BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a prior art A-coil heat exchanger;
FIG. 2 is a perspective view of an A-coil heat exchanger in accordance with an embodiment of the present invention;
FIG. 3 is an end elevation view of the A-coil heat exchanger of FIG. 2;
FIG. 4 is a side elevation view of the A-coil heat exchanger of FIG. 2;
FIG. 5 is a top plan view of the A-coil heat exchanger of FIG. 2; and
FIG. 6 is a perspective view of a header component used in the heat exchanger of FIG. 2.
BEST MODE FOR CARRYING OUT THE INVENTION
The best mode for carrying out the invention will now be described with reference to the accompanying drawings. Like parts are marked in the specification and drawings with the same respective reference numbers. In some instances, proportions may have been exaggerated in order to depict certain features of the invention.
Referring now to FIGS. 2-6, an A-coil heat exchanger 30 is comprised of first and second coil slabs 32, 34 that are coupled together at respective ends thereof by a connector plate 36 and are in divergent relationship to define a generally “A” shape. Each slab 32, 34 has plural heat transfer fluid carrying tubes 38, which are laced through a plurality of fins 40. Tubes 38 each have an internal passageway to accommodate the flow of a first heat transfer fluid (e.g., a vapor compression refrigerant) therethrough. Fins 40 are in parallel, closely spaced relationship and cooperate with tubes 38 to provide multiple paths for a second heat transfer fluid (e.g., air to be cooled) to flow across heat exchanger 30 on the outside of tubes 38. Heat is transferred from the second heat transfer fluid to the first heat transfer fluid.
Four rows of tubes 38 (two rows on each slab 32,34) are shown in FIG. 1, by way of example. One skilled in the art will recognize that the number of tube rows may be greater or less than two. Each tube row defines a discrete fluid circuit, with each circuit comprising multiple passes through the corresponding slab 32, 34. Return bends 42 connect distal ends of adjacent tubes 38. Tubes 38 penetrate through end plates 44 at the opposed ends of each slab 32,34. Only one end plate 44 is shown on each slab 32, 34 in FIG. 1.
As will be described in greater detail hereinbelow, a first pair of adapter tubes 46 and a second pair of adapter tubes 47 connect the outlets of the respective tube circuits to an outlet header 48 in fluid communication with the suction side of a compressor (not shown) when heat exchanger 30 is used in a vapor compression air conditioning or refrigeration system. When heat exchanger 30 is oriented for horizontal air flow, as shown in FIGS. 2-5, slabs 32, 34 are coupled together by connector plate 36 along a vertical axis. Header 48 is positioned with respect to the coupled ends of slabs 32, 34, such that no portion of header 48 would be located in a horizontal air stream flowing through slabs 32,34. Although not shown in FIGS. 2-5, heat exchanger 30 also includes plural distributor tubes connecting the inlets of the respective tube circuits to an inlet header in fluid communication with the discharge side of the compressor. A drain pan (not shown) is preferably positioned under heat exchanger 30 to collect condensate runoff.
In operation, when heat exchanger 30 is used as an evaporator, the refrigerant enters heat exchanger 30 through the distributor tubes in substantially liquid form, makes multiple passes through heat exchanger 30 in each tube circuit, is substantially vaporized in heat exchanger 30 and exits heat exchanger 30 through adapter tubes 46, 47. Further, when heat exchanger 30 is oriented in a “horizontal coil” configuration, as shown in FIGS. 2-5, air or other fluid to be cooled flows horizontally into the region between slabs 32, 34 and horizontally outwardly through both slabs 32, 34, as indicated by arrows 49, whereby the air or other fluid is cooled.
As can be best seen in FIG. 6, header 48 defines the general shape of a two-pronged fork and is comprised of a main body section 50 and first and second tubular branches 52, 54 depending therefrom. Branches 52, 54 are in parallel relationship. Respective major axes of main body section 50 and tubular branches 52, 54 are oriented along respective vertical axes parallel to the vertical axis along which slabs 32,34 are coupled together. Main body section 50 has a flared open end 50a, which is adapted to connect header 48 to a compressor suction line (not shown). An opposite end of main body section 50 is defined by a bulbous portion 50b containing first and second sockets (not shown) in which respective open ends of first and second tubular branches 52,54 are received. The respective opposite ends of tubular branches 52, 54 are closed. First tubular branch 52 is in fluid communication with first coil slab 32 by means of adapter tubes 46, which extend horizontally outwardly from first tubular branch 52 along respective axes that are perpendicular to the major axis of first tubular branch 52. Second tubular branch 54 is in fluid communication with second coil slab 34 by means of adapter tubes 47, which extend horizontally outwardly from second tubular branch 54 along respective axes that are perpendicular to the major axis of second tubular branch 54.
Adapter tubes 46 are in divergent relationship with respect to adapter tubes 47, corresponding to the divergent relationship between slabs 32 and 34. Further, the two tubes 46 are stacked vertically one above the other and the two tubes 47 are stacked vertically one above the other, so that each adapter tube 46, 47 defines a generally straight section of conduit between the corresponding tubular branch 52, 54 and the corresponding coil slab 32, 34. One skilled in the art will recognize that the aforementioned configuration of adapter tubes 46,47 eliminates the need for one or more bends in the adapter tubes characterized by prior art A-coil heat exchangers.
As can be best seen in FIG. 3, main body section 50 and first and second branches 52,54 are oriented vertically and extend generally parallel to a vertical axis along which first and second coil slabs 32, 34 are coupled by connector plate 36. Header 48 is located with respect to coil slabs 32, 34 such that when heat exchanger 30 is positioned in a horizontal air stream, header 48 is substantially isolated from air flowing through first and second coil slabs 32, 34.
The best mode for carrying out the invention has now been described in detail. Since changes in and modifications to the above-described preferred embodiment may be made without departing from the nature, spirit and scope of the invention, the invention is not to be limited to said details, but only by the appended claims and their equivalents.