HEAT EXCHANGER HAVING A CONTOURED INSERT AND METHOD OF ASSEMBLING THE SAME
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.
The present invention relates to heat exchangers and more particularly, to an exhaust gas recirculation cooler and a method of assembling the same.
SUMMARYIn some embodiments, the present invention provides a heat exchanger for transferring heat between a first working fluid and a second working fluid. The heat exchanger can include 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 a length of the one of the tubes between the pair of headers. The insert can include a number of dimples extending into and spaced along the fold.
The present invention also 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.
In some embodiments, 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 serpentine fold extending in a direction substantially parallel to a length of the tube between the pair of headers.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
Also, it is to be understood that phraseology and terminology used herein with reference to device or element orientation (such as, for example, terms like “central,” “upper,” “lower,” “front,” “rear,” and the like) are only used to simplify description of the present invention, and do not alone indicate or imply that the device or element referred to must have a particular orientation. In addition, terms such as “first” and “second” are used herein for purposes of description and are not intended to indicate or imply relative importance or significance.
During operation and as explained in greater detail below, the heat exchanger 10 can transfer heat from a high temperature first working fluid (e.g., exhaust gas, water, engine coolant, CO2, an organic refrigerant, R12, R245fa, air, and the like) to a lower temperature second working fluid (e.g., water, engine coolant, CO2, an organic refrigerant, R12, R245fa, air, and the like). In addition, while reference is made herein to transferring heat between two working fluids, in some embodiments of the present invention, the heat exchanger 10 can operate to transfer heat between three or more fluids. Alternatively or in addition, the heat exchanger 10 can operate as a recuperator and can transfer heat from a high temperature location of a heating circuit to a low temperature location of the same heating circuit. In some such embodiments, the heat exchanger 10 can transfer heat from a working fluid traveling through a first portion of the heat transfer circuit to the same working fluid traveling through a second portion of the heat transfer circuit.
As shown in
As shown in
In some embodiments, such as the illustrated embodiment, the tubes 26 are secured to the first and second headers 18, 20 and the first and second tanks 30, 32 such that the first working fluid enters the heat exchanger 10 through a first inlet aperture 40 in the first tank 30, travels through the tubes 26 of the heat exchanger 10 along the first flow path 34, and is prevented from entering the second flow path 36. In these embodiments, the tubes 26 can be secured to the first and second headers 18, 20 and the first and second tanks 30, 32 such that the second working fluid enters the heat exchanger 10 through a second inlet aperture 42 in the second tank 32, travels through the heat exchanger 10 along the second flow path 36 between the tubes 26, and is prevented from entering the first flow path 34.
In other embodiments, the tubes 26 can have other orientations and configurations and the first and second flow paths 34, 36 can be maintained separate by dividers, inserts, partitions, and the like. In still other embodiments, the first flow path 34 can extend through some of the tubes 26 while the second flow path 36 can extend through other tubes 26.
As shown in
In the illustrated embodiment, the heat exchanger 10 is configured as a cross-flow heat exchanger such that the first flow path 34 or a portion of the first flow path 34 is opposite to the second flow path 36 or a portion of the second flow path 36. In other embodiments, the heat exchanger 10 can have other configurations and arrangements, such as, for example, a parallel-flow or a counter-flow configuration.
In the illustrated embodiment, the heat exchanger 10 is configured as a single-pass heat exchanger with the first working fluid traveling along the first flow path 34 through at least one of a number of tubes 26 and with the second working fluid traveling along the second flow path 36 between adjacent tubes 26. In other embodiments, the heat exchanger 10 can be configured as a multi-pass heat exchanger with the first working fluid traveling in a first pass through one or more of the tubes 26 and then traveling in a second pass through one or more different tubes 26 in a direction opposite to the flow direction of the first working fluid in the first pass. In these embodiments, the second working fluid can travel along the second flow path 36 between adjacent tubes 26.
In yet other embodiments, the heat exchanger 10 can be configured as a multi-pass heat exchanger with the second working fluid traveling in a first pass between a first pair of adjacent tubes 26 and then traveling in a second pass between another pair of adjacent tubes 26 in a direction opposite to the flow direction of the second working fluid in the first pass. In these embodiments, the first working fluid can travel along the first flow path 34 through at least one of the tubes 26.
In the illustrated embodiment, the heat exchanger 10 includes seven tubes 26, each of which has a substantially rectangular cross-sectional shape. In other embodiments, the heat exchanger 10 can include one, two, three, four, five, six, eight, or more tubes 26, each of which can have a triangular, circular, square or other polygonal, oval, or irregular cross-sectional shape.
As mentioned above, in some embodiments, the second flow path 36 or a portion of the second flow path 36 can extend across the outer surface 28 of one or more of the tubes 26. In some such embodiments, ribs 56 (see
In embodiments, such as the illustrated embodiment of
Additional elevations, recesses, or deformations 64 can also or alternatively be provided on the outer surfaces 28 of the tubes 26 to provide structural support to the heat exchanger 10, prevent the deformation or crushing of one or more tubes 26, maintain a desired spacing between adjacent tubes 26, improve heat exchange between the first and second working fluids, and/or generate turbulence along one or both of the first and second flow paths 34, 36.
