JP2003148833A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger which prevents the increase of pressure loss, and is thinned while achieving the uniformity of a temperature of the air passed therethrough. SOLUTION: This heat exchanger provided with a group of laminated tubes communicating an upper tank with a lower one, is composed of: a heat exchange part composed of a group of tubes vertically arranged in parallel, seen from the air flowing direction, and forming heat exchanging medium channels independently from each other; and a heat exchange part composed of a group of tubes forming a common unidirectional heat exchanging medium channel of a vertical position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated heat exchanger in which tubes and fins are alternately laminated, and more particularly to a heat exchanger optimal for use in a vehicle air conditioner.

[0002]

2. Description of the Related Art Conventionally, for example, a laminated heat exchanger in which tubes and fins are alternately laminated is well known as an evaporator used in a vehicle air conditioner or the like. In recent years, especially in the field of vehicle air conditioning systems, there is an increasing demand for space saving. Therefore, there is an increasing demand for an evaporator having a thinner depth dimension (that is, an air flow direction) and an evaporator having a connection portion for introducing and discharging the refrigerant disposed on one side surface of the evaporator so as to reduce the occupied space. ing. Further, as the performance is improved, there is an increasing demand for making the temperature of air blown out from the evaporator uniform.

Therefore, in order to achieve a thinner evaporator and a smaller installation space, for example, FIG.
2778) and FIG. 10 (Japanese Patent Laid-Open No. 9-17850). In FIG.
Reference numeral 100 denotes a heat exchanger. The heat exchanger 100 has an upper tank 102 and a lower tank 103 which are connected to each other by a tube group 101. The upper tank 102 is composed of an upper front tank 104 arranged on the front side in the air flow direction (hereinafter, also referred to as a ventilation direction) and an upper rear tank 105 arranged on the rear side in the ventilation direction. . Further, a partition plate 106 is provided in the upper front tank 104, and the partition plate 106 allows the interior of the upper front tank 104 to be a chamber 1.
It is divided into 07 and the room 108. On the other hand, a partition plate 109 is also provided in the upper rear tank 105, and is partitioned by the partition plate 109 into a chamber 110 and a chamber 111.

The chamber 108 of the upper front tank 104 and the chamber 111 of the upper rear tank 105 are connected to each other via a communication passage 112.

The lower tank 103 comprises a lower front tank 113 arranged on the front side in the ventilation direction and a lower rear tank 114 arranged on the rear side in the ventilation direction.

In the heat exchanger 100 as described above,
Inlet 11 provided in the chamber 107 of the upper front tank 104
The refrigerant introduced from No. 5 forms a flow path as shown in FIG. 9 and flows out from the outlet section 116 provided in the chamber 110 of the upper rear tank 105. That is, in the heat exchanger 100 as described above, the communication passage 112 is provided and the circulation direction of the refrigerant is reversed in the communication passage 112, so that the inlet portion 115 and the outlet portion 116 are connected to each other.
It is possible to install it on one side surface of No. 0 to save installation space.

Further, in FIG. 10, 117 indicates a heat exchanger. The heat exchanger 117 has an upper tank 118 and a lower tank 119, and both tanks have a tube group 1
It is communicated by 20. The upper tank 118 includes an upper front tank 121 arranged on the front side in the ventilation direction and an upper rear tank 122 arranged on the rear side. A partition plate 123 is provided in the upper front tank 121, and
It is divided into 24 and a chamber 125. Also, lower tank 1
19 includes a lower front tank 126 and a lower rear tank 127. A partition plate 128 is provided in the lower rear tank 127, and the lower rear tank 127 is divided into a chamber 129 and a chamber 130.

In addition, the chamber 125 of the upper front tank 121,
The chamber 130 of the lower rear tank 127 is in communication with each other via a communication passage 131.

In the heat exchanger 117 as described above,
Inlet part 1 provided in the chamber 129 of the lower rear tank 127
The refrigerant introduced from 32 forms a flow path as shown in FIG. 10, and the refrigerant is led out from the outlet portion 133 provided in the chamber 124 of the upper front tank 121. Also in the heat exchanger 117 as described above, the tube group 120
By providing the communication portion 131 protruding in the stacking direction of
The inlet portion 132 and the outlet portion 133 are provided on one side surface of the heat exchanger 117 to save the installation space of the heat exchanger 117. Further, in the heat exchanger 117 as described above, the tube group in which the gas-phase refrigerant is easily introduced by the inertial force of the gas-liquid mixed refrigerant and the tube group in which the liquid-phase refrigerant is easily introduced do not overlap in the ventilation direction. With this configuration, the temperature at which the air is blown out is uniform over the entire tube group 120.

