TECHNICAL FIELD

[0101] The present application relates generally to air conditioning and refrigeration systems and more particularly relates to a microchannel coil manifold system that permits the connection of multiple microchannel coils

BACKGROUND OF THE INVENTION

[0102] Modem air conditioning and refrigeration systems provide cooling. ventilation, and humidity control for all or part of an enclosure such as a building, a cooler, and the like. Generally described, the refrigeration cycle includes four basic stages to provide cooling. First, a vapor refrigerant is compressed within a compressor at high pressure and heated to a high temperature. Second, the compressed vapor is cooled w ithin a condenser by heat exchange with ambient air drawn or blown across a condenser coil by a fan and the like Third, the liquid refrigerant is passed through an expansion device that reduces both the pressure and the temperature of the liquid refrigerant The liquid refrigerant is then pumped within the enclosure to an evaporator The liquid refrigerant absorbs heat from the sun-oundings in an evaporator coil as the liquid refrigerant evaporates to a vapor. Finally, the vapor is returned to the compressor and the cy cle repeats. Various alternatives on this basic refrigeration cycle are known and also may be used herein.

[0103] Traditionally, the heat exchangers used within the condenser and the evaporator have been common copper tube and fin designs. These heat exchanger designs often were simply increased in size as cooling demands increased. Changes in the nature of the refrigerants permitted to be used, however, have resulted in refrigerants with distinct and sometimes insufficient heat transfer characteristics. As a result, further increases in the size and weight of traditional heat exchangers also have been limited w ithin reasonable cost ranges.

[0104] As opposed to copper tube and fin designs, recent heat exchanger designs have focused on the use of aluminum microchannel coils MicroChannel coils generally include multiple flat tubes with small channels therein for the flow of refrigerant. Heat transfer is then maximized by the insertion of angled and/or louvered fins in betw een the flat tubes. The flat tubes are then joined with a number of manifolds. Compared to known copper tube and fin designs, the air passing over the microchannel coil designs has a longer dwell time so as to increase the efficiency and the rate of heat transfer The increase in heat exchanger effectiveness also allows the microchannel heat exchangers to be smaller while having the same or improved performance and the same volume as a conventional heat exchanger. MicroChannel coils thus provide improved heat transfer properties with a smaller size and weight, provide improved durability and serv iceability , improved corrosion protection, and also may reduce the required refrigerant charge by up to about fifty percent (50%).

[0105] MicroChannel coils generally are connected to the refrigeration system as a whole via an assembly or a refrigerant inlet manifold on one side of the coil and an assembly or a refrigerant outlet manifold on the other side. The microchannel coils may be connected in series, in parallel, or combinations thereof. The refrigerant inlet and outlet manifolds, however, should be able to accommodate these various configurations while permitting ease of installation, access, repair, removal, and/or reconfiguration and the like.

[0106] There is a desire therefore for an improv ed microchannel coi! manifold system. Such an improved system should accommodate as many microchannel coils in as many different configurations as may be desired. Preferably, the manifold system may allow the easy reconfiguration of the microchannel coils in the field as well as in the factory .

SUMMARY OF THE INVENTION

(0107J The present application thus provides a microchannel coil manifold system. The microchannel coil manifold system may include a number of assembly inlet manifold sections that terminate in a first stub tube, a number of assembly outlet manifold sections that terminate in a second stub rube, and one or more microchannel coils. Each pair of assembly inlet and outlet manifold sections may be in communication with the one or more microchannel coils.

[0108) The microchannel coil manifold system further may include a coil manifold in communication with each microchannel coil and one of the assembly inlet manifold sections and one of the assembly outlet manifold sections. The coil manifold may include a coil manifold inlet brazed to an assembly inlet manifold section and a coil manifold outlet brazed to an assembly outlet manifold section. Each of the assembly inlet manifold sections and each of the assembly outlet manifold sections may be in communication with a pair of microchannel coils. A number of manifold coils may be used. Each stub tube may include a plug.

[0109] The microchannel coil manifold system further may include a frame with a slot. The microchannel coil may be positioned within the slot and the microchannel coil manifold system may be attached to the frame. The microchannel coil manifold s stem further may include a coil manifold in communication with each microchannel coil The manifold coil may be attached to the frame via a coil attachment. The microchannel coil ma slide within the slot The microchannel coil may include a number of flat microchannel tubes with a number of fins extending therefrom. The microchannel coil may include an extruded aluminum.

[0110] The present application further may provide a method of installing a microchannel coil within a microchannel coil condenser assembly. The method may include the steps of attaching a first assembly inlet manifold section and a first assembly outlet manifold section to the microchannel coil, removing a first stub tube from the first assembly inlet manifold section and a second stub tube from the first assembly outlet manifold section, and attaching the first assembly inlet manifold section and the first assembly outlet section to a second assembly inlet manifold section and a second assembly outlet manifold section

[0111] The method further may include the step of sliding the microchannel coil within a slot of a condenser assembly frame, attaching a coil manifold of the microchannel coil to a first end of the frame v ia a coil attachment, brazing an attachment between the coil manifold of the microchannel coil and the first assembly inlet manifold section and the first assembly outlet section, and installing a number of microchannel coils within the microchannel coil condenser assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

[0112] Fig. 1 is a perspective view of a portion of a microchannel coil as may be used herein. [0113] Fig. 2 is a side cross-sectional view of a portion of the microchannel coil of Fig. 1.

