JP2010255918A - Air heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve heat transfer performance while suppressing an increase of a material in extrusion molding in an air heat exchanger having a flat porous heat transfer tube manufactured by extrusion molding. <P>SOLUTION: The air heat exchanger 1 is equipped with a heating medium heat transfer tube 2 comprising a plurality of flat porous tube having broad plane parts 21 in a state of facing each other with a ventilation space for passing air toward a width direction of the plane part 21 between, having a plurality of passage holes 22 for making heating mediums internally pass therethrough in a row in the width direction of the plane part 21, and manufactured by extrusion molding. An outer face of the plane part 21 is uneven along a shape of an inner circumferential surface of each passage hole 22 when seeing the heating medium heat transfer tube 2 from a longitudinal direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an air heat exchanger, and more particularly to an air heat exchanger having a flat multi-hole heat transfer tube manufactured by extrusion molding.

  Conventionally, there is an air heat exchanger having a flat multi-hole tube manufactured by extrusion molding as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 6-74609). The flat multi-hole tube has a wide flat surface portion, and a plurality of flat multi-hole tubes are arranged facing each other with a ventilation space through which air flows. The flat portion has a flat surface with a wide outer surface facing the ventilation space, and has a plurality of flow passage holes having a rectangular cross-sectional shape when viewed from the longitudinal direction of the flat multi-hole tube. However, the rectangular short sides are formed in parallel in the width direction. A heat medium flows inside the flat multi-hole tube (that is, a plurality of flow path holes), and heat exchange is performed with air flowing in the ventilation space outside the flat multi-hole tube.

  However, the conventional air heat exchanger having a flat multi-hole tube is manufactured by extrusion molding in order to meet the demand for thickening such as the pressure of the heat medium flowing inside is increased. Therefore, the amount of a material made of a metal material used for manufacturing a flat multi-hole tube tends to increase. Moreover, in the air heat exchanger having a flat multi-hole tube, further improvement in heat transfer performance is also required.

  The subject of this invention is improving the heat-transfer performance, suppressing the increase in the material at the time of extrusion molding in the air heat exchanger which has the flat multi-hole heat-transfer tube manufactured by extrusion molding.

  A plurality of air heat exchangers according to the first invention are arranged in a state where the wide flat surface portions face each other with a ventilation space through which air flows in the width direction of the flat surface portions, and a plurality of heat media flow inside. The flow path holes are formed side by side in the width direction of the flat portion, and are provided with a heat medium heat transfer tube made of a flat multi-hole tube manufactured by extrusion molding. When viewed from the direction, it is uneven so as to follow the shape of the inner peripheral surface of each flow path hole.

  In this air heat exchanger, unlike the flat portion having a flat outer surface in the above-described conventional flat multi-hole tube, the outer surface of the flat portion has a shape of each flow path hole when the heat medium heat transfer tube is viewed from the longitudinal direction. Since it is uneven so as to conform to the shape of the inner peripheral surface, the internal shape of the flat part formed by the plurality of flow path holes and the external shape of the flat part approach a similar shape, and the portion that becomes uselessly thick decreases. As a result, the heat transfer area of the outer surface of the flat portion increases, and the turbulence of the air flowing through the ventilation space is promoted.

  Thereby, in this air heat exchanger, the heat transfer performance can be improved while suppressing an increase in material during extrusion molding.

  The air heat exchanger according to a second aspect of the present invention is the air heat exchanger according to the first aspect of the present invention, wherein the outer surface of the flat portion has a thickness from the inner peripheral surface of each flow path hole to the outer surface of the flat portion. It is uneven to be the same.

  An air heat exchanger according to a third aspect of the present invention is the air heat exchanger according to the first or second aspect of the present invention, further comprising heat transfer fins made of corrugated fins arranged in the ventilation space.

