Air conditioning unit and refrigeration cycle device

Abstract

This air conditioning unit comprises: a housing that constitutes an outer shell; a heat exchanger that is provided inside the housing, the heat exchanger including a first heat exchanger and a second heat exchanger; and a blower that is provided between the first heat exchanger and the second heat exchanger, the blower sending air to the first heat exchanger and the second heat exchanger. The first heat exchanger has a first vertical section that faces the blower and extends in a vertical direction, a first extension section that faces the blower and extends in a direction intersecting the first vertical section, and a first curved section that connects the first vertical section and the first extension section.

Description

Air conditioning unit and refrigeration cycle device

[0001] The present disclosure relates to an air conditioning unit and a refrigeration cycle device equipped with a heat exchanger.

[0002] Conventionally, refrigeration cycle devices including air conditioning units each equipped with a heat exchanger have been known. Patent Document 1 discloses an air conditioner in which a compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are all provided for each of a first refrigeration cycle and a second refrigeration cycle. The air conditioner of Patent Document 1 uses two refrigeration cycle devices to reduce the amount of refrigerant in each refrigeration cycle and avoid various risks due to refrigerant leakage.

[0003] Japanese Patent Application Laid-Open No. 2008-209083

[0004] The air conditioner disclosed in Patent Document 1 has two refrigeration cycles, which avoids various risks caused by refrigerant leakage and improves the heat exchanger performance of the air conditioner to provide air conditioning capacity suited to the air conditioning load. However, there is a need for an air conditioning unit and refrigeration cycle device that uses a single refrigeration cycle to improve safety in the event of refrigerant leakage and heat exchanger performance.

[0005] The present disclosure has been made to solve the above-mentioned problems, and provides an air conditioning unit and a refrigeration cycle device that improves safety in the event of a refrigerant leak and improves heat exchanger performance, regardless of the number of refrigeration cycles.

[0006] The air conditioning unit of the present disclosure comprises a housing that forms an outer shell, a heat exchanger that is provided inside the housing and has a first heat exchanger and a second heat exchanger, and a blower that is provided between the first heat exchanger and the second heat exchanger and sends air to the first heat exchanger and the second heat exchanger, and the first heat exchanger has a first vertical portion that extends vertically opposite the blower, a first extension portion that extends in a direction intersecting the first vertical portion opposite the blower, and a first curved portion that connects the first vertical portion and the first extension portion.

[0007] The refrigeration cycle device of the present disclosure includes the above-mentioned air conditioning unit, a compressor, an expansion section, and a third heat exchanger, and the compressor, the first heat exchanger, the second heat exchanger, the expansion section, and the third heat exchanger are connected by refrigerant piping to form a refrigerant circuit.

[0008] According to the present disclosure, the first heat exchanger has a first vertical portion, a first extension portion, and a first curved portion, thereby providing a large heat transfer area and high heat exchange efficiency. Furthermore, the heat exchanger includes a second heat exchanger separate from the first heat exchanger, improving the heat exchange performance of the air conditioning unit. Furthermore, a blower is provided between the first and second heat exchangers. Even if refrigerant leaks from one of the heat exchangers, the leaked refrigerant is discharged outside the housing together with the post-heat-exchange air by the blower. This prevents the leaked refrigerant from accumulating within the housing, improving safety in the event of a refrigerant leak.

[0009] 1 is a circuit diagram showing a refrigeration cycle apparatus according to embodiment 1. FIG. 2 is a circuit diagram showing a refrigeration cycle apparatus according to a modified example. FIG. 3 is a diagram showing an example of a heat transfer tube of a heat exchanger according to embodiment 1. FIG. 4 is a diagram showing another example of a heat transfer tube of a heat exchanger according to embodiment 1. FIG. 5 is a diagram showing yet another example of a heat transfer tube of a heat exchanger according to embodiment 1. FIG. 6 is a diagram showing an example of a cross-sectional shape of a heat transfer tube. FIG. 7 is a diagram showing another example of a cross-sectional shape of a heat transfer tube. FIG. 8 is a diagram showing yet another example of a cross-sectional shape of a heat transfer tube. FIG. 9 is a schematic diagram illustrating the internal structure of an air conditioning unit according to embodiment 1. FIG. 10 is a perspective view illustrating the internal structure of an air conditioning unit according to embodiment 1. FIG. 11 is a top view illustrating the internal structure of an air conditioning unit according to embodiment 1. FIG. 12 is a schematic diagram illustrating the internal structure of an air conditioning unit according to embodiment 1. FIG. 13 is a perspective view illustrating the internal structure of an air conditioning unit according to embodiment 1. FIG. 14 is a schematic diagram illustrating the internal structure of an air conditioning unit according to embodiment 1. FIG. 15 is a perspective view illustrating the internal structure of an air conditioning unit according to embodiment 1. FIG. 16 is a schematic diagram illustrating the internal structure of an air conditioning unit according to embodiment 1. 21. FIG. 22 is a perspective view illustrating the internal structure of an air conditioning unit according to embodiment 4. FIG. 23 is a perspective view illustrating a second heat exchanger according to embodiment 4. FIG. 24 is a diagram illustrating the flow of refrigerant in a heat exchanger according to embodiment 5. FIG. 25 is an enlarged view of region A in FIG. 21. FIG. 26 is a diagram illustrating the distribution of frost on a heat transfer tube according to embodiment 5. FIG. 27 is a diagram illustrating a comparative example of the distribution of frost on a heat transfer tube. FIG. 28 is a top view illustrating the internal structure of an air conditioning unit according to embodiment 6.

[0010] Hereinafter, an embodiment in which an air conditioning unit according to the present disclosure is applied to an outdoor unit of an air conditioner will be described with reference to the drawings. Note that the present disclosure is not limited to the embodiment described below. Also, the size relationships between the components in the following drawings, including FIG. 1, may differ from the actual size relationships.

[0011] In the following, directions when describing the air conditioning unit will be described using the terms X direction, Y direction, and Z direction. The X direction and Y direction are directions along a horizontal plane, and the X direction and the Y direction are perpendicular to each other. The Z direction is a vertical direction. Furthermore, the mutually opposite directions of the X direction, Y direction, and Z direction are indicated as directions X1 and X2, directions Y1 and Y2, and directions Z1 and Z2. Direction Z1 is upward, and direction Z2 is downward. Note that these terms indicating directions are used to facilitate understanding of the present disclosure and do not limit the present disclosure.

[0012] Embodiment 1. Fig. 1 is a circuit diagram showing a refrigeration cycle apparatus 101 according to embodiment 1. The refrigeration cycle apparatus 101 is, for example, an air conditioning apparatus that conditions the air in a space to be air-conditioned, and as shown in Fig. 1, includes an air conditioning unit 100 applied to an outdoor unit and an indoor unit 3. The air conditioning unit 100 includes, for example, a compressor 6, a heat exchanger 8, a blower 9, an expansion section 10, a control device 13, and a refrigerant leak detection section 14. The indoor unit 3 includes, for example, a third heat exchanger 11 and a load-side blower 12. Note that, although the following description illustrates a case in which the air conditioning unit 100 is applied to an outdoor unit, the air conditioning unit 100 may also be applied to an indoor unit.

[0013] The refrigerant circuit 4 is formed by connecting a compressor 6, a heat exchanger 8, an expansion section 10, and a third heat exchanger 11 via refrigerant piping 5. The compressor 6 draws in refrigerant in a low-temperature, low-pressure state, compresses the drawn refrigerant, and discharges it as refrigerant in a high-temperature, high-pressure state. The compressor 6 is, for example, a capacity-controllable inverter compressor. The heat exchanger 8 exchanges heat between, for example, outdoor air and the refrigerant. The heat exchanger 8 functions as a condenser during cooling operation. The expansion section 10 is a pressure reducing valve or expansion valve that reduces the pressure of the refrigerant and expands it.

[0014] The heat exchanger 8 has a first heat exchanger 8a and a second heat exchanger 8b, which are connected in parallel. That is, the heat exchanger 8 is divided into the first heat exchanger 8a and the second heat exchanger 8b. The blower 9 is a device that sends outdoor air to the heat exchanger 8. Specifically, the blower 9 sends outdoor air to both the first heat exchanger 8a and the second heat exchanger 8b. The expansion section 10 is, for example, an electronic expansion valve whose opening degree is adjustable.

[0015] The third heat exchanger 11 exchanges heat between, for example, indoor air and the refrigerant. The third heat exchanger 11 functions as an evaporator during cooling operation. The load-side blower 12 sends indoor air to the third heat exchanger 11.

