Air conditioning device

Abstract

Provided is an air conditioning device capable of improving heat exchange efficiency.　An air conditioning device 1 comprises a plurality of outdoor heat exchangers 20, and at an end part of each of the outdoor heat exchangers 20, a connection part 25 connected to a refrigerant flow path of another of the outdoor heat exchangers 20 is provided.

Description

air conditioning equipment

[0001] The present disclosure relates to an air conditioning apparatus.

[0002] Conventionally, there have been techniques for arranging multiple outdoor heat exchangers in the outdoor unit of an air conditioner. Patent Document 1 discloses a technique for connecting two outdoor heat exchangers with a bent pipe. Patent Document 2 discloses a technique for connecting an outdoor heat exchanger to an integrated header by bending it to form a stress absorption section. Patent Document 3 discloses an air conditioner technique for determining whether or not a refrigerant leaks using the degree of subcooling of the outdoor heat exchanger during heating operation as a threshold. Patent Document 4 discloses an air conditioning system in which a shutoff valve is installed in each air-conditioned space, refrigerant leakage is detected based on the refrigerant concentration in the air-conditioned space, and the indoor unit of the leaking air-conditioned space is shut off from the system.

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

[0004] International Publication No. 2021 / 014522

[0005] JP 2017-076760 A

[0006] Japanese Patent Application Laid-Open No. 2021-143827

[0007] The present disclosure provides an air conditioner that can improve heat exchange efficiency and can continue air conditioning even after a refrigerant leak, thereby reducing maintenance costs.

[0008] This specification includes the entire contents of Japanese Patent Application No. 2024-101281 filed on June 24, 2024. An air conditioning apparatus according to the present disclosure includes a plurality of heat exchangers, each of which has a connection portion at its end connected to the refrigerant flow path of the other heat exchangers. This specification includes the entire contents of Japanese Patent Application No. 2024-086878 filed on May 29, 2024. The air conditioning apparatus according to the present disclosure includes a plurality of heat exchangers, a detection means for detecting the state of refrigerant in the heat exchangers, a shutoff mechanism for shutting off the flow of refrigerant to each of the heat exchangers, and a control unit for determining whether or not a refrigerant leak is occurring in each of the heat exchangers based on the detection result of the detection means, and for closing the shutoff mechanism of the heat exchanger from which the refrigerant is leaking, if a refrigerant leak is occurring.

[0009] The air conditioner according to the present disclosure can increase the heat transfer area, thereby improving the efficiency of heat exchange. Furthermore, the air conditioner according to the present disclosure can continue air conditioning even after a refrigerant leak, and can reduce maintenance costs.

[0010] FIG. 1 is a diagram showing the configuration of an air conditioning apparatus in embodiment 1. FIG. 2 is a schematic perspective view of an outdoor unit in embodiment 1. FIG. 3 is a perspective view of a plurality of outdoor heat exchangers in embodiment 1. FIG. 4 is a perspective view of an outdoor heat exchanger in embodiment 1. FIG. 5 is a schematic perspective view of an outdoor unit in embodiment 2. FIG. 6 is a perspective view of a plurality of outdoor heat exchangers in embodiment 2. FIG. 7 is a schematic perspective view of an outdoor unit in embodiment 3. FIG. 8 is a perspective view of a plurality of outdoor heat exchangers in embodiment 3. FIG. 9 is a perspective view of a connection in embodiment 3. 10 is a diagram showing the configuration of the refrigeration cycle of an air conditioner in embodiment 4. FIG. 11 is a schematic perspective view of an outdoor unit in embodiment 4. FIG. 12 is a schematic plan view of an outdoor unit in embodiment 4. FIG. 13 is a block diagram showing the main control configuration of a control device, outdoor unit, and indoor unit in embodiment 4. FIG. 14 is a flowchart showing the operation of the control device in embodiment 4. FIG. 15 is a schematic perspective view of an outdoor unit in another embodiment. FIG. 16 is a schematic plan view of an indoor unit in another embodiment.

[0011] (Findings underlying the present disclosure) At the time the inventors conceived the present disclosure, there was a technology in which multiple heat exchangers in an air conditioner were connected with bent piping. However, the inventors discovered a problem with the conventional technology: the large gap between two adjacent heat exchangers reduced the heat transfer area available for heat exchange between the heat exchangers, thereby reducing the heat exchange efficiency of the air conditioner. To solve this problem, the present disclosure constituted the subject matter of the present disclosure. Therefore, the present disclosure provides an air conditioner that can improve heat exchange efficiency. Furthermore, at the time the inventors conceived the present disclosure, there was a technology in place that detected refrigerant leaks in each indoor unit or outdoor unit and isolated each indoor unit or outdoor unit from the air conditioner. However, with the conventional technology, if a refrigerant leak occurred, the refrigerant in the indoor unit or outdoor unit would leak, and if the indoor unit or outdoor unit was isolated from the air conditioner, the air conditioner would be unavailable until maintenance was completed, which required replacing the entire heat exchanger. The inventors discovered a problem in that after a refrigerant leak, air conditioning must be stopped until maintenance is completed, and the entire heat exchanger must be replaced, resulting in high maintenance costs. To solve this problem, the present disclosure provides an air conditioning device that can continue air conditioning even after a refrigerant leak and reduce maintenance costs.

[0012] Hereinafter, embodiments will be described in detail with reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed description of already well-known matters or redundant description of substantially the same configuration may be omitted. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0013] (Embodiment 1) [1-1. Configuration] Fig. 1 is a diagram showing the configuration of an air conditioner 1 including an outdoor unit 3 and an indoor unit 2. Fig. 2 is a schematic perspective view of the outdoor unit 3.

[0014] As shown in Fig. 1 , the indoor unit 2 includes an indoor heat exchanger 4 and an indoor blower fan 5. The outdoor unit 3 includes a compressor 6, a four-way valve 7, a plurality of outdoor heat exchangers 20, and an expansion valve 8. The four-way valve 7 is connected to the discharge side of the compressor 6. The outdoor heat exchanger 20, which includes an outdoor blower fan 9, is connected to the four-way valve 7. The outdoor heat exchanger 20 is configured to exchange heat between the air sent by the outdoor blower fan 9 and the refrigerant. The outdoor heat exchanger 20 is an example of a heat exchanger.

[0015] An expansion valve 8 is also connected to the outdoor heat exchanger 20. The various components of the air conditioning apparatus 1 are connected by refrigerant piping 10. The multiple outdoor heat exchangers 20 are connected to one another by connectors 25, which will be described later. As shown in Figure 2, the outdoor unit 3 has a housing 11. The multiple outdoor heat exchangers 20 are arranged on two adjacent sides of the four side surfaces of the outdoor unit 3 extending in the vertical direction.

[0016] Fig. 3 is a perspective view showing a plurality of outdoor heat exchangers 20. Fig. 4 is a perspective view showing one outdoor heat exchanger 20.

[0017] The outdoor heat exchanger 20 is configured as a so-called flat tube heat exchanger and includes a header 21 and flat tubes 22. The flat tubes 22 are an example of heat transfer tubes. The outdoor heat exchanger 20 is formed in a rectangular flat plate shape, and a plane including the header 21 and the flat tubes 22 is defined as a heat exchanger plane.

[0018] An end of the outdoor heat exchanger 20 is formed by a header 21. A plurality of flat tubes 22 are provided between a pair of headers 21 that extend substantially parallel to each other. The extension direction of the flat tubes 22 is substantially perpendicular to the extension direction of the header 21. Each flat tube 22 has a plurality of fins, which are plate members having a plurality of insertion holes formed on a plane thereof, through which the flat tubes 22 can be inserted. In this embodiment, the header 21 and the flat tubes 22 are both formed of aluminum or an aluminum alloy.

[0019] The header 21 is configured as a so-called vertical header, which is disposed extending in the vertical direction. However, the header 21 is not limited to this, and may be configured as a so-called horizontal header, which is disposed in the horizontal direction.

[0020] 3, the two outdoor heat exchangers 20 may be connected so that their heat exchanger planes are parallel to each other, or so that their heat exchanger planes are perpendicular to each other. The phrase "the two outdoor heat exchangers 20 are connected perpendicularly or parallel to each other" is defined as "their heat exchanger planes are perpendicular to each other or parallel to each other."

[0021] In this embodiment, there are three outdoor heat exchangers 20. When the three outdoor heat exchangers 20 are described separately, they are referred to as a first outdoor heat exchanger 20A, a second outdoor heat exchanger 20B, and a third outdoor heat exchanger 20C, respectively. When there is no need to distinguish between the first outdoor heat exchanger 20A, the second outdoor heat exchanger 20B, and the third outdoor heat exchanger 20C, they are collectively referred to as the outdoor heat exchanger 20.

