CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Application No. 63/365,517, filed May 31, 2022, the entirety of which is hereby incorporated by reference.

TECHNICAL FIELD

[0002] The present disclosure relates, in general, to an air handler and, more specifically relates, to an air handler having a round tube plate fin heat exchanger.

BACKGROUND

[0003] Air handlers are used to supply large volumes of conditioned air to an enclosed space, such as living spaces or work spaces in commercial environments. The large volumes of conditioned air, much of which may be recycled, are supplied and removed with large air movers, such as fans within the air handler. Further, the conditioned air must be supplied to the enclosed space by the air handler at a minimum pressure. For the purpose of conditioning, the air is drawn by the fan across a heat exchanger, such as an evaporator coil. The air flowing across refrigerant tubes of the heat exchanger exchanges heat with refrigerant flowing through the refrigerant tubes. In order to achieve a maximum heat transfer between the air and the refrigerant tubes, pressure of the refrigerant flowing through the refrigerant tubes may need to be regulated.

SUMMARY

[0004] According to one aspect of the present disclosure, an air handler is disclosed. The air handler includes a cabinet and a plurality of refrigerant tubes, where each refrigerant tube has a diameter of 7 mm. The air handler includes a V -shaped round tube plate fin heat exchanger disposed within the cabinet and including a plurality of louvered fins. Each louvered fin defines a plurality of holes configured to receive the refrigerant tubes. The plurality of holes defines a linear offset configuration of the louvered fin. The air handler further includes an axial fan housing disposed within the cabinet and located downstream of the V-shaped round tube plate fin heat exchanger, a distributor in fluid communication with the refrigerant tubes, and a plurality of feeder tubes extending between the distributor and the refrigerant tubes. Each feeder tube is configured to allow flow of refrigerant therethrough.

[0005] In an embodiment, the linear offset configuration of the plurality of holes includes a first set of holes defined along a first axis, a second set of holes defined along a second axis, and a third set of holes are defined along a third axis. The second set of holes are offset from the first set of holes along a longitudinal axis of the louvered fin and the third set of holes are offset from the second set of holes along the longitudinal axis of the louvered fin. Each of the first axis, the second axis, and the third axis extends substantially parallel to the longitudinal axis of the louvered fin. A first offset distance defined between the second set of holes and the first set of holes is greater than a second offset distance defined between the third set of holes and the second set of holes. The second set of holes and the third set of holes define a substantially obtuse trapezoidal matrix.

[0006] In an embodiment, each of two opposite wider angles of the obtuse trapezoidal matrix is in a range of about 95 degrees to about 105 degrees.

[0007] In an embodiment, a length of each feeder tube is in a range of 20 inches to 30 inches.

[0008] In an embodiment, a ratio of sum of pressure drops across the distributor and across the feeder tube to the pressure drop across the V-shaped round tube plate fin heat exchanger is in a range of about 6 to 7.

[0009] In an embodiment, a ratio of sum of pressure drops across the distributor and across the feeder tube to the pressure drop across the V-shaped round tube plate fin heat exchanger is 3.

[0010] In an embodiment, each of the plurality of holes forms an interference fit with an outer surface of the refrigerant tube passing therethrough.

[0011] In an embodiment, each of the plurality of louvered fins defines at least one cropped comer.

[0012] In an embodiment, the axial fan housing is disposed vertically above the V- shaped evaporator coil.

[0013] These and other aspects and features of non-limiting embodiments of the present disclosure will become apparent to those skilled in the art upon review of the following description of specific non-limiting embodiments of the disclosure in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] A better understanding of embodiments of the present disclosure (including alternatives and/or variations thereof) may be obtained with reference to the detailed description of the embodiments along with the following drawings, in which:

[0015] FIG. 1 is a perspective view of an air handler, according to an embodiment of the present disclosure;

[0016] FIG. 2 is a perspective view of a heat exchanger of the air handler of FIG. 1, according to an embodiment of the present disclosure;

[0017] FIG. 3A is a front view of a louvered fin of the heat exchanger, according to an embodiment of the present disclosure;

[0018] FIG. 3B is an enlarged view of a portion “B” in FIG. 3A, according to an embodiment of the present disclosure; and

[0019] FIG. 4 is a front view of a louvered fin, according to another embodiment of the present disclosure.

