Heat exchanger and air conditioning device

Abstract

This heat exchanger is provided with: a first heat exchange unit comprising a first heat transfer tube group and a first header that is connected to lower ends of a plurality of heat transfer tubes constituting the first heat transfer tube group and allows a refrigerant to circulate through the plurality of heat transfer tubes; a second heat exchange unit comprising a second heat transfer tube group and a second header that is connected to lower ends of a plurality of heat transfer tubes constituting the second heat transfer tube group and allows a refrigerant tp circulate through the plurality of heat transfer tubes; and a third header for allowing a refrigerant to circulate between the first heat exchange unit and the second heat exchange unit. The first header and the second header are formed so as to extend along a direction in which the plurality of heat transfer tubes are arranged spaced apart from one another; the first header and the second header are arranged facing each other; and if a gap which is a section constituting the shortest distance between the first header and the second header is defined as an inter-header gap δ (mm), the inter-header gap δ is at least 0.5 (mm).

Description

Heat exchanger and air conditioning device

[0001] The present disclosure relates to a heat exchanger and an air conditioning apparatus in which two headers are arranged side by side.

[0002] Conventional heat exchangers include two headers provided at the lower ends of multiple heat transfer tubes extending in the vertical direction, with the two headers, one on the inlet side and one on the outlet side of the refrigerant, arranged side by side in the horizontal direction (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2019-215161

[0004] When the heat exchanger of Patent Document 1 is installed in an outdoor unit, frost forms on its surface during operation in low-temperature environments. In this case, hot gas refrigerant is passed through the heat exchanger to defrost it, and the meltwater generated by the defrosting flows toward the lower part of the heat exchanger (which has two headers). The heat exchanger of Patent Document 1 does not take into consideration the freezing of meltwater that flows between the two headers on the refrigerant inlet and outlet sides. If the gap between the two headers for drainage is insufficient, or if the corrugated fins arranged between the heat transfer tubes are configured so that a large amount of meltwater flows into the gap between the headers, meltwater may not be properly drained between the headers. If meltwater is not properly drained between two adjacent headers, the meltwater present between the two adjacent headers may become a source of ice under low-temperature conditions, and the frozen meltwater may cause deformation of the headers.

[0005] The present disclosure is intended to solve the above-mentioned problems, and provides a heat exchanger and an air conditioning apparatus that prevent deformation of the header due to freezing of meltwater and improves freeze resistance.

[0006] The heat exchanger according to the present disclosure includes a first heat exchange section having a first heat transfer tube group consisting of a plurality of heat transfer tubes extending in the vertical direction and a first header connected to lower ends of the heat transfer tubes constituting the first heat transfer tube group and allowing a refrigerant to flow through the plurality of heat transfer tubes; a second heat exchange section having a second heat transfer tube group consisting of a plurality of heat transfer tubes extending in the vertical direction and a second header connected to lower ends of the heat transfer tubes constituting the second heat transfer tube group and allowing a refrigerant to flow through the plurality of heat transfer tubes; and a third header into which upper ends of the heat transfer tubes constituting the first heat exchange section and the second heat exchange section are inserted and allowing a refrigerant to flow between the first heat exchange section and the second heat exchange section. , and the first header and the second header are formed to extend in a direction in which the plurality of heat transfer tubes are arranged at intervals from each other, and when the direction in which the plurality of heat transfer tubes extend is defined as a first direction, the direction in which the first header and the second header extend is defined as a second direction, and a direction perpendicular to the first and second directions is defined as a third direction, the first header and the second header are arranged opposite each other in the third direction, and when the spacing of the portion constituting the shortest distance between the first header and the second header in the third direction is defined as a header gap δ [mm], the header gap δ is configured to be 0.5 [mm] or more.

[0007] The air conditioning apparatus of the present disclosure is composed of a compressor and a heat exchanger of the above-described configuration, and is equipped with a heat exchanger that exchanges heat between outdoor air and the refrigerant flowing inside, a throttling device that reduces the pressure of the refrigerant flowing inside, and an indoor heat exchanger that exchanges heat between indoor air and the refrigerant flowing inside.

[0008] According to the present disclosure, a heat exchanger and an air conditioner are provided that prevent deformation of a header due to freezing of meltwater and improve freeze resistance.

[0009] 1 is a conceptual diagram showing the configuration of a refrigerant circuit of an air conditioner according to an embodiment. FIG. 2 is a perspective view schematically showing a heat exchanger of an air conditioner according to embodiment 1. FIG. 3 is a conceptual diagram of a heat exchanger of an air conditioner according to embodiment 1. FIG. 4 is a conceptual diagram showing the positional relationship between a first header and a second header in a heat exchanger of an air conditioner according to embodiment 1. FIG. 5 is a perspective view of an outdoor unit of an air conditioner according to embodiment 1, seen from the front. FIG. 6 is an exploded perspective view of an outdoor unit of an air conditioner according to embodiment 1, seen from the front. FIG. 7 is a conceptual diagram showing a plan view of the internal configuration of an outdoor unit of an air conditioner according to embodiment 1. FIG. 8 is a diagram showing the relationship between inter-header gaps and the amount of residual water between headers. FIG. 9 is a conceptual diagram showing the positional relationship between a first header and a second header in a heat exchanger of an air conditioner according to embodiment 2. FIG. 10 is a conceptual diagram showing a side view of the first header in a heat exchanger of an air conditioner according to embodiment 2. FIG. 11 is a conceptual diagram of a partition plate in a heat exchanger of an air conditioner according to embodiment 2. FIG. 12 is a conceptual diagram showing the positional relationship between a first header and a second header in a heat exchanger of an air conditioner according to embodiment 3. FIG. 13 is a conceptual diagram showing a side view of the first header in a heat exchanger of an air conditioner according to embodiment 3. 10 is a conceptual diagram showing a partition plate and an inner pipe portion in a heat exchanger of an air conditioning apparatus according to Embodiment 3. FIG.

[0010] Hereinafter, a heat exchanger and an air conditioning apparatus according to an embodiment will be described with reference to the drawings. Note that in the following drawings, including FIG. 1, the relative dimensional relationships and shapes of the components may differ from those in reality. In the following drawings, the same reference numerals denote the same or equivalent components, and this applies throughout the entire specification. To facilitate understanding, directional terms (e.g., up, down, right, left, front, rear, etc.) are used as appropriate, but these notations are merely for the convenience of explanation and do not limit the arrangement or orientation of the device or components.

[0011] Embodiment 1. [Air Conditioning Apparatus 100] Fig. 1 is a conceptual diagram showing the configuration of a refrigerant circuit 101 of an air conditioning apparatus 100 according to an embodiment. The air conditioning apparatus 100 will be described using Fig. 1. The air conditioning apparatus 100 performs air conditioning by heating or cooling the room by transferring heat between the outside air and the indoor air via a refrigerant. The air conditioning apparatus 100 has an outdoor unit 10 and an indoor unit 20. Note that Fig. 1 shows one outdoor unit 10 and one indoor unit 20, but there may be multiple outdoor units 10 and multiple indoor units 20.

