WO2016038865A1

WO2016038865A1 - Outdoor unit and refrigeration cycle device using same

Info

Publication number: WO2016038865A1
Application number: PCT/JP2015/004514
Authority: WO
Inventors: 雅也太田; 健介足達; 準市馬場
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2014-09-12
Filing date: 2015-09-07
Publication date: 2016-03-17
Also published as: CN105765308B; JPWO2016038865A1; CN105765308A; JP6318371B2

Abstract

This outdoor unit comprises: a heat exchanger provided with a plurality of fins, a heat transfer pipe, and a plurality of connection pipes; and a blower. A first end connection pipe and a second end connection pipe are provided at an end of the heat exchanger. The second end connection pipe is located below the first end connection pipe. The second end connection pipe comprises an aluminum refrigerant pipe which consists of aluminum or an aluminum alloy, a copper refrigerant pipe which consists of copper or a copper alloy, and a joint refrigerant pipe which is disposed between the aluminum refrigerant pipe and the copper refrigerant pipe. The joint refrigerant pipe is disposed closer to the blower than the connection pipe provided closest to the blower among the plurality of connection pipes.

Description

Outdoor unit and refrigeration cycle apparatus using the same

The present invention relates to an outdoor unit and a refrigeration cycle apparatus using the same.

As a conventional refrigeration cycle apparatus, particularly in an air conditioner, copper or copper is connected to an outdoor heat exchanger and a heat transfer pipe disposed inside the indoor heat exchanger, and a refrigerant pipe connecting these heat exchangers. The mainstream is to use a pipe member (copper refrigerant pipe) formed of a copper alloy. However, due to demands for weight reduction and cost reduction, in recent years, it has been proposed to use a pipe member (aluminum refrigerant pipe) partially formed of aluminum or an aluminum alloy (see Patent Document 1).

However, since aluminum is a material that has a relatively high ionization tendency, corrosion (electric corrosion) is likely to occur due to contact with different metals such as copper. Such corrosion occurs not only by direct contact between aluminum and copper but also by contact of water droplets containing copper ions with aluminum. In particular, in an air conditioner, low-temperature refrigerant flows through the refrigerant pipe of the indoor heat exchanger during cooling operation and through the refrigerant pipe of the outdoor heat exchanger during heating operation. For this reason, water vapor contained in the outside air is condensed and water droplets adhere to the refrigerant tube, and the water droplets may corrode aluminum. Therefore, in the above-mentioned Patent Document 1, a technique for covering a joint portion between an aluminum refrigerant pipe and a copper refrigerant pipe is proposed.

However, in the case of Patent Document 1, a new covering member is required, and it is difficult to meet the demand for cost reduction. Moreover, the work process in the field which installs refrigeration cycle apparatuses, such as an air conditioner, will increase. Further, unless the covering member is properly covered, corrosion of the aluminum refrigerant pipe cannot be prevented. Furthermore, there is a restriction that the service life of the covering member must be taken into consideration.

JP 2005-90761 A

In view of the circumstances as described above, the present invention provides an outdoor unit and a refrigeration cycle apparatus including a heat exchanger that can more appropriately prevent corrosion of an aluminum refrigerant pipe connected to a copper refrigerant pipe. For the purpose.

In order to solve the above-described conventional problems, an outdoor unit according to the present invention includes a plurality of fins stacked at a predetermined interval, a heat transfer tube penetrating in a direction orthogonal to a planar direction of the plurality of fins, and a plurality of heat transfer tubes. A heat exchanger including a plurality of connecting pipes that connect each other, and a blower that is provided in the planar direction of the fin and blows an airflow to the heat exchanger. A first end connecting pipe and a second end connecting pipe that connect the refrigerant pipe and the heat transfer pipe are provided at the end of the heat exchanger. The second end connecting pipe is located below the first end connecting pipe. The second end connection pipe includes an aluminum refrigerant pipe containing aluminum or an aluminum alloy, a copper refrigerant pipe containing copper or a copper alloy, and a joining refrigerant disposed between the aluminum refrigerant pipe and the copper refrigerant pipe. With a tube. The joining refrigerant pipe is arranged on the side where the blower is provided rather than the connection pipe located on the side where the blower is provided most among the plurality of connection pipes.

According to this, it is possible to reduce the dripping of water droplets condensed by other connecting pipes at the joint portion between the aluminum refrigerant pipe and the copper refrigerant pipe without increasing the size of the outdoor unit. For this reason, corrosion of the aluminum refrigerant pipe connected to the copper refrigerant pipe can be appropriately suppressed.

According to the present invention, it is possible to provide an outdoor unit and a refrigeration cycle apparatus that can more appropriately prevent corrosion of an aluminum refrigerant pipe connected to a copper refrigerant pipe.

FIG. 1 is a schematic diagram of an air conditioner that is a type of refrigeration cycle apparatus according to Embodiment 1. FIG. FIG. 2 is a partial schematic diagram of the heat exchanger according to the first embodiment. FIG. 3 is a schematic diagram of the outdoor unit according to the first embodiment. FIG. 4 is a partial front view of the outdoor heat exchanger according to the first embodiment. FIG. 5 is a side view of the outdoor heat exchanger according to the first embodiment. FIG. 6 is a top view of the outdoor heat exchanger according to the first embodiment. 7A is a rear view of the downstream end connecting pipe according to Embodiment 1. FIG. 7B is a side view of the downstream end connecting pipe according to Embodiment 1. FIG. FIG. 7C is a top view of the downstream end connecting pipe according to Embodiment 1. FIG. 8A is a side view for explaining the arrangement of the U-bend and the multi-curved pipe in the outdoor heat exchanger according to Embodiment 1. FIG. 8B is a side view for explaining the arrangement of the connecting pipes excluding the upstream end connecting pipe and the downstream end connecting pipe in the outdoor heat exchanger according to Embodiment 1.

