Heat Exchangers and Methods of Forming Heat Exchangers

Abstract

Examples of the disclosure relate to heat exchangers. The heat exchangers could be evaporators or condensers. The heat exchangers can comprise a plurality of structures extending from a base plate where adjacent structures are separated by at least a first distance. The heat exchangers can also comprise at least one cover plate positioned over ends of the plurality of structures so that the at least one cover plate is spaced from the ends of the plurality of structures by a second distance where the second distance is smaller than the first distance. The at least one cover plate is brazed to the plurality of structures by brazing material provided between the ends of the plurality of structures and the at least one cover plate. The brazing material is provided in a discontinuous configuration so that gaps are provided between portions of brazing material so that a brazing join is formed from brazing materials that has flowed into spacing between the at least one cover plate and the ends of the plurality of structures.

1 . A heat exchanger comprising:
 a plurality of structures extending from a base plate where adjacent structures are separated by at least a first distance; and   at least one cover plate positioned over ends of the plurality of structures so that the at least one cover plate is spaced from the ends of the plurality of structures by a second distance where the second distance is smaller than the first distance;   wherein the at least one cover plate is brazed to the plurality of structures by brazing material provided between the ends of the plurality of structures and the at least one cover plate; and   wherein the brazing material is provided in a discontinuous configuration so that gaps are provided between portions of brazing material so that a brazing join is formed from brazing materials that has flowed into spacing between the at least one cover plate and the ends of the plurality of structures.   
     
     
         2 . The heat exchanger of  claim 1 , wherein the brazing material is provided in a thickness that is smaller than the first distance. 
     
     
         3 . The heat exchanger of  claim 1 , wherein the first distance and the second distance are selected so that Laplace pressure causes the brazing material to flow into gaps between the ends of the plurality of structures and the at least one cover plate. 
     
     
         4 . The heat exchanger of  claim 1 , wherein the plurality of structures extend substantially perpendicularly out of the base plate. 
     
     
         5 . The heat exchanger of  claim 1 , wherein the plurality of structures are spaced closer together at edges of the base plate than in a center of the base plate. 
     
     
         6 . The heat exchanger of  claim 1 , comprising a stiffener structure comprising a plurality projecting portions configured to extend between the plurality of structures so as to restrict bending of the plurality of structures. 
     
     
         7 . The heat exchanger of  claim 1 , wherein at least some of the plurality of structures extend through the at least one cover plate and further coupling devices provided on the ends of the plurality of structures that extend through the at least one cover plate. 
     
     
         8 . The heat exchanger of  claim 1 , wherein the plurality of structures comprises fins. 
     
     
         9 . The heat exchanger of  claim 1 , wherein the heat exchanger comprises an evaporator or a condenser. 
     
     
         10 . A method comprising:
 providing a plurality of structures extending from a base plate where the plurality of structures are separated by at least a first distance;   providing brazing material overlaying, at least some of the plurality of structures wherein the brazing material is provided in a discontinuous configuration so that gaps are provided between portions of brazing material;   providing at least one cover plate over ends of the plurality of structures and the brazing material so that the at least one cover plate is spaced from the ends of the plurality of structures by a second distance where the second distance is smaller than the first distance; and   heating the brazing material so that the brazing material flows into spacing between the at least one cover plate and the ends of the plurality of structures.   
     
     
         11 . The method of  claim 10 , wherein the brazing material is provided in a thickness that is smaller than the first distance. 
     
     
         12 . The method as claimed in any of claims of  claim 10 , wherein the first distance and the second distance are selected so that Laplace pressure causes the brazing material to flow into gaps between the ends of the plurality of structures and the at least one cover plate. 
     
     
         13 . A heat exchanger comprising:
 a base plate;   a plurality of structures extending out of the base plate; and   at least one stiffener structure comprising a plurality projecting portions configured to extend between the plurality of structures so as reduce bending of the plurality of structures.   
     
     
         14 . The heat exchanger of  claim 13 , comprising a cover plate wherein the at least one stiffener structure is provided as part of the cover plate. 
     
     
         15 . The heat exchanger of  claim 13 ,
 wherein the heat exchanger is configured to provide larger channels for flow of working fluid towards in a central portion of the base plate compared to edges of the base plate.