Refrigeration Cycle Equipment

Abstract

To provide a refrigeration cycle device in which even if a joining portion between an aluminum refrigerant pipe and a copper refrigerant pipe is arranged while being inclined in a horizontal direction, electrolytic corrosion caused by the intervention of water including a copper ion can be prevented.SOLUTION: In a refrigeration cycle device having an aluminum-made or aluminum-alloy made aluminum refrigerant pipe 22 connected to an end portion 18a of a tube which is arranged in a heat exchanger 11, and protruding to the outside of the heat exchanger, a copper-made or copper-alloy made copper refrigerant pipe 23 connected to a control component such as a four-way valve and an expansion valve, and a joining portion 24 for joining the aluminum refrigerant pipe and the copper refrigerant pipe, the joining portion is arranged along a vertical direction vertical to a bottom face 3 of the heat exchanger, the aluminum refrigerant pipe is arranged at an upper side of the joining portion, and a copper linear line part 27 linearly extending downward from the joining portion by a length equal to or longer than an outside diameter of the copper refrigerant pipe is arranged at the copper refrigerant pipe which is arranged at a lower side of the joining portion.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a refrigeration cycle device. [Background technology]

[0002] In an air conditioner as a refrigeration cycle device, an indoor heat exchanger, an outdoor heat exchanger, a compressor, and control parts (four-way valve, expansion valve, etc.) are connected by refrigerant piping, and the refrigerant piping used is made of copper or copper alloy (hereinafter referred to as copper refrigerant piping). In recent years, due to the demand for 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 tubes installed in the indoor heat exchanger and the outdoor heat exchanger and the refrigerant piping protruding outside the indoor heat exchanger and the outdoor heat exchanger.

[0003] On the other hand, due to reliability and manufacturing issues, copper refrigerant pipes, which are more malleable than aluminum, are generally used for the refrigerant piping connected to the control components. Therefore, joints are formed to join the aluminum refrigerant pipes protruding from the indoor heat exchanger and the outdoor heat exchanger to the copper refrigerant pipes connected to the control components.

[0004] During heating operation of an air conditioner, low-temperature refrigerant flows through the refrigerant pipe of the outdoor heat exchanger used as an evaporator, and water vapor contained in the outside air condenses, causing dew to adhere to the copper refrigerant tube. When dew adheres to the copper refrigerant tube, water containing copper ions is generated, and when this water containing copper ions flows to the joint between the aluminum refrigerant tube and the copper refrigerant tube, there is a risk of electrolytic corrosion occurring in the aluminum refrigerant tube at the joint. Furthermore, when heating operation is performed under low outside air temperatures, the water generated in the copper refrigerant tube freezes, and frost or ice may adhere to the copper refrigerant tube. When the frost or ice that has adhered to the copper refrigerant tube is melted by defrosting operation, water containing copper ions is generated, and when this water flows to the joint between the aluminum refrigerant tube and the copper refrigerant tube, there is a risk of electrolytic corrosion occurring in the aluminum refrigerant tube.

[0005] As a technique for preventing water containing copper ions from flowing into the joint between an aluminum refrigerant tube and a copper refrigerant tube, there is known a technique in which at least one of an inverted U-shaped portion in which the aluminum refrigerant tube has an upwardly convex shape and a U-shaped portion in which the copper refrigerant tube has a downwardly convex shape is provided near the joint (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2014-159952 A Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, the technology of Patent Document 1 prevents water containing copper ions from flowing into the joint when the joint between the aluminum refrigerant tube and the copper refrigerant tube protruding outside the outdoor heat exchanger is arranged horizontally. However, when the joint is arranged at an angle to the horizontal direction, for example, when the joint is located below the U-shaped portion made of the copper refrigerant tube, water containing copper ions generated in the U-shaped portion flows toward the joint, and there is a risk of electrolytic corrosion occurring in the aluminum refrigerant tube at the joint. Therefore, the present invention has been made to solve such problems, and has an object to provide a refrigeration cycle device that can prevent electrolytic corrosion caused by the presence of water containing copper ions, even if the joint between the aluminum refrigerant tube and the copper refrigerant tube is arranged at an angle to the horizontal direction. [Means for solving the problem]

