EP2947411A1

EP2947411A1 - Heat exchanger for air-conditioning device

Info

Publication number: EP2947411A1
Application number: EP13872232.7A
Authority: EP
Inventors: Atsushi Nagasawa
Original assignee: Toshiba Corp; Toshiba Consumer Electronics Holdings Corp; Toshiba Home Appliances Corp
Current assignee: Toshiba Lifestyle Products and Services Corp
Priority date: 2013-01-21
Filing date: 2013-11-27
Publication date: 2015-11-25
Also published as: JP2014139493A; WO2014112217A1; EP2947411A4; CN104919266A

Abstract

A heat exchanger for an air conditioner is provided with a plurality of microchannel portions and a plurality of fin portions. Each of the microchannel portions is shaped like a plate having a plurality of refrigerant flow channels provided therein and is spaced apart from one another while being provided with one side located in an upstream side of an incoming external airflow and one side located in a downstream side of the incoming external airflow, the microchannel portions being sloped so that the upstream side thereof is higher than the downstream side thereof. Each of the fin portions is disposed between and in contact with two adjacent microchannel portions. An end portion of each of the fin portions located in at least either of the upstream side or the downstream side of the incoming external airflow is located on an imaginary line linking end portions of the microchannel portions.

Description

TECHNICAL FIELD

Embodiments of the present invention relate to a heat exchanger for an air conditioning device.

BACKGROUND

A microchannel heat exchanger is one example of a heat exchanger used in an air conditioner. The microchannel heat exchanger is provided with a microchannel portion containing a plurality of refrigerant flow channels and a fin portion disposed in contact with the microchannel portion. The microchannel portion provided in these types of heat exchangers may be sloped to remove the dew condensate resulting from heat exchange. Such arrangement allows the dew condensate to fall by gravity along the sloped microchannel portion and thereby achieve efficient removal of the dew condensate.
The microchannel heat exchanger is assembled by positioning the plurality of microchannel portions and the fin portions, which were separately manufactured, according to a planned layout and thereafter bonding the microchannel portions and the fin portions by brazing, etc. Thus, when employing a sloped microchannel portion structure, it is difficult to position the fin portions along the sloped microchannel portion and results in poor manufacturability.

PRIOR ART DOCUMENTS

PATENT DOCUMENT

Patent Document 1: JP 2011-237062 A

SUMMARY OF THE INVENTION

PROBLEMS TO BE OVERCOME BY THE INVENTION

Thus, a heat exchanger for an air conditioner is provided in which improved manufacturability is achieved by facilitating assembly of the sloped microchannel portion and the fin portion.

MEANS FOR OVERCOMMING THE PROBLEMS

A heat exchanger for an air conditioner of the present embodiment is provided with a plurality of microchannel portions spaced apart from one another, each of the microchannel portions being shaped like a plate having a plurality of refrigerant flow channels provided therein and being provided with one side located in an upstream side of an incoming external airflow and one side located in a downstream side of the incoming external airflow, the microchannel portions being sloped so that the upstream side thereof is higher than the downstream side thereof; and a plurality of fin portions each disposed between and in contact with two adjacent microchannel portions. An end portion of each of the fin portions located in at least either of the upstream side or the downstream side of the incoming external airflow is located on an imaginary line linking end portions of the microchannel portions.

BRIEF DESCRIPTIONS OF THE DRAWINGS

[FIG.1] FIG.1 is a perspective view illustrating a heat exchanger of a first embodiment.
[FIG.2] FIG.2 is a front view of the heat exchanger.
[FIG.3] FIG.3 is a vertical cross-sectional side view of the heat exchanger.
[FIG.4] FIG.4 illustrates the relative positioning of microchannel portions and fin portions.
[FIG.5] FIG.5 is a transverse cross-sectional view of the fin portion illustrating the periphery of cut-raised portions.
[FIG.6] FIG. 6 is a schematic view illustrating the interior structure of an indoor unit of the air conditioner provided with the heat exchanger.
[FIG.7] FIG.7 illustrates an assembly jig of the heat exchanger.
[FIG.8] FIG.8 schematically illustrates an assembly sequence (a) to (d) of the heat exchanger.
[FIG.9] FIG.9 pertains to a second embodiment and corresponds to FIG.4.
[FIG.10] FIG.10 pertains to a third embodiment and corresponds to FIG.4.

EMBODIMENTS OF THE INVENTION

Embodiments of a heat exchanger for an air conditioner will be described hereinafter with reference to the drawings. Elements that are substantially identical across the embodiments are identified with identical reference symbols and are not re-described.

