Heat exchanger and air conditioning device

Abstract

To provide a heat exchanger capable of appropriately grasping a temperature of a coolant passing a lower side of the heat exchanger, and an air conditioning device.SOLUTION: A heat exchanger comprises: a plurality of flat tubes 28 including a first flat tube 28x, and a second flat tube 28y which is disposed at an upper side of the first flat tube 28x; a liquid header 60 to which the plurality of flat tubes 28 is connected; a liquid coolant connection pipe 20a which is connected to the liquid header 60; and a temperature sensor 80. The liquid header 60 includes: a confluent channel C extending from a connection portion of the liquid coolant connection pipe 20a; a first coolant channel A connecting a connection portion of the first flat tube 28x with the confluent channel C; and a second coolant channel B connecting a connection portion of the second flat tube 28y with the confluent channel C. The temperature sensor 80 detects a temperature of a coolant flowing in the first coolant channel A.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present disclosure relates to a heat exchanger and an air conditioning apparatus. [Background technology]

[0002] Conventionally, in an air conditioner, when frost forms on an outdoor heat exchanger through which a refrigerant with a temperature lower than that of the outdoor air flows during heating operation, a defrosting operation is performed to melt the frost by supplying a gas refrigerant to the outdoor heat exchanger. This defrosting operation ends when the frost that has formed on the heat exchanger is removed.

[0003] For example, Patent Document 1 (JP 2012-088005 A) describes an air conditioner that proposes using the temperature of the refrigerant that has passed through an outdoor heat exchanger to determine the timing to end the defrosting operation. DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0004] During defrosting operation, the refrigerant supplied to the heat exchanger and condensed tends to stagnate in the area below the heat exchanger, and the refrigerant flow rate in the area below the heat exchanger tends to decrease. Therefore, the frost that has adhered to the lower part of the heat exchanger tends to melt at the end of the defrosting operation. Therefore, if the temperature of the refrigerant flowing below the heat exchanger can be grasped, it is possible to appropriately grasp the timing for ending the defrosting operation.

[0005] In contrast, in the air conditioner described in Patent Document 1, the temperature of the mixture of the refrigerant that has flowed below the heat exchanger and the refrigerant that has flowed above the heat exchanger during defrosting operation is used to determine the timing to end the defrosting operation. This makes it difficult to appropriately determine the timing to end the defrosting operation.

[0006] For the above reasons, in a heat exchanger in which refrigerant that has flowed through a plurality of heat transfer tubes joins in a header, it is desirable to appropriately grasp the temperature of the refrigerant that has flowed below the heat exchanger. [Means for solving the problem]

[0007] A heat exchanger according to a first aspect includes a plurality of heat transfer tubes, a header, a refrigerant pipe, and a temperature sensor. The plurality of heat transfer tubes include a first heat transfer tube and a second heat transfer tube. The second heat transfer tube is disposed above the first heat transfer tube. The header is connected to the plurality of heat transfer tubes. The refrigerant pipes are connected to the header. The header has a junction flow path, a first refrigerant flow path, and a second refrigerant flow path. The junction flow path extends from a connection portion of the refrigerant pipes. The first refrigerant flow path connects the connection portion of the first heat transfer tube and the junction flow path. The second refrigerant flow path connects the connection portion of the second heat transfer tube and the junction flow path. The temperature sensor detects the temperature of the refrigerant flowing through the first refrigerant flow path.

[0008] When this heat exchanger is used in an air conditioner and frost forms, and the frost is removed, the temperature sensor can detect the temperature of the refrigerant flowing through the first refrigerant flow path from the first heat transfer tube located below the second heat transfer tube to the merging flow path in the header, making it possible to properly grasp the temperature of the refrigerant that has flowed below the heat exchanger.

[0009] A heat exchanger according to a second aspect is the heat exchanger of the first aspect, wherein the detection position of the temperature sensor is closer to the first refrigerant flow path than to the second refrigerant flow path and closer to the first refrigerant flow path than to the refrigerant piping.

[0010] With this heat exchanger, when detecting the temperature of the refrigerant that has passed below the heat exchanger, it is possible to minimize the influence of the temperature due to the refrigerant flowing through the second refrigerant flow path and the refrigerant flowing through the refrigerant piping.

[0011] A heat exchanger according to a third aspect is the heat exchanger according to the first or second aspect, wherein the first heat transfer tube includes a portion located lowest among the plurality of heat transfer tubes.

[0012] With this heat exchanger, it is easy to know when all the frost on the heat exchanger has melted.

[0013] A heat exchanger according to a fourth aspect is the heat exchanger according to any one of the first to third aspects, wherein the header has an outer wall portion. The outer wall portion is located on the opposite side of the header from the side where the heat transfer tube and the header are connected. The first refrigerant flow path has a first piping portion. The first piping portion is located on the opposite side of the outer wall portion from the side where the heat transfer tube and the header are connected.

[0014] In this heat exchanger, a location can be created where it is easy to grasp the temperature of the refrigerant flowing below the heat exchanger.

[0015] A heat exchanger according to a fifth aspect is the heat exchanger according to the fourth aspect, wherein the temperature sensor detects the temperature of the refrigerant flowing through the first piping section.

[0016] With this heat exchanger, it is possible to improve the accuracy of detecting the temperature of the refrigerant that has passed below the heat exchanger.

[0017] A heat exchanger according to a sixth aspect is the heat exchanger according to the fifth aspect, wherein the temperature sensor detects the temperature of the refrigerant flowing through a detection target portion of the first piping section. The detection target portion is a portion through which the refrigerant flows in the vertical direction.

[0018] In this heat exchanger, it is possible to reduce detection errors of the temperature sensor caused by the way the refrigerant flows.

[0019] A heat exchanger according to a seventh aspect is the heat exchanger according to any one of the fourth to sixth aspects, wherein the second refrigerant flow path has a second piping portion located on the opposite side of the outer wall portion to the side where the connection portion between the heat transfer tube and the header is located.

[0020] In this heat exchanger, it is easy to adjust the state of refrigerant division between the first refrigerant flow path and the second refrigerant flow path.

[0021] A heat exchanger according to an eighth aspect is the heat exchanger according to the seventh aspect, wherein the first piping section and the second piping section are equal in length.

[0022] In this heat exchanger, it is easier to adjust the state of refrigerant division between the first refrigerant flow path and the second refrigerant flow path.

[0023] A heat exchanger according to a ninth aspect is the heat exchanger according to the seventh or eighth aspect, wherein a lower end of the first piping section is positioned lower than a lower end of the second piping section.

[0024] In this heat exchanger, the first refrigerant flow path is connected to the first heat transfer tube, which is located lower than the second heat transfer tube, so that this structure can be easily obtained.

[0025] A heat exchanger according to a tenth aspect is the heat exchanger according to any one of the first to third aspects, wherein the header has an outer wall portion. The outer wall portion is located on the side of the header opposite to the side where the heat transfer tube and the header are connected. The outer wall portion includes a first protruding portion protruding toward the side opposite to the side where the heat transfer tube and the header are connected. The first refrigerant flow path includes a portion that flows the refrigerant along the first protruding portion on the side of the outer wall portion where the heat transfer tube and the header are connected.

[0026] In this heat exchanger, a location can be created where it is easy to grasp the temperature of the refrigerant flowing below the heat exchanger.

[0027] A heat exchanger according to an eleventh aspect is the heat exchanger according to the tenth aspect, wherein the temperature sensor detects the temperature of the refrigerant flowing along the first protruding portion.

[0028] With this heat exchanger, it is possible to improve the accuracy of detecting the temperature of the refrigerant that has passed below the heat exchanger.

[0029] A heat exchanger according to a twelfth aspect is the heat exchanger according to the eleventh aspect, in which the temperature sensor detects the temperature of the refrigerant flowing through a detection target portion of the first protruding portion. The detection target portion is a portion through which the refrigerant flows in the vertical direction.

[0030] In this heat exchanger, it is possible to reduce detection errors of the temperature sensor caused by the way the refrigerant flows.

[0031] A heat exchanger according to a thirteenth aspect is the heat exchanger according to any one of the tenth to twelfth aspects, wherein the outer wall portion includes a second protruding portion. The second protruding portion protrudes toward an opposite side to a side where a connection portion between the heat transfer tube and the header is located. The second refrigerant flow path includes a portion that causes the refrigerant to flow along the second protruding portion on the side of the outer wall portion where the connection portion between the heat transfer tube and the header is located.

[0032] In this heat exchanger, it is easy to adjust the state of refrigerant division between the first refrigerant flow path and the second refrigerant flow path.

[0033] A heat exchanger according to a fourteenth aspect is the heat exchanger of the thirteenth aspect, wherein a flow path length of the first protruding portion of the first refrigerant flow path is equal to a flow path length of the second protruding portion of the second refrigerant flow path.

