Heat Exchanger with Fluted Fin

Abstract

A heat exchanger used in a heating, ventilation, and/or air conditioning (HVAC) system may include a first row of substantially parallel tubes and a second row of substantially parallel tubes disposed downstream of the first row of tubes, where the first row of tubes and the second row of tubes are disposed through a pattern of holes in a plate-like fin that may include a notch on a leading edge of the fin. The notch may be disposed between adjacent tubes in the first row and substantially aligned with a tube in the second row of tubes with respect to an airflow travelling in a primary airflow direction across the fin. The notch may serve to increase the amount of heat exchange and/or the heat exchange efficiency between the incoming airflow and the second row of tubes.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority under 35 U.S.C. 119(e) to U.S. Provisional Patent Application No. 61/933,264 filed on Jan. 29, 2014 by Mark Eldo Groskreutz and entitled "Heat Exchanger with Fluted Fin," the disclosure of which is hereby incorporated by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not applicable.

REFERENCE TO A MICROFICHE APPENDIX

[0003] Not applicable.

BACKGROUND

[0004] Heat exchangers are widely used in both residential and commercial heating, ventilating, and/or air conditioning (HVAC) systems and applications. A plate fin heat exchanger generally comprises a plurality of thin metal plates or fins having holes that may be arranged to accept tubes through the holes. The fins and tubes may generally be configured to increase heat transfer between an ambient airflow passing over the fins and tubes and a fluid refrigerant flowing through tubes to which the fins are attached. In most conventional plate-fin heat exchangers, the fins may be constructed to create a large amount of surface area that facilitates the transfer of heat.

SUMMARY

[0005] In some embodiments of the disclosure, a plate-fin heat exchanger slab is disclosed as comprising: a fin comprising a leading edge comprising a first notch.

[0006] In other embodiments of the disclosure, a heating, ventilation, and air conditioning (HVAC) system is disclosed as comprising: a plate-fin heat exchanger, comprising a first fin comprising a leading edge comprising a first notch.

[0007] In yet other embodiments of the disclosure, a method of exchanging heat is disclosed as comprising: providing a heat exchanger comprising a first row of tubes and a second row of tubes, providing a first fin comprising a leading edge and a trailing edge in the heat exchanger, providing a first notch on the leading edge, and passing an airflow into contact with a tube of the second row, wherein the air first contacts the fin at a notched portion of the leading edge.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description:

[0009] FIG. 1 is a schematic diagram of an HVAC system according to an embodiment of the disclosure;

[0010] FIG. 2 is an oblique front view of a heat exchanger slab of the heat exchanger in FIG. 1 according to an embodiment of the disclosure;

[0011] FIG. 3 is a partial schematic top view of a fin of the heat exchanger slab of FIG. 2 according to an embodiment of the disclosure;

[0012] FIG. 4 is a partial schematic top view of a fin according to an alternative embodiment of the disclosure;

[0013] FIG. 5 is a partial schematic top view of a fin according to another alternative embodiment of the disclosure;

[0014] FIG. 6 is a partial schematic top view of a plurality of the fins of FIG. 5;

[0015] FIG. 7 is a partial schematic top view of a fin according to yet another alternative embodiment of the disclosure;

[0016] FIG. 8 is a partial schematic top view of a fin according to still another alternative embodiment of the disclosure; and

[0017] FIG. 9 is a flowchart of a method of exchanging heat according to an embodiment of the disclosure.

DETAILED DESCRIPTION

[0018] Referring now to FIG. 1, a schematic diagram of an HVAC system 100 is shown according to an embodiment of the disclosure. HVAC system 100 generally comprises an indoor unit 102, an outdoor unit 104, and a system controller 106. The system controller 106 may generally control operation of the indoor unit 102 and/or the outdoor unit 104. As shown, the HVAC system 100 is a so-called heat pump system that may be selectively operated to implement one or more substantially closed thermodynamic refrigeration cycles to provide a cooling functionality and/or a heating functionality.

[0019] Indoor unit 102 generally comprises an indoor heat exchanger 108, an indoor fan 110, and an indoor metering device 112. Indoor heat exchanger 108 may generally comprise a plate fin heat exchanger. In other embodiments, indoor heat exchanger 108 may comprise a spine fin heat exchanger, a microchannel heat exchanger, or any other suitable type of heat exchanger. Indoor heat exchanger 108 may generally comprise a heat exchanger slab 200 that may be configured to allow heat exchange between refrigerant carried within internal tubing of the heat exchanger slab 200 and fluids that contact the heat exchanger slab 200 but that are kept segregated from the refrigerant. In some embodiments, the indoor heat exchanger 108 may comprise a plurality of heat exchanger slabs 200 that may be configured in an A-frame configuration. However, in other embodiments, the indoor heat exchanger 108 may comprise a plurality of heat exchanger slabs 200 that may be configured in a V-frame arrangement.

[0020] The indoor fan 110 is a centrifugal blower comprising a blower housing, a blower impeller at least partially disposed within the blower housing, and a blower motor configured to selectively rotate the blower impeller. In other embodiments, the indoor fan 110 may comprise a mixed-flow fan and/or any other suitable type of fan. The indoor fan 110 is configured as a modulating and/or variable speed fan capable of being operated at many speeds over one or more ranges of speeds. In other embodiments, the indoor fan 110 may be configured as a multiple speed fan capable of being operated at a plurality of operating speeds by selectively electrically powering different ones of multiple electromagnetic windings of a motor of the indoor fan 110. In yet other embodiments, the indoor fan 110 may be a single speed fan.

[0021] The indoor metering device 112 is an electronically controlled motor driven electronic expansion valve (EEV). In alternative embodiments, the indoor metering device 112 may comprise a thermostatic expansion valve, a capillary tube assembly, and/or any other suitable metering device. The indoor metering device 112 may comprise and/or be associated with a refrigerant check valve and/or refrigerant bypass for use when a direction of refrigerant flow through the indoor metering device 112 is such that the indoor metering device 112 is not intended to meter or otherwise substantially restrict flow of the refrigerant through the indoor metering device 112.