However, in the field of heat exchangers used in air conditioners for vehicles in recent years, there is an increasing demand for space saving by further reducing the thickness (for example, the depth dimension is 40 mm or less).

[0011]

However, when the heat exchanger having the four-pass refrigerant passage as shown in FIGS. 9 and 10 is thinned as it is, the following problems may occur. . That is, when the dimension in the depth direction is reduced, the flow passage cross-sectional area of each tube is reduced by that amount, and the pressure loss of the refrigerant is increased. As a result, the amount of refrigerant circulation may decrease, the temperature of the refrigerant introduced into the evaporator may rise, and the amount of heat exchange may decrease. On the other hand, if one partition plate is removed and the number of passes is reduced in order to reduce the pressure loss, there is a possibility that a temperature distribution of the blown air may occur. For example, assuming that the partition plate 109 is removed in FIG. 9, the refrigerant flowing out from the communication passage 112 must be uniformly flown into all the tubes communicated with the upper rear tank 105. However, if the flow path length in the tank width direction becomes long, it is difficult to allow the refrigerant to uniformly flow into all the tubes due to the difference in inertial force between the vapor-phase refrigerant and the liquid-phase refrigerant.

Further, the heat exchangers shown in FIGS. 9 and 10 have a structure in which a flow passage having a small flow passage cross-sectional area is provided in the middle of the heat exchange medium flow passage, and all the refrigerant is concentrated in this communication portion. Therefore, pressure loss is likely to occur. Further, the communication portion hardly contributes to heat exchange. Further, in the case of the heat exchanger shown in FIG. 10, since the communicating portion projects in the width direction, the heat exchanger has a side tank for introducing and discharging the heat exchange medium in the width direction of the heat exchanger. The size in the width direction of the exchanger may increase.

An object of the present invention is to provide a heat exchanger capable of achieving a reduction in size of the apparatus, in particular, a reduction in thickness thereof, while preventing an increase in pressure loss of the refrigerant and making an air blowing temperature uniform.

[0014]

In order to solve the above-mentioned problems, the heat exchanger of the present invention is a heat exchanger provided with a group of laminated tubes communicating between upper and lower tanks, and is located at the front and rear positions in the air flow direction. And a heat exchange section that is arranged in parallel with each other and that includes a tube group that independently forms a heat exchange medium flow path, and a heat exchange section that includes a tube group that forms a one-way heat exchange medium flow path that is common to the front and rear positions. And are provided.

The heat exchange section consisting of a group of tubes forming heat exchange medium flow paths independently of each other is the same as the first heat exchange section provided on the rear side in the air flow direction on the heat exchange medium inlet / outlet side. It can be constituted by a third heat exchange portion provided on the front side of the first heat exchange portion in the air flow direction. In this case, the heat exchanging part formed of the tube group forming the one-way heat exchanging medium flow path common to the front and rear positions is composed of the second heat exchanging part provided on the side of the anti-heat exchange medium inlet / outlet part. can do. In this case, the heat exchange medium flow path can be formed in the order of the first heat exchange section, the second heat exchange section, and the third heat exchange section.

Further, the heat exchanging portion composed of a group of tubes forming the heat exchanging medium flow path independently of each other is the first heat exchanging portion formed on the rear side in the air flow direction on the heat exchanging medium inlet / outlet side. Section and a second heat exchange section adjacent to the first heat exchange section in the tube group stacking direction, a fifth heat exchange section and a second heat provided on the front side in the ventilation direction of the first heat exchange section. It can be configured with a fourth heat exchange section provided on the front side in the ventilation direction of the exchange section.
Further, the heat exchanging part formed of a group of tubes forming the one-way heat exchanging medium flow path common to the front and rear positions can be composed of a third heat exchanging part provided on the side of the anti-heat exchange medium inlet / outlet part. In this case, the heat exchange medium flow path includes the first heat exchange section and the second heat exchange section.
The heat exchange part, the third heat exchange part, the fourth heat exchange part, and the fifth heat exchange part can be formed in this order.

