A variety of heat exchangers exist in which a number of tubes are connected to and in fluid communication with a collection tank for introducing and/or removing fluid from the flat tubes. In many cases, the applications of such heat exchangers result in high pressure and thermal stresses, such as in locations at and adjacent to the connections of the flat tubes to the collection tank. Also, it is desirable for such collection tanks and the connections of the flat tubes thereto to withstand significant pressure without excessive deformation or damage—despite the desire to construct collection tanks from increasingly thinner and lighter materials. Particularly in cases in which the collection tanks are constructed of multiple parts (e.g., a header plate and a structure defining the remainder of the collection tank), this capability should extend to the interface between the collection tank parts.
Further design issues for many heat exchangers relate to the use of gaskets between heat exchanger components, such as tube-to-header plate gaskets, gaskets located between header plates and other collection tank components, and the like. Such gaskets must perform their hydraulic or pneumatic sealing functions while being exposed in some applications to high pressures and/or temperatures, material expansion and contraction, and other challenges. Reliable gaskets and gasket retention continue to be elusive in many applications.
Accordingly, it will be appreciated that heat exchangers having collection tanks and collection tank-to-flat tube joints adapted to withstand thermal and/or pressure stresses and cycling are welcome additions to the industry, as are reliable heat exchanger gaskets and gasket retention designs, and heat exchangers that are relatively light weight and that can be produced more efficiently and at a lower cost.
Some embodiments of the present invention provide a header for a collection tank of a heat exchanger. The header can provide an increased level of strength to the heat exchanger and to connections between the header and tubes connected thereto. The header can have a convex shape configured to reduce thermal mechanical stresses at tube-to-header joints, and to reduce pressure stresses.
In some embodiments, the header of the collection tank is manufactured from plastic, and is curved about a longitudinal axis of the collection tank, thereby presenting a generally convex shape toward the tubes connected thereto, and a generally concave shape toward an interior of the collection tank. The tubes can have any cross-section shape desired. However, unique advantages can be achieved by the use of flat tubes (i.e., tubes having opposing substantially broad flat sides joined by opposing narrow sides) connected to the header.
By virtue of a curved header as described above, plastic headers can withstand internal collection tank pressures that could otherwise generate significant header deformation. Under pressure loading of the curved plastic header described above, there is a considerably reduced degree of header deformation. In some embodiments, such deformation can even be eliminated. As a result, the mechanical load experienced by connections between the header and tubes fastened thereto is considerably reduced.
Additionally, by virtue of the curved plastic header as described above, it is possible in some embodiments to achieve increased strength of the header and of the connections between the header and tubes. Since the strength of the header and the tube-to-header connections often decreases from the periphery of the header toward the center of the header, the above-described header curvature in a central region of the header significantly increases the strength of the header in the central region. As a result of the increased strength, it is possible to achieve weight and cost savings by reduction of the thickness of the material from which the header and/or tubes is constructed. The increased mechanical strength also increases the service life of a collection tank and heat exchanger having such a header. Such advantages do not necessarily require any additional expenditure with regard to the header and collection tank material, the number of header and collection tank components, and the individual production stages of the header and collection tank. Also, reproducible and permanently sealed connections between the header and individual tubes are possible using the curved header described above and relatively low production tolerances.
Other aspects of the present invention relate to manners in which a header can be connected to the rest of a collection tank while retaining a gasket or other seal in position with respect to such parts, manners in which to provide a seal at the interfaces between the tubes and header of a heat exchanger, and manners in which the collection tank and portions of the collection tank and header interface can be reinforced to increase the pressure capacity of the collection tank and/or to enable the use of thinner and different collection tank materials.
In some embodiments, a heat exchanger is provided, and comprises a plurality of tubes each having opposing broad and substantially flat sides joined by two opposing narrow sides; a header having a plurality of apertures each dimensioned to receive a corresponding tube of the plurality of tubes; a collection tank coupled to the header and having an internal chamber in fluid communication with the plurality of tubes; a gasket located between the collection tank and the header; and at least one reinforcement extending across the internal chamber.
Some embodiments of the present invention provide a heat exchanger, comprising a plurality of tubes each having opposing broad and substantially flat sides joined by two opposing narrow sides; a plastic collection tank having an internal chamber in fluid communication with the plurality of tubes; a metal header coupled to the plastic collection tank and having a plurality of apertures each dimensioned to receive a corresponding tube of the plurality of tubes, the metal header elongated in a longitudinal direction and curved about a longitudinal axis of the metal header to present a concave shape to the internal chamber and a convex shape away from the internal chamber; a gasket at least partially separating the metal header from the plastic collection tank and sealing a gap between the metal header and the plastic collection tank; and a reinforcement extending across the internal chamber and at least partially retaining the gasket in position between the metal header and the plastic collection tank.