[0016] The control device 13 is configured as dedicated hardware or a CPU (also referred to as a central processing unit, processing device, arithmetic unit, microprocessor, microcomputer, or processor) that executes a program stored in a storage device. When the control device 13 is dedicated hardware, the control device 13 is, for example, a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. Each functional unit realized by the control device 13 may be realized by separate hardware, or each functional unit may be realized by a single piece of hardware.

[0017] When the control device 13 is a CPU, each function executed by the control device 13 is realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in a storage device. The CPU realizes each function by reading and executing the programs stored in the storage device. Note that some of the functions of the control device 13 may be realized by dedicated hardware, and other functions may be realized by software or firmware. The storage device may be configured as a hard disk, or may be configured as a volatile storage device such as random access memory (RAM) that can temporarily store data. The storage device may also be configured as a non-volatile storage device such as flash memory that can store data long-term. Note that, although the first embodiment illustrates a case in which the control device 13 is provided in the air conditioning unit 100, the control device 13 may also be provided in the indoor unit 3 or an external unit.

[0018] The refrigerant leakage detection unit 14 detects refrigerant leakage. The refrigerant leakage detection unit 14 is, for example, a sensor that detects refrigerant. The refrigerant leakage detection unit 14 may operate based on the operating state of the refrigeration cycle apparatus 101. Examples of the operating state include low pressure, high discharge temperature of the compressor 6, and high suction superheat or low subcooling degree of the compressor 6.

[0019] (Cooling Operation) Next, the operation of the refrigeration cycle apparatus 101 will be described. In cooling operation, the refrigerant drawn into the compressor 6 is compressed by the compressor 6 and discharged in a high-temperature, high-pressure gas state. The high-temperature, high-pressure gas refrigerant discharged from the compressor 6 flows into the heat exchanger 8, which functions as a condenser, where it exchanges heat with outdoor air sent by the blower 9, condensing and liquefying. Specifically, the refrigerant branches into the first heat exchanger 8a and the second heat exchanger 8b, where it exchanges heat with outdoor air sent by the blower 9, condensing and liquefying. The condensed liquid refrigerant then joins the two branches and flows into the expansion section 10, where it expands and is decompressed to become a low-temperature, low-pressure, two-phase gas-liquid refrigerant. The refrigerant in the gas-liquid two-phase state then flows into the third heat exchanger 11, which functions as an evaporator, where it exchanges heat with the indoor air sent by the load-side blower 12 and evaporates into gas. At this time, the indoor air is cooled, and the room is cooled. The evaporated refrigerant in a low-temperature, low-pressure gas state is drawn into the compressor 6.

[0020] Although the first embodiment illustrates the case where the refrigeration cycle apparatus 101 is a cooling-only machine, the refrigeration cycle apparatus 101 may be a heating-only machine. The refrigeration cycle apparatus 101 may also have a flow path switching device. In this case, the refrigeration cycle apparatus 101 can switch between cooling operation and heating operation.

[0021] (Modification) Fig. 2 is a circuit diagram showing a refrigeration cycle apparatus 102 according to a modification. As shown in Fig. 2, the first heat exchanger 8a and the second heat exchanger 8b of the heat exchanger 8 of the refrigeration cycle apparatus 102 may be connected in series. In this case, the refrigerant drawn into the compressor 6 is compressed by the compressor 6 and discharged in a high-temperature, high-pressure gas state. The high-temperature, high-pressure gas refrigerant discharged from the compressor 6 flows into the heat exchanger 8 functioning as a condenser, where it exchanges heat with outdoor air sent by the blower 9, condensing and liquefying.

[0022] Specifically, the refrigerant first flows into the second heat exchanger 8b, where it exchanges heat with outdoor air sent by the blower 9. The refrigerant that has exchanged heat in the second heat exchanger 8b then flows into the first heat exchanger 8a, where it exchanges heat with outdoor air sent by the blower 9 and condenses to become a liquid. The condensed liquid refrigerant flows into the expansion section 10, where it expands and reduces its pressure to become a low-temperature, low-pressure, two-phase gas-liquid refrigerant. The two-phase gas-liquid refrigerant then flows into the third heat exchanger 11, which functions as an evaporator, where it exchanges heat with indoor air sent by the load-side blower 12 and evaporates to become a gas. At this time, the indoor air is cooled, and the room is cooled. The evaporated low-temperature, low-pressure gas refrigerant is drawn into the compressor 6.

[0023] Next, the heat transfer tubes 41 of the heat exchanger 8 will be described with reference to Figs. 3 to 8. Fig. 3 is a diagram showing an example of the heat transfer tubes 41 of the heat exchanger 8 according to the first embodiment. Fig. 4 is a diagram showing another example of the heat transfer tubes 41 of the heat exchanger 8 according to the first embodiment. Fig. 5 is a diagram showing yet another example of the heat transfer tubes 41 of the heat exchanger 8 according to the first embodiment. Fig. 6 is a diagram showing an example of the cross-sectional shape of the heat transfer tube 41. Fig. 7 is a diagram showing another example of the cross-sectional shape of the heat transfer tube 41. Fig. 8 is a diagram showing yet another example of the cross-sectional shape of the heat transfer tube 41.

[0024] As shown in FIGS. 3 to 5, the heat exchanger 8 includes a plurality of heat transfer tubes 41. The plurality of heat transfer tubes 41 may extend in the X direction as shown in FIG. 3, or may extend in the Z direction as shown in FIGS. 4 and 5. Alternatively, the plurality of heat transfer tubes 41 may be provided so as to penetrate a plurality of fins 92 as shown in FIG. 3. The fins 92 shown in FIG. 3 are so-called plate fins. Alternatively, a fin 92 may be provided between a pair of heat transfer tubes 41 as shown in FIG. 4. The fins 92 shown in FIG. 4 are so-called corrugated fins. Alternatively, the heat exchanger 8 may be a so-called finless heat exchanger that does not have fins as shown in FIG. 5.

[0025] The cross-sectional shape of the heat transfer tube 41 is not particularly limited. For example, the cross section of the heat transfer tube 41 may be circular as shown in Fig. 6, or may be a rectangular or substantially rectangular flattened shape having a longitudinal direction and a lateral direction as shown in Fig. 7. Fig. 7 shows an example of a multi-hole flattened tube in which a plurality of holes serving as flow paths are provided inside the flattened heat transfer tube 41. The heat transfer tube 41 may also have protrusions 93 that protrude outward as shown in Fig. 8.

[0026] In the heat exchanger 8, the first heat exchanger 8a and the second heat exchanger 8b may have the same heat transfer tubes 41. The heat transfer tubes 41 of the first heat exchanger 8a and the second heat exchanger 8b may have different extending directions and cross-sectional shapes.

[0027] Next, an air conditioning unit 100 according to the present embodiment will be described with reference to Figures 9 to 11. Figure 9 is a schematic diagram illustrating the internal structure of the air conditioning unit 100 according to embodiment 1. Figure 10 is a perspective view illustrating the internal structure of the air conditioning unit 100 according to embodiment 1. Figure 11 is a top view illustrating the internal structure of the air conditioning unit 100 according to embodiment 1. Figures 10 and 11 show components housed inside a housing 15, and the housing 15 is not shown.

[0028] The air conditioning unit 100 includes a housing 15 that forms the outer shell. The housing 15 is roughly a rectangular parallelepiped and has a top surface, a bottom surface, and four side surfaces connecting the top surface and the bottom surface. As shown in FIG. 9 , a heat exchanger 8, a blower 9, and a machine room 20 are provided within the housing 15. Although not shown, the housing 15 has an intake port and an exhaust port, which are openings through which air passes. The intake port is formed on a surface facing the heat exchanger 8. The exhaust port is formed on a surface facing the outlet 23 of the blower 9.

[0029] The machine room 20 is a compartment formed within the housing 15, and houses electrical components such as a circuit board 94. The circuit board 94 is a board on which an electrical circuit that controls the operation of the components that make up the air conditioning unit 100 is mounted. The machine room 20 may also house the compressor 6 that circulates the refrigerant, a power supply device that supplies power to the electrical components, etc.

[0030] In this embodiment, the machine room 20 is disposed in the lower part of the housing 15, below the heat exchanger 8 and the blower 9. As shown in Fig. 11 , the machine room 20 is disposed in a position overlapping at least a part of the heat exchanger 8 in a top view.

[0031] In this embodiment, the area inside the housing 15 other than the machine chamber 20 is referred to as an air blowing chamber 21. The heat exchanger 8 and the air blower 9 are disposed in the air blowing chamber 21.

