JP2019132531A - Heat exchanger - Google Patents

Abstract

To solve the problem in which throttling and closing an end part of a pipe is difficult in the case where an aluminum pipe different from a conventional copper pipe is used in a header part of a heat exchanger.SOLUTION: A header part 100 of heat exchanger includes: a pipe 101 made of aluminum or aluminum alloy which has an opening 121 at an end; and a welded part 201 for closing the opening 121. The pipe 101 includes: a body 111 in which the diameter of the cross section is constant; a first annular part 112 which is closer to the opening 121 than the body 111, which is annular and which protrudes to the outside; and a second annular part 113 which is closer to the opening 121 than the first annular part 112, which is annular and which protrudes to the inside.SELECTED DRAWING: Figure 8

Description

  A heat exchanger using an aluminum tube as a header, and an air conditioner including the heat exchanger.

  In order to seal the end of the pipe of the header part of the heat exchanger, a method of attaching an end cap by brazing is common. For this brazing, various devices have been made as disclosed in Patent Document 1, for example.

The method using the end cap increases the number of parts. On the other hand, if the diameter of the tube is reduced by drawing, and the tube can be sealed without using an end cap, the number of components can be reduced and the configuration can be simplified. On the other hand, particularly when an aluminum tube is used, drawing is not common. This is because an aluminum tube is not easy to be drawn.

  The heat exchanger according to the first aspect is used for an air conditioner. The heat exchanger includes a header portion that forms a refrigerant collecting space therein. The header portion has a tube having an opening at the end and a welded portion that closes the opening. The tube is made of aluminum or an aluminum alloy. The tube has a main body having a constant cross-sectional diameter, a first annular portion that is closer to the opening than the main body, and a second annular portion that is closer to the opening than the first annular portion. The first annular portion is annular and protrudes outward. The second annular portion is annular and protrudes inward.

  By adopting the configuration according to the first aspect, sealing of the end portion of the circular tube of the header portion of the heat exchanger can be easily realized by drawing processing, and a configuration without using an end cap is possible.

  The heat exchanger according to the second aspect is the heat exchanger according to the first aspect, and further, a corrosion-resistant layer is formed on the surface of the tube. The diameter of the tube opening is smaller than the sacrificial corrosion protection distance.

  In the heat exchanger according to the second aspect, by making the diameter of the opening smaller than the sacrificial corrosion prevention distance, even if the welded portion in the opening does not have the corrosion resistant layer, the corrosion resistant layer on the surface of the pipe is corroded. Can be prevented.

  The heat exchanger according to the third aspect is the heat exchanger according to the second aspect, wherein the welded portion is formed so as to cover the corrosion-resistant layer. With such a configuration, the anticorrosion effect of the header portion becomes more reliable.

The heat exchanger of the 4th viewpoint is a heat exchanger in any one of the 1st viewpoint-the 3rd viewpoint, and a welding part has an approach part which has entered the inside of a pipe from the opening of a pipe.
When the heat exchanger of the 5th viewpoint is a heat exchanger of the 4th viewpoint when it sees in the cross section which passes along the center of a pipe, it has the shape where two hypotenuses where the entrance part is a triangle bent to the inside of the triangle.

  In the heat exchanger according to the fifth aspect, since the entry portion has a triangular shape, when the pressure in the refrigerant collecting space inside the pipe becomes high, the entry portion is pressed against the pipe wall and is difficult to come off. Therefore, the closed state of the header part is easily maintained.

  The heat exchanger of the sixth aspect is a heat exchanger of the fourth aspect, and has a shape in which the two oblique sides of the trapezoidal approach portion are bent inwardly of the trapezoid when viewed in a cross section passing through the center of the tube. The base farther from the trapezoidal opening is longer than the base closer to the trapezoidal opening.

  In the heat exchanger of the sixth aspect, the entrance portion has a trapezoidal shape, and the bottom side farther from the trapezoidal opening is longer than the bottom side closer to the trapezoidal opening. When the pressure increases, the entry portion is pressed against the tube wall and is difficult to come off. Therefore, the closed state of the header part is easily maintained.

