EP4700322A1

EP4700322A1 - Heat exchanger and refrigeration device

Info

Publication number: EP4700322A1
Application number: EP25779713.4A
Authority: EP
Inventors: Masahito Sekiya; Kiyotaka TOYOYAMA; Yusuke UETSUKI; Takuro MAKIHARA
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2024-07-04
Filing date: 2025-06-20
Publication date: 2026-02-25
Also published as: JP7759011B1; WO2026009734A1; JP2026008870A

Abstract

A heat exchanger includes a plurality of flat tubes (28), a fin (29), and a header. The plurality of flat tubes are arranged in a first direction. The fin is joined to the flat tube. The flat tubes are connected to the header. The header includes a first member and a second member. The first member includes a first opening. The flat tube is inserted into the first opening. The second member is stacked on fin side of the first member in a second direction in which the flat tube extends. The second member includes a second opening. The second opening is formed along outer edges of the flat tube. The first opening includes a first region (321) and a second region (322). The first region has a length in the first direction that is shorter than a predetermined length. The second region is longer than the predetermined length.

Description

TECHNICAL FIELD

The present disclosure relates to a heat exchanger and a refrigeration apparatus.

BACKGROUND ART

Conventionally, a heat exchanger including flat tubes and a header has been known. An example of such a heat exchanger is Japanese Patent No. 6822525 (PTL 1).
A liquid side header 40 of a heat exchanger of PTL 1 is a lamination header in which a first liquid side member 46, a second liquid side member 41, a third liquid side member 45, a fourth liquid side member 44, a fifth liquid side member 43, and a sixth liquid side member 42 are joined by brazing. The outer edge of a sixth opening 42x of the sixth liquid side member 42 is configured to be located outside the outer edge of a liquid side flat tube connection opening 41x formed in the second liquid side member 41 in the stacking direction.

SUMMARY OF INVENTION

In PTL 1 above, in order to prevent a refrigerant passage 28b of a flat tube 28 from being clogged by a brazing material at the time of brazing, the sixth opening x of the sixth liquid side member 42 is made large. Therefore, according to PTL 1, pressure resistance is low.

The present inventor has found a problem in that a flat tube is pulled and broken due to deformation of a second member (the second liquid side member 41 in PTL 1) attributable to a uniform width of a first opening (the sixth opening 42x in PTL 1) of a first member (the sixth liquid side member 42 in PTL 1) for insertion of the flat tube.
In view of this, a heat exchanger of a first aspect includes a plurality of flat tubes, a fin, and a header. The plurality of flat tubes are arranged in a first direction. The fin is joined to the flat tube. The flat tube is connected to the header. The header includes a first member and a second member. The first member includes a first opening. The flat tube is inserted into the first opening. The second member is stacked on the fin side of the first member in a second direction in which the flat tube extends. The second member includes a second opening. The second opening is formed along an outer edge of the flat tube. The first opening includes a first region and a second region. The first region has a length in the first direction that is shorter than a predetermined length. The second region is longer than the predetermined length.
According to the heat exchanger of the first aspect, in the first opening, the first region having a short length in the first direction is located at a portion imposing a large impact on the pressure resistance strength, whereby pressure resistance can be improved.
The heat exchanger of a second aspect is the heat exchanger of the first aspect, wherein the first region is located at a central portion in a third direction intersecting the first direction and the second direction.
The present inventor has found that the problem of breakage of the flat tube due to deformation of the second member is particularly attributable to the large central portion of the first opening of the first member. Therefore, according to the heat exchanger according to the second aspect, in the first opening, the first region located in the central portion imposing a large impact on the pressure resistance strength has a short length. Thus, the pressure resistance can be further improved.
A heat exchanger of a third aspect is the heat exchanger of the first aspect or the second aspect, wherein a longitudinal direction of the first opening is a third direction intersecting the first direction and the second direction. The first member has an inner edge portion defining the first opening. The inner edge portion includes a first inner edge portion and a second inner edge portion respectively on one and another sides in the first direction.
According to the heat exchanger of the third aspect, the longitudinal direction of the first opening is the same direction as the width direction of the flat tube, enabling the flat tube to be easily inserted into the first opening.
A heat exchanger of a fourth aspect is the heat exchanger of the third aspect, wherein the first inner edge portion includes a protrusion portion that protrudes toward the other side in the first direction, or the second inner edge portion includes a protrusion portion that protrudes toward the one side in the first direction.
As in the heat exchanger of the fourth aspect, the inner edge portion defining the first opening may include the protrusion portion on one side in the longitudinal direction.
A heat exchanger of a fifth aspect is the heat exchanger of the fourth aspect, wherein at least one of the first inner edge portion and the second inner edge portion has a plurality of the protrusion portions.
As in the heat exchanger of the fifth aspect, the inner edge portion defining the first opening may include a plurality of the protrusion portion on at least one side in the longitudinal direction.
A heat exchanger of a sixth aspect is the heat exchanger of the fifth aspect, wherein the plurality of protrusion portions have different lengths in the third direction.
As in the heat exchanger of the sixth aspect, the inner edge portion defining the first opening may include protrusion portions having different lengths in the longitudinal direction.
A heat exchanger of a seventh aspect is the heat exchanger of any of the third aspect to the sixth aspect, wherein one end portion of the inner edge portion in the third direction includes a first recessed portion.
According to the heat exchanger of the seventh aspect, when brazing is performed with the first recessed portion being on the lower side in the direction of gravity, the molten brazing material can move to the protruding portion of the first opening defined by the recessed portion. Thus, brazing clogging can be suppressed.
A heat exchanger of an eighth aspect is the heat exchanger of the seventh aspect, wherein the inner edge portion further includes a second recessed portion, a third recessed portion, and a fourth recessed portion. The first recessed portion is located at one end portion of the inner edge portion in the third direction and at one end portion of the inner edge portion in the first direction. The second recessed portion is located at one end portion of the inner edge portion in the third direction and at the other end portion of the inner edge portion in the first direction. The third recessed portion is located at the other end portion of the inner edge portion in the third direction and at one end portion of the inner edge portion in the first direction. The fourth recessed portion is located at the other end portion of the inner edge portion in the third direction and at the other end portion of the inner edge portion in the first direction.
According to the heat exchanger of the eighth aspect, when brazing is performed with the first recessed portion and the second recessed portion, or the third recessed portion and the fourth recessed portion being on the lower side in the gravity direction, the molten brazing material can move to the two protruding portions of the first opening defined by the recessed portions on the lower side in the gravity direction. Thus, the brazing clogging can be further suppressed.
The heat exchanger of a ninth aspect is the heat exchanger of any of the first aspect to the eighth aspect, wherein the first opening is symmetrical about a median line in the third direction intersecting the first direction and the second direction.
According to the heat exchanger of the ninth aspect, since the first opening is symmetrical about the longitudinal direction, the first member can also be applied to another location.
A heat exchanger of a tenth aspect is the heat exchanger of any of the first aspect to the eighth aspect asymmetric about a median line in the first direction.
As in the heat exchanger of the tenth aspect, the first opening that is asymmetric about a shorter direction may be provided.
A heat exchanger of an eleventh aspect is the heat exchanger of any of the first aspect to the tenth aspect, further including a third member that is stacked on the opposite side of the first member from the fin in the second direction, and has a third opening forming a flow path for a refrigerant. The first region and the third opening overlap in the second direction view.
According to the heat exchanger of the eleventh aspect, the refrigerant can be made to flow from the third opening forming the refrigerant flow path to the first region of the first opening.
A heat exchanger of a twelfth aspect is the heat exchanger of any of the first aspect to the eleventh aspect, wherein the second region is located at both ends in a third direction intersecting the first direction and the second direction.
According to the heat exchanger of the twelfth aspect, at the time of brazing, the molten brazing material is likely to move to at least one of the second regions located at both ends in the longitudinal direction. Thus, the brazing clogging can be suppressed.
A heat exchanger of a thirteenth aspect is the heat exchanger of any of the first aspect to the twelfth aspect, wherein a ratio of a length of the first region in the first direction to a length of the second region in the first direction is 1/4 or more and less than 1.
According to the heat exchanger of the thirteenth aspect, since the ratio between the length of the first region having a large influence on the pressure resistance strength and the length of the second region having a small influence on the pressure resistance strength is within the above range, improvement of the pressure resistance and suppression of clogging with the brazing material can be effectively realized.
A heat exchanger of a fourteenth aspect is the heat exchanger of any of the first aspect to the thirteenth aspect, wherein a ratio of a length of the second member in the second direction to a length of the first member in the second direction is 1/2 or more and 3/2 or less.
The present inventor has found that a shorter length (smaller thickness) of the second member in the second direction is more likely to the problem of low pressure resistance. According to the heat exchanger of the fourteenth aspect, since the first region, imposing a large impact on the pressure resistance strength, has a short length in the first direction, breakage of the flat tube can be suppressed even when the thickness of the second member is small as described above.
A heat exchanger of a fifteenth aspect is the heat exchanger of any of the first aspect to the fourteenth aspect, further comprising a fourth member. The fourth member is stacked on the opposite side of the first member from the fin in the second direction. The fourth member includes a fourth opening. In the second direction view, a third inner edge portion defining the fourth opening of the fourth member overlaps the flat tube. The fourth opening includes a third region and a fourth region. The length of the third region in the first direction is shorter than the predetermined length. The fourth region is longer than the predetermined length.
According to the heat exchanger of the fifteenth aspect, the third inner edge portion defining the fourth opening of the fourth member overlaps the flat tube. Thus, the flat tube can be abutted against the third inner edge portion. Therefore, the fourth member can determine the insertion position of the flat tube in the header.
At the time of brazing, the molten brazing material can move to the fourth region having a longer length in the first direction in the fourth opening. Therefore, it is possible to suppress clogging of the flow path of the flat tube by the brazing material.
A heat exchanger of a sixteenth aspect is the heat exchanger of the fifteenth aspect, wherein one end portion of the third inner edge portion in the third direction includes a fifth recessed portion.
According to the heat exchanger of the sixteenth aspect, when brazing is performed with the fifth recessed portion of the fourth member being on the lower side in the direction of gravity, the molten brazing material can move to the protruding portion of the fourth opening defined by the recessed portion. Thus, brazing clogging can be suppressed.
A heat exchanger of the seventeenth aspect is the heat exchanger of the sixteenth aspect, wherein the third inner edge portion further includes a sixth recessed portion, a seventh recessed portion, and an eighth recessed portion. The fifth recessed portion is located at one end portion of the third inner edge portion in the third direction and at one end portion of the third inner edge portion in the first direction. The sixth recessed portion is located at one end portion of the third inner edge portion in the third direction and at the other end portion of the third inner edge portion in the first direction. The seventh recessed portion is located at the other end portion of the third inner edge portion in the third direction and at one end portion of the third inner edge portion in the first direction. The eighth recessed portion is located at the other end portion of the third inner edge portion in the third direction and at the other end portion of the third inner edge portion in the first direction.
According to the heat exchanger of the seventeenth aspect, when brazing is performed with the fifth recessed portion and the sixth recessed portion, or the seventh recessed portion and the eighth recessed portion being on the lower side in the gravity direction, the molten brazing material can move to the two protruding portions of the fourth opening defined by the recessed portions on the lower side in the gravity direction. Thus, the brazing clogging can be further suppressed.
The heat exchanger of the eighteenth aspect is the heat exchanger of any of the first aspect to the seventeenth aspect, wherein the refrigerant includes carbon dioxide.
According to the heat exchanger of the eighteenth aspect, since pressure resistance can be improved, it is possible to use a refrigerant containing carbon dioxide.
A refrigeration apparatus of a nineteenth aspect includes the heat exchanger of any one of the first to the eighteenth aspects.
The refrigeration apparatus of the nineteenth aspect includes a heat exchanger in which the header can be formed by a smaller number of members. Thus, cost reduction can be achieved.

BRIEF DESCRIPTION OF DRAWINGS

[Fig. 1] Fig. 1 is a configuration diagram of an air conditioning apparatus including a heat exchanger according to an embodiment of the present disclosure.
[Fig. 2] Fig. 2 is a perspective view of an outdoor heat exchanger serving as the heat exchanger according to an embodiment of the present disclosure.
[Fig. 3] Fig. 3 is a partially enlarged view of a heat exchanging part of the outdoor heat exchanger.
[Fig. 4] Fig. 4 is a schematic view illustrating a state in which a heat transfer fin of the heat exchanging part is attached to the flat tubes.
[Fig. 5] Fig. 5 is a schematic view illustrating a flow of a refrigerant in the outdoor heat exchanger functioning as a evaporator for a refrigerant.
[Fig. 6] Fig. 6 is a perspective view illustrating an external appearance of an inlet/outlet header.
[Fig. 7] Fig. 7 is an exploded perspective view of the liquid header portion.
[Fig. 8A] Fig. 8A is a plan view of the liquid header portion.
[Fig. 8B] Fig. 8B is a cross-sectional view of a liquid header.
[Fig. 9] Fig. 9 is a plan view illustrating a state in which a liquid refrigerant connection pipe and the flat tube are connected to the liquid header portion.
[Fig. 10] Fig. 10 is a front view illustrating the vicinity of an opening of a second liquid member and the flat tube.
[Fig. 11] Fig. 11 is a partially enlarged view of the second liquid member.
[Fig. 12] Fig. 12 is a partially enlarged view illustrating the vicinity of a third opening of a third liquid member, the flat tube, and a fourth opening.
[Fig. 13] Fig. 13 is a partial perspective view illustrating the third liquid member, a fourth liquid member, and the flat tubes.
[Fig. 14] Fig. 14 is an exploded perspective view of a gas header portion.
[Fig. 15] Fig. 15 is a partially enlarged view illustrating the vicinity of the second opening of the second liquid member and the flat tube according to a first modification.
[Fig. 16] Fig. 16 is a partially enlarged view illustrating the vicinity of the second opening of the second liquid member and the flat tube according to a second modification.
[Fig. 17] Fig. 17 is a partially enlarged view illustrating the vicinity of the second opening of the second liquid member and the flat tube according to a third modification.
[Fig. 18] Fig. 18 is a partially enlarged view illustrating the vicinity of the second opening of the second liquid member and the flat tube according to a fourth modification.
[Fig. 19] Fig. 19 is a partially enlarged view illustrating the vicinity of a third opening of a third liquid member and the flat tube according to a seventh modification.
[Fig. 20] Fig. 20 is a partially enlarged view illustrating the vicinity of the third opening of the third liquid member and the flat tube according to an eighth modification.
[Fig. 21] Fig. 21 is a partially enlarged view illustrating the vicinity of the third opening of the third liquid member and the flat tube according to a ninth modification.
[Fig. 22] Fig. 22 is a partially enlarged view illustrating the vicinity of the third opening of the third liquid member and the flat tube according to a tenth modification.
[Fig. 23] Fig. 23 is a partially enlarged view illustrating the vicinity of the third opening of the third liquid member and the flat tube according to an eleventh modification.
[Fig. 24] Fig. 24 is a partially enlarged view illustrating the vicinity of the second opening of the second liquid member and the flat tube according to Comparative Example.
[Fig. 25] Fig. 25 is a diagram for explaining a problem.
[Fig. 26] Fig. 26 is a partially enlarged view illustrating the vicinity of the second opening of the second liquid member and the flat tube according to a fifth modification.
[Fig. 27] Fig. 27 is a partially enlarged view illustrating the vicinity of the second opening of the second liquid member and the flat tube according to a sixth modification.
[Fig. 28] Fig. 28 is a partially enlarged view illustrating the vicinity of the third opening of the third liquid member and the flat tube according to a twelfth modification.
[Fig. 29] Fig. 29 is a partially enlarged view illustrating the vicinity of the third opening of the third liquid member and the flat tube according to a thirteenth modification.
[Fig. 30] Fig. 30 is a partially enlarged view illustrating the vicinity of the third opening of the third liquid member and the flat tube according to a fourteenth modification.
[Fig. 31] Fig. 31 is a partially enlarged view illustrating the vicinity of the third opening of the third liquid member and the flat tube according to a fifteenth modification.
[Fig. 32] Fig. 32 is a partially enlarged view illustrating the vicinity of the third opening of the third liquid member and the flat tube according to a sixteenth modification.
[Fig. 33] Fig. 33 is a partially enlarged view illustrating the vicinity of the third opening of the third liquid member and the flat tube according to a seventeenth modification.
[Fig. 34] Fig. 34 is a partially enlarged view illustrating the vicinity of the third opening of the third liquid member and the flat tube according to an eighteenth modification.
[Fig. 35] Fig. 35 is a partially enlarged view illustrating the vicinity of the third opening of the third liquid member and the flat tube according to a nineteenth modification.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of a heat exchanger of the present disclosure and a refrigeration apparatus employing the heat exchanger will be described.