The outdoor unit according to the first invention includes a plurality of fins stacked at a predetermined interval, a heat transfer tube penetrating in a direction orthogonal to the planar direction of the plurality of fins, and a plurality of connections connecting the plurality of heat transfer tubes. A heat exchanger provided with a tube, and a blower that is provided in the planar direction of the fin and blows an airflow to the heat exchanger. A first end connecting pipe and a second end connecting pipe that connect the refrigerant pipe and the heat transfer pipe are provided at the end of the heat exchanger. The second end connecting pipe is located below the first end connecting pipe. The second end connection pipe includes an aluminum refrigerant pipe containing aluminum or an aluminum alloy, a copper refrigerant pipe containing copper or a copper alloy, and a joining refrigerant disposed between the aluminum refrigerant pipe and the copper refrigerant pipe. With a tube. The joining refrigerant pipe is arranged on the side where the blower is provided rather than the connection pipe located on the side where the blower is provided most among the plurality of connection pipes. Here, “orthogonal” includes “substantially orthogonal”.

According to this, it is possible to reduce the water droplets condensed on the other connection pipes from dropping at the joint portion between the aluminum refrigerant pipe and the copper refrigerant pipe without increasing the size of the outdoor unit. For this reason, corrosion of the aluminum refrigerant pipe connected to the copper refrigerant pipe can be appropriately suppressed.

According to a second aspect of the invention, in particular, in the first aspect of the invention, the joining refrigerant pipe is a stainless steel refrigerant pipe containing iron and nickel or chromium, and the joining refrigerant pipe is formed by expanding an aluminum refrigerant pipe to form a joining refrigerant pipe. A first joining portion that is inserted; and a second joining portion in which the joining refrigerant tube is expanded and a copper refrigerant tube is inserted. The first joining portion is disposed above the second joining portion. .

According to this, since the joining refrigerant pipe (stainless steel refrigerant pipe) has only to be connected to the connection partner member at the manufacturing site or repair site, the work at the site becomes easy. Moreover, it can prevent that the water | moisture content adhering to the copper refrigerant | coolant pipe | tube moves to an aluminum refrigerant pipe | tube by providing a 1st junction part above a 2nd junction part.

In the third invention, particularly in the second invention, the first expanded portion where the aluminum refrigerant tube is expanded and the second expanded portion where the bonded refrigerant tube is expanded are arranged so that the opening faces downward. Has been.

Thereby, it is possible to prevent water droplets from staying at the place where the dissimilar metal is in contact with each other because the brazed portion is located below the first expanded portion and the second expanded portion in both the first bonded portion and the second bonded portion.

According to a fourth aspect of the invention, particularly in the third aspect of the invention, the copper refrigerant pipe includes an inclined portion that is inclined toward the second joint portion from above at a gentler angle than the inclination angle of the joint refrigerant tube.

According to this, the water droplets flowing down through the joining refrigerant pipe can be merged with the water droplets flowing down through the inclined portion. Furthermore, water droplets can be quickly dripped downward from the lowermost part of the connection location between the joining refrigerant pipe and the inclined portion.

According to a fifth aspect of the present invention, in the first aspect of the invention, the joining refrigerant pipe is a refrigerant pipe in which a pipe member formed of aluminum or an aluminum alloy and a pipe member formed of copper or a copper alloy are eutectic bonded. is there.

According to this, since the joining refrigerant pipe having the eutectic bonding portion may be connected to the counterpart member at the manufacturing site or the repair site, the work at the site becomes easy.

The sixth invention is a refrigeration cycle apparatus including the outdoor unit according to any one of the first to fifth.

According to this, since the outdoor unit including the heat exchanger that more appropriately prevents the corrosion of the aluminum refrigerant pipe connected to the copper refrigerant pipe can be employed, the weight of the refrigeration cycle apparatus as a whole can be reduced. Cost can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
Hereinafter, an air conditioner that is a type of a refrigeration cycle apparatus including an outdoor unit according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of an air conditioner according to the present embodiment. As shown in FIG. 1, the air conditioner 1 is configured by connecting an outdoor unit 1A and an indoor unit 1B.

The air conditioner 1 exchanges heat between the refrigerant and the outside air and becomes a condenser during the cooling operation and becomes an evaporator during the heating operation, and becomes an evaporator during the cooling by exchanging heat between the refrigerant and the room air. An indoor heat exchanger 3 serving as a condenser during heating and a refrigeration cycle circuit 4 including the

heat exchangers

2 and 3 are provided. Further, in the vicinity of the outdoor heat exchanger 2 and the indoor heat exchanger 3, fans 7 and 8, which are blowers driven by motors 5 and 6, respectively, are provided. The airflow generated by the rotational drive of the fans 7 and 8 flows through the

heat exchangers

2 and 3.

