Air conditioning device

Abstract

An air conditioning device (10) includes a blower device (7) capable of blowing air in either a first blowing direction for blowing air to a second indoor heat exchanger (3) via a first indoor heat exchanger (5) or a second blowing direction for blowing air to the first indoor heat exchanger (5) via the second indoor heat exchanger (3). Control devices (31, 32) control the blower device (7) so as to blow air in the first blowing direction in a cooling operation, and control the blower device (7) so as to blow air in the second blowing direction in a defrosting operation.

Description

air conditioning equipment

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

[0002] Air conditioners include those that perform constant temperature and humidity operation, which can maintain the temperature and humidity in a room within a certain range. In air conditioners that perform constant temperature and humidity operation, the indoor unit is provided with a reheater and a humidifier in addition to an indoor heat exchanger.

[0003] When performing this type of constant temperature and humidity operation, the air conditioner cools and dehumidifies the indoor air using a heat exchanger, then adjusts the sensible heat using a reheater and adjusts the latent heat using a humidifier. This allows the air conditioner to simultaneously perform control to adjust the sensible heat and control to adjust the latent heat.

[0004] When performing constant temperature and humidity operation, if the evaporation capacity of the indoor heat exchanger of the indoor unit is increased, control is performed to lower the evaporation temperature. When control to lower the evaporation temperature is performed in this way, if the evaporation temperature drops too much, frost may form on the indoor heat exchanger.

[0005] Patent Document 1 discloses an air conditioner that, after frost forms on the indoor heat exchanger during cooling operation, switches to heating operation to make the indoor heat exchanger function as a condenser, thereby using the heat of condensation to defrost the indoor heat exchanger.

[0006] JP 2010-014288 A

[0007] However, the conventional air conditioners described above have a problem in that their ability to dehumidify indoor air decreases when the indoor heat exchanger is defrosted. Specifically, conventional air conditioners simply switch to heating operation when the indoor heat exchanger is defrosted, so the cooling capacity decreases, and the ability to dehumidify indoor air also decreases.

[0008] The present disclosure is intended to solve the above-mentioned problems, and its purpose is to provide an air conditioner that can suppress a decrease in dehumidification capacity when defrosting an indoor heat exchanger.

[0009] The present disclosure relates to an air conditioner. The air conditioner includes an outdoor unit, an indoor unit, and a control device that controls air conditioning. The outdoor unit includes an outdoor heat exchanger that exchanges heat between a refrigerant and outdoor air. The indoor unit includes a first indoor heat exchanger that exchanges heat between the refrigerant and indoor air, a second indoor heat exchanger that exchanges heat between the refrigerant and indoor air, a first expansion valve that is provided in a refrigerant path between the first indoor heat exchanger and the second indoor heat exchanger and reduces the pressure of the refrigerant, and a blower that can blow air in either a first blowing direction that sends air via the first indoor heat exchanger to the second indoor heat exchanger or a second blowing direction that sends air via the second indoor heat exchanger to the first indoor heat exchanger. During cooling operation, the refrigerant circulates through the compressor, the outdoor heat exchanger, the second indoor heat exchanger, the first expansion valve, and the first indoor heat exchanger, in that order. The control device controls the blower to blow air in a first blowing direction in the cooling operation, and controls the blower to blow air in a second blowing direction in the defrosting operation.

[0010] According to the air conditioning apparatus of the present disclosure, the air blower can blow air in either a first air blowing direction in which the air passes through the first indoor heat exchanger to the second indoor heat exchanger, or a second air blowing direction in which the air passes through the second indoor heat exchanger to the first indoor heat exchanger. In the air conditioning apparatus, the control device controls the air blower to blow air in the first air blowing direction in cooling operation, and controls the air blower to blow air in the second air blowing direction in defrosting operation, thereby suppressing a decrease in dehumidification capacity when the indoor heat exchanger is defrosted.

[0011] FIG. 1 is a diagram showing the configuration of an air conditioner of embodiment 1. FIG. 2 is a cross-sectional view showing the configuration of a blower according to embodiment 1. FIG. 3 is a cross-sectional view showing the configuration of a blower according to embodiment 1. FIG. 4 is a block diagram showing the control configuration of the air conditioner of embodiment 1. FIG. 5 is a flowchart showing an example of control of the defrost mode according to embodiment 1. FIG. 6 is a diagram showing the configuration of an air conditioner of embodiment 2. FIG. 7 is a block diagram showing the control configuration of the air conditioner of embodiment 2. FIG. 8 is a flowchart showing an example of control of the defrost mode according to embodiment 2. FIG. 9 is a diagram showing the configuration of an air conditioner of embodiment 3. FIG. 10 is a block diagram showing the control configuration of the air conditioner of embodiment 3. FIG. 11 is a flowchart showing an example of control of the defrost mode according to embodiment 3. FIG. 12 is a diagram showing the configuration of an air conditioner of embodiment 4. FIG. 13 is a block diagram showing the control configuration of the air conditioner of embodiment 4. FIG. 14 is a flowchart showing an example of control of the defrost mode according to embodiment 4. FIG. 15 is a diagram showing the configuration of an air conditioner of embodiment 5. FIG. 16 is a block diagram showing the control configuration of the air conditioner of embodiment 5. FIG. 17 is a flowchart showing an example of control of the defrost mode according to embodiment 5. FIG. 18 is a cross-sectional view showing the configuration of a blower for an air conditioner of embodiment 6. FIG. 19 is a cross-sectional view showing the configuration of a blower for an air conditioner of embodiment 6. FIG. 19 is a block diagram showing the control configuration of the air conditioner of embodiment 6. FIG. 19 is a flowchart showing an example of control of the defrost mode according to embodiment 6.

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. While several embodiments will be described below, it was originally intended that the configurations described in each embodiment be combined as appropriate. Note that identical or corresponding parts in the drawings will be designated by the same reference numerals, and their description will not be repeated.

[0013] Embodiment 1 (Overall configuration of air conditioning apparatus 10) Fig. 1 is a diagram showing the configuration of an air conditioning apparatus 10 according to embodiment 1. The air conditioning apparatus 10 includes an indoor unit 11 and an outdoor unit 12. The indoor unit 11 and the outdoor unit 12 are connected by a first extension pipe 61 and a second extension pipe 62.

[0014] The indoor unit 11 includes a first indoor heat exchanger 5, a first expansion valve 4, a second indoor heat exchanger 3, a blower 7, a humidifier 8, and a first control device 31. The outdoor unit 12 includes a compressor 1, an outdoor heat exchanger 2, and a second control device 32.

[0015] In the air conditioning apparatus 10, a refrigerant circuit 60 through which a refrigerant flows is formed by the compressor 1, the outdoor heat exchanger 2, the second indoor heat exchanger 3, the first expansion valve 4, and the first indoor heat exchanger 5. In the air conditioning apparatus 10, a refrigeration cycle is formed by the refrigerant circuit 60, which performs compression, condensation, expansion, and evaporation of the refrigerant. The name of the expansion valve, first expansion valve 4, is used in the description of the first embodiment to distinguish it from the second expansion valve 96, which is an expansion valve shown in Figure 12.

[0016] The air conditioner 10 performs constant temperature and humidity operation to control the indoor temperature and humidity within a certain range. The constant temperature and humidity operation is performed by operating the refrigeration cycle in the refrigerant circuit 60, which is made up of the compressor 1, the outdoor heat exchanger 2, the second indoor heat exchanger 3, the first expansion valve 4, and the first indoor heat exchanger 5, in cooling mode.

[0017] The cooling mode is an operation mode in which the refrigerant circuit 60 performs a cooling operation and the air blowing direction of the air blowing device 7 is set as a first air blowing direction. A specific example of the air blowing direction of the air blowing device 7 will be described later.

[0018] In the air conditioning device 10, refrigerant is circulated in a refrigerant circuit 60 that includes a compressor 1, an outdoor heat exchanger 2, a first extension pipe 61, a second indoor heat exchanger 3, a first expansion valve 4, a first indoor heat exchanger 5, and a second extension pipe 62.

[0019] The compressor 1 compresses the refrigerant flowing through the refrigerant circuit 60 and supplies the high-temperature, high-pressure refrigerant to the outdoor heat exchanger 2. The compressor 1 is driven by, for example, an inverter-controlled motor.

[0020] The outdoor heat exchanger 2 exchanges heat between the refrigerant and outdoor air. The refrigerant discharged from the compressor 1 flows into the outdoor heat exchanger 2 during cooling operation. The outdoor heat exchanger 2 functions as a refrigerant condenser. The liquid refrigerant condensed by the outdoor heat exchanger 2 flows out of the outdoor heat exchanger 2, passes through the first extension pipe 61, and flows into the second indoor heat exchanger 3.

[0021] The second indoor heat exchanger 3 exchanges heat between the refrigerant and the indoor air. The second indoor heat exchanger 3 functions as a refrigerant condenser during cooling operation. After being condensed by the second indoor heat exchanger 3, the refrigerant flows out of the second indoor heat exchanger 3 and into the first expansion valve 4.

[0022] The first expansion valve 4 has a function of reducing the pressure of the refrigerant and expanding it. The first expansion valve 4 is, for example, an electronic expansion valve. The refrigerant expanded by the first expansion valve 4 flows into the first indoor heat exchanger 5.

[0023] The first indoor heat exchanger 5 exchanges heat between the refrigerant and the indoor air. The first indoor heat exchanger 5 functions as a refrigerant evaporator during cooling operation. The temperature of the first indoor heat exchanger 5 drops as the refrigerant evaporates. As a result, the first indoor heat exchanger 5 exchanges heat to cool the indoor air.

[0024] The gas refrigerant evaporated by the first indoor heat exchanger 5 flows out of the first indoor heat exchanger 5, passes through the second extension pipe 62, and flows into the suction port of the compressor 1. The compressor 1 compresses the refrigerant that has flowed in this way as described above.

[0025] The blower 7 blows air in the indoor unit 11. The blower 7 includes an impeller 70 and an air passage (see FIG. 2). In FIG. 1, the blower 7 is illustrated as an impeller 70 that is driven to rotate by a drive source such as a motor. The blower 7 can blow air in either a first air blowing direction or a second air blowing direction by switching the rotation direction of the impeller 70.

[0026] The first air blowing direction, as indicated by the solid arrow, is the direction in which air is blown through the first indoor heat exchanger 5 to the second indoor heat exchanger 3. The second air blowing direction, as indicated by the dashed arrow, is the direction in which air is blown through the second indoor heat exchanger 3 to the first indoor heat exchanger 5.

[0027] The humidifier 8 can humidify the indoor air. The humidifier 8 can humidify the air by using steam generated by evaporating water using, for example, an electric heater. By generating steam in this way, the humidifier 8 humidifies the indoor air blown by the blower 7.

[0028] In the indoor unit 11, the first indoor heat exchanger 5 is used as an evaporator. As a result, when indoor air drawn into the indoor unit 11 is blown in the first air blowing direction by the blower 7, the air cooled by the heat of evaporation in the first indoor heat exchanger 5 passes through the second indoor heat exchanger 3, the blower 7, and the humidifier 8, and is sent out to the outside of the indoor unit 11.

