| 摘要 |
<p>Provided is an air conditioner, in which a zeotropic refrigerant mixture is used, comprising: a hermetic electric compressor that compresses the zeotropic refrigerant mixture and is lubricated with a compressor oil having a predetermined dynamic viscosity; a first heat exchanger having a heat transfer tube for causing the zeotropic refrigerant mixture discharged from the hermetic electric compressor to give off heat; an expansion valve for expanding the zeotropic refrigerant mixture discharged from the first heat exchanger; a second heat exchanger having a heat transfer tube for causing the zeotropic refrigerant mixture discharged from the expansion valve to absorb heat; and a four-way valve for controlling the direction of circulation of the zeotropic refrigerant mixture. The air conditioner constitutes a heat pump cycle in which the zeotropic refrigerant mixture discharged from the second heat exchanger is returned to the hermetic electric compressor. The zeotropic refrigerant mixture contains difluoromethane, tetrafluoropropene, and monochloro trifluoro propene, has a global warming potential of 350 or lower, and is non-flammable. The heat transfer tube is an inner grooved tube having inner surface helical grooves, and the fins constituting the inner grooves are saw-tooth-shaped fins.</p> |