(1) Configuration of Air Conditioning Apparatus

Hereinafter, an air conditioning apparatus 1, which is an embodiment of a refrigeration apparatus, will be described with reference to the drawings. Fig. 1 is a schematic configuration diagram of an air conditioning apparatus 1 serving as a refrigeration apparatus and including an outdoor heat exchanger 11 as a heat exchanger according to an embodiment of the present disclosure.
The air conditioning apparatus 1 illustrated in Fig. 1 is an apparatus that cools and heats an air conditioning target space by implementing a vapor compression refrigeration cycle. Examples of the air conditioning target space include a space in a building such as an office building, commercial facility, and residence. Note that the air conditioning apparatus is merely an example of a refrigeration cycle apparatus, and the heat exchanger of the present disclosure may also be used in other refrigeration cycle apparatuses such as refrigerators, freezers, water heaters, and floor heating systems for example. The refrigerant used in the air conditioning apparatus 1 is not limited, and includes, for example, carbon dioxide, R290, R32, and the like. In the present embodiment, carbon dioxide refrigerant is used.
The air conditioning apparatus 1 mainly includes an outdoor unit 2, an indoor unit 9, a liquid-refrigerant connection pipe 4, a gas-refrigerant connection pipe 5, and a control unit 3 for controlling devices forming the outdoor unit 2 and the indoor unit 9. The liquid-refrigerant connection pipe 4 and the gas-refrigerant connection pipe 5 are refrigerant connection pipes that connect the outdoor unit 2 and the indoor unit 9. In the air conditioning apparatus 1, the outdoor unit 2 and the indoor unit 9 are connected via the liquid-refrigerant connection pipe 4 and the gas-refrigerant connection pipe 5. Thus, a refrigerant circuit 6 is formed.
The air conditioning apparatus 1 which includes one indoor unit 9 in Fig. 1, may alternatively include a plurality of the indoor units 9 connected in parallel with each other to the outdoor unit 2 through the liquid-refrigerant connection pipe 4 and the gas-refrigerant connection pipe 5. Further, the air conditioning apparatus 1 may include a plurality of the outdoor units 2. In addition, the air conditioning apparatus 1 may be an integrated air conditioning apparatus in which the outdoor unit 2 and the indoor unit 9 are integrally formed.

(1-1) Outdoor Unit

The outdoor unit 2 is installed outside the air conditioning target space, that is, for example, on the rooftop of a building, in the vicinity of a wall surface of the building, or the like.
The outdoor unit 2 mainly includes an accumulator 7, a compressor 8, a four-way switching valve 10, an outdoor heat exchanger 11, an outdoor expansion valve 12, a liquid-side shutoff valve 13, a gas-side shutoff valve 14, and an outdoor fan 16.
The outdoor unit 2 mainly includes a suction pipe 17, a discharge pipe 18, a first gas refrigerant pipe 19, a liquid refrigerant pipe 20, and a second gas refrigerant pipe 21 as refrigerant pipes that connect various devices forming the refrigerant circuit 6. The suction pipe 17 connects the four-way switching valve 10 and the suction side of the compressor 8. The suction pipe 17 is provided with the accumulator 7. The discharge pipe 18 connects the discharge side of the compressor 8 and the four-way switching valve 10. The first gas refrigerant pipe 19 connects the four-way switching valve 10 and the gas side of the outdoor heat exchanger 11. The liquid refrigerant pipe 20 connects the liquid side of the outdoor heat exchanger 11 and the liquid-side shutoff valve 13. The liquid refrigerant pipe 20 is provided with the outdoor expansion valve 12. The second gas refrigerant pipe 21 connects the four-way switching valve 10 and the gas-side shutoff valve 14.
The compressor 8 is a device that intakes low-pressure refrigerant in the refrigeration cycle from the suction pipe 17, compresses the refrigerant with a compression mechanism (not illustrated), and discharges the compressed refrigerant to the discharge pipe 18.
The four-way switching valve 10 is a mechanism that changes the state of the refrigerant circuit 6 between a cooling operation state and a heating operation state by switching the direction of flow of the refrigerant. When the refrigerant circuit 6 is in the cooling operation state, the outdoor heat exchanger 11 functions as a radiator for the refrigerant, and an indoor heat exchanger 91 functions as an evaporator for the refrigerant. When the refrigerant circuit 6 is in the heating operation state, the outdoor heat exchanger 11 functions as an evaporator for the refrigerant, and the indoor heat exchanger 91 functions as a radiator for the refrigerant. When the four-way switching valve 10 sets the state of the refrigerant circuit 6 to the cooling operation state, the four-way switching valve 10 establishes communication between the suction pipe 17 and the second gas refrigerant pipe 21 and establishes communication between the discharge pipe 18 and the first gas refrigerant pipe 19 (see the solid line inside the four-way switching valve 10 in Fig. 1). When the four-way switching valve 10 sets the state of the refrigerant circuit 6 to the heating operation state, the four-way switching valve 10 establishes communication between the suction pipe 17 and the first gas refrigerant pipe 19 and establishes communication between the discharge pipe 18 and the second gas refrigerant pipe 21 (see the broken line inside the four-way switching valve 10 in Fig. 1).
The outdoor heat exchanger 11 is a device in which heat is exchanged between the refrigerant flowing inside and a fluid such as air at the installation location of the outdoor unit 2. Details of the outdoor heat exchanger 11 will be described below.
The outdoor expansion valve 12 is disposed between the outdoor heat exchanger 11 and the indoor heat exchanger 91 in the refrigerant circuit 6. In the present embodiment, the outdoor expansion valve 12 is disposed in the liquid refrigerant pipe 20 between the outdoor heat exchanger 11 and the liquid-side shutoff valve 13. The outdoor expansion valve 12 has a mechanism for adjusting the pressure and flow rate of the refrigerant flowing through the liquid refrigerant pipe 20.
The accumulator 7 is a container having a gas-liquid separation function that separates the incoming refrigerant into gas refrigerant and liquid refrigerant. In addition, the accumulator 7 is a container having a function of storing extra refrigerant generated as a result of a variation in operation load or the like.
The liquid-side shutoff valve 13 is a valve provided at the connecting portion between the liquid refrigerant pipe 20 and the liquid-refrigerant connection pipe 4. The gas-side shutoff valve 14 is a valve provided at the connecting portion between the second gas refrigerant pipe 21 and the gas-refrigerant connection pipe 5. The liquid-side shutoff valve 13 and the gas-side shutoff valve 14 are open while the air conditioning apparatus 1 is operating.
The outdoor fan 16 is a fan for taking external heat source air into a casing (not illustrated) of the outdoor unit 2, supplying the air to the outdoor heat exchanger 11, and discharging the air that has exchanged heat with the refrigerant in the outdoor heat exchanger 11 to the outside of the casing of the outdoor unit 2. The outdoor fan 16 is, for example, a propeller fan.

(1-2) Indoor Unit

The indoor unit 9 is a unit installed in the air conditioning target space. The indoor unit 9 is, for example, a ceiling-embedded unit, but may be a ceiling-suspended unit, a wallmounted unit, or a floor-mounted unit. Also, the indoor unit 9 may be installed outside the air conditioning target space. For example, the indoor unit 9 may be installed in an attic, a machine chamber, a garage, or the like. In this case, an air passage is provided for supplying the air that has exchanged heat with the refrigerant in the indoor heat exchanger 91 from the indoor unit 9 to the air conditioning target space. The air passage is, for example, a duct.
The indoor unit 9 mainly includes the indoor heat exchanger 91, an indoor expansion valve 93, and an indoor fan 92.
In the indoor heat exchanger 91, heat exchange is performed between the refrigerant flowing through the indoor heat exchanger 91 and the air in the air conditioning target space. The indoor heat exchanger 91 is, for example, a fin-and-tube heat exchanger including a plurality of heat transfer tubes and fins (not illustrated). One end of the indoor heat exchanger 91 is connected to the indoor expansion valve 93 via a refrigerant pipe. The other end of the indoor heat exchanger 91 is connected to the gas-refrigerant connection pipe 5 via a refrigerant pipe.
The indoor expansion valve 93 is disposed between the indoor heat exchanger 91 and the liquid-refrigerant connection pipe 4 in the refrigerant circuit 6. The indoor expansion valve 93 has a mechanism for adjusting the pressure and flow rate of the refrigerant passing through the indoor expansion valve 93.
The indoor fan 92 is a mechanism that takes air in the air conditioning target space into a casing (not illustrated) of the indoor unit 9, supplies the air to the indoor heat exchanger 91, and blows out the air that has exchanged heat with the refrigerant in the indoor heat exchanger 91 to the air conditioning target space. The indoor fan 92 is, for example, a turbofan.

(1-3) Control Unit

The control unit 3 is a functional unit that controls the operations of various devices forming the air conditioning apparatus 1.
The control unit 3 is configured such that, for example, an outdoor control unit (not illustrated) for the outdoor unit 2 and an indoor control unit (not illustrated) for the indoor unit 9 are communicably connected via a transmission line (not illustrated). The outdoor control unit and the indoor control unit are, for example, units having a microcomputer or the like including a processor such as a central processing unit (CPU), a memory such as a ROM and a RAM storing various programs for controlling the air conditioning apparatus 1 that can be executed by the processor, and the like. In Fig. 1, for the sake of convenience, the control unit 3 is depicted at a position away from the outdoor unit 2 and the indoor unit 9.
The control unit 3 is electrically connected to various devices of the outdoor unit 2 and the indoor unit 9, such as the compressor 8, the four-way switching valve 10, the outdoor expansion valve 12, the outdoor fan 16, the indoor fan 92, and the indoor expansion valve 93. The control unit 3 is also electrically connected to various sensors provided in the outdoor unit 2 and the indoor unit 9. The control unit 3 is configured to be able to communicate with a remote controller (not illustrated) operated by a user of the air conditioning apparatus 1.
The control unit 3 controls the operation and turning off of the air conditioning apparatus 1 and the operations of various devices forming the air conditioning apparatus 1 based on measurement signals from the various sensors, commands received from the remote controller (not illustrated), and the like.

(2) Configuration of Outdoor Heat Exchanger

The configuration of the outdoor heat exchanger 11 (an example of "heat exchanger") will be described with reference to the drawings. Fig. 2 is a schematic perspective view of the outdoor heat exchanger 11. Fig. 3 is a partially enlarged view of a heat exchanging part 27, which will be described below, in the outdoor heat exchanger 11. Fig. 4 is a schematic view illustrating a state in which a fin 29, which will be described below, is attached to a flat tube 28 in the heat exchanging part 27. Fig. 5 is a schematic configuration diagram of the outdoor heat exchanger 11. The arrows of the heat exchanging part 27 illustrated in Fig. 5 indicate the flow of the refrigerant during the cooling operation (when the outdoor heat exchanger 11 functions as an evaporator for the refrigerant). Fig. 6 is an external perspective view of an inlet/outlet header 40.
In the following description, expressions such as "upper", "lower", "left", "right", "front", and "rear" may be used to describe directions and positions. These expressions follow the directions of the arrows drawn in Fig. 2 unless otherwise specified. These expressions representing directions and positions are used for convenience of description, and unless otherwise specified, do not specify the orientation and position of the entire outdoor heat exchanger 11 and each component of the outdoor heat exchanger 11 to the directions and positions described.
In the following description, an example is explained where the direction in which the plurality of flat tubes 28 are arranged, the longitudinal direction of the inlet/outlet header 40, the longitudinal direction of a gas header portion 50, and the longitudinal direction of a liquid header portion 30 are the up-down direction (an example of "first direction"). Also, an example is described where the direction in which the flat tubes 28 extend, specifically, the direction in which the connecting portion of the flat tubes 28 with the inlet/outlet header 40 extend, and the direction in which plate-shaped members forming the liquid header portion 30 are stacked are the front-rear direction (an example of "second direction"). Furthermore, an example is described where the direction intersecting (orthogonal to, in the present embodiment) the up-down direction and the front-rear direction is the left-right direction (an example of "third direction").
The outdoor heat exchanger 11 is a device in which heat is exchanged between the refrigerant flowing inside and the outdoor air.
As illustrated in Figs. 2 to 5, the outdoor heat exchanger 11 mainly includes a plurality of the flat tubes 28, a plurality of the fins 29, a return header 60, and the inlet/outlet header 40. In the present embodiment, the flat tubes 28, the fins 29, the return header 60, and the inlet/outlet header 40 are made of aluminum or an aluminum alloy.
The flat tubes 28 and the fins 29 fixed to the flat tubes 28 form the heat exchanging part 27. In the outdoor heat exchanger 11, air flows in a ventilation channel defined by the flat tubes 28 and the fins 29 of the heat exchanging part 27, and thus heat exchange is performed between the refrigerant flowing through the flat tubes 28 and the air flowing through the ventilation channel.

(2-1) Flat Tube

As illustrated in Fig. 3, the flat tube 28 is a flat heat transfer tube having upper and lower flat surfaces 28a serving as heat transfer surfaces. A plurality of flow paths 28b through which the refrigerant flows are formed in the flat tube 28. For example, the flat tube 28 is a flat multichanneled tube in which a large number of the flow paths 28b having a small passage cross-sectional area through which the refrigerant flows are formed. In the present embodiment, these plurality of flow paths 28b are arranged in the air flow direction.
In the outdoor heat exchanger 11, as illustrated in Fig. 5, the flat tubes 28 that extend in the horizontal direction between the return header 60 side and the inlet/outlet header 40 side are arranged vertically in a plurality of stages.
Note that in the present embodiment, the flat tubes 28 extending between the return header 60 side and the inlet/outlet header 40 side are bent at two locations. Thus, the heat exchanging part 27 formed by the flat tubes 28 is formed in a C shape in plan view. In the present embodiment, the plurality of flat tubes 28 are arranged at a regular interval in the vertical direction.
The outdoor fan 16 driven produces an air flow passing through the main surface of the outdoor heat exchanger 11 from the rear side to the front side, an air flow passing through the left side surface portion of the outdoor heat exchanger 11 from the left side to the right side, and an air flow passing through the right side surface portion of the outdoor heat exchanger 11 from the right side to the left side.
As illustrated in Fig. 5, the outdoor heat exchanger 11 includes a first flow path group X, a second flow path group Y, and a third flow path group Z arranged in the up-down direction. In the outdoor heat exchanger 11, each of the flat tubes 28 arranged in the up-down direction belongs to one of the plurality of flow path groups X, Y, and Z. The first flow path group X to which a plurality of first flat tubes 28x belong is the lowest flow path group. The second flow path group Y to which a plurality of second flat tubes 28y belong is a flow path group located above the first flow path group X and below the third flow path group Z. The third flow path group Z to which a plurality of third flat tubes 28z belong is the uppermost flow path group.

