The present invention relates to heat exchangers, and to side plates used in heat exchangers.
Vapor compression systems are commonly used for refrigeration and/or air conditioning and/or heating, among other uses. In a typical vapor compression system, a refrigerant, sometimes referred to as a working fluid, is circulated through a continuous thermodynamic cycle in order to transfer heat energy to or from a temperature and/or humidity controlled environment and from or to an uncontrolled ambient environment. While such vapor compression systems can vary in their implementation, they most often include at least one heat exchanger operating as an evaporator, and at least one other heat exchanger operating as a condenser.
One especially useful type of heat exchanger used in some such systems is the parallel flow (PF) style of heat exchanger. Such a heat exchanger can be characterized by having multiple, parallel arranged channels, especially micro-channels, for conducting the refrigerant through the heat transfer region from an inlet manifold to an outlet manifold.
In part to increase the performance of vapor compression systems, parallel flow heat exchangers having multiple tube rows are being proposed for both condenser and evaporator use. Such heat exchanger architectures can result in different thermal gradients occurring within each of the rows, and can lead to thermal stress concerns that are substantially different than those found in more conventional single row heat exchangers.
According to an embodiment of the invention, a side plate is provided for use in a heat exchanger. The heat exchanger has a width dimension, and includes a first and a second row of parallel arranged tubes. Each of the tubes extends in the direction of the width dimension. A first and a second header are arranged at one common end of the width dimension to receive the ends of the tubes in the first and second rows, respectively. The side plate includes a first body section joined to and extending from the first header, the first body section defining a first outer periphery. The side plate also includes a second body section joined to and extending from the second header, the second body section defining a second outer periphery. The second outer periphery is spaced apart from the first outer periphery such that each one of the first and second body sections is allowed to more relative to the other in the direction of the width dimension.
In some embodiments, one or more point connections are provided between the first body section and the second body section. Each of the point connections breaks in shear when one of the first and second body sections moves relative to the other in the direction of the width dimension. In some embodiments at least one of the first and second body sections of the side plate includes a planar base and a bent flange joined to the planar base.
In some embodiments the side plate includes a third body section arranged away from the first and second headers and defining a third outer periphery. The third outer periphery is spaced apart from the first and the second outer peripheries such that each of the first and second body sections is allowed to move relative to the third body section in the direction of the width dimension. In some such embodiments the third body section is arranged away from the first and second headers by a distance of no less than one tenth of the width dimension. In some embodiments the first body section is disposed directly over the first row of tubes and the second body section is disposed directly over the second row of tubes.
According to another embodiment of the invention, a side plate for use in a heat exchanger includes a substantially planar base section having a long dimension between opposing first and second short sides, and a short dimension between opposing first and second long sides. One or more first elongated slots extends through the substantially planar base section at an approximately central position in the short dimension, and is oriented to be aligned with the long dimension. The slots extend in the long dimension direction from the first short side to a first terminating location positioned a fraction of the long dimension away from the first short side. One or more second elongated slots extend through the substantially planar base section and are generally oriented to be at an angle to the long dimension. The second elongated slots extend from approximately the first terminating location to a second terminating location. The second terminating location is coincident with the first long side and is located further away from the first short side than the first terminating location
In some embodiments a first breaking point is located at approximately the first terminating location and separates the second elongated slots from the first elongated slots. In some embodiments the side plate includes a bent flange joined to the substantially planar base section at the first long side, and one or more third elongated slots extending through the bent flange at approximately the second terminating location.
In some embodiments the side plate includes one or more third elongated slots extending through the substantially planar base section and generally oriented to be at an angle to the long dimension. The third elongated slots extend from approximately the first terminating location to a third terminating location, which is coincident with the second long side and is located further away from the first short side than the first terminating location.
According to another embodiment of the invention, a heat exchanger includes first and second tubular headers arranged adjacent to one another at one end of the heat exchanger, a first tube joined to and extending from the first tubular header in a core width direction of the heat exchanger, and a second tube joined to and extending from the second tubular header in the core width direction. The first tube is one of a first row of tubes, and the second tube is one of a second row of tubes. A flat outer surface of the second tube is arranged to be co-planar with a flat outer surface of the first tube. The heat exchanger further includes a corrugated fin having a plurality of flanks joined by alternating crests and troughs. The troughs are joined to the flat outer surfaces of the first and second tubes. A side plate has a planar base section that is joined to the crests of the corrugated fin. A first slot extends through the planar base section and is disposed between the first and second tubes, and a second slot extends through the planar base section and is disposed over the first tube.
