| 摘要 |
PROBLEM TO BE SOLVED: To shorten a defrosting time while suppressing the lowering of a temperature at an utilization side at performing 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, and a latter stage-side injection pipe 19 for branching the refrigerant cooled in the heat source-side heat exchanger 4 or the utilization-type heat exchanger 6 and returning it to the latter stage-side compressing element. In the air conditioner 1, the refrigerant distributed from the heat source-side heat exchanger 4 to the utilization-side heat exchanger 6 is returned to the latter stage-side compressing element by using the latter stage-side injection pipe 19 at performing an inverse cycle defrosting operation for defrosting the heat source-side heat exchanger 4 by switching the switching mechanism 3 to a cooling operation state. COPYRIGHT: (C)2009,JPO&INPIT |
