Cascade refrigeration cycle apparatus

Abstract

Provided is a cascade refrigeration cycle apparatus that is highly efficient. The cascade refrigeration cycle apparatus includes a fan, a first cycle, a second cycle, and a cascade heat exchanger. In the first cycle, a first refrigerant having a critical point of 40° C. or higher circulates. The first cycle includes a condenser in which air supplied by the fan and the first refrigerant exchange heat. In the second cycle, carbon dioxide as a second refrigerant circulates. The second cycle includes a first heat exchanger functioning as a radiator in which air supplied by the fan and the second refrigerant exchange heat. In the cascade heat exchanger, the first refrigerant and the second refrigerant exchange heat. The condenser is disposed on a windward side of the radiator in an airflow direction that is a direction of an airflow generated by the fan.

1 . A cascade refrigeration cycle apparatus comprising:
 a fan;   a first cycle through which a first refrigerant having a critical point of 40° C. or higher circulates, the first cycle including a condenser in which air supplied by the fan and the first refrigerant exchange heat;   a second cycle through which carbon dioxide circulates as a second refrigerant, the second cycle including a radiator in which air supplied by the fan and the second refrigerant exchange heat; and   a heat exchanger in which the first refrigerant and the second refrigerant exchange heat, wherein   the condenser is on a windward side of the radiator in a first direction, the first direction being a direction of an airflow generated by the fan.   
     
     
         2 . The cascade refrigeration cycle apparatus according to  claim 1 , wherein the radiator includes:
 a first region overlapping the condenser in the first direction, and   a second region not overlapping the condenser in the first direction.   
     
     
         3 . The cascade refrigeration cycle apparatus according to  claim 1 , wherein
 the condenser has a first inlet through which the first refrigerant flows into,   the radiator has a second inlet through which the second refrigerant flows into, and   the second inlet is adjacent to the first inlet.   
     
     
         4 . The cascade refrigeration cycle apparatus according to  claim 2 , wherein
 the condenser has a first inlet through which the first refrigerant flows into,   the radiator has a second inlet through which the second refrigerant flows into, and   the second inlet is adjacent to the first inlet.   
     
     
         5 . The cascade refrigeration cycle apparatus according to  claim 1 , wherein:
 the fan includes an impeller, and   the condenser at least partially overlaps the impeller when viewed in an axial direction of the impeller.   
     
     
         6 . The cascade refrigeration cycle apparatus according to  claim 2 , wherein:
 the fan includes an impeller, and   the condenser at least partially overlaps the impeller when viewed in an axial direction of the impeller.   
     
     
         7 . The cascade refrigeration cycle apparatus according to  claim 3 , wherein:
 the fan includes an impeller, and   the condenser at least partially overlaps the impeller when viewed in an axial direction of the impeller.   
     
     
         8 . The cascade refrigeration cycle apparatus according to  claim 1 , wherein:
 the condenser includes a first heat transfer tube,   the radiator includes a second heat transfer tube,   the first heat transfer tube and the second heat transfer tube are in a same fin, and   the fin includes a slit between a through portion of the first heat transfer tube and a through portion of the second heat transfer tube.   
     
     
         9 . The cascade refrigeration cycle apparatus according to  claim 8 , wherein:
 the condenser further includes a first tube plate, made of metal, through which the first heat transfer tube extends and that supports the first heat transfer tube,   the radiator further includes a second tube plate, made of metal, through which the second heat transfer tube extends and that supports the second heat transfer tube, and   the first tube plate and the second tube plate are separate members.   
     
     
         10 . The cascade refrigeration cycle apparatus according to  claim 2 , wherein:
 the condenser includes a first heat transfer tube,   the radiator includes a second heat transfer tube,   the first heat transfer tube and the second heat transfer tube are in a same fin, and   the fin includes a slit between a through portion of the first heat transfer tube and a through portion of the second heat transfer tube.   
     
     
         11 . The cascade refrigeration cycle apparatus according to  claim 10 , wherein:
 the condenser further includes a first tube plate, made of metal, through which the first heat transfer tube extends and that supports the first heat transfer tube,   the radiator further includes a second tube plate, made of metal, through which the second heat transfer tube extends and that supports the second heat transfer tube, and   the first tube plate and the second tube plate are separate members.   
     
     
         12 . The cascade refrigeration cycle apparatus according to  claim 3 , wherein:
 the condenser includes a first heat transfer tube,   the radiator includes a second heat transfer tube,   the first heat transfer tube and the second heat transfer tube are in a same fin, and   the fin includes a slit between a through portion of the first heat transfer tube and a through portion of the second heat transfer tube.   
     
     
         13 . The cascade refrigeration cycle apparatus according to  claim 12 , wherein:
 the condenser further includes a first tube plate, made of metal, through which the first heat transfer tube extends and that supports the first heat transfer tube,   the radiator further includes a second tube plate, made of metal, through which the second heat transfer tube extends and that supports the second heat transfer tube, and   the first tube plate and the second tube plate are separate members.   
     
     
         14 . The cascade refrigeration cycle apparatus according to  claim 5 , wherein:
 the condenser includes a first heat transfer tube,   the radiator includes a second heat transfer tube,   the first heat transfer tube and the second heat transfer tube are in a same fin, and   the fin includes a slit between a through portion of the first heat transfer tube and a through portion of the second heat transfer tube.   
     
     
         15 . The cascade refrigeration cycle apparatus according to  claim 14 , wherein:
 the condenser further includes a first tube plate, made of metal, through which the first heat transfer tube extends and that supports the first heat transfer tube,   the radiator further includes a second tube plate, made of metal, through which the second heat transfer tube extends and that supports the second heat transfer tube, and   the first tube plate and the second tube plate are separate members.   
     
     
         16 . The cascade refrigeration cycle apparatus according to  claim 1 , wherein:
 the fan blows out air having passed through the condenser and the radiator upward, and   the condenser is at a position at least partially overlapping an upper part of the radiator.   
     
     
         17 . The cascade refrigeration cycle apparatus according to  claim 2 , wherein:
 the fan blows out air having passed through the condenser and the radiator upward, and   the condenser is at a position at least partially overlapping an upper part of the radiator.   
     
     
         18 . The cascade refrigeration cycle apparatus according to  claim 3 , wherein:
 the fan blows out air having passed through the condenser and the radiator upward, and   the condenser is at a position at least partially overlapping an upper part of the radiator.   
     
     
         19 . The cascade refrigeration cycle apparatus according to  claim 8 , wherein:
 the fan blows out air having passed through the condenser and the radiator upward, and   the condenser is at a position at least partially overlapping an upper part of the radiator.   
     
     
         20 . The cascade refrigeration cycle apparatus according to  claim 9 , wherein:
 the fan blows out air having passed through the condenser and the radiator upward, and   the condenser is at a position at least partially overlapping an upper part of the radiator.