The invention relates to heat exchangers, and in particular, to plate and fin type heat exchangers of the type commonly used in vehicles.
In the past, engine coolant heat exchangers, such as radiators, have been made by providing a plurality of parallel, spaced-apart flat tubes with cooling fins located therebetween to form a core. Opposed ends of the tubes pass through openings formed in manifolds or headers located on each side of the core at the respective ends of the tubes. A difficulty with this type of construction is that the tube to header joints are difficult to fabricate and prone to leakage. As well, there is a tendency for the tube to header joints to fail as a result of stresses caused by thermal cycling. Therefore, this type of construction presents problems with both the manufacture and operation of the heat exchanger.
A method of overcoming these difficulties is shown in U.S. Pat. No. 3,265,126 which issued to D. M. Donaldson. In this patent, manifolds are provided with a continuous longitudinal opening, and the tubes are formed with specifically shaped ends to fit into this continuous opening, thus simplifying the assembly and reducing the leakage problem. A difficulty with the Donaldson structure, however, is that the shape of the various components is quite complex resulting in high tooling costs.
In order to facilitate the design of heat exchanger components and thereby reduce manufacturing costs, various improvements to headerless heat exchangers have been made. For instance, U.S. Pat. No. 6,332,495 which issued to Jamison et al. discloses a clip-on manifold heat exchanger formed from a plurality of stacked plate pairs having raised peripheral edge portions to define flow channels inside the plate pairs. The plates of the plate pairs are formed with offset, diverging end flanges that space the plate pairs apart. A U-shaped channel envelopes the plate end flanges to form part of a manifold at each end of the plate pairs, and end caps or plates close the open ends of the U-shaped channels to complete the manifolds. The components are typically joined together by brazing or any other suitable technique.
U.S. Pat. No. 6,513,585 which issued to Brost et al. discloses a headerless vehicle radiator formed of tubes having end walls which are bifurcated for a short distance from the ends of the tubes and having one or both of the sidewalls in the bifurcated segment of the tube formed outwardly and adapted to contact and be joined in a fluid tight manner with the sidewall of an adjacent tube in the radiator core. A collecting tank (or manifold) has walls extending partially over the radiator core to a distance beyond the bifurcation of the sidewalls, the collecting tank walls being joined to the end walls of the tubes in a fluid tight manner. Once again, the various components of the heat exchanger (or radiator) are typically joined together by brazing or any other suitable technique.
In both the Jamison et al. and Brost et al. heat exchangers, the performance of the heat exchanger depends in part on the effectiveness of the joint achieved between the plate pairs and the walls of the U-shaped channels or manifolds. Due to the thicknesses of the materials used in creating the components of these types of heat exchangers, it can be difficult to achieve an effective seal or bond between the plate pairs.
In the present invention, the plates in the plate pairs are oriented at 90 degrees to one another, so that end portions of the plate sidewalls provide more surface area to better seal with the manifold walls.
According to the invention, there is provided a heat exchanger comprising a plurality of stacked, alternating first and second heat exchange plates having an inverted U-shaped cross-section. The plates have closed peripheral sidewalls and open ends, and the open ends of the first plates are oriented at 90 degrees to the open ends of the second plates. The sidewalls of the first and second plates have end portions which, in adjacent plates, are aligned to form corners of the heat exchanger. Opposed U-shaped bodies are provided having open ends and lateral walls joined in a fluid tight manner to the aligned first and second plate sidewall end portions. End plates close the open ends of the U-shaped bodies to form manifolds for the flow of fluid through the plate open ends in the second plates. The manifolds also include inlet and outlet openings for the flow of fluid into and out of the heat exchanger.
Preferred embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
Referring to the drawings, there is shown in
Heat exchanger 10 includes a core 12 formed of a plurality of stacked, alternating first and second heat exchange plates 14, 16 with cooling fins 18 located therebetween. Cooling fins 18 are the usual type of corrugated cooling fins having transverse undulations or louvres formed therein to increase heat transfer. However, any type of cooling fin could be used in the present invention or even no cooling fin at all, if desired.