[0008] One aspect of the invention is a refrigeration cycle device having an aluminum refrigerant tube made of aluminum or an aluminum alloy connected to an end of a tube provided inside a heat exchanger and protruding outside the heat exchanger, a copper refrigerant tube made of copper or a copper alloy connected to control components such as a four-way valve and an expansion valve, and a joint that joins the aluminum refrigerant tube and the copper refrigerant tube, the joint being arranged in a vertical direction perpendicular to a bottom surface of the heat exchanger, the aluminum refrigerant tube being arranged above the joint, and the copper refrigerant tube arranged below the joint being provided with a copper straight portion that extends linearly downward from the joint with a length equal to or greater than the outer diameter of the copper refrigerant tube. Effect of the Invention

[0009] According to the refrigeration cycle device of the present invention, even if the joint between the aluminum refrigerant tube and the copper refrigerant tube is arranged at an angle to the horizontal direction, it is possible to prevent electrolytic corrosion at the joint due to the presence of water containing copper ions. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing the appearance of an outdoor unit constituting a refrigeration cycle apparatus according to the present invention; [Diagram 2] FIG. 2 is a diagram showing the internal structure of the outdoor unit. [Diagram 3] FIG. 2 is a diagram showing a heat exchanger disposed inside the outdoor unit. [Figure 4] FIG. 2 is a diagram showing a specific arrangement of a first refrigerant tube consisting of an aluminum refrigerant tube and a copper refrigerant tube connected to a tube of a heat exchanger. [Diagram 5] FIG. 11 is a diagram showing the arrangement of first refrigerant pipes when the heat exchanger is arranged at an angle. [Figure 6] FIG. 11 is a view showing a joint portion of an aluminum refrigerant tube and a copper refrigerant tube in a second embodiment. [Figure 7] FIG. 13 is a diagram showing a joint portion of an aluminum refrigerant tube and a copper refrigerant tube in a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Next, an embodiment of the present invention will be described with reference to the drawings. The embodiments shown below are examples of devices and methods for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention does not specify the materials, shapes, structures, arrangements, etc. of the components to be described below. The technical idea of ​​the present invention can be modified in various ways within the technical scope defined by the claims.

[0012] [Outdoor unit of the first embodiment] FIG. 1 is a diagram showing the external appearance of an outdoor unit 1 of an air conditioner, which is a type of refrigeration cycle device, and FIG. As shown in Fig. 1, the outdoor unit 1 has a box-shaped housing 2. The housing 2 has a base 3 (see Fig. 2) that forms the bottom surface of the housing 2, a front panel 4 that forms the front surface of the housing 2, a right panel 5 and a left panel 6 that form the sides of the housing 2, and a top plate 7 that forms the top surface of the housing 2. An air outlet is provided in the front panel 4, and a fan guard 8 is attached to the air outlet. The base 3 corresponds to the bottom surface of the present invention.

[0013] As shown in FIG. 2, the housing 2 accommodates a compressor 10, a heat exchanger (outdoor heat exchanger) 11, an expansion valve 12, a blower fan 13, an electrical unit 14, and the like. The internal space of the housing 2 is divided by a partition plate 15 into a machine chamber 16 in which the compressor 10, expansion valve 12, electrical unit 14, etc. are arranged, and a heat exchange chamber 17 in which the blower fan 13 and heat exchanger 11 are arranged.

