WO2021234961A1

WO2021234961A1 - Heat exchanger, outdoor unit for air conditioning device, and air conditioning device

Info

Publication number: WO2021234961A1
Application number: PCT/JP2020/020354
Authority: WO
Inventors: 洋次尾中; 崇松本; 七海岸田; 哲二七種; 祐基中尾; 裕之森本
Original assignee: 三菱電機株式会社
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2021-11-25
Also published as: JPWO2021234961A1; JP7366255B2

Abstract

The heat exchanger according to the present disclosure is provided with: a first heat exchanger including a first heat exchange body that has a plurality of heat conduction pipes spaced apart from each other, a first inner header that is provided to upper or lower ends of the plurality of heat conduction pipes of the first heat exchange body, a second heat exchange body that is provided in the direction of air passage of the first heat exchange body and that has a plurality of heat conduction pipes spaced apart from each other, and a first outer header that is provided to upper or lower ends of the plurality of heat conduction pipes of the second heat exchange body; a second heat exchanger including a third heat exchange body that has a plurality of heat conduction pipes spaced apart from each other, a second inner header that is provided to upper or lower ends of the plurality of heat conduction pipes of the third heat exchange body, a fourth heat exchange body that is provided in the direction of air passage of the third heat exchange body and that has a plurality of heat conduction pipes spaced apart from each other, and a second outer header that is provided to upper or lower ends, but on the same side where the first outer header is provided, of the plurality of heat conduction pipes of the fourth heat exchange body; and a connection pipe that connects the first and second outer headers together and that has a bent section. A refrigerant flowing from the first heat exchanger to the second heat exchanger and a refrigerant flowing from the second heat exchanger to the first heat exchanger flow only through the connection pipe.

Description

Heat exchanger, outdoor unit of air conditioner and air conditioner

The present disclosure discloses a heat exchanger comprising a first heat exchanger including a plurality of rows of heat exchangers having a plurality of heat transfer tubes and a second heat exchanger containing a plurality of rows of heat exchangers having a plurality of heat transfer tubes, air harmonizing. Regarding the outdoor unit of the device and the air conditioner.

A first heat exchanger having heat transfer tubes arranged in rows at intervals and a second heat exchange having heat transfer tubes arranged in rows at intervals and provided in parallel with the first heat exchanger. Heat exchangers including the body are known. Then, two such heat exchangers are provided. Here, for convenience of explanation, one of the two heat exchangers is referred to as a first heat exchanger and the other is referred to as a second heat exchanger.

The first heat exchanger and the second heat exchanger are arranged in directions substantially orthogonal to each other. The first heat exchanger and the second heat exchanger are a bent connection pipe connecting the inner header of the first heat exchanger and the inner header of the second heat exchanger, and the outer header of the first heat exchanger and the second. It is connected by a bent connection pipe that connects to the outer header of the heat exchanger.

Then, the first heat exchanger and the second heat exchanger connected by two bent connecting pipes function as one heat exchanger (see, for example, Patent Document 1).

Japanese Patent No. 6595125

The inner headers and outer headers of the first heat exchanger and the second heat exchanger are connected by two bent connecting pipes. Therefore, by having a connection pipe connecting the inner headers of the first heat exchanger and the second heat exchanger, the mounting area of at least one longitudinal length of the first heat exchanger and the second heat exchanger is provided. There is a problem that becomes smaller.

The present disclosure has been made in view of the above circumstances, and it is possible to improve the mounting area of the heat exchanger having the first heat exchanger and the second heat exchanger connected to the first heat exchanger. It is an object of the present invention to provide an outdoor unit of a heat exchanger, an air conditioner, and an air conditioner.

According to the heat exchanger according to the present disclosure, a first heat exchanger having a plurality of heat transfer tubes arranged at intervals and one end of the upper side or the lower side of the plurality of heat transfer tubes of the first heat exchanger. A first inner header provided, a second heat exchanger having a plurality of heat transfer tubes provided in the ventilation direction of the first heat exchanger and arranged at intervals, and a plurality of the second heat exchangers. A first heat exchanger including a first outer header provided at one end of the upper or lower end of the heat transfer tube, a third heat exchanger having a plurality of heat transfer tubes arranged at intervals, and the first heat exchanger. A plurality of heat exchangers provided at one end of the upper or lower ends of the plurality of heat exchangers of the three heat exchangers and a plurality of heat exchangers provided at intervals in the ventilation direction between the third heat exchanger and the third heat exchanger. A second including a fourth heat exchanger having a heat exchanger and a second outer header provided at one upper or lower end on the same side as the first outer header of the plurality of heat transfer tubes of the fourth heat exchanger. The heat exchanger is provided with a connection pipe connecting the first outer header and the second outer header and having a bent portion, and the refrigerant flowing from the first heat exchanger to the second heat exchanger and the said. The refrigerant flowing from the second heat exchanger to the first heat exchanger flows only through the connecting pipe.

According to the present disclosure, the first outer header and the second outer header are connected by a connecting pipe. The refrigerant flowing from the first heat exchanger to the second heat exchanger and the refrigerant flowing from the second heat exchanger to the first heat exchanger flow only through the connecting pipes. Therefore, according to the heat exchanger of the present disclosure, a connection pipe for connecting the inner header of the first heat exchanger and the inner header of the third heat exchanger is not required, so that the mounting area of the heat exchanger is improved. Can be done.

