| 摘要 |
PROBLEM TO BE SOLVED: To perform an efficient operation as a whole by switching an operation of a high-order side refrigerating cycle according to a hot water supply temperature and a water flow rate between hot water supply and hot-water heating.SOLUTION: A transient critical cycle operation for heating the water in a hot water supply section by sensible heat of a refrigerant in a supercritical region is performed in an operation cycle of a high-order side refrigerant circuit 10 in hot water supply with high hot water supply temperature and small water flow rate, and the operation is switched to a subcritical cycle operation for heating the water in the hot water supply section by condensation heat of the refrigerant in the operation cycle of the high-order side refrigerant circuit 10 in the hot-water heating with hot water supply temperature lower than that in the hot water supply and water flow more than that in the hot water supply. |