[0034] In this heat exchanger, it is easier to adjust the state of refrigerant division between the first refrigerant flow path and the second refrigerant flow path.

[0035] A heat exchanger according to a fifteenth aspect is the heat exchanger according to any one of the thirteenth aspect to the fourteenth aspect, wherein a lower end of the first protruding portion is positioned lower than a lower end of the second protruding portion.

[0036] In this heat exchanger, the first refrigerant flow path is connected to the first heat transfer tube, which is located lower than the second heat transfer tube, so that this structure can be easily obtained.

[0037] A heat exchanger according to a sixteenth aspect is the heat exchanger according to any one of the first to fifteenth aspects, in which the header has a plate-shaped member. The plate-shaped member has an opening penetrating in a plate thickness direction. The opening constitutes a part of the merging flow path, a part of the first refrigerant flow path, and a part of the second refrigerant flow path.

[0038] In this heat exchanger, the opening formed in the plate-like member makes it possible to create a refrigerant flow path in which the first refrigerant flow path and the second refrigerant flow path join into a joining flow path.

[0039] An air conditioner according to a seventeenth aspect includes the heat exchanger according to any one of the first to sixteenth aspects, and a control unit. The control unit is capable of switching between an operation in which the heat exchanger functions as an evaporator of a refrigerant, and a defrosting operation in which the heat exchanger is defrosted. The control unit performs the defrosting operation based on a temperature detected by a temperature sensor.

[0040] In this air conditioner, when the frost adhering to the heat exchanger melts, it becomes possible to end the defrosting operation and start an operation in which the heat exchanger functions as an evaporator of the refrigerant.

[0041] An air conditioner according to an eighteenth aspect is the air conditioner of the seventeenth aspect, wherein the control unit ends the defrosting operation based on a temperature detected by the temperature sensor.

[0042] In this air conditioner, it is possible to end the defrosting operation early after the melting of the frost adhering to the heat exchanger is completed.

[0043] An air conditioner according to a nineteenth aspect is the air conditioner according to either the seventeenth or eighteenth aspect, further comprising an outdoor unit. The outdoor unit includes a heat exchanger.

[0044] In this air conditioner, it is possible to appropriately grasp the timing at which melting of frost is completed in the heat exchanger provided in the outdoor unit during defrosting operation. [Brief description of the drawings]

[0045] [Figure 1] FIG. 1 is a schematic diagram of an air conditioning device. [Diagram 2] FIG. 2 is a schematic perspective view of an outdoor heat exchanger. [Diagram 3] 3 is a partial enlarged view of a heat exchange portion of the outdoor heat exchanger. FIG. [Figure 4] 4 is a schematic diagram showing a state in which heat transfer fins are attached to flat tubes in a heat exchange section. FIG. [Diagram 5] FIG. 4 is a schematic explanatory diagram showing a state of a refrigerant flow in an outdoor heat exchanger functioning as an evaporator of the refrigerant. [Figure 6]FIG. 2 is an external perspective view of the entrance / exit header. [Figure 7] FIG. 2 is a schematic exploded perspective view of a gas header. [Figure 8] FIG. 2 is a schematic exploded perspective view of the liquid header. [Figure 9] FIG. 11 is a schematic exploded perspective view of a liquid header according to another embodiment A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] Hereinafter, embodiments of a heat exchanger according to the present disclosure and an air-conditioning apparatus in which the heat exchanger is used will be described.

[0047] (1) Air conditioning system configuration The air conditioner 1 will be described with reference to the drawings.

[0048] FIG. 1 is a schematic configuration diagram of an air conditioner 1 having a heat exchanger according to an embodiment of the present disclosure as an outdoor heat exchanger 11.

[0049] The air conditioner 1 is a device that performs cooling and heating of a space to be air-conditioned by performing a vapor compression refrigeration cycle. The space to be air-conditioned is, for example, a space inside a building such as an office building, a commercial facility, or a residence. Note that the air conditioner is merely one example of a refrigerant cycle device, and the heat exchanger of the present disclosure may be used in other refrigerant cycle devices, for example, a refrigerator, a freezer, a water heater, a floor heating device, etc.

[0050] 1, the air conditioner 1 mainly comprises an outdoor unit 2, an indoor unit 9, a liquid refrigerant connection pipe 4, a gas refrigerant connection pipe 5, and a control unit 3 that controls the equipment that makes up the outdoor unit 2 and the indoor unit 9. The liquid refrigerant connection pipe 4 and the gas refrigerant connection pipe 5 are refrigerant connection pipes that connect the outdoor unit 2 and the indoor unit 9. In the air conditioner 1, the outdoor unit 2 and the indoor unit 9 are connected via the liquid refrigerant connection pipe 4 and the gas refrigerant connection pipe 5 to form a refrigerant circuit 6.

[0051] 1, the air conditioner 1 has one indoor unit 9, but the air conditioner 1 may have a plurality of indoor units 9 connected in parallel to the outdoor unit 2 by a liquid refrigerant connection pipe 4 and a gas refrigerant connection pipe 5. The air conditioner 1 may also have a plurality of outdoor units 2. The air conditioner 1 may also be an integrated air conditioner in which the outdoor unit 2 and the indoor unit 9 are formed integrally.

[0052] (1-1) Outdoor unit The outdoor unit 2 is installed outside the space to be air-conditioned, for example, on the roof of a building or near a wall of a building.

[0053] The outdoor unit 2 mainly has an accumulator 7, a compressor 8, a four-way switching valve 10, an outdoor heat exchanger 11, an outdoor expansion valve 12, a liquid-side shut-off valve 13, a gas-side shut-off valve 14, and an outdoor fan 16.

[0054] The outdoor unit 2 mainly has a suction pipe 17, a discharge pipe 18, a first gas refrigerant pipe 19, a liquid refrigerant pipe 20, and a second gas refrigerant pipe 21 as refrigerant pipes that connect various devices that constitute the refrigerant circuit 6. The suction pipe 17 connects the four-way switching valve 10 and the suction side of the compressor 8. The accumulator 7 is provided in the suction pipe 17. The discharge pipe 18 connects the discharge side of the compressor 8 and the four-way switching valve 10. The first gas refrigerant pipe 19 connects the four-way switching valve 10 and the gas side of the outdoor heat exchanger 11. The liquid refrigerant pipe 20 connects the liquid side of the outdoor heat exchanger 11 and the liquid side stop valve 13. The liquid refrigerant pipe 20 is provided with an outdoor expansion valve 12. The second gas refrigerant pipe 21 connects the four-way switching valve 10 and the gas side stop valve 14.

[0055] The compressor 8 is a device that draws in low-pressure refrigerant in a refrigeration cycle from a suction pipe 17, compresses the refrigerant using a compression mechanism (not shown), and discharges the compressed refrigerant to a discharge pipe .

[0056] The four-way switching valve 10 is a mechanism that changes the state of the refrigerant circuit 6 between a cooling operation state and a heating operation state by switching the flow direction of the refrigerant. When the refrigerant circuit 6 is in a cooling operation state, the outdoor heat exchanger 11 functions as a radiator or condenser of the refrigerant, and the indoor heat exchanger 91 functions as an evaporator of the refrigerant. When the refrigerant circuit 6 is in a heating operation state, the outdoor heat exchanger 11 functions as an evaporator of the refrigerant, and the indoor heat exchanger 91 functions as a condenser of the refrigerant. When the four-way switching valve 10 sets the state of the refrigerant circuit 6 to a cooling operation state, the four-way switching valve 10 communicates the suction pipe 17 with the second gas refrigerant pipe 21 and communicates the discharge pipe 18 with the first gas refrigerant pipe 19 (see the solid lines in the four-way switching valve 10 in FIG. 1). When the four-way switching valve 10 sets the state of the refrigerant circuit 6 to a heating operation state, the four-way switching valve 10 connects the suction pipe 17 to the first gas refrigerant pipe 19 and connects the discharge pipe 18 to the second gas refrigerant pipe 21 (see the dashed lines within the four-way switching valve 10 in Figure 1).

[0057] The outdoor heat exchanger 11 is a device that exchanges heat between the refrigerant flowing inside and the air in the installation location of the outdoor unit 2. The outdoor heat exchanger 11 will be described in detail later.

[0058] The outdoor expansion valve 12 is disposed between the outdoor heat exchanger 11 and the indoor heat exchanger 91 in the refrigerant circuit 6. In this embodiment, the outdoor expansion valve 12 is disposed in a liquid refrigerant pipe 20 between the outdoor heat exchanger 11 and the liquid side stop valve 13. The outdoor expansion valve 12 has a mechanism for adjusting the pressure and flow rate of the refrigerant flowing through the liquid refrigerant pipe 20.

[0059] The accumulator 7 is a container having a gas-liquid separation function that separates the refrigerant that flows in into a gas refrigerant and a liquid refrigerant. The accumulator 7 is also a container having a storage function for excess refrigerant that occurs in response to fluctuations in the operating load, etc.

