Air conditioner

Abstract

The present invention aims at using an aluminum pipe in an indoor heat exchanger and suppressing refrigerant sound. An air conditioner has a heat conducting pipe formed of aluminum or an aluminum alloy and provided in an indoor heat exchanger, and a connection pipe connected to the heat conducting pipe and at least a part of which is formed of aluminum or an aluminum alloy. A thin diameter portion formed at an end of the connection pipe is inserted into the heat conducting pipe, and the length of at least one of the thin diameter portions inserted into two refrigerant outlets of the indoor heat exchanger is shorter than the length of the thin diameter portion inserted into a refrigerant outlet of an outdoor heat exchanger.

Description

Technical Field

[0001] This invention relates to an air conditioner. Background Technology

[0002] Air conditioner heat exchangers use copper pipes, but aluminum is cheaper than copper. Therefore, in recent years, there has been an increase in the use of aluminum pipes in outdoor unit heat exchangers. Patent Document 1 discloses an outdoor heat exchanger utilizing aluminum pipes.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2023-13765 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the connection section between the connecting pipe between the indoor and outdoor units and the heat-conducting pipe in the heat exchanger, a shrinkage section formed at the end of the connecting pipe is inserted into the end of the heat-conducting pipe. Compared to copper pipes, aluminum pipes require a larger wall thickness. Therefore, when using aluminum pipes, the ratio of the inner diameter of the heat-conducting pipe to the inner diameter of the shrinkage section is larger than that of copper pipes, resulting in increased pressure loss and a problem of increased refrigerant noise.

[0008] The present invention was made in view of the following problem, and its purpose is to utilize aluminum tubes in an indoor heat exchanger and suppress refrigerant noise.

[0009] Solution for solving the problem

[0010] The present invention is an air conditioner comprising: a heat-conducting pipe formed of aluminum or aluminum alloy and disposed in an indoor heat exchanger; and a connecting pipe connected to the heat-conducting pipe, at least a portion of which is formed of aluminum or aluminum alloy, wherein a narrow diameter portion formed at the end of the connecting pipe is inserted into the heat-conducting pipe, and at least one of the narrow diameter portions inserted into two refrigerant inlets / outlets of the indoor heat exchanger has a shorter length than the narrow diameter portion inserted into the refrigerant inlet / outlet of the outdoor heat exchanger.

[0011] The present invention is an air conditioner comprising: a heat-conducting pipe formed of aluminum or aluminum alloy and disposed in an indoor heat exchanger; and a connecting pipe inserted into the heat-conducting pipe, at least a portion of which is formed of aluminum or aluminum alloy, the heat-conducting pipe having a large diameter portion whose outer diameter is larger than the outer diameter of the portion overlapping with the fin area of ​​the indoor heat exchanger, a small diameter portion formed at the end of the connecting pipe being inserted into the heat-conducting pipe, and at least one of the small diameter portions, which are respectively inserted into two refrigerant inlets and outlets of the indoor heat exchanger, having a length shorter than the length of the large diameter portion.

[0012] The present invention is an air conditioner comprising: a heat-conducting pipe formed of aluminum or aluminum alloy and disposed in an indoor heat exchanger; and a connecting pipe inserted into the heat-conducting pipe, at least a portion of which is formed of aluminum or aluminum alloy, wherein the connecting pipe is inserted into a portion of the indoor heat exchanger that overlaps with the fin area, and the length of the portion of the connecting pipe inserted into at least one of the two refrigerant inlets / outlets of the indoor heat exchanger that overlaps with the fin area is shorter than the length of the portion of the connecting pipe inserted into the refrigerant inlet / outlet of the outdoor heat exchanger that overlaps with the fin area.

[0013] Invention Effects

[0014] According to the present invention, aluminum tubes can be used in indoor heat exchangers, and refrigerant noise can be suppressed. Attached Figure Description

[0015] Figure 1 This is a diagram showing the external structure of an air conditioner.

[0016] Figure 2 This is a diagram showing the refrigerant circuit of an air conditioner.

