air conditioner

Abstract

To provide an air conditioner capable of suppressing deterioration of dehumidification efficiency.SOLUTION: An air conditioner includes: an outdoor unit having an outdoor heat exchanger, a compressor and an expansion valve; an indoor unit having an indoor heat exchanger; refrigerant piping that connects the outdoor heat exchanger, the compressor, the expansion valve and the indoor heat exchanger and in which a refrigerant circulates; a first temperature sensor that acquires a first temperature of a portion on an upstream side in the refrigerant flowing direction in the indoor heat exchanger and on a downstream side of an inflow portion to which the refrigerant flows in the indoor heat exchanger; a ventilation device that supplies outdoor air toward a downstream side region in the refrigerant flowing direction in the indoor heat exchanger; and a control section controlling the compressor, the expansion valve and the ventilation device on the basis of the first temperature in dehumidification operation including supplying the outdoor air.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present disclosure relates to an air conditioner. [Background technology]

[0002] Conventionally, there has been known an air conditioner that is configured with an indoor unit that is placed inside a room to be air-conditioned and an outdoor unit that is placed outside the room, as described in Patent Document 1. This air conditioner is configured so that outdoor air can be supplied from the outdoor unit to the indoor unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-91000 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for an air conditioner that can suppress a decrease in dehumidification efficiency.

[0005] Therefore, an object of the present disclosure is to provide an air conditioner that can suppress a decrease in dehumidification efficiency. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, according to one aspect of the present invention, an outdoor unit having an outdoor heat exchanger, a compressor, and an expansion valve; an indoor unit having an indoor heat exchanger; a refrigerant pipe that connects the outdoor heat exchanger, the compressor, the expansion valve, and the indoor heat exchanger and through which a refrigerant circulates; a first temperature sensor that acquires a first temperature of a portion of the indoor heat exchanger that is upstream in a flow direction of the refrigerant and downstream of an inflow portion into the indoor heat exchanger where the refrigerant flows; a ventilation device that supplies outdoor air toward a downstream region of the indoor heat exchanger in a flow direction of the refrigerant; a control unit that controls the compressor, the expansion valve, and the ventilation device based on the first temperature in the dehumidifying operation including supplying the outdoor air; An air conditioner comprising: [Effects of the Invention]

[0007] According to the present disclosure, an air conditioner capable of suppressing a decrease in dehumidification efficiency is provided. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of an air conditioner according to an embodiment of the present disclosure; [Figure 2] Schematic diagram of ventilation system [Figure 3] Schematic diagram of the ventilation system during ventilation operation [Figure 4] Schematic diagram of ventilation system during humidification operation [Figure 5] Schematic diagram of ventilation system during dehumidification operation [Figure 6] Block diagram showing a configuration for controlling an air conditioner [Figure 7A] Schematic diagram showing an example of the internal structure of an indoor unit [Figure 7B] Schematic diagram showing an example of the refrigerant flow in an indoor heat exchanger [Figure 8] Schematic diagram showing an example of the arrangement of multiple temperature sensors in an indoor heat exchanger. [Figure 9] Flowchart showing an example of the operation of an air conditioner [Figure 10] Flowchart showing an example of adsorption operation control [Figure 11] Timing chart of an example of control of an air conditioner [Figure 12] Flowchart showing adsorption operation control of a modified example [Figure 13] Flowchart showing adsorption operation control of a modified example [Figure 14] Flowchart showing adsorption operation control of a modified example DETAILED DESCRIPTION OF THE INVENTION

[0009] (Background to this disclosure) In recent years, air conditioners have become known that supply dry outdoor air to the room during cooling or dehumidifying operation. These air conditioners supply outdoor air to the indoor heat exchanger of the indoor unit, thereby preventing excessive cooling during cooling operation and reducing indoor humidity.

[0010] However, condensation may occur on the indoor heat exchanger of the indoor unit during cooling or dehumidifying operation. If outdoor air is supplied to the part of the indoor heat exchanger where condensation has occurred, the heat of the outdoor air will evaporate the condensed water. This results in moist outdoor air being supplied indoors, which can lead to a problem of inefficient dehumidification.

[0011] Therefore, the inventors discovered a configuration that suppresses the occurrence of condensation in the area of ​​the indoor heat exchanger to which outdoor air is supplied by controlling the expansion valve and compressor of the outdoor unit, and arrived at the following invention.

[0012] An air conditioner according to one embodiment of the present invention comprises an outdoor unit having an outdoor heat exchanger, a compressor, and an expansion valve; an indoor unit having an indoor heat exchanger; refrigerant piping connecting the outdoor heat exchanger, the compressor, the expansion valve, and the indoor heat exchanger and through which a refrigerant circulates; a first temperature sensor that acquires a first temperature of a portion of the indoor heat exchanger upstream in the flow direction of the refrigerant and downstream of an inlet portion where the refrigerant flows into the indoor heat exchanger; a ventilation device that supplies outdoor air toward a region downstream in the flow direction of the refrigerant in the indoor heat exchanger; and a control unit that controls the compressor, the expansion valve, and the ventilation device based on the first temperature during dehumidification operation that includes supplying the outdoor air.