[0060] The liquid side shut-off valve 13 is a valve provided at the connection between the liquid refrigerant pipe 20 and the liquid refrigerant connection pipe 4. The gas side shut-off valve 14 is a valve provided at the connection between the second gas refrigerant pipe 21 and the gas refrigerant connection pipe 5. The liquid side shut-off valve 13 and the gas side shut-off valve 14 are open when the air conditioning apparatus 1 is operating.

[0061] The outdoor fan 16 is a fan that draws external heat source air into a casing of the outdoor unit 2 (not shown), supplies it to the outdoor heat exchanger 11, and exhausts the air that has exchanged heat with the refrigerant in the outdoor heat exchanger 11 to the outside of the casing of the outdoor unit 2. The outdoor fan 16 is, for example, a propeller fan.

[0062] (1-2) Indoor unit The indoor unit 9 is a unit installed in the space to be air-conditioned. The indoor unit 9 is, for example, a ceiling-embedded unit, but may also be a ceiling-suspended, wall-mounted, or floor-standing unit. The indoor unit 9 may also be installed outside the space to be air-conditioned. For example, the indoor unit 9 may be installed in an attic, a machine room, a garage, or the like. In this case, an air passage is installed to supply the air that has exchanged heat with the refrigerant in the indoor heat exchanger 91 from the indoor unit 9 to the space to be air-conditioned. The air passage is, for example, a duct.

[0063] The indoor unit 9 mainly includes an indoor heat exchanger 91, an indoor expansion valve 93, and an indoor fan 92.

[0064] In the indoor heat exchanger 91, heat exchange takes place between the refrigerant flowing through the indoor heat exchanger 91 and the air in the space to be air-conditioned. The indoor heat exchanger 91 is, for example, a fin-and-tube type heat exchanger having a plurality of heat transfer tubes and fins (not shown). One end of the indoor heat exchanger 91 is connected to the indoor expansion valve 93 via a refrigerant piping. The other end of the indoor heat exchanger 91 is connected to the gas refrigerant communication pipe 5 via a refrigerant piping.

[0065] The indoor expansion valve 93 is disposed in the refrigerant circuit 6 between the indoor heat exchanger 91 and the liquid refrigerant communication pipe 4. The indoor expansion valve 93 has a mechanism for adjusting the pressure and flow rate of the refrigerant passing through the indoor expansion valve 93.

[0066] The indoor fan 92 is a mechanism that draws air in the space to be air-conditioned into a casing (not shown) of the indoor unit 9, supplies it to the indoor heat exchanger 91, and blows out the air that has exchanged heat with the refrigerant in the indoor heat exchanger 91 into the space to be air-conditioned. The indoor fan 92 is, for example, a turbo fan.

[0067] (1-3) Control section The control unit 3 is a functional unit that controls the operations of the various devices that make up the air conditioner 1.

[0068] The control unit 3 is configured, for example, by connecting an outdoor control unit (not shown) of the outdoor unit 2 and an indoor control unit (not shown) of the indoor unit 9 so that they can communicate with each other via a transmission line (not shown). The outdoor control unit and the indoor control unit are units having, for example, a microcomputer including a processor such as a CPU (Central Processing Unit) and memories such as ROM and RAM in which various programs for controlling the air conditioner 1 that can be executed by the processor are stored. Note that, for the sake of convenience, in FIG. 1, the control unit 3 is drawn at a position separate from the outdoor unit 2 and the indoor unit 9.

[0069] The control unit 3 is electrically connected to various devices of the outdoor unit 2 and the indoor unit 9, including the compressor 8, the four-way switching valve 10, the outdoor expansion valve 12, the outdoor fan 16, the indoor fan 92, and the indoor expansion valve 93. The control unit 3 is also electrically connected to various sensors (not shown) provided in the outdoor unit 2 and the indoor unit 9. The control unit 3 is also configured to be able to communicate with a remote control (not shown) operated by a user of the air conditioning apparatus 1.

[0070] The control unit 3 controls the operation and shutdown of the air conditioner 1 and the operation of various devices that make up the air conditioner 1, based on measurement signals from various sensors and commands received from a remote control (not shown).

[0071] (2) Configuration of outdoor heat exchanger The configuration of the outdoor heat exchanger 11 will be described with reference to the drawings.

[0072] Fig. 2 is a schematic perspective view of the outdoor heat exchanger 11. Fig. 3 is a partial enlarged view of a heat exchange section 27, described later, of the outdoor heat exchanger 11. Fig. 4 is a schematic view showing a mounting state of fins 29, described later, to flat tubes 28 in the heat exchange section 27. Fig. 5 is a schematic configuration diagram of the outdoor heat exchanger 11. Arrows in the heat exchange section 27 shown in Fig. 5 indicate the flow of refrigerant during heating operation (when the outdoor heat exchanger 11 functions as an evaporator). Fig. 6 shows an external perspective view of the inlet / outlet header 40.

[0073] In the following description, expressions such as "upper," "lower," "left," "right," "front (front side)," and "rear (back side)" may be used to describe directions and positions. Unless otherwise specified, these expressions follow the directions of the arrows drawn in FIG. 2. Note that these expressions indicating directions and positions are used for the convenience of description, and do not specify the directions and positions of the outdoor heat exchanger 11 as a whole or each component of the outdoor heat exchanger 11 to the directions and positions of the expressions described, unless otherwise specified.

[0074] The outdoor heat exchanger 11 is a device that performs heat exchange between the refrigerant flowing inside and the air.

[0075] The outdoor heat exchanger 11 mainly has a plurality of flat tubes 28, a plurality of fins 29, a turn-back header 30, and an inlet / outlet header 40. In this embodiment, the flat tubes 28, the fins 29, the turn-back header 30, and the inlet / outlet header 40 are all made of aluminum or an aluminum alloy.

[0076] The flat tubes 28 and the fins 29 fixed to the flat tubes 28 form a heat exchange section 27. In the outdoor heat exchanger 11, air flows through an air passage formed by the flat tubes 28 and the fins 29 of the heat exchange section 27, whereby heat is exchanged between the refrigerant flowing through the flat tubes 28 and the air flowing through the air passage.

[0077] (2-1) Flat tube The flat tube 28 is a flat heat transfer tube having flat surfaces 28a on the top and bottom, which serve as heat transfer surfaces, as shown in Fig. 3. The flat tube 28 has a plurality of refrigerant passages 28b through which the refrigerant flows, as shown in Fig. 3. For example, the flat tube 28 is a flat multi-hole tube in which a large number of refrigerant passages 28b, each having a small cross-sectional area through which the refrigerant flows, are formed. In this embodiment, the plurality of refrigerant passages 28b are arranged side by side in the air flow direction.

[0078] In the outdoor heat exchanger 11, as shown in FIG. 5, flat tubes 28 extending horizontally between the return header 30 side and the entrance / exit header 40 side are arranged vertically in a plurality of stages.

[0079] In this embodiment, the flat tubes 28 extending between the turn-back header 30 side and the inlet / outlet header 40 side are bent at one location, and the heat exchange section 27 formed by the flat tubes 28 is formed into a substantially L-shape in a plan view. In this embodiment, the flat tubes 28 are arranged vertically at regular intervals.

[0080] When the outdoor fan 16 is driven, an air flow passes over the main surface of the outdoor heat exchanger 11 from the rear to the front, and an air flow passes over the left side portion of the outdoor heat exchanger 11 from the left to the right.

[0081] (2-2) Fin The multiple fins 29 are members for increasing the heat transfer area of ​​the outdoor heat exchanger 11. Each fin 29 is a plate-shaped member extending in the row direction in which the flat tubes 28 are arranged. The outdoor heat exchanger 11 is used in a mode in which the multiple flat tubes 28 extending in the horizontal direction are arranged in a vertical direction. Therefore, when the outdoor heat exchanger 11 is installed in the outdoor unit 2, each fin 29 extends in the vertical direction.

[0082] As shown in FIG. 4, each fin 29 is formed with a plurality of notches 29a extending along the insertion direction of the flat tubes 28 so that the flat tubes 28 can be inserted. The notches 29a extend in the direction in which the fins 29 extend and in a direction perpendicular to the thickness direction of the fins 29. When the outdoor heat exchanger 11 is installed in the outdoor unit 2, the notches 29a formed in each fin 29 extend horizontally. The notches 29a are formed in the fins 29 at intervals corresponding to the arrangement intervals of the flat tubes 28. In the outdoor heat exchanger 11, the multiple fins 29 are arranged side by side along the extension direction of the flat tubes 28. The flat tubes 28 are inserted into the multiple notches 29a of the multiple fins 29, and the spaces between the adjacent flat tubes 28 are divided into a plurality of ventilation passages through which air flows.

