MICROCHANNEL HEAT EXCHANGER

Abstract

 A heat exchanger (100) is disclosed. The heat exchanger (100) comprises an inlet header (102) that comprises first compartments (104-1... 104-N) separated by first walls (106-1... 106-N), a plurality of microchannel tubes (108) extending between and in fluidic connection with the first compartments (104-1... 104-N) and an outlet header (110) of the heat exchanger (100), and a first distributor (200) comprising an inlet port (202) and a plurality of outlet ports (204). A plurality of feeder pipes (206) is configured between the first compartments (104-1... 104-N) of the inlet header (102) and the outlet ports (204) of the first distributor (200), such that each of the first compartments (104-1... 104-N) remains fluidically connected to one of the outlet ports (204) of the first distributor (200) by one of the feeder pipes (206) to allow the flow of an equal volume of fluid from the first distributor (200) into each of the first compartments (104-1... 104-N). Further, a second distributor is configured within the inlet header (102) to mix and allow the flow of fluid into each of the first compartments (104-1... 104-N).

Description

BACKGROUND

[0001] This invention relates to a microchannel heat exchanger.

SUMMARY

[0002] According to a first aspect of the invention there is provided a heat exchanger. The heat exchanger comprises an inlet header that comprises first compartments separated by first walls, a plurality of microchannel tubes extending between and in fluidic connection with the first compartments and an outlet header of the heat exchanger, a first distributor comprising an inlet port and a plurality of outlet ports, wherein a plurality of feeder pipes is configured between the first compartments of the inlet header and the outlet ports of the first distributor, such that each of the first compartments remains fluidically connected to one of the outlet ports of the first distributor by one of the feeder pipes to allow flow of an equal volume of fluid from the first distributor into each of the first compartments, and a second distributor configured within the inlet header or in the first compartments, the second distributor configured to mix and allow uniform flow of fluid into each of the microchannel tubes of the first compartments.

[0003] Optionally, the first distributor comprises a housing of a predefined shape that comprises the inlet port at a first end of the housing and the plurality of outlet ports at a second end of the housing, wherein the inlet port is in fluidic communication with the plurality of outlet ports via a plurality of fluidic passages extending within the housing.

[0004] Optionally, the first distributor has a solid conical shape that comprises a substantially circular base, and a curved lateral surface extending from a vortex end of the first distributor to the circular base, wherein the first distributor comprises the inlet port at the vortex end, and the plurality of outlet ports being configured circumferentially around the circular base and in fluidic communication with the inlet port via a plurality of fluidic passages.

[0005] Optionally, the inlet header is a hollow member having the first compartments, and the outlet header is a hollow member having second compartments separated by second walls, wherein a first end of the plurality of tubes is fluidically connected to at least one of the first compartments of the inlet header and a second end of the corresponding tube is fluidically connected to at least one of the second compartments of the outlet header.

[0006] Optionally, the heat exchanger comprises a fluid collector fluidically connected to the second compartments of the outlet header, wherein the collector device is configured to receive and collect the fluid from each of the second compartments.

[0007] Optionally, the inlet header and the outlet header are configured in a vertical orientation, with the plurality of tubes extending between the inlet header and the outlet header.

[0008] Optionally, the feeder tube associated with each of the first compartments is connected to a bottom end of the corresponding first compartment.

[0009] Optionally, the plurality of tubes is in a single-pass configuration.

[0010] Optionally, the plurality of tubes is in a multi-pass configuration comprising a predefined number of passes and a predefined number of turns.

[0011] Optionally, a number of tubes in a subsequent pass among the predefined number of passes is less than a number of tubes in a corresponding preceding pass.

[0012] Optionally, a number of tubes in a subsequent pass among the predefined number of passes is greater than a number of tubes in a corresponding preceding pass.

[0013] Optionally, adjacent passes among the predefined number of passes are fluidically connected by a flow-mixing device.

[0014] Optionally, the heat exchange section comprises a plurality of circuits, wherein each of the circuits comprises a group of tubes that is a subset of a total number of the plurality of tubes.

[0015] Optionally, the group of tubes associated with each of the refrigerant circuits comprises a predefined number of passes and a predefined number of turns.

