HEAT EXCHANGER AND AIR HANDLING UNIT

Abstract

A heat exchanger prevents corrosion in a portion that is not covered with a heat transfer fin of a heat transfer tube. The heat exchanger includes a plurality of flat tubes, a heat transfer fin, and a cover. The flat tubes are arranged in a first direction. The heat transfer fin is provided between the adjacent flat tubes. The cover covers a part of the flat tube. Each of the plurality of flat tubes includes a first portion, a second portion, and a connecting portion. The connecting portion connects the first portion and the second portion such that an angle between a direction in which the first portion extends and a direction in which the second portion extends is less than 180°. The heat transfer fin is fixed to the first portion and the second portion. The cover covers at least a part of the plurality of connecting portions.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of PCT International Application No. PCT/JP2024/034854, filed on September 30, 2024, which claims priority under 35 U.S.C. § 119(a) to Patent Application No. JP 2023-170894, filed in Japan on September 29, 2023, all of which are hereby expressly incorporated by reference into the present application.

TECHNICAL FIELD

The present invention relates to a heat exchanger and an air handling unit.

BACKGROUND ART

As disclosed in PTL 1 (U.S. Patent No. 5,904,053), there is a known air handling unit including a fin-and-tube type heat exchanger that exchanges heat between a refrigerant and air.

SUMMARY

In a heat exchanger according to a first aspect, a heat exchange portion exchanges heat between air carried by an air flow and a refrigerant. The heat exchanger includes a plurality of flat tubes, a heat transfer fin, and a covering member. The flat tubes are arranged along a first direction, allow the refrigerant to flow inside, and are made of an aluminum or aluminum alloy as a material. The heat transfer fin is provided between the adjacent flat tubes and is made of an aluminum or aluminum alloy as a material. The covering member covers at least a part of the flat tube.

The plurality of flat tubes each include a first portion, a second portion, and a connecting portion. The first portion extends in a predetermined direction when viewed from the first direction. The second portion extends in a predetermined direction different from a direction in which the first portion extends when viewed from the first direction. The connecting portion connects the first portion and the second portion such that an angle between the direction in which the first portion extends and a direction in which the second portion extends is less than 180° when viewed from the first direction.

The heat transfer fin is fixed to the first portion and the second portion. The covering member covers at least a part of a plurality of the connecting portions.

Since the connecting portion of the flat tube is not covered with the heat transfer fin, the connecting portion may become corroded due to chloride ions contained in the air when it is exposed to the air flow. In particular, since the flat tube is sometimes formed to have a thin wall thickness compared to a heat transfer tube having a tubular shape, there is a high possibility that the refrigerant flowing inside leaks when corrosion occurs compared to the heat transfer tube having a tubular shape. In the heat exchanger according to the first aspect, the covering member prevents at least a part of the connecting portion from being exposed to the air flow. Thus, the heat exchanger according to the first aspect can prevent the occurrence of corrosion in the connecting portion, which is a portion of the flat tube that is not covered with the heat transfer fin.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of the inside of an air handling unit 10 according to an embodiment when viewed from a first direction D1.

FIG. 2 is a side view of the inside of the air handling unit 10 according to the embodiment when viewed from a third direction D3.

FIG. 3 is a perspective view of the periphery of a covering member 215 of a heat exchange unit 20 according to the embodiment.

FIG. 4 is a side view of the heat exchange unit 20 according to the embodiment when viewed from the first direction D1.

FIG. 5 is a side view of the heat exchange unit 20 according to Modification A when viewed from the first direction D1.

DESCRIPTION OF EMBODIMENTS

-Embodiment-

(1) Overall Configuration of Air Handling Unit 10

An air handling unit 10 includes a casing 11, a support 12, a heat exchange unit 20, and a blower unit 30. As illustrated in FIGS. 1 and 2, the air handling unit 10 is installed vertically such that the longitudinal direction of the casing 11 extends along the vertical direction. The internal space of the casing 11 is partitioned by the support 12 into a heat exchange chamber 17 and a blower chamber 18. The heat exchange chamber 17 is located above the blower chamber 18. The heat exchange unit 20 is installed in the heat exchange chamber 17. The blower unit 30 is installed in the blower chamber 18.