  Since this air heat exchanger has a structure in which heat transfer fins made of corrugated fins are arranged in the ventilation space, the heat transfer area is increased and the heat transfer performance is further improved.

  An air heat exchanger according to a fourth aspect of the present invention is the air heat exchanger according to the first or second aspect of the present invention, further comprising a heat transfer fin comprising a plate fin in which a through hole through which the heat medium heat transfer tube passes is formed. The heat transfer tube is fixed to the heat transfer fin by being expanded in a state of passing through the through hole.

  Since this air heat exchanger has a structure in which the heat transfer pipes are penetrated by the heat transfer fins made of plate fins, the heat transfer area is increased and the heat transfer performance is further improved. Moreover, the heat medium heat transfer tube is fixed to the heat transfer fins by expanding the tube, but as described above, when the outer surface of the flat portion of the heat medium heat transfer tube is viewed from the longitudinal direction of the heat medium heat transfer tube, Since it is uneven so as to conform to the shape of the inner peripheral surface of each flow path hole, the outer surface of the flat surface portion will be uniformly expanded when expanding the tube, whereby heat transfer fins (more specifically, , The peripheral edge of the through-hole) and the flat portion are improved, which contributes to the improvement of heat transfer performance.

  An air heat exchanger according to a fifth aspect of the present invention is the air heat exchanger according to any of the first to fourth aspects of the present invention, wherein each flow passage hole is circular when the heat medium heat transfer tube is viewed from the longitudinal direction. The cross-sectional shape is as follows.

  An air heat exchanger according to a sixth aspect of the present invention is the air heat exchanger according to any one of the first to fourth aspects, wherein each flow path hole has a quadrangular cross-sectional shape, When the heat tube is viewed from the longitudinal direction, the pair of corner portions of the quadrangular shape are arranged so as to protrude toward both outer surfaces of the plane portion.

  An air heat exchanger according to a seventh aspect of the present invention is the air heat exchanger according to any one of the first to fourth aspects of the invention, wherein each flow path hole is 5 when the heat medium heat transfer tube is viewed from the longitudinal direction. It has a polygonal cross-sectional shape with corners or more.

  As described above, according to the present invention, the following effects can be obtained.

  In the first, second, and fifth to seventh inventions, the heat transfer performance can be improved while suppressing an increase in material during extrusion molding.

  In the third invention, the heat transfer area is increased and the heat transfer performance is further improved.

  In the fourth invention, the heat transfer area is increased and the heat transfer performance is further improved. In addition, the adhesion between the heat transfer fins and the flat portion is improved, contributing to the improvement of the heat transfer performance.

It is a schematic block diagram of the air heat exchanger concerning 1st Embodiment of this invention. It is an expansion perspective view of the A section of FIG. It is the figure which looked at FIG. 2 from the longitudinal direction of the heat carrier heat exchanger tube. FIG. 3 is an exploded perspective view of FIG. 2. It is a figure which shows the air heat exchanger concerning the modification 1 of 1st Embodiment, Comprising: It is a figure corresponded in FIG. It is a figure which shows the air heat exchanger concerning the modification 2 of 1st Embodiment, Comprising: It is a figure equivalent to FIG. It is a schematic block diagram of the air heat exchanger concerning 2nd Embodiment of this invention. It is an expansion perspective view of the A section of FIG.

  Hereinafter, an embodiment of an air heat exchanger according to the present invention will be described with reference to the drawings.

-First embodiment-
<Overall configuration of air heat exchanger>
1 is a schematic configuration diagram of an air heat exchanger 1 according to a first embodiment of the present invention, FIG. 2 is an enlarged perspective view of a portion A in FIG. 1, and FIG. 3 is an arrow B in FIG. FIG. 4 is an exploded perspective view of FIG. 2. The air heat exchanger 1 is a heat exchanger that performs heat dissipation (condensation) and heating (evaporation) of a heat medium using air as a cooling source or a heating source, and constitutes, for example, a refrigerant circuit of a vapor compression refrigeration apparatus. It is adopted as a heat exchanger. Here, carbon dioxide is used as the heat medium circulating in the refrigerant circuit.