DETAILED DESCRIPTION

[0020] Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Wherever possible, corresponding, or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts. Moreover, references to various elements described herein, are made collectively or individually when there may be more than one element of the same ty pe. However, such references are merely exemplary in nature. It may be noted that any reference to elements in the singular may also be constmed to relate to the plural and vice-versa without limiting the scope of the disclosure to the exact number or type of such elements unless set forth explicitly in the appended claims.

[0021] Although various aspects of the disclosed technology are explained in detail herein, it is to be understood that other aspects of the disclosed technology are contemplated. Accordingly, it is not intended that the disclosed technology is limited in its scope to the details of construction and arrangement of components expressly set forth in the following description or illustrated in the drawings. The disclosed technology can be implemented and practiced or carried out in various ways. Accordingly, when the present disclosure is described as a particular example or in a particular context, it will be understood that other implementations can take the place of those referred to.

[0022] It should also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. References to a composition containing “a” constituent is intended to include other constituents in addition to the one named.

[0023] Also, in describing the disclosed technology, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.

[0024] Ranges may be expressed herein as from “about” or “approximately” or “substantially” one particular value and/or to “about” or “approximately” or “substantially” another particular value. When such a range is expressed, the disclosed technology can include from the one particular value and/or to the other particular value. Further, ranges described as being between a first value and a second value are inclusive of the first and second values. Likewise, ranges described as being from a first value and to a second value are inclusive of the first and second values.

[0025] It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Moreover, although the term “step” can be used herein to connote different aspects of methods employed, the term should not be interpreted as implying any particular order among or between various steps herein disclosed unless and except when the order of individual steps is explicitly required. Further, the disclosed technology does not necessarily require all steps included in the methods and processes described herein. That is, the disclosed technology includes methods that omit one or more steps expressly discussed with respect to the methods described herein.

[0026] Herein, the use of terms such as “having,” “has,” “including,” or “includes” are open-ended and are intended to have the same meaning as terms such as “comprising” or “comprises” and not preclude the presence of other structure, material, or acts. Similarly, though the use of terms such as “can” or “may” are intended to be open-ended and to reflect that structure, material, or acts are not necessary, the failure to use such terms is not intended to reflect that structure, material, or acts are essential. To the extent that structure, material, or acts are presently considered to be essential, they are identified as such.

[0027] The components described hereinafter as making up various elements of the disclosed technology are intended to be illustrative and not restrictive. Many suitable components that would perform the same or similar functions as the components described herein are intended to be embraced within the scope of the disclosed technology'. Such other components not described herein can include, but are not limited to, similar components that are developed after development of the presently disclosed subject matter.

[0028] Referring to FIG. 1, a perspective view of an air handler 100 is illustrated. The air handler 100 includes a cabinet 102. A body cover 104 is shown detached from the cabinet 102 to illustrate internal components of the air handler 100. A lower portion of the cabinet 102 houses a V-shaped round tube plate fin heat exchanger 106. In some aspects, the V-shaped round tube plate fin heat exchanger 106 (hereinafter referred to as “the coil 106”) may be implemented as an evaporator coil. The air handler 100 includes an axial fan housing 108 disposed within the cabinet 102. Particularly, the axial fan housing 108 is disposed vertically above and downstream of the coil 106 with respect to an airflow passage. A support plank 110 fastened to edges of the cabinet 102 may be provided and configured to support the axial fan housing 108 within the cabinet 102. The axial fan housing 108 is configured to house an axial fan 112.