In the heat exchanger as described above, a heat exchange section composed of a group of tubes that are independent of each other and that form heat exchange medium flow passages and are arranged in parallel at the front and rear positions in the air flow direction, and the front and rear Since a heat exchange section including a group of tubes forming a unidirectional heat exchange medium flow path common to the positions is provided,
Even if the heat exchanger is thinned, at least three heat exchange parts can be configured. For this reason, the flow path length of the heat exchange medium in the longitudinal direction of the tank can be shortened while sufficiently securing the flow path cross-sectional area per one section (one heat exchange section), so that the pressure loss of the heat exchange medium is reduced. At the same time, the temperature distribution of each tube can be prevented from occurring and the temperature of the passing air can be made uniform. Further, the heat exchanging portion including a group of tubes forming the one-way heat exchange medium passage common to the front and rear positions can be used as a communicating portion that connects the front and rear tanks. That is, since the heat exchange capacity can be imparted also to the communication portion, the dimension in the width direction of the heat exchanger can be reduced without reducing the heat exchange performance while reducing the pressure loss in the communication portion.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the heat exchanger of the present invention will be described below with reference to the drawings. 1 to 7 show a heat exchanger according to a first embodiment of the present invention. In the figure, 1 has shown the heat exchanger. In this embodiment, the heat exchanger 1 is a laminated heat exchanger in which the tubes 2 and the fins 3 are alternately laminated. A side tank 4 is provided on one of the outermost layers of the laminated portion formed by the tubes 2 and the fins 3, and an end plate 5 is provided on the other side.

A tube group 6 composed of a plurality of tubes 2 comprises a first tube group 7 and a second tube group 8. The first tube group 7 is formed by joining and stacking two forming plates 9 shown in FIG. The molding plate 9 has a recess 10 extending in the longitudinal direction,
Have 11. The recesses 10 and 11 are partitioned by a wall 12. In addition, at the end portion of the molding plate 9 in the longitudinal direction, the communicating portions 13, 14, 1 protruding outward of the plate
5, 16 are provided. By joining the two molding plates 9 to each other, two partitioned channels 17 and 18 are formed inside. Since the recesses 10 and 11 are provided with bosses 19 (projecting toward the inside of the flow path), when the plates 9 are joined together, the bosses 19 come into contact with each other. The boss 1
The presence of 9 improves the heat exchange performance and pressure resistance of the tube. However, the boss 19 may be omitted and inner fins may be provided in the flow paths 17 and 18.
By joining the two molding plates 9 to each other and connecting and connecting the connecting portions, the tube group 7 and the below-described upper front tank 33, upper rear tank 34, lower front tank 37,
The lower rear tank 38 is configured.

The second tube group 8 is formed by laminating two molding plates 20 shown in FIG. 5 to each other. The molding plate 20 has a recess 2 extending in the longitudinal direction.
It has 1 and 22. The recesses 21 and 22 are partitioned by a wall 23. In addition, at the end portion of the molding plate 20 in the longitudinal direction, the connecting portions 24, 2 protruding outward from the plate are provided.
5, 26, 27 are provided. As shown in FIG. 5, the adjacent connecting portions 24 and 26 are connected to each other. Further, the connecting portion 25 and the connecting portion 27 are communicated with each other. Then, the flow paths 28 and 29 are formed inside by joining the two molding plates 20 to each other. However, since the adjacent connecting portions are communicated with each other as described above, the flow paths 28 and 29 are necessarily one-way heat exchange medium flow paths in which the heat exchange medium flows in the same direction. Since the bosses 30 are provided in the recesses 21 and 22, when the plates 20 are joined to each other, the bosses 30 come into contact with each other. The presence of the boss 30 improves the heat exchange performance and pressure resistance of the tube. However, the boss 30 may be omitted and a separate inner fin may be provided. In this way, the two molding plates 20 are joined to each other and the connecting portions are connected to each other, whereby the tube group 8 is formed.
An upper communication tank 35 and a lower communication tank 39, which will be described later, are configured.

