Microchannel heat exchanger

Abstract

The present disclosure provides a heat exchanger (100) for a heating, ventilation, and / or air conditioning (HVAC) system (30), the heat exchanger comprising: a header (106) having a longitudinal axis (160); a first plurality (114) of microchannel tubes (102) coupled to the header (106), wherein each microchannel tube (102) of the first plurality (114) of microchannel tubes (102) has a first width (150); and a second plurality (116) of microchannel tubes (102) coupled to the header (106), wherein each microchannel tube (102) of the second plurality (116) of microchannel tubes (102) has a second width (152) that is greater than the first width (150).

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to U.S. Provisional Patent Application No. 63 / 082,905, filed on September 24, 2020, entitled “MICROCHANNEL HEAT EXCHANGER,” which is incorporated herein by reference in its entirety for all purposes. Background Technology

[0003] This section is intended to introduce the reader to various aspects of the technology that may be associated with the various aspects of this disclosure described below. This discussion is intended to help provide the reader with background information to facilitate a better understanding of the various aspects of this disclosure. Therefore, it should be noted that these statements should be read in this context and not as an endorsement of prior art.

[0004] Cooler systems or vapor compression systems utilize a working fluid (e.g., a refrigerant) that changes phase between vapor, liquid, and combinations thereof in response to varying temperatures and pressures exposed within cooler system components. Cooler systems can establish a heat exchange relationship between the working fluid and a conditioning fluid (e.g., water) and can deliver the conditioning fluid to regulated equipment and / or regulated environments served by the cooler system. In such applications, the conditioning fluid can pass through downstream devices such as air processors or terminal units to regulate other fluids, such as air within a building.

[0005] In a typical cooler, a conditioning fluid is cooled by an evaporator, within which a working fluid absorbs heat from the conditioning fluid, causing the working fluid to evaporate. The working fluid is then compressed by a compressor and transferred to a condenser. In the condenser, the working fluid is typically cooled by a flow of water or air and condenses into a liquid. Air-cooled condensers typically include condenser coils and a fan that forces air through these coils. The evaporator and condenser can have any of a variety of configurations, such as shell-and-tube, tube-and-fin, etc. In some embodiments, the tubes of the evaporator and / or condenser can be microchannel tubes, where each microchannel tube includes multiple flow paths formed therein, configured to guide the working fluid through them. Unfortunately, heat exchangers with microchannel tubes can be prone to causing undesirable pressure drops in the working fluid flowing through them, which may limit or otherwise affect the performance of the cooler system. Summary of the Invention

[0006] The following describes a summary of certain embodiments disclosed herein. It should be noted that these aspects are presented only to provide the reader with a brief overview of these particular embodiments, and are not intended to limit the scope of this disclosure. In fact, this disclosure may cover various aspects that may not be set forth below.

[0007] In one embodiment, a heat exchanger for a heating, ventilation, and / or air conditioning (HVAC) system includes: a manifold having a longitudinal axis; a first plurality of microchannel tubes coupled to the manifold, wherein each of the first plurality of microchannel tubes has a first width; and a second plurality of microchannel tubes coupled to the manifold, wherein each of the second plurality of microchannel tubes has a second width greater than the first width.

[0008] In another embodiment, a heat exchanger for a heating, ventilation, and / or air conditioning (HVAC) system includes: a manifold having a longitudinal axis; a first plurality of microchannel tubes coupled to the manifold and configured to guide a working fluid flow through therethrough, wherein each of the first plurality of microchannel tubes has a first width extending at a first angle relative to the longitudinal axis; and a second plurality of microchannel tubes coupled to the manifold and configured to guide a working fluid flow through therethrough, wherein each of the second plurality of microchannel tubes has a second width extending at a second angle relative to the longitudinal axis, and wherein the first angle and the second angle are different from each other.

[0009] In a further embodiment, a heat exchanger for a heating, ventilation, and / or air conditioning (HVAC) system includes: a manifold having a longitudinal axis; a first plurality of microchannel tubes coupled to the manifold and configured to guide a working fluid flow through it, wherein each of the first plurality of microchannel tubes has a first width extending at a first angle relative to the longitudinal axis; and a second plurality of microchannel tubes coupled to the manifold and configured to guide a working fluid flow through it, wherein each of the second plurality of microchannel tubes has a second width extending at a second angle relative to the longitudinal axis, the second width being greater than the first width, and the first angle and the second angle being different from each other. Attached Figure Description

[0010] A better understanding of the various aspects of this disclosure can be achieved by reading the following detailed description and referring to the accompanying drawings, in which:

[0011] Figure 1 This is a perspective view of a building in a commercial environment that can utilize a heating, ventilation, and air conditioning (HVAC) system, according to one aspect of this disclosure;

[0012] Figure 2 This is a schematic diagram of an embodiment of a vapor compression system according to one aspect of the present disclosure;

[0013] Figure 3This is a schematic diagram of a heat exchanger having multiple microchannel tubes according to one aspect of this disclosure; and

[0014] Figure 4 This is a schematic cross-sectional view of a heat exchanger having multiple microchannel tubes according to one aspect of the present disclosure. Detailed Implementation

[0015] One or more specific embodiments will be described below. To provide a concise description of these embodiments, not all features of the actual implementations are described in the specification. It should be noted that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developer's specific objectives, such as complying with system-related and business-related constraints, which may vary from implementation to implementation. Furthermore, it should be noted that such development work may be complex and time-consuming, but these are routine tasks of design, manufacture, and production for those skilled in the art who benefit from this disclosure.