[0022] Of the three outdoor heat exchangers 20, adjacent two, the first outdoor heat exchanger 20A and the second outdoor heat exchanger 20B, are arranged so that their heat exchanger planes are perpendicular to each other. Of the three outdoor heat exchangers 20, adjacent two, the second outdoor heat exchanger 20B and the third outdoor heat exchanger 20C, are arranged so that their heat exchanger planes are perpendicular to each other.

[0023] The headers 21 have connecting portions 25 that can be structurally fitted together. The connecting portions 25 are detachable. The connecting portions 25 are connected to and communicate with the refrigerant flow paths of the outdoor heat exchangers 20 in which the connecting portions 25 are provided. The connecting portions 25 are formed from a material different from that of the outdoor heat exchangers 20, and in this embodiment, are made from stainless steel. The two outdoor heat exchangers 20 are connected to each other by the connecting portions 25 provided on the headers 21.

[0024] The connecting portion 25 is divided into a protruding portion 26 and a receiving recessed portion 27. When the protruding portion 26 and the receiving recessed portion 27 are not distinguished from each other, they are collectively referred to as the connecting portion 25.

[0025] The connecting portions 25 can be directly connected to each other by fitting the protruding portion 26 and the receiving recess 27 together. The protruding portion 26 and the receiving recess 27 may be configured as a joint.

[0026] The receiving recess 27 is recessed from the header 21 so that the protrusion 26 fits into it.

[0027] The receiving recess 27 may have a direction, i.e., a concave direction, parallel to the heat exchanger plane or perpendicular to the heat exchanger plane. The direction of the receiving recess 27 refers to the direction relative to the heat exchanger plane of the outdoor heat exchanger 20 in which the receiving recess 27 is provided.

[0028] The receiving recess 27 is formed to protrude from the header 21 in a tubular shape.

[0029] The direction of the protrusions 26, or the direction in which they protrude, may be parallel to the heat exchanger plane or perpendicular to the heat exchanger plane. The direction of the protrusions 26 refers to the direction relative to the heat exchanger plane of the outdoor heat exchanger 20 on which the protrusions 26 are provided.

[0030] Hereinafter, the patterns of the relationship between the direction of the protrusions 26 or the receiving recesses 27 and the directions of two adjacent outdoor heat exchangers 20 will be described.

[0031] When the protrusions 26 and the receiving recesses 27 are parallel to the heat exchanger plane, the two outdoor heat exchangers 20 are connected so that their heat exchanger planes are parallel to each other. When the protrusions 26 are parallel to the heat exchanger plane and the receiving recesses 27 are perpendicular to the heat exchanger plane, the two outdoor heat exchangers 20 are connected so that their heat exchanger planes are perpendicular to each other. When the protrusions 26 are perpendicular to the heat exchanger plane and the receiving recesses 27 are parallel to the heat exchanger plane, the two outdoor heat exchangers 20 are connected so that their heat exchanger planes are perpendicular to each other. When the protrusions 26 and the receiving recesses 27 are perpendicular to the heat exchanger plane, the two outdoor heat exchangers 20 are connected so that their heat exchanger planes are perpendicular to each other.

[0032] The first outdoor heat exchanger 20A, the second outdoor heat exchanger 20B, and the third outdoor heat exchanger 20C of this embodiment are each formed in the same shape and include three similar connecting portions 25.

[0033] Specifically, the outdoor heat exchanger 20 has two protrusions 26 and one receiving recess 27. One outdoor heat exchanger 20 is formed in a rectangular shape, and the four corners of the rectangle are defined, in order, as a first corner A, a second corner B, a third corner C, and a fourth corner D. The outdoor heat exchanger 20 has, at the position of the first corner A, the receiving recess 27 that is parallel to the heat exchanger plane and recessed in the extension direction of the flat tubes 22, a protrusion 26 at the position of the second corner B that is parallel to the heat exchanger plane and protrudes in the extension direction of the flat tubes 22, and a protrusion 26 at the position of the third corner C that protrudes perpendicular to the heat exchanger plane and perpendicular to the extension direction of the flat tubes 22.

[0034] The refrigerant piping 10 is connected to the receiving recess 27 located at the first corner A of the first outdoor heat exchanger 20A. The protrusion 26 located at the third corner C of the first outdoor heat exchanger 20A is connected to the receiving recess 27 located at the first corner A of the second outdoor heat exchanger 20B. The protrusion 26 located at the second corner B of the second outdoor heat exchanger 20B is connected to the receiving recess 27 located at the first corner A of the third outdoor heat exchanger 20C. The refrigerant piping 10 is connected to the protrusion 26 located at the second corner B of the third outdoor heat exchanger 20C.

[0035] The protrusion 26 located at the second corner B of the first outdoor heat exchanger 20A and the protrusions 26 located at the third corner C of the second outdoor heat exchanger 20B and the third outdoor heat exchanger 20C are sealed by sealing means (not shown) to prevent refrigerant leakage.

[0036] [1-2. Actions, etc.] Heat is exchanged between the air sent by the outdoor blower fan 9 and the refrigerant flowing in the outdoor heat exchanger 20. In particular, the refrigerant flowing through the plurality of flat tubes 22 exchanges heat with the air while the heat exchange is promoted by the fins.

[0037] If the outdoor heat exchanger 20 is arranged in a substantially L-shape by bending the flat tubes 22, the flat tubes 22 must be bent gently to prevent damage to the flat tubes 22. The bent portions of the flat tubes 22 reduce the heat transfer area compared to when the two outdoor heat exchangers 20 are perpendicular to each other. Furthermore, if the headers 21 of the two outdoor heat exchangers 20 are connected by bent piping, the flat tubes 22 are not arranged between the two outdoor heat exchangers 20, and the heat transfer area is reduced.

[0038] The vertically extending headers 21 of the two outdoor heat exchangers 20 are connected by a connection portion 25. More specifically, a protrusion 26 protruding from the first outdoor heat exchanger 20A in a direction perpendicular to the heat exchanger plane fits into a receiving recess 27 of the second outdoor heat exchanger 20B that is recessed in a direction parallel to the heat exchanger plane, thereby disposing the two outdoor heat exchangers 20 perpendicular to each other. This allows the ends of the two outdoor heat exchangers 20 to fit together structurally, reducing the gap between the ends of the outdoor heat exchangers 20 and increasing the heat transfer area.

[0039] Furthermore, depending on the arrangement of the connecting portions 25 in the outdoor heat exchanger 20 of this embodiment, any number of outdoor heat exchangers 20 having the same configuration can be connected so that the heat exchanger planes are parallel. Furthermore, two outdoor heat exchangers 20 can be connected perpendicularly.

[0040] [1-3. Effects, etc.] As described above, the air conditioning apparatus 1 in this embodiment is equipped with a plurality of outdoor heat exchangers 20, and each outdoor heat exchanger 20 is provided at its end with a connecting portion 25 that connects to the refrigerant flow path of the other outdoor heat exchangers 20. In this way, the ends are fitted together by the connecting portion 25, thereby reducing the gap between the ends of the outdoor heat exchangers 20. This increases the heat transfer area over which the outdoor heat exchanger 20 can exchange heat, and improves the efficiency of heat exchange in the outdoor unit 3.

[0041] Furthermore, at least one of two adjacent outdoor heat exchangers 20 is arranged orthogonally, and in this embodiment, the first outdoor heat exchanger 20A and the second outdoor heat exchanger 20B are arranged orthogonally. This reduces the gap between the ends of two adjacent outdoor heat exchangers 20 that are arranged orthogonally. This increases the heat transfer area available for heat exchange by the outdoor heat exchanger 20, and improves the efficiency of heat exchange in the outdoor unit 3.

[0042] The outdoor heat exchanger 20 also includes a pair of headers 21, and the connection portion 25 is provided on the headers 21. This reduces the gap between two adjacent headers 21, and in turn reduces the gap between the ends of the outdoor heat exchanger 20. This increases the heat transfer area over which the outdoor heat exchanger 20 can exchange heat, and improves the efficiency of heat exchange in the outdoor unit 3.

[0043] The connecting portion 25 is composed of a protrusion 26 that communicates with the refrigerant flow path of the header 21 and a concave receiving recess 27 that communicates with the refrigerant flow path of the header 21 and receives the protrusion 26. The refrigerant flow paths of the outdoor heat exchangers 20 are connected by connecting the protrusion 26 with the receiving recess 27. This allows the ends of the two outdoor heat exchangers 20 to be connected so as to fit together, improving strength.