A suction port 13 is formed in an upper surface 11a of the casing 11. A blow-out port 14 is formed in a lower surface 11b of the casing 11. A suction duct 15 is connected to the top of the suction port 13. A blow-out duct 16 is connected to the bottom of the blow-out port 14. The suction port 13 is connected to the suction duct 15 and the heat exchange chamber 17. The blow-out port 14 is connected to the blow-out duct 16 and the blower chamber 18. The heat exchange chamber 17 communicates with the blower chamber 18.

The blower unit 30 includes a centrifugal fan such as a sirocco fan and a motor that drives the centrifugal fan. By driving the centrifugal fan, the blower unit 30 generates an air flow that is a flow of air from the suction port 13 toward the blow-out port 14 via the heat exchange chamber 17 and the blower chamber 18. The air flows downward in the vertical direction in the internal space of the casing 11 from the suction port 13 toward the blow-out port 14. The air carried by the air flow is heat-exchanged by the heat exchange unit 20 when passing through the heat exchange chamber 17. The air handling unit 10 suctions the air from the suction port 13 and blows out the air from the blow-out port 14 after the temperature has been adjusted by heat exchange by the heat exchange unit 20.

(2) Detailed Configuration of Heat Exchange Unit 20

The heat exchange unit 20 includes a heat exchanger 21 and a drain pan 22.

(2-1) Heat Exchanger 21

The heat exchanger 21 exchanges heat between the refrigerant and the air carried by the air flow generated by the blower unit 30. The heat exchanger 21 includes a plurality of flat tubes 211, a heat transfer fin 212, a first header 213, a second header 214, and a covering member 215. The heat exchanger 21 forms a part of a refrigerant circuit (not illustrated) that performs a vapor compression refrigeration cycle.

In FIGS. 1, 4, and 5, for the sake of convenience, a part of the heat transfer fin 212 is illustrated to be transparent through a part of the plurality of flat tubes 211, and a connecting portion 211c is illustrated to be transparent through a part of the covering member 215.

(2-1-1) Plurality of Flat Tubes 211

The plurality of flat tubes 211 are heat transfer tubes that allow the refrigerant to flow inside and are made of an aluminum or aluminum alloy as a material. As illustrated in FIGS. 2 and 3, the plurality of flat tubes 211 are arranged side by side along a predetermined direction. Hereinafter, the direction in which the plurality of flat tubes 211 are arranged side by side is referred to as a first direction D1. The first direction D1 is parallel to the horizontal direction. The refrigerant, which exchanges heat with the air passing through the heat exchange chamber 17, flows inside each of the plurality of flat tubes 211. The first header 213 and the second header 214 are connected to both ends of the plurality of flat tubes 211.

Each of the flat tubes 211 includes one first portion 211a, one second portion 211b, and the one connecting portion 211c. As illustrated in FIGS. 1, 3, and 4, the first portion 211a extends in a predetermined direction when viewed from the first direction D1. The second portion 211b extends in a predetermined direction different from the direction in which the first portion 211a extends when viewed from the first direction D1. As illustrated in FIG. 4, the connecting portion 211c connects the first portion 211a and the second portion 211b such that smaller angles α and β between the direction in which the first portion 211a extends and the direction in which the second portion 211b extends are less than 180° when viewed from the first direction D1. The connecting portion 211c may connect the first portion 211a and the second portion 211b such that the angles α and β are 90° or less when viewed from the first direction D1.

