Systems and methods are provided for adjusting a composition, pressure, and/or flow rate of a mixed refrigerant (MR) fluid in a liquefaction system to provide refrigeration to natural gas (NG) feedstock to produce liquefied natural gas (LNG). The MR fluid that is in circulation within a liquefaction system can include heavy components and light components. During LNG production, heavy components and/or light components of the MR fluid can be selectively removed from, and reintroduce into the MR fluid, thereby altering the composition of the remaining MR fluid in circulation. Adjusting the composition of the MR fluid in circulation within a liquefaction system can allow the system to be optimized to maximize efficiency, LNG production, and or profitability while the system is in operation.

The present invention is to provide a BOG processing apparatus. The BOG processing apparatus includes a cooling device, a second cooling device, and a recovery device. The cooling device has a cooling drum, a BOC inlet part introducing the BOG, a first spray spraying LNG in an upward direction, a first filled layer contacting with the LNG and the BOG, a second spray spraying the LNG in a downward direction, a third spray spraying the LNG in a downward direction, a second filled layer adsorbing mist in the BOG, and a mist eliminator eliminating the mist in the BOG.

A method for liquefying a hydrocarbon stream using a heat exchanger having a plurality of plates parallel to each other and to a longitudinal direction that is substantially vertical, the exchanger having a length measured in the longitudinal direction, the plates being stacked with spacing so as to define between them at least one first series of passages for the flow of at least part of a two-phase cooling stream vaporizing by exchanging heat with at least the hydrocarbon stream.

A refrigerator according to the present invention includes: a cooling part for cooling an object to be cooled through heat exchange with a refrigerant; an expander-integrated compressor including a compressor for compressing the refrigerant and an expander for expanding the refrigerant integrated therein; and a refrigerant circulation line configured to circulate the refrigerant through the compressor, the expander, and the cooling part. The compressor includes a low-stage compressor, a middle-stage compressor, and a high-stage compressor disposed in series in the refrigerant circulation line. The expander-integrated compressor includes: the middle-stage compressor; an expander for adiabatically expanding and cooling the refrigerant discharged from the high-stage compressor; a first motor having an output shaft connected to the middle-stage compressor and to the expander; at least one non-contact type bearing, disposed between the middle-stage compressor and the expander, for supporting the output shaft of the first motor without being in contact with the output shaft; and a casing for housing the middle-stage compressor, the expander, and the at least one non-contact type bearing.

The invention relates to a heat exchanger system (1) for heat exchange between at least a first medium (M), in particular in the form of a hydrocarbon-rich phase, and a second medium (K), with at least first and second pipe space sections (101, 103; 103, 105) for accommodating the first medium (M), and with a first pipe space section connecting means (102; 104), via which the two pipe space sections (101, 103; 103, 105) are connected to one another in a flow-guiding manner. The first pipe space section (101; 103) is surrounded by a first shell space (201, 203), and the second pipe space section (103; 105) is surrounded by a second shell space (203, 205) for accommodating the second medium (K). The first shell space (201; 203) is defined by a first shell (301; 303) and the second shell space (203; 205) is defined by a second shell (303; 305).

Described herein is a method of removing refrigerant from a natural gas liquefaction system in which vaporized mixed refrigerant is withdrawn from the closed-loop refrigeration circuit and introduced into a distillation column so as to be separated into an overhead vapor enriched in methane and a bottoms liquid enriched in heavier components. Overhead vapor is withdrawn from the distillation column to form a methane enriched stream that is removed from the liquefaction system, and bottoms liquid is reintroduced from the distillation column into the closed-loop refrigeration circuit. Also described are methods of altering the rate of production in a natural gas liquefaction system in which refrigerant is removed as described above, and a natural gas liquefaction systems in which such methods can be carried out.

Described herein is a method and system for liquefying a natural gas feed stream to produce an LNG product. The natural gas feed stream is liquefied, by indirect heat exchange with a gaseous methane or natural gas refrigerant circulating in a gaseous expander cycle, to produce a first LNG stream. The first LNG stream is expanded, and the resulting vapor and liquid phases are separated to produce a first flash gas stream and a second LNG stream. The second LNG stream is then expanded, with the resulting vapor and liquid phases being separated to produce the second flash gas stream and a third LNG stream, all or a portion of which forms the LNG product. Refrigeration is recovered from the second flash gas by using said stream to sub-cool the second LNG stream or a supplementary LNG stream.

A heat exchanger having multiple plates which are mutually parallel and parallel to a longitudinal direction, the exchanger having a length measured in the longitudinal direction, the plates being stacked with spacing so as to define a first series of passages for the flow, in a general flow direction parallel to the longitudinal direction, of at least a first refrigerant fluid and a second refrigerant fluid, at least one passage of the first series being defined between two adjacent plates.

A method of producing liquefied natural gas (LNG) is disclosed. A natural gas stream is provided from a supply of natural gas. The natural gas stream is compressed in at least two serially arranged compressors to a pressure of at least 2,000 psia to form a compressed natural gas stream. The compressed natural gas stream is cooled to form a cooled compressed natural gas stream. The cooled compressed natural gas stream is expanded in at least one work producing natural gas expander to a pressure that is less than 3,000 psia and no greater than the pressure to which the at least two serially arranged compressors compress the natural gas stream, to thereby form a chilled natural gas stream. The chilled natural gas stream is liquefied.

A cooling circuit for a system for supplying and cooling a gas in a floating structure having a tank, the cooling circuit having a coolant flowing through it and including a main loop having: a compression device; a heat exchanger; an internal heat exchanger; and a turbocompressor, the cooling circuit includes a regulating branch connected to the main loop, the regulating branch having a valve that is configured to control the flow of coolant within the regulating branch, the main loop including a pressure sensor, the valve controlling the amount of coolant present in the main loop according to the pressure measured by the pressure sensor.