Heat exchanger and refrigeration cycle apparatus including the same

Abstract

A heat exchanger includes: a plurality of flat heat transfer tubes each having an elongated cross-sectional shape, each including refrigerant flow passages therein, and arranged apart from and in parallel with each other; and corrugated fins each provided between associated adjacent ones of the flat heat transfer tubes. Each of the corrugated fins has fin portions each having a plate shape, and is bent into a wave shape such that the fin portions are arranged alongside of each other in an axial direction of the flat heat transfer tubes. The fin portions include louvers. The louvers are made as different types of louvers to have different configurations, such that the different types of louvers are provided at respective selected sets of fin portions, to thereby cause different amounts of frost to be formed on the fin portions.

1 . A heat exchanger comprising:
 a plurality of flat heat transfer tubes each having an elongated cross-sectional shape, each including a plurality of refrigerant flow passages therein, and arranged apart from each other and in parallel with each other; and   a plurality of corrugated fins each provided between associated adjacent ones of the flat heat transfer tubes,   wherein   each of the plurality of corrugated fins has a plurality of fin portions each having a plate shape, and is bent into a wave shape such that the plurality of fin portions are arranged alongside of each other in an axial direction of the flat heat transfer tubes,   the plurality of fin portions include louvers, and   the louvers are made as different types of louvers to have different configurations, such that the different types of louvers are provided at respective selected sets of fins portions of the plurality of fin portions, to thereby cause different amounts of frost to be formed on the plurality of fin portions.   
     
     
         2 . The heat exchanger of  claim 1 , wherein the different types of louvers are arranged at respective repetitive patterns in the axial direction of the flat heat transfer tubes. 
     
     
         3 . The heat exchanger of  claim 1  , wherein the different types of louvers are different in width in a direction in which the flat heat transfer tubes are arranged. 
     
     
         4 . The heat exchanger of  claim 1 , wherein the different types of louvers are different in number of the louvers provided at one fin portion. 
     
     
         5 . The heat exchanger of  claim 1 , wherein
 each of the louvers has a slit through which air passes and a plate portion that is inclined relative to an associated one of the plurality of fin portions and guides air into the slit, and   the different types of louvers are different in inclined angle of the plate portion.   
     
     
         6 . The heat exchanger of  claim 1 , wherein the plurality of fin portions include the fin portions having no louver. 
     
     
         7 . The heat exchanger of  claim 1 , wherein
 the plurality of fin portions have drain holes to drain water that flows over upper surfaces of the plurality of fin portions, and   the drain holes are made as different types of drain holes to have different configurations, such that the different types of drain holes are formed in respective selected sets of fin portions of the plurality of fin portions, to thereby cause different amounts of frost to be formed on the fins portions.   
     
     
         8 . The heat exchanger of  claim 7 , wherein the drain types of drain holes are different in total opening area of the drain holes formed in the one fin portion. 
     
     
         9 . The heat exchanger of  claim 1 , wherein a dimension of each of the plurality of fin portions in a flow direction of air is 22 mm or more. 
     
     
         10 . A refrigeration cycle apparatus comprising the heat exchanger of  claim 1 .