It is a refrigerant circuit diagram of the air conditioner which concerns on Embodiment 1. FIG. It is a perspective view which shows the outdoor unit of the air conditioner which concerns on Embodiment 1. FIG. It is a perspective view which shows the 1st outdoor heat exchanger and the 2nd outdoor heat exchanger of the air conditioner which concerns on Embodiment 1. FIG. It is a figure which shows an example of the 1st outer header of the air conditioner which concerns on Embodiment 1. FIG. It is sectional drawing which shows an example of the cross section orthogonal to the pipe extension direction of the 1st outer header of the air conditioner which concerns on Embodiment 1. FIG. It is a figure which shows the comparative example for demonstrating the effect of the air conditioner which concerns on Embodiment 1. FIG. It is a figure for demonstrating the effect of the air conditioner which concerns on Embodiment 1. FIG. It is a figure which shows the flow path cross-sectional area per one of the plurality of flat pipes of the 1st outdoor heat exchanger and the 2nd outdoor heat exchanger of the air conditioner which concerns on Embodiment 2. FIG. It is a figure for demonstrating the flow of the refrigerant of the 1st outdoor heat exchanger and the 2nd outdoor heat exchanger 3b of the air conditioner which concerns on Embodiment 2. FIG. It is a figure for demonstrating the connection relationship between the 1st outer header and the 2nd outer header of the air conditioner which concerns on Embodiment 3. FIG.

Hereinafter, the air conditioner according to the embodiment will be described with reference to the drawings. In the drawings, the same components will be described with the same reference numerals, and duplicate explanations will be given only when necessary. The present disclosure may include any combination of configurable configurations among the configurations described in each of the following embodiments.

Embodiment 1.
<Structure of air conditioner 100>
FIG. 1 is a refrigerant circuit diagram of the air conditioner 100 according to the first embodiment. As shown in FIG. 1, the air conditioner 100 includes an outdoor unit 10 and a plurality of

indoor units

11, 12, and 13. A plurality of

indoor units

11, 12 and 13 are connected to the outdoor unit 10. The

indoor units

11, 12 and 13 are connected in parallel with each other. The refrigerant circulates inside the outdoor unit 10 and the plurality of

indoor units

11, 12, and 13. The air conditioner 100 is a multi-type air conditioner. In the first embodiment, three

indoor units

11, 12 and 13 are connected to the outdoor unit 10. However, the first embodiment does not limit the number of indoor units connected to the outdoor unit 10.

The air conditioner 100 has a refrigerant circuit in which a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an expansion valve 5, an indoor heat exchanger 6, and an accumulator 8 are connected by a refrigerant pipe. .. In the outdoor heat exchanger 3, the air is exchanged with the refrigerant flowing inside by the wind generated by the fan 4. In the indoor heat exchanger 6, the air is exchanged with the refrigerant flowing inside by the wind generated by the fan 7.

During the cooling operation, the refrigerant of the high-temperature and high-pressure gas compressed by the compressor 1 is transferred from the refrigerant pipe 26 connecting the four-way valve 2 and the outdoor heat exchanger 3 to the outdoor heat exchanger 3 via the four-way valve 2. Inflow. The refrigerant flowing into the outdoor heat exchanger 3 exchanges heat with the wind generated by the fan 4, and then flows out from the refrigerant pipe 27 connecting the outdoor heat exchanger 3 and the expansion valve 5. In the case of heating operation, that is, when the outdoor heat exchanger 3 functions as an evaporator, the refrigerant flows in the direction opposite to the refrigerant flow direction in the case of the above-mentioned condenser.

<Structure of outdoor unit 10 of air conditioner 100>
FIG. 2 is a perspective view showing the outdoor unit 10 of the air conditioner 100 according to the first embodiment. As shown in FIG. 2, the outdoor unit 10 of the air conditioner 100 includes a compressor 1, a fan 4, and an outdoor heat exchanger 3. The outdoor heat exchanger 3 includes four first outdoor heat exchangers 3a, a second outdoor heat exchanger 3b, a third outdoor heat exchanger 3c, and a fourth outdoor heat exchanger 3d. The housing 9 of the outdoor unit 10 of the air conditioner 100 has a rectangular parallelepiped portion 9a and a fan accommodating portion 9b. A compressor 1 and four first outdoor heat exchangers 3a to a fourth outdoor heat exchanger 3d are arranged in the rectangular parallelepiped portion 9a. The four first outdoor heat exchangers 3a to the fourth outdoor heat exchanger 3d are attached to the side surfaces of the rectangular parallelepiped portion 9a of the housing 9, respectively. The fan storage portion 9b is formed on the upper portion of the rectangular parallelepiped portion 9a, and the fan 4 is arranged.

Each of the first outdoor heat exchangers 3a to the fourth outdoor heat exchanger 3d is located near the fan 4 and is located at the upper part of the rectangular parallelepiped portion 9a where the intake efficiency of the fan 4 is high.

The fan 4 is arranged above the outdoor heat exchanger 3 and blows air upward. That is, the outdoor unit 10 of the air conditioner 100 is a top-flow type in which a fan 4 that blows air upward is arranged above the outdoor heat exchanger 3.

The compressor 1 is arranged at the lower part inside the rectangular parallelepiped portion 9a of the housing 9. The lower end of the first outdoor heat exchanger 3a to the fourth outdoor heat exchanger 3d is located higher than the upper end of the compressor 1.

The first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b are connected by an L-shaped connecting pipe 31 (see FIG. 2). The first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b have a function as one heat exchanger. Similarly, the third outdoor heat exchanger 3c and the fourth outdoor heat exchanger 3d are connected by an L-shaped connecting pipe, and the third outdoor heat exchanger 3c and the fourth outdoor heat exchanger 3d are one. It has a function as a heat exchanger.

