JP6636110B1 - Air conditioner equipped with heat exchanger, pipe expansion member, and heat exchanger - Google Patents

Abstract

A heat exchanger realizing high heat exchange performance or an air conditioner including the heat exchanger is provided. A heat exchanger according to the present invention expands and joins a flat porous heat transfer tube 1 having at least four partition walls 3 whose width is divided in the width direction and having a substantially parallel refrigerant flow path 2 and a flat porous heat transfer tube. A heat exchanger comprising: a fin having an insertion hole; and a header communicating a refrigerant flow path at each end of the flat porous heat transfer tube, wherein the flat porous heat transfer tube has flow passages at both ends in a width direction. The partition walls were arranged such that the width was wider than the flow path width of the other part. Further, the air conditioner of the present invention has the heat exchanger. [Selection diagram] FIG.

Description

The present invention relates to a heat exchanger such that a refrigerant flow path is formed by a flat perforated heat transfer tubes.

  Conventionally, in a refrigeration cycle device such as an air conditioner, it has been mainstream to use a pipe member made of copper or a copper alloy for a heat transfer tube constituting a heat exchanger or a refrigerant pipe connecting between the heat exchangers. . However, in recent years, from the viewpoint of weight reduction and cost reduction, a heat exchanger using not only fins but also heat transfer tubes made of aluminum or an aluminum alloy has been proposed.

  This heat exchanger achieves high heat exchange performance by manufacturing by attaching a brazing material made of an aluminum alloy and brazing a plate-like fin and a flat porous heat transfer tube. However, this manufacturing method has a problem that the plate-shaped fins of the brazed heat exchanger must be subjected to a hydrophilic treatment.

As a method of manufacturing a heat exchanger instead of brazing, there is a method of mechanically joining a plate-like fin and a flat porous heat transfer tube.
For example, in Patent Literature 1, a flat porous heat transfer tube is attached so as to penetrate a plate-like fin, and the internal pressure of the flat porous heat transfer tube is increased by a fluid to expand the heat transfer tube, thereby joining the heat transfer tube and the fin. A method is described. In the flat perforated heat transfer tube of Patent Document 1, the partition wall in the heat transfer tube has a bent or curved shape, and the heat transfer tube is expanded by straightening the partition wall.

  Further, in Patent Document 2, a flat porous heat transfer tube provided with a substantially U-shaped partition wall is attached so as to penetrate a plate-like fin having a polygonal insertion hole, and the flat tube is plastically deformed by water pressure or the like. And a method of mechanically joining the fin with the fin.

Japanese Patent No. 4109444 JP 2004-353954 A

According to Patent Literature 1 and Patent Literature 2, the fin and the flat porous heat transfer tube can be mechanically joined to each other. There is no need to perform a coating process.
However, depending on the shape of the flat perforated heat transfer tube, the contact pressure between the fin and the heat transfer tube when expanded is not uniform, and the contact heat resistance between the fin and the flat perforated heat transfer tube is increased, resulting in high heat exchange performance. There are problems that cannot be realized.
An object of the present invention is to provide a heat exchanger or the like that solves the above-described problems and realizes high heat exchange performance.

In order to solve the above-mentioned problems, a heat exchanger according to the present invention is configured such that a flat porous heat transfer tube having a substantially parallel refrigerant flow path in which the inside of a pipe is divided in a width direction by at least four partition walls, and an expansion joining of the flat porous heat transfer tube. A fin having an insertion hole to be inserted, and a header communicating with the refrigerant flow path at each end of the flat porous heat transfer tube, wherein the flat porous heat transfer tube has a widthwise central portion. The partition width is arranged such that the width of the flow path is narrower than any of the flow path widths of the other parts, and the flow path width of the other part is located at one end side with respect to the central part. for even the other portion located on the other side for the other parts, the heat exchanger the ratio of the maximum and minimum channel width is arranged the partition wall to be approximately the same width of 1.16 or less did.
Further, the air conditioner of the present invention includes the heat exchanger.

ADVANTAGE OF THE INVENTION According to this invention, since a flat porous heat exchanger tube can be expanded and the contact thermal resistance at the time of joining a fin and a flat porous heat exchanger tube can be improved, a heat exchanger etc. with high heat exchange performance can be provided.

