Air conditioner

Abstract

To provide an air conditioner capable of suppressing corrosion of an aluminum refrigerant pipe and securing an interior space.SOLUTION: An air conditioner includes: an aluminum refrigerant pipe 91 formed of aluminum or metal containing aluminum; a copper refrigerant pipe 92 formed of copper or metal including copper; and a connection part 93 that connects the aluminum refrigerant pipe 91 and the copper refrigerant pipe 92 so that one end part 911 of the aluminum refrigerant pipe is located on the lower side of one end part 921 of the copper refrigerant pipe. A central axis of the connection part 93 is disposed at an angle of 45 degrees or less with respect to the vertical direction, and the aluminum refrigerant pipe 91 includes an inclination part 913 inclined upwardly toward a direction separating from the central axis of the connection part 93. A lower end part of the inclination part 913 is disposed on the lower side of the connection part 93. A cover member 94 for covering at least from the connection part 93 to the lower end part of the inclination part 913 is provided.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to an air conditioner.

Background Art

[0002] Conventionally, the refrigerant pipes provided in air conditioners were made of copper or a metal containing copper. However, in recent years, from the viewpoints of weight reduction and cost reduction, a part of the refrigerant pipes is made of aluminum or a metal containing aluminum. Aluminum is known to be prone to so-called dissimilar metal contact corrosion, in which corrosion is accelerated by contact with other metals. Therefore, corrosion is likely to occur at the connection part between the aluminum refrigerant pipe made of aluminum or a metal containing aluminum and the copper refrigerant pipe made of copper or a metal containing copper. When corrosion occurs, holes may form in the aluminum refrigerant pipe, and there is a risk of refrigerant leakage from there.

[0003] Patent Document 1 discloses an air conditioner provided with an inverted U-shaped portion in which the aluminum refrigerant pipe is convex upward or a U-shaped portion in which the copper refrigerant pipe is convex downward in the vicinity of the above connection part. By adopting such a configuration, it is possible to suppress the water droplets adhering to the copper refrigerant pipe from flowing down to the aluminum refrigerant pipe and prevent the corrosion of the aluminum refrigerant pipe.

[0004] However, with the miniaturization of air conditioners, there has been a problem that the internal space (space inside the unit) of the indoor unit or the outdoor unit is compressed by providing the above U-shaped portion or inverted U-shaped portion. In addition, in order to prevent water droplets adhering to the copper refrigerant pipe or the like from adhering to the aluminum refrigerant pipe, it is common to arrange the copper refrigerant pipe below the aluminum refrigerant pipe. For example, when it is desired to route the refrigerant pipe from below upward, after routing the aluminum refrigerant pipe upward, it is necessary to turn it back and then connect it to the copper refrigerant pipe, which may increase the total length of the refrigerant pipe and compress the space inside the unit.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present disclosure is to provide an air conditioner capable of suppressing corrosion of an aluminum refrigerant pipe and securing an internal space in the machine.

Means for Solving the Problems

[0007] The air conditioner of the present disclosure includes an aluminum refrigerant pipe formed of aluminum or a metal containing aluminum, a copper refrigerant pipe formed of copper or a metal containing copper, and a connection portion that connects them such that one end portion of the aluminum refrigerant pipe is below one end portion of the copper refrigerant pipe. The central axis of the connection portion is arranged to be within 45 degrees with respect to the vertical direction. The aluminum refrigerant pipe includes an inclined portion that inclines upward in a direction away from the central axis of the connection portion. The lower end portion of the inclined portion is arranged below the connection portion, and includes a covering material that covers at least from the connection portion to the lower end portion of the inclined portion.

[0008] According to such a configuration, water droplets adhering to the copper refrigerant pipe flow down along the covering material. And it can be suppressed that the water droplets reach a portion of the aluminum refrigerant pipe that is not covered with the covering material by the inclined portion. Further, since the inclined portion does not compress the internal space (space inside the machine) of the outdoor unit or the indoor unit as compared with a conventional U-shaped portion or the like, it is possible to secure the space inside the machine. Thereby, it is possible to suppress corrosion of the aluminum refrigerant pipe and secure the space inside the machine.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

DETAILED DESCRIPTION OF THE INVENTION

[0010] An example of the air conditioner 100 of the present disclosure will be described with reference to FIG. 1. FIG. 1 is a configuration diagram showing the refrigeration cycle of the air conditioner 100. In FIG. 1 (similarly in FIGS. 2 and 3), the dimensional ratio in the drawing and the actual dimensional ratio do not necessarily match, and the dimensional ratios between the drawings also do not necessarily match. The air conditioner 100 is, for example, a room air conditioner, a package air conditioner, a multi-air conditioner for buildings, or the like.

