A method of cooling a boil-off gas (BOG) stream from a liquefied gas tank comprising at least the step of heat exchanging the BOG stream with a first refrigerant in a heat exchanger, the heat exchanger having an entry port and a warmer exit port, and comprising at least the steps of: (a) passing the first refrigerant into the entry port of the heat exchanger and into a first zone of the heat exchanger to exchange heat with the BOG stream, to provide a first warmer refrigerant stream; (b) withdrawing the first warmer refrigerant stream from the heat exchanger at an intermediate exit port between the entry port and the warmer exit port; (c) admixing the first warmer refrigerant stream with an oil-containing refrigerant stream to provide a combined refrigerant stream; (d) passing the combined refrigerant stream into the heat exchanger through an entry port located in a second zone of the heat exchanger that is warmer than the first zone; (e) passing the combined refrigerant stream out of the heat exchanger through the warmer exit port. The present invention is a modification of a refrigerant cycle for BOG cooling, and LNG re-liquefaction in particular, that allows the use of a cost-efficient oil-injected screw compressor in the refrigerant system. The present invention is also able to accommodate the possibility of different flows or flow rates of the first refrigerant stream and the oil-containing refrigerant stream, such that there is reduced or no concern by the user of the process in relation to possible oil freezing and clogging of the heat exchanger caused by variation of the flow or flow rate of the oil-containing refrigerant stream.

A method for the liquefaction of hydrogen is provided. The can include the steps of: precooling a hydrogen feed stream in a precooling cold box having a heat exchanger disposed therein to form a cooled hydrogen stream, wherein the heat exchanger is configured to cool down the feed stream within the precooling cold box by indirect heat exchange between the hydrogen feed stream and a precooling refrigerant; and withdrawing the cooled hydrogen stream from the precooling cold box; introducing the cooled hydrogen stream to a plurality of liquefaction cold boxes, wherein the cooled hydrogen stream liquefies within the plurality of liquefaction cold boxes by indirect heat exchange against a liquefaction refrigerant to form a product hydrogen stream in each of the plurality of liquefaction cold boxes, wherein the product hydrogen stream is in liquid form or pseudo-liquid form wherein there are M total precooling cold boxes and N total liquefaction cold boxes, wherein M is less than N.

A heat exchanger system includes a core-in-shell heat exchanger and a liquid/gas separator. The liquid/gas separator is configured to receive a liquid/gas mixture and to separate the gas from the liquid. The liquid/gas separator is connected to the core-in-shell heat exchanger via a first line for transmitting gas from the liquid/gas separator to a first region in the core-in-shell heat exchanger and connected to the core-in-shell heat exchanger via a second line for transmitting liquid from the liquid/gas separator to a second region of the core-in-shell heat exchanger.

A dual-mode LNG liquefier arrangement that is configurable to operate in a first mode broadly characterized as a low pressure, liquid nitrogen add LNG liquefier without turbo-expansion or a second mode broadly characterized as a low pressure, liquid nitrogen add LNG liquefier with turbo-expansion.

Provided is a cooling device with which it is possible to cool a fluid to be cooled, even before maintenance work, if a fault such as a blockage or a breakage occurs in a part of a channel. The cooling device (1) is provided with four heat exchangers (1A-1D) and a plurality of heat exchanger connection parts (111-120), each of the heat exchanger connection parts allowing natural gas to flow therethrough. Each of the heat exchangers has: a drum (101, 102, 103, fourth drum 104), a refrigerant reservoir (T), a plurality of heat exchanger core parts (121, 122, 123, 124) immersed in liquid propane in the refrigerant reservoir (T), and a demister (106). A plurality of cooling channels allowing natural gas to flow therethrough are installed, independent of each other, from the first heat exchanger (1A) to the fourth heat exchanger (1D).

A hydrogen liquefaction apparatus is provided. The apparatus can include: one or more precooling zones; a plurality of liquefaction zones; a precooling refrigeration cycle configured to provide refrigeration to the precooling zone; and a cold end refrigeration cycle configured to provide refrigeration to the plurality of liquefaction zones, wherein the cold end refrigeration cycle comprises a common recycle compression system, wherein there are M total one or more precooling zones and N total liquefaction zones, wherein M is less than N.

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.

A floating liquefied natural gas (“FLNG”) commissioning system and method are described. A system for commissioning a FLNG vessel comprises a floating liquefaction vessel positioned offshore proximate a shipyard, the floating liquefaction vessel comprising a natural gas liquefaction module and a first LNG storage tank cryogenically coupled to the natural gas liquefaction module, a regasification vessel positioned alongside the floating liquefaction vessel, the regasification vessel comprising a second LNG storage tank fluidly coupled to a regasification facility onboard the regasification vessel, a high pressure natural gas conduit extending between an output of the regasification facility and an input of the liquefaction module, a cryogenic transfer member extending between the second LNG storage tank and the first LNG storage tank, and a gaseous natural gas coupling extending between the natural gas liquefaction module and one of the first LNG storage tank, the second LNG storage tank or a combination thereof.

An installation for refrigerating a same application by means of a single refrigerator/liquefier or several refrigerators/liquefiers arranged in parallel, the refrigerator(s)/liquefier(s) using a working gas of the same type having a low molar mass, each refrigerator/liquefier comprising a compression station to compress the working gas, a cold box intended for cooling the working gas at the outlet of the compression station, the compression station comprising only compression machines of the lubricated screw type and systems for removing the oil from the working fluid at the outlet of the compression machines, and the compression station comprises a plurality of compression machines defining several levels of pressure for the working fluid, the compression station comprising at least two compression machines defining at least two levels of pressure increasing above the level of pressure of the fluid at the inlet of the compression station, two main compression machines being arranged in series and defining, at their respective fluid outlet, levels of pressure respectively called “low” and “high”, another secondary compression machine being supplied at the inlet with a fluid coming from the cold boxes at an intermediate level of pressure called “medium” between the low and high levels, this secondary compression machine also defining, at its fluid outlet, a “high” level of pressure.

A method for liquefying a hydrocarbon stream using at least one heat exchanger of the plate and fin type having at least one first part and one second part, the first and second parts being physically separate and each comprising at least one stack of a plurality of plates that are parallel to one another and to a longitudinal direction that is substantially vertical, the plates of the first part and the plates of the second part being stacked in a stacking direction that is orthogonal to the plates, the plates being stacked with spacing so as to define between them a plurality of first passages for the flow of at least part of a second two-phase cooling stream in the first part and a plurality of second passages for the flow of at least part of a first two-phase cooling stream in the second part.