[0044] Furthermore, the exterior dimensions of each outdoor heat exchanger 20 are substantially the same, which can reduce the cost of producing or procuring the outdoor heat exchangers 20 .

[0045] Furthermore, the connection portions 25 of the outdoor heat exchangers 20 are formed in the same manner. As a result, the outdoor heat exchangers 20, including the connection portions 25, are formed in the same manner, which can further reduce the cost of producing or procuring the outdoor heat exchangers 20.

[0046] The connection portion 25 of each outdoor heat exchanger 20 is formed to be detachable. This allows the outdoor heat exchanger 20 to be detached, which improves workability in maintenance and other work.

[0047] Each outdoor heat exchanger 20 includes flat tubes 22. This allows the two outdoor heat exchangers 20 to be arranged perpendicular to each other without bending the flat tubes 22, which are difficult to bend in a direction different from the direction in which the flat tubes 22 extend.

[0048] The outdoor heat exchangers 20 are arranged in at least one of a direction perpendicular to or parallel to the axial direction of the flat tubes 22 included in the outdoor heat exchangers 20. This allows the outdoor heat exchangers 20 to be arranged in various layouts depending on the size and function of the outdoor unit 3, improving the versatility of the outdoor heat exchangers 20.

[0049] Furthermore, two adjacent outdoor heat exchangers 20 are arranged in a substantially straight line, and the connection portion 25 is provided so as to face the adjacent outdoor heat exchanger 20. Furthermore, two adjacent outdoor heat exchangers 20 are arranged substantially perpendicular to each other, and the connection portion 25 is provided so as to face the adjacent outdoor heat exchanger 20. According to this, the connection portion 25 is connected to other connection portions 25 in a straight line, and the gap between the ends of the two adjacent outdoor heat exchangers 20 is reduced.

[0050] Furthermore, the connecting portion 25 is formed of a material different from that of the outdoor heat exchanger 20. This allows the connecting portion 25 to be formed of a material having a different hardness and strength from that of the outdoor heat exchanger 20. In this embodiment, the outdoor heat exchanger 20 is formed of an aluminum alloy, and the connecting portion 25 is formed of stainless steel.

[0051] The outdoor heat exchanger 20 also includes flat tubes 22. When the heat transfer tubes of the outdoor heat exchanger 20 are configured as flat tubes 22, the flat tubes 22 have a larger longitudinal diameter than circular tubes when the outdoor heat exchanger 20 is bent. This results in a large difference between the inner and outer diameters after bending. If the bending angle is small, this difference between the inner and outer diameters can cause the flat tubes 22 to buckle at the bent points due to compressive stress. Therefore, the outdoor heat exchanger 20 including the flat tubes 22 needs to have a larger bending angle than a heat exchanger whose heat transfer tubes are configured as circular tubes. Due to these issues, in an outdoor heat exchanger 20 equipped with flat tubes 22, the heat transfer area over which the outdoor heat exchanger 20 can exchange heat is likely to be reduced, and the impact of the issues involved in installing the outdoor heat exchanger 20 becomes greater. However, with this configuration, since the outdoor heat exchanger 20 is equipped with flat tubes 22, the heat transfer area can be increased when multiple outdoor heat exchangers 20 are installed as in this embodiment.

[0052] (Embodiment 2) [2-1. Configuration] Fig. 5 is a schematic perspective view of an outdoor unit 203 in embodiment 2. The outdoor unit 203 includes eight outdoor heat exchangers 20. The refrigerant branches into the four upper outdoor heat exchangers 20 and the four lower outdoor heat exchangers 20.

[0053] Fig. 6 is a perspective view showing a plurality of outdoor heat exchangers 20 according to Embodiment 2. Fig. 6 shows four outdoor heat exchangers 20. The four outdoor heat exchangers 20 shown in Fig. 6 have the same configuration whether they are located above or below the outdoor unit 203.

[0054] 5, the second outdoor heat exchanger 20B and the third outdoor heat exchanger 20C are arranged side by side in the horizontal direction, while the upper second outdoor heat exchanger 20B and the third outdoor heat exchanger 20C and the lower second outdoor heat exchanger 20B and the third outdoor heat exchanger 20C are arranged side by side in the vertical direction.

[0055] The fourth outdoor heat exchanger 20D is connected perpendicularly to the third outdoor heat exchanger 20C. The fourth outdoor heat exchanger 20D is arranged on the same side as the first outdoor heat exchanger 20A, the second outdoor heat exchanger 20B, and the third outdoor heat exchanger 20C. In other words, the four outdoor heat exchangers 20 are arranged in a substantially C-shape.

[0056] The fourth outdoor heat exchanger 20D has a receiving recess 27 formed at a corner opposite the second corner B of the third outdoor heat exchanger 20C. A protrusion 26 located at the second corner B of the third outdoor heat exchanger 20C is fitted into the receiving recess 27 of the fourth outdoor heat exchanger 20. The fourth outdoor heat exchanger 20D has a connecting portion 25 on the side opposite the receiving recess 27, and is connectable to the refrigerant pipe 10 via the connecting portion 25.

[0057] The fourth outdoor heat exchanger 20D is different from the first outdoor heat exchanger 20A, the second outdoor heat exchanger 20B, and the third outdoor heat exchanger 20C in the arrangement and number of connecting portions 25, but is otherwise configured similarly. In this way, in the second embodiment, all of the outdoor heat exchangers 20 are formed to have approximately the same external dimensions.

[0058] [2-2. Actions, etc.] The same actions as those of embodiment 1 are achieved. Furthermore, because the outdoor heat exchangers 20 are arranged side by side in the vertical direction, the outdoor heat exchanger 20 of the present disclosure can be applied even to outdoor units 3 whose housings 11 are large in the vertical direction. For example, the outdoor heat exchangers 20 arranged side by side in the vertical direction are suitable for top-flow type outdoor units 3 that have an outdoor blower fan 9 at the top of the outdoor unit 3.

[0059] Furthermore, when connecting multiple indoor units 2 to one outdoor unit 3, a branched outdoor heat exchanger 20 may be necessary. The outdoor heat exchanger 20 of the present disclosure is arranged so that the outdoor heat exchanger 20 branches in the vertical direction, making it suitable for a multi-type air conditioner 1 in which multiple indoor units 2 are connected to one outdoor unit 3.

[0060] [2-3. Effects, etc.] As described above, the air conditioning apparatus 1 in this embodiment is equipped with a plurality of outdoor heat exchangers 20, and each outdoor heat exchanger 20 is provided at its end with a connecting portion 25 that connects to the refrigerant flow path of the other outdoor heat exchangers 20. In this way, the ends are fitted together by the connecting portion 25, thereby reducing the gap between the ends of the outdoor heat exchangers 20. This increases the heat transfer area over which the outdoor heat exchanger 20 can exchange heat, and improves the efficiency of heat exchange in the outdoor unit 3.

[0061] Furthermore, at least one of two adjacent outdoor heat exchangers 20 is arranged orthogonally, and in this embodiment, the first outdoor heat exchanger 20A and the second outdoor heat exchanger 20B are arranged orthogonally. This reduces the gap between the ends of two adjacent outdoor heat exchangers 20 that are arranged orthogonally. This increases the heat transfer area available for heat exchange by the outdoor heat exchanger 20, and improves the efficiency of heat exchange in the outdoor unit 3.

[0062] The outdoor heat exchanger 20 also includes a pair of headers 21, and the connection portion 25 is provided on the headers 21. This reduces the gap between two adjacent headers 21, and in turn reduces the gap between the ends of the outdoor heat exchanger 20. This increases the heat transfer area over which the outdoor heat exchanger 20 can exchange heat, and improves the efficiency of heat exchange in the outdoor unit 3.

[0063] The connecting portion 25 is composed of a protrusion 26 that communicates with the refrigerant flow path of the header 21 and a concave receiving recess 27 that communicates with the refrigerant flow path of the header 21 and receives the protrusion 26. The refrigerant flow paths of the outdoor heat exchangers 20 are connected by connecting the protrusion 26 with the receiving recess 27. This allows the ends of the two outdoor heat exchangers 20 to be connected so as to fit together, improving strength.

[0064] The exterior dimensions of each outdoor heat exchanger 20 are generally the same, which can reduce the cost of producing or procuring the heat exchangers 20.

[0065] The connection portion 25 of each outdoor heat exchanger 20 is formed to be detachable. This allows the outdoor heat exchanger 20 to be detached, which improves workability in maintenance and other work.

