A natural gas liquefying apparatus includes: a precooling unit, which is a treatment unit configured to precool natural gas; a liquefying unit, which is a treatment unit configured to liquefy the natural gas; a refrigerant cooling unit, which is a treatment unit configured to cool a liquefying refrigerant; a compression unit configured to compress vaporized refrigerants; and a pipe rack including air-cooled coolers arrayed and arranged on an upper surface. The treatment units and the compression unit are separately arranged in a first arrangement region and a second arrangement region arranged opposed to each other across a long side of the pipe rack. The pipe rack interposed between the first and second arrangement regions has a region in which no air-cooled cooler is arranged in order to arrange a plurality of pipes, through which refrigerants are allowed to flow, in a direction of a short side of the pipe rack.

Integration of a natural gas liquefaction system, a hydrogen production system, and power generation system to increase CO2 capture and improve overall plant efficiency. The predominantly methane endflash is sent to the hydrogen production system which produces hydrogen and CO2. The CO2 may be captured or beneficially used. At least a portion of the hydrogen produced is used to fuel gas turbines in the power generation which, in turn, provides power for the refrigeration compressor of the natural gas liquefaction system—either in the form of mechanical work or electricity.

Described herein are systems and processes for precooling hydrogen or helium gas streams for liquefaction using liquid nitrogen having reduced energy consumption and amount of liquid nitrogen usage. The systems include a stream of pressurized liquid nitrogen, at least one turboexpander, and at least one heat exchanger.

A module for a natural gas liquefaction apparatus is provided to include air-cooled heat exchanger groups and another equipment group. The air-cooled heat exchanger groups another equipment group. The air-cooled heat exchanger groups are arranged side by side on an upper surface of a structure, and are each configured to cool a fluid handled in the natural gas liquefaction apparatus. The another equipment group is arranged on a lower side from an arrangement height of each air-cooled heat exchanger groups, and forms a part of the natural gas liquefaction apparatus. When equipment groups are classified into a pretreatment unit equipment group provided in a pretreatment unit configured to perform pretreatment of natural gas before being liquefied, and a liquefaction processing unit equipment group provided in a liquefaction processing unit associated with processing of liquefying the natural gas after being treated in the pretreatment unit, the another equipment group is formed of the pretreatment unit equipment group.

A drive system for liquefied natural gas (LNG) refrigeration compressors in a LNG liquefaction plant. Each of three refrigeration compression strings include refrigeration compressors and a multi-shaft gas turbine capable of non-synchronous operation. The multi-shaft gas turbine is operationally connected to the refrigeration compressors and is configured to drive the one or more refrigeration compressors. The multi-shaft gas turbine uses its inherent speed turndown range to start the one or more refrigeration compressors from rest, bring the one or more refrigeration compressors up to an operating rotational speed, and adjust compressor operating points to maximize efficiency of the one or more refrigeration compressors, without assistance from electrical motors with drive-through capability and variable frequency drives.

A compressor system is disclosed, including a first compressor unit having: at least a first gas inlet at a first gas pressure level; a second gas inlet at a second gas pressure level; and a gas discharge; a second compressor unit having: at least a third gas inlet at a third gas pressure level; a fourth gas inlet at a fourth gas pressure level; and a gas delivery. The gas discharge of the first compressor unit is fluidly coupled to one of the third gas inlet and fourth gas inlet of the second compressor unit.

Provided is a method of designing a heat exchanger group being installed in a processing plant and having multiple ACHEs. In a first step, at least one design variable relating to ACHE design and the number of installed ACHEs are set as variable parameters, and a variable range and a change unit of each of the variable parameters are set. In a second step, a design value of the ACHE, which includes a value of a design variable non-selected as the variable parameter, is set. In a third step, Pareto solutions for at least two objective functions selected from an objective function group consisting of an installation length of the heat exchanger group, a total heat transfer area of heat transfer tubes, and total power consumption of fans are calculated by using a computer while the variable parameter are changed.

A method to control the cooldown of main heat exchangers in liquefied natural gas plant. The method provides for the automated control of a flow rate of a natural gas feed stream through a heat exchanger based on one or more process variables and set points. The flow rate of refrigerant streams through the heat exchanger is controlled by different process variables and set points, and is controlled independently of the flow rate of the natural gas feed stream.

A system and method for producing liquefied natural gas (LNG) from a natural gas stream. Each of a plurality of LNG trains liquefies a portion of the natural gas stream to generate a warm LNG stream in a first operating mode, and a cold LNG stream in a second operating mode. A sub-cooling unit is configured to, in the first operating mode, sub-cool the warm LNG streams generated by each of the plurality of LNG trains to thereby generate a plurality of cold LNG streams. The warm LNG streams have a higher temperature than a temperature of the cold LNG streams in the second operating mode and the plurality of cold LNG streams. The combined flow rate of the plurality of cold LNG streams has, in the first operating mode, a higher flow rate than the combined flow rate of the cold LNG streams in the second operating mode.

A drive system for liquefied natural gas (LNG) production. A standardized machinery string consisting of a multi-shaft gas turbine with no more than three compressor bodies, where the compressor bodies are applied to one or more refrigerant compressors employed in one or more refrigerant cycles (e.g., single mixed refrigerant, propane precooled mixed refrigerant, dual mixed refrigerant). The standardized machinery strings and associated standardized refrigerators are designed for a generic range of feed gas composition and ambient temperature conditions and are installed in opportunistic liquefaction plants without substantial reengineering and modifications. The approach captures D1BM (“Design 1 Build Many) cost and schedule efficiencies by allowing for broader variability in liquefaction efficiency with location and feed gas composition.