Heat exchanger tube with a compressed return bend, a serpentine heat exchanger tube with compressed return bends and heat exchanger implementing the same

Abstract

A heat exchanger tube includes a tube body forming a hollow passageway and having a U-shaped tube section defining a return bend, a pair of straight tube sections and a pair of transition sections. Respective ones of the straight tube sections are connected to the return section with respective ones of the transition sections disposed therebetween. The straight tube sections extend generally parallel to one another. Each straight tube section has a straight tube cross-sectional width and the return bend has a return bend cross-sectional width that is smaller than the straight tube cross-sectional width. Multiple heat exchanger tubes can be connected together to form a serpentine heat exchanger tube. Multiple serpentine heat exchanger tubes or multiple heat exchanger tubes can be assembled together to form a heat exchanger apparatus.

1 . A tube, comprising: 
 a tube body forming a hollow passageway and having a U-shaped tube section defining a return bend, a pair of straight tube sections and a pair of transition sections, respective ones of the straight tube sections connected to the return bend with respective ones of the transition sections disposed therebetween, the straight tube sections extending generally parallel to one another, each straight tube section having a straight tube cross-sectional width, the return bend having a return bend cross-sectional width being smaller than the straight tube cross-sectional width.    
   
   
       2 . A tube according to  claim 1 , wherein a width ratio of the straight tube cross-sectional width to the return bend cross-sectional width is in a range of approximately 1.2 and 1.3.  
   
   
       3 . A tube according to  claim 1 , wherein a width ratio of the straight tube cross-sectional width to the return bend cross-sectional width is in a range of approximately 1.1 and 1.6.  
   
   
       4 . A tube according to  claim 1 , wherein the straight tube sections have a generally uniform straight tube section cross-sectional configuration.  
   
   
       5 . A tube according to  claim 4 , wherein the straight tube section cross-sectional configuration is circularly-shaped or elliptically-shaped.  
   
   
       6 . A tube according to  claim 1 , wherein at least a substantial entirety of the return bend has a generally uniform return bend cross-sectional configuration.  
   
   
       7 . A tube according to  claim 6 , wherein the return bend cross-sectional configuration is generally one of oval-shaped with opposing parallel sidewalls, oval-shaped, elliptically-shaped and elliptically-shaped with opposing parallel sidewalls.  
   
   
       8 . A tube according to  claim 1 , wherein each transition section includes an opposing pair of first walls tapering inwardly from the straight tube section towards the return bend and an opposing pair of second walls tapering inwardly from the return bend towards the straight tube section, individual ones of the opposing pairs of first and second walls integrally connected in an alternating manner.  
   
   
       9 . A tube according to  claim 1 , wherein the return bend has a return bend cross-sectional area and each straight tube section has a straight tube cross-sectional area being at least substantially equal to relative to each other and at least substantially equal to the return bend cross-sectional area.  
   
   
       10 . A serpentine tube, comprising: 
 a serpentine tube body disposed in plane, forming a hollow passageway and having a plurality of straight tube sections arranged generally parallel with one another, a plurality of return bends and a plurality of transition sections, a respective one of the plurality of transition sections interconnecting respective ones of the plurality of straight tube sections and the return bends to form a serpentine configuration, each straight tube section having a generally uniform straight tube section cross-sectional configuration and a straight tube cross-sectional width, each return bend having a generally uniform return bend cross-sectional configuration and a return bend cross-sectional width being smaller than the straight tube cross-sectional width.    
   
   
       11 . A serpentine tube according to  claim 10 , wherein a width ratio of the straight tube cross-sectional width to the return bend cross-sectional width is in a range of approximately 1.2 and 1.3.  
   
   
       12 . A serpentine tube according to  claim 10 , wherein a width ratio of the straight tube cross-sectional width to the return bend cross-sectional width is in a range of approximately 1.1 and 1.6.  
   
   
       13 . A heat exchanger apparatus, comprising: 
 an inlet header;    an inlet connection connected to the inlet header;    an outlet header;    an outlet connection connected to the outlet header; and    a plurality of adjacent serpentine tube bodies staggered in an alternating fashion, respective ones of the plurality of adjacent serpentine tube bodies connected to and between and in fluid communication with the inlet header and the outlet header, each serpentine tube body disposed in a selected one of a plurality of parallel planes in a juxtaposed manner, forming a hollow passageway and having a plurality of straight tube sections arranged generally parallel with one another, a plurality of return bends and a plurality of transition sections, a respective one of the plurality of transition sections interconnecting respective ones the plurality of straight tube sections and the return bends to form a serpentine configuration, each straight tube section having a generally uniform straight tube section cross-sectional configuration and a straight tube cross-sectional width, each return bend having a generally uniform return bend cross-sectional configuration and a return bend cross-sectional width being smaller than the straight tube cross-sectional width, staggered juxtaposed ones of the return bends contacting one another at a location where the staggered juxtaposed ones of the return bends cross one another.    
   
   
       14 . A heat exchanger according to  claim 13 , wherein a width ratio of the straight tube cross-sectional width to the return bend cross-sectional width is in a range of approximately 1.2 and 1.3.  
   
   
       15 . A heat exchanger according to  claim 13 , wherein a width ratio of the straight tube cross-sectional width to the return bend cross-sectional width is in a range of approximately 1.1 and 1.6.