An upper tank 31 is provided above the tube group 6 and a lower tank 32 is provided below the tube group 6. In addition, in the present specification, the description of “upper and lower” is provided for the sake of easy understanding of the invention,
The top and bottom may be reversed. The upper tank 31 is an upper front tank 33 provided on the front side in the ventilation direction (that is, on the windward side).
And an upper rear tank 34 provided on the rear side (that is, the leeward side) in the ventilation direction, and an upper communication tank 35 communicating with the upper rear tank 34. A partition 36 is provided between the upper front tank 33 and the upper communication tank 35.

The lower tank 32, which communicates with the upper tank 31 via the tube group 6, includes a lower front tank 37 provided on the front side in the ventilation direction and a lower rear tank 38 provided on the rear side in the ventilation direction. , And a lower communication tank 39 that communicates with the lower front tank 37. A partition 40 is provided between the lower rear tank 38 and the lower communication tank 39.

In a side tank 4 provided on one side surface of the heat exchanger 1, a heat exchange medium introducing passage 41 for introducing the heat exchange medium and a heat exchange medium introducing passage 42 for extracting the heat exchange medium are provided.
And are formed. The heat exchange medium introduction passage 41 communicates with the lower rear tank 38. On the other hand, the heat exchange medium outlet path 4
2 communicates with the upper front tank 33. Further, the side tank 4 is provided with a flange 43 to which an expansion valve (not shown) is connected. The flange 43 is provided with a heat exchange medium inlet 44 and a heat exchange medium outlet 45.

Next, the heat exchange medium flow path in the heat exchanger 1 will be described with reference to FIG. The heat exchange medium introduced from the heat exchange medium inlet portion 44 of the side tank 4 into the heat exchange medium introduction passage 41 flows into the lower rear tank 38, and flows upward through the flow passage 17 of the first tube group 7. It flows into the side tank 34. The flow path 17 from the lower rear tank 38 to the upper rear tank 34 constitutes the first heat exchange section 46. Subsequently, the heat exchange medium flowing out from the upper rear tank 34 flows into the upper communication tank 35, and then flows into the lower communication tank 39 via the flow paths 28 and 29 of the tube group 8. Upper communication tank 3
The second heat exchange section 47 is configured by the flow paths 28 and 29 extending from 5 to the lower communication tank 39. Further, the heat exchange medium flowing out from the lower communication tank 39 flows into the lower front tank 32, and then flows into the upper front tank 33 via the flow path 18 of the tube group 7. The flow path 18 from the lower front tank 32 to the upper front tank 33 constitutes a third heat exchange section 48. The heat exchange medium flowing out from the upper front side tank 33 is led out to the outside from the heat exchange medium outlet passage 42 of the side tank 4 through the heat exchange medium outlet portion 45.

That is, in the heat exchanger 1, the first heat exchange section 4 is provided on the rear side in the air flow direction on the heat exchange medium inlet / outlet side.
6 is provided, the third heat exchange section 48 is provided on the front side thereof, and the first heat exchange section 46 and the third heat exchange section 46 are provided on the anti-heat exchange medium inlet / outlet side.
The second heat exchanging portion 47 that communicates with the heat exchanging portion 48 is provided.

In the heat exchanger as in this embodiment,
The flow path 17 provided at the front side in the air flow direction configures the first heat exchange section 46, and the flow path 18 provided at the rear side configures the third heat exchange section 48. . In addition, the flow paths 28 and 29 allow the second heat exchange portion 47
Is configured. Therefore, even if the heat exchanger 1 is made thin, at least three heat exchange parts are configured, so that one section, that is, a flow passage cross-sectional area per one heat exchange part is sufficiently secured and the longitudinal direction of each tank is increased. The flow path length of the heat exchange medium can be shortened. Therefore, the pressure loss of the heat exchange medium flowing in the heat exchanger 1 can be prevented, and the temperature distribution of the heat exchange medium can be prevented from occurring between the tubes constituting each heat exchange section. In addition, in the heat exchanger 1 of the present embodiment, the second heat exchanging portion 47 functions as a communicating portion that communicates the front and rear tanks. Therefore, the size in the width direction of the device can be shortened without reducing the heat exchange performance while reducing the pressure loss in the communication portion.