[0014] 2, the heat exchanger 11 is provided in an L-shape from the rear side to the left side of the housing 2, and has a meandering tube 18 and a plurality of fins 19 formed from a thin metal plate. The plurality of fins 19 extend in the vertical direction and are arranged at equal intervals in the horizontal direction to form an L-shape. The tube 18 is a refrigerant pipe made of aluminum or an aluminum alloy, and is inserted in a direction perpendicular to the plurality of fins 19 arranged in the L-shape and folded back so as to be aligned parallel to the vertical direction.

[0015] As shown in Fig. 3, one end of the tube 18 protrudes outward from the lower side of the right side of the heat exchanger 11, and one end of a first refrigerant pipe 20 is joined to one end 18a (see Fig. 4) of the tube 18. The expansion valve 12 is connected to the other end of the first refrigerant pipe 20. The other end 18b of the tube 18 protrudes outward from the upper side of the right side of the heat exchanger 11, and one end of a second refrigerant pipe 21 is joined to the other end 18b of the tube 18. The compressor 10 is connected to the other end of the second refrigerant pipe 21.

[0016] During heating operation of the air conditioner, the heat exchanger 11 is used as an evaporator, and the low-temperature refrigerant reduced in pressure by the expansion valve 12 flows through the first refrigerant pipe 20, the tube 18 of the heat exchanger 11, the second refrigerant pipe 21, and the compressor 10 in that order. The first refrigerant pipe 20 has an aluminum refrigerant pipe 22 made of aluminum or an aluminum alloy that is joined to one end 18a of the tube 18, and a copper refrigerant pipe 23 made of copper or a copper alloy that is joined to the expansion valve 12.

[0017] The aluminum refrigerant pipe 22 and the copper refrigerant pipe 23 are straight pipe members having the same outer diameter, and a joint 24 is formed by joining the ends of the pipes. A cylindrical waterproof covering material 31 made of an insulating material is attached to the joint 24, the outer periphery of the end of the aluminum refrigerant pipe 22, and the outer periphery of the end of the copper refrigerant pipe 24. This waterproof covering material 31 is a heat shrink tube that fits closely to the outer periphery of the end of the joint 24, the second straight portion 26b, and the copper straight portion 27.

[0018] The straight aluminum refrigerant pipe 22 is bent to have an aluminum straight portion 25 and an aluminum U-shaped portion 26 formed continuously from an end of the aluminum straight portion 25. The aluminum U-shaped portion 26 has a first straight portion 26a bent in a direction perpendicular to the aluminum straight portion 25, a second straight portion 26b extending parallel to the first straight portion 26a and being longer than the first straight portion 26a, with a joint portion 24 formed on the end side, and a semicircular arc portion 26c connecting one ends of the first straight portion 26a and the second straight portion 26b. The straight copper refrigerant pipe 23 is bent to have a copper straight portion 27 having a joint portion 24 formed on the end side thereof, and a U-shaped copper U-shaped portion 28 formed continuously from the end of the copper straight portion 27. The length L of the copper straight portion 27 is set to a dimension equal to or greater than the outer diameter φ of the copper refrigerant pipe 23.

[0019] The aluminum refrigerant tube 22 is arranged so that the aluminum U-shaped portion 26 is convex upward, and the end of the aluminum straight portion 25 is joined to one end 18a of the tube 18 so that the aluminum straight portion 25 extends parallel to the base 3. As a result, the second straight portion 26b of the aluminum U-shaped portion 26 is arranged along the up-down direction perpendicular to the base. The joining position of the aluminum straight portion 25 and one end 18a of the tube 18 is referred to as the heat exchanger side joining portion 29. The aluminum U-shaped portion 26 arranged in an upward convex shape corresponds to the inverted U-shaped portion of the aluminum refrigerant tube in the present invention. The length L of the copper straight portion 27 corresponds to a length equal to or greater than the outer diameter of the copper refrigerant tube extending linearly downward from the joining portion of the copper straight portion in the present invention.

