Liquefaction apparatus
AssigneeBHP Petroleum Pty Ltd.
InventorsChristopher A. T. Dubar, Oliver Leh Ming Tu
Life of this patent
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Abstract
A support structure that is either floatable or otherwise adapted to be disposed in an offshore location at least partially above sea level. A natural gas liquefaction system is located on or in the support structure and has a series of heat exchangers for cooling the natural gas in a countercurrent heat exchange relationship with a refrigerant. One or more compressors compress the refrigerant which is divided into two separate streams. Each stream is fed to a liquid expansion turbine where it is isentropically expanded. The expanded streams of refrigerant are then fed to the cool end of one of the heat exchangers.
Claims23
An offshore apparatus for liquefying natural gas, comprising:
- a support structure which is either floatable or is otherwise adapted to be disposed in an offshore location at least partially above sea level, and
- natural gas liquefaction means disposed on or in the support structure, the natural gas liquefaction means comprising
- a series of heat exchangers for cooling the natural gas in countercurrent heat exchange relationship with a refrigerant,
- compression means for compressing the refrigerant,
- expansion means for isentropically expanding at least two separate streams of the compressed refrigerant, wherein said expanded streams of refrigerant communicate with a cool end of a respective one of the heat exchangers,
- a flash vessel for separating the natural gas cooled by said series of heat exchangers into a liquid phase stream and a gaseous phase stream, the gaseous phase stream being arranged in countercurrent head exchange relationship with part of the refrigerant by means, and
- wherein the flash vessel and at least some of the or each series of heat exchangers and pipework connected thereto are disposed within a single, common heat insulating housing.
A natural gas apparatus, for offshore installation, comprising:
- natural gas liquefaction means comprising a series of heat exchangers for cooling the natural gas in countercurrent heat exchange relationship with a refrigerant, compression means for compressing the refrigerant, expansion means for isentropically expanding at least two separate streams of the compressed refrigerant, wherein said expanded streams fo refrigerant communicate with a cool end of a respective one of the heat exchangers into a liquid phase stream and a gaseous phase stream, the gaseous phase stream being arranged in countercurrent heat exchange relationship with part of the refrigerant by means, and wherein the flash vessel and at least some of the or each series of heat exchangers and pipework connected thereto are disposed within a single, common heat insulating housing;
- and a support frame carrying the components of the liquefaction means as a single unit for transportation to, and installation at, the offshore location.
Dependencies are inferred from the claim text.