(2-2) Fin

The plurality of fins 29 are members for increasing the heat transfer area of the outdoor heat exchanger 11. Each of the fins 29 is a plate-shaped member extending in the first direction in which the flat tubes 28 are arranged. Here, the outdoor heat exchanger 11 is used in a mode in which the plurality of flat tubes 28 extending in the horizontal direction are arranged in the up-down direction. Therefore, in a state in which the outdoor heat exchanger 11 is installed in the outdoor unit 2, each fin 29 extends in the up-down direction.
As illustrated in Fig. 4, the fins 29 have a plurality of respective notches 29a formed to extend along the insertion direction of the flat tubes 28 so that the plurality of flat tubes 28 can be inserted. The notches 29a extend in a direction orthogonal to the extending direction of the fin 29 and the thickness direction of the fin 29. In a state in which the outdoor heat exchanger 11 is installed in the outdoor unit 2, the notches 29a formed in the fins 29 extend in the horizontal direction. The notches 29a are formed in the fins 29 at an interval corresponding to the arrangement interval of the flat tubes 28. In the outdoor heat exchanger 11, the plurality of fins 29 are arranged side by side and along the direction in which the flat tubes 28 extend. By inserting the flat tube 28 into each of the plurality of notches 29a of the plurality of fins 29, the space between adjacent flat tubes 28 is partitioned into a plurality of ventilation channel through which air flows.
As illustrated in Figs. 3 and 4, each fin 29 includes a communication portion 29b for communication in the up-down direction on the upstream side or the downstream side in the air flow direction with respect to the flat tubes 28. In the present embodiment, the communication portion 29b of the fin 29 is located on the windward side with respect to the flat tubes 28.

(2-3) Inlet/Outlet Header

As illustrated in Figs. 5 and 6, the inlet/outlet header 40 has the gas header portion 50 located in an upper part and the liquid header portion 30 located in a lower part. The gas header portion 50 and the liquid header portion 30 are vertically partitioned by a partition plate 41. The gas header portion 50 has an internal space, and the liquid header portion 30 has a space isolated from the internal space of the gas header portion 50 by the partition plate 41. The upper end of the gas header portion 50 is closed by an upper lid 42. The partition plate 41 also functions as a bottom plate of the gas header portion 50.
A gas refrigerant connection pipe 19a forming one end of the first gas refrigerant pipe 19 is connected to the gas header portion 50. A liquid refrigerant connection pipe 20a forming one end of the liquid refrigerant pipe 20 is connected to the liquid header portion 30.
As illustrated in Fig. 5, one end of each flat tube 28 is connected to the gas header portion 50 and the liquid header portion 30 of the inlet/outlet header 40, and the other end of each flat tube 28 is connected to the return header 60. The outdoor heat exchanger 11 is disposed inside a casing (not illustrated) of the outdoor unit 2 such that the longitudinal direction of the return header 60 and the inlet/outlet header 40 substantially coincides with the vertical direction. Here, the number of flat tubes 28 connected to the gas header portion 50 is larger than the number of flat tubes 28 connected to the liquid header portion 30.
Details of the gas header portion 50 and the liquid header portion 30 will be described below.

(2-4) Return Header

End portions different from the end portions of the flat tubes 28 connected to the gas header portion 50 and the liquid header portion 30 of the inlet/outlet header 40 are connected to the return header 60. The outdoor heat exchanger 11 is disposed inside the casing (not illustrated) of the outdoor unit 2 such that the longitudinal direction of the return header 60 and the inlet/outlet header 40 substantially coincides with the vertical direction.
The return header 60 is formed by surrounding and crimping a stack of a plurality of plate-shaped members with a crimping member 61 having a C-shape in plan view to which the flat tubes 28 are connected. The plate-shaped members stacked on the crimping member 61 include a member having the same shape as the members forming the liquid header portion 30 and the gas header portion 50. This makes it possible to commonly use the members.

(3) Flow of Refrigerant During each Operation and in Outdoor Heat Exchanger

The control unit 3 receives detection information from various sensors, commands from a remote controller, or the like, switches among cooling operation, heating operation, and the like, and implements the operation.
When the air conditioning apparatus 1 performs the heating operation, the control unit 3 switches the connection state of the four-way switching valve 10 to the state indicated by the broken line in Fig. 1 and operates the compressor 8. The refrigerant discharged from the compressor 8 releases heat by exchanging heat with indoor air in the indoor heat exchanger 91, is decompressed in the indoor expansion valve 93 or the outdoor expansion valve 12, and is then sent to the outdoor heat exchanger 11. The refrigerant sent to the outdoor heat exchanger 11 evaporates by exchanging heat with the outside air and is taken into the compressor 8 again.
As described above, when the outdoor heat exchanger 11 functions as an evaporator for the refrigerant during the heating operation, the refrigerant in the liquid state or the gas-liquid two-phase state that has reached the liquid header portion 30 from the liquid refrigerant pipe 20 is divided into the refrigerant flowing through the first flow path group X and the refrigerant flowing through the second flow path group Y in the internal space of the liquid header portion 30. Thereafter, the divided refrigerants respectively flow through the plurality of first flat tubes 28x belonging to the first flow path group X and the plurality of second flat tubes 28y belonging to the second flow path group Y. The refrigerant that flows through the plurality of first flat tubes 28x and second flat tubes 28y partially evaporates by exchanging heat with the air, and reaches a lower region of the internal space of the return header 60. The refrigerant sent to the lower region of the internal space of the return header 60 is sent to an upper region of the internal space of the return header 60. The refrigerant sent to the upper region of the return header 60 flows through the plurality of third flat tubes 28z belonging to the third flow path group Z connected to the upper region of the return header 60. The refrigerant flowing through the plurality of third flat tubes 28z further evaporates by exchanging heat with the air again, and reaches the gas header portion 50. Once reaching the gas header portion 50, the refrigerants merge and then flow through the first gas refrigerant pipe 19.
When the air conditioning apparatus 1 performs the cooling operation, the control unit 3 switches the connection state of the four-way switching valve 10 to the state indicated by the solid line in Fig. 1 and operates the compressor 8. The refrigerant discharged from the compressor 8 releases heat by exchanging heat with the outside air in the outdoor heat exchanger 11, is decompressed in the outdoor expansion valve 12 or the indoor expansion valve 93, and is then sent to the indoor heat exchanger 91. The refrigerant sent to the indoor heat exchanger 91 evaporates by exchanging heat with the indoor air, and is taken into the compressor 8 again.
In this way, when the outdoor heat exchanger 11 functions as a radiator for the refrigerant during the cooling operation, the refrigerant discharged from the compressor 8 flows into the gas header portion 50 after flowing through the first gas refrigerant pipe 19. The gaseous refrigerant that has reached the gas header portion 50 is divided in the internal space of the gas header portion 50, and then flows through the plurality of third flat tubes 28z belonging to the third flow path group Z connected to the gas header portion 50. The refrigerant flowing through the plurality of third flat tubes 28z partially releases heat by exchanging heat with the air, and reaches the upper region of the internal space of the return header 60. The refrigerant sent to the upper region of the internal space of the return header 60 is sent to the lower region of the return header 60. The refrigerant sent to the lower region of the return header 60 is divided to flow through the plurality of first flat tubes 28x belonging to the first flow path group X and the plurality of second flat tubes 28y belonging to the second flow path group Y, which are connected to the lower region of the return header 60. The refrigerant flowing through the plurality of first flat tubes 28x and second flat tubes 28y further releases heat by again exchanging heat with the air, and reaches the liquid header portion 30. The refrigerant that has flowed through the plurality of first flat tubes 28x belonging to the first flow path group X and the refrigerant that has flowed through the plurality of second flat tubes 28y belonging to the second flow path group Y merge in the liquid header portion 30, and then flows through the liquid refrigerant pipe 20.

(4) Details of Liquid Header Portion

Fig. 7 is a schematic exploded perspective view of the liquid header portion 30. In Fig. 7, the two dot chain line arrows indicate how the refrigerant flows while the outdoor heat exchanger 11 functions as an evaporator for the refrigerant. Fig. 8a is a plan view of the liquid header portion 30. Fig. 8b is a cross-sectional plan view of the liquid header portion 30 at a position where a first opening 310, a second opening 320, and a third opening 330 overlap. Fig. 9 is a plan view illustrating how the liquid refrigerant pipe 20 and the flat tube 28 are connected to the liquid header portion 30.
As illustrated in Figs. 7 to 9, the liquid header portion 30 includes a first liquid member 31 (an example of "second member"), a second liquid member 32 (an example of "first member"), a third liquid member 33, a fourth liquid member 34 (an example of "third member"), a fifth liquid member 35, a sixth liquid member 36, and a seventh liquid member 37. The liquid header portion 30 is formed by joining the first liquid member 31, the second liquid member 32, the third liquid member 33, the fourth liquid member 34, the fifth liquid member 35, the sixth liquid member 36, and the seventh liquid member 37 to each other by brazing. Specifically, the first liquid member 31, the third liquid member 33, and the fifth liquid member 35 before brazing each have a surface provided with a clad layer containing a brazing material. The surfaces of the second liquid member 32, the fourth liquid member 34, the sixth liquid member 36, and the seventh liquid member 37 before the brazing do not have the clad layer containing a brazing material. These members are joined with the brazing material melting and moving at the time of brazing.
In the present embodiment, each of the first liquid member 31, the second liquid member 32, the third liquid member 33, the fourth liquid member 34, the fifth liquid member 35, the sixth liquid member 36, and the seventh liquid member 37 has a thickness in the plate thickness direction (the front-rear direction in Fig. 7, an example of the second direction) smaller than a length in the vertical direction (the up-down direction in Fig. 7, an example of the first direction) and smaller than a length in the left-right direction (an example of third direction). The first liquid member 31, the second liquid member 32, the third liquid member 33, the fourth liquid member 34, the fifth liquid member 35, the sixth liquid member 36, and the seventh liquid member 37 each have a length in the vertical direction (the up-down direction in Fig. 7, an example of the first direction) longer than a length in the left-right direction (an example of third direction). The first liquid member 31, the second liquid member 32, the third liquid member 33, the fourth liquid member 34, the fifth liquid member 35, the sixth liquid member 36, and the seventh liquid member 37 are stacked in this order in the stacking direction (the front-rear direction in Fig. 7, an example of a second direction), which is the plate thickness direction.

(4-1) First Liquid Member

The first liquid member 31 is a member that integrates the second liquid member 32, the third liquid member 33, the fourth liquid member 34, the fifth liquid member 35, the sixth liquid member 36, and the seventh liquid member 37. The first liquid member 31 forms an outer contour of the liquid header portion 30 together with the seventh liquid member 37.
The first liquid member 31 includes a stack portion 31a, a first wall portion 31b, a second wall portion 31c, a first claw portion 31d, and a second claw portion 31e. Although not limited, the first liquid member 31 of the present embodiment can be formed by bending a single sheet metal obtained by rolling along a fold line which is the longitudinal direction of the liquid header portion 30. In this case, the plate thickness is uniform among portions of the first liquid member 31.
The stack portion 31a extends in the up-down direction. Here, the stack portion 31a is a flat plate that spreads in both up-down direction and left-right direction.
The stack portion 31a includes the first opening 310 (an example of second opening) formed along the outer edge of the flat tube 28. Therefore, here, the first opening 310 has a flat shape in the front-rear direction view (an example of second direction view). In Fig. 7, a plurality of the first openings 310 arranged in the up-down direction are formed in the stack portion 31a. The plurality of first openings 310 have the same shape. Each of the first openings 310 is an opening formed through the stack portion 31a in the thickness direction. The flat tube 28 is joined to the first opening 310 by brazing in a state in which the flat tube 28 is inserted with one end of the flat tube 28 completely passing therethrough. In the state after the brazed joining, the entire inner circumference surface of the first opening 310 and the entire outer circumference surface of the flat tube 28 are in contact with each other.
Since the thickness of the first liquid member 31 is formed to be relatively thin, for example, about 1.0 mm or more and 2.0 mm or less, the length of the inner edge portion forming the first opening 310 is short in the plate thickness direction. Therefore, when performing the work of inserting the flat tube 28 into the first opening 310 as a procedure prior to joining by brazing, friction generated between the inner edge portion defining the first opening 310 and the outer circumference surface of the flat tube 28 can be kept small, so that the insertion work can be easily performed.
The first wall portion 31b is a planar shaped portion extending forward from the end portion of the stack portion 31a on the right side (the inside of the outdoor unit 2). The second wall portion 31c is a planar shaped portion extending forward from the end portion of the stack portion 31a on the left side (the outside of the outdoor unit 2).
A plurality of the first claw portions 31d are provided at the front end portion of the first wall portion 31b so as to be arranged in the up-down direction. A plurality of the second claw portions 31e are provided at the front end portion of the second wall portion 31c so as to be arranged in the up-down direction.
Now, the manufacturing process will be described. The first claw portions 31d and the second claw portions 31e extend on the extensions of the first wall portion 31b and the second wall portion 31c, respectively, as illustrated in Fig. 7, in a state before the second liquid member 32, the third liquid member 33, the fourth liquid member 34, the fifth liquid member 35, the sixth liquid member 36, and the seventh liquid member 37 are placed inside the first liquid member 31 in plan view (an example of first direction view). Then, in a state where the second liquid member 32, the third liquid member 33, the fourth liquid member 34, the fifth liquid member 35, the sixth liquid member 36, and the seventh liquid member 37 are arranged inside the first liquid member 31 in plan view, the first claw portions 31d and the second claw portions 31e are bent toward each other, and as illustrated in Fig. 8a and Fig. 8b, the second liquid member 32, third liquid member 33, fourth liquid member 34, fifth liquid member 35, sixth liquid member 36, and the seventh liquid member 37 are crimped by the first liquid member 31 to be fixed to each other. Then, in this state, brazing is performed in a furnace or the like, whereby the members are joined and completely fixed to each other by brazing.