(FIRST EMBODIMENT)

First, a description will be given hereinafter on a first embodiment with reference to FIGS.1 to 8.
A heat exchanger 10 of the present invention is a microchannel type and is generally shaped like a rectangular plate as illustrated in FIGS.1 and 2. Heat exchanger 10 is provided with a refrigerant inlet 20, a refrigerant outlet 30, a plurality of microchannel portions 40, and a plurality of fin portions 50. In the present embodiment, the length-wise directions of the refrigerant inlet 20 and the refrigerant outlet 30 represent the longitudinal direction of the heat exchanger and the direction orthogonal to this direction, in other words, the length-wise direction of the microchannel portion 40 represents the lateral direction of the heat exchanger 10. Further, the direction orthogonal to the longitudinal direction as well as the lateral direction of the heat exchanger 10 represents the thickness-wise direction of the heat exchanger 10. In FIG.1, the longitudinal direction of the heat exchanger 10 is represented by arrow X, the lateral direction is represented by arrow Y and the thickness-wise direction is represented by arrow Z.
The heat exchanger 10 allows the supply of incoming external air to pass through the heat exchanger 10 along the thickness-wise direction to cause a heat exchange between the air and the refrigerant flowing within the heat exchanger 10. The arrow A indicated in the figures represents the direction in which the supply of incoming external air flows. In the example illustrated in FIG.1, the far left side of the page with respect to the heat exchanger 10 indicates the airflow upstream side and the near right side of the page with respect to the heat exchanger 10 indicates the airflow downstream side. Further, in FIGS.3 to 6, the left side of the page with respect to the heat exchanger 10 indicates the airflow upstream side and the right side of the page with respect to the heat exchanger 10 indicates the airflow downstream side.
As illustrated in FIGS.1 and 2, the refrigerant inlet 20 and the refrigerant outlet 30 are structured like a tube extending in a longitudinal direction of the heat exchanger 10. A plurality of microchannel portions 40 and a plurality of fin portions 50 are provided so as to be disposed between refrigerant inlet 20 and refrigerant outlet 30. The refrigerant inlet 20 and the refrigerant outlet 30 are each connected to a refrigerant pipeline 60 of the refrigeration cycle. The refrigerant flowing through the refrigerant pipeline is distributed to each microchannel portion 40 by the refrigerant inlet 20 as indicated by arrow B of FIGS.1 and 2 and thereafter passes through each microchannel portion 40 and discharged from the refrigerant pipeline 60 after being collected at refrigerant outlet 30.
The microchannel portion 40 is a flat plate member extending in the lateral direction of the heat exchanger 10 and is formed of a material having a relatively large thermal conductivity such as aluminum. Each of the microchannel portions 40 are spaced apart from one another along the longitudinal direction of the heat exchanger 10. The microchannel portion 40 is sloped with respect to the direction of airflow of the incoming external supply of air so as to be higher in the upstream side and lower in the downstream side. In other words, the microchannel portion 40 is downwardly sloped so as to become lower towards the downstream side of the direction of airflow. In this example, the angle in which the microchannel portion 40 is sloped with respect to the thickness-wise direction of the heat exchanger 10 is configured to α° as illustrated in FIG.3.
The microchannel portion 40 is somewhat thick and contains multiple refrigerant flow channels 41 extending in the length-wise direction of the microchannel portion 40, that is, in the lateral direction of the heat exchanger 10. The refrigerant flow channel 41 connects the refrigerant inlet 20 and the refrigerant outlet 30. The refrigerant in the refrigerant inlet 20 side flows toward the refrigerant outlet 30 side through each of the refrigerant flow channels 41.
The fin portion 50 is made of a material having relatively large thermal conductivity such as aluminum. The fin portion 50 is formed by for example alternately folding a thin plate of aluminum into an accordion fold as illustrated in FIGS.1 and 2. The fin portion 50 is structured to generally extend in the length-wise direction of the microchannel portion 40, that is, in the lateral direction of the heat exchanger 10. The fin portion 50 is disposed between two microchannel portions 40 adjacent in the longitudinal direction of the heat exchanger 10 so as to be sloped along the microchannel portions 40. A mountain folded upper portion 51 and a valley folded lower portion 52 of the fin portion 50 each contact a microchannel portion 40.
In FIG.4, the line linking the end portions 43 at the downstream side of each of the microchannel portions 40 is indicated as an imaginary front end line C of the microchannel portions 40. Further, the line linking the end portions 44 at the upstream side of each of the microchannel portions 40 is indicated as an imaginary rear end line D of the microchannel portions 40. The fin portions 50 are positioned so that at least either of the end portions 53, 54 in the upstream side or the downstream side of the incoming external airflow is located on the line linking the end portions 43, 44 of each of the microchannel portions 40. In this example, the end portions 53 in the downstream side of the fin portions 50 are located on the front end line C linking end portions 43 of the downstream side of each of the microchannel portions 40. Stated differently, the heat exchanger 10 is structured so that the end portions 43 in the most downstream side of the microchannel portions 40 and the end portions 53 in the most downstream side of the fin portions 50 as viewed along the thickness-wise direction of the heat exchanger 10 are aligned on the front end line C.
The fin portions 50 are provided with multiple cut-raised portions 55. The cut-raised portion 55 is formed by cutting and raising a portion of a plate member structuring the fin portion 50 as illustrated in FIG.5. Thus, the cut-raised portion 55 protrudes in the direction orthogonal to the direction of airflow of incoming external supply of air, that is, the direction indicated by arrow A. In this example, the upstream side of the cut-raised portion 55, with respect to the airflow passing through the heat exchanger 10, defines an opening.
