| 摘要 |
PROBLEM TO BE SOLVED: To provide a refrigerating unit and a heat exchanger used for the refrigerating unit, capable of exhibiting equal cooling performance even if a substitute refrigerant is used, without largely changing a component of a refrigerating cycle. SOLUTION: This refrigerating unit is constituted so that a condensing part 16 and a supercooling part 17 have respectively the fluid passage cross-sectional area of a substantially flat cross-sectional shape having uniform internal resistance, and metallic tubes 20 as a plurality of tubes for flowing the substitute refrigerant, are juxtaposed by 41 pieces in the horizontal direction. A rate of the number of metallic tubes 20 of this supercooling part 17 to the number of these whole metallic tubes 20 falls within 15-35%, and in this embodiment, the number is set to 8 pieces so that cooling power provided by an increasing enthalpy difference becomes equivalent to cooling power of an HFC134a refrigerating system by this spercooling part 17 at the same refrigerant flow rate, and the whole number ratio is set so as to fall within 15-35% and 20-35% in the heat radiating area ratio. COPYRIGHT: (C)2009,JPO&INPIT
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