The refrigeration cycle circuit 4 is provided with a compressor 11, a four-way valve 12 for switching the refrigerant circuit during the cooling / heating operation, and a throttling device 13 for decompressing the refrigerant. The compressor 11 compresses and heats the low-temperature and low-pressure refrigerant from the indoor heat exchanger 3 to the outdoor heat exchanger 2 during the cooling operation to increase the pressure, and during the heating operation, it compresses the outdoor heat exchanger 2 to the indoor heat exchanger. The low-temperature and low-pressure refrigerant going to 3 is compressed to increase the pressure and temperature. Although not shown, a normal accumulator is connected in front of the compressor 11 to perform gas-liquid separation of the refrigerant so that the liquid refrigerant does not return to the compressor 11. As the throttle device 13, a capillary tube, an electric expansion valve, or the like can be employed.

The outdoor unit 1A includes an outdoor heat exchanger 2, a motor 5, a fan 7, a compressor 11, a four-way valve 12, a throttling device 13, and the like. The indoor unit 1B includes a motor 6, a fan 8, an indoor heat exchanger 3, and the like.

In the following description, the expressions “upstream” and “downstream” are used for convenience. These mean “upstream” and “downstream” in the refrigerant flow in the refrigeration cycle circuit 4 when the air conditioner 1 is in cooling operation. And the arrow attached | subjected along the refrigerating-cycle circuit 4 shown in FIG. 1 has shown the direction through which a refrigerant | coolant flows from "upstream" to "downstream" at the time of air_conditionaing | cooling operation. In addition, the refrigerant flow during the heating operation is opposite to the refrigerant flow during the cooling operation, as indicated by a broken line.

As shown in FIG. 1, the compressor 11 is provided with a refrigerant pipe 4 a, and its downstream end is connected to the first port of the four-way valve 12. In the four-way valve 12, a refrigerant pipe 4b is provided at a second port that communicates with the first port during cooling operation. The downstream end of the refrigerant pipe 4 b is connected to the upstream end of the heat transfer pipe 20 that is provided in the outdoor heat exchanger 2 and forms a part of the refrigeration cycle circuit 4. Another refrigerant pipe 4 c is provided at the downstream end of the heat transfer pipe 20 in the outdoor heat exchanger 2, and the downstream end of the refrigerant pipe 4 c is connected to the expansion device 13.

Another refrigerant pipe 4 d extends from the expansion device 13, and the downstream end of the refrigerant pipe 4 d is connected to one port of the two-way valve 14. The other port of the two-way valve 14 is provided with a liquid side connection pipe 41 that connects the outdoor unit 1A and the indoor unit 1B. The downstream end of the liquid side connection pipe 41 is connected to the indoor unit liquid side connection 15 (upstream connection as viewed from the indoor heat exchanger 3). Further, another refrigerant pipe 4 e is extended from the indoor unit liquid side connection portion 15, and the downstream end of the refrigerant pipe 4 e is provided in the indoor heat exchanger 3 and constitutes a part of the refrigeration cycle circuit 4. The heat pipe 30 is connected to the upstream end.

Another refrigerant pipe 4f is provided at the downstream end of the heat transfer pipe 30 in the indoor heat exchanger 3, and the downstream end of the refrigerant pipe 4f is connected to the indoor unit gas side connecting portion 16 (downstream as viewed from the indoor heat exchanger 3). Side connection part). The indoor unit gas side connection portion 16 is provided with a gas side connection pipe 42 that connects the outdoor unit 1A and the indoor unit 1B. A refrigerant pipe 4 g is connected to the downstream end of the gas side connection pipe 42 via the three-way valve 17. The downstream end of the refrigerant pipe 4g is connected to the third port of the four-way valve 12. In the four-way valve 12, a refrigerant pipe 4h extends from the fourth port communicating with the third port during cooling operation, and the downstream end of the refrigerant pipe 4h is connected to the compressor 11.

In this way, the refrigerant pipes 4a to 4h, the heat transfer pipe 20, the heat transfer pipe 30, the liquid side connection pipe 41, and the gas side connection pipe 42 constitute the refrigeration cycle circuit 4, and the refrigeration cycle circuit 4 compresses the refrigeration cycle circuit 4. The machine 11, the four-way valve 12, the outdoor heat exchanger 2, the expansion device 13, the indoor heat exchanger 3 and the like are connected.

The

refrigerant tubes

4a, 4d to 4h are copper refrigerant tubes containing copper or a copper alloy (hereinafter simply referred to as copper refrigerant tubes). The

refrigerant tubes

4b and 4c are a copper refrigerant tube, an aluminum refrigerant tube containing aluminum or an aluminum alloy (hereinafter simply referred to as an aluminum refrigerant tube), and a bonded refrigerant tube connecting the copper refrigerant tube and the aluminum refrigerant tube. It consists of and.

Next, the outdoor heat exchanger 2 that is a heat exchanger according to the embodiment of the present invention will be described in detail.

The outdoor heat exchanger 2 is a so-called fin-and-tube heat exchanger. As shown in FIG. 2, the fin-and-tube heat exchanger is mainly inserted into flat fins 21 stacked in large numbers at predetermined intervals, and through holes provided in the fins 21 at predetermined intervals. And a plurality of heat transfer tubes 20. The fin 21 typically has a rectangular and flat plate shape. The fins 21 are arranged at regular intervals (fin pitch FP). The fin pitch FP can be adjusted to a range of 1.0 to 1.5 mm, for example.