[0020] The joint 24 between the aluminum refrigerant pipe 22 and the copper refrigerant pipe 23 is formed by butt-welding the upper end of the copper straight portion 27 of the copper refrigerant pipe 23 to the lower end of the second straight portion 26b of the aluminum refrigerant pipe 22, and this joint 24 is arranged along the up-down direction perpendicular to the base 3.

[0021] The copper U-shaped portion 28 of the copper refrigerant tube 23 is disposed so as to form a downwardly convex shape, and the heat exchanger side joint portion 29 between the aluminum straight portion 25 and one end 18a of the tube 18 is disposed in a position above the joint portion 24 and the copper U-shaped portion 28 of the copper refrigerant tube 23. The copper U-shaped portion 28 disposed so as to form a downwardly convex shape corresponds to the U-shaped portion of the copper refrigerant piping in the present invention. Here, another copper refrigerant tube 30 is joined by welding to the other end of the copper U-shaped portion 28, and this copper refrigerant tube 30 corresponds to the second copper refrigerant tube in the present invention and is connected to the expansion valve 12.

[0022] The waterproof covering material 31 adheres closely to the outer periphery of the joint 24, the lower end of the second straight portion 26b, and the upper end of the copper straight portion 27, thereby ensuring watertightness of the joint 24 and the copper straight portion 27 and preventing water containing copper ions from being generated at the joint 24 and the copper straight portion 27 close to 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. In other words, the waterproof covering material 31 needs to be attached to at least the joint 24 and the copper straight portion 27. The waterproof covering material 31 is not limited to a heat shrink tube, and watertightness can also be ensured by using a water-repellent coating, butyl rubber, or the like.

[0023] Here, when the joint between the copper U-shaped portion 28 and the copper refrigerant pipe 30 is welded, it is sufficient that the flame of the welding burner does not directly strike the waterproof covering material 31 and the aluminum refrigerant pipe 22, and that the heat of the welding burner does not cause the shape of the waterproof covering material 31 to deform, thereby impairing the covering effect. In other words, this distance corresponds to the distance in the present invention where the thermal effect of welding is not exerted on the waterproof covering material and the joint.

[0024] Next, the operation of the heat exchanger 11 having the first refrigerant pipe 20 will be described with reference to Fig. 4 and Fig. 5. Fig. 4 shows a state in which the base 3 of the housing 2 is installed on a horizontal installation surface, and Fig. 5 shows a state in which the base 3 of the housing 2 is installed on an installation surface inclined at Θ = 5°, which is the maximum inclination angle at which the heat exchanger 11 can be installed. Hereinafter, Fig. 4 will be referred to as the horizontal installation state, and Fig. 5 will be referred to as the inclined installation state.

[0025] When the air conditioner is operated in heating mode under low outdoor air temperatures, a low-temperature refrigerant flows through the first refrigerant tube 20 of the heat exchanger 11 used as an evaporator, and the water vapor contained in the outdoor air condenses, causing frost or ice to adhere to the copper refrigerant tube 23. When the frost or ice that has adhered to the copper refrigerant tube 23 is melted by defrosting operation, water containing copper ions is generated, which may accumulate in the copper U-shaped portion 28.

[0026] The joint 24 of the first refrigerant pipe 20 is arranged along the vertical direction, whether in the horizontal installation state of FIG. 4 or the inclined installation state of FIG. 5, and the second straight portion 26b of the aluminum refrigerant pipe 22 is arranged above the joint 24, and the copper straight portion 27 of the copper refrigerant pipe 23 is arranged below the joint 24, so that water containing copper ions that has accumulated in the copper U-shaped portion 28 does not flow to the joint 24.

[0027] In addition, since the length L of the copper straight portion 27 is set to a dimension equal to or larger than the outer diameter of the copper straight portion 27 and the distance between the copper U-shaped portion 28 and the joint 24 is ensured to be larger than the size of water droplets generated by condensation, even if frost or ice generated in the copper U-shaped portion 28 grows, it is difficult for it to reach the joint 24. Therefore, even if the frost or ice generated in the copper U-shaped portion 28 is melted by the defrosting operation, water containing copper ions is generated in the joint 24, and it is possible to prevent the water from reaching the aluminum refrigerant pipe 22.

