Heat exchanger
A heat exchanger is provided. The heat exchanger includes a stack assembly with a plurality of plates and a plurality of frames arranged in an alternating stacked relationship with the plates along a predetermined direction. Each of the plates has a plurality of first openings and each of the frames has a plurality of second openings. A plurality of first and second fluid channels extends through the stack assembly along the predetermined direction and through the plurality of first and second openings. A first fluid flow path includes a first inlet channel in fluid communication with the plurality of first fluid channels, and a first outlet channel in fluid communication with the plurality of second fluid channels. A second fluid flow path is in thermal contact with the first fluid flow path and fluidically isolated from the first fluid flow path.
The present application claims priority from U.S. Provisional Application Ser. No. 60/753,812, filed Dec. 23, 2005, which is fully incorporated herein.
TECHNICAL FIELDThe present disclosure is directed to a heat exchanger, and more particularly to a stacked plate heat exchanger and method of assembly thereof.
BACKGROUNDPlate-type heat exchangers are used for certain industrial applications in place of fin and tube or shell and tube type heat exchangers because they are less expensive and easier to make than most forms of heat exchangers. In one form of such plate-type heat exchangers, a plurality of primary surface plates are brazed together in a unitary structure with spacer frames located between adjacent plates and traversing a course adjacent to the plate peripheries. Flow of the two fluids involved in heat exchange is through alternate layers defined by the brazed plates. The space between the plates may be occupied by protuberances or fins formed in the plates to increase turbulence or heat exchange in the fluid flow. All of the fluid flowing in a given defined space is in contact with the plates to enhance heat transfer.
In order to handle larger heat loads, existing plate-type heat exchangers may be scaled up in size by adding more layers or using denser configurations of layers. However, one problem that arises with some designs is that the pressure loss across the heat exchanger increases. One technique used to decrease the pressure loss is to transversely supply each layer from a single conduit. The conduit is sized to minimize any pressure drops. An example of such a heat exchanger is disclosed in U.S. Pat. No. 5,911,273 to Brenner et al. (“the '273 patent”). The '273 patent discloses a heat exchanger having a stacked plate construction made of four distinct parts: a cover, a flow duct plate, a connection cover plate, and a connection plate. These parts are alternated and rotated in a stack assembly. A first fluid flows into the heat exchanger through a connection opening, into a single connection conduit, then transversely through fluidically parallel layers. A second fluid has a similar flow pattern, with the heat exchange occurring across the parallel layers of the stack assembly.
While the configuration of the '273 patent attempts to decrease pressure losses, it results in an increased manifold volume or supply conduit volume to heat exchanger volume ratio. As the size or the number of layers in the heat exchanger increases, the size of the manifold volume increases as well. For applications requiring a compact construction, this may prove to be unacceptable. In addition, there may be non-uniform heat exchange such that layers farthest from the supply conduit inlets may receive less flow than layers closest to the supply conduit inlets.
The present disclosure is directed to overcoming one or more of the problems set forth above.
SUMMARY OF THE INVENTIONIn one aspect, the present disclosure is directed to a heat exchanger. The heat exchanger includes a stack assembly with a plurality of plates and a plurality of frames arranged in an alternating stacked relationship with the plates along a predetermined direction. Each of the plates has a plurality of first openings and each of the frames has a plurality of second openings. A plurality of first and second fluid channels extends through the stack assembly along the predetermined direction and through the plurality of first and second openings. A first fluid flow path includes a first inlet channel in fluid communication with the plurality of first fluid channels and a first outlet channel in fluid communication with the plurality of second fluid channels. A second fluid flow path is in thermal contact with the first fluid flow path and fluidically isolated from the first fluid flow path.
In another aspect, the present disclosure is directed to a method of making a heat exchanger including the steps of providing a plurality of plates having a plurality of first openings and providing a plurality of frames having a plurality of second openings. The method also includes the steps of alternately stacking the plates with the frames along a stack direction and aligning the plurality of first openings with the plurality of second openings to define a first and second plurality of fluid channels extending through the plates and the frames along the stack direction. The method also includes the steps of coupling a first manifold to each of the first plurality of fluid channels along the stack direction and coupling a second manifold to each of the second plurality of fluid channels along the stack direction. The method also includes the step of sealingly interconnecting the stacked plates and frames to each other.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will now be made in detail to the drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
Stack assembly 20 is made up of layers of plates 30 and frames 40. As seen in
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Stack assembly 20 is placed onto a bottom cover 50. As seen in
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As the heat exchanger 10 is stacked, the alignment of openings 32, 42, 52 and voids 43 in the plates 30, frames 40, and covers 50, 60 define a plurality of fluid channels 95, 96, 97, 98 that extend through the stack assembly 20 along the stack direction 10. Fluid channels 95, 96 are defined in the first row 34, 44, 54, 64 of plates 30, frames 40, and covers 50, 60, while fluid channels 97, 98 are defined in the second row 36, 46, 56, 66 of plates 30, frames 40, and covers 50, 60. In one exemplary embodiment, fluid channels 95, 96 alternate openings 32, 42, 52, 62 and voids 43 throughout first row 34, 44, 54, 64, so that each fluid channel 95 is adjacent a fluid channel 96. Similarly, fluid channels 97, 98 alternate openings 32, 42, 52, 62 and voids 43 throughout second row 36, 46, 56, 66, so that each fluid channel 97 is adjacent a fluid channel 98.
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These inserts may be placed in the interior periphery 141 of every frame 140, or only used with alternate frames 140, as is shown in
In another exemplary embodiment, a gas to fluid heat exchanger (not shown) may be constructed by substituting layers of frames 340, as shown in
Heat exchangers 10, 110 may be formed using a brazing operation. Before assembly, a flux is applied to the peripheries of each of manifolds 82, 84, 86, 88; covers 50, 60, frames 40, and plates 30. Thin sheets of solder may be placed between each layer to ensure a solder seal extending around the entire periphery. After assembly, the heat exchanger 10, 110 may be clamped together and heated to form a sealed unit. Alternately, the heat exchanger 10, 110 may be formed from any other technique known in the art, such as welding.
