Combined heat source heat pump system

摘要

To provide a composite heat-source heat pump device which switches between a main power source and an auxiliary power source when a defrosting operation of an air heat pump device is frequently performed.SOLUTION: Once a temperature of the heated circulation liquid L reaches a target temperature, a compressor rotation speed of an auxiliary power source is reduced prior to a main power source. A control device 6 detects frequency of a defrosting operation of a second heat pump circuit 5 when a second compressor 53 of the second heat pump circuit 5 is driven as the main power source and a first compressor 43 of a first heat pump circuit 4 is driven as the auxiliary power source. If the detected frequency of the defrosting operation is more than a predefined frequency, the first compressor 43 of the first heat pump circuit 4 is switched as the main power source and the second compressor 53 of the second heat pump circuit 53 is switched as the auxiliary power source.SELECTED DRAWING: Figure 2