  An air conditioner according to a seventh aspect includes the heat exchanger according to any one of the first aspect to the sixth aspect.

It is a schematic block diagram of the air conditioning apparatus of 1st Embodiment. It is an external appearance perspective view of the outdoor unit of 1st Embodiment. 1 is a schematic perspective view of a heat exchanger according to Embodiment 1. FIG. It is an enlarged view of the linear part of the rear part of the heat exchanger of FIG. It is a figure of the gas side header part vicinity of the heat exchanger of FIG. It is a figure of the liquid side header part vicinity of the heat exchanger of FIG. It is an enlarged view of the edge of the header part of the heat exchanger of a 1st embodiment. It is sectional drawing which passes along the centerline of the header part of FIG. It is an enlarged view of the approach part of the welding part of the header part of 1st Embodiment. It is an enlarged view of another approach part of the welding part of the header part of 1st Embodiment. It is a figure which shows each process in manufacture of the conventional header part. (A) A state in which a tube is prepared, (b) a state in the middle of spatula drawing, (c) a state in which spatula drawing is finished, and (d) a state in which brazing is finished. It is a figure which shows each process in manufacture of the header part of Embodiment 1. (A) A state in which a pipe is prepared, (b) a state in the middle of spatula drawing, (c) a state in which spatula drawing is finished, and (d) a state in which welding is finished. It is a flowchart which shows the manufacturing method of the header part of 1st Embodiment. In manufacture of the header part of Embodiment 1, it is a figure explaining cutting | disconnection of the front-end | tip part of a pipe | tube.

<First Embodiment>
(1) Configuration of Air Conditioner The air conditioner 1 using the outdoor heat exchanger 11 as a heat exchanger will be described with reference to the drawings. The schematic block diagram of the air conditioning apparatus 1 is shown in FIG.

  The air conditioner 1 is an air conditioner capable of cooling and heating a room such as a building by performing a vapor compression refrigeration cycle. The air conditioner 1 mainly includes an outdoor unit 2, indoor units 3a and 3b, a liquid refrigerant communication tube 4 and a gas refrigerant communication tube 5 that connect the outdoor unit 2 and the indoor units 3a and 3b, an outdoor unit 2 and And a control unit 23 that controls the constituent devices of the indoor units 3a and 3b. The vapor compression refrigerant circuit 6 of the air conditioner 1 is configured by connecting the outdoor unit 2 and the indoor units 3 a and 3 b via the refrigerant communication tubes 4 and 5.

  The outdoor unit 2 is installed outdoors (on the roof of a building, in the vicinity of the wall surface of the building, etc.) and constitutes a part of the refrigerant circuit 6. 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 as an expansion mechanism, a liquid side closing valve 13, and a gas side closing. A valve 14 and an outdoor fan 15 are provided. Each device and the valve are connected by refrigerant pipes 16 to 22.

  The indoor units 3 a and 3 b are installed indoors (such as a living room or a ceiling space) and constitute a part of the refrigerant circuit 6. The indoor unit 3a mainly has an indoor expansion valve 31a, an indoor heat exchanger 32a, and an indoor fan 33a. The indoor unit 3b mainly includes an indoor expansion valve 31b as an expansion mechanism, an indoor heat exchanger 32b, and an indoor fan 33b.

  The refrigerant communication pipes 4 and 5 are refrigerant pipes that are constructed on site when the air conditioner 1 is installed at an installation location such as a building. One end of the liquid refrigerant communication tube 4 is connected to the liquid side closing valve 13 of the outdoor unit 2, and the other end of the liquid refrigerant communication tube 4 is connected to the liquid side ends of the indoor expansion valves 31a and 31b of the indoor units 3a and 3b. Has been. One end of the gas refrigerant communication pipe 5 is connected to the gas side shut-off valve 14 of the outdoor unit 2, and the other end of the gas refrigerant communication pipe 5 is connected to the gas side end of the indoor heat exchangers 32a and 32b of the indoor units 3a and 3b. It is connected.