[0011] As shown in FIG. 1, the air conditioner 100 includes an outdoor unit 1, an indoor unit 2, and a refrigerant pipe 9 connecting them. FIG. 1 shows an example in which one indoor unit 2 is connected to one outdoor unit 1, but the present invention is not limited to this. For example, a plurality of outdoor units may be connected to one indoor unit, or a plurality of indoor units may be connected to one outdoor unit. In FIG. 1, the solid line arrow indicates the flow of the refrigerant during the cooling operation, and the broken line arrow indicates the flow of the refrigerant during the heating operation.

[0012] The outdoor unit 1 includes an outdoor heat exchanger 3, an expansion valve 4, a compressor 5, a four-way valve 6, and an outdoor fan (not shown). The compressor 5, the four-way valve 6, the outdoor heat exchanger 3, and the expansion valve 4 are connected by the refrigerant pipe 9. The outdoor fan is arranged adjacent to the outdoor heat exchanger 3 so that outdoor air can be sucked from the back side of the outdoor unit 1, passed through the outdoor heat exchanger 3, and then discharged from the front side of the outdoor unit 1.

[0013] The indoor unit 2 includes an indoor heat exchanger 7 and an indoor fan (not shown). The expansion valve 4 and the indoor heat exchanger 7 are connected by the refrigerant pipe 9. The indoor fan is arranged adjacent to the indoor heat exchanger 7 so that indoor air can be sucked, passed through the indoor heat exchanger 7, and then discharged to the outside of the indoor unit 2, that is, blown into the room.

[0014] The air conditioner 100 configured as such operates as follows to perform heating operation and cooling operation.

[0015] When performing heating operation (dashed arrow), the refrigerant in a gaseous state compressed by the compressor 5 flows through the four-way valve 6 into the indoor heat exchanger 7. Then, heat exchange is performed between the indoor air and the refrigerant in the indoor heat exchanger 7 by the air flow generated by the indoor fan, and heat is released to the indoor air. At this time, the refrigerant condenses from the gaseous state and changes to the liquid state. The refrigerant in the liquid state flows through the expansion valve 4 into the outdoor heat exchanger 3. The refrigerant in the liquid state absorbs heat from the outdoor air by the air flow generated by the outdoor fan in the outdoor heat exchanger 3 and performs heat exchange. At this time, the refrigerant evaporates from the liquid state and becomes a gaseous state, and flows through the four-way valve 6 back to the compressor 5.

[0016] When performing cooling operation (solid arrow), the flow direction of the refrigerant is reversed from that in the heating operation by switching the four-way valve 6. That is, the refrigerant in a gaseous state compressed by the compressor 5 flows through the four-way valve 6 into the outdoor heat exchanger 3. Then, heat exchange is performed between the outdoor air and the refrigerant in the outdoor heat exchanger 3 by the air flow generated by the outdoor fan, and heat is released to the outdoor air. At this time, the refrigerant condenses from the gaseous state and changes to the liquid state. The refrigerant in the liquid state flows through the expansion valve 4 and the refrigerant pipe 9 into the indoor heat exchanger 7. The refrigerant in the liquid state absorbs heat from the indoor air by the air flow generated by the indoor fan in the indoor heat exchanger 7 and performs heat exchange. At this time, the refrigerant evaporates from the liquid state and becomes a gaseous state, and flows through the four-way valve 6 back to the compressor 5. The air cooled by the indoor heat exchanger 7 is discharged into the room by the indoor fan.

