A liquefied natural gas compression system includes: a first gas turbine that drives a rotary machine; a first steam boiler including a first heat recovery steam generator that recovers heat from exhaust gas from the first gas turbine; a first steam turbine that drives a first refrigerant compressor; a common header steam line through which steam from the first steam boiler flows to an inlet of the first steam turbine; an auxiliary steam line; and a letdown valve that connects the common header steam line to the auxiliary steam line and that opens in response to pressure of the common header steam line exceeding a predetermined threshold value.

A plant and process are used to liquefy and purify a high pressure ethane feed stream. The plant includes a cascaded refrigeration system that refrigerates the ethane feed stream. The refrigeration system includes a propylene circuit, an ethylene circuit and a mixed refrigerant circuit. The mixed refrigerant circuit includes a refrigerant that includes ethane and methane. The plant includes a demethanizer that is configured to remove methane and other natural gas liquids from the refrigerated ethane stream.

A plant and process are used to liquefy and purify a high pressure ethane feed stream. The plant includes a cascaded refrigeration system that refrigerates the ethane feed stream. The refrigeration system includes a propylene circuit, an ethylene circuit and a mixed refrigerant circuit. The mixed refrigerant circuit includes a refrigerant that includes ethane and methane. The plant includes a demethanizer that is configured to remove methane and other natural gas liquids from the refrigerated ethane stream.

A liquefied natural gas compression system includes: a first gas turbine that drives a rotary machine; a first steam boiler including a first heat recovery steam generator that recovers heat from exhaust gas from the first gas turbine; a first steam turbine that drives a first refrigerant compressor; a common header steam line through which steam from the first steam boiler flows to an inlet of the first steam turbine; an auxiliary steam line; and a letdown valve that connects the common header steam line to the auxiliary steam line and that opens in response to pressure of the common header steam line exceeding a predetermined threshold value.

The invention relates to a method for condensing a gas, wherein the gas is subjected to cooling in indirect heat exchange with a refrigerant and at least part of the refrigerant is subjected, after the heat exchange with the gas, to compression by means of a drive (GT1) that produces waste heat and to a partial or complete condensing process. After the partial or complete condensing process, a first portion of the refrigerant is subjected to the heat exchange with the gas and a second portion of the refrigerant is subjected, in succession, to pressurization, heating by means of the waste heat of the drive (GT1) and work-performing expansion and thereafter is fed back to the partial or complete condensing process. The invention further relates to a corresponding system.

A method of producing LNG. According to the method, a natural gas stream is compressed using first and second compressors. A cooler cools the natural gas stream so that the second compressor produces a cooled, compressed natural gas stream, which is liquefied in a liquefaction process. The liquefaction process uses a refrigerant compressor configured to compress a stream of refrigerant used to chill, condense, or liquefy the cooled, compressed natural gas stream. Using a heat recovery steam generation (HRSG) system, heat is recovered from a power source of the refrigerant compressor. A stream of pressurized steam is generated from the recovered heat. At least one of the first and second compressors is powered using at least part of the stream of pressurized steam.

An LNG refrigerant compressor train (1) is disclosed. The train comprises: a driver section (11), drivingly coupled to a compressor section (13) through a shaft line (1). The compressor section is comprised of at least one refrigerant fluid compressor, driven into rotation by the driver section (11).

Systems and methods are provided for the production of liquefied natural gas. At least one of the systems may include a plurality of compression assemblies in fluid communication with a precooler assembly. One compression assembly may be a part of a precooling loop and may include at least one compressor driven by a variable or fixed speed motor. Another compression assembly may be part of a liquefaction loop and may include at least one pair of compressors, each compressor driven by a respective turbine. The liquefaction loop may be fluidly coupled to a main heat exchanger utilized to liquefy at least a portion of a feed gas stream containing natural gas flowing through the main heat exchanger, thereby producing liquefied natural gas.

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.