Refrigeration cycle device

Abstract

A refrigeration cycle device is provided with: an aluminum or aluminum alloy aluminum refrigerant tube (22) which is connected to an end (18a) of a tube provided inside a heat exchanger (11) and which protrudes to the outside of the heat exchanger; a copper refrigerant pipe (23) made of copper or copper alloy and connected with control components such as a four-way valve and an expansion valve; in the refrigeration cycle device, the joining part is arranged in the vertical direction perpendicular to the bottom surface (3) of the heat exchanger, the aluminum refrigerant pipe is arranged on the upper side of the joining part, and a copper straight part (27) is arranged on the copper refrigerant pipe arranged on the lower side of the joining part. The copper straight portion (27) extends linearly downward from the joining portion at a length equal to or greater than the outer diameter of the copper refrigerant tube.

Description

Technical Field

[0001] This invention relates to a refrigeration cycle apparatus. Background Technology

[0002] In air conditioners that function as refrigeration cycle units, the indoor heat exchanger, outdoor heat exchanger, compressor, and control components (four-way valve, expansion valve, etc.) are connected by refrigerant piping. Copper or copper alloy refrigerant piping (hereinafter referred to as copper refrigerant piping) is used as the refrigerant piping. In recent years, due to the requirements of cost reduction and weight reduction, it has been proposed to use aluminum or aluminum alloy refrigerant piping (hereinafter referred to as aluminum refrigerant piping) for the pipes installed inside the indoor and outdoor heat exchangers, as well as for the refrigerant piping protruding to the outside of the indoor and outdoor heat exchangers.

[0003] On the other hand, considering reliability and manufacturing issues, refrigerant piping connected to control components generally uses copper refrigerant pipes, which have higher ductility than aluminum. Therefore, a joint is formed to connect the aluminum refrigerant pipes protruding to the indoor and outdoor heat exchangers, as well as the copper refrigerant pipes connected to the control components.

[0004] When an air conditioner is in heating mode, the low-temperature refrigerant flows through the refrigerant piping of the outdoor heat exchanger, which acts as the evaporator. As a result, water vapor contained in the outside air condenses and forms dew that adheres to the copper refrigerant pipes. This dew creates water containing copper ions, which flows towards the junction of the aluminum and copper refrigerant pipes, potentially causing electrolytic corrosion on the aluminum pipe at the junction. Furthermore, during heating operation at low outside air temperatures, the water formed on the copper refrigerant pipes may freeze, forming frost or ice. If this frost or ice melts during defrosting, it also creates water containing copper ions, which flows towards the junction of the aluminum and copper refrigerant pipes, potentially causing electrolytic corrosion on the aluminum pipe.

[0005] As a technique to prevent water containing copper ions from flowing to the joint between the aluminum refrigerant pipe and the copper refrigerant pipe, it is known to provide at least one of an inverted U-shaped portion that makes the aluminum refrigerant pipe convex upward and a U-shaped portion that makes the copper refrigerant pipe convex downward near the joint (for example, Patent Document 1).

[0006] Prior art literature

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2014-159952 Summary of the Invention

[0009] The technical problem that the invention aims to solve

[0010] However, in the technology of Patent Document 1, when the joint between the aluminum refrigerant pipe and the copper refrigerant pipe protruding to the outside of the outdoor heat exchanger is arranged horizontally, water containing copper ions is prevented from flowing to the joint. However, when the joint is arranged at an angle relative to the horizontal direction, for example, when the joint is located below the U-shaped section formed by the copper refrigerant pipe, water containing copper ions generated in the U-shaped section will flow to the joint side, potentially causing electrolytic corrosion on the aluminum refrigerant pipe at the joint.

[0011] Therefore, the present invention was made to solve such a problem, and its object is to provide a refrigeration cycle device that can prevent electrolytic corrosion caused by the introduction of water containing copper ions, even when the joint between the aluminum refrigerant pipe and the copper refrigerant pipe is arranged at an angle relative to the horizontal direction.