Further, a slit 56 is formed as the result of forming the cut-raised portion 55. The cut-raised portion 55 and slit 56 extend in the longitudinal direction of the heat exchanger 10 and in this example, extends substantially in the vertical direction as illustrated in FIG.4. The cut-raised portion 55 partially disturbs the airflow passing through the heat exchanger 10 and thus, produces turbulence around the cut-raised portion 55. This improves the heat exchange performance of the fin portion 50.
The heat exchanger 10 is disposed inside an indoor equipment 100 of an air conditioner as illustrated in FIG.6 for example. The heat exchanger 10 is configured to perform heat exchange of incoming external supply of air by the ventilation performed by the blower 101 as indicated by arrow A of FIG.6. Though not illustrated in detail, the heat exchanger 10 may be disposed inside an outdoor equipment of an air conditioner.
Next, a description will be given on assembling of the heat exchanger 10 with reference to FIGS.7 and 8. The assembling of the heat exchanger 10 is performed by using a jig 110 illustrated for example in FIG. 7. In FIGS.7 and 8, the up and down direction of the page corresponds to the thickness-wise direction of the heat exchanger 10. In this example, the lower side of the page corresponds to the upstream side of airflow and the upper side of the page corresponds to the downstream side of airflow.
The jig 110 is formed of a base portion 111 and sidewalls 112. The base portion 111 is shape like a rectangular plate. The sidewalls 112 are provided at the two ends of the base portion 111 in the lateral direction of the heat exchanger 10 and extend along the longitudinal direction of the heat exchanger 10. The sidewalls 112 are provided so as to be orthogonal with respect to the base portion 111. One side of the base portion 111 on which the sidewalls 112 are provided is referred to as the front surface of the base portion 111 and the opposite side is referred to as the rear surface of the base portion 111.
Multiple grooves 113 are formed on the sidewalls 112 by entrenching the sidewalls 112 by notching. The grooves 113 are sloped by α° with respect to the direction orthogonal to the surface of the base portion 111, in other words, the thickness-wise direction of the heat exchanger 10. The slope angle of the microchannel portion 40 is determined by the slope angle α° of the grooves 113. The bottom portion 114 of the groove 113 is coplanar with the front surface of the base portion 111 or is located further toward the rear surface side of the base portion 111 from the front surface of the base portion 111.
The heat exchanger 10 is assembled as described in the following. First, separate pieces of microchannel portions 40 are each placed on the jig 110 as illustrated in FIG.8(a). In this example, the two length-wise end portions of the microchannel portions 40 are fitted into the grooves 113 of the jig 110. Then, the microchannel portions 40 are pushed in until the end portions 43 in the downstream side thereof are placed in contact with the front surface of the base portion 111. As a result, each of the microchannel portions 40 are positioned so as to be spaced apart from one another while being sloped by α° with respect to the thickness-wise direction of the heat exchanger 10.
Then, as illustrated in FIG.8(b), separate pieces of fin portions 50 are each inserted between two adjacent microchannel portions 40. The fin portions 50 are pressed in until the end portions 53 in the downstream side thereof are placed in contact with the front surface of the base portion 111. As a result, the end portions 43 in the downstream side of the microchannel portions 40 and the end portions 53 in the downstream side of the fin portions 50 are located in the same position taken along the thickness-wise direction of the heat exchanger 10. In other words, the microchannel portions 40 and the fin portions 50 are positioned so that the end portions 43 in the downstream side of the microchannel portions 40 and the end portions 53 in the downstream side of the fin portions 50 aligned along the longitudinal direction of the heat exchanger 10.
Then, as illustrated in FIG.8(c), the jig 110 is removed from the assembly of microchannel portions 40 and fin portions 50. The assembly is compressed in the longitudinal direction of the heat exchanger 10 and the upper portions 51 and the lower portions 52 of the fin portions 50 are placed in intimate contact with the microchannel portions 40. Then, as illustrated in FIG.8(d), the refrigerant inlet 20 and the refrigerant outlet 30 are attached to the two length-wise ends of each microchannel portion 40. Then, the assembly of the refrigerant inlet 20, the refrigerant outlet 30, microchannel portions 40, and the fin portions 50 are brazed in a furnace to bond each component together. The heat exchanger 10 is assembled in the above described manner.
Accordingly, the microchannel portion 40 is sloped with respect to the direction of airflow of the incoming external supply of air so as to be higher in the upstream side and lower in the downstream side. Thus, the dew condensate produced at the microchannel portions 40 drop not only by gravity but also along the flow of air supplied from the outside. It is thus, possible to efficiently remove the dew condensate produced at the microchannel portions 40.
Each of the fin portions 50 are positioned so that at least either of the end portions 53, 54 in the upstream side or the downstream side of the incoming external airflow are located on the line linking the end portions 43, 44 of each of the microchannel portions 40. In this example, the end portions 53 in the downstream side of the fin portions 50 are located on the front end line C linking the end portions 43 of the downstream side of each of the microchannel portions 40. Stated differently, the end portions 43 in the downstream side of the microchannel portions 40 and the end portions 53 in the downstream side of the fin portions 50 are in alignment along the longitudinal direction of the heat exchanger 10. Thus, even in a heat exchanger 10 in which the microchannel portions 40 are sloped, it is possible to readily position the fin portions 50 along the sloped microchannel portions 40 by using the jig 110 being simply structured as described above. It is thus, possible to improve the manufacturability of the heat exchanger 10.