[0016] Optionally, a first end of the group of tubes associated with each of the circuits is fluidically connected to one of the first compartments of the inlet header, and a second end of the group of tubes associated with each of the circuits is fluidically connected to one of the second compartments of the outlet header.

[0017] Optionally, the outlet ports of the first distributor are non-uniform in size such that different volume of fluid is provided in the first compartments of the inlet header.

[0018] Optionally, the feeder tubes have non-uniform predetermined diameters and predetermined lengths such that a predetermined target pressure drop is achieved in the feeder tubes.

[0019] Optionally, the second distributor comprises a distribution tube extending longitudinally through the first compartments, the distribution tube comprises a plurality of cavities extending longitudinally along a length of the distribution tube and configured radially around a central axis of the distribution tube, wherein each of the cavities comprises one or more ports opening in each of the first compartments.

[0020] Optionally, the second distributor comprises an elongated member extending within the inlet header through the first compartments, the elongated member comprises a plurality of fluid passages substantially parallel to each other and extending longitudinally along a length of the elongated member, and a plurality of outlet ports disposed on a face of the elongated member and fluidically connected to at least one of the outlet ports, wherein at least one of the outlet ports open in each of the first compartments.

[0021] Optionally, the second distributor comprises a plurality of distribution tubes extending longitudinally through the inlet header, such that each of the distribution tubes extends up to and remains fluidically connected to one of the first compartments of the inlet header.

[0022] Optionally, the inlet header and/or the outlet header comprises one or more orifice plates configured coaxially within the corresponding compartments.

[0023] Optionally, the heat exchanger comprises a plurality of heat-dissipating fins in thermal contact with the plurality of tubes.

[0024] Optionally, the heat exchanger is associated with one or more of a heating, ventilation, air-conditioning, and cooling (HVAC) system, and a transport refrigeration unit.

[0025] According to a second aspect of the invention there is provided a fluid distributor for a header comprising compartments separated by walls. The fluid distributor comprises a housing of a predefined shape that comprises an inlet port, and a plurality of outlet ports in fluidic communication with the inlet port via a plurality of fluidic passages extending within the housing. The fluid distributor further comprises a plurality of feeder pipes, wherein a first end of the feeder pipe is fluidically connected to one of the outlet ports of the housing, wherein a second end of the corresponding feeder pipe is configured to be fluidically connected to one of the compartments of the header to allow flow of an equal volume of fluid from the distributor into each of the compartments

[0026] Optionally, the housing has a solid conical shape that comprises a substantially circular base, and a curved lateral surface extending from a vortex end of the distributor to the circular base, wherein the housing comprises the inlet port at the vortex end, and the plurality of outlet ports being configured circumferentially around the circular base and in fluidic communication with the inlet port via the plurality of fluidic passages.

[0027] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, features, and techniques of the invention will become more apparent from the following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0029] In the drawings, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label. Certain exemplary embodiments will now be described in greater detail by way of example only and with reference to the accompanying drawings in which:

FIG. 1A illustrates an exemplary view of the heat exchanger having a single-pass configuration.

FIG. 1B illustrates an exemplary view of a single circuit heat exchanger having a multi-pass configuration.

FIG. 1C illustrates an exemplary view of a multi-circuit heat exchanger having a multi-pass configuration.

FIG. 1D illustrates an exemplary view of a heat exchanger comprising a distribution tube extending internally within the inlet header.

FIG. 1E illustrates an exemplary view of a multi-circuit heat exchanger having a multi-pass configuration comprising orifice plates within the first compartments for fluid mixing.

FIGs. 2A and 2B illustrate exemplary views of the first distributor.

FIG. 3 illustrates an exemplary view of the first distributor configured with feeder pipes.

FIG. 4 illustrates an exemplary view of the heat exchanger having a V-coil configuration.

DETAILED DESCRIPTION

[0030] The following is a detailed description of embodiments depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the invention. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.

[0031] Various terms are used herein. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.

[0032] In the specification, reference may be made to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the specification, the components of this invention. described herein may be positioned in any desired orientation. Thus, the use of terms such as "above," "below," "upper," "lower," "first", "second" or other like terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components, respectively, as the inlet header, outlet header, first distributor, multichannel tubes, heat exchanger, feeder pipes, and corresponding components, described herein may be oriented in any desired direction.