It is a figure showing an important section of a heat exchanger of an embodiment. It is a figure showing a section of a longitudinal direction of a flat perforated heat exchanger tube. It is a figure showing appearance of a plate-like fin. It is a figure showing the manufacture flow of the heat exchanger of an embodiment. It is a figure showing the section of a flat perforated heat exchanger tube. It is a figure which shows the flatness and joinability of the flat porous heat transfer tube from which the distance between partition walls differs. FIG. 4 is a cross-sectional view of a flat porous heat transfer tube of Comparative Example 1. FIG. 9 is a cross-sectional view of a flat perforated heat transfer tube of Comparative Example 2. FIG. 9 is a cross-sectional view of a flat perforated heat transfer tube of Comparative Example 3 . It is sectional drawing of the flat porous heat exchanger tube which formed the radiation fin in the refrigerant | coolant flow path. It is sectional drawing of the flat porous heat exchanger tube which formed the radiation fin in the refrigerant flow path except a center part.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Drawing 1 is a figure showing the important section of the heat exchanger of an embodiment. The heat exchanger of the embodiment functions as a condenser or an evaporator of an air conditioner, and is used as either an indoor heat exchanger or an outdoor heat exchanger.

  The heat exchanger includes a flat porous heat transfer tube 1 through which a refrigerant flows, a plate-like fin 10 provided with a plurality of insertion holes 11 through which the flat porous heat transfer tube 1 expands and joins, and both ends of the flat porous heat transfer tube 1. And a header (not shown) that communicates the flat porous heat transfer tube 1.

  The refrigerant flowing into one of the headers is distributed to the plurality of flat porous heat transfer tubes 1 and flows through the flat porous heat transfer tubes 1. At this time, the latent heat and sensible heat of the refrigerant are transferred to the plate-like fins 10 joined to the flat porous heat transfer tube 1. Although details will be described later, the contact thermal resistance between the flat porous heat transfer tube 1 and the plate-like fin 10 affects the heat exchange performance of the heat exchanger. For this reason, in the heat exchanger of the embodiment, the contact heat resistance is reduced by appropriately setting the contact surface pressure at the joint between the flat porous heat transfer tube 1 and the plate-like fin 10, and the heat exchange performance of the heat exchanger is improved. Has improved.

Referring to FIG. 2, the flat porous heat transfer tube 1 will be described in detail.
FIG. 2 shows a cross section of the flat porous heat transfer tube 1 in the longitudinal direction.
The flat porous heat transfer tube 1 is made of aluminum or an aluminum alloy, and is provided with a plurality of refrigerant passages 2 divided by a plurality of partition walls 3 provided in a longitudinal direction of the tube cross section (width direction of the tube). As will be described in detail later, at the time of manufacturing, the flat porous heat transfer tube 1 is supplied with a high-pressure compressed fluid to the refrigerant flow path 2 surrounded by the bent or curved partition wall 3 and the pipe wall 4 to extend the partition wall 3. As a result, the pipe expands in the short axis direction (the thickness direction of the pipe) in the cross section of the pipe.
In the flat porous heat transfer tube 1 of the present embodiment, the partition walls are arranged such that the flow path width at the center in the width direction is narrower than any of the flow path widths at the other parts, and the flow rate at the other parts is reduced. Regarding the road width, the ratio between the maximum and minimum flow path widths of the other portion located on one end side and the other portion located on the other end side of the central portion is substantially the same width of 1.16 or less. The partitions are arranged as follows.
In addition, as for the flat porous heat transfer tube 1 (that is, the expanded tube member) before being expanded into the flat porous heat transfer tube 1, the interval between the partition walls at the central portion in the width direction is located at one end side with the central portion interposed therebetween. together are arranged partition walls so any narrower than the spacing of the partition wall between the other portion located at a portion and the other end side, for the other parts of even the other end to the other portion of the one end side, respectively said other The partitions are arranged such that the distance between the partitions in the portion is approximately the same width with the ratio of the maximum to the minimum distance of 1.16 or less.

Next, the details of the plate-like fin 10 will be described with reference to FIG.
FIG. 3 is a diagram showing an appearance of the plate-like fin 10. As shown in FIG.
The plate-like fin 10 is made of aluminum or an aluminum alloy, and has an outer surface subjected to a hydrophilic film treatment.

A plurality of insertion holes 11 into which the flat porous heat transfer tubes 1 are inserted are provided in the plate-like fin 10 at predetermined intervals. A fin collar 12 bent on one surface side of the plate-like fin 10 is provided on an outer peripheral portion of the insertion hole 11, and is joined to the flat porous heat transfer tube 1 inserted and expanded. By providing the fin collar 12, the contact thermal resistance between the plate-like fin 10, the flat porous heat transfer tube 1, and the joint can be reduced.
The insertion hole 11 is formed with a clearance of about 0 to 150 μm for inserting the flat porous heat transfer tube 1 before expansion.