(SECOND EMBODIMENT)

Next, a description is given on a second embodiment with reference to FIG.9. In FIG.9, the line linking the end portions 43 at the downstream side of each of the microchannel portions 40 is indicated as an imaginary front end line C of the microchannel portions 40 as was the case in the first embodiment. Further, the line linking the end portions 44 at the upstream side of each of the microchannel portions 40 is indicated as an imaginary rear end line D of the microchannel portions 40.
In the second embodiment, the end portions 53 in the downstream side of the fin portions 50 are located in the downstream side from the front end line C. That is, the fin portions 50 extend further toward the downstream side from the end portions 43 in the downstream side of the microchannel portions 40. The end portions 54 of the upstream side of the fin portions 50, on the other hand, are located on the rear end line D. That is, the heat exchanger 10 is structured so that the end portions 44 in the most upstream side of the microchannel portions 40 and the end portions 54 in the most upstream side of the fin portions 50 as viewed along the thickness-wise direction of the heat exchanger 10 are aligned on the rear end line D. Stated differently, the end portions 44 in the upstream side of the microchannel portions 40 and the end portions 54 in the upstream side of the fin portions 50 are in alignment along the longitudinal direction of the heat exchanger 10. In this example, when assembling the heat exchanger 10, the end portions 44 in the upstream side of the microchannel portions 40 and the end portions 54 in the upstream side of the fin portions 50 are placed in the jig 110 so as to be disposed on the base portion 111 side of the jig 110.
Accordingly, the end portions 53 in the downstream side of the fin portions 50 extend further toward the downstream side from the end portions 43 in the downstream side of the microchannel portions 40. Thus, the dew condensate produced at the microchannel portion 40 flows along the fin portion 50 toward the downstream side of the fin portion 50 and falls from the vicinity of the end portion 53 in the downstream side. The dew condensate having fallen from the vicinity of the end portion 53 in the downstream side of the fin portion 50 falls downward without falling onto other microchannel portions 40 located further downward. It is thus, possible to prevent the dew condensate falling from the fin portion 50 from contacting the microchannel portions located further downward and thereby allowing the dew condensate produced at the microchannel portion to be removed more efficiently.
Further, the end portions 44 in the upstream side of the microchannel portions 40 and the end portions 54 in the upstream side of the fin portions 50 are aligned on the rear end line D taken along the longitudinal direction of the heat exchanger 10. Thus, even in a heat exchanger 10 in which the microchannel portions 40 are sloped, it is possible to readily position the fin portions 50 along the sloped microchannel portions 40 as was the case in the first embodiment. It is thus, possible to improve the manufacturability of the heat exchanger 10.