Heat exchanger 10 has a pair of manifold members 20, 22 located at the respective ends of the heat exchanger core 12. Inlet and outlet nipples or fittings 24, 26 are mounted in one of the manifold members 20, 22 for the flow of coolant into and out of the heat exchanger 10. While the inlet and outlet fittings 24, 26 are shown in
A top end plate 28 closes the upper ends of manifold members 20, 22 and provides a location for a filler cap fitting 30 and filler cap 32, as well as a mounting bracket 34 used for mounting the heat exchanger 10 in a desired location. The filler cap fitting 30 also includes an overflow or pressure relief outlet 33. A bottom end plate 36 is also provided for closing the lower ends of manifold members 20, 22. Bottom end plate 36 also provides a location for the attachment of another mounting bracket 38 for mounting heat exchanger 10 in the desired location. It will be understood that although the filler cap fitting 30 and filler cap 32 have been shown as being mounted in the top end plate 28, these components could in fact be mounted in or attached to either manifold member 20, 22 as opposed to the top end plate 28.
The second heat exchange plates 16 are also formed of inverted, generally U-shaped channel members each having a top wall 52, two downwardly depending closed peripheral sidewalls 54, and open ends 56. The closed peripheral side walls 54 also include inwardly bent flange portions 64 for resting on the adjacent first heat exchange plate 14 when the first and second plates 14, 16 are stacked together in their alternating relationship. As well, the second heat exchange plates 16 have end portions 58 (see
The heat exchanger core 12 is assembled so that as the first and second heat exchange plates 14, 16 are stacked together the open ends 44 of the first plates 14 are oriented at 90 degrees to the open ends 56 of the second plates 16. Accordingly, the end portions 46 of the first plates 14 are aligned with the end portions 58 of the second plates 16 to form corners of the heat exchanger core 12. Flange portions 50 of the first plates 14 rest on the top wall 52 of the adjacent second plate 16 along the corresponding open end 56 thereof. Similarly, the flange portions 64 of the second plates 16 rest on the top wall 40 of the adjacent first plate 14 along the corresponding open end 44 thereof. Flange portions 50, 64 allow for an appropriate amount of surface contact between the respective first and second plates 14, 16 to create a good seal between the components when the first and second plates 14, 16 are joined together by brazing (or by any other suitable method).
The stacking of the first and second plates 14, 16 creates a first set of flow channels between the open ends 44 of the first plates 14 for the flow of a first fluid therethrough. Similarly, a second set of flow channels is created between the open ends 56 of the second heat exchange plates 16 for the flow of a second fluid therethrough. As the open ends 44, 56 of the first and second plates 14, 16 are oriented at 90 degrees to one another, the flow of the first fluid is transverse to the flow of the second fluid through the heat exchanger core 12. Cooling fins 18 are located in the first set of flow channels created between the first and second plates 14, 16 to help increase heat exchange between the first and second fluids. When used as the radiator of an internal combustion engine, the first fluid is usually air and the second fluid is coolant.
Referring now to
The shaping of the side walls 42′ forms a sloping or funnel-like structure surrounding the open ends 56 of the second heat exchange plates 16, when the first and second plates 14′, 16 are stacked in their alternating relationship. The funnel-like structure created by the triangular profile of the side walls 42′ helps to minimize entrance pressures losses into the second set of flow channels in the heat exchanger core 12′ formed by the second heat exchange plates 16.
