Technical Field
[0001] The invention relates to manifolds having multiple passages. More specifically, the
invention relates to extruded manifolds with multiple passages and cross-counterflow
heat exchangers incorporating such manifolds.
Background of the Invention
[0002] 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.
[0003] Another type of cross-counterflow heat exchanger assembly is shown in
US Patent No. 5,941,303, issued to James D. Gowan on August 24, 1998 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
[0004] In summary, the invention provides a manifold for use in a heat exchanger assembly
and a method of forming the manifold. The method starts with the step 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. The method is finalized
with the step of permanently fixing the first member to the second member to define
a first manifold after the separately forming step.
Brief Description of the Drawings
[0005] 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:
[0006] Figure 1 is a perspective and exploded view of the exemplary embodiment of the invention;
[0007] Figure 2 is a cross-sectional view of the first and second manifolds and the tubes
taken along line 2-2 of Figure 1;
[0008] Figure 3 is a front view of the first member of the exemplary embodiment of the invention;
[0009] Figure 4 is a front view of the second member of the exemplary embodiment of the
invention; and
[0010] Figure 5 is a cross-sectional view of one of the tubes taken along line 5-5 of Figure
2.
Description of the preferred embodiment
[0011] Referring to Figure 1, a heat exchanger assembly
20 is generally shown and includes a first member
22 at least partially defining an interior. Referring to Figure 3, in the exemplary
embodiment, the first member
22 is a channel having a cross-section defining a U-shape and presenting arms
24 integrally connected to a base
26 and extending forwardly to arm ends
28. Referring again to Figure 1, the base
26 of the first member
22 presents a plurality of first tube slots
30 longitudinally spaced from one another. The first tube slots
30 can be formed by conventional machining methods including stamping, grinding, or
milling.
[0012] Referring to Figure 2, the assembly
20 includes a second member
32 comprising a plate
34 and a wall
36 extending transversly to the plate
34. The plate
34 extends between and engages the arm ends
28 of the first member
22 and the wall
36 engages the base
26 of the first member
22 to divide the interior into a plurality of chambers
38, 40. Referring again to Figure 1, the second member
32 includes a plurality of notches being spaced to correspond with the first tube slots
30 of the first member
22. The second member
32 is permanently fixed to the first member
22 to define an first manifold
42, which is generally indicated. In the exemplary embodiment, the second member
32 is brazed to the first member
22, but any other method of permanently fixing the first and second members
22, 32 may also be used.
[0013] Other geometries for the first and second members
22, 32 may be used and are meant to be included in the scope of the invention. For example,
the first member may be a flat shield presenting a plurality of first tube slots,
and the second member may include a flat plate extending in spaced and parallel relationship
with the first member and having a plurality of arms extending transversely therebetween
to define an interior divided into a plurality of chambers. The first member may also
be cylindrically shaped and present a unified interior defining a plurality of first
tube slots. The second member would then be inserted into the first member to divide
the unified interior into a plurality of chambers.
[0014] The assembly
20 also includes a plurality of tubes
44 extending between first and second tube ends
46, 48. The first tube end
46 of each tube
44 is disposed in one of the first tube slots
30 of the first manifold
42. Referring to Figure 5, each tube
44 defines at least one tube divider
50 disposed in the tube
44 and extending between the first and second tube ends
46, 48 to define a first passage
52 in fluid communication with one of the chambers
38, 40 and a second passage
54 in fluid communication with the other of the chambers
38, 40. The tube divider
50 at the first tube end
46 abuts and is permanently fixed to the wall
36 of the second member
32.
[0015] The assembly
20 further includes a second manifold
56 extending in spaced and parallel relationship with the first manifold
42. The second manifold
56 presents a plurality of second tube slots
58 spaced from each other to correspond with the spacing of the first tube slots
30 of the first manifold
42. The second tube end
48 of each tube
44 extends into and engages the corresponding second tube slot
58 to establish fluid communication between the tubes
44 and the second manifold
56. The second manifold
56 directs the flow of coolant from one of the passages
52, 54 of the tubes
44 to the other to define a two-pass cross-counterflow heat exchanger assembly
20.
