METHOD OF LIQUEFYING HYDROCARBON-RICH FRACTION Russian patent published in 2018 - IPC F25J1/02 

FIELD: liquefaction or curing of gases.

SUBSTANCE: described is a method for liquefying a hydrocarbon-rich fraction, in particular natural gas, by indirect heat exchange with a refrigerant mixture of a refrigerant circuit. Refrigerant mixture is compressed, divided into a liquid phase, which is rich in high-boiling components (HMR) of the refrigerant mixture, and a gas phase which is rich in low-boiling components (LMR) of the refrigerant mixture, and said phases are mixed before indirect heat exchange. According to the invention, indirect heat exchange is carried out in at least two heat exchangers (E3, E4), wherein first heat exchanger (E4) serves for pre-cooling, and second heat exchanger (E3) serves to liquefy the hydrocarbon-rich fraction. Refrigerant mixture is supplied to the first heat exchanger, said mixture containing 5 to 50% of liquid phase (3, 15), which is rich in high-boiling components (HMR) of the refrigerant mixture, and is thus mixed with gas phase (6, 14) which is rich in low-boiling components (LMR) of the refrigerant mixture, which sets the HMR/LMR ratio of the mixture between 1, 2 and 10.

EFFECT: technical result is higher accuracy of temperature control.

5 cl, 2 dwg