[0017] FIG. 2 is a perspective view showing the outdoor heat exchanger 3, and FIG. 3 is an enlarged view of the refrigerant pipe 9 shown in FIG. 2. As shown in FIGS. 2 and 3, the air conditioner 100 includes an aluminum refrigerant pipe 91 formed of aluminum or a metal containing aluminum (aluminum alloy), and a copper refrigerant pipe 92 formed of copper or a metal containing copper (copper alloy). In the present embodiment, the refrigerant pipe 9 is composed of an aluminum refrigerant pipe 91 and a copper refrigerant pipe 92. The thickness of the aluminum refrigerant pipe 91 is larger than the thickness of the copper refrigerant pipe 92.

[0018] The air conditioner 100 includes a connection part 93 that connects one end part 911 of the aluminum refrigerant pipe 91 and one end part 921 of the copper refrigerant pipe 92. The aluminum refrigerant pipe 91 and the copper refrigerant pipe 92 are connected (joined) by, for example, brazing, welding, or eutectic bonding. The connection part between the aluminum refrigerant pipe 91 and the copper refrigerant pipe 92 is the connection part 93. In the present embodiment, one end part 911 of the aluminum refrigerant pipe 91 is flared (see FIG. 3). Then, one end part 921 of the copper refrigerant pipe 92 is fitted into one end part 911 of the aluminum refrigerant pipe 91, and the respective end parts 911 and 921 are connected by brazing. By flaring one end part 911 of the aluminum refrigerant pipe 91, it is possible to prevent the brazing material from dripping from the connection part 93. Before and after the connection part 93, the outer diameter of the aluminum refrigerant pipe 91 (excluding one end part 911) is substantially the same as the outer diameter of the copper refrigerant pipe 92.

[0019] One end part 911 of the aluminum refrigerant pipe 91 is arranged to be lower than one end part 921 of the copper refrigerant pipe 92. The aluminum refrigerant pipe 91 extends such that one end part 911 thereof faces upward, and the copper refrigerant pipe 92 extends such that one end part 921 thereof faces downward. One end part 911 of the aluminum refrigerant pipe 91 and one end part 921 of the copper refrigerant pipe 92 extend along the vertical direction.

[0020] The central axis CL of the connection part 93 is arranged so as to be within 45 degrees with respect to the vertical direction (up-and-down direction). That is, the connection part 93 is arranged along the vertical direction. In the present embodiment, the central axis CL of the connection part 93 is arranged to coincide with the vertical direction, but it may be arranged inclined with respect to the vertical direction. The central axis CL of the connection part 93 coincides with the central axis of one end part 911 of the aluminum refrigerant pipe 91 and the central axis of one end part 921 of the copper refrigerant pipe 92.

[0021] The aluminum refrigerant pipe 91 is provided with an inclined part 913 that inclines upward in a direction away from the central axis CL of the connection part 93. The lower end part 913b of the inclined part 913 is arranged below the connection part 93. When one aluminum refrigerant pipe 91 has a plurality of parts that incline upward in a direction away from the central axis CL of the connection part 93, the part with the smallest distance along the aluminum refrigerant pipe 91 from the connection part 93 among those parts is the inclined part 913.

[0022] The air conditioner 100 is provided with a covering material 94 that covers at least the entire circumference of the refrigerant pipe 9 from the connection part 93 to the lower part of the inclined part 913. According to such a configuration, the water droplets adhering to the copper refrigerant pipe 92 flow down along the covering material 94. And it can be suppressed that the water droplets reach the part of the aluminum refrigerant pipe 91 that is not covered by the covering material 94 due to the inclined part 913. Further, since the inclined part 913 does not compress the internal space (space inside the machine) of the outdoor unit 1 or the indoor unit 2 compared to a conventional U-shaped part or the like, it is possible to secure the space inside the machine. Thereby, it is possible to suppress the corrosion of the aluminum refrigerant pipe 91 and secure the space inside the machine.

[0023] As shown in FIG. 3, the angle θ1 of the inclined part 913 (the straight part 913a to be described later) with respect to the horizontal plane is preferably 10 degrees or more. Thereby, when the outdoor unit 1 (or the indoor unit 2) provided with the aluminum refrigerant pipe 91 is installed, it can be suppressed that the inclined part 913 faces the horizontal direction or the downward direction due to the inclination of the installation surface or the like. The angle θ1 may be 15 degrees or more, may be 20 degrees or more, or may be 25 degrees or more.