[0022] Outdoor unit 104 generally comprises an outdoor heat exchanger 114, a compressor 116, an outdoor fan 118, an outdoor metering device 120, and a reversing valve 122. Outdoor heat exchanger 114 is a spine fin heat exchanger configured to allow heat exchange between refrigerant carried within internal passages of the outdoor heat exchanger 114 and fluids that contact the outdoor heat exchanger 114 but that are kept segregated from the refrigerant. In other embodiments, outdoor heat exchanger 114 may comprise a plate fin heat exchanger, a microchannel heat exchanger, or any other suitable type of heat exchanger.

[0023] The compressor 116 is a multiple speed scroll type compressor configured to selectively pump refrigerant at a plurality of mass flow rates. In alternative embodiments, the compressor 116 may comprise a modulating compressor capable of operation over one or more speed ranges, a reciprocating type compressor, a single speed compressor, and/or any other suitable refrigerant compressor and/or refrigerant pump.

[0024] The outdoor fan 118 is an axial fan comprising a fan blade assembly and fan motor configured to selectively rotate the fan blade assembly. In other embodiments, the outdoor fan 118 may comprise a mixed-flow fan, a centrifugal blower, and/or any other suitable type of fan and/or blower. The outdoor fan 118 is configured as a modulating and/or variable speed fan capable of being operated at many speeds over one or more ranges of speeds. In other embodiments, the outdoor fan 118 may be configured as a multiple speed fan capable of being operated at a plurality of operating speeds by selectively electrically powering different ones of multiple electromagnetic windings of a motor of the outdoor fan 118. In yet other embodiments, the outdoor fan 118 may be a single speed fan.

[0025] The outdoor metering device 120 is a thermostatic expansion valve. In alternative embodiments, the outdoor metering device 120 may comprise an electronically controlled motor driven EEV similar to indoor metering device 112, a capillary tube assembly, and/or any other suitable metering device. The outdoor metering device 120 may comprise and/or be associated with a refrigerant check valve and/or refrigerant bypass for use when a direction of refrigerant flow through the outdoor metering device 120 is such that the outdoor metering device 120 is not intended to meter or otherwise substantially restrict flow of the refrigerant through the outdoor metering device 120.

[0026] The reversing valve 122 is a so-called four-way reversing valve. The reversing valve 122 may be selectively controlled to alter a flow path of refrigerant in the HVAC system 100 as described in greater detail below. The reversing valve 122 may comprise an electrical solenoid or other device configured to selectively move a component of the reversing valve 122 between operational positions.

[0027] The system controller 106 may generally comprise a touchscreen interface for displaying information and for receiving user inputs. The system controller 106 may display information related to the operation of the HVAC system 100 and may receive user inputs related to operation of the HVAC system 100. However, the system controller 106 may further be operable to display information and receive user inputs tangentially and/or unrelated to operation of the HVAC system 100. In some embodiments, the system controller 106 may not comprise a display and may derive all information from inputs from remote sensors and remote configuration tools. In some embodiments, the system controller 106 may comprise a temperature sensor and may further be configured to control heating and/or cooling of zones associated with the HVAC system 100. In some embodiments, the system controller 106 may be configured as a thermostat for controlling supply of conditioned air to zones associated with the HVAC system 100.

[0028] In some embodiments, the system controller 106 may also selectively communicate with an indoor controller 124 of the indoor unit 102, with an outdoor controller 126 of the outdoor unit 104, and/or with other components of the HVAC system 100. In some embodiments, the system controller 106 may be configured for selective bidirectional communication over a communication bus 128. In some embodiments, portions of the communication bus 128 may comprise a three-wire connection suitable for communicating messages between the system controller 106 and one or more of the HVAC system 100 components configured for interfacing with the communication bus 128. Still further, the system controller 106 may be configured to selectively communicate with HVAC system 100 components and/or any other device 130 via a communication network 132. In some embodiments, the communication network 132 may comprise a telephone network, and the other device 130 may comprise a telephone. In some embodiments, the communication network 132 may comprise the Internet, and the other device 130 may comprise a smartphone and/or other Internet-enabled mobile telecommunication device. In other embodiments, the communication network 132 may also comprise a remote server.

[0029] The indoor controller 124 may be carried by the indoor unit 102 and may be configured to receive information inputs, transmit information outputs, and otherwise communicate with the system controller 106, the outdoor controller 126, and/or any other device 130 via the communication bus 128 and/or any other suitable medium of communication. In some embodiments, the indoor controller 124 may be configured to communicate with an indoor personality module 134 that may comprise information related to the identification and/or operation of the indoor unit 102. In some embodiments, the indoor controller 124 may be configured to receive information related to a speed of the indoor fan 110, transmit a control output to an electric heat relay, transmit information regarding an indoor fan 110 volumetric flow-rate, communicate with and/or otherwise affect control over an air cleaner 136, and communicate with an indoor EEV controller 138. In some embodiments, the indoor controller 124 may be configured to communicate with an indoor fan controller 142 and/or otherwise affect control over operation of the indoor fan 110. In some embodiments, the indoor personality module 134 may comprise information related to the identification and/or operation of the indoor unit 102 and/or a position of the outdoor metering device 120.

[0030] In some embodiments, the indoor EEV controller 138 may be configured to receive information regarding temperatures and/or pressures of the refrigerant in the indoor unit 102. More specifically, the indoor EEV controller 138 may be configured to receive information regarding temperatures and pressures of refrigerant entering, exiting, and/or within the indoor heat exchanger 108. Further, the indoor EEV controller 138 may be configured to communicate with the indoor metering device 112 and/or otherwise affect control over the indoor metering device 112. The indoor EEV controller 138 may also be configured to communicate with the outdoor metering device 120 and/or otherwise affect control over the outdoor metering device 120.