One end portion of the first portion 211a is connected to the first header 213. The other end portion of the first portion 211a is connected to the connecting portion 211c. One end portion of the second portion 211b is connected to the second header 214. The other end portion of the second portion 211b is connected to the connecting portion 211c. The plurality of flat tubes 211 are arranged such that the connecting portion 211c is located above the first header 213 and the second header 214. Therefore, as illustrated in FIG. 1, the plurality of flat tubes 211 have a V-shape rotated by 180° when viewed from the first direction D1.

The first portion 211a and the second portion 211b are flat multi-hole tubes including a plurality of passages (not illustrated) through which the refrigerant passes. The plurality of passages of the first portion 211a are arranged side by side along a direction orthogonal to the direction in which the first portion 211a extends when viewed from the first direction D1. The plurality of passages of the second portion 211b are arranged side by side along a direction orthogonal to the direction in which the second portion 211b extends when viewed from the first direction D1.

The connecting portion 211c is a flat multi-hole tube that connects the first portion 211a and the second portion 211b and includes a plurality of passages (not illustrated) that allow the plurality of passages of the first portion 211a and the plurality of passages of the second portion 211b to communicate with each other. When viewed from the first direction D1, the connecting portion 211c is partially curved as illustrated in FIG. 3 so that the (smaller) angles α and β between the direction in which the first portion 211a extends and the direction in which the second portion 211b extends are less than 180°.

Hereinafter, for the sake of convenience, the direction in which a bisector L of the angle formed between the direction in which the first portion 211a extends and the direction in which the second portion 211b extends is referred to as a second direction. Further, the direction orthogonal to the bisector L when viewed from the first direction D1 is referred to as a third direction. According to the present embodiment, a second direction D2 is parallel to the vertical direction. In other words, the second direction D2 is parallel to the direction in which the air flow generated by the blower unit 30 flows. A third direction D3 is parallel to the horizontal direction. The third direction is a direction orthogonal to the first direction D1 and the second direction D2.

As illustrated in FIGS. 1 to 4, the first portion 211a and the second portion 211b are arranged such that the main surfaces thereof extend along the second direction D2 and the third direction D3. The first portion 211a and the second portion 211b are arranged at a predetermined interval along the first direction D1 orthogonal to the main surfaces.

(2-1-2) Heat Transfer Fin 212

The heat transfer fin 212 promotes heat exchange between the refrigerant flowing inside the flat tube 211 and the air carried by the air flow generated by the blower unit 30. The heat transfer fin 212 is a corrugated fin. A material of the heat transfer fin 212 is an aluminum or aluminum alloy. In FIGS. 2 and 3, the heat transfer fin 212 is not illustrated.

The heat transfer fin 212 is fixed to the first portion 211a and the second portion 211b between the adjacent flat tubes 211 along the first direction D1. More specifically, the heat transfer fin 212 is provided between the adjacent first portions 211a along the first direction D1. The apex of the wave shape is fixed to the main surface of the first portion 211a so that the heat transfer fin 212 is fixed to the first portion 211a. Further, the heat transfer fin 212 is also provided between the adjacent second portions 211b along the first direction D1. The apex of the wave shape is fixed to the main surface of the second portion 211b so that the heat transfer fin 212 is fixed to the second portion 211b. Accordingly, the first portion 211a and the second portion 211b of the flat tube 211 except for the connecting portion 211c are covered with the heat transfer fin 212.

(2-1-3) First Header 213 and Second Header 214

The first header 213 and the second header 214 are connected to both ends of the plurality of flat tubes 211. The first header 213 and the second header 214 are arranged to extend in the first direction D1. The first header 213 and the second header 214 are located above the drain pan 22. The first header 213 and the second header 214 are connected to an external refrigerant circuit via a refrigerant pipe (not illustrated).

(2-1-4) First Heat Exchange Portion 41 and Second Heat Exchange Portion 42

The heat exchanger 21 includes a first heat exchange portion 41 and a second heat exchange portion 42. The first heat exchange portion 41 and the second heat exchange portion 42 each include the plurality of flat tubes 211, the heat transfer fin 212, the one first header 213, the one covering member 215, and the one second header 214. The first heat exchange portion 41 is connected to the second heat exchange portion 42 via a refrigerant pipe (not illustrated).