[0012] Technical methods for solving technical problems

[0013] One aspect of the invention is a refrigeration cycle device, characterized in that the refrigeration cycle device comprises: an aluminum or aluminum alloy refrigerant pipe, which is connected to the end of a pipe disposed inside a heat exchanger and protrudes to the outside of the heat exchanger; a copper or copper alloy refrigerant pipe, which is connected to control components such as a four-way valve and an expansion valve; and a joint that connects the aluminum refrigerant pipe and the copper refrigerant pipe. In this refrigeration cycle device, the joint is arranged in a vertical direction perpendicular to the bottom surface of the heat exchanger. An aluminum refrigerant pipe is arranged at a position above the joint, and a copper straight section is provided on the copper refrigerant pipe arranged at a position below the joint. The copper straight section extends downward in a straight line from the joint with a length greater than the outer diameter of the copper refrigerant pipe.

[0014] Invention Effects

[0015] According to the refrigeration cycle apparatus of the present invention, even if the joint between the aluminum refrigerant tube and the copper refrigerant tube is arranged at an angle relative to the horizontal direction, electrolytic corrosion caused by the intrusion of water containing copper ions at the joint can be prevented. Attached Figure Description

[0016] Figure 1 This is a diagram showing the appearance of the outdoor unit that constitutes the refrigeration cycle device involved in this invention.

[0017] Figure 2 This is a diagram showing the internal structure of the outdoor unit.

[0018] Figure 3 This is a diagram showing the heat exchanger installed inside the outdoor unit.

[0019] Figure 4 This is a diagram showing the specific configuration of the first refrigerant pipe, which includes aluminum and copper refrigerant pipes, connected to the heat exchanger.

[0020] Figure 5 This is a diagram showing the configuration of the first refrigerant pipe when the heat exchanger is tilted.

[0021] Figure 6 This is a diagram showing the joint between the aluminum refrigerant tube and the copper refrigerant tube in the second embodiment.

[0022] Figure 7 This is a diagram showing the joint of the aluminum refrigerant tube and the copper refrigerant tube in the third embodiment. Detailed Implementation

[0023] Next, embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments shown below are illustrative examples of apparatuses and methods for embodying the technical concept of the present invention. The technical concept of the present invention does not limit the materials, shapes, structures, and arrangements of the constituent components to the following descriptions. Various modifications can be made to the technical concept of the present invention within the technical scope defined by the claims.

[0024] [Outdoor unit of the first embodiment]

[0025] Figure 1 This is a diagram showing the appearance of the outdoor unit 1 of an air conditioner, which is a type of refrigeration cycle device. Figure 2 This is a diagram showing the internal structure of outdoor unit 1.

[0026] like Figure 1 As shown, the outdoor unit 1 has a box-shaped housing 2. The housing 2 has a base 3 forming the bottom surface of the housing 2 (see reference). Figure 2 The front surface panel 4 forms the front surface of the housing 2; the right side panel 5 and left side panel 6 form the sides of the housing 2; and the top plate 7 forms the upper surface of the housing 2. An air outlet is provided on the front surface panel 4, and a fan cover 8 is installed on the air outlet. It should be noted that the base 3 corresponds to the bottom surface of the invention.

[0027] like Figure 2 As shown, the compressor 10, heat exchanger (outdoor heat exchanger) 11, expansion valve 12, blower fan 13, electrical unit 14, etc. are housed inside the housing 2.

[0028] The interior space of the housing 2 is divided into a mechanical chamber 16 and a heat exchange chamber 17 by a partition 15. The mechanical chamber 16 is equipped with a compressor 10, an expansion valve 12, an electrical unit 14, etc., while the heat exchange chamber 17 is equipped with a blower fan 13 and a heat exchanger 11.