(4-2) Second Liquid Member

The second liquid member 32 is stacked on the side of the first liquid member 31 opposite to the fins 29 in the front-rear direction (an example of second direction). Specifically, the second liquid member 32 is stacked so as to be in contact with the stack portion 31a. The second liquid member 32 spreads in parallel to the stack portion 31a, and has a plate shape whose plate thickness direction is the direction in which the flat tubes 28 extend.
The second liquid member 32 extends in the up-down direction (an example of first direction). Here, the second liquid member 32 is a flat plate spreading in the up-down direction and left-right direction.
The second liquid member 32 includes the plurality of second openings 320 (an example of first opening). The second openings 320 are arranged in the up-down direction. The second opening 320 is defined by an inner edge portion 32a.
The second opening 320 is an opening through which the flat tube 28 is inserted and is formed through the second liquid member 32 in the plate thickness direction. The plurality of second openings 320 have the same shape. The center of each of the second openings 320 in the left-right direction coincides with the center of the second liquid member 32 in the left-right direction.
Fig. 10 is a rear side view of the vicinity of the second opening 320 of the second liquid member 32 and the flat tube 28. As illustrated in Figs. 8 to 10, in a stacking direction view (an example of second direction view), the outer edge of the second opening 320 is located outside the outer edge of the flat tube 28. In other words, in a front-rear direction view (an example of second direction view), the inner edge portion 32a defining the second opening 320 encompasses the flat tube 28. Therefore, the second opening 320 is larger than the first opening 310. In detail, in a state where the second liquid member 32 is stacked on the stack portion 31a of the first liquid member 31, the outer edge of each second opening 320 is located outside the outer edge of each first opening 310 in the front-rear direction view. Thus, in the front-rear direction view, the second opening 320 encompasses the first opening 310.
The flat tube 28 is joined by brazing in a state where the flat tube 28 is inserted in the second opening 320, with one end of the flat tube 28 completely passing through the second opening 320. In the brazed joining state, the entire inner circumference surface of the second opening 320 and the entire outer circumference surface of the flat tube 28 are in contact with each other.
The thickness of the second liquid member 32 is adjusted to be larger than the thickness of any of the first liquid member 31, the third liquid member 33, the fourth liquid member 34, the fifth liquid member 35, the sixth liquid member 36, and the seventh liquid member 37 forming the liquid header portion 30. As a result, even if there is an error in the degree of insertion of the flat tube 28 into the liquid header portion 30, as long as the error is within the range of the length of the second liquid member in the front-rear direction, it is less likely to lead to problems such as the production of a blocked location or a location where the refrigerant has difficulty flowing in a flow of refrigerant when the liquid header portion 30 completed. In addition, it is possible to suppress blocking of the flow paths 28b of the flat tube 28 during brazed joining, by the brazing material moving due to capillary action.
The thickness of the second liquid member 32 may be smaller than the thickness of the first liquid member 31. Specifically, as illustrated in Fig. 8a and Fig. 8b, a ratio (L31/L32) of a length (plate thickness) L31 of the stack portion 31a of the first liquid member 31 in the front-rear direction to a length (plate thickness) L32 of the second liquid member 32 in the front-rear direction is preferably 1/2 or more and 3/2 or less, and more preferably 1/2 or more and 3/4 or less.
Here, the shape of the second opening 320 will be described with reference to Figs. 10 and 11. Fig. 11 is a rear side view of a part of the second liquid member 32. In the present embodiment, the longitudinal direction of the second opening 320 is the left-right direction (an example of third direction). The longitudinal direction of the second opening 320 is the width direction of the flat tube 28.
As illustrated in Figs. 10 and 11, the second opening 320 includes a first region 321 and a second region 322. In the present embodiment, the second opening 320 is formed by the first region 321 and the second region 322. The length of the first region 321 in the up-down direction (an example of first direction) is shorter than the length of the second region 322 in the up-down direction (an example of first direction). In other words, the length of the first region 321 in the up-down direction is shorter than a predetermined length, and the length of the second region 322 in the up-down direction is longer than the predetermined length. Thus, the length of the second opening 320 in the up-down direction is not uniform.
The first region 321 has a short length in the up-down direction, and thus has a function of improving pressure resistance. Since the second region 322 is long in the up-down direction, it serves as a space into which the brazing material molten during brazing moves.
The first region 321 is located at a central portion of the second opening 320 in the left-right direction (an example of third direction). In other words, the first region 321 includes the center of the second opening 320 in the left-right direction. Note that the center is the center of the length in the left-right direction, and the central portion is a region including the center. Here, the first region 321 overlaps the center of the second liquid member 32 in the left-right direction. Further, in the longitudinal direction of the second opening 320, the center of the first region 321 coincides with the center of the second opening 320. The first region 321 is not located at both ends of the second opening 320 in the left-right direction. For example, the first region 321 is preferably provided within a range of 1/3 or less from the center to the left and right ends of the second opening 320.
The second region 322 is located at both end portions of the second opening 320 in the left-right direction. In other words, the second region 322 includes both ends of the second opening 320 in the left-right direction. Here, the second region 322 is not located at the center of the second opening 320 in the longitudinal direction of the second opening 320.
A ratio (L321/L322) of a length L321 of the first region 321 in the up-down direction to a length L322 of the second region 322 in the up-down direction is preferably 1/4 or more and less than 1, and more preferably 1/2 or more and 3/4 or less. With this configuration, pressure resistance can be improved even when a high-pressure refrigerant such as carbon dioxide is used.
In the front-rear direction view, the first region 321 overlaps a fourth opening 340 (an example of third opening) of the fourth liquid member 34 described below. In the present embodiment, in the front-rear direction view, a central portion of the first region 321 overlaps an ascending space 343 of the fourth opening 340 described below. In other words, in the front-rear direction, the end portions of the first region 321 in the left-right direction do not overlap the fourth opening 340.
As described above, the second liquid member 32 includes the inner edge portion 32a defining the second opening 320. The inner edge portion 32a defines a circumference and includes a portion extending in the left-right direction and a portion extending in the up-down direction. Specifically, the inner edge portion 32a includes a first inner edge portion 32b and a second inner edge portion 32c. The first inner edge portion 32b and the second inner edge portion 32c extend in the left-right direction. Here, the first inner edge portion 32b and the second inner edge portion 32c extend in the longitudinal direction of the second opening 320. The first inner edge portion 32b is located on the upper side in the up-down direction (an example of one side in the first direction). The second inner edge portion 32c is located on the lower side in the up-down direction (an example of the other side in the first direction).
The first inner edge portion 32b includes a protrusion portion 32b1 that protrudes toward the lower side in the up-down direction. The second inner edge portion 32c includes a protrusion portion 32c1 that protrudes toward the upper side in the up-down direction. In Figs. 10 and 11, the first inner edge portion 32b has one protrusion portion 32b1, and the second inner edge portion 32c has one protrusion portion 32c1. Here, the protrusion portions 32b1 and 32c1 are located at the central portion of the second opening 320 in the longitudinal direction. Also, the positions and lengths of the protrusion portions 32b1 and 32c1 in the left-right direction are the same. The corners of the protrusion portions 32b1 and 32c1 are curved in an arc shape.
In the up-down direction of the second opening 320, a region opposed to the protrusion portions 32b1 and 32c1 is the first region 321. Here, a region interposed between the protrusion portions 32b1 and 32c1 is the first region 321. In the up-down direction of the second opening 320, a region that is not opposed to the protrusion portion 32b1 is the second region 322.
The second opening 320 is symmetrical about a center line (median line) L in the left-right direction. Here, the second opening 320 is symmetrical about the longitudinal direction. The second opening 320 is also symmetrical about the center line in the up-down direction.

(4-3) Third Liquid Member

The third liquid member 33 has both a function of abutting and stopping the flat tube 28 to define an insertion margin and a function of adjusting the amount of refrigerant flowing from the refrigerant flow path of the liquid header portion 30 to the flat tube 28.
As illustrated in Figs. 7 to 9, in the front-rear direction (an example of second direction), the third liquid member 33 is stacked on the side of the second liquid member 32 opposite to the first liquid member 31. Specifically, the third liquid member 33 is stacked to come into contact with the front surface of the second liquid member 32. The third liquid member 33 spreads in parallel to the second liquid member 32, and has a plate shape whose plate thickness direction is the direction in which the flat tubes 28 extend.
The third liquid member 33 extends in the up-down direction (an example of first direction). Here, the third liquid member 33 is a flat plate spreading in the up-down direction and the left-right direction.
The third liquid member 33 includes a plurality of the third openings 330. The third openings 330 are arranged in the up-down direction. Fig. 12 is a rear side view of the vicinity of the third opening 330 of the third liquid member 33, the flat tube 28, and the fourth opening 340 of the fourth liquid member 34, which will be described below. As illustrated in Fig. 12, the third opening 330 is defined by an inner edge portion 33a.
The third opening 330 communicates with the refrigerant flow path 28b of the flat tube 28. As illustrated in Fig. 7, the third opening 330 is an opening formed through the third liquid member 33 in the plate thickness direction. The plurality of third openings 330 have the same shape. The center of each of the third openings 330 in the left-right direction coincides with the center of the third liquid member 33 in the left-right direction.
The third openings 330 overlap the respective second openings 320 of the second liquid member 32 in the front-rear direction view. Here, as illustrated in Figs. 8a, 8b, and 9, the third opening 330 is encompassed in the second opening 320 in the front-rear direction view (an example of second direction view). Therefore, each of the third openings 330 communicates with each of the second openings 320. As a result, the refrigerant flowing through the ascending space 343 of the fourth liquid member 34, which will be described below, can be divided to flow toward the respective third openings 330, and the refrigerant can be distributed to the flat tubes 28 connected to correspond to the respective third openings 330.
The front surface of the third liquid member 33 other than the portion where the third opening 330 is formed defines the contour of the ascending space 343 described below.
Fig. 13 is a partial perspective view illustrating the third liquid member 33, the fourth liquid member 34, and the flat tube 28. As illustrated in Figs. 12 and 13, in a plate thickness direction view (an example of second direction view), the inner edge portion 33a defining the third opening 330 overlaps the flat tube 28. Thus, the third opening 330 regulates the insertion of the flat tube 28, thereby determining the insertion position of the flat tube 28.
In the present embodiment, both end portions of the flat tube 28 in the longitudinal direction in cross sectional view overlap the inner edge portion 33a defining the third opening 330. In other words, the length of the third opening 330 is shorter than the length of the flat tube 28 in the left-right direction. In Fig. 12, the length of the third opening 330 is longer than the length of the flat tube 28 in the up-down direction. Accordingly, the flat tube 28 is brought into contact with the inner edge portion 33a located on the outer side of both ends of the third opening 330 in the left-right direction, whereby the insertion of the flat tube 28 is regulated. Thus, the insertion position of the flat tube 28 is determined.
Now, the shape of the third opening 330 will be described with reference to Fig. 12. In the present embodiment, the longitudinal direction of the third opening 330 is the left-right direction (an example of third direction). The longitudinal direction of the third opening 330 is the width direction of the flat tube 28.
As illustrated in Fig. 12, the third opening 330 includes a first region 331 and a second region 332. In the present embodiment, the third opening 330 is formed by the first region 331 and the second region 332. The length of the first region 331 in the up-down direction (an example of first direction) is shorter than the length of the second region 332 in the up-down direction (an example of first direction). In other words, the length of the first region 331 in the up-down direction is shorter than the predetermined length, and the length of the second region 332 in the up-down direction is longer than the predetermined length. As described above, the length of the third opening 330 in the up-down direction is not uniform.
Since the first region 331 has a short length in the up-down direction and overlaps the fourth opening 340 of the fourth liquid member 34, the amount of refrigerant flowing from the fourth opening 340 is adjusted. The flow rate of refrigerant can be controlled by adjusting the length of the first region 331 in the up-down direction. The second region 332 serves as a space into which a brazing material molten during brazing moves.
The first region 331 is located at a central portion of the third opening 330 in the left-right direction (an example of third direction). In other words, the first region 331 includes the center of the third opening 330 in the left-right direction. Note that the center is the center of the length in the left-right direction, and the central portion is a region including the center. Here, the first region 331 overlaps the center of the third liquid member 33 in the left-right direction. Further, in the longitudinal direction of the third opening 330, the center of the first region 331 coincides with the center of the third opening 330.
The second region 332 is located at both end portions of the third opening 330 in the left-right direction. In other words, the second region 332 includes both ends of the third opening 330 in the left-right direction. Here, the second region 332 is not located at the center of the third opening 330 in the longitudinal direction of the third opening 330.
With this configuration, pressure resistance can be improved even when a high-pressure refrigerant such as carbon dioxide is used.
The third opening 330 is symmetrical about the center line L in the left-right direction. Here, the third opening 330 is symmetrical about the longitudinal direction. The third opening 330 is also symmetrical about the center line in the up-down direction.
As described above, the third liquid member 33 includes the inner edge portion 33a defining the third opening 330. The inner edge portion 33a defines a circumference and includes a portion extending in the left-right direction and a portion extending in the up-down direction. Specifically, the inner edge portion 33a includes a first inner edge portion 33b and a second inner edge portion 33c. The first inner edge portion 33b and the second inner edge portion 33c extend in the left-right direction. Here, the first inner edge portion 33b and the second inner edge portion 33c extend in the longitudinal direction of the third opening 330. The first inner edge portion 33b is located on the upper side in the up-down direction (an example of one side in the first direction). The second inner edge portion 33c is located on the lower side in the up-down direction (an example of the other side in the first direction).
The first inner edge portion 33b includes a protruding portion 33b1 that protrudes toward the lower side in the up-down direction. The second inner edge portion 33c includes a protruding portion 33c1 that protrudes toward the upper side in the up-down direction. In Fig. 12, the first inner edge portion 33b includes one protruding portion 33b1 and the second inner edge portion 33c includes one protruding portion 33c1. Here, the protruding portions 33b1 and 33c1 are located at the central portion of the third opening 330 in the longitudinal direction. Also, the positions and length of the protruding portions 33b1 and 33c1 in the left-right direction are the same. The corners of the protruding portions 33b1 and 33c1 are curved in an arc shape.
In the up-down direction of the third opening 330, a region opposing the protruding portions 33b1 and 33c1 is the first region 331. Here, a region interposed between the protruding portions 33b1 and 33c1 is the first region 331. In the up-down direction of the third opening 330, a region that is not opposed to the protruding portion 33b1 is the second region 332.
As illustrated in Fig. 12, a region R1 where the inner edge portion 33a and the flat tube 28 overlap is different from a region R2 where the inner edge portion 33a and the fourth opening 340 to be described below overlap. Here, the region R1 is a region in which a portion of the inner edge portion 33a extending in the up-down direction overlap both end portions of the flat tube 28 in the left-right direction. The inner edge portion 33a forming the region R1 has a function of determining the insertion position of the flat tube 28 in the third liquid member 33. The region R2 is a region where a portion forming the first region 331 and the ascending space 343 of the fourth opening 340, which will be described below, overlap each other in the first inner edge portion 33b and the second inner edge portion 33c extending in the left-right direction. The region R2 has a function of adjusting the amount of refrigerant flowing from the fourth opening 340. As described above, in the present embodiment, the function of abutting and stopping the flat tube 28 and the function of adjusting the amount of refrigerant are realized by different portions of the third opening 330.