<Structure of 1st outdoor heat exchanger 3a and 2nd outdoor heat exchanger 3b>
FIG. 3 is a perspective view showing the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b of the air conditioner 100 according to the first embodiment. Here, the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b will be described as representatives. The configuration of the third outdoor heat exchanger 3c is the same as that of the first outdoor heat exchanger 3a, and the configuration of the fourth outdoor heat exchanger 3d is the same as that of the second outdoor heat exchanger 3b. The description of the third outdoor heat exchanger 3c and the fourth outdoor heat exchanger 3d will be omitted in the first embodiment. The white arrows in the figure indicate the flow of wind generated by the fan 4.

As shown in FIG. 3, the first outer header 24aa of the first outdoor heat exchanger 3a is connected to the second outer header 24bb of the second outdoor heat exchanger 3b by a connecting pipe 31.

The connection pipe 31 is an L-shaped bent pipe and has a bent portion 31r. Here, the bent portion 31r is a portion of the connecting pipe 31 having a predetermined curvature other than the straight portion. The refrigerant flowing from the first outdoor heat exchanger 3a to the second outdoor heat exchanger 3b and the refrigerant flowing from the second outdoor heat exchanger 3b to the first outdoor heat exchanger 3a flow only through the connection pipe 31.

The first outdoor heat exchanger 3a has a first heat exchanger 20aa and a second heat exchanger 20ab. The first heat exchanger 20aa has a plurality of flat tubes 21 arranged at intervals in the horizontal direction with the vertical direction as the tube extending direction. The second heat exchanger 20ab has a plurality of flat tubes 21 arranged at intervals in the horizontal direction with the vertical direction as the tube extending direction.

The first heat exchanger 20aa has fins 22 joined to the flat tube 21. The second heat exchanger 20ab has fins 22 joined to the flat tube 21. The plurality of flat tubes 21 are arranged in the horizontal direction at intervals so that the wind generated by the fan 4 flows. The plurality of flat tubes 21 are arranged so as to extend in the vertical direction. Refrigerant flows in the vertical direction in the pipes of the plurality of flat pipes 21. The plurality of flat tubes 21 of the first heat exchanger 20aa are arranged parallel to the plurality of flat tubes 21 of the second heat exchanger 20ab in the ventilation direction.

The fins 22 of the first heat exchanger 20aa are connected between adjacent flat tubes 21 of the first heat exchanger 20aa and transfer heat to the flat tubes 21. The fins 22 of the second heat exchanger 20ab are connected between adjacent flat tubes 21 of the second heat exchanger 20ab and transfer heat to the flat tubes 21.

The fin 22 improves the heat exchange efficiency between air and the refrigerant, and for example, a corrugated fin is used. However, the fin 22 is not limited to the corrugated fin. Since heat exchange between air and the refrigerant is performed on the surface of the flat tube 21, the fins 22 may be omitted.

A first inner header 23a is provided at the lower part of the first heat exchanger 20aa on the leeward side of the first outdoor heat exchanger 3a. The lower ends of a plurality of flat tubes 21 of the first heat exchanger 20aa of the first outdoor heat exchanger 3a are inserted into the first inner header 23a. The first inner header 23a is connected to the refrigerant pipe 26 of the refrigerant circuit of the air conditioner 100, and hot gas refrigerant flows in from the refrigerant circuit. The first inner header 23a is also referred to as a gas header. During the cooling operation, the high-temperature and high-pressure gas refrigerant from the compressor 1 flows into the first inner header 23a. During the heating operation, the refrigerant after heat exchange in the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b flows out from the first inner header 23a.

A first outer header 24aa is provided at the lower part of the first heat exchanger 20aa on the windward side. The first outer header 24aa is arranged parallel to the first inner header 23a in the ventilation direction. The first outer header 24aa is connected to the second outer header 24bb of the second outdoor heat exchanger 3b via the connection pipe 31.

A first folded header 25a is provided on the upper part of the first heat exchanger 20aa and the second heat exchanger 20ab. The upper end portions of the plurality of flat tubes 21 inserted in the first inner header 23a and the first outer header 24aa are inserted into the first folded header 25a.

The second outdoor heat exchanger 3b has a third heat exchanger 20ba and a fourth heat exchanger 20bb. The third heat exchanger 20ba has a plurality of flat tubes 21 arranged at intervals in the horizontal direction with the vertical direction as the tube extending direction. The fourth heat exchanger 20bb has a plurality of flat tubes 21 arranged at intervals in the horizontal direction with the vertical direction as the tube extending direction.

The third heat exchanger 20ba has fins 22 joined to the flat tube 21. The fourth heat exchanger 20bb has fins 22 joined to the flat tube 21. The plurality of flat tubes 21 are arranged in the horizontal direction at intervals so that the wind generated by the fan 4 flows. The plurality of flat tubes 21 are arranged so as to extend in the vertical direction. Refrigerant flows in the vertical direction in the pipes of the plurality of flat pipes 21. The plurality of flat tubes 21 of the third heat exchanger 20ba are arranged parallel to the plurality of flat tubes 21 of the fourth heat exchanger 20bb in the ventilation direction.

The fins 22 of the third heat exchanger 20ba are connected between adjacent flat tubes 21 of the third heat exchanger 20ba and transfer heat to the flat tubes 21. The fins 22 of the fourth heat exchanger 20bb are connected between adjacent flat tubes 21 of the fourth heat exchanger 20bb and transfer heat to the flat tubes 21.

