Method and apparatus for cooling and liquefying at least one gas with a low boiling point, such as for example natural gas

摘要

The present invention relates to a method and an apparatus for liquefying a gas with a low boiling point, such as natural gas, by heat exchange with a main refrigerant fluid having several components. The whole of the vapor phase of this main refrigerant fluid, after being condensed and subcooled, is expanded at once to at least one first pressure, and the whole of the liquid phase of the subcooled main refrigerant fluid is expanded at once to at least one second pressure, different from the said first pressure.