| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot water heat source machine capable of quickly performing a defrosting operation while saving energy, in the defrosting operation using a reversible refrigerating cycle of binary refrigerating cycle. SOLUTION: This hot water heat source machine 50 includes a low order-side refrigerating cycle 1 as a reversible refrigerating cycle in which a low order-side refrigerant is circulated, and a high order-side refrigerating cycle 2 as a reversible refrigerating cycle in which a high order-side refrigerant is circulated, and performing a hot water heating operation, includes an evaporator refrigerant temperature detecting means 16 detecting a refrigerant temperature in the low order-side evaporator, and a control section 5 performing the defrosting operation by using the low order-side refrigerating cycle, when the refrigerant temperature detected by the evaporator refrigerant temperature detecting means becomes a first reference temperature or lower, and performing the defrosting operation by using the high order-side refrigerating cycle in addition to the defrosting operation by using the low order-side refrigerating cycle, when the refrigerant temperature detected by the evaporator refrigerant temperature detecting means is a second reference temperature or less even after the lapse of a prescribed time from the defrosting operation by using the low order-side refrigerating cycle. COPYRIGHT: (C)2011,JPO&INPIT |
