FIELD: gas industry, particularly to cool pressurized liquefied natural gas containing methane and hydrocarbons with two or more carbon atoms.
SUBSTANCE: method involves expanding above pressurized liquefied natural gas to obtain expanded liquefied gas flow; separating the obtained gas flow into the first head fraction having greater volatility and the first tail fraction having lesser volatility; accumulating the first tail fraction comprising cooled liquefied natural gas; heating the first head fraction, compressing thereof in the first compressor and cooling the first head fraction to obtain the first compressed fraction of combustible gas; accumulating the first fraction of combustible gas; extracting the second compressed fraction from the first compressed one; cooling the second compressed fraction and mixing thereof with expanded liquefied natural gas flow; compressing the second compressed fraction in the second compressor communicated with turboexpander to obtain the third compressed fraction; cooling the third compressed fraction and separating thereof into the forth and the fifth compressed fractions; cooling the forth compressed fraction and expanding thereof in turboexpander connected to the second compressor to obtain expanded fraction; heating the expanded fraction and introducing thereof into the first medium-pressure compressor stage; cooling the fifth fraction and mixing thereof with expanded liquefied natural gas flow.
EFFECT: increased output.
13 cl, 11 tbl
