Heat exchanger and refrigeration cycle apparatus including heat exchanger

Abstract

A heat exchanger includes: multi-channeled flat tubes disposed side by side in a vertical direction; and a pressure loss part through which refrigerant flows. The multi-channeled flat tubes are divided into: a first tube group including one or more of the multi-channeled flat tubes disposed at a lowermost stage in the heat exchanger; and a second tube group including a remainder of the multi-channeled flat tubes not in the first tube group. The first tube group forms a first flow path of the refrigerant. The second tube group forms a second flow path of the refrigerant. In response to the heat exchanger functioning as an evaporator, at least some of the refrigerant in the heat exchanger flows into the pressure loss part after flowing through the first flow path and further flows into the second flow path after flowing through the pressure loss part.

What is claimed is: 
     
         1 . A heat exchanger comprising:
 multi-channeled flat tubes disposed side by side in a vertical direction; and   a pressure loss part through which refrigerant flows, wherein   the multi-channeled flat tubes are divided into:
 a first tube group including one or more of the multi-channeled flat tubes disposed at a lowermost stage in the heat exchanger; and 
 a second tube group including a remainder of the multi-channeled flat tubes not in the first tube group, 
   the first tube group forms a first flow path of the refrigerant,   the second tube group forms a second flow path of the refrigerant, and   in response to the heat exchanger functioning as an evaporator, at least some of the refrigerant in the heat exchanger flows into the pressure loss part after flowing through the first flow path and further flows into the second flow path after flowing through the pressure loss part.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein, in response to the heat exchanger functioning as an evaporator, all of the refrigerant in the heat exchanger flows into the pressure loss part after flowing through the first flow path and further flows into the second flow path after flowing through the pressure loss part. 
     
     
         3 . The heat exchanger according to  claim 1 , wherein the first tube group includes two or more of the multi-channeled flat tubes disposed in parallel with respect to a flow of the refrigerant. 
     
     
         4 . The heat exchanger according to  claim 1 , wherein a flow path area of each of the multi-channeled flat tubes of the first tube group is larger than a flow path area of each of the multi-channeled flat tubes of the second tube group. 
     
     
         5 . The heat exchanger according to  claim 1 , wherein a number of the multi-channeled flat tubes of the first tube group is smaller than a number of the multi-channeled flat tubes of the second tube group. 
     
     
         6 . The heat exchanger according to  claim 1 , wherein the pressure loss part is an orifice in a flow path of the refrigerant between the first flow path and the second flow path. 
     
     
         7 . The heat exchanger according to  claim 1 , wherein the pressure loss part is a flow divider in a flow path of the refrigerant between the first flow path and the second flow path. 
     
     
         8 . The heat exchanger according to  claim 1 , further comprising:
 a header in a flow path of the refrigerant between the first flow path and the second flow path, wherein   the pressure loss part is a nozzle inside the header.   
     
     
         9 . The heat exchanger according to  claim 1 , further comprising a bypass path through which the refrigerant is guided to the second flow path without flowing through the first flow path. 
     
     
         10 . The heat exchanger according to  claim 1 , wherein
 the multi-channeled flat tubes are disposed in rows in a direction of an air flow generated by a fan that sends air to the heat exchanger, and   the first flow path is disposed only on a windward side in the direction of the air flow.   
     
     
         11 . A refrigeration cycle apparatus comprising:
 a refrigerant circuit comprising:
 the heat exchanger according to  claim 1  as a heat source heat exchanger; and 
 a compressor that compresses the refrigerant; and 
   a fan that sends air to the heat exchanger.