Patent Application
20100132917
The invention relates to heat exchanger assemblies, particularly to an A-frame heat exchanger assembly that offers improved packing density and ease of assembly.
Heat exchangers are commonly used in heating, air conditioning, or refrigeration equipment to transfer heat between air and a working fluid. The use of heat exchangers in an A-frame configuration to improve heating or cooling capacity in a given equipment volume is well known. In an A-frame configuration, two generally flat heat exchanger core portions are arranged so that in an edge view the portions resemble a letter “A” (or an inverted “V”), with the portions coming together at the apex and spread apart from each other at the base.
Actual fabrication of such an A-frame structure may be achieved in a number of ways. One approach is to start with a planar heat exchanger core section having a length equal to the entire length of both legs of the A, and bend the section partially upon itself at the apex to form the A shape. A second approach is to fabricate the A-frame structure by brazing two planar core sections at the appropriate angle to a common manifold that forms the apex of the A. A third approach may be to mount two individual planar core sections to a bracket that affixes the sections at the desired angle at the apex using appropriate mounting hardware.
Typically, the heat exchanger is manufactured in one location and shipped to a different location (hereafter referred to as the “customer location”) where it is installed in the heating or cooling equipment. For this reason, it is desirable to maximize the packaging density of the heat exchanger assembly for efficient transport. Each of the aforementioned approaches to forming an A-frame configuration presents challenges to achieving desirable packaging density.
Bending flat sections to form the A-frame requires specialized equipment to bend the core section with an appropriate bend radius to avoid damaging the core. It is generally not economically feasible to install such bending equipment at the customer location. This necessitates bending the heat exchanger core at one location and shipping a preformed A-frame structure, which does not have optimal packaging density, to the customer location.
Forming the A-frame structure by brazing two planar core sections at the appropriate angle to a common manifold that forms the apex of the A would be very difficult to do with a conventional braze oven. This also necessitates fabricating the heat exchanger assembly in a different location and shipping a preformed A-frame structure whose packaging density is not optimal.
Assembling two planar core sections to a bracket that affixes the sections to each other at the desired angle can be done before shipping the assembly to the customer location also results in shipping a pre-formed A-frame structure whose packaging density is not optimal. Alternatively, the core sections, brackets, and required mounting hardware can be assembled at the customer location. While this may improve packaging density for shipping the components, it adds labor at the customer location, as well as complicating supply chain management and inventory control.
What is desired is an A-frame heat exchanger structure that can be packaged efficiently for shipment to a customer location, and then easily deployed to the desired A-frame configuration at the customer location.
A heat exchanger assembly comprises a pair of generally rectangular heat exchanger cores. Each core has a pair of opposed, parallel, substantially cylindrical manifold tanks. In a shipping position, the cores are oriented face to face, with the manifold tanks in adjacent, aligned pairs. In an operative position, the cores are oriented in an A-frame configuration with one pair of tanks remaining adjacent at the apex of the A and the other two tanks spread apart at the base of the A.
The heat exchanger assembly additionally comprises a tank attachment bracket at the apex of the A. This bracket has a gripping portion that conforms to a sufficient portion of one pair of tanks to maintain them in the adjacent position during shipping. At least one of the tanks at the apex can rotate within the gripping portion of the bracket as the pair of tanks at the base of the A is spread apart to the operative position.
Further features and advantages of the invention will appear more clearly on a reading of the following detailed description of exemplary embodiments of the invention, which is given by way of non-limiting example only and with reference to the accompanying drawings.
This invention will be further described with reference to the accompanying drawings in which:
In accordance with an exemplary embodiment of this invention, referring to
Still referring to
The rotational range of one or both of tanks 16, 22 within the bracket 32 also includes an operative position, as shown in
As shown in detail in
In the embodiment previously described, both of the tanks 16 and 22 are rotatable within bracket 32 to allow the assembly to assume a shipping position or alternatively an operative position. In an alternative embodiment of this invention, one of the tanks 16, 22 may be non-rotatably affixed to bracket 32, and the other of tanks 16, 22 may be rotatable through an angular range including both the shipping position and the operative position.
While the manifold tanks 16 and 22 have been previously described as substantially cylindrical, this description is not intended to limit this invention to tanks having a circular cross sectional shape. In the context of this disclosure, the term substantially cylindrical is construed to include non-circular cross sectional shapes, for example elliptical, polygonal, and polygonal with rounded vertices.
In the case of a non-circular cross sectional shape for tanks 16, 22, the radial asymmetry of the cross sectional shape may be used to advantage to urge the tanks into a preferred position. For example, the gripping portion of bracket 32 may be disposed to cooperate with the outer surface of tanks 16, 22 to produce a detent torque that urges the tanks into either the shipping position or the operative position and resists rotation of the tanks out of those preferred positions.
Additionally, it is not necessary to maintain the same cross sectional shape of the tanks 16, 22 over their entire length. It may, for example, be preferable for the tanks 16, 22 to have a polygonal cross sectional shape in the portions where the tanks interface with the gripping portions of bracket 32, and to have a circular cross sectional shape over the remainder of the length of the tanks to conform to the non-gripping portion of the bracket 32, thereby facilitating sealing to impede the flow of air through the apex of the A-frame assembly in the operative position.
While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow.