[0029] In the indoor unit 11, the second indoor heat exchanger 3 is used as a condenser. As a result, when air is blown in the first air blowing direction by the blower device 7, the air sent to the second indoor heat exchanger 3 via the first indoor heat exchanger 5 is heated by the heat of condensation in the second indoor heat exchanger 3. This heating of the air in the second indoor heat exchanger 3 is called reheating, as it heats air that has once been cooled by the first indoor heat exchanger 5. The second indoor heat exchanger 3 is used as a reheater.

[0030] When reheating is performed by the second indoor heat exchanger 3, it is possible to adjust the temperature of the air sent from the indoor unit 11 into the room, for example, by heating air that has been overcooled by the first indoor heat exchanger 5, thereby suppressing excessive cooling by the first indoor heat exchanger 5.

[0031] In the indoor unit 11, when air is blown in the first blowing direction by the blower 7, the air is sent to the second indoor heat exchanger 3 via the first indoor heat exchanger 5, and the reheated air is sent to the outside of the indoor unit 11 via the humidifier 8, so that the humidity is adjusted by the humidifier 8. When the humidity is adjusted by the humidifier 8, it is possible to adjust the temperature of the air sent from the indoor unit 11 into the room, for example, by humidifying air that has been excessively dehumidified by cooling by the first indoor heat exchanger 5.

[0032] In the indoor unit 11, frost may form on the first indoor heat exchanger 5 due to a drop in temperature caused by excessive evaporation of the refrigerant. When frost forms on the first indoor heat exchanger 5 in this way, the air blowing direction of the indoor unit 11 is switched from the first air blowing direction to the second air blowing direction by the air blower 7, and air heated by the second indoor heat exchanger 3 is blown to the first indoor heat exchanger 5. As a result, when the air blowing direction of the air blower 7 in the indoor unit 11 is the second air blowing direction, the first indoor heat exchanger 5 is defrosted by the air heated by the second indoor heat exchanger 3.

[0033] The operation mode in which the air blowing direction of the air blower 7 is switched to the second air blowing direction to defrost the first indoor heat exchanger 5 is called a defrosting mode. In the defrosting mode, the refrigerant circuit 60 performs cooling operation, and the air blowing direction of the air blower 7 is set to the second air blowing direction to perform a defrosting operation.

[0034] In the indoor unit 11, a temperature sensor 51 that detects the surface temperature of the first indoor heat exchanger 5 is provided on the first indoor heat exchanger 5. The indoor unit 11 is provided with a plurality of sensors (not shown except for the temperature sensor 51) that detect the operating state of the indoor unit 11, including the temperature sensor 51. The outdoor unit 12 is provided with a plurality of sensors (not shown) that detect the operating state of the outdoor unit 12, such as a sensor that detects the suction temperature of the refrigerant in the compressor 1.

[0035] In the indoor unit 11, when the blower 7 blows air in the first blowing direction, the air is sent to the second indoor heat exchanger 3 via the first indoor heat exchanger 5, and the air reheated in the second indoor heat exchanger 3 is sent to the outside of the indoor unit 11 via the humidifier 8, so that the humidity is adjusted by the humidifier 8.

[0036] The first control device 31 is electrically connected to and controls various devices provided in the indoor unit 11, such as the first expansion valve 4, the blower 7, and the humidifier 8. The first control device 31 can control the various devices provided in the indoor unit 11, for example, based on detection information from the above-mentioned multiple sensors.

[0037] The second control device 32 is electrically connected to and controls various devices such as the compressor 1 provided in the outdoor unit 12. The second control device 32 can control various devices provided in the indoor unit 11 based on, for example, detection information from the above-mentioned plurality of sensors.

[0038] The first control device 31 and the second control device 32 are electrically connected to enable bidirectional information communication. The first control device 31 can control the various devices provided in the indoor unit 11 based on control information of the various devices provided in the outdoor unit 12 and detection information from the above-mentioned multiple sensors. The second control device 32 can control the various devices provided in the outdoor unit 12 based on control information of the various devices provided in the indoor unit 11 and detection information from the above-mentioned multiple sensors.

[0039] The first control device 31 and the second control device 32 communicate information bidirectionally to check the overall status of the air conditioning device 10, and as an integrated control device, control the various devices provided in the indoor unit 11 and the various devices provided in the outdoor unit 12. For example, the first control device 31 and the second control device 32 control the various devices provided in the indoor unit 11 and the various devices provided in the outdoor unit 12 to perform operation in an operation mode selected from a plurality of operation modes including a cooling mode and a defrosting mode.

[0040] In addition, as a control device for the air conditioning device 10, a control device that can realize the control functions of the first control device 31 and the second control device 32 with a single control device may be provided, and such a single control device may be provided in the indoor unit 11 or the outdoor unit 12, and the single control device may control various devices provided in both the indoor unit 11 and the outdoor unit 12.

[0041] 2 and 3 are cross-sectional views showing the configuration of the blower 7 according to embodiment 1. 2 and 3 show a cross-sectional view of the air passage 30 of the blower 7, and the arrangement of the first indoor heat exchanger 5, the second indoor heat exchanger 3, the impeller 70, and the humidifier 8.

[0042] In Fig. 2, the air blowing direction when the air blowing device 7 blows air in the first air blowing direction is indicated by a solid arrow. In Fig. 3, the air blowing direction when the air blowing device 7 blows air in the second air blowing direction is indicated by a dashed arrow.

[0043] 2 and 3, the blower device 7 includes an impeller 70 and an air passage 30. The impeller 70 is a rotary blade having a plurality of blades, and is driven to rotate by a motor. The impeller 70 generates air when driven to rotate.

[0044] The air passage 30 is provided to surround the first indoor heat exchanger 5, the second indoor heat exchanger 3, the impeller 70, and the humidifier 8. A first opening 41 is formed at one end of the air passage 30. A second opening 42 is formed at the other end of the air passage 30. The first opening 41 is used as an inlet or outlet for air blown by the blower 7. The second opening 42 is used as an inlet or outlet for air blown by the blower 7.

[0045] As shown in Fig. 2, when the blower 7 blows air in a first blowing direction, the first opening 41 is used as an air inlet, and the second opening 42 is used as an air outlet. On the other hand, as shown in Fig. 3, when the blower 7 blows air in a second blowing direction, the second opening 42 is used as an air inlet, and the first opening 41 is used as an air outlet.

[0046] The air flow path 30 is a hollow member that houses the first indoor heat exchanger 5, the second indoor heat exchanger 3, the impeller 70, and the humidifier 8. In the internal space of the air flow path 30, the first indoor heat exchanger 5, the second indoor heat exchanger 3, the impeller 70, and the humidifier 8 are arranged at a predetermined distance from each other in the direction from the first opening 41 to the second opening 42.

[0047] In the blower device 7, when air is blown in the first blowing direction by rotating the impeller 70 in the first rotation direction, air is drawn into the internal space of the air passage 30 from the first opening 41, as shown by the solid arrow in Fig. 2. In this case, the drawn air flows through the internal space of the air passage 30 in this order: the first indoor heat exchanger 5, the second indoor heat exchanger 3, the impeller 70, and the humidifier 8, and is then blown out of the air passage 30 from the second opening 42.

[0048] When air is blown in the second blowing direction by rotating the impeller 70 in a second rotational direction opposite to the first rotational direction in the blower device 7, air is drawn into the internal space of the air passage 30 through the second opening 42, as shown by the dashed arrow in Fig. 3. In this case, the drawn air flows through the internal space of the air passage 30 in the order of humidifier 8, impeller 70, second indoor heat exchanger 3, and first indoor heat exchanger 5, and is then blown out of the air passage 30 through the first opening 41.

[0049] (Control Configuration of Air Conditioning Apparatus 10) Next, a description will be given of the control configuration of the air conditioning apparatus 10. Fig. 4 is a block diagram showing the control configuration of the air conditioning apparatus 10 according to the first embodiment.

[0050] The first control device 31 is configured to include a CPU (Central Processing Unit) 311, memory 312 (ROM (Read Only Memory) and RAM (Random Access Memory)), an input / output buffer (not shown), etc. The CPU 311 deploys a program stored in the ROM into the RAM, etc., and executes it. The program stored in the ROM is a program that describes the control processing procedures to be executed by the first control device 31. The first control device 31 controls various devices in the air conditioning device 10 in accordance with such a program.

[0051] The second control device 32 is configured to include a CPU 321, memory 322 (ROM and RAM), an input / output buffer (not shown), etc. The CPU 321 deploys a program stored in the ROM into the RAM, etc., and executes it. The program stored in the ROM is a program that describes the control processing procedures to be executed by the second control device 32. The second control device 32 controls various devices in the air conditioning device 10 in accordance with such a program.

[0052] The control of the devices in the first control device 31 and the second control device 32 is not limited to processing by software, but can also be processed by dedicated hardware (electronic circuitry).

[0053] The air conditioning apparatus 10 is provided with various sensors capable of detecting the temperature, pressure, rotation speed, and other conditions at predetermined locations. Detection signals from these various sensors are input to either the first control device 31 or the second control device 32.

[0054] The various sensors 52 in the indoor unit 11 include a temperature sensor 51. Detection signals from the various sensors 52 in the indoor unit 11 are input to the first control device 31. Detection signals from the various sensors 53 in the outdoor unit 12 are input to the second control device 32.

[0055] The first control device 31 checks the state of the air conditioning device 10 based on detection signals from the various sensors 52 and controls the various devices provided in the indoor unit 11. The second control device 32 checks the state of the air conditioning device 10 based on detection signals from the various sensors 53 and controls the various devices provided in the outdoor unit 12.

[0056] The first control device 31 and the second control device 32 perform the following control, for example. The first control device 31 sends a control signal to the first expansion valve 4 to control the opening degree of the first expansion valve 4. The first control device 31 sends a control signal to the blower 7 to control the air blowing direction of the blower 7. The first control device 31 sends a control signal to the humidifier 8 to control the humidification state of the humidifier 8. The second control device 32 sends a control signal to the compressor 1 to control the operating state of the compressor 1.

[0057] (Example of Operation of Air Conditioning Apparatus 10) Next, the operation of the air conditioning apparatus 10 will be described using Figures 1 to 4. The air conditioning apparatus 10 is capable of performing constant temperature and constant humidity operation.

[0058] The operating modes of the air conditioner 10 include a cooling mode and a defrosting mode. The cooling mode is an operating mode in which cooling is performed to achieve constant temperature and humidity operation. The defrosting mode is an operating mode in which defrosting is performed to remove frost that has adhered to the first indoor heat exchanger 5.

[0059] First, we will explain the cooling mode of the air conditioner 10. In the cooling mode, a cooling operation is performed in the refrigeration cycle of a refrigerant circuit 60 that is configured by a compressor 1, an outdoor heat exchanger 2, a second indoor heat exchanger 3, a first expansion valve 4, and a first indoor heat exchanger 5 as shown in FIG.

[0060] In the cooling operation, the refrigerant is compressed by the compressor 1 in the outdoor unit 12. The refrigerant compressed by the compressor 1 is discharged from a discharge port of the compressor 1. The refrigerant discharged from the discharge port of the compressor 1 is a high-temperature, high-pressure gas refrigerant.