[0012] In the air conditioning apparatus 100, the indoor unit 20 and the outdoor unit 10 are connected by refrigerant piping 90 to form a refrigerant circuit 101 through which refrigerant circulates. In the refrigerant circuit 101, a compressor 11, a flow switching device 12, an indoor heat exchanger 22, a throttling device 21, a right heat exchanger 30a, a rear heat exchanger 30b, a left heat exchanger 30c, a first flow control valve 13, a second flow control valve 14, and an accumulator 15 are connected by the refrigerant piping 90. The right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c are each one of a plurality of heat exchangers 30. The term "heat exchanger 30" collectively refers to the right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c.

[0013] As shown in FIG. 1 , in the refrigerant circuit 101 of the air conditioning apparatus 100, the rear heat exchanger 30b may be connected in parallel with the right heat exchanger 30a and the left heat exchanger 30c. Furthermore, in the air conditioning apparatus 100, the right heat exchanger 30a may be connected in parallel with the left heat exchanger 30c. The configuration of the refrigerant circuit 101 shown in FIG. 1 is merely an example, and other configurations may be used. For example, the air conditioning apparatus 100 may not have the flow path switching device 12, and may not have the accumulator 15. Furthermore, the number of heat exchangers 30 may be one or more.

[0014] [Indoor unit 20] The indoor unit 20 has an expansion device 21 and an indoor heat exchanger 22. The indoor unit 20 may further have a blower fan (not shown). The indoor unit 20 generates cold air or warm air by exchanging heat between indoor air passing through the indoor heat exchanger 22 and the refrigerant flowing inside the indoor heat exchanger 22. The indoor unit 20 blows the cold air or warm air to the outside of the indoor unit 20, and sends conditioned air into the room.

[0015] The indoor heat exchanger 22 exchanges heat between the indoor air and the refrigerant. During cooling operation, the indoor heat exchanger 22 functions as an evaporator that evaporates the refrigerant and cools the indoor air with the heat of vaporization. During heating operation, the indoor heat exchanger 22 functions as a condenser that radiates heat from the refrigerant to the indoor air to condense the refrigerant.

[0016] [Outdoor Unit 10] The outdoor unit 10 has a compressor 11, a flow path switching device 12, a first flow control valve 13, a second flow control valve 14, an accumulator 15, and a plurality of heat exchangers 30. The plurality of heat exchangers 30 are composed of a right heat exchanger 30a, a rear heat exchanger 30b, and a left heat exchanger 30c.

[0017] The compressor 11 draws in a low-temperature, low-pressure refrigerant, compresses the drawn refrigerant, and discharges a high-temperature, high-pressure refrigerant. The compressor 11 is an inverter compressor whose capacity, which is the amount of refrigerant delivered per unit time, is controlled by, for example, changing the operating frequency.

[0018] The flow path switching device 12 is, for example, a four-way valve, and switches between cooling operation and heating operation by switching the direction of refrigerant flow. During cooling operation, the flow path switching device 12 switches to the state shown by the solid line, which will be described later, and connects the discharge side of the compressor 11 to the heat exchanger 30. During heating operation, the flow path switching device 12 switches to the state shown by the dashed line, and connects the discharge side of the compressor 11 to the indoor heat exchanger 22.

[0019] The right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c are heat exchangers 30 that exchange heat between outdoor air and the refrigerant. During cooling operation, the right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c function as condensers that radiate heat from the refrigerant to the outdoor air to condense the refrigerant. During heating operation, the right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c function as evaporators that absorb heat from the outdoor air to evaporate the refrigerant. Details will be described later using Figures 5 to 7 , but the right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c in the first embodiment are independent heat exchangers 30 and are located on the right, rear, and left sides of the outdoor unit 10, respectively.

[0020] The first flow control valve 13 and the second flow control valve 14 are, for example, electronic expansion valves that can adjust the throttle opening. The first flow control valve 13 is provided corresponding to the right heat exchanger 30 a and the left heat exchanger 30 c, and by changing its opening, it adjusts the flow rate of refrigerant flowing into the right heat exchanger 30 a and the left heat exchanger 30 c. The second flow control valve 14 is provided corresponding to the rear heat exchanger 30 b, and by changing its opening, it adjusts the flow rate of refrigerant flowing into the rear heat exchanger 30 b.

[0021] The opening degrees of the first flow control valve 13 and the second flow control valve 14 are determined for each site where the outdoor unit 10 is to be installed, for example, during construction of the outdoor unit 10. For example, when it is expected that the air volume passing through the right heat exchanger 30a and the left heat exchanger 30c will be small, the opening degree of the first flow control valve 13 is set smaller than when it is expected that the air volume passing through the right heat exchanger 30a and the left heat exchanger 30c will be normal or large. In this case, the opening degree of the second flow control valve 14 may be set larger than when it is expected that the air volume passing through the right heat exchanger 30a and the left heat exchanger 30c will be normal or large.

[0022] By setting the opening degrees of the first flow control valve 13 and the second flow control valve 14 in this manner, even when the air volume passing through the right heat exchanger 30a and the left heat exchanger 30c is small, the flow rate of refrigerant flowing into the right heat exchanger 30a and the left heat exchanger 30c can be reduced, thereby preventing excess refrigerant from flowing through the right heat exchanger 30a and the left heat exchanger 30c. Note that if a wall or another outdoor unit 10 is adjacent to the side of the outdoor unit 10 facing the right heat exchanger 30a or the left heat exchanger 30c, the air volume passing through the right heat exchanger 30a and the left heat exchanger 30c is expected to be small. The arrangement of the right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c will be described later.

[0023] The accumulator 15 is provided on the intake side of the compressor 11 and serves to store excess refrigerant that occurs due to differences in operating conditions between cooling and heating, or excess refrigerant that occurs due to transient changes in operation, etc. Furthermore, the accumulator 15 serves to prevent liquid compression in the compressor 11.

[0024] The expansion device 21 is, for example, an electronic expansion valve that can adjust the opening degree of the expansion valve, and by adjusting the opening degree, the pressure of the refrigerant flowing into the right heat exchanger 30a, the rear heat exchanger 30b, the left heat exchanger 30c, or the indoor heat exchanger 22. In the first embodiment, the expansion device 21 is provided in the indoor unit 20, but it may also be provided in the outdoor unit 10, and the installation location is not limited.

[0025] The air conditioning device 100 includes a heat exchanger 30 that exchanges heat between the outdoor air and the refrigerant flowing inside, a throttling device 21 that reduces the pressure of the refrigerant flowing inside, and an indoor heat exchanger 22 that exchanges heat between the indoor air and the refrigerant flowing inside.

[0026] <Cooling Operation> Here, the behavior of the air conditioning apparatus 100 during each operation will be described. In cooling operation, as shown by the solid line in Fig. 2, the flow path switching device 12 is switched so that the discharge side of the compressor 11 is connected to the heat exchanger 30. The high-temperature, high-pressure gas refrigerant discharged from the compressor 11 flows into the right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c via the flow path switching device 12. The high-temperature, high-pressure gas refrigerant that flows into the right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c exchanges heat with the outdoor air, condenses while releasing heat, and flows out as low-temperature, high-pressure liquid refrigerant.