[0083] Each fin 29 has a communication portion 29b that communicates in the vertical direction on the upstream side or downstream side in the air flow direction with respect to the flat tubes 28. In this embodiment, the communication portion 29b of the fin 29 is located on the upwind side with respect to the flat tubes 28.

[0084] (2-3) Entrance / Exit Header As shown in Figures 5 and 6, the inlet / outlet header 40 has a gas header 50 located at the top and a liquid header 60 located at the bottom. The gas header 50 and the liquid header 60 are partitioned vertically by a partition plate 41. The gas header 50 has an internal space, and the liquid header 60 has a space isolated from the internal space of the gas header 50 by the partition plate 41. The upper end of the gas header 50 is closed by an upper lid 42. The partition plate 41 also functions as a bottom plate for the gas header 50.

[0085] To the liquid header 60, a gas refrigerant connection pipe 19a that constitutes one end of the first gas refrigerant pipe 19 is connected.

[0086] To the gas header 50, a liquid refrigerant connection pipe 20a which constitutes one end of the liquid refrigerant pipe 20 is connected.

[0087] 5, one end of each of the flat tubes 28 is connected to the turn-back header 30, and the other end of each of the flat tubes 28 is connected to the gas header 50 and the liquid header 60 of the inlet / outlet header 40. The outdoor heat exchanger 11 is disposed in a casing (not shown) of the outdoor unit 2 so that the longitudinal directions of the turn-back header 30 and the inlet / outlet headers 40 roughly coincide with the vertical direction.

[0088] (2-4) Folded header To the turn-back header 30, ends of the flat tubes 28 different from the ends of the flat tubes 28 connected to the gas header 50 and liquid header 60 of the inlet / outlet header 40 are connected.

[0089] The outdoor heat exchanger 11 has a first flow passage group X, a second flow passage group Y, and a third flow passage group Z arranged in the vertical direction. In the outdoor heat exchanger 11, each flat tube 28 arranged in the vertical direction belongs to one of the multiple flow passage groups X, Y, and Z. The first flow passage group X is the flow passage group located at the lowest position, and includes the multiple first flat tubes 28x. The second flow passage group Y is the flow passage group located above the first flow passage group X and below the third flow passage group Z, and includes the multiple second flat tubes 28y. The third flow passage group Z is the flow passage group located at the highest position, and includes the multiple third flat tubes 28z.

[0090] (3) Refrigerant flow during each operation and in the outdoor heat exchanger The control unit 3 receives detection information from various sensors or commands from a remote control or the like, and switches between and executes a cooling operation, a heating operation, a defrosting operation, or the like.

[0091] When the air conditioner 1 performs heating operation, the control unit 3 switches the connection state of the four-way switching valve 10 to the state shown by the dashed line in Fig. 1 to operate the compressor 8. The refrigerant discharged from the compressor 8 condenses by exchanging heat with indoor air in the indoor heat exchanger 91, is depressurized in the indoor expansion valve 93 or the outdoor expansion valve 12, and is then sent to the outdoor heat exchanger 11. The refrigerant sent to the outdoor heat exchanger 11 evaporates by exchanging heat with the outdoor air, and is sucked back into the compressor 8.

[0092] In this way, when the outdoor heat exchanger 11 functions as a refrigerant evaporator during heating operation, the refrigerant in a liquid state or a gas-liquid two-phase state that reaches the liquid header 60 from the liquid refrigerant tube 20 is divided into a refrigerant flowing through the first flow passage group X and a refrigerant flowing through the second flow passage group Y in the internal space of the liquid header 60. The divided refrigerant then flows through the first flat tubes 28x belonging to the first flow passage group X and the second flat tubes 28y belonging to the second flow passage group Y, respectively. The refrigerant flowing through the first flat tubes 28x and the second flat tubes 28y is partially evaporated by heat exchange with the air and reaches a lower region of the internal space of the turn-back header 30. The refrigerant sent to the lower region of the internal space of the turn-back header 30 is sent to the upper region of the internal space of the turn-back header 30. The refrigerant that reaches the upper region of the turn-back header 30 flows through the third flat tubes 28z belonging to the third flow passage group Z connected to the upper region of the turn-back header 30. The refrigerant flowing through the multiple third flat tubes 28z again exchanges heat with the air and further evaporates, and reaches the gas header 50. The refrigerant that reaches the gas header 50 merges and then flows through the first gas refrigerant pipe 19.

[0093] When the air conditioner 1 performs cooling operation, the control unit 3 switches the connection state of the four-way switching valve 10 to the state shown by the solid line in Fig. 1 to operate the compressor 8. The refrigerant discharged from the compressor 8 is condensed by exchanging heat with outdoor air in the outdoor heat exchanger 11, is depressurized in the outdoor expansion valve 12 or the indoor expansion valve 93, and is then sent to the indoor heat exchanger 91. The refrigerant sent to the indoor heat exchanger 91 evaporates by exchanging heat with the indoor air, and is sucked back into the compressor 8.

[0094] In addition, when the air conditioner 1 is performing a heating operation, if a predetermined defrosting start condition is satisfied, the control unit 3 switches the connection state of the four-way switching valve 10 to the state shown by the solid line in FIG. 1 to operate the compressor 8, and performs a defrosting operation in which a high-temperature, high-pressure discharged refrigerant is supplied to the outdoor heat exchanger 11. This defrosting operation melts the frost adhering to the outdoor heat exchanger 11. The predetermined defrosting start condition is not particularly limited, and may be, for example, a case in which the outdoor air temperature is below a predetermined temperature for a predetermined period of time or more. In addition, the defrosting operation is terminated when a predetermined defrosting end condition is satisfied, and the connection state of the four-way switching valve 10 is switched to the state shown by the broken line in FIG. 1 to operate the compressor 8, thereby restarting the heating operation. The predetermined defrosting end condition is a condition determined based on a detection value of a temperature sensor 80 described later, and may be, for example, a condition that is satisfied when a state in which the detection value of the temperature sensor 80 is above a predetermined temperature continues for a predetermined period of time or more. The control unit 3 determines the defrost start condition and the defrost end condition.

[0095] In this way, when the outdoor heat exchanger 11 functions as a refrigerant condenser during cooling operation or defrosting operation, the refrigerant discharged from the compressor 8 flows through the first gas refrigerant pipe 19 and then flows into the gas header 50. The gaseous refrigerant that reaches the gas header 50 is divided in the internal space of the gas header 50 and then flows through the third flat tubes 28z belonging to the third flow path group Z connected to the gas header 50. The refrigerant that flows through the third flat tubes 28z exchanges heat with the air, and a part of the refrigerant dissipates heat or condenses, and reaches an upper region of the internal space of the turn-back header 30. The refrigerant sent to the upper region of the internal space of the turn-back header 30 is sent to the lower region of the turn-back header 30. The refrigerant that reaches the lower region of the turn-back header 30 is divided and flows through the first flat tubes 28x belonging to the first flow path group X and the second flat tubes 28y belonging to the second flow path group Y, which are connected to the lower region of the turn-back header 30. The refrigerant flowing through the multiple first flat tubes 28x and the second flat tubes 28y again exchanges heat with the air, thereby further releasing heat or condensing, and reaches the liquid header 60. The refrigerant that has flowed through the multiple first flat tubes 28x belonging to the first flow passage group X and the refrigerant that has flowed through the multiple second flat tubes 28y belonging to the second flow passage group Y join together in the liquid header 60 and then flow through the liquid refrigerant pipe 20.

[0096] (4) Gas header details FIG. 7 shows a schematic exploded perspective view of the gas header 50. As shown in FIG.

[0097] The gas header 50 has a gas header member 51, an upper portion of a first common member 52, an upper portion of a second common member 53, and an upper portion of a third common member 54. The gas header 50 is configured by joining the gas header member 51, the upper portion of the first common member 52, the upper portion of the second common member 53, and the upper portion of the third common member 54 to one another by brazing.

[0098] Furthermore, the first common member 52, the second common member 53 and the third common member 54 are all members shared in the liquid header 60 described below, and are plate-like members extending from the upper end to the lower end of the inlet / outlet header 40.

[0099] (4-1) Gas header parts The gas header member 51 is a member stacked so as to be joined to the right surface of the first common member 52. The front-to-rear length of this gas header member 51 is the same as the front-to-rear lengths of the first common member 52 and the second common member 53, and is also the same as the front-to-rear length of the flat tube connecting plate 54a of the third common member 54 excluding both side surface portions 54b.

[0100] The gas header member 51 is a member made of a metal such as an aluminum alloy.

[0101] The gas header member 51 has a gas header plate-shaped portion 51a and a semicircular portion 51b.

[0102] The gas header plate-shaped portions 51a are plate-shaped portions extending in the up-down direction and in the front-rear direction on both the front and rear sides of the semicircular portion 51b.