[0016] In describing the elements of various embodiments of this disclosure, the articles “a” and “the” are intended to mean that one or more of the stated elements are present. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that additional elements besides those listed may be present. Furthermore, it should be noted that references to “an embodiment” or “an embodiment” in this disclosure are not intended to exclude the existence of other embodiments that also incorporate the described features.

[0017] Embodiments of this disclosure relate to heating, ventilation, and / or air conditioning (HVAC) systems configured to cool a conditioning fluid. For example, an HVAC system may receive conditioning fluid from a structure (e.g., a building) and may cool the conditioning fluid. The HVAC system may then return the cooled conditioning fluid to the structure for further conditioning (e.g., cooling, dehumidifying, etc.) of another fluid, such as airflow supplied to the structure. In a particular embodiment, the HVAC system includes a vapor compression system (e.g., a refrigerant circuit) configured to cool a working fluid (e.g., a refrigerant) and to place the cooled working fluid in a heat exchange relationship with the conditioning fluid to absorb heat or thermal energy from the conditioning fluid, thereby cooling the conditioning fluid. For example, an evaporator in the vapor compression system may place the cooled working fluid in a heat exchange relationship with the conditioning fluid to cause the working fluid to evaporate and cool the conditioning fluid.

[0018] The vapor compression system may also include a condenser configured to exchange heat between a heated working fluid (e.g., a refrigerant that has absorbed heat or thermal energy from a conditioning fluid) and a cooling fluid (such as an ambient air flow) to cool the working fluid for reuse in cooling the conditioning fluid in an evaporator. It should be understood that the evaporator and condenser are each heat exchangers configured to exchange heat between two fluids (e.g., both the working fluid, the cooling fluid, and the conditioning fluid) to enable heat transfer between them. In some embodiments, the heat exchanger of the condenser and / or evaporator may be a microchannel heat exchanger having multiple microchannel tubes, each microchannel tube having multiple flow paths configured to guide fluid (e.g., the working fluid) through it. Unfortunately, the working fluid flowing through a microchannel heat exchanger may be susceptible to undesirable pressure drops, which can adversely affect the performance of the vapor compression system.

[0019] It is currently recognized that there is a need to improve the operation of microchannel heat exchangers, such as by reducing the pressure drop of the working fluid guided through them. Therefore, embodiments of this disclosure relate to a microchannel heat exchanger having a plurality of microchannel tubes, wherein at least two microchannel tubes have different dimensions. For example, according to currently disclosed techniques, different microchannel tubes within a common heat exchanger may have different tube widths or lateral dimensions, different flow path areas (e.g., the cumulative cross-sectional area of ​​the microchannels formed within the microchannel tubes), or other dimensions different from another microchannel tube in the microchannel heat exchanger. In some embodiments, the microchannel tubes of the microchannel heat exchanger may be grouped or divided into a first subgroup of microchannel tubes and a second subgroup of microchannel tubes. For example, each microchannel tube in the first subgroup may have a first width or lateral dimension (e.g., a dimension intersecting the direction of the working fluid flowing through the microchannels of the microchannel tube), and each microchannel tube in the second subgroup may have a second width or lateral dimension different from (e.g., greater than) the first width or lateral dimension. However, each microchannel tube in the first subgroup and each microchannel tube in the second subgroup can be connected to one or more common manifolds of the microchannel heat exchanger so that the working fluid can flow through each microchannel tube of the microchannel heat exchanger.

[0020] As discussed in further detail below, the manifold of a microchannel heat exchanger can be sized to accommodate a first subgroup of microchannel tubes with a first width arranged in a conventional orientation (e.g., substantially perpendicular to the longitudinal axis of the manifold, or horizontally oriented relative to the vertical direction of the manifold, etc.). To implement a second subgroup of microchannel tubes with a second width greater than the first width, this second subgroup of microchannel tubes can be fluidly connected to the manifold at an angled orientation, such as an inclined angle (e.g., relative to the orientation of the first subgroup of microchannel tubes, or relative to the longitudinal axis of the manifold, etc.). In this way, the second subgroup of microchannel tubes can be larger (e.g., wider) than the first subgroup of microchannel tubes. In other words, the second subgroup of microchannel tubes connected to the manifold at the aforementioned angle can be larger or wider than microchannel tubes connected to the manifold in a conventional orientation (e.g., where the width of the microchannel tube extends substantially perpendicular to the longitudinal axis of the manifold).

[0021] The larger size of the microchannel tubes in the second subgroup provides an increase in heat transfer surface area (e.g., between the working fluid and the cooling fluid) and / or an increase in the cumulative flow path area of ​​the microchannel tubes in the second subgroup (e.g., by including larger microchannels and / or an additional number of microchannels in each microchannel tube). It should be understood that the increased heat transfer surface area and / or increased flow path area of ​​the microchannels in the microchannel tubes of the second subgroup may be able to reduce the pressure drop of the working fluid flowing through the microchannel heat exchanger (e.g., through the microchannel tubes of the second subgroup). Furthermore, the angled orientation of the microchannel tubes in the second subgroup allows for the use of smaller manifolds with the microchannel heat exchanger, which reduces the costs associated with the manufacture of the microchannel heat exchanger. In particular, this technology enables the use of manifolds designed (e.g., sized) for a first microchannel tube connected to the manifold in a conventional (e.g., horizontal, generally vertical, etc.) configuration, while also incorporating a second microchannel tube with a larger width or lateral dimension than the first microchannel tube. Although the following discussion describes this technique in the context of a condenser, it should be understood that this technique can be implemented with any microchannel heat exchanger.