[0016] In the exemplary embodiment, the tubes
44 and the first and second tube slots
30, 58 each have a cross-section presenting flat sides
60 and round ends. However, the tubes
44 may be have any shape capable of transmitting a fluid between the first and second
manifolds
42, 56. The flat sides
60 of adjacent tubes
44 are spaced from one another to define a plurality of air passages for the flow of
air therebetween. A corrugated air fin
62 is disposed between and brazed to the parallel flat sides
60 of adjacent tubes
44 and extends between the first and second manifolds
42, 56.
[0017] One of the chambers
38, 40 of the first manifold
42 includes an input
64 to define an input chamber
38 for receiving a fluid, and the other of the chambers
38, 40 includes an output
66 to define an output chamber
40 for dispensing the coolant after it has passed through the heat exchanger assembly
20. In the preferred embodiment, the input
64 is disposed on the chamber that is downstream of the direction of the flow of air
and the output
66 is disposed on the chamber upstream of the input chamber
38. The input
64 and output
66 may have any shape capable of delivering a fluid to the input and output chambers
38, 40 of the first manifold
42.
[0018] The embodiment shown in the drawings is for a two-pass counter crossflow 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 second 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 first manifold
into two chambers, the second manifold has one wall, and each tube has two tube dividers.
[0019] The invention also includes a method of forming a first manifold
42 for use in a heat exchanger assembly
20. The method starts with the step of separately forming a first member
22 at least partially defining an interior and a second member
32. The first member
22 has a spaced set of first tube slots
30 and the second member
32 has a wall
36 that is positioned against the first tube slots
30 to divide the interior into a plurality of chambers
38, 40. The method continues with the step of permanently fixing the first member
22 to the second member
32 to define a first manifold
42 after the separately forming step. The second member
32 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
22 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
26 and arms
24 extending forwardly to arm ends
28. Rolling the first member
22 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
22 to the second member
32.
[0020] The method proceeds with the step of forming a plurality of tubes
44 extending between first and second tube ends
46, 48. The method then continues with the step of forming a tube divider
50 extending between the first and second tube ends
46, 48 in each of the tubes
44 to separate each tube
44 into a first passage
52 and a second passage
54. Referring to Figure 5, in one embodiment, the forming each tube
44 is further defined by rolling a flat sheet of material into a tube
44 defining a tube divider
50. Rolling each tube
44 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 bazing material
may then later be used for the step of fixing and sealing the tube ends
46, 48 to the first and second tube slots
30, 58 of the manifolds
42, 56. However, any other method of forming the tube divider
50 may also be used.
[0021] The method continues with the step of inserting the first tube end
46 of each tube
44 into one of the first tube slots
30 of the first manifold
42 and abutting the divider of each tube
44 against the wall 36 of the second member
32 to establish fluid communication between the first passage
52 of the tubes
44 and one of the chambers
38, 40 of the first manifold
42 and to establish fluid communication between the second passage
54 of the tubes
44 and the other of the chambers
38, 40 of the first manifold
42. The first tube end
46 of each tube
44 is then permanently fixed to the associated first tube slot
30 first manifold
42.
[0022] The method further continues with the step of forming a second manifold
56 having a set of second tube slots
58 being spaced from each other to correspond with the set of first tube slots
30 of the first manifold
42. The method proceeds with the step of inserting the second tube end
48 of each of the tubes
44 into the corresponding second tube slot
58 of the second manifold
56 to establish fluid communication between the first and second passages
52, 54 of each tube
44 and the second manifold
56.
[0023] The method is finished with the steps of forming a plurality of air fins
62 and inserting one of the air fins
62 between adjacent tubes
44 to dissipate heat from the tubes
44. In the exemplary embodiment, the tubes
44, manifold, and air fins
62 are all brazed together to define a unified heat exchanger assembly
20.
[0024] 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. Many
of the traditional methods for forming the tube slots in the first manifold of the
Gowan '303 patent must be abandoned in order to avoid interfering with the dividing
wall of the first 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
30 of the present invention may be formed in the first member
22 using a variety of manufacturing methods including stamping before the step of permanently
fixing the first and second members
22, 32 together. This leads to significantly greater manufacturing efficiency, thereby reducing
the cost and time to assemble the first manifold
42 and of the heat exchanger assembly
20.