In some embodiments, the side plate includes a third slot extending through the planar base section and disposed over the second tube. In some embodiments the second slot is separated from the first slot by a breaking point. In some embodiments the first tube is fluidly connected to the second tube to at least partially define a fluid flow path from the first header to the second header.
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 accompanying 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.
The present invention will be described hereinafter as a refrigerant heat exchanger such as, for example, an evaporator, a condenser, or a heat exchanger capable of operation as both a condenser and an evaporator in a reversible system. However, it should be understood that the invention is applicable to other types of heat exchangers as well, including but not limited to radiators, charge-air coolers, oil coolers, and the like.
Referring to
The convoluted fins 4 are generally of a serpentine design, and are defined by flanks joined by alternating crests and troughs. The flanks provide a large amount of surface area to facilitate convective heat transfer to or from the flow of air passing over the fin surfaces. The crests of a fin 4 join to the flat surface of a tube 3 on one side of the convoluted fin 4, whereas the troughs join to the flat surface of a tube 3 on the opposite side of the fin 4. While the convoluted fins 4 of the accompanying figures are shown to be plain fins absent of heat transfer enhancement features such as bumps, slits, louvers, or the like, it should be appreciated by those skilled in the art that such known enhancement features can be provided on the flanks of the fins 4.
In addition to the core 2, the heat exchanger 1 further includes a tubular inlet header 5 and a tubular outlet header 6. The headers 5 and 6 are arranged in side-by-side fashion at a common end of the heat exchanger. Each of the tubular headers 5 and 6 is provided with a series of tube slots 10 penetrating through an outer wall of each header 5, 6 and facing towards the core 2. The number of tube slots 10 is in like proportion to the number of tubes 3, so that an end of each of the tubes 3 can be received into one of the tube slots 10 in order to provide for a fluid flow path from the interiors of the tubular headers 5, 6 to the micro-channels provided within the tubes 3. As shown in
As shown in
The heat exchanger 1 as shown in
In order to allow for the interconnection of the heat exchanger 1 into a refrigerant system, the heat exchanger 1 is further provided with an inlet port 7 and an outlet port 8. The inlet port 7 is connected to the inlet header 6 to allow the refrigerant circulating through the refrigerant system to enter into the heat exchanger 1, while the outlet port 8 is connected to the outlet header 6 to allow the refrigerant to exit the heat exchanger 1 after having circulated through the core 2. A particularly preferable refrigerant system incorporating the heat exchanger 1 is shown in
As the refrigerant 37 travels through the tubes, heat is removed from the refrigerant by air that is directed over the tubes by an air mover 36. The air flow is represented by arrows extending from the air mover 36, and as depicted in
At some point (specifically, point E) within the first row of tubes 38, and typically fairly close to the inlet header 5, the refrigerant reaches its saturation temperature. From there on, the refrigerant maintains an essentially constant temperature as it releases latent heat through condensation to a liquid phase. The refrigerant 37 leaves the outlet header 6 by way of the outlet port 8 as a slightly sub-cooled liquid refrigerant at the elevated pressure (corresponding to the point A). The refrigerant is then expanded to the lower pressure through an expansion valve 33, thereby flashing to a two-phase (liquid and vapor) condition (corresponding to point B). The refrigerant is subsequently routed through an evaporator 34. Heat is transferred to the refrigerant as it passes through the evaporator 34, so that the refrigerant exits the evaporator 34 as the superheated refrigerant of point C. This transfer of heat within the evaporator can be used to cool and/or dehumidify a flow of air provided by an air mover 35 and passing through the evaporator 34, making the system 31 useful for climate comfort, refrigeration, or other similar purposes. Alternatively, the transfer of heat within the evaporator can be used for other purposes, for example to produce a chilled water supply.
In some embodiments, the refrigerant system 31 can be modified to be a reversible heat pump system. In such a system, one or more valves are arranged along the flow path of the refrigerant to selectively allow for operation of the system in either the mode described above, or a reversed mode in which the heat exchanger 34 functions as the condenser and the heat exchanger 1 functions as the evaporator. In such a reversed mode, the flow of refrigerant through each of the heat exchangers is reversed from that shown in
Turning now to
Referring back to
Generally speaking, the side plate 12 is of a rectangular shape, with two spaced apart long sides 15a and 15b extending in the direction of the core width dimension, and two spaced apart short sides 16a and 16b at the header ends of the side plate 12. The side plate 12 can additionally be provided with a bent flange 14 extending from the planar base 13 along one or both the long sides 15. The bent flange 14 can provide increased structural rigidity to the side plate 12, as well as optionally providing mounting holes 29 for installation of the heat exchanger 1. While the exemplary embodiment shows only a single bent flange along the long side 15a, a similar bent flange can also be provided along the opposing long side 15b. In any event, the bent flange is an optional feature and need not be present in all embodiments of the invention.
