JP2005037002A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger capable of enhancing the heat exchange performance, ensuring water drainage performance of condensed water, and suppressing abrupt performance degradation caused by frost formation. <P>SOLUTION: The pitch of a corrugated fin is set to be 2.0-3.0 mm, the fin angle is set to be 10-40°, and a large number of louvers of large height are provided on an intermediate wall part of the corrugated fin. Water drainage property is excellent. Though the surface of the fin is frosted during the heating operation by using the heat exchanger for an outdoor unit of an air-conditioner, an air flow passage of the corrugated fin is continuously ensured, and the effect of suppressing abrupt and considerable degradation of the performance is obtained. Further, since the height of the louvers is increased, flow-in air adequately passes through the louvers, and the effect of increasing the heat exchange capacity can be maintained by improvement of the heat transfer with the temperature boundary layer front edge effect and the air flow mixing and stirring effect. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat exchanger used in an outdoor unit of an air conditioner that is also used for both air conditioning and heating, and more particularly to a heat exchanger having corrugated fins between vertical flat tubes and adjacent flat tubes.
[0002]
[Prior art]
This type of conventional heat exchanger has a large number of flat plates arranged in parallel with each other at a predetermined pitch, with the longitudinal direction being the vertical direction, like the heat exchanger having a basic configuration shown in FIGS. Between the tube 1, a horizontal upper header 10 that connects the upper ends of the flat tubes 1, a horizontal lower header 11 that connects the lower ends of the flat tubes 1, and the adjacent flat tubes 1. The flat tube 1 is joined or brought into close contact with the flat tube 1 by brazing, bonding, or the like, and as shown in FIGS. 3 and 4, the top portion 21 and the intermediate wall portion 22 are bent and formed alternately and repeatedly, and air passes through the gap. In the heat exchanger including the corrugated fin 2, the top portion 21 of the corrugated fin 2 is formed in a flat shape, the fin angle θ1 is 0.5 to 3 °, and the louver angle θ2 is 30 to 30. By setting the louver pitch L3 to 0 °, 0.7 to 1.0 mm, and defining the length L1 and louver length L2 of the flat top 21 within predetermined numerical ranges, respectively, the heat transfer coefficient is significantly reduced. Without use, the water drainage when used as an evaporator is improved (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 6-241678 (pages 2 to 5 and FIGS. 1 to 4)
[0004]
[Problems to be solved by the invention]
In general, when a heat exchanger is used in an outdoor unit of an air conditioner that is also used for air conditioning and heating, when the air conditioner is operated for heating and the outside air temperature becomes low, the surface temperature of the corrugated fin 2 becomes below freezing point, and moisture in the air The frost gradually adheres to the corrugated fins 2, and the frost gradually increases, the frost becomes thick, and eventually the air ventilation path is blocked by the frost formation. It increases, the air volume decreases, the evaporation performance decreases, and the heating performance of the air conditioner decreases. Although the above conventional configuration has the effect of improving water drainage when used as an evaporator as described above, there is a problem that the ventilation path is blocked very quickly due to this frost formation, and the heating capacity is extremely reduced. It was. That is, in the above-described conventional configuration, the corrugated fin 2 is provided with a louver 2a for high performance, but the front edge of the louver 2a has a high local heat transfer rate, so that frosting proceeds quickly. Further, since the front edge and the rear edge of the louver 2a provided in the adjacent intermediate wall portion 22 are close to each other, the substantial interval between the corrugated fins 2 is narrow, and the air passage due to frost formation is very quickly blocked. The heating capacity declined extremely quickly.
[0005]
The present invention solves such a conventional problem, and when used as an evaporator without significantly reducing the heat exchange capacity, the condensed water generated on the fin surface by the heat exchange with the circulating air can flow well. And when used as a heat exchanger for an air conditioner outdoor unit that also serves as an air conditioner, and when frosting occurs on the fin surface as the outside air temperature decreases during the heating operation of the air conditioner, It is an object of the present invention to provide a heat exchanger that has an effect of suppressing the performance from being remarkably deteriorated due to a sudden blockage of an air flow path.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the heat exchanger of the present invention has a vertical pitch of corrugated fin bending of 2.0 to 3.0 mm, and a fin angle between adjacent intermediate wall portions of 10 to 40 °. A plurality of louvers having an angle of 20 to 40 ° and a pitch substantially equal to the vertical pitch of the corrugated fin, or a height of 1.0 mm or more, and the intermediate wall portion of the corrugated fin, A large number of louvers having approximately 1/3 or more and approximately 2/3 or less of the vertical pitch of corrugated fins are provided.