[0027] The low-temperature, low-pressure liquid refrigerant flowing out of the right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c flows into the expansion device 21, where it is decompressed to become a low-temperature, low-pressure two-phase gas-liquid refrigerant, which then flows into the indoor heat exchanger 22. The low-temperature, low-pressure two-phase gas-liquid refrigerant that has flowed into the indoor heat exchanger 22 exchanges heat with the indoor air, absorbing heat and evaporating, becoming a low-temperature, low-pressure gas refrigerant that flows out of the indoor heat exchanger 22. At this time, the indoor air is cooled, and cooling is performed inside the room. The low-temperature, low-pressure gas refrigerant that has flowed out of the indoor heat exchanger 22 is drawn into the compressor 11 via the flow switching device 12 and the accumulator 15, and becomes a high-temperature, high-pressure gas refrigerant again.

[0028] <Heating Operation> In heating operation, as shown by the dashed line in Fig. 1 , the flow path switching device 12 is switched so that the discharge side of the compressor 11 is connected to the indoor heat exchanger 22. The high-temperature, high-pressure gas refrigerant discharged from the compressor 11 flows into the indoor heat exchanger 22 via the flow path switching device 12. The high-temperature, high-pressure gas refrigerant that flows into the indoor heat exchanger 22 exchanges heat with the indoor air and condenses while releasing heat, becoming a low-temperature, high-pressure liquid refrigerant that flows out of the indoor heat exchanger 22. At this time, the indoor air is heated, and heating is performed in the room. The low-temperature, high-pressure liquid refrigerant that flows out of the indoor heat exchanger 22 flows to the expansion device 21, where it is decompressed to become a low-temperature, low-pressure two-phase gas-liquid refrigerant.

[0029] The low-temperature, low-pressure two-phase gas-liquid refrigerant flows into the right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c. The low-temperature, low-pressure two-phase gas-liquid refrigerant that flows into the right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c exchanges heat with the outdoor air, absorbing heat and evaporating, and flows out as low-temperature, low-pressure gas refrigerant. The low-temperature, low-pressure gas refrigerant that flows out of the right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c is drawn into the compressor 11 via the flow switching device 12 and the accumulator 15, and becomes high-temperature, high-pressure gas refrigerant again.

[0030] <Defrosting Operation> FIG. 2 is a perspective view schematically illustrating the heat exchanger 30 of the air conditioning apparatus 100 according to the first embodiment. The arrows in FIG. 2 indicate the inflow and outflow directions of the refrigerant when the heat exchanger 30 functions as a condenser. When heating operation is performed in a low-temperature environment where the surface temperatures of the heat transfer tubes 32 and the fins 33 are below 0°C, frost may form on the heat exchanger 30. When the amount of frost on the heat exchanger 30 exceeds a certain level, the air passage of the heat exchanger 30 through which the air generated by the fan 50 (see FIG. 6) passes is blocked, deteriorating the performance of the heat exchanger 30 and the heating performance. Therefore, when heating performance is reduced, a defrosting operation is performed to melt the frost on the surface of the heat exchanger 30.

[0031] In defrosting operation, the fan 50 (see FIG. 6 ) is stopped, the flow path switching device 12 is switched to the same state as in cooling operation, and high-temperature, high-pressure gas refrigerant flows into the heat exchanger 30. This melts the frost adhering to the heat transfer tubes 32 and fins 33. The high-temperature refrigerant flowing into the heat transfer tubes 32 melts the frost adhering to the heat transfer tubes 32 and fins 33 and turns them into water. The water produced by the melted frost is drained below the heat exchanger 30 along the heat transfer tubes 32 or the fins 33. Once the frost has melted, the defrosting operation is terminated and heating operation is resumed.

[0032] [Configuration of Heat Exchanger 30] Figure 3 is a conceptual diagram of the heat exchanger 30 of the air conditioning apparatus 100 according to Embodiment 1. The hatched arrows in Figure 3 indicate the inflow or outflow direction of the refrigerant when the heat exchanger 30 functions as a condenser. The dashed arrows in Figure 3 indicate an example of the direction of refrigerant flow inside the heat exchanger 30 when the heat exchanger 30 functions as a condenser. The hollow arrows in Figure 3 indicate an example of the direction of air flow. Note that Figure 3 omits illustration of a portion of the heat transfer tubes 32 and the fins 33.

[0033] The configuration of the heat exchanger 30 will now be described in detail with reference to Figures 2 and 3. The right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c all have the same configuration, and therefore will be described here as heat exchanger 30. The heat exchanger 30 is an air-cooled heat exchanger that exchanges heat between the refrigerant flowing therein and the air. The heat exchanger 30 is, for example, a corrugated fin tube type with a parallel piping configuration.

[0034] The heat exchanger 30 includes a first header 31, heat transfer tubes 32, fins 33, a third header 34, and a second header 35. The first header 31 and the second header 35 correspond to the "headers" in the present disclosure. In the heat exchanger 30 according to the first embodiment, a pair of headers, consisting of the first header 31 and the third header 34, and the second header 35, are arranged separately above and below.

[0035] The heat exchanger 30 has a plurality of heat transfer tubes 32 arranged between the first header 31, the second header 35 and the third header 34, with their flat surfaces facing each other and parallel to each other and perpendicular to the first header 31, the second header 35 and the third header 34.

[0036] Groups of heat transfer tubes 32 (hereinafter also referred to as flat tube groups) made up of a plurality of heat transfer tubes 32 are arranged in two rows in the air flow direction. The group of heat transfer tubes 32 in one row is connected to the first header 31 or the second header 35. That is, the group of heat transfer tubes 32 is connected to the first header 31 and the second header 35, respectively.

[0037] In the first embodiment, the heat exchanger 30 is a corrugated fin tube type heat exchanger in which groups of heat transfer tubes 32 are arranged in two rows, but this is not limited to this, and the heat exchanger may be a heat exchanger in which groups of heat transfer tubes 32 are arranged in three or more rows.

[0038] The first header 31 of the heat exchanger 30 and the heat transfer tubes 32 inserted into the first header 31 are collectively referred to as a first heat exchange section 301. Similarly, the second header 35 of the heat exchanger 30 and the heat transfer tubes 32 inserted into the second header 35 are collectively referred to as a second heat exchange section 302. The first heat exchange section 301 and the second heat exchange section 302 may have fins 33 joined between adjacent heat transfer tubes 32.

[0039] The heat exchanger 30 has a first heat exchange section 301 and a second heat exchange section 302. The first heat exchange section 301 is one of a plurality of heat exchange sections 300, and the second heat exchange section 302 is one of a plurality of heat exchange sections 300. The heat exchange section 300 is a general term for the first heat exchange section 301 and the second heat exchange section 302.

[0040] The first heat exchange section 301 has a first heat transfer pipe group 32A composed of a plurality of heat transfer pipes 32 extending in the vertical direction, and a first header 31 connected to the lower ends of the plurality of heat transfer pipes 32 that make up the first heat transfer pipe group 32A and circulating refrigerant through the plurality of heat transfer pipes 32.

