The resultant cooled compressed natural gas stream is expanded, thereby forming a chilled natural gas stream that is separated into a refrigerant stream and a non-refrigerant stream. The refrigerant stream recycled to the heat exchanger to be warmed through heat exchange with one or more process streams associated with pretreating the natural gas stream, thereby generating a warmed refrigerant stream. The warmed refrigerant stream and the non-refrigerant stream are liquefied.

Systems and processes for natural gas processing, liquefaction, and storage are described. The systems and processes include one or more arrangements of features which are capable of liquefying all of the gas entering an inlet of the system or a portion of the entering gas. The portion of the entering gas that is liquefied can vary based on the pressure of an outlet of the system, which can be fixed or vary based on usage downstream.