Heat exchanger

Abstract

A heat exchanger includes: heat transfer units that each comprise heat transfer channel portions and auxiliary heat transfer portions. The heat transfer channel portions and the auxiliary heat transfer portions extend in a first direction and are disposed in a second direction that intersects with or is perpendicular to the first direction. The heat transfer units are disposed in a third direction that is different from both of the first direction and the second direction. The heat transfer units each has an airflow-upstream region and an airflow-downstream region in the second direction. When the heat exchanger is used as an evaporator, the heat exchanger causes a refrigerant to flow into a heat transfer channel portion disposed in the airflow-upstream region, and then causes the refrigerant to flow out to a heat transfer channel portion disposed in the airflow-downstream region.

1 - 9 . (canceled) 
     
     
         10 . A heat exchanger comprising:
 heat transfer units that each comprise heat transfer channel portions and auxiliary heat transfer portions, wherein   the heat transfer channel portions and the auxiliary heat transfer portions extend in a first direction and are disposed in a second direction that intersects with or is perpendicular to the first direction,   the heat transfer units are disposed in a third direction that is different from both of the first direction and the second direction,   the heat transfer units each has an airflow-upstream region and an airflow-downstream region in the second direction, and   when the heat exchanger is used as an evaporator, the heat exchanger causes a refrigerant to flow into a heat transfer channel portion disposed in the airflow-upstream region, and then causes the refrigerant to flow out to a heat transfer channel portion disposed in the airflow-downstream region.   
     
     
         11 . The heat exchanger according to claim  1 , wherein a number of heat transfer channel portions disposed in the airflow-downstream region is larger than a number of heat transfer channel portions disposed in the airflow-upstream region. 
     
     
         12 . The heat exchanger according to  claim 10 , further comprising:
 a decompressing mechanism that decompresses the refrigerant,   wherein the heat exchanger causes the refrigerant to flow from the heat transfer channel portion disposed in the airflow-upstream region into the heat transfer channel portion disposed in the airflow-downstream region via the decompressing mechanism.   
     
     
         13 . The heat exchanger according to  claim 10 , further comprising:
 an upper header connected to the heat transfer units from above in the first direction; and   a lower header connected to the heat transfer units from below in the first direction, wherein   the upper header and the lower header form a part of a channel of the refrigerant.   
     
     
         14 . The heat exchanger according to  claim 13 , wherein the airflow-upstream region and the airflow-downstream region are separated by a partition disposed inside of at least one of the upper header or the lower header. 
     
     
         15 . The heat exchanger according to  claim 10 , wherein
 each of the heat transfer units comprises eight or more heat transfer channel portions, and   at least two or more of the heat transfer channel portions are disposed in the airflow-upstream region.   
     
     
         16 . The heat exchanger according to  claim 10 , wherein, when viewed from the first direction, a heat insulator is applied to an end portion of each of the heat transfer units in the second direction. 
     
     
         17 . The heat exchanger according to claim  7 , wherein
 in each of the heat transfer units, one of the auxiliary heat transfer portions is at an end of the respective heat transfer units in the second direction when viewed from the first direction, and   the one of the auxiliary heat transfer portion in each of the heat transfer units has a closed shape.   
     
     
         18 . An air conditioner comprising the heat exchanger according to  claim 10 .