[0017] Figure 3 This is a diagram showing an indoor heat exchanger.

[0018] Figure 4 This is a schematic cross-sectional view of the connection between the heat pipe and the connecting piping.

[0019] Figure 5 This is an enlarged view of the fixed component. Detailed Implementation

[0020] Figure 1 This is a structural diagram showing the external appearance of the air conditioner 1 according to this embodiment. The air conditioner 1 performs air conditioning by circulating refrigerant in a refrigeration cycle. Figure 1 As shown, the air conditioner 1 includes an indoor unit 2 installed indoors (in the space where the air is conditioned), an outdoor unit 3 installed outdoors, and a remote control 4 operated by the user.

[0021] The indoor unit 2 is equipped with a remote control communication unit 5. The remote control communication unit 5 transmits and receives predetermined signals with the remote control 4 via infrared communication or the like. For example, the remote control communication unit 5 receives signals from the remote control 4 such as operation commands, stop commands, changes to the set temperature, changes to the operating mode, or timer settings. Furthermore, although in Figure 1 The details are omitted, but indoor unit 2 and outdoor unit 3 are connected via refrigerant piping and communication lines.

[0022] Figure 2 This is a diagram showing the refrigerant circuit Q of the air conditioner 1 according to the embodiment. Additionally, Figure 2The solid arrows shown indicate the flow of refrigerant during heating operation. Additionally, Figure 2 The dashed arrows shown indicate the flow of refrigerant during refrigeration operation.

[0023] In addition to the remote control communication unit 5, the indoor unit 2 also includes an indoor heat exchanger 6 and a cross-flow fan (also called a cross-flow fan or indoor fan) 7. In the indoor heat exchanger 6, heat exchange occurs between the refrigerant flowing through the heat pipes (described later) and the indoor air supplied from the cross-flow fan 7. The indoor heat exchanger 6 operates as either a condenser or an evaporator by switching the four-way valve 13 (described later). The cross-flow fan 7 is located near the indoor heat exchanger 6. Driven by the indoor fan motor 8, the cross-flow fan 7 supplies indoor air to the indoor heat exchanger 6. The specific structure of this indoor unit 2 will be described later.

[0024] The outdoor unit 3 includes a compressor 9, an outdoor heat exchanger 10, an outdoor fan 11, an outdoor expansion valve (expansion valve) 12, and a four-way valve 13. The compressor 9, driven by a compressor motor 14, compresses a low-temperature, low-pressure gaseous refrigerant and discharges it as a high-temperature, high-pressure gaseous refrigerant. In the outdoor heat exchanger 10, heat exchange occurs between the refrigerant flowing through the heat pipes and the outside air supplied from the outdoor fan 11. The outdoor heat exchanger 10 operates as either a condenser or an evaporator by switching via the four-way valve 13.

[0025] like Figure 1 As shown, the outdoor fan 11 is located near the outdoor heat exchanger 10. Driven by the outdoor fan motor 11a, the outdoor fan 11 draws outside air into the outdoor heat exchanger 10. The outdoor expansion valve 12 functions to depressurize the refrigerant after it has condensed in the condenser (one of the outdoor heat exchanger 10 and the indoor heat exchanger 6). Furthermore, the refrigerant depressurized in the outdoor expansion valve 12 is directed to the evaporator (the other of the outdoor heat exchanger 10 and the indoor heat exchanger 6).

[0026] The four-way valve 13 is a valve that switches the refrigerant flow path according to the operating mode of the air conditioner 1. By switching the four-way valve 13, during cooling operation, as shown by the dashed arrow, a refrigeration cycle is formed where the refrigerant circulates in the order of compressor 9, outdoor heat exchanger (condenser) 10, outdoor expansion valve 12, and indoor heat exchanger (evaporator) 6. Conversely, by switching the four-way valve 13, during heating operation, as shown by the solid arrow, a refrigeration cycle is formed where the refrigerant circulates in the order of compressor 9, indoor heat exchanger (condenser) 6, outdoor expansion valve 12, and outdoor heat exchanger (evaporator) 10. That is, in the refrigerant circuit Q where the refrigerant circulates sequentially through compressor 9, "condenser," outdoor expansion valve 12, and "evaporator," one of the aforementioned "condenser" and "evaporator" is the outdoor heat exchanger 10, and the other is the indoor heat exchanger 6.