  The control unit 23 is configured by communication connection of control boards and the like (not shown) provided in the outdoor unit 2 and the indoor units 3a and 3b. In FIG. 1, for the sake of convenience, the outdoor unit 2 and the indoor units 3a and 3b are illustrated at positions away from each other. The control unit 23 controls the components 8, 10, 12, 15, 31a, 31b, 33a, 33b of the air conditioner 1 (here, the outdoor unit 2 and the indoor units 3a, 3b), that is, the air conditioner 1 The whole operation control is performed.

(2) Operation of the air conditioner The air conditioner 1 has three types of operation modes: a cooling operation, a heating operation, and a defrosting operation. Selection of the operation mode and control of each operation mode are performed by the control unit 23. During the cooling operation, the refrigerant is circulated in the order of the compressor 8, the outdoor heat exchanger 11, the outdoor expansion valve 12, the indoor expansion valves 31a and 31b, and the indoor heat exchangers 32a and 32b. During the heating operation, the refrigerant is circulated in the order of the compressor 8, the indoor heat exchangers 32a and 32b, the indoor expansion valves 31a and 31b, the outdoor expansion valve 12, and the outdoor heat exchanger 11. During the heating operation, a defrosting operation for melting frost adhering to the outdoor heat exchanger 11 is performed. The refrigerant flow during the defrosting operation is the same as that during the cooling operation.

(3) Configuration of Outdoor Unit FIG. 2 is an external perspective view of the outdoor unit 2.

  The outdoor unit 2 mainly includes a substantially rectangular parallelepiped box-shaped casing 40, an outdoor fan 15 as a blower, an accumulator 7, a compressor 8, an outdoor heat exchanger 11, a four-way switching valve 10, and an outdoor expansion valve 12. And refrigerant pipes 16 to 22 are included. In the following description, “top”, “bottom”, “left”, “right”, “front”, “back”, “front”, and “back” are shown in FIG. 2 unless otherwise specified. The direction when the outdoor unit 2 to be viewed is viewed from the front (left oblique front side of the drawing) is meant.

  By the rotation of the outdoor fan 15 (blower), air is sucked from the suction ports 40a, 40b, and 40c on the side surfaces (here, the rear surface and the left and right side surfaces), and heat exchange between the refrigerant and the air is performed in the outdoor heat exchanger 11. The air is discharged from the top surface outlet 40d.

(4) Configuration and operation of outdoor heat exchanger The outdoor heat exchanger 11 of the first embodiment will be described with reference to the drawings. 3 is a schematic perspective view, and FIG. 4 is an enlarged view of a straight line portion on the rear surface. 5 is a view of the left front portion of the outdoor heat exchanger 11 as viewed from the gas side first header portion 70 side (right front side), and FIG. 6 is a view of the same portion as viewed from the liquid side header portion 80 side (left front side). It is a figure.

  The outdoor heat exchanger 11 is a heat exchanger that performs heat exchange between the refrigerant and the outdoor air. The outdoor heat exchanger 11 includes a gas-side second header part 50, a connection pipe 77, a gas-side first header part 70, a liquid-side diversion part 84, a liquid-side header part 80, a connection header part 90, A plurality of flat tubes 63 and a plurality of fins 64 are provided. Here, the gas side second header part 50, the connecting pipe 77, the gas side first header part 70, the liquid side header part 80, the connection header part 90, the flat pipe 63 and the fins 64 are all formed of aluminum or an aluminum alloy. Are joined to each other by brazing or the like.

  The gas-side first header portion 70 includes a vertically long cylindrical tube 71 that extends vertically and a closing portion 72 that closes the opening at the end of the tube 71. The gas side first header part 70 further has a single partition part 73. The inside of the pipe 71 is partitioned by a partition 73 into a lowermost first path and other paths described later. The gas side first header part 70 communicates with the inside of the gas side second header part 50 via the inside of the connection pipe 77. The gas side second header portion 50 is further connected to a U-shaped tube 51 and a copper tube 52.