[0066] Furthermore, two adjacent outdoor heat exchangers 20 are arranged in a substantially straight line, and the connection portion 25 is provided so as to face the adjacent outdoor heat exchanger 20. Furthermore, two adjacent outdoor heat exchangers 20 are arranged substantially perpendicular to each other, and the connection portion 25 is provided so as to face the adjacent outdoor heat exchanger 20. According to this, the connection portion 25 is connected to other connection portions 25 in a straight line, and the gap between the ends of the two adjacent outdoor heat exchangers 20 is reduced.

[0067] The outdoor heat exchangers 20 are arranged in at least one of a direction perpendicular to or parallel to the axial direction of the flat tubes 22 included in the outdoor heat exchangers 20. This allows the outdoor heat exchangers 20 to be arranged in various layouts depending on the size and function of the outdoor unit 3, improving the versatility of the outdoor heat exchangers 20.

[0068] (Embodiment 3) [3-1. Configuration] Fig. 7 is a schematic perspective view of an outdoor unit 303 in embodiment 3. The outdoor unit 303 includes three outdoor heat exchangers 20.

[0069] The outdoor heat exchanger 20 of the third embodiment is configured as a so-called horizontal header, in which the header 21 is arranged horizontally. Of the three outdoor heat exchangers 20, the fifth outdoor heat exchanger 20E and the sixth outdoor heat exchanger 20F, which are adjacent to each other, are arranged so that their heat exchanger planes are perpendicular to each other. Of the three outdoor heat exchangers 20, the sixth outdoor heat exchanger 20F and the seventh outdoor heat exchanger 20G, which are adjacent to each other, are arranged so that their heat exchanger planes are perpendicular to each other.

[0070] The fifth outdoor heat exchanger 20E and the seventh outdoor heat exchanger 20G are arranged on the same side with respect to the sixth outdoor heat exchanger 20F. The three outdoor heat exchangers 20 are arranged in a substantially C-shape.

[0071] A substantially L-shaped reinforcing member 330 is provided on the headers 21 above two adjacent outdoor heat exchangers 20. The reinforcing member 330 is disposed across the two outdoor heat exchangers 20 that are disposed perpendicular to each other, and reinforces the connection between the two outdoor heat exchangers 20. The reinforcing member 330 is made of, for example, a resin with high hardness.

[0072] Fig. 8 is a perspective view of a plurality of outdoor heat exchangers 20 according to the third embodiment. Fig. 9 is a schematic plan view showing a connection portion 25 according to the third embodiment.

[0073] Each outdoor heat exchanger 20 has a connecting portion 25 so that the outdoor heat exchangers 20 can be connected to each other. Each connecting portion 25 is configured with a protruding portion 26 or a receiving recess 27. In the third embodiment, the connecting portion 25 further has a relay member 325. The protruding portion 26 and the receiving recess 27 are configured as a so-called joint, with the protruding portion 26 configured as a male side and the receiving recess 27 configured as a female side.

[0074] In this case, the relay member 325 is a pipe joint. In this case, the connection portion 25 and the relay member 325 are made of stainless steel, which is a different material from the aluminum alloy that constitutes the header 21. The relay member 325 covers the protrusion 26 and is sized to be insertable into the receiving recess 27.

[0075] [3-2. Actions, etc.] The same actions as those of the first embodiment are achieved. The action of a horizontal-header outdoor heat exchanger 20 in which the headers 21 are arranged extending horizontally, as in the third embodiment, will be described. If the outdoor heat exchangers 20 were arranged by integrating the headers 21 of two or more outdoor heat exchangers 20 and forming a bent portion, it would be difficult to provide the flat tubes 22 at the bent portion, and the heat transfer area would be reduced. Furthermore, even if the flat tubes 22 were provided at the bent portion, the flat tubes 22 would be arranged along the shape of the bent portion, and therefore the gaps between the flat tubes 22 would be larger than those of the flat tubes 22 arranged at the location of the header 21 that extends linearly, and the heat transfer area would be reduced.

[0076] The horizontally extending headers 21 of the two outdoor heat exchangers 20 are connected by a connecting portion 25. More specifically, the outdoor heat exchangers 20 are arranged perpendicular to each other by the connecting portion 25 via the relay member 325. This allows the ends of the two outdoor heat exchangers 20 to be structurally fitted together, reducing the gap between the ends of the outdoor heat exchangers 20 and increasing the heat transfer area.

[0077] Furthermore, the outdoor heat exchanger 20 is connected at one connection point 25, and this connection is reinforced by a reinforcing member 330. The outdoor heat exchanger 20 is prone to vibration due to the compressor 6, and this vibration may have an adverse effect on the connection at the connection point 25, but by providing the additional reinforcing member 330, the effects of this vibration can be reduced.

[0078] [3-3. Effects, etc.] As described above, in the air conditioning device 1 of this embodiment, the protrusion 26 at the end and the receiving recess 27 are connected by the relay member 325. This allows the protrusion 26 and the receiving recess 27 to be easily fitted together by the relay member 325.

[0079] The outdoor heat exchangers 20 are arranged in at least one of a direction perpendicular to or parallel to the axial direction of the flat tubes 22 included in the outdoor heat exchangers 20. In the present embodiment, the outdoor heat exchangers 20 are arranged in both a vertical direction, which is a direction parallel to the axial direction of the flat tubes 22, and a horizontal direction, which is a direction perpendicular to the axial direction of the flat tubes 22. This allows the layout of the outdoor heat exchangers 20 to be changed in various ways depending on the size and function of the outdoor unit 3, improving the versatility of the outdoor heat exchanger 20.

[0080] Furthermore, reinforcing members 330 are provided at the ends of two adjacent outdoor heat exchangers 20 to connect the outdoor heat exchangers 20. With this, even if the connection parts 25 alone are not enough to absorb vibrations in the various parts of the outdoor unit 3 and the strength of the connection between the outdoor heat exchangers 20 is not ensured, the outdoor heat exchangers 20 can be connected well by additionally providing the reinforcing members 330.

[0081] (Embodiment 4) [4-1. Configuration] Fig. 10 is a diagram showing the configuration of the refrigeration cycle of air conditioning apparatus 401. Fig. 11 is a schematic diagram of outdoor unit 402. Fig. 12 is a schematic diagram of indoor unit 403. Fig. 13 is a block diagram showing the main control configuration of control device 500, outdoor unit 402, and indoor unit 403. As shown in Fig. 10, air conditioning apparatus 401 comprises indoor unit 403, outdoor unit 402, and control device 500. Air conditioning apparatus 401 forms a refrigerant cycle with indoor unit 403 and outdoor unit 402, and is a device that conditions air by circulating a refrigerant.

[0082] The indoor unit 403 includes an indoor unit housing 404, an indoor blower fan 405 inside the indoor unit housing 404, and an indoor heat exchanger 406 that branches into two. The components inside the indoor unit housing 404 are connected by refrigerant piping 409.

[0083] The indoor blower fan 405 is composed of a motor and blades. The indoor blower fan 405 takes in air from the room where the indoor unit 403 is installed into the indoor unit housing 404, exchanges heat with the indoor heat exchanger 406, and blows out the air.

[0084] As shown in Fig. 12, the indoor unit 403 is provided with an air outlet 407 that exchanges heat with one indoor heat exchanger 406 and blows out air. In this embodiment, two air outlets 407 are provided corresponding to the two indoor heat exchangers 406. The indoor unit 403 is provided with a flap 408 that adjusts the direction of air blown out from the air outlet 407. The two flaps 408 are driven by a first blade drive unit 410 and a second blade drive unit 411, which serve as blade drives, respectively, and their directions can be changed. The flap 408 covers the air outlet 407 and can restrict the air from being blown out.

[0085] The branched indoor heat exchanger 406 and the refrigerant pipe 409 are collectively called a system.

[0086] The system of the indoor heat exchanger 406 is provided with a shutoff mechanism 461 , a supercooling sensor 462 , and a superheating sensor 463 .

[0087] The shutoff mechanism 461 is a general term for the first indoor shutoff valve 431, the second indoor shutoff valve 432, the first outdoor shutoff valve 441, the second outdoor shutoff valve 442, and the third outdoor shutoff valve 443, which will be described later, when no distinction is made between them. The shutoff mechanism 461 is an example of a removable part. The indoor heat exchanger 406 and the outdoor heat exchanger 417, which will be described later, can be separated from the refrigeration cycle at the shutoff mechanism 461 and removed.

[0088] The subcooling sensor 462 is a general term used when no distinction is made between a first indoor subcooling sensor 435, a second indoor subcooling sensor 437, a first outdoor subcooling sensor 446, a second outdoor subcooling sensor 448, and a third outdoor subcooling sensor 450, which will be described later. The subcooling sensor 462 is an example of a detection means.