[0028] In addition, the aluminum refrigerant pipe 22 is provided with an aluminum straight section 25 extending parallel to the base 3 above the joint 24, and an aluminum U-shaped section 26 arranged in an upwardly convex shape between the aluminum straight section 25 and the joint 24, so that vibrations caused by the compressor can be prevented from being transmitted to the heat exchanger side joint 29 via the copper refrigerant pipe 23.

[0029] Furthermore, the heat exchanger-side joint 29 between 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. Therefore, even in the inclined installation state shown in FIG. 5, water containing copper ions that has accumulated in the copper U-shaped section 28 is reliably prevented from flowing into the aluminum straight section 25 and the heat exchanger 11. Furthermore, since a waterproof covering material 31 is attached to the outer periphery of the joint 24 to ensure watertightness, water containing copper ions is reliably prevented from flowing into the joint 24.

[0030] Therefore, even if the heat exchanger 11 is installed on an inclined surface, the joint 24 of the first refrigerant pipe 20 is arranged along the vertical direction, so that water containing copper ions does not flow to the joint 24 of the copper refrigerant pipe 23 (copper straight portion 27) and the aluminum refrigerant pipe 22 (second straight portion 26b), and electrolytic corrosion of the aluminum refrigerant pipe 22 (second straight portion 26b) can be reliably prevented. Furthermore, the joint between the copper U-shaped portion 28 and the copper refrigerant pipe 30 is positioned at a distance such that the flame from the welding burner does not directly strike the waterproof covering material 31 and the aluminum refrigerant pipe 22 when the end faces are welded together, so that the welding work between the copper U-shaped portion 28 and the copper refrigerant pipe 30 can be performed easily and accurately.

[0031] [Joints of the second and third embodiments] Next, Figures 6 and 7 show second and third embodiments of the joints, which have a structure different from the joint 24 of the first embodiment of the aluminum refrigerant pipe 22 (second straight portion 26b) and the copper refrigerant pipe 23 (copper straight portion 27) shown in Figure 4. 6 shows a joint in the second embodiment, in which a stainless steel pipe 32 is disposed between the upper end of the copper straight section 27 and the lower end of the second straight section 26b, the upper end of the copper straight section 27 is joined to one end of the stainless steel pipe 32 by welding, and the lower end of the second straight section 26b is joined to the other end of the stainless steel pipe 32 by welding to form a joint 33. A waterproof covering material 31 is attached to the outer periphery of the joint 33, the second straight section 26b, and the copper straight section 27.

[0032] In the second embodiment, the joint 33 of the copper refrigerant pipe 23 (copper straight portion 27) and the aluminum refrigerant pipe 22 (second straight portion 26b) is arranged along the vertical direction. Therefore, even if the heat exchanger 11 is installed on an inclined surface, water containing copper ions does not flow to the joint 33, and electrolytic corrosion of the aluminum refrigerant pipe 22 (second straight portion 26b) can be reliably prevented.

[0033] 7 shows a joint in the second embodiment, in which an upper end of the copper straight portion 27 and a lower end of the second straight portion 26b are butted together, and the copper straight portion 27 and the second straight portion 26b are joined by a joint member 34 attached to the outer periphery of the copper straight portion 27 and the second straight portion 26b to form a joint 35. A waterproof covering material 31 is attached to the outer periphery of the joint 35, the second straight portion 26b and the copper straight portion 27.

