| 摘要 |
A refrigerant circuit (1) of this air conditioner includes a main circuit (6) which allows a refrigerant medium to flow through a compressor (2), a condenser (3), a supercooling heat exchanger (10), a first expansion mechanism (4) and an evaporator in the order named, and a bypass circuit (11) which branches from the main circuit (6) at a point between the condenser (3) and the expansion mechanism (4), allows the refrigerant to flow through a capillary tube (12) constituting a second expansion mechanism and the supercooling heat exchanger (10) in the order named and joins the main circuit (6) on the suction side of the compressor (2). The capillary tube (12) imparts a throttle quantity to a bypass flow refrigerant such that a discharge pipe temperature Td of the compressor (2) is higher than a predetermined lower limit value under an assumed critical condition. Therefore, reliability of the compressor can be secured even under an assumed critical condition where an outdoor temperature is -5 DEG C and an indoor temperature is 28 DEG C (WB). |