  The contact surface pressure at the joint between the plate-like fin 10 and the flat perforated heat transfer tube 1 is affected by springback accompanying the deformation of the insertion hole 11. For this reason, the expansion amount of the flat porous heat transfer tube 1 is determined by the sum of the clearance of the insertion hole 11 for inserting the flat porous heat transfer tube 1 and the deformation amount of the insertion hole 11 that generates a contact surface pressure.

  At this time, it is desirable to make the expansion amount of the flat porous heat transfer tube 1 constant in the width direction so that the contact surface pressure of the joint portion in the width direction (the major axis direction of the cross section) of the flat porous heat transfer tube 1 becomes uniform. . However, when the pressure is evenly applied, since both ends of the flat porous heat transfer tube 1 are difficult to expand, the expansion amount of both ends of the flat porous heat transfer tube 1 is smaller than the expansion amount of the central portion.

  For this reason, it is conceivable that the hole width of the insertion hole 11 is changed between the end portion and the center portion to keep the deformation amount of the plate-like fin 10 constant. In this case, however, there is a problem in forming the fin collar 12. Can occur. Therefore, in the heat exchanger of the embodiment, although the details will be described later, the hole width of the insertion hole 11 is fixed, and the arrangement of the partition walls 3 of the flat porous heat transfer tube 1 is changed to optimize the expansion amount of the flat porous heat transfer tube 1. I do.

Here, a method for manufacturing the heat exchanger of the embodiment will be described with reference to FIG.
FIG. 4 is a diagram illustrating a manufacturing flow of the heat exchanger of the embodiment.
In step S41, a hydrophilic film treatment is applied to an aluminum plate made of aluminum or an aluminum alloy material, and in step S42, a plate-shaped fin 10 is manufactured by pressing into a predetermined shape.

In step S43, the aluminum or aluminum alloy material is, for example, extruded or drawn, cut into a predetermined size corresponding to the size of the heat exchanger of the embodiment, and the flat porous heat transfer tube 1 (expanding member) is cut. To manufacture.
Then, in step S44, the plurality of flat perforated heat transfer tubes 1 are aligned at predetermined intervals.

  In step S45, the plurality of flat perforated heat transfer tubes 1 aligned in step S44 are inserted into the insertion holes 11 of the plate-like fin 10. At this time, there is no gap or a slight gap (0 to 150 μm) is formed between the outer periphery of the flat porous heat transfer tube 1 and the fin collar 12.

Next, in step S46, both ends of the flat porous heat transfer tube 1 inserted into the insertion holes 11 of the plate-like fins 10 are inserted into joining holes provided in the header. Then, both ends of the flat porous heat transfer tube 1 and the header are joined by brazing or other appropriate methods.
In step S47, by supplying the compressed fluid to the flat porous heat transfer tube 1 via the header, the internal pressure of the refrigerant flow path 2 is increased to pressurize the flat porous heat transfer tube 1, and the flat porous heat transfer tube 1 is expanded. The plate-like fin 10 and the flat porous heat transfer tube 1 are joined.
In the heat exchanger according to the embodiment, the flat porous heat transfer tube 1 whose contact heat resistance described later is reduced and expanded and mechanically joined to the plate-like fin 10 by the above-described manufacturing method. The fin 10 can be subjected to a hydrophilic coating treatment, which facilitates the manufacture of the heat exchanger.

Hereinafter, the arrangement state of the partition walls 3 of the flat porous heat transfer tube 1 in the heat exchanger of the embodiment will be described in detail.
FIG. 5 is a view showing a cross section of the flat porous heat transfer tube 1.

The flat porous heat transfer tube 1 (expanding member) is a flat tube formed so that upper and lower tube walls 4 are substantially parallel to each other. The flat porous heat transfer tube 1 is connected to the upper and lower tube walls 4 inside the tube. In addition, the flat porous heat transfer tube 1 is provided with a plurality of partition walls 3 whose cross-sectional shape is bent in a long axis direction in the longitudinal direction of the cross-section of the flat porous heat transfer tube 1 (a hiragana “ku” shape or a “ku” mirror character shape). The inside of the flat porous heat transfer tube 1 is divided by these partition walls 3, and a plurality of refrigerant channels 2 are provided in parallel.