[0027] Figure 3 This is a schematic diagram of the indoor heat exchanger 6. The indoor heat exchanger 6 has multiple fins 100, and multiple heat-conducting tubes (hairpin tubes) 110 are arranged through the fins 100. Moreover, the two ends of each heat-conducting tube 110 are connected to the ends of adjacent heat-conducting tubes 110 through a return pipe 112. The return pipe 112 is formed in a U-shape. In this way, multiple heat-conducting tubes 110 are connected in series through the return pipe 112 to form a long refrigerant flow path.

[0028] Two refrigerant inlets / outlets 114 in the indoor heat exchanger 6 within the heat pipe 110 are respectively connected to connecting pipes 120. In this embodiment, the heat pipe 110 and the connecting pipes 120 do not have branches but are connected through a single passage. The connecting pipes 120 are connected to the heat pipe 110 by brazing. The heat pipe 110, the return pipe 112, and the connecting pipes 120 are all made of aluminum or aluminum alloy.

[0029] Figure 4 This is a schematic cross-sectional view of the connection between the heat pipe 110 and the connecting pipe 120. Figure 3 The heat-conducting pipes 110 and connecting pipes 120 of the two refrigerant inlets / outlets 114 shown are all... Figure 4 The connection state is shown. A secondary expansion section 1101, with an enlarged inner diameter, is formed on the end side of the heat pipe 110. Furthermore, after the heat pipe 110 is inserted into the through hole provided in the fin 100, it undergoes primary expansion along its entire straight length, thereby tightly adhering to the fin 100. Then, the end of the heat pipe 110 that does not overlap with the fin 100 in the length direction is expanded (secondary expansion), thus forming the secondary expansion section 1101. That is, the secondary expansion section 1101 has a larger inner diameter than the portion of the through fin 100 that has undergone primary expansion. On the other hand, a contraction section 1201, with a reduced inner diameter, is formed on the end side of the connecting pipe 120. And, as... Figure 4 As shown, the shrink tube section 1201 is inserted into the refrigerant inlet / outlet 114 of the heat pipe 110, and brazing filler metal is injected between the shrink tube section 1201 and the refrigerant inlet / outlet 114, thereby connecting the heat pipe 110 to the connecting pipe 120. That is, the shrink tube section 1201 has a smaller inner diameter than the portion not inserted into the refrigerant inlet / outlet 114.

[0030] The shrinkage section 1201 is an example of a narrow-diameter section in the connecting pipe 120 whose outer diameter is smaller than the portion where the refrigerant inlet / outlet 114 is not inserted. Here, the shrinkage section 1201 (narrow-diameter section) extends from the starting point 1202 where the inner diameter of the connecting pipe 120 decreases to the end point 121 of the connecting pipe 120. The inner diameter at any point along the length of the shrinkage section 1201 is a dimension smaller than or equal to the inner diameter at the starting point 1202. That is, the inner diameters of the shrinkage sections 1201 may be the same or different. For example, the inner diameter of the shrinkage section 1201 may decrease as it approaches the end point 121 of the shrinkage section 1201.

[0031] Furthermore, the secondary expansion section 1101 is an example of a coarse-diameter section in the heat pipe 110 whose inner diameter is larger (thicker) than the portion penetrating the fins 100. Here, the secondary expansion section 1101 (coarse-diameter section) is the portion of the heat pipe 110 that does not penetrate the fins 100 of the indoor heat exchanger 6, extending from the starting point 1102 where the inner diameter of the heat pipe 110 increases to the end of the heat pipe 110 (refrigerant inlet / outlet 114). The inner diameter at any position along the length of the secondary expansion section 1101 is a dimension greater than or equal to the inner diameter at the starting point 1102. That is, the inner diameter of the secondary expansion section 1101 can be the same or different. For example, the inner diameter of the secondary expansion section 1101 can also increase as it approaches the end of the secondary expansion section 1101.