INDUSTRIAL APPLICABILITY In operation, a first and a second fluid flow path 92, 94 are defined through the heat exchanger 10, 110. A first fluid, such as heated engine oil, follows first fluid flow path 92 and enters through manifold 82. From manifold 82, the first fluid next flows into the fluid channels 96 extending through the stack assembly 20 defined by the first row 54 of openings 52 in the bottom cover 50 (as seen in
Similarly, a second fluid, such as coolant, follows second fluid flow path 94 and enters through manifold 86. From manifold 86, the second fluid next flows into fluid channels 97 extending through the stack assembly 20 defined by the second row 56 of openings 52 in the bottom cover 50 (as seen in
Foam inserts 100 or turbulators 38 may also be used to increase the heat exchange that occurs across primary surface sheet or plate 30, 130. Additional heat exchange may also occur in alternating channels in each of the first and second rows (as seen in
It will be apparent to those having ordinary skill in the art that various modifications and variations can be made to the disclosed heat exchanger without departing from the scope of the invention. Other embodiments of the invention will be apparent to those having ordinary skill in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the invention being indicated by the following claims and their equivalents.
Claims
1. A heat exchanger comprising:
- a stack assembly including: a plurality of plates, each of the plates having a plurality of first openings; a plurality of frames arranged in an alternating stacked relationship with the plates along a predetermined direction, each of the frames having a plurality of second openings; and wherein a plurality of first and second fluid channels extend through the stack assembly along the predetermined direction and through the plurality of first and second openings;
- a first fluid flow path including: a first inlet channel in fluid communication with the plurality of first fluid channels; and a first outlet channel in fluid communication with the plurality of second fluid channels; and
- a second fluid flow path in thermal contact with the first fluid flow path and fluidically isolated from the first fluid flow path.
2. The heat exchanger of claim 1, wherein a plurality of third and fourth fluid channels are defined along the predetermined direction through the plurality of first and second openings; and
- the second fluid flow path includes a second inlet channel in fluid communication with the plurality of third fluid channels and a second outlet channel in fluid communication with the plurality of fourth fluid channels.
3. The heat exchanger of claim 1, wherein the first inlet channel is configured to provide substantially equal fluid flow to each of the first plurality of fluid channels.
4. The heat exchanger of claim 3, further comprising a tapered insert in the first inlet channel.
5. The heat exchanger of claim 1, wherein the second fluid flow path is substantially perpendicular to the predetermined direction.
6. The heat exchanger of claim 1, wherein each of the plurality of plates has a first array of turbulators on a first surface.
7. The heat exchanger of claim 6, wherein each of the plurality of plates has a second array of turbulators on a second surface.
8. The heat exchanger of claim 1, wherein the plurality of first openings are aligned in a first and a second row, the first and second rows are positioned along parallel edges of each of the plates, and each of the first openings in the first row and each of the first openings in the second row are positioned a predetermined distance apart.
9. The heat exchanger of claim 8, wherein the plurality of second openings are aligned in a third and a fourth row, the third and fourth rows are positioned along parallel edges of each of the frames, and each of the second openings in the third rows and each of the second openings in the fourth rows are positioned twice the predetermined distance apart.
10. The heat exchanger of claim 1, wherein the stack assembly includes a plurality of foam layers arranged in an alternating stacked relationship with the plates and frames along the predetermined direction.
11. The heat exchanger of claim 10, wherein the plurality of foam layers are aluminum or carbon foam.
12. The heat exchanger of claim 1 further comprising a top and a bottom cover positioned on opposite sides of the stack assembly along the predetermined direction, the top and bottom cover having a plurality of third openings, and
- wherein the first and second plurality of fluid channels extend through the top and bottom cover through the plurality of third openings.
13. The heat exchanger of claim 12, wherein the top and bottom cover are substantially identical.
14. A method of making a heat exchanger comprising:
- providing a plurality of plates, each of the plates having a plurality of first openings;
- providing a plurality of frames, each of the frames having a plurality of second openings;
- alternately stacking the plates with the frames along a stack direction;
- aligning the plurality of first openings with the plurality of second openings to define a first and second plurality of fluid channels extending through the plates and the frames along the stack direction;
- coupling a first manifold to each of the first plurality of fluid channels along the stack direction;
- coupling a second manifold to each of the second plurality of fluid channels along the stack direction; and
- sealingly interconnecting the stacked plates and frames to each other.
15. The method of claim 14, further comprising rotating alternate frames 180 degrees about the stack direction.
16. The method of claim 15, further comprising tapering the first manifold to provide substantially equal flows to each of the first plurality of fluid channels.
17. The method of claim 14, wherein each of the plurality of plates has a first array of turbulators on a first surface and a second array of turbulators on a second surface opposite the first surface, and
- further comprising rotating alternate plates about a second direction perpendicular to the stack direction.
18. The method of claim 14, further comprising:
- providing a plurality of foam layers; and
- stacking the foam layers with the plates and frames along a stack direction.
19. The method of claim 14, further comprising:
- providing at least one cover having a plurality of third openings; and
- aligning the plurality of third openings with the first and second plurality of fluid channels extending through the plates and the frames along the stack direction.
Type: Application
Filed: Dec 20, 2006
Publication Date: Oct 11, 2007
Inventor: Youssef Dakhoul (East Peoria, IL)
Application Number: 11/642,147
International Classification: F28F 3/08 (20060101); F28D 9/00 (20060101);