JP2004270959A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve heat exchange performance, ensure water draining property of condensed water, and suppress abrupt reduction of performance due to frosting. <P>SOLUTION: This heat exchanger has a plurality of flat tubes arranged in parallel to each other at a predetermined pitch, an upper side header communicating and connecting one ends of the plurality of flat tubes, a lower side header communicating and connecting the other ends of the plurality of flat tubes, and a colgate fin which is arranged between adjacent flat tubes, joins a part close to the flat tube with the flat tube or brings it into close adhesion with the flat tube, and lets air pass through a clearance. The colgate fin is provided with a plurality of crest parts and valley parts in which ridge lines extend in the direction of substantially right angle to the direction of circulation of air alternately in the direction of circulation of air, and a cut-in part is provided on the ridge line in the valley part. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a heat exchanger used particularly for an outdoor unit of an air conditioner for both cooling and heating, and more particularly to a heat exchanger having a flat tube and a corrugated fin between adjacent flat tubes.
[0002]
[Prior art]
Conventional heat exchangers of this type include a large number of heat exchangers arranged in parallel at a predetermined pitch with a longitudinal direction being vertical, like a heat exchanger having a basic configuration generally used as shown in FIGS. Between the flat tubes 1, a horizontal upper header 10 that connects the upper ends of these tubes 1 in communication, a horizontal lower header 11 that connects the lower ends of the flat tubes 1 in communication, and the adjacent flat tubes 1. And the flat tube 1 is joined or adhered to the flat tube 1 by brazing, bonding, or the like, and the top portion 21 and the intermediate wall portion 22 are bent and formed alternately and repeatedly, and the corrugated fins 2 through which air passes through the gap are provided. The top 21 of the corrugated fin 2 is formed in a flat shape, and the fin angle θ1, the length L1 of the flat top 21, the louver length L2, the louver angle θ 2. By specifying the louver pitch L3 within a predetermined numerical range, the aim is to improve the drainage property when used as an evaporator without causing a significant decrease in heat transfer coefficient (for example, see Patent Reference 1).
[0003]
However, when this heat exchanger is used as an outdoor unit of an air conditioner that is also used for cooling and heating, and the air conditioner is operated for heating, the outside air temperature decreases, and the surface temperature of the corrugated fins 2 falls below freezing, Moisture adheres to the corrugated fins 2 as frost, and this frost gradually progresses, the frost becomes thicker, and the air passage is blocked by the frost. During this time, the ventilation resistance of the heat exchanger increases, the air volume decreases, the evaporation performance decreases, and the heating performance of the air conditioner decreases. In particular, the louver 3 is provided on the corrugated fin 2 for high performance. However, the front edge of the louver 3 has a high local heat transfer coefficient, so that the progress of frosting is fast and the louver 3 is provided. As a result, there is a problem that the substantial interval between the steps of the corrugated fin 2 is narrow, the ventilation passage is blocked very quickly due to frost, and the heating capacity decreases extremely quickly.
[0004]
Therefore, the ventilation upstream end of the corrugated fin does not have a louver, or it protrudes to the windward side from the end of the flat tube, and every other flat tube is replaced with a partition plate, or the shape of the louver is changed to the windward. There is disclosed a heat exchanger that changes sequentially from lee to lee (for example, see Patent Document 2).
[0005]
Also disclosed is a heat exchanger in which a louver having a small angle is formed in the leeward portion of the corrugated fin, a louver having an angle larger than the leeward portion is formed in the leeward portion, and the louver in the leeward portion of the corrugated fin is eliminated. (For example, see Patent Document 3).
[0006]
In addition, a corrugated fin is provided with a louver portion having a large angle and a flat portion or an uneven portion or a louver portion having a small angle, and the position of the louver portion having a large angle and the flat portion or the uneven portion or a louver portion having a small angle is defined as a gas flow path. There is disclosed a heat exchanger in which corrugated fins adjacent to each other are alternately arranged (see, for example, Patent Document 4).
[0007]
[Patent Document 1]
JP-A-6-241678 (pages 2 to 5, FIGS. 1 to 4)
[Patent Document 2]
JP-A-6-147785 (pages 2 to 5, FIGS. 1 to 6)
[Patent Document 3]
JP-A-6-221787 (pages 2 to 4, FIGS. 1 to 7)
[Patent Document 4]
Japanese Patent No. 3068761 (pages 1 to 5, FIGS. 1 to 6)
[0008]
[Problems to be solved by the invention]
However, in the above-described conventional configuration, since the louver for improving the performance is provided somewhere in the corrugated fin 2, it is not possible to significantly delay the blockage of the ventilation path due to frost. There was a problem that it was only possible to suppress a rapid decrease in the heating performance of the air conditioner at a low outside temperature.
