HEAT EXCHANGER HAVING INTEGRAL ELASTIC REGIONS
The invention provides, among other things, a heat exchanger including a header, a number of tubes extending outwardly from the header, and an elastic sleeve supported between the header and one of the tubes to allow movement of the tube relative to the header in a direction substantially parallel to a length of the tube defined between a first end of the tube adjacent to the header and a second end of the tube spaced away from the header. Together, the tube, the header, and the elastic sleeve can at least partially define a flow path for a working fluid.
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The present application claims priority to U.S. Provisional Patent Application Ser. No. 60/830,232, filed Jul. 12, 2006, the entire contents of which is hereby incorporated by reference.
FIELD OF THE INVENTIONThe present invention relates to a heat exchanger and a method of manufacturing a heat exchanger.
SUMMARYTube and insert type exhaust gas recirculation (“EGR”) coolers are commonly subjected to high tube stresses caused by extreme thermal gradients, repeated transient events, and/or rigid tube to header joints. Moreover, future EGR coolers will be required to handle increased thermally induced stresses.
Current heat exchanger designs also fail to provide for tube expansion caused by non-uniform thermal loading and non-uniform flow distributions. This condition can be more severe in heat exchangers having cores with two or more rows of tubes. In these constructions, a number of different failures, such as, for example, cracked headers, can be caused by non-uniform thermal loading and/or non-uniform flow distributions.
Among other things, the present invention can remove the guesswork from EGR cooler design by allowing each tube in a heat exchanger to expand freely and independently of the other tubes, thereby making load sharing between adjacent tubes a non-issue and relieving tube stress caused by flexing of adjacent tubes and/or flexing of the heat exchanger casing. The present invention can also or alternatively provide a header of a heat exchanger having significantly reduced loading, thereby enabling the use of two-row heat exchanger cores without causing header cracking.
In some embodiments, the present invention provides an elastic region including a beaded elastic sleeve positioned between a header and each tube in a heat exchanger core. The elastic sleeve can allow each tube to expand independently of the other tubes, thereby maintaining stresses below critical levels.
The present invention also provides a method of hydro-forming a series of beaded expansion joints from an elongated tube. A number of individual sleeves can then be cut from the tube.
The present invention also provides an elastic sleeve, which can establish a header-to-header length of a heat exchanger. In this manner, the elastic sleeve can assist with core assembly. Alternatively or in addition, beads located along the elastic sleeve can provide positive stops for the header to assist with core assembly.
In some embodiments, the present invention provides a method of assembling a heat exchanger using current fabricating processes. In some embodiments, at least portions of the heat exchanger of the present invention can be compatible with other components of existing heat exchanger designs, such as, for example, existing housing and header components.
The present invention also provides an expansion bead or bellows formed integrally with a heat exchanger tube. In some embodiments, the bead or bellows can be formed adjacent to a tube end. In other embodiments, the bead or bellows can be strategically placed along the tube length.
In some embodiments, the present invention provides a heat exchanger tube including a series of expansion regions, which can act together as a spring. The expansion regions can include expansion beads, which can act as baffles to direct fluid flow through the heat exchanger. These expansion beads can eliminate the need for additional parts. In some embodiments, the beads can be used to assist with heat exchanger core assembly because the beads can act as positive stops for the header.
The present invention also provides a heat exchanger including a header, a number of tubes extending outwardly from the header, and an elastic sleeve supported between the header and one of the tubes to allow movement of the tube relative to the header in a direction substantially parallel to a length of the tube defined between a first end of the tube adjacent to the header and a second end of the tube spaced away from the header. Together, the tube, the header, and the elastic sleeve can at least partially define a flow path for a working fluid.
In some embodiments, the present invention provides a heat exchanger including a header and a number of tubes extending outwardly from the header. Each of the tubes can be independently moveable relative to the header in a direction substantially parallel to a length of one of tubes defined between a first end of the tube adjacent to the header and a second end of the tube spaced away from the header. The tubes can be sealed to the header such that together the header and the tubes define a flow path for a working fluid.
In some embodiments, the present invention provides a heat exchanger including a header and a tube extending outwardly from the header. Together with the header, the tube can define a flow path for a working fluid. The tube can have a first end secured to the header, a second end spaced from the header, and a number of elastic regions spaced along a length of the tube between the first end and the second end.