[0022] Now turn to the attached diagram. Figure 1This is a perspective view of an embodiment of an application for a heating, ventilation, and / or air conditioning (HVAC) system. Typically, such systems can be applied to environments both within and outside the HVAC domain. HVAC systems can provide cooling to data centers, electrical installations, chillers, coolers, or other environments via vapor compression refrigeration, absorption refrigeration, or thermoelectric cooling. However, in the applications currently envisioned, HVAC systems can be used in residential, commercial, light industrial, industrial, and / or any other application for heating or cooling spaces or enclosures such as residences, buildings, structures, etc. HVAC systems can be used in industrial applications for basic cooling and heating of various fluids, where appropriate.

[0023] The illustrated embodiment shows an HVAC system for building environment management that can utilize a heat exchanger. Building 10 is cooled by a system including a cooler 12 and a boiler 14. As shown, the cooler 12 is located on the roof of building 10, and the boiler 14 is located in the basement; however, the cooler 12 and boiler 14 may be located in other equipment rooms or areas adjacent to building 10. The cooler 12 may be an air-cooled or water-cooled unit that implements a refrigeration cycle to cool water or other conditioning fluids. The cooler 12 is housed in a structure that includes a refrigeration circuit, a natural cooling system, and associated equipment such as pumps, valves, and pipes. For example, the cooler 12 may be a separate, integral roof unit combined with a natural cooling system. The boiler 14 is a closed container in which water is heated. Water from the cooler 12 and boiler 14 circulates within building 10 via water conduits 16. The water conduits 16 are routed to air processors 18 located on individual floors and within sections of building 10.

[0024] Air processors 18 are coupled to a duct system 20 adapted to distribute air between air processors 18 and receive air from an external inlet (not shown). Air processors 18 include heat exchangers that circulate chilled water from cooler 12 and hot water from boiler 14 to provide heated or cooled air to regulated spaces within building 10. Fans within air processors 18 draw in or force air across the heat exchangers to regulate the air and direct the regulated air to environments within building 10, such as rooms, apartments, or offices, to maintain the environment at a specified temperature. A control device 22, shown in the illustrated embodiment as including a thermostat, can be used to specify the temperature of the regulated air. Control device 22 can also be used to control the flow of air through and from air processors 18. Other devices may be included in the system, such as control valves that regulate the flow and pressure of water and / or temperature sensors or switches that sense the temperature and pressure of water, air, etc. Furthermore, control device 22 may include a computer system integrated with or separate from other building control or monitoring systems, even those located remotely from building 10.

[0025] Figure 2 This is a schematic diagram of an embodiment of a vapor compression system 30 (e.g., an HVAC system) configured to utilize a working fluid, such as a refrigerant, to transfer heat between various fluid flows, such as water and / or air. For example, the vapor compression system 30 may be part of an air-cooled cooler (e.g., cooler 12). However, it should be understood that the disclosed techniques can be combined with various other types of coolers, vapor compression systems, or other HVAC systems. The vapor compression system 30 includes a refrigerant circuit 34 configured to circulate a working fluid, such as a refrigerant, through which a compressor 36 (e.g., a screw compressor) is disposed. The refrigerant circuit 34 also includes a flash tank 32, a condenser 38, an expansion valve or device 40, and a liquid cooler or evaporator 42. The components of the refrigerant circuit 34 enable heat transfer between the working fluid and other fluids (e.g., conditioning fluid, cooling fluid, air, water, etc.) to regulate at least one of the fluids and provide conditioning of an environment such as the interior of building 10.

[0026] Some examples of working fluids that can be used as refrigerants in vapor compression system 30 are: hydrofluorocarbon (HFC) based refrigerants, such as R-410A, R-407, R-134a, hydrofluoroolefins (HFO); “natural” refrigerants, such as ammonia (NH3), R-717, carbon dioxide (CO2), R-744; or hydrocarbon-based refrigerants, water vapor, refrigerants with low global warming potential (GWP), or any other suitable refrigerant. In some embodiments, vapor compression system 30 may be configured to effectively utilize refrigerants with a standard boiling point of about 19 degrees Celsius (66 degrees Fahrenheit or lower) at one atmosphere, which are also referred to as low-pressure refrigerants relative to medium-pressure refrigerants such as R-134a. As used herein, “standard boiling point” may refer to the boiling point temperature measured at one atmosphere.

[0027] The vapor compression system 30 may further include a control panel 44 (e.g., a controller) that includes an analog-to-digital (A / D) converter 46, a microprocessor 48, non-volatile memory 50, and / or an interface board 52. In some embodiments, the vapor compression system 30 may include one or more of a variable speed drive (VSD) 54 and a motor 56. The motor 56 may drive the compressor 36 and may be powered by the VSD 54. The VSD 54 is configured to receive AC power with a specific fixed line voltage and fixed line frequency from an alternating current (AC) power source and to supply the motor 56 with power with variable voltage and frequency to drive the operation of the compressor 36. In other embodiments, the motor 56 may be directly powered by an AC or direct current (DC) power source. The motor 56 may include any type of motor that can be powered by the VSD 54 or directly by an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically rectified permanent magnet motor, or another suitable motor.