[0061] The refrigerant discharged from the compressor 1 flows into the outdoor heat exchanger 2. In the outdoor heat exchanger 2, heat is exchanged between the high-temperature, high-pressure gas refrigerant that has flowed in and the outdoor air. The gas refrigerant releases heat through heat exchange with the outdoor air and is condensed into a high-pressure liquid refrigerant. The refrigerant that has changed from gas refrigerant to liquid refrigerant in the outdoor heat exchanger 2 flows out of the outdoor unit 12 and flows into the indoor unit 11 via the first extension pipe 61.

[0062] In the indoor unit 11, the refrigerant sent from the outdoor heat exchanger 2 flows into the second indoor heat exchanger 3. In the second indoor heat exchanger 3, heat is exchanged between the flowing refrigerant and the indoor air. As a result, the refrigerant is further condensed in the second indoor heat exchanger 3. The refrigerant further condensed in the second indoor heat exchanger 3 flows into the first expansion valve 4. In the cooling mode, the indoor air is heated by the heat exchange in the second indoor heat exchanger 3.

[0063] In the first expansion valve 4, the high-pressure liquid refrigerant that has flowed in is expanded and decompressed to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant that has been expanded and decompressed in the first expansion valve 4 flows into the first indoor heat exchanger 5.

[0064] In the first indoor heat exchanger 5, heat is exchanged between the inflowing gas-liquid two-phase refrigerant and the indoor air. The gas-liquid two-phase refrigerant evaporates through heat exchange with the indoor air, becoming a low-temperature, low-pressure gas refrigerant. In the cooling mode, the indoor air is cooled by the heat exchange in the first indoor heat exchanger 5.

[0065] The refrigerant that has changed from the gas-liquid two-phase refrigerant to gas refrigerant in the first indoor heat exchanger 5 flows out of the first indoor heat exchanger 5. The refrigerant that has flowed out of the first indoor heat exchanger 5 flows outside the indoor unit 11 and into the outdoor unit 12 via the second extension pipe 62. The refrigerant that has flowed into the outdoor unit 12 via the second extension pipe 62 flows into the compressor 1 from the suction port of the compressor 1.

[0066] As described above, in the cooling mode, the refrigerant in the refrigerant circuit 60 flows in the order of compressor 1, outdoor heat exchanger 2, second indoor heat exchanger 3, and first indoor heat exchanger 5, and then returns to compressor 1, thereby performing cooling operation.

[0067] In the cooling mode, in addition to the cooling operation in the refrigerant circuit 60, the impeller 70 is rotated in a first rotational direction, thereby performing first air blowing control to blow air in a first air blowing direction indicated by the solid arrows in Figure 1 and Figure 2. Specifically, the first air blowing direction is the direction in which air flows through the first indoor heat exchanger 5, the second indoor heat exchanger 3, the impeller 70, and the humidifier 8 in this order.

[0068] In this way, in the cooling mode in which air is blown in the first air blowing direction by the first air blowing control, the air that has been cooled once in the first indoor heat exchanger 5 is reheated by the second indoor heat exchanger 3. As a result, in the cooling mode, in addition to performing the cooling operation, the second indoor heat exchanger 3 adjusts the sensible heat of the air to be blown, thereby adjusting the temperature of the air to be blown.

[0069] In the cooling mode in which air is blown in the first air blowing direction by the first air blowing control, the air whose temperature has been adjusted by the second indoor heat exchanger 3 is humidified by the humidifier 8. As a result, in the cooling mode, in addition to performing the cooling operation, the humidifier 8 adjusts the latent heat of the air to be blown, thereby adjusting the humidity.

[0070] In the cooling mode, the temperature and humidity of the room are controlled within a certain range by adjusting the temperature in the second indoor heat exchanger 3 and adjusting the humidity in the humidifier 8 for the air blown in the first air blowing direction. As a result, constant temperature and constant humidity operation is performed in the cooling mode.

[0071] Next, we will explain the defrosting mode in the air conditioner 10. In the air conditioner 10, if the evaporation temperature in the first indoor heat exchanger 5 drops extremely, frost may form on the first indoor heat exchanger 5.

[0072] In the air conditioning apparatus 10, when the surface temperature of the first indoor heat exchanger 5 detected by the temperature sensor 51 remains below a threshold value for a certain period of time, the first control device 31 determines that frost has formed on the first indoor heat exchanger 5 and operates in a defrosting mode to defrost the heat. The threshold value in this case is set, for example, to the upper limit of the surface temperature at which it can be determined that the first indoor heat exchanger 5 is in a frosted state.

[0073] In the defrosting mode, a cooling operation similar to that in the cooling mode is performed in the refrigeration cycle of the refrigerant circuit 60, which is constituted by the compressor 1, the outdoor heat exchanger 2, the second indoor heat exchanger 3, the first expansion valve 4, and the first indoor heat exchanger 5 as shown in Fig. 1. In this way, in the defrosting mode, a cooling operation similar to that in the cooling mode is performed in the refrigeration cycle of the refrigerant circuit 60.

[0074] In the defrosting mode, a second air blowing control is performed to blow air in a second air blowing direction, as shown by the dashed arrows in Fig. 1 and Fig. 3. The second air blowing direction is opposite to the first air blowing direction in the cooling mode. Specifically, the second air blowing direction is the direction in which air flows through the humidifier 8, impeller 70, second indoor heat exchanger 3, and first indoor heat exchanger 5 in this order.

[0075] In this way, in the defrost mode in which air is blown in the second air blowing direction by the second air blowing control, the air to be blown is humidified by the humidifier 8 and then heated by the second indoor heat exchanger 3. The air heated by the second indoor heat exchanger 3 is then blown to the first indoor heat exchanger 5, thereby melting the frost that has adhered to the first indoor heat exchanger 5. In this way, in the defrost mode, while the refrigeration cycle operates in the same way as in the cooling mode, air is blown in the opposite direction to that in the cooling mode, thereby performing a defrosting operation to defrost the first indoor heat exchanger 5.

[0076] (Control Example of Defrosting Mode) Fig. 5 is a flowchart showing a control example of the defrosting mode according to Embodiment 1. The control shown in Fig. 5 is executed by the first control device 31 shown in Figs.

[0077] In step S1, the first control device 31 determines whether or not a defrosting start condition is satisfied. In step S1, for example, during cooling operation in the cooling mode, if the surface temperature of the first indoor heat exchanger 5 detected by the temperature sensor 51 continues to be equal to or lower than the threshold value for determining that frost has formed on the first indoor heat exchanger 5 for a certain period of time, the first control device 31 determines that the defrosting start condition is satisfied.

[0078] If it is determined in step S1 that the defrosting start condition is not met, the first control device 31 ends the process. On the other hand, if it is determined in step S1 that the defrosting start condition is met, the first control device 31 switches the air blowing direction of the air blower 7 of the indoor unit 11 from the first air blowing direction in the cooling mode to the second air blowing direction in the defrosting mode in step S2. As a result, defrosting operation in the defrosting mode is started in step S2.

[0079] In step S3, the first control device 31 determines whether or not the defrost termination condition is satisfied during the defrosting operation started in step S2. In step S3, for example, during the defrosting operation in the defrost mode, if the surface temperature of the first indoor heat exchanger 5 detected by the temperature sensor 51 remains higher than the threshold value for determining that frost has formed on the first indoor heat exchanger 5 for a certain period of time, the first control device 31 determines that the defrost termination condition is satisfied.

[0080] If it is determined in step S3 that the defrost termination condition is not satisfied, the first control device 31 repeats step S3 until the defrost termination condition is satisfied. On the other hand, if it is determined in step S3 that the defrost termination condition is satisfied, the first control device 31 switches the air blowing direction of the air blower 7 of the indoor unit 11 from the second air blowing direction in the defrost mode to the first air blowing direction in the cooling mode in step S4, and ends the process. As a result, the defrosting operation in the defrost mode is ended in step S4.

[0081] In the air conditioning apparatus 10 described above, as shown in Fig. 1, control related to air conditioning is executed by the first control device 31 and the second control device 32. In the air conditioning apparatus 10, as shown in Fig. 5, control of the defrost mode is executed by the first control device 31.

[0082] In the air conditioning apparatus 10, as shown in Figures 1 to 5, during cooling operation in the cooling mode, the blower device 7 is controlled so that the air blowing direction by the blower device 7 is the first air blowing direction that blows air to the second indoor heat exchanger 3 via the first indoor heat exchanger 5.

[0083] 1 to 5 , in defrosting operation in the defrost mode, the air conditioner 10 controls the air blower 7 so that the air blowing direction by the air blower 7 is the second air blowing direction that blows air to the first indoor heat exchanger 5 via the second indoor heat exchanger 3. In this way, in defrosting operation in the defrost mode, the air conditioner 10 switches the air blowing direction to the second air blowing direction while continuing the cooling operation in the refrigerant circuits 60 provided in the indoor unit 11 and the outdoor unit 12. This makes it possible to suppress a decrease in cooling capacity and a decrease in indoor air dehumidification capacity (dehumidification amount) in the defrosting operation.

[0084] As shown in Figures 2, 3, and 5, the air conditioning device 10 controls the impeller 70 of the blower device 7 to rotate in a first rotational direction when blowing air in a first air blowing direction, and controls the impeller 70 of the blower device 7 to rotate in a second rotational direction that is opposite to the first rotational direction when blowing air in a second air blowing direction, so that the blowing direction by the blower device 7 can be easily switched.

[0085] When the air conditioning apparatus 10 performs a defrosting operation, the refrigerant circuit 60 is controlled to circulate the refrigerant in the following order: compressor 1, outdoor heat exchanger 2, second indoor heat exchanger 3, first expansion valve 4, and first indoor heat exchanger 5. As a result, during the defrosting operation, the refrigerant circuit 60 performs a cooling operation, thereby suppressing a decrease in cooling capacity.

[0086] 1 to 3, in the air conditioning apparatus 10, a humidifier 8 is provided downwind of the second indoor heat exchanger 3 in the first air blowing direction. The humidifier 8 humidifies the air blown in the first air blowing direction and the air blown in the second air blowing direction. This makes it possible to adjust the humidity of both the air blown in the first air blowing direction and the air blown in the second air blowing direction to within a certain range.

[0087] In the first embodiment, an example has been shown in which the impeller 70 of the blower device 7 is provided between the second indoor heat exchanger 3 and the humidifier 8. However, this is not limiting, and the impeller 70 of the blower device 7 may be provided between the second indoor heat exchanger 3 and the first indoor heat exchanger 5. Furthermore, the impeller 70 of the blower device 7 may be provided downstream of the humidifier 8 in the first air blowing direction. Furthermore, the impeller 70 of the blower device 7 may be provided upstream of the first indoor heat exchanger 5 in the first air blowing direction.

[0088] Embodiment 2. Figure 6 is a diagram showing the configuration of an air conditioning apparatus 10A according to embodiment 2. In embodiment 2, an outdoor unit 12A is configured to include a first outdoor heat exchanger 21, a second outdoor heat exchanger 22, a flow path switching valve 91, and a first on-off valve 92, instead of the outdoor heat exchanger 2 shown in Figure 1 and other figures.