[0034] In the third embodiment, the joint 35 of the copper refrigerant pipe 23 (copper straight portion 27) and the aluminum refrigerant pipe 22 (second straight portion 26b) is arranged along the vertical direction. Therefore, even if the heat exchanger 11 is installed on an inclined surface, water containing copper ions does not flow to the joint 35, and electrolytic corrosion of the aluminum refrigerant pipe 22 (second straight portion 26b) can be reliably prevented. [Explanation of symbols]

[0035] 1 Outdoor unit 2. Chassis 3. Bass 4 Front Panel 5 Right Panel 6 Left Side Panel 7. Tabletop 8 Fan Guard 10 Compressor 11 Heat exchanger 12 Expansion valve 13 Blower fan 14 Electrical unit 15 Partition 16 Machine room 17 Heat exchange room 18 Tube 18a One end of the tube 18b Other end of tube 19 Finn 20 First refrigerant pipe 21 Second refrigerant pipe 22 Aluminum refrigerant pipe 23 Copper refrigerant pipe 24 Joint 25 Aluminum straight section 26 Aluminum U-shaped section 26a 1st straight section 26b 2nd straight section 26c Semicircular arc section 27 Copper straight section 28 Copper U-shaped part 29 Heat exchanger side joint 30 Copper refrigerant pipe 31 Waterproof covering material 32 Stainless Steel Pipe 33 Joint 34 Joint members 35 Joint

Claims

1. an aluminum refrigerant tube made of aluminum or an aluminum alloy, which is connected to an end of a tube provided inside the heat exchanger and protrudes outside the heat exchanger; A copper refrigerant pipe made of copper or copper alloy and connected to a four-way valve or an expansion valve; a joint portion for joining the aluminum refrigerant pipe and the copper refrigerant pipe, The joint portion is disposed along a vertical direction perpendicular to a bottom surface of the heat exchanger, The aluminum refrigerant pipe is disposed above the joint, The copper refrigerant tube disposed below the joint has a copper straight portion extending downward from the joint in a straight line with a length equal to or greater than the outer diameter of the copper refrigerant tube, A U-shaped portion having a downward convex shape is provided at a lower end of the copper straight portion, The aluminum refrigerant pipe is provided with an inverted U-shaped portion joined to the joint portion and having an upwardly convex shape, a heat exchanger that is connected to the inverted U-shaped portion of the aluminum refrigerant pipe;

2. 2. The refrigeration cycle apparatus according to claim 1, further comprising a waterproof covering material for covering said joints and said copper straight portions.

3. A waterproof coating material is provided at one end of the copper refrigerant pipe to cover the joint portion and the copper straight portion, 3. The refrigeration cycle device according to claim 1, wherein the other end of the copper refrigerant tube is joined to a second copper refrigerant tube by welding, and a distance between the joint portion and a portion where the second copper refrigerant tube and the U-shaped portion are joined is set to a distance that does not cause a thermal effect due to welding on the waterproof coating material and the aluminum refrigerant tube.

4. 3. The refrigeration cycle apparatus according to claim 1, wherein a heat exchanger-side joint portion for joining the tube and the aluminum refrigerant pipe is disposed at a position above the joint portion.

5. An aluminum refrigerant tube made of aluminum or an aluminum alloy, connected to an end of a tube provided inside a heat exchanger and protruding outside the heat exchanger; A copper refrigerant pipe made of copper or copper alloy and connected to a four-way valve or an expansion valve; a joint portion for joining the aluminum refrigerant pipe and the copper refrigerant pipe, The joint portion is disposed along a vertical direction perpendicular to a bottom surface of the heat exchanger, The aluminum refrigerant pipe is disposed above the joint, The copper refrigerant tube disposed below the joint has a copper straight portion extending downward from the joint in a straight line with a length equal to or greater than the outer diameter of the copper refrigerant tube, A U-shaped portion having a downward convex shape is provided at a lower end of the copper straight portion, The aluminum refrigerant pipe is provided with an inverted U-shaped portion joined to the joint portion and having an upwardly convex shape, The aluminum refrigerant pipe is connected to an end of the tube provided below the heat exchanger and protrudes outside the heat exchanger.

Images