As illustrated in FIG. 4, in the heat exchange unit 20, the first heat exchange portion 41 and the second heat exchange portion 42 are arranged side by side along the second direction D2 in which the air flows. More specifically, the first heat exchange portion 41 and the second heat exchange portion 42 are provided such that the connecting portions 211c thereof are arranged side by side along the second direction D2 in which the air flows. The first heat exchange portion 41 is provided on the windward side of the second heat exchange portion 42.

More specifically, the second heat exchange portion 42 is provided so that each portion has the following positional relationship with respect to the first heat exchange portion 41. The plurality of connecting portions 211c of the second heat exchange portion 42 are located between a first tube row 41a and a second tube row 41b of the first heat exchange portion 41. Further, a first tube row 42a of the second heat exchange portion 42 is opposed to the first tube row 41a of the first heat exchange portion 41. Further, a second tube row 42b of the second heat exchange portion 42 is opposed to the second tube row 41b of the first heat exchange portion 41.

Here, the first tube row 41a is a tube row formed by the plurality of first portions 211a of the first heat exchange portion 41, and the second tube row 41b is a tube row formed by the plurality of second portions 211b of the first heat exchange portion 41. Moreover, the first tube row 42a is a tube row formed by the plurality of first portions 211a of the second heat exchange portion 42, and the second tube row 42b is a tube row formed by the plurality of second portions 211b of the second heat exchange portion 42.

(2-1-5) Covering Member 215

The covering member 215 covers at least a part of the flat tube 211. The covering member 215 prevents at least a part of the flat tube 211 from being exposed to (coming into contact with) the air flow generated by the blower unit 30. More specifically, the covering member 215 covers (coats) the plurality of connecting portions 211c to prevent at least a part of the plurality of connecting portions 211c included in the flat tube 211 from being exposed to the air flow. According to the present embodiment, the covering member 215 covers all of the plurality of connecting portions 211c arranged side by side in the first direction D1. A material of the covering member 215 is nonmetallic such as a resin. The covering member 215 is flexible and has a band shape elongated in the first direction D1.

The covering member 215 includes a first covering member 215a and a second covering member 215b. The first covering member 215a is fixed to the plurality of connecting portions 211c to cover the plurality of connecting portions 211c of the first heat exchange portion 41. The second covering member 215b is fixed to the plurality of connecting portions 211c to cover the plurality of connecting portions 211c of the second heat exchange portion 42.

The first covering member 215a is fixed to the plurality of connecting portions 211c to cover the plurality of connecting portions 211c of the first heat exchange portion 41 from both ends in the up-down direction, which is the vertical direction, and the first direction D1.

The second covering member 215b is fixed to the plurality of connecting portions 211c to cover the plurality of connecting portions 211c of the second heat exchange portion 42 from both ends in the up-down direction, which is the vertical direction, and the first direction D1.

For example, the covering member 215 is fixed to the plurality of connecting portions 211c to be wound along the first direction D1.

By being covered with the covering member 215, the connecting portion 211c is prevented from being exposed to the air flow. In order to prevent the portion of the connecting portion 211c covered with the covering member 215 from being exposed to the air flow as much as possible, the covering member 215 is preferably fixed to be in close contact with the connecting portion 211c.

In FIG. 3, in order to illustrate the connecting portion 211c of the first heat exchange portion 41, the first covering member 215a and the second covering member 215b are illustrated to be partially transparent.

(2-2) Drain Pan 22

The drain pan 22 receives condensation water from the heat exchanger 21. The condensation water is water generated on the surfaces of the plurality of flat tubes 211, the heat transfer fin 212, the first header 213, and the second header 214 due to heat exchange between the refrigerant flowing inside the plurality of flat tubes 211 and the air passing through the heat exchange chamber 17. The generated condensation water flows down along the surfaces of the plurality of flat tubes 211, the heat transfer fin 212, the first header 213, and the second header 214 due to its own weight and is received by the drain pan 22. The drain pan 22 is fixed to the support 12.