[0032] The first heat exchanger 8a in the heat exchanger 8 is formed from a first vertical portion 42a, a first extension portion 43a, and a first curved portion 44a. The first vertical portion 42a extends in the Z direction facing the blower 9. The first extension portion 43a extends in a direction intersecting the first vertical portion 42a facing the blower 9. The first curved portion 44a is a curved portion connecting the first vertical portion 42a and the first extension portion 43a. The second heat exchanger 8b is formed from a second vertical portion 42b, a second extension portion 43b, and a second curved portion 44b. The second vertical portion 42b extends in the Z direction facing the blower 9. The second extension portion 43b faces the blower 9 and extends in a direction intersecting the second vertical portion 42b. The second curved portion 44b is a curved portion connecting the second vertical portion 42b and the second extension portion 43b. In the following description, when there is no need to particularly distinguish between the first vertical portion 42a and the second vertical portion 42b, they may be referred to as the vertical portion 42, when there is no need to particularly distinguish between the first extension portion 43a and the second extension portion 43b, they may be referred to as the extension portion 43, and when there is no need to distinguish between the first curved portion 44a and the second curved portion 44b, they may be referred to as the curved portion 44.

[0033] The first vertical portion 42a and the second vertical portion 42b face each other with the blower 9 sandwiched therebetween. The surface of the first vertical portion 42a facing the blower 9 is referred to as a first vertical surface 42a1. The surface of the second vertical portion 42b facing the blower 9 is referred to as a second vertical surface 42b1. Note that in this embodiment and the following embodiments, when referring to a "vertical portion" or a "vertical surface," it is not necessary for them to extend strictly vertically, but rather they may extend in a direction closer to the vertical direction than the horizontal direction.

[0034] The first extension portion 43a extends from the first curved portion 44a toward the second extension portion 43b. The second extension portion 43b extends from the second curved portion 44b toward the first extension portion 43a. The first extension portion 43a and the second extension portion 43b may extend in the X direction, or may extend toward Z1 or Z2 at an angle relative to the X direction. As shown in FIGS. 9 to 11 , the first extension portion 43a and the second extension portion 43b are provided on the Z1 side of the first vertical portion 42a and the second vertical portion 42b. The surface of the first extension portion 43a facing the blower 9 is referred to as a first extension surface 43a1. The surface of the second extension portion 43b facing the blower 9 is referred to as a second extension surface 43b1. The first extension surface 43a1 and the second extension surface 43b1 face the upper surface 9a of the blower 9. In the following description, the upper surface 9a of the blower 9 may be referred to as the Z1 side surface of the blower 9.

[0035] The surface of the first curved portion 44a facing the blower 9 is referred to as a first curved surface 44a1. The surface of the second curved portion 44b facing the blower 9 is referred to as a second curved surface 44b1.

[0036] The area of ​​the first vertical surface 42a1 is larger than the sum of the area of ​​the first extended surface 43a1 and the area of ​​the first curved surface 44a1. The area of ​​the second vertical surface 42b1 is larger than the sum of the area of ​​the second extended surface 43b1 and the area of ​​the second curved surface 44b1.

[0037] The blower 9 is disposed between the first heat exchanger 8a and the second heat exchanger 8b, and passes air through the first heat exchanger 8a and the second heat exchanger 8b. The blower 9 is a double-suction blower that draws air from two directions. As shown in Figures 9 and 10, the blower 9 in this embodiment is disposed inside the first heat exchanger 8a and the second heat exchanger 8b in all of the X, Y, and Z directions, and does not protrude outside the heat exchangers 8a and 8b.

[0038] The blower 9 has two suction ports 22 and one outlet port 23. The position of the suction ports 22 is indicated by a dashed line in FIG. 9 . In this embodiment, the outlet port 23 opens in the Y2 direction. The blower 9 is a double-suction centrifugal fan, such as a sirocco fan, turbo fan, or radial fan. If the blower 9 is a propeller fan, the air speed decreases with increasing distance from the propeller fan, which may prevent the refrigerant from being sufficiently discharged to the outside in the event of a refrigerant leak.

[0039] The air that passes through the first heat exchanger 8a and the second heat exchanger 8b and is drawn into the blower 9 via the air inlet 22 is discharged from the air outlet 23 of the blower 9 to the outside of the housing 15 via the exhaust port of the housing 15. More specifically, the air that passes through the first heat exchanger 8a and is drawn into the blower 9 is discharged from the air outlet 23 to the outside of the housing 15 without flowing to the second heat exchanger 8b. The air that passes through the second heat exchanger 8b and is drawn into the blower 9 is discharged from the air outlet 23 to the outside of the housing 15 without flowing to the first heat exchanger 8a.

[0040] In this embodiment, the housing 15 has no openings other than an intake port formed on the surface facing the heat exchanger 8 and an exhaust port formed on the surface facing the outlet 23 of the blower 9. Therefore, the air drawn into the blower 9 in the blower chamber 21 passes through the first heat exchanger 8a or the second heat exchanger 8b, and an air path is formed in the blower chamber 21 for drawing air from the heat exchanger 8.

[0041] The effects of the air conditioning unit 100 according to Embodiment 1 will be described below. The air conditioning unit 100 according to this embodiment includes a housing 15 that forms an outer shell, a heat exchanger 8 that is provided inside the housing 15 and has a first heat exchanger 8a and a second heat exchanger 8b, and a blower 9 that is provided between the first heat exchanger 8a and the second heat exchanger 8b and sends air to the first heat exchanger 8a and the second heat exchanger 8b. The first heat exchanger 8a has a first vertical portion 42a that extends vertically opposite the blower 9, a first extension portion 43a that extends in a direction intersecting the first vertical portion 42a opposite the blower 9, and a first curved portion 44a that connects the first vertical portion 42a and the first extension portion 43a.

[0042] According to the above configuration, the first heat exchanger 8a has the first vertical portion 42a, the first extension portion 43a, and the first curved portion 44a. This provides a larger heat transfer area and higher heat exchange efficiency than a heat exchanger with only one heat transfer surface. Furthermore, the heat exchanger 8 includes the second heat exchanger 8b in addition to the first heat exchanger 8a, improving the heat exchange performance of the air conditioning unit 100. Furthermore, since the blower 9 is provided between the first heat exchanger 8a and the second heat exchanger 8b, even if refrigerant leaks from one of the heat exchangers, the leaked refrigerant is discharged outside the housing 15 by the blower 9 together with the air after heat exchange. This prevents the leaked refrigerant from accumulating within the housing 15, improving safety in the event of a refrigerant leak.

[0043] Furthermore, in the first heat exchanger 8a of the air conditioning unit 100 according to this embodiment, the area of ​​the first vertical surface 42a1 where the first vertical portion 42a faces the blower 9 is larger than the sum of the area of ​​the first extended surface 43a1 where the first extended portion 43a faces the blower 9 and the area of ​​the first curved surface 44a1 where the first curved portion 44a faces the blower 9. With this configuration, the center of gravity of the first heat exchanger 8a is closer to the first vertical portion 42a than to the first extended portion 43a, and therefore the first heat exchanger 8a can be stably installed within the housing 15.

[0044] Furthermore, the second heat exchanger 8b of the air conditioning unit 100 according to this embodiment has a second vertical portion 42b extending in the vertical direction Z facing the blower 9, a second extension portion 43b facing the blower 9 and extending in a direction intersecting the second vertical portion 42b, and a second curved portion 44b connecting the second vertical portion 42b and the second extension portion 43b. The first extension portion 43a and the second extension portion 43b each face the upper surface 9a of the blower 9. With this configuration, the second heat exchanger 8b has the second vertical portion 42b, the second extension portion 43b, and the second curved portion 44b, which provides a larger heat transfer area and higher heat exchange efficiency than a heat exchanger having only one heat transfer area. This further improves the heat exchanger performance of the air conditioning unit 100.

[0045] Furthermore, in the second heat exchanger 8b of the air conditioning unit 100 according to this embodiment, the area of ​​the second vertical surface 42b1 where the second vertical portion 42b faces the blower 9 is larger than the sum of the area of ​​the second extended surface 43b1 where the second extended portion 43b faces the blower 9 and the area of ​​the second curved surface 44b1 where the second curved portion 44b faces the blower 9. With this configuration, the center of gravity of the second heat exchanger 8b is closer to the second vertical portion 42b than to the second extended portion 43b, and therefore the second heat exchanger 8b can be stably installed within the housing 15.