[0013] According to this aspect, it is possible to suppress a decrease in dehumidification efficiency.

[0014] For example, the control unit may acquire the indoor temperature and the set temperature, and when it determines that the indoor temperature is lower than the set temperature, switch to the dehumidification operation and reduce the opening of the expansion valve and the frequency of the compressor.

[0015] For example, the control unit may start the supply of the outdoor air from the ventilation device when the first temperature becomes equal to or higher than a first threshold value.

[0016] For example, the control unit may stop the supply of the outdoor air from the ventilation device when the first temperature becomes equal to or lower than a second threshold value.

[0017] For example, the air conditioner may further include a second temperature sensor that acquires a second temperature of the inlet portion, and the control unit may control the compressor and the expansion valve based on the second temperature.

[0018] For example, the control unit may calculate a temperature difference between the first temperature and the second temperature, and control the compressor, the expansion valve, and the ventilation device based on the temperature difference.

[0019] For example, the control unit may stop the supply of the outdoor air from the ventilation device when the temperature difference becomes equal to or less than a third threshold value.

[0020] For example, the control unit may increase the opening of the expansion valve and the frequency of the compressor when the second temperature becomes equal to or lower than a fourth threshold value.

[0021] For example, the air conditioner may further include a third temperature sensor that acquires a third temperature of a region downstream in the flow direction of the refrigerant in the indoor heat exchanger, and the control unit may control the compressor and the expansion valve based on the third temperature during cooling operation.

[0022] For example, during the dehumidification operation, the control unit may acquire the indoor temperature and the set temperature, and when it determines that the indoor temperature is higher than the set temperature, it may stop the supply of outdoor air from the ventilation device and increase the opening of the expansion valve and the frequency of the compressor.

[0023] For example, the ventilation device may include an absorbent material that absorbs moisture in the outdoor air, a flow path that connects the outdoors to the indoor unit and through which the outdoor air flows, a heater that is positioned upstream of the absorbent material in the flow path, a fan that sends the outdoor air to the flow path, and a damper device that distributes the outdoor air flowing through the flow path between the outdoors and the indoor unit, and the control unit may control the heater to heat and dry the absorbent material, control the fan to dry the outdoor air by passing it through the absorbent material, and control the damper device to distribute the dried outdoor air to the indoor unit.

[0024] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0025] FIG. 1 is a schematic diagram of an air conditioner according to an embodiment of the present disclosure.

[0026] As shown in FIG. 1, an air conditioner 10 according to this embodiment has an indoor unit 20 arranged in a room Rin to be air-conditioned, and an outdoor unit 30 arranged in an outdoor room Rout.

[0027] The indoor unit 20 is provided with an indoor heat exchanger 22 that exchanges heat with the indoor air A1, and a fan 24 that draws the indoor air A1 into the indoor unit 20 and blows the indoor air A1 into the room Rin after heat exchange with the indoor heat exchanger 22.

[0028] The outdoor unit 30 is provided with an outdoor heat exchanger 32 that exchanges heat with outdoor air A2, and a fan 34 that draws the outdoor air A2 into the outdoor unit 30 and blows the outdoor air A2 out to the outdoor Rout after exchanging heat with the outdoor heat exchanger 32. The outdoor unit 30 is also provided with a compressor 36, an expansion valve 38, and a four-way valve 40 that execute a refrigeration cycle with the indoor heat exchanger 22 and the outdoor heat exchanger 32.

[0029] The indoor heat exchanger 22, the outdoor heat exchanger 32, the compressor 36, the expansion valve 38, and the four-way valve 40 are each connected by a refrigerant pipe 42 through which a refrigerant flows. In cooling operation and dehumidification operation (weak cooling operation), the air conditioner 10 executes a refrigeration cycle in which the refrigerant flows from the compressor 36 through the four-way valve 40, the outdoor heat exchanger 32, the expansion valve 38, and the indoor heat exchanger 22 in that order, before returning to the compressor 36. In heating operation, the air conditioner 10 executes a refrigeration cycle in which the refrigerant flows from the compressor 36 through the four-way valve 40, the indoor heat exchanger 22, the expansion valve 38, and the outdoor heat exchanger 32 in that order, before returning to the compressor 36.

[0030] In addition to air conditioning operation using a refrigeration cycle, the air conditioner 10 also performs air conditioning operation in which outdoor air A3 is introduced into the room Rin. To this end, the air conditioner 10 has a ventilation device 50. The ventilation device 50 is provided in the outdoor unit 30.

[0031] FIG. 2 is a schematic diagram of a ventilation system.