[0024] The angle θ1 of the inclined portion 913 with respect to the horizontal plane is preferably 45 degrees or less. Thereby, it is possible to suppress the compression of the in-cabin space due to the provision of the inclined portion 913. The angle θ1 is more preferably 35 degrees or less.

[0025] The aluminum refrigerant pipe 91 includes a first curved portion 916 curved so as to be convex downward and a second curved portion 917 curved so as to be convex upward. The inclined portion 913 includes a straight portion 913a disposed between the first curved portion 916 and the second curved portion 917. Among the first curved portion 916 and the second curved portion 917, a portion inclined upward in a direction away from the central axis CL of the connection portion 93 is included in the inclined portion 913. In the present embodiment, the inclined portion 913 is composed of the straight portion 913a, the lower end portion 916a of the first curved portion 916, and the upper end portion 917a of the second curved portion 917. That is, at least a part of the inclined portion 913 is constituted by the first curved portion 916 and the second curved portion 917. Note that the inclined portion 913 may be composed of the lower end portion 916a and the upper end portion 917a without including the straight portion 913a.

[0026] The first curved portion 916 is disposed at a position lower than the second curved portion 917. The first curved portion 916 is disposed on the one end portion 911 side of the aluminum refrigerant pipe 91, and the second curved portion 917 is disposed on the other end portion 912 side of the aluminum refrigerant pipe 91. The lower end portion 913b of the inclined portion 913 is the lower end portion 916a of the first curved portion 916, and the upper end 913c portion of the inclined portion 913 is the upper end portion 917a of the second curved portion 917.

[0027] The aluminum refrigerant pipe 91 is provided with a one - end straight portion 914 including one - end portion 911. The one - end straight portion 914 extends linearly along the vertical direction and is connected to the first curved portion 916. The angle θ2 between the one - end straight portion 914 and the inclined portion 913 (the straight portion 913a thereof) is, for example, less than 90 degrees. The length of the straight portion 913a is smaller than the length of the one - end straight portion 914 and the length of the rising portion 915 to be described later. The length of the straight portion 913a is appropriately set according to the outer diameter of the aluminum refrigerant pipe 91 and the like. In the present embodiment, the one - end straight portion 914 is arranged to coincide with the vertical direction, but it may be arranged inclined with respect to the vertical direction.

[0028] In the present embodiment, all of the inclined portion 913 is arranged below the connecting portion 93, but it is not limited to this. The upper - end portion 913c of the inclined portion 913 or a part of the straight portion 913a may be arranged above the connecting portion 93.

[0029] The covering material 94 has waterproofness and is formed of a material capable of covering the refrigerant pipe 9 without a gap. The covering material 94 is preferably a heat - shrinkable tube that shrinks and cures by applying heat. The heat - shrinkable tube is formed of, for example, polyolefin, fluorine - based polymer, thermoplastic elastomer, and the like. In addition, a coating film formed by coating the refrigerant pipe 9 may be used as the covering material.

[0030] The covering material 94 covers at least the lower - end portion 913b of the inclined portion 913. The covering material 94 preferably covers the straight portion 913a. Thereby, it is possible to further suppress the water droplets flowing down from the copper refrigerant pipe 92 from reaching the portion of the aluminum refrigerant pipe 91 not covered by the covering material 94. The covering material 94 may cover the upper - end portion 913c of the inclined portion 913.

[0031] The covering material 94 preferably covers at least from one end 921 of the copper refrigerant pipe 92 to the lower end 913b of the inclined portion 913. According to such a configuration, it is possible to suppress water droplets adhering to the copper refrigerant pipe 92 from seeping in through the gap between the covering material 94 and the connection portion 93 and corroding the portion of the aluminum refrigerant pipe 91 covered by the covering material 94.