[0009]
The present invention solves such a conventional problem, and greatly improves both the condensation performance and the evaporation performance, and furthermore, when used as an evaporator, generates heat on the fin surface due to heat exchange with flowing air. It allows condensed water to flow down well and is used as a heat exchanger for an outdoor unit of an air conditioner that also serves as a cooling and heating unit.During the heating operation of the air conditioner, frost forms on the fin surface as if the outside air temperature had dropped. It is an object of the present invention to provide a heat exchanger that has an effect of suppressing a sharp decrease in performance due to a rapid blockage of an air flow channel due to frost growth.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, the heat exchanger of the present invention is provided with a number of peaks and valleys whose corrugated fins extend in a direction perpendicular to the direction of air flow alternately in the direction of air flow, at least the valleys. Is provided with a cut in the ridge line.
[0011]
With the above configuration, the air flowing into the heat exchanger flows along the undulations of a number of peaks and valleys in which ridges provided alternately in the direction of air flow extend in a direction perpendicular to the direction of air flow. Since the heat transfer performance is improved by repeating the separation and reattachment of the boundary layer, the effect of greatly increasing the heat exchange capacity can be obtained even when the heat exchanger of the present invention is used as a condenser or an evaporator. Things. In addition, when used as an evaporator, condensed water generated on the fin surface by heat exchange with flowing air flows down the corrugated fins at least through the cuts provided at the ridges of the valleys, so that excellent drainage performance is achieved. Is obtained. Further, the heat exchanger of the present invention is used as an outdoor unit of an air conditioner that is also used for cooling and heating, and during the heating operation of the air conditioner, frost forms on the fin surface when the outside air temperature decreases, but the heat transfer performance is improved. Therefore, the corrugated fin's undulating shape by alternately repeating peaks and valleys does not make the interval between adjacent corrugated fins much like louvers and cut-and-raise, so that frost adheres and grows rapidly due to growth. The flow path is not blocked, and the effect of suppressing a rapid and remarkable decrease in performance can be obtained.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The basic structure of the heat exchanger of the present invention is similar to the general heat exchangers shown in FIGS. 5 and 6 described in the related art, with the longitudinal direction being vertical and being arranged parallel to each other at a predetermined pitch. A plurality of flat tubes 1, a horizontal upper header 10 that connects the upper ends of these tubes 1 in communication, a horizontal lower header 11 that connects the lower ends of the flat tubes 1 in communication, and the adjacent flat tubes 1 and is provided with a corrugated fin 2 which is joined or adhered to the flat tube 1 by brazing or bonding, is repeatedly bent and formed, and has air passing through the gap. Therefore, the surface shape of the corrugated fin will be described in detail.
[0013]
(Embodiment 1)
Embodiment 1 will be described with reference to FIG. 1 and FIG. FIG. 1 is an enlarged perspective view of a main part of a heat exchanger according to a first embodiment of the present invention. In FIG. 1, the surface of the corrugated fin 2 of the vertical flat tube 1 has a ridge line extending in a direction perpendicular to the air flow direction as shown in an enlarged sectional view of the corrugated fin 2 in the air passage direction (FIG. 2). And a plurality of valleys 202 having cuts 203 at ridges extending in a direction perpendicular to the air flow direction are provided alternately in the air flow direction.
[0014]
In the above configuration, the air flowing into the heat exchanger flows along the undulations of a number of peaks 201 and valleys 202 in which ridges provided alternately in the direction of air flow extend in a direction perpendicular to the direction of air flow. The heat transfer performance is improved by repeating the separation and reattachment of the temperature boundary layer, and the effect of greatly increasing the heat exchange capacity is obtained when the heat exchanger of the present embodiment is used as either a condenser or an evaporator. It is something that can be done.
[0015]
When the heat exchanger of the present embodiment is used as an evaporator, condensed water generated on the fin surface due to heat exchange with the flowing air flows down the corrugated fin 2 while passing through the notch 203 provided on the ridgeline of the valley 202. As a result, excellent drainage properties can be obtained.
[0016]
Furthermore, the heat exchanger of the present embodiment is used as an outdoor unit of an air conditioner that is also used for cooling and heating. During the heating operation of the air conditioner, when the outside air temperature decreases, frost formation on the surface of the corrugated fin 2 proceeds. However, the undulating shape of the corrugated fins 2 provided in the corrugated fins 2 to improve the heat transfer performance due to the repeated repetition of the ridges 201 and the valleys 202 greatly increases the distance between the adjacent corrugated fins, like the louver of the conventional heat exchanger. The frost does not concentrate on the front edge of the louver, which has a high local heat transfer coefficient, and the air flow path is rapidly blocked due to frost adhesion and growth. Thus, the effect of suppressing a rapid and remarkable decrease in performance can be obtained.
[0017]
(Embodiment 2)
Embodiment 2 will be described with reference to FIG. 3 and FIG. FIG. 3 is an enlarged perspective view of a main part of a heat exchanger according to a second embodiment of the present invention. In FIG. 3, as shown in an enlarged sectional view of the corrugated fin 2 in the air passage direction (FIG. 4), a ridge line extending in a direction perpendicular to the air flow direction is provided on the surface of the corrugated fin 2 of the flat tube 1 in the vertical direction. A plurality of peaks 301 having cuts 303 and valleys 302 having cuts 304 at ridges extending in a direction perpendicular to the direction of air flow are provided alternately in the direction of air flow.