[0033] Microchannel heat exchangers (MCHX), also known as parallel-flow heat exchangers employing microchannel tubes are important components in many applications including heat pump systems, facilitating efficient heat transfer between different fluid streams. Microchannel heat exchangers use large number of parallel refrigerant flow channels configured as flat tubes, among which the refrigerant is distributed and flown in a parallel manner. The heat exchange tubes are oriented generally substantially perpendicular to a refrigerant direction in the inlet, intermediate, and outlet manifolds that are in flow communication with the heat exchange tubes. These heat exchangers are employed in a wide range of applications, including residential and commercial heating, ventilation, and air conditioning and refrigeration (HVACR) systems. The primary reasons for the deployment of the MCHX technology are related to its superior performance, high degree of compactness, lower cost and lower charge utilization. MCHX are now utilized in both condensers and evaporator applications for multiple products and system designs and configurations. The evaporator applications, although promising greater benefits and rewards, are more challenging and problematic. An important challenge in the design and operation of MCHX as evaporator is the uniform distribution of the working fluid (refrigerant) across all microchannels and tubes to ensure optimal heat transfer performance and capacity. The working fluid may be in two phases, vapor and liquid. When two phases are present, the two phases must be homogeneously mixed to facilitate effective distribution.

[0034] As known, refrigerant maldistribution in parallel-flow heat exchangers occurs because of unequal pressure fields inside the channels and in the inlet and outlet manifolds. In the manifolds, the difference in length of the refrigerant paths, phase separation, and gravity are the primary factors responsible for maldistribution. Internal to the tube channels, variations in the heat transfer rate, airflow distribution, nonuniformity of channel hydraulic diameter, and gravity are the dominant factors. Maldistribution of the working fluid within MCHX can lead to significant imbalances in thermal characteristics and a reduction in overall heat transfer efficiency. One of the primary concerns associated with mal-distribution is the varying heat transfer coefficient between the vapor and liquid phases. Due to the lower heat transfer coefficient of the vapor phase, an uneven distribution can result in localized areas of reduced heat transfer, leading to decreased capacity and overall performance of the heat pump system.

[0035] In the refrigerant systems utilizing microchannel heat exchangers, the inlet and outlet manifolds or headers usually have a conventional cylindrical shape with flat tubes inserted laterally such that the tube axis is substantially perpendicular to the header axis. When the two-phase flow enters the header, the vapor phase is usually separated from the liquid phase due to many factors mentioned before. Since the vapor phase occupies an overwhelmingly larger space than liquid and both phases flow independently, refrigerant maldistribution tends to occur.

[0036] The header (or manifold) forms a conduit to deliver working fluid to the heat exchange tubes. The header may be vertical, horizontal or some intermediate angle between vertical and horizontal. The header includes compartments dedicated to a group of heat exchange tubes which is a subset of the total number of heat exchange tubes. Typically, a distribution tube is located within the header to provide working fluid to the microchannel tubes of the compartments. The distribution tube may have cavities opening in the compartments to provide working fluid to the compartments of the header. Another embodiment of the internal distributor could be a tube with spaced ports on the body of the tube.

[0037] However, the problem of mal-distribution becomes exacerbated when the header of the MCHX is in a vertical configuration. In such configurations, the influence of gravity plays a role in causing separation between the vapor and liquid phases due to the differing densities of these phases. This vapor-liquid separation may lead to increased mal-distribution of fluid across the microchannel tubes and compromise the overall heat transfer efficiency of the system. Moreover, the maldistribution phenomenon may cause the two-phase (zero superheat) conditions at the exit of some tubes, promoting potential flooding of the compressor suction that may quickly lead to compressor failure.

[0038] There is a need for a solution to address the challenges posed by mal-distribution in MCHX, particularly in MCHX having vertical headers, by providing an improved and effective fluid distribution system that helps the MCHX achieve a more uniform distribution of the working fluid phases across all the microchannel tubes, thereby enhancing the overall thermal performance of the MCHX.

[0039] The term "feeder tubes" and "feeder pipe" may be used interchangeably to refer to the same feature thoughout the present application.