[0041] The second heat exchange section 302 has a second heat transfer tube group 32B composed of a plurality of heat transfer tubes 32 extending in the vertical direction, and a second header 35 connected to the lower ends of the plurality of heat transfer tubes 32 that make up the second heat transfer tube group 32B and circulating the refrigerant through the plurality of heat transfer tubes 32.

[0042] [Detailed Configuration of Heat Exchanger 30] As described above, the heat exchanger 30 has the first header 31, heat transfer tubes 32, fins 33, third header 34, and second header 35. In other words, the heat exchanger 30 has the first heat exchange section 301, the second heat exchange section 302, and the third header 34. The first header 31 is provided at the bottom of the heat exchanger 30. The first header 31 is connected to other devices that make up the air conditioning apparatus 100, and is a pipe through which the refrigerant flows in and out and through which the refrigerant branches or merges. A refrigerant inlet / outlet pipe 36 through which the refrigerant flows in and out from the outside is connected to the first header 31. The lower ends of the multiple heat transfer tubes 32 that make up the first heat exchange section 301 are inserted into the first header 31.

[0043] The first header 31 is formed in a long box shape. The first header 31 is formed to extend in the direction in which the multiple heat transfer tubes 32 are arranged at intervals from one another. The first header 31 is in communication with the internal spaces of the multiple heat transfer tubes 32. The first header 31 forms a space that distributes the refrigerant that flows into the first heat exchange unit 301 from the outside to the multiple heat transfer tubes 32. Alternatively, the first header 31 forms a space that merges the refrigerant that flows into the first header 31 from the multiple heat transfer tubes 32. The first header 31 is provided below the heat exchanger 30, and hot gas refrigerant flows into the first header 31 from the refrigerant circuit 101 during defrosting operation.

[0044] The heat transfer tubes 32 are arranged in parallel in the horizontal direction at intervals so that air generated by a fan 50 (see FIG. 6 ) flows between adjacent heat transfer tubes 32. The heat transfer tubes 32 are arranged at intervals along the extension direction of the first header 31, the second header 35, and the third header 34. The heat transfer tubes 32 are arranged to extend in the vertical direction, and a refrigerant flows through the heat transfer tubes 32 along the extension direction of the heat transfer tubes 32. The heat transfer tubes 32 are arranged to extend in the vertical direction, for example. As an example, the heat transfer tubes 32 are flat tubes. The heat transfer tubes 32 are not limited to flat tubes, and may be tubes of other shapes, such as circular tubes.

[0045] When the heat transfer tubes 32 are flat tubes, the heat transfer tubes 32 have a flat cross section, with the outer surface on the long side of the flat shape along the air flow direction being flat, and the outer surface on the short side perpendicular to the long side being curved. When the heat transfer tubes 32 are flat tubes, the heat transfer tubes 32 are, for example, multi-hole flat tubes having multiple holes inside the tube that serve as refrigerant flow paths. The holes in the heat transfer tubes 32 are formed facing in the vertical direction because they serve as flow paths between the first header 31, the second header 35, and the third header 34. Fins 33 are arranged between adjacent heat transfer tubes 32.

[0046] The fins 33 are heat transfer promoting members, and are disposed between adjacent heat transfer tubes 32 among the plurality of heat transfer tubes 32, and are connected to the heat transfer tubes 32. The fins 33 are brazed to the heat transfer tubes 32. The fins 33 are connected between adjacent heat transfer tubes 32, and transfer heat between the connected heat transfer tubes 32. The fins 33 improve the heat exchange efficiency between the air and the refrigerant, and corrugated fins, for example, are used as the fins 33. When the fins 33 are corrugated fins, the fins 33 have a wave shape, are disposed between two adjacent heat transfer tubes 32, and have multiple apexes joined to the flat surfaces of the heat transfer tubes 32.

[0047] The heat exchanger 30 shown in Fig. 2 has flat tubes as the heat transfer tubes 32 and corrugated fins as the fins 33. In the heat exchanger 30, the heat transfer tubes 32 and the fins 33 are alternately arranged in the arrangement direction of the heat transfer tubes 32, i.e., in the axial direction of the third header 34. The fins 33 are not limited to corrugated fins and may be other heat transfer promoting members such as plate fins. Furthermore, because heat exchange between the air and the refrigerant occurs on the surfaces of the heat transfer tubes 32, the heat exchanger 30 may have a so-called finless heat exchange section 300 without fins 33 as long as heat exchange capacity is ensured.

[0048] The third header 34 serves as a bridge connecting the group of heat transfer tubes 32 in one row to the group of heat transfer tubes 32 in the other row. The heat exchanger 30 is provided with the third header 34 above the plurality of heat exchange sections 300, into which the upper ends of the plurality of heat transfer tubes 32 inserted in the first header 31 and the second header 35 are inserted.

[0049] The third header 34 is provided at an end of the plurality of heat transfer tubes 32 on the side opposite to the connection side of the two headers, the first header 31 and the second header 35. The third header 34 is provided opposite the first header 31 and the second header 35 with the heat transfer tubes 32 interposed therebetween.

[0050] The third header 34 connects the upper part of the first heat exchange unit 301 and the upper part of the second heat exchange unit 302. The upper ends of the heat transfer tubes 32 constituting the first heat exchange unit 301 and the second heat exchange unit 302 are inserted into the third header 34, and the refrigerant is circulated between the first heat exchange unit 301 and the second heat exchange unit 302. For example, the third header 34 circulates the refrigerant flowing through the first heat exchange unit 301 to the second heat exchange unit 302 that faces the first heat exchange unit 301 in the short direction. The third header 34 forms a turning point for the refrigerant flow between the first heat exchange unit 301 and the second heat exchange unit 302.

[0051] The third header 34 allows refrigerant to flow between the plurality of heat transfer tubes 32 connected to one of the two headers, the first header 31 and the second header 35, and the plurality of heat transfer tubes 32 connected to the other header. The third header 34 forms a flow path that communicates with each of the heat transfer tubes 32 arranged opposite each other in the short side direction. The third header 34 connects rows of condensed liquid refrigerant or refrigerant in a gas-liquid two-phase state.

[0052] The second header 35 is provided below the heat exchanger 30. The second header 35 is connected to other devices that make up the air conditioning apparatus 100, and is a pipe through which the refrigerant flows in and out and through which the refrigerant branches or merges. A refrigerant inlet / outlet pipe 37 through which the refrigerant flows in and out from the outside is connected to the second header 35. The lower ends of the multiple heat transfer pipes 32 that make up the second heat exchange section 302 are inserted into the second header 35.

[0053] The second header 35 is formed in a long box shape. The second header 35 is formed to extend in the direction in which the plurality of heat transfer tubes 32 are arranged at intervals from one another. The second header 35 is in communication with the internal spaces of the plurality of heat transfer tubes 32. The second header 35 forms a space where the refrigerant that flows into the second header 35 from the plurality of heat transfer tubes 32 joins together. Alternatively, the second header 35 forms a space where the refrigerant that flows into the second heat exchange unit 302 from the outside to the plurality of heat transfer tubes 32 that make up the second heat exchange unit 302 is distributed.

