JP7366255B2 - Heat exchangers, outdoor units of air conditioners, and air conditioners - Google Patents

Description

The present disclosure provides a heat exchanger, an air conditioner, a first heat exchanger including a plurality of rows of heat exchangers having a plurality of heat transfer tubes, and a second heat exchanger including a plurality of rows of heat exchangers having a plurality of heat transfer tubes. Related to outdoor units and air conditioners.

A first heat exchanger having heat exchanger tubes arranged in rows at intervals, and a second heat exchanger having heat exchanger tubes provided in parallel to the first heat exchanger and arranged in rows at intervals. A heat exchanger including a body is known. Two such heat exchangers are then provided. Here, for convenience of explanation, one of the two heat exchangers will be referred to as a first heat exchanger, and the other will be 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 include bent connection piping that connects 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 heat exchanger. It is connected by a bent connecting pipe that connects to the outer header of the heat exchanger.

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

Patent No. 6595125

The inner headers of the first heat exchanger and the second heat exchanger and the outer headers of the first heat exchanger and the second heat exchanger are connected to each other by two bent connecting pipes. Therefore, since there is a connecting pipe connecting the inner headers of the first heat exchanger and the second heat exchanger, the mounting area of at least one of the first heat exchanger and the second heat exchanger in the longitudinal direction is The problem is that it becomes small.

The present disclosure has been made in view of the above circumstances, and it is possible to improve the mounting area of a heat exchanger having a first heat exchanger and a second heat exchanger connected to the first heat exchanger. The purpose is to provide heat exchangers, outdoor units for air conditioners, and air conditioners.

According to the heat exchanger according to the present disclosure, there is provided a first heat exchange body having a plurality of heat exchanger tubes arranged at intervals; a second heat exchanger having a plurality of heat transfer tubes arranged at intervals and provided in the ventilation direction of the first heat exchanger; and a plurality of heat exchanger tubes of the second heat exchanger. a first heat exchanger including a first outer header provided at one end of the upper or lower side of the heat exchanger tubes; a third heat exchanger having a plurality of heat exchanger tubes arranged at intervals; A second inner header provided at one end of the upper side or the lower side of the plurality of heat exchanger tubes of the heat exchanger, and a plurality of heat exchanger tubes arranged at intervals and provided in the ventilation direction of the third heat exchanger. and a second outer header provided at one end of the upper or lower side of the plurality of heat exchanger tubes of the fourth heat exchanger on the same side as the first outer header. An exchanger, a connecting pipe connecting the first outer header and the second outer header and having a bent part, the pipe connecting the first inner header and the second inner header 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 through the connection 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, there is no need for connection piping to connect the inner header of the first heat exchanger and the inner header of the third heat exchanger, so the mounting area of the heat exchanger is improved. I can do it.

FIG. 2 is a refrigerant circuit diagram of the air conditioner according to the first embodiment. 1 is a perspective view showing an outdoor unit of an air conditioner according to Embodiment 1. FIG. FIG. 2 is a perspective view showing a first outdoor heat exchanger and a second outdoor heat exchanger of the air conditioner according to the first embodiment. FIG. 3 is a diagram showing an example of a first outer header of the air conditioner according to the first embodiment. FIG. 3 is a sectional view showing an example of a cross section of the first outer header of the air conditioner according to the first embodiment, which is perpendicular to the pipe extending direction. FIG. 3 is a diagram showing a comparative example for explaining the effects of the air conditioner according to the first embodiment. FIG. 3 is a diagram for explaining the effects of the air conditioner according to the first embodiment. FIG. 7 is a diagram showing the flow passage cross-sectional area of each of a plurality of flat tubes of a first outdoor heat exchanger and a second outdoor heat exchanger of the air conditioner according to Embodiment 2; FIG. 7 is a diagram for explaining the flow of refrigerant in the first outdoor heat exchanger and the second outdoor heat exchanger 3b of the air conditioner according to the second embodiment. FIG. 7 is a diagram for explaining a connection relationship between a first outer header and a second outer header of an air conditioner according to Embodiment 3;

Hereinafter, an air conditioner according to an embodiment will be described with reference to the drawings. In addition, in the drawings, the same components will be described with the same reference numerals, and repeated description will be given only when necessary. The present disclosure may include any combination of combinable configurations among the configurations described in each embodiment below.