[0103] The semicircular portion 51b is provided to connect between the front portion of the gas header plate portion 51a and the rear portion of the gas header plate portion 51a, and is a semicircular arc portion formed by half of an arc whose axial direction is the longitudinal direction of the gas header 50. The semicircular portion 51b bulges outward from the gas header plate portion 51a toward the side opposite to the first common member 52. The semicircular portion 51b is provided with a connection opening 51x that is connected to the gas refrigerant connection piping 19a of the first gas refrigerant pipe 19.

[0104] In addition, the front and rear portions of the gas header plate portion 51a of the gas header member 51 contact the claw portions 54c of the third common member 54 described below, and are crimped from the right side by the claw portions 54c of the third common member 54.

[0105] The partition plate 41 and the upper lid 42 are provided between the gas header member 51 and the first common member 52, and function as a lower lid and an upper lid for forming the internal space of the gas header 50.

[0106] (4-2) First common part The first common member 52 is a laminated member so as to face and contact the right side surface of the second common member 53 and to face and contact the left side surface of the gas header plate portion 51a of the gas header member 51. The front-to-rear length of this first common member 52 is the same as the front-to-rear length of the second common member 53.

[0107] The first common member 52 has a first common plate-shaped portion 52a and a plurality of openings 52x.

[0108] The first common plate-shaped portion 52a has a flat plate shape that is wide in the up-down direction and in the front-rear direction.

[0109] The multiple openings 52x are arranged side by side in the vertical direction and are openings that penetrate the first common plate-shaped portion 52a in the plate thickness direction.

[0110] The front and rear edges of each opening 52x are located more inward than the openings 53x of the second common member 53 when viewed in the plate thickness direction of the first common member 52, and more inward than the flat tube connection openings 54x formed in the flat tube connection plate 54a of the third common member 54. The front-rear width of the multiple openings 52x of the first common member 52 is narrower than the front-rear width of the flat tubes 28. Note that the upper and lower edges of the multiple openings 52x of the first common member 52 are openings located more outward than the flat tube connection openings 54x formed in the flat tube connection plate 54a of the third common member 54 when viewed in the plate thickness direction of the first common member 52.

[0111] This allows the front and rear ends of the tip of each flat tube 28 inserted into the gas header 50 to abut against the edges of each opening 52x of the first common member 52, thereby determining the degree to which the flat tubes 28 are inserted into the gas header 50.

[0112] (4-3) Second common member The second common member 53 is a laminated member that faces and contacts the right side surface of the flat tube connecting plate 54a of the third common member 54 and faces and contacts the left side surface of the first common member 52. The length in the front-to-rear direction of this second common member 53 is the same as the length in the front-to-rear direction of the flat tube connecting plate 54a of the third common member 54 excluding both side surface portions 54b.

[0113] The second common member 53 has a second common plate-shaped portion 53a and a plurality of openings 53x.

[0114] The second common plate-shaped portion 53a has a flat plate shape that is wide in the up-down direction and in the front-rear direction.

[0115] The multiple openings 53x are arranged side by side in the vertical direction and are openings that penetrate the second common plate-shaped portion 53a in the plate thickness direction.

[0116] Each opening 53x of the second common member 53 is larger than each flat tube connection opening 54x formed in the flat tube connection plate 54a of the third common member 54. When the second common member 53 is stacked on the flat tube connection plate 54a of the third common member 54, the outer edge of each opening 53x of the second common member 53 is configured to be located outside the outer edge of each flat tube connection opening 54x formed in the flat tube connection plate 54a of the third common member 54 when viewed in the plate thickness direction of the second common member 53.

[0117] (4-4) Third common part The third common member 54 is a member that mainly constitutes the periphery of the outer shape of the gas header 50 together with the gas header member 51.

[0118] The third common member 54 has a flat tube connecting plate 54a, a side surface portion 54b, and a claw portion 54c.

[0119] The flat tube connection plate 54a is a flat plate-shaped portion that spreads in the vertical direction and the front-rear direction. The flat tube connection plate 54a has a plurality of flat tube connection openings 54x arranged side by side in the vertical direction. Each flat tube connection opening 54x is an opening that penetrates the flat tube connection plate 54a in the thickness direction. The flat tube 28 is inserted into the flat tube connection opening 54x so that one end of the flat tube 28 passes completely through the flat tube connection opening 54x, and the flat tube 28 is joined by brazing. Note that each opening 53x of the second common member 53 is larger than the flat tube 28, and when the flat tube 28 is inserted into the flat tube connection opening 54x, no friction occurs between the flat tube 28 and each opening 53x of the second common member 53, making the insertion operation easy.

[0120] The side portion 54b has a surface that extends toward the right side in front of the flat tube connecting plate 54a and widens vertically, and a surface that extends toward the right side in the rear of the flat tube connecting plate 54a and widens vertically.

[0121] The claw portion 54c has a portion that extends rearward from the right end portion of the front side surface portion 54b, and a portion that extends frontward from the right end portion of the rear side surface portion 54b.

[0122] The claws 54c extend along the extensions of the side surfaces 54b before the second common member 53, the first common member 52, and the gas header plate portion 51a of the gas header member 51 are disposed inside the third common member 54 in plan view. The claws 54c are bent so as to approach each other in a state in which the second common member 53, the first common member 52, and the gas header plate portion 51a of the gas header member 51 are disposed inside the third common member 54. As a result, the second common member 53, the first common member 52, and the gas header member 51 are crimped by the third common member 54. Then, in this state, brazing is performed in a furnace, and the members are joined by brazing and completely fixed to each other.

[0123] (5) Liquid header details FIG. 8 shows a schematic exploded perspective view of the liquid header 60.

[0124] The liquid header 60 has a first plate-shaped member 61, a second plate-shaped member 62, a third plate-shaped member 63, a fourth plate-shaped member 64, a fifth plate-shaped member 65, a lower portion of the first common member 52, a lower portion of the second common member 53, and a lower portion of the third common member 54. The liquid header 60 is configured by joining the first plate-shaped member 61, the second plate-shaped member 62, the third plate-shaped member 63, the fourth plate-shaped member 64, the fifth plate-shaped member 65, the lower portion of the first common member 52, the lower portion of the second common member 53, and the lower portion of the third common member 54 to each other by brazing.

[0125] The liquid header 60 is made of a metal such as an aluminum alloy.

[0126] Furthermore, connected to the liquid header 60 are a first connection pipe 71 (an example of a "first piping section"), a second connection pipe 72 (an example of a "second piping section"), and a liquid refrigerant connection pipe 20a.

[0127] In the liquid header 60, the refrigerant flowing in through the liquid refrigerant connection pipe 20a passes through the merging flow path C, and is then divided into the first refrigerant flow path A and the second refrigerant flow path B. The first refrigerant flow path A is a flow path from the connecting portion with the merging flow path C to the first flat tube 28x included in the first flow path group X, and has first flow path portions A1, A2, A3, A4, A5, and A6. The second refrigerant flow path B is a flow path from the connecting portion with the merging flow path C to the second flat tube 28y included in the second flow path group Y, and has second flow path portions B1, B2, B3, B4, B5, and B6. In the first refrigerant flow path A, the refrigerant flows in the order of the first flow path portions A1, A2, A3, A4, A5, and A6. In the second refrigerant flow path B, the refrigerant flows in the order of the second flow path portions B1, B2, B3, B4, B5, and B6. The refrigerant that flows through the first refrigerant flow path A in the liquid header 60 flows into the first flat tubes 28x that are included in the first flow path group X among the multiple flat tubes 28. The refrigerant that flows through the second refrigerant flow path B in the liquid header 60 flows into the second flat tubes 28y that are included in the second flow path group Y among the multiple flat tubes 28.

[0128] (5-1) First plate-shaped member The first plate-shaped member 61 is a plate-shaped member that constitutes the outer wall portion on the right side of the liquid header 60, and is connected to the liquid refrigerant connection pipe 20a.

[0129] The first plate-shaped member 61 has a first plate-shaped portion 61a, a pipe connection opening 61x, a first outer wall opening 61b, a second outer wall opening 61c, a third outer wall opening 61d, and a fourth outer wall opening 61e. The first plate-shaped portion 61a is a plate-shaped member that has a plate thickness direction in the left-right direction and is extended in the up-down and front-rear directions. The pipe connection opening 61x is an opening that penetrates the first plate-shaped member 61 in the plate thickness direction near the lower end thereof, and is connected to the liquid refrigerant connection pipe 20a. The first outer wall opening 61b, the second outer wall opening 61c, the third outer wall opening 61d, and the fourth outer wall opening 61e are openings that are provided to penetrate the first plate-shaped member 61 in the plate thickness direction.

