FIELD: cooling of fluid medium flows. SUBSTANCE: flow of fluid medium is passed through hot side 1d, 1b, 1c of main heat exchanger 1, compressed in compressor unit 7, partially condensed in condenser 12 and enters main separator 13. The first condensed fraction 15 is cooled in auxiliary heat exchanger 2 to obtain condensed fraction 20. The first gas fraction 16 is cooled in auxiliary heat exchanger 2 to obtain two-phase medium 26. Cooling is effected by evaporation of liquid at intermediate pressure from cold side 2a. Produced in this case two-phase medium 28 is separated into the second liquid fraction 33 and the second gas fraction 32, and then both fractions are cooled in main heat exchanger 1 owing to evaporation of low-pressure liquid. One part of the second liquid fraction 49 is supplied to auxiliary heat exchanger 2. EFFECT: reduced energy consumption for compression of coolant. 14 cl, 2 dwg