[0040] Referring to FIGs. 1A to 1E, the heat exchanger 100 can include an inlet header 102 comprising one or more hollow compartments 104-1 to 104-N (collectively designated as first compartments 104, herein) separated by one or more first walls 106-1 to 106-N (collectively referred to as first walls or first partition walls 106, herein). In addition, the heat exchanger can further include an outlet header 110, which may or may not include partitioned compartments. Further, the heat exchanger 100 can include a heat exchange section comprising a plurality of microchannel tubes (collectively designated as MCHX tubes 108, herein) extending between and fluidically connected to at least one of the first compartments 104-1 to 104-N and the outlet header 110. Furthermore, the heat exchange section of the heat exchanger 100 can include a plurality of heat-dissipating fins (F) in thermal contact with the plurality of tubes 108 to increase the exchange/transfer area of the tubes 108 and correspondingly enhance the heat exchange. In one or more embodiments, the heat exchanger can be associated with one or more of a heating, ventilation, air-conditioning, and cooling (HVAC) system, and a transport refrigeration unit, but is not limited to the like.

[0041] In one or more embodiments, the inlet header 102 and the outlet header 110 may be configured in a vertical orientation, with the plurality of tubes 108 extending between the inlet header 102 and the outlet header 110. However, the inlet header 102 and the outlet header 110 may also be horizontal or some intermediate angle between vertical and horizontal.

[0042] In one or more embodiments, the heat exchanger 100 can include an external fluid distributor 200 (also referred to as first distributor, herein) comprising an inlet port 202 and a plurality of outlet ports 204 (shown in FIG. 2A and 2B), where the inlet port 202 of the first distributor 200 can be fluidically connected to an expansion valve (EV) associated with the heat exchanger 100 to receive a fluid (two-phase refrigerant). Further, the heat exchanger assembly 100 can include a plurality of feeder pipes 206 (collectively referred to as feeder pipe 206, herein) configured between the first compartments 104 of the inlet header 102 and the outlet ports 204 of the first distributor 200, such that each of the first compartments 104 remains fluidically connected to one of the outlet ports 204 of the first distributor 200 by one of the feeder pipes 206 to allow flow of an equal volume of fluid (two-phase refrigerant supplied by the expansion valve EV) from the first distributor 200 into each of the first compartments 104.

[0043] In one or more embodiments, the first distributor 200 can include a housing of a predefined shape that can include the inlet port 202 at a first end of the housing and the plurality of outlet ports at a second end of the housing. Further, the inlet port 202 can be in fluidic communication with the plurality of outlet ports 204 via a plurality of fluidic passages extending within the housing. In one or more embodiments, the outlet ports 204 of the first distributor 200 can be non-uniform in size such that different volume of fluid can be provided in different first compartments 104 of the inlet header 102. This may overcome the effect of air flow maldistribution on the heat exchanger involving a fan, where the location of the fan or orientation of the fan with respect to the heat exchanger may cause the air flow maldistribution. Referring to FIG. 4, a heat exchanger 400 having a V-coil configuration is shown. The heat exchanger 400 can include a fan 402 which may cause air flow maldistribution. For instance, the section 'A' of the heat exchanger 400 may receive lesser air flow compared to the section 'B' of the heat exchanger 400. However, the non-uniform size of the outlet ports 204 of the first distributor 200 may cause different volume of fluid to flow in different first compartments 104 of the inlet header 102, such that negative effects of the air flow maldistribution may be mitigated. Similarly, the non-uniform size of the outlet ports 204 of the first distributor 200 may mitigate the negative effects of the air flow maldistribution in heat exchangers having other configurations as well.

[0044] Referring to FIGs. 2A and 2B, in one or more embodiments, the first distributor 200 can have a solid conical shape that can include a substantially circular base 208-1, and a curved lateral surface 208-3 extending from a vortex end 208-2 of the first distributor 200 to the circular base 208-1. The conical distributor 200 can include the inlet port 202 at the vortex end 208-2, and the plurality of outlet ports 204 being configured circumferentially around the circular base 208-1 and in fluidic communication with the inlet port via a plurality of fluidic passages to form a shower-head type construction. Further, referring to FIG. 3, the feeder pipes 206 can extend from the outlet ports 204 at the base 208-1 of the conical header 200 and can be further fluidically connected to the first compartments 104 of the inlet header 102 as shown in FIGs. 1A to 1C. In one or more embodiments, the diameter and length of the feeder tube 206 can be non-uniform having predetermined diameters and predetermined lengths such that a predetermined target pressure drop is achieved in the feeder tubes 206. In one or more embodiments, the predetermined diameters and predetermined lengths can be selected such equal pressure drop is achieved in all the feeder tubes 206 to supply equal volume of fluid through each of the feeder tubes 206.