[0130] The first outer wall opening 61b and the second outer wall opening 61c are connected via a first connection pipe 71. The first connection pipe 71 has a first lower pipe portion 71a, a first intermediate pipe portion 71b, and a first upper pipe portion 71c. The first lower pipe portion 71a extends from the first outer wall opening 61b toward the right side, which is a direction away from the first plate-shaped member 61 in the plate thickness direction of the first plate-shaped member 61. The first intermediate pipe portion 71b extends vertically upward from the right end portion of the first lower pipe portion 71a. The first upper pipe portion 71c extends from the upper end portion of the first intermediate pipe portion 71b toward the left side, which is a direction approaching the first plate-shaped member 61 in the plate thickness direction of the first plate-shaped member 61, to the second outer wall opening 61c.

[0131] The first intermediate pipe portion 71b is provided with a temperature sensor 80 that detects the temperature of the refrigerant flowing in the vertical direction through the first intermediate pipe portion 71b. In this embodiment, the temperature sensor 80 detects the temperature of the first intermediate pipe portion 71b in order to detect the temperature of the refrigerant flowing through the first intermediate pipe portion 71b. In this embodiment, the temperature sensor 80 detects the temperature of the first intermediate pipe portion 71b of the first connection pipe 71 at a position away from the liquid refrigerant connection pipe 20a and the second connection pipe 72. In this embodiment, the temperature sensor 80 is provided at a position away from the first plate-shaped member 61 and the liquid header 60. As a result, when the temperature sensor 80 detects the temperature of the first intermediate pipe portion 71b of the first connection pipe 71, the influence of the temperature of the refrigerant flowing through the liquid refrigerant connection pipe 20a, the temperature of the refrigerant flowing through the second connection pipe 72, and the temperature of the first plate-shaped member 61 is reduced, thereby improving the detection accuracy. In addition, in the first intermediate piping portion 71b, which is a portion extending in the vertical direction, the difference in the distribution state of the refrigerant flowing up and down inside is suppressed. This allows the temperature sensor 80 to improve the detection accuracy. In addition, since the temperature sensor 80 is attached to a position in the first connection piping 71 away from the liquid header 60, the installation work can be facilitated.

[0132] The third outer wall opening 61d and the fourth outer wall opening 61e are connected via a second connection pipe 72. The second connection pipe 72 has a second lower pipe portion 72a, a second intermediate pipe portion 72b, and a second upper pipe portion 72c. The second lower pipe portion 72a extends from the third outer wall opening 61d toward the right side, which is a direction away from the first plate-like member 61 in the plate thickness direction of the first plate-like member 61. The second intermediate pipe portion 73b extends vertically upward from the right end portion of the second lower pipe portion 72a. The second upper pipe portion 72c extends from the upper end portion of the second intermediate pipe portion 72b toward the left side, which is a direction approaching the first plate-like member 61 in the plate thickness direction of the first plate-like member 61, to the fourth outer wall opening 61e.

[0133] The first connecting pipe 71 and the second connecting pipe 72 have the same flow path length. In addition, the flow path length of the first intermediate pipe portion 71b of the first connecting pipe 71 and the flow path length of the second intermediate pipe portion 72b of the second connecting pipe 72 are the same. As a result, the pressure loss of the refrigerant passing through the first connecting pipe 71 and the pressure loss of the refrigerant passing through the second connecting pipe 72 are configured to be approximately equal. As a result, it is easy to adjust the divided state of the refrigerant flowing through the first connecting pipe 71 and the second connecting pipe 72, for example, by adjusting the flow rate of the refrigerant to be approximately the same. Furthermore, in this embodiment, the flow path length of the portion of the first refrigerant flow path A excluding the first connecting pipe 71 and the flow path length of the portion of the second refrigerant flow path B excluding the second connecting pipe 72 are configured to be equal. As a result, in the liquid header 60 of this embodiment, the pressure loss suffered by the refrigerant flowing through the first refrigerant flow path A and the pressure loss suffered by the refrigerant flowing through the second refrigerant flow path B can be made equal. This makes it possible to distribute the refrigerant evenly to the first flat tubes 28x included in the first flow passage group X and the second flat tubes 28y included in the second flow passage group Y.

[0134] Furthermore, the lower end of the first interconnection pipe 71 is located lower than the lower end of the second interconnection pipe 72. Since the first interconnection pipe 71 belongs to the first refrigerant flow path A which is located lower than the second refrigerant flow path B to which the second interconnection pipe 72 belongs, the flow path configuration in the liquid header 60 can be simplified.

[0135] The first communication pipe 71, the first outer wall opening 61b, and the second outer wall opening 61c constitute a first flow path portion A2 included in the first refrigerant flow path A. The second communication pipe 72, the third outer wall opening 61d, and the fourth outer wall opening 61e constitute a second flow path portion B2 included in the second refrigerant flow path B.

[0136] (5-2) Second plate-shaped member The second plate-like member 62 is located between the first plate-like member 61 and the third plate-like member 63 in the plate thickness direction, and has a second plate-like portion 62a, a branch opening 62b, a first communication opening 62c, and a second communication opening 62d. The second plate-like portion 62a is a plate-like member whose plate thickness direction is the left-right direction and which spreads in the up-down and front-rear directions. The branch opening 62b, the first communication opening 62c, and the second communication opening 62d are all openings that penetrate the second plate-like member 62 in the plate thickness direction.

[0137] When viewed from the stacking direction of the first plate-shaped member 61 and the second plate-shaped member 62, which is the plate thickness direction of the second plate-shaped member 62, the branch opening 62b is a single opening connecting a portion overlapping with the pipe connection opening 61x of the first plate-shaped member 61, a portion overlapping with the second outer wall opening 61c of the first plate-shaped member 61, and a portion overlapping with the third outer wall opening 61d of the first plate-shaped member 61. The branch opening 62b extends upward from the portion overlapping with the pipe connection opening 61x of the first plate-shaped member 61, and then branches into a flow path extending toward the portion overlapping with the second outer wall opening 61c of the first plate-shaped member 61 and a flow path extending toward the portion overlapping with the third outer wall opening 61d of the first plate-shaped member 61 in a narrow portion functioning as a nozzle. Here, the portion of the branch opening 62b from the portion overlapping with the pipe connection opening 61x of the first plate-like member 61 to the portion functioning as a nozzle constitutes the merging flow path C. Also, the portion of the branch opening 62b extending from the portion functioning as a nozzle toward the portion overlapping with the second outer wall opening 61c of the first plate-like member 61 constitutes a first flow path portion A1 included in the first refrigerant flow path A. Furthermore, the portion of the branch opening 62b extending from the portion functioning as a nozzle toward the portion overlapping with the third outer wall opening 61d of the second plate-like member 62 constitutes a second flow path portion B1 included in the second refrigerant flow path B.

[0138] The first communication opening 62c is an opening that extends from a portion overlapping with the first outer wall opening 61b of the first plate-shaped member 61 toward a portion overlapping with the third lower opening 63l of the third plate-shaped member 63. The first communication opening 62c constitutes a first flow path portion A3 included in the first refrigerant flow path A.

[0139] The second communication opening 62d is an opening that extends from a portion overlapping with the fourth outer wall opening 61e of the first plate-shaped member 61 toward a portion overlapping with the third upper opening 63h of the third plate-shaped member 63. The second communication opening 62d constitutes a second flow path portion B3 included in the second refrigerant flow path B.

[0140] (5-3) Third plate-shaped member The third plate-shaped member 63 is located between the second plate-shaped member 62 and the fourth plate-shaped member 64 in the plate thickness direction, and has a third plate-shaped portion 63a, a third lower opening 63l, and a third upper opening 63h. The third plate-shaped portion 63a is a plate-shaped member whose plate thickness direction is the left-right direction and which extends in the up-down and front-rear directions. The third lower opening 63l and the third upper opening 63h are both openings that penetrate the third plate-shaped member 63 in the plate thickness direction.

[0141] The third lower opening 63l is an opening that overlaps with the introduction area of ​​the lower circulation opening 64l of the fourth plate-shaped member 64 when viewed from the stacking direction of the third plate-shaped member 63 and the fourth plate-shaped member 64, which is the thickness direction of the third plate-shaped member 63.

[0142] The third upper opening 63h is an opening that overlaps with the introduction area of ​​the upper circulation opening 64h of the fourth plate-shaped member 64 when viewed from the stacking direction of the third plate-shaped member 63 and the fourth plate-shaped member 64, which is the thickness direction of the third plate-shaped member 63.

[0143] (5-4) Fourth plate-shaped member The fourth plate-shaped member 64 is located between the third plate-shaped member 63 and the fifth plate-shaped member 65 in the plate thickness direction, and has a fourth plate-shaped portion 64a, a lower circulation opening 64l, and an upper circulation opening 64h. The fourth plate-shaped portion 64a is a plate-shaped member whose plate thickness direction is the left-right direction and which extends in the up-down and front-rear directions. The lower circulation opening 64l and the upper circulation opening 64h are both openings that penetrate the fourth plate-shaped member 64 in the plate thickness direction.