The present invention also provides a method of assembling a heat exchanger including a header and a number of outwardly extending tubes. The method can include the acts of forming an elastic sleeve and securing the elastic sleeve between the header and one of the tubes such that the tube is moveable independently relative to the header and another of the tubes in a direction substantially parallel to a length of the other tube and such that together the header, the elastic sleeve, and the tube define a flow path for a working fluid.
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 8 can transfer heat energy 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., exhaust gas, water, engine coolant, CO2, an organic refrigerant, R12, R245fa, air, and the like).
The heat exchanger 8 can include one or more headers 18 positioned at one or both ends of a stack of heat exchanger tubes 11. The stack of tubes 11 can at least partially define a heat exchanger core 10. In the illustrated embodiment of
As shown in
In some embodiments, such as the illustrated embodiment of
Elastic regions 13 including elastic sleeves 15 can be positioned between ends of the tubes 11 and the header(s) 18. In the illustrated embodiment of
Ends of the elastic sleeves 15 can be at least partially received in the apertures 16 in the header(s) 18. As shown in
As shown in
In some embodiments, the first ends of the sleeves 15 are brazed, welded, and/or soldered to the walls of the header 18 defining the apertures 16 and the second ends of the sleeves 15 are brazed, welded, and/or soldered to tube 11 ends. In some such embodiments, braze alloy can be added to the intersection of each of the tubes 11 and the sleeves 15 and/or the intersection of each of the elastic sleeves 15 and the header(s) 18. While reference is made herein to brazed, welded, and/or soldered connections, in other embodiments, other connectors and connecting methods including, but not limited to, interference fits, cohesive and adhesive bonding materials, friction fits, and the like can also or alternatively be used to secure the sleeves 15 to the header(s) 18 and the tubes 11.
The elastic sleeves 15 of the elastic regions 13 reduce the tube 11 and header 18 stresses by absorbing non-uniform loading caused by thermal expansion of the tubes 11, which may or may not be uniform between the different tubes 11 or across a single tube 11. The elastic sleeves 15 of the elastic regions 13 can also or alternatively absorb and/or compensate for bending stresses experienced by each of the tubes 11. For example, in some embodiments, the elasticity provided by the elastic sleeves 15 of the elastic regions 13 allows each tube 11 to move independently relative to a header 18 and in a direction substantially parallel to a length L of each tube 11 to accommodate non-uniform loading caused by thermal expansion of the tubes 11. In some embodiments, elasticity provided by the elastic sleeves 15 of the elastic regions 13 can also or alternatively allow each of the tubes 11 to move independently relative to a header 18 and in a direction substantially normal to the length L of each tube 11 so that, for example, a top side of each tube 11 is moved more closely to the header 18 than a bottom side of the tube 11. Alternatively or in addition, the heat exchanger core 10 or a substantial portion of the core 10 (e.g., two or more tubes 11) can move together relative to a header 18 in a direction substantially parallel to a length L of one of the tubes 11 and/or in a direction substantially normal to the length L of one of the tubes 11 so that, for example, a top side of the core 10 is moved more closely to the header 18 than a bottom side of the core 10.
Alternatively or in addition, the elastic sleeves 15 of the elastic regions 13 can simplify assembly of the heat exchanger 8 by allowing tubes 11 of different lengths to be assembled together in a single heat exchanger core 10. In some embodiments, portions of the elastic sleeves 15, such as, for example, the expansion beads 14, can act as an assembly stop to simplify and/or improve assembly of the heat exchanger core 10.
With reference to
In other embodiments, two-piece sleeves 15 can be formed from substantially flat stock that is stamped, rolled, or shaped in another manner to form a first sleeve part (e.g., a first half) of a sleeve 15. A second sleeve part (e.g., a second half) of the sleeve 15 can also or alternatively be stamped, rolled, or otherwise shaped from the substantially flat stock. The two sleeve parts can then be mated together and brazed, welded, or soldered together to provide a single sleeve 15.
In some such embodiments, the first and second sleeve parts can be formed as mirror images of one another. In other embodiments, the first and second sleeve parts can have different relative sizes, shapes and configurations such that one sleeve part can be at least partially nested inside the other sleeve part. In still other embodiments, the sleeves 15 can be formed from three or more sleeve parts, which can be similarly or differently sized. In yet other embodiments, an elastic region 13 can include two or more elastic sleeves 15, each of which can include one, two, or three sleeve parts. While reference is made herein to brazed, welded, and/or soldered connections, in other embodiments, other connectors and connecting methods including, but not limited to, interference fits, cohesive and adhesive bonding materials, friction fits, and the like can also or alternatively be used to secure the sleeves pieces together.