[0018]
In the above configuration, the air flowing into the heat exchanger flows along the undulations of a number of peaks 301 and valleys 302 in which ridges provided alternately in the direction of air flow extend in a direction perpendicular to the direction of air flow. The heat transfer performance is improved by repeating the separation and reattachment of the temperature boundary layer, and the effect of greatly increasing the heat exchange capacity is obtained when the heat exchanger of the present embodiment is used as either a condenser or an evaporator. It is something that can be done.
[0019]
When the heat exchanger of the present embodiment is used as an evaporator, condensed water generated on the fin surface by heat exchange with the flowing air flows down the corrugated fin 2 while passing through the notch 304 provided on the ridge line of the valley 302. As a result, excellent drainage properties can be obtained.
[0020]
Furthermore, the heat exchanger of the present embodiment is used as an outdoor unit of an air conditioner that is also used for cooling and heating. During the heating operation of the air conditioner, when the outside air temperature decreases, frost formation on the surface of the corrugated fin 2 proceeds. However, the corrugated fins 2 provided on the corrugated fins 2 to improve the heat transfer performance have an undulating shape formed by alternately repeating a plurality of peaks 301 and valleys 302, which greatly increases the distance between adjacent corrugated fins, as in the case of a conventional heat exchanger louver. The frost does not concentrate on the front edge of the louver, which has a high local heat transfer coefficient, and the air flow path is rapidly blocked due to frost adhesion and growth. Thus, the effect of suppressing a rapid and remarkable decrease in performance can be obtained. Further, since the notch 303 is also provided on the ridge line of the peak portion 301, when assembling the heat exchanger, the corrugated fin 2 may be in any vertical direction, and the workability is good.
[0021]
【The invention's effect】
As is clear from the above, the heat exchanger of the present invention is provided with a number of peaks and valleys whose corrugated fins extend in a direction perpendicular to the direction of air flow in the corrugated fins alternately in the direction of air flow, and at least the valleys. According to this configuration, the air flowing into the heat exchanger has a large number of ridges in which the ridges provided alternately in the air flow direction extend in a direction perpendicular to the air flow direction. Flow along the undulations of the valleys, and the heat transfer performance is improved by repeating the separation and re-attachment of the temperature boundary layer, so that the heat exchanger of the present invention can be used as either a condenser or an evaporator. The effect of greatly increasing the exchange capacity can be obtained. In addition, when used as an evaporator, condensed water generated on the fin surface by heat exchange with flowing air flows down the corrugated fins at least through the cuts provided at the ridges of the valleys, so that excellent drainage performance is achieved. Is obtained. Further, the heat exchanger of the present invention is used as an outdoor unit of an air conditioner that is also used for cooling and heating, and during the heating operation of the air conditioner, frost forms on the fin surface when the outside air temperature decreases, but the heat transfer performance is improved. Therefore, the corrugated fin's undulating shape formed by the alternating repetition of peaks and valleys does not significantly reduce the distance between adjacent corrugated fins like louvers and cut-and-raised parts. The flow path is not blocked, and the effect of suppressing a rapid and remarkable decrease in performance can be obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view of a main part of a corrugated fin of a heat exchanger showing a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view taken along the line AA in FIG. 1. FIG. FIG. 4 is an enlarged cross-sectional view of BB in FIG. 3 of a corrugated fin of a heat exchanger. FIG. 5 is a perspective view showing a basic configuration of a conventional heat exchanger. FIG. 7 is an enlarged front view of a corrugated fin of a conventional heat exchanger. FIG. 8 is an enlarged cross-sectional view of a corrugated fin of a conventional heat exchanger in an air passage direction.
DESCRIPTION OF SYMBOLS 1 Flat tube 2 Corrugated fin 10 Upper header 11 Lower header 201, 301 Crest 202, 302 Valley 203, 303, 304 Cut

Claims (2)

A plurality of flat tubes arranged in parallel with each other at a predetermined pitch, an upper header that communicates and connects one end of the plurality of flat tubes, and a lower header that communicates and connects the other ends of the many flat tubes are adjacent to each other. A heat exchanger having a corrugated fin disposed between the flat tubes and having a portion adjacent to the flat tube joined or adhered to the flat tube and having a gap passing through the air, wherein the corrugated fin has a ridge line formed of air. A heat exchanger having a plurality of peaks and valleys extending in a direction substantially perpendicular to the direction of air flow alternately provided in the direction of air flow, and ridges of the valleys provided with cuts. A plurality of flat tubes arranged in parallel with each other at a predetermined pitch, an upper header that communicates and connects one end of the plurality of flat tubes, and a horizontal lower header that communicates and connects the other ends of the plurality of flat tubes. In the heat exchanger having a corrugated fin disposed between the adjacent flat tubes, a portion adjacent to the flat tube is bonded or adhered to the flat tube, and a gap passes between the corrugated fins. Heat exchange in which a plurality of peaks and valleys whose ridges extend in a direction substantially perpendicular to the direction of air flow are provided alternately in the direction of air flow, and both the ridges of the peaks and the ridges of the valleys are cut. vessel.

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