  The air heat exchanger 1 mainly includes a heat medium heat transfer tube 2, heat transfer fins 3, and header tubes 4 and 5.

<Heat transfer tube>
The heat transfer tube 2 is configured such that the long and wide flat surface portion 21 faces in the vertical direction, and the air flows in the width direction of the flat surface portion 21 in the vertical direction (in FIG. 1 to FIG. A plurality (eight in this case) are arranged with a ventilation space through which the heat medium flows, and are composed of flat tubes through which the heat medium flows, and the number of the channel holes 22 of the heat medium heat transfer tube 2 is eight. It is not limited and can be set arbitrarily.

  A plurality of (in this case, eight) flow passage holes 22 are formed in the flat portion 21 so as to pass through the flat portion 21 in the longitudinal direction. 22 flows. The heat medium heat transfer tube 2 is made of a metal material such as aluminum and is manufactured by extrusion molding.

  Each flow path hole 22 has a circular cross-sectional shape when the heat medium heat transfer tube 2 is viewed from the longitudinal direction. And the outer surface of the plane part 21 is uneven | corrugated so that the shape of the internal peripheral surface of each flow path hole 22 may be seen, when the heat-medium heat exchanger tube 2 is seen from a longitudinal direction. More specifically, the outer surface of the flat portion 21 is uneven so that the thickness from the inner peripheral surface of each flow path hole 22 to the outer surface of the flat portion 21 is substantially the same.

  Thus, since the flat multi-hole tube in which the several flow-path hole 22 was formed is employ | adopted as the heat-medium heat transfer tube 2 here, the heat transfer rate by the side of a heat medium is improving. In addition, here, unlike the flat portion having a flat outer surface in the conventional flat multi-hole tube, when the outer surface of the flat portion 21 looks at the heat medium heat transfer tube 2 from the longitudinal direction, Since it is uneven so as to conform to the shape of the inner peripheral surface, the internal shape of the flat surface portion 21 formed by the plurality of flow passage holes 22 and the external shape of the flat surface portion 21 approach a similar shape, and there is a portion that becomes uselessly thick. While decreasing, the heat transfer area of the outer surface of the plane part 21 increases, and the turbulent flow of the air flowing through the ventilation space (particularly, the air passing through the vicinity of the heat medium heat transfer tube 2) is promoted. Thus, the heat transfer performance can be improved while suppressing an increase in the material during extrusion molding. In particular, here, since the heat medium flowing in the heat medium heat transfer tube 2 is carbon dioxide circulating in the refrigerant circuit of the vapor compression refrigeration apparatus, the pressure of the heat medium is high and a thickening is required. As described above, since the portion where the thickness becomes useless is reduced, the effect of suppressing the increase in the material during the extrusion is remarkable.

<Header tube>
The header tubes 4 and 5 have a function of supporting the heat medium heat transfer tube 2, a function of flowing the heat medium into the heat medium heat transfer tube 2 (here, a plurality of flow path holes 22), and a heat medium heat transfer tube 2 ( Here, it is a member having a function of causing the heat medium to flow out from the plurality of flow passage holes 22), and is joined to both ends of the heat medium heat transfer tubes 2 arranged in the vertical direction by brazing. Here, the header pipe on the right side in FIG. 1 is a first header pipe 4, and the header pipe on the left side in FIG. 1 is a second header pipe 5. In addition, the structure of the header pipe | tubes 4 and 5 is not limited to the structure of FIG. 1, A various structure is applicable.