The flow paths of the heat exchange medium in the heat exchanger 1 are the first heat exchange section 46, the second heat exchange section 47, and the third heat exchange section 47.
Since the heat exchange parts 48 are formed in this order, the heat exchange medium having a higher temperature than that of the other heat exchange parts circulates in the third heat exchange part 48. However, the low-temperature heat exchange medium immediately after introduction flows to the rear side of the third heat exchange unit 48 in the ventilation direction.
Since the heat exchanging section 46 is provided, even if the heat exchanging in the third heat exchanging section 48 is insufficient, the heat exchanging section 46 can sufficiently exchange the heat in the first heat exchanging section. Therefore, the occurrence of the temperature distribution of the passing air can be prevented.

Further, in the heat exchanger 1 according to this embodiment, when the heat exchange medium is introduced from the upper tank 31, the heat exchange medium is necessarily drawn out from the lower tank 32. On the contrary, if the heat exchange medium is introduced from the lower tank 32, the heat exchange medium will be derived from the upper tank 31.
Therefore, the inlet passage 41 and the outlet passage 42 of the side tank 4
Can be arranged in a vertical positional relationship, so that even if the heat exchanger 1 is thinned, a sufficient flow passage cross-sectional area of the inlet / outlet path of the side tank 4 can be secured and the heat exchange medium in the side tank 4 can be secured. The pressure loss of can be reduced.

FIG. 8 shows the heat exchange medium flow path of the heat exchanger 50 according to the second embodiment of the present invention. Note that, in FIG. 8, the same members as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. In this embodiment,
Since the partition 51 is provided in the upper rear tank 34 and the partition 52 is provided in the lower front tank 37, the heat exchange medium flow path in the heat exchanger 50 is formed as follows. A fifth heat exchange section is configured. Heat exchange medium introduction path 4 of the side tank 4
The heat exchange medium introduced into No. 1 flows into the lower rear tank 38, and then flows into the upper rear tank 34 via the flow path 17a of the first tube group 7. The flow path 17a extending from the lower rear tank 38 to the upper rear tank 34 constitutes the first heat exchange section 53. Further, since the partition 51 with the communicating portion is provided in the upper rear tank 34, the heat exchange medium flowing into the upper rear tank 34 flows into the lower rear tank 38 via the flow path 17b. To do. The flow path 17b from the upper rear tank 34 to the lower rear tank 38 constitutes the second heat exchange section 54. The heat exchange medium that has flowed into the lower rear tank 38 further flows into the lower communication tank 39, and then flows into the upper communication tank 35 via the flow paths 28 and 29. Lower communication tank 39
To the upper communication tank 35 by the flow paths 28 and 29
The heat exchange section 55 is configured.

Subsequently, the heat exchange medium that has flowed into the upper communication tank 35 further flows into the upper front tank 33 (in the tank 33 on the side of the anti-heat exchange medium inlet / outlet portion partitioned by the partition 36) and the flow path 18a. Through the lower front side tank 37. The flow path 18a from the upper front tank 33 to the lower front tank 37 constitutes the fourth heat exchange section 56. Further, the heat exchange medium that has flowed into the lower front side tank 37 flows into the upper front side tank 33 (inside the heat exchange medium inlet / outlet side tank 33 partitioned by the partition 36) via the flow path 18b. The flow path 18b from the lower front tank 37 to the upper front tank 33 constitutes the fifth heat exchange unit 57. The heat exchange medium that has flowed into the upper front side tank 33 is led out of the heat exchanger 1 from the heat exchange medium lead-out path 42 of the side tank 4.

Also in this embodiment, it is possible to prevent pressure loss of the heat exchange medium in accordance with the operation of the first embodiment while preventing the temperature distribution of the heat exchange medium between the tubes constituting each heat exchange section. . Also in this embodiment,
Fourth heat exchange section 5 into which a relatively high temperature heat exchange medium flows
6, a second heat exchange section 54 and a first heat exchange section 53, which are close to the heat exchange medium inlet and through which a relatively low temperature heat exchange medium flows, are provided on the rear side of the fifth heat exchange section 57. Therefore, the temperature distribution of the passing air can be prevented.