[0045] It should be obvious to a person skilled in the art that while various embodiments of this invention have been elaborated for the first distributor 200 having a conical shape or shower-head type construction, however, the teachings of this specification are equally applicable for the first distributor 200 having a different shape or types as far as the outlet ports of the first distributor 200 are connected to each first compartment of the inlet header via the feeder pipes to supply an equal volume of the fluid comprising of liquid-vapor mixture from the expansion valve into the first compartments, and all such embodiments are well within the scope of this invention.

[0046] In one or more embodiments, the feeder pipe 206 associated with each of the first compartment 104 can be connected to the bottom end of the corresponding first compartment 104 to prevent accumulation of the fluid or creation of standing column of the fluid within the first compartments 104 of the header 102 and further facilitate even distribution of the fluid into the tubes 108, however, the feeder pipe 206 associated with each of the first compartment 104 may also be connected to a middle end or an upper end or other position in the corresponding first compartment 104 as long as the standing column of the fluid is not created in the compartments of the inlet header 102.

[0047] Accordingly, the fluid (two-phase refrigerant) supplied by the expansion valve EV can be received by the first distributor 200 at the inlet port 202 and the outlet ports 204 can further meter an equal or predetermined volume of the fluid into each of the first compartments 104 of the inlet header 102. In addition, the smaller volume of the first compartments 104 (compared to an inlet header of the same size and without any partition walls) can allow the fluid (received from the first distributor 200 via the feeder pipes 206) to be uniformly mixed and evenly distributed into the ports of the microchannel tubes 108 associated with the corresponding compartment 104. Additionally, an internal flow mixer or distribution device can be present. Thus, the heat exchanger 100 can achieve a more uniform distribution of the fluid across all the microchannel tubes 108, thereby enhancing the overall thermal performance of the heat exchanger 100.

[0048] In one or more embodiments, the outlet header 110 can also include one or more hollow compartments 112-1 to 112-N (collectively designated as second compartments 112, herein) separated by one or more second walls 114-1 to 114-N (collectively referred to as second walls or partition walls 114, herein). The inlet header 102 and the outlet header 110 can be hollow members having parallelly placed walls separated by a predefined distance to create the compartments therewithin. In one or more embodiments, the inlet header 102 and the outlet header 110 may have a cylindrical profile or a substantially curved profile with flat bases at the two opposite ends but is not limited to the like. Referring to FIG. 1C, in one or more embodiments, the heat exchanger 100 can include a fluid collector device 116 fluidically connected to the second compartments 112 of the outlet header 110. The collector device 116 can be configured to receive and collect the fluid from each of the second compartments 112.

[0049] In one or more embodiments, the first compartments 104 and/or the second compartments 112 may have equal volumes or the volumes may vary. When the compartment volumes vary the number of microchannel tubes 108 associated with the corresponding compartments 104, 112 may vary as well. In one or more embodiments, the heat exchange section can include a plurality of circuits 108-A to 108-N, where each circuit 108-A to 108-N can include a group of tubes 108 that can be a subset of a total number of the plurality of tubes 108 based on the volume of the corresponding compartment 104. Further, the group of tubes associated with each refrigerant circuit 108-A to 108-N can include a predefined number of passes and a predefined number of turns.

[0050] In one or more embodiments, in a single-pass configuration, the outlet header 110 may not have any partition walls. Further, a first end of the group of tubes 108 associated with each of the circuits can be fluidically connected to one of the first compartments 104 of the inlet header 102, and a second end of the corresponding group of tubes 108 associated with each of the circuits can be fluidically connected to the outlet header 110.