[0029] like Figure 2As shown, the heat exchanger 11 is arranged in an L-shape from the back of the housing 2 along its left side, and includes: a tube 18 formed in a meandering shape; and a plurality of fins 19 formed from a thin metal plate. The plurality of fins 19 extend vertically and are arranged at equal intervals horizontally to each other, forming an L-shape. The tube 18 is a refrigerant tube made of aluminum or aluminum alloy, inserted in a direction orthogonal to the plurality of fins 19 arranged in the L-shape, and folded back in a manner parallel to the vertical direction.

[0030] like Figure 3 As shown, one end of tube 18 protrudes outward from the lower side of the right side of heat exchanger 11, at one end 18a of tube 18 (refer to...). Figure 4 One end of the first refrigerant pipe 20 is connected to the other end of the first refrigerant pipe 20. An expansion valve 12 is connected to the other end of the first refrigerant pipe 20. In addition, the other end 18b of the pipe 18 protrudes outward from the upper side of the right side portion of the heat exchanger 11, and one end of the second refrigerant pipe 21 is connected to the other end of the pipe 18b. A compressor 10 is connected to the other end of the second refrigerant pipe 21.

[0031] When the air conditioner is in heating mode, the heat exchanger 11 is used as an evaporator. The low-temperature refrigerant, after being depressurized by the expansion valve 12, flows in the order of the first refrigerant pipe 20, the pipe 18 of the heat exchanger 11, the second refrigerant pipe 21, and the compressor 10.

[0032] The first refrigerant pipe 20 has: an aluminum refrigerant pipe 22 made of aluminum or aluminum alloy that is connected to one end 18a of the pipe 18; and a copper refrigerant pipe 23 made of copper or copper alloy that is connected to the expansion valve 12.

[0033] Aluminum refrigerant pipe 22 and copper refrigerant pipe 23 are straight pipe components with the same outer diameter, and their ends are joined together to form a joint 24.

[0034] A cylindrical waterproof covering material 31 made of insulating material is installed on the outer periphery of the joint 24, the end of the aluminum refrigerant pipe 22, and the end of the copper refrigerant pipe 24. The waterproof covering material 31 is a heat shrinkable tube that is tightly attached to the outer periphery of the end of the joint 24, the second straight section 26b, and the copper straight section 27.

[0035] The straight aluminum refrigerant tube 22 is bent in the following manner: an aluminum straight section 25; and an aluminum U-shaped section 26 continuously formed from the end of the aluminum straight section 25. The aluminum U-shaped section 26 has: a first straight section 26a, which is bent in a direction orthogonal to the aluminum straight section 25; a second straight section 26b, which extends parallel to the first straight section 26a and is longer than the first straight section 26a, and has a joint 24 formed at its end; and a semi-circular arc section 26c, which connects one end of the first straight section 26a and the second straight section 26b to each other.

[0036] The straight copper refrigerant tube 23 is bent in the following manner: a copper straight section 27 with a joint 24 formed at the end; and a copper U-shaped section 28 continuously formed from the end of the copper straight section 27. The length L of the copper straight section 27 is set to be a dimension greater than or equal to the outer diameter φ of the copper refrigerant tube 23.

[0037] The aluminum refrigerant tube 22 is arranged in a convex shape with an upward-facing aluminum U-shaped portion 26, and the end of the aluminum straight portion 25 extends parallel to the base 3 and joins one end 18a of the tube 18. Thus, the second straight portion 26b of the aluminum U-shaped portion 26 is arranged in a vertical direction perpendicular to the base. The joining position of this aluminum straight portion 25 and one end 18a of the tube 18 is called the heat exchanger-side joining portion 29. It should be noted that the upward-facing convex aluminum U-shaped portion 26 corresponds to the inverted U-shaped portion of the aluminum refrigerant tube in this invention. Furthermore, the length L of the copper straight portion 27 corresponds to the length above the outer diameter of the copper refrigerant tube extending linearly downward from the joining portion in this invention.