  The first header pipe 4 is a cylindrical member extending in the vertical direction with a first opening 41 for exchanging the heat medium at the top and closed at the lower end, and here, from the center in the vertical direction. In the first header pipe 4 at a slightly higher position (more specifically, a position between the heat medium heat transfer pipe 2 at the third stage from the top and the heat medium heat transfer pipe 2 at the fourth stage from the top). A first partition plate 42 that partitions the space into two upper and lower portions is provided. As a result, the first header pipe 4 includes the first upper header 43 communicating with the three heat medium heat transfer pipes 2 and the first opening 41 from the first stage to the third stage from the top, and the remaining five heat medium transmissions. And a first lower header 44 communicating with the heat pipe 2.

  The second header pipe 5 is a cylindrical member that extends in the vertical direction and has a second opening 51 for exchanging the heat medium at the bottom and has an upper end closed, and here, from the center in the vertical direction. Inside the second header pipe 5 at a slightly lower position (more specifically, a position between the heat medium heat transfer pipe 2 at the sixth stage from the top and the heat medium heat transfer pipe 2 at the seventh stage from the top). A second partition plate 52 is provided to partition the space into upper and lower parts. As a result, the second header pipe 5 includes the second heat transfer pipe 2 and the second lower header 54 communicating with the second opening 51 from the first stage to the second stage from the bottom, and the remaining six heat transfer pipes. And a second upper header 53 communicating with the heat pipe 2.

  As a result, when the air heat exchanger 1 functions as a heat medium radiator (condenser), the heat medium flows into the first upper header 43 through the first opening 41, and from the top to the third stage. The three heat medium heat transfer tubes 2 up to the stage are distributed and flown in, flown through the three heat medium heat transfer tubes 2, and then flow out to the second upper header 53 to be collected. The heat medium gathered in the second upper header 53 is distributed and flows into the three heat medium heat transfer tubes 2 from the fourth to the sixth step from the top, and flows through the three heat medium heat transfer tubes 2. Later, it flows out to the first lower header 44 and is assembled. The heat medium gathered in the first lower header 44 is distributed and flows into the two heat medium heat transfer tubes 2 from the seventh to the eighth step from the top, and flows through the two heat medium heat transfer tubes 2. It flows out to the second lower header 54 later and gathers, and then flows out from the second lower header 54 through the second opening 51. When the air heat exchanger 1 functions as a heating medium heater (evaporator), the heating medium flows into the second lower header 54 through the second opening 51, and the seventh to eighth stages from the top. The two heat medium heat transfer tubes 2 are distributed and flowed in, and after flowing through the two heat medium heat transfer tubes 2, they flow out to the first lower header 44 and are collected. The heat medium assembled in the first lower header 44 is distributed and flows into the three heat medium heat transfer tubes 2 from the fourth to the sixth step from the top, and flows through the three heat medium heat transfer tubes 2. Later, it flows out to the second upper header 53 and gathers. The heat medium gathered in the second upper header 53 is distributed and flows into the three heat medium heat transfer tubes 2 from the first to the third step from the top, and flows through the three heat medium heat transfer tubes 2. Afterwards, it flows out to the first upper header 43 and gathers, and flows out from the first upper header 43 through the first opening 41. Further, both ends of the heat medium heat transfer tube 2 are joined to the header tubes 4 and 5 by brazing. At this time, the flow path hole 22 formed in the heat medium heat transfer tube 2 is different from the conventional flat multi-hole tube. In the case of having a similar rectangular cross-sectional shape, the brazing material easily flows into the rectangular corners of the flow path holes, which may cause clogging in some of the flow path holes and reduce heat transfer performance. However, since the channel hole 22 has a circular cross-sectional shape here, there is no corner portion, and the possibility that the brazing material flows and a part of the plurality of channel holes is clogged is reduced.

<Heat transfer fin>
The heat transfer fins 3 are plate fins formed with through holes 31 through which the heat medium heat transfer tubes 2 pass, and a plurality of heat transfer fins 3 are arranged at substantially equal intervals along the longitudinal direction of the heat medium heat transfer tubes 2. The through hole 31 has the same hole shape as the outer shape in the longitudinal direction of the heat medium heat transfer tube 2.