[0007]
With the above configuration, when the heat exchanger of the present invention is used as an evaporator, condensed water is generated on the fin surface by heat exchange with circulating air, and this condensed water passes through the opening of the louver part and corrugated fins. As the water flows down, excellent drainage is obtained. Furthermore, when the heat exchanger of the present invention is used for an outdoor unit of an air conditioner that also serves as an air conditioner, and the air temperature decreases during the heating operation of the air conditioner, the fin surface frosts, but the corrugated fin is bent. Since the pitch in the vertical direction of 2.0 to 3.0 mm and the fin angle formed by the intermediate wall portion adjacent to the corrugated fin is 10 to 40 °, even if frost adheres and the growth proceeds, Since the air flow path of the corrugated fin is continuously secured and does not close rapidly, an effect of suppressing the performance from being rapidly deteriorated can be obtained.
[0008]
The louvers provided on the intermediate wall portion of the corrugated fin have an angle of 20 to 40 ° and a pitch substantially equal to a pitch in the vertical direction of the corrugated fin bending, or a height of 1. Since it is 0 mm or more and about 1/3 or more and about 2/3 or less of the vertical pitch of the corrugated fin, a large amount of air flowing into the heat exchanger is provided on the intermediate wall portion of the corrugated fin. The heat transfer performance is improved and the heat exchanger of the present invention is condensed by the effect of the leading edge of the temperature boundary layer and the mixing and stirring effect of the airflow across the front and back of the corrugated fins. The effect of increasing the heat exchanging ability can be maintained when used as an evaporator or an evaporator.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. The basic configuration of the heat exchanger of the present invention is arranged in parallel with each other at a predetermined pitch with the longitudinal direction set to the vertical direction, like the general heat exchanger shown in FIGS. A plurality of flat tubes 1, a horizontal upper header 10 that connects the upper ends of the flat tubes 1, a horizontal lower header 11 that connects the lower ends of the flat tubes 1, and an adjacent flat tube 1. And a corrugated fin 2 that is joined or closely bonded to the flat tube 1 by brazing or bonding, the top portion 21 and the intermediate wall portion 22 are alternately bent and formed, and air passes through the gap. However, since the shape of the corrugated fin 2 is characteristic, the shape of the corrugated fin 2 will be described in detail.
[0010]
(Embodiment 1)
The first embodiment will be described with reference to FIGS.
[0011]
FIG. 1 is an enlarged front view of a main part of a corrugated fin 2 of a heat exchanger showing a first embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the corrugated fin 2 of FIG. 1 and 2, the vertical pitch Pf of the corrugated fin 2 is set to 2.0 to 3.0 mm, the fin angle θ1 formed by the adjacent intermediate wall portion 22 is set to 10 to 40 °, and the corrugated fin 2 A large number of louvers 2 a are provided on the intermediate wall portion 22, the angle θ 2 of the louvers 2 a is set to 20 to 40 °, and the pitch L 3 of the louvers 2 a is formed to be approximately equal to the vertical pitch P f of the corrugated fin 2.