[0028] Compressor 36 is configured to compress refrigerant vapor within refrigerant circuit 34 and deliver the compressed refrigerant vapor to oil separator 58, which is configured to separate oil from the refrigerant vapor. The refrigerant vapor is then directed along refrigerant circuit 34 to condenser 38, and the oil is returned to compressor 36. The refrigerant vapor delivered to condenser 38 can transfer heat to a cooling fluid at condenser 38. For example, the cooling fluid can be ambient air 60 forced across the heat exchanger coils of condenser 38 by condenser fan 62. Through heat transfer with the cooling fluid (e.g., ambient air 60), the refrigerant vapor within the heat exchanger coils can condense into refrigerant liquid in condenser 38.

[0029] The liquid refrigerant exits the condenser 38 and continues flowing along the refrigerant loop 34 to the first expansion device 64 (e.g., expansion device 40, electronic expansion valve, etc.). The first expansion device 64 may be a flash tank feed valve configured to control the flow of liquid refrigerant to the flash tank 32. The first expansion device 64 is also configured to reduce the pressure of the liquid refrigerant received from the condenser 38 (e.g., to expand the liquid refrigerant). During the expansion process, a portion of the liquid refrigerant may evaporate, and therefore the flash tank 32 can be used to separate the vaporized refrigerant from the liquid refrigerant received from the first expansion device 64. Additionally, the flash tank 32 can provide further expansion of the liquid refrigerant due to the pressure drop experienced by the liquid refrigerant upon entering the flash tank 32 (e.g., due to the rapid increase in volume experienced by the liquid refrigerant upon entering the flash tank 32).

[0030] Vaporized refrigerant in flash tank 32 can exit and flow along refrigerant circuit 34 to compressor 36. For example, vaporized refrigerant can be drawn into an intermediate or discharge stage (e.g., not the suction stage) of compressor 36. Valve 66 (e.g., economizer valve, solenoid valve, etc.) can be included in refrigerant circuit 34 to control the flow of vaporized refrigerant from flash tank 32 to compressor 36. In some embodiments, when valve 66 is open (e.g., fully open), additional liquid refrigerant in flash tank 32 can evaporate and provide additional subcooling of the liquid refrigerant in flash tank 32. Due to the expansion of the liquid refrigerant at the first expansion device 64 and / or flash tank 32, the enthalpy of the liquid refrigerant collected in flash tank 32 may be lower than the enthalpy of the liquid refrigerant leaving condenser 38. Liquid refrigerant can flow from flash tank 32 through second expansion device 68 (e.g., expansion device 40, orifice, etc.) and to evaporator 42. In some embodiments, the refrigerant circuit 34 may further include a valve 70 (e.g., a drain valve) configured to regulate the flow of liquid refrigerant from the flash tank 32 to the evaporator 42. For example, the valve 70 may be controlled based on the amount of suction superheat of the liquid refrigerant (e.g., via control panel 44).

[0031] The liquid refrigerant delivered to evaporator 42 may absorb heat from a conditioning fluid, which may or may not be the same cooling fluid used in condenser 38. The liquid refrigerant in evaporator 42 may undergo a phase change to become vapor refrigerant. For example, evaporator 42 may include a bundle of tubes fluidly connected to supply line 72 and return line 74, which are connected to a cooling load (e.g., air handler 18). A conditioning fluid (e.g., water, oil, calcium chloride brine, sodium chloride brine, or any other suitable fluid) enters evaporator 42 via return line 74 and exits evaporator 42 via supply line 72. Evaporator 42 may reduce the temperature of the conditioning fluid in the tube bundle via heat transfer with the refrigerant, making the conditioning fluid available to provide cooling to the conditioned environment. The tube bundle in evaporator 42 may include multiple tubes and / or multiple tube bundles. In any case, refrigerant vapor exits evaporator 42 and returns to compressor 36 via suction line to complete the refrigerant cycle.

[0032] As described above, the vapor compression system 30 may include one or more microchannel heat exchangers. For example, the evaporator 42 and / or condenser 38 may include one or more microchannel heat exchangers. It should be understood that a microchannel heat exchanger includes a plurality of microchannel tubes, each of which includes a plurality of flow paths (e.g., microchannels, working fluid flow paths, etc.) formed therein. As discussed in detail below, this technology relates to a microchannel heat exchanger having at least two microchannel tubes with different dimensions, such as different widths or lateral dimensions. A microchannel tube with a larger width or lateral dimension provides an increased heat transfer surface area and / or an increased microchannel flow path area, which enables improved heat transfer between the working fluid and the conditioning fluid, as well as a reduced working fluid pressure drop across the microchannel heat exchanger. The microchannel tube with a larger width or lateral dimension is fluidly coupled to the manifold of the microchannel heat exchanger at an angle (e.g., an angle of inclination relative to the longitudinal axis of the manifold) to enable a reduction in the size of the manifold and the combination of the microchannel tube with a larger width or lateral dimension. It should be understood that the techniques described herein can be combined with microchannel heat exchangers to be implemented in any suitable HVAC system, such as coolers, combined air conditioners, split air conditioners, etc.