  The liquid-side header portion 80 includes a vertically long, cylindrical tube 81 that extends vertically, and a closing portion 82 that closes the opening at the end of the tube 81. The liquid side header portion 80 further includes a plurality of partition portions 83, and the inside of the pipe 81 is divided into a plurality of refrigerant collecting spaces 85 by the partition portions 83. One or more upwind flat tubes 63a are connected to each refrigerant collecting space 85. The number of connected flat tubes is, for example, 1 or more and 10 or less. Each refrigerant collecting space 85 of the liquid side header portion 80 communicates with the inside of the liquid side branch portion 84 via the inside of the liquid side branch tube 87.

  The connection header portion 90 includes a vertically long hollow cylindrical tube 91 extending vertically and a closing portion 92 that closes an opening at the end of the tube 91. The connection header portion 90 further includes a plurality of partition portions 93, and the inside of the tube 91 partitions between one end portions in the longitudinal direction of the flat tubes adjacent in the vertical direction and is adjacent to the tube row direction. A plurality of refrigerant spaces 95 in which one end portions in the longitudinal direction communicate with each other are formed.

  The flat tube 63 has a flat plate shape and has a plurality of through holes for circulating the refrigerant. FIG. 4 is a perspective view of the rear straight portion of FIG. As shown in FIG. 4, in the flat tube 63, the windward flat tube 63a and the leeward flat tube 63b are arranged in two rows. And the fin 64 is arrange | positioned so that it may become perpendicular | vertical to the flat tube 63, and may be parallel to the air flow direction. The fins 64 are bonded to the flat tube 63 by brazing or the like. The fins 64 promote heat exchange between the refrigerant flowing in the flat tube 63 and the air.

  The flow of the refrigerant in the outdoor heat exchanger 11 will be described with reference to FIG. The arrow of FIG. 3 has shown the direction of the flow of the refrigerant | coolant in the flat tube at the time of heating. Then, during the cooling operation, the refrigerant flows in the direction opposite to the arrow. Next, the flow of the refrigerant during the cooling operation will be described. The refrigerant that has flowed into the gas side second header portion 50 from the compressor 8 flows in a plurality of connection pipes 77 and gathers at the gas side first header portion 70. The refrigerant that has flowed out of the gas-side first header portion 70 is divided into a plurality of leeward flat tubes 63b and flows into the refrigerant spaces 95 of the leeward flat tubes 63b of the connection header portion 90. Next, the refrigerant flowing into each refrigerant space 95 of the connection header portion 90 flows into each windward flat tube 63a connected to each refrigerant space 95, and is nth from the bottom of the liquid side header portion 80 (n is 2 to 2). An integer of 9. The first pass is divided into the refrigerant collecting space 85 and flows in later. The refrigerant is divided into a plurality of refrigerant paths corresponding to the plurality of refrigerant collecting spaces 85 in the liquid side header portion 80. Here, the number of passes is set to 9, but the number of passes is set as appropriate. For example, the number of paths is 2 or more and 30 or less. The refrigerant passes through the nth liquid side branch pipe 87 from the nth refrigerant collecting space 85 and reaches the liquid side branch section 84. In the liquid side branching portion 84, the refrigerants that have flowed through the nine refrigerant paths merge and are sent to the indoor expansion valves 31a and 31b. During the heating operation, the refrigerant flowing into the liquid side diverting portion 84 through the reverse path is divided into respective paths in the liquid side header portion 80, exchanges heat with air, and merges in the gas side second header portion 50 to be accumulators. To 7

  In the present embodiment, the lowermost first pass is exceptionally the refrigerant between the gas side first header portion 70 (or the liquid side header portion 80) and the connection header portion 90 is twice that of the other passes. It is configured to flow twice. The reason for this is to prevent frost formation. However, as with the other refrigerant paths, during heating, the refrigerant is separated from the liquid side diverter 84, and after heat exchange, the refrigerant is merged in the gas side second header portion 50. It is configured to flow.