[0032] As shown in FIG. 2, the aluminum refrigerant pipe 91, the copper refrigerant pipe 92, and the connection portion 93 are arranged in the outdoor unit 1. The other end (not shown) of the copper refrigerant pipe 92 is connected to the refrigerant inlet / outlet (not shown) of the outdoor unit 1, and the other end 912 of the aluminum refrigerant pipe 91 is connected to the refrigerant inlet 31 of the outdoor heat exchanger 3 when the outdoor heat exchanger 3 serves as an evaporator. It is preferable that the refrigerant inlet / outlet of the outdoor unit 1 is located upward of the refrigerant inlet 31 of the outdoor heat exchanger 3 when the outdoor heat exchanger 3 serves as an evaporator. According to such a configuration, it is possible to suppress an increase in the total length of the liquid pipe through which two-phase flow flows in the refrigerant pipe 9. The other end of the copper refrigerant pipe 92 is connected to the refrigerant inlet / outlet of the outdoor unit 1 via an expansion valve 4 (see FIG. 1), or the other end 912 of the aluminum refrigerant pipe 91 is connected to the outdoor heat exchanger 3 via the expansion valve 4. Note that the aluminum refrigerant pipe 91, the copper refrigerant pipe 92, and the connection portion 93 may be arranged in the indoor unit 2.

[0033] The aluminum refrigerant pipe 91 preferably includes a rising portion 915 that rises upward between the other end 912 and the second curved portion 917. According to such a configuration, a space can be provided at the lower part in the outdoor unit 1 (or the indoor unit). Thereby, for example, piping can be passed through the empty space. The rising portion 915 extends along the vertical direction.

[0034] In this embodiment, the rising portion 915 extends linearly in the vertical direction and is connected to the second curved portion 917. The rising portion 915 is arranged so as to be substantially parallel to the one-end straight portion 914. Thereby, the aluminum refrigerant pipe 91 forms a substantially Z shape in the one-end straight portion 914, the inclined portion 913, and the rising portion 915. In this embodiment, the rising portion 915 is arranged so as to coincide with the vertical direction. Note that the rising portion 915 is not limited to the above. For example, the rising portion 915 may extend in a curved manner, or the rising portion 915 may be arranged to be inclined with respect to the vertical direction.

[0035] (Modification example) The connection portion 93 may be provided with a stainless steel refrigerant pipe formed of stainless steel. That is, the aluminum refrigerant pipe 91 and the copper refrigerant pipe 92 may be connected via the stainless steel refrigerant pipe. According to such a configuration, by connecting the aluminum refrigerant pipe 91 and the copper refrigerant pipe 92 via the stainless steel refrigerant pipe, corrosion of the aluminum refrigerant pipe 91 can be further suppressed.

[0036] [1] As described above, the air conditioner 100 according to this embodiment includes an aluminum refrigerant pipe 91 formed of aluminum or a metal containing aluminum, a copper refrigerant pipe 92 formed of copper or a metal containing copper, and a connection portion 93 that connects the one-end portion 911 of the aluminum refrigerant pipe 91 so as to be below the one-end portion 921 of the copper refrigerant pipe 92. The central axis CL of the connection portion 93 is arranged to be within 45 degrees with respect to the vertical direction. The aluminum refrigerant pipe 91 includes an inclined portion 913 that inclines upward in a direction away from the central axis CL of the connection portion 93. The lower end portion 913b of the inclined portion 913 is arranged below the connection portion 93. The air conditioner 100 includes a covering material 94 that covers at least from the connection portion 93 to the lower end portion 913b of the inclined portion 913.

[0037] According to such a configuration, the water droplets adhering to the copper refrigerant pipe 92 flow down along the covering material 94. Then, it is possible to suppress the water droplets from reaching the portion of the aluminum refrigerant pipe 91 that is not covered by the covering material 94 by the inclined portion 913. Further, since the inclined portion 913 does not compress the internal space (the space inside the unit) of the outdoor unit 1 or the indoor unit 2 as compared with a conventional U-shaped portion or the like, it is possible to secure the space inside the unit. As a result, it is possible to suppress the corrosion of the aluminum refrigerant pipe 91 and secure the space inside the unit.

[0038] [2] In the air conditioner 100 of the above [1], the aluminum refrigerant pipe 91 includes a first curved portion 916 curved so as to be convex downward and a second curved portion 917 curved so as to be convex upward, and at least a part of the inclined portion 913 is preferably configured by the first curved portion 916 and the second curved portion 917.