[0032] As shown in FIG. 2, the ventilation device 50 includes an absorbent material 52 therein through which the outdoor air A3 and A4 passes.

[0033] The absorbent material 52 is a member through which air can pass and which collects moisture from the air passing through it or adds moisture to the air passing through it. In this embodiment, the absorbent material 52 is disk-shaped and rotates around a rotation center line C1 that passes through the center of the absorbent material 52. The absorbent material 52 is rotationally driven by a motor 54.

[0034] The absorbent 52 is preferably a polymeric adsorbent that adsorbs moisture in the air. The polymeric adsorbent is, for example, composed of cross-linked sodium polyacrylate. Compared to adsorbents such as silica gel and zeolite, the polymeric adsorbent absorbs a larger amount of moisture per volume, can desorb the moisture it holds at a low heating temperature, and can hold the moisture for a long period of time.

[0035] Inside the ventilation device 50, a first flow path P1 and a second flow path P2 are provided, through which the outdoor air A3 and A4 flow, respectively, passing through the absorbent material 52. The first flow path P1 and the second flow path P2 pass through the absorbent material 52 at different positions.

[0036] The first flow path P1 is a flow path through which the outdoor air A3 flows toward the indoor unit 20. The outdoor air A3 flowing through the first flow path P1 is supplied into the indoor unit 20 via a ventilation duct 56.

[0037] In this embodiment, the first flow path P1 includes a plurality of branch flow paths P1a, P1b on the upstream side of the absorbent material 52. In this specification, the terms "upstream" and "downstream" are used with respect to the flow of air.

[0038] The plurality of tributary channels P1a, P2a join together upstream of the absorbent material 52. The plurality of tributary channels P1a, P1b are provided with first and second heaters 58, 60, respectively, that heat the outside air A3.

[0039] The first and second heaters 58, 60 may have the same heating capacity or different heating capacities. Furthermore, the first and second heaters 58, 60 are preferably PTC (Positive Temperature Coefficient) heaters, which increase electrical resistance as current flows and the temperature rises, thereby preventing excessive increases in heating temperature. In the case of heaters using nichrome wire or carbon fiber, the heating temperature (surface temperature) continues to rise as current continues to flow, so the temperature must be monitored. In the case of PTC heaters, the heaters themselves adjust the heating temperature within a certain temperature range, eliminating the need to monitor the heating temperature.

[0040] The first flow path P1 is provided with a first fan 62 that generates a flow of outdoor air A3 toward the indoor unit 20. In the present embodiment, the first fan 62 is disposed downstream of the absorbent material 52. When the first fan 62 is operated, the outdoor air A3 flows from the outdoor Rout into the first flow path P1 and passes through the absorbent material 52.

[0041] The first flow path P1 is provided with a damper device 64 that distributes the outdoor air A3 flowing through the first flow path P1 to the room Rin (i.e., the indoor unit 20) or the outdoor Rout. In the present embodiment, the damper device 64 is disposed downstream of the first fan 62. The outdoor air A3 distributed to the indoor unit 20 by the damper device 64 enters the indoor unit 20 via the ventilation duct 56 and is blown out into the room Rin by the fan 24.

[0042] The second flow path P2 is a flow path through which the outdoor air A4 flows. Unlike the outdoor air A3 flowing through the first flow path P1, the outdoor air A4 flowing through the second flow path P2 does not head toward the indoor unit 20. The outdoor air A4 flowing through the second flow path P2 passes through the absorbent material 52 and then flows out to the outdoor Rout.

[0043] A second fan 66 that generates a flow of outdoor air A4 is provided in the first flow path P1. In the present embodiment, the second fan 66 is disposed downstream of the absorbent material 52. When the second fan 66 is operated, the outdoor air A4 flows from the outdoor Rout into the second flow path P2, passes through the absorbent material 52, and then flows out to the outdoor Rout.

[0044] The ventilation device 50 selectively performs ventilation operation, humidification operation, and dehumidification operation by selectively using an absorbent material 52, a motor 54, a first heater 58, a second heater 60, a first fan 62, a damper device 64, and a second fan 66.

[0045] FIG. 3 is a schematic diagram of the ventilation device during ventilation operation.

[0046] Ventilation operation is an air conditioning operation in which the outdoor air A3 is supplied directly to the room Rin (i.e., the indoor unit 20) via the ventilation duct 56. As shown in FIG. 3, during ventilation operation, the motor 54 continues to rotate the absorbent material 52. The first heater 58 and the second heater 60 are in the OFF state and do not heat the outdoor air A3. The first fan 62 is in the ON state, thereby causing the outdoor air A3 to flow through the first flow path P1. The damper device 64 distributes the outdoor air A3 in the first flow path P1 to the indoor unit 20. The second fan 66 is in the OFF state, thereby causing no flow of outdoor air A4 to occur through the second flow path P2.