[0033] With this in mind, Figure 3 This is a schematic diagram of a microchannel heat exchanger 100 having a plurality of microchannel tubes 102 connected to a manifold 104 of the microchannel heat exchanger 100. Specifically, a first manifold 106 is connected to a first end 108 of each microchannel tube 102, and a second manifold 110 is connected to a second end 112 of each microchannel tube 102. It should be understood that each microchannel tube 102 includes a plurality of channels or flow paths formed therethrough to guide the flow of working fluid between the first manifold 106 and the second manifold 108. In a particular embodiment, the microchannel heat exchanger 100 may be used as a condenser 38 within a vapor compression system 30. For example, the microchannel heat exchanger 100 may be a component of a cooler 12 (e.g., an air-cooled cooler) and may be exposed to the surrounding environment to enable heat exchange between refrigerant guided through the microchannel tubes 102 and ambient air flow guided across the microchannel heat exchanger 100. In some embodiments, the microchannel heat exchanger 100 may be a heat exchanger plate of the condenser 38 and may be combined with one or more other microchannel heat exchangers 100 of the condenser 38 (e.g., arranged in a V- or W-shaped configuration).

[0034] In the illustrated embodiment, the microchannel heat exchanger 100 is a dual-pass heat exchanger. For this purpose, the microchannel tubes 102 may be divided or grouped into a first subgroup 114 (e.g., a first plurality, a first passage, etc.) and a second subgroup 116 (e.g., a second plurality, a second passage, etc.) of the microchannel tubes 102. Furthermore, the first manifold 106 is divided into a first section 118 and a second section 120 by a baffle 122 disposed within the first manifold 106. In operation, a working fluid (e.g., vapor refrigerant discharged by the compressor 36) may enter the first section 118 of the first manifold 106 (as indicated by arrow 124) and may subsequently flow into the first subgroup 114 of the microchannel tubes 102. As indicated by arrow 126, the working fluid is guided toward the second manifold 110 through the first subgroup 114 of the microchannel tubes 102. The working fluid then flows from the first subgroup 114 of the microchannel tube 102 into the second manifold 110, and the second manifold 110 directs the working fluid to the second subgroup 116 of the microchannel tube 102, as indicated by arrow 128. Thereafter, the working fluid is directed through the second subgroup 116 of the microchannel tube 102 (as indicated by arrow 130) and into the second section 120 of the first manifold 106, from which the working fluid is discharged from the microchannel heat exchanger 100 (as indicated by arrow 132) to continue flowing along the refrigerant circuit 34.

[0035] In some embodiments, the microchannel heat exchanger 100 may be configured to operate as a condenser (such as condenser 38). Therefore, the microchannel heat exchanger 100 can be used to transfer heat from a working fluid to a cooling fluid directed across the microchannel heat exchanger 100, thereby cooling (e.g., condensing) the working fluid. In some embodiments, a first portion of the microchannel heat exchanger 100 may be used to condense the working fluid, and a second portion of the microchannel heat exchanger 100 may be used to subcool the working fluid (e.g., after the working fluid has been condensed by the first portion of the microchannel heat exchanger 100). For example, the first portion may include a first subgroup 114 of the microchannel tubes 102 that at least partially condenses the working fluid from vapor to liquid. The second portion may include a second subgroup 116 of the microchannel tubes 102 that may be used to at least partially subcool the working fluid (e.g., reduce the temperature of the working fluid to above or below its saturation temperature).

[0036] While the illustrated embodiments include five microchannel tubes 102 in a first subgroup 114 and five microchannel tubes 102 in a second subgroup 116, it should be understood that other embodiments may have any suitable number of microchannel tubes in the first subgroup 114 and the second subgroup 116. For example, the first subgroup 114 may comprise about 60% of the total number of microchannel tubes 102 in the microchannel heat exchanger 100, and the second subgroup 116 may comprise about 40% of the total number of microchannel tubes 102 in the microchannel heat exchanger 100. In another embodiment, the first subgroup 114 may comprise about two-thirds of the total number of microchannel tubes 102 in the microchannel heat exchanger 100, and the second subgroup 116 may comprise about one-third of the total number of microchannel tubes 102 in the microchannel heat exchanger 100. The corresponding number of microchannel tubes 102 included in the first subgroup 114 and the second subgroup 116 may depend on any of a variety of factors, such as the expected or predicted operating parameters (e.g., flow rate, temperature, etc.) of the airflow guided across the microchannel heat exchanger 100, the arrangement of the microchannel heat exchanger 100 within the vapor compression system 30 (e.g., as part of a V-shaped condenser 38 configuration or a plate), the expected or predicted cooling load of the vapor compression system 30, other operating parameters of the microchannel heat exchanger 100 and / or the vapor compression system 30, other factors related to the operation of the microchannel heat exchanger 100 and / or the vapor compression system 30, or any combination thereof.

[0037] As described above, the microchannel heat exchanger 100 includes at least two microchannel tubes 102 with different dimensions (e.g., width or lateral dimension). For example, each microchannel tube 102 in the first subgroup 114 of the microchannel tubes 102 may have a different width or lateral dimension than each microchannel tube 102 in the second subgroup 116 of the microchannel tubes 102. To better illustrate, Figure 4 It is along Figure 3 The cross-sectional view taken by line 4-4 shows the different widths of the microchannel tubes 102 of the microchannel heat exchanger 100. Specifically, in the illustrated embodiment, each microchannel tube 102 of the first subgroup 114 of the microchannel tubes 102 has a first width 150 or lateral dimension, and each microchannel tube 102 of the second subgroup 116 of the microchannel tubes 102 has a second width 152 or lateral dimension that is greater than the first width 150 or lateral dimension.