The outdoor heat exchanger 2 is configured to exchange heat between the air A (outdoor air) passing between the plurality of fins 21 and the medium B flowing inside the heat transfer tube 20. The medium B is a refrigerant such as hydrofluorocarbon, for example.

In this specification, the arrangement direction of the fins 21 is defined as the width direction, the longitudinal direction of the fins 21 is defined as the height direction, and the direction perpendicular to the width direction and the height direction is defined as the airflow direction (the flow direction of the air A). In other words, the airflow direction is perpendicular to the longitudinal direction of the fins 21. The airflow direction, the width direction, and the height direction correspond to the X direction, the Y direction, and the Z direction, respectively.

The heat transfer tube 20 is an aluminum refrigerant tube containing aluminum or an aluminum alloy. A U-bend 22a, which is a kind of connection pipe of the present invention, is provided at the end of the plurality of heat transfer tubes 20 located in the center in the refrigerant flow direction of the outdoor heat exchanger 2, and another heat transfer tube 20 in the vicinity thereof is provided. (See FIG. 4). Thereby, the heat exchanger tubes 20 meander and are connected. The heat transfer tubes 20 may be connected to form one flow path by the U bend 22a, or may be connected to form a plurality of flow paths by combining with other connection pipes such as branch pipes. Good. The connecting pipe such as the U bend 22a is an aluminum refrigerant pipe.

An end plate 27 made of a steel plate or the like is provided on the outer side of the outermost fin 21 (on the side where the U bend 22a is provided). The heat transfer tubes 20 protruding from the fins 21 are inserted into through holes provided in the end plates 27 and are connected to each other by U-bends 22a and the like.

FIG. 3 is a schematic configuration diagram of the outdoor unit 1A according to the present embodiment (viewed from the positive side in the Z direction to the negative side).

The bottom of the outdoor unit 1A is constituted by a substrate 50, and the top of the outdoor unit 1A is covered with a top plate (not shown). Further, the periphery of the outdoor unit 1 </ b> A is covered with a casing exterior plate 51 except for a portion where the outdoor heat exchanger 2 is exposed.

The interior of the outdoor unit 1A is partitioned into a compressor storage portion 53 and a blower storage portion 54 by a partition plate 52 fixed to the substrate 50 and the end plate 27 of the outdoor heat exchanger 2.

The compressor storage section 53 is a space that is partitioned on all sides by a part of the partition plate 52 and the casing exterior plate 51 and is vertically partitioned by a part of the top plate and a part of the substrate 50. The compressor storage unit 53 stores main components of the refrigeration cycle circuit 4 such as the compressor 11, the four-way valve 12, and the expansion device 13, the connection pipe of the outdoor heat exchanger 2, and the like.

The blower storage portion 54 stores a portion (heat exchange portion) closer to the fin 21 than the end plate 27 of the outdoor heat exchanger 2 and a fan 7 that is a blower that blows air to the outdoor heat exchanger 2.

The outdoor heat exchanger 2 is configured by bending two heat exchangers having a form as shown in FIG. 2 into a substantially L shape and arranging two in the X direction. Note that the end plates 27 of the two heat exchangers are integrally formed.

The fan 7, the compressor 11, the four-way valve 12, and the expansion device 13 that send air to the outdoor heat exchanger 2 are arranged on the inner side of the outdoor unit 1A from the outdoor heat exchanger 2.

FIG. 4 is a partial front view of the portion housed in the compressor housing portion 53 outside the end plate 27 of the outdoor heat exchanger 2 in the present embodiment (seeing the negative side from the positive side in the X direction). FIG. 5 is a side view thereof (view of the positive side from the negative side in the Y direction), and FIG. 6 is a top view thereof (view of the negative side from the positive side in the Z direction). It is. Note that the fan 7, the compressor 11, the four-way valve 12, and the expansion device 13 that blow the air to the outdoor heat exchanger 2 are on the positive side in the X direction in FIGS. 5 and 6 (the left side in FIG. 5 and FIG. 6). Has been placed.

Hereinafter, with reference to FIG. 4 to FIG. 6, the joint portion between the refrigerant tube 4b and the heat transfer tube 20 of the outdoor heat exchanger 2 and the joint portion between the heat transfer tube 20 and the refrigerant tube 4c will be described in detail.

First, the connection part of the upstream end of the outdoor heat exchanger 2 (point P1 indicated by a broken-line circle shape in FIG. 1) will be described in detail.

The connection part of the upstream end of the outdoor heat exchanger 2 is configured by an upstream end connection pipe 23. The upstream end connecting pipe 23 includes a U-shaped header lower pipe 23a that is a copper refrigerant pipe, a straight header pipe 23b that is an aluminum refrigerant pipe, and a header lower pipe 23a and a header pipe 23b. It is comprised by the upstream joint refrigerant pipe 23c which is the provided joint refrigerant pipe.

The header lower pipe 23a is formed so that one end of the U-shape is longer than the other end, and the four-way valve 12 is connected to the end of the longer side via the refrigerant pipe 4b. The other end side of the header lower pipe 23a is connected to the upstream side joining refrigerant pipe 23c. Further, both U-shaped linear portions are provided so as to be parallel to the height direction (Z direction) of the outdoor heat exchanger 2.

