Heat exchanger having a contoured insert and method of assembling the same

Abstract

The present invention provides a heat exchanger for transferring heat between a first working fluid and a second working fluid, including a pair of spaced apart headers, a number of tubes extending between the pair of headers and providing a flow path for the first working fluid and being positioned along a flow path for the second working fluid, and an insert supportable in one of the tubes and having a fold extending in a direction substantially parallel to the flow path for the first working fluid through the tubes. The fold can define first and second legs of the insert. A dimple can be formed on the first leg and a protrusion can be formed on the second leg opposite to the dimple on the first leg.

1 . A heat exchanger for transferring heat between a first working fluid and a second working fluid, the heat exchanger comprising:
 a pair of spaced apart headers;   a plurality of tubes extending between the pair of headers and providing a flow path for the first working fluid and being positioned along a flow path for the second working fluid; and   an insert supportable in one of the plurality of tubes and having a fold extending in a direction substantially parallel to a length of the one of the plurality of tubes between the pair of headers, the insert including a plurality of dimples extending into and spaced along the fold.   
   
   
       2 . The heat exchanger of  claim 1 , wherein the fold defines first and second legs of the insert, and wherein, at a height of the first leg between the fold and a distal end of the first leg, a width between the first and second legs is substantially constant between opposite ends of the insert spaced apart in the direction of the fold. 
   
   
       3 . The heat exchanger of  claim 1 , wherein the fold defines first and second legs of the insert, wherein the dimple extends across the first leg, and wherein the second leg includes an outwardly extending protrusion shaped to be matingly receivable in the dimple of the first leg. 
   
   
       4 . The heat exchanger of  claim 1 , wherein the fold is a first fold, wherein the insert includes a second fold extending across the insert in a direction substantially parallel to the first fold, and wherein at least one of the plurality of dimples extends across a leg of the insert between the first fold and the second fold. 
   
   
       5 . The heat exchanger of  claim 1 , wherein the insert has as first side and a second side opposite to the first side, and wherein the plurality of dimples are formed on the first side and form protrusions on the second side, the protrusions extending into the fold. 
   
   
       6 . The heat exchanger of  claim 1 , wherein the flow path for the first working fluid extends through the plurality of dimples to provide a circuitous path between opposite ends of the tube. 
   
   
       7 . The heat exchanger of  claim 1 , wherein the plurality of dimples at least partially define an elastic region moveable relative to the tube in the direction substantially parallel to the length of the tube to accommodate thermal expansion of one of the tube and the insert. 
   
   
       8 . The heat exchanger of  claim 1 , wherein the fold provides a non-linear spine of the insert. 
   
   
       9 . The heat exchanger of  claim 1 , wherein the heat exchanger is an exhaust gas recirculation cooler, and wherein the first working fluid is engine exhaust and the second working fluid is a coolant. 
   
   
       10 . The heat exchanger of  claim 1 , wherein the fold defines first and second legs of the insert, wherein the dimple extends across the first leg at a distance from an inlet to the flow path for the first working fluid, and wherein a protrusion extends across the second leg opposite to the dimple of the first leg. 
   
   
       11 . The heat exchanger of  claim 10 , wherein a cross-sectional area of the flow path for the first working fluid is substantially the same between the first and second legs at the inlet to the flow path for the first working fluid and between the dimple and the protrusion. 
   
   
       12 . A heat exchanger for transferring heat between a first working fluid and a second working fluid, the heat exchanger comprising:
 a pair of spaced apart headers;   a plurality of tubes extending between the pair of headers and providing a flow path for the first working fluid and being positioned along a flow path for the second working fluid; and   an insert supportable in one of the plurality of tubes and having a fold extending in a direction substantially parallel to the flow path for the first working fluid through the plurality of tubes, the fold defining first and second legs of the insert, a dimple being formed on the first leg and a protrusion being formed on the second leg opposite to the dimple on the first leg.   
   