[0032] Here, the length L2 of the shrinking section 1201 is shorter than the length L1 of the secondary expanding section 1101. This results in a shorter connecting pipe 120 inserted into the heat-conducting pipe 110. For example, the length L1 of the secondary expanding section 1101 is 11 mm, while the length L2 of the shrinking section 1201 is 7 mm. Furthermore, in the outdoor heat exchanger 10, similarly to the indoor heat exchanger 6, the two pipes are connected by connecting the shrinking section of the connecting pipe to the expanding section of the heat-conducting pipe. The length of the shrinking section 1201 connected to the heat-conducting pipe 110 of the indoor heat exchanger 6 is shorter than the length of the shrinking section at the refrigerant inlet / outlet of the heat-conducting pipe inserted into the outdoor heat exchanger 10. The inner diameter of the shrinking section 1201 is smaller than the inner diameter of the connecting pipe 120 and the heat-conducting pipe 110, thus increasing pressure loss and refrigerant noise. In contrast, in the air conditioner 1 of this embodiment, by shortening the length of the shrink tube 1201, refrigerant noise can be suppressed.

[0033] On the other hand, the shrinkage section 1201 is inserted into the heat pipe 110 along its length until it overlaps with the fin region 1001 where the fins 100 are arranged. Here, the fin region 1001 is the range from one end of the fins 100 to the other end of the plurality of fins 100. The length L3 of the portion 1203 of the shrinkage section 1201 that overlaps with the fins 100 is shorter than the length of the portion of the connecting pipe inserted into the refrigerant inlet / outlet of the outdoor heat exchanger 10 that overlaps with the fins 100. In this way, by ensuring the portion 1203 of the shrinkage section 1201 that overlaps with the fins 100, the connection strength between the heat pipe 110 and the connecting pipe 120 can be maintained at a high level. In addition, by ensuring a predetermined length for the shrinkage section 1201, it is possible to prevent solder from flowing into the interior of the heat pipe 110.

[0034] In addition, as described above, the heat pipe 110 and the connecting pipe 120 are made of aluminum or aluminum alloy, therefore, the shrinking section 1201 and the secondary expanding section 1101 are also made of aluminum or aluminum alloy.

[0035] Furthermore, the connecting pipe 120 is made of aluminum or an aluminum alloy, and therefore has a thicker wall than the connecting pipe 120 made of copper. More specifically, the connecting pipe 120 of the air conditioner 1 includes both a gas pipe for gaseous refrigerant flow and a liquid pipe for liquid refrigerant or two-phase refrigerant flow. The connecting pipe 120 made of aluminum or an aluminum alloy used as a gas pipe has a thicker wall than the copper connecting pipe used as a gas pipe. Similarly, the connecting pipe 120 made of aluminum or an aluminum alloy used as a liquid pipe has a thicker wall than the copper connecting pipe used as a liquid pipe.

[0036] like Figure 3 As shown, both connecting pipes 120 connected to the two refrigerant inlets / outlets 114 of the heat pipe 110 are fixed to the return pipe 112. In this embodiment, both connecting pipes 120 are fixed to the return pipe 112a at the position closest to the refrigerant inlets / outlets 114 (the connection portion between the connecting pipe 120 and the heat pipe 110). When installing the air conditioner 1, the indoor unit 2 is installed indoors, and the outdoor unit 3 is installed outdoors. Moreover, the connecting pipe 120 of the indoor unit 2 is appropriately bent by a service personnel depending on the installation status of the indoor unit 2. When a portion of the connecting pipe 120 is bent, due to its stress, the connecting pipe 120 may sometimes break at the connection portion with the heat pipe 110. In contrast, in this embodiment, the connecting pipe 120 is fixed to the return pipe 112 from the connection portion with the heat pipe 110 to the bent portion. Therefore, stress during bending can be prevented from being transmitted to the connection between the heat pipe 110 and the connecting pipe 120, and the connecting pipe 120 can be prevented from breaking at the connection. Furthermore, by fixing the connecting pipe 120 to the return pipe 112a, which is closest to the refrigerant inlet / outlet 114, the winding space of the connecting pipe 120 can be reduced.