The side plate 12 also includes edges 30 arranged along the short side 16a to structurally join the side plate 12 to the headers 5 and 6. Such a structural connection is known to provide beneficial strengthening of the tubular headers to allow them to resist the pressure forces that may be imposed upon them by the pressurized refrigerant contained within. The connection between the headers 5, 6 and the edges 30 can be provided by welding and/or by brazing. Similar connections can be provided at the opposing short 16b, but are generally not necessary when the rather flat return header 11 is employed.
The components of the heat exchanger 1 can be joined into a monolithic assembly through a brazing operation. Preferably, all of the components are formed from a similar metal alloy (such as, for example, an aluminum alloy), and a braze filler metal having a lower melting point than that alloy is provided at the joints between components. The assembled components are placed into a brazing furnace at high temperature, such that the braze filler metal becomes liquid and wets the adjoining surfaces. When the temperature is sufficiently reduced, the filler metal re-solidifies to permanently join the various components.
Heat exchangers (specifically, condensers) having a similar construction, but with only a single row of flat tubes extending between spaced apart tubular headers, are known to be sensitive to damage incurred by differential thermal expansion between the tubes and the side plate during operation. The refrigerant passing through the tubes of a condenser is by necessity at an elevated temperature with respect to the cooling air flow. In contrast, the side plate is at a temperature that is generally equal to the cooling air temperature. As a result, the tubes would ordinarily experience a greater amount of thermal expansion that the side plate. The tubes and the side plates are constrained, however, by virtue of being joined to the opposing headers. Consequently, this differential thermal expansion results in stresses at the header, and can lead to premature failure of the heat exchanger. This known problem has in the past been alleviated by cutting or sawing through the side plate after the construction of the heat exchanger, or by including breaking features in the side plate, as described in U.S. Pat. No. 6,412,547 to Siler and U.S. Pat. No. 7,621,317 to Rousseau et al., among others. Such solutions avoid the thermal stress issues while still providing the beneficial strengthening of the tubular headers against internal pressure as described earlier.
The inventors have found that these known solutions can be insufficient for use in the multi-row heat exchanger 1 when that heat exchanger operates as a refrigerant condenser. As indicated by the plot of
As a solution to this problem, the inventors have found that certain features can be added to the side plate 12 in order to allow for the tube rows 38 and 39 to expand as needed while still maintaining the known benefits of the side plate. These features will now be described with specific reference to the embodiments shown in
The side plate 12 of
The slot 17 is elongated in the direction of the width dimension, is located to be approximately midway between the rows 38 and 39 of the core 2, and extends from the short side 16a to a terminating location 43 spaced a distance away from that side. The terminating location 43 is preferably selected to approximately correspond to the point E during expected operation of the heat exchanger 1. Such a desired location can often be estimated as a percentage of the overall width dimension of the heat exchanger. For example, in some preferable embodiments the terminating location is spaced away from the short side 16a by a distance that is approximately one tenth of the width dimension.
The embodiment of
Point connections are provided between the body sections 40 and 41 to allow for handling and assembly of the side plate 12 as a single component during manufacturing of the heat exchanger. A first point connection 21 is provided at the terminating location 43, and separates a slot 17 from a slot 18. The point connection 21 is preferably configured to break in shear when relative movement in the width dimension direction occurs between the body sections 40 and 41. The point connection 21 can thereby remain intact until the operation of the heat exchanger induces a sufficient differential thermal expansion between the rows of tubes to break the point connection 21. While only a single, continuous slot 17 is shown in the embodiment of
In similar fashion, one or more point connections 23 (only one is shown) can be provided to connect the outer periphery 26 to the outer periphery 27 between adjacent ones of the slots 18. The point connections 23 can again provide some structural integrity to the side plate 12 during handling and assembly, but will break in shear to allow for relative movement of the body sections 40 and 41 in the width dimension direction.