[0089] In the second embodiment, in the cooling mode, heat exchange is performed using two outdoor heat exchangers, the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22. In the second embodiment, in the defrosting mode, heat exchange is performed using one of the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22.

[0090] (Overall Configuration of Air Conditioning Apparatus 10A) Referring to FIG. 6, the configuration of air conditioning apparatus 10A differs from the configuration of air conditioning apparatus 10 in FIG. 1 in the following respects.

[0091] The outdoor unit 12A is provided with two outdoor heat exchangers: a first outdoor heat exchanger 21 and a second outdoor heat exchanger 22. The first outdoor heat exchanger 21 and the second outdoor heat exchanger 22 have the same heat exchange capacity. The outdoor unit 12A is further provided with a flow path switching valve 91 and a first opening / closing valve 92.

[0092] In the outdoor unit 12A, a first outdoor heat exchanger 21 and a second outdoor heat exchanger 22 are connected in parallel between the discharge port of the compressor 1 and one end of the first extension pipe 61. A flow path switching valve 91 is provided between the discharge port of the compressor 1 and the refrigerant inlet of the second outdoor heat exchanger 22.

[0093] The flow path switching valve 91 is a valve configured to close one of the four ports of a four-way valve. The flow path switching valve 91 is configured to switch the refrigerant flow direction between a cooling mode and a defrost mode. The flow path of the flow path switching valve 91 becomes a first flow path indicated by a solid line in the cooling mode and a second flow path indicated by a dashed line in the defrost mode.

[0094] The flow path switching valve 91 is controlled by the second control device 32. The second control device 32 controls the flow path switching valve 91 to switch between the first flow path and the second flow path.

[0095] In the flow path switching valve 91, the first flow path is formed to connect the refrigerant discharge port of the compressor 1 to the refrigerant inlet of the second outdoor heat exchanger 22. In the flow path switching valve 91, the second flow path is formed to connect the refrigerant suction port of the compressor 1 and one end of the second extension pipe 62 to the refrigerant inlet of the second outdoor heat exchanger 22.

[0096] When the flow path of the flow path switching valve 91 is set to the first flow path, the refrigerant flows from the compressor 1 into both the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22. In such a case, heat exchange is carried out between the refrigerant and the outdoor air in both the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22. In both the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22, the gas refrigerant releases heat through heat exchange with the outdoor air and is condensed to become a high-pressure liquid refrigerant.

[0097] A first on-off valve 92 is provided in a path closer to the refrigerant outlet in the second outdoor heat exchanger 22 than the confluence of the path that discharges the refrigerant from the refrigerant outlet in the first outdoor heat exchanger 21 toward one end of the first extension pipe 61 and the pipe that discharges the refrigerant from the refrigerant outlet in the second outdoor heat exchanger 22 toward one end of the first extension pipe 61.

[0098] The first on-off valve 92 is controlled by the second control device 32. The second control device 32 controls the first on-off valve 92 to switch between an open state and a closed state.

[0099] In the air conditioning apparatus 10A, in the cooling mode, the second control device 32 controls the flow path switching valve 91 so that the flow path of the flow path switching valve 91 becomes the first flow path. As a result, in the air conditioning apparatus 10A, the refrigerant discharged from the compressor 1 flows into the two outdoor heat exchangers, the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22.

[0100] Furthermore, in the air conditioning apparatus 10A, in the cooling mode, the second control device 32 controls the first on-off valve 92 to an open state. As a result, in the air conditioning apparatus 10A, the refrigerant that flows from the compressor 1 into the two outdoor heat exchangers, the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22, undergoes heat exchange in these two outdoor heat exchangers and then flows out. The refrigerant that flows out of the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22 join together and flows into the second indoor heat exchanger 3 via the first extension pipe 61.

[0101] In the air conditioning apparatus 10A, in the defrost mode, the second control device 32 controls the flow path switching valve 91 so that the flow path of the flow path switching valve 91 becomes the second flow path. As a result, in the air conditioning apparatus 10A, the refrigerant discharged from the compressor 1 does not flow into the second outdoor heat exchanger 22, but flows only into the first outdoor heat exchanger 21.

[0102] Furthermore, in the air conditioning apparatus 10A, in the defrost mode, the second control device 32 closes the first on-off valve 92. As a result, in the air conditioning apparatus 10A, refrigerant flows from the compressor 1 only into the first outdoor heat exchanger 21, and after heat exchange, the refrigerant flows out only from the first outdoor heat exchanger 21. The refrigerant that flows out only from the first outdoor heat exchanger 21 passes through the first extension pipe 61 and flows into the second indoor heat exchanger 3.

[0103] As explained above, in the cooling mode, the air conditioning apparatus 10A uses two outdoor heat exchangers, the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22, for heat exchange with the outdoor air. On the other hand, in the defrosting mode, the air conditioning apparatus 10A uses only the first outdoor heat exchanger 21 of the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22 for heat exchange with the outdoor air.

[0104] (Control Configuration of Air Conditioning Apparatus 10A) Next, a description will be given of the control configuration of the air conditioning apparatus 10 A. Fig. 7 is a block diagram showing the control configuration of the air conditioning apparatus 10A according to the second embodiment.

[0105] The control configuration of the air conditioning apparatus 10A of Embodiment 2 differs from the control configuration of the air conditioning apparatus 10 of Embodiment 1 shown in Fig. 4 in the following points. The second control device 32 sends a control signal to the flow path switching valve 91, and controls the flow path of the flow path switching valve 91 to switch between the first flow path and the second flow path. The second control device 32 sends a control signal to the first opening / closing valve 92, and controls the first opening / closing valve 92 to either an open state or a closed state.

[0106] (Control Example of Defrosting Mode) Fig. 8 is a flowchart showing a control example of the defrosting mode according to embodiment 2. The control shown in Fig. 8 is executed by the first control device 31 and the second control device 32 shown in Figs. 6 and 7.

[0107] The control example of the defrosting mode shown in Fig. 8 differs from the control example of the defrosting mode shown in Fig. 5 in that step S2a and step S4a are executed. Step S2a is executed between step S2 and step S3. Step S4a is executed after step S4.

[0108] In step S2a, the second control device 32 operates the flow path switching valve 91 and the first on-off valve 92 to stop the flow of refrigerant in the second outdoor heat exchanger 22. Specifically, in step S2a, the flow path switching valve 91 is switched to the second flow path, and the first on-off valve 92 is closed. By executing step S2a, in the air conditioning apparatus 10A, of the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22, only the first outdoor heat exchanger 21 is used for heat exchange with outdoor air in the defrost mode.

[0109] In step S4a, the second control device 32 operates the flow path switching valve 91 and the first on-off valve 92 to restore the flow of refrigerant through the second outdoor heat exchanger 22. Specifically, in step S4a, the flow path switching valve 91 is switched to the first flow path, and the first on-off valve 92 is opened.

[0110] When it is determined in step S3 that the defrost termination condition is met, step S4a is executed after step S4, whereby the defrost mode ends and the cooling mode is executed, and in the air conditioning apparatus 10A, both the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22 are used for heat exchange with the outdoor air.

[0111] In addition to the technical effects achieved by the air conditioning apparatus 10 of the first embodiment, the air conditioning apparatus 10A of the second embodiment described above can achieve the following effects. In the air conditioning apparatus 10A, in the defrost mode, heat exchange is performed using one of the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22. In this case, the heat exchange capacity of the outdoor heat exchanger is reduced in the defrost mode compared to the cooling mode. As a result, the amount of condensation heat of the refrigerant in the outdoor heat exchanger is reduced more in the defrost mode than in the cooling mode. Therefore, in the air conditioning apparatus 10A, the amount of heat released in the outdoor heat exchanger according to the amount of condensation heat is reduced more in the defrost mode than in the cooling mode.

[0112] In this way, in the defrost mode, the amount of heat dissipated in the outdoor heat exchanger is suppressed compared to the cooling mode, so the enthalpy of the refrigerant flowing into the second indoor heat exchanger 3 is higher than in the cooling mode. As a result, in the defrost mode, the amount of heat of condensation of the refrigerant generated by heat exchange in the second indoor heat exchanger 3 is increased compared to the cooling mode, so the amount of heat dissipated in the second indoor heat exchanger 3 is greater.

[0113] In this way, if the amount of heat dissipated by the second indoor heat exchanger 3 is greater in defrost mode than in cooling mode, the amount of heat of the air blown from the second indoor heat exchanger 3 to the first indoor heat exchanger 5 is greater in defrost mode than in cooling mode, making it easy to defrost the first indoor heat exchanger 5.

[0114] In the second embodiment, an example has been shown in which, in the defrosting mode, heat exchange is performed using only the first outdoor heat exchanger 21 out of the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22. However, the present invention is not limited to this, and in the defrosting mode, heat exchange may be performed using only the second outdoor heat exchanger 22 out of the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22.

[0115] Furthermore, in the second embodiment, an example has been described in which the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22 have the same heat exchange capacity. However, this is not limiting, and the first outdoor heat exchanger 21 and the second outdoor heat exchanger 22 may have different heat exchange capacities. In this case, the outdoor heat exchanger that performs heat exchange in the defrost mode may be selected as the outdoor heat exchanger with the lower heat exchange capacity, or may be selected as the outdoor heat exchanger with the higher heat exchange capacity.

[0116] Embodiment 3. Figure 9 is a diagram showing the configuration of an air conditioning apparatus 10B according to embodiment 3. In embodiment 3, an outdoor unit 12B further comprises a bypass passage 23, a second on-off valve 94, and a third on-off valve 95 in addition to the components of the indoor unit 12 shown in Figure 1 etc. In embodiment 3, the second control device 32 controls the second on-off valve 94 and the third on-off valve 95 in the defrost mode so that the refrigerant does not flow through the outdoor heat exchanger 2 but flows through the bypass passage 23.

[0117] In the cooling mode in the third embodiment, the outdoor unit 12B uses a path through which the refrigerant discharged from the compressor 1 flows to the indoor unit 11 via the outdoor heat exchanger 2. In the defrosting mode in the third embodiment, the outdoor unit 12B uses a bypass path 23 through which the refrigerant discharged from the compressor 1 bypasses the outdoor heat exchanger 2 and flows to the indoor unit 11.

[0118] (Overall Configuration of Air Conditioning Apparatus 10B) Referring to FIG. 9, the configuration of the air conditioning apparatus 10B differs from the configuration of the air conditioning apparatus 10 of FIG. 1 in the following respects.

[0119] In the outdoor unit 12B, a second on-off valve 94 is provided downstream of the outdoor heat exchanger 2 in the refrigerant circuit 60. In the outdoor unit 12B, a bypass path 23 and a third on-off valve 95 are provided in parallel to the outdoor heat exchanger 2 and the second on-off valve 94 in the refrigerant circuit 60.

[0120] The second on-off valve 94 and the third on-off valve 95 are controlled to open and close by the second control device 32. In the cooling mode, the second control device 32 controls the second on-off valve 94 to an open state and the third on-off valve 95 to a closed state. As a result, in the cooling mode, in the outdoor unit 12B, the refrigerant discharged from the compressor 1 flows through the outdoor heat exchanger 2 to the indoor unit 11. Therefore, in the cooling mode, heat exchange is performed by the outdoor heat exchanger 2 in the outdoor unit 12B.