Embodiment 1.
<Configuration of air conditioner 100>
FIG. 1 is a refrigerant circuit diagram of an 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. Indoor units 11, 12, and 13 are connected in parallel to 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. Note that 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 via refrigerant piping. . In the outdoor heat exchanger 3, heat is exchanged between the refrigerant flowing inside and the air by the wind generated by the fan 4. In the indoor heat exchanger 6, heat is exchanged between the refrigerant flowing inside and the air by the wind generated by the fan 7.

During cooling operation, the high-temperature, high-pressure gas refrigerant 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 opposite direction to the refrigerant flow direction in the case of the above-mentioned condenser.

<Configuration 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 storage portion 9b. The compressor 1 and four first to fourth outdoor heat exchangers 3a to 3d are arranged in the rectangular parallelepiped portion 9a. The four first to fourth outdoor heat exchangers 3a to 3d are respectively attached to the side surfaces of the rectangular parallelepiped portion 9a of the housing 9. The fan storage section 9b is formed in the upper part of the rectangular parallelepiped section 9a, and the fan 4 is arranged therein.

Each of the first outdoor heat exchanger 3a to the fourth outdoor heat exchanger 3d is located close to the fan 4, and is arranged in the upper part of the rectangular parallelepiped portion 9a where the fan 4 has a high air intake efficiency.

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 the 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 part 9a of the housing 9. The lower ends of the first to fourth outdoor heat exchangers 3a to 3d are located at a higher position 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 connection pipe 31 (see FIG. 2). The first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b 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 connection pipe, and the third outdoor heat exchanger 3c and the fourth outdoor heat exchanger 3d are connected to one It functions as a heat exchanger.

<Configuration of the first outdoor heat exchanger 3a and the second 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 representatively explained. 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. Descriptions of the third outdoor heat exchanger 3c and the fourth outdoor heat exchanger 3d are omitted in the first embodiment. The white arrows in the figure indicate the flow of air 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 connecting pipe 31 is an L-shaped bent pipe and has a bent part 31r. Here, the bent portion 31r is a portion of the connecting pipe 31 that has 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 connecting pipe 31.

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

The first heat exchange body 20aa has fins 22 joined to the flat tubes 21. The second heat exchange body 20ab has fins 22 joined to the flat tubes 21. The plurality of flat tubes 21 are arranged horizontally at intervals so that the wind generated by the fan 4 can flow therethrough. The plurality of flat tubes 21 are arranged to extend in the vertical direction. Refrigerant flows vertically within the plurality of flat tubes 21 . The plurality of flat tubes 21 of the first heat exchange body 20aa are arranged parallel to the plurality of flat tubes 21 of the second heat exchange body 20ab in the ventilation direction.

The fins 22 of the first heat exchange body 20aa are connected between adjacent flat tubes 21 of the first heat exchange body 20aa, and heat is transferred to the flat tubes 21. The fins 22 of the second heat exchange body 20ab are connected between adjacent flat tubes 21 of the second heat exchange body 20ab, and heat is transferred to the flat tubes 21.

Note that the fins 22 improve the heat exchange efficiency between the air and the refrigerant, and for example, corrugated fins are used. However, the fins 22 are not limited to corrugated fins. Since heat exchange between the air and the refrigerant takes place 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 exchange body 20aa on the leeward side of the first outdoor heat exchanger 3a. The lower end portions of the plurality of flat tubes 21 of the first heat exchange body 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 from the refrigerant circuit. The first inner header 23a is also called a gas header. During cooling operation, high-temperature, high-pressure gas refrigerant from the compressor 1 flows into the first inner header 23a. During heating operation, the refrigerant that has undergone 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 connecting pipe 31.

A first folded header 25a is provided above the first heat exchange body 20aa and the second heat exchange body 20ab. The upper ends of the plurality of flat tubes 21 inserted into 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 includes a third heat exchange body 20ba and a fourth heat exchange body 20bb. The third heat exchanger 20ba has a plurality of flat tubes 21 arranged at intervals in the horizontal direction, with the vertical direction being 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 being the tube extending direction.

The third heat exchange body 20ba has fins 22 joined to the flat tubes 21. The fourth heat exchange body 20bb has fins 22 joined to the flat tubes 21. The plurality of flat tubes 21 are arranged horizontally at intervals so that the wind generated by the fan 4 can flow therethrough. The plurality of flat tubes 21 are arranged to extend in the vertical direction. Refrigerant flows vertically within the plurality of flat tubes 21 . The plurality of flat tubes 21 of the third heat exchange body 20ba are arranged parallel to the plurality of flat tubes 21 of the fourth heat exchange body 20bb in the ventilation direction.