The header pipe 23b is provided so as to be parallel to the height direction (Z direction) of the outdoor heat exchanger 2, and includes a straight pipe whose one end is closed, and a plurality of extension pipes 23b1 communicating with the side portion of the straight pipe. It has. The extension tube 23b1 is connected to the heat transfer tube 20 of the outdoor heat exchanger 2, and extends the heat transfer tube 20 in the longitudinal direction. In the present embodiment, eight extension pipes 23b1 are provided, and the refrigerant flowing from the refrigerant pipe 4b to the upstream end of the outdoor heat exchanger 2 is divided into eight flow paths to the heat transfer pipe 20. Will flow in. Also, any two of the extension pipes 23b1 are arranged side by side in the X direction, and the heat exchanger is located on the downstream side in the air flow direction (A direction) (positive side from the negative side in the X direction). Is connected to a heat transfer tube 20 provided in the case (see FIGS. 8A and 8B described later).

The upstream joining refrigerant pipe 23c is a stainless steel refrigerant pipe (hereinafter simply referred to as a stainless steel refrigerant pipe) containing iron and nickel or chromium. The upstream joint refrigerant pipe 23c has a first joint 23c1 in which the lower end of the straight pipe of the header pipe 23b is expanded and the upstream joint refrigerant pipe 23c is inserted, and the upstream joint refrigerant pipe 23c is expanded to form a header lower pipe 23a. It is a straight pipe provided with the 2nd junction part 23c2 which inserted one end. The upstream joint refrigerant pipe 23c is arranged such that the first joint 23c1 is above the second joint 23c2.

Note that the upstream-side joining refrigerant tube 23c may be a refrigerant tube in which a tube member formed of aluminum or an aluminum alloy and a tube member formed of copper or a copper alloy are eutectic bonded.

Next, the connection location of the downstream end of the outdoor heat exchanger 2 (point P2 indicated by a broken-line circle shape in FIG. 1) will be described in detail.

The connection part of the downstream end part of the outdoor heat exchanger 2 is composed of a downstream end connection pipe 24. The downstream end connection pipe 24 includes a substantially L-shaped first connection pipe 24a that is a copper refrigerant pipe, a second connection pipe 24b that includes a plurality of bent portions that are aluminum refrigerant pipes, and a first connection pipe. It is comprised by the downstream side joining refrigerant pipe 24c which is a joining refrigerant pipe provided between 24a and the 2nd connection pipe 24b. One end of the downstream end connection pipe 24 is connected to the heat transfer pipe 20 provided on the upstream side in the air flow direction at the bottom of the outdoor heat exchanger 2 (see FIGS. 8A and 8B described later). The other end of the downstream end connecting pipe 24 is connected to the refrigerant pipe 4 c connected to the expansion device 13 via the strainer 26.

The downstream end connection pipe 24 is connected to the lower side of the upstream end connection pipe 23 in the height direction (Z direction) of the outdoor heat exchanger 2. Further, the downstream end connection pipe 24 has a pipe diameter smaller than that of the upstream end connection pipe 23.

As shown in FIG. 6 or FIG. 3, the substrate 50 is housed in the compressor of the outdoor unit 1A, vertically below the joint bent portion 24d, which is a connection portion between the first connection pipe 24a and the downstream joint refrigerant pipe 24c. A drain hole 55 is provided for communicating the portion 53 with the outside.

FIG. 7A is a rear view of the downstream end connection pipe 24 (viewed from the negative side in the X direction to the positive side). FIG. 7B is a side view of the downstream end connecting pipe 24 (viewed from the positive side in the Y direction to the negative side). FIG. 7C is a top view of the downstream end connecting pipe 24 (viewed from the positive side in the Z direction to the negative side).

As shown in FIGS. 7A to 7C, the first connecting pipe 24a is connected to the first rising portion 24a1 provided in parallel to the height direction (Z direction) of the outdoor heat exchanger 2 and the first rising portion 24a1. An inclined portion 24a2 bent at an obtuse angle and an insertion portion 24a3 bent at an obtuse angle with respect to the inclined portion 24a2 are provided. The inclined portion 24a2 is provided to be inclined with respect to the horizontal direction (XY plane) so that the first rising portion 24a1 side is above the insertion portion 24a3 side.

The second connection pipe 24b includes an extension part 24b1 extending the heat transfer pipe 20 in the longitudinal direction, a plurality of bending parts 24b2 bent at an obtuse angle with respect to the extension part 24b1, and a second rising rising substantially perpendicularly from the bending part 24b2. And a first expanded portion 24b4 that is bent at an acute angle with respect to the second rising portion 24b3 and has an end portion expanded.

The second connection pipe 24b includes the second rising part 24b3, so that the first pipe expansion part 24b4 is located above the extension part 24b1. The second connecting pipe 24b includes a bent portion 24b2 that is bent in the direction intersecting the longitudinal direction of the extension portion 24b1 and on which the fan 7 is provided. Thereby, the 1st pipe expansion part 24b4 becomes a side (positive side of the X direction) in which the fan 7 was provided from the longitudinal direction of the extension part 24b1.

1st pipe expansion part 24b4 is bent from 2nd standing part 24b3 so that the expanded opening may become below.

The downstream-side joining refrigerant pipe 24c is a stainless steel refrigerant pipe. One end is provided with a first joining section 24c1 inserted into the first pipe expanding section 24b4, and the other end is provided with a second joining section 24c2 expanded. It is a straight pipe. The downstream joint refrigerant pipe 24c is provided to be inclined with respect to the horizontal direction (XY plane) so that the first joint 24c1 is located above the second joint 24c2.