A second inner header 23b is provided at the lower part of the third heat exchanger 20ba on the leeward side of the second outdoor heat exchanger 3b. The lower ends of the plurality of flat tubes 21 of the third heat exchanger 20ba of the second outdoor heat exchanger 3b are inserted into the second inner header 23b. The lower ends of the plurality of flat tubes 21 of the third heat exchanger 20ba of the second outdoor heat exchanger 3b are directly inserted into the second inner header 23b. The second inner header 23b is connected to the refrigerant pipe 27 of the refrigerant circuit of the air conditioner 100. In the second inner header 23b, the refrigerant after heat exchange by the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b during the cooling operation is output to the refrigerant pipe 27. During the heating operation, the refrigerant from the expansion valve 5 flows into the second inner header 23b.

A second outer header 24bb is provided at the lower part of the fourth heat exchanger 20bb on the windward side. The second outer header 24bb is arranged parallel to the second inner header 23b in the ventilation direction. The second outer header 24bb is connected to the first outer header 24aa of the first outdoor heat exchanger 3a via the connection pipe 31.

A second folded header 25b is provided on the upper part of the third heat exchanger 20ba and the fourth heat exchanger 20bb. The upper end portions of the plurality of flat tubes 21 inserted in the second inner header 23b and the second outer header 24bb are inserted into the second folded header 25b.

A plurality of flat pipes 21, fins 22, first inner header 23a, second inner header 23b, first outer header 24aa, second outer header 24bb, first folded header 25a, second folded header 25b, and

refrigerant pipes

26, 27. Are all made of aluminum.

In the first embodiment, the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b are arranged at right angles in the substantially horizontal direction, but the present disclosure describes the first. The case is not limited to the case where the outdoor heat exchanger 3a and the second outdoor heat exchanger 3b are arranged at substantially right angles. The outdoor heat exchanger 3 of the present disclosure includes a case where the direction of the second outdoor heat exchanger 3b is different from the direction of the first outdoor heat exchanger 3a.

<First outer header 24aa and second outer header 24bb>
FIG. 4 is a diagram showing an example of the first outer header 24aa of the air conditioner 100 according to the first embodiment. FIG. 5 is a cross-sectional view showing an example of a cross section orthogonal to the pipe extension direction of the first outer header 24aa of the air conditioner 100 according to the first embodiment. Although FIG. 5 shows the first outer header 24aa, the second outer header 24bb has the same configuration. As shown in FIGS. 4 and 5, the first outer header 24aa is provided below the windward first heat exchanger 20aa. When the first outer header 24aa has a double pipe structure having an inner pipe 24a and an outer pipe 24b, the gas-liquid two-phase refrigerant can be distributed relatively uniformly, and the first outer header 24aa is a normal pipe. Distributing performance is better than in the case of structure. Similar to the first outer header 24aa, if the second outer header 24bb also has a double pipe structure having an inner pipe and an outer pipe, the gas-liquid two-phase refrigerant can be distributed relatively uniformly, and the second outer side can be distributed relatively uniformly. Distributing performance is better than when the header 24bb has a normal pipe structure.

The inner pipe 24a is a circular pipe. A plurality of refrigerant flow holes 24c through which the refrigerant flows are formed in the inner pipe 24a at intervals. The refrigerant flow hole 24c is provided in the lower part of the inner pipe 24a.

The position of the refrigerant flow hole 24c may be between adjacent flat pipes 21. Further, the position where the refrigerant flow hole 24c is provided may be, for example, the position of the liquid level of the refrigerant flowing through the outer pipe 24b. Specifically, the refrigerant flow hole 24c has an angle θ of 10 ° from the lower end of the vertical inner pipe 24a passing through the center of the inner pipe 24a as seen from the center of the inner pipe 24a to the position where the refrigerant flow hole 24c exists. It is provided in the range of ≦ | θ | ≦ 80 °. In this case, there is only one refrigerant flow hole 24c in the vertical cross section of the inner pipe 24a at the position where the refrigerant flow hole 24c is provided.

The inner pipe 24a is inserted inside the outer pipe 24b. The outer pipe 24b is a pipe having a U-shaped cross section formed in an arc shape below. The outer pipe 24b having a U-shaped cross section smoothly changes the refrigerant from the refrigerant flow hole 24c opened downward along the arc. The inner pipe 24a and the outer pipe 24b extend straight in the pipe extending direction. The inner pipe 24a and the outer pipe 24b are joined by brazing.

When the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b function as condensers, the refrigerant flattens the second heat exchanger 20ab on the wind side from the first folded header 25a of the first outdoor heat exchanger 3a. It flows into the outer tube 24b via the tube 21. The refrigerant that has flowed into the outer pipe 24b of the first outer header 24aa flows into the inner pipe 24a through the refrigerant flow hole 24c provided in the inner pipe 24a. The refrigerant that has flowed into the inner pipe 24a flows into the second outer header 24bb of the second outdoor heat exchanger 3b via the connecting pipe 31.

The connection pipe 31 is configured by bending the inner inner pipe 24a. That is, the inner pipe 24a of the first outer header 24aa may be the connecting pipe 31. The connection pipe 31 is connected to the inner pipe of the second outer header 24bb.