[0046] Furthermore, the blower 9 of the air conditioning unit 100 according to this embodiment is a centrifugal fan, which can immediately discharge the refrigerant to the outside even in the event of a refrigerant leak. The blower 9 according to this embodiment is a double-suction centrifugal fan that draws in air from both directions along the rotational axis. Therefore, the air drawn into the blower 9 passes through at least one of the first heat exchanger 8a and the second heat exchanger 8b, allowing efficient heat exchange in both the first heat exchanger 8a and the second heat exchanger 8b.

[0047] Embodiment 2. The configuration of a heat exchanger 8A according to embodiment 2 will be described with reference to Figures 12 to 14. This embodiment differs from embodiment 1 in that the internal volumes of the first heat exchanger 8Aa and the second heat exchanger 8Ab are different. In this embodiment, an aspect in which the configurations of the first heat exchanger and the second heat exchanger are different from those of embodiment 1 will be described. Note that this embodiment will be described mainly focusing on the differences from embodiment 1.

[0048] Fig. 12 is a schematic diagram illustrating the internal structure of the air conditioning unit 100A according to embodiment 2. Fig. 13 is a perspective view illustrating the internal structure of the air conditioning unit 100A according to embodiment 2. Fig. 14 is a top view illustrating the internal structure of the air conditioning unit 100A according to embodiment 2.

[0049] In this embodiment, the heat exchanger 8A has a first heat exchanger 8Aa and a second heat exchanger 8Ab. The first heat exchanger 8Aa is formed of a first vertical portion 42a-1, a first extension portion 43a-1, and a first curved portion 44a-1. The first vertical portion 42a-1 extends in the Z direction facing the blower 9. The first extension portion 43a-1 extends in a direction intersecting the first vertical portion 42a-1 facing the blower 9. The first curved portion 44a-1 is a curved portion connecting the first vertical portion 42a-1 and the first extension portion 43a-1. The second heat exchanger 8Ab has a second vertical portion 42b-1 extending in the Z direction facing the blower 9. Unlike the first embodiment, the second heat exchanger 8Ab is flat and does not have portions corresponding to the extended portion and the curved portion.

[0050] The first vertical portion 42a-1 and the second vertical portion 42b-1 face each other with the blower 9 sandwiched between them. The surface of the first vertical portion 42a-1 facing the blower 9 is referred to as a first vertical surface 42a1-1. The surface of the second vertical portion 42b-1 facing the blower 9 is referred to as a second vertical surface 42b1-1.

[0051] The first extension portion 43a-1 extends from the first curved portion 44a in a direction intersecting with the first vertical portion 42a-1. The first extension portion 43a-1 may extend toward X2, or may extend toward Z1 or Z2 at an angle relative to the X direction. As shown in FIGS. 12 to 14, the first extension portion 43a-1 is provided on the Z1 side of the first vertical portion 42a-1. FIG. 14 shows an example in which the first extension portion 43a-1 completely covers the upper surface 9a of the blower 9 in the X direction. However, the first extension portion 43a-1 does not have to completely cover the upper surface 9a of the blower 9. The surface of the first extension portion 43a-1 facing the blower 9 is referred to as the first extension surface 43a1-1. The upper end of the second vertical surface 42b1-1 faces the first extension portion 43a-1.

[0052] The surface of the first curved portion 44a-1 facing the blower 9 is referred to as a first curved surface 44a1-1.

[0053] Because the first heat exchanger 8Aa has the first extension portion 43a-1, its internal volume is larger than that of the second heat exchanger 8Ab, which does not have an extension portion. In this embodiment, the internal volume of a heat exchanger refers to the total internal volume of the heat transfer tubes. Because the internal volume of the second heat exchanger 8Ab is smaller than that of the first heat exchanger 8Aa, the amount of refrigerant flowing through the second heat exchanger 8Ab is less than the amount of refrigerant flowing through the first heat exchanger 8Aa. Therefore, if refrigerant leaks from the first heat exchanger 8Aa and the second heat exchanger 8Ab, the amount of refrigerant leaking from the second heat exchanger 8Ab is less than the amount of refrigerant leaking from the first heat exchanger 8Aa. Furthermore, if refrigerant leaks, refrigerant diffusion is promoted if the refrigerant leaks from a position farther from the shield. Therefore, if a shield 17 as shown in FIG. 14 is present at the installation location of the housing 15 and the air conditioning unit 100A, it is advisable to place the second heat exchanger 8Ab on the shield 17 side.

[0054] For example, if the air conditioning unit 100A is installed in the outdoor space 18, as shown in FIG. 14 , the second heat exchanger 8Ab may face the wall 17a separating the indoor space 16 from the outdoor space 18. Furthermore, if the housing 15 includes a reinforcing panel 17b for reinforcing a portion of the housing 15, the second heat exchanger 8Ab may be located closer to the reinforcing panel 17b than the first heat exchanger 8Aa. FIG. 14 illustrates an example in which the reinforcing panels 17b are provided at both ends of the X2-side side of the housing 15 in the Y direction. By locating the second heat exchanger 8Ab, which leaks less refrigerant, closer to the wall 17a and the reinforcing panel 17b, the refrigerant can be quickly dispersed. Furthermore, even if refrigerant leaks from the first heat exchanger 8Aa, the first heat exchanger 8Aa is far from the wall 17a and the reinforcing panel 17b, allowing the refrigerant to quickly disperse.

[0055] In the present embodiment, the wall 17a and the reinforcing panel 17b are examples of the shielding object 17. A member housed in the housing 15 may also serve as the shielding object 17. Furthermore, a pillar or another building located in the location where the air conditioning unit 100A is installed may also serve as the shielding object 17.

[0056] As described above, in the air conditioning unit 100A according to this embodiment, the shield 17 provided in the housing 15 is located closer to the second heat exchanger 8Ab than to the first heat exchanger 8Aa. The internal volume of the second heat exchanger 8Ab is smaller than the internal volume of the first heat exchanger 8Aa. Therefore, even if refrigerant leaks from the second heat exchanger 8Ab, the amount of leaked refrigerant is smaller than if refrigerant leaks from the first heat exchanger 8Aa. Therefore, even if the shield 17 prevents the refrigerant from accumulating in the housing 15, the shield 17 is less likely to prevent the refrigerant from accumulating in the housing 15. Furthermore, even if refrigerant leaks from the first heat exchanger 8Aa, the shield 17 is less likely to prevent the refrigerant from accumulating in the housing 15.

[0057] The internal volume of the second heat exchanger is smaller than the internal volume of the first heat exchanger not only when the second heat exchanger does not have an extension portion but also when the cross-sectional area of ​​the heat transfer tubes of the second heat exchanger is smaller than the cross-sectional area of ​​the heat transfer tubes of the first heat exchanger. Also, the internal volume of the second heat exchanger is smaller than the internal volume of the first heat exchanger even when the number of heat transfer tubes of the second heat exchanger is fewer than the number of heat transfer tubes of the first heat exchanger.

[0058] Embodiment 3. The configuration of a heat exchanger 8B according to embodiment 3 will be described with reference to Figures 15 to 17. In embodiment 1, several modes of the heat transfer tubes 41 that can be provided in the heat exchanger 8 were described, but in this embodiment, modes of the heat transfer tubes 41B provided in the first heat exchanger 8Ba and the second heat exchanger 8Bb will be described. Note that in this embodiment, differences from embodiment 1 will be mainly described.

[0059] Fig. 15 is a schematic diagram illustrating the internal structure of an air conditioning unit 100B according to embodiment 3. Fig. 16 is a perspective view illustrating the internal structure of an air conditioning unit 100B according to embodiment 3. Fig. 17 is a diagram illustrating the flow of refrigerant in a heat exchanger 8B according to embodiment 3.

[0060] In this embodiment, the heat exchanger 8B includes a first heat exchanger 8Ba and a second heat exchanger 8Bb. The first heat exchanger 8Ba and the second heat exchanger 8Bb are each formed of a vertical portion 42, an extension portion 43, and a curved portion 44, as in the first embodiment, and therefore a description thereof will be omitted.

[0061] The first heat exchanger 8Ba includes a plurality of first heat transfer tubes 41Ba. The second heat exchanger 8Bb includes a plurality of second heat transfer tubes 41Bb. In the following description, when there is no need to particularly distinguish between the first heat transfer tubes 41Ba and the second heat transfer tubes 41Bb, they may be referred to as heat transfer tubes 41B.

