Heat Exchanger Tube, Heat Exchanger Tube Assembly, And Methods Of Making The Same

Abstract

A tube for use in a tube assembly for a heat exchanger includes a flat section located away from a tube end. The flat section includes broad, flat, parallel tube sides joined by narrow sides so that the tube is relatively thin in one direction. A cylindrical section extends from the end of the tube, and a transition section connects the cylindrical section and the flat tube section. The geometry of the transition section provides resistance to bending at the intersection between the flat tube section and the transition section.

We claim: 
     
         1 . A tube for a heat exchanger, comprising
 a first cylindrical section extending from a first tube end;   a second cylindrical section extending from a second tube end opposite the first tube end;   a flat tube section located between the first and second ends, the flat tube section comprising two broad and flat, spaced apart parallel sides joined by two relatively short sides;   a first transition region located between the first cylindrical section and a first end of the flat tube section proximal to the first cylindrical section; and   a second transition region located between the second cylindrical section and a second end of the flat tube section proximal to the second cylindrical section, the intersections of each of the first and second transition regions and each of the broad and flat sides defining curvilinear paths.   
     
     
         2 . The tube of  claim 1 , wherein the two relatively short sides are arcuate in profile. 
     
     
         3 . The tube of  claim 1 , wherein each of the curvilinear paths includes an apex located at a center plane of the tube. 
     
     
         4 . The tube of  claim 3 , wherein each of the curvilinear paths includes an arcuate path segment at the apex. 
     
     
         5 . The tube of  claim 1 , wherein the first cylindrical section defines a tube diameter and the first transition region extends, in the tube-axial direction, over a length at least equal to the tube diameter. 
     
     
         6 . The tube of  claim 5 , wherein the tube diameter is a first tube diameter, the second cylindrical section defines a second tube diameter, and the second transition region extends, in the tube-axial direction, over a length at least equal to the second tube diameter. 
     
     
         7 . The tube of  claim 1 , wherein the first cylindrical section defines a first tube outer perimeter and the flat tube section defines a second tube outer perimeter greater than the first tube outer perimeter. 
     
     
         8 . The tube of  claim 7 , wherein the second tube outer perimeter exceeds the first tube outer perimeter by more than twenty-five percent. 
     
     
         9 . The tube of  claim 1 , wherein the flat tube section defines a tube major dimension between a first outermost point on one of the relatively short sides and a second outermost point on the other of the relatively short sides, and each of the curvilinear paths is longer than the tube major dimension. 
     
     
         10 . The tube of  claim 1 , wherein at least one of the first and second cylindrical sections includes a circumferential bead. 
     
     
         11 . The tube of  claim 1 , wherein the tube comprises an aluminum alloy. 
     
     
         12 . A tube for a heat exchanger, comprising
 a tube end;   a flat tube section located away from the tube end, the flat tube section comprising two broad and flat, spaced apart parallel sides joined by two relatively short sides;   a cylindrical section extending from the tube end to a first location proximal to the tube end; and   a transition region connecting the cylindrical section and the flat tube section and extending in a tube-axial direction from the first location to a second location distal to the tube end, wherein at least a portion of the flat tube section is between the first location and the second location.   
     
     
         13 . The tube of  claim 12 , wherein the transition region tapers to an apex at the second location. 
     
     
         14 . The tube of  claim 12 , wherein the intersection of the transition region and one of the broad and flat sides defines a curvilinear path. 
     
     
         15 . The tube of  claim 12 , wherein the cylindrical section defines a tube diameter and the distance in the tube-axial direction between the first and second locations is at least equal to the tube diameter. 
     
     
         16 . The tube of  claim 12 , wherein the cylindrical section defines a first tube outer perimeter and the flat tube section defines a second tube outer perimeter greater than the first tube outer perimeter. 
     
     
         17 . The tube of  claim 16 , wherein the second tube outer perimeter exceeds the first tube outer perimeter by more than twenty-five percent. 
     
     
         18 . The tube of  claim 12 , wherein the tube end is a first tube end, the cylindrical section is a first cylindrical section, and the transition region is a first transition region, the tube further comprising:
 a second tube end arranged opposite the first tube end;   a second cylindrical section extending from the second tube end to a third location proximal to the second tube end; and   a second transition region connecting the second cylindrical section and the flat tube section and extending in a tube-axial direction from the third location to a fourth location distal to the second tube end, wherein at least a portion of the flat tube section is between the third location and the fourth location.   
     
     
         19 . The tube of  claim 12 , wherein the intersections of each of the first and second transition regions and each of the broad and flat sides define curvilinear paths. 
     
     
         20 . The tube of  claim 19 , wherein each of the curvilinear paths includes an apex located at a center plane of the tube.