Curved heat exchanger and method of manufacturing

Abstract

A heat exchanger has an upper manifold with a first curved section; a lower manifold spaced from and extending parallel to the upper manifold and having a second curved section; a plurality of refrigerant tubes, and a plurality of corrugated fins. Each corrugated fin is formed by a strip having radiused portions alternating with planar portions, and the radiused portions are in contact with the respective adjacent refrigerant tubes. Each of the fins has a curve-inner edge and a curve outer edge and at least one edge of the curve-inner edge and the curve outer edge of at least one fin has a recessed portion in the planar portions that is recessed inward toward a center of the core.

What is claimed is: 
     
         1 . A heat exchanger comprising:
 an upper manifold having a first curved section;   a lower manifold spaced from and extending parallel to the upper manifold and having a second curved section;   a plurality of refrigerant tubes, each refrigerant tube of the plurality of refrigerant tubes extending along a tube length from the upper manifold to the lower manifold and in hydraulic communication with the upper and lower manifolds;   a plurality of corrugated fins, each of the corrugated fins inserted between respective adjacent ones of the refrigerant tubes, the refrigerant tubes and corrugated fins defining a core having a plurality of air channels from a curve-outer face of the core to a curve-inner face of the core, each corrugated fin of the plurality of corrugated fins being formed by a strip having radiused portions alternating with planar portions, wherein the radiused portions are in contact with the respective adjacent refrigerant tubes,   wherein each of the fins has a curve-inner edge and a curve outer edge and at least one edge of the curve-inner edge and the curve outer edge of at least one fin extending between the first curved section and the second curved section has a recessed portion in the planar portions that is recessed inward toward a center of the core.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein the recessed portion in the planar portions is bent toward the lower manifold. 
     
     
         3 . The heat exchanger according to  claim 1 , wherein the recessed portion is a central subsection of the planar portions between two subsections of the planar portion, where the edge extends as far outward from the core as the edge of the radiused portions. 
     
     
         4 . The heat exchanger according to  claim 1 , wherein the recessed portion is recessed by a depth within a range of 2% to 50% of a local heater core depth. 
     
     
         5 . The heat exchanger according to  claim 1 , wherein the recessed portion is present in each of the planar portions of the fin at least on the curve-inner edge or on the curve outer edge. 
     
     
         6 . The heat exchanger according to  claim 1 , wherein the recessed portion is present on both the curve-inner edge and the curve outer edge. 
     
     
         7 . The heat exchanger according to  claim 1 , wherein at least two of the fins have a recessed edge, wherein the at least two of the fins are spaced apart by at least one intermediate fin lacking a recessed portion on a side where the at least two of the fins adjacent to the intermediate fin have a recessed portion. 
     
     
         8 . The heat exchanger according to  claim 1 , wherein the recessed portion is on the curve-inner edge, wherein a subsection of the curve-inner edge is folded down to extend downward toward the lower manifold. 
     
     
         9 . The heat exchanger according to  claim 1 , wherein the recessed portion comprises an incision formed in the at least one edge, the incision extending inward toward the center of the core. 
     
     
         10 . The heat exchanger according to  claim 8 , wherein the edge is bent downward toward the lower manifold in regions laterally adjoining the incision. 
     
     
         11 . The heat exchanger according to  claim 1 , wherein the recessed portion is disposed on both the curve-inner edge and the curve-outer edge, wherein a subsection of the curve-inner edge is folded down to extend downward toward the lower manifold and wherein an incision is formed in the curve-outer edge, the incision extending inward toward the center of the core. 
     
     
         12 . The heat exchanger according to  claim 1 , wherein the recessed portion is disposed on both the curve-inner edge and the curve-outer edge, wherein an incision is formed in both the curve-inner edge and the curve-outer edge, the incision extending inward toward the center of the core. 
     
     
         13 . A method of making a curved heat exchanger, the method comprising the following steps:
 assembling parts of the heat exchanger, the parts, after assembly, form a flat heat exchanger including:
 an upper manifold having a straight elongated shape; 
 an lower manifold spaced from and extending parallel to the upper manifold; 
 a plurality of refrigerant tubes, each refrigerant tube of the plurality of refrigerant tubes extending along a tube length with one tube end attached to the upper manifold and another tube end attached to the lower manifold; and 
 a plurality of corrugated fins, each of the corrugated fins inserted between two respective adjacent ones of the refrigerant tubes, the refrigerant tubes and corrugated fins defining a core having a plurality of air channels for airflow from a first face of the core to a second face of the core, each corrugated fin of the plurality of corrugated fins being formed by a strip having radiused portions alternating with planar portions, wherein the radiused portions are in contact with the respective adjacent refrigerant tubes; 
   driving an edge tool along the first face of the core between the respective adjacent refrigerant tubes in a direction parallel to the refrigerant tubes so as to form a respective recessed portion in a plurality of the planar portions; and   bending the first manifold, the second manifold, and the core about a common bending axis extending parallel to the refrigerant tubes to form a curved portion of the heat exchanger, wherein the curved portion of the heat exchanger includes the recessed portions.   
     
     
         14 . The method according to  claim 13 , wherein the step of driving the edge tool along the first face also bends the fin downward toward the lower manifold. 
     
     
         15 . The method according to  claim 13 , comprising the further step of driving the edge tool along the first face of the core between additional two adjacent refrigerant tubes so as to form a respective recessed portion in a plurality of the planar portions of a different one of the plurality of corrugated fins. 
     
     
         16 . The method according to  claim 13 , wherein the first face including the recessed portions is a curve-inner face of the core. 
     
     
         17 . The method according to  claim 13 , wherein the first face including the recessed portions is a curve-outer face of the core. 
     
     
         18 . The method according to  claim 13 , comprising the further step of driving the edge tool or a different edge tool along the second face of the core between the respective adjacent refrigerant tubes or between different adjacent refrigerant tubes in a direction parallel to the refrigerant tubes so as to form further respective recessed portions in a plurality of the planar portions. 
     
     
         19 . The method according to  claim 13 , wherein the edge tool is a folding tool and the recessed portions are formed by folded-down edge portions. 
     
     
         20 . The method according to  claim 13 , wherein the edge tool is a scoring tool and the recessed portions are formed by cut edge portions.