FIELD: machine building.
SUBSTANCE: method includes at least the following stages: the first cooling of a raw materials flow (10) is carried out with the help of the first cooling medium, which circulates in the first cooling circuit (100). At the same time the first cooling medium contains more than 90 mol % of propane; the second cooling of the cooled gas flow (20) is carried out to the liquefied flow (60) with the help of the first mixed cooling medium circulating in the first circuit (200) for the mixed cooling medium. At the same time the specified second cooling is carried out in two or more heat exchangers (42, 44), at least two of which operate under different pressures, and supercooling of the liquefied flow (60) is carried out with the help of the second mixed cooling medium or with the help of a nitrogen cooling medium, which circulates in the supercooling circuit (300), thus the supercooled flow of hydrocarbons (70) is produced.
EFFECT: using the invention will make it possible to improve efficiency of the liquefaction process.
17 cl, 2 dwg, 3 tbl