[0038] The joint 24 between the aluminum refrigerant tube 22 and the copper refrigerant tube 23 is formed by joining the upper end of the copper straight section 27 of the copper refrigerant tube 23 with the lower end of the second straight section 26b of the aluminum refrigerant tube 22 by welding. The joint 24 is arranged in a vertical direction perpendicular to the base 3.

[0039] The copper U-shaped portion 28 of the copper refrigerant pipe 23 is arranged in a downwardly convex shape, and the heat exchanger-side joint 29 of the aluminum straight portion 25 and one end 18a of the pipe 18 is positioned above the joint 24 and the copper U-shaped portion 28 of the copper refrigerant pipe 23. It should be noted that the downwardly convex copper U-shaped portion 28 corresponds to the U-shaped portion of the copper refrigerant piping in this invention. Here, another copper refrigerant pipe 30 is welded to the other end of the copper U-shaped portion 28; this copper refrigerant pipe 30 corresponds to the second copper refrigerant pipe in this invention and is connected to the expansion valve 12.

[0040] Furthermore, the waterproof covering material 31 is tightly adhered to the outer periphery of the joint 24, the lower end of the second straight section 26b, and the upper end of the copper straight section 27, thereby ensuring watertightness relative to the joint 24 and the copper straight section 27 and preventing the generation of water containing copper ions at the joint 24 and the copper straight section 27 near the aluminum refrigerant pipe 22. Therefore, the waterproof covering material 31 can prevent water containing copper ions generated in the copper refrigerant pipe 23 from flowing into the aluminum refrigerant pipe 22. That is, the waterproof covering material 31 needs to be installed at least at the joint 24 and the copper straight section 27. The waterproof covering material 31 is not limited to heat shrink tubing; watertightness can also be ensured by using a water-repellent coating, butyl rubber, etc.

[0041] Here, the joint between the aforementioned copper U-shaped portion 28 and the copper refrigerant pipe 30 is positioned at a distance such that, during welding, the flame from the welding burner does not directly contact the waterproof covering material 31 and the aluminum refrigerant pipe 22, and the shape of the waterproof covering material 31 is not deformed by the heat of the welding burner, thus preserving the covering effect. In other words, this distance corresponds to a distance that, in the invention, will not cause heat effects from welding on the waterproof covering material and the joint.

[0042] Next, refer to Figure 4 and Figure 5 The function of the heat exchanger 11 having the first refrigerant pipe 20 will be explained. Figure 4 This indicates that the base 3 of the housing 2 is installed on a horizontal surface. Figure 5 This indicates that the base 3 of the housing 2 is installed on the installation surface with an inclination angle of Θ=5°, which is the maximum tilt angle that the heat exchanger 11 can be set at. Hereinafter, Figure 4 The state shown is called the horizontal setting state. Figure 5 The state shown is called the tilt setting state.

[0043] If the air conditioner is operated in heating mode at a low outside air temperature, the low-temperature refrigerant flows in the first refrigerant pipe 20 of the heat exchanger 11, which serves as the evaporator. As a result, water vapor contained in the outside air condenses, and frost and ice adhere to the copper refrigerant pipe 23. If the frost and ice adhering to the copper refrigerant pipe 23 melts due to defrosting operation, water containing copper ions is sometimes produced and accumulates in the copper U-shaped section 28.

[0044] Regardless of the joint 24 of the first refrigerant pipe 20 Figure 4 In the horizontal setting state, it is still in Figure 5 In the tilted setting state, they are all arranged in the vertical direction. The second straight section 26b of the aluminum refrigerant pipe 22 is arranged on the upper side of the joint 24, and the copper straight section 27 of the copper refrigerant pipe 23 is arranged on the lower side of the joint 24. Therefore, the water containing copper ions accumulated in the copper U-shaped section 28 will not flow to the joint 24.

