Manifold with multiple passages and cross-counterflow heat exchanger incorporating the same

Abstract

A manifold having multiple chambers for use in a cross-counterflow heat exchanger assembly includes a first member having arms extending from a base to arm ends. A second member is secured to the first member to define the manifold. The second member includes an inner plate edge that defines a first mating surface that extends inwardly along the inner plate edge from each of the plate ends to mate with arm ends. A wall extends transversely to the inner plate edge to a wall end. The wall end mates with an inner base surface to divide the interior of the manifold into a plurality of chambers. At least one lip extends transversely to the inner plate edge to define a second mating surface that extends perpendicularly from the first mating surface and mates with an inner arm surface of the arms.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to manifolds having multiple chambers. More specifically, the invention relates to extruded manifolds with multiple chambers and cross-counterflow heat exchangers incorporating such manifolds.

2. Description of the Prior Art

Air-cooling (or heating) cross-counterflow heat exchangers are often used in applications where space limitations restrict the surface area of the heat exchanger. Cross-counterflow heat exchangers typically include a plurality of stacked, assembled modules, with each module including a pair of spaced manifolds interconnected by a plurality of spaced and parallel tubes. The modules are stacked such that air flows in a direction perpendicular to the face of the heat exchanger, and air fins are disposed between adjacent pairs of tubes for transferring heat from the tubes to the passing air.

Another type of cross-counterflow heat exchanger assembly is shown in U.S. Pat. No. 5,941,303, issued to James D. Gowan on Aug. 24, 1999 and hereinafter referred to as Gowan '303. Gowan '303 discloses a cross-counterflow heat exchanger comprising a pair of spaced and continually extruded manifolds. Each of the manifolds includes an interior, and each of the manifolds includes at least one dividing wall to divide the interior into a plurality of flow paths. A plurality of tubes extends and establishes fluid communication between the pair of manifolds. Each of the tubes includes at least one tube divider to separate it into a plurality of passages.

SUMMARY OF THE INVENTION

In summary, the invention provides a manifold having multiple chambers for use in a cross-counterflow heat exchanger assembly. The manifold includes a first member having arms extending from a base to arm ends. A second member is secured to the first member to define the manifold. The second member includes an inner plate edge that defines a first mating surface that extends inwardly along the inner plate edge from each of the plate ends to mate with arm ends. A wall extends transversely to the inner plate edge to a wall end. The wall end mates with an inner base surface to divide the interior of the manifold into a plurality of chambers. At least one lip extends transversely to the inner plate edge to define a second mating surface that extends perpendicularly from the first mating surface and mates with an inner arm surface of the arms.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a perspective and partial view of the exemplary embodiment of the invention;

FIG. 2 is a cross-sectional view of the manifold, return manifold and the tubes taken along line 2-2 of FIG. 1;

FIG. 3 is a plan view of the first member of the exemplary embodiment of the invention;

FIG. 4 is a plan view of the second member of the exemplary embodiment of the invention;

FIG. 5 is a cross-sectional view of one of the tubes taken along line 5-5 of FIG. 2;

FIG. 6 is an enlarged view of the lip taken from section 6 of FIG. 2; and

FIG. 7 is a perspective view of the manifold of the exemplary embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the Figures, wherein like numerals indicate corresponding parts throughout the several views, an exemplary heat exchanger assembly 20 is generally shown.

The exemplary heat exchanger assembly 20 includes a manifold 22 generally indicated having a first member 24 at least partially defining an interior. Referring to FIG. 3, in an exemplary embodiment, the first member 24 is a longitudinally extending channel having a cross-section defining a U-shape and presenting arms 26 integrally connected to a base 28 and extending forwardly to arm ends 30. Each of the arms 26 include an inner arm surface 32 and an outer arm surface. Each of the arms 26 include a stress therein to cant the arm ends 30 toward one another.

Referring to FIGS. 1 and 3, the base 28 of the first member 24 includes an inner base surface 34 and the base 28 presents a plurality of first tube slots 36 longitudinally spaced from one another. The base 28 further defines at least one opening 38 that is disposed between adjacent first tube slots 36. The opening 38 is generally circular in cross section but may be any shape known in art. Additionally, while the exemplary embodiment shows the opening 38 being disposed between adjacent first tubes 40 slot, the opening 38 may be disposed in the area between the first tube slot 36 and the end of the first member 24. The first tube slots 36 and at least one opening 38 may be formed by conventional machining methods including stamping, grinding, or milling.

