| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent frost formation of an evaporator in a refrigeration circuit 2 at a low temperature side, or to defrost thereof while preventing degradation in operation capacity for heating/hot water supply in a cascade-type heat pump system. <P>SOLUTION: The cascade-type heat pump system includes a low temperature side refrigeration circuit 2, a high temperature side refrigeration circuit 3, and a cascade heat exchanger 4 for exchanging heat at a high temperature side of the low temperature side refrigeration circuit 2 and at low temperature side of the high temperature side refrigeration circuit 3. The cascade-type heat pump system includes: a circulation circuit 6 which returns again a circulation liquid from the high temperature side of the high temperature side refrigeration circuit 3 to the high temperature side of the high temperature side refrigeration circuit 3 through an evaporator 24 of the low temperature side refrigeration circuit 2; and a circulating liquid-refrigerant heat exchanger 7 for heat exchanging between the circulating liquid flowing through the circulation circuit 6 and a high temperature side refrigerant of the high temperature side refrigeration circuit 3. <P>COPYRIGHT: (C)2012,JPO&INPIT |