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

A second inner header 23b is provided at the lower part of the third heat exchange body 20ba on the leeward side of the second outdoor heat exchanger 3b. The lower end portions of the plurality of flat tubes 21 of the third heat exchange body 20ba of the second outdoor heat exchanger 3b are inserted into the second inner header 23b. The lower end portions of the plurality of flat tubes 21 of the third heat exchange body 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. The refrigerant that has undergone heat exchange with the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b during cooling operation is output to the second inner header 23b to the refrigerant pipe 27. During heating operation, refrigerant from the expansion valve 5 flows into the second inner header 23b.

A second outer header 24bb is provided at the bottom 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 connecting pipe 31.

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

A plurality of flat tubes 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. Both are made of aluminum.

Note that in the first embodiment, the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b are arranged substantially at right angles in the horizontal direction; The present invention 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 sectional view showing an example of a cross section of the first outer header 24aa of the air conditioner 100 according to the first embodiment, which is perpendicular to the pipe extending direction. Although FIG. 5 shows the first outer header 24aa, the second outer header 24bb also has a similar configuration. As shown in FIGS. 4 and 5, the first outer header 24aa is provided below the first heat exchanger 20aa on the windward side. If 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 has a double pipe structure having an inner pipe 24a and an outer pipe 24b. The distribution performance is better than that of a conventional structure. Like the first outer header 24aa, the second outer header 24bb has a double pipe structure having an inner pipe and an outer pipe, so that the gas-liquid two-phase refrigerant can be distributed relatively uniformly, and the second outer header 24bb The distribution performance is better than when the header 24bb has a normal pipe structure.

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

Note that the refrigerant flow holes 24c may be located between adjacent flat tubes 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 tube 24b. Specifically, the refrigerant flow hole 24c has an angle θ of 10 degrees from the lower end of the inner pipe 24a to the position where the refrigerant flow hole 24c is located, which is a vertical line passing through the center of the inner pipe 24a when viewed from the center of the inner pipe 24a. 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 tube 24a at the position where the refrigerant flow hole 24c is provided.

The inner tube 24a is inserted into the outer tube 24b. The outer tube 24b is a tube with a U-shaped cross section and an arcuate lower portion. The outer tube 24b, which has a U-shaped cross section, smoothly changes the refrigerant from the refrigerant flow hole 24c, which is open downward, upward along an arc. The inner tube 24a and the outer tube 24b extend straight in the tube extending direction. The inner tube 24a and the outer tube 24b are joined by brazing.

When the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b function as condensers, the refrigerant flows from the first folded header 25a of the first outdoor heat exchanger 3a to the second heat exchanger 20ab on the windward side. 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 from 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 constructed by bending the 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 shown in 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 radiates heat by the wind generated by the fan 7, condenses, and liquefies. The liquefied refrigerant is depressurized by the expansion valve 5 and enters the outdoor heat exchanger 3 via the refrigerant pipe 27 in a gas-liquid two-phase state of low temperature and low pressure. The refrigerant that has flowed 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 through the refrigerant circuit. In addition to the refrigerant, refrigeration oil necessary for driving the compressor 1 also circulates within the refrigerant circuit. On the other hand, in the case of cooling operation, the flow of refrigerant and refrigerating machine oil rotates in the refrigerant circuit in the opposite direction.

<Operation of the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b>
Here, the operations of the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b will be representatively explained. 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. Descriptions of the third outdoor heat exchanger 3c and the fourth outdoor heat exchanger 3d are 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 a condenser. The refrigerant, which is compressed by the compressor 1 and becomes a high-temperature, high-pressure gas, flows into the outdoor heat exchanger 3 via the four-way valve 2 . Among the high-temperature, high-pressure gas refrigerants, 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 that has flowed into the first inner header 23a ascends through the plurality of flat tubes 21 inserted into the first inner header 23a, exchanges heat with the air carried by the wind generated by the fan 4, and gradually liquefies. The first folded header 25a of the first outdoor heat exchanger 3a is reached. The refrigerant that has reached the first folded header 25a descends through the plurality of flat tubes 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 and merged with the first outer header 24aa flows into the second outer header 24bb of the second outdoor heat exchanger 3b via the connecting pipe 31.

The refrigerant that has reached the second outer header 24bb ascends through the plurality of flat tubes 21 of the fourth heat exchanger 20bb of the second outdoor heat exchanger 3b, and gradually exchanges heat with the air carried by the wind generated by the fan 4. While being liquefied, 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 through the plurality of flat tubes 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 opposite direction to the refrigerant flow direction in the case of the above-mentioned condenser.