Referring to FIG. 2, the assembly includes a second member 42 having a plate 44 and a wall 46 extending transversely to the plate 44. The second member 42 has a cross section that defines a T-shape. The plate 44 extends between plate ends 48, and transversely between an inner plate edge 50 and an outer plate edge 52. The inner plate edge 50 defines a first mating surface 54 that extends inwardly along the inner plate edge 50 from each of the plate ends 48 to mate with arm ends 30. The wall 46 extends transversely to the inner plate edge 50 of the plate 44 to a wall end 56. The wall end 56 is contoured to conform with the inner base surface 34 for positioning the wall end 56 against the inner base surface 34 and the first tube slots 36 to divide the interior of the manifold 22 into a plurality of chambers 58, 60. The wall end 56 of the second member 42 defines a plurality of notches 62 being spaced to correspond with the first tube slots 36 of the first member 24.

The wall 46 includes at least one locking arm 96 that extends outwardly from the wall end 56 to mate with at least one opening 38. The locking arm 96 secures the second member 42 to the first member 24. The locking arm 96 is generally circular in cross section, but may be any shape known in the art.

The subject invention is distinguished by at least one lip 64 that extends transversely to the inner plate edge 50 to define a second mating surface 66, and thus creating a boot shape as seen in FIG. 4. The second mating surface 66 extends perpendicularly from the first mating surface 54 and mates with the inner arm surface 32 of the arms 26. The canted arms 26 of the first member 24 create a clamping force F on the second mating surface 66 of the lip 64 to temporally securing the second member 42 to the first member 24 before brazing the first and second members 24, 42 together. The second member 42 is then permanently fixed to the first member 24 to form the manifold 22. In the exemplary embodiment, the second member 42 is brazed to the first member 24, but any other method of permanently fixing the first and second members 24, 42 may also be used. The manifold 22 extends longitudinally between first and second manifold ends 68, 70. The second member 42 defines a longitudinally extending groove 72 that extends between the first and second mating surfaces 54, 66 for accommodating a burr between the first and second members 24, 42.

Prior to brazing the first member 24 to the second member 42 to a cap 98 is disposed on each of the first and second manifold ends 68, 70 of the manifold 22. In addition to the clamping force F of the first member 24 on the second member 42, the cap 98 temporally secures the manifold 22 prior to being permanently secured.

The heat exchanger assembly 20 further includes a plurality of tubes 40 extending between first and second tube ends 74, 76. The first tube end 74 of each tube 40 is disposed in one of the first tube slots 36 of the manifold 22. Referring to FIG. 5, each tube 40 defines at least one tube divider 78 disposed in the tube 40 and extending between the first and second tube ends 74, 76 to define a first passage 80 in fluid communication with one of the chambers 58, 60 of the manifold 22 and a second passage 82 in fluid communication with the other of the chambers 58, 60 of the manifold 22. The tube divider 78 at the first tube end 74 abuts and is permanently fixed to the notches 62 in the wall end 56 of the second member 42.

The assembly further includes a return manifold 84 extending in spaced and parallel relationship with the manifold 22. The return manifold 84 presents a plurality of second tube slots 86 longitudinally spaced from each other to correspond with the spacing of the first tube slots 36 of the manifold 22. The second tube end 76 of each tube 40 extends into and engages the corresponding second tube slot 86 to establish fluid communication between the tubes 40 and the return manifold 84. The return manifold 84 directs the flow of coolant from one of the passages of the tubes 40 to the other of the passages to define a two-pass cross-counterflow heat exchanger assembly 20. In an exemplary embodiment, the return manifold 84 is D-shaped to direct the flow of coolant from the one passages of the tubes 40 to the other passage of the passages, but the return manifold 84 may be any shape known in the art.

In the exemplary embodiment, the tubes 40 and the first and second tube slots 36, 86 each have a cross-section presenting parallel flat sides 88 that extend between round ends. However, the tubes 40 may be have any shape capable of transmitting a fluid between the first and second manifold 22. The flat sides 88 of adjacent tubes 40 are spaced from one another to define a plurality of air passages for the flow of air therebetween. A corrugated air fin 90 is disposed between and brazed to the parallel flat sides 88 of adjacent tubes 40 and extends between the first and return manifolds 22, 84 for dissipating heat from the tubes 40.

One of the chambers 58, 60 of the manifold 22 includes an input 92 in communication with an input chamber 58 for receiving a fluid, and an output 94 in communication with an output chamber 60 for dispensing the coolant after it has passed through the heat exchanger assembly 20. In an exemplary embodiment, the input 92 is disposed on the input chamber 58 that is downstream of the direction of the flow of air and the output 94 is disposed on the output chamber 60 upstream of the input chamber 58. The input 92 and output 94 may have any shape capable of delivering a fluid to the input chamber 58 and output chamber 60 of the manifold 22.