[0054] The second header 35 is arranged in parallel to the first header 31. In the heat exchanger 30, the first header 31 and the second header 35 are arranged adjacent to each other in the horizontal direction. In the heat exchanger 30, the first header 31 and the second header 35 are arranged adjacent to each other in the flow direction of air passing through the heat exchanger 30.

[0055] 2 and 3, the direction in which the heat transfer tubes 32 extend is defined as a first direction D1, the direction in which the first header 31 and the second header 35 extend is defined as a second direction D2, and the direction perpendicular to the first direction D1 and the second direction D2 is defined as a third direction D3. In this case, the first header 31 and the second header 35 are arranged opposite each other in the third direction D3.

[0056] The third direction D3 is perpendicular to the extension direction of the heat transfer tubes 32 and perpendicular to the extension direction of the first header 31 and the second header 35, and is the direction in which air flows through the heat exchanger 30. The second direction D2 is also the direction in which the heat transfer tubes 32 are arranged at intervals from each other, and is also the axial direction of the first header 31 and the second header 35.

[0057] Fig. 4 is a conceptual diagram showing the positional relationship between the first header 31 and the second header 35 in the heat exchanger 30 of the air conditioning apparatus 100 according to Embodiment 1. Fig. 4 shows the positional relationship between the first header 31 and the second header 35 when viewed in the axial direction of the heat transfer tubes 32, i.e., the vertical direction of the heat exchanger 30. Note that Fig. 4 does not show the heat transfer tubes 32, the third header 34, etc.

[0058] The heat exchanger 30 is configured so that, when the spacing between the parts constituting the shortest distance between the first header 31 and the second header 35 in the third direction D3 is the header gap δ [mm], the header gap δ is 0.5 [mm] or more (header gap δ≧0.5).

[0059] [Configuration of the Outdoor Unit 10] FIG. 5 is a perspective view of the outdoor unit 10 of the air conditioning apparatus 100 according to Embodiment 1, as seen from the front. FIG. 6 is an exploded perspective view of the outdoor unit 10 of the air conditioning apparatus 100 according to Embodiment 1, as seen from the front. FIG. 7 is a conceptual plan view of the internal configuration of the outdoor unit 10 of the air conditioning apparatus 100 according to Embodiment 1. Note that FIG. 6 illustrates a state in which some of the components constituting the outdoor unit 10 have been removed. The hatched arrows in FIG. 7 indicate the flow of air. FIGS. 5 to 7 show an example of the configuration of the outdoor unit 10 equipped with a heat exchanger 30. In the following figures, arrows appropriately indicate directions, with the outdoor unit 10 positioned in a usable state as the reference, with the left being −X, the right being +X, the front being −Y, the rear being +Y, the bottom being −Z, and the top being +Z.

[0060] The outdoor unit 10 has a housing 40 that forms an outer shell. The outdoor unit 10 is a top-flow type device in which an air outlet 41 is formed in the center of the top of the housing 40. The air outlet 41 is an opening through which air blown by a fan 50, which will be described later, is discharged.

[0061] The housing 40 has four side surfaces: a right surface 40a, a rear surface 40b, a left surface 40c, and a front surface 40d, and these four side surfaces form a substantially rectangular parallelepiped shape that rises substantially perpendicularly from a lower surface 40e that forms the bottom of the housing 40. A removable sealing plate 43 is provided on the front surface 40d that forms the front of the housing 40. The sealing plate 43 is removed during maintenance of the outdoor unit 10, for example.

[0062] 5 and 6, the compressor 11, the accumulator 15, and the like are housed inside the housing 40. A fan 50 is also housed in the upper part of the housing 40, directly below the air outlet 41. The fan 50 supplies outdoor air to the right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c, and the airflow rate is adjusted by controlling the rotation speed of the fan 50.

[0063] 5, the right heat exchanger 30a is generally flat and is disposed so that its entire area faces the right surface 40a that forms the right portion of the housing 40. The rear heat exchanger 30b is generally flat and is disposed so that its entire area faces the rear surface 40b that forms the rear portion of the housing 40. The left heat exchanger 30c is generally flat and is disposed so that its entire area faces the left surface 40c that forms the left portion of the housing 40. Here, the right heat exchanger 30a, the rear heat exchanger 30b, and the left heat exchanger 30c are disposed so that, when functioning as a condenser, their refrigerant inlets are inside the housing 40 and their refrigerant outlets are outside the housing 40 and upwind of the outdoor air flow.

[0064] [Operation of Outdoor Unit 10 of Air Conditioning Apparatus 100] When the fan 50 of the outdoor unit 10 of the air conditioning apparatus 100 rotates, air around the outdoor unit 10 is drawn into the housing 40. The air drawn into the housing 40 passes through the heat exchanger 30, and as it passes through the heat exchanger 30, heat is exchanged between the air and the refrigerant flowing inside the heat exchanger 30. The air that has passed through the heat exchanger 30 passes through the air outlet 41 and is discharged to the outside of the housing 40.

[0065] FIG. 8 is a graph showing the relationship between the header gap δ and the amount of residual water between headers w. The horizontal axis of FIG. 8 represents the header gap δ [mm], and the vertical axis represents the amount of residual water between headers w [g]. The inventors conducted experiments to investigate the relationship between the header gap δ [mm] and the amount of residual water between headers w [g]. Based on the inventors' experimental results, as shown in FIG. 8, narrowing the header gap δ [mm] from 1 [mm] to 0.5 [mm] slightly increased the amount of residual water between headers w [g] from approximately 0.1 [g] to approximately 0.3 [g]. In other words, widening the header gap δ [mm] from 0.5 [mm] to 1.0 [mm] decreased the amount of residual water between headers w [g] from approximately 0.3 [g] to approximately 0.1 [g].

[0066] 8, when the header gap δ [mm] was narrowed from 0.5 [mm] to 0.25 [mm], the amount of residual water between the headers w [g] suddenly increased from approximately 0.3 [g] to approximately 1.0 [g]. In other words, when the header gap δ [mm] was widened from 0.25 [mm] to 0.5 [mm], the amount of residual water between the headers w [g] suddenly decreased from approximately 1.0 [g] to approximately 0.3 [g].

[0067] As shown in Figure 8, when the header gap δ [mm] is 0.5 mm or more, the rate of increase in the amount of residual water w [g] between the headers when the header gap δ [mm] is narrowed is smaller than when the header gap δ [mm] is less than 0.5 mm. When the header gap δ [mm] is less than 0.5 mm, the rate of increase in the amount of residual water w [g] between the headers when the header gap δ [mm] is narrowed is larger than when the header gap δ [mm] is 0.5 mm or more. Therefore, in order to improve the drainage between the first header 31 and the second header 35, it is desirable that the header gap δ [mm] be 0.5 mm or more (header gap δ ≧ 0.5).

