| 摘要 |
PROBLEM TO BE SOLVED: To suppress the deterioration of a defrosting capacity 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, a bypass pipe 9 and an injection pipe 19. In the air conditioner 1, the refrigerant flows in the heat source-side heat exchanger 4, the intermediate cooler 7 and an injection pipe 19 in 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, and the refrigerant is not allowed to flow to the intermediate cooler 7 by using the bypass pipe 9, and an opening of an injection valve 19a of the injection pipe 19 is controlled to be increased after the completion of the defrosting of the intermediate cooler 7 is detected. COPYRIGHT: (C)2009,JPO&INPIT |