[0121] In the defrost mode, the second control device 32 controls the second on-off valve 94 to a closed state and the third on-off valve 95 to an open state. As a result, in the defrost mode, in the outdoor unit 12B, the refrigerant discharged from the compressor 1 flows to the indoor unit 11 via the bypass path 23 without passing through the outdoor heat exchanger 2. Therefore, in the defrost mode, heat exchange by the outdoor heat exchanger 2 is not performed in the outdoor unit 12B.

[0122] (Control Configuration of Air Conditioning Apparatus 10B) Next, a description will be given of the control configuration of the air conditioning apparatus 10B. Fig. 10 is a block diagram showing the control configuration of the air conditioning apparatus 10B according to the third embodiment.

[0123] The control configuration of the air conditioning apparatus 10B of Embodiment 3 differs from the control configuration of the air conditioning apparatus 10 of Embodiment 1 shown in Fig. 4 in the following points. The second control device 32 sends a control signal to the second on-off valve 94 to control the second on-off valve 94 to either an open state or a closed state. The second control device 32 sends a control signal to the third on-off valve 95 to control the third on-off valve 95 to either an open state or a closed state.

[0124] (Control Example of Defrosting Mode) Fig. 11 is a flowchart showing a control example of the defrosting mode according to embodiment 3. The control shown in Fig. 11 is executed by the first control device 31 and the second control device 32 shown in Figs. 9 and 10.

[0125] The control example of the defrosting mode shown in Fig. 11 differs from the control example of the defrosting mode shown in Fig. 5 in that step S2b and step S4b are executed. Step S2b is executed between step S2 and step S3. Step S4b is executed after step S4.

[0126] In step S2b, the second control device 32 operates the second on-off valve 94 and the third on-off valve 95 in the defrosting mode so that the refrigerant discharged from the compressor 1 does not flow through the outdoor heat exchanger 2 but flows through the bypass path 23 that bypasses the outdoor heat exchanger 2.

[0127] Specifically, in step S2b, the second control device 32 controls the second on-off valve 94 to a closed state and the third on-off valve 95 to an open state. As a result, in the defrost mode, in the outdoor unit 12B, the refrigerant discharged from the compressor 1 flows to the indoor unit 11 via the bypass path 23 without passing through the outdoor heat exchanger 2. Therefore, in the air conditioning apparatus 10B, heat exchange using the outdoor heat exchanger 2 is not performed in the defrost mode.

[0128] In step S4b, the second control device 32 operates the second on-off valve 94 and the third on-off valve 95 so that the refrigerant discharged from the compressor 1 flows through the outdoor heat exchanger 2 without flowing through the bypass path 23 that bypasses the outdoor heat exchanger 2.

[0129] Specifically, in step S4b, the second control device 32 controls the second on-off valve 94 to an open state and controls the third on-off valve 95 to a closed state. As a result, in the cooling mode after the defrosting mode ends, the refrigerant discharged from the compressor 1 in the outdoor unit 12B flows to the indoor unit 11 via the outdoor heat exchanger 2 without passing through the bypass path 23.

[0130] In addition to the technical effects obtained with the air conditioner 10 of Embodiment 1, the air conditioner 10B of Embodiment 3 described above can achieve the following effect. In the air conditioner 10B, in defrost mode, heat exchange using the outdoor heat exchanger 2 is not performed. In that case, the high-temperature, high-pressure refrigerant discharged from the compressor 1 flows directly into the second indoor heat exchanger 3 in the indoor unit 11 without undergoing heat exchange in the outdoor unit 12B.

[0131] Therefore, in the defrosting mode, the temperature of the refrigerant flowing into the second indoor heat exchanger 3 is higher than in the cooling mode. As a result, in the defrosting mode, the amount of condensation heat of the refrigerant generated by heat exchange in the second indoor heat exchanger 3 is greater than in the cooling mode, and the amount of heat released by the second indoor heat exchanger 3 is therefore greater.

[0132] In this way, if the amount of heat dissipated by the second indoor heat exchanger 3 is greater in defrost mode than in cooling mode, the amount of heat of the air blown from the second indoor heat exchanger 3 to the first indoor heat exchanger 5 is greater in defrost mode than in cooling mode, making it easy to defrost the first indoor heat exchanger 5.

[0133] Embodiment 4. Figure 12 is a diagram showing the configuration of an air conditioning apparatus 10C according to Embodiment 4. The indoor unit 11A according to Embodiment 4 is configured such that the indoor unit 11 shown in Figure 1 etc. further includes a third refrigerant path 60c and a second expansion valve 96. In Embodiment 4, the first control device 31 controls the amount of condensation heat in the second indoor heat exchanger 3 by adjusting the opening degree of the first expansion valve 4 and the opening degree of the second expansion valve 96.

[0134] (Overall Configuration of Air Conditioning Apparatus 10C) Referring to FIG. 12, the configuration of air conditioning apparatus 10C differs from the configuration of air conditioning apparatus 10 in FIG. 1 in the following respects.

[0135] The indoor unit 11A of the air conditioning apparatus 10C is provided with a third refrigerant path 60c that connects a first refrigerant path 60a between the outdoor heat exchanger 2 and the second indoor heat exchanger 3 and a second refrigerant path 60b between the first indoor heat exchanger 5 and the second indoor heat exchanger 3. Specifically, the third refrigerant path 60c is provided in the second refrigerant path 60b between the first indoor heat exchanger 5 and the first expansion valve 4. The indoor unit 11A of the air conditioning apparatus 10C is provided with a second expansion valve 96 that decompresses the refrigerant in the third refrigerant path 60c. The second expansion valve 96 is, for example, an electronic expansion valve. The indoor unit 11A of the air conditioning apparatus 10C is further provided with a fourth opening / closing valve 97 in the first refrigerant path 60a that opens and closes the first refrigerant path 60a.

[0136] In the air conditioning apparatus 10C, in the cooling mode and the defrosting mode, the fourth opening / closing valve 97 is basically controlled to an open state.

[0137] The opening degree of the second expansion valve 96 is controlled by the first control device 31. The first control device 31 controls the amount of condensation heat of the second indoor heat exchanger 3 by adjusting the opening degree of the first expansion valve 4 and the opening degree of the second expansion valve 96, as will be described below.

[0138] For example, when the first control device 31 executes control to increase the opening degree of the first expansion valve 4 and decrease the opening degree of the second expansion valve 96, the flow rate of the refrigerant in the second indoor heat exchanger 3 increases. The amount of condensation heat in the second indoor heat exchanger 3 increases in response to the increase in the flow rate of the refrigerant in the second indoor heat exchanger 3. When the amount of condensation heat in the second indoor heat exchanger 3 increases in this way, the amount of heat radiation increases according to the amount of condensation heat of the refrigerant generated by heat exchange in the second indoor heat exchanger 3.

[0139] Furthermore, when the first control device 31 executes control to decrease the opening degree of the first expansion valve 4 and increase the opening degree of the second expansion valve 96, the flow rate of the refrigerant in the second indoor heat exchanger 3 decreases. The amount of condensation heat in the second indoor heat exchanger 3 decreases in response to the decrease in the flow rate of the refrigerant in the second indoor heat exchanger 3. When the amount of condensation heat in the second indoor heat exchanger 3 decreases in this way, the amount of heat radiation corresponding to the amount of condensation heat of the refrigerant generated by heat exchange in the second indoor heat exchanger 3 decreases.

[0140] In the air conditioning unit 10C, in cooling mode, the first control device 31 controls the opening of the first expansion valve 4 to a first set opening and the opening of the second expansion valve 96 to a second set opening, thereby making it possible to reheat the air blown in the first blowing direction in the second indoor heat exchanger 3 with a constant amount of heat dissipation.

[0141] In addition, in the air conditioning unit 10C, in cooling mode, the first control device 31 controls the opening degree of the first expansion valve 4 and the opening degree of the second expansion valve 96, thereby making it possible to adjust the amount of heat dissipated by the second indoor heat exchanger 3 when reheating air blown in the first blowing direction.

[0142] In the air conditioning unit 10C, in defrost mode, the first control device 31 controls the opening of the first expansion valve 4 to a third set opening degree and the opening of the second expansion valve 96 to a fourth set opening degree, thereby making it possible to heat the air blown in the second blowing direction in the second indoor heat exchanger 3 with a constant amount of heat radiation.

[0143] In addition, in the air conditioning unit 10C, in defrost mode, the first control device 31 controls the adjustment of the opening degree of the first expansion valve 4 and the opening degree of the second expansion valve 96, thereby making it possible to adjust the amount of heat dissipation from the second indoor heat exchanger 3, which heats the air blown in the second blowing direction.

[0144] For example, the first control device 31 can increase the amount of heat of the air blown in the second air blowing direction in the defrost mode by controlling the first control device 31 to increase the opening degree of the first expansion valve 4 and decrease the opening degree of the second expansion valve 96. On the other hand, the first control device 31 can decrease the amount of heat of the air blown in the second air blowing direction in the defrost mode by controlling the first control device 31 to decrease the opening degree of the first expansion valve 4 and increase the opening degree of the second expansion valve 96.

[0145] In addition, in the air conditioning unit 10C, in the cooling mode and the defrost mode, when the first control device 31 controls the fourth opening / closing valve 97 to the closed state, the refrigerant stops flowing in the second indoor heat exchanger 3, and it is possible to reduce the amount of heat in the air blown in the first air blowing direction and the air blown in the second air blowing direction.

[0146] (Control Configuration of Air Conditioning Apparatus 10C) Next, the control configuration of the air conditioning apparatus 10C will be described. Fig. 13 is a block diagram showing the control configuration of the air conditioning apparatus 10C according to the fourth embodiment.

[0147] The control configuration of the air conditioning apparatus 10C of Embodiment 4 differs from the control configuration of the air conditioning apparatus 10 of Embodiment 1 shown in Fig. 4 in the following points: The first control device 31 sends a control signal to the second expansion valve 96 to control the opening degree of the second expansion valve 96. The first control device 31 sends a control signal to the fourth on-off valve 97 to control the fourth on-off valve 97 to either an open state or a closed state.

[0148] (Control Example of Defrosting Mode) Fig. 14 is a flowchart showing a control example of the defrosting mode according to embodiment 4. The control shown in Fig. 14 is executed by the first control device 31 shown in Figs.

[0149] The control example of the defrosting mode shown in Fig. 14 differs from the control example of the defrosting mode shown in Fig. 5 in that step S2c and step S4c are executed. Step S2c is executed between step S2 and step S3. Step S4c is executed after step S4.

[0150] In step S2c, the first control device 31 executes control to adjust the opening degree of the first expansion valve 4 and the opening degree of the second expansion valve 96 in order to increase the amount of condensation heat in the second indoor heat exchanger 3 in the indoor unit 11A. Specifically, in step S2c, the first control device 31 executes control to increase the opening degree of the first expansion valve 4 and decrease the opening degree of the second expansion valve 96. As a result, in the defrost mode, the amount of condensation heat in the second indoor heat exchanger 3 increases, and the amount of heat dissipated in the second indoor heat exchanger 3 increases.

