Heat exchanger and method

Abstract

A heat exchanger including a first flow path for a first working fluid, a second flow path for a second working fluid, a tube at least partially defining one of the first and second flow paths, and a corrugated insert secured to the tube and positioned along the first flow path. A structural deficit is provided at a location on the insert such that structural failures occur at the location in preference to other locations on the insert.

1 . A heat exchanger comprising:
 a first flow path for a first working fluid;   a second flow path for a second working fluid;   a corrugated insert positioned along the first flow path;   a structural deficit provided at a location on the insert such that structural failures occur at the location in preference to other locations on the insert; and   a tube at least partially defining one of the first and second flow paths, the insert being secured to the tube.   
   
   
       2 . The heat exchanger of  claim 1 , wherein the structural deficit comprises a groove. 
   
   
       3 . The heat exchanger of  claim 1 , wherein the structural deficit comprises a staggered groove. 
   
   
       4 . The heat exchanger of  claim 1 , wherein the corrugated insert comprises a peak and an adjacent valley and wherein the structural deficit is positioned between the peak and the valley. 
   
   
       5 . The heat exchanger of  claim 4 , wherein the peak and valley extend along a longitudinal dimension of the insert and the structural deficit extends along a portion of the longitudinal dimension of the insert in a direction substantially parallel to a fold of the insert. 
   
   
       6 . The heat exchanger of  claim 4 , wherein the structural deficit is positioned substantially equidistantly between the peak and valley such that structural failures occur at a midpoint between the peak and valley. 
   
   
       7 . The heat exchanger of  claim 1 , wherein the insert comprises adjacent folds such that the insert extends between opposing surfaces of the tube and is secured to the surfaces of the tube at the folds. 
   
   
       8 . The heat exchanger of  claim 7 , wherein the structural deficit is located midway along a height of the insert between the opposing surfaces of the tube. 
   
   
       9 . The heat exchanger of  claim 7 , wherein the structural deficit is spaced away from the folds of the insert. 
   
   
       10 . The heat exchanger of  claim 7 , wherein the folds are secured to the surfaces of the tube by one of welded, soldered, and brazed connections. 
   
   
       11 . A heat exchanger comprising:
 a header;   a tube secured to the header; and   a corrugated insert secured to at least one surface of the tube, the insert having a groove formed along at least a portion of a length of the insert and spaced apart from the surface of the tube to which the insert is secured.   
   
   
       12 . The heat exchanger of  claim 11 , wherein the insert defines adjacent legs, and wherein the groove is located along one of the legs. 
   
   
       13 . The heat exchanger of  claim 12 , wherein at least a portion of one of the legs has a wavy cross-section. 
   
   
       14 . The heat exchanger of  claim 12 , wherein the insert is secured between opposing surfaces of the tube, and wherein the groove is positioned along the insert such that the insert remains secured to the opposing surfaces after a structural failure. 
   
   
       15 . The heat exchanger of  claim 14 , wherein the legs of the insert provide sufficient structural support for the opposing surfaces of the tube after a structural failure. 
   
   
       16 . The heat exchanger of  claim 12 , wherein the corrugated insert comprises a peak and an adjacent valley and wherein the groove is positioned between the peak and the valley. 
   
   
       17 . The heat exchanger of  claim 12 , wherein the corrugated insert comprises a peak and an adjacent valley, and wherein the groove is positioned substantially equidistantly between the peak and valley such that the structural failures occur at a midpoint between the peak and valley. 
   
   
       18 . The heat exchanger of  claim 12 , wherein the groove has a cross-section that is substantially V-shaped. 
   
   
       19 . A heat exchanger having a tube and an insert supported by the tube, the insert comprising:
 a corrugation defining a peak and an adjacent valley;   a groove extending along a longitudinal dimension of the insert between the peak and the adjacent valley and providing a preferred location for structural failures.   
   
   
       20 . The heat exchanger of  claim 19 , wherein the groove is positioned substantially equidistantly between the peak and the valley such that structural failures occur at a midpoint between the peak and the valley. 
   
   
       21 . The heat exchanger of  claim 19 , wherein the groove is located at a maximum distance between the peak and the valley. 
   
   
       22 . The heat exchanger of  claim 19 , wherein the insert is attached to opposing surfaces of the tube in at least one location along at least one of the peak and the valley. 
   
   
       23 . The heat exchanger of  claim 19 , wherein the groove extends substantially along the entire longitudinal dimension of the insert. 
   
   
       24 . The heat exchanger of  claim 19 , wherein the longitudinal dimension of the insert terminates in opposing ends of the insert, and wherein the groove extends from an end to a location along the longitudinal dimension of the insert. 
   
   
       25 . The heat exchanger of  claim 24 , and further comprising a header into which an end of the tube extends, wherein the insert extends substantially the entire length of the tube and the groove extends to a location where the tube connects to the header. 
   
   
       26 . The heat exchanger of  claim 24 , and further comprising a header into which an end of the tube extends, wherein the insert extends substantially the entire length of the tube and the groove extends beyond a location where the tube connects to the header. 
   
   
       27 . A method of assembling a heat exchanger comprising the steps of:
 providing a heat exchanger tube;   positioning an insert in the tube;   connecting the insert to a surface of the tube;   forming a structural deficiency along at least a portion of a length of the insert at a maximum distance from a point of connection between the insert and the surface of the tube so that failures occur along the structural deficiency.   
   
   
       28 . The method of  claim 27 , wherein forming the structural deficiency includes forming a groove, and wherein the structural deficiency is formed having a cross-section that is one of substantially U-shaped, V-shaped, or rectangular. 
   
   
       29 . The method of  claim 27 , wherein the structural deficiency is formed by one of scoring, stamping, and etching. 
   
   
       30 . The method of  claim 27 , wherein the insert is connected to the surface of the tube by one of brazing, soldering, or welding. 
   
   
       31 . The method of  claim 27 , and further comprising folding the insert to form alternating peaks and valleys. 
   
   
       32 . The method of  claim 31 , wherein the structural deficiency is formed prior to the folding of the insert. 
   
   
       33 . The method of  claim 31 , wherein the structural deficiency is formed after the folding of the insert. 
   
   
       34 . The method of  claim 31 , wherein the peaks and valleys of the insert are connected to opposing surfaces of the tube.