[0031] The outdoor controller 126 may be carried by the outdoor unit 104 and may be configured to receive information inputs, transmit information outputs, and otherwise communicate with the system controller 106, the indoor controller 124, and/or any other device via the communication bus 128 and/or any other suitable medium of communication. In some embodiments, the outdoor controller 126 may be configured to communicate with an outdoor personality module 140 that may comprise information related to the identification and/or operation of the outdoor unit 104. In some embodiments, the outdoor controller 126 may be configured to receive information related to an ambient temperature associated with the outdoor unit 104, information related to a temperature of the outdoor heat exchanger 114, and/or information related to refrigerant temperatures and/or pressures of refrigerant entering, exiting, and/or within the outdoor heat exchanger 114 and/or the compressor 116. In some embodiments, the outdoor controller 126 may be configured to transmit information related to monitoring, communicating with, and/or otherwise affecting control over the outdoor fan 118, a compressor sump heater, a solenoid of the reversing valve 122, a relay associated with adjusting and/or monitoring a refrigerant charge of the HVAC system 100, a position of the indoor metering device 112, and/or a position of the outdoor metering device 120. The outdoor controller 126 may further be configured to communicate with a compressor drive controller 144 that is configured to electrically power and/or control the compressor 116.

[0032] The HVAC system 100 is shown configured for operating in a so-called cooling mode in which heat is absorbed by refrigerant at the indoor heat exchanger 108 and heat is rejected from the refrigerant at the outdoor heat exchanger 114. In some embodiments, the compressor 116 may be operated to compress refrigerant and pump the relatively high temperature and high pressure compressed refrigerant from the compressor 116 to the outdoor heat exchanger 114 through the reversing valve 122 and to the outdoor heat exchanger 114. As the refrigerant is passed through the outdoor heat exchanger 114, the outdoor fan 118 may be operated to move air into contact with the outdoor heat exchanger 114, thereby transferring heat from the refrigerant to the air surrounding the outdoor heat exchanger 114. The refrigerant may primarily comprise liquid phase refrigerant and the refrigerant may flow from the outdoor heat exchanger 114 to the indoor metering device 112 through and/or around the outdoor metering device 120 which does not substantially impede flow of the refrigerant in the cooling mode. The indoor metering device 112 may meter passage of the refrigerant through the indoor metering device 112 so that the refrigerant downstream of the indoor metering device 112 is at a lower pressure than the refrigerant upstream of the indoor metering device 112. The pressure differential across the indoor metering device 112 allows the refrigerant downstream of the indoor metering device 112 to expand and/or at least partially convert to a two-phase (vapor and gas) mixture. The two phase refrigerant may enter the indoor heat exchanger 108. As the refrigerant is passed through the indoor heat exchanger 108, the indoor fan 110 may be operated to move air into contact with the indoor heat exchanger 108, thereby transferring heat to the refrigerant from the air surrounding the indoor heat exchanger 108, and causing evaporation of the liquid portion of the two phase mixture. The refrigerant may thereafter re-enter the compressor 116 after passing through the reversing valve 122.

[0033] To operate the HVAC system 100 in the so-called heating mode, the reversing valve 122 may be controlled to alter the flow path of the refrigerant, the indoor metering device 112 may be disabled and/or bypassed, and the outdoor metering device 120 may be enabled. In the heating mode, refrigerant may flow from the compressor 116 to the indoor heat exchanger 108 through the reversing valve 122, the refrigerant may be substantially unaffected by the indoor metering device 112, the refrigerant may experience a pressure differential across the outdoor metering device 120, the refrigerant may pass through the outdoor heat exchanger 114, and the refrigerant may reenter the compressor 116 after passing through the reversing valve 122. Most generally, operation of the HVAC system 100 in the heating mode reverses the roles of the indoor heat exchanger 108 and the outdoor heat exchanger 114 as compared to their operation in the cooling mode.

[0034] Referring now to FIG. 2, an oblique front view of the heat exchanger slab 200 is shown according to an embodiment of the disclosure. Heat exchanger 200 may generally comprise a top side 202, a bottom side 204, a left side 206, a right side 208, a front side 210 that is associated with an upstream facing side of the heat exchanger slab 200 with respect to an airflow through the heat exchanger slab 200, and a back side 212 that is associated with a downstream facing side of the heat exchanger slab 200 with respect to an airflow through the heat exchanger slab 200. It will be appreciated that heat exchanger slab 200 may be installed in various orientations, and such directional descriptions of heat exchanger slab 200 are provided to assist the reader in understanding the physical orientation of the various component parts of the heat exchanger slab 200. Accordingly, such directional descriptions of heat exchanger slab 200 shall not be interpreted as indicating absolute locations and/or directional limits of the heat exchanger slab 200, but shall instead indicate that a plurality of described and/or labeled directional descriptions shall provide general directional orientation to the reader so that directionality may be easily followed. Furthermore, the component parts (i.e. fin 214) of the heat exchanger slab 200 may be described as generally having top, bottom, left, right, front, and back sides which should be understood as being consistent in orientation with the top side 202, bottom side 204, left side 206, right side 208, front side 210, and back side 212 of the heat exchanger slab 200.

[0035] Heat exchanger slab 200 may generally comprise a plurality of fins 214 and tubes 216. The fins 214 may generally comprise a substantially plate-like structure comprising a fin length that extends from the left side 206 to the right side 208 of the heat exchanger slab 200 and a fin width that extends from the front side 210 to the back side 212 of the heat exchanger slab 200. Each fin 214 may also comprise a leading edge 220 and a trailing edge 222. The leading edge 220 of each fin 214 may generally be associated with the front side 210 of the heat exchanger slab 200, while the trailing edge 222 of each fin 214 may generally be associated with the back side 212 of the heat exchanger slab 200. Accordingly, the fin width may alternatively be referred to as the distance between the leading edge 220 and the trailing edge 222 of a fin 214.