[0029] FIG. 2 illustrates a perspective view of the coil 106 within the cabinet 102. The coil 106 includes a first arm 202 and a second arm 204. The air handler 100 includes a multiple circuits of refrigerant tubes 206, a distributor 208 in fluid communication with the refrigerant tubes 206, and multiple feeder tubes 210 extending between the distributor 208 and the refrigerant tubes 206. The feeder tubes 210 are configured to allow flow of refrigerant therethrough, thereby supplying the refrigerant from the distributor 208 to the refrigerant tubes 206 in each of the first arm 202 and the second arm 204 of the coil 106. According to an aspect of the present disclosure, each refrigerant tube 206 has a diameter of 7 mm and a predetermined thickness to minimize development of hoop stress therein. In an embodiment, a length of each feeder tube is in a range of 20 inches to 30 inches. The coil 106 includes multiple refrigerant tube circuits to reduce a refrigerant mass flux per refrigerant circuit. [0030] According to an aspect, a ratio of sum of pressure drops across the distributor 208 and across the feeder tubes 210 to the pressure drop across the coil 106 is maintained in a predetermined range. In an embodiment, the ratio may be in a range of 3 to 7, or any ratios therebetween. In a particular embodiment, the ratio is 3. In another embodiment, the ratio is 6. It will be understood to a person skilled in the art that the distributor 208 includes an orifice (not shown). Pressure drop across the distributor 208 refers a pressure drop across the orifice thereof. For example, the pressure drop across the distributor 208 may be 20 units and the pressure drop across the feeder tubes 210 may be 4 units. So, the sum of pressure drops across the distributor 208 and across the feeder tubes 210 is 24 units. The pressure drop through the coil 106 may be 4 units. Therefore, the ratio would be 24/4 = 6, which is acceptable. Similarly, certain design parameters of the distributor 208, the feeder tubes 210, and number of refrigerant tube circuits in the coil 106 may be predefined so that the pressure drops across the distributor 208, the feeder tubes 210, and the coil 106 may be adjusted to achieve preferable ratio values. In some aspects, more pressure drop may be created in the feeder tubes 210 as part of the expansion of the refrigerant, to ensure minimum impact on performance of the coil 106 due to air maldistribution effects.

[0031] FIG. 3A illustrates a front view of a louvered fin 300 (hereinafter referred to as “the fin 300”). According to an embodiment of the present disclosure, the coil 106 includes multiple fins 300 stacked together to constitute the first arm 202 and the second arm 204 thereof. The fin 300 includes a leading edge 302 and a trailing edge 304 opposite to the leading edge 302. As used herein, the term “leading edge” refers to a feature of the fin 300 that is upstream with respect to a direction of flow of air across the fin 300 and the term “trailing edge” refers to a feature of the fin 300 that is relatively downstream with respect to the direction of flow of air across the fin 300. These terminologies are well known in the art of fins, for example heat exchanger fins. The fin 300 further includes a surface 306 extending between the leading edge 302 and the trailing edge 304. Preferably, the surface 306 is wavy in structure. As used herein, the term “wavy” refers to a structure of the fin 300 including adjacent concave and convex portions, or multiple crests and troughs, along a width “W” of the fin 300. According to an aspect of the present disclosure, multiple fins, each having a configuration described below, are stacked to constitute a heat exchanging medium of the coil 106.

[0032] The surface 306 of the fin 300 defines a plurality of holes that form a linear offset configuration. The linear offset configuration includes a first set of holes 308, a second set of holes 310, and a third set of holes 312. Each of the plurality of holes is configured to allow the refrigerant tubes 206 to pass therethrough. The phrase “set of holes” may be alternatively referred and understood as “row of holes”. In an embodiment, each hole of the first set of holes 308, the second set of holes 310, and the third set of holes 312 is forms an interference fit with an outer surface of the refrigerant tube 206 passing therethrough. According to an aspect of the present disclosure, the fin 300 preferably includes three rows of holes as illustrated in FIG. 3A. The first set of holes 308 are defined along a first axis “Al” located proximal to the leading edge 302 of the fin 100.