[0012]
In the above configuration, when the heat exchanger of the present embodiment is used as an evaporator, condensed water is generated on the fin surface by heat exchange with the circulating air, and this condensed water passes through the opening of the louver 2a. As the corrugated fins flow down, excellent water drainage is obtained. Further, the heat exchanger of the present embodiment is used for an outdoor unit of an air conditioner that also serves as an air conditioner. During the heating operation of the air conditioner, frost is formed on the fin surface when the outside air temperature decreases. Since the vertical pitch Pf of bending is set to 2.0 to 3.0 mm and the fin angle θ1 formed by the adjacent intermediate wall portion 22 of the corrugated fin 2 is set to 10 to 40 °, frost adheres and growth proceeds. However, since the air flow path of the corrugated fin 2 is continuously secured and does not close rapidly, the effect of suppressing the performance from being rapidly lowered significantly can be obtained. In addition, the large number of louvers 2a provided on the intermediate wall portion 22 of the corrugated fin 2 have an angle θ2 of 20 to 40 ° and a pitch L3 substantially equal to the vertical pitch Pf of the corrugated fin 2 being bent. The air that has flowed into the exchanger can appropriately pass through a large number of louvers 2 a provided on the intermediate wall portion 22 of the corrugated fin 2 without passing through it, and the temperature boundary layer leading edge effect and the airflow over the corrugated fin 2 With this mixing and stirring effect, the heat transfer performance is improved, and even when the heat exchanger of this embodiment is used as either a condenser or an evaporator, the effect of increasing the heat exchange capability can be maintained. .
[0013]
(Embodiment 2)
The second embodiment will be described with reference to FIGS. 1 and 2 in the same manner as the first embodiment.
[0014]
1 and 2, the vertical pitch Pf of the corrugated fin 2 is set to 2.0 to 3.0 mm, the fin angle θ1 formed by the adjacent intermediate wall portion 22 is set to 10 to 40 °, and the corrugated fin 2 A large number of louvers 2 a are provided on the intermediate wall portion 22. The louver 2a is formed to have a height of 1.0 mm or more and about 1/3 or more and about 2/3 or less of the vertical pitch Pf of the corrugated fins 2.
[0015]
In the above configuration, when the heat exchanger of the present embodiment is used as an evaporator, condensed water is generated on the fin surface by heat exchange with the circulating air, and this condensed water passes through the opening of the louver 2a while corrugating. Since the fin 2 flows down, excellent water drainage is obtained. Further, the heat exchanger of the present embodiment is used for an outdoor unit of an air conditioner that also serves as an air conditioner. During the heating operation of the air conditioner, frost is formed on the fin surface when the outside air temperature decreases. Since the vertical pitch Pf of bending is set to 2.0 to 3.0 mm and the fin angle θ1 formed by the adjacent intermediate wall portion 22 of the corrugated fin 2 is set to 10 to 40 °, frost adheres and growth proceeds. However, since the air flow path of the corrugated fin 2 is continuously secured and does not close rapidly, the effect of suppressing the performance from being rapidly lowered significantly can be obtained. A number of louvers 2 a provided on the intermediate wall portion 22 of the corrugated fin 2 have a height of 1.0 mm or more, and approximately 1/3 or more and approximately 2/3 or less of the vertical pitch Pf of the corrugated fin 2. Therefore, the air that has flowed into the heat exchanger can appropriately pass through the numerous louvers 2a provided on the intermediate wall portion 22 of the corrugated fin 2 without passing through it, and the temperature boundary layer leading edge effect and the corrugated fin The heat transfer performance is improved by the mixing and stirring effect of the airflow over the front and back of 2, and the effect of increasing the heat exchange capacity is maintained even when the heat exchanger of this embodiment is used as either a condenser or an evaporator. It is something that can be done.
[0016]
In addition, in each of the above embodiments, a flat tube is used, so even if the tube thickness is the same, the tube diameter is small, so the pressure resistance is large, especially when using a high pressure carbon dioxide refrigerant. A heat exchanger of the form is effective.
[0017]
In addition, since the volume of the flat tube is small, the amount of refrigerant can be reduced, and the heat exchanger of each of the above embodiments is effective when using HC refrigerant or the like that is a combustible refrigerant.