As a result, as shown in FIG. 7A, the joint bent portion 24d, which is a connection portion between the first connection pipe 24a and the downstream joint refrigerant pipe 24c, protrudes downward (the negative side in the Z direction).

The length of the downstream joint refrigerant pipe 24c is longer than the length of the inclined portion 24a2 of the first connection pipe 24a. Further, the inclination of the downstream joint refrigerant pipe 24c with respect to the horizontal direction (XY plane) is larger (steep) than the inclination of the inclined portion 24a2 of the first connection pipe 24a with respect to the horizontal direction (XY plane).

Further, as shown in FIGS. 7B and 7C, the downstream-side joining refrigerant pipe 24c has a second joining portion 24c2 side that is closer to the first joining portion 24c1 side than the side on which the fan 7 is provided (positive side in the X direction). It is provided to become. The inclined portion 24a2 of the first connecting pipe 24a is provided so that the insertion portion 24a3 side is closer to the side where the fan 7 is provided (the positive side in the X direction) than the first rising portion 24a1 side. As a result, the joint bent portion 24d protrudes from the first rising portion 24a1 and the second rising portion 24b3 to the side where the fan 7 is provided (positive side in the X direction).

The downstream joint refrigerant pipe 24c is also a refrigerant obtained by eutectic bonding of a pipe member formed of aluminum or an aluminum alloy and a pipe member formed of copper or a copper alloy, similarly to the upstream joint refrigerant pipe 23c. It may be a tube.

Furthermore, the connection between the heat transfer tubes 20 arranged inside the outdoor heat exchanger 2 will be described. FIG. 8A omits the description of the upstream end connection pipe 23, the downstream end connection pipe 24, and a branch pipe described later from FIG. 5, and describes the arrangement of the U-bend 22a and the multi-curved pipe 22b. It is a side view for explaining.

In FIG. 8A, the heat transfer tubes 20 connected to the eight extension tubes 23b1 are connected by the adjacent heat transfer tubes 20, the U-bend 22a, and the multi-curved tube 22b which is a kind of the connection tube of the present invention. A flow path is formed in the heat exchanger 2. The multi-curved tube 22b is a connecting tube having a large number of bent portions. The U-bend 22a connects the adjacent heat transfer tubes 20, whereas the multi-curved tube 22b connects the heat transfer tubes 20 arranged at positions away from the U-bend 22a. The multi-curved tube 22b is an aluminum refrigerant tube.

Thus, the refrigerant (arrow on the left side in FIG. 8A) that is divided into eight flow paths and flows into the heat transfer tubes 20 arranged on the downstream side in the air flow direction is arranged on the upstream side in the air flow direction. It flows out from the eight heat transfer tubes 20 provided in the heat exchanger (right arrow in FIG. 8A).

A branch pipe that joins the refrigerant flowing out of the eight heat transfer pipes 20 will be described with reference to FIG. 8B. FIG. 8B is a side view for explaining the arrangement of the connection pipes, omitting the description of the upstream end connection pipe 23 and the downstream end connection pipe 24 from FIG. 5. The outdoor heat exchanger 2 is a first branch pipe connected to the upper four heat transfer tubes 20 among the eight heat transfer tubes 20 provided in the heat exchanger arranged on the upstream side in the air flow direction. 25a, the second branch pipe 25b connected to the lower four heat transfer pipes 20, the downstream side of the first branch pipe 25a and the downstream side of the second branch pipe 25b via the plurality of heat transfer pipes 20 And a third branch pipe 25c to be connected.

Both the first branch pipe 25a and the second branch pipe 25b are provided with refrigerant pipes, one of which (upstream side) is connected to the four heat transfer pipes 20, respectively, and the other (downstream side) branches and joins them. A merging refrigerant pipe 25a1 and a second merging refrigerant pipe 25b1 are provided. Further, the third branch pipe 25c includes a refrigerant pipe whose one (upstream side) is connected to each of the first merged refrigerant pipe 25a1 and the second merged refrigerant pipe 25b1, and branches and merges them on the other (downstream side). The third combined refrigerant pipe 25c1 is provided.

In the third branch pipe 25c, the longitudinal direction of the refrigerant pipe connected to each of the first and second combined refrigerant pipes 25a1 and 25b1 and the third combined refrigerant pipe 25c1 is the width of the outdoor heat exchanger 2. It arrange | positions so that it may become parallel to a direction (Y direction). According to this, the passage sound of the refrigerant flowing through the third branch pipe 25c can be reduced.

As described above, the refrigerant divided into the eight flow paths and flowing into the heat transfer tube 20 is firstly divided into the first combined refrigerant tube 25a1 of the first branch tube 25a and the second combined refrigerant tube 25b1 of the second branch tube 25b. Merges every four flow paths. Thereafter, the refrigerant flows through several heat transfer tubes 20, and then merges at the third merged refrigerant tube 25c1 of the third branch tube 25c. Eventually, the refrigerant flows out from one heat transfer tube 20 provided at the lowermost portion of the upstream heat exchanger in the air flow direction via the downstream end connection tube 24 (in FIG. 8B). At the bottom right).