[0038] As used herein, the “width” or “lateral dimension” of the microchannel tube 102 may refer to the dimension of the microchannel tube 102 along its axis 154, which extends through each microchannel 156 (e.g., a flow path) of the microchannel tube 102. That is, the axis 154 passes through and / or extends along the microchannel tube 102 in the direction in which the microchannels 156 are arranged within the microchannel tube 102. In some embodiments, the width or lateral dimension may refer to the dimension of the microchannel tube 102 extending between its sides or edges (e.g., lateral sides or edges) 158 (such as upstream and downstream edges (e.g., relative to the direction of airflow guided across the microchannel heat exchanger 100)).

[0039] In the illustrated embodiment, each microchannel tube 102 in the first subgroup 114 is fixed and fluidly coupled to the first manifold 106 (e.g., the first segment 118) such that a first width 150 of each microchannel tube 102 extends substantially perpendicular to (e.g., intersecting, at an angle 159, at approximately 90 degrees, etc.) the longitudinal axis 160 of the first manifold 106. Thus, when the first manifold 106 is arranged in a substantially vertical orientation, the first width 150 of each microchannel tube 102 extends in a substantially horizontal orientation, as shown. The microchannel tubes 102 of the first subgroup 114 may also be arranged to be substantially aligned with the direction 161 of the airflow across the microchannel heat exchanger 100. Each microchannel tube 102 in the first subgroup 114 may similarly be fixed and fluidly coupled to the second manifold 110.

[0040] Each microchannel tube 102 in the second subgroup 116 is fluidly coupled to the first manifold 106 (e.g., the second segment 120) such that the second width 152 of each microchannel tube 102 extends at an angle 162 (e.g., non-acute) relative to the longitudinal axis 160 of the first manifold 106 and / or relative to the direction 161 of the airflow across the microchannel heat exchanger 100. Each microchannel tube 102 in the second subgroup 116 may similarly be fixed and fluidly coupled to the second manifold 110. The tilt angle 162 can be any suitable size or value (e.g., 5 degrees, 10 degrees, 20 degrees, 30 degrees, 40 degrees, or 45 degrees) and can be selected based on a variety of factors, such as the expected or predicted operating parameters of the airflow guided across the microchannel heat exchanger 100 (e.g., flow rate, temperature, etc.), the arrangement of the microchannel heat exchanger 100 within the vapor compression system 30 (e.g., as part of a V-shaped condenser 38 configuration), the expected operating capacity or operating capacity range of the microchannel heat exchanger 100 and / or the vapor compression system 30 having the microchannel heat exchanger 100, other factors related to the operation of the microchannel heat exchanger 100, or any combination thereof. In some embodiments, the microchannel tubes 102 of the second subgroup 116 can extend at different tilt angles 162 relative to the longitudinal axis 150 and relative to each other.

[0041] It should be understood that the microchannel tubes 102 of the second subgroup 116 can be connected to the first manifold 106 at an angle 162 relative to the longitudinal axis 160, so that a microchannel tube 102 having a second width 152 can be implemented, wherein the first manifold 106 has a smaller size. In other words, if the microchannel tubes 102 of the second subgroup 116 were instead oriented in a generally horizontal and / or vertical arrangement (e.g., similar to the arrangement of the first subgroup 114 of the microchannel tubes 102), a larger-sized manifold 106 would be used with the microchannel heat exchanger 100. However, with the disclosed arrangement and orientation of the second subgroup 116 of the microchannel tubes 102, the first manifold 106 can have a reduced size, thereby enabling a reduction in the manufacturing costs associated with using the microchannel tubes 102 having a second width 152. In fact, in some embodiments, the second width 152 of the second subgroup 116 of the microchannel tube 102 may be greater than the diameter 164 of the first manifold 106, but the orientation of the second subgroup 116 of the microchannel tube 102 at an angle 162 may allow the second width 152 to be adapted to the diameter 161 of the first manifold 106.

[0042] The embodiment of the microchannel tube 102 having a second width 152 enables several performance advantages of the microchannel heat exchanger 100 and the vapor compression system 30, wherein the second width is greater than the first width 150 of the microchannel tubes 102 in the first subgroup. For example, the increased second width 152 provides an increased heat transfer surface area for the second subgroup 116 of the microchannel tubes 102. In other words, because the second width 152 is greater than the first width 150, the outer surface 166 of each microchannel tube 102 in the second subgroup 116 can have a larger area than the outer surface 168 of each microchannel tube 102 in the first subgroup 114. Similarly, the heat exchanger fins of the second subgroup 116 of the microchannel tubes 102 can also have an increased size (e.g., an increased width) compared to the heat exchanger fins of the first subgroup 114 of the microchannel tubes 102, which further allows for an increase in heat transfer surface area. Therefore, the overall heat transfer capacity of the microchannel heat exchanger 100 is improved.

[0043] Furthermore, the second subgroup 116 of the microchannel tubes 102 can be used in a portion of the working fluid of the microchannel heat exchanger 100, configured to be subcooled and guided through the microchannel heat exchanger 100, as discussed above. For example, the second subgroup 116 of the microchannel tubes 102 can be positioned downstream of the first subgroup 114 of the microchannel tubes 102 relative to the flow path of the working fluid through the microchannel heat exchanger 100. That is, the working fluid flowing through the microchannel heat exchanger 100 can first flow through the first subgroup 114 of the microchannel tubes 102 (e.g., to condense the working fluid), and then flow through the second subgroup 116 of the microchannel tubes 102 (e.g., to subcool the working fluid). Therefore, the increased heat transfer capacity of the second subgroup 116 of the microchannel tubes 102 and the corresponding fins connected thereto enables additional subcooling of the working fluid. In this way, the cooling capacity of the vapor compression system 30 can be increased, and more efficient operation of the vapor compression system 30 can be achieved.