[0033] The second set of holes 310 are defined along a second axis “A2” and are offset from the first set of holes 308 along a longitudinal axis “L” of the fin 300. The second axis “A2” extends along the longitudinal axis “L” and is located between the first axis “Al” and the trailing edge 304. For the purpose of brevity, the second axis “A2” is shown coinciding with the longitudinal axis “L”.

[0034] The third set of holes 312 are defined along a third axis “A3” that is located proximal to the trailing edge 304 of the fin 300. Each of the first axis “Al”, the second axis “A2”, and the third axis “A3” extends substantially parallel to the longitudinal axis “L” of the fin 300. The third set of holes 312 are offset from the second set of holes 310 along the longitudinal axis “L” of the fin 300. The second set of holes 310 are offset at a first offset distance “DI” from the first set of holes 308 and the third set of holes 312 are offset at a second offset distance “D2” from the first set of holes 308. Preferably, the second offset distance “D2” is less than the first offset distance “DI”. For the purpose of the present disclosure, the offset distances are calculated with respect to centers of the holes as indicated in FIG. 3A.

[0035] FIG. 3B illustrates an enlarged view of a portion “B” of FIG. 3A, according to an embodiment of the present disclosure. As can be seen from FIG. 3B, the third set of holes 312 are offset from the second set of holes 310 along the longitudinal axis “L”. As such, the second set of holes 310 and the third set of holes 312 define a substantially obtuse trapezoidal matrix. An obtuse trapezoid refers to a geometric shape including one acute angle and one obtuse angle defined on a base thereof. For example, centers “Cl” of a first hole 310-1, “C2” of a second hole 310-2, “C3” of a third hole 312-1, and “C4” of a fourth hole 312-2 define vertices of the obtuse trapezoid. Line segments “SI” extending between “Cl” and “C2”, “S2” extending between “C2” and “C3”, “S3” extending between “C3” and “C4”, and “S4” extending between “C4” and “Cl” define sides of the obtuse trapezoid. Line segments “SI” and “S4” define an acute angle “01”, “SI” and “S2” define an obtuse angle “92”, and similarly “S3” and “S4” define an obtuse angle “04”. As such, “02” and “04” are two opposite wider angles of the obtuse trapezoid. In an embodiment, each of the two opposite wider angles of the obtuse trapezoid is in a range of about 95 degrees to about 105 degrees. Similarly, adjacent set of four holes define another obtuse trapezoid. As such, owing to the offset, the second set of holes 310 and the third set of holes 312 define an array of obtuse trapezoids along the longitudinal axis “L” of the fin 300, which together constitutes the obtuse trapezoidal matrix.

[0036] FIG. 4 illustrates a front view of a louvered fin 400, according to another embodiment of the present disclosure. Preferably, two fins 400A and 400B may be die stamped on an aluminum sheet to achieve the design illustrated in FIG. 4. Further, the fin 400A may be separated from the fin 400B, by known means, along a line of contact “Yl”. Upon separation, multiple such fins may be disposed adjacent to each other and may be stacked together with refrigerant tubes 206 to constitute the first arm 202 and the second arm 204 of the coil 106. Each of the fins 400 A, 400B includes three rows of holes defined between cropped comers 402, 404, and gagged regions 406 around holes defined proximal to the cropped comers 402, 404. For the purpose of brevity, configuration of the fin 400A is described herein. A first row of holes 408 is defined along a first axis “A4”, a second row of holes 410 is defined along a second axis “A5”, and a third row of holes 412 is defined along a third axis “A6” Each axis extends substantially parallel to a longitudinal axis of the fin 400A. The second row of holes 410 are offset from the first row of holes 408 in a direction along a length of the fin 400A, and the third row of holes 412 are offset from the second row of holes 410 in the direction along the length of the fin 400A. The second row of holes 410 and the third row of holes define a substantially obtuse trapezoidal matrix. For the purpose of illustration, one obtuse trapezoid “Tl” is indicated in fin 400A. Interior angles each obtuse trapezoid formed in the fin 400A may preferably be equal to those described with respect to FIG. 3B.