<Operation of refrigerant circuit>
Next, the operation of the refrigerant circuit of FIG. 1 will be briefly described. In the case of heating operation, the refrigerant is compressed by the compressor 1, and the refrigerant that has become a high-temperature and high-pressure gas flows into the plurality of indoor heat exchangers 6 via the four-way valve 2. The refrigerant that has flowed into the indoor heat exchanger 6 dissipates heat due to the wind generated by the fan 7, condenses, and liquefies. The liquefied refrigerant is depressurized by the expansion valve 5, becomes a low-temperature low-pressure gas-liquid two-phase state, and flows into the outdoor heat exchanger 3 via the refrigerant pipe 27. The refrigerant flowing into the outdoor heat exchanger 3 exchanges heat with the air generated by the fan 4, evaporates and gasifies, and flows out through the first inner header 23a. The refrigerant flowing out through the first inner header 23a is sucked into the compressor 1 again through the refrigerant pipe 26 and the accumulator 8 in this order, and circulates in the refrigerant circuit. In addition to the refrigerant, the refrigerating machine oil required to drive the compressor 1 also circulates in the refrigerant circuit. On the other hand, in the case of cooling operation, the flow of the refrigerant and the refrigerating machine oil rotates in the reverse direction in the refrigerant circuit.

<Operation of the 1st outdoor heat exchanger 3a and the 2nd outdoor heat exchanger 3b>
Here, the operations of the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b will be described as representatives. The flow of the refrigerant in the third outdoor heat exchanger 3c is the same as that in the first outdoor heat exchanger 3a, and the flow of the refrigerant in the fourth outdoor heat exchanger 3d is the same as that in the second outdoor heat exchanger 3b. The description of the third outdoor heat exchanger 3c and the fourth outdoor heat exchanger 3d will be omitted in the first embodiment.

In the case of cooling operation, the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b function as condensers. The refrigerant compressed by the compressor 1 and turned into a high-temperature high-pressure gas flows into the outdoor heat exchanger 3 via the four-way valve 2. Of the high-temperature and high-pressure gas refrigerants, the refrigerants other than the refrigerant flowing into the third outdoor heat exchanger 3c flow into the first inner header 23a of the first outdoor heat exchanger 3a via the refrigerant pipe 26. The refrigerant flowing into the first inner header 23a rises in the plurality of flat tubes 21 inserted in the first inner header 23a, exchanges heat with the air on the wind generated by the fan 4, and gradually liquefies the first. 1 It reaches the first folded header 25a of the outdoor heat exchanger 3a. The refrigerant that has reached the first folded header 25a descends the plurality of flat pipes 21 of the second heat exchanger 20ab of the first outdoor heat exchanger 3a and reaches the first outer header 24aa. The refrigerant that has reached the first outer header 24aa and merged flows into the second outer header 24bb of the second outdoor heat exchanger 3b via the connection pipe 31.

The refrigerant that has reached the second outer header 24bb rises in the plurality of flat pipes 21 of the fourth heat exchanger 20bb of the second outdoor heat exchanger 3b, and gradually exchanges heat with the air on the wind generated by the fan 4. While liquefying, it reaches the second folded header 25b of the second outdoor heat exchanger 3b. The refrigerant that has reached the second folded header 25b descends from the plurality of flat pipes 21 of the third heat exchanger 20ba, reaches the second inner header 23b, and is output from the refrigerant pipe 27 to the expansion valve 5. On the other hand, in the case of heating operation, that is, when the outdoor heat exchanger 3 functions as an evaporator, the refrigerant flows in the direction opposite to the refrigerant flow direction in the case of the above-mentioned condenser.

Although the outdoor heat exchanger 3 of the air conditioner 100 has been described in the first embodiment, the connection between the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b of the first embodiment is connected by the connection pipe 31. The configuration can also be applied to the indoor heat exchanger 6.

Further, in the first embodiment, the case where the first outer header 24aa and the second outer header 24bb are connected via the connection pipe 31 has been described. When the first wrapping header 25a has an inner header and an outer header and the second wrapping header 25b has an inner header and an outer header, the outer header of the first wrapping header 25a and the outer header of the second wrapping header 25b are used. It may be connected by the connection pipe 31.

<Effect of Embodiment 1>
A bent connection pipe is required to connect headers that extend in orthogonal directions. The bending of the connecting pipe should be as curved as possible in order to suppress the resistance of the refrigerant. However, in particular, a large space was required between the headers in order to secure the curvature of the connecting pipe on the inner side.

According to the air conditioner 100 according to the first embodiment, the first outer header 24aa and the second outer header 24bb are connected by a connection pipe 31. The refrigerant flowing from the first outdoor heat exchanger 3a to the second outdoor heat exchanger 3b and the refrigerant flowing from the second outdoor heat exchanger 3b to the first outdoor heat exchanger 3a flow only through the connection pipe 31. Therefore, since a connection pipe for connecting the first inner header 23a of the first heat exchanger and the second inner header 23b of the third heat exchanger is not required, the first heat exchanger 20aa and the second heat exchanger 20ab are not required. The mounting area with and can be improved.

FIG. 6 is a diagram showing a comparative example for explaining the effect of the air conditioner 100 according to the first embodiment. FIG. 7 is a diagram for explaining the effect of the air conditioner 100 according to the first embodiment.

As shown in FIG. 6, the first inner header 23a of the first heat exchanger 20aa arranged inside the first outdoor heat exchanger 3a and the third heat arranged inside the second outdoor heat exchanger 3b. The second inner header 23b of the exchange body 20ba is connected to the second inner header 23b by a connecting pipe 31a. Further, the first outer header 24aa arranged outside the first outdoor heat exchanger 3a and the second outer header 24bb arranged outside the second outdoor heat exchanger 3b are connected by a connecting pipe 31b. ..