[0144] The lower circulation opening 64l is an opening configured so that the refrigerant flowing from the third lower opening 63l of the third plate-shaped member 63 toward the introduction area at the rear lower side is sent to the rising area through a nozzle. In this lower circulation opening 64l, the refrigerant that reaches the upper part of the rising area moves to the front side and then descends in the descending area. In addition, the refrigerant that descends in the descending area is guided to the rear side and returned to the lower part of the rising area again. In this way, the refrigerant flows in a circulating manner in the lower circulation opening 64l. Here, in the rising area, the refrigerant flows in an upward manner and is diverted to the diverting opening 65x corresponding to the first flow path portion A5 among the diverting openings 65x formed in the fifth plate-shaped member 65.

[0145] The upper circulation opening 64h has a shape similar to that of the lower circulation opening 64l, and is configured so that the refrigerant that has flowed into the introduction area at the rear lower side from the third upper opening 63h of the third plate-shaped member 63 circulates in the upper circulation opening 64h. Here, the refrigerant also flows upward in the ascending area of ​​the upper circulation opening 64h, and is diverted to the diversion opening 65x formed in the fifth plate-shaped member 65 that corresponds to the second flow path portion B5.

[0146] (5-5) Fifth plate-shaped member The fifth plate-shaped member 65 is located between the fourth plate-shaped member 64 and the first common member 52 in the plate thickness direction, and has a fifth plate-shaped portion 65a and a plurality of flow-diversion openings 65x. The fifth plate-shaped portion 65a is a plate-shaped member whose plate thickness direction is the left-right direction and which extends in the up-down and front-rear directions. All of the plurality of flow-diversion openings 65x are openings that penetrate the fifth plate-shaped member 65 in the plate thickness direction.

[0147] The multiple flow dividing openings 65x are provided lined up in the vertical direction at positions biased toward the rear side of the fifth plate-shaped member 65. Here, the rear side of the fifth plate-shaped member 65 corresponds to the windward side when the outdoor fan 16 is driven. This allows a large amount of refrigerant to be guided to the windward side of the multiple flat tubes 28, thereby improving heat exchange efficiency.

[0148] The multiple flow dividing openings 65x overlap with the openings 52x of the first common member 52 and the openings 53x of the second common member 53 in the plate thickness direction. Among the flow dividing openings 65x formed in the fifth plate-shaped member 65, the flow dividing opening 65x corresponding to the first flow path portion A5 communicates with the openings 52x of the first common member 52 and the openings 52x and 53x of the openings 53x of the second common member 53 corresponding to the first flow path portion A6 in the plate thickness direction. Among the flow dividing openings 65x formed in the fifth plate-shaped member 65, the flow dividing opening 65x corresponding to the second flow path portion B5 communicates with the openings 52x of the first common member 52 and the openings 52x and 53x of the openings 53x of the second common member 53 corresponding to the second flow path portion B6 in the plate thickness direction.

[0149] As described above in the gas header 50, the openings 52x of the first common member 52, the openings 53x of the second common member 53, and the flat tube connection openings 54x of the third common member 54 communicate with each other in the plate thickness direction. Here, the tips of the flat tubes 28 are inserted so as to pass through the flat tube connection openings 54x of the third common member 54, which are wider than the cross section of the flat tubes 28, and the openings 53x of the second common member 53. Furthermore, the insertion of the flat tubes 28 is stopped at the openings 52x of the first common member 52, which has a smaller front-to-rear width than the flat tubes 28.

[0150] As in the gas header 50, in the liquid header 60, the claw portion 54c is bent in a state in which the second common member 53, the first common member 52, the fifth plate-shaped member 65, the fourth plate-shaped member 64, the third plate-shaped member 63, the second plate-shaped member 62, and the first plate-shaped member 61 are arranged inside the third common member 54. As a result, the second common member 53, the first common member 52, the fifth plate-shaped member 65, the fourth plate-shaped member 64, the third plate-shaped member 63, the second plate-shaped member 62, and the first plate-shaped member 61 are crimped by the third common member 54. Then, in this state, brazing is performed in a furnace, and the members are joined by brazing and completely fixed to each other.

[0151] (6) Features of the embodiment In the outdoor heat exchanger 11 of the air conditioner 1, when frost formed during heating operation is melted by defrosting operation, the refrigerant in a liquid state that has condensed inside the outdoor heat exchanger 11 is likely to accumulate below the outdoor heat exchanger 11. For this reason, it becomes difficult to ensure a refrigerant flow rate below the outdoor heat exchanger 11 during defrosting operation, and the frost that has formed below the outdoor heat exchanger 11 tends to melt last during the defrosting operation.

[0152] In contrast, in the outdoor heat exchanger 11 of this embodiment, temperature detection by the temperature sensor 80 is capable of detecting the temperature of only the refrigerant in the first refrigerant flow path A, through which the refrigerant flows after passing through the first flat tube 28x belonging to the first flow path group X, which is located at the lowest among the multiple flat tubes 28 that the outdoor heat exchanger 11 has.

[0153] This makes it possible to accurately determine the timing when all the frost adhering to the outdoor heat exchanger 11 has melted during the defrosting operation based on the temperature detected by the temperature sensor 80. This makes it possible to speed up the timing of returning from the defrosting operation to the heating operation, for example, compared to the case where the defrosting operation is performed for only a predetermined time that is set longer.

[0154] Moreover, the temperature sensor 80 detects the temperature of the first intermediate pipe portion 71b at a position away from the liquid refrigerant connecting pipe 20a, away from the second connecting pipe 72, and away from the first plate-shaped member 61. This enables the temperature sensor 80 to reduce the effects of the temperature of the refrigerant flowing through the liquid refrigerant connecting pipe 20a, the temperature of the refrigerant flowing through the second connecting pipe 72, and the temperature of the first plate-shaped member 61, thereby improving detection accuracy.

[0155] In addition, the first intermediate pipe section 71b where the temperature sensor 80 is provided extends vertically, and the refrigerant flows in the vertical direction. Therefore, it is possible to detect the temperature at a location where the difference in the refrigerant temperature is suppressed, and the detection accuracy can be improved.

[0156] In this embodiment, by improving the detection accuracy of the temperature sensor 80, it is possible to avoid a situation in which defrosting operation is continued even though the frost adhering to the outdoor heat exchanger 11 has completely melted, and to optimize the timing for resuming heating operation.

[0157] In addition, in the liquid header 60 of the outdoor heat exchanger 11, the refrigerant flowing in through the liquid refrigerant connection pipe 20a can be divided inside the liquid header 60. Therefore, there is no need to provide a conventionally known flow divider separately from the liquid header 60. Therefore, the installation space of the outdoor heat exchanger 11 can be made compact, the parts cost can be reduced, and the production process can be simplified by eliminating the need for the connection work of the conventionally known flow divider. Note that, as the conventionally known flow divider referred to here, for example, there is one that divides the refrigerant flowing in from one end of the main body into a plurality of capillary tubes connected to the other end of the main body. In this embodiment, no flow divider that divides the refrigerant is provided between the liquid refrigerant side of the outdoor heat exchanger 11 and the outdoor expansion valve 12. In particular, in the outdoor heat exchanger 11 of this embodiment, the refrigerant flowing in to the liquid header 60 through the liquid refrigerant connection pipe 20a is divided by devising the opening shape provided in the second plate-like member 62, which is one plate-like member constituting the liquid header 60. Therefore, even when the flow is divided inside the liquid header 60, it is possible to keep the thickness of the liquid header 60 in the left-right direction small.

[0158] Furthermore, in the liquid header 60 of this embodiment, not only does the junction flow path C branch into the first refrigerant flow path A and the second refrigerant flow path B, but the refrigerant flowing through the first refrigerant flow path A can be further branched at the branch openings 65x of the fifth plate-shaped member 65 and then flowed into each of the first flat tubes 28x, and the refrigerant flowing through the second refrigerant flow path B can be further branched at the branch openings 65x of the fifth plate-shaped member 65 and then flowed into each of the second flat tubes 28y. This makes it possible to improve the heat exchange efficiency in the outdoor heat exchanger 11.

[0159] (7) Other embodiments (7-1) Other embodiment A In the above embodiment, the case in which the first connection pipe 71 and the second connection pipe 72 are connected in the liquid header 60 and the temperature sensor 80 is provided in the first connection pipe 71 has been described as an example.

[0160] Here, the structure for detecting the temperature of the refrigerant flowing through the first refrigerant flow path A using the temperature sensor 80 is not limited to this, and for example, as shown in Fig. 10, instead of providing the first communication pipe 71 as in the above embodiment, the first plate-like member 61 may have a first protruding portion 171 protruding in the plate thickness direction. Similarly, the second communication pipe 72 may have a second protruding portion 172 protruding in the plate thickness direction of the first plate-like member 61 instead of providing the second communication pipe 72 of the above embodiment.