[0089] The overheat sensor 463 is a general term for a first indoor overheat sensor 436, a second indoor overheat sensor 438, a first outdoor overheat sensor 447, a second outdoor overheat sensor 449, and a third outdoor overheat sensor 451, which will be described later. The overheat sensor 463 is an example of a detection means.

[0090] Regarding the indoor heat exchangers 406, specifically, the system of one indoor heat exchanger 406A is provided with a first indoor shutoff valve 431, a first indoor subcooling sensor 435, and a first indoor superheat sensor 436 on both sides of the indoor heat exchanger 406. The system of the other indoor heat exchanger 406B is provided with a second indoor shutoff valve 432, a second indoor subcooling sensor 437, and a second indoor superheat sensor 438 on both sides of the indoor heat exchanger 406. When there is no need to distinguish between the two indoor heat exchangers 406A, 406B, they are referred to as indoor heat exchangers 406.

[0091] In the refrigerant pipes 409 other than the two systems, a main indoor subcooling sensor 433 and a main indoor superheating sensor 434 are provided on both sides of the two indoor heat exchangers 406, respectively.

[0092] The first indoor subcooling sensor 435, the second indoor subcooling sensor 437, and the main indoor subcooling sensor 433 are configured as temperature sensors and detect the temperature of the condensed refrigerant. The first indoor superheat sensor 436, the second indoor superheat sensor 438, and the main indoor superheat sensor 434 are configured as temperature sensors and detect the temperature of the evaporated refrigerant.

[0093] The outdoor unit 402 includes an outdoor unit housing 416, and inside the outdoor unit housing 416, a compressor 412, a four-way valve 413, an expansion valve 414, an outdoor blower fan 415, and an outdoor heat exchanger 417 that branches into three. The components inside the outdoor unit housing 416 are connected by refrigerant piping 409. In Figure 11, some of the components included in the outdoor unit 402 are omitted from the illustration.

[0094] The outdoor blower fan 415 takes in outdoor air where the outdoor unit 402 is installed into the outdoor unit housing 416, exchanges heat with the outdoor heat exchanger 417, and then blows out the air.

[0095] The outdoor heat exchangers 417 are arranged one on each of the three horizontal side surfaces of the outdoor unit housing 416. The three outdoor heat exchangers 417 are arranged in a substantially C-shape when viewed vertically.

[0096] The branched outdoor heat exchanger 417 and the refrigerant pipe 409 are collectively referred to as a system.

[0097] The system for the first outdoor heat exchanger 417A is provided with a first outdoor shutoff valve 441, a first outdoor subcooling sensor 446, and a first outdoor superheat sensor 447 on both sides of the outdoor heat exchanger 417. The system for the second outdoor heat exchanger 417B is provided with a second outdoor shutoff valve 442, a second outdoor subcooling sensor 448, and a second outdoor superheat sensor 449 on both sides of the outdoor heat exchanger 417. The system for the third outdoor heat exchanger 417C is provided with a third outdoor shutoff valve 443, a third outdoor subcooling sensor 450, and a third outdoor superheat sensor 451 on both sides of the outdoor heat exchanger 417. When the three outdoor heat exchangers 417A, 417B, and 417C are not to be distinguished from one another, they are collectively referred to as outdoor heat exchangers 417.

[0098] In the refrigerant pipes 409 other than the three systems, a main outdoor subcooling sensor 444 and a main outdoor superheating sensor 445 are provided on both sides of the two outdoor heat exchangers 417, respectively.

[0099] The first outdoor subcooling sensor 446, the second outdoor subcooling sensor 448, the third outdoor subcooling sensor 450, and the main outdoor subcooling sensor 444 are configured as temperature sensors and detect the temperature of condensed refrigerant. The first outdoor superheat sensor 447, the second outdoor superheat sensor 449, the third outdoor subcooling sensor 450, and the main outdoor superheat sensor 445 are configured as temperature sensors and detect the temperature of evaporated refrigerant.

[0100] The control configuration of the control device 500 will be described with reference to Fig. 13. The control device 500 includes a control unit 510 and a display unit 522.

[0101] The control unit 510 includes a processor 511, which is a processor that executes programs such as a CPU or an MPU, and a storage unit 520, and controls each unit of the control device 500. The control unit 510 executes various processes through cooperation of hardware and software, such that the processor 511 reads out a program 521 stored in the storage unit 520 and executes the process.

[0102] The storage unit 520 has a storage area for storing the program 521 executed by the processor 511 and data processed by the processor 511. The storage unit 520 stores the control program executed by the processor 511, setting data related to various settings of the control device 500, and various other data. The storage unit 520 has a non-volatile storage area for non-volatilely storing the program and data. The storage unit 520 may also have a volatile storage area and constitute a work area for temporarily storing the program executed by the processor 511 and data to be processed.

[0103] The control unit 510 is connected to the indoor blower fan 405, the first blade drive unit 410, the second blade drive unit 411, the first indoor shutoff valve 431, and the second indoor shutoff valve 432 equipped in the indoor unit 403, and to the compressor 412, the four-way valve 413, the expansion valve 414, the outdoor blower fan 415, the first outdoor shutoff valve 441, the second outdoor shutoff valve 442, and the third outdoor shutoff valve 443 equipped in the outdoor unit 402, and controls each unit.

[0104] The control unit 510 calculates the degree of subcooling or superheating from the detection results of each sensor and determines whether or not a refrigerant leaks based on this degree of subcooling or superheating. Specifically, the control unit 510 determines whether or not a refrigerant leaks based on whether a predetermined appropriate degree of subcooling or superheating is equal to or greater than a predetermined threshold. The control unit 510 determines whether or not a refrigerant leaks in any of the indoor heat exchangers 406 based on the detection results of the main indoor subcooling sensor 433 or the main indoor superheat sensor 434. In this way, the main indoor subcooling sensor 433 or the main indoor superheat sensor 434 is an example of a second detection means that detects a refrigerant leak in any of the indoor heat exchangers 406 among all of the indoor heat exchangers 406.

[0105] The control unit 510 determines whether or not there is a refrigerant leak in the indoor heat exchanger 406 in these systems based on the detection results from the first indoor subcooling sensor 435 or the first indoor superheating sensor 436. The control unit 510 determines whether or not there is a refrigerant leak in the indoor heat exchanger 406 in these systems based on the detection results from the second indoor subcooling sensor 437 or the second indoor superheating sensor 438.

[0106] In addition, if the control unit 510 determines that refrigerant is leaking in one of the indoor heat exchangers 406 and determines that refrigerant is not leaking in the systems of the indoor heat exchangers 406 other than one indoor heat exchanger 406, it can determine that refrigerant is leaking in the system of the remaining indoor heat exchanger 406.

[0107] The control unit 510 operates the shutoff valve in the system determined to be leaking refrigerant, and shuts off the indoor heat exchanger 406. For example, if it is determined that refrigerant is leaking in the system of one of the indoor heat exchangers 406, the control unit 510 closes the two first indoor shutoff valves 431, thereby isolating the system of the indoor heat exchanger 406 from the refrigerant cycle.

[0108] Furthermore, the control unit 510 activates the blade drive unit corresponding to the blocked system of the indoor heat exchanger 406 , and closes the flap 408 so as to cover the air outlet 407 .

[0109] The control unit 510 determines whether or not there is a refrigerant leak in any of the outdoor heat exchangers 417 based on the detection result from the main outdoor subcooling sensor 444 or the main outdoor superheat sensor 445. In this way, the main outdoor subcooling sensor 444 or the main outdoor superheat sensor 445 is an example of a second detection means that detects whether there is a refrigerant leak in any of the outdoor heat exchangers 417 among all of the outdoor heat exchangers 417.

[0110] Based on the detection results of the first outdoor subcooling sensor 446 or the first outdoor superheating sensor 447, the control unit 510 determines whether or not refrigerant is leaking from the outdoor heat exchanger 417 in these systems.

[0111] Based on the detection results of the second outdoor subcooling sensor 448 or the second outdoor superheating sensor 449, the control unit 510 determines whether or not refrigerant is leaking from the outdoor heat exchanger 417 in these systems.

[0112] Based on the detection results of the third outdoor subcooling sensor 450 or the third outdoor superheating sensor 451, the control unit 510 determines whether or not refrigerant is leaking from the outdoor heat exchanger 417 in these systems.

[0113] When the control unit 510 determines that refrigerant is leaking in one of the outdoor heat exchangers 417 and determines that refrigerant is not leaking in the systems of the outdoor heat exchangers 417 other than one outdoor heat exchanger 417, it can determine that refrigerant is leaking in the system of the remaining outdoor heat exchanger 417.