[0037] Furthermore, the connecting pipe 120 is fixed to the return pipe 112 at its straight portion 120a. This improves the workability of fixing the connecting pipe 120 to the return pipe 112.

[0038] The straight portion 120a of the connecting pipe 120 is covered by a covering member 130 and fixed to the return pipe 112a via a fixing member 132. The covering member 130 is formed of a material with a lower thermal conductivity than the connecting pipe. Specifically, the covering member 130 is formed of rubber or resin. This prevents heat exchange between the refrigerant flowing in the return pipe 112a and the refrigerant flowing in the portion of the connecting pipe 120 fixed to the return pipe 112a.

[0039] Furthermore, the fixing member 132 is made of resin. Thus, the fixing member 132 is made of a material softer than aluminum. This prevents the connecting pipe 120 and the return pipe 112 from being cut by the fixing member 132. Additionally, by using resin, it can have sufficient fixing strength.

[0040] Figure 5 This is an enlarged view of the fixing component 132. The fixing component 132 includes a strap portion 132a and a head portion 132b. The strap portion 132a is a strap-shaped component for bundling multiple components. The head portion 132b is a component for fixing both ends of the strap portion 132a. The strap portion 132a bundles the cover component 130 and the return pipe 112a together and fixes them by the head portion 132b. The head portion 132b is positioned on the cover component 130, not on the return pipe 112a. That is, the head portion 132b contacts the cover component 130 but not the return pipe 112a. With this configuration, damage to the return pipe 112a by the head portion 132b can be prevented.

[0041] Furthermore, the fixed position where the connecting pipe 120 and the return pipe 112 are fixed is the position in the return pipe 112 furthest from the fin 100, that is, the bottom part of the U-shape of the return pipe 112. This ensures the bending diameter during bending operations of the connecting pipe 120.

[0042] As described above, in the air conditioner 1 of this embodiment, the constricted portion 1201 of the connecting pipe 120 is shorter than conventionally used at the connection between the connecting pipe 120 and the heat transfer pipe 110. Therefore, even when using an aluminum pipe as the heat transfer pipe of the indoor heat exchanger 6, refrigerant noise can be suppressed. Furthermore, since the connecting pipe 120 is fixed to the return pipe 112a, the connecting pipe 120 can be prevented from breaking when bending it during the installation of the air conditioner 1.

[0043] Furthermore, the present invention is not limited to this specific embodiment. For example, variations of one embodiment can be applied to other embodiments, and various modifications / changes can be made within the scope of the spirit of the invention as described in the claims.

[0044] As a first variation, the connecting pipe 120 only needs to be fixed to the return pipe 112, and its position and the number of fixed points are not limited to the embodiment. The fixing position is preferably close to the connection portion between the heat pipe 110 and the connecting pipe 120, but on the other hand, if there are limitations due to the configuration of other components, the return pipe 112 may not be located in the closest position. Furthermore, the connecting pipe 120 may be fixed to multiple return pipes 112 at multiple locations.

[0045] As a second variation, the connecting pipe 120 can be fixed inside the indoor unit 2 to other components besides the connecting pipe, and the fixing target is not limited to the return pipe 112. For example, the connecting pipe 120 can also be fixed inside the indoor unit 2 to the housing.

[0046] As a third variation, the length L2 of the constricted tube section 1201 of at least one of the two refrigerant inlets / outlets 114 of the indoor heat exchanger 6 is shorter than the length of the constricted tube section (narrow diameter section) inserted into the refrigerant inlet / outlet of the outdoor heat exchanger 10.

[0047] As a fourth variation, in at least one of the two refrigerant inlets and outlets 114 of the indoor heat exchanger 6, the length L2 of the shrinking section 1201 is shorter than the length L1 of the secondary expanding section 1101.