[0037] To this end, a combination of the V-shaped round tube plate fin heat exchanger 106, the refrigerant tubes 206 of 7 mm diameter, and the linear offset configuration of the holes defined in the louvered fin 300, 400 allows for enhanced heat transfer across the coil 106. By adjusting the pressure drops across the distributor 208 and the feeder tubes 210, momentum effects of the refrigerant flowing through the feeder tubes 210 and the refrigerant tubes 206 in the coil 106 may be greater than effects of gravity downstream of the flow of the refrigerant. As such, the coil 106 may funchon in a multi-poise manner and may be rendered immune to the effects of gravity that impacts the performance of the coil 106. Additionally, the length of the feeder tubes 210 can be adjusted in order to maintain pressure drop across the distributor 208 to a minimum of 3 units as described earlier. The distributor 208 is located at a predetermined height between the first arm 202 and the second arm 204 of the coil 106. Due to such location of the distributor 208, the refrigerant flowing through the feeder tubes 210 does not require any energy to be supplied to cause the flow. This allows a greater pressure drop to be created through the feeder tubes 210 due to the expansion of the refrigerant flowing therethrough. Thus, impact on the performance of the coil 106 due to air maldistribution effects may be minimized.

[0038] While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.

[0039] Embodiment 1 may include an air handler comprising: a cabinet; a plurality of refrigerant tubes, each refrigerant tube having a diameter of 7 mm; a V-shaped round tube plate fin heat exchanger disposed within the cabinet and comprising a plurality of louvered fins, wherein each louvered fin defines a plurality of holes configured to receive the refrigerant tubes, and wherein the plurality of holes defines a linear offset configuration of the louvered fin; an axial fan housing disposed within the cabinet and located do m stream of the V-shaped round tube plate fin heat exchanger; a distributor in fluid communication w ith the refrigerant tubes; and a plurality of feeder tubes extending between the distributor and the refrigerant tubes, each feeder tube configured to allows flow of refrigerant therethrough.

[0040] Embodiment 2 may include Embodiment 1, wherein the linear offset configuration of the plurality of holes comprises: a first set of holes defined along a first axis; a second set of holes defined along a second axis, wherein the second set of holes are offset from the first set of holes along a longitudinal axis of the louvered fin; and a third set of holes defined along a third axis, wherein the third set of holes are offset from the second set of holes along the longitudinal axis of the louvered fin, and wherein a first offset distance defined between the second set of holes and the first set of holes is greater than a second offset distance defined between the third set of holes and the second set of holes, wherein each of the first axis, the second axis, and the third axis extends substantially parallel to the longitudinal axis of the louvered fin, and wherein the second set of holes and the third set of holes define a substantially obtuse trapezoidal matrix.

[0041] Embodiment 3 may include any one of Embodiments 1 to 2, wherein each of two opposite wider angles of the obtuse trapezoidal matrix is in a range of about 95 degrees to about 105 degrees.

[0042] Embodiment 4 may include any one of Embodiments 1 to 3, wherein a length of each feeder tube is in a range of 20 inches to 30 inches.

[0043] Embodiment 5 may include any one of Embodiments 1 to 4, wherein a ratio of sum of pressure drops across the distributor and across the feeder tube to the pressure drop across the V-shaped round tube plate fin heat exchanger is in a range of about 3 to 7.

[0044] Embodiment 6 may include any one of Embodiments 1 to 5, wherein a ratio of sum of pressure drops across the distributor and across the feeder tube to the pressure drop across the V-shaped round tube plate fin heat exchanger is 3.