[0114] The control unit 510 operates the shutoff valve in the system determined to be leaking refrigerant, and shuts off the outdoor heat exchanger 417. For example, if it is determined that refrigerant is leaking in the system of the first outdoor heat exchanger 417, the control unit 510 closes the two first outdoor shutoff valves 441, thereby isolating the system of the indoor heat exchanger 406 from the refrigerant cycle.

[0115] The control unit 510 notifies the user of the occurrence of a refrigerant leak in either the indoor heat exchanger 406 or the outdoor heat exchanger 417 using the display unit 522. The display unit 522 is a display. However, the display unit 522 is not limited to this and may be a light-emitting unit such as a lamp or a sound-generating unit such as a speaker.

[0116] [4-2. Operation] Next, the operation of this embodiment will be described with reference to the flowchart shown in Fig. 14. The operations of steps ST1-7 shown in Fig. 14 are all performed by the control unit 510. The operations shown in Fig. 14 are performed on the premise that the air conditioning device 401 is performing air conditioning and operating. The operations shown in Fig. 14 end when an instruction to stop operation is received from a remote controller (not shown) or the like.

[0117] In the following description, when there is no need to distinguish between the indoor heat exchanger 406 and the outdoor heat exchanger 417, they will be referred to as heat exchangers. Furthermore, when there is no need to distinguish between the first blade drive unit 410 and the second blade drive unit 411, they will be referred to as blade drive units. Furthermore, as described above, when there is no need to distinguish between the first indoor shutoff valve 431, the second indoor shutoff valve 432, the first outdoor shutoff valve 441, the second outdoor shutoff valve 442, and the third outdoor shutoff valve 443, they will be referred to as shutoff mechanisms 461.

[0118] The control unit 510 determines whether a refrigerant leak has been detected (ST1). If a refrigerant leak has not been detected (ST1, NO), the control unit 510 repeats the determination in step ST1. That is, in this case, the air conditioning device 401 continues air conditioning operation.

[0119] If a refrigerant leak is detected (ST1, YES), the control unit 510 identifies the heat exchanger from which the refrigerant has leaked (ST2).

[0120] Next, the control unit 510 closes the shutoff mechanism 461 included in the system of the heat exchanger identified in step ST2 (ST3).

[0121] Next, the control unit 510 determines whether the heat exchanger from which the refrigerant has leaked is the indoor heat exchanger 406 (ST4). If it determines that the refrigerant has leaked from the indoor heat exchanger 406 (ST4, YES), it closes the flap 408 corresponding to the system of the indoor heat exchanger 406 by operating the blade drive unit (ST5).

[0122] After step ST5 is completed, or if it is determined that there is no refrigerant leakage from the indoor heat exchanger 406 (ST4, NO), the control unit 510 notifies that there is a refrigerant leakage (ST6).

[0123] Next, the control unit 510 continues the air conditioning operation of the air conditioner 401 (ST7). After this, a maintenance person can perform maintenance by removing the heat exchanger from which the refrigerant is leaking, which has been separated by the shut-off mechanism 461.

[0124] [4-3. Effects, etc.] As described above, the air conditioning apparatus 401 in this embodiment includes an outdoor unit 402, a plurality of outdoor heat exchangers 417, detection means 62 and 63 that detect the state of the refrigerant in the outdoor heat exchangers 417, a shutoff mechanism 461 that shuts off the flow of refrigerant to each outdoor heat exchanger 417, and a control unit 510 that determines whether or not a refrigerant is leaking in each outdoor heat exchanger 417 based on the detection results of the detection means 62 and 63, and, if a refrigerant is leaking, closes the shutoff mechanism 461 of the outdoor heat exchanger 417 from which the refrigerant is leaking. As a result, the outdoor heat exchanger 417 from which the refrigerant is leaking is shut off, so air conditioning can continue even after a refrigerant leak occurs, and maintenance costs can be reduced.

[0125] As described above, the air conditioning apparatus 401 in this embodiment includes an indoor unit 403, a plurality of indoor heat exchangers 406, detection means 62 and 63 that detect the state of the refrigerant in the indoor heat exchangers 406, a shutoff mechanism 461 that shuts off the flow of refrigerant to each indoor heat exchanger 406, and a control unit 510 that determines whether or not a refrigerant is leaking in each outdoor heat exchanger 417 based on the detection results of the detection means 62 and 63, and, if a refrigerant is leaking, closes the shutoff mechanism 461 of the indoor heat exchanger 406 from which the refrigerant is leaking. This shuts off the indoor heat exchanger 406 from which the refrigerant is leaking, making it possible to continue air conditioning even after a refrigerant leak and reducing maintenance costs.

[0126] The control unit 510 determines whether or not a refrigerant leak has occurred based on the degree of subcooling. This allows the determination of whether or not a refrigerant leak has occurred based on whether or not the degree of subcooling is equal to or greater than a predetermined threshold. Specifically, the first outdoor subcooling sensor 446, the second outdoor subcooling sensor 448, and the third outdoor subcooling sensor 450 are provided in the outdoor heat exchanger 417, and the first indoor subcooling sensor 435 and the second indoor subcooling sensor 437 are provided in the indoor heat exchanger 406, respectively, in the liquid-side refrigerant piping 409 where the refrigerant condenses.

[0127] The control unit 510 determines whether or not a refrigerant leaks based on the degree of superheat. This allows the determination of whether or not a refrigerant leaks based on whether the degree of superheat is equal to or greater than a predetermined threshold. Specifically, the first outdoor superheat sensor 447, the second outdoor superheat sensor 449, and the third outdoor superheat sensor 451 are provided in the outdoor heat exchanger 417, and the first indoor superheat sensor 436 and the second indoor superheat sensor 438 are provided in the indoor heat exchanger 406, respectively, in the liquid-side refrigerant piping 409 where the refrigerant condenses.

[0128] Furthermore, the control unit 510 closes the shutoff mechanism 461 to shut off the indoor heat exchanger 406 or the outdoor heat exchanger 417 from which the refrigerant has leaked, and then continues the air conditioning operation using the other heat exchangers. In this way, by continuing the air conditioning even after the refrigerant leaks, user comfort is improved.

[0129] Furthermore, each heat exchanger is individually removable. This allows each indoor heat exchanger 406 or each outdoor heat exchanger 417 to be partially removed, thereby reducing maintenance costs. Specifically, the indoor heat exchanger 406 or the outdoor heat exchanger 417 is provided with a shutoff mechanism 461 as a removable part, and the indoor heat exchanger 406 or the outdoor heat exchanger 417 that is shut off by the shutoff mechanism 461 is configured to be removable from the shutoff mechanism 461.

[0130] The indoor unit 403 has air outlets 407 provided corresponding to each indoor heat exchanger 406, and flaps 408 that cover each air outlet 407. The control device 500 closes the blocking mechanism 461, and then operates the blade drive unit of the flap 408 that corresponds to the blocked indoor heat exchanger 406, thereby covering the air outlet 407. This makes it possible to prevent air that has not been heat exchanged from being blown into the room, and to suppress a decrease in user comfort.

[0131] The air conditioning apparatus 401 is equipped with multiple indoor heat exchangers 406, each equipped with a shut-off mechanism 461 that shuts off the flow of refrigerant to the indoor heat exchanger 406, and each indoor heat exchanger 406 except for one indoor heat exchanger 406 is equipped with a subcooling sensor 462 and a superheat sensor 463. Furthermore, the air conditioning apparatus 401 may be equipped with a main indoor subcooling sensor 433 and a main indoor superheat sensor 434 as second detection means for detecting refrigerant leakage in any of the indoor heat exchangers 406. This allows the indoor unit 403 to determine whether refrigerant has leaked in any of the indoor heat exchangers 406, without providing subcooling sensors 462 and superheat sensors 463 in all of the indoor heat exchangers 406.

[0132] The air conditioning apparatus 401 may include a plurality of branched outdoor heat exchangers 417, each of which is equipped with a shutoff mechanism 461 that shuts off the flow of refrigerant to the outdoor heat exchanger 417, and each of the outdoor heat exchangers 417 except for one of the outdoor heat exchangers 417 may include a subcooling sensor 462 and a superheat sensor 463. Furthermore, the air conditioning apparatus 401 may include a main outdoor subcooling sensor 444 and a main outdoor superheat sensor 445 as second detection means for detecting refrigerant leakage in any of the outdoor heat exchangers 417. This allows the outdoor unit 402 to determine whether refrigerant has leaked in any of the outdoor heat exchangers 417, without providing subcooling sensors 462 and superheat sensors 463 in all of the outdoor heat exchangers 417.