On the other hand, according to the air conditioner 100 according to the first embodiment, the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b are connected by only one connection pipe 31. The connection pipe 31 connects the first outer header 24aa arranged on the outside and the second outer header 24bb arranged on the outside.

Therefore, according to the air conditioner 100 according to the first embodiment, as shown in FIG. 7, since the connection pipe 31b is not required, the lengths of the first heat exchanger 20aa and the second heat exchanger 20ab are set. It can be extended by L. As a result, the mounting area of the first heat exchanger 20aa and the second heat exchanger 20ab can be improved.

Further, the connection pipe 31 connects the inner pipe 24a of the first outer header 24aa and the inner pipe of the second outer header 24bb. Therefore, as compared with the case where the connection pipe 31 connects the outer pipe 24b of the first outer header 24aa and the outer pipe of the second outer header 24bb, the first heat exchanger 20aa and the second heat exchanger are further connected. The mounting area of 20ab can be improved.

Embodiment 2.
In the second embodiment, in the first embodiment, a partition is provided to block the refrigerant flow path of the second outer header 24bb, the second inner header 23b, and the second folded header 25b of the second outdoor heat exchanger 3b. In the second embodiment, the refrigerant pipe 27 will be described as being connected to the second outer header 24bb due to the flow of the refrigerant due to the partition.

The partition of the second outdoor heat exchanger 3b is the second folded header 25b and the second outer header 24bb partitioned by the partition when the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b function as a condenser. Of the above regions, the cross-sectional area of the refrigerant flow path of the plurality of flat pipes 21 connected to the refrigerant flow region where the refrigerant is an upward flow is provided so as to be small in the process of phase change from the gas refrigerant to the liquid refrigerant. Specifically, in the second embodiment, when the second outdoor heat exchanger 3b functions as a condenser, the refrigerant is included in the regions of the second folded header 25b and the second outer header 24bb partitioned by the partition. The cross-sectional area of the refrigerant flow path of the plurality of flat tubes 21 of the second outdoor heat exchanger 3b in the region on the downstream side where is an upward flow is the cross-sectional area of the second outdoor heat exchanger 3b in the region on the upstream side where the refrigerant is an upward flow. It is smaller than the cross-sectional area of the refrigerant flow path of the plurality of flat tubes 21.

Further, among the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b, the gas-liquid two-phase refrigerant flow flowing in the refrigerant flow region that is the most downstream of the gas refrigerant flow and is the upward flow has a flooding constant. It is designed so that C> 1 or more. Here, the flooding constant C is defined based on the flow rate in the intermediate load capacity (50% capacity) operation of the condenser flowing into the corresponding region.

The definition of the flooding constant C is, for example, according to the generally known Wellis equation, C = J _G ^0.5 + J _L ^0.5 ... (1)
Defined in.

Here, J _G is the apparent speed of the dimensionless gas, and J _L is the apparent speed of the dimensionless liquid.

J _G and J _L are defined as follows.
_{_{J G = U G × {ρ}} G / [9.81 × D eq (ρ L -ρ G)]} 0.5 ... (2)
_{_{J L = U L × {ρ}} L / [9.81 × D eq (ρ L -ρ G)]} 0.5 ... (3)

Figure 8 is a view showing a flow path cross-sectional area A ₁ per one of the first outdoor heat exchanger 3a and a plurality of flat tubes 21 of the second outdoor heat exchanger 3b of the air-conditioning apparatus 100 according to the second embodiment Is.
here,
Deq is a corresponding diameter [m] defined by the number of flat tubes and the cross-sectional area of the flow path connected to the most downstream and ascending flow region when functioning as a condenser.
A _eq = A ₁ x N ... (4)
D _eq = [(4 x A _eq) /3.14] ^0.5 ... (5)
It is represented by.

N is the number of flat tubes connected to the most downstream and upstream flow region when the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b function as condensers. In the second embodiment, the number of flat tubes connected to the region L4 shown in FIG. 9 corresponds.

Further, the liquid density of the _{ρ L} ^{refrigerant [kg / m 3} ] and ρ _G are the gas density of the refrigerant [kg / m ³ ]. ρ _L and ρ _G are state quantities that can be calculated by the type and pressure of the refrigerant flowing into the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b.

_UG is the apparent gas speed [m / s], _UL is the apparent liquid speed [m / s], and x is the dryness of the refrigerant.
U _G = (G × x) / ρ _G … (6)
_UL = [G × (1-x)] / ρ _L … (7)
Defined in.

^{Here, G is the flow velocity [kg / m 2} s] of the gas refrigerant flowing into the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b, and M is the first outdoor heat exchanger 3a and the second outdoor heat exchange. It is the flow rate [kg / s] of the gas refrigerant flowing into the vessel 3b, and is obtained by _{G = M / A eq.}

x is the dryness of the refrigerant flowing into the flow region flowing in the ascending flow at the most downstream. x can be calculated from, for example, the amount and capacity of heat exchange in the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b. For example, it is assumed that the dryness of the refrigerant changes from 1 to 0 at the inlet to the outlet of the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b, and the heat exchange amount ∝ heat transfer area. In this case, x can be estimated by the ratio of the number of heat transfer tubes located upstream of the target flow region to the total number of flat tubes. For example, considering FIG. 9, it is defined as follows.

x = 1- (number of flat tubes in regions L1, L2, L3)
/ (Number of flat tubes in regions L1, L2, L3, L4) ... (8)

FIG. 9 is a diagram for explaining the flow of the refrigerant in the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b of the air conditioner 100 according to the second embodiment. Here, the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b will be described as representatives, but the third outdoor heat exchanger 3c is the first outdoor heat exchanger 3a and the fourth outdoor heat exchanger 3d. The configuration is the same as that of the second outdoor heat exchanger 3b.