[0036] Still further, each fin 214 may comprise a leading edge 220 comprising a notch 224 disposed along the leading edge 220 of the respective fin 214. In some embodiments, however, some fins 214 may comprise a leading edge 220 comprising a plurality of notches 224 disposed along the leading edge 220 of the respective fins 214. In some embodiments, the plurality of notches 224 may comprise a substantially evenly-spaced pattern that may be commensurate with a pattern of tubes 216 disposed in the heat exchanger slab 200. In some embodiments, the leading edge 224 may comprise notches 224 disposed along the leading edge 220 of a fin 214 and disposed lengthwise between adjacent tubes 216 of a first row 226 of tubes 216 that are generally disposed closest to the leading edge 220 of the heat exchanger slab 200. In some embodiments, the notches 224 may be aligned with a second row 228 of tubes 216 disposed relatively further from the leading edge 220 and closer to the back side 212 of the heat exchanger slab 200 as compared to the first row 226 of tubes 216. Furthermore, while only a first row 226 of tubes 216 and a second row 228 of tubes 216 are shown, the heat exchanger slab 200 may comprise additional rows of tubes 216 and/or any arrangement of a plurality of additional tubes 216.

[0037] The plurality of fins 214 may also comprise a substantially similar hole pattern formed in each fin 214 and may generally be arranged in a substantially parallel stack, with adjacent fins 214 equally offset from each other by a fin pitch distance. In this arrangement, each of the plurality of tubes 216 may be received through the corresponding holes that are formed in the plurality of fins 214. In other words, each tube 216 may be inserted substantially orthogonally through the corresponding holes in the arrangement of fins 214, so that the fins 214 are disposed longitudinally along the tubes 216 at a fin pitch separation distance, thereby forming what may be referred to as the heat exchanger slab 200. Furthermore, while the fins 214 are arranged in the substantially parallel stack, the plurality of notches 224 may also be aligned from the top side 202 to the bottom side 204 of the heat exchanger slab 200 to form a notch channel 230 that extends along the front side 210 of the heat exchanger slab 200 from the uppermost fin 214 located closest to the top side 202 to the bottommost fin 214 located closest to the bottom side 204 of the heat exchanger slab 200.

[0038] In some embodiments, the first row 226 of tubes 216 may comprise a configuration that is substantially parallel to and/or equidistant from the flat portion of the leading edge 220. In this embodiment, the second row 228 of tubes 216 comprises a configuration that is substantially parallel to and/or equidistant from the leading edge 220 and/or the first row 226 of tubes 216. However, in alternative embodiments, the second row 228 of tubes 216 comprises a configuration that is substantially parallel to and/or equidistant from the trailing edge 222. In some embodiments, each fin 214 may also comprise a substantially annular collar 218 that secures the fin 214 to the respective tubes 216. The collars 218 may generally lie substantially coaxial with a hole formed in the fin 214 and/or the respective tube 216. The collars 218 may increase the mechanical strength of the joinder between a fin 214 and a tube 216 that passes through the hole formed in the fin 214. The collar 218 may also increase the heat conductivity between a tube 216 and a fin 214. In some embodiments, the collars 218 may extend from a top surface of a fin 214 to a bottom surface of an adjacently located fin 214 and comprise an axial length that is substantially equal to the fin pitch separation distance. Furthermore, it will be appreciated that while the tubes 216 may generally be configured to carry a refrigerant through the tubes 216 to effect heat transfer with an incoming airflow, the tubes 216 may be joined by bends, 180.degree. joints, and/or a combination of other connections that join the substantially parallel tubes 216 in fluid communication.

[0039] The heat exchanger slab 200 may generally be configured to allow heat exchange between a refrigerant carried within the tubes 216 of the heat exchanger slab 200 and an incoming airflow that may contact the fins 214, the tubes 216, and/or the collars 218 of the heat exchanger slab 200. Accordingly, the fins 214, tubes 216, and/or the collars 218 may be formed from a suitable thermally-conductive material, including, but not limited to, aluminum, copper, and/or stainless steel. When the HVAC system 100 is operated in a cooling mode, the incoming airflow may transfer heat to the fluid flowing through the tubes 216. When the HVAC system 100 is operated in a heating mode, heat may be transferred from the fluid flowing through the tubes 216 to the incoming airflow. It will be appreciated that the above-described transferring of heat between the incoming airflow and the fluid flowing through the tubes 216 may generally be accomplished in part by transferring heat through at least one of the fins 214, the tubes 216, and/or the collars 218 as intermediate heat conductors between the incoming airflow and the fluid flowing through the tubes 216.

[0040] Referring now to FIG. 3, a partial schematic top view of the fin 214 is shown according to an embodiment of the disclosure. Fin 214 may generally comprise a leading edge 220 comprising a notch 224. A notch 224 may represent a portion of fin 214 that has been removed from the leading edge 220. Further, the leading edge 220 may generally be described as comprising a flat portion and as comprising a notch 224. In some embodiments, however, the leading edge 220 of fin 214 may comprise a plurality of notches 224. Accordingly, the leading edge 220 may generally be described as comprising a flat portion disposed between two adjacent notches 224 that are disposed along the leading edge 224. In this embodiment, notch 224 comprises a shape that is triangular. However, in other embodiments, notch 224 may be trapezoidal, square, rectangular, semi-circular, and/or any other appropriate shape. In some embodiments, the notches 224 may be substantially similarly shaped and sized. However, in alternative embodiments, the notches 224 on a single fin 214 may comprise dissimilar shapes and/or sizes. In some embodiments, the plurality of notches 224 may comprise a substantially evenly-spaced lengthwise pattern that may be commensurate with a lengthwise pattern of tubes 216 disposed through the fin 214. In some embodiments, the notches 224 may be disposed substantially equidistant from adjacent tubes 216 that are disposed on leftward and rightward of each respective notch 224 and/or adjacent tube centers 232 of each of the respective adjacent tubes 216.