With the above configuration, in the outdoor heat exchanger 2 according to the present embodiment, the second connecting pipe 24b includes the bent portion 24b2, and the downstream end connecting pipe 24 is more than the upstream end connecting pipe 23. Is disposed on the side provided with (a positive side in the X direction). As a result, the downstream end connecting pipe 24 which is narrower than the upstream end connecting pipe 23 and is positioned below can be shifted from the vertically lower side of the upstream end connecting pipe 23 and other connecting pipes. Therefore, it can reduce that a water drop dripping to the downstream junction refrigerant pipe 24c from the upstream end part connection pipe 23 or another connection pipe.

Also, as shown in FIGS. 5 and 6, the second connecting pipe 24b includes a bent portion 24b2, so that the downstream-side joining refrigerant pipe 24c has a U-bend 22a, a multi-curved pipe 22b, and an upstream end connecting pipe 23. The side on which the fan 7 is provided (the positive side in the X direction) from all other connecting pipes provided in the outdoor heat exchanger 2 such as the first branch pipe 25a, the second branch pipe 25b, and the third branch pipe 25c. It becomes.

Thereby, since the downstream side joining refrigerant pipe 24c can be shifted from the vertically lower side of all the other connecting pipes, it is possible to reduce the condensation of water droplets on the downstream side joining refrigerant pipe 24c. Further, by shifting to the fan 7 side, it is possible to prevent the outdoor unit 1A from becoming larger than when shifting to the anti-fan 7 side. For this reason, corrosion of the 2nd connection pipe 24b which is an aluminum refrigerant pipe connected to the 1st connection pipe 24a which is a copper refrigerant pipe can be controlled appropriately.

Further, by inserting the downstream-side joining refrigerant pipe 24c having the second joint part 24c2 expanded in advance into the first expanded part 24b4 of the second connection pipe 24b, the work at the manufacturing site, the repair site, etc. is easy. become. Alternatively, if a downstream end connecting pipe 24 is prepared in which the downstream joining refrigerant pipe 24c is a joining refrigerant pipe having a eutectic bonding portion in advance, connection work in the field to the outdoor heat exchanger 2 or the refrigerant pipe 4b can be performed. It becomes easy.

Further, the downstream-side joining refrigerant pipe 24c is provided so that the first joining portion 24c1 is located above the second joining portion 24c2. Thus, moisture condensed on the surface of the second connecting pipe 24b that is an aluminum refrigerant pipe can be drained to the first connecting pipe 24a side that is a copper refrigerant pipe, and the first connecting pipe 24a that is a copper refrigerant pipe. It is possible to prevent moisture condensed on the surface from flowing to the second connecting pipe 24b side which is an aluminum refrigerant pipe.

Furthermore, the first expanded portion 24b4 and the expanded second joint portion 24c2 are arranged so that the opening faces downward. Thereby, the location brazed after inserting downstream junction refrigerant pipe 24c and the 1st connecting pipe 24a will be located below the expansion section. Thereby, it is possible to prevent water droplets from staying at the brazing location.

Further, since the downstream-side joining refrigerant pipe 24c is provided so as to be inclined with respect to the horizontal direction (XY plane), the step difference on the side opposite to the opening of the expanded pipe part of each of the first joint part 24c1 and the second joint part 24c2 is provided. It is possible to suppress the accumulation of water droplets on the top.

In addition, the inclination of the downstream joint refrigerant pipe 24c with respect to the horizontal direction (XY plane) is larger than the inclination of the inclined portion 24a2 of the first connection pipe 24a with respect to the horizontal direction (XY plane). Thereby, the water droplet flowing down through the downstream-side joining refrigerant pipe 24c can be merged with the water droplet flowing down through the inclined portion 24a2. Therefore, water droplets adhering to the surfaces of the downstream-side bonded refrigerant pipe 24c and the inclined portion 24a2 can be quickly dropped downward from the lowermost portion of the bonded bent portion 24d.

Furthermore, since the drainage hole 55 is provided below the joint bent portion 24d in the substrate 50, water droplets dropped from the joint bent portion 24d can be quickly discharged out of the casing of the outdoor unit 1A.

Next, the operation of the above-described refrigeration cycle apparatus will be described. First, the cooling operation and the heating operation which are normal operation modes will be described.

During the cooling operation, the refrigerant compressed by the compressor 11 becomes a high-temperature and high-pressure refrigerant and is sent to the outdoor heat exchanger 2 through the four-way valve 12. The high-temperature and high-pressure refrigerant promotes heat exchange with the outside air by the fan 7 to dissipate heat, and is sent to the expansion device 13 as a high-pressure liquid refrigerant. The high-pressure liquid refrigerant is decompressed by the expansion device 13 to become a low-temperature and low-pressure two-phase refrigerant, and is sent to the indoor heat exchanger 3 through the liquid-side connection pipe 41.

The indoor air sucked in by the fan 8 passes through the indoor heat exchanger 3 and exchanges heat with the refrigerant. As a result of absorbing the heat of the indoor air, the refrigerant evaporates and becomes a low-temperature gas refrigerant. At this time, the indoor air absorbed by the refrigerant is lowered in temperature and humidity and blown out into the room by the fan 8 to cool the room. The gas refrigerant passes through the gas side connection pipe 42 and enters the four-way valve 12, and returns to the compressor 11.