[0062] Each of the heat transfer tubes 41B is formed in an L-shape along the tube axis and has a first portion 411B, a second portion 412B, and a third portion 413B. In Figures 15 to 17, the respective portions of the first heat transfer tube 41Ba are designated by adding a subscript a to refer to the first portion 411Ba, the second portion 412Ba, and the third portion 413Ba. The respective portions of the second heat transfer tube 41Bb are designated by adding a subscript b to refer to the first portion 411Bb, the second portion 412Bb, and the third portion 413Bb.

[0063] The first portion 411B extends in the vertical direction in the vertical portion 42. The second portion 412B extends in a direction intersecting the first portion 411B in the extension portion 43. The third portion 413B connects the first portion 411B and the second portion 412B at the curved portion 44. Although the second portion 412B in FIGS. 15 to 17 extends in the X direction, it may extend toward Z1 or Z2 at an angle relative to the X direction. The first portion 411B, the second portion 412B, and the third portion 413B are connected together to form an L-shaped heat transfer tube 41B.

[0064] Because each heat transfer tube 41B is curved at the third portion 413B, the wall thickness of the outer periphery of the third portion 413B is thin. Therefore, when the internal pressure of each heat transfer tube 41B increases, the outer periphery of the third portion 413B is most likely to break. Therefore, the third portion 413B of each heat transfer tube 41B functions as a breakage induction structure that has a lower pressure resistance than the other portions. As shown in Figures 15 and 16 , the third portion 413B is located at the upper end of the heat exchanger 8B.

[0065] As shown in Figures 15 and 16, the heat exchanger 8B may include a first header 51 and a second header 52. The first header 51 and the second header 52 are arranged so that the tube axis direction extends horizontally. In this embodiment, the first header 51 and the second header 52 are arranged along the Y direction. The first header 51 and the second header 52 of the first heat exchanger 8Ba are referred to as the first header 51a and the second header 52a, respectively, with the addition of a sub-symbol a. The first header 51 and the second header 52 of the second heat exchanger 8Bb are referred to as the first header 51b and the second header 52b, respectively, with the addition of a sub-symbol b.

[0066] The first header 51 and the second header 52 are components that distribute the heat medium to the multiple heat transfer tubes 41B or merge the heat medium flowing in from the multiple heat transfer tubes 41B. The multiple heat transfer tubes 41B are inserted into the first header 51 in the Z2 direction. The multiple heat transfer tubes 41B are inserted into the second header 52 in the X direction. The multiple first heat transfer tubes 41Ba are inserted into the second header 52a in the X2 direction, and the multiple second heat transfer tubes 41Bb are inserted into the second header 52b in the X1 direction. Note that if the second portions 412B of each heat transfer tube 41B are inclined with respect to the X direction, the direction in which each heat transfer tube 41B is inserted into the second header 52 does not have to be the X direction.

[0067] The first header 51 and the second header 52 have a flow path therein through which the heat medium flows and are connected to a heat medium pipe (not shown). The first header 51 and the second header 52 may be circular pipes or square pipes. Furthermore, the first header 51 or the second header 52, which functions as a heat medium distributor, may have a partition inside to partially separate the flow path.

[0068] Next, the flow of refrigerant in the heat exchanger 8B will be described with reference to FIG. 17 . In FIG. 17 , the flow of refrigerant is indicated by outline arrows. In this embodiment, the first header 51 side of the heat exchanger 8B is the upstream side in the refrigerant flow direction, and the second header 52 side is the downstream side. When the heat exchanger 8B functions as an evaporator, the refrigerant flows from the first header 51 into each of the heat transfer tubes 41B. The refrigerant flows through the first portion 411B, the third portion 413B, and the second portion 412B of each heat transfer tube 41B into the second header 52 and then flows out of the heat exchanger 8B from the second header 52. Therefore, in this embodiment, the first header 51 functions as a branch pipe, and the second header 52 functions as a junction pipe.

[0069] Generally, when a heat exchanger functions as an evaporator, a two-phase refrigerant flows into the heat transfer tubes of the heat exchanger and flows through the tubes while exchanging heat with a heat medium. As a result, the refrigerant transitions to a single-phase gas toward the downstream side of the flow in the heat exchanger. When the refrigerant transitions to a single-phase gas, the heat transfer coefficient in the heat transfer tube decreases and the temperature of the refrigerant itself increases, resulting in a decrease in the amount of heat exchange. As a result, the surface temperature of the outer surface of the heat transfer tube is higher downstream than upstream. A high surface temperature of the outer surface of the heat transfer tube makes it less likely for condensation to form on the outer surface of the heat transfer tube.

[0070] In this embodiment, the refrigerant flowing through the first portion 411B of the heat transfer tube 41B has not transitioned to a single-phase gas, so condensation is likely to occur on the outer peripheral surface, and condensed water 200 may adhere to the outer peripheral surface, as shown in FIG. 17 . However, the refrigerant flowing through the second portion 412B has transitioned to a single-phase gas, so condensation is unlikely to occur on the outer peripheral surface, and therefore the adhesion of condensed water 200 is suppressed. In this embodiment, the outer peripheral surface of the heat transfer tube where condensed water 200 is unlikely to form is referred to as the refrigerant dry area DA. In FIG. 17 , the refrigerant dry area DA on the outer peripheral surface of the second portion 412B is indicated by a hatched area.

[0071] If condensed water 200 adheres to second portion 412B, the condensed water 200 is likely to detach from second portion 412B due to gravity. Therefore, if condensed water 200 adheres to second portion 412B, the condensed water 200 is likely to be sucked into blower 9, and the condensed water 200 is likely to splash from blower 9 to the outside of housing 15. In this embodiment, first portion 411B, where condensed water is likely to occur, extends vertically. Therefore, even if condensed water 200 is generated, it is unlikely to fall due to gravity and be sucked into blower 9. Furthermore, a refrigerant dry region DA, where condensed water 200 is unlikely to form, is disposed above blower 9. Therefore, in heat exchanger 8B, condensed water 200 can be prevented from detaching from heat transfer tube 41B and splashing from blower 9.

[0072] As described above, in the heat exchanger 8B of the air conditioning unit 100B according to this embodiment, the first heat exchanger 8Ba has a plurality of first heat transfer tubes 41Ba, and each of the plurality of first heat transfer tubes 41Ba has a first portion 411Ba extending in the vertical direction Z in the first vertical portion 42a, a second portion 412Ba extending in a direction intersecting the first portion 411Ba in the first extension portion 43a, and a third portion 413Ba connecting the first portion 411Ba and the second portion 412Ba in the first curved portion 44a.

[0073] Furthermore, in the heat exchanger 8B of the air conditioning unit 100B according to this embodiment, the second heat exchanger 8Bb has a plurality of second heat transfer tubes 41Bb, and each of the plurality of second heat transfer tubes 41Bb has a first portion 411Bb extending in the vertical direction Z in the second vertical portion 42b, a second portion 412Bb extending in a direction intersecting the first portion 411Bb in the second extension portion 43b, and a third portion 413Bb connecting the first portion 411Bb and the second portion 412Bb in the second curved portion 44b.

[0074] In the heat exchanger 8B according to the present embodiment, the third portions 413B of the heat transfer tubes 41B are bent in a direction intersecting the Z direction at the same positions in the Z direction. The first portion 411B, the second portion 412B, and the third portion 413B are formed by bending the heat transfer tubes 41B, which facilitates the manufacture of the heat exchanger 8B.

[0075] Furthermore, in the first heat exchanger 8Ba according to this embodiment, the first curved portion 44a is positioned above the center of the first heat exchanger 8Ba in the height direction. Similarly, in the second heat exchanger 8Bb, the second curved portion 44b is positioned above the center of the second heat exchanger 8Bb in the height direction. Here, because the third portions 413Ba and 413Bb are curved, their outer peripheral wall thickness is thinner than their inner peripheral wall thickness. Therefore, when internal pressure in each heat transfer tube 41B increases, the third portions 413Ba and 413Bb function as a breakage induction structure and break first. Therefore, even if the internal pressure of the heat transfer tube 41B increases and the third portions 413Ba and 413Bb break, refrigerant will leak from the top of the first heat exchanger 8Ba and the second heat exchanger 8Bb. This prevents refrigerant from accumulating at the bottom of the housing 15. Furthermore, if the refrigerant is lighter than air, it diffuses from above the housing 15 to the outside of the housing 15, and if the refrigerant is heavier than air, it is also likely to diffuse to the outside of the housing 15 as it flows to the bottom of the housing 15. Therefore, if each heat transfer tube 41B breaks, the refrigerant is less likely to stagnate within the housing 15.