[0041] In some embodiments, the notches 224 may be substantially aligned with a tube 216 in the second row 228 along a construction line that lies orthogonally relative to the leading edge 220. More specifically, in some embodiments, each notch 224 may be substantially aligned with the tube center 232 of a corresponding tube 216 in the second row 228 along a construction line that lies orthogonally relative to the leading edge 220 and that bisects the notch 224. In some embodiments, the notches 224 may be substantially aligned with a tube 216 in the second row 228 with respect to a primary airflow direction 234 across fin 214. In some embodiments, a center of each notch 224 may be substantially aligned with the tube center 232 of a corresponding tube 216 in the second row 228 with respect to the primary airflow direction 234 across the fin 214. Additionally, while only a first row 226 of tubes 216 and a second row 228 of tubes 216 are shown, it will be appreciated that fin 214 may comprise a plurality of additional rows of tubes 216 and/or any arrangement of a plurality of additional tubes 216.

[0042] Fin 214 may generally be configured to allow heat exchange between a refrigerant carried within the tubes 216 and an incoming airflow travelling in the primary airflow direction 234 that may contact fin 214, tubes 216, and/or collars 218. The exchange of heat between the refrigerant and the incoming airflow may generally be accomplished by transferring heat through at least one of fin 214, tubes 216, and/or collars 218 as intermediate heat conductors between the incoming airflow and the refrigerant. A conventional fin with a flat leading edge generally provides an airflow a longer time of residence that the airflow is in contact with the fin, allowing a longer amount of time to exchange heat between the fin and the incoming airflow. As compared to the conventional fin with a flat leading edge, the notches 224 formed in fin 214 may cause the fin 214 and/or first row 226 of tubes 216 to exchange less heat with an incoming airflow by reducing the fin width as measured from a notch 224 to the trailing edge 222, which may also reduce the time of residence an airflow may be in contact with fin 214.

[0043] Due to the reduced heat exchange caused by a notch 224, the airflow across fin 214 may consequently reach the second row 228 of tubes 216 with a lower temperature as compared to an airflow across the conventional fin. This may be in part due to the notch 224 allowing relatively less heating of the air prior to reaching the second row 228 of tubes 216 of the fin 214. Thus, in some embodiments, an airflow that that reaches the second row 228 of tubes 216 of fin 214 with a lower temperature may exchange a higher amount of heat with the second row 228 of tubes 216 as compared to the heat exchange with a second row of tubes in a conventional fin. In some embodiments, the increased heat exchange with the second row 228 of tubes 216 of fin 214 over a conventional fin may be caused by an increased temperature differential between the airflow that contacts the second row 228 of tubes 216 and the temperature of the second row 228 of tubes 216 and/or the refrigerant flowing through the second row 228 of tubes 216. In some embodiments, a fin 214 with a notch 224 may allow a heat exchange efficiency as high as about 95% with the second row 228 of tubes 216. In embodiments with a plurality of rows, a fin 214 with a notch 224 may increase the heat exchange efficiency with other rows of tubes 216 disposed downstream of the second row 228 of tubes 216 with respect to the primary airflow direction 234. Thus, in some embodiments, a fin 214 with a notch 224 may allow a heat exchange efficiency as high as about 65% with a third row of tubes 216 and as high as about 50% with a fourth row of tubes 216.

[0044] Referring now to FIG. 4, a partial schematic top view of a fin 300 is shown according to an alternative embodiment of the disclosure. Fin 300 may generally be substantially similar to fin 214. Fin 300 may generally comprise a left side 302, a right side 304, a front side 306, a back side 308, a plurality of tubes 310 having tube centers 326, a plurality of collars 312, a leading edge 314, a trailing edge 316, a plurality of notches 318, a first row 320 of tubes 310, a second row 322 of tubes 310, and a plurality of notch channels 324. However, a trailing edge 316 of fin 300 may also comprise a notch 318. However, in some embodiments, fin 300 may comprise trailing edge 316 comprising a plurality of notches 318 that may be disposed along the trailing edge 316.

[0045] A notch 318 disposed along the trailing edge 316 may represent a portion of fin 300 that has been removed. In some embodiments, notch 318 disposed along the trailing edge 316 may comprise a shape that is triangular, trapezoidal, square, rectangular, semi-circular, and/or any other appropriate shape. In some embodiments, the notches 318 disposed on the leading edge 314 and the trailing edge 316 may be substantially similarly shaped and sized. However, in alternative embodiments, the notches 318 on a single fin 300 may comprise dissimilar shapes and/or sizes. In some embodiments, the plurality of notches 318 disposed along the trailing edge 316 may comprise a substantially evenly-spaced pattern that may be commensurate with a lengthwise pattern of tubes 310 disposed through the fin 300. In some embodiments, the notches 318 disposed lengthwise along the trailing edge 316 may be disposed substantially equidistant from adjacent tubes 310 that are disposed leftward and rightward of each respective notch 318 and/or adjacent tube centers 326 of each of the respective adjacent tubes 310.

[0046] In some embodiments, the notches 318 along the trailing edge 316 may be substantially aligned with a tube 310 in the first row 320 along a construction line that lies orthogonally relative to the trailing edge 316. More specifically, in some embodiments, each notch 318 on the trailing edge 316 may be substantially aligned with the tube center 326 of a corresponding tube 310 in the first row 320 along a construction line that lies orthogonally to the trailing edge 316 and that bisects the notch 318. In some embodiments, the notches 318 on the trailing edge 316 may be substantially aligned with a tube 310 in the first row 320 with respect to a primary airflow direction 328 across fin 300. In some embodiments, a center of each notch 318 may be substantially aligned with the tube center 326 of a corresponding tube 310 in the first row 320 with respect to the primary airflow direction 328 across the fin 300. Additionally, while only a first row 320 of tubes 310 and a second row 322 of tubes 310 are shown, it will be appreciated that fin 300 may comprise a plurality of additional rows of tubes 310 and/or any arrangement of a plurality of additional tubes 310.