The embodiment shown in the drawings is for a two-pass counter cross-flow heat exchanger assembly. However, the manifolds and tubes may be designed to allow for more than two passes by inserting walls in either or both of the first and return manifolds and including a plurality of tube dividers in each tube. For example, in a three-pass heat exchanger assembly, the second member has one wall to divide the manifold into two chambers, the return manifold has one wall, and each tube has two tube dividers.

The invention also includes a method of forming a manifold 22 for use in a heat exchanger assembly 20. The method starts with the step of separately forming a first member 24 at least partially defining an interior and a second member 42. The first member 24 has a spaced set of first tube slots 36 and the second member 42 has a wall 46 that is positioned against the first tube slots 36 to divide the interior into a plurality of chambers 58, 60.

Next, the first member 24 is temporally secured to the second member 42. The arm ends 30 of the first member 24 are rolled to be canted toward one another. This creates a stress in the arms 26 of the first member 24 so that when the inner arm surface 32 of the first member 24 is brought into contact with the second mating surface 66 of the lip 64 of the second member 42, the first member 24 will be secured to the second member 42.

The method may further include the step of placing a cap 98 on each of the first and second manifold ends 68, 70. The shape of the cap 98 is contoured to mate with the outer periphery of the first and second manifold ends 68, 70. The cap 98 temporally secures the first member 24 to the second member 42 by the clamping force F.

The method continues with the step of permanently fixing the first member 24 to the second member 42 to define a manifold 22 after the temporally securing step. The second member 42 is preferably extruded and then cut to size, but may also be formed by other methods including casting and machining. In one embodiment, the forming the first member 24 is further defined as rolling a flat sheet of material into a channel having a cross-section presenting a U-shape and having a base 28 and arms 26 extending forwardly to arm ends 30. Rolling the first member 24 from a flat sheet provides advantages because the flat sheet can be a stock sheet of metal with a brazing material pre-disposed on either side of it. The brazing material then may be used for the step of permanently fixing the first member 24 to the second member 42.

The method proceeds with the step of forming a plurality of tubes 40 extending between first and second tube ends 74, 76. The method then continues with the step of forming a tube divider 78 extending between the first and second tube ends 74, 76 in each of the tubes 40 to separate each tube 40 into a first passage 80 and a second passage 82. Referring to FIG. 5, in one embodiment, the forming each tube 40 is further defined by rolling a flat sheet of material into a tube 40 defining a tube divider 78. Rolling each tube 40 from a flat sheet provides advantages because the flat sheet can be a stock sheet of metal having a pre-disposed brazing material on either side of it. The brazing material may then later be used for the step of fixing and sealing the tube ends 74, 76 to the first and second tube slots 36, 86 of the manifolds 22, 84. However, any other method of forming the tube divider 78 may also be used.

The method continues with the step of inserting the first tube end 74 of each tube 40 into one of the first tube slots 36 of the manifold 22 and abutting the divider of each tube 40 against the wall 46 of the second member 42 to establish fluid communication between the first passage 80 of the tubes 40 and one of the chambers 58, 60 of the manifold 22 and to establish fluid communication between the second passage 82 of the tubes 40 and the other of the chambers 58, 60 of the manifold 22. The first tube end 74 of each tube 40 is then permanently fixed to the associated first tube slot 36 manifold 22.

The method further continues with the step of forming a return manifold 84 having a set of second tube slots 86 being spaced from each other to correspond with the set of first tube slots 36 of the manifold 22. The method proceeds with the step of inserting the second tube end 76 of each of the tubes 40 into the corresponding second tube slot 86 of the return manifold 84 to establish fluid communication between the first and second passages 80, 82 of each tube 40 and the return manifold 84.

The method is finished with the steps of forming a plurality of air fins 90 and inserting one of the air fins 90 between adjacent tubes 40 to dissipate heat from the tubes 40. In the exemplary embodiment, the tubes 40, manifold 22, and air fins 90 are all brazed together to define a unified heat exchanger assembly 20.

The subject invention provides for a manifold and a cross-counterflow heat exchanger assembly 20 that is both cheaper and quicker to manufacture than those of the prior art. Additionally, the exemplary embodiment provides a more sturdy structure prior to and following brazing. Many of the traditional methods for forming the tube slots in the manifold of the Gowan '303 patent must be abandoned in order to avoid interfering with the dividing wall of the manifold. The first tube slots of the Gowan '303 patent must be milled or grinded, either of which is a very time consuming and costly process. The first tube slots 36 of the present invention may be formed in the first member 24 using a variety of manufacturing methods including stamping before the step of permanently fixing the first and second members 24, 42 together. This leads to significantly greater manufacturing efficiency, thereby reducing the cost and time to assemble the manifold 22 and of the heat exchanger assembly 20.