In addition, in Embodiment 1, the outdoor heat exchanger 3 of the air conditioner 100 was explained, but the connection by the connection pipe 31 between the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b in Embodiment 1 is explained. The configuration can also be applied to the indoor heat exchanger 6.

Furthermore, in the first embodiment, a case has been described in which the first outer header 24aa and the second outer header 24bb are connected via the connection pipe 31. If the first folded header 25a has an inner header and an outer header, and the second folded header 25b has an inner header and an outer header, the outer header of the first folded header 25a and the outer header of the second folded header 25b are The connection may be made using a connecting pipe 31.

<Effects of Embodiment 1>
Connecting headers that extend in orthogonal directions requires curved connecting piping. It is preferable that the connecting pipe be curved as much as possible in order to suppress the resistance of the refrigerant. However, in order to ensure the curvature of the connecting pipes on the inner side, a large space was required between the headers.

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 the connecting pipe 31. The refrigerant flowing from the first outdoor heat exchanger 3 a to the second outdoor heat exchanger 3 b and the refrigerant flowing from the second outdoor heat exchanger 3 b to the first outdoor heat exchanger 3 a flow only through the connecting pipe 31 . Therefore, since there is no need for connection piping to connect the first inner header 23a of the first heat exchanger and the second inner header 23b of the third heat exchanger, the first heat exchanger 20aa and the second heat exchanger 20ab The mounting area can be improved.

FIG. 6 is a diagram showing a comparative example for explaining the effects of the air conditioner 100 according to the first embodiment. FIG. 7 is a diagram for explaining the effects 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 disposed inside the first outdoor heat exchanger 3a, and the third heat exchanger 23a disposed inside the second outdoor heat exchanger 3b. The second inner header 23b of the exchanger 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 connecting pipe 31b is not required, the lengths of the first heat exchanger 20aa and the second heat exchanger 20ab can be reduced. It can be extended by L. As a result, the mounting area of the first heat exchange body 20aa and the second heat exchange body 20ab can be improved.

Further, the connecting pipe 31 connects the inner pipe 24a of the first outer header 24aa and the inner pipe of the second outer header 24bb. Therefore, compared to the case where the connecting 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 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 paths 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 addition, in Embodiment 2, the refrigerant pipe 27 will be described as being connected to the second outer header 24bb due to the flow of refrigerant due to the partition.

When the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b function as a condenser, the partition of the second outdoor heat exchanger 3b is a second folded header 25b and a second outer header 24bb separated by the partition. Among the regions, the refrigerant flow path cross-sectional area of the plurality of flat tubes 21 connected to the refrigerant flow region where the refrigerant flows upwardly becomes smaller in the process of phase change from gas refrigerant to liquid refrigerant. Specifically, in the second embodiment, when the second outdoor heat exchanger 3b functions as a condenser, the refrigerant is removed from the area of the second folded header 25b and the second outer header 24bb, which are partitioned by a partition. The refrigerant flow path cross-sectional area of the plurality of flat tubes 21 of the second outdoor heat exchanger 3b in the downstream region where the refrigerant flows upward is the same as that of the second outdoor heat exchanger 3b in the upstream region where the refrigerant flows upward. It is smaller than the cross-sectional area of the refrigerant flow path of the plurality of flat tubes 21.

In addition, 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 an upward flow among the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b 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 flowing into the corresponding region when the condenser is operated at intermediate load capacity (50% capacity).

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

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

_JG and _JL 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)

FIG. 8 is a diagram showing the flow passage cross-sectional area _A1 of each of the plurality of flat tubes 21 of the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b of the air conditioner 100 according to the second embodiment. It is.
here,
Deq is the equivalent diameter [m] defined by the number of flat pipes and the cross-sectional area of the flow path connected to the most downstream and upward flow region when functioning as a condenser,
A _eq = A ₁ ×N…(4)
D _eq = [(4×A _eq) /3.14] ^0.5 ...(5)
It is expressed as

When the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b function as condensers, N is the number of flat tubes that are connected to the most downstream flow region that flows in an upward flow. In the second embodiment, this corresponds to the number of flat tubes connected to region L4 shown in FIG.