[0151] In step S4c, the first control device 31 executes control to adjust the opening degree of the first expansion valve 4 and the opening degree of the second expansion valve 96 in order to restore the amount of condensation heat of the second indoor heat exchanger 3 in the indoor unit 11A to the amount of condensation heat in cooling mode. Specifically, in step S4c, the first control device 31 executes control to decrease the opening degree of the first expansion valve 4 and increase the opening degree of the second expansion valve 96. This makes it possible to restore the amount of condensation heat of the second indoor heat exchanger 3 in the indoor unit 11A to the amount of condensation heat in cooling mode.

[0152] The air conditioning apparatus 10C of embodiment 4 described above can achieve the following effect in addition to the technical effects achieved by the air conditioning apparatus 10 of embodiment 1. In the air conditioning apparatus 10C, by controlling the opening of the first expansion valve 4 and the opening of the second expansion valve 96 in defrost mode, the amount of condensation heat of the refrigerant generated by heat exchange in the second indoor heat exchanger 3 increases compared to cooling mode, and the amount of heat dissipated in the second indoor heat exchanger 3 increases.

[0153] In this way, if the amount of heat dissipated by the second indoor heat exchanger 3 is greater in defrost mode than in cooling mode, the amount of heat in the air flowing from the second indoor heat exchanger 3 to the first indoor heat exchanger 5 is greater in defrost mode than in cooling mode, making it easier to defrost the first indoor heat exchanger 5.

[0154] Embodiment 5. Figure 15 is a diagram showing the configuration of an air conditioning apparatus 10D according to embodiment 5. The outdoor unit 12C according to embodiment 5 is configured by further including a four-way valve 9 in addition to the indoor unit 12 shown in Figure 1 etc. In embodiment 5, in the defrosting mode, the second control device 32 controls heating operation by switching the flow path of the four-way valve 9, and the first control device 31 controls switching the air blowing direction of the air blower 7.

[0155] (Overall Configuration of Air Conditioning Apparatus 10D) Referring to FIG. 15, the configuration of air conditioning apparatus 10D differs from the configuration of air conditioning apparatus 10 in FIG. 1 in the following respects.

[0156] In the outdoor unit 12C of the air conditioning apparatus 10D, a four-way valve 9 is provided in the path between the compressor 1 and the outdoor heat exchanger 2. The four-way valve 9 switches between a first path indicated by a solid line and a second path indicated by a dashed line. A second control device 32 controls the switching of the path of the four-way valve 9.

[0157] In the cooling mode, the second control device 32 controls the four-way valve 9 so that the flow path of the four-way valve 9 becomes the first flow path. In the defrosting mode, the second control device 32 controls the four-way valve 9 so that the flow path of the four-way valve 9 becomes the second flow path.

[0158] (Control Configuration of Air Conditioning Apparatus 10D) Next, the control configuration of the air conditioning apparatus 10D will be described. Fig. 16 is a block diagram showing the control configuration of the air conditioning apparatus 10D according to the fifth embodiment.

[0159] The control configuration of the air conditioning apparatus 10D of Embodiment 5 differs from the control configuration of the air conditioning apparatus 10 of Embodiment 1 shown in Figure 4 in the following points: The second control device 32 sends a control signal to the four-way valve 9 and controls the switching of the flow path of the four-way valve 9.

[0160] (Example of Operation of Air Conditioning Apparatus 10D) Next, the operation of the air conditioning apparatus 10D will be described using Figs. 15 and 16 .

[0161] In the cooling mode, the second control device 32 controls the four-way valve 9 so that the flow path of the four-way valve 9 becomes the first flow path. As a result, high-temperature, high-pressure gas refrigerant discharged from the discharge port of the compressor 1 flows into the outdoor heat exchanger 2 through the first flow path of the four-way valve 9. The subsequent flow of the refrigerant is the same as the flow of the refrigerant in the cooling mode described in embodiment 1. As a result, in the cooling mode, the cooling operation that performs the cooling action described in embodiment 1 is performed.

[0162] In the cooling mode, the first air blowing control is executed, which is the same as the control of the air blower 7 in the cooling mode described in the first embodiment, and air is blown in the first air blowing direction.

[0163] In the defrosting mode, the second control device 32 controls the four-way valve 9 so that the flow path of the four-way valve 9 becomes the second flow path. As a result, the high-temperature, high-pressure gas refrigerant discharged from the discharge port of the compressor 1 flows out of the outdoor unit 12C through the second flow path of the four-way valve 9 and then flows into the indoor unit 11 through the second extension pipe 62.

[0164] In the indoor unit 11, the refrigerant sent from the compressor 1 flows into the first indoor heat exchanger 5. In the first indoor heat exchanger 5, heat is exchanged between the high-temperature, high-pressure gas refrigerant that has flowed in and the indoor air. The gas refrigerant releases heat through heat exchange with the indoor air and is condensed to become high-pressure liquid refrigerant. In the defrost mode, the indoor air is heated by heat exchange in the first indoor heat exchanger 5. The refrigerant that has changed from gas refrigerant to liquid refrigerant in the first indoor heat exchanger 5 flows into the first expansion valve 4.

[0165] In the first expansion valve 4, the high-pressure liquid refrigerant that has flowed in is expanded and decompressed to become a low-temperature, low-pressure two-phase gas-liquid refrigerant. The two-phase gas-liquid refrigerant that has been expanded and decompressed in the first expansion valve 4 flows into the second indoor heat exchanger 3.

[0166] In the second indoor heat exchanger 3, heat is exchanged between the inflowing gas-liquid two-phase refrigerant and the indoor air. The gas-liquid two-phase refrigerant evaporates through heat exchange with the indoor air, becoming a low-temperature, low-pressure gas refrigerant. In the defrost mode, the indoor air is cooled by heat exchange in the first indoor heat exchanger 5.

[0167] The refrigerant that has changed from the gas-liquid two-phase refrigerant to gas refrigerant in the second indoor heat exchanger 3 flows out of the second indoor heat exchanger 3. The refrigerant that has flowed out of the second indoor heat exchanger 3 flows out of the indoor unit 11 and into the outdoor unit 12C via the second extension pipe 62.

[0168] In the outdoor unit 12C, the refrigerant sent from the second indoor heat exchanger 3 flows into the outdoor heat exchanger 2. In the outdoor heat exchanger 2, heat is exchanged between the flowing refrigerant and the outdoor air. As a result, the refrigerant is further evaporated in the outdoor heat exchanger 2. The refrigerant further evaporated in the outdoor heat exchanger 2 passes through the flow path of the four-way valve 9 and flows into the compressor 1 from the suction port of the compressor 1.

[0169] As described above, in the defrost mode, a heating operation is performed in which the refrigerant flows in the refrigerant circuit 60 in the order of compressor 1, first indoor heat exchanger 5, second indoor heat exchanger 3, and outdoor heat exchanger 2, and then returns to the compressor 1. In the defrost mode, this heating operation enables defrosting in the first indoor heat exchanger 5.

[0170] In the defrosting mode, in addition to the heating operation in the refrigerant circuit 60, the impeller 70 is rotated in the second rotation direction, thereby performing second air blowing control to blow air in the second air blowing direction indicated by the dashed arrow in Fig. 15. Specifically, the second air blowing direction is the direction in which air flows through the humidifier 8, the impeller 70, the second indoor heat exchanger 3, and the first indoor heat exchanger 5 in this order.

[0171] In this way, in the defrost mode in which air is blown in the second air blowing direction by the second air blowing control, the air that has been cooled once by the second indoor heat exchanger 3 is heated by the first indoor heat exchanger 5. As a result, in the defrost mode, in addition to performing the heating operation, the first indoor heat exchanger 5 adjusts the sensible heat of the air to be blown, thereby adjusting the temperature of the air to be blown.

[0172] In the defrost mode in which the air is blown in the second air blowing direction by the second air blowing control, the air to be blown is humidified by the humidifier 8. As a result, in the defrost mode, in addition to performing the heating operation, the humidifier 8 adjusts the latent heat of the air to be blown, thereby adjusting the humidity.

[0173] In the defrosting mode, the air blown in the second blowing direction is temperature-adjusted by the first indoor heat exchanger 5 and humidity-adjusted by the humidifier 8, thereby controlling the indoor temperature and humidity within a certain range.

[0174] In this way, in the defrost mode, heating operation is performed, which facilitates defrosting of the first indoor heat exchanger 5. In the defrost mode, the air blown in the second air blowing direction by the second air blowing control is cooled and dehumidified by the second indoor heat exchanger 3 before being heated by the first indoor heat exchanger 5. As a result, in the defrost mode, the ability to dehumidify the indoor air can be improved compared to when the unit is simply in heating operation.

[0175] (Control Example of Defrosting Mode) Fig. 17 is a flowchart showing a control example of the defrosting mode according to embodiment 5. The control shown in Fig. 17 is executed by the first control device 31 shown in Figs.

[0176] The control example of the defrost mode shown in Fig. 17 differs from the control example of the defrost mode shown in Fig. 5 in that step S1a and step S3a are executed. Step S1a is executed between step S1 and step S2. Step S3a is executed between step S3 and step S4.

[0177] In step S1a, the second control device 32 controls the operation of each device in the refrigerant circuit 60 to switch from cooling operation to heating operation. Specifically, in step S1a, the second control device 32 controls the operation to switch from cooling operation to heating operation by switching the flow path of the four-way valve 9 from the first flow path to the second flow path.

[0178] In step S3a, the second control device 32 controls the operation of each device in the refrigerant circuit 60 to switch from heating operation to cooling operation. Specifically, in step S3a, the second control device 32 controls the operation to switch from heating operation to cooling operation by switching the flow path of the four-way valve 9 from the second flow path to the first flow path.

[0179] The air conditioning apparatus 10D of the fifth embodiment described above can achieve the following effect in addition to the technical effect achieved by the air conditioning apparatus 10 of the first embodiment. In the air conditioning apparatus 10D, by performing heating operation in defrost mode, defrosting of the first indoor heat exchanger 5 can be easily performed. In the air conditioning apparatus 10D, in defrost mode, the blower device 7 is controlled to blow air in the second blowing direction, which blows air to the first indoor heat exchanger 5 via the second indoor heat exchanger 3. In this way, in the defrost mode, the air conditioning apparatus 10D switches the blowing direction so that indoor air that has been once cooled and dehumidified by the second indoor heat exchanger 3 is heated by the first indoor heat exchanger 5. This makes it possible to suppress a decrease in the dehumidification capacity (dehumidification amount) of indoor air during defrost operation.

[0180] Sixth Embodiment In a sixth embodiment, another example of a configuration in which the air blowing direction of the air blowing device 7A is switched between the first air blowing direction and the second air blowing direction as described above will be described.

[0181] (Overall Configuration of Air Conditioning Apparatus 10E) FIGS. 18 and 19 are cross-sectional views showing the configuration of a blower device 7A of an air conditioning apparatus 10E according to Embodiment 6.