Manifold members 20, 22 are positioned on the respective ends of heat exchanger core 12′ in a similar manner as described in connection with the embodiment shown in
In this embodiment, the side walls 42″ of the first plates 14″ further include offset portions 76 that precede and project slightly beyond the base of flange portions 50″. Offset portions 76 help position first plates 14″ with respect to the second plates 16 as they are stacked in their alternating relationship. As first plates 14″ are positioned on top of second plates 16, offset portions 76 abut the end edge of top wall 52, thereby aligning the first plate 14″ with respect to the associated second plate 16. Accordingly, the first and second heat exchange plates 14″, 16 are considered to be “self-fixturing”. While the “self-fixturing” features of the heat exchange plates have only been described in connection with the embodiment shown in
Once again, manifold members 20, 22 (not shown) are positioned on the respective ends of the heat exchanger core 12″ in a similar manner as described in connection with the embodiment shown in
Referring now to
The second heat exchange plates 116 are also formed of inverted, generally U-shaped channel members each having a top wall 152, two downwardly depending closed peripheral sidewalls 154, and open ends 156. The closed peripheral side walls 154 have end portions 158 which, as described in connection with
To form the core 112, the first and second heat exchange plates 114, 116 are alternatingly stacked together so that the open ends 144 of the first plates 114 are at 90 degrees to the open ends of the second plates 116. However, in this embodiment, the first plates 114 are designed so as to be wider than second plates 116, and second plates 116 are designed so as to be longer than first plates 114. Accordingly, end portions 146 of the first plates 114 overhang the side walls 152 of the second plates 116 by a distance D1, and end portions 158 of the second plates overhang the side walls 142 of the first plates 114 by a distance D2. Therefore, when the first and second plates 114, 116 are stacked in their alternating relationship, end portions 146 and 158 align in such a way so as to form corners of the heat exchanger core 120 defined by planar regions 78 and 160. As shown in
To form the heat exchanger, manifold members 120, 122, are positioned at respective ends of the heat exchanger core 112. Manifold members 120, 122 are each formed of a generally U-shaped body having a rear wall 166, a pair of lateral walls 168, and open upper and lower ends 170. The manifold members 120, 122 are sized so as to fit snugly around the heat exchanger core 112 and the lateral walls 168 have end portions 172 which correspond to and are adapted to engage the corners of the core 112.
In the embodiment shown in
In the embodiment shown in
Manifold members (not shown) are positioned on the respective ends of heat exchanger core 212 in a similar manner as described in connection with the embodiment shown in
The heat exchanger core 212 shown in
Referring now to
According to the embodiment shown in
Manifold members 20, 22 (not shown) are positioned on the respective ends of the heat exchanger core 312 in a similar manner as described above in connection with the various other embodiments. Therefore, as manifold members 20, 22 are positioned on the core 312, they create both butt joints and lap joints with the respective end portions 346, 58 of the first and second heat exchange plates 314, 16. However, in this embodiment, the inwardly spiraling circular side walls 342 provide almost twice as much surface area for creating the butt joints with the manifold members 20, 22 when the components are joined together. The circular side walls 342 also provide a certain give or spring-like action when assembling the heat exchanger core 312, which assists in the assembly of the device.
While the present invention has been described with reference to certain preferred embodiments, it will be understood by persons skilled in the art that the invention is not limited to these precise embodiments and that variations or modifications can be made without departing from the scope of the invention as described herein. For example, if the subject heat exchangers were used as oil coolers with oil flowing through the manifolds, the height of second heat exchange plates 16, 116 would be larger and turbulizers or other heat transfer augmentation devices such as dimples or ribs formed in the top wall of the plates probably would be used inside second heat exchange plates 16, 116. In other applications, the height of the second heat exchange plates 16, 116 may be much smaller and turbulizers or other heat transfer augmentation devices may or may not be used. Accordingly, it will be appreciated that the heat exchanger disclosed in the present application can be adapted to suit various applications.
Number | Name | Date | Kind |
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2376749 | Belaieff | May 1945 | A |
3265126 | Donaldson | Aug 1966 | A |
3805889 | Coolidge | Apr 1974 | A |
4125153 | Stoneberg | Nov 1978 | A |
4343355 | Goloff et al. | Aug 1982 | A |
4348604 | Thode | Sep 1982 | A |
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4442886 | Dinulescu | Apr 1984 | A |
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5681538 | Sung et al. | Oct 1997 | A |
5785117 | Grinbergs | Jul 1998 | A |
6311768 | Jamison et al. | Nov 2001 | B1 |
6332495 | Jamison et al. | Dec 2001 | B1 |
6446713 | Insaiaco | Sep 2002 | B1 |
6513585 | Brost et al. | Feb 2003 | B2 |
6516874 | Mathur et al. | Feb 2003 | B2 |
6530424 | Jamison et al. | Mar 2003 | B2 |
6668916 | Zobel et al. | Dec 2003 | B2 |
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Number | Date | Country |
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2 809 482 | Nov 2001 | FR |
1064282 | Jul 2001 | KR |
WO 8303663 | Oct 1983 | WO |
Entry |
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International Search Report and Preliminary Written Opinion dated Nov. 16, 2007 in respect of International Application No. PCT/CA2007/001422. |
Number | Date | Country | |
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20080041570 A1 | Feb 2008 | US |