[0076] In the heat exchanger 8B of the air conditioning unit 100B according to this embodiment, the first heat exchanger 8Ba has a first header 51a connected to the first portions 411Ba of the first heat transfer tubes 41Ba and a second header 52a connected to the second portions 412Ba of the first heat transfer tubes 41Ba. The second heat exchanger 8Bb has a first header 51b connected to the first portions 411Bb of the second heat transfer tubes 41Bb and a second header 52b connected to the second portions 412Bb of the second heat transfer tubes 41Bb. In this configuration, the first header 51a and the second header 52a of the first heat exchanger 8Ba are positioned so as not to overlap in the horizontal direction X and the vertical direction Z. Furthermore, the first header 51b and the second header 52b of the second heat exchanger 8Bb are provided in positions where they do not overlap in the horizontal direction X and the vertical direction Z. This allows the first header 51 and the second header 52 to be provided in the heat exchanger 8B without increasing the area of ​​the bottom of the housing 15. Furthermore, even when the first heat exchanger 8Ba and the second heat exchanger 8Bb each have two headers, the housing 15 can be made smaller.

[0077] In the heat exchanger 8B of the air conditioning unit 100B according to this embodiment, when the first heat exchanger 8Ba functions as an evaporator, refrigerant flows into the first portion 411Ba of each of the first heat transfer tubes 41Ba and flows out of the second portion 412Ba. In the heat exchanger 8B, when the second heat exchanger 8Bb functions as an evaporator, refrigerant flows into the first portion 411Bb of each of the second heat transfer tubes 41Bb and flows out of the second portion 412Bb. In this configuration, the outer peripheral surface of the second portion 412B of each heat transfer tube 41B forms a refrigerant dry region DA where condensation water 200 is unlikely to occur. This prevents condensation water 200 from escaping from the heat transfer tubes 41B and scattering from the blower 9.

[0078] Fourth Embodiment The configuration of a heat exchanger 8C according to a fourth embodiment will be described with reference to Figures 18 to 20. In this embodiment, the configuration of a second heat exchanger 8Cb is different from the configuration of the second heat exchanger according to the first to third embodiments. In this embodiment, the differences from the first to third embodiments will be mainly described.

[0079] Fig. 18 is a schematic diagram illustrating the internal structure of an air conditioning unit 100C according to embodiment 4. Fig. 19 is a perspective view illustrating the internal structure of an air conditioning unit 100C according to embodiment 4. Fig. 20 is a perspective view illustrating a second heat exchanger 8Cb according to embodiment 4. In this embodiment, the heat exchanger 8C has a first heat exchanger 8Ca and a second heat exchanger 8Cb. The first heat exchanger 8Ca has the same configuration as the first heat exchanger 8Aa according to embodiment 2, and therefore description thereof will be omitted.

[0080] As shown in Fig. 20, the second heat exchanger 8Cb is formed of a second vertical portion 42b-2, a second extension portion 43b-2, and a second curved portion 44b-2. As shown in Fig. 19, the second vertical portion 42b-2 extends along the YZ plane, facing the first vertical portion 42a-1 and the blower 9. The surface of the second vertical portion 42b-2 facing the blower 9 is referred to as a second vertical surface 42b1-2.

[0081] The second extension portion 43b-2 extends along the X-Z plane, facing the side surface 9b of the blower 9 opposite the surface on which the air outlet 23 is provided. The side surface 9b of the blower 9 facing the second extension portion 43b-2 is a curved surface connecting the upper surface 9a and lower surface 9c of the blower 9. The second extension portion 43b-2 is provided on the Y1 side of the second vertical portion 42b-2. As shown in FIG. 20 , the second extension portion 43b-2 extends in the X1 direction from the second curved portion 44b-2. Note that the second extension portion 43b-2 only needs to extend in a direction intersecting the second vertical portion 42b-2, and the extension direction of the second extension portion 43b-2 and the extension direction of the second vertical portion 42b-2 do not have to be orthogonal. For example, the second extension portion 43b-2 may extend from the second curved portion 44b-2 toward the Y1 or Y2 direction so as to be inclined with respect to the X direction.

[0082] The second curved portion 44b-2 is a portion that connects the second vertical portion 42b-2 and the second extending portion 43b-2. The surface of the second curved portion 44b-2 that faces the blower 9 is referred to as a second curved surface 44b1-2.

[0083] As shown in Figures 18 and 19, four of the six sides surrounding the fan 9 are surrounded by the first heat exchanger 8Ca and the second heat exchanger 8Cb. More specifically, as shown in Figure 19, the first heat exchanger 8Ca faces the X1-side and Z1-side faces of the fan 9, and the second heat exchanger 8Cb faces the X2-side and Y1-side faces of the fan 9. On the other hand, in the first embodiment, the first extension portion 43a and the second extension portion 43b each face the Z1-side face of the fan 9, so the first heat exchanger 8a and the second heat exchanger 8b can surround three sides. Therefore, the area of ​​the face of the fan 9 facing the heat exchanger 8 according to the present embodiment is larger than the area of ​​the face of the fan 9 facing the heat exchanger 8 according to the first embodiment. Since the mounting area of ​​the heat exchanger 8C can be increased, the heat exchange efficiency of the heat exchanger 8C can be improved.

[0084] The first heat exchanger 8Ca includes a plurality of first heat transfer tubes 41Ca. The second heat exchanger 8Cb includes a plurality of second heat transfer tubes 41Cb. In the following description, when there is no need to particularly distinguish between the first heat transfer tubes 41Ca and the second heat transfer tubes 41Cb, they may be referred to as heat transfer tubes 41C.

[0085] Each of the heat transfer tubes 41C is formed in an L-shape along the tube axis and has a first portion 411C, a second portion 412C, and a third portion 413C. In Figures 18 to 20, the respective portions of the first heat transfer tube 41Ca are designated with a subscript a and are referred to as the first portion 411Ca, the second portion 412Ca, and the third portion 413Ca. The respective portions of the second heat transfer tube 41Cb are designated with a subscript b and are referred to as the first portion 411Cb, the second portion 412Cb, and the third portion 413Cb.

[0086] The first portion 411Ca of the first heat transfer tube 41Ca extends in the vertical direction Z at the first vertical portion 42a-1. The second portion 412Ca extends in a direction intersecting with the first portion 411Ca at the first extension portion 43a-1. The second portion 412Ca is provided on the Z1 side of the first portion 411Ca. The third portion 413Ca connects the first portion 411Ca and the second portion 412Ca at the first curved portion 44a-1. Although the second portion 412Ca in FIGS. 18 and 19 extends from the third portion 413Ca in the X2 direction, it may extend from the third portion 413Ca toward Z1 or Z2 so as to be inclined with respect to the X direction. The first portion 411Ca, the second portion 412Ca, and the third portion 413Ca are connected together to form an L-shaped first heat transfer tube 41Ca.

[0087] The first portion 411Cb of the second heat transfer tube 41Cb extends in the horizontal direction Y at the second vertical portion 42b-2. The second portion 412Cb extends in a direction intersecting with the first portion 411Cb at the second extension portion 43b-2. The second portion 412Cb is provided on the Y1 side of the first portion 411Cb. The third portion 413Cb connects the first portion 411Cb and the second portion 412Cb at the second curved portion 44b-2. In FIGS. 18 to 20, the second portion 412Cb extends from the third portion 413Cb in the X1 direction, but it may also extend from the third portion 413Cb toward Y1 or Y2 so as to be inclined with respect to the X direction. The first portion 411Cb, the second portion 412Cb, and the third portion 413Cb are connected together to form an L-shaped second heat transfer tube 41Cb.

[0088] The third portion 413C of each heat transfer tube 41C functions as a breakage induction structure similar to the third portion 413B according to embodiment 3. Therefore, in this embodiment, if the internal pressure of each first heat transfer tube 41Ca increases and the third portion 413Ca breaks, the refrigerant leaks from the top of the first heat exchanger 8Ca. Therefore, the refrigerant leaking from the first heat exchanger 8Ca is more likely to diffuse outside the housing 15 without accumulating at the bottom of the housing 15.

[0089] As shown in Figures 18 and 19, the first heat exchanger 8Ca may include a first header 51Ca and a second header 52Ca. Furthermore, as shown in Figures 18 to 20, the second heat exchanger 8Cb may include a first header 51Cb and a second header 52Cb. In the following description, the first header 51Ca and the first header 51Cb may be referred to as the first header 51C, and the second header 52Ca and the second header 52Cb may be referred to as the second header 52C. The configurations of the first header 51Ca and the second header 52Ca are similar to those of the first header 51a and the second header 52a according to the third embodiment, and therefore description thereof will be omitted.