(THIRD EMBODIMENT)

Next, a description will be given on a third embodiment with reference to FIG.10. In the third embodiment, the cut-raised portion 55 differs in structure from the second embodiment. FIG.10 only illustrates the cut-raised portion 55 located below the end portion 43 in the downstream side of the microchannel portion 40 among the multiple cut-raised portions 55 formed on the fin portion 50. In the cut-raised portion 55 located below the end portion 43 in the downstream side of the microchannel portion 40, an end portion 57 in the gravitationally upper side is located on the front end line C or in the upstream side of the front end line C. In this example, the upper end portion 57 of the cut-raised portion 55 is located in the upstream side of the front end line C. An end portion 58 in the gravitationally lower side, on the other hand, is located on the front end line C or in the downstream side of the front end line C. In this example, the lower end portion 58 of the cut-raised portion 55 is located in the downstream side of the front end line C. That is, a cut-raised portion 55 downwardly sloped toward the airflow downstream so as to extend across the front end line C is provided at the fin portion 50 located below the end portion 43 in the downstream side of the microchannel portion 40.
Accordingly, the dew condensate produced at the microchannel portion 40 is blown toward the end portion 43 in the downstream side of the microchannel portion 40 and when further moved to the fin portion 50 from the end portion 43, the dew condensate is received by the cut-raised portion 55 located below the end portion 43. Then, the dew condensate runs along the cut-raised portion 55 and is lead further downstream than the end portion 43 in the downstream side of other lower microchannel portions 40 and thereafter falls from the fin portion 50. Thus, the dew condensate streaming along the cut-raised portion 55 and eventually falling from the fin portion 50 is more effectively inhibited from attaching to other lower microchannel portions 40. As a result, it is possible to remove the dew condensate produced at the microchannel portions 40.
As was the case in the second embodiment, the end portions 44 in the upstream side of the microchannel portions 40 and the end portions 54 in the upstream side of the fin portions 50 are aligned on the rear end line D taken along the longitudinal direction of the heat exchanger 10. Thus, it is possible to readily determine the relative positioning of the multiple microchannel portions 40 and the multiple fin portions 50 by using the above described jig 110 when assembling the heat exchanger 10. That is, it is possible to accurately position the cut-raised portion 55 provided at the fin portion 50 to be located below the end portion 43 in the downstream side of the microchannel portion 40. As a result, it is possible to improve the manufacturability of the heat exchanger 10.
In the embodiments described above, the channel portions are sloped so as to be spaced apart from one another while being sloped with respect to the direction of airflow of the incoming external supply of air so as to be higher in the upstream side and lower in the downstream side. The fin portions are disposed between two adjacent microchannel portions so as to contact the microchannel portions. Further, an end portion of each of the fin portions located in at least either of the upstream side or the downstream side of the incoming external airflow is located on an imaginary line linking end portions of the microchannel portions.
Thus, even in a heat exchanger in which the performance of removing dew condensate has been improved by employing sloped microchannel portions, it is possible to readily position the fin portions along the sloped microchannel portions and thereby improve the manufacturability of the heat exchanger.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.

Claims

A heat exchanger for an air conditioner comprising:
a plurality of microchannel portions spaced apart from one another, each of the microchannel portions being shaped like a plate having a plurality of refrigerant flow channels provided therein and being provided with one side located in an upstream side of an incoming external airflow and one side located in a downstream side of the incoming external airflow, the microchannel portions being sloped so that the upstream side thereof is higher than the downstream side thereof; and

a plurality of fin portions each disposed between and in contact with two adjacent microchannel portions,

wherein an end portion of each of the fin portions located in at least either of the upstream side or the downstream side of the incoming external airflow is located on an imaginary line linking end portions of the microchannel portions.
The heat exchanger for an air conditioner according to claim 1, wherein an end portion in a downstream side of each of the fin portions is located in a downstream side of a front end line linking end portions in a downstream side of the microchannel portions and the an end portion in an upstream side of each of the fin portions is located on a rear end line linking end portions in an upstream side of the microchannel portions.
The heat exchanger for an air conditioner according to claim 2, wherein each of the fin portions is provided with a cut-raised portion protruding in a direction orthogonal to the airflow, the cut-raised portion having a gravitationally upper side end portion located on the front end line or in an upstream side of the front end line and a gravitationally lower side end portion located on the front end line or in a downstream side of the front end line.