In some embodiments, a heat exchanger is provided, and comprises a plurality of tubes each having opposing broad and substantially flat sides joined by two opposing narrow sides; a collection tank having an internal chamber in fluid communication with the plurality of tubes; a header coupled to the collection tank and having a plurality of apertures each dimensioned to receive a corresponding tube of the plurality of tubes, the header elongated in a longitudinal direction and curved about a longitudinal axis of the header to present a concave shape to the internal chamber and a convex shape away from the internal chamber; and a gasket received on a tube of the plurality of tubes and curved about the longitudinal axis of the header.
Some embodiments of the present invention provide a heat exchanger comprising a plurality of tubes each having opposing broad and substantially flat sides joined by two opposing narrow sides; a collection tank having an inlet port and an internal chamber in fluid communication with the plurality of tubes; a header coupled to the collection tank and having a plurality of apertures each dimensioned to receive a corresponding tube of the plurality of tubes; a gasket at least partially separating the header from the collection tank and sealing a gap between the header and the collection tank; a reinforcement at least partially retaining the gasket in position between the header and the collection tank, the reinforcement including a first web extending across the internal chamber and a second web spaced apart from the first web and extending across the internal chamber; and a baffle coupled to and extending between the first web and the second web, the baffle extending across at least a portion of the internal chamber between the inlet port and the plurality of tubes.
In some embodiments, a heat exchanger is provided, and comprises a plurality of tubes each having opposing broad and substantially flat sides joined by two opposing narrow sides; a collection tank having an inlet port and an internal chamber in fluid communication with the plurality of tubes; a header coupled to the collection tank and having a plurality of apertures each dimensioned to receive a corresponding tube of the plurality of tubes, the header elongated in a longitudinal direction and curved about a longitudinal axis of the header to present a concave shape to the internal chamber and a convex shape away from the internal chamber; a gasket at least partially separating the header from the collection tank and sealing a gap between the header and the collection tank; a reinforcement extending across the internal chamber and at least partially retaining the gasket in position between the header and the collection tank; and a baffle coupled to the reinforcement and extending across at least a portion of the internal chamber between the inlet port and the plurality of tubes.
Some embodiments of the present invention provide a heat exchanger comprising a plurality of tubes each having opposing broad and substantially flat sides joined by two opposing narrow sides; a plastic collection tank having an inlet port and an internal chamber in fluid communication with the plurality of tubes; a metal header coupled to the plastic collection tank and having a plurality of apertures each dimensioned to receive a corresponding tube of the plurality of tubes, the metal header elongated in a longitudinal direction and curved about a longitudinal axis of the metal header to present a concave shape to the internal chamber and a convex shape away from the internal chamber; a gasket at least partially separating the metal header from the plastic collection tank and sealing a gap between the metal header and the plastic collection tank; a reinforcement at least partially retaining the gasket between the metal header and the plastic collection tank, the reinforcement including a first web extending across the internal chamber and a second web spaced apart from the first web and extending across the internal chamber; and a baffle coupled to and extending between the first web and the second web, the baffle extending across at least a portion of the internal chamber between the inlet port and the plurality of tubes.
Still other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
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 following 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 collection tank assembly 110 illustrated in
In some embodiments, the first portion 100A of the collection tank 100 is made of aluminum, steel, iron, or other metal, whereas the header (e.g., header 104) is made of plastic. Although this material combination provides unique performance results (including a thin-walled but strong first portion 100A able to withstand significant pressures while permitting the use of a less expensive and/or easy to manufacture plastic header), other materials and material combinations are possible. For example, in other embodiments, both the first portion 100A and the header are made of plastic. As another example, in other embodiments, both the first portion 100A and the header are made of metal. Alternatively, in still other embodiments, the first portion 100A is made of plastic, while the header is made of metal.
The first portion 100A of the collection tank 100 can be secured to the header (e.g., header 204 shown in
To prevent leakage of fluid out of the collection tank 100, a gasket 108 is located between the first portion 100A of the collection tank 100 and the header. The illustrated gasket 108 extends about the periphery of the first portion 100A and the header, and can be made of rubber, plastic, or any other material suitable for forming a seal.
As mentioned above, the collection tank assembly 110 shown in
The tank reinforcement member 104 illustrated in
The illustrated gasket 108 includes gasket cross-webs 120 configured to provide additional support to the gasket 108. In some embodiments, the cross-webs 120 extend across the internal chamber of the collection tank 100. In some embodiments, the gasket 108 further includes positioning shoulders 124 which guide placement of the gasket 108 within the interlock slots 112 (e.g., insuring that the cross-webs 120 are positioned properly within the collection tank 100 upon installation of the gasket 108 and/or maintaining a peripheral portion of the gasket 108 in proper position within a seat 111 defined by the tank reinforcement member 104).