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

U _G is gas apparent velocity [m/s], U _L is liquid apparent velocity [m/s], x is refrigerant dryness,
U _G = (G×x)/ρ _G …(6)
U _L = [G×(1-x)]/ρ _L …(7)
Defined by

Here, G is the flow rate [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 flow rate of the gas refrigerant flowing into the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b. It is the flow rate [kg/s] of the gas refrigerant flowing into the vessel 3b, and is determined by G=M/A _eq .

x is the dryness of the refrigerant flowing into the most downstream, upwardly flowing flow region. x can be calculated, for example, from the heat exchange amount and capacity of the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b. For example, it is assumed that the refrigerant dryness changes from 1 to 0 from the inlet to the outlet of the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b, and that the heat exchange amount∝heat transfer area. In this case, x can be estimated by the ratio of the number of heat exchanger 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 areas L1, L2, L3, L4)...(8)

FIG. 9 is a diagram for explaining the flow of 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 explained as representatives, but the third outdoor heat exchanger 3c is the first outdoor heat exchanger 3a and the fourth outdoor heat exchanger 3d is The configuration is similar to that of the second outdoor heat exchanger 3b.

In the case of cooling operation, the outdoor heat exchanger 3 functions as a condenser. Among the refrigerants compressed by the compressor 1 and turned into high-temperature, high-pressure gas, refrigerants other than the refrigerant flowing into the third outdoor heat exchanger 3c are transferred to the first inner side of the first outdoor heat exchanger 3a via the refrigerant pipe 26. The data flows into the header 23a (see FIG. 3). The refrigerant that has flowed into the first inner header 23a rises through the plurality of flat tubes 21 (see FIG. 3) inserted into the first inner header 23a, and heats up with the air carried by the wind generated by the fan 4 (see FIG. 2). While being exchanged and gradually liquefied, it reaches the first folded header 25a (see FIG. 3) of the first outdoor heat exchanger 3a. The refrigerant that has reached the first folded header 25a descends through the plurality of flat tubes 21 of the second heat exchanger 20ab (see FIG. 3) of the first outdoor heat exchanger 3a, and then passes through the first outer header 24aa (see FIG. 3). reach. The refrigerant that has reached and merged with the first outer header 24aa flows into the second outer header 24bb (see FIG. 3) of the second outdoor heat exchanger 3b via the connecting pipe 31. Here, the area of the first inner header 23a becomes the area L1.

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

A partition 41b is provided downstream of the partition 41a of the second inner header 23b and the second folded header 25b. The partition 41b provided on the second folding header 25b is provided directly above the partition 41b provided on 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, ascends from the second outer header 24bb through the plurality of flat tubes 21 of the fourth heat exchanger 20bb (see FIG. 3). The refrigerant rising through the plurality of flat tubes 21 exchanges heat with the air carried by the wind generated by the fan 4 and gradually liquefies, until it reaches the second folded header 25b of the second outdoor heat exchanger 3b. Here, the region L2 extends from the refrigerant inlet of the second outside 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 through the plurality of flat tubes 21 of the third heat exchange body 20ba in the area corresponding to the area L2, and descends into the second folded header 25b. 2 reaches the inner header 23b and merges.

The refrigerant that has reached the second inner header 23b flows to a 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 on the second outer header 24bb to the partition 41b provided on the second inner header 23b is the area L3. The refrigerant flowing through the second inner header 23b ascends through the plurality of flat tubes 21 of the third heat exchanger 20ba in the area L3 of the second inner header 23b, and gradually exchanges heat with the air riding on the wind generated by the fan 4. While being liquefied, it reaches the second folding header 25b and merges therewith. 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 and merged with the second folded header 25b descends through the plurality of flat tubes 21 of the fourth heat exchanger 20bb in region L4, and reaches and merges with the second outer header 24bb.

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, some of the refrigerant flowing through the region L4 of the second outer header 24bb descends through the plurality of flat tubes 21 of the third heat exchanger 20ba (see FIG. 3) in the region corresponding to the region L4, and flows down the plurality of flat tubes 21 of the third heat exchanger 20ba (see FIG. 3) in the region corresponding to the region L4. 23b and merge.

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 opposite direction to the refrigerant flow direction in the case of the above-mentioned condenser.

Note that 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 connecting pipe 31. Furthermore, the positions 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. Furthermore, 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 condensers, the refrigerant of the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b flows upward in the downstream area. The flow passage cross-sectional area of the plurality of flat tubes 21 is smaller than the refrigerant flow passage 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 condensers, 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 in the upstream region. , the pressure of the refrigerant increases and, as a result, the flow rate of the refrigerant can be increased. Moreover, the heat exchange performance of the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b can be improved.