[0045] Furthermore, the length L of the copper straight section 27 is set to be a dimension greater than or equal to the outer diameter of the copper straight section 27. This ensures that the distance between the copper U-shaped section 28 and the joint 24 is larger than the size of water droplets generated due to condensation. Therefore, even if frost or ice grows in the copper U-shaped section 28, it is difficult for it to reach the joint 24. Thus, even if frost or ice generated in the copper U-shaped section 28 melts due to defrosting operation, water containing copper ions can be prevented from being generated in the joint 24 and reaching the aluminum refrigerant pipe 22.

[0046] In addition, the aluminum refrigerant pipe 22 is provided with an aluminum straight section 25 that extends parallel to the base 3 above the joint 24; and an aluminum U-shaped section 26 that is arranged in an upward convex shape between the aluminum straight section 25 and the joint 24. Therefore, it is possible to suppress the transmission of vibration caused by the compressor to the heat exchanger side joint 29 via the copper refrigerant pipe 23.

[0047] Furthermore, the heat exchanger-side joint 29 of the aluminum straight section 25 and one end 18a of the tube 18 is positioned above the joint 24 and the copper U-shaped section 28 of the copper refrigerant tube 23, so even when Figure 5 In the tilted configuration shown, it also reliably prevents water containing copper ions accumulated in the copper U-shaped section 28 from flowing to the aluminum straight section 25 and the heat exchanger 11.

[0048] In addition, a waterproof covering material 31 is installed on the outer periphery of the joint 24 to ensure water tightness, thus reliably preventing water containing copper ions from flowing into the joint 24.

[0049] Therefore, even if the heat exchanger 11 is installed on an inclined surface, since the joint 24 of the first refrigerant pipe 20 is arranged in the vertical direction, water containing copper ions will not flow to the joint 24 of the copper refrigerant pipe 23 (copper straight section 27) and the aluminum refrigerant pipe 22 (second straight section 26b), thus reliably preventing electrolytic corrosion of the aluminum refrigerant pipe 22 (second straight section 26b).

[0050] Furthermore, the joint between the copper U-shaped section 28 and the copper refrigerant pipe 30 is configured at a distance such that when the end faces are joined together by welding, the flame of the welding burner does not directly contact the waterproof covering material 31 and the aluminum refrigerant pipe 22, thus enabling easy and accurate welding of the copper U-shaped section 28 and the copper refrigerant pipe 30.

[0051] [Joint portion of the second and third embodiments]

[0052] then, Figure 6 and Figure 7 The joint portion representing the second and third embodiments has a structure similar to... Figure 4 The joint 24 of the first embodiment of the aluminum refrigerant pipe 22 (second straight section 26b) and the copper refrigerant pipe 23 (copper straight section 27) shown has a different structure.

[0053] Figure 6The joint portion of the second embodiment is shown in which a stainless steel tube 32 is disposed between the upper end of the copper straight portion 27 and the lower end of the second straight portion 26b. The upper end of the copper straight portion 27 is joined to one end of the stainless steel tube 32 by welding, and the lower end of the second straight portion 26b is joined to the other end of the stainless steel tube 32 by welding, thereby forming a joint portion 33. Furthermore, a waterproof covering material 31 is installed on the outer periphery of the joint portion 33, the second straight portion 26b, and the copper straight portion 27.

[0054] In the second embodiment, the joint 33 of the copper refrigerant pipe 23 (copper straight section 27) and the aluminum refrigerant pipe 22 (second straight section 26b) is arranged in the vertical direction. Therefore, even if the heat exchanger 11 is provided on an inclined surface, water containing copper ions will not flow to the joint 33, and electrolytic corrosion of the aluminum refrigerant pipe 22 (second straight section 26b) can be reliably prevented.

[0055] Figure 7 The joint portion of the second embodiment is shown, wherein the upper end of the copper straight portion 27 is abutted to the lower end of the second straight portion 26b, and the copper straight portion 27 and the second straight portion 26b are joined by a connector member 34 installed on the outer periphery of the copper straight portion 27 and the second straight portion 26b, thereby forming a joint portion 35. Furthermore, a waterproof covering material 31 is installed on the outer periphery of the joint portion 35, the second straight portion 26b, and the copper straight portion 27.

