NATURAL GAS LIQUEFACTION METHOD "POLAR STAR" AND INSTALLATION FOR ITS IMPLEMENTATION Russian patent published in 2021 - IPC F25J1/02 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to natural gas liquefaction techniques. Proposed plant comprises natural gas pre-cooling line, coolant circuit, liquefied, liquefied and separated liquids liquefaction and separation means and gas return line. Pre-cooling line includes series-connected compressor 1, cooling device 2 and coolant evaporators 3. Means of liquefaction, overcooling and separation include high, medium and low pressure separators 8, 9, 10, chokes 11 and 12, high and low pressure compressors 14, 15 and a line for recuperation of cold of non-liquid gases, which are separated in at least one separator. High pressure expander 6 is connected by its output to input of cold recuperation line of non-liquid gases. Mean pressure expander 7 is connected by input to output of cold recuperation line of non-liquid gases, and by outlet with separator 8. Throttles 11 and 12 are installed at the inlet of separators 9 and 10 respectively. Compressors 15 and 14 are installed in series on gas outlet line from separator 10. Separator 8 is connected to gas return line by gas outlet and separator 9 to compressor 14.

EFFECT: invention is aimed at simplification of cooling process of natural gases.

11 cl, 3 dwg