[0182] 18 shows a state in which a first air flow path 301 that blows air in a first air flow direction is formed as an air flow path between the first opening 41 and the impeller 70 in the air blowing device 7A. In Fig. 18, the air flow direction when the first air flow path 301 is formed is indicated by a solid arrow.

[0183] 19 shows a state in which a second air flow path 302 that blows air in a second air flow direction is formed as an air flow path between the first opening 41 and the impeller 70 in the air blower device 7A. In Fig. 19, the air flow direction when the second air flow path 302 is formed is indicated by a dashed arrow.

[0184] 18 and 19, the configuration of blower device 7A differs from the configuration of blower device 7 of FIG. 1 in the following points.

[0185] In the blower device 7A, a plurality of movable members 71, 72, 73, and 74 are provided inside the air passage 300 between the first opening 41 and the impeller 70. In the blower device 7A, the plurality of movable members 71, 72, 73, and 74 can be operated.

[0186] In the blower device 7A, by operating multiple movable members 71, 72, 73, and 74, it is possible to switch the air flow path 300 between the first opening 41 and the impeller 70 between either a first air flow path 301 that sends the air generated by the impeller 70 in a first air flow direction, or a second air flow path 302 that sends the air generated by the impeller 70 in a second air flow direction.

[0187] Next, the configuration of the blower 7A will be described in detail. As shown in Figures 18 and 19, a plurality of fixed walls 101, 102, 103, and 104 and a plurality of movable members 71, 72, 73, and 74 are provided between the first opening 41 and the impeller 70.

[0188] The movable member 71 is plate-shaped and rotatable about a rotation shaft 81. The movable member 71 rotates in response to the rotation shaft 81 being rotated by a drive source such as a motor. The movable member 72 is plate-shaped and rotatable about a rotation shaft 82. The movable member 72 rotates in response to the rotation shaft 82 being rotated by a drive source such as a motor. The movable member 73 is plate-shaped and rotatable about a rotation shaft 83. The movable member 73 rotates in response to the rotation shaft 83 being rotated by a drive source such as a motor. The movable member 74 is plate-shaped and rotatable about a rotation shaft 84. The movable member 74 rotates in response to the rotation shaft 84 being rotated by a drive source such as a motor.

[0189] The operating states of the plurality of movable members 71 , 72 , 73 , and 74 are controlled by a first control device 31 .

[0190] 18 , first air flow passage 301 is formed so that air that enters air flow passage 300 through first opening 41 can be blown through first indoor heat exchanger 5 to second indoor heat exchanger 3, then through impeller 70 to humidifier 8, and then exit through second opening 42. The direction in which air is blown in first air flow passage 301 corresponds to the first air blowing direction in the first embodiment.

[0191] As shown in Figure 18, the first air flow path 301 is an air passage formed by forming a first wall portion 111 in which the fixed wall 101, the movable member 71, the fixed wall 103, and the movable member 73 are lined up in a series, and a second wall portion 112 in which the fixed wall 102, the movable member 72, the fixed wall 104, and the movable member 74 are lined up in a series.

[0192] As shown in Figure 19, the second air flow path 302 is formed so that air that enters the inside of the air flow path 300 from the first opening 41 is blown through the second indoor heat exchanger 3 to the first indoor heat exchanger 5, then blown through the impeller 70 to the humidifier 8, and exits from the second opening 42.

[0193] As shown in Figure 19, the second air flow path 302 is an air passage formed by the rotation of movable members 71, 72, 73, and 74, thereby forming a series of walls as follows.

[0194] A series of walls is formed by the fixed wall 102, the movable member 71, and the fixed wall 103. Furthermore, a series of walls is formed by the fixed wall 103, the movable member 71, and the movable member 72. Furthermore, a series of walls is formed by the movable member 72, the inner wall of the air flow path 300, and the movable member 73. Furthermore, a series of walls is formed by the movable member 74 and the fixed wall 104.

[0195] The combination of these series of walls forms second air flow path 302 through which air that has entered air flow path 300 from first opening 41 is blown through second indoor heat exchanger 3 to first indoor heat exchanger 5, and then through impeller 70 to humidifier 8. The direction in which air is blown in second air flow path 302 corresponds to the second air blowing direction in the first embodiment.

[0196] Impeller 70 is rotated in the same direction when first air passage 301 is formed and when second air passage 302 is formed. When first air passage 301 is formed, air that enters air passage 300 from first opening 41 passes through first air passage 301 and reaches impeller 70. When second air passage 302 is formed, air that enters air passage 300 from first opening 41 passes through second air passage 302 and reaches impeller 70.

[0197] (Control Configuration of Air Conditioning Apparatus 10E) Next, the control configuration of the air conditioning apparatus 10E will be described. Fig. 20 is a block diagram showing the control configuration of the air conditioning apparatus 10E according to the sixth embodiment.

[0198] The control configuration of the air conditioning apparatus 10E of the fifth embodiment differs from the control configuration of the air conditioning apparatus 10 of the first embodiment shown in FIG. 4 in the following points.

[0199] The first control device 31 sends a control signal to the impeller drive device 700 to rotate the impeller 70. The first control device 31 sends a control signal to the first drive device 810 that drives the movable member 71 to control it to rotate the movable member 71. The first control device 31 sends a control signal to the second drive device 820 that drives the movable member 72 to control it to rotate the movable member 72. The first control device 31 sends a control signal to the third drive device 830 that drives the movable member 73 to control it to rotate the movable member 73. The first control device 31 sends a control signal to the fourth drive device 840 that drives the movable member 74 to control it to rotate the movable member 74.

[0200] (Control Example of Defrosting Mode) Fig. 21 is a flowchart showing a control example of the defrosting mode according to embodiment 6. The control shown in Fig. 21 is executed by the first control device 31 shown in Fig. 20 .

[0201] The control example of the defrost mode shown in FIG. 17 differs from the control example of the defrost mode shown in FIG. 5 in that step S2d is executed instead of step S2 in FIG. 5, and step S4d is executed instead of step S4 in FIG. 5.

[0202] In step S2d, the second control device 32 operates the multiple movable members 71, 72, 73, and 74 to switch the air blowing direction of the air blower 7A of the indoor unit 11 from the first air blowing direction to the second air blowing direction. This forms the first air blowing path 301 in the air blower 7A. In this way, in step S2d, defrosting operation in the defrost mode is started.

[0203] In step S4d, the second control device 32 operates the multiple movable members 71, 72, 73, and 74 to switch the air blowing direction of the air blower 7A of the indoor unit 11 from the second air blowing direction to the first air blowing direction. This forms the second air blowing path 302 in the air blower 7A. In this way, in step S4d, the defrosting operation in the defrost mode is ended.

[0204] In the air conditioning device 10E described above, by operating the multiple movable members 71, 72, 73, and 74, it is possible to switch the interior of the air flow path 300 between a first air flow path 301 that sends the air generated by the impeller 70 in a first air flow direction, and a second air flow path 302 that sends the air generated by the impeller 70 in a second air flow direction. This makes it possible to switch between the first air flow direction and the second air flow direction in the air conditioning device 10E without switching the rotation direction of the impeller 70.

[0205] (Summary) Hereinafter, the embodiment will be summarized with reference to the drawings again.

[0206] (Item 1) The present disclosure relates to an air conditioner (air conditioner 10, 10A, 10B, 10C, 10D, 10E). The air conditioner (air conditioner 10, 10A, 10B, 10C, 10D, 10E) includes an outdoor unit (outdoor unit 12, 12A, 12B, 12C), an indoor unit (indoor unit 11, 11A), and a control device (first control device 31, second control device 32) that controls air conditioning. The outdoor unit (outdoor unit 12, 12A, 12B, 12C) includes a compressor (compressor 1) that compresses a refrigerant, and an outdoor heat exchanger (outdoor heat exchanger 2) that exchanges heat between the refrigerant and outdoor air. ), and the indoor unit (indoor unit 11, 11A) includes a first indoor heat exchanger (first indoor heat exchanger 5) that exchanges heat between the refrigerant and the indoor air, a second indoor heat exchanger (second indoor heat exchanger 3) that exchanges heat between the refrigerant and the indoor air, a first expansion valve (first expansion valve 4) that is provided in a refrigerant path between the first indoor heat exchanger (first indoor heat exchanger 5) and the second indoor heat exchanger (second indoor heat exchanger 3) and that reduces the pressure of the refrigerant, and and a blower (blower device 7, 7A) capable of blowing air in either a first blowing direction in which the air is blown through the compressor (compressor 1), the outdoor heat exchanger (outdoor heat exchanger 2), the second indoor heat exchanger (second indoor heat exchanger 3), and a second blowing direction in which the air is blown through the second indoor heat exchanger (second indoor heat exchanger 3) and the first indoor heat exchanger (first indoor heat exchanger 5). The refrigerant circulates through the first expansion valve (first expansion valve 4), the first expansion valve (first expansion valve 5), and the first indoor heat exchanger (first indoor heat exchanger 5) in that order, and the control devices (first control device 31, second control device 32) control the air blowers (air blowers 7, 7A) to blow air in the first air blowing direction during the cooling operation, and control the air blowers (air blowers 7, 7A) to blow air in the second air blowing direction during the defrosting operation (steps S1 to S4).

[0207] With this configuration, the air blower can blow air in either a first air blowing direction, in which the air passes through the first indoor heat exchanger and then to the second indoor heat exchanger, or a second air blowing direction, in which the air passes through the second indoor heat exchanger and then to the first indoor heat exchanger. In the air conditioning apparatus, the control device controls the air blower to blow air in the first air blowing direction during cooling operation, and controls the air blower to blow air in the second air blowing direction during defrosting operation, thereby suppressing a decrease in dehumidifying capacity when the indoor heat exchanger is defrosted.

[0208] (2) In the air conditioning apparatus described in 1, the blower (blower 7) includes an impeller (impeller 70) that rotates to generate wind, and the control device (first control device 31) controls the impeller (impeller 70) to rotate in a first rotational direction when the blower (blower 7) blows air in the first blowing direction, and to rotate the impeller (impeller 70) in a second rotational direction opposite to the first rotational direction when the blower (blower 7) blows air in the second blowing direction (step S4).

[0209] With this configuration, when the blower device blows air in a first blowing direction, the impeller is controlled to rotate in a first rotation direction, and when the blower device blows air in a second blowing direction, the impeller is controlled to rotate in a second rotation direction opposite to the first rotation direction. This makes it easy for the air conditioning apparatus to switch the blowing direction of the blower device.

[0210] (Item 3) In the air conditioning apparatus described in Item 1, the blower (blower 7A) includes an impeller (impeller 70) that rotates to generate airflow, and airflow ducts (first airflow duct 301, second airflow duct 302) that send the air generated by the impeller (impeller 70) in the first airflow direction or the second airflow direction, and the airflow ducts (first airflow duct 301, second airflow duct 302) include a plurality of movable members (movable members 71, 72, 73, 74), and the plurality of movable members (movable members 71, 72, 73, 74) are operated to send the air generated by the impeller (impeller 70) in the first airflow direction. It is possible to switch between a first air passage (first air passage 301) and a second air passage (second air passage 302) that sends the air generated by the impeller (impeller 70) in the second air flow direction, and the control device (first control device 31) controls the operation of the plurality of movable members (movable members 71, 72, 73, 74) so ​​as to switch the air passage (first air passage 301, second air passage 302) to the first air passage (first air passage 301) in the cooling operation, and to switch the air passage (first air passage 301, second air passage 302) to the second air passage (second air passage 302) in the defrosting operation.