[0045] Embodiment 7 may include any one of Embodiments 1 to 6, wherein each of the plurality of holes forms an interference fit with an outer surface of the refrigerant tube passing therethrough.

[0046] Embodiment 8 may include any one of Embodiments 1 to 7, wherein each of the plurality of louvered fins defines at least one cropped comer.

[0047] Embodiment 9 may include any one of Embodiments 1 to 8, wherein the axial fan housing is disposed vertically above the V-shaped round tube plate fin heat exchanger.

[0048] Embodiment 10 may include a heating, ventilation, and air conditioning (HVAC) system comprising: a plurality of refrigerant tubes; a V-shaped round tube plate fin heat exchanger comprising a plurality of louvered fins, wherein each louvered fin defines a plurality of holes configured to receive the refrigerant tubes, and wherein the plurality of holes defines a linear offset configuration of the louvered fin; an axial fan housing disposed downstream of the V-shaped round tube plate fin heat exchanger; a distributor in fluid communication with the refrigerant tubes; and a plurality of feeder tubes extending between the distributor and the refrigerant tubes, each feeder tube configured to allow flow of refrigerant therethrough. [0049] Embodiment 11 may include Embodiment 10, wherein the linear offset configuration of the plurality of holes comprises: a first set of holes defined along a first axis; a second set of holes defined along a second axis, wherein the second set of holes are offset from the first set of holes along a longitudinal axis of the louvered fin; and a third set of holes defined along a third axis, wherein the third set of holes are offset from the second set of holes along the longitudinal axis of the louvered fin, and wherein a first offset distance defined between the second set of holes and the first set of holes is greater than a second offset distance defined between the third set of holes and the second set of holes.

[0050] Embodiment 12 may include any one of Embodiments 10 to 11, wherein each of the first axis, the second axis, and the third axis extends substantially parallel to the longitudinal axis of the louvered fin, and wherein the second set of holes and the third set of holes define a substantially obtuse trapezoidal matrix.

[0051] Embodiment 13 may include any one of Embodiments 10 to 12, wherein each of two opposite wider angles of the obtuse trapezoidal matrix is in a range of about 95 degrees to about 105 degrees.

[0052] Embodiment 14 may include any one of Embodiments 10 to 13, wherein a length of each feeder tube is in a range of 20 inches to 30 inches.

[0053] Embodiment 15 may include any one of Embodiments 10 to 14, wherein a ratio of sum of pressure drops across the distributor and across the feeder tube to the pressure drop across the V-shaped round tube plate fin heat exchanger is in a range of about 3 to 7.

[0054] Embodiment 16 may include any one of Embodiments 10 to 15, wherein a ratio of sum of pressure drops across the distributor and across the feeder tube to the pressure drop across the V-shaped round tube plate fin heat exchanger is 3.

[0055] Embodiment 17 may include any one of Embodiments 10 to 16, wherein each of the plurality of holes forms an interference fit with an outer surface of the refrigerant tube passing therethrough.

[0056] Embodiment 18 may include any one of Embodiments 10 to 17, wherein each of the plurality of louvered fins defines at least one cropped comer.

[0057] Embodiment 19 may include any one of Embodiments 10 to 18, wherein the axial fan housing is disposed vertically above the V-shaped round tube plate fin heat exchanger. [0058] Embodiment 20 may include an HVAC system comprising: an outdoor unit; and an air handler comprising: a plurality of refrigerant tubes; a V-shaped round tube plate fin heat exchanger comprising a plurality of louvered fins, wherein each louvered fin defines a plurality of holes configured to receive the refrigerant tubes, and wherein the plurality of holes defines a linear offset configuration of the louvered fin; an axial fan housing disposed downstream of the V-shaped round tube plate fin heat exchanger; a distributor in fluid communication with the refrigerant tubes; and a plurality of feeder tubes extending between the distributor and the refrigerant tubes, each feeder tube configured to allow flow of refrigerant therethrough.