(4-4) Fourth Liquid Member

As illustrated in Figs. 7 to 9, in the front-rear direction (an example of second direction), the fourth liquid member 34 is stacked on the side of the third liquid member 33 opposite to the second liquid member 32. Specifically, the fourth liquid member 34 is stacked to come into contact with the front surface of the third liquid member 33. The fourth liquid member 34 spreads in parallel to the third liquid member 33, and has a plate shape whose plate thickness direction is the direction in which the flat tubes 28 extend.
The fourth liquid member 34 extends in the up-down direction (an example of first direction). Here, the fourth liquid member 34 is a flat plate that spreads in both the up-down direction and the left-right direction.
The fourth liquid member 34 includes the fourth opening 340 (an example of third opening) forming the refrigerant flow path. The fourth opening 340 is an opening formed through the fourth liquid member 34 in the plate thickness direction.
In the present embodiment, the fourth opening 340 includes an introduction space 341, a nozzle 342, and the ascending space 343. The introduction space 341, the nozzle 342, and the ascending space 343 are provided so as to be arranged in the vertical direction in this order from the lower side.
The introduction space 341, the nozzle 342, and the ascending space 343 are spaces interposed between a front surface of the third liquid member 33 and a rear surface of a fifth liquid member 35 described below, in the front-rear direction. The introduction space 341, the nozzle 342, and the ascending space 343 form a blow-up space in which the refrigerant flows from the lower side (an example of one side in the first direction) toward the upper side (an example of the other side in the first direction).
The introduction space 341 faces the third liquid member 33, does not overlap the third opening 330 in the front-rear direction view, and does not communicate with the third opening 330. In the front-rear direction view, the introduction space 341 overlaps a second communication opening 351 of the fifth liquid member 35, which will be described below, and communicates with the second communication opening 351. In this way, since the rear side of the introduction space 341 is covered with a plate-shaped portion of the third liquid member 33, a gas-phase refrigerant and a liquid-phase refrigerant flowing into the introduction space 341 are mixed by abutting the third liquid member 33, and the refrigerant as a mixture of the gas-phase refrigerant and the liquid-phase refrigerant can be sent to the nozzle 342.
The nozzle 342 faces the third liquid member 33, does not overlap the third opening 330 in the front-rear direction view, and does not communicate with the third opening 330. Note that the nozzle 342 faces the fifth liquid member 35, which will be described below, and does not overlap or communicate with the second communication opening 351, a return flow path 352, and an outbound flow path 353 in the front-rear direction view. The nozzle 342 is provided in the vicinity of the center of the fourth liquid member 34 in the left-right direction.
The ascending space 343 overlaps the plurality of third openings 330 in the front-rear direction view, and communicates with the plurality of third openings 330. In the front-rear direction view, the ascending space 343 does not overlap the second communication opening 351, which will be described below, but overlaps the return flow path 352 and the outbound flow path 353. Therefore, the ascending space 343 does not communicate with the second communication opening 351, but communicates with the return flow path 352 and the outbound flow path 353. The length of the ascending space 343 in the longitudinal direction of the liquid header portion 30 is longer than the length of the introduction space 341 in the longitudinal direction of the liquid header portion 30 and is longer than the length of the nozzle 342 in the longitudinal direction of the liquid header portion 30. Thus, a larger number of flat tubes 28 communicating via the ascending space 343 can be provided.
The ascending space 343 forms a refrigerant flow path for upward flow along the longitudinal direction of the liquid header portion 30, using the front surface of the third liquid member 33, the rear surface of the fifth liquid member 35 to be described below, and a thick portions of the left and right edges of the fourth opening 340 of the fourth liquid member 34. The resultant structure is less likely to involve errors in the flow path cross-sectional area during manufacturing, making it easier to obtain the liquid header portion 30 enabling stable upward flow of the refrigerant.
The length of the nozzle 342 in the left-right direction is shorter than the length of the introduction space 341 in the left-right direction and shorter than the length of the ascending space 343 in the left-right direction. Thus, when the outdoor heat exchanger 11 is used as an evaporator for a refrigerant, the refrigerant sent to the introduction space 341 has the flow velocity increased while passing through the nozzle 342, making it easier to reach the upper portion of the ascending space 343. Note that the width of the ascending space 343 in the left-right direction is smaller than the width of the introduction space 341 in the left-right direction, and a refrigerant passage cross-sectional area in the ascending space 343 can be reduced. Therefore, a high flow velocity of the refrigerant flowing upward in the ascending space 343 can be maintained.
In the front-rear direction view, the liquid refrigerant connection pipe 20a is connected to the center of the introduction space 341 in the left-right direction. In the front-rear direction view, the connection portion between the introduction space 341 and the corresponding liquid refrigerant connection pipe 20a, the nozzle 342, and the ascending space 343 are arranged in the vertical direction. Therefore, the refrigerant that has flowed through the liquid refrigerant connection pipe 20a flows into the center in the left-right direction of the introduction space 341 of the fourth opening 340 of the fourth liquid member 34 through a seventh opening 370 of the seventh liquid member 37, a first communication opening 361 of a sixth opening 360 of the sixth liquid member 36, and a second communication opening 351, which will be described below, and is blown upward vertically from the introduction space 341 toward the ascending space 343 via the nozzle 342 without moving in the left-right direction or without moving much in the left-right direction. In this way, the fourth opening 340 forms a blow-up space in which the refrigerant flows upward from below.
Now, the relationship between the third opening 330 and the fourth opening 340 will be described with reference to Figs. 12 and 13.
As illustrated in Figs. 12 and 13, the fourth opening 340 overlaps the plurality of third openings 330 as in the front-rear direction view (an example of second direction view). In detail, in the front-rear direction view, the ascending space 343 of the fourth opening 340 overlaps the first regions 331 of the plurality of third openings 330. Further, in the front-rear direction view (second direction view), the second region 332 of the third opening 330 overlaps a portion of the fourth liquid member 34 other than the fourth opening 340. Here, in the front-rear direction view, the entire second region 332 overlaps a portion of the fourth liquid member 34 other than the fourth opening 340. In other words, in the front-rear direction view, the fourth opening 340 does not overlap the second region 332.
In the front-rear direction view, both ends of the first region 331 are located outside the fourth opening 340 in the left-right direction. Here, in the front-rear direction view, both ends of the first region 331 in the left-right direction are located more on the outer side than both ends of the ascending space 343 of the fourth opening 340 in the left-right direction. In other words, the length of the first region 331 in the left-right direction is longer than the length of the ascending space 343 in the left-right direction. Here, the length of the first region 331 in the left-right direction is longer than the length of the fourth opening 340 in the left-right direction.

(4-5) Fifth Liquid Member

The fifth liquid member 35 is stacked on the side of the fourth liquid member 34 opposite to the third liquid member 33 in the front-rear direction (an example of second direction). Specifically, the fifth liquid member 35 is stacked to come into contact with the front surface of the fourth liquid member 34. The fifth liquid member 35 spreads in parallel to the fourth liquid member 34, and has a plate shape whose plate thickness direction is the direction in which the flat tubes 28 extend.
The fifth liquid member 35 extends in the up-down direction (an example of first direction). Here, the fifth liquid member 35 is a flat plate that spreads in both the up-down direction and the left-right direction.
The fifth liquid member 35 includes a fifth opening 350 forming a flow path of the refrigerant. The fifth opening 350 is an opening formed through the fifth liquid member 35 in the plate thickness direction.
In the present embodiment, the fifth opening 350 includes the second communication opening 351, the return flow path 352, and the outbound flow path 353. The second communication opening 351, the return flow path 352, and the outbound flow path 353 are independent openings arranged in this order from the bottom.
The second communication opening 351 overlaps and communicates with the introduction space 341 of the fourth opening 340 of the fourth liquid member 34 in the front-rear direction view. Additionally, the second communication opening 351 overlaps and communicates with the first communication opening 361 of the sixth liquid member 36, which will be described below, in the front-rear direction view. The second communication opening 351 does not overlap or communicate with the nozzle 342 and the ascending space 343 of the fourth opening 340 of the fourth liquid member 34 in the front-rear direction view. The second communication opening 351 does not overlap or communicate with a descending space 362 of the sixth liquid member 36, which will be described below, in the front-rear direction view.
The return flow path 352 overlaps a portion in the vicinity of the lower end of the ascending space 343 of the first opening of the fourth liquid member 34 in the front-rear direction view, and communicates with the portion in the vicinity of the lower end of the ascending space 343. The return flow path 352 does not overlap the nozzle 342 in the front-rear direction view or communicate with the nozzle 342.
In the front-rear direction view, the outbound flow path 353 overlaps a portion of the fourth opening 340 of the fourth liquid member 34 in the vicinity of the upper end of the ascending space 343, and communicates with the portion in the vicinity of the upper end of the ascending space 343. In the present embodiment, when the liquid header portion 30 is viewed in the stacking direction of the members, the outbound flow path 353 is formed to have a larger area than the return flow path 352. Thus, the refrigerant that has ascended in the ascending space 343 and reached the vicinity of the upper end can easily pass through the outbound flow path 353. Further, in the present embodiment, when the liquid header portion 30 is viewed in the stacking direction of the members, the return flow path 352 is formed to have a smaller area than the outbound flow path 353. Thus, it is possible to prevent the refrigerant from flowing backward from the ascending space 343 to the return flow path 352.

(4-6) Sixth Liquid Member

The sixth liquid member 36 is stacked on the side of the fifth liquid member 35 opposite to the fourth liquid member 34 in the front-rear direction (an example of the second direction). Specifically, the sixth liquid member 36 is stacked so as to be in contact with the front surface of the fifth liquid member 35. The sixth liquid member 36 spreads in parallel to the fifth liquid member 35, and has a plate shape whose plate thickness direction is the direction in which the flat tubes 28 extend.
The sixth liquid member 36 extends in the up-down direction (an example of first direction). Here, the sixth liquid member 36 is a flat plate that spreads in both the up-down direction and the left-right direction.
The sixth liquid member 36 includes the sixth opening 360 forming a flow path of the refrigerant. The sixth opening 360 is an opening formed through the sixth liquid member 36 in the plate thickness direction.
In the present embodiment, the sixth opening 360 includes the first communication opening 361 and the descending space 362. The first communication opening 361 and the descending space 362 are independent openings arranged in this order from the bottom, and both are openings formed through in the plate thickness direction.
The first communication opening 361 overlaps and communicates with the second communication opening 351 of the fifth liquid member 35 in the front-rear direction view. In addition, the first communication opening 361 overlaps and communicates with the seventh opening 370 of the seventh liquid member 37, which will be described below, in the front-rear direction view.
The descending space 362 overlaps the return flow path 352 and the outbound flow path 353 in the front-rear direction view, and is in a state of communicating with both the return flow path 352 and the outbound flow path 353. Note that the descending space 362 does not overlap or communicate with the seventh opening 370 of the seventh liquid member 37, which will be described below, in the front-rear direction view.
In the longitudinal direction of the liquid header portion 30, the descending space 362 and the ascending space 343 have the same length, and communicate via the outbound flow path 353 in the vicinity of the upper end, and via the return flow path 352 in the vicinity of the lower end. Note that the width of the descending space 362 in the left-right direction is larger than the width of the ascending space 343 in the left-right direction. Accordingly, it is possible to reduce the pressure loss when the refrigerant passes through the descending space 362 while suppressing a decrease in the flow velocity when the refrigerant ascends and flows in the ascending space 343.

(4-7) Seventh Liquid Member

The seventh liquid member 37 is stacked on the side of the sixth liquid member 36 opposite to the fifth liquid member 35 in the front-rear direction (an example of second direction). Specifically, the seventh liquid member 37 is stacked to be in contact with the front surface of the sixth liquid member 36. The seventh liquid member 37 spreads in parallel to the sixth liquid member 36, and has a plate shape whose plate thickness direction is the direction in which the flat tube 28 extends.
The seventh liquid member 37 extends in the up-down direction (an example of first direction). Here, the seventh liquid member 37 is a flat plate spreading in the up-down direction and the left-right direction.
The seventh liquid member 37 forms an outer contour of the liquid header portion 30. By forming the seventh liquid member 37 in a plate shape, pressure resistance can be improved.
The front surface of the seventh liquid member 37 is crimped in contact with the first claw portion 31d and the second claw portion 31e of the first liquid member 31.
The seventh liquid member 37 includes the seventh opening 370. The seventh opening 370 is an opening formed through in the plate thickness direction. The seventh opening 370 overlaps and communicates with a part of the first communication opening 361 of the sixth liquid member 36 in the front-rear direction view. The seventh opening 370 does not overlap or communicate with the descending space 362 of the sixth liquid member 36 in the front-rear direction view.
The seventh opening 370 is a circular opening into which the liquid refrigerant connection pipe 20a is inserted and connected. Thus, when the outdoor heat exchanger 11 functions as an evaporator for the refrigerant, the refrigerant flowing through the liquid refrigerant connection pipe 20a is sent to the introduction space 341 of the fourth opening 340 through the first communication opening 361 and the second communication opening 351.

(5) Flow of Refrigerant in Liquid Header Portion

Hereinafter, a flow of the refrigerant in the liquid header portion 30 when the outdoor heat exchanger 11 functions as an evaporator for the refrigerant will be described. When the outdoor heat exchanger 11 functions as a radiator for the refrigerant, the refrigerant flows in a direction substantially opposite to that when the outdoor heat exchanger 11 functions as an evaporator.
The liquid refrigerant or the gas-liquid two-phase refrigerant flows through the liquid refrigerant connection pipe 20a, to pass through the seventh opening 370 of the seventh liquid member 37, and flows into the first communication opening 361 of the sixth liquid member 36. The refrigerant that has flowed into the first communication opening 361 flows into the introduction space 341 of the fourth opening 340 of the fourth liquid member 34 through the second communication opening 351 of the fifth liquid member 35. The refrigerant flowing into the introduction space 341 has the flow velocity increased while passing through the nozzle 342, and ascends in the ascending space 343. Since the width of the ascending space 343 in the left-right direction is smaller than that of the introduction space 341, the refrigerant flowing into the ascending space 343 can easily reach the plurality of third openings 330 of the third liquid member 33 located in the vicinity of the upper end of the ascending space 343 even in a case where the amount of refrigerant circulating in the refrigerant circuit 6 is small such as, for example, a case where the driving frequency of the compressor 8 is low.
The refrigerant that has flowed into the ascending space 343 flows toward the vicinity of the upper end of the ascending space 343 while branching and flowing toward the first regions 331 of the respective third openings 330. In a case where the amount of refrigerant circulating in the refrigerant circuit 6 is large, such as a case where the driving frequency of the compressor 8 is high, the amount of refrigerant reaching the vicinity of the upper end of the ascending space 343 is large, and the refrigerant reaches the descending space 362 of the sixth liquid member 36 through the outbound flow path 353 of the fifth liquid member 35. The refrigerant that has reached the descending space 362 descends and again returns to the space above the nozzle 342 that is in the vicinity of the lower side of the ascending space 343 of the fourth liquid member 34 through the return flow path 352 of the fifth liquid member 35. Here, in the ascending space 343, since the refrigerant has the flow velocity increased while passing through the nozzle 342, the static pressure at the portion of the ascending space 343 in the vicinity of the return flow path 352 is lower than that at the portion of the descending space 362 in the vicinity of the return flow path 352. Therefore, the refrigerant descending in the descending space 362 easily returns to the ascending space 343 through the return flow path 352. Thus, the refrigerant can be circulated through the ascending space 343, the outbound flow path 353, the descending space 362, and the return flow path 352. When the refrigerant flows to ascend in the ascending space 343, even if there is a refrigerant not branching and thus flowing to none of the third openings 330, such a refrigerant can return to the ascending space 343 again through the outbound flow path 353, the descending space 362, and the return flow path 352, facilitating the flow of the refrigerant to any of the third openings 330.
Since the fourth opening 340 forming the refrigerant flow path overlaps the plurality of third openings 330, the refrigerant flowing out from the fourth opening 340 forming the refrigerant flow path has the flow rate adjusted and flows into each first region 331 of each third opening 330. The refrigerant that has branched and flowed into each first region 331 flows into the flow path 28b of each flat tube 28 through the second opening 320 of the second liquid member 32 with the branched state maintained.
As described above, the fourth opening 340 of the fourth liquid member 34, the fifth opening 350 of the fifth liquid member 35, and the sixth opening 360 of the sixth liquid member 36 form a loop structure in which refrigerant circulates within the liquid header portion 30. The fourth opening 340 forms a blow-up space in which the refrigerant flows upward from below.