[0044] It should be understood that the working fluid may be more susceptible to pressure drop when guided through a flow path such as microchannel 156. Advantageously, the disclosed embodiments also enable the reduction of pressure drop of the working fluid (e.g., subcooled working fluid) guided through the microchannel heat exchanger 100. More specifically, the second width 152 of the microchannel tubes 102 in the second subgroup 116 allows for an increase in the size of the flow path area of ​​the microchannel 156 in each microchannel tube 102 of the second subgroup 116. For example, in the illustrated embodiment, each microchannel tube 102 in the second subgroup 116 includes more microchannels 156 compared to each microchannel tube 102 in the first subgroup 114 of the microchannel tubes 102. In other or alternative embodiments, the increased size of the microchannel tubes 102 in the second subgroup 116 (e.g., the second width 152) allows for an increase in the size of the microchannels 156 in the microchannel tubes 102 of the second subgroup 116 (e.g., diameter 170, cross-sectional area, etc.). For example, the diameter 170 of one or more microchannels 156 in the microchannel tube 102 of the second subgroup 116 may be larger than the diameter 172 of one or more microchannels 156 in the microchannel tube 102 of the first subgroup 114. In this way, the cumulative flow path area of ​​the microchannel tube 102 of the second subgroup 116 can be increased, which makes it possible to reduce the velocity of the working fluid guided through it and thus reduce the pressure drop of the working fluid guided through the microchannel tube 102 of the second subgroup 116.

[0045] The disclosed technology can also be implemented in embodiments of the microchannel heat exchanger 100 with different configurations. In practice, the microchannel heat exchanger 100 may have different numbers of microchannel tubes 102, different numbers of subgroups of microchannel tubes 102, different orientations of microchannel tubes 102, and different dimensions of microchannel tubes 102 (e.g., width, lateral dimensions, etc.) (e.g., within a common subgroup of microchannel tubes 102). For example, a first subgroup 114 and / or a second subgroup 116 of microchannel tubes 102 may include a first number of microchannel tubes 102 positioned in a first orientation (e.g., perpendicular to the longitudinal axis 160 of the first manifold 106) and a second number of microchannel tubes 102 positioned in a second orientation (e.g., at an angle relative to the longitudinal axis 160 of the first manifold 106). In some embodiments, subgroups of microchannel tubes 102 may be grouped based on the pathways in which the microchannel tubes 102 of the microchannel heat exchanger 100 are located and / or based on the orientation of the microchannel tubes 102 (e.g., relative to the longitudinal axis 160 of the manifold 104) (e.g., perpendicular to the longitudinal axis 106 of the manifold 104 and / or the direction of airflow 161, at an angle relative to the longitudinal axis 160 of the manifold 104 and / or the direction of airflow 161, etc.).

[0046] The spacing between each of the microchannel tubes 102 (e.g., along the longitudinal axis 160 of the first manifold 106) may also vary and / or be selected based on different operating parameters of the microchannel heat exchanger 100 and / or the vapor compression system 30. In some embodiments, the manifold 104 may have different configurations. For example, in one embodiment, a first segment 118 of the first manifold 106 may have a first size (e.g., a first diameter 164 dimension), and a second segment 120 of the first manifold 106 may have a second size (e.g., a second diameter 164 dimension) different from the first size. In practice, many variations of the configuration of the microchannel heat exchanger 100 can be utilized, and these variations can be combined with preset techniques.

[0047] In any case, the orientation of at least a portion of the microchannel tube 102 at an angle 162 to the manifold 104 enables improved heat transfer between the working fluid and the airflow guided across the microchannel heat exchanger 100, reduces the pressure drop of the working fluid flowing through the microchannel heat exchanger 100, and improves the operation of the vapor compression system 30. More specifically, a particular microchannel tube 102 may be larger (e.g., wider) than other microchannel tubes 102 and may be fixed to the manifold 104 of the microchannel heat exchanger 100 at an angle 162 to provide improved heat transfer and reduced working fluid pressure drop, while also utilizing a manifold 104 with a smaller diameter 164.

[0048] Although only specific features and embodiments of this disclosure have been shown and described, many modifications and variations (e.g., variations in the size, dimensions, structure, shape and proportion of various elements, parameter values ​​(e.g., temperature, pressure, etc.), installation arrangements, material use, color, orientation, etc.) will occur to those skilled in the art without substantially departing from the novel teachings and advantages of the subject matter described in the claims. The order or sequence of any process or method steps may be varied or reordered according to alternative embodiments. Therefore, it should be noted that the appended claims are intended to cover all such modifications and variations falling within the true spirit of this disclosure. Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual implementations (i.e., those features irrelevant to the currently envisioned best mode for implementing this disclosure, or those features irrelevant to implementing the claimed embodiments) may not have been described. It should be understood that in the development of any such actual implementation, as in any engineering or design project, a large number of implementation-specific decisions may be made. Such development work may be complex and time-consuming, but these are routine tasks of design, manufacture, and production for those skilled in the art who benefit from this disclosure, without requiring excessive experimentation.

[0049] The technical references presented and asserted herein are applied to tangible objects and specific examples of practical nature that demonstrate improvements to the technical field of the invention and are therefore not abstract, intangible, or purely theoretical. Furthermore, if any claim appended to this specification contains one or more elements expressed as "means for [performing] [function]..." or "steps for [performing] [function]...", such elements are intended to be interpreted in accordance with 35U.SC112(f). However, for any claim containing elements specified in any other manner, it is intended that such elements not be interpreted in accordance with 35U.SC112(f).