[0090] The first header 51Cb and the second header 52Cb included in the second heat exchanger 8Cb are components that distribute the heat medium to the multiple second heat transfer tubes 41Cb or merge the heat medium flowing in from the multiple second heat transfer tubes 41Cb. The first header 51Cb and the second header 52Cb are arranged with their tube axes aligned along the Z direction. The multiple second heat transfer tubes 41Cb are inserted into the first header 51Cb in the Y2 direction. The multiple second heat transfer tubes 41Cb are inserted into the second header 52Cb in the X1 direction. Note that if the second portion 412Cb is inclined with respect to the X direction, the second heat transfer tubes 41Cb do not need to be inserted into the second header 52Cb in the X1 direction.

[0091] As described above, in the heat exchanger 8C of the air conditioning unit 100C according to this embodiment, the second heat exchanger 8Cb has a second vertical portion 42b-2 that faces the blower 9 and extends in the vertical direction Z, a second extension portion 43b-2 that faces the blower 9 and extends in a direction intersecting the second vertical portion 42b-2, and a second curved portion 44b-2 that connects the second vertical portion 42b-2 and the second extension portion 43b-. The first extension portion 43a-1 faces the top surface 9a of the blower 9, and the second extension portion 43b-2 faces the side surface 9b of the blower 9.

[0092] In this configuration, the first vertical portion 42a-1 and the first extension portion 43a-1 of the first heat exchanger 8Ca and the second vertical portion 42b-1 and the second extension portion 43b-2 of the second heat exchanger 8Cb each face different outer peripheral surfaces of the blower 9. This allows four of the six sides of the periphery of the blower 9 to be surrounded by the heat exchanger 8C, increasing the area for heat exchange by the heat exchanger 8C. This allows the mounting area for the heat exchanger 8C to be increased without increasing the size of the housing 15.

[0093] The second heat exchanger 8Cb according to this embodiment includes a plurality of second heat transfer tubes 41Cb, each of which includes a first portion 411Cb extending in the horizontal direction Y at the second vertical portion 42b-1, a second portion 412Cb extending in the horizontal direction X at the second extension portion 43b-2, and a third portion 413Cb connecting the first portion 411Cb and the second portion 412Cb at the second curved portion 44b-2. In this configuration, the third portions 413Cb of each of the plurality of second heat transfer tubes 41Cb are bent in a direction intersecting the Y direction at the same positions in the Y direction. The first portion 411Cb, the second portion 412Cb, and the third portion 413Cb are formed by bending the second heat transfer tube 41Cb, which facilitates the manufacture of the second heat exchanger 8Cb.

[0094] Embodiment 5 In this embodiment, a refrigerant flow different from that of the heat exchanger 8B according to embodiment 3 will be described. The air conditioning unit 100D according to this embodiment includes a heat exchanger 8B, similar to the air conditioning unit 100C according to embodiment 3. The configuration of the heat exchanger 8B is the same as that of the heat exchanger 8B according to embodiment 3, and therefore description thereof will be omitted.

[0095] The flow of refrigerant in the heat exchanger 8B in this embodiment will be described with reference to FIG. 21 . FIG. 21 is a diagram illustrating the flow of refrigerant in the heat exchanger 8B according to the fifth embodiment. In FIG. 21 , the flow of refrigerant is indicated by outline arrows. In this embodiment, the second header 52 side of the heat exchanger 8B is the upstream side in the refrigerant flow direction, and the first header 51 side is the downstream side. When the heat exchanger 8B functions as an evaporator, the refrigerant flows from the second header 52 into each of the heat transfer tubes 41B. The refrigerant flows through the second portion 412B, the third portion 413B, and the first portion 411B of each heat transfer tube 41B into the first header 51 and then flows out of the heat exchanger 8B from the first header 51. Therefore, in this embodiment, the second header 52 functions as a branch pipe, and the first header 51 functions as a junction pipe.

[0096] Next, with reference to FIG. 22 , the refrigerant distribution in the second portion 412B of the heat transfer tube 41B of the heat exchanger 8B will be described. FIG. 22 is an enlarged view of region A in FIG. 21 . FIG. 22 schematically illustrates the internal state of the second portion 412Ba of the first heat transfer tube 41Ba of the first heat exchanger 8Ba indicated by region A. In FIG. 22 , the outline arrows indicate the refrigerant flow direction, and the diagonal arrows indicate the air flow direction. The refrigerant flows in the X1 direction, and the air flows in the Z2 direction. FIG. 22 also illustrates an example in which the first heat transfer tube 41Ba has multiple internal flow paths, with the shaded areas indicating the liquid refrigerant flowing through each flow path. The following description will be given using the first heat transfer tube 41Ba of the first heat exchanger 8Ba as an example, but these descriptions also apply to the second heat transfer tube 41Bb of the second heat exchanger 8Bb. The configuration of the heat transfer tube 41B is not limited to that shown in FIG.

[0097] When the first heat exchanger 8Ba functions as an evaporator, the refrigerant flowing from the second header 52a into the first heat transfer tube 41Ba is a two-phase refrigerant. Of the two-phase refrigerant, liquid refrigerant tends to flow through the Z2 side due to gravity, while gas refrigerant tends to flow through the Z1 side. The Z1 side is upstream in the air flow direction, and the temperature and humidity differences between the refrigerant and the air, which serves as a heat medium, are greater on the Z1 side than on the Z2 side. Therefore, the amount of heat exchange between the refrigerant and the air increases on the Z1 side, and the refrigerant is more likely to transition to a single-phase gas state on the Z1 side.

[0098] Next, with reference to Figures 23 and 24, the frost distribution on the second portion 412B of the heat transfer tube 41B when the first heat exchanger 8Ba functions as an evaporator will be described. Figure 23 is a diagram illustrating the frost distribution on the heat transfer tube 41B according to embodiment 5. Figure 24 is a diagram illustrating a comparative example of frost distribution on a heat transfer tube. In Figures 23 and 24, the open arrows indicate the refrigerant flow direction, and the hatched arrows indicate the air flow direction. The refrigerant flows in the X1 direction, and the air flows in the Z2 direction. The shaded area FA shows an example of frost distribution when frost forms on the second portion 412Ba of the first heat transfer tube 41Ba. The darker the shaded area, the greater the amount of frost, and the lighter the shaded area, the less the amount of frost.

[0099] When the heat exchanger functions as an evaporator at low outdoor temperatures, frost may form on the heat transfer tubes. Generally, when the refrigerant condition in the heat transfer tube is uniform, the amount of frost on the heat transfer tube is greater upstream than downstream in the airflow direction. Therefore, if the refrigerant condition in the second portion 412Ba of the first heat transfer tube 41Ba is uniform, the amount of frost will be greater on the Z1 side than on the Z2 side, making the air passage more likely to be blocked on the Z1 side than on the Z2 side. Figure 24 shows an example in which the amount of frost decreases from Z1 to Z2 when the refrigerant condition in the heat transfer tube is uniform.

[0100] In the second portion 412Ba, the heat exchange rate on the Z1 side is greater than that on the Z2 side, so there is more single-phase gas refrigerant on the Z1 side than on the Z2 side. This increases the temperature of the outer peripheral surface of the second portion 412Ba on the Z1 side, suppressing the formation of frost. This uniforms the amount of frost that forms on the Z1 side and the Z2 side of the second portion 412Ba, resulting in a uniform frost distribution, as shown in FIG. 23 .

[0101] As described above, in the heat exchanger 8B of the air conditioning unit 100D according to this embodiment, when the first heat exchanger 8Ba functions as an evaporator, refrigerant flows into the second portion 412Ba of each of the first heat transfer tubes 41Ba and flows out of the first portion 411Ba. In this configuration, liquid refrigerant flows through the Z2 side of the second portion 412Ba, and gas refrigerant flows through the Z1 side. This reduces the amount of frost formation on the Z1 side, and the frost distribution in the second portion 412Ba tends to be more uniform.

[0102] Sixth Embodiment In this embodiment, a mode will be described in which a machine chamber 20E is arranged in a position different from that of the machine chamber 20 in the first embodiment. In this embodiment, the differences from the first embodiment will be mainly described.

[0103] 25 is a top view illustrating the internal structure of an air conditioning unit 100E according to embodiment 6. A machine room 20E is provided inside the housing 15 of the air conditioning unit 100E. The air conditioning unit 100E of this embodiment differs from embodiment 1 in the arrangement of the machine room 20E.