  The heat transfer tube 2 is fixed to the heat transfer fins 3 by passing through the heat transfer fins 3 through the through holes 31 (see arrow B in FIG. 4) and expanding in a state of passing through the through holes 31. . Here, as a method of expanding the tube, considering that the heat medium heat transfer tube 2 has a multi-hole tube structure having a plurality of fluid holes 22, a high-pressure liquid or gas is supplied from the tube end of the heat medium heat transfer tube 2. Then, a fluid pressure expansion method for expanding the heat medium heat transfer tube 2 is employed.

  Thus, since it has the structure which makes the heat-transfer heat pipe 3 penetrate the heat-transfer fin 3 which consists of a plate fin here, a heat-transfer area increases and heat-transfer performance is improving further. Moreover, the heat medium heat transfer tubes 2 are fixed to the heat transfer fins 3 by expanding the tubes. As described above, the outer surface of the flat portion 21 of the heat medium heat transfer tubes 2 connects the heat medium heat transfer tubes 2 from the longitudinal direction. When viewed, since it is uneven so as to conform to the shape of the inner peripheral surface of each flow path hole 22, the outer surface of the flat surface portion 21 is uniformly expanded during the tube expansion (before the tube expansion in FIG. 4). , Refer to the two-dot chain line indicating the flat surface portion 21 and the flow path hole 22 and the solid line indicating the flat surface portion 21 and the flow path hole 22 after the pipe expansion), whereby the heat transfer fin 3 (more specifically, the through hole) (Periphery of 31) and the flat part 21 are improved, which contributes to the improvement of heat transfer performance.

<Modification 1>
In the air heat exchanger 1 according to the above-described embodiment, the flow path hole 22 is formed to have a circular cross-sectional shape when the heat medium heat transfer tube 2 is viewed from the longitudinal direction, and the planar portion 22. When the heat medium heat transfer tube 2 is viewed from the longitudinal direction, the outer surface of the heat medium heat transfer tube 2 is employed so as to conform to the shape of the inner peripheral surface of each flow path hole 22. As shown, the channel hole 22 is formed to have a quadrangular (here, approximately square) cross-sectional shape, and when the heat transfer tube 2 is viewed from the longitudinal direction, the quadrangular 1 The pair of corners are arranged so as to protrude toward both outer surfaces of the flat surface portion 21, and when the heat medium heat transfer tube 2 is viewed from the longitudinal direction of the outer surface of the flat surface portion 22, You may employ | adopt the heat-medium heat exchanger tube 2 uneven | corrugated so that the shape of the inner peripheral surface of 22 may be followed.

  Also in this modified example, like the above-described embodiment, it is possible to obtain effects such as improving heat transfer performance while suppressing an increase in material during extrusion molding.

<Modification 2>
In the air heat exchanger 1 according to the above-described embodiment, the flow path hole 22 is formed to have a circular cross-sectional shape when the heat medium heat transfer tube 2 is viewed from the longitudinal direction, and the planar portion 22. When the heat medium heat transfer tube 2 is viewed from the longitudinal direction, the heat medium heat transfer tube 2 that is uneven so as to conform to the shape of the inner peripheral surface of each flow path hole 22 is employed. As shown, the flow path hole 22 is formed to have a polygonal cross-sectional shape of five or more corners (here, six corners), and the outer surface of the plane portion 22 is the heat medium heat transfer tube 2. When viewed from the longitudinal direction, the heat medium heat transfer tube 2 that is uneven so as to follow the shape of the inner peripheral surface of each flow path hole 22 may be employed.

  Also in this modified example, like the above-described embodiment, it is possible to obtain effects such as improving heat transfer performance while suppressing an increase in material during extrusion molding.