In the case of cooling operation, the outdoor heat exchanger 3 functions as a condenser. Of the refrigerants compressed by the compressor 1 and turned into high-temperature and high-pressure gas, the refrigerants other than the refrigerant flowing into the third outdoor heat exchanger 3c are the first inside of the first outdoor heat exchanger 3a via the refrigerant pipe 26. It flows into the header 23a (see FIG. 3). The refrigerant flowing into the first inner header 23a rises in a plurality of flat tubes 21 (see FIG. 3) inserted in the first inner header 23a, and the air and heat generated by the fan 4 (see FIG. 2) ride on the wind. It reaches the first folded header 25a (see FIG. 3) of the first outdoor heat exchanger 3a while being replaced and gradually liquefied. The refrigerant that has reached the first folded header 25a descends from the plurality of flat tubes 21 of the second heat exchanger 20ab (see FIG. 3) of the first outdoor heat exchanger 3a, and descends from the first outer header 24aa (see FIG. 3). To reach. The refrigerant that has reached the first outer header 24aa and merged flows into the second outer header 24bb (see FIG. 3) of the second outdoor heat exchanger 3b via the connection pipe 31. Here, the region of the first inner header 23a is the region L1.

A partition 41a is provided on the second outer header 24bb and the second folded header 25b (see FIG. 3). The partition 41a provided in the first folded header 25a is provided directly above the partition 41b provided in the second outer header 24bb.

A partition 41b is provided on the downstream side of the partition 41a of the second inner header 23b and the second folded header 25b. The partition 41b provided in the second folded header 25b is provided directly above the partition 41b provided in the second inner header 23b.

The refrigerant that has reached the second outer header 24bb of the second outdoor heat exchanger 3b flows through the second outer header 24bb to the partition 41a and turns. The refrigerant flowing through the second outer header 24bb including the refrigerant turned by the partition 41a rises from the second outer header 24bb to the plurality of flat tubes 21 of the fourth heat exchanger 20bb (see FIG. 3). The refrigerant rising from the plurality of flat tubes 21 reaches the second folded header 25b of the second outdoor heat exchanger 3b while exchanging heat with the air generated by the fan 4 and gradually liquefying. Here, the region L2 is from the inlet of the refrigerant of the second outer header 24bb of the second outdoor heat exchanger 3b to the partition 41a. The refrigerant that has reached the second folded header 25b is turned by the partition 41a provided in the second folded header 25b, descends from the plurality of flat tubes 21 of the third heat exchanger 20ba in the region corresponding to the region L2, and is the second. 2 Reach the inner header 23b and join.

The refrigerant that has reached the second inner header 23b flows to the partition 41b provided in the second inner header 23b and turns. The area of the second inner header 23b from the position corresponding to the partition 41a provided in the second outer header 24bb to the partition 41b provided in the second inner header 23b is the area L3. The refrigerant flowing through the second inner header 23b rises in the plurality of flat pipes 21 of the third heat exchanger 20ba in the region L3 of the second inner header 23b, and gradually exchanges heat with the air on the wind generated by the fan 4. While liquefying, it reaches the second folded header 25b and joins. The area from the position corresponding to the partition 41b of the second folded header 25b to the end of the second folded header 25b is the area L4. The refrigerant that has reached the second folded header 25b and merged has descended from the plurality of flat pipes 21 of the fourth heat exchanger 20bb in the region L4, reached the second outer header 24bb, and merged.

The refrigerant that has reached the second outer header 24bb flows out from the second outdoor heat exchanger 3b via the refrigerant pipe 27. Further, a part of the refrigerant flowing through the region L4 of the second outer header 24bb descends the plurality of flat tubes 21 of the third heat exchanger 20ba (see FIG. 3) in the region corresponding to the region L4, and the second inner header It reaches 23b and joins.

On the other hand, in the case of heating operation, that is, when the outdoor heat exchanger 3 functions as an evaporator, the refrigerant flows in the direction opposite to the refrigerant flow direction in the case of the above-mentioned condenser.

The first outer header 24aa of the first outdoor heat exchanger 3a and the second outer header 24bb of the second outdoor heat exchanger 3b may be connected only by the connection pipe 31. Further, the position and number of partitions are not limited to the positions and numbers described in the second embodiment.

According to the air conditioner 100 of the second embodiment, the partition 41a is provided in the second folded header 25b and the second outer header 24bb. Further, a partition 41b is provided on the second inner header 23b.

When the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b function as a condenser, in the region on the downstream side where the refrigerant of the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b becomes an upward flow. The flow path cross-sectional area of the plurality of flat tubes 21 is smaller than the refrigerant flow path cross-sectional area of the plurality of flat tubes 21 in the upstream region. Therefore, when the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b function as a condenser, the cross-sectional area of the refrigerant flow path in the downstream region is smaller than the cross-sectional area of the refrigerant flow path on the upstream side. , The pressure of the refrigerant increases, and as a result, the flow velocity of the refrigerant can be increased. Further, the heat exchange performance of the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b can be improved.

Embodiment 3.
In the first and second embodiments, the connection between the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b is connected by an L-shaped connection pipe 31. In the air conditioner 100 of the third embodiment, the L-shaped connection pipe 31 is not used for the connection between the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b. In the third embodiment, the first outer header 24aa is stretched. The first outer header 24aa and the second outer header 24bb are connected by a linear connecting pipe 51.

