To provide a cascade cycle capable of switching a unit cycle operation and a cascade cycle operation without newly adding an auxiliary evaporator or a fan that is not used in a normal cascade cycle system.
A cascade cycle system 100 comprises: a primary side refrigerant circuit 1; a secondary side refrigerant circuit 2; and an object medium flow passage 33 through which an object medium that is a heat exchanging object flows and that is configured to exchange heat between it and at least a secondary side condensing part. The cascade cycle system is configured to exchange heat between a primary side condensing part 13 and a secondary side evaporation part 25. The cascade cycle system comprises a cascade heat exchanger 200 in which at least the primary side condensing part 13, the secondary side evaporation part 25 and the object medium flow passage 33 are integrally formed, and is configured to exchange heat between the object medium flow passage 33 and the primary side condensing part 13 in a unit cycle operation, and exchange heat between the object medium flow passage 33 and the secondary side condensing part 13 in a cascade cycle operation.
Akiko Sato
Saito Shindai