[0104] The machine room 20E in this embodiment is arranged in a position aligned with the heat exchanger 8 and the blower 9 in the Y direction. In Fig. 25, the machine room 20E is arranged on the Y1 side of the heat exchanger 8 and the blower 9 so as not to block the air outlet 23 of the blower 9 provided on the Y2 side.

[0105] In this way, by arranging the machine room 20E alongside the heat exchanger 8 and the blower 9 in the Y direction, when performing maintenance on the machine room 20E, the heat exchanger 8 and the blower 9 can be easily removed from the housing 15 without moving them. This improves safety in the event of a refrigerant leak from the heat exchanger 8 and also improves the ease of maintenance of the machine room 20E.

[0106] The air conditioning units 100 to 100E described in the first to sixth embodiments are applied as outdoor or indoor units in the refrigeration cycle apparatuses 101 and 102. In the refrigeration cycle apparatuses 101 and 102, a compressor 6, a first heat exchanger, a second heat exchanger, an expansion section 10, and a third heat exchanger 11 are connected by a refrigerant pipe 5 to form a refrigerant circuit 4. When the air conditioning units 100 to 100E are indoor units, the heat exchangers provided in the air conditioning units 100 to 100E function as indoor heat exchangers. When the air conditioning units 100 to 100E are outdoor units, the heat exchangers provided in the air conditioning units 100 to 100E function as outdoor heat exchangers. In either case, if refrigerant leaks from the heat exchanger, the leaked refrigerant is prevented from accumulating within the housing, thereby improving safety in the event of a refrigerant leak.

[0107] The components constituting the air conditioning units 100 to 100E described in the first to sixth embodiments may be used in any suitable combination within the scope of compatibility.

[0108] 3 Indoor unit, 4 Refrigerant circuit, 5 Refrigerant piping, 6 Compressor, 8 Heat exchanger, 8a First heat exchanger, 8b Second heat exchanger, 8A Heat exchanger, 8Aa First heat exchanger, 8Ab Second heat exchanger, 8B Heat exchanger, 8Ba First heat exchanger, 8Bb Second heat exchanger, 8C Heat exchanger, 8Ca First heat exchanger, 8Cb Second heat exchanger, 9 Blower, 9a Top surface, 9b Side surface, 9c Bottom surface, 10 Expansion section, 11 Third heat exchanger, 12 Load side blower, 13 Control device, 14 Refrigerant leak detection section, 15 Housing, 16 Indoor, 17 Shield, 17a Wall, 17b Reinforcement panel, 18 Outdoor, 20 Machine room, 20E Machine room, 21 Blower room, 22 Inlet, 23 Outlet, 41 Heat transfer tube, 41B Heat transfer tube, 41Ba First heat transfer tube, 41Bb Second heat transfer tube, 41C Heat transfer tube, 41Ca First heat transfer tube, 41Cb Second heat transfer tube, 42 Vertical portion, 42a First vertical portion, 42a-1 First vertical portion, 42a1 First vertical surface, 42a1-1 First vertical surface, 42b Second vertical portion, 42b-1 Second vertical portion, 42b-2 Second vertical portion, 42b1 Second vertical surface, 42b1-1 Second vertical surface, 42b1-2 Second vertical surface, 43 Extension portion, 43a First extension portion, 43a-1 First extension portion, 43a1 First extension surface, 43a1-1 First extension surface, 43b Second extension portion, 43b-2 Second extension portion, 43b1 Second extension surface, 43b1-2 Second extension surface, 44 Curved portion, 44a First curved portion, 44a-1 First curved portion, 44a1 First curved surface, 44a1-1 First curved surface, 44b Second curved portion, 44b-2 Second curved portion, 44b1 Second curved surface, 44b1-2 Second curved surface, 51 First header, 51a First header, 51b First header, 51C First header, 51Ca First header, 51Cb First header, 52 Second header, 52a Second header, 52b Second header, 52C Second header, 52Ca Second header, 52Cb Second header, 92 Fin, 93 Protrusion, 94 Circuit board, 100 Air conditioning unit, 100A Air conditioning unit, 100B Air conditioning unit, 100C Air conditioning unit, 100D Air conditioning unit, 100E Air conditioning unit, 101 Refrigeration cycle device, 102 Refrigeration cycle device, 200 Condensed water, 411B First part,411Ba part 1, 411Bb part 1, 411C part 1, 411Ca part 1, 411Cb part 1, 412B part 2, 412Ba part 2, 412Bb part 2, 412C part 2, 412Ca part 2, 412Cb part 2, 413B part 3, 413Ba part 3, 413Bb part 3, 413C part 3, 413Ca part 3, 413Cb part 3.

Claims

1. An air conditioning unit comprising: a housing forming an outer shell; a heat exchanger provided inside the housing and having a first heat exchanger and a second heat exchanger; and a blower provided between the first heat exchanger and the second heat exchanger and sending air to the first heat exchanger and the second heat exchanger, wherein the first heat exchanger has: a first vertical portion extending vertically opposite the blower; a first extension portion extending in a direction intersecting the first vertical portion opposite the blower; and a first curved portion connecting the first vertical portion and the first extension portion.

2. An air conditioning unit as described in claim 1, wherein the area of ​​a first vertical surface where the first vertical portion faces the blower is greater than the sum of the area of ​​a first extension surface where the first extension portion faces the blower and the area of ​​a first curved surface where the first curved portion faces the blower.

3. An air conditioning unit as described in claim 1 or claim 2, wherein a shield provided in the housing is provided closer to the second heat exchanger than to the first heat exchanger, and the internal volume of the second heat exchanger is smaller than the internal volume of the first heat exchanger.

4. An air conditioning unit as described in any one of claims 1 to 3, wherein the first heat exchanger comprises a plurality of first heat transfer tubes, each of the plurality of first heat transfer tubes comprising a first portion extending vertically in the first vertical section, a second portion extending in a direction intersecting the first portion in the first extension section, and a third portion connecting the first portion and the second portion at the first curved section.

5. An air conditioning unit as described in claim 4, wherein the first heat exchanger has: a first header connected to the first portion of each of the plurality of first heat transfer tubes; and a second header connected to the second portion of each of the plurality of first heat transfer tubes.

6. An air conditioning unit as described in claim 4 or claim 5, wherein the first curved portion is positioned above the center of the height of the first heat exchanger.

7. An air conditioning unit as described in any one of claims 4 to 6, wherein the second heat exchanger has a second vertical portion extending vertically opposite the blower, a second extension portion extending in a direction intersecting the second vertical portion opposite the blower, and a second curved portion connecting the second vertical portion and the second extension portion, wherein the first extension portion faces an upper surface of the blower, and the second extension portion faces a side surface of the blower.

8. An air conditioning unit as described in claim 7, wherein the second heat exchanger comprises a plurality of second heat transfer tubes, each of the plurality of second heat transfer tubes comprising a first portion extending horizontally at the second vertical portion, a second portion extending horizontally at the second extension portion, and a third portion connecting the first portion and the second portion at the second curved portion.

9. An air conditioning unit as described in any one of claims 4 to 6, wherein the second heat exchanger has a second vertical portion extending vertically opposite the blower, a second extension portion extending in a direction intersecting the second vertical portion opposite the blower, and a second curved portion connecting the second vertical portion and the second extension portion, and each of the first extension portion and the second extension portion faces an upper surface of the blower.

10. The air conditioning unit described in claim 9, wherein the second heat exchanger comprises a plurality of second heat transfer tubes, each of the plurality of second heat transfer tubes comprising a first portion extending vertically in the second vertical portion, a second portion extending in a direction intersecting the first portion in the second extension portion, and a third portion connecting the first portion and the second portion at the second curved portion.

11. An air conditioning unit as described in any one of claims 4 to 10, wherein when the first heat exchanger functions as an evaporator, refrigerant flows in from the first portion of each of the plurality of first heat transfer tubes and flows out from the second portion.

12. An air conditioning unit as described in any one of claims 4 to 10, wherein when the first heat exchanger functions as an evaporator, refrigerant flows in from the second portion of each of the plurality of first heat transfer tubes and flows out from the first portion.

13. An air conditioning unit according to any one of claims 1 to 12, wherein the blower is a centrifugal fan.

14. The air conditioning unit according to claim 13, wherein the centrifugal fan is a double suction centrifugal fan that draws in air from both directions in the direction of the rotation axis.

15. A refrigeration cycle device comprising: an air conditioning unit according to any one of claims 1 to 14; a compressor; an expansion section; and a third heat exchanger, wherein the compressor, the first heat exchanger, the second heat exchanger, the expansion section, and the third heat exchanger are connected by refrigerant piping to form a refrigerant circuit.

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