[0051] In one or more embodiments, in a multi-pass configuration, the outlet header 110 can include the second compartments 112. Further, a first end of the group of tubes 108 associated with each of the circuits can be fluidically connected to one of the first compartments 104 of the inlet header 102, and a second end of the corresponding group of tubes 108 associated with each of the circuits can be fluidically connected to one of the second compartments 112 of the outlet header 110. Furthermore, the group of tubes 108 associated with each of the circuits can include the predefined number of passes and the predefined number of turns.

[0052] In one or more embodiments, when the heat exchanger 100 is configured as an evaporator, the number of the tubes 108 in a subsequent pass among the predefined number of passes can be greater than the number of the tubes 108 in a corresponding preceding pass. In an example, as shown in FIG. 1C, the number of tubes in the pass P1 can be greater than the number of tubes in the pass P2. Further, the number of tubes in the pass P2 can be greater than the number of tubes in the pass P3.

[0053] In one or more embodiments, when the heat exchanger 100 is configured as a condenser, the number of the tubes 108 in a subsequent pass among the predefined number of passes can be less than the number of the tubes 108 in a corresponding preceding pass. In an example, as shown in FIG. 1C, the number of tubes 108 in the pass P1 can be less than the number of tubes 108 in the pass P2. Further, the number of tubes 108 in the pass P2 can be less than the number of tubes 108 in the pass P3.

[0054] In one or more embodiments, (not shown) each of the passes associated with the circuits can be fluidically connected by a flow-mixing device or an internal flow distribution device. An outlet end of the tubes 108 associated with a preceding pass can be connected to inlet(s) of the flow-mixing device and an inlet end of the tubes 108 associated with a subsequent pass can be connected to outlets of the flow-mixing device. Further, in one or more embodiments, the flow mixing device(s) can be disposed of in each of the second compartments 112 associated with the outlet header 110, however, the flow mixing device(s) can also remain outside of the outlet header 110.

[0055] Referring to FIG. 1D, in one or more embodiments, the second distributor of the inlet header 102 can include a distribution tube 118, that may or may not be partitioned, extending longitudinally through the first compartments 104-1 to 104-N over an entire length of the inlet header 102. The distribution tube 118 can include a plurality of cavities extending longitudinally along a length of the distribution tube 118, where the cavities can include one or more ports opening in each of the first compartments. The distribution tube 118 can include the plurality of cavities extending longitudinally along a length of the distribution tube 118 and configured radially around a central axis of the distribution tube, where each of the cavities can include the ports opening in each of the first compartments 104-1 to 104-N. In addition (not shown), the cavities of the distribution tube can be in the form of concentric rings, where the exterior of the distribution tube may have a stepped shape resulting from the termination of the ring after the ports opening in the destination compartment 104. Accordingly, the distribution tube 118 can act as an internal fluid distributor for the inlet header 102, which can receive fluid from the expansion valve (EV) and supply the fluid into each of the compartments 104 and further evenly distribute the fluid into the microchannel tubes associated with the corresponding compartment 104.

[0056] In one or more embodiments, the second distributor of the inlet header 102 can include a plurality of distribution tubes extending longitudinally through the inlet header 102, such that each of the distribution tubes extends up to and remains fluidically connected to one of the first compartments 104-1 to 104-N, thereby fluidically connecting the expansion valve (EV) to each of the first compartments 104-1 to 104-N of the inlet header 102. Accordingly, each of the distribution tubes can act as an internal fluid distributor for one of the first compartments 104 of the inlet header 102, which can receive fluid from the expansion valve (EV) and supply the fluid into the respective first compartments 104 and further evenly distribute the fluid into the microchannel tubes associated with the corresponding first compartment 104.

[0057] Referring to FIG. 1E, in one or more embodiments, in the multi-pass configuration, each of the first compartments 104 of the inlet header 102 and the second compartments 112 of the outlet header 110 can include an orifice plate 120 having openings. The orifice plate 120 can be configured coaxially within the inlet header 102. Further, a first end of the group of tubes 108 associated with each of the circuits can be fluidically connected to one of the first compartments 104 of the inlet header 102, and a second end of the corresponding group of tubes 108 associated with each of the circuits can be fluidically connected to one of the second compartments 112 of the outlet header 110, such that the fluid can flow between the first compartments 104 and the second compartments 112 while flowing through the orifice plates 120 and finally flowing out of the outlet header 110 into the fluid collector device 116.