[0047] Fin 300 may generally be configured to allow heat exchange between a refrigerant carried within the tubes 310 and an incoming airflow travelling in the primary airflow direction 328 that may contact fin 300, tubes 310, and/or collars 312. The exchange of heat between the refrigerant and the incoming airflow may generally be accomplished by transferring heat through at least one of fin 300, tubes 310, and/or collars 312 as intermediate heat conductors between the incoming airflow and the refrigerant. Similarly to fin 214, fin 300 may also increase the heat exchange efficiency of the second row 322 of tubes 310 as compared to a conventional fin without notches 318. Again, similarly to fin 214, this may generally be caused by the notches 318 on the leading edge 314 of the fin 300 that cause an increased temperature differential between the incoming airflow and the temperature of the second row 228 of tubes 216 and/or the refrigerant flowing through the second row 228 of tubes 216.

[0048] Accordingly, in some embodiments, fin 300 comprising notches 318 may allow a heat exchange efficiency as high as about 95% with the second row 322 of tubes 310. In embodiments with a plurality of rows, fin 300 comprising notches 318 may increase the heat exchange efficiency with other rows of tubes 310 disposed downstream of the second row 322 of tubes 310 with respect to the primary airflow direction 328. Thus, in some embodiments, fin 300 may allow a heat exchange efficiency as high as about 65% with a third row of tubes 310 and as high as about 50% with a fourth row of tubes 310. Additionally, the notches 318 on the trailing edge 316 may reduce a pressure drop experienced by an airflow across fin 300. Removing the material of fin 300 to form notches 318 on the trailing edge 316 may decrease the fin width between the leading edge 314 and a notch 318 disposed on the trailing edge 316, thereby reducing the time of residence an airflow may be in contact with fin 300. This may effectively reduce the pressure differential that an airflow travelling along a primary airflow direction 328 experiences as it travels across fin 300 from the leading edge 314 to the trailing edge 316. Accordingly, reducing the pressure drop by disposing notches 318 on a trailing edge 316 may also increase the heat transfer efficiency of fin 300 and/or a heat exchanger slab, such as heat exchanger slab 200, that may comprise a plurality of fins 300.

[0049] Referring now to FIG. 5, a partial schematic top view of a fin 400 is shown according to another alternative embodiment of the disclosure. Fin 400 may generally be substantially similar to fin 300 in FIG. 4. Fin 400 may generally comprise a left side 402, a right side 404, a front side 406, a back side 408, a plurality of tubes 410 having tube centers 426, a plurality of collars 412, a leading edge 414, a trailing edge 416, a plurality of notches 418 disposed on the leading edge 414 and the trailing edge 416, a first row 420 of tubes 410, a second row 422 of tubes 410, and a plurality of notch channels 424. However, fin 400 may comprise a so-called "nested" leading edge 430 and a "nested" trailing edge 432. The leading edge 414 and the plurality of notches 418 disposed on the leading edge 414 may collectively form the nested leading edge 432. The trailing edge 416 and the plurality of notches 418 disposed on the trailing edge 416 may collectively form the nested trailing edge 432.

[0050] The nested leading edge 430 and the nested trailing edge 432 may generally comprise a plurality of notches 418 that may be removed in a substantially continuous pattern to form a plurality of protrusions 434 on the leading edge 414 and the trailing edge 416, respectively. The notches 418 may generally be configured in a pattern and comprise a substantially similar size and shape, so that the protrusions 434 formed by removing the fin 400 material to form the notches 418 comprise a substantially complimentary shape and/or profile to the notches 418. Accordingly, the nested leading edge 430 may comprise an alternating pattern of notches 418 and protrusions 434 that comprises a substantially complimentary profile to the pattern of notches 418 and protrusions 430 that form the nested trailing edge 432. Thus, the nested leading edge 430 of one fin 400 may substantially interface with and be substantially complimentary to the nested trailing edge 432 of a second fin 400. The substantial interfacing and/or complimentary profiles between a nested leading edge 430 of one fin and a nested trailing edge 432 of another fin may be referred to as "nesting" and/or a "nested" edge. It will be appreciated that fin 400 may similarly increase a heat transfer efficiency with the second row 422 of tubes 410 and/or reduce a pressure drop of an airflow traveling in a primary airflow direction 428 across fin 300 as compared to a conventional fin.

[0051] Referring now to FIG. 6, a partial schematic top view of a plurality of the fins 400', 400'' of FIG. 5 are shown. The first fin 400' may generally comprise a first fin leading edge 414', a first fin trailing edge 416', a plurality of first fin notches 418', a first fin nested leading edge 430', a first fin nested trailing edge 432', and a plurality of first fin protrusions 434'. The second fin 400'' may generally comprise a second fin leading edge 414'', a second fin trailing edge 416'', a plurality of second fin notches 418'', a second fin nested leading edge 430'', a second fin nested trailing edge 432'', and a plurality of second fin protrusions 430''.

[0052] Generally, the second fin nested leading edge 430'' may comprise an alternating pattern of second fin notches 418'' and second fin protrusions 434'' that comprises a substantially complimentary profile to the pattern of first fin notches 418' and first fin protrusions 434' that form the first fin nested trailing edge 432'. Thus, the second fin nested leading edge 430'' of the second fin 400'' may comprise a profile that is substantially complimentary to the first fin nested trailing edge 432' of the first fin 400', such that the second fin nested leading edge 430'' may be nested with the first fin nested trailing edge 432'. Additionally, the first fin nested leading edge 430' may also be configured to nest with a substantially complimentary nested trailing edge of a substantially similar third fin, and the second fin nested trailing edge 432'' may also be configured to nest with a substantially complimentary nested leading edge of a substantially similar fourth fin.

[0053] This configuration of nested leading and trailing edges may allow a plurality of fins 400 to be manufactured from a single sheet of material. In some embodiments, a plurality of fins 400 may be formed from a single sheet of material by cutting along a cutting line 436. The cutting line 436 may substantially divide the first fin 400' from the second fin 400'' along the first fin nested trailing edge 432' and/or the second fin nested leading edge 430''. Accordingly, manufacturing a plurality of fins 400 comprising substantially complimentary nested leading edges 430 and nested trailing edges 432 that may be separated at the cutting line 436 may reduce material waste as compared to manufacturing the fins 400 and later removing the material to form the plurality of notches 418. Still further, the reduced amount of waste from manufacturing fins 400 that comprise substantially complimentary nested leading edges 430 and nested trailing edges 432 may also reduce manufacturing costs.