[0068] [Effects of the Heat Exchanger 30] The heat exchanger 30 has the first header 31 and the second header 35 arranged opposite to each other in the third direction D3. The heat exchanger 30 has a header gap δ of 0.5 mm or greater, where the header gap δ is the distance between the first header 31 and the second header 35 along the shortest path in the third direction D3. This configuration of the heat exchanger 30 ensures an excellent header gap δ, improving drainage in the gap between the first header 31 and the second header 35. Therefore, the heat exchanger 30 can reduce the amount of meltwater retained between the headers to suppress the formation of ice, prevent deformation of the first header 31 and the second header 35 due to freezing of the meltwater, and improve frost resistance.

[0069] Because the air conditioning apparatus 100 has the heat exchanger 30, it can achieve the same effects as the heat exchanger 30. That is, the air conditioning apparatus 100 can reduce the amount of meltwater retained between the headers to suppress the formation of ice roots, prevent deformation of the first header 31 and the second header 35 due to freezing of the meltwater, and improve frost resistance.

[0070] Embodiment 2 Fig. 9 is a conceptual diagram showing the positional relationship between the first header 31 and the second header 35 in the heat exchanger 30 of the air conditioning apparatus 100 according to Embodiment 2. Fig. 10 is a conceptual diagram seen from the side of the first header 31 in the heat exchanger 30 of the air conditioning apparatus 100 according to Embodiment 2. Fig. 11 is a conceptual diagram of a partition plate 315 in the heat exchanger 30 of the air conditioning apparatus 100 according to Embodiment 2.

[0071] A heat exchanger 30 according to the second embodiment will be described using Figures 9 to 11. The heat exchanger 30 according to the second embodiment has the same configuration as the heat exchanger 30 according to the first embodiment except for the configuration described below, and components having the same functions and actions as those in the first embodiment are denoted by the same reference numerals and their description will be omitted. Furthermore, while Figure 10 shows the configuration of the first header 31, the configuration of the second header 35 is the same as that of the first header 31, and therefore a conceptual diagram of the second header 35 as viewed from the side will be omitted.

[0072] The heat exchanger 30 according to the second embodiment has partition plates 315 inside the first header 31 and the second header 35. The first header 31 and the second header 35 of the heat exchanger 30 each have at least one partition plate 315 disposed inside the first header 31 and the second header 35.

[0073] The first header 31 and the second header 35 have at least one partition plate 315 in the axial direction, i.e., in the direction in which the headers extend. An outer edge portion 315b of the partition plate 315 is fixed to the inner wall portion 316 of the first header 31 and the second header 35. The partition plate 315 is used to ensure the strength of the headers such as the first header 31 and the second header 35.

[0074] The partition plate 315 is formed in a plate shape. An opening 315a is formed in the partition plate 315. At least one partition plate 315 is formed in a flat plate shape and has the opening 315a penetrating in the extension direction of the first header 31 and the second header 35. The opening 315a constitutes a through hole formed in the partition plate 315. The refrigerant that flows into the inside of the first header 31 and the second header 35 moves through the opening 315a.

[0075] The partition plate 315 of the first header 31 and the partition plate 315 of the second header 35 may be disposed at the same position in the axial direction of the first header 31 and the second header 35, i.e., in the direction in which the headers extend. In other words, the partition plate 315 of the first header 31 and the partition plate 315 of the second header 35 may be disposed at opposing positions in a direction perpendicular to the axial direction of the first header 31 and the second header 35 and perpendicular to the axial direction of the heat transfer tubes 32.

[0076] Note that this configuration is just one example, and the partition plate 315 of the first header 31 and the partition plate 315 of the second header 35 may be positioned at different positions in the axial direction of the first header 31 and the second header 35, i.e., in the direction in which the headers extend.

[0077] [Operation and Effect of Heat Exchanger 30] Each of the first header 31 and the second header 35 has at least one partition plate 315 disposed inside the first header 31 and the second header 35. Each of the at least one partition plate 315 is formed in a flat plate shape and has an opening 315a penetrating in the extension direction of the first header 31 and the second header 35. An outer edge portion 315b of the partition plate 315 is fixed to an inner wall portion 316 of the first header 31 and the second header 35.

[0078] The heat exchanger 30 according to the second embodiment has the partition plates 315 inside the first header 31 and the second header 35, thereby improving the strength of the first header 31 and the second header 35 compared to a case where the heat exchanger 30 does not have the partition plates 315. Therefore, the heat exchanger 30 can ensure the strength of the headers even if ice forms between the headers, and can prevent the headers from being deformed due to freezing of meltwater.

[0079] When a refrigerant flows into the headers, such as the first header 31 and the second header 35, the headers may be subjected to pressure that causes the headers to expand due to the pressure of the refrigerant. The heat exchanger 30 according to the second embodiment has the partition plates 315 inside the first header 31 and the second header 35, thereby ensuring the strength of the first header 31 and the second header 35. Therefore, by having the partition plates 315 inside the first header 31 and the second header 35, the heat exchanger 30 according to the second embodiment can resist expansion of the headers due to the pressure of the refrigerant.

[0080] Depending on the material constituting the first header 31 and the second header 35, the internal pressure of the refrigerant in the first header 31 and the second header 35 may cause the portions of the first header 31 and the second header 35 that do not have the partition plate 315 to expand. By providing the partition plate 315 in the first header 31 and the second header 35, the heat exchanger 30 can suppress expansion of the header in the portion having the partition plate 315, even when affected by the internal pressure of the refrigerant, and can ensure the size of the gap between the headers.

[0081] When the portions of the first header 31 and the second header 35 that do not have the partition plate 315 expand due to the internal pressure of the refrigerant, the header gap δ [mm] is the gap of the portion that constitutes the shortest distance between the first header 31 and the second header 35. In other words, the header gap δ [mm] is the gap of the portion that constitutes the shortest distance between the first header 31 and the second header 35 when the heat exchanger 30 is in operation.

[0082] The partition plates 315 of the first header 31 and the partition plates 315 of the second header 35 are arranged in the same position in the extension direction of the first header 31 and the second header 35. In the first header 31 and the second header 35, the portions having the partition plates 315 are less likely to deform than portions not having the partition plates 315. Therefore, the portions of the first header 31 and the second header 35 where the partition plates 315 are arranged can ensure a larger gap between the headers even if the headers expand, compared to when the partition plates 315 are arranged in portions where the partition plates 315 are arranged in different positions. Therefore, when the partition plates 315 of the first header 31 and the partition plates 315 of the second header 35 are arranged in the same position in the extension direction of the first header 31 and the second header 35, drainage can be improved compared to when this configuration is not included.

[0083] Because the air conditioning apparatus 100 includes the heat exchanger 30, it can achieve the same effects as the heat exchanger 30. That is, the air conditioning apparatus 100 can reduce the amount of meltwater retained between the headers to suppress the formation of ice roots, prevent deformation of the first header 31 and the second header 35 due to freezing of the meltwater, and improve frost resistance. Furthermore, the air conditioning apparatus 100 can ensure the strength of the first header 31 and the second header 35 by using the partition plate 315, and suppress deformation of the first header 31 and the second header 35.