[0047] According to this ventilation operation, the outdoor air A3 flows into the first flow path P1 and passes through the absorbent material 52 without being heated by the first and second heaters 58, 60. The outdoor air A3 that has passed through the absorbent material 52 is distributed to the indoor unit 20 by the damper device 64. The outdoor air A3 that has passed through the damper device 64 and reached the indoor unit 20 via the ventilation duct 56 is blown out into the room Rin by the fan 24. According to this ventilation operation, the outdoor air A3 is supplied as is to the room Rin, and the room Rin is ventilated.

[0048] FIG. 4 is a schematic diagram of the ventilation device during humidification operation.

[0049] The humidification operation is an air conditioning operation in which the outdoor air A3 is humidified and the humidified outdoor air A3 is supplied to the room Rin (i.e., the indoor unit 20). As shown in FIG. 4, during the humidification operation, the motor 54 continues to rotate the absorbent material 52. The first heater 58 and the second heater 60 are in the ON state and heat the outdoor air A3. The first fan 62 is in the ON state, thereby causing the outdoor air A3 to flow through the first flow path P1. The damper device 64 distributes the outdoor air A3 in the first flow path P1 to the indoor unit 20. The second fan 66 is in the ON state, thereby causing the outdoor air A4 to flow through the second flow path P2.

[0050] In this humidification operation, the outdoor air A3 flows into the first flow path P1, is heated by the first and second heaters 58, 60, and passes through the absorbent 52. At this time, the heated outdoor air A3 can remove a larger amount of moisture from the absorbent 52 than when the outdoor air A3 is not heated. As a result, the outdoor air A3 carries a larger amount of moisture. The outdoor air A3 that has passed through the absorbent 52 and carried a larger amount of moisture is distributed to the indoor unit 20 by the damper device 64. The outdoor air A3 that has passed through the damper device 64 and reached the indoor unit 20 via the ventilation duct 56 is blown into the room Rin by the fan 24. In this humidification operation, the outdoor air A3 carrying a larger amount of moisture is supplied to the room Rin, and the room Rin is humidified.

[0051] In addition, by turning off either the first heater 58 or the second heater 60, the amount of moisture that the outdoor air A3 removes from the absorbent material 52 can be reduced, i.e., a weak humidification operation can be performed in which the amount of humidification of the indoor air Rin is reduced.

[0052] As moisture is removed by the heated outdoor air A3, the water retention capacity of the absorbent 52 decreases, i.e., the absorbent 52 dries. When the absorbent 52 dries, the outdoor air A3 flowing through the first flow path P1 cannot remove moisture from the absorbent 52. To address this, the absorbent 52 removes moisture from the outdoor air A4 flowing through the second flow path P2. This keeps the water retention capacity of the absorbent 52 approximately constant, allowing the humidification operation to continue.

[0053] FIG. 5 is a schematic diagram of the ventilation device during dehumidification operation.

[0054] The dehumidifying operation is an air conditioning operation in which the outdoor air A3 is dehumidified and the dehumidified outdoor air A3 is supplied to the room Rin (i.e., the indoor unit 20). As shown in Fig. 5, in the dehumidifying operation, the adsorption operation and the regeneration operation are performed alternately.

[0055] The adsorption operation is an operation in which moisture contained in the outdoor air A3 is adsorbed onto the absorbent material 52, thereby dehumidifying the outdoor air A3. As shown in FIG. 5, during the adsorption operation, the motor 54 continues to rotate the absorbent material 52. The first heater 58 and the second heater 60 are in the OFF state and do not heat the outdoor air A3. The first fan 62 is in the ON state, thereby causing the outdoor air A3 to flow through the first flow path P1. The damper device 64 distributes the outdoor air A3 in the first flow path P1 to the indoor unit 20. The second fan 66 is in the OFF state, thereby causing no flow of outdoor air A4 to occur through the second flow path P2.

[0056] During this adsorption operation, the outdoor air A3 flows into the first flow path P1 and passes through the absorbent 52 without being heated by the first and second heaters 58, 60. At this time, the moisture carried in the outdoor air A3 is adsorbed by the absorbent 52. This reduces the amount of moisture carried by the outdoor air A3, i.e., the outdoor air A3 is dried. The outdoor air A3 that has passed through the absorbent 52 and is then distributed to the indoor unit 20 by the damper device 64. The outdoor air A3 that has passed through the damper device 64 and reached the indoor unit 20 via the ventilation duct 56 is then blown into the room Rin by the fan 24. During this adsorption operation, the dried outdoor air A3 is supplied to the room Rin, and the room Rin is dehumidified.

[0057] As the adsorption operation continues, the amount of water held by the absorbent 52 continues to increase, resulting in a decrease in the absorbent 52's ability to adsorb the moisture contained in the outdoor air A3. In order to recover the adsorption ability, a regeneration operation is performed to regenerate the absorbent 52.