(5) Configuration of Header Part The header part of the present disclosure can be applied to the closed parts of various header parts of the heat exchanger. In the present embodiment, the present invention can be applied to the gas side first header part 70, the gas side second header part 50, the liquid side header part 80, the connection header part 90, and the like. Here, the case where it applies to the gas side 2nd header part 50 is demonstrated. As for the gas-side second header portion 50, it is not necessary to close the one connected to the U-shaped tube 51 out of both ends of the tube. Will be described.

  FIG. 7 is an enlarged view of the lower end portion of the gas side second header portion 50. For convenience, FIG. 7 is upside down compared to FIG. Below, the gas side 2nd header part 50 is called the header part 100. FIG. FIG. 8 is a cross-sectional view of the header portion 100 of FIG. 7 that is cut so as to include the center line 141 of the tube 101 and the diameter 131. Here, the diameter 131 of the tube 101 is a line segment connecting two outer peripheral points of the tube 101, and is the most perpendicular to the center line 141 and passing through the same center (a point on the center line 141). It's long. When the tube 101 is a circular tube, the diameter is a diameter. When the cross section of the tube 101 is an ellipse, the diameter is a major axis. 9 and 10 are enlarged views of the entry portion 202 of the welded portion 201 of FIG. 9 shows a case where the opening 121 of the tube 101 is narrow, and FIG. 10 shows a case where the opening 121 of the tube 101 is wide.

  The header unit 100 includes a pipe 101 having an opening 121 at an end and a welded part 201 that closes the opening 121.

  As shown in FIGS. 7 and 8, the tube 101 includes a main body 111, a first annular portion 112, and a second annular portion 113. The second annular portion 113 may include an opening 121. The main body 111 is a portion having a constant cross-sectional diameter 131. The first annular portion 112 is closer to the opening 121 than the main body 111, is annular, and protrudes outward. The second annular portion 113 is closer to the opening 121 than the first annular portion 112, is annular, and protrudes inward. As the main body 111 approaches the first annular portion 112 and the second annular portion 113, the diameter gradually decreases.

  The tube 101 is made of aluminum or an aluminum alloy. For example, the material of the tube 101 is 99% or more of Al. Another example is an Al alloy containing 1 to 1.5% of Mn. More specifically, it is Japanese Industrial Standard A1100 or A3003.

  A corrosion resistant layer 151 is formed on the outer surface of the tube 101. The corrosion resistant layer 151 may be a sacrificial anticorrosive layer. The corrosion resistant layer 151 is an aluminum alloy. An example of the corrosion resistant layer 151 is an aluminum alloy containing Zn. More specifically, for example, A4N43 (Japanese Industrial Standard).

  The thickness of the tube 101 is, for example, 2 mm or more and 3 mm or less. More specifically, for example, it is 2.4 mm. In the case of the conventional copper pipe, it was about 1.1 mm to 1.3 mm, but in comparison with it, the case made of aluminum or aluminum alloy is thick.

  The diameter of the tube 101 is, for example, 20 mm or more and 40 mm or less. More specifically, for example, it is 27.6 mm.

  The diameter of the opening 121 is not more than the sacrificial corrosion protection distance. The sacrificial corrosion protection distance is 20 mm or more and 30 mm or less.