Claims

1. A heat exchanger for a heating, ventilation, and / or air conditioning (HVAC) system, comprising: manifold, the manifold including a longitudinal axis; A plurality of microchannel tubes, the plurality of microchannel tubes being coupled to the manifold, wherein each of the plurality of microchannel tubes includes a first width; and A second plurality of microchannel tubes are connected to the manifold, wherein each of the second plurality of microchannel tubes includes a second width greater than the first width. The second width extends along the second axis, and the second axis extends at an angle relative to the longitudinal axis.

2. The heat exchanger of claim 1, wherein the first width extends along a first axis of a microchannel extending through a corresponding microchannel of one of the first plurality of microchannel tubes, and the second axis extends through a microchannel of a corresponding microchannel of one of the second plurality of microchannel tubes.

3. The heat exchanger of claim 2, wherein each of the first plurality of microchannel tubes is connected to the manifold such that the first axis of each microchannel tube extends substantially perpendicular to the longitudinal axis.

4. The heat exchanger according to claim 1, wherein the tilt angle is 45 degrees or less.

5. The heat exchanger of claim 1, wherein the first plurality of microchannel tubes define a first passage of the heat exchanger, and the second plurality of microchannel tubes define a second passage of the heat exchanger.

6. The heat exchanger of claim 1, wherein the heat exchanger is a condenser, the first plurality of microchannel tubes are configured to condense the working fluid received via the manifold, and the second plurality of microchannel tubes are configured to subcool the working fluid and guide the working fluid into the manifold.

7. The heat exchanger of claim 1, wherein each of the first plurality of microchannel tubes includes a first plurality of microchannels defining a first flow path, each of the second plurality of microchannel tubes includes a second plurality of microchannels defining a second flow path, and the cross-sectional area of ​​the second flow path is greater than the cross-sectional area of ​​the first flow path.

8. The heat exchanger according to claim 7, wherein the number of the second plurality of microchannels in each of the second plurality of microchannel tubes is greater than the number of the first plurality of microchannels in each of the first plurality of microchannel tubes.

9. The heat exchanger of claim 7, wherein the diameter of each microchannel of each microchannel in the second plurality of microchannel tubes is greater than the diameter of each microchannel in each microchannel of the first plurality of microchannel tubes.

10. A heat exchanger for a heating, ventilation, and / or air conditioning (HVAC) system, comprising: manifold, the manifold including a longitudinal axis; A plurality of microchannel tubes, the plurality of microchannel tubes being coupled to the manifold and configured to guide working fluid flow through them, wherein each of the plurality of microchannel tubes includes a first width extending at a first angle relative to the longitudinal axis; and A second plurality of microchannel tubes, coupled to the manifold and configured to guide the working fluid flow through it, wherein each of the second plurality of microchannel tubes includes a second width extending at a second angle relative to the longitudinal axis. The first angle and the second angle are different from each other.

11. The heat exchanger according to claim 10, wherein the second angle is an inclination angle.

12. The heat exchanger of claim 10, wherein the second width is greater than the first width.

13. The heat exchanger of claim 10, wherein the first microchannel tube in the first plurality of microchannel tubes comprises a first plurality of microchannels, the second microchannel tube in the second plurality of microchannel tubes comprises a second plurality of microchannels, and the first number of the first plurality of microchannels is less than the second number of the second plurality of microchannels.

14. The heat exchanger of claim 10, wherein the first microchannel tube of the first plurality of microchannel tubes includes a first plurality of microchannels defining a first flow path, the second microchannel tube of the second plurality of microchannel tubes includes a second plurality of microchannels defining a second flow path, and the first cross-sectional area of ​​the first flow path is smaller than the second cross-sectional area of ​​the second flow path.

15. The heat exchanger of claim 10, wherein the second plurality of microchannel tubes are located downstream of the first plurality of microchannel tubes relative to the direction in which the working fluid flows through the heat exchanger.

16. A heat exchanger for a heating, ventilation, and / or air conditioning (HVAC) system, comprising: manifold, the manifold including a longitudinal axis; A plurality of microchannel tubes, the plurality of microchannel tubes being coupled to the manifold and configured to guide working fluid flow through them, wherein each of the plurality of microchannel tubes includes a first width extending at a first angle relative to the longitudinal axis; and A second plurality of microchannel tubes, coupled to the manifold and configured to guide the working fluid flow through it, wherein each of the second plurality of microchannel tubes includes a second width extending at a second angle relative to the longitudinal axis. Wherein, the second width is greater than the first width, and the first angle and the second angle are different from each other.

17. The heat exchanger of claim 16, wherein the first angle is ninety degrees and the second angle is an inclination angle.

18. The heat exchanger of claim 16, wherein the first plurality of microchannel tubes define a first passage of the heat exchanger, and the second plurality of microchannel tubes define a second passage of the heat exchanger.

19. The heat exchanger of claim 16, wherein the first microchannel tube of the first plurality of microchannel tubes includes a first plurality of microchannels defining a first flow path, and the second microchannel tube of the second plurality of microchannel tubes includes a second plurality of microchannels defining a second flow path, and wherein... The first number of the first plurality of microchannels is less than the second number of the second plurality of microchannels, the first cross-sectional area of ​​the first flow path is less than the second cross-sectional area of ​​the second flow path, or both are true.

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