[0039] [3] The air conditioner 100 of the above [1] or [2] includes an outdoor unit 1 having an outdoor heat exchanger 3, and the aluminum refrigerant pipe 91, the copper refrigerant pipe 92, and the connection portion 93 are disposed in the outdoor unit 1. The other end of the copper refrigerant pipe 92 is connected to the refrigerant inlet / outlet of the outdoor unit 1, and the other end 912 of the aluminum refrigerant pipe 91 is connected to the refrigerant inlet 31 of the outdoor heat exchanger 3 when the outdoor heat exchanger 3 serves as an evaporator. The refrigerant inlet / outlet of the outdoor unit 1 is preferably located upward of the refrigerant inlet 31 of the outdoor heat exchanger 3 when the outdoor heat exchanger 3 serves as an evaporator.

[0040] According to such a configuration, it is possible to suppress an increase in the total length of the liquid pipe through which the two-phase flow flows in the refrigerant pipe 9.

[0041] [4] In the air conditioner 100 of any one of the above [1] to [3], the aluminum refrigerant pipe 91 preferably includes a rising portion 915 that rises upward between its other end 912 and the second curved portion 917.

[0042] According to such a configuration, a space can be provided at the lower part inside the outdoor unit 1 (or the indoor unit 2). Thereby, for example, pipes can be passed through the empty space.

[0043] Note that the air conditioner 100 is not limited to the configuration of the above-described embodiment, nor is it limited to the above-described effects. Also, the air conditioner 100 can of course be variously modified within a range not departing from the gist of the present invention. For example, it is of course possible to arbitrarily select one or more of the configurations and methods according to the above-described various modification examples and adopt them in the configurations and methods according to the above-described embodiment.

Description of Reference Numerals

[0044] 1... outdoor unit, 2... indoor unit, 3... outdoor heat exchanger, 31... refrigerant inlet, 4... expansion valve, 5... compressor, 6... four-way valve, 7... indoor heat exchanger, 9... refrigerant pipe, 91... aluminum refrigerant pipe, 911... one end portion, 912... the other end portion, 913... inclined portion, 913a... straight portion, 913b... lower end portion, 913c... upper end portion, 914... one end straight portion, 915... rising portion, 916... first bending portion, 916a... lower end portion, 917... second bending portion, 917a... upper end portion, 92... copper refrigerant pipe, 921... one end portion, 93... connection portion, 94... covering material, 100... air conditioner, CL... central axis

Claims

1. An aluminum refrigerant pipe formed of aluminum or a metal containing aluminum, and A copper refrigerant pipe formed of copper or a metal containing copper, and A connecting portion that connects them such that one end portion of the aluminum refrigerant pipe is below one end portion of the copper refrigerant pipe, The central axis of the connecting portion is arranged to be within 45 degrees with respect to the vertical direction, The aluminum refrigerant pipe includes an inclined portion that inclines upward in a direction away from the central axis of the connecting portion, The lower end portion of the inclined portion is arranged below the connecting portion, An air conditioner including a covering material that covers at least from the connecting portion to the lower end portion of the inclined portion.

2. The aluminum refrigerant pipe includes a first curved portion that curves convexly downward and a second curved portion that curves convexly upward, At least a part of the inclined portion is constituted by the first curved portion and the second curved portion, the air conditioner according to claim 1.

3. An outdoor unit having an outdoor heat exchanger, The aluminum refrigerant pipe, the copper refrigerant pipe, and the connecting portion are arranged in the outdoor unit, The other end portion of the copper refrigerant pipe is connected to the refrigerant inlet / outlet of the outdoor unit, The other end portion of the aluminum refrigerant pipe is connected to the refrigerant inlet of the outdoor heat exchanger when the outdoor heat exchanger serves as an evaporator, The refrigerant inlet / outlet of the outdoor unit is located above the refrigerant inlet of the outdoor heat exchanger when the outdoor heat exchanger serves as an evaporator, the air conditioner according to claim 1.

4. The aluminum refrigerant pipe includes a rising portion that rises upward between the other end portion of the aluminum refrigerant pipe and the second curved portion, the air conditioner according to claim 2.

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