[0054] Referring now to FIG. 7, a partial schematic top view of a fin 500 is shown according to yet another alternative embodiment of the disclosure. Fin 500 may generally be substantially similar to fin 400 in FIGS. 5 and 6. Fin 500 may comprise a left side 502, a right side 504, a front side 506, a back side 508, a plurality of tubes 510 having tube centers 526, a plurality of collars 512, a leading edge 514, a trailing edge 516, a plurality of notches 518 disposed on the leading edge 514 and the trailing edge 516, a first row 520 of tubes 510, a second row 522 of tubes 510, a plurality of notch channels 524, a nested leading edge 530, a nested trailing edge 532, and a plurality of protrusions 534. However, fin 500 may comprise a so-called "nested" leading edge 530 and a "nested" trailing edge 532 where the edges of the notches 518 and the protrusions 534 are substantially rounded and/or radiused such that no portion of the nested leading edge 530 or the nested trailing edge 532 is relatively flat. Accordingly, fin 500 may be defined as having a rounded nested leading edge 530 and a rounded nested trailing edge 532.

[0055] In some embodiments, a notch 518 on the nested leading edge 530 may be substantially aligned with a tube 510 in the second row 522 along a construction line that intersects the corresponding tube center 526 of the tube 510 in the second row 522 and bisects the curve of the notch 518 on the nested leading edge 530. In some embodiments, a notch 318 on the notched leading edge 530 may be substantially aligned with a tube 510 in the second row 522 with respect to a primary airflow direction 528 across fin 500. Additionally, a notch 518 on the nested trailing edge 532 may be substantially aligned with a tube 510 in the first row 520 along a construction line that intersects the corresponding tube center 526 of the tube 510 in the first row 520 and bisects the curve of the notch 518 on the nested trailing edge 532. In some embodiments, a notch 318 on the notched trailing edge 532 may be substantially aligned with a tube 510 in the first row 520 with respect to a primary airflow direction 528 across fin 500.

[0056] Most generally, the nested leading edge 530 of one fin 500 may substantially interface with and be substantially complimentary to the nested trailing edge 532 of a second fin 500. Accordingly, fins 500 that comprise a nested leading edge 530 and a nested trailing edge 532 may allow a plurality of fins 500 to be manufactured from a single sheet of material. In some embodiments, a plurality of fins 500 may be laid out in a nested arrangement similarly to fins 400', 400'' in FIG. 6 on the single sheet of material and cut along a cutting line, similar to cutting line 436. The cutting line may divide substantially similar fins 500 along the nested trailing edge 532 and/or the nested leading edge 530. Accordingly, manufacturing a plurality of fins 500 comprising substantially complimentary nested leading edges 530 and nested trailing edges 532 that may be separated at a cutting line may reduce material waste as compared to manufacturing the fins 500 and later removing the material for the plurality of notches 518. Still further, the reduced amount of waste from manufacturing fins 500 that comprise substantially complimentary nested leading edges 530 and nested trailing edges 532 may also reduce manufacturing costs.

[0057] Referring now to FIG. 8, a partial schematic top view of fin 600 comprising a variable notched leading edge 614 is shown according to still another alternative embodiment of the disclosure. Fin 600 may generally be substantially similar to fin 214 in FIGS. 2 and 3. Fin 600 may generally comprise a left side 602, a right side 604, a front side 606, a back side 608, a plurality of tubes 610 having tube centers 626, a plurality of collars 612, a leading edge 614, a trailing edge 616, a plurality of notches 618, a first row 620 of tubes 610, a second row 622 of tubes 610, and a plurality of notch channels 624. However, the leading edge 614 of fin 600 may also comprise different notches 618 including a first notch 618' and a second notch 618''. In some embodiments, the first notch 618' may be associated with a primary airflow direction 628', while the second notch 618'' may be associated with a secondary airflow direction 628''. In some embodiments where a fin 600 may experience a turbulent airflow and/or an airflow may enter the fin 600 at both a primary airflow direction 628' and a secondary airflow direction 628'', associating different notches 618', 618'' may further increase the heat transfer efficiency with the second row 622 of tubes 610.

[0058] For a primary airflow direction 628' that may enter a fin 600 substantially orthogonally to the leading edge 614, a first notch 618' may be aligned with a tube 610 in the second row 622 along a construction line that lies orthogonally to the leading edge 614. More specifically, each first notch 618' may be substantially aligned with the tube center 626 of a corresponding tube 610 in the second row 622 along a construction line that lies orthogonally to the leading edge 614 and that bisects the first notch 618'. In some embodiments, the first notch 618' may be substantially aligned with a tube 610 in the second row 622 with respect to the primary airflow direction 628' across fin 600. For a secondary airflow direction 628'' that may enter a fin 600 at any angle that is not substantially orthogonal to the leading edge 614, a second notch 618'' may be disposed between adjacent tubes 610 in the first row 620, but may be aligned with a tube 610 in the second row 622 that is coincident with the secondary airflow direction 628''. More specifically, the second notch 618'' may comprise a shape and/or an angled side of the second notch 618'' that is substantially aligned with the tube center 626 of a corresponding tube 610 in the second row 622 along a construction line that is substantially parallel with the secondary airflow direction 628''. Accordingly, in some embodiments, the second notch 618'' may comprise a shape that is substantially dissimilar to the shape of the first notch 618'. In some embodiments, first notches 618' may be employed toward a center of fin 600 and/or where an airflow is substantially orthogonal to the leading edge 614 and/or laminar, while second notches 618'' may be employed toward an outer edge of a fin 600, an outer edge of a heat exchanger slab, such as heat exchanger slab 200 in FIG. 2, that is close to an airflow duct, and/or where an airflow is substantially non-orthogonal to the leading edge 614 and/or more turbulent.