The condensation water received by the drain pan 22 is discharged as drainage water from a drain outlet (not illustrated) provided in the drain pan 22.

In FIGS. 1 and 2, the drain pan 22 is illustrated to be partially transparent in order to illustrate the first header 213 and the second header 214.

(3) Feature

(3-1)

The heat exchanger 21 exchanges heat between the air carried by the air flow and the refrigerant. The heat exchanger 21 includes the plurality of flat tubes 211, the heat transfer fin 212, and the covering member 215. The flat tubes 211 are arranged side by side along the first direction D1, allow the refrigerant to flow inside, and are made of an aluminum or aluminum alloy as a material. The heat transfer fin 212 is provided between the adjacent flat tubes 211 and is made of an aluminum or aluminum alloy as a material. The covering member 215 covers at least a part of the flat tube 211.

Each of the plurality of flat tubes 211 includes the first portion 211a, the second portion 211b, and the connecting portion 211c. The first portion 211a extends in a predetermined direction when viewed from the first direction D1. The second portion 211b extends in a predetermined direction different from the direction in which the first portion 211a extends when viewed from the first direction D1. The connecting portion 211c connects the first portion 211a and the second portion 211b such that the angle between the direction in which the first portion 211a extends and the direction in which the second portion 211b extends is less than 180° when viewed from the first direction D1. The connecting portion 211c may connect the first portion 211a and the second portion 211b such that the angles α and β are 90° or less when viewed from the first direction D1.

The heat transfer fin 212 is fixed to the first portion 211a and the second portion 211b. The covering member 215 covers at least a part of the plurality of connecting portions 211c.

Since the connecting portion 211c of the flat tube 211 is not covered with the heat transfer fin 212, the connecting portion 211c may become corroded due to the influence of chloride ions contained in the air when it is exposed to the air flow. In particular, since the flat tube 211 is sometimes formed to have a thin wall thickness compared to a heat transfer tube having a tubular shape, there is a high possibility that the refrigerant flowing inside leaks when corrosion occurs compared to the heat transfer tube having a tubular shape. In the heat exchanger 21, the covering member 215 prevents at least a part of the connecting portion 211c from being exposed to the air flow. Thus, the heat exchanger 21 can prevent the occurrence of corrosion in the connecting portion 211c, which is a portion of the flat tube 211 that is not covered with the heat transfer fin 212.

(3-2)

A material of the covering member 215 is nonmetallic.

When different kinds of metals are brought into contact with each other, bimetallic corrosion may occur in one of the metals. Since a material of the covering member 215 is nonmetallic, the heat exchanger 21 can prevent the occurrence of bimetallic corrosion.

(3-3)

A material of the covering member 215 is a resin.

Since a material of the covering member 215 is a resin, the heat exchanger 21 can prevent the occurrence of bimetallic corrosion and can prevent an increase in weight.

(3-4)

The heat exchanger 21 includes the first heat exchange portion 41 and the second heat exchange portion 42 each including the plurality of flat tubes 211, the heat transfer fin 212, and the covering member 215.

In the second heat exchange portion, the plurality of connecting portions 211c are located between the first tube row 41a formed by the plurality of first portions 211a of the first heat exchange portion 41 and the second tube row 41b formed by the plurality of second portions 211b of the first heat exchange portion 41. The first tube row 42a formed by the plurality of first portions 211a of the second heat exchange portion 42 is opposed to the first tube row 41a of the first heat exchange portion 41. Further, the second tube row 42b formed by the plurality of second portions 211b of the second heat exchange portion 42 is opposed to the second tube row 41b of the first heat exchange portion 41.