[0114] Fig. 3 is a perspective view of a microchannel condenser assembly as is described herein.

(0115) Fig. 4 is a partial exploded view of a microchannel coil being installed within the microchannel condenser assembly of Fig. 3.

|0U6| Fig. 5 is a partial perspective view of the microchannel coil installed at a first end of the microchannel condenser assembly of Fig. 3.

[0117] Fig. 6 is a partial perspective view of the microchannel coil attached at a second end of the microchannel condenser assembly of Fig. 3.

|01 IS) Fig. 7 is a side plan view of the microchannel coil manifold system as may be described herein.

(0119) Fig. 8 is a top plan view of a microchannel coil condenser assembly with the microchannel coil manifold system of Fig. 7

[0120] Fig 9 is a side plan view of the microchannel coil condenser assembly of

Fig. 8.

DETAILED DESCRIPTION

[0121] Referring now to the drawings, in which like numerals refer to like elements throughout the several views, Figs. I and 2 show a portion of a known microchannel coil 10 similar to that described above Specifically, the microchannel coil 10 may include a number of microchannel tubes 20 with a number of microchannels 25 therein. The microchannel tubes 20 generally are elongated and substantially flat. Each microchannel tube 20 may have any number of microchannels 25 therein. A refrigerant flows through the microchannels 25 in various directions.

(0122] The microchannel tubes 20 generally extend from one or more manifolds 30. The manifolds 30 may be in communication with the overall air-conditioning system as is described above. Each of the microchannel tubes 20 may have a number of fins 40 positioned thereon. The fins 40 may be straight or angled. The combination of a number of small tubes 20 w ith the associated high density fins 40 thus provides more surface area per unit volume as compared to known copper fin and tube designs for improved heat transfer. The fins 40 also may be louvered over the microchannel tubes 20 for an even further increase in surface area. The overall microchannel coil 10 generally is made out of extruded aluminum and the like.

[0123] Examples of known microchannel coils 10 include those offered by Hussmann Corporation of Bridgeton, Missouri; Modine Manufacturing Company of Racine, Wisconsin; Carrier Commercial Refrigeration, Inc. of Charlotte, North Carolina; Delphi of Troy, Michigan; Danfoss of Denmark; and from other sources. The microchannel coils 10 generally may be provided in standard or predetermined shapes and sizes. Any number of microchannel coils 10 may be used together, either in parallel, series, or combinations thereof. Various types of refrigerants may be used herein.

[0124] Fig. 3 shows a microchannel condenser assembly 100 as may be described herein The microchannel condenser assembly 100 may include a number of microchannel coils 1 10. The microchannel coils 1 10 may be similar to the microchannel coil 10 described above or otherwise. Although two (2) microchannel coils 1 10 are shown, a first microchannel coil 120 and a second microchannel coil 130, any number of microchannel coils 1 10 may be used herein. As described above, the microchannel coils 1 10 may be connected in series, in parallel, or otherwise.

[0125] The microchannel coils 1 10 may be supported by a frame 140 The frame 140 may have any desired shape, size, or configuration The frame 140 also may be modular as is described in more detail below. Operation of the microchannel coils 1 10 and the microchannel condenser assembly 100 as a whole may be controlled by a controller 150 The controller 150 may or may not be programmable. A number of fans 160 may be positioned about each microchannel coil 1 10 and the frame 140 The fans 160 may direct a flow of air across the microchannel coils 1 10. Any number of fans 160 may be used herein. Other types of air movement devices also may be used herein. Each fan 160 may be driven by an electrical motor 170. The electrical motor 170 may operate via either an AC or a DC power source The electrical motors 170 may be in communication with the controller 150 or otherwise.

(0126] Fig. 4 shows the insertion of one of the microchannel coils 1 10 into a slot 180 within the frame 140 of the microchannel condenser assembly 100. As is shown and as is described above, the microchannel coil 1 10 includes a number of microchannel tubes 190 in communication with a coil manifold 200. The coil manifold 200 has at least one coil manifold inlet 210 and at least one a coil manifold outlet 220. Refrigerant passes into the microchannel coil 1 10 via the coil manifold inlet 210, passes through the microchannel tubes 190 with the microchannels therein, and exits via the coil manifold outlet 220. The refrigerant may enter as a vapor and exit as a liquid as the refrigerant exchanges heat with the ambient air. The refrigerant also may enter as a liquid and continue to release heat therein.