[0058] It should be obvious to a person skilled in the art that while various embodiments of this invention have been elaborated for the headers having a specific number of compartments and the refrigerant circuits having a specific configuration and number of passes for the sake of simplicity and better explanation purpose, however, the teachings of this specification are equally applicable for the headers having a different number of compartments and the refrigerant circuits having a different number of passes and configuration, and all such embodiments are well within the scope of this invention.

[0059] Thus, this invention overcomes the drawbacks, limitations, and shortcomings associated with existing heat exchangers and corresponding fluid distributors by providing an improved, effective, and compact solution that helps the heat exchanger supply an equal volume of the fluid into the compartments of the inlet header and further helps achieve a more uniform distribution of the fluid phases across all the microchannel tubes, thereby enhancing the overall thermal performance of the heat exchanger.

[0060] While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention as defined by the appended claims. Modifications may be made to adopt a particular situation or material to the teachings of the invention without departing from the scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention includes all embodiments falling within the scope of the invention as defined by the appended claims.

[0061] In interpreting the specification, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refer to at least one of something selected from the group consisting of A, B, C .... and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.

Claims

1. A heat exchanger (100) comprising:

an inlet header (102) that comprises first compartments (104-1... 104-N) separated by first walls (106-1... 106-N);

a plurality of microchannel tubes (108) extending between and in fluidic connection with the first compartments and an outlet header (110) of the heat exchanger; and

a first distributor (200) comprising an inlet port (202) and a plurality of outlet ports (204), wherein a plurality of feeder pipes (206) is configured between the first compartments of the inlet header and the outlet ports of the first distributor, such that each of the first compartments remains fluidically connected to one of the outlet ports of the first distributor by one of the feeder pipes to allow flow of an equal volume of fluid from the first distributor into each of the first compartments; and

a second distributor configured within the inlet header or in the first compartments, the second distributor configured to mix and allow uniform flow of fluid into the microchannel tubes of each of the first compartments.

2. The heat exchanger (100) of claim 1, wherein the first distributor (200) comprises a housing of a predefined shape that comprises the inlet port (202) at a first end of the housing and the plurality of outlet ports (204) at a second end of the housing, wherein the inlet port is in fluidic communication with the plurality of outlet ports via a plurality of fluidic passages extending within the housing,
and/or,
wherein the first distributor (200) has a solid conical shape that comprises a substantially circular base (208-1), and a curved lateral surface (208-3) extending from a vortex end (208-2) of the first distributor to the circular base, wherein the first distributor comprises the inlet port (202) at the vortex end, and the plurality of outlet ports (204) being configured circumferentially around the circular base and in fluidic communication with the inlet port via a plurality of fluidic passages.

3. The heat exchanger (100) of claim 1 or 2, wherein the inlet header (102) is a hollow member having the first compartments (104-1... 104-N), and the outlet header (110) is a hollow member having second compartments (112-1... 112-N) separated by second walls (114-1... 114-N), and
wherein a first end of the plurality of tubes (108) is fluidically connected to at least one of the first compartments (104-1... 104-N) of the inlet header (102) and a second end of the corresponding tube is fluidically connected to at least one of the second compartments (112-1... 112-N) of the outlet header (110).

4. The heat exchanger (100) of any of claims 1 to 3 wherein the heat exchanger comprises a fluid collector (116) fluidically connected to the second compartments (112-1... 112-N) of the outlet header (110), wherein the collector device is configured to receive and collect the fluid from each of the second compartments.

5. The heat exchanger (100) of any of claims 1 to 4, wherein the inlet header (102) and the outlet header (110) are configured in a vertical orientation, with the plurality of tubes (108) extending between the inlet header and the outlet header,
and/or,
wherein the feeder tube (206) associated with each of the first compartments (104-1... 104-N) is connected to a bottom end of the corresponding first compartment.

6. The heat exchanger (100) of any of claims 1 to 5, wherein the plurality of tubes (108) is in a single-pass configuration.