-Modification-

(1) Modification A

In the heat exchanger 21 according to Modification A, as illustrated in FIG. 5, the heat transfer fin 212 of the first heat exchange portion 41 is not provided in a region a (see FIG. 5) between the connecting portion 211c and a position Lb where two straight lines La intersects with an outer edge 41e of the first heat exchange portion 41 in the third direction D3 when viewed from the first direction D1. When viewed from the first direction, the two straight lines La are straight lines that are parallel to the second direction and that pass end portions 215c on both sides of the second covering member 215b included in the second heat exchange portion 42 in the third direction D3. When viewed from the first direction D1, the position Lb is a line segment whose one end is in contact with the intersection of the straight line La and the outer edge 41e and which is orthogonal to the direction in which the first portion 211a or the second portion 211b extends.

A part of the air flow that is generated by the blower unit 30 and flows downward in the vertical direction along the second direction D2 comes into contact with the second covering member 215b of the second heat exchange portion 42 when passing through the heat exchanger 21. The air flow in contact with the second covering member 215b is inhibited from flowing along the second direction D2. For this reason, on the upstream side of the air flow with respect to the second covering member 215b included in the second heat exchange portion 42, a suitable air flow is hindered as compared with other portions, and thus efficient heat exchange becomes difficult.

In the heat exchanger 21 according to Modification A, the heat transfer fin 212 is not provided in the region a, and thus the cost of providing the heat transfer fin 212 is reduced as compared with the case where the heat transfer fin 212 is provided throughout the first portion 211a and the second portion 211b. As a result, the heat exchanger 21 according to the modification suppresses the manufacturing cost.

In the heat exchanger 21 according to Modification A, in order to prevent corrosion of the region a that is not covered with the heat transfer fin 212, the first covering member 215a is provided to cover not only the connecting portion 211c but also the region a.

(2) Modification B

According to the above-described embodiment, the respective connecting portions 211c of the first heat exchange portion 41 and the second heat exchange portion 42 are covered with the different covering members 215 (the first covering member 215a and the second covering member 215b), but the respective connecting portions 211c of the first heat exchange portion 41 and the second heat exchange portion 42 may be covered with the one covering member 215.

(3) Modification C

According to the above-described embodiment, the air flows downward in the vertical direction, but the direction in which the air flows is not limited, and for example, the air may flow upward in the vertical direction.

(4) Modification D

The covering member 215 does not need to be a flexible band-shaped member as long as the covering member 215 covers the plurality of connecting portions 211c to prevent at least a part of the plurality of connecting portions 211c from being exposed to the air flow. The covering member 215 may be realized by, for example, painting or covering that covers at least a part of the plurality of connecting portions 211c.

-Conclusion-

Although the embodiment according to the present disclosure is described above, it is understood that various modifications may be made to forms and details without departing from the spirit and scope of the present disclosure described in the scope of claims.

REFERENCE SIGNS LIST

10 air handling unit

20 heat exchange unit

21 heat exchanger

211 flat tube

211a first portion

211b second portion

211c connecting portion

211ca curved portion (first heat exchange portion)

211cb curved portion (second heat exchange portion)

212 heat transfer fin

213 first header

214 second header

215 covering member

215a first covering member

215b second covering member

215c end portion

24 drain pan

30 blower unit

41 first heat exchange portion (heat exchange portion)

41e outer edge of first heat exchange portion

42 second heat exchange portion (heat exchange portion)

D1 first direction

D2 second direction

D3 third direction

L bisector of an angle formed between a direction in which the first portion extends and a direction in which the second portion extends

La straight line passing end portions on both sides of the covering member included in the second heat exchange portion

Lb position where the straight line La intersects with an outer edge of the first heat exchange portion