  The welded portion 201 has an outer portion 203 that is outside the opening 121 of the tube 101 and an entry portion 202 that is inside the tube 101 rather than the opening 121. The welded portion 201 is one in which the welding rod is once melted and solidified again. The material of the weld 201 is aluminum or an aluminum alloy, and is the same as the material of the tube 101. The outer part 203 of the welded part 201 is formed so as to cover the end of the corrosion-resistant layer 151. Further, the entry portion 202 is disposed inside the tube 101, particularly inside the second annular portion 113. A part of the entry portion 202 may be inside the first annular portion 112. When the cross section of the entry portion is enlarged, it is a substantially triangular shape as shown in FIG. 9 or a substantially trapezoidal shape as shown in FIG. When the opening 121 of the tube 101 is narrow, it becomes a substantially triangular shape as shown in FIG. 9, and when the opening 121 is wide, it becomes a substantially trapezoidal shape as shown in FIG. 9 and 10, the substantially triangular shape and the substantially trapezoidal shape are the portions in contact with the inside of the tube 101, the triangular AB, the AC line, the trapezoidal DE line, and the GF line on the inner side of the triangle. Protruding, bent to the inside of the trapezoid. This indicates that these lines are generally in contact with the inside of the second annular portion. A line segment that is substantially triangular or substantially trapezoidal with a line parallel to the substantially triangular base BC or the substantially trapezoidal lower base EF, L11 and L12 in FIG. 9, L21 in FIG. The length of the line segment such as L22 is gradually shortened from the main body 111 of the tube 101 toward the opening 121. Naturally, DG <EF in FIG. However, when there are sagging portions P and Q such as dotted lines below BC and EF in the approach portion, such a portion is excluded. That is, only the line segment closer to the opening 121 than the apexes B, C or E, F that are substantially in contact with the tube 101 is considered.

(6) Manufacturing method of header part Next, the manufacturing method of a header part is demonstrated using drawing. FIG. 11 is a diagram for explaining a conventional method for producing a header portion, and FIG. 12 is a diagram for explaining a method for producing a header portion of the present embodiment. FIG. 13 is a flowchart for explaining the method for manufacturing the header portion of the present embodiment, and FIG. 14 is a view for explaining a case where the distal end portion of the tube 101 is cut.

  For comparison, processing for manufacturing a header portion of a copper tube will be described with reference to FIG. First, as shown in FIG. 11A, a cylindrical copper tube 301 having a constant diameter is prepared. The copper tube 301 is subjected to a spatula process using a spatula 321 to reduce the opening as shown in FIGS. 11 (b) and 11 (c). Then, in the case of the copper tube 301, the first annular portion 303 protruding outward is formed. After such a spatula drawing process, as shown in FIG. 11D, the opening is closed by brazing, and a brazing portion 311 is formed. In this way, the end opening can be closed in the case of a copper tube.

  Next, the processing method of the header part of this embodiment using aluminum or an aluminum alloy will be described with reference to FIGS. First, as shown in FIG. 12A, a tubular aluminum tube 101 having a constant diameter is prepared (S1 in FIG. 13). Next, the pipe 101 is drawn (S2). In the case of the aluminum tube 101, there is a limit to the narrowing so that only the first annular portion protruding in the same shape as that of the copper tube, that is, the outside is formed (FIG. 12B). There are two possible reasons for this. First, since aluminum has a lower melting point than copper, aluminum melted by frictional heat sticks to the spatula, reducing the thickness of the tube. Secondly, since aluminum is less malleable than copper, elongation cannot keep up with deformation due to drawing, and large deformation cannot be achieved. The aluminum drawing is preferably performed so that a first annular portion protruding outward and a second annular portion protruding inward are formed (FIG. 12C). After the drawing process (S2), welding is performed to close the opening, and the opening 121 is closed by the welded portion 201 (FIG. 12 (d), S3 in FIG. 13). As a welding method, a welding method such as MIG welding or TIG welding is used.

  It should be noted that after drawing (S2) (FIG. 12 (c)) and before welding (S3), the end of the pipe is indicated by a line C in FIG. 14 (usually corresponding to the second annular portion). May be cut off, and then welded to the opening of the portion excluding the tip to close it. By doing in this way, the non-functional part of the front-end | tip of a pipe | tube can be reduced and the pipe | tube 101 can be shortened. However, since the opening at the portion C is larger than the opening at the tip portion before cutting, the opening becomes larger than before cutting, and particularly when the opening exceeds the sacrificial corrosion protection distance, the corrosion resistance decreases. That is, it is desirable to use without cutting the tip.

