| 摘要 |
PROBLEM TO BE SOLVED: To provide a low-temperature refrigerating machine for mixed refrigerants where refrigerant fractionating equipment is combined with a refrigerant heat exchanger and a cryogenic refrigeration is enabled by unitary one-stage compression. SOLUTION: The mixed refrigerant discharged by a compressor 1 is separated into a liquefied refrigerant having a high boiling point and a gaseous refrigerant having a low boiling point in a receiver tank 3. The liquefied refrigerant having the high boiling point is subjected to reduced pressure evaporation by a first expansion valve 5 to cool the gaseous refrigerant having the low boiling point by a first heat exchanger 4. The refrigerant having the low boiling point that is cooled and liquefied partially further separates a refrigerant having a lower boiling point by refrigerant fractionating equipment 6. It is cooled by a second heat exchanger 7 again, and is subjected to reduced pressure cooling by a brine evaporator 10 via a third expansion valve 9, thus achieving a final cooling temperature by the refrigerant having the low boiling point, and hence obtaining a cryogenic temperature of -40°C or less. In this manner, the cryogenic temperature refrigeration that has been conventionally carried out by binary refrigeration or two-stage compression refrigeration is made by unitary one-stage compression refrigeration, thus obtaining effect such as the miniaturization of the apparatus, reduction of costs, improvement of reliability, and the like. COPYRIGHT: (C)2004,JPO
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