[0133] (Other Embodiments) As described above, the above-mentioned embodiments 1 to 4 have been described as examples disclosed in the present application. However, the technology in the present disclosure is not limited to these, and can also be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. It is also possible to combine the components described in the above-mentioned embodiments 1 to 4 to create new embodiments. Therefore, other embodiments will be described below as examples.

[0134] In the third embodiment, the reinforcing member 330 is illustrated as being arranged across two outdoor heat exchangers 20 that are arranged perpendicular to each other. However, the present invention is not limited to this, and the outdoor units 3, 203 of the first and second embodiments may further be provided with a substantially I-shaped reinforcing member that is arranged across two outdoor heat exchangers 20 that are arranged in parallel.

[0135] The relay member 325 exemplified in the third embodiment may be provided in the outdoor units 3 and 203 of the first and second embodiments.

[0136] In the third embodiment, the outdoor heat exchanger 20 is configured to be branched into the upper and lower outdoor heat exchangers 20, but this is not limiting. The outdoor heat exchanger 20 may be configured to include a connecting portion 25 at the top or bottom, so as to be connectable in the vertical direction.

[0137] In the above embodiment, the two headers 21 are configured to be connected by one connection portion 25, but this is not limited thereto, and they may be connected by two or more connection portions 25. In the headers 21 in the first and second embodiments, connection portions 25 may be provided at multiple locations on one header 21. Furthermore, in the horizontal header in the third embodiment, the upper and lower headers 21 may each be configured to be connected to the other headers 21 by a connection portion 25.

[0138] The protrusion 26 may be configured as a joint corresponding to the male thread side, and the receiving recess 27 may be configured as a joint corresponding to the female thread side.

[0139] The presence or absence of refrigerant leakage may be determined by either the supercooling sensor 462 or the superheat sensor 463 in each heat exchanger.

[0140] Figure 15 is a schematic perspective view of an outdoor unit 402 according to another embodiment. The outdoor unit 402 includes 12 outdoor heat exchangers 417. Each outdoor heat exchanger 417 includes heat transfer tubes, and the axial direction of the heat transfer tubes extends vertically or perpendicularly. As shown in Figure 14, the outdoor heat exchangers 417 are arranged in a row parallel or perpendicular to the axial direction of the heat transfer tubes. This allows the outdoor heat exchangers 417, which are arranged on the side of the outdoor unit housing 416 of the outdoor unit 402, to be subdivided, allowing outdoor heat exchangers 417 that have leaked refrigerant to be partially removed, thereby reducing maintenance costs.

[0141] FIG. 16 is a schematic plan view of an indoor unit 403 according to another embodiment. Components similar to those in FIGS. 10, 12, and 13 are designated by the same reference numerals, and descriptions thereof will be omitted. In the first embodiment, the indoor unit 403 shown in FIG. 12 is a two-cassette type having two air outlets 407, but is not limited to this. As shown in FIG. 16, the indoor unit 403 may be a four-cassette type having four indoor heat exchangers 406 and four air outlets 407 corresponding to these indoor heat exchangers 406. Each of the four outdoor heat exchangers 417 has a shut-off mechanism 461.

[0142] The processor 511 may be configured with a single processor or multiple processors. These processors may be hardware programmed to realize corresponding functional units. That is, these processors may be configured with, for example, an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0143] The configuration of the air conditioning device 401 in Figure 13 is one example, and the specific implementation form is not particularly limited. In other words, it is not necessarily necessary to implement hardware corresponding to each unit individually, and it is also possible to configure the system so that a single processor executes a program to realize the functions of each unit. Furthermore, some of the functions realized by software in the above-mentioned embodiment may be implemented as hardware, or some of the functions realized by hardware may be implemented by software.

[0144] The step units of the operation shown in Figure 14 are divided according to the main processing content to make the operation easier to understand, and the operation is not limited by the way the processing units are divided or the names of the processing units. The operation may be divided into more step units depending on the processing content. Furthermore, one step unit may be divided so that it includes more processing. Furthermore, the order of the steps may be changed as appropriate within the scope that does not interfere with the purpose of this disclosure.

[0145] It should be noted that the above-described embodiments are intended to illustrate the technology of the present disclosure, and various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents.

[0146] (Additional Notes) The above description of the embodiments discloses the following techniques.

[0147] (Technology 1) An air conditioning device including multiple heat exchangers, each with a connector at its end that connects to the refrigerant flow path of the other heat exchangers. By fitting the ends together with the connector, the gap between the ends of the heat exchangers is reduced. This increases the heat transfer area through which the heat exchangers can exchange heat, improving the efficiency of heat exchange.

[0148] (Technology 2) The air conditioning apparatus according to Technology 1, wherein the heat exchanger includes a pair of headers, and the connecting portion is provided on the headers. This reduces the gap between two adjacent headers, thereby reducing the gap between the ends of the heat exchanger. This increases the heat transfer area available for heat exchange by the heat exchanger, thereby improving heat exchange efficiency.

[0149] (Technology 3) In the air conditioning apparatus according to Technology 2, the connecting portion is composed of a protruding portion that communicates with the refrigerant flow path of the header and a concave receiving recess that communicates with the refrigerant flow path of the header and receives the protruding portion, and the refrigerant flow paths of the heat exchangers are connected by connecting the protruding portion and the receiving recess. This allows the ends of the two heat exchangers to be connected so as to fit together, improving strength.

[0150] (Technology 4) The air conditioning apparatus according to Technology 3, wherein the protrusion and the receiving recess are connected via a relay member. This allows the protrusion and the receiving recess to be easily fitted together by the relay member.

[0151] (Technology 5) The air conditioning apparatus according to any one of Technologies 1 to 4, wherein the heat exchangers are formed to have substantially the same external dimensions. This can reduce the cost of producing or procuring the heat exchangers.

[0152] (Technology 6) The air conditioning apparatus according to Technology 1, wherein two adjacent heat exchangers are arranged in a substantially straight line, and the connecting portion is provided so as to be directed toward the adjacent heat exchanger. In this way, the connecting portion is connected to another connecting portion in a straight line, and the gap between the ends of the two adjacent heat exchangers is reduced.

[0153] (Technology 7) The air conditioning apparatus according to Technology 1, wherein two adjacent heat exchangers are arranged substantially perpendicular to each other, and the connecting portion is provided so as to be directed toward the adjacent heat exchanger. In this way, the connecting portion is connected to other connecting portions in a straight line, and the gap between the ends of the two adjacent heat exchangers is reduced.

[0154] (Technology 8) The air conditioning apparatus according to Technology 1, wherein reinforcing members are provided at the ends of two adjacent heat exchangers to connect the heat exchangers. With this, even in cases where the connection parts alone are unable to absorb vibrations caused by the parts of the air conditioning apparatus and the strength of the connection between the heat exchangers is not ensured, the heat exchangers can be connected satisfactorily by providing additional reinforcing members.

[0155] (Technology 9) The air conditioning apparatus according to Technology 1, wherein the connecting portion is formed of a material different from that of the heat exchanger. This allows the connecting portion to be formed of a material different in hardness or strength from that of the heat exchanger.

[0156] (Technology 10) The air conditioning apparatus according to any one of Technology 1 to Technology 9, wherein the heat exchanger includes flat tubes. When the heat transfer tubes of the heat exchanger are configured as flat tubes, the difference between the inner and outer diameters of the flat tubes is large when the heat exchanger is bent. Because the flat tubes have a larger longitudinal diameter than circular tubes, the difference between the inner and outer diameters increases during bending. If the bending angle is small, this difference between the inner and outer diameters can cause the flat tubes to buckle at the bent points due to compressive stress. Therefore, heat exchangers with flat tubes require a larger bending angle than heat exchangers with circular tubes. Due to this issue, heat exchangers with flat tubes tend to have a smaller heat transfer area available for heat exchange, significantly increasing the impact of the heat exchanger installation issues. However, the configuration of Technology 10, which uses flat tubes, significantly achieves the functions and effects described in Technology 1.

[0157] (Technology 11) An air conditioning apparatus comprising: a plurality of heat exchangers; a detection means for detecting the state of refrigerant in the heat exchangers; a shutoff mechanism for shutting off the flow of refrigerant to each of the heat exchangers; and a control unit for determining whether or not a refrigerant is leaking from each of the heat exchangers based on the detection result of the detection means, and for closing the shutoff mechanism of the heat exchanger from which the refrigerant is leaking if a refrigerant is leaking. With this, because the heat exchanger from which the refrigerant is leaking is shut off, air conditioning can be continued even after a refrigerant leak occurs, and maintenance costs can be reduced.