(0127) The microchannel condenser assembly 100 likewise may include an assembly inlet manifold 230 with an assembly inlet connector 235 and an assembly outlet manifold 240 with an assembly outlet connector 245. The assembly inlet manifold 230 is in communication with the coil manifold 200 v ia the coil manifold inlet 210 and the assembly inlet connector 235 while the assembly outlet manifold 240 is in communication with the coil manifold 200 via the coil outlet manifold 220 and the assembly outlet connector 245. Other connections may be used herein. The assembly manifolds 230, 240 may be supported by one or more brackets 250 or otherwise. The assembly manifolds 230. 240 may be in communication with other elements of the overall refrigeration system as was described above

10128] The coil manifold inlets and outlets 210, 220 and/or the assembly connectors 235, 245 may include stainless steel with copper plating at one end. The coil inlets and outlets 210, 220 and the assembly connectors 235, 245 may be connected via a brazing or welding operation and the like. Because the copper and the aluminum do not come in contact with one another, there is no chance for galvanic corrosion and the like. Other types of fluid-tight connections and/or quick release couplings also may be used herein

[0129] Fig. 5 shows one of the microchannel coils 1 10 installed within the slot 180 of the frame 140 at a first end 185 thereof. As described above, the coil manifold 200 may be in communication with the assembly inlet and outlet manifolds 230, 240. The coil manifold 200 also may be attached to the frame 140 at the first end 185 via a coil attachment 260. The coil attachment 260 may include a clamp 265 that surrounds the coil manifold 200 and is secured to the frame 140 via screws, bolts, other types of fasteners, and the like. Other shapes may be used herein. A rubber or polymeric bushing 270 also may be used between the manifold 200 and the clamp 265 so as to dampen any vibrations therein. Other types of isolation means may be used herein. [0130] Fig. 6 shows the opposite end of the microchannel coil 1 10 as installed within the slot 180 at a second end 275 of the frame 140. The slot 180 may extend for the length of the frame 140 or otherwise The microchannel coil 1 10 may slide along the slot 180. Alternatively, wheels and/or other types of motion assisting devices may be used herein. The microchannel coil 1 10 may be held in place via a rear bracket or a tab 290 The rear bracket 290 may be any structure that secures the microchannel coil 1 10 in place. The rear bracket 290 may be secured to the back of the frame 140 once the microchannel coil 1 10 has been slid therein. Other types of attachment means and/or fasteners may be used herein.

[0131 ] Fig. 7 shows a microchannel coil manifold system 300 as is described herein. As is shown, the microchannel coil manifold system 300 may include the coil manifold 200 as well as the assembly inlet manifold 230 and the assembly outlet manifold 240. In this case, the assembly inlet manifold 230 may include a number of assembly inlet manifold sections 310. Each of the assembly inlet manifold sections 310 may include a number of stub tubes, a first end stub tube 320 and a second end stub tube 330. Each stub tube 320, 330 may be positioned at an end of each manifold section 310 and generally adjacent to the assembly inlet and outlet connectors 235, 245. Other positions may be used herein. The stub tubes 320. 330 may enclose each end of the manifold section 310 as is shown. A stopper such as a plug 335 or other type of enclosing means also may be used herein. Likewise, the microchannel coil manifold sy stem 300 also may include a number of assembly outlet manifold sections 34 The assembly outlet manifold sections 340 also each may include a first stub tube 350 and a second end stub tube 360.

|0132J In use, one end of each assembly manifold 230, 240 of the microchannel coil manifold system 300 will be connected to the refrigeration system as a whole and the other end will terminate at a stub tube 320, 330, 350. 360 Other configurations may be used herein.

[0133] As is shown in Figs. 8 and 9, the microchannel coil condenser assembly 100 may include as many microchannel coils 1 10 as may be desired. Through the use of the microchannel coil manifold system 300, the stub tubes 320, 330 of the assembly inlet manifold section 310 may be removed and additional assembly inlet manifold sections 310 may be connected thereto. Likewise, the stub tubes 350, 360 of the assembly outlet manifold section 340 may be remov ed and additional assembly outlet manifold sections 340 may be connected as desired. The additional microchannel coils 1 10 then may be connected to the assembly manifold sections 310, 340 as is described above. The frame 140 may be modular in construction so as to accommodate the addition or removal of the microchannel coils 1 10.

[0134] Not only does the use of the microchannel coil manifold system 300 allow for the connection of as many microchannel coils 1 10 as may be desired, but the combination of the microchannel manifold sy stem 300 and the ability to slide the microchannel coils 1 10 into the frame 140 via the slot 180 further provides ease of access for installation, removal, and repair. Moreover, the microchannel condenser assembly 1 0 as a whole may be more compact given the use of manifolding only on one side of the microchannel coils 1 10. Further, although the microchannel coils 1 10 are positioned on one side of the microchannel coil manifold system 300, the microchannel coils 1 10 themselv es may be positioned on both sides of the microchannel coil system 300 if desired, providing an even more compact system as a whole.