[0058] During regeneration operation, the motor 54 continues to rotate the absorbent material 52. The first heater 58 and the second heater 60 are ON and heat the outdoor air A3. The first fan 62 is ON and causes the outdoor air A3 to flow through the first flow path P1. The damper device 64 distributes the outdoor air A3 in the first flow path P1 to the outdoor Rout rather than to the indoor unit 20. The second fan 66 is OFF and causes no flow of outdoor air A4 to occur in the second flow path P2.

[0059] According to this regeneration operation, the outdoor air A3 flows into the first flow path P1, is heated by the first and second heaters 58, 60, and passes through the absorbent 52. At this time, the heated outdoor air A3 removes a large amount of moisture from the absorbent 52. As a result, the outdoor air A3 carries a large amount of moisture. At the same time, the water retention capacity of the absorbent 52 decreases, that is, the absorbent 52 dries and its adsorption capacity is regenerated. The outdoor air A3 that has passed through the absorbent 52 and carries a large amount of moisture is diverted by the damper device 64 to the outdoor Rout and discharged to the outdoor Rout. As a result, during the regeneration operation in the dehumidification operation, the outdoor air A3 carrying a large amount of moisture due to the regeneration of the absorbent 52 is not supplied to the indoor Rin.

[0060] By alternately performing the adsorption operation and the regeneration operation in this manner, the adsorption capacity of the absorbent material 52 is maintained, and the dehumidification operation can be carried out continuously.

[0061] The above-mentioned air conditioning operations using the refrigeration cycle (cooling operation, dehumidifying operation (weak cooling operation), heating operation) and the air conditioning operations using the ventilation device 50 (ventilation operation, humidifying operation, dehumidifying operation) can be performed separately or simultaneously. For example, if the dehumidifying operation using the refrigeration cycle and the dehumidifying operation using the ventilation device 50 are performed simultaneously, it is possible to dehumidify the room Rin while maintaining the room temperature constant.

[0062] The user selects the air conditioning operation to be performed by the air conditioner 10. For example, when the user performs a selection operation on the remote controller 70 shown in Figure 1, the air conditioner 10 performs the air conditioning operation corresponding to that operation.

[0063] Up to this point, we have given an overview of the configuration and operation of the air conditioner 10 according to this embodiment. From here on, we will explain further features of the air conditioner 10 according to this embodiment.

[0064] FIG. 6 is a block diagram showing a configuration for controlling an air conditioner.

[0065] As shown in FIG. 6, the components of the air conditioner 10 are controlled by a control unit 90. The control unit 90 includes, for example, a memory that stores programs and a processing circuit corresponding to a processor such as a CPU (Central Processing Unit). The functions of the control unit 90 may be configured solely by hardware, or may be realized by combining hardware and software. The control unit 90 realizes predetermined functions by reading data and programs stored in the memory and performing various arithmetic processing. In this embodiment, the control unit 90 controls the compressor 36, the expansion valve 38, the motor 54, the first heater 58, the second heater 60, the first fan 62, the damper device 64, and the second fan 66.

[0066] FIG. 7A is a schematic diagram showing an example of the internal structure of the indoor unit.

[0067] As shown in Fig. 7A, the indoor unit 20 has an indoor heat exchanger 22, a fan 24, and a nozzle 57. The nozzle 57 is provided inside the indoor unit 20 so as to blow out outdoor air A3 supplied from the ventilation device 50 through a ventilation duct 56 into the indoor unit 20. Specifically, the nozzle 57 is arranged inside the indoor unit 20 so that the blown out outdoor air A3 avoids the wet path PA1 in the indoor heat exchanger 22, passes through an area DP1 in the dry path PA2, and heads towards the fan 24. The fan 24 is, for example, a crossflow fan.

[0068] "Wet path PA1" and "dry path PA2" refer to wet and dry regions that are generated in the indoor heat exchanger 22 by controlling the frequency of the compressor 36 and the opening of the expansion valve 38 during weak cooling operation (dehumidifying operation) of the air conditioner 10. Specifically, wet path PA1 is a wet region that is formed upstream in the refrigerant flow direction in the indoor heat exchanger 22 by reducing the frequency of the compressor 36 and the opening of the expansion valve 38 during weak cooling operation (dehumidifying operation). Dry path PA2 is a dry region that is formed downstream of wet path PA1 in the indoor heat exchanger 22 by reducing the frequency of the compressor 36 and the opening of the expansion valve 38 during weak cooling operation (dehumidifying operation).

[0069] The "area DP1" is a region that is drier than other regions in the indoor heat exchanger 22. The region DP1 is a region downstream in the refrigerant flow direction in the indoor heat exchanger 22, and is a region to which outdoor air A3 is supplied from the ventilation device 50. The region DP1 is formed downstream of the dry path PA2. Such an "area DP1" can be determined experimentally or by simulation.