[0158] (Technology 12) The air conditioning apparatus according to Technology 11, wherein the control unit determines whether or not there is a refrigerant leak based on the degree of subcooling. This makes it possible to determine whether or not there is a refrigerant leak based on whether or not the degree of subcooling is equal to or greater than a predetermined threshold.

[0159] (Technology 13) The air conditioning apparatus according to Technology 11 or 12, wherein the control unit determines whether or not there is a refrigerant leak based on the degree of superheat. This makes it possible to determine whether or not there is a refrigerant leak based on whether or not the degree of superheat is equal to or greater than a predetermined threshold.

[0160] (Technology 14) The air conditioning apparatus according to any one of Technologies 11 to 13, wherein the control unit closes the shutoff mechanism to shut off the heat exchanger from which refrigerant has leaked, and then continues air conditioning operation using the other heat exchangers. This improves user comfort by continuing air conditioning even after a refrigerant leak.

[0161] (Technology 15) The air conditioning apparatus according to any one of Technologies 11 to 14, wherein each of the heat exchangers is provided so as to be individually removable. This allows each heat exchanger to be partially removed, thereby reducing maintenance costs.

[0162] (Technology 16) The air conditioning apparatus according to any one of Technologies 11 to 15, wherein the heat exchanger is an outdoor heat exchanger provided in an outdoor unit. According to this, a plurality of outdoor heat exchangers are provided, and an outdoor heat exchanger in which refrigerant has leaked is shut off, so that air conditioning can be continued even after a refrigerant leak occurs, and maintenance costs can be reduced.

[0163] (Technology 17) The air conditioning apparatus according to any one of Technologies 11 to 15, wherein the heat exchanger is an indoor heat exchanger provided in an indoor unit. According to this, a plurality of indoor heat exchangers are provided, and an indoor heat exchanger in which refrigerant has leaked is shut off, so that air conditioning can be continued even after a refrigerant leak occurs, and maintenance costs can be reduced.

[0164] (Technology 18) The air conditioning apparatus according to Technology 17, wherein the indoor unit includes air outlets provided corresponding to the indoor heat exchangers and flaps that cover the air outlets, and the control device activates the shutoff mechanism and then activates the flaps that correspond to the shutoff indoor heat exchangers to cover the air outlets. This makes it possible to prevent air that has not undergone heat exchange from being blown into the room, thereby suppressing a decrease in user comfort.

[0165] (Technology 19) The air conditioning apparatus according to any one of Technologies 11 to 15, wherein the heat exchanger includes heat transfer tubes arranged parallel or perpendicular to the axial direction of the heat transfer tubes. This allows the heat exchanger to be subdivided, and a heat exchanger that has leaked refrigerant can be partially removed, thereby reducing maintenance costs.

[0166] As described above, the air conditioner according to the present invention can be used to improve the heat exchange efficiency of a heat exchanger. Also, as described above, the air conditioner according to the present invention can be used to temporarily continue air conditioning even in the event of a refrigerant leak.

[0167] 1, 401 Air conditioner 2, 403 Indoor unit 3, 203, 303, 402 Outdoor unit 4, 406, 406A, 406B Indoor heat exchanger 5, 405 Indoor blower fan 6, 412 Compressor 7, 413 Four-way valve 8, 414 Expansion valve 9, 415 Outdoor blower fan 10 Refrigerant piping 11 Housing 20, 417, 417A, 417B, 417C Outdoor heat exchanger (heat exchanger) 20A First outdoor heat exchanger 20B Second outdoor heat exchanger 20C Third outdoor heat exchanger 20D Fourth outdoor heat exchanger 20E Fifth outdoor heat exchanger 20F Sixth outdoor heat exchanger 20G Seventh outdoor heat exchanger 21 Header 22 Flat tube 25 Connection part 26 Protrusion part 27 Receiving recess 325 Relay member 330 Reinforcement member 404 Indoor unit housing 407 Air outlet 408 Flap 409 Refrigerant piping 410 First blade drive part 411 Second blade drive part 416 Outdoor unit housing 431 First indoor shutoff valve (shutoff mechanism, detachable part) 432 Second indoor shutoff valve (shutoff mechanism, detachable part) 433 Main indoor subcooling sensor 434 Main indoor superheat sensor 435 First indoor subcooling sensor 436 First indoor superheat sensor 437 Second indoor subcooling sensor 438 Second indoor superheat sensor 441 First outdoor shutoff valve (shutoff mechanism, detachable part) 442 Second outdoor shutoff valve (shutoff mechanism, detachable part) 443 Third outdoor shutoff valve (shutoff mechanism, detachable part) 444 Main outdoor subcooling sensor 445 Main outdoor superheat sensor 446 First outdoor subcooling sensor 447 First outdoor superheat sensor 448 Second outdoor subcooling sensor 449 Second outdoor superheat sensor 450 Third outdoor subcooling sensor 451 Third outdoor superheat sensor 461 Shut-off mechanism 462 Subcooling sensor 463 Superheat sensor 500 Control device 510 Control unit 511 Processor 520 Memory unit 521 Program

Claims

1. An air conditioning apparatus comprising a plurality of heat exchangers, each of which is provided at its end with a connecting portion for connection to the refrigerant flow path of another of the heat exchangers.

2. The air conditioning apparatus according to claim 1, wherein the heat exchanger includes a pair of headers, and the connection portion is provided on the headers.

3. An air conditioning device as described in claim 2, wherein the connecting portion is composed of a protrusion portion that communicates with the refrigerant flow path of the header and a concave receiving recess that communicates with the refrigerant flow path of the header and receives the protrusion portion, and the refrigerant flow paths of each heat exchanger are connected by connecting the protrusion portion and the receiving recess.

4. The air conditioning apparatus according to claim 3, wherein the protrusion and the receiving recess are connected via a relay member.

5. An air conditioning apparatus according to any one of claims 1 to 4, wherein the heat exchangers are formed to have substantially the same external dimensions.

6. The air conditioning apparatus according to claim 1, wherein two adjacent heat exchangers are arranged in a substantially straight line, and the connecting portion is provided so as to be directed toward the adjacent heat exchanger.

7. The air conditioning apparatus according to claim 1, wherein two adjacent heat exchangers are arranged substantially perpendicular to each other, and the connection portion is provided so as to be directed toward the adjacent heat exchanger.

8. The air conditioning apparatus according to claim 1, wherein reinforcing members are provided at the ends of two adjacent heat exchangers to connect the heat exchangers.

9. The air conditioning apparatus according to claim 1, wherein the connection portion is formed of a material different from that of the heat exchanger.

10. An air conditioning apparatus according to any one of claims 1 to 4 and claims 6 to 9, wherein the heat exchanger comprises flat tubes.

11. An air conditioning apparatus comprising: a plurality of heat exchangers; a detection means for detecting the state of refrigerant in the heat exchangers; a shut-off mechanism for shutting off the flow of refrigerant to each of the heat exchangers; and a control unit for determining whether or not refrigerant is leaking in each of the heat exchangers based on the detection result of the detection means, and for closing the shut-off mechanism of the heat exchanger from which refrigerant is leaking if refrigerant is leaking.

12. The air conditioner according to claim 11, wherein the control unit determines whether or not a refrigerant leaks based on the degree of subcooling.

13. The air conditioner according to claim 11, wherein the control unit determines whether or not a refrigerant leaks based on the degree of superheat.

14. The air conditioning apparatus according to claim 11, wherein the control unit closes the shutoff mechanism to shut off the heat exchanger from which refrigerant has leaked, and then continues air conditioning operation using the other heat exchangers.

15. The air conditioning apparatus according to claim 11, wherein each of the heat exchangers is provided so as to be individually removable.

16. The air conditioning apparatus according to any one of claims 11 to 15, wherein the heat exchanger is an outdoor heat exchanger provided in an outdoor unit.

17. The air conditioning apparatus according to any one of claims 11 to 15, wherein the heat exchanger is an indoor heat exchanger provided in an indoor unit.

18. An air conditioning apparatus as described in claim 17, wherein the indoor unit is provided with air outlets provided corresponding to each of the indoor heat exchangers and flaps covering each of the air outlets, and the control unit, after activating the blocking mechanism, activates the flap corresponding to the blocked indoor heat exchanger to cover the air outlet.

19. An air conditioning apparatus according to any one of claims 11 to 15, wherein the heat exchanger comprises heat transfer tubes arranged in a direction parallel or perpendicular to the axial direction of the heat transfer tubes.

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