Microchannel, flat tube heat exchanger with bent tube configuration

Abstract

A heat exchanger assembly includes a first header having an inlet and a second header having an outlet spaced parallel from each other. A plurality of tube members having an ultimate strength (Us) and a width (w), extend between the first header and the second header. The tube members define a plurality of fluid passages for the flow of a liquid through the tube members and between the first and second headers. The tube members extend through at least one bend having a bend radius (r) in the range of 50.00 mm to straight (∞) through angles between 0 and 100 degrees. A plurality of corrugated air fins are brazed between adjacent tube members. The bends of the tube members satisfy a bending formula (w/r)Us≦30 mega Pascal.

1 . A heat exchanger assembly for use in residential air conditioning units comprising; 
 a first header and a second header spaced parallel from each other, a plurality of tube members extending between said first header and said second header and having a width from a first nose to a second nose and defining a plurality of fluid passages for the flow of a liquid through said tube members and between said first and second headers,    said tube members extending through at least one bend having a bend radius (r),    said tube members having an ultimate strength (Us), and    a plurality of air fins disposed between adjacent ones of said tube members for dissipating heat from said tube members,    said bends of said tube members satisfying a bending formula (w/r)Us≦30 mega Pascal.    
   
   
       2 . An assembly as set forth in  claim 1  wherein said bend radius (r) is in the range of 50.00 mm to straight (∞) through angles between 0 and 100 degrees.  
   
   
       3 . An assembly as set forth in  claim 2  wherein said width (w) of said tube members is in the range of 12.00 mm to 27.00 mm.  
   
   
       4 . An assembly as set forth in  claim 3  wherein said tube members include two parallel flat sides extending between said semi-circular first and second noses.  
   
   
       5 . An assembly as set forth in  claim 4  wherein said plurality of air fins are corrugated and brazed between two of said parallel flat sides of adjacent ones of said tube members for dissipating heat from said tube members.  
   
   
       6 . An assembly as set forth in  claim 5  wherein said tube members include an internal wall thickness (t i ) between each of said passages and the next adjacent one of said passages in the range of 0.15 mm to 0.40 mm.  
   
   
       7 . An assembly as set forth in  claim 6  wherein said tube members include an external wall thickness (t e ) between each of said passages and said flat sides in the range of 0.15 mm to 0.40 mm.  
   
   
       8 . An assembly as set forth in  claim 7  wherein said tube members include a nose thickness (t n ) between each of said first and second noses and the adjacent one of said passages in the range of 0.15 mm to 1.00 mm.  
   
   
       9 . An assembly as set forth in  claim 8  wherein said passages are generally round in cross section.  
   
   
       10 . An assembly as set forth in  claim 9  wherein said passages include a diameter (d) in the range of 0.50 mm to 1.00 mm.  
   
   
       11 . An assembly as set forth in  claim 10  wherein said tube members are aluminum.  
   
   
       12 . A heat exchanger assembly for use in residential air conditioning units comprising; 
 a first header and a second header spaced parallel from each other,    a plurality of tube members extending between said first header and said second header and having two parallel flat sides extending between semi-circular first and second noses spaced a width (w) from said first nose to said second nose and defining a plurality of fluid passages each being generally round in cross section for the flow of a liquid through said tube members and between said first and second headers,    said tube members extending through at least one bend having a bend radius (r) in the range of 50.00 mm to straight (∞) through angles between 0 and 100 degrees,    said tube members being of aluminum and having an ultimate strength (Us),    said width (w) of said tube members being in the range of 12.00 mm to 27.00 mm,    said tube members having an internal wall thickness between each of said passages and the next adjacent one of said passages in the range of 0.15 mm to 0.40 mm,    said tube members having an external wall thickness (t e ) between each of said passages and said flat sides in the range of 0.15 mm to 0.40 mm,    said tube members having a nose thickness (t n ) between each of said first and second noses and the adjacent one of said passages in the range of 0.15 mm to 1.00 mm,    said passages having a diameter (d) in the range of 0.50 mm to 1.00 mm, and    a plurality of air fins being corrugated and brazed between two of said parallel flat sides of adjacent ones of said tube members for dissipating heat from said tube members,    said bends of said tube members satisfying a bending formula (w/r) Us≦30 mega Pascal.    
   
   
       13 . A method for manufacturing a heat exchanger assembly having a plurality of bent tube members for use in residential air conditioning units comprising the steps of; 
 preparing a straight condenser having a plurality of headers spaced parallel from each other and a plurality of tube members defining a plurality of flow passages extending between the headers and a plurality of air fins extending between the tube members,    brazing joints between the headers and the tube members and between the tube members and the air fins, and    bending the straight condenser to at least one predetermined bend satisfying a bending formula (w/r)Us≦30 mega Pascal and wherein w equals a width (w) extending between semi-circular noses and r equals a bend radius (r) and Us equals the ultimate strength (Us) of the tube members.    
   
   
       14 . A method as set forth in  claim 13  wherein the bend radius (r) is in the range of 50.00 mm to straight (∞) through angles between 0 and 100 degrees.  
   
   
       15 . A method as set forth in  claim 14  wherein the width (w) is in the range of 12.00 mm and 27.00 mm.