[0084] Embodiment 3. Figure 12 is a conceptual diagram showing the positional relationship between the first header 31 and the second header 35 in the heat exchanger 30 of the air conditioning apparatus 100 according to Embodiment 3. Figure 13 is a conceptual diagram seen from the side of the first header 31 in the heat exchanger 30 of the air conditioning apparatus 100 according to Embodiment 3. Figure 14 is a conceptual diagram showing the partition plate 315 and the inner pipe portion 312 in the heat exchanger 30 of the air conditioning apparatus 100 according to Embodiment 3.

[0085] A heat exchanger 30 according to a third embodiment will be described using Figures 12 to 14. The heat exchanger 30 according to the third embodiment is similar in configuration to the heat exchanger 30 according to the first and second embodiments, except for the configuration described below. Components having the same functions and actions as those in the first and second embodiments are denoted by the same reference numerals, and descriptions thereof will be omitted. Furthermore, while Figure 13 shows the configuration of the first header 31, the configuration of the second header 35 is similar to that of the first header 31, and therefore a conceptual diagram of the second header 35 as viewed from the side will be omitted.

[0086] The first header 31 and the second header 35 each have a cylindrical inner pipe portion 312 that distributes the refrigerant to the multiple heat transfer pipes 32, and an outer pipe portion 311 that houses the inner pipe portion 312 and into which the multiple heat transfer pipes 32 are inserted. The inner pipe portion 312 constitutes the cylindrical inner pipe of the first header 31 and the second header 35, and the outer pipe portion 311 constitutes the cylindrical outer pipe of the first header 31 and the second header 35. The first header 31 and the second header 35 each have a double-pipe structure formed by the inner pipe portion 312 and the outer pipe portion 311.

[0087] Each of the first header 31 and the second header 35 is a header with a double-pipe structure having a cylindrical inner pipe portion 312 with a plurality of through holes 314 formed at intervals from each other, and an outer pipe portion 311 that houses the inner pipe portion 312 and into which a plurality of heat transfer pipes 32 are inserted. Each of the first header 31 and the second header 35 also has at least one partition plate 315 that divides the intra-cylindrical space between the outer pipe portion 311 and the inner pipe portion 312 in the axial direction of the first header 31 and the second header 35.

[0088] (Inner pipe portion 312) The inner pipe portion 312 functions as a refrigerant distributor that distributes refrigerant to the multiple heat transfer pipes 32. The inner pipe portion 312 is a long, cylindrical member that is open at both ends and has a space formed therein. The inner pipe portion 312 is housed inside the outer pipe portion 311. The inner pipe portion 312 is disposed inside the outer pipe portion 311 with its pipe axis direction held horizontal. In the axial direction of the inner pipe portion 312, one end is connected to the refrigerant inlet / outlet pipe 36 or the refrigerant inlet / outlet pipe 37, and is connected to the refrigerant piping 90 (see FIG. 1 ) via the refrigerant inlet / outlet pipe 36 or the like, and the other end is sealed with a cap 313.

[0089] A plurality of through holes 314 are formed in the inner pipe portion 312. The through holes 314 are also referred to as orifices. The plurality of through holes 314 are provided along the pipe axis direction of the inner pipe portion 312. The plurality of through holes 314 are arranged at intervals in the longitudinal direction of the inner pipe portion 312. The plurality of through holes 314 are provided in the inner pipe portion 312 at least in a range facing the plurality of heat transfer tubes 32 inserted in the outer pipe portion 311.

[0090] The refrigerant flowing inside the inner pipe portion 312 passes through the through holes 314 and flows out to the outside of the inner pipe portion 312. Alternatively, when the first header 31 or the second header 35 defines a space where the refrigerants that have flowed into the inside of the first header 31 from the multiple heat transfer tubes 32 join together, the refrigerant flowing outside the inner pipe portion 312 passes through the through holes 314 and flows into the inside of the inner pipe portion 312.

[0091] In the header that distributes the refrigerant, either the first header 31 or the second header 35, the refrigerant passes through the interior of the inner pipe portion 312 and flows out into the intra-cylinder space of the outer pipe portion 311 through a plurality of through holes 314 that are arranged at intervals in the longitudinal direction of the inner pipe portion 312. By providing a plurality of through holes 314 arranged in a row in the inner pipe portion 312 and through which the refrigerant flows out, the heat exchanger 30 can ensure that the refrigerant flows evenly through the plurality of heat transfer pipes 32 of the heat exchanger 30, thereby improving the performance of the heat exchanger 30.

[0092] (Outer pipe portion 311) The outer pipe portion 311 is a long, cylindrical member whose both ends are closed except for the connection portion of the refrigerant inlet / outlet pipe 36 or the refrigerant inlet / outlet pipe 37, and a space is formed inside. The outer pipe portion 311 is formed in a cylindrical shape with an inner diameter larger than that of the inner pipe portion 312. The outer pipe portion 311 houses the inner pipe portion 312 inside. A plurality of heat transfer pipes 32 are connected to the outer peripheral surface of the outer pipe portion 311. The first header 31 and the second header 35 form a space between the cylindrical outer pipe portion 311 and the inner pipe portion 312.

[0093] The outer pipe portion 311 is formed in a rectangular shape in a cross section perpendicular to the tube axis direction of the outer pipe portion 311. Note that the outer pipe portion 311 only needs to be formed in a cylindrical shape, and the outer pipe portion 311 may be formed in another shape, such as a perfect circle or a polygonal shape, in a cross section perpendicular to the tube axis direction of the outer pipe portion 311.

[0094] Partition plates 315 are provided in the internal spaces of the first header 31 and the second header 35. The partition plates 315 form walls that separate the internal spaces of the headers into multiple spaces in a direction parallel to the axial direction of the first header 31 and the second header 35. The partition plates 315 divide the internal spaces of the first header 31 and the second header 35 in a direction parallel to the axial direction of the headers, forming multiple spaces inside the headers.

[0095] The partition plates 315 are formed in a plate shape. At least one partition plate 315 has an opening 315a formed therein, which supports the inner pipe portion 312 while the inner pipe portion 312 passes through the opening 315a. The opening 315a constitutes a through-hole formed in the partition plate 315.

[0096] The partition plate 315 of the first header 31 and the partition plate 315 of the second header 35 may be disposed at the same position in the extension direction of the first header 31 and the second header 35. In a direction perpendicular to the axial direction of the first header 31 and the second header 35 and perpendicular to the axial direction of the heat transfer tubes 32, the partition plate 315 of the first header 31 and the partition plate 315 of the second header 35 may be disposed at opposing positions.

[0097] [Operation and Effect of Heat Exchanger 30] Each of the first header 31 and the second header 35 has a double-pipe structure including a cylindrical inner pipe portion 312 with a plurality of through holes 314 formed at intervals from each other, and an outer pipe portion 311 that houses the inner pipe portion 312 and into which a plurality of heat transfer pipes 32 are inserted. Each of the first header 31 and the second header 35 has at least one plate-shaped partition plate 315 that divides the intra-cylindrical space between the outer pipe portion 311 and the inner pipe portion 312 in the axial direction of the first header 31 and the second header 35. The partition plate 315 has an opening 315a formed therein that supports the inner pipe portion 312 while it passes through.