[0070] 7A, when viewed in the direction in which the rotation center line of the fan 24 extends (when viewed in the U-axis direction), the indoor heat exchanger 22 is provided in the indoor unit 20 so as to partially surround the fan 24 (in this embodiment, so as to surround the fan 24 except for the area below it). The indoor heat exchanger 22 is also made up of a first portion 22a located behind the fan 24 and a second portion 22b located in front of the fan 24. Refrigerant supplied from the compressor 36 flows through this indoor heat exchanger 22.

[0071] FIG. 7B is a schematic diagram showing an example of the flow of refrigerant in the indoor heat exchanger.

[0072] As shown in Figure 7B, when the air conditioner 10 is in cooling operation or weak cooling operation (dehumidification operation), when viewed in the direction of extension of the rotation center line of the fan 24, the refrigerant flows in the following order: (A) → (B) → (C1, C2, C3) → (D, E1, E2, F) → (G1, G2, G3, G4).

[0073] The refrigerant flows into the first refrigerant flow path "(A) → (B)" from the refrigerant inlet 22c of the indoor heat exchanger 22. The first refrigerant flow path "(A) → (B)" is provided on the outer surface side of the center of the first portion 22a of the indoor heat exchanger 22, and is a flow path through which the refrigerant flows downward. The outer surface of the first portion 22a is the surface of the first portion 22a on the side where the housing of the indoor unit 20 that houses the indoor heat exchanger 22 is located.

[0074] The refrigerant flows through the first refrigerant flow path "(A) → (B)" and then through the second refrigerant flow path "(B) → (C1, C2, C3)." The second refrigerant flow path "(B) → (C1, C2, C3)" is provided on the outer surface side of the center of the second portion 22b of the indoor heat exchanger 22, and is a flow path through which the refrigerant flows upward. The outer surface of the second portion 22b is the surface of the second portion 22b on the side where the housing of the indoor unit 20 that houses the indoor heat exchanger 22 is located.

[0075] In the indoor heat exchanger 22, the temperature of the refrigerant flowing in from the refrigerant inlet 22c is lower than in other parts. Therefore, the upstream side of the refrigerant flow path of the indoor heat exchanger 22 functions as a cooling part and is in a wet state. The cooling part is a part where the refrigerant flowing in the indoor heat exchanger 22 becomes a low-pressure liquid refrigerant by narrowing the opening of the expansion valve 38. In this embodiment, the first refrigerant flow path "(A) → (B)" and the second refrigerant flow path "(B) → (C1, C2, C3)" function as cooling parts and are the wet path PA1.

[0076] After the refrigerant flows through the second refrigerant flow path "(B) → (C1, C2, C3)", it further branches off into three other refrigerant flow paths. The three refrigerant flow paths include a third refrigerant flow path "(C1) → (D)", a fourth refrigerant flow path "(C2) → (E1, E2)", and a fifth refrigerant flow path "(C3) → (F)".

[0077] The third refrigerant flow path "(C1) → (D)" is provided in the center of the second portion 22b, from the outer surface of the second portion 22b toward the inner surface thereof, and is a flow path through which the refrigerant flows from the outer surface of the second portion 22b toward the inner surface thereof. The inner surface of the second portion 22b is the surface of the second portion 22b on which the fan 24 is located. After flowing through the third refrigerant flow path "(C1) → (D)", the refrigerant flows through the sixth refrigerant flow path "(D) → (G1)".

[0078] The fourth refrigerant flow path "(C2) → (E1, E2)" is provided above the center of the second portion 22b, from the outer surface of the second portion 22b toward the inner surface thereof, and is a flow path through which the refrigerant flows from the outer surface of the second portion 22b toward the inner surface thereof. After flowing through the fourth refrigerant flow path "(C2) → (E1, E2)", the refrigerant is further divided into two refrigerant flow paths. The two refrigerant flow paths include a seventh refrigerant flow path "(E1) → (G2)" and an eighth refrigerant flow path "(E2) → (G3)".

[0079] The fifth refrigerant flow path "(C3) → (F)" is provided above the fourth refrigerant flow path, extending from the outer surface of the second portion 22b toward the inner surface thereof, and is a flow path through which the refrigerant flows from the outer surface of the second portion 22b toward the inner surface thereof. After flowing through the fifth refrigerant flow path "(C3) → (F)", the refrigerant flows through the ninth refrigerant flow path "(F) → (G4)".

[0080] The sixth refrigerant flow path "(D)→(G1)" is located below the center of the second portion 22b, extending from the outer surface of the second portion 22b toward the inner surface, and is a flow path through which the refrigerant flows from the outer surface of the second portion 22b toward the inner surface.

[0081] The seventh refrigerant flow path "(E1) → (G2)" is located above the center of the first portion 22a, extending from the outer surface of the first portion 22a toward the inner surface and from the upper side to the lower side of the first portion 22a, and is a flow path through which the refrigerant flows from the outer surface of the first portion 22a toward the inner surface and downward.