[0059] In some embodiments, notches 618', 618'' may comprise shapes that are triangular, trapezoidal, square, rectangular, semi-circular, and/or any other appropriate shape. Furthermore, it will be appreciated that fin 600 may also comprise a plurality of first configured notches 618' disposed on the leading edge 614 where the primary airflow direction 628' may be orthogonal to the leading edge 614 and may comprise a plurality of second notches 618'' where the secondary airflow direction 628'' may not be substantially orthogonal to the leading edge 614. Thus, in some embodiments, a slab comprising a plurality of fins 600 may comprise notch channels 624', 624'' that comprise both first notches 618' and second notches 618'', respectively, based on the airflow across a plurality of fins 600. Alternatively, fin 600 may comprise a plurality of notch channels 624', 624'' that may comprise only first notch 618' or only second notches 618''. Furthermore, the trailing edge 616 of fin 600 may also comprise a plurality of first notches 618' and second notches 618'' disposed along the trailing edge 616 of fin 600 in a manner substantially similar to that of fin 300, fin 400, and/or fin 500.

[0060] Referring now to FIG. 9, a flowchart of a method 700 of exchanging heat is shown according to an embodiment of the disclosure. The method 700 may begin at block 702 by providing a heat exchanger comprising a first row of tubes and a second row of tubes. The method 700 may continue at block 704 by providing a first fin comprising a leading edge and a trailing edge in the heat exchanger. The method 700 may continue at block 706 by providing a first notch on the leading edge. The method 700 may conclude at block 708 by passing an airflow into contact with a tube of the second row, wherein the air first contacts the fin at a notched portion of the leading edge.

[0061] At least one embodiment is disclosed and variations, combinations, and/or modifications of the embodiment(s) and/or features of the embodiment(s) made by a person having ordinary skill in the art are within the scope of the disclosure. Alternative embodiments that result from combining, integrating, and/or omitting features of the embodiment(s) are also within the scope of the disclosure. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a numerical range with a lower limit, R.sub.l, and an upper limit, R.sub.u, is disclosed, any number falling within the range is specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R=R.sub.l+k*(R.sub.u-R.sub.l), wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . , 50 percent, 51 percent, 52 percent, . . . , 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Unless otherwise stated, the term "about" shall mean plus or minus 10 percent of the subsequent value. Moreover, any numerical range defined by two R numbers as defined in the above is also specifically disclosed. Use of the term "optionally" with respect to any element of a claim means that the element is required, or alternatively, the element is not required, both alternatives being within the scope of the claim. Use of broader terms such as comprises, includes, and having should be understood to provide support for narrower terms such as consisting of, consisting essentially of, and comprised substantially of. Accordingly, the scope of protection is not limited by the description set out above but is defined by the claims that follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated as further disclosure into the specification and the claims are embodiment(s) of the present invention.

Claims

1. A plate-fin heat exchanger, comprising: a fin comprising a leading edge comprising a first notch.

2. The heat exchanger of claim 1, further comprising: a first row of tubes that pass through the first fin, wherein the first notch is disposed between a first tube and a second tube in the first row of tubes.

3. The heat exchanger of claim 2, further comprising: a second row of tubes that pass through the first fin and that is disposed downstream relative to an airflow from the first row of tubes, wherein a center of the first notch is substantially aligned with a center of a tube in the second row.

4. The heat exchanger of claim 1, further comprising: a first trailing notch disposed on a trailing edge of the first fin.

5. The heat exchanger of claim 4, wherein a center of the first trailing notch is substantially aligned with a center of at least one of the first tube and the second tube in the second row.

6. The heat exchanger of claim 1, wherein the leading edge comprises a plurality of notches.

7. The heat exchanger of claim 4, wherein the trailing edge comprises a plurality of trailing notches.

8. The heat exchanger of claim 4, wherein the leading edge comprises a plurality of notches and the trailing edge comprises a plurality of trailing notches.

9. The heat exchanger of claim 8, wherein the leading edge and the trailing edge can nest in each other.

10. The heat exchanger of claim 1, further comprising: a second fin comprising a leading edge comprising a second notch, wherein the second fin is offset by a fin pitch distance from the first fin.

11. The heat exchanger of claim 10, wherein the first notch is substantially aligned with the second notch and wherein the first notch and the second notch form a notch channel.

11. A heating, ventilation, and air conditioning (HVAC) system, comprising: a plate-fin heat exchanger, comprising: a first fin comprising a leading edge comprising a first notch.

12. The HVAC system of claim 11, further comprising: a first row of tubes that pass through the first fin, wherein the first notch is disposed between a first tube and a second tube in the first row of tubes.

13. The HVAC system of claim 12, further comprising: a second row of tubes that pass through the first fin and that is disposed downstream relative to an airflow from the first row of tubes, wherein a center of the first notch is substantially aligned with a center of a tube in the second row with respect to a primary airflow direction.

14. The HVAC system of claim 11, further comprising: a first trailing notch disposed on a trailing edge of the first fin.

15. The HVAC system of claim 14, wherein a center of the first trailing notch is substantially aligned with a center of at least one of the first tube and the second tube in the second row.

16. The HVAC system of claim 11, further comprising: a second fin comprising a leading edge comprising a second notch, wherein the second fin is offset by a fin pitch distance from the first fin.

17. The HVAC system of claim 16, wherein the first notch is substantially aligned with the second notch, and wherein the first notch and the second notch form a notch channel.

18. A method of exchanging heat, comprising: providing a heat exchanger comprising a first row of tubes and a second row of tubes; providing a first fin comprising a leading edge and a trailing edge in the heat exchanger; providing a first notch on the leading edge; and passing an airflow into contact with a tube of the second row, wherein the air first contacts the fin at a notched portion of the leading edge.

19. The method of claim 18, wherein the first notch is disposed between a first tube and a second tube in the first row of tubes.

20. The method of claim 19, wherein a center of the first notch is substantially aligned with a center of a tube in the second row.