[0211] With this configuration, by operating the multiple movable members, it is possible to switch the air flow path between the first air flow path that sends air in the first air flow direction and the second air flow path that sends air in the second air flow direction. This allows the air conditioning device to switch between the first air flow direction and the second air flow direction without switching the rotation direction of the impeller.

[0212] (4) In the air conditioning apparatus described in any one of paragraphs 1 to 3, the control devices (first control device 31, second control device 32) control the refrigerant to circulate in the following order during the defrosting operation: the compressor (compressor 1), the outdoor heat exchanger (outdoor heat exchanger 2), the second indoor heat exchanger (second indoor heat exchanger 3), the first expansion valve (first expansion valve 4), and the first indoor heat exchanger (first indoor heat exchanger 5).

[0213] With this configuration, during defrosting operation, the refrigerant is controlled to circulate through the compressor, the outdoor heat exchanger, the second indoor heat exchanger, the first expansion valve, and the first indoor heat exchanger in this order, thereby enabling the air conditioner to defrost while performing cooling operation.

[0214] (Clause 5) In the air conditioning apparatus described in any one of clauses 1 to 4, the outdoor heat exchanger (outdoor heat exchanger 2) includes a first outdoor heat exchanger (first outdoor heat exchanger 21) and a second outdoor heat exchanger (second outdoor heat exchanger 22), and the control device (second control device 32) controls the first outdoor heat exchanger (first outdoor heat exchanger 21) and the second outdoor heat exchanger (second outdoor heat exchanger 22) to exchange heat between the refrigerant and the indoor air during the cooling operation, and controls the first outdoor heat exchanger (first outdoor heat exchanger 21) to exchange heat between the refrigerant and the indoor air without using the second outdoor heat exchanger (second outdoor heat exchanger 22) during the defrosting operation.

[0215] With this configuration, in cooling operation, control is performed to exchange heat between the refrigerant and the indoor air using the first outdoor heat exchanger and the second outdoor heat exchanger, and in defrosting operation, control is performed to exchange heat between the refrigerant and the indoor air using the first outdoor heat exchanger without using the second outdoor heat exchanger. As a result, in the air conditioner, the amount of heat released by the second indoor heat exchanger increases in defrosting operation, making defrosting easier.

[0216] (Item 6) In the air conditioner described in any one of Items 1 to 4, the outdoor unit (outdoor unit 12B) further includes a bypass path (bypass path 23) that causes refrigerant discharged from the compressor (compressor 1) to bypass the outdoor heat exchanger (outdoor heat exchanger 2) and flow to the indoor unit, and the control device (second control device 32) controls the cooling operation to perform heat exchange between the refrigerant and the outdoor air using the outdoor heat exchanger (outdoor heat exchanger 2) without using the bypass path (bypass path 23) (step S4b), and controls the defrosting operation to cause the refrigerant to flow to the indoor unit (indoor unit 11) via the bypass path (bypass path 23) without using the outdoor heat exchanger (outdoor heat exchanger 2) (step S2b).

[0217] With this configuration, in cooling operation, the outdoor heat exchanger is used to exchange heat between the refrigerant and the outdoor air without using the bypass passage, and in defrosting operation, the refrigerant is circulated to the indoor unit via the bypass passage without using the outdoor heat exchanger. As a result, in the air conditioner, the amount of heat released by the second indoor heat exchanger increases during defrosting operation, making defrosting easier.

[0218] (7) In the air conditioner according to any one of paragraphs 1 to 6, in the indoor unit, a third refrigerant path (first refrigerant path 60a) is connected between the outdoor heat exchanger (outdoor heat exchanger 2) and the second indoor heat exchanger (second indoor heat exchanger 3), and a second refrigerant path (second refrigerant path 60b) is connected between the first indoor heat exchanger (first indoor heat exchanger 5) and the second indoor heat exchanger (second indoor heat exchanger 3). The control device (first control device 31) controls the amount of condensation heat of the second indoor heat exchanger (second indoor heat exchanger 3) by adjusting the opening degree of the first expansion valve (first expansion valve 4) and the opening degree of the second expansion valve (second expansion valve 96) (step S2c, step S4c).

[0219] With this configuration, the amount of condensation heat in the second indoor heat exchanger is controlled by adjusting the opening degrees of the first expansion valve and the second expansion valve. As a result, in the air conditioning apparatus, by adjusting the opening degrees of the first expansion valve and the second expansion valve, the amount of heat dissipated by the second indoor heat exchanger during defrosting operation is increased, making defrosting easier.

[0220] (Clause 8) In the air conditioning apparatus described in any one of clauses 1 to 3, the control devices (first control device 31, second control device 32) control the refrigerant to circulate in the order of the compressor (compressor 1), the first indoor heat exchanger (first indoor heat exchanger 5), the first expansion valve (first expansion valve 4), the second indoor heat exchanger (second indoor heat exchanger 3), and the outdoor heat exchanger (outdoor heat exchanger 2) during the defrosting operation.

[0221] With this configuration, during defrosting operation, control is performed to circulate the refrigerant through the compressor, the first indoor heat exchanger, the first expansion valve, the second indoor heat exchanger, and the outdoor heat exchanger in that order. As a result, the air conditioner performs heating operation during defrosting operation, making defrosting easy.

[0222] (Clause 9) In the air conditioning apparatus described in any one of clauses 1 to 8, the indoor unit (indoor unit 11, 11A) further includes a humidifier (humidifier 8) that is provided downwind in the first air blowing direction from the second indoor heat exchanger (second indoor heat exchanger 3) and humidifies the air blown in the first air blowing direction and the air blown in the second air blowing direction.

[0223] According to this configuration, a humidifier is further provided, which is located downwind of the second indoor heat exchanger in the first air blowing direction and humidifies the air blown in the first air blowing direction and the air blown in the second air blowing direction, thereby enabling the air conditioning apparatus to adjust the humidity of the air being blown.

[0224] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims.

[0225] 10, 10A, 10B, 10C, 10D, 10E Air conditioning apparatus, 12, 12A, 12B, 12C Outdoor unit, 11, 11A Indoor unit, 31 First control device, 32 Second control device, 1 Compressor, 2 Outdoor heat exchanger, 5 First indoor heat exchanger, 3 Second indoor heat exchanger, 7, 7A Blower, 70 Impeller, 301 First air flow path, 302 Second air flow path, 71, 72, 73, 74 Movable member, 23 Bypass path, 60a First refrigerant path, 60b Second refrigerant path, 60c Third refrigerant path, 96 Second expansion valve, 8 Humidifier.

Claims

1. An air conditioner comprising an outdoor unit, an indoor unit, and a control device for controlling air conditioning, wherein the outdoor unit includes a compressor for compressing a refrigerant, and an outdoor heat exchanger for exchanging heat between the refrigerant and outdoor air, wherein the indoor unit includes a first indoor heat exchanger for exchanging heat between the refrigerant and indoor air, a second indoor heat exchanger for exchanging heat between the refrigerant and indoor air, a first expansion valve for reducing the pressure of the refrigerant provided in a refrigerant path between the first indoor heat exchanger and the second indoor heat exchanger, and a blower capable of blowing air in either a first blowing direction for blowing air via the first indoor heat exchanger to the second indoor heat exchanger or a second blowing direction for blowing air via the second indoor heat exchanger to the first indoor heat exchanger, wherein in cooling operation, the refrigerant circulates in the order of the compressor, the outdoor heat exchanger, the second indoor heat exchanger, the first expansion valve, and the first indoor heat exchanger, and wherein the control device The air conditioner controls the blower so as to blow air in the first air blowing direction in the cooling operation, and controls the blower so as to blow air in the second air blowing direction in the defrosting operation.

2. The air conditioning apparatus of claim 1, wherein the blower includes an impeller that rotates to generate wind, and the control device controls the impeller to rotate in a first rotational direction when the blower blows air in the first blowing direction, and to rotate the impeller in a second rotational direction opposite to the first rotational direction when the blower blows air in the second blowing direction.

3. The air conditioning apparatus of claim 1, wherein the air blowing device includes an impeller that rotates to generate air, and an air duct that sends the air generated by the impeller in the first air blowing direction or the second air blowing direction, the air duct includes a plurality of movable members, and by operating the plurality of movable members, it is possible to switch between a first air duct that sends the air generated by the impeller in the first air blowing direction and a second air duct that sends the air generated by the impeller in the second air blowing direction, and the control device controls the operation of the plurality of movable members so as to switch the air duct to the first air duct in the cooling operation and to switch the air duct to the second air duct in the defrosting operation.

4. An air-conditioning apparatus as described in any one of claims 1 to 3, wherein the control device controls the refrigerant to circulate through the compressor, the outdoor heat exchanger, the second indoor heat exchanger, the first expansion valve, and the first indoor heat exchanger in that order during the defrosting operation.

5. An air-conditioning apparatus as described in any one of claims 1 to 4, wherein the outdoor heat exchanger includes a first outdoor heat exchanger and a second outdoor heat exchanger, and the control device controls the first outdoor heat exchanger and the second outdoor heat exchanger to exchange heat between the refrigerant and the indoor air during the cooling operation, and controls the first outdoor heat exchanger without using the second outdoor heat exchanger to exchange heat between the refrigerant and the indoor air during the defrosting operation.

6. An air-conditioning apparatus as claimed in any one of claims 1 to 4, further comprising a bypass path in the outdoor unit for causing refrigerant discharged from the compressor to bypass the outdoor heat exchanger and flow to the indoor unit, and wherein the control device performs control to exchange heat between the refrigerant and the outdoor air using the outdoor heat exchanger without using the bypass path during the cooling operation, and performs control to cause the refrigerant to flow to the indoor unit via the bypass path without using the outdoor heat exchanger during the defrosting operation.

7. An air-conditioning apparatus as described in any one of claims 1 to 6, wherein the indoor unit is provided with a first refrigerant path between the outdoor heat exchanger and the second indoor heat exchanger and a third refrigerant path connecting a second refrigerant path between the first indoor heat exchanger and the second indoor heat exchanger, and a second expansion valve provided in the third refrigerant path for reducing the pressure of the refrigerant, and the control device controls the amount of condensation heat of the second indoor heat exchanger by adjusting the opening degree of the first expansion valve and the opening degree of the second expansion valve.

8. An air-conditioning apparatus as described in any one of claims 1 to 3, wherein the control device controls the refrigerant to circulate through the compressor, the first indoor heat exchanger, the first expansion valve, the second indoor heat exchanger, and the outdoor heat exchanger in that order during the defrosting operation.

9. An air conditioning apparatus as described in any one of claims 1 to 8, further comprising a humidifier provided in the indoor unit on the downwind side of the second indoor heat exchanger in the first air blowing direction, for humidifying the air blown in the first air blowing direction and the air blown in the second air blowing direction.

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