(6) Gas Header Portion

Fig. 14 is a schematic exploded perspective view of the gas header portion 50. In Fig. 14, an arrow of a two dot chain line indicates a flow of the refrigerant when the outdoor heat exchanger 11 functions as a radiator for the refrigerant.
The gas header portion 50 includes a first gas member 51, a second gas member 52, and a third gas member 53. The gas header portion 50 is formed by joining the first gas member 51, the second gas member 52, and the third gas member 53 to each other by brazing.
The first gas member 51 is similar to the first liquid member 31. Therefore, the first gas member 51 has an opening 510 into which the flat tube 28 is inserted. In the present embodiment, the first gas member 51 is continuous with the first liquid member 31 in the up-down direction. Therefore, the first liquid member 31 and the first gas member 51 are members extending in a plate shape from the upper end to the lower end of the inlet/outlet header 40.
The second gas member 52 is similar to the second liquid member 32. Therefore, the second gas member 52 has an opening 520 into which the flat tube 28 is inserted. In the present embodiment, the second gas member 52 is continuous with the second liquid member 32 in the up-down direction. Therefore, the second liquid member 32 and the second gas member 52 are members extending in a plate shape from the upper end to the lower end of the inlet/outlet header 40.
The third gas member 53 is stacked on the side of the second gas member 52 opposite to the first gas member 51 in the front-rear direction. Specifically, the third gas member 53 is stacked to be in contact with the front surface of the second gas member 52. The third gas member 53 spreads in parallel to the second gas member 52, and has a plate shape whose plate thickness direction is the direction in which the flat tubes 28 extend.
The third gas member 53 includes a plurality of openings 530. The plurality of openings 530 are arranged in the up-down direction, and are openings formed through the third gas member 53 in the plate thickness direction.
The left and right edges of each of the openings 530 are located more on the inner side than the opening 520 of the second gas member 52 and than each opening 510 of the first gas member 51 in the front-rear direction view. The width of the plurality of openings 530 of the third gas member 53 in the left-right direction is smaller than the width of the flat tube 28 in the left-right direction.
Note that the upper and lower edges of the plurality of openings 530 of the third gas member 53 defines an opening more on the outer side than each opening 510 of the first gas member 51 in the front-rear direction view.
As a result, the vicinities of both ends in the left-right direction of the distal end of each of the flat tubes 28 inserted into the gas header portion 50 can be brought into contact with the inner edge portion defining each of the openings 530 of the third gas member 53. Therefore, how much the flat tube 28 can be inserted into the gas header portion 50 can be determined.
A fourth gas member 54 includes a plate-shaped portion 54a and a semicircular portion 54b. The plate-shaped portion 54a is a plate-shaped portion spreading in the up-down direction and the left-right direction on each of the left side and the right side of the semicircular portion 54b.
The semicircular portion 54b is provided to connect between the right side portion and the left side portion of the plate-shaped portion 54a. The semicircular portion 54b is a semicircular arc-shaped portion formed by a semicircular arc whose axial direction is the longitudinal direction of the gas header portion 50. The semicircular portion 54b bulges toward the side of the plate-shaped portion 54a opposite to the first gas member 51 side. The semicircular portion 54b is provided with the opening 510 that is connected to the gas refrigerant connection pipe 19a of the first gas refrigerant pipe 19.
The left side portion and the right side portion of the plate-shaped portion 54a of the fourth gas member 54 come into contact with a claw portion 51c of the first gas member 51 and are crimped by the claw portion of the first gas member 51.
The partition plate 41 and the upper lid 42 are provided between the second gas member 52 and the fourth gas member 54, and function as a lower lid and an upper lid defining the internal space of the gas header portion 50.

(7) Features

(7-1)
The outdoor heat exchanger 11 as the heat exchanger of the present embodiment includes the plurality of flat tubes 28, the fin 29, and the liquid header portion 30. The plurality of flat tubes 28 are arranged in the up-down direction (first direction). The flat tube 28 is connected the fin 29. The liquid header portion 30 includes the second liquid member 32 (first member) and the first liquid member 31 (second member). The second liquid member 32 includes the second opening 320 (first opening). The flat tube 28 is inserted into the second opening 320. The first liquid member 31 is stacked on the fin 29 side of the second liquid member 32 in the front-rear direction (second direction) in which the flat tubes 28 extend. The first liquid member 31 includes the first opening 310 (second opening). The first opening 310 is formed along the outer edge of the flat tube 28. The second opening 320 includes the first region 321 and the second region 322. The length of the first region 321 in the up-down direction is shorter than a predetermined length. The length of the second region 322 in the up-down direction is longer than the predetermined length.
According to the outdoor heat exchanger 11 of the present embodiment, the width (the length in the up-down direction) of the second opening 320 is not uniform. Therefore, in the second opening 320, the first region 321 having a short length in the up-down direction is located at a portion imposing a large impact on the pressure resistance strength, so that deformation of the second liquid member 32 can be suppressed, thereby suppressing damage of the flat tube 28 as a result of being pulled. Therefore, the pressure resistance of the liquid header portion 30 can be improved.
In addition, it is possible to suppress an increase in the weight of the second liquid member 32 due to the second region 322 having a long length in the up-down direction.
Furthermore, when the first liquid member 31 and the second liquid member 32 are brazed, the molten brazing material can move to the second region 322 of the second opening 320, which has a long length in the up-down direction. Therefore, it is possible to suppress blocking of the flow path 28b of the flat tube 28 by the brazing material.
Furthermore, since the heat capacity is reduced by reducing the number of members forming the liquid header portion 30, a shorter brazing time can also be achieved.
(7-2)
In the outdoor heat exchanger 11 as the heat exchanger of the present embodiment, the first region 321 is located in the central portion in the left-right direction (third direction) intersecting both the up-down direction (first direction) and the front-rear direction (second direction).
The present inventor has found that the problem of breakage of the flat tube 28 due to deformation of the first liquid member 31 is particularly attributable to the large central portion of the second opening 320 of the second liquid member 32. For this reason, here, in the second opening 320, the first region 321 located in the central portion imposing a large impact on the pressure resistance strength has a short length. Thus, the pressure resistance can be further improved.
(7-3)
In the outdoor heat exchanger 11 as the heat exchanger of the present embodiment, the longitudinal direction of the second opening 320 (first opening) is the left-right direction (third direction) intersecting the up-down direction (first direction) and the front-rear direction (second direction). The second liquid member 32 (first member) includes the inner edge portion 32a that defines the second opening 320 (first opening). The inner edge portion 32a includes the first inner edge portion 32b on the upper side (one side) in the first direction and the second inner edge portion 32c on the lower side (the other side) in the first direction.
Here, since the longitudinal direction of the second opening 320 is the same as the width direction of the flat tube 28, the flat tube 28 can be easily inserted into the second opening 320.
(7-4)
In the outdoor heat exchanger 11 as the heat exchanger of the present embodiment, the first inner edge portion 32b includes the protrusion portion 32b1 that protrudes toward the lower side (the other side) in the up-down direction (the first direction), and the second inner edge portion 32c includes the protrusion portion 32c1 that protrudes toward the upper side (one side) in the up-down direction (the first direction).
As described above, the inner edge portion 32a defining the second opening 320 may include the protrusion portions 32b1 and 32c1 on both sides in the longitudinal direction.
(7-5)
In the outdoor heat exchanger 11 as the heat exchanger of the present embodiment, the second opening 320 (first opening) is symmetrical about the median line in the left-right direction (third direction) intersecting the up-down direction (first direction) and the front-rear direction (second direction).
Here, since the second opening 320 is symmetrical about the longitudinal direction, the second liquid member 32 can be applied to another location.
(7-6)
The outdoor heat exchanger 11 as the heat exchanger of the present embodiment further includes the fourth liquid member 34 (third member) that is stacked on the side of the second liquid member 32 (first member) opposite to the fins 29 in the front-rear direction (second direction) and includes the fourth opening 340 (third opening) forming the flow path of the refrigerant. The first region 321 and the fourth opening 340 overlap in the front-rear direction view (in the second direction view).
Here, the refrigerant can flow from the fourth opening 340 forming the refrigerant flow path to the first region 321 of the second opening 320.
(7-7)
In the outdoor heat exchanger 11 as the heat exchanger of the present embodiment, the second regions 322 are located at both ends in the left-right direction (third direction) intersecting the up-down direction (first direction) and the front-rear direction (second direction).
Here, at the time of brazing, the molten brazing material is likely to move to at least one of the second regions 322 located at both ends in the longitudinal direction, and thus it is possible to suppress brazing clogging.
(7-8)
In the outdoor heat exchanger 11 as the heat exchanger of the present embodiment, the ratio of the length of the first region 321 in the first direction to the length of the second region 322 in the up-down direction (first direction) is 1/4 or more and less than 1.
Here, since the ratio of the length of the first region 321 imposing a large impact on the pressure resistance strength to the length of the second region 322 imposing a limited impact on the pressure resistance strength is within the above range, improvement in the pressure resistance and suppression of clogging by the brazing material can be effectively achieved.
(7-9)
In the outdoor heat exchanger 11 as the heat exchanger of the present embodiment, the ratio of the length of the first liquid member 31 (second member) in the second direction to the length of the second liquid member 32 (first member) in the front-rear direction (second direction) is 1/2 or more and 3/2 or less.
The present inventor has found that a shorter length (smaller thickness) of the first liquid member 31 in the front-rear direction is more likely to lead to the problem of low pressure resistance. Here, the first region 321 imposing a large impact on the pressure resistance strength has a short length in the up-down direction, so that the breakage of the flat tube 28 can be suppressed regardless of the thickness of the first liquid member 31, also in a case where the thickness of the first liquid member 31 is small.
The present inventor has found that, in the liquid header portion 30 in which the ratio of the length of the first liquid member 31 (second member) in the second direction to the length of the second liquid member 32 in the front-rear direction is 1/2 or more and 3/2 or less, the amount of strain can be reduced by about 10% by setting the ratio of the length of the first region 321 in the first direction to the length of the second region 322 in the up-down direction to 1/4 or more and less than 1.
(7-10)
In the outdoor heat exchanger 11 as the heat exchanger of the present embodiment, the refrigerant includes carbon dioxide. Here, the refrigerant including carbon dioxide can be used since pressure resistance can be improved.
(7-11)
The outdoor heat exchanger 11 as the heat exchanger of the present embodiment further includes the third liquid member 33 (fourth member). The third liquid member is stacked on the side of the second liquid member 32 (first member) opposite to the fin 29 in the front-rear direction (second direction). The third liquid member 33 includes the third opening 330 (fourth opening). In the second direction view, the inner edge portion 33a (third inner edge portion) defining the third opening 330 in the third liquid member 33 overlaps the flat tube 28. The third opening 330 includes the first region 321 (third region) and the second region 332 (fourth region). The length of the first region 321 in the first direction is shorter than the predetermined length. The second region 332 is longer than the predetermined length.
Here, since the inner edge portion 33a defining the third opening 320 of the third liquid member 33 overlaps the flat tube 28, the flat tube 28 can be brought into contact with the inner edge portion 33a. Therefore, the third liquid member 33 can determine the insertion position of the flat tube 28 in the liquid header portion 30.
In addition, at the time of brazing, the molten brazing material can move to the second region 332 of the third opening 330 having a long length in the first direction. Therefore, it is possible to suppress clogging of the flow paths of the flat tube 28 by the brazing material.
(7-12)
The air conditioning apparatus 1 as a refrigeration apparatus of the present embodiment includes any one of the above-described outdoor heat exchangers 11. Here, since the outdoor heat exchanger 11 enabling the liquid header portion 30 to be formed by a smaller number of members is provided, the cost can be reduced.
Furthermore, the refrigeration apparatus including the outdoor heat exchanger 11 of the present embodiment is configured to be operable using a high-pressure refrigerant having a pressure exceeding 5 MPa.

(8) Modifications

(8-1) First Modification

In the above embodiment, the first inner edge portion 32b on the upper side defining the second opening 320 includes one protrusion portion 32b1, and the second inner edge portion 32c on the lower side includes one protrusion portion 32c1, but the present disclosure is not limited to this example. In the present modification, as illustrated in Fig. 15, at least one of the first inner edge portion 32b and the second inner edge portion 32c includes a plurality of protrusion portions. Fig. 15 is a rear side view of the vicinity of the second opening 320 of the second liquid member 32 and the flat tube 28 according to the first modification.
Specifically, the first inner edge portion 32b located on the upper side and defining the second opening 320 includes the plurality of protrusion portions 32b1, and the second inner edge portion 32c located on the lower side includes the plurality of protrusion portions 32c1. Here, the first inner edge portion 32b includes two protrusion portions 32b1, and the second inner edge portion 32c includes two protrusion portions 32c1. The two protrusion portions 32b1 on the upper side and the two protrusion portions 32c1 on the lower side face each other. The two protrusion portions 32b1 on the upper side have the same length in the left-right direction. The two protrusion portions 32c1 on the lower side have the same length in the left-right direction.
Further, the second opening 320 includes two first regions 321 and three second regions 322. The first regions 321 and the second regions 322 are alternately arranged in the left-right direction. Here, the second region 322, the first region 321, the second region 322, the first region 321, and the second region 322 are arranged in this order from one side to the other side in the left-right direction.
In the outdoor heat exchanger 11 of the present modification, at least one of the first inner edge portion 32b and the second inner edge portion 32c that defines the second opening 320 includes the plurality of protrusion portions 32b1 and 32c1. As described above, the inner edge portion 32a defining the second opening 320 may include a plurality of protrusion portions 32b1 and 32c1 on at least one side in the longitudinal direction.

(8-2) Second Modification

In the first modification described above, the plurality of protrusion portions have the same length in the left-right direction, but the present disclosure is not limited to this example. In the present modification, as illustrated in Fig. 16, the plurality of protrusion portions have different lengths in the left-right direction. Fig. 16 is a rear side view of the vicinity of the second opening 320 of the second liquid member 32 and the flat tube 28 according to the second modification.
Specifically, the first inner edge portion 32b includes three protrusion portions 32b1, and the second inner edge portion 32c includes three protrusion portions 32c1. The three protrusion portions 32b1 on the upper side and the three protrusion portions 32c1 on the lower side face each other. The two protrusion portions 32b1 in the vicinity of both ends on the upper side have the same length in the left-right direction. However, the length, in the left-right direction, of the two protrusion portions 32b1 in the vicinity of both ends is shorter than the length, in the left-right direction, of one protrusion portion 32b1 in the central portion. The two protrusion portions 32c1 in the vicinity of both ends on the lower side have the same length in the left-right direction. However, the length, in the left-right direction, of the two protrusion portions 32c1 in the vicinity of both ends is shorter than the length, in the left-right direction, of one protrusion portion 32c1 in the central portion.
Further, the second opening 320 includes three first regions 321 and four second regions 322. The first regions 321 and the second regions 322 are alternately arranged in the left-right direction. Here, the length, in the left-right direction, of the first region 321 located at the center is different from the length, in the left-right direction, of the first region 321 not located at the center. Further, the length, in the left-right direction, of the second regions 322 located at both ends in the left-right direction is different from the length, in the left-right direction, of the second region 322 on the side close to the center.
In the outdoor heat exchanger 11 of the present modification, the plurality of protrusion portions 32b1 and 32c1 have different lengths in the left-right direction (third direction). As described above, the inner edge portion 32a defining the second opening 320 may include the protrusion portions 32b1 and 32c1 having different lengths in the longitudinal direction.

(8-3) Third Modification

In the above embodiment, the second opening 320 is symmetrical about the center lines in the up-down direction and the left-right direction, but the present disclosure is not limited to this example. In the present modification, as illustrated in Fig. 17, the second opening 320 is symmetrical about the center line L in the left-right direction, but is not symmetrical about the center line in the up-down direction. Fig. 17 is a rear side view of the vicinity of the second opening 320 of the second liquid member 32 and the flat tube 28 according to the third modification.
Specifically, the position in the left-right direction of the protrusion portion 32b1 of the first inner edge portion 32b located on the upper side and defining the second opening 320 is different from the position in the left-right direction of the protrusion portion 32c1 of the second inner edge portion 33c located on the lower side. In other words, the protrusion portion 32b1 of the first inner edge portion 32b and the second inner edge portion 32c do not face each other.
In the second opening 320, the region formed by at least one of the protrusion portion 32b1 and the protrusion portion 32c1 is the first region 321, and the region formed by a portion other than the protrusion portion 32b1 and the protrusion portion 32c1 is the second region 322.
In the outdoor heat exchanger 11 of the present modification, the second opening 320 is asymmetric about the center line in the up-down direction (first direction). Thus, the second opening 320 asymmetric about the shorter direction may be provided.