In operation, the tank reinforcement member 104 can be placed in the collection tank 100 immediately after the collection tank 100 is molded. Alternatively, the tank reinforcement member 104 can be placed in the collection tank 100 any time prior to usage. The collection tank 100 can be shaped and dimensioned to receive the tank reinforcement member 104 by a clearance fit, snap fit, press fit, or in any other mating manner. For example, the tank reinforcement member 104 illustrated in
By virtue of the relationship between the gasket 108 and the tank reinforcement member 104 described above with regard to some embodiments of the present invention, the gasket 108 can be installed on the tank reinforcement member 104 (e.g., by pressing cross-webs 120 or other portions of the gasket 108 into apertures 112 in the tank reinforcement member 104), and the tank reinforcement member 104 and gasket 108 can be moved or otherwise manipulated by a user or machine for installation in the collection tank 100. In those embodiments in which there is an interference fit of the gasket 108 with the tank reinforcement member 104 (e.g., within the apertures 112 described above), this movement or manipulation can even place the tank reinforcement member and gasket assembly in an inverted position.
In light of the relationship between the gasket 108 and the tank reinforcement member 104 described above, assembly of a resulting heat exchanger can be simplified and improved. Also, the gasket 108 can be retained in proper position with respect to the collection tank 100 and header throughout the life of the heat exchanger.
Although a separate tank reinforcement member 104 as described above is desirable in many applications, it should be noted that the tank reinforcement member 104 and any of the gasket retention features described above can instead be integral with the collection tank 100 (e.g., molded as part of the collection tank 100) in other embodiments.
With reference to the embodiments of
Also by virtue of the curved shape of the central header portion 220 described above and illustrated in
With continued reference to the illustrated header embodiments of
In some embodiments, the header 204 of the collection tank 200 is manufactured from plastic, and is curved about a longitudinal axis of the collection tank 200, thereby presenting a generally convex shape toward the tubes connected thereto, and a generally concave shape toward an interior of the collection tank 200. In other embodiments, other header materials can instead be used as desired. Also, any of the material combinations described above in connection with the embodiment of
The tubes for connection to the headers 204 shown in
The collection tank assemblies 210 illustrated in
In some embodiments, the tank reinforcement member 203 can be assembled with the header 204 prior to or during core assembly. The tank reinforcement member 203 can be connected to the header 204, for example, in any manner desired, including without limitation by brazing or welding, by Tox® rivets (Tox Pressotechnik GmbH & Co. KG), or in any other manner desired. For example, a complete braze joint between the header 204 and tank reinforcement member 203 can be used in those embodiments in which the tank reinforcement member 203 at least partially defines a sealing surface for the gasket 208.
Some embodiments of the present invention utilize additional collection tank strengthening elements alone or in conjunction with any of those described above (e.g., the tank reinforcing members 104, 203). FIGS. 6A and 6G-6I provide examples of such strengthening elements. With reference first to
Similar to the reinforcement member 104 discussed above, the illustrated reinforcement member 326 includes a plurality of cross-webs 334. The baffle member 330 is coupled to some of the cross-webs 334 and extends across the internal chamber of the collection tank 314. In the illustrated embodiment, the baffle member 330 includes a plate defining a plurality of openings 338 and is integrally formed as a single piece with the reinforcement member 326. For example, in some embodiments, the baffle member 330 and the reinforcement member 326 may be injection molded as a single plastic component. In other embodiments, the openings 338 may be relatively larger or smaller, or the plate may include relatively fewer or more openings 338. In still other embodiments, the baffle member 330 may be a separate element that is permanently or removably secured to the reinforcement member 326.
The baffle member 330 extends across the internal chamber of the collection tank 314 with the reinforcement member 326 and extends along the length of the collection tank 314 and the header 318. In the illustrated embodiment, the baffle member 330 only extends along a portion of the length of the collection tank 314 and the header 318. For example, as shown in
The illustrated baffle member 330 is positioned within the internal chamber of the collection tank 314 generally between an inlet port 342 (
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.
The present application is a continuation-in-part of U.S. patent application Ser. No. 12/738,862, filed Jul. 13, 2010, which is a national stage entry of International Application Serial No. PCT/US08/12434, filed Nov. 3, 2008, which claims the benefit of U.S. Provisional Application Ser. No. 61/001,438, filed Nov. 1, 2007, the entire contents of each of which are hereby incorporated by reference.
Number | Date | Country | |
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61001438 | Nov 2007 | US |
Number | Date | Country | |
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Parent | 12738862 | Jul 2010 | US |
Child | 12942608 | US |