Another embodiment of the side plate 12 is illustrated in
Slots 19 similar to the slots 18 extend through the substantially planar base section 13 of the side plate 12 and separate the body section 41 from the body section 42. A point connection 22, similar to the point connection 21, is provided at the terminating location 43 and separates a slot 17 from a slot 19. The slots 19 extend from the terminating location 43 to a third terminating location 45 located along the long edge 15b, so that the slots 19 are disposed over the second row of tubes 39 in the heat exchanger 1. The terminating location 45 is spaced further away from the short edge 16a than is the terminating location 43, so that the slots 18 extend at an angle to the width dimension direction. In some embodiments the terminating locations 44 and 45 are spaced equidistantly from the short edge 16a, although this need not be the case in all embodiments.
Slots 20 extend through the flange 14 of the side plate 12 and intersect with the slot 19 extending through the base section 13 at the terminating location 45. The slots 20 are elongated in a direction that is generally perpendicular to the planar base section 13, and are offset from one another in the width dimension direction by an amount that is slightly greater than the width of the slots 20. A point connection 25 between the flanges of the body sections 41 and 42 is thereby created, and can break in shear when those body sections move relative to one another in the width dimension direction.
The embodiment of
As an alternative to relying on the thermal response of an operating heat exchanger 1 to break the point connections 21, 22, 23, 24, and/or 25, one or more of such point connections can be severed after the components of the heat exchanger 1 have been joined together.
Various alternatives to the certain features and elements of the present invention are described with reference to specific embodiments of the present invention. With the exception of features, elements, and manners of operation that are mutually exclusive of or are inconsistent with each embodiment described above, it should be noted that the alternative features, elements, and manners of operation described with reference to one particular embodiment are applicable to the other embodiments.
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 in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/US2014/061766 | 10/22/2014 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2015/061447 | 4/30/2015 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
5954123 | Richardson | Sep 1999 | A |
5964281 | Voss et al. | Oct 1999 | A |
6412547 | Siler | Jul 2002 | B1 |
7108050 | Reichle et al. | Sep 2006 | B2 |
7198095 | Nguyen | Apr 2007 | B2 |
7231966 | Katoh et al. | Jun 2007 | B2 |
7389810 | Harada | Jun 2008 | B2 |
7594327 | Nakayama et al. | Sep 2009 | B2 |
7621317 | Rousseau et al. | Nov 2009 | B2 |
7921902 | Horoho | Apr 2011 | B2 |
8136579 | Riondet et al. | Mar 2012 | B2 |
8776873 | Mross et al. | Jul 2014 | B2 |
8794300 | Irmler et al. | Aug 2014 | B2 |
20020023735 | Uchikawa et al. | Feb 2002 | A1 |
20040251002 | Reichle | Dec 2004 | A1 |
20050102836 | Kroetsch | May 2005 | A1 |
20050121178 | Nguyen | Jun 2005 | A1 |
20050224219 | Reier et al. | Oct 2005 | A1 |
20060086486 | Sudo | Apr 2006 | A1 |
20070175619 | Watanabe et al. | Aug 2007 | A1 |
20070256819 | Alcaine et al. | Nov 2007 | A1 |
20070261820 | Rousseau et al. | Nov 2007 | A1 |
20080047689 | Hirose et al. | Feb 2008 | A1 |
20080190596 | Bachner | Aug 2008 | A1 |
20090007593 | Kerler et al. | Jan 2009 | A1 |
Number | Date | Country |
---|---|---|
1104761 | Jul 1995 | CN |
1155067 | Jul 1997 | CN |
112007000019 | Dec 2012 | DE |
2452785 | Mar 2009 | GB |
H09210591 | Aug 1997 | JP |
H11325783 | Nov 1999 | JP |
2004225990 | Aug 2004 | JP |
2005172357 | Jun 2005 | JP |
2008014622 | Jan 2008 | JP |
2008281258 | Nov 2008 | JP |
2013213755 | Oct 2013 | JP |
2013058953 | Apr 2013 | WO |
Entry |
---|
Office Action from the Japanese Intellectual Property Office for Application No. JP2016526198 dated Jul. 12, 2017 (13 pages). |
First Office Action from the State Intellectual Property Office of China for Application No. 201480058348.4 dated Feb. 3, 2017 (16 pages). |
PCT/US2014/061766 International Preliminary Report on Patentability dated Apr. 26, 2016 (1 pages). |
International Search Report and Written Opinion for Application No. PCT/US2014/061766 dated May 28, 2015 (12 pages). |
Number | Date | Country | |
---|---|---|---|
20160238325 A1 | Aug 2016 | US |
Number | Date | Country | |
---|---|---|---|
61894476 | Oct 2013 | US |