[0161] The first protruding portion 171 is formed in the first plate-like member 61 so as to bulge toward the right side, which is the outer side of the liquid header 60 in the plate thickness direction of the first plate-like member 61. The left side, which is the inner side of the first protruding portion 171, is formed with a first recessed portion 171a recessed toward the right side in the plate thickness direction. As a result, the end of the branch opening 62b in the second plate-like member 62 opposite to the joining flow path C side of the portion constituting the first flow path portion A1 and the first communication opening 62c in the second plate-like member 62 are connected via a flow path formed by being sandwiched between the first recessed portion 171a, which is the back surface of the first protruding portion 171 of the first plate-like member 61, and the second plate-like portion 62a of the second plate-like member 62. The flow path sandwiched between the first recessed portion 171a and the second plate-like portion 62a constitutes the first flow path portion A2.

[0162] The second protrusion 172 is similar to the first protrusion 171, and is formed in the first plate-like member 61 so as to bulge toward the right side, which is the outer side of the liquid header 60 in the plate thickness direction of the first plate-like member 61. The left side, which is the inner side of the second protrusion 172, is formed with a second recess 172a recessed toward the right side in the plate thickness direction. As a result, the end of the branch opening 62b in the second plate-like member 62 opposite to the joining flow path C side of the part constituting the second flow path portion B1 and the second communication opening 62d in the second plate-like member 62 are connected via a flow path formed by sandwiching the second recess 172a, which is the back surface of the second protrusion 172 of the first plate-like member 61, and the second plate-like portion 62a of the second plate-like member 62. The flow path sandwiched between the second recess 172a and the second plate-like portion 62a constitutes the second flow path portion B2.

[0163] Both the first protruding portion 171 and the second protruding portion 172 extend in the vertical direction, and allow the refrigerant to pass therethrough in the vertical direction.

[0164] The temperature sensor 80 is attached to a detection portion 171b on the right side of the first protruding portion 171, which is outside the liquid header 60. The temperature sensor 80 is preferably provided so as not to contact the first plate-shaped portion 61a of the first plate-shaped member 61, and may be attached to the front or rear side of the first protruding portion 171.

[0165] The lengths of the coolant flow paths in the first protruding portion 171 and the second protruding portion 172 are equal to each other.

[0166] In addition, the lower end of the first protruding portion 171 is located lower than the lower end of the second protruding portion 172.

[0167] The above configuration can also achieve the same effects as the above embodiment.

[0168] (7-2) Other embodiment B In the above embodiment, an example of a liquid header 60 was described in which the refrigerant that flows into the liquid header 60 via the liquid refrigerant connection pipe 20a and reaches the junction flow path is divided into two flow paths, a first refrigerant flow path A and a second refrigerant flow path B, and further, the refrigerant flowing through the first refrigerant flow path A is divided into two or more flow paths within the liquid header 60, and the refrigerant flowing through the second refrigerant flow path B is divided into two or more flow paths within the liquid header 60.

[0169] In contrast, the refrigerant that has flowed into the header may be diverted once or three or more times before reaching the heat transfer tubes such as flat tubes.

[0170] Furthermore, the number of branches when the refrigerant that has flowed into the header is first branched is not limited to two, and may be three or more.

[0171] (Additional Note) Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure described in the claims. [Explanation of symbols]

[0172] 1. Air conditioning equipment 2 Outdoor unit (outdoor unit) 3. Control Unit 11 Outdoor heat exchanger (heat exchanger) 19 First gas refrigerant pipe 19a Gas refrigerant connection pipe 20 Liquid refrigerant pipe 20a Liquid refrigerant connection pipe (refrigerant pipe) 27 Heat exchange section 28 Flat tube (heat transfer tube) 28x 1st flat tube (1st heat transfer tube) 28y 2nd flat tube (2nd heat transfer tube) 28z 3rd flat tube 30 Folded Header 40 Entrance / Exit Header 50 Gas Header 51 Gas header parts 51a Gas header plate part 52 First common part 53 Second common member 54 Third common part 54c Claw part 60 Liquid Header (Header) 61 First plate-shaped member (outer wall portion) 62 Second plate-shaped member (plate-shaped member) 62b Branching aperture (aperture) 71 First connecting pipe (first pipe section) 71b 1st intermediate piping section (detected section) 72 Second connecting pipe (second piping section) 80 Temperature Sensor 171 1st protrusion 171a First recess 171b Detected part 172 Second protrusion 172a Second recess A First refrigerant flow path B Second coolant flow path C. Confluence [Prior art documents] [Patent documents]

[0173] [Patent Document 1] JP 2012-088005 A

Claims

1. a plurality of heat transfer tubes (28) including a first heat transfer tube (28x) and a second heat transfer tube (28y) disposed above the first heat transfer tube; A header (60) to which a plurality of the heat transfer tubes are connected; A refrigerant pipe (20a) connected to the header; A temperature sensor (80); Equipped with the header has a junction flow path (C) extending from a connection portion of the refrigerant pipe, a first refrigerant flow path (A) connecting the connection portion of the first heat transfer tube and the junction flow path, and a second refrigerant flow path (B) connecting the connection portion of the second heat transfer tube and the junction flow path, The temperature sensor detects a temperature of the refrigerant flowing through the first refrigerant flow path. Heat exchanger (11).

2. A detection position of the temperature sensor is closer to the first refrigerant flow path than the second refrigerant flow path and is closer to the first refrigerant flow path than the refrigerant piping.

2. The heat exchanger of claim 1.

3. The first heat transfer tube includes a portion located at the lowest position among the plurality of heat transfer tubes.

3. A heat exchanger according to claim 1 or 2.

4. The header has an outer wall (61); the outer wall portion is located on an opposite side to a side of the header where a connection portion between the heat transfer tube and the header is located, The first refrigerant flow path has a first piping portion (71), The first piping portion is located on an opposite side of the outer wall portion to a side on which the connection portion between the heat transfer tube and the header is located.

3. A heat exchanger according to claim 1 or 2.

5. The temperature sensor detects the temperature of the refrigerant flowing through the first piping section.

5. The heat exchanger of claim 4.

6. The temperature sensor detects the temperature of the refrigerant flowing through a detection target portion (71b) of the first piping section, The detection portion is a portion through which the refrigerant flows in the vertical direction.

6. The heat exchanger according to claim 5.

7. The second refrigerant flow path has a second piping portion (72), The second piping portion is located on an opposite side of the outer wall portion to a side on which the connection portion between the heat transfer tube and the header is located.

5. The heat exchanger of claim 4.

8. The first piping section and the second piping section have the same length.

8. The heat exchanger of claim 7.

9. A lower end of the first piping section is located lower than a lower end of the second piping section.

8. The heat exchanger of claim 7.

10. The header has an outer wall (61); the outer wall portion is located on an opposite side to a side of the header where a connection portion between the heat transfer tube and the header is located, The outer wall portion includes a first protrusion (171) protruding toward an opposite side to a side where the connection portion between the heat transfer tube and the header is located, the first refrigerant flow path includes a portion through which the refrigerant flows along the first protruding portion on a side of the outer wall portion where the connection portion between the heat transfer tube and the header is located, 3. A heat exchanger according to claim 1 or 2.

11. The temperature sensor detects a temperature of the coolant flowing along the first protrusion.

11. The heat exchanger of claim 10.

12. The temperature sensor detects the temperature of the refrigerant flowing through a detection target portion (171b) of the first protrusion, The detection portion is a portion through which the refrigerant flows in the vertical direction.

12. The heat exchanger of claim 11.

13. The outer wall portion includes a second protruding portion (172) protruding toward the opposite side to the side where the connection portion between the heat transfer tube and the header is located, the second refrigerant flow path includes a portion through which the refrigerant flows along the second protruding portion on a side of the outer wall portion where the connection portion between the heat transfer tube and the header is located.

11. The heat exchanger of claim 10.

14. A flow path length of the first protruding portion of the first refrigerant flow path is equal to a flow path length of the second protruding portion of the second refrigerant flow path.

14. The heat exchanger of claim 13.

15. A lower end of the first protrusion is located lower than a lower end of the second protrusion.

14. The heat exchanger of claim 13.

16. The header has a plate-like member (62) having an opening (62b) penetrating in a plate thickness direction, The opening constitutes a part of the junction flow path, a part of the first refrigerant flow path, and a part of the second refrigerant flow path.

3. A heat exchanger according to claim 1 or 2.

17. A heat exchanger according to claim 1 or 2; A control unit (3) capable of switching between an operation in which the heat exchanger functions as an evaporator of the refrigerant and a defrosting operation in which the heat exchanger is defrosted; Equipped with The control unit performs the defrosting operation based on the temperature detected by the temperature sensor. Air conditioning equipment.

18. The control unit terminates the defrosting operation based on the temperature detected by the temperature sensor.

18. An air conditioning apparatus as claimed in claim 17.

19. The heat exchanger is provided in an outdoor unit (2).

18. An air conditioning apparatus as claimed in claim 17.

Images