   
       13 . The heat exchanger of  claim 12 , wherein a cross-sectional area of the flow path for the first working fluid is substantially the same between the first and second legs at an outlet of the flow path for the first working fluid and between the dimple and the protrusion. 
   
   
       14 . The heat exchanger of  claim 12 , wherein the protrusion of the second leg is shaped to be matingly receivable in the dimple of the second leg. 
   
   
       15 . The heat exchanger of  claim 12 , wherein the dimple extends into the fold. 
   
   
       16 . The heat exchanger of  claim 12 , wherein, at a height of the first leg between the fold and a distal end of the first leg, a width between the first and second legs is substantially constant between opposite ends of the insert spaced apart in the direction of the fold. 
   
   
       17 . The heat exchanger of  claim 12 , wherein the fold is a first fold, wherein the insert includes a second fold extending across the insert in the direction substantially parallel to the flow path for the first working fluid through the plurality of tubes, and wherein the dimple extends across the first leg between the first fold and the second fold. 
   
   
       18 . The heat exchanger of  claim 12 , wherein the protrusion is a first protrusion, wherein the insert has a first side and a second side opposite to the first side, and wherein the dimple extends across the first side and forms a second protrusion on the second side. 
   
   
       19 . The heat exchanger of  claim 12 , wherein the fold provides a serpentine spine of the insert. 
   
   
       20 . The heat exchanger of  claim 19 , wherein the plurality of dimples are roll-formed along the insert. 
   
   
       21 . The heat exchanger of  claim 12 , wherein the heat exchanger is an exhaust gas recirculation cooler, and wherein the first working fluid is engine exhaust and the second working fluid is a coolant. 
   
   
       22 . A heat exchanger for transferring heat between a first working fluid and a second working fluid, the heat exchanger comprising:
 a pair of spaced apart headers;   a plurality of tubes extending between the pair of headers and providing a flow path for the first working fluid and being positioned along a flow path for the second working fluid; and   an insert supportable in one of the plurality of tubes and having a serpentine fold extending in a direction substantially parallel to a length of the tube between the pair of headers.   
   
   
       23 . The heat exchanger of  claim 22 , wherein the fold defines first and second legs of the insert, and wherein, at a height of the first leg between the fold and a distal end of the first leg, a width between the first and second legs is substantially constant between opposite ends of the insert spaced apart in the direction of the fold. 
   
   
       24 . The heat exchanger of  claim 22 , wherein the fold defines first and second legs of the insert, wherein a dimple extends across the first leg, and wherein the second leg includes an outwardly extending protrusion shaped to be matingly receivable in the dimple of the first leg. 
   
   
       25 . The heat exchanger of  claim 22 , wherein the fold is a first fold, wherein the insert includes a second fold extending across the insert in a direction substantially parallel to the first fold, and further comprising a dimple extending across the insert between the first fold and the second fold. 
   
   
       26 . The heat exchanger of  claim 22 , wherein the insert has a first side and a second side opposite to the first side, and wherein a dimple is formed on the first side and forms a protrusion on the second side, the protrusion extending into the fold. 
   
   
       27 . The heat exchanger of  claim 22 , further comprising a plurality of dimples roll-formed along the insert. 
   
   
       28 . The heat exchanger of  claim 22 , wherein a plurality of dimples are spaced along the fold. 
   
   
       29 . The heat exchanger of  claim 22  wherein the heat exchanger is an exhaust gas recirculation cooler, and wherein the first working fluid is engine exhaust and the second working fluid is a coolant. 
   
   
       30 . The heat exchanger of  claim 22 , wherein the fold defines first and second legs of the insert, wherein a dimple extends across the first leg at a distance from an inlet to the flow path for the first working fluid, and wherein a protrusion extends across the second leg opposite to the dimple of the first leg. 
   
   
       31 . The heat exchanger of  claim 30 , wherein a cross-sectional area of the flow path for the first working fluid is substantially the same between the first and second legs at the inlet to the flow path for the first working fluid and between the dimple and the protrusion.