The heat exchanger 10 can include inserts 66, which improve heat transfer between the first and second working fluids as the first and second working fluids travel along the first and second flow paths 34, 36, respectively. The inserts 66 can provide the heat exchanger core (i.e., the tubes 26) with increased surface area for distribution of the heat provided by the first and/or second working fluids. As shown in
In the illustrated embodiment of
In some embodiments, the ends 68 of the tubes 26 can be press-fit into one or both of the first and second headers 18, 20. In some such embodiments, the ends 68 of the tubes 26 and the inserts 66 supported in the tubes 26 or between the tubes 26 can be at least partially deformed when the tubes 26 and/or the inserts 66 are press-fit into the first and/or second headers 18, 20. As such, the tubes 26 and/or the inserts 66 are pinched and maintained in compression to secure the tubes 26 and/or the inserts 66 in a desired orientation and to prevent leaking. In some embodiments, the tubes 26 can be brazed, soldered, or welded to the first and/or second headers 18, 20.
In the illustrated embodiments, roll-formed sheets of metal are folded to form the inserts 66 in a method that will be described in further detail below. In other embodiments, the inserts 66 can be cast or molded in a desired shape and can be formed from other materials (e.g., aluminum, copper, iron, and other metals, composite material, alloys, and the like). In still other embodiments, the inserts 66 can be cut or machined to shape in any manner, can be extruded or pressed, can be manufactured in any combination of such operations, and the like.
As most clearly shown in
The illustrated embodiment of the insert 66 includes a series of parallel-running spines 76 that form alternating peaks 78 and valleys 80 along the width W of the insert 66. As shown in
As illustrated by
As shown in
In some embodiments, contour elements can extend along the entire height h of the leg 82 from one fold 76 to an adjacent fold 76 (i.e., from a peak 78 to an adjacent valley 80 or vice versa). Each contour element has a width d, as shown in
As shown in
As illustrated in
In embodiments having inserts 66 with wavy or contoured cross-sections, such as the illustrated embodiments, the inserts 66 operate as elastic members to absorb or at least partially absorb vibrations and/or to absorb expansions and contractions of the inserts 66 caused by fluctuating temperatures of the first and/or second working fluids. In some such embodiments, the elasticity of the contoured inserts 66 prevents or reduces cracking and breaking of the inserts 66. Alternatively or in addition, the elasticity of the contoured inserts 66 prevents and/or reduces cracking and breaking of connections (e.g., solder points, braze points, weld points, etc.) between the spines 76 of the inserts 66 and the interior sides of the tubes 26.
As shown in
As shown in
The shape and size of the projections 104 with respect to the thickness of the sheet of material 100 can be such that the dimples 86 formed by contact of projections 104 with the first side 110 of the sheet of deformable material 100 create their geometric complement on a second side (not visible) of the sheet 100 which is opposite to the first side 110. Thus, dimples 86 and protrusions 88 can be simultaneously formed on the first side 110 and an opposite second side of the sheet 100, respectively.
A second cylindrically-shaped roller 112 having projections 114 positioned in longitudinal rows along its curved surface 116 can be positioned adjacent to the opposite side of the sheet 100 from the first roller 102. The second roller 112 can also be rotated about its axis 118 as it makes contact with the second side of the sheet of deformable material 100, positioned tangentially with respect to the curved surface 116. In this way, dimples 86 can be formed on the second side of the sheet 100, and corresponding projections 88 can be formed on the first side 110.
The rollers 102, 112 can be formed by axially stacking cylindrical disks, the boundaries of which are illustrated by dashed lines in
A second star-shaped disk 130 in
The first and second star-shaped disks 120, 130 can be positioned with respect to each other such that each ridge 122 of the first disk 120 fits within a crevasse 134 of the second disk 130 and each ridge 132 of the second disk 130 fits within a crevasse 124 of the first disk 120 as the disks 120, 130 turn on their respective axes. Thus, when the sheet of deformable material 100 is fed between the star-shaped disks 120, 130, the corresponding ridges 122 and crevasses 134 fold the material to form peaks 78, and corresponding ridges 132 and crevasses 124 fold the material to form valleys 80. Similarly, the projections 126, 136 and corresponding indentions 138, 128 form dimples 86 and protrusions 88 in the insert 66.
Star-shaped rollers can be made up of star-shaped disks 120 that are stacked axially, similar to the arrangement discussed above with respect to the embodiment of
After the inserts 66 have been roll-formed and folded, they can be cut to the appropriate size and then inserted into tubes 26. In other embodiments, the inserts 66 can be cut before they are folded. Alternatively, the tubes 26 can be assembled around the inserts 66. In still other embodiments, the tubes 26 and the inserts 66 can be cut to size simultaneously.
The embodiments described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention.
Claims
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.
Type: Application
Filed: Apr 2, 2008
Publication Date: Oct 8, 2009
Inventors: Frank M. Grippe (Kansasville, WI), Rifaquat Cheema (Kenosha, WI), David E. Janke (Racine, WI), Robert J. Barfknecht (Waterford, WI)
Application Number: 12/061,191
International Classification: F28D 7/00 (20060101);