7. The heat exchanger (100) of any of claims 1 to 5, wherein the plurality of tubes (108) is in a multi-pass configuration comprising a predefined number of passes and a predefined number of turns,

optionally,

wherein adjacent passes among the predefined number of passes are fluidically connected by a flow-mixing device.

8. The heat exchanger (100) of claim 7, wherein a number of the tubes (108) in a subsequent pass among the predefined number of passes is less than a number of the tubes in a corresponding preceding pass,
or,
wherein a number of the tubes (108) in a subsequent pass among the predefined number of passes is greater than a number of the tubes in a corresponding preceding pass.

9. The heat exchanger (100) of any preceding claim, wherein the heat exchange section comprises a plurality of circuits (108-A... 108-N), wherein each of the circuits comprises a group of tubes (108) that is a subset of a total number of the plurality of tubes,

optionally,

wherein the group of tubes (108) associated with each of the refrigerant circuits (108-A... 108-N) comprises a predefined number of passes and a predefined number of turns,

optionally,

wherein a first end of the group of tubes (108) associated with each of the circuits (108-A... 108-N) is fluidically connected to one of the first compartments (104-1... 104-N) of the inlet header (102), and a second end of the group of tubes associated with each of the circuits is fluidically connected to one of the second compartments (112-1... 112-N) of the outlet header (110).

10. The heat exchanger (100) of any of claims 1 to 9, wherein the outlet ports (204) of the first distributor (200) are non-uniform in size such that different volume of fluid is provided in the first compartments (104-1... 104-N) of the inlet header (102),
and/or,
wherein the feeder tubes (206) have non-uniform predetermined diameters and predetermined lengths such that a predetermined target pressure drop is achieved in the feeder tubes.

11. The heat exchanger (100) of any of claims 1 to 10, wherein the second distributor comprises a distribution tube (118) extending longitudinally through the first compartments (104-1... 104-N), the distribution tube comprises a plurality of cavities extending longitudinally along a length of the distribution tube and configured radially around a central axis of the distribution tube, wherein each of the cavities comprises one or more ports opening in each of the first compartments,
or,

wherein the second distributor comprises an elongated member extending within the inlet header (102) through the first compartments (104-1... 104-N), the elongated member comprises a plurality of fluid passages substantially parallel to each other and extending longitudinally along a length of the elongated member, and a plurality of outlet ports disposed on a face of the elongated member and fluidically connected to at least one of the outlet ports, wherein at least one of the outlet ports open in each of the first compartments,
or,

wherein the second distributor comprises a plurality of distribution tubes extending longitudinally through the inlet header (102), such that each of the distribution tubes extends up to and remains fluidically connected to one of the first compartments (104-1... 104-N) of the inlet header.

12. The heat exchanger (100) of any of claims 1 to 11, wherein the inlet header (102) and/or the outlet header (110) comprises one or more orifice plates (120) configured coaxially within the corresponding compartments.

13. The heat exchanger (100) of any of claims 1 to 12, wherein the heat exchanger comprises a plurality of heat-dissipating fins (F) in thermal contact with the plurality of tubes (108),
and/or,
wherein the heat exchanger (100) is associated with one or more of a heating, ventilation, air-conditioning, and cooling, HVAC, system, and a transport refrigeration unit.

14. A fluid distributor (200) for a header (102) comprising compartments (104-1... 104-N) separated by walls (106-1... 106-N), the fluid distributor comprising:

a housing of a predefined shape that comprises an inlet port (202), and a plurality of outlet ports (204) in fluidic communication with the inlet port via a plurality of fluidic passages extending within the housing; and

a plurality of feeder pipes (206), wherein a first end of the feeder pipe is fluidically connected to one of the outlet ports of the housing,

wherein a second end of the corresponding feeder pipe is configured to be fluidically connected to one of the compartments of the header to allow flow of an equal volume of fluid from the distributor into each of the compartments.

15. The fluid distributor (200) of claim 14, wherein the housing has a solid conical shape that comprises a substantially circular base (208-1), and a curved lateral surface (208-3) extending from a vortex end (208-2) of the distributor to the circular base, wherein the housing comprises the inlet port (202) at the vortex end, and the plurality of outlet ports (204) being configured circumferentially around the circular base and in fluidic communication with the inlet port via the plurality of fluidic passages.

Drawing