| 摘要 |
PROBLEM TO BE SOLVED: To provide an air-conditioning refrigeration unit capable of performing efficient defrosting operation of an air conditioner in a store or the like where indoor air conditioning or internal cooling of a cooling storage facility is performed. SOLUTION: This refrigeration unit comprises a cascade heat exchanger 21 for heat-exchanging the low pressure side of an air conditioning refrigerant circuit 7 with the high pressure side of a cooling storage facility refrigerant circuit 9. In the defrosting operation of the refrigerant circuit 7, the refrigerant discharged from a compressor 37 of the cooling storage facility refrigerant circuit 9 is carried to a condenser 38 through the cascade heat exchanger 21, and the refrigerant discharged from compressors 13A and 13B of the air-conditioning refrigerant circuit 7 is carried to the heat-exchanger 21 through a heat source-side heat exchanger 16, whereby the waste heat of the high-pressure side refrigerant of the refrigerant circuit 9 can be recovered to efficiently perform the defrosting of the heat source-side heat exchanger 16. The refrigerant carried to using-side heat exchangers 27 and 27 is interrupted by a using-side heat exchanger pressure reducing valve 18, whereby the fear of making a user feel a sense of cold air can be eliminated. COPYRIGHT: (C)2005,JPO&NCIPI |