[0018]
【The invention's effect】
As apparent from the above, in the heat exchanger of the present invention, the vertical pitch of corrugated fin bending is 2.0 to 3.0 mm, and the fin angle formed by the adjacent intermediate wall portions is 10 to 40 °. A plurality of louvers having an angle of 20 to 40 ° and a pitch substantially equal to the vertical pitch of the corrugated fin, or a height of 1.0 mm or more, and the intermediate wall portion of the corrugated fin, When a large number of louvers having a pitch of about 1/3 to about 2/3 of the vertical pitch of corrugated fins are provided, according to this configuration, when the heat exchanger of the present invention is used as an evaporator Condensed water is generated on the fin surface by heat exchange with the circulating air, and this condensed water flows down the corrugated fins while passing through the opening of the louver. In addition, the heat exchanger of the present invention is used for the outdoor unit of an air conditioner that is also used for air conditioning, and during the heating operation of the air conditioner, frosting occurs on the fin surface when the outside air temperature decreases, Since the vertical pitch of the corrugated fin is set to 2.0 to 3.0 mm and the fin angle formed by the intermediate wall adjacent to the corrugated fin is set to 10 to 40 °, frost adheres and grows. Even if it progresses, the corrugated fin air flow path is sufficiently secured and does not close rapidly, so that it is possible to obtain an effect of suppressing the rapid deterioration of the performance. The plurality of louvers provided on the intermediate wall portion have an angle of 20 to 40 ° and a pitch substantially equal to the vertical pitch of the corrugated fin, or a height of 1.0 mm or less. On the other hand, the vertical pitch of the corrugated fin is set to approximately 1/3 or more and approximately 2/3 or less, so that a large amount of air flowing into the heat exchanger is provided on the intermediate wall portion of the corrugated fin. The heat transfer performance is improved by the leading edge effect of the temperature boundary layer and the mixing and stirring effect of the airflow across the front and back of the corrugated fin, and the heat exchanger of the present invention is condensed. The effect of increasing the heat exchanging ability can be maintained when used as an evaporator or an evaporator.
[Brief description of the drawings]
FIG. 1 is an enlarged front view of a corrugated fin of a heat exchanger showing the first and second embodiments of the present invention. FIG. 2 is a view of a corrugated fin of a heat exchanger of the first and second embodiments of the present invention. FIG. 3 is an enlarged front view of a corrugated fin of a conventional heat exchanger. FIG. 4 is an enlarged sectional view of a corrugated fin of a conventional heat exchanger in an air passing direction. Front view of a heat exchanger having a basic configuration [FIG. 6] Side view of the heat exchanger shown in FIG.
DESCRIPTION OF SYMBOLS 1 Flat tube 2 Corrugated fin 2a Louver 10 Upper header 11 Lower header 21 Top part 22 of corrugated fin Intermediate wall part of corrugated fin

Claims (5)

A large number of flat tubes arranged in parallel with each other at a predetermined pitch with the longitudinal direction as a vertical direction, a horizontal upper header that connects the upper ends of the flat tubes, and a horizontal that connects the lower ends of the flat tubes It is arranged between the lower header in the direction and the adjacent flat tube, and a portion adjacent to the flat tube is joined or adhered to the flat tube by brazing or bonding, and the top portion and the intermediate wall portion are alternately arranged. A heat exchanger having corrugated fins that are repeatedly bent and through which air passes, the vertical pitch of the corrugated fins being bent is 2.0 to 3.0 mm. The heat exchanger according to claim 1, wherein a fin angle formed by the adjacent intermediate wall portions is 10 to 40 °. A large number of flat tubes arranged in parallel with each other at a predetermined pitch with the longitudinal direction as a vertical direction, a horizontal upper header that connects the upper ends of the flat tubes, and a horizontal that connects the lower ends of the flat tubes It is arranged between the lower header in the direction and the adjacent flat tube, and a portion adjacent to the flat tube is joined or adhered to the flat tube by brazing or bonding, and the top portion and the intermediate wall portion are alternately arranged. A heat exchanger having corrugated fins that are repeatedly bent and through which air passes, the fin angle formed by adjacent intermediate wall portions is 10 to 40 °. A number of louvers are provided in the intermediate wall portion of the corrugated fin, the angle of the louver is set to 20 to 40 °, and the pitch of the louver is approximately equal to the vertical pitch of the corrugated fin. 2. The heat exchanger according to 2. A number of louvers are provided on the intermediate wall portion of the corrugated fin, the height of the louver is 1.0 mm or more, and approximately 1/3 or more and approximately 2/3 or less of the vertical pitch of the corrugated fin. The heat exchanger according to claim 1 or 2.

Images