[0048] As a fifth variation, in at least one of the two refrigerant inlets and outlets 114 of the indoor heat exchanger 6, the length L3 of the portion 1203 of the constricted tube section 1201 that overlaps with the fin region 1001 is shorter than the length of the portion of the connecting pipe inserted into the refrigerant inlet and outlet of the outdoor heat exchanger that overlaps with the fins.

[0049] Symbol Explanation

[0050] 1—Air conditioner; 2—Indoor unit; 3—Outdoor unit; 4—Remote control; 5—Remote control communication unit; 6—Indoor heat exchanger; 7—Crossflow fan; 8—Indoor fan motor; 9—Compressor; 10—Outdoor heat exchanger; 11—Outdoor fan; 11a—Outdoor fan motor; 12—Outdoor expansion valve; 13—Four-way valve; 14—Compressor motor; 100—Fin; 110—Heat pipe; 112—Return pipe; 112a—Return pipe; 114—Refrigerant inlet / outlet; 120—Connecting piping; 120a—Straight section; 120b—Part; 121—End; 130—Covering component; 132—Fixing component; 1001—Fin area; 1101—Expanding section; 1201—Contracting section; 1202—Starting point; 1203—Overlapping section.

Claims

1. An air conditioner, characterized in that, have: A heat pipe, formed of aluminum or an aluminum alloy, is installed in an indoor heat exchanger; and Connecting piping, which is connected to the heat pipe, and at least a portion thereof is formed of aluminum or an aluminum alloy. The narrow diameter portion formed at the end of the connecting pipe is inserted into the heat-conducting pipe. At least one of the narrow diameter portions inserted into the two refrigerant inlets and outlets of the indoor heat exchanger is shorter than the length of the narrow diameter portion inserted into the refrigerant inlet and outlet of the outdoor heat exchanger.

2. An air conditioner, characterized in that, have: A heat pipe, formed of aluminum or an aluminum alloy, is installed in an indoor heat exchanger; and Connecting piping, which is connected to the heat pipe, and at least a portion thereof is formed of aluminum or an aluminum alloy. The heat pipe has a larger outer diameter portion than the portion overlapping the fin area of ​​the indoor heat exchanger. The narrow diameter portion formed at the end of the connecting pipe is inserted into the heat-conducting pipe. At least one of the narrow diameter portions inserted into the two refrigerant inlets and outlets of the indoor heat exchanger is shorter than the length of the wide diameter portion.

3. An air conditioner, characterized in that, have: A heat pipe, formed of aluminum or an aluminum alloy, is installed in an indoor heat exchanger; and Connecting piping, which is inserted into the heat-conducting pipe, and at least a portion thereof is formed of aluminum or an aluminum alloy. The connecting pipe is inserted into the portion of the indoor heat exchanger that overlaps with the fin area. The length of the portion of at least one of the connecting pipes inserted into the two refrigerant inlets and outlets of the indoor heat exchanger that overlaps with the fin area is shorter than the length of the portion of the connecting pipe inserted into the refrigerant inlet and outlet of the outdoor heat exchanger that overlaps with the fin area.

4. The air conditioner according to any one of claims 1 to 3, characterized in that, The connecting pipe is connected to the heat pipe through a passage.

5. The air conditioner according to any one of claims 1 to 3, characterized in that, The connecting pipe and the heat-conducting pipe are connected by brazing filler metal.

6. The air conditioner according to any one of claims 1 to 3, characterized in that, At least one of the connecting pipes is fixed to other components other than the connecting pipes.

7. The air conditioner according to claim 6, characterized in that, At least one of the connecting pipes is fixed to the return pipe that connects the heat pipes to each other.

8. The air conditioner according to claim 1, characterized in that, The narrow section is inserted into the portion of the indoor heat exchanger that overlaps with the fin area.

9. The air conditioner according to claim 2, characterized in that, The narrow section is inserted into the portion of the indoor heat exchanger that overlaps with the fin area.

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