The solid line in FIG. 5 shows a cross section of the flat porous heat transfer tube 1 before expansion, and the broken line shows a cross section of the flat porous heat transfer tube 1 after expansion. In addition, the cross section (broken line) after the expansion in FIG. 5 exaggerates the expanded state.
In the expansion of the flat perforated heat transfer tube 1, the partition wall 3 bent in a chevron shape is linearly extended, and the dimension of the cross section in the minor axis direction (the thickness direction of the tube) increases. The amount of increase in the dimension of this cross section in the minor axis direction (the thickness direction of the pipe) is the expansion amount.

The amount of expansion is determined by the shape of the partition wall 3. However, in the refrigerant flow passages 2 at both ends of the flat porous heat transfer tube 1, the expanded state is different because one side is different from the partition wall 3. Further, the refrigerant flow path 2 adjacent to the refrigerant flow paths 2 at both ends of the flat porous heat transfer tube 1 is affected by the expansion at the end.
For this reason, when the partition walls 3 are evenly spaced, the expansion amount has a distribution in the major axis direction of the cross section. Specifically, the expansion amount decreases toward the end of the flat porous heat transfer tube 1.

Since the tension applied to the partition wall 3 at the time of expanding the pipe is generated by the pressure of the compressed fluid inside the pipe wall 4 sandwiched between the partition walls 3, the tension applied to the partition wall 3 is proportional to the interval between the partition walls 3. In the flat perforated heat transfer tube 1 of the embodiment, the expansion amount is adjusted by changing the interval between the partition walls 3 based on this.
As described above, the end of the flat perforated heat transfer tube 1 is harder to expand than the central portion, and it is desirable to increase the interval between the partition walls 3 at the end, but the end in the length direction of the insertion hole 11 has high rigidity. Therefore, there is an upper limit to the amount of tube expansion to obtain a uniform contact surface pressure. That is, there is an upper limit to the length of the interval between the partition walls 3 at the end of the flat porous heat transfer tube 1.
In addition, since the partition 3 is deformed so as to extend the shape of a letter, the interval between the partitions 3 does not change before and after the tube expansion.

Next, the relationship between the spacing of the partition walls 3 of the flat porous heat transfer tube 1, the difference in the expansion amount in the longitudinal direction of the cross section, and the bonding property in the insertion hole 11 will be described with reference to FIGS.
FIG. 6 is a diagram showing the ratio of the distance between the partition walls 3 at the end and the center (for each example in which the distances (L _c , L ₁ , L ₂ , L _T ) between the partition walls 3 provided in the flat porous heat transfer tube 1 are different). L _T / L _c ), the flatness (ΔYmax−ΔYmin) of the flat porous heat transfer tube 1, and the bondability of the flat porous heat transfer tube 1 in the insertion hole 11 are shown.

Intervals of the partition walls _{3 (L c, L 1,} L 2, L T) corresponds to the distance between the partition walls of the partition wall 3 shown in FIG.
Distance L _c is the distance between the flattened perforated heat transfer tubes 1 of the nearest flow path to the central partition wall (length definitive wall 4).
Distance L _T is the distance of the straight portion between the partition wall and the tube end of the end flow passage of the flat porous heat transfer tube 1.
The intervals L ₁ , L ₂ indicate the distance between the partition walls of the flow passage adjacent to the central flow passage of the flat porous heat transfer tube 1 toward the end thereof.
In this specification, the intervals (L _c , L ₁ , L ₂ , L _T ) between the partition walls 3 may be referred to as a channel width.
ΔYmax and ΔYmin indicate the maximum value and the minimum value of the expanded width on one side of the flat porous heat transfer tube 1, and the difference is defined as flatness. A smaller flatness indicates flatness.

Flat perforated heat transfer tube 1 of Comparative Example 1 in FIG. 6 are shown in FIG. 7, a L _{c, L} 1, _{L 2,} when the total pore equal equal length of L _T.
When the flat porous heat transfer tube 1 of Comparative Example 1 is expanded, the tube wall 4 of the central flow passage expands greatly and the flatness increases.
Since the high heat exchange performance is obtained by expanding the flat porous heat transfer tube 1 and bringing the outer surface of the tube wall 4 into close contact with the fin collar 12, it is preferable that the outer surface of the tube wall 4 be changed into a corrugated shape or unevenness by expanding the tube. Therefore, the bonding property between the flat porous heat transfer tube 1 and the fin collar 12 is insufficient (x mark).