[0032]

As described above, according to the heat exchanger of the present invention, heat composed of a group of tubes that are independent of each other and are arranged in parallel at the front and rear positions in the air flow direction. Since the exchange part and the heat exchange part consisting of a group of tubes forming a common one-way heat exchange medium flow path in the front and rear are provided, sufficient flow path cross-sectional area is secured even when the heat exchanger is made thin. The pressure loss can be reduced. Also,
Prevents the temperature distribution of the heat exchange medium between each tube,
A uniform temperature of the passing air can be achieved.

[Brief description of drawings]

FIG. 1 is a perspective view of a heat exchanger according to a first embodiment of the present invention.

FIG. 2 is a front view of the heat exchanger of FIG.

FIG. 3 is a top view of the heat exchanger of FIG.

FIG. 4 is a plan view of a molded plate of a tube that constitutes first and third heat exchange parts of the heat exchanger of FIG. 1.

5 is a plan view of a molded plate of a tube forming a second heat exchange section of the heat exchanger of FIG. 1. FIG.

6 is a perspective view showing a heat exchange medium flow path of the heat exchanger of FIG. 1. FIG.

7 is a front view of a side tank of the heat exchanger of FIG.

FIG. 8 is a perspective view showing a heat exchange medium flow path of the heat exchanger according to the second embodiment of the present invention.

FIG. 9 is a perspective view showing a heat exchange medium flow path of a conventional heat exchanger.

FIG. 10 is a perspective view showing a heat exchange medium flow path of another conventional heat exchanger.

[Explanation of symbols]

1,50 heat exchanger 2 tubes Three fins 4 side tank 5 End plate 6 tubes 7 First tube group 8 Second tube group 9 Molded plate 10, 11 recess 12 walls 13, 14, 15, 16 Connection part 17, 18, 17a, 17b, 18a, 18b Flow path 19 Boss 20 Molded plate 21, 22 recess 23 walls 24, 25, 26, 27 Connection part 28, 29 channels 30 boss 31 Upper tank 32 Lower tank 33 Upper front tank 34 Upper rear tank 35 Upper communication tank 36, 40 partitions 37 Lower front tank 38 Lower rear tank 39 Lower communication tank 41 Heat exchange medium introduction path 42 Heat exchange medium outlet 43 flange 44 Heat exchange medium inlet 45 Heat exchange medium outlet 46, 53 First heat exchange section 47, 54 Second heat exchange section 48, 55 Third heat exchange section 51,52 partition 56 Fourth heat exchange unit 57 Fifth Heat Exchange Section

Claims (3)

[Claims] 1. A heat exchanger provided with a laminated tube group communicating between upper and lower tanks, wherein the tube groups are arranged in parallel at front and rear positions in the air flow direction and independently form heat exchange medium flow paths. And a heat exchange section including a tube group forming a unidirectional heat exchange medium flow path common to the front and rear positions. 2. A first heat exchange unit, wherein a heat exchange unit including a group of tubes that independently form heat exchange medium passages is provided on the rear side in the air flow direction on the heat exchange medium inlet / outlet side. Section and a third heat exchange section provided on the front side in the air flow direction of the first heat exchange section, and a tube group forming a one-way heat exchange medium flow path common to the front and rear positions. The heat exchange section is composed of a second heat exchange section provided on the side of the anti-heat exchange medium inlet / outlet section, and the heat exchange medium flow path is the first heat exchange section,
The heat exchanger according to claim 1, wherein the second heat exchange section and the third heat exchange section are formed in this order. 3. A first heat exchange unit, wherein a heat exchange unit including a group of tubes forming heat exchange medium flow paths independent of each other is provided on the rear side in the air flow direction on the heat exchange medium inlet / outlet side. Section and a second heat exchange section adjacent to the first heat exchange section in the tube group stacking direction, a fifth heat exchange section provided on the front side in the air flow direction on the heat exchange medium inlet / outlet side, and The fourth heat exchange portion adjacent to the fifth heat exchange portion in the tube group stacking direction, and the heat exchange portion including the tube group forming the one-way heat exchange medium flow path common to the front and rear positions is The third heat exchange section is provided at the heat exchange medium inlet / outlet section, and the heat exchange medium flow path has a first heat exchange section, a second heat exchange section, a third heat exchange section, and a fourth heat exchange section. The heat exchanger according to claim 1, wherein the heat exchange portion and the fifth heat exchange portion are formed in this order.