Embodiment 3.
In Embodiment 1 and Embodiment 2, the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b are 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 to connect the first outdoor heat exchanger 3a and the second outdoor heat exchanger 3b. In the third embodiment, the first outer header 24aa is extended. The first outer header 24aa and the second outer header 24bb are connected by a straight 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 disposed on the outside is longer than the first inner header 23aa and is formed to extend. The first inner header 23aa and the second outer header 24bb are connected by a straight connecting pipe 51.

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

Therefore, the first inner header 23aa and the second outer header 24bb can be connected using the straight connecting pipe 51 without using the connecting pipe 31 having the bent part 31r, so that the positioning of the pipes can be easily determined. 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 Embodiment 1, Embodiment 2, and Embodiment 3 is also called a first heat exchanger, and the second outdoor heat exchanger 3b is also called a second heat exchanger. Further, the second return header 25b is also referred to as a common header.

The embodiments are presented as examples and are not intended to limit the scope of the claims. The embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the embodiments. These embodiments and their modifications are included within the scope and gist of the embodiments.

1 Compressor, 2 Four-way valve, 3 Outdoor heat exchanger, 3a First outdoor heat exchanger, 3b Second outdoor heat exchanger, 3c Third outdoor heat exchanger, 3d Fourth outdoor heat exchanger, 4 Fan, 5 Expansion valve, 6 Indoor heat exchanger, 7 Fan, 8 Accumulator, 9 Housing, 9a Rectangular parallelepiped part, 9b Fan storage part, 10 Outdoor unit, 11, 12, 13 Indoor unit, 20aa 1st heat exchange body, 20ab 2nd Heat exchanger, 20ba Third heat exchanger, 20bb Fourth heat exchanger, 21 Flat tube, 22 Fin, 23a First inner header, 23b Second inner header, 24aa First outer header, 24bb Second outer header, 24a Inner pipe, 24b Outer pipe, 24c Refrigerant flow hole, 25a First folded header, 25b Second folded header, 26, 27 Refrigerant pipe, 31 Connection pipe, 31r Bent part, 41a First partition, 41b Second partition, 51 Connection Piping, 100 Air conditioner, A ₁ Flow passage cross-sectional area per flat tube 21.

Claims (7)

a first heat exchanger having a plurality of heat exchanger tubes arranged at intervals; a first inner header provided at one end of the upper or lower side of the plurality of heat exchanger tubes of the first heat exchanger; a second heat exchanger provided in the ventilation direction of the first heat exchanger and having a plurality of heat exchanger tubes arranged at intervals; and one end of the upper or lower side of the plurality of heat exchanger tubes of the second heat exchanger. a first heat exchanger including a first outer header provided;
a third heat exchanger having a plurality of heat exchanger tubes arranged at intervals; a second inner header provided at one end of the upper or lower side of the plurality of heat exchanger tubes of the third heat exchanger; a fourth heat exchanger having a plurality of heat exchanger tubes arranged at intervals and provided in the ventilation direction with respect to the third heat exchanger; and the first outer header of the plurality of heat exchanger tubes of the fourth heat exchanger; a second outer header provided at one end of the upper or lower side of the same side;
A connecting pipe connecting the first outer header and the second outer header and having a bent part,
No piping is provided to connect the first inner header and the second inner header,
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 connection 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
Provided on the other end side of the plurality of heat exchanger tubes of the third heat exchanger and on the other end side of the plurality of heat exchanger tubes of the fourth heat exchanger, and provided between the third heat exchanger and the fourth heat exchanger. and a common header provided in common.
The common header and the second outer header are provided with a partition that prevents refrigerant from passing through,
When the heat exchanger functions as a condenser, the second heat exchange in a region on the downstream side where the refrigerant flows upward among the regions of the common header and the second outer header that are partitioned by the partition. The refrigerant flow cross-sectional area of the plurality of heat exchanger tubes of the second heat exchanger is smaller than the refrigerant flow cross-sectional area of the plurality of heat exchanger tubes of the second heat exchanger in an upstream region where the refrigerant flows upward.
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 straight,
The heat exchanger according to any one of claims 1 to 3. comprising a fan disposed above the first heat exchanger and the second heat exchanger,
The second heat exchange body is located outside the first heat exchange body when viewed from the fan in plan view,
The heat exchanger according to any one of claims 1 to 4, wherein the fourth heat exchange body is located outside the third heat exchange body when viewed from the fan in plan view. An outdoor unit of an air conditioner comprising the heat exchanger according to any one of claims 1 to 5. An air conditioner comprising the outdoor unit of the air conditioner according to claim 6.

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