Flat perforated heat transfer tubes 1 of the comparative example 2 in FIG. 6 are shown in FIG. 8, a case L _c, a short length of L _T for the length of _{L 1,} L _2.
In this case, the pipe wall 4 of the central flow path after the expansion is greatly expanded, the flatness is increased, and the bondability between the flat porous heat transfer tube 1 and the fin collar 12 is insufficient (marked by x).

Flat perforated heat transfer tube 1 of Example 1 in FIG. 6, the length of _{L T is} a case longer than the L _c, the length of L 1, _{L 2.}
In this case, after the pipe expansion, the pipe wall 4 of the refrigerant flow path 2 expands almost uniformly, and the flatness decreases. Thereby, the bonding property between the flat porous heat transfer tube 1 and the fin collar 12 becomes excellent (marked with ◎), and a heat exchanger having high heat exchange property can be obtained.

Flat perforated heat transfer tubes 1 of the second embodiment of FIG. 6, the length of _{L T} is an _{L T} than the _{L c,} L 1, is longer than the average length of _{L 2.}
Also in this case, after expansion, the pipe wall 4 of the refrigerant flow path 2 expands substantially evenly, and the flatness decreases. Thereby, the bonding property between the flat porous heat transfer tube 1 and the fin collar 12 becomes excellent (marked with ◎), and a heat exchanger having high heat exchange property can be obtained.

Flat perforated heat transfer tubes 1 of the third embodiment of FIG. 6, the length of _{L c is} the case L _1, L 2, shorter than the average length of _{L T.}
Also in this case, after expansion, the pipe wall 4 of the refrigerant flow path 2 expands substantially evenly, and the flatness decreases. Thereby, the bonding property between the flat porous heat transfer tube 1 and the fin collar 12 becomes excellent (marked with ◎), and a heat exchanger having high heat exchange property can be obtained.

Flat perforated heat transfer tube 1 of Comparative Example 3 in FIG. 6 are shown in FIG. 9, the length of _{L c is} the shorter the length of _{L 1, L 2, L T} .
In this case, while the pipe wall 4 of the end flow path after expansion expands, the pipe wall 4 of the central flow path does not expand, the flatness decreases, and the flat porous heat transfer tube 1 and the fin collar 12 Are good (○).

As shown in FIG. 6, for flattened perforated heat transfer tubes 1 of Examples 1 3, the bonding between the flat porous heat transfer tube 1 and the fin collar 12 is good excellent (◎ mark), the heat exchanger having high heat exchange You can get a bowl. On the other hand, in the flat porous heat transfer tubes 1 of Comparative Examples 1 and 2, the bonding property between the flat porous heat transfer tube 1 and the fin collar 12 is insufficient. For this reason, it is particularly desirable that the bonding property be excellent. In the flat porous heat transfer tube 1, the flow path width Lt at both ends in the width direction and the flow path width Lc at the center in the width direction are 1. The partition walls 3 are arranged so that 31 ≦ (Lt / Lc) ≦ 1.67 .

  As described above, according to the flat porous heat transfer tube 1 of the embodiment, the unevenness of the outer surface of the tube at the time of expansion is reduced, so that the contact heat resistance is reduced and the heat exchanger having high heat exchange performance can be provided. it can.

FIGS. 10 and 11 are cross-sectional views of the flat porous heat transfer tubes 1 (expanding members) of Examples 1 to 3 of FIG.
In detail, a protruding portion 13 that extends in the longitudinal direction of the flat porous heat transfer tube 1 and serves as a radiation fin is formed on a flat portion of the inner surface of the refrigerant flow passage 2 to improve the heat transfer coefficient with the refrigerant. The heat exchange performance of the flat porous heat transfer tube 1 is improved.

As shown in FIG. 11, the projection 13 may not be formed in the central cooling channel. As a result, a decrease in the flow path cross-sectional area can be prevented, so that a decrease in the refrigerant flow rate (an increase in pressure loss) can be suppressed.
It is needless to say that the cross-sectional shape of the projection 13 is not limited to a triangle, but may be an arc or a quadrangle.