(8-4) Fourth Modification

In the above embodiment, the second opening 320 is symmetrical about the center lines in the up-down direction and the left-right direction, but the present disclosure is not limited to this example. In the present modification, as illustrated in Fig. 18, the second opening 320 is symmetrical about the center line in the up-down direction, but is not symmetrical about the center line L in the left-right direction. Fig. 18 is a rear side view of the vicinity of the second opening 320 of the second liquid member 32 and the flat tube 28 according to the fourth modification.
Specifically, the center of the second opening 320 in the left-right direction is different from the center of the first region 321 in the left-right direction. Here, the second regions 322 are located at both end portions in the left-right direction, and the second regions 322 located at both end portions have different lengths in the left-right direction. In the present modification, the first region 321 is located at the center of the second opening 320 in the longitudinal direction.
Further, the center in the left-right direction of the protrusion portion 32b1 of the first inner edge portion 32b defining the second opening 320 is different from the center of the first inner edge portion 32b. Further, the center, in the left-right direction, of the protrusion portion 32c1 of the second inner edge portion 32c defining the second opening 320 is different from the center of the second inner edge portion 32c in the left-right direction.
The outdoor heat exchanger 11 of the present modification is asymmetrical about the center line L in the left-right direction (third direction). Thus, the second opening 320 asymmetric in the longitudinal direction may be provided.
Note that the first region 321 of the second opening 320 is preferably disposed so as to overlap the fourth opening 340 forming the flow path of the refrigerant of the fourth liquid member 34 in the front-rear direction view (in the second direction view). Therefore, the present modification is suitably used when the center of the fourth opening 340 in the left-right direction is shifted toward an end portion.

(8-5) Fifth Modification

In the above embodiment, an example of the shape of the second opening 320 is illustrated in Fig. 10, but the present disclosure is not limited to this example. As illustrated in Fig. 26, in the second opening 320 of the present modification, a ratio (L321/L322) of a length L321 of the first region 321 to a length L322 of the second region 322 in the up-down direction (first direction) is higher than that in the above embodiment. Fig. 26 is a rear side view of the vicinity of the second opening 320 of the second liquid member 32 and the flat tube 28 according to the fifth modification.
In addition, in the left-right direction (third direction), a ratio (L'322/L'321) of a length L'322 of the second region 322 on one side to a length L'321 of the first region 321 is lower than that in the above embodiment. In the left-right direction (third direction), the ratio (L'322/L'321) of the length L'322 of the second region 322 on one side to the length L'321 of the first region 321 is, for example, 1/20 or more and less than 1/2.

(8-6) Sixth Modification

(8-6-1) Configuration

In the above embodiment, the end portions of the second opening 320 on one and the other end in the third direction include no protrusion or recess, but the present disclosure is not limited to this example. In the second opening 320 of the present modification, as illustrated in Fig. 27, an end portion of the inner edge portion 32a on one side in the third direction includes a recessed portion 32d. The recessed portion 32d is a brazing material reservoir for storing a brazing material. Fig. 27 is a rear side view of the vicinity of the second opening 320 of the second liquid member 32 and the flat tube 28 according to the sixth modification.
Specifically, as illustrated in Fig. 27, the inner edge portion 32a includes a first recessed portion 32d1, a second recessed portion 32d2, a third recessed portion 32d3, and a fourth recessed portion 32d4 as the recessed portion 32d.
The first recessed portion 32d1 is located at the right side end portion of the inner edge portion 32a in the left-right direction and at the upper side end portion of the inner edge portion 32a in the up-down direction. The first recessed portion 32d1 is recessed toward the upper side.
The second recessed portion 32d2 is located at the right side end portion of the inner edge portion 32a in the left-right direction, and at the lower side end portion of the inner edge portion 32a in the up-down direction. The second recessed portion 32d2 is recessed toward the lower side.
The third recessed portion 32d3 is located at the left side end portion of the inner edge portion 32a in the left-right direction, and at the upper side end portion of the inner edge portion 32a in the up-down direction. The third recessed portion 32d3 is recessed toward the upper side.
The fourth recessed portion 32d4 is located at the left side end portion of the inner edge portion 32a in the left-right direction, and at the lower side end portion of the inner edge portion 32a in the up-down direction. The fourth recessed portion 32d4 is recessed toward the lower side.
Further, the second opening 320 may not have a point-symmetric shape, but preferably has a point-symmetric shape.
The inner edge portion 32a defining the first region 321 may include the recessed portion 32d, but the inner edge portion 32a defining the second region 322 preferably includes the recessed portion 32d.

(8-6-2) Features

In the outdoor heat exchanger 11 as the heat exchanger of the present modification, an end portion of the inner edge portion 32a on one side in the third direction includes the first recessed portion 32d1.
When brazing is performed with the first recessed portion 32d1 being on the lower side in the direction of gravity, the molten brazing material can move to the protruding portion of the second opening 320 defined by the first recessed portion 32d1. Thus, brazing clogging can be suppressed.
In the outdoor heat exchanger 11 as the heat exchanger of the present modification, the inner edge portion 32a further includes the second recessed portion 32d2, the third recessed portion 32d3, and the fourth recessed portion 32d4. The first recessed portion 32d1 is located at one end portion of the inner edge portion 32a in the left-right direction (third direction) and at an end portion of the inner edge portion 32a in the up-down direction (first direction). The second recessed portion 32d2 is located at one end portion of the inner edge portion 32a in the left-right direction and at the other end portion of the inner edge portion 32a in the up-down direction. The third recessed portion 32d3 is located at the other end portion of the inner edge portion 32a in the left-right direction and at one end portion of the inner edge portion 32a in the up-down direction. The fourth recessed portion 32d4 is located at the other end portion of the inner edge portion 32a in the left-right direction and at the other end portion of the inner edge portion 32a in the up-down direction.
Here, when brazing is performed with the first recessed portion 32d1 and the second recessed portion 32d2, or the third recessed portion 32d3 and the fourth recessed portion 32d4 being on the lower side in the gravity direction, the molten brazing material can move to the two protruding portions of the second opening 320 defined by the recessed portion 32d on the lower side in the gravity direction, thus brazing clogging can be more effectively suppressed.
In Fig. 27, four recessed portions are illustrated as an example of the recessed portion 32d, but the number of recessed portions 32d may be one to three. In addition, a shape in which the recessed portion 32d is located at end portions on one side and the other side in the left-right direction is described as an example, but the recessed portion 32d may be located at a central portion in the left-right direction.
In addition, the recessed portion 32d has a shape recessed in the up-down direction (first direction) is described as an example, but may have a shape recessed in the left-right direction (third direction). However, since the flat tube 28 is inserted in the second opening 320, the length between the left-right direction end of the second liquid member 32 and the left-right direction end of the second opening 320 is short. Therefore, the first recessed portion 31d1, the second recessed portion 32d2, the third recessed portion 32d3, and the fourth recessed portion 32d4 preferably have a shape that is recessed in the up-down direction (the first direction).

(8-7) Seventh Modification

In the above embodiment, the third opening 330 has one first region 331, but the present disclosure is not limited to this example. In the present modification, as illustrated in Fig. 19, the third opening 330 includes a plurality of the first regions 331. Fig. 19 is a rear side view of the vicinity of the third opening 330 of the third liquid member 33 and the flat tube 28 according to the seventh modification.
Specifically, in Fig. 19, the third opening 330 includes two first regions 331 and three second regions 332. The first regions 331 and the second regions 332 are alternately arranged in the left-right direction (an example of third direction). Here, the second region 332, the first region 331, the second region 332, the first region 331, and the second region 332 are arranged in this order from one side to the other side in the left-right direction.
In the present modification, the first regions 331 have the same length in the left-right direction, and the second regions 332 have the same length in the left-right direction. The plurality of first regions 331 may have the same shape or different shapes. In addition, the plurality of second regions 332 may have the same shape or different shapes.
In the present modification, the second region 332 is located at the center of the third opening 330 in the longitudinal direction.
In addition, the first inner edge portion 33b located on the upper side and defining the third opening 330 includes the plurality of protruding portions 33b1, and the second inner edge portion 33c located on the lower side includes the plurality of protruding portions 33c1. Here, the first inner edge portion 33b includes two protruding portions 33b1 and the second inner edge portion 33c includes two protruding portions 33c1. The two protruding portions 33b1 on the upper side and the two protruding portions 33c1 on the lower side face each other.
In the outdoor heat exchanger 11 of the present modification, the plurality of first regions 331 are formed in the left-right direction (third direction) of the third opening 330. Thus, the plurality of first regions 331 may be provided in the longitudinal direction.

(8-8) Eighth Modification

In the above embodiment, the third opening 330 is symmetrical about the center line in the up-down direction and the left-right direction, but the present disclosure is not limited to this example. In the present modification, as illustrated in Fig. 20, the third opening 330 is symmetrical about the center line L in the left-right direction, but is not symmetrical about the center line in the up-down direction. Fig. 20 is a rear side view of the vicinity of the third opening 330 of the third liquid member 33 and the flat tube 28 according to the eighth modification.
Specifically, the protrusion length of the protruding portion 33b1 of the first inner edge portion 33b located on the upper side and defining the third opening 330 is shorter than the protrusion length of the protruding portion 33c1 of the second inner edge portion 33c located on the lower side.
As in the present modification, the third opening 330 may not be symmetrical about the up-down direction (first direction).

(8-9) Ninth Modification

In the above embodiment, the first inner edge portion 33b includes one protruding portion 33b1, and the second inner edge portion 33c includes one protruding portion 33c1, but the present disclosure is not limited to this example. As illustrated in Fig. 21, one inner edge portion may include no protruding portion. Fig. 21 is a rear side view of the vicinity of the third opening 330 of the third liquid member 33 and the flat tube 28 according to the ninth modification.
Specifically, the first inner edge portion 33b located on the upper side and defining the third opening 330 includes the protruding portion 33b1. On the other hand, the second inner edge portion 33c located on the lower side extends linearly in the left-right direction, and includes no protruding portion.
The third opening 330 illustrated in Fig. 21 is symmetrical about the center line L in the left-right direction, but is not symmetrical about the center line in the up-down direction, as in the eighth modification described above.
In the outdoor heat exchanger 11 of the present modification, the inner edge portion 33a of the third liquid member 33 includes the first inner edge portion 33b on the upper side (one side) in the up-down direction (first direction) and the second inner edge portion 33c on the lower side (other side). The first inner edge portion 33b includes the protruding portion 33b1 protruding toward the lower side, or the second inner edge portion 33c includes the protruding portion 33c1 protruding toward the upper side. Thus, the inner edge portion 33a defining the third opening 330 may include a protruding portion on one side in the longitudinal direction.

(8-10) Tenth Modification

In the above embodiment, the third opening 330 is symmetrical about the median lines in the up-down direction and the left-right direction, but the present disclosure is not limited to this example. In the present modification, as illustrated in Fig. 22, the third opening 330 is symmetrical about the center line in the up-down direction, but is not symmetrical about the center line L in the left-right direction. Fig. 22 is a rear side view of the vicinity of the third opening 330 of the third liquid member 33 and the flat tube 28 according to the tenth modification.
Specifically, the center of the third opening 330 in the left-right direction is different from the center of the first region 331 in the left-right direction. In Fig. 22, the center of the first region 331 in the left-right direction is located closer to the end portion on one side than the center of the third opening in the left-right direction.
Here, the second regions 332 are located at both end portions in the left-right direction, and the second regions 332 located at both end portions have different lengths in the left-right direction. In the present modification, the first region 331 is located at the center of the third opening 330 in the longitudinal direction.
The center, in the left-right direction, of the protruding portion 33b1 of the first inner edge portion 33b defining the third opening 330 is different from the center of the first inner edge portion 33b in the left-right direction. The center, in the left-right direction, of the protruding portion 33c1 of the second inner edge portion 33c defining the third opening 330 is different from the center of the second inner edge portion 33c in the left-right direction.
In the outdoor heat exchanger 11 of the present modification, the center of the third opening 330 in the left-right direction (third direction) is different from the center of the first region 331 in the third direction. Thus, the first region 331 may be provided at a position shifted from the center of the third opening 330 in the left-right direction.

(8-11) Eleventh Modification

In the above embodiment, the second regions 332 are located at both end portions in the left-right direction, but the present disclosure is not limited to this example. In the present modification, as illustrated in Fig. 23, the second region 332 is located only at an end portion of the third opening 330 on one side. Fig. 23 is a rear side view of the vicinity of the third opening 330 of the third liquid member 33 and the flat tube 28 according to the eleventh modification.
Specifically, the first region 331 is located at an end portion of the third opening 330 on one side in the left-right direction. The length of the first region 331 in the left-right direction is longer than the length of the second region 332 in the left-right direction. In the present modification, the first region 331 is located at the center of the third opening 330 in the longitudinal direction.
The third opening 330 of the present modification is symmetrical about the center line in the up-down direction, but is not symmetrical about the center line L in the left-right direction, as in the tenth modification. The center of the third opening 330 in the left-right direction is different from the center of the first region 331 in the third direction.
In the outdoor heat exchanger 11 of the present modification, the first region 331 is located at an end portion of the third opening 330 on one side in the left-right direction (third direction). Thus, the first region 331 may be provided at an end portion on one side in the longitudinal direction.

(8-12) Twelfth Modification

(8-12-1) Configuration

In the above embodiment, the end portions of the third opening 330 on one side and the other side in the third direction include no recess or protrusion, but the present disclosure is not limited to this example. In the third opening 330 of the present modification, as illustrated in Fig. 28, an end portion of the inner edge portion 33a on one side in the third direction includes a recessed portion 33d. The recessed portion 33d is a brazing material reservoir for storing a brazing material. Fig. 28 is a rear side view of the vicinity of the third opening 330 of the third liquid member 33 and the flat tube 28 according to the twelfth modification.
More specifically, as illustrated in Fig. 28, the inner edge portion 33a includes a first recessed portion 33d1, a second recessed portion 33d2, a third recessed portion 33d3, and a fourth recessed portion 33d4 as the recessed portion 33d.
The first recessed portion 33d1 is located at an end portion of the inner edge portion 33a on the right side in the left-right direction and at an end portion of the inner edge portion 33a on the upper side in the up-down direction. The first recessed portion 33d1 is recessed toward the right side.
The second recessed portion 33d2 is located at an end portion of the inner edge portion 33a on the right side in the left-right direction, and at an end portion of the inner edge portion 33a on the lower side in the up-down direction. The second recessed portion 33d2 is recessed toward the right side.
The third recessed portion 33d3 is located at an end portion of the inner edge portion 33a on the left side in the left-right direction, and at an end portion of the inner edge portion 33a on the upper side in the up-down direction. The third recessed portion 33d3 is recessed toward the left side.
The fourth recessed portion 33d4 is located at an end portion of the inner edge portion 33a on the left side in the left-right direction and at an end portion of the inner edge portion 33a on the lower side in the up-down direction. The fourth recessed portion 33d4 is recessed toward the left side.
Further, the third opening 330 may not have a point-symmetric shape, but preferably has a point-symmetric shape.
The inner edge portion 33a defining the first region 331 may include the recessed portion 33d, but the inner edge portion 33a defining the second region 332 preferably includes the recessed portion 33d.
The recessed portion 33d may be located in the central portion in the left-right direction, but is preferably located in at least one of end portions on one side and the other ends in the left-right direction. In the latter case, the third liquid member 33 has a function of bringing the flat tube 28 into contact with the inner edge portion 33a. When the flat tube 28 is brought into contact in the up-down direction (the length of the third opening 330 is shorter than the length of the flat tube 28 in the up-down direction), blocking of the protruding portion of the third opening 330 defined by the recessed portion 33d by the flat tube 28 can be suppressed.

