摘要 |
PROBLEM TO BE SOLVED: To suppress the humidity wetness of a refrigerant sucked to a latter stage-side compressing element in an inverse cycle defrosting operation, in a refrigerating device having a refrigerant circuit constituted to switch a cooling operation and a heating operation, and performing a multistage compression type refrigerating cycle by using a refrigerant activated in a supercritical region. SOLUTION: An air conditioner 1 uses a carbon dioxide as the refrigerant, and comprises a two-stage compression type compressing mechanism 2, a heat source-side heat exchanger 4, an expanding mechanism 5, an utilization-side heat exchanger 6, a switching mechanism 3, an intermediate cooler 7 and a latter stage-side injection pipe 19. In the air conditioner 1, the refrigerant flows in the heat source-side heat exchanger 4, the intermediate cooler 7 and the latter stage-side injection pipe 19 in the inverse cycle defrosting operation for defrosting the heat source-side heat exchanger 4 by switching the switching mechanism 3 to a cooling operation state, and a flow rate of the refrigerant returned to the latter stage-side compressing element through the latter stage-side injection pipe 19 is reduced when it is detected that the refrigerant is condensed in the intermediate cooler 7. COPYRIGHT: (C)2009,JPO&INPIT
|