  As described above, the thickness of the tube wall 4 of the flat porous heat transfer tube 1 is designed so as to be able to withstand the pressure due to the fluid in the tube when used as a heat exchanger. In the cross section, the wall thickness at both ends in the major axis direction of the cross section of the pipe is larger than the bent or curved partition wall arranged in the pipe. For this reason, at the time of expanding the flat porous heat transfer tube 1, both ends in the major axis direction of the tube cross section are less elongated in the short axis direction of the tube cross section than the partition wall 2, and the tube wall 4 of the flat porous heat transfer tube 1 is formed. A non-uniformly swollen state results.

  When the flat porous heat transfer tube 1 is expanded by the fluid pressure, the force expanding in the minor axis direction of the tube cross section of the tube is proportional to the length of the flat portion on the inner surface of the multi-hole tube corresponding to each space between the partition walls. In the flat porous heat transfer tube 1 of the embodiment, the length of the flat portion in both ends of the flow path in the longitudinal direction of the cross section is made longer than the length of the flat portion (distance between the partition walls) in the other flow paths. The pipe is expanded by increasing the load applied to the flat part of the flow path. Thereby, the tube wall of the flat perforated heat transfer tube 1 is uniformly swelled, and the joining property between the fin and the heat transfer tube is improved.

  Although the case where the flat porous heat transfer tube 1 of the embodiment is divided by the six partitions 3 and has the seven refrigerant channels 2 has been described, the number of the partitions 3 (the refrigerant channels 2) is not limited to this. What is necessary is just a flat porous heat transfer tube 1 having at least five refrigerant channels 2.

  According to the heat exchanger and the air conditioner using the flat perforated heat transfer tube 1 of the embodiment, the heat exchange performance of the heat exchanger can be improved, and at the same time, high hydrophilicity, corrosion resistance, deodorizing property, antibacterial property, and prevention can be achieved. A heat exchanger having mold properties can be easily realized.

DESCRIPTION OF SYMBOLS 1 Flat perforated heat transfer tube 2 Refrigerant flow path 3 Partition wall 4 Tube wall 10 Plate fin 11 Insertion hole 12 Fin collar

Claims (9)

A flat perforated heat transfer tube having a substantially parallel refrigerant flow channel, the inside of which is divided in the width direction by at least four partition walls,
A fin having an insertion hole for expanding and joining the flat porous heat transfer tube;
A header that communicates the refrigerant flow path at each end of the flat porous heat transfer tube,
A heat exchanger comprising:
The flat porous heat transfer tube, the partition wall is arranged such that the flow path width of the central part in the width direction is narrower than any of the flow path widths of other parts,
Regarding the flow width of the other part, the ratio of the maximum flow width to the minimum flow width of the other part located on one end side with respect to the central part and the other part located on the other end side is 1. A heat exchanger in which the partition walls are arranged so as to have the same width of 16 or less. The heat exchanger according to claim 1,
In the flat porous heat transfer tube, the partition walls are arranged such that the flow path width Lt at both ends in the width direction and the flow path width Lc at the center in the width direction satisfy 1.31 ≦ (Lt / Lc) ≦ 1.67. The heat exchanger in place. The heat exchanger according to claim 1 or 2,
The heat exchanger, wherein the partition wall is arranged symmetrically with respect to a vertical axis in a width direction of the flat porous heat transfer tube. The heat exchanger according to any one of claims 1 to 3,
A heat exchanger in which a protrusion extends in the longitudinal direction of the tube on the inner surface of the refrigerant channel of the flat porous heat transfer tube. The heat exchanger according to claim 4,
The heat exchanger wherein the protrusion is provided in a refrigerant flow path other than the central part. The heat exchanger according to any one of claims 1 to 5,
The heat exchanger wherein the hole width of the insertion hole is constant. The heat exchanger according to any one of claims 1 to 6,
The fins are made of aluminum or aluminum alloy whose surface is treated with a hydrophilic coating,
The flat porous heat transfer tube is a heat exchanger made of aluminum or an aluminum alloy. A tube expanding member for forming the flat porous heat transfer tube in the heat exchanger according to any one of claims 1 to 7,
The partition wall of the pipe expanding member has a bent or curved cross-sectional shape,
Interval of the partition wall between the central portion in the width direction, the to be narrower than both of the partition wall between the spacing of the other portion located on the other part and the other end located at one end side across the central portion While arranging the partition,
Regarding the other portion on the one end side and the other portion on the other end side, the interval between the partition walls in the other portion is substantially the same width as the ratio of the maximum to the minimum interval is 1.16 or less. A pipe expanding member in which the partition is disposed. An air conditioner comprising the heat exchanger according to claim 1.

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