[0025] 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.
1. A method of forming a manifold for use in a heat exchanger assembly
(20) including the steps of:
separately forming a first member (22) at least partially defining an interior and having a spaced set of first tube slots
(30) and a second member (32) having a wall (36) positioned against the first tube slots (30) and dividing the interior into a plurality of chambers (38, 40); and
permanently fixing the first member (22) to the second member (32) to define a first manifold (42) after the separately forming step.
2. The method as set forth in claim 1 wherein the forming the first member (22) is further defined as rolling a flat sheet of material into a channel having a cross-section
presenting a U-shape presenting a base (26) and arms (24) extending forwardly to arm ends (28).
3. The method as set forth in claim 1 further including the steps of:
forming a plurality of tubes (44) extending between first and second tube ends (46, 48), wherein the forming each tube (44) is further defined by rolling a flat sheet of material into a tube (44) defining a tube divider (50),
forming a tube divider (50) extending between the first and second tube ends (46, 48) in each of the tubes (44) to separate each tube (44) into a first passage (52) and a second passage (54),
inserting the first tube end (46) of each tube (44) into one of the first tube slots (30) of the first manifold (42) and abutting the tube divider (50) of each tube (44) against the wall (36) to establish fluid communication between the first passage (52) of the tubes (44) and one of the chambers (38, 40) of the first manifold (42) and to establish fluid communication between the second passage (54) of the tubes (44) and the other of the chambers (38, 40) of the first manifold (42).
4. The method as set forth in claim 3 further including the steps of:
forming a second manifold (56) having a set of spaced second tube slots (58) to correspond with the set up first tube slots (30) of the first manifold (42).
inserting the second tube end (48) of each of the tubes (44) into the corresponding second tube slot (58) of the second manifold (56) to establish fluid communication between the first and second passages (52, 54) of each tube (44) and the second manifold (56).
5. An assembly (20) manufactured according to the method of claim 1.
6. The assembly (20) as set forth in claim 5 wherein said first member (22) extends longitudinally and said first tube slots (30) are longitudinally spaced from each other.
7. The assembly (20) as set forth in claim 5 wherein said first member (22) is a channel having a cross-section defining a U-shape and presenting arms (24) integrally connected to a base (26) and extending forwardly to arm ends (28).
8. The assembly (20) as set forth in claim 7 wherein said second member (32) includes a plate (34) extending between said arm ends (28) of said channel and said wall (36) extends transversely from said plate (34) to said tube slots (30, 58) of said channel.
9. The assembly
(20) as set forth in claim 5 further comprising:
an input (64) disposed on one of said chambers (38, 40) to receive a fluid and to define an input chamber (38) and an output (66) disposed on the other of said chambers (38, 40) to dispense the fluid and to define an output chamber (40).
10. The assembly
(20) as set forth in claim 11 further comprising:
a plurality of tubes (44) extending between first and second tube ends (46, 48);
said first tube end (46) of each of said tubes (44) is disposed in one of said first tube slots (30) of said first manifold (42),
wherein each of said tubes (44) defines a tube divider (50) extending between said
first and second tube ends (46, 48) to define a first passage (52) in fluid communication
with one of said chambers (38, 40) of said first manifold (42) and a second passage
(54) in fluid communication with the other of said chambers (38, 40); and
said tube divider (50) at said first tube end (46) abuts said wall (36) of said second member (32).
11. The assembly
(20) as set forth in claim 10 further comprising:
a second manifold (56) extending in spaced and parallel relationship with said first manifold (42) and end engaging said second tube ends (48) of said plurality of tubes (44) to establish fluid communication between said first and second passages (52, 54) of said tubes (44) and said second manifold (56).
12. The assembly (20) as set forth in claim 11 wherein said second manifold (56) defines a plurality of second tube slots (58) spaced from each other to correspond with said first tube slots (30) of said first manifold (42), and
said second end of each of said tubes (44) extends into said corresponding second tube slot (58).