(7) Features (7-1)
The header portion 100 of the heat exchanger 11 of the present embodiment includes an aluminum or aluminum alloy tube 101 having an opening 121 at an end, and a welded portion 201 that closes the opening 121. A first annular portion 112 that is a protrusion, and a second annular portion 113 that is closer to the opening 121 than the first annular portion 112 and protrudes inward. Thus, since the pipe 101 has a special shape, it is possible to close the pipe without using an endless cap of an aluminum pipe, which has been difficult in the past, thereby contributing to the reduction in the number of parts and the cost.

(7-2)
In the header portion of the heat exchanger of the present embodiment, the pipe 101 has a corrosion-resistant layer 151 formed on the surface thereof, and the diameter of the opening 121 of the pipe 101 is smaller than the sacrificial corrosion prevention distance.
In the header portion of the heat exchanger of the present embodiment, the diameter of the opening 121 is made smaller than the sacrificial corrosion protection distance, so that the corrosion resistant layer 151 on the surface of the tube 101 prevents corrosion.

(7-3)
In the header portion of the heat exchanger of this embodiment, the entry portion 202 of the welded portion 201 has a shape in which two oblique sides of the triangle are bent inwardly of the triangle, or two oblique sides of the trapezoid protrude inward of the trapezoid. The diameter of the entry portion 202 is smaller from the side closer to the main body 111 of the tube 101 toward the opening 121 of the tube 101. Since the entry part 202 has such a shape, when the pressure of the refrigerant collecting space inside the pipe 101 becomes high, the entry part 202 is pressed against the pipe wall of the second annular part of the pipe 101 and is not easily removed. . On the other hand, in the case of a header using a conventional copper tube, since the bottom side of the brazing portion 311 is outward and the apex is inward, it has an inverted triangular shape. When the pressure is applied, there is a risk that the brazing part 311 may come off relatively easily.

  While the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as set forth in the claims. .

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 2 Outdoor unit 11 Outdoor heat exchanger 50 Gas side 2nd header part 63 Flat tube 64 Fin 70 Gas side 1st header part 101 Pipe 77 Connection pipe 80 Liquid side header part 84 Liquid side branch part 87 Liquid side branch Pipe 100 Header part 111 Main body 112, 303 First annular part 113 Second annular part 131 Diameter 141 Center line 201 Welding part 202 Incoming part 203 External 321 Spatula

JP 2013-139940 A

Claims (7)

A heat exchanger (11) used in the air conditioner (1),
A header portion (50, 100) that forms a refrigerant gathering space inside;
The header part (50, 100)
An aluminum or aluminum alloy tube (101) with an opening (121) at the end;
A weld (201) that closes the opening;
Have
The tube (101)
A body (111) having a constant cross-sectional diameter;
A first annular portion (112) that is closer to the opening (121) than the body (111), is annular, and protrudes outward;
A second annular portion (113) that is closer to the opening (121) than the first annular portion (112), is annular, and protrudes inward;
Having
Heat exchanger (11). The pipe (101) has a corrosion-resistant layer (151) formed on the surface,
The diameter of the opening is smaller than the sacrificial corrosion protection distance,
The heat exchanger (11) according to claim 1. The weld (201)
Formed to cover the corrosion-resistant layer (151),
The heat exchanger (11) according to claim 2. The weld (201)
Having an entry portion (202) entering the inside of the tube from the opening of the tube (101),
The heat exchanger according to any one of claims 1 to 3. When viewed in a cross section through the center of the tube (101),
The entry portion (202) has a shape in which two hypotenuses of a triangle are bent inwardly of the triangle,
The heat exchanger according to claim 4. When viewed in a cross section through the center of the tube (101),
The entry part (202) has a shape in which two oblique sides of a trapezoid are bent inwardly of the trapezoid, and a base farther from the opening of the trapezoid than a base of the trapezoid closer to the opening Too long,
The heat exchanger according to claim 4.   An air conditioner (1) comprising the heat exchanger (11) according to any one of claims 1 to 6.

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