-Second Embodiment-
<Overall configuration of air heat exchanger>
FIG. 7 is a schematic configuration diagram of an air heat exchanger 101 according to the second embodiment of the present invention, and FIG. 8 is an enlarged perspective view of a portion A in FIG. The air heat exchanger 101 performs heat radiation (condensation) and heating (evaporation) of the heat medium using air as a cooling source or a heating source, similarly to the air heat exchanger 1 according to the first embodiment and the modification thereof. For example, the heat exchanger is employed as a heat exchanger constituting a refrigerant circuit of a vapor compression refrigeration apparatus. Here, carbon dioxide is used as the heat medium circulating in the refrigerant circuit.

  The air heat exchanger 101 mainly includes the heat medium heat transfer tube 2, the heat transfer fins 103, and the header tubes 4 and 5. Here, the heat medium heat transfer pipe 2 and the header pipes 4 and 5 are the same as the heat medium heat transfer pipe 2 and the header pipes 4 and 5 in the above-described first embodiment and the modifications thereof, and thus the description thereof is omitted here. The heat transfer fin 103 will be described.

<Heat transfer fin>
The heat transfer fin 103 is formed of a corrugated fin formed by bending a plate-like material into a corrugated shape along the longitudinal direction of the heat transfer tube 2.

  The heat transfer fins 103 are disposed in the ventilation space between the upper and lower directions of the plane portion 21, and the upper end and the lower end formed by bending into a corrugated shape are joined to the lower surface and the upper surface of the plane portion 21 by brazing or the like. . Further, in order to improve the heat exchange efficiency, the heat transfer fins 103 are formed with a plurality of cut-and-raised portions 103 by cutting up the central portion in the vertical direction of the heat transfer fins 103. Here, the main body side cut-and-raised portion 131 is cut and raised in a louver shape, and is formed so that the inclination direction with respect to the ventilation direction is reversed between the upstream portion and the downstream portion in the ventilation direction. Note that the shape and the like of the cut-and-raised portion 103 is not limited to the shape and the like of FIG. 8, and various configurations can be applied. Thus, here, since it has the structure which arrange | positions the heat-transfer fin 103 which consists of a corrugated fin in ventilation space, a heat-transfer area increases and heat-transfer performance is improving further.

  And also in the air heat exchanger 103 in this embodiment, the effect of improving heat-transfer performance, etc. can be acquired, suppressing the increase in the material at the time of extrusion molding similarly to the above-mentioned 1st Embodiment. .

<Modification>
In the air heat exchanger 103 in the above-described embodiment, the flow path hole 22 is formed to have a circular cross-sectional shape when the heat medium heat transfer tube 2 is viewed from the longitudinal direction, and the planar portion 22. The heat medium heat transfer tubes 2 that are uneven so as to conform to the shape of the inner peripheral surface of each flow path hole 22 when the heat medium heat transfer tubes 2 are viewed from the longitudinal direction are employed. Similarly to the air heat exchanger 1 (see FIGS. 5 and 6) in the first and second modifications of the embodiment, the flow path hole 22 is formed to have a quadrangular (here, substantially square) cross-sectional shape. And when the heat-medium heat transfer tube 2 is viewed from the longitudinal direction, a pair of corners of the quadrangular shape are arranged so as to protrude toward both outer surfaces of the plane part 21, and the outer surface of the plane part 22 However, when the heat transfer tube 2 is viewed from the longitudinal direction, it is uneven so as to follow the shape of the inner peripheral surface of each flow path hole 22. Alternatively, the heat transfer tube 2 may be employed, and the flow path hole 22 is formed to have a polygonal cross-sectional shape of five or more corners (here, six corners), and the planar portion 22. Alternatively, the heat medium heat transfer tube 2 may be employed in which the outer surface of the heat medium heat transfer tube 2 is uneven so as to follow the shape of the inner peripheral surface of each flow path hole 22 when the heat medium heat transfer tube 2 is viewed from the longitudinal direction.