[0098] When the first header 31 performs the distribution function, the refrigerant flows into one end of the inner pipe section 312 through the refrigerant inlet / outlet pipe 36 of the first header 31. The refrigerant that flows into the interior of the inner pipe section 312 flows out of the inner pipe section 312 through the multiple through holes 314 and flows into the space between the inner pipe section 312 and the outer pipe section 311. The refrigerant that flows out of the inner pipe section 312 and flows between the inner pipe section 312 and the outer pipe section 311 is distributed to the multiple heat transfer pipes 32. By providing the multiple through holes 314 arranged side by side in the inner pipe section 312 through which the refrigerant flows, the heat exchanger 30 can more evenly flow through the multiple heat transfer pipes 32 of the heat exchanger 30, thereby improving the performance of the heat exchanger 30 compared to a heat exchanger not having this configuration.

[0099] The heat exchanger 30 according to the third embodiment has the partition plates 315 inside the first header 31 and the second header 35, thereby improving the strength of the first header 31 and the second header 35 compared to a configuration without the partition plates 315. Therefore, the heat exchanger 30 can ensure the strength of the headers even if ice forms between the headers, preventing the headers from deforming due to the freezing of meltwater. Furthermore, the heat exchanger 30 can ensure the strength of the headers using the partition plates 315 and prevent the headers from deforming due to the freezing of meltwater, thereby preventing deformation of the inner pipe portion 312.

[0100] The heat exchanger 30 according to the third embodiment has the partition plates 315 inside the first header 31 and the second header 35, thereby ensuring the strength of the first header 31 and the second header 35. Therefore, the heat exchanger 30 according to the third embodiment has the partition plates 315 inside the first header 31 and the second header 35, thereby being able to resist expansion of the headers due to refrigerant pressure. Furthermore, by having the partition plates 315 in the first header 31 and the second header 35, the heat exchanger 30 can suppress expansion of the headers in the areas where the partition plates 315 are present, even when affected by the internal pressure of the refrigerant, and can therefore ensure the size of the gap between the headers.

[0101] The partition plates 315 of the first header 31 and the partition plates 315 of the second header 35 are arranged in the same position in the extension direction of the first header 31 and the second header 35. The portions where the partition plates 315 of the first header 31 and the second header 35 are arranged can ensure a larger gap between the headers even if the headers expand, compared to when the partition plates 315 are arranged in portions where they are arranged in different positions. Therefore, when the partition plates 315 of the first header 31 and the partition plates 315 of the second header 35 are arranged in the same position in the extension direction of the first header 31 and the second header 35, drainage performance can be improved compared to when this configuration is not included.

[0102] Because the air conditioning apparatus 100 includes the heat exchanger 30, it can achieve the same effects as the heat exchanger 30. That is, the air conditioning apparatus 100 can reduce the amount of meltwater retained between the headers to suppress the formation of ice roots, prevent deformation of the first header 31 and the second header 35 due to freezing of the meltwater, and improve frost resistance. Furthermore, the air conditioning apparatus 100 can ensure the strength of the first header 31 and the second header 35 by using the partition plate 315, and suppress deformation of the first header 31 and the second header 35.

[0103] The above-described first to third embodiments can be implemented in combination with one another. The configurations shown in the above-described embodiments are merely examples, and can be combined with other known technologies. Parts of the configurations can also be omitted or modified without departing from the spirit of the invention.

[0104] REFERENCE SIGNS LIST 10 Outdoor unit, 11 Compressor, 12 Flow path switching device, 13 First flow control valve, 14 Second flow control valve, 15 Accumulator, 20 Indoor unit, 21 Throttle device, 22 Indoor heat exchanger, 30 Heat exchanger, 30a Right heat exchanger, 30b Rear heat exchanger, 30c Left heat exchanger, 31 First header, 32 Heat transfer tube, 32A First heat transfer tube group, 32B Second heat transfer tube group, 33 Fin, 34 Third header, 35 Second header, 36 Refrigerant inlet / outlet pipe, 37 Refrigerant inlet / outlet pipe, 40 Housing, 40a Right surface, 40b Rear surface, 40c Left surface, 40d Front surface, 40e Bottom surface, 41 Air outlet, 43 Sealing plate, 50 Fan, 90 Refrigerant piping, 100 Air conditioning device, 101 Refrigerant circuit, 300 heat exchange section, 301 first heat exchange section, 302 second heat exchange section, 311 outer pipe section, 312 inner pipe section, 313 cap, 314 through hole, 315 partition plate, 315a opening, 315b outer edge section, 316 inner wall section.

Claims

1. A first heat exchange unit having a first heat transfer tube group consisting of a plurality of heat transfer tubes extending in the vertical direction and a first header connected to lower ends of the plurality of heat transfer tubes constituting the first heat transfer tube group and allowing a refrigerant to flow through the plurality of heat transfer tubes; a second heat exchange unit having a second heat transfer tube group consisting of a plurality of heat transfer tubes extending in the vertical direction and a second header connected to lower ends of the plurality of heat transfer tubes constituting the second heat transfer tube group and allowing a refrigerant to flow through the plurality of heat transfer tubes; and a third header into which upper ends of the plurality of heat transfer tubes constituting the first heat exchange unit and the second heat exchange unit are inserted and which allows a refrigerant to flow between the first heat exchange unit and the second heat exchange unit, wherein the first header and the second header are formed to extend in a direction in which the plurality of heat transfer tubes are arranged at intervals from each other, A heat exchanger configured such that, when the direction in which the plurality of heat transfer tubes extend is defined as a first direction, the direction in which the first header and the second header extend is defined as a second direction, and a direction perpendicular to the first direction and the second direction is defined as a third direction, the first header and the second header are arranged opposite each other in the third direction, and when the spacing constituting the shortest distance between the first header and the second header in the third direction is defined as a header gap δ [mm], the header gap δ is 0.5 [mm] or more.

2. A heat exchanger as described in claim 1, wherein each of the first header and the second header has at least one partition plate arranged inside the first header and the second header, each of the at least one partition plate is formed in a flat plate shape and has an opening that penetrates in the second direction, and the outer edge of each of the at least one partition plate is fixed to the inner wall portion of the first header and the second header.

3. The heat exchanger according to claim 1, wherein each of the first header and the second header is a header of a double-pipe structure having a cylindrical inner pipe section with a plurality of through holes formed at intervals from each other, and an outer pipe section that houses the inner pipe section and into which the plurality of heat transfer pipes are inserted, and each of the first header and the second header has at least one plate-shaped partition plate that divides the intra-cylindrical space between the outer pipe section and the inner pipe section in the second direction, and an opening is formed in the at least one partition plate to support the inner pipe section while it is inserted therethrough.

4. A heat exchanger as described in claim 2 or 3, wherein the partition plate of the first header and the partition plate of the second header are arranged at the same position in the extension direction of the first header and the second header.

5. An air conditioning system comprising: a compressor; a heat exchanger according to any one of claims 1 to 4, said heat exchanger performing heat exchange between outdoor air and a refrigerant flowing therethrough; a throttling device for reducing the pressure of the refrigerant flowing therethrough; and an indoor heat exchanger performing heat exchange between indoor air and the refrigerant flowing therethrough.

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