[0082] The eighth refrigerant flow path "(E2) → (G3)" is provided in the center of the first portion 22a, extending from the outer surface of the first portion 22a toward the inner surface, and from the center of the first portion 22a toward the downward side, and is a flow path through which the refrigerant flows from the outer surface of the first portion 22a toward the inner surface.

[0083] The ninth refrigerant flow path "(F) → (G4)" is located below the center of the second portion 22b and above the sixth refrigerant flow path "(D) → (G1)", extending from the outer surface of the second portion 22b toward the inner surface, and is a flow path through which the refrigerant flows from the outer surface of the second portion 22b toward the inner surface.

[0084] The refrigerant flows through the sixth refrigerant flow path "(D) → (G1)", the seventh refrigerant flow path "(E1) → (G2)", the eighth refrigerant flow path "(E2) → (G3)" and the ninth refrigerant flow path "(F) → (G4)", and then merges and is discharged from the refrigerant outlet 22d.

[0085] The third to ninth refrigerant flow paths function as superheating sections and are in a dry state. The superheating section is a section where the refrigerant has reached its saturation temperature but has not undergone a phase change and is therefore at a higher temperature than the cooling section. In this embodiment, the third to ninth refrigerant flow paths are dry paths PA2.

[0086] As a result of this refrigerant flow, in the indoor heat exchanger 22, the first refrigerant flow path and the second refrigerant flow path become wet paths PA1, and the third to ninth refrigerant flow paths become dry paths PA2. Because the temperature of the refrigerant increases while flowing from upstream to downstream of the indoor heat exchanger 22, condensation is less likely to occur in the region DP1 located downstream of the dry path PA2 than in other parts (less condensed water adheres). In this embodiment, the sixth refrigerant flow path "(D) → (G1)" and the ninth refrigerant flow path "(F) → (G4)" form the region DP1.

[0087] The first to ninth refrigerant flow paths are formed by, for example, piping.

[0088] A plurality of temperature sensors 26 to 28 are arranged in the indoor heat exchanger 22. In this embodiment, the plurality of temperature sensors 26 to 28 include a first temperature sensor 26, a second temperature sensor 27, and a third temperature sensor 28.

[0089] FIG. 8 is a schematic diagram showing an example of the arrangement of a plurality of temperature sensors in the indoor heat exchanger.

[0090] 8, the indoor heat exchanger 22 is provided with a refrigerant inlet 22c through which the refrigerant flows in and a refrigerant outlet 22d through which the refrigerant flows out. The refrigerant inlet 22c is connected to the refrigerant pipe 42 in the indoor heat exchanger 22, and is an opening through which the refrigerant flows from the refrigerant pipe 42 into the indoor heat exchanger 22. The refrigerant outlet 22d is connected to the refrigerant pipe 42 in the indoor heat exchanger 22, and is an opening through which the refrigerant flows out from the indoor heat exchanger 22 to the refrigerant pipe 42.

[0091] In this embodiment, the refrigerant inlet 22c is provided in a flow path connected to the first refrigerant flow path of the indoor heat exchanger 22. The refrigerant outlet 22d is provided in a flow path connected to the fifth to eighth refrigerant flow paths.

[0092] In the indoor heat exchanger 22, the refrigerant inlet 22c side is upstream in the refrigerant flow direction, and the refrigerant outlet 22d side is downstream in the refrigerant flow direction.

[0093] In the indoor heat exchanger 22, the region DP1 to which the outdoor air A3 is supplied is located downstream in the refrigerant flow direction in the indoor heat exchanger 22. In other words, the region DP1 is located downstream in the refrigerant flow direction between the refrigerant inlet 22c and the refrigerant outlet 22d. Specifically, the region DP1 is located below the second portion 22b of the indoor heat exchanger 22.

[0094] The first temperature sensor 26 acquires a first temperature T1 at a portion of the indoor heat exchanger 22 that is upstream in the refrigerant flow direction and downstream of the inlet portion where the refrigerant flows into the indoor heat exchanger 22. Specifically, the first temperature sensor 26 acquires the first temperature T1 of the indoor heat exchanger 22 at an outlet of the wet path PA1 that is downstream of the inlet of the wet path PA1. The outlet of the wet path PA1 is the outlet of a portion of the refrigerant flow path in the indoor heat exchanger 22 that is upstream of the refrigerant flow path and through which a refrigerant with a relatively low temperature compared to the downstream side of the refrigerant flow path flows. In other words, the outlet of the wet path PA1 is the boundary between the cooling section and the superheating section. In this embodiment, the first temperature sensor 26 is disposed on the outer surface side of the second section 22b in the center of the second section 22b of the indoor heat exchanger 22. Specifically, the first temperature sensor 26 is disposed at the outlet of the second refrigerant flow path "(B) → (C1, C2, C3)".