  Also in this modified example, like the above-described embodiment, it is possible to obtain effects such as improving heat transfer performance while suppressing an increase in material during extrusion molding.

-Other embodiments-
As mentioned above, although embodiment of this invention and its modification were demonstrated based on drawing, specific structure is not restricted to these embodiment and its modification, It changes in the range which does not deviate from the summary of invention. Is possible.

(1)
In the above-mentioned embodiment and its modification, although eight flow-path holes 22 of the heat-medium heat exchanger tube 2 are formed in the width direction, it is not limited to this. The number of channel holes may be set arbitrarily.

(2)
The configuration of the header pipe is not limited to the configuration of the above-described embodiment and its modifications, and various configurations can be applied.

(3)
In the first and second embodiments described above, the flow path hole 22 has a substantially circular cross-sectional shape, but is not limited thereto, and may have an elliptical cross-sectional shape.

(4)
In the modified example 1 of the first embodiment and the modified example of the second embodiment, the flow path hole 22 has a substantially square cross-sectional shape. It may have a square cross-sectional shape.

(5)
In the modification 2 of the above-described embodiment and the modification of the second embodiment, the flow path hole 22 has a hexagonal cross-sectional shape, but is not limited thereto, and has a polygonal cross-sectional shape of five or more corners. Any cross-sectional shape such as a pentagon or a heptagon may be used.

(6)
In the above-described second embodiment and the modifications thereof, the shape of the cut-and-raised portion 103 is a louver shape, but is not limited to this, and various shapes can be applied.

  The present invention is widely applicable to an air heat exchanger having a flat multi-hole heat transfer tube manufactured by extrusion molding.

DESCRIPTION OF SYMBOLS 1,101 Air heat exchanger 2 Heat-medium heat exchanger tube 3, 103 Heat transfer fin 21 Planar part 22 Channel hole 31 Through-hole

JP-A-6-74609

Claims (7)

A plurality of wide planar portions (21) are arranged facing each other with a ventilation space through which air flows in the width direction of the planar portion, and a plurality of flow path holes (22) through which a heat medium flows are provided. It is formed side by side in the width direction of the flat portion, and includes a heat medium heat transfer tube (2) made of a flat multi-hole tube manufactured by extrusion molding,
The outer surface of the flat portion is uneven so as to follow the shape of the inner peripheral surface of each flow path hole when the heat transfer tube is viewed from the longitudinal direction.
Air heat exchanger (1, 101).   The outer surface of the flat portion (21) is uneven so that the thickness from the inner peripheral surface of each flow path hole (22) to the outer surface of the flat portion is substantially the same. Air heat exchanger (1, 101).   The air heat exchanger (101) according to claim 1 or 2, further comprising a heat transfer fin (103) made of corrugated fins arranged in the ventilation space. A heat transfer fin (3) comprising a plate fin formed with a through hole (31) through which the heat transfer tube (2) passes;
The heat medium heat transfer tube is fixed to the heat transfer fin by being expanded in a state of passing through the through hole.
The air heat exchanger (1, 101) according to claim 1 or 2.   Each said flow-path hole (22) has the circular cross-sectional shape, when the said heat-medium heat exchanger tube (2) is seen from a longitudinal direction, The air heat in any one of Claims 1-4 Exchanger (1, 101).   Each of the channel holes (22) has a quadrangular cross-sectional shape, and when the heat medium heat transfer tube (2) is viewed from the longitudinal direction, a pair of corners of the quadrangular shape is the plane. The air heat exchanger (1, 101) according to any one of claims 1 to 4, wherein the air heat exchanger (1, 101) is disposed so as to protrude toward both outer surfaces of the portion (21).   Each said flow-path hole (22) has a polygonal cross-sectional shape of 5 or more corners, when the said heat-medium heat exchanger tube (2) is seen from a longitudinal direction. The air heat exchanger (1, 101) described in 1.

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