In the illustrated embodiment of
The elastic regions 113 reduce tube 111 and header 118 stresses by absorbing non-uniform loading caused by thermal expansion of the tubes 111, which may or may not be uniform between the different tubes 111 of the heat exchanger core 110. The elastic regions 113 can also or alternatively absorb and/or compensate for bending stresses experienced by each of the tubes 111. Alternatively or in addition, the elastic regions 113 can simplify assembly of the heat exchanger 108 by allowing tubes 111 of differently lengths to be assembled together in a single heat exchanger core 110. In some embodiments, portions of the elastic regions 113, such as, for example, the expansion beads 114, can act as an assembly stop to simplify and/or improve assembly of the heat exchanger core 110. Moreover, the elastic regions 113 of the present invention can be incorporated into existing heat exchanger designs without requiring changes to other components, such as, for example, to the heat exchanger housing 142 and/or with minimal changes to the assembly lines and equipment used for assembly.
In some embodiments, at least some of the beads 114 can be formed by hydro-forming. Alternatively or in addition, at least some of the beads 114 can be formed by bulge-forming using elastomeric materials. In some such embodiments, rubber plugs and/or rigid (e.g., steel) dies can also or alternatively be used.
In some embodiments, such as the illustrated embodiment of
With reference to
In the illustrated embodiment, the beads 140 extend around only a portion of the perimeter of the outer housing 142, as best seen in
As shown in
As shown in
The heat exchanger 308 can include a flow control or bypass valve 360. In the illustrated embodiment of
As shown in
In some embodiments, the valve 360 can include an actuator 364, which extends outwardly from the tank 362 and is engageable by an operator. In these embodiments, an operator can grip the actuator 364 to move the valve member 358 between the opened and closed positions. In other embodiments, the valve 360 can be controlled remotely and can also or alternatively be controlled by an electronic controller.
In embodiments having a valve 360, the mass flow rate of the working fluid traveling through the tubes 311 can be adjusted by moving the valve member 358 between the opened and closed positions. For example, when the valve member 358 is moved toward the closed position, working fluid is prevented from entering at least one of the tubes 311 and/or the flow of the working fluid to at least one of the tubes 311 is restricted. In this manner, the mass flow rate of working fluid traveling through the remaining tubes 311 can be increased. As best seen in
As shown in
In the illustrated embodiment of
As shown in
In embodiments, such as the illustrated embodiment of
In some embodiments, the heat exchanger 408 can include fins supported in one or more of the tubes 411 and extending between the tube ends or between approximate ends of the tubes 411. In these embodiments, undesirable fin cracking typical of some conventional heat exchangers can be eliminated and/or reduced because the fins are not constrained by the headers 418. Furthermore, the heat exchanger 408 of the present invention allows the fins to be retracted from the header 418 without causing a tube failure, as is common in some conventional heat exchangers, because the elastic sleeves 415 absorb some or all of the axial stresses applied to the tubes 411 and/or the fins. Alternatively or in addition, the fins can be located within the tubes 411 without being secured to one or both of the headers 418.
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 are possible.
Claims
1. A heat exchanger comprising:
- a header;
- a plurality of tubes extending outwardly from the header; and
- an elastic sleeve supported between the header and one of the plurality of tubes to allow movement of the tube relative to the header in a direction substantially parallel to a length of the tube defined between a first end of the tube adjacent to the header and a second end of the tube spaced away from the header, together the tube, the header, and the elastic sleeve at least partially defining a flow path for a working fluid.
2. The heat exchanger of claim 1, wherein the elastic sleeve is integrally formed with the tube.
3. The heat exchanger of claim 1, wherein an elastic sleeve is supported between the header and each of the plurality of tubes to allow each of the plurality of tubes to move relative to an other of the plurality of tubes.
4. The heat exchanger of claim 1, wherein a wall thickness of the elastic sleeve is less than a wall thickness of the tube.
5. The heat exchanger of claim 1, wherein the elastic sleeve includes a plurality of convolutions.
6. The heat exchanger of claim 1, wherein the working fluid is a first working fluid, and wherein the elastic sleeve includes an outwardly extending protrusion for altering a flow of a second working fluid through the heat exchanger.
7. The heat exchanger of claim 1, wherein a plurality of elastic regions are spaced along the length of the tube.
8. The heat exchanger of claim 1, wherein the elastic sleeve is brazed to the header and the tube.
9. The heat exchanger of claim 1, wherein a first side of the tube is moveable a different distance from the header than a second side of the tube, the first and second sides being generally perpendicular to the header.