On the other hand, during the heating operation, the refrigerant compressed by the compressor 11 becomes a high-temperature and high-pressure refrigerant, passes through the four-way valve 12, and is sent to the gas side connection pipe. The indoor air sucked by the fan 8 passes through the indoor heat exchanger 3 and exchanges heat with the refrigerant. As a result of radiating heat to the indoor air, the refrigerant condenses and becomes a high-pressure liquid refrigerant. At this time, the indoor air absorbs the heat of the refrigerant and is blown out into the room by the fan 8 in a state where the temperature is raised, thereby heating the room. The liquid refrigerant is sent to the expansion device 13 through the liquid side connection pipe 41 and is decompressed in the expansion device 13 to become a low-temperature low-pressure two-phase refrigerant. The low-temperature and low-pressure two-phase refrigerant is sent to the outdoor heat exchanger 2, promotes heat exchange with the outside air by the fan 7, evaporates, and returns to the compressor 11 through the four-way valve 12.

According to the refrigeration cycle apparatus of the present embodiment, it is possible to employ the outdoor unit 1A including the outdoor heat exchanger 2 that more appropriately prevents corrosion of the aluminum refrigerant pipe connected to the copper refrigerant pipe. It is possible to reduce the weight and cost of the entire refrigeration cycle apparatus.

In addition, it is clear that even if the joint portion configured as in the embodiment described above is further covered with a covering member that prevents water droplets from adhering, the possibility of corrosion of aluminum can be further reduced. The effect of is not limited to the configuration without the covering member.

The present invention can provide a refrigeration cycle apparatus that can more appropriately prevent corrosion of an aluminum refrigerant pipe connected to a copper refrigerant pipe.

DESCRIPTION OF SYMBOLS 1 Air conditioner 1A Outdoor unit 1B Indoor unit 2 Outdoor heat exchanger 3 Indoor heat exchanger 4

Refrigeration cycle circuit

4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h Refrigerant tube 5, 6 Motor 7, 8 Fan ( Blower)
DESCRIPTION OF SYMBOLS 11 Compressor 12 Four-way valve 13 Throttle device 14 Two-way valve 15 Indoor unit liquid side connection part 16 Indoor unit gas side connection part 17 Three-

way valve

20, 30 Heat transfer pipe 21 Fin 22a U bend 22b Multi-curved pipe 23 Upstream end part connection Pipe 23a Header lower pipe 23b Header pipe 23b1 Extension pipe 23c Upstream joint refrigerant pipe 24 Downstream end connection pipe 24a First connection pipe 24a1 First rising part 24a2 Inclined part 24a3 Insertion part 24b Second connection pipe 24b1 Extension part 24b2 Bending Portion 24b3 Second rising portion 24b4 First expanded pipe portion 24c Downstream side joined refrigerant tube 23c1, 24c1 First joined portion 23c2, 24c2 Second joined portion 24d Joint bent portion 25a First branch pipe 25a1 First joined refrigerant pipe 25b Second branch Pipe 25b1 Second combined refrigerant pipe 25c Third branch pipe 25c1 Third combined refrigerant 26 strainer 27 end plate 41 liquid-side connection pipe 42 a gas-side connecting pipe 50 substrate 51 exterior casing plate 52 partition plate 53 compressor housing 54 blower housing portion 55 drainage hole

Claims

A plurality of fins stacked at predetermined intervals;
A heat transfer tube penetrating in a direction perpendicular to the planar direction of the plurality of fins;
A plurality of connecting pipes connecting the plurality of heat transfer pipes;
A heat exchanger with
An outdoor unit provided in a plane direction of the fins and provided with a blower that blows an airflow to the heat exchanger,
At the end of the heat exchanger, a first end connecting pipe and a second end connecting pipe that connect the refrigerant pipe and the heat transfer pipe are provided,
The second end connecting pipe is located below the first end connecting pipe,
The second end connection pipe is disposed between an aluminum refrigerant pipe containing aluminum or an aluminum alloy, a copper refrigerant pipe containing copper or a copper alloy, and the aluminum refrigerant pipe and the copper refrigerant pipe. And a joined refrigerant pipe
The joining refrigerant pipe is an outdoor unit disposed on the side where the blower is provided, rather than the connection pipe located on the side where the blower is provided most of the plurality of connection pipes.
The joining refrigerant pipe is a stainless steel refrigerant pipe containing iron and nickel or chromium,
The joining refrigerant pipe includes a first joining portion in which the aluminum refrigerant pipe is expanded and the joining refrigerant pipe is inserted, and a second joining in which the joining refrigerant pipe is expanded and the copper refrigerant pipe is inserted. With
The outdoor unit according to claim 1, wherein the first joint portion is disposed above the second joint portion.
The outdoor unit according to claim 2, wherein the first expanded portion where the aluminum refrigerant tube is expanded and the second expanded portion where the joined refrigerant tube is expanded are arranged so that the opening faces downward. .
The outdoor unit according to claim 3, wherein the copper refrigerant pipe includes an inclined portion that is inclined toward the second joint portion from above at an angle that is gentler than an inclination angle of the bonded refrigerant tube.
The outdoor unit according to claim 1, wherein the joining refrigerant pipe is a refrigerant pipe in which a pipe member formed of aluminum or an aluminum alloy and a pipe member formed of copper or a copper alloy are eutectic bonded.
A refrigeration cycle apparatus comprising the outdoor unit according to any one of claims 1 to 5.