CITATION LIST

PATENT LITERATURE

PTL 1: U.S. Patent No. 5,904,053

Claims

1. A heat exchanger that exchanges heat between air carried by an air flow and a refrigerant, the heat exchanger comprising: a plurality of flat tubes that are arranged along a first direction, allow the refrigerant to flow inside, and are made of an aluminum or aluminum alloy as a material; a heat transfer fin that is provided between the adjacent flat tubes and is made of an aluminum or aluminum alloy as a material; and a cover covering at least a part of the flat tube, wherein each of the plurality of flat tubes includes a first portion extending in a predetermined direction when viewed from the first direction, a second portion extending in a predetermined direction different from a direction in which the first portion extends when viewed from the first direction, and a connecting portion that connects the first portion and the second portion such that an angle between the direction in which the first portion extends and a direction in which the second portion extends is less than 180° when viewed from the first direction, the heat transfer fin is connected to the first portion and the second portion, andthe cover covers at least a part of a plurality of the connecting portions.

2. The heat exchanger according to claim 1, wherein a material of the cover is nonmetallic.

3. The heat exchanger according to claim 1, wherein a material of the cover is a resin.

4. The heat exchanger according to claim 1, comprising a first heat exchange portion and a second heat exchange portion each including the plurality of flat tubes, the heat transfer fin, and the cover, wherein in the second heat exchange portion, the plurality of the connecting portions are located between a first tube row formed by a plurality of the first portions of the first heat exchange portion and a second tube row formed by a plurality of the second portions of the first heat exchange portion, a first tube row formed by a plurality of the first portions of the second heat exchange portion is opposed to the first tube row of the first heat exchange portion, and a second tube row formed by a plurality of the second portions of the second heat exchange portion is opposed to the second tube row of the first heat exchange portion.

5. The heat exchanger according to claim 4, wherein the first heat exchange portion and the second heat exchange portion are provided such that the connecting portions thereof are arranged side by side along a second direction that is a direction in which a bisector of an angle extends, which is formed between the direction in which the first portion extends and the direction in which the second portion extends, and when viewed in the first direction, the heat transfer fin included in the first heat exchange portion is not provided between the connecting portion and a position where two straight lines, which are parallel to the second direction and pass end portions on both sides of the cover included in the second heat exchange portion in a third direction that is a direction orthogonal to the second direction when viewed in the first direction, intersect with an outer edge of the first heat exchange portion in the third direction.

6. An air handling unit comprising: the heat exchanger according to claim 1; and a blower unit that generates the air flow.

7. The heat exchanger according to claim 2, wherein a material of the cover is a resin.

8. The heat exchanger according to claim 2, comprising a first heat exchange portion and a second heat exchange portion each including the plurality of flat tubes, the heat transfer fin, and the cover, wherein in the second heat exchange portion, the plurality of the connecting portions are located between a first tube row formed by a plurality of the first portions of the first heat exchange portion and a second tube row formed by a plurality of the second portions of the first heat exchange portion, a first tube row formed by a plurality of the first portions of the second heat exchange portion is opposed to the first tube row of the first heat exchange portion, and a second tube row formed by a plurality of the second portions of the second heat exchange portion is opposed to the second tube row of the first heat exchange portion.

9. The heat exchanger according to claim 3, comprising a first heat exchange portion and a second heat exchange portion each including the plurality of flat tubes, the heat transfer fin, and the cover, wherein in the second heat exchange portion, the plurality of the connecting portions are located between a first tube row formed by a plurality of the first portions of the first heat exchange portion and a second tube row formed by a plurality of the second portions of the first heat exchange portion, a first tube row formed by a plurality of the first portions of the second heat exchange portion is opposed to the first tube row of the first heat exchange portion, and a second tube row formed by a plurality of the second portions of the second heat exchange portion is opposed to the second tube row of the first heat exchange portion.

10. An air handling unit comprising: the heat exchanger according to claim 2; and a blower unit that generates the air flow.

11. An air handling unit comprising: the heat exchanger according to claim 3; and a blower unit that generates the air flow.

12. An air handling unit comprising: the heat exchanger according to claim 4; and a blower unit that generates the air flow.

13. An air handling unit comprising: the heat exchanger according to claim 5; and a blower unit that generates the air flow.