[0056] In the third embodiment, the joint 35 between the copper refrigerant tube 23 (copper straight section 27) and the aluminum refrigerant tube 22 (second straight section 26b) is arranged in the vertical direction. Therefore, even if the heat exchanger 11 is provided on an inclined surface, water containing copper ions will not flow to the joint 35, and electrolytic corrosion of the aluminum refrigerant tube 22 (second straight section 26b) can be reliably prevented.

[0057] Explanation of reference numerals in the attached figures

[0058] 1. Outdoor unit

[0059] 2. Shell

[0060] 3. Base

[0061] 4. Front Surface Panel

[0062] 5. Right side panel

[0063] 6. Left side panel

[0064] 7. Top Slab

[0065] 8. Fan cover

[0066] 10 Compressors

[0067] 11 Heat Exchanger

[0068] 12 Expansion valve

[0069] 13. Blower Fan

[0070] 14 Electrical Units

[0071] 15 partitions

[0072] 16. Machine Room

[0073] 17 Heat Exchange Chamber

[0074] 18 tubes

[0075] One end of the 18a tube

[0076] The other end of the 18b tube

[0077] 19 Fins

[0078] 20 First refrigerant pipe

[0079] 21 Second refrigerant pipe

[0080] 22 Aluminum refrigerant pipe

[0081] 23 Copper refrigerant pipe

[0082] 24 Joint

[0083] 25 Aluminum Straight Section

[0084] 26 Aluminum U-shaped section

[0085] 26a First straight section

[0086] 26b Second straight section

[0087] 26c Semicircular part

[0088] 27. Copper Straight Section

[0089] 28. Copper U-shaped section

[0090] 29 Heat exchanger side joint

[0091] 30 Copper refrigerant pipe

[0092] 31 Waterproof Covering Material

[0093] 32 stainless steel pipe

[0094] 33 Joint

[0095] 34 Joint components

[0096] 35 Joint.

Claims

1. A refrigeration circulation device, characterized in that, The refrigeration cycle device has: Aluminum or aluminum alloy refrigerant pipes are connected to the ends of pipes located inside the heat exchanger and protrude to the outside of the heat exchanger. Copper or copper alloy refrigerant pipes, which connect to control components such as four-way valves and expansion valves; and The joint connects the aluminum refrigerant tube to the copper refrigerant tube. The joint is arranged in a vertical direction perpendicular to the bottom surface of the heat exchanger, and the aluminum refrigerant pipe is arranged at a position above the joint. Furthermore, the copper refrigerant tube, which is positioned lower than the joint, is provided with a copper straight section, which extends downward in a straight line from the joint with a length exceeding the outer diameter of the copper refrigerant tube.

2. The refrigeration cycle apparatus according to claim 1, characterized in that, A U-shaped section with a downward convex shape is provided at the lower end of the copper straight section.

3. The refrigeration cycle apparatus according to claim 1 or 2, characterized in that, The aluminum refrigerant pipe is provided with: an aluminum straight section that extends parallel to the bottom surface of the heat exchanger above the joint; and an inverted U-shaped section that is disposed between the aluminum straight section and the joint and is formed into a convex shape on the upward side.

4. The refrigeration cycle apparatus according to claim 1 or 2, characterized in that, A waterproof covering material is provided to cover the joint and the copper straight section.

5. The refrigeration cycle apparatus according to claim 2, characterized in that, A waterproof covering material is provided at one end of the copper refrigerant pipe to cover the joint and the straight copper section. The other end of the copper refrigerant tube is joined to the second copper refrigerant tube by welding. The distance between the joint of the second copper refrigerant tube and the U-shaped part and the joint is set to a distance that will not cause heat effects from welding on the waterproof covering material and the aluminum refrigerant tube.

6. The refrigeration cycle apparatus according to claim 1 or 2, characterized in that, The heat exchanger-side joint where the tube connects to the aluminum refrigerant tube is positioned above the joint.

Images