10. A heat exchanger comprising:
- a header; and
- a plurality of tubes extending outwardly from the header, each of the plurality of tubes being independently moveable relative to the header in a direction substantially parallel to a length of one of the plurality of tubes defined between a first end of the tube adjacent to the header and a second end of the tube spaced away from the header, the plurality of tubes being sealed to the header such that together the header and the plurality of tubes define a flow path for a working fluid.
11. The heat exchanger of claim 10, further comprising an elastic region integrally formed with the one of the plurality of tubes, the elastic region facilitating movement of the one of the plurality of tubes relative to the header.
12. The heat exchanger of claim 10, further comprising an elastic sleeve supported between the one of the plurality of tubes and the header, and wherein a wall thickness of the elastic sleeve is less than a wall thickness of the tube.
13. The heat exchanger of claim 10, further comprising an elastic sleeve supported between the one of the plurality of tubes and the header, and wherein the elastic sleeve is corrugated.
14. The heat exchanger of claim 10, further comprising an elastic sleeve supported between the one of the plurality of tubes and the header, wherein the working fluid is a first working fluid, and wherein the elastic sleeve includes an outwardly extending bead for altering a flow of a second working fluid through the heat exchanger.
15. The heat exchanger of claim 10, wherein a plurality of elastic regions are spaced along the length of the one of the plurality of the tubes between the first end of the tube and the second end of the tube, and wherein at least one of the plurality of elastic regions is integrally formed with the one of the plurality of tubes.
16. The heat exchanger of claim 10, further comprising an elastic sleeve brazed to the header and the one of the plurality of tubes to facilitate movement of the one of the plurality of tubes relative to the header.
17. The heat exchanger of claim 10, wherein the plurality of tubes at least partially define a core, and wherein a first side of the core is moveable a first distance from the header and a second side of the core is moveable a second distance from the header, the first difference being different than the second distance and the first and second sides being generally perpendicular to the header.
18. A heat exchanger comprising:
- a header; and
- a tube extending outwardly from the header and, together with the header, defining a flow path for a working fluid, the tube having a first end secured to the header, a second end spaced from the header, and a plurality of elastic regions spaced along a length of the tube between the first end and the second end.
19. The heat exchanger of claim 18, wherein the second end of the tube is moveable relative to the first end of the tube in a direction substantially parallel to the length of the tube between the first end and the second end.
20. The heat exchanger of claim 18, wherein the tube is a first tube, and further comprising a second tube extending outwardly from the header, the elastic regions facilitating movement of the first tube relative to the second tube.
21. The heat exchanger of claim 18, wherein one of the plurality of elastic regions includes an elastic sleeve received in an opening defined in the header, and wherein an end of the elastic sleeve extends through the header.
22. The heat exchanger of claim 18, wherein a wall thickness of the tube is smallest at one of the elastic regions.
23. The heat exchanger of claim 18, wherein the tube is corrugated in each of the plurality of elastic regions.
24. The heat exchanger of claim 18, wherein the working fluid is a first working fluid, and wherein the elastic regions include outwardly extending protrusions for altering a flow of a second working fluid through the heat exchanger.
25. The heat exchanger of claim 18, wherein a first side of the tube is moveable a different distance from the header than a second side of the tube, the first and second sides being generally perpendicular to the header.
26. A method of assembling a heat exchanger, the heat exchanger including a header and a plurality of outwardly extending tubes, the method comprising the acts of:
- forming an elastic sleeve; and
- securing the elastic sleeve between the header and one of the plurality of tubes such that the one of the plurality of tubes is moveable independently relative to the header and an other of the plurality of tubes in a direction substantially parallel to a length of the other of the plurality of tubes and such that together the header, the elastic sleeve, and the one of the plurality of tubes define a flow path for a working fluid.
27. The method of claim 26, wherein forming the elastic sleeve includes corrugating an elongated sleeve and cutting the elongated sleeve to form a plurality of elastic sleeves.
28. The method of claim 26, wherein forming the elastic sleeve includes hydro-forming corrugations along the sleeve.
29. The method of claim 26, further comprising brazing the elastic sleeve to one of the header and the tube.
Type: Application
Filed: Jul 10, 2007
Publication Date: Jan 17, 2008
Applicant: MODINE MANUFACTURING COMPANY (Racine, WI)
Inventor: Steven P. Meshenky (Racine, WI)
Application Number: 11/775,499
International Classification: F28F 9/04 (20060101);