While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A manifold for use in a heat exchanger assembly comprising:

a first member presenting arms integrally connected to a base having an inner base surface, each of said arms having an inner arm surface and extending from said base to an arm end;

a second member secured to said first member to define said manifold, said second member having a plate extending between plate ends and between an inner plate edge and an outer plate edge, and said inner plate edge defining a first mating surface extending inwardly along said inner plate edge from each of said plate ends to mate with arm ends;

a wall extending transversely to said inner plate edge of said plate to a wall end, said wall end mating with said inner base surface to divide the interior of said manifold into a plurality of chambers; and

at least one lip extending transversely to said inner plate edge of said second member to define a second mating surface that extends perpendicularly from said first mating surface and mates with said inner arm surface of said arms.

2. The manifold as set forth in claim 1 wherein each of said arms includes a stress therein to cant said arm ends toward one another and wherein said canted arms create a clamping force on said second mating surface of said lip for temporally securing said second member to said first member.

3. The manifold as set forth in claim 1 wherein said base defines a plurality of longitudinally spaced first tube slots and at least one opening disposed between adjacent ones of said first tube slots.

4. The manifold as set forth in claim 3 wherein said wall end is contoured to conform with said inner base surface for positioning said wall end against said inner base surface and said first tube slots.

5. The manifold as set forth in claim 4 wherein said wall end of the second member defines a plurality of notches being spaced to correspond with said first tube slots of said first member.

6. The manifold as set forth in claim 3 wherein said wall includes at least one locking arm extending from said wall end to mate with said at least one opening to secure said second member to said first member.

7. The manifold as set forth in claim 1 wherein said manifold extends longitudinally between first and second manifold ends.

8. The manifold as set forth in claim 7 including a cap disposed at each of said first and second manifold ends.

9. The manifold as set forth in claim 1 further including an input in communication with an input chamber for receiving a fluid and an output in communication with an output chamber for dispensing the fluid.

10. The manifold as set forth in claim 1 wherein said second member defines a longitudinally extending groove between said first and second mating surfaces for accommodating a burr between said first and second members.

11. A cross-counterflow heat exchanger assembly comprising:

a first member presenting arms integrally connected to a base having an inner base surface, each of said arms having an inner arm surface and extending from said base to an arm end, said base defining a plurality of longitudinally spaced first tube slots;

a second member secured to said first member to define a manifold, said second member having a plate extending between plate ends and between an inner plate edge and an outer plate edge, and said inner plate edge defining a first mating surface extending inwardly along said inner plate edge from each of said plate ends to mate with arm ends;

a wall extending transversely to said inner plate edge of said plate to a wall end, said wall end mating with said inner base surface to divide the interior of said manifold into a plurality of chambers;

at least one lip extending transversely to said inner plate edge of said second member to define a second mating surface that extends perpendicularly from said first mating surface and mates with said inner arm surface of said arms;

a return manifold extending in spaced and parallel relationship with said manifold and defining a plurality of longitudinally spaced second tube slots to correspond with said first tube slots of said manifold;

a plurality of tubes extending between first and second tube ends, each of said first tube ends engaging each of said first tube slots and each of said second tube ends engaging each of said second tube slots to establish fluid communication between said manifold and said return manifold, and wherein adjacent tubes are spaced from one another to define a plurality of air passages for the flow of air between said adjacent tubes; and

an air fin disposed between and brazed to said tubes and extending between said manifold and said return manifold for dissipating heat from said tubes.

12. The assembly as set forth in claim 11 wherein each of said tubes define a tube divider extending between said first and second tube ends to define a first passage in fluid communication with one of said chambers of said manifold and a second passage in fluid communication with the other of said chambers of said manifold.

13. The assembly as set forth in claim 11 wherein said wall end of the second member defines a plurality of notches being spaced to correspond with said first tube slots of said first member and wherein said tube divider at said first tube end abuts said notches of said wall end of said second member.

14. The assembly as set forth in claim 11 wherein each of said tubes has a cross-section defining parallel flat sides extending between round ends.

15. A method of forming a manifold for use in a heat exchanger assembly including the steps of:

separately forming a first member at least partially defining an interior and having a spaced set of first tube slots and a second member having a wall positioned against the first tube slots and dividing the interior into a plurality of chambers;

temporarily fixing the first member to the second member to define a manifold extending between first and second manifold ends after the separately forming step; and

permanently fixing the first member to the second member.

16. The method as set forth in claim 15 wherein the temporarily fixing step is further defined as canting arms of the first member inwardly to create a stress therein and on a second mating surface defined by a lip on said second member.

17. The method as set forth in claim 15 further including the step of:

placing a cap on the first and second manifold ends prior to the permanently fixing step.

18. The method as set forth in claim 15 wherein the forming the first member is further defined as rolling a flat sheet of material into a channel having a cross-section presenting a U-shape presenting a base and arms extending forwardly to arm ends.