FIG. 10 is a diagram for explaining the connection relationship between the first outer header 24aa and the second outer header 24bb of the air conditioner 100 according to the third embodiment.

As shown in FIG. 10, the first outer header 24aa arranged on the outer side is formed to be longer and extend than the first inner header 23aa. The first inner header 23aa and the second outer header 24bb are connected by a linear connecting pipe 51.

According to the air conditioner 100 according to the third embodiment, the first outer header 24aa is stretched. The extended first inner header 23aa and the second outer header 24bb are connected by a linear connecting pipe 51.

Therefore, the first inner header 23aa and the second outer header 24bb can be connected by using the linear connecting pipe 51 without using the connecting pipe 31 having the bent portion 31r, so that the positioning of the pipe can be performed. Performance can be improved. As a result, the piping space used for positioning can be reduced, and the mounting area of the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b can be improved.

The first outdoor heat exchanger 3a of the first embodiment, the second embodiment and the third embodiment is also referred to as a first heat exchanger, and the second outdoor heat exchanger 3b is also referred to as a second heat exchanger. Further, the second folded header 25b is also referred to as a common header.

The embodiment is presented as an example and is not intended to limit the scope of claims. The embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the embodiment. These embodiments and variations thereof are included in the scope and gist of the embodiments.

1 Compressor, 2 4-way valve, 3 Outdoor heat exchanger, 3a 1st outdoor heat exchanger, 3b 2nd outdoor heat exchanger, 3c 3rd outdoor heat exchanger, 3d 4th outdoor heat exchanger, 4 fans, 5 Expansion valve, 6 indoor heat exchanger, 7 fan, 8 accumulator, 9 housing, 9a square body, 9b fan storage, 10 outdoor unit, 11, 12, 13 indoor unit, 20aa 1st heat exchanger, 20ab second Heat exchanger, 20ba 3rd heat exchanger, 20bb 4th heat exchanger, 21 flat tube, 22 fins, 23a 1st inner header, 23b 2nd inner header, 24aa 1st outer header, 24bb 2nd outer header, 24a Inner pipe, 24b outer pipe, 24c refrigerant flow hole, 25a 1st folded header, 25b 2nd folded header, 26, 27 refrigerant pipe, 31 connection pipe, 31r bend, 41a 1st partition, 41b 2nd partition, 51 connection pipe, 100 flow path cross-sectional area per one of the air conditioner, _{a 1} flat tubes 21.

Claims

A first heat exchanger having a plurality of heat transfer tubes arranged at intervals, a first inner header provided at one upper or lower end of the plurality of heat transfer tubes of the first heat exchanger, and the first. 1 A second heat exchanger having a plurality of heat transfer tubes provided in the ventilation direction of the heat exchanger and arranged at intervals, and one end of the upper side or the lower side of the plurality of heat transfer tubes of the second heat exchanger. A first heat exchanger, including a first outer header provided, and
A third heat exchanger having a plurality of heat transfer tubes arranged at intervals, a second inner header provided at one upper or lower end of the plurality of heat transfer tubes of the third heat exchanger, and the first. A fourth heat exchanger having a plurality of heat transfer tubes provided in the ventilation direction with the three heat exchangers and arranged at intervals, and the first outer header of the plurality of heat transfer tubes of the fourth heat exchanger. A second heat exchanger, including a second outer header provided at one end on the same side, upper or lower.
The first outer header and the second outer header are connected to each other, and a connecting pipe having a bent portion is provided.
The refrigerant flowing from the first heat exchanger to the second heat exchanger and the refrigerant flowing from the second heat exchanger to the first heat exchanger flow only in the connecting pipe.
Heat exchanger.
The first outer header is a double-structured pipe having a first inner pipe having a refrigerant flow hole and a first outer pipe accommodating the first inner pipe.
The second outer header is a double-structured pipe having a second inner pipe having a refrigerant flow hole and a second outer pipe accommodating the second inner pipe.
The heat exchanger according to claim 1, wherein the connection pipe connects the first inner pipe of the first outer header and the second inner pipe of the second outer header.
The second heat exchanger is
The third heat exchanger and the fourth heat exchanger are provided on the other end side of the plurality of heat transfer tubes of the third heat exchanger and the other end side of the plurality of heat transfer tubes of the fourth heat exchanger. Equipped with a common header provided in common,
The common header and the second outer header are provided with a partition for preventing the refrigerant from passing through.
When the heat exchanger functions as a condenser, the second heat exchange in the downstream region where the refrigerant flows up in the common header and the second outer header region partitioned by the partition. The cross-sectional area of the refrigerant flow paths of the plurality of heat transfer tubes of the vessel is smaller than the cross-sectional area of the refrigerant flow paths of the plurality of heat transfer tubes of the second heat exchanger in the region on the upstream side where the refrigerant is an upward flow.
The heat exchanger according to claim 1 or 2.
The first heat exchanger is
The first outer header is longer than the first inner header,
The connecting pipe is linear.
The heat exchanger according to any one of claims 1 to 3.
A fan arranged above the first heat exchanger and the second heat exchanger is provided.
The second heat exchanger is located outside the first heat exchanger in a plan view from the fan.
The heat exchanger according to any one of claims 1 to 4, wherein the fourth heat exchanger is located outside the third heat exchanger in a plan view from the fan.
An outdoor unit of an air conditioner including the heat exchanger according to any one of claims 1 to 5.
An air conditioner including the outdoor unit of the air conditioner according to claim 6.