(8-12-2) Features

In the outdoor heat exchanger 11 as the heat exchanger of the present modification, an end portion of the inner edge portion 33a (third inner edge portion) on one side in the left-right direction (third direction) includes the first recessed portion 33d1 (fifth recessed portion).
Here, when brazing is performed with the first recessed portion 33d1 of the third liquid member 33 (fourth member) being on the lower side in the gravity direction, the molten brazing material can move to the protruding portion of the third opening 330 (fourth opening) defined by the recessed portion 33d, so that brazing clogging can be suppressed.
In the outdoor heat exchanger 11 as the heat exchanger of the present modification, the inner edge portion 33a (third inner edge portion) further includes the second recessed portion 33d2 (sixth recessed portion), the third recessed portion 33d3 (seventh recessed portion), and the fourth recessed portion 33d4 (eighth recessed portion). The first recessed portion 33d1 is located at an end portion of the inner edge portion 33a on one side in the left-right direction (third direction) and at an end portion of the inner edge portion 33a on one side in the up-down direction (first direction). The second recessed portion 33d2 is located at one end portion of the inner edge portion 33a in the left-right direction and at the other end portion of the inner edge portion 33a in the up-down direction. The third recessed portion 33d3 is located at the other end portion of the inner edge portion 33a in the left-right direction and at one end portion of the inner edge portion 33a in the up-down direction. The fourth recessed portion 33d4 is located at the other end portion of the inner edge portion 33a in the left-right direction and at the other end portion of the inner edge portion 33a in the up-down direction.
Here, when brazing is performed with the first recessed portion 33d1 and the second recessed portion 33d2, or the third recessed portion 33d3 and the fourth recessed portion 33d4 being on the lower side in the gravity direction, the molten brazing material can move to the two protruding portions of the third opening 330 defined by the recessed portion 33d on the lower side in the gravity direction, thus brazing clogging can be more effectively suppressed.

(8-13) Thirteenth Modification

In the twelfth modification described above, the third opening 330 includes four recessed portions 33d, but the present disclosure is not limited to this example. In the present modification, as illustrated in Fig. 29, the first recessed portion 33d1 and the second recessed portion 33d2 are provided. Fig. 29 is a rear side view of the vicinity of the third opening 330 of the third liquid member 33 and the flat tube 28 according to the thirteenth modification.
According to the present modification, when brazing is performed with the first recessed portion 33d1 and the second recessed portion 33d2 being on the lower side in the gravity direction, the molten brazing material can move to two protruding portions of the third opening 330 defined by the first recessed portion 33d1 and the second recessed portion 33d2, whereby brazing clogging can be more effectively suppressed.

(8-14) Fourteenth Modification

In the twelfth modification described above, the third opening 330 includes four recessed portions 33d, but the present disclosure is not limited to this example. In the present modification, as illustrated in Fig. 30, the first recessed portion 33d1 and the fourth recessed portion 33d4 are provided. Fig. 30 is a rear side view of the vicinity of the third opening 330 of the third liquid member 33 and the flat tube 28 according to the fourteenth modification.
According to the present modification, when brazing is performed with the first recessed portion 33d1 or the fourth recessed portion 33d4 being on the lower side in the gravity direction, the molten brazing material can move to protruding portions of the third opening 330 defined by the first recessed portion 33d1 or the fourth recessed portion 33d4, whereby brazing clogging can be more effectively suppressed.

(8-15) Fifteenth modification

In the twelfth modification described above, the recessed portion 33d is recessed toward one side or the other side in the left-right direction (the third direction), but the present disclosure is not limited to this example. The present modification features, as illustrated in Fig. 31, a recess toward one side or the other side in the up-down direction (first direction). Fig. 31 is a rear side view of the vicinity of the third opening 330 of the third liquid member 33 and the flat tube 28 according to the fifteenth modification.
Here, the first recessed portion 33d1 and the third recessed portion 33d3 are recessed toward the upper side. The second recessed portion 33d2 and the fourth recessed portion 33d4 are recessed toward the lower side.

(8-16) Sixteenth Modification

In the fifteenth modification described above, the third opening 330 has four recessed portions 33d, but the present disclosure is not limited to this example. In the present modification, as illustrated in Fig. 32, the first recessed portion 33d1 and the second recessed portion 33d2 are provided. Fig. 32 is a rear side view of the vicinity of the third opening 330 of the third liquid member 33 and the flat tube 28 according to the sixteenth modification.

(8-17) Seventeenth Modification

In the above twelfth and fifteenth modifications, each recessed portion 33d is recessed in one direction, but the present disclosure is not limited to this example. In the present modification, as illustrated in Fig. 33, the first recessed portion 33d1 and the second recessed portion 33d2 are recessed toward the right side. The third recessed portion 33d3 is recessed toward the upper side. The fourth recessed portion 33d4 is recessed toward the lower side. Fig. 33 is a rear side view of the vicinity of the third opening 330 of the third liquid member 33 and the flat tube 28 according to the seventeenth modification.

(8-18) Eighteenth Modification

In the fifteenth modification described above, the left-right direction width of the recessed portion 33d is small, but the present disclosure is not limited to this example. In the present modification, as illustrated in Fig. 34, the recessed portion 33d has a larger width in the left-right direction. Fig. 34 is a rear side view of the vicinity of the third opening 330 of the third liquid member 33 and the flat tube 28 according to the eighteenth modification.

(8-19) Nineteenth Modification

In the twelfth and the fifteenth modifications described above, the recessed portion 33d is recessed in one direction, but the present disclosure is not limited to this example. In the present modification, as illustrated in Fig. 35, each recessed portion 33d is recessed in the up-down direction and the left-right direction. Fig. 35 is a rear side view of the vicinity of the third opening 330 of the third liquid member 33 and the flat tube 28 according to the nineteenth modification.
Specifically, the first recessed portion 33d1 is recessed toward the upper side and toward the right side. The second recessed portion 33d2 is recessed toward the lower side and toward the right side. The third recessed portion 33d3 is recessed toward the upper side and the left side. The fourth recessed portion 33d4 is recessed toward the lower side and the left side.

(8-20) Twentieth Modification

In the above embodiment, the first to the seventh liquid members 31 to 37 forming the liquid header portion 30 have a plate shape. However, the present disclosure is not limited to this example, and any shape can be adopted.

(8-21) Twenty-First Modification

In the above embodiment, the liquid header portion 30 has a loop structure in which the refrigerant circulates, but the present disclosure is not limited to this example. The heat exchanger of the present disclosure may include a header without a loop structure.

(8-22) Twenty-Second Modification

In the above embodiment, the heat exchanging part 27 of the outdoor heat exchanger 11 is formed in a C shape in plan view, but the present disclosure is not limited to this example. The heat exchanging part 27 of the present modification is formed in an L shape.

(8-23) Twenty-Third Modification

In the above embodiment, the opening 530 of the third gas member 53 of the gas header portion 50 and the third opening 330 of the third liquid member 33 of the liquid header portion 30 have different shapes, but the present disclosure is not limited to this example. The third gas member 53 may have the same shape as the third liquid member 33 so that these members can be commonly used.

(8-24) Twenty-Fourth Modification

The above embodiment is applied to the outdoor heat exchanger 11 including the liquid header portion 30, but the present disclosure is not limited to this example. The heat exchanger of the present disclosure may be applied to the outdoor heat exchanger 11 including the gas header portion 50, may be applied to the outdoor heat exchanger 11 including the return header 60, or may be applied to the indoor heat exchanger 91.

(8-25) Twenty-Fifth Modification

In the above embodiment, the heat exchanger is applied to the air conditioning apparatus 1, but the present disclosure is not limited to this example. The heat exchanger may be applied to a refrigeration apparatus such as a hot water supply apparatus, a floor heating apparatus, or a refrigerator.
Note that a combination of the features of the above-described embodiment and modifications are originally intended.

EXAMPLES

In the present Example, the problem attributable to the uniform width of the opening of the member for inserting the flat tube was examined.
Fig. 24 is a rear side view of the vicinity of a second opening 320-1 of a second liquid member 32-1 of Comparative Example and the flat tube 28. As illustrated in Fig. 24, the second liquid member 32-1 of Comparative Example includes the second opening 320-1 with a uniform width. The stress applied to a heat exchanger including the second liquid member 32-1 of Comparative Example during operation was examined. The results are illustrated in Fig. 25. Fig. 25 is a diagram illustrating, using shading, a stress distribution in a state where an internal pressure is applied in the first liquid member 31, the second liquid member 32-1, and a third liquid member 33-1 of Comparative Example. In Fig. 25, a region in which the stress applied to the heat exchanger is relatively large is illustrated darkly. In Fig. 25, the boundary lines of the first liquid member 31, the second liquid member 32-1, and the third liquid member 33-1 before deformation due to the internal pressure are indicated by a one dot chain line. In Fig. 25, the pressure applied to the second opening 320-1 and the flat tube 28 is indicated by arrows.
In the heat exchanger of Comparative Example, when the internal pressure is applied, the first liquid member 31 is deformed toward the rear side. As a result, the maximum stress is applied to a portion A in Fig. 25 in the flat tube 28. Then, the flat tube 28 may be pulled and broken. Due to the second opening 320-1 having a uniform width, this problem was significant particularly in the central portion of the second opening 320-1.
In view of this, the present inventors came up with an idea of reducing the width of a part of the second opening 320 of the second liquid member 32 as in the above embodiment. A smaller width of a part of the second opening 320 leads to a smaller pressure receiving area of the first liquid member 31, and thus is expected to lead to suppression of the deformation of the first liquid member 31 due to the internal pressure. Therefore, the stress applied during the operation was examined with the opening area of the second opening 320 made equal to the opening area of the second opening 320-1 of Comparative Example, and with the shape obtained including the first region 321 shorter than a width L320-1 of the second opening 320-1 of Comparative Example and the second region 322 longer than the width of the second opening 320-1 Comparative Example. As a result, it was found that by arranging the first region 321 at a portion imposing a large impact on the pressure resistance strength and placing the second region 322 at a portion imposing a limited impact on the pressure resistance strength, a small width can be achieved compared with Comparative Example in which the second opening 320-1 has a uniform width.
As described above, a problem has been found in that the flat tube is pulled and damaged due to the deformation of the member for integration, attributable to the uniform width of the opening of the member for inserting the flat tube. To solve problem, the opening of the member for inserting the flat tube was provided with the first region shorter than the predetermined length and the second region longer than the predetermined length in the direction in which the flat tubes are arranged. By positioning the first region at a portion imposing a large impact on pressure resistance strength, when internal pressure is applied, the deformation of the member for integration is suppressed, thereby suppressing the damaging of the flat tube pulled. It was found that the pressure resistance of the header can be improved accordingly.
While embodiments and examples of the present disclosure have been described above, it should be understood that various changes in mode and detail may be made without departing from the spirit and scope of the present disclosure as set forth in the claims.

REFERENCE SIGNS LIST

1: air conditioning apparatus (refrigeration apparatus)
11: outdoor heat exchanger (heat exchanger)
28: flat tube
29: fin
30: liquid header portion (header)
31: first liquid member (second member)
32: second liquid member (first member)
32a: inner edge portion
32b: first inner edge portion
32b1: protrusion portion
32c: second inner edge portion
32c1: protrusion portion
32d1: first recessed portion
32d2: second recessed portion
32d3: third recessed portion
32d4: fourth recessed portion
33: third liquid member (fourth member)
33d1: first recessed portion (fifth recessed portion)
33d2: second recessed portion (sixth recessed portion)
33d3: third recessed portion (seventh recessed portion)
33d4: fourth recessed portion (eighth recessed portion)
34: fourth liquid member (third member)
310: first opening (second opening)
320: second opening (first opening)
321: first region
322: second region
330: third opening (fourth opening)
331: first region (third region)
332: second region (fourth region)
340: fourth opening (third opening)

CITATION LIST

PATENT LITERATURE

PTL 1: Japanese Patent No. 6822525

Claims

A heat exchanger (11) comprising:
a plurality of flat tubes (28) arranged in a first direction;

a fin (29) joined to the flat tube; and

a header (30) to which the flat tube is connected, wherein

the header includes
a first member (32) including a first opening (320) into which the flat tube is inserted, and

a second member (31) that is stacked on the fin side of the first member in a second direction in which the flat tube extends, and includes a second opening (310) formed along an outer edge of the flat tube,

the first opening includes
a first region (321) having a length in the first direction that is shorter than a predetermined length, and

a second region (322) that is longer than the predetermined length.
The heat exchanger according to claim 1, wherein the first region is located at a central portion in a third direction intersecting the first direction and the second direction.
The heat exchanger according to claim 1 or 2, wherein a longitudinal direction of the first opening is a third direction intersecting the first direction and the second direction,
the first member has an inner edge portion (32a) forming the first opening,

the inner edge portion includes a first inner edge portion (32b) on one side in the first direction and a second inner edge portion (32c) on the other side in the first direction.
The heat exchanger according to claim 3, wherein the first inner edge portion has a protrusion portion (32b1) protruding toward the other side in the first direction, or
the second inner edge portion has a protrusion portion (32c1) protruding toward the one side in the first direction.
The heat exchanger according to claim 4, wherein at least one of the first inner edge portion and the second inner edge portion has a plurality of the protrusion portions.
The heat exchanger according to claim 5, wherein the plurality of protrusion portions have different lengths in the third direction.
The heat exchanger according to any one of claims 3 to 6, wherein one end portion of the inner edge portion in the third direction includes a first recessed portion (32d1).
The heat exchanger according to claim 7, wherein the inner edge portion further includes a second recessed portion (32b2), a third recessed portion (32d3), and a fourth recessed portion (32d4),
the first recessed portion is located at one end portion of the inner edge portion in the third direction and at one end portion of the inner edge portion in the first direction,

the second recessed portion is located at one end portion of the inner edge portion in the third direction and at the other end portion of the inner edge portion in the first direction,

the third recessed portion is located at the other end portion of the inner edge portion in the third direction and at one end portion of the inner edge portion in the first direction, and

the fourth recessed portion is located at the other end portion of the inner edge portion in the third direction and at the other end portion of the inner edge portion in the first direction.
The heat exchanger according to any one of claims 1 to 8, wherein the first opening is symmetrical about a median line in a third direction intersecting the first direction and the second direction.
The heat exchanger according to any one of claims 1 to 8, wherein the first opening is asymmetric about a median line in the first direction.
The heat exchanger according to any one of claims 1 to 10, further comprising a third member (34) that is stacked on the opposite side of the first member from the fin in the second direction, and has a third opening (340) forming a flow path for a refrigerant, and
the first region and the third opening overlap in the second direction view.
The heat exchanger according to any one of claims 1 to 11, wherein the second region is located at both ends in a third direction intersecting the first direction and the second direction.
The heat exchanger according to any one of claims 1 to 12, wherein a ratio of a length (L321) of the first region in the first direction to a length (L322) of the second region in the first direction is 1/4 or more and less than 1.
The heat exchanger according to any one of claims 1 to 13, wherein a ratio of a length (L31) of the second member in the second direction to a length (L32) of the first member in the second direction is 1/2 or more and 3/2 or less.
The heat exchanger according to any one of claims 1 to 14, further comprising a fourth member (33) that is stacked on the opposite side of the first member from the fin in the second direction, and has a fourth opening (330), wherein
in the second direction view, a third inner edge portion (33a) defining the fourth opening of the fourth member overlaps the flat tube, and

the fourth opening includes

a third region (331) having a length in the first direction that is shorter than a predetermined length, and

a fourth region (332) that is longer than the predetermined length.
The heat exchanger according to claim 15, wherein one end portion of the third inner edge portion in the third direction includes a fifth recessed portion (33d1).
The heat exchanger according to claim 16, wherein the third inner edge portion further includes a sixth recessed portion (33d2), a seventh recessed portion (33d3), and an eighth recessed portion (33d4),
the fifth recessed portion is located at one end portion of the third inner edge portion in the third direction and at one end portion of the third inner edge portion in the first direction,

the sixth recessed portion is located at one end portion of the third inner edge portion in the third direction and at the other end portion of the third inner edge portion in the first direction,

the seventh recessed portion is located at the other end portion of the third inner edge portion in the third direction and at one end portion of the third inner edge portion in the first direction, and

the eighth recessed portion is located at the other end portion of the third inner edge portion in the third direction and at the other end portion of the third inner edge portion in the first direction.
The heat exchanger according to any one of claims 1 to 17, wherein the refrigerant includes carbon dioxide.
A refrigeration apparatus (1) comprising the heat exchanger according to any one of claims 1 to 18.