[0095] The second temperature sensor 27 acquires a second temperature T2 of the indoor heat exchanger 22 at an inlet portion where the refrigerant flows into the indoor heat exchanger 22. Specifically, the second temperature sensor 27 acquires the second temperature T2 of the indoor heat exchanger 22 at the refrigerant inlet 22c. The second temperature sensor 27 is disposed near the refrigerant inlet 22c or at the refrigerant inlet 22c. In this embodiment, the second temperature sensor 27 is disposed on the outer surface side of the first portion 22a, in the center of the first portion 22a. Specifically, the second temperature sensor 27 is disposed at the inlet of the first refrigerant flow path "(A) → (B)".

[0096] The third temperature sensor 28 acquires a third temperature T3 of a region DP1 on the downstream side in the refrigerant flow direction in the indoor heat exchanger 22. The third temperature sensor 28 acquires a third temperature T3 of the indoor heat exchanger 22 downstream of the first temperature sensor 26 in the refrigerant flow direction. The third temperature T3 may be the temperature of the indoor heat exchanger 22 at the refrigerant outlet 22d. In this embodiment, the third temperature sensor 28 is disposed in a lower part of the second portion 22b. Specifically, the third temperature sensor 28 is disposed at the inlet of the sixth refrigerant flow path "(D) → (G1)".

[0097] Fig. 9 is a flowchart showing an example of the operation of the air conditioner, Fig. 10 is a flowchart showing an example of adsorption operation control, and Fig. 11 is a timing chart showing an example of control of the air conditioner.

[0098] The processing shown in Figures 9 and 10 is performed by the control unit 90 controlling the components of the air conditioner 10. Note that the processing shown in Figures 9 and 10 is an example, and the present embodiment is not limited to the processing shown in Figures 9 and 10.

[0099] The process shown in FIG. 9 starts when the cooling operation is turned on by a user's selection operation on the remote controller 70 shown in FIG. 1, for example.

[0100] 9, in step S10, the control unit 90 determines whether or not the start condition is met. If the control unit 90 determines that the start condition is met, the process proceeds to step S20. If the control unit 90 determines that the start condition is not met, the process repeats step S10.

[0101] The start conditions are conditions for starting the cooling operation, and may include, for example, at least one of the operation mode, humidity, humidity control, operation frequency, inverter current, temperature, and the presence or absence of an abnormality.

[0102] If the control unit 90 determines that the start condition is not met, the control unit 90 may carry out control to make the start condition met.

[0103] In step S20, the control unit 90 performs cooling operation control. Specifically, the control unit 90 controls the compressor 36, the expansion valve 38, and the four-way valve 40 to execute a refrigeration cycle in which the refrigerant flows from the compressor 36 through the four-way valve 40, the outdoor heat exchanger 32, the expansion valve 38, and the indoor heat exchanger 22 in this order, and then returns to the compressor 36.

[0104] During cooling operation, the control unit 90 controls the compressor 36 and the expansion valve 38 based on the third temperature T3 acquired by the third temperature sensor 28. Specifically, the control unit 90 controls the frequency of the compressor 36 and the opening degree of the expansion valve 38 based on the third temperature T3.

[0105] 11, when the third temperature T3 at the start of the cooling operation is relatively high, the control unit 90 increases the opening of the expansion valve 38 and increases the frequency of the compressor 36. For example, the control unit 90 controls the opening of the expansion valve 38 to be between approximately 40% and approximately 50% at the start of the cooling operation, and controls the frequency of the compressor 36 to be approximately 80 Hz.

[0106] During cooling operation, as the third temperature T3 decreases, the control unit 90 reduces the opening of the expansion valve 38 and decreases the frequency of the compressor 36. For example, the control unit 90 reduces the opening of the expansion valve 38 in a range from about 50% to about 8% in accordance with the third temperature T3. The control unit 90 reduces the frequency of the compressor 36 in a range from about 80 Hz to about 30 Hz.

[0107] In cooling operation control, the control unit 90 acquires the room temperature Tr and the set temperature Ts. For example, the control unit 90 may acquire the room temperature Tr from an room temperature sensor provided in the indoor unit 20. For example, the control unit 90 may acquire the set temperature Ts from a memory unit. In this case, the memory unit may store information about the set temperature Ts input by the user to the remote controller 70.

[0108] The control unit 90 controls the frequency of the compressor 36 and the opening of the expansion valve 38 based on the third temperature T3 until the indoor temperature Tr becomes lower than the set temperature Ts. For example, the control unit 90 controls the frequency of the compressor 36 and the opening of the expansion valve 38 based on the third temperature T3 until the indoor temperature Tr becomes lower than the set temperature Ts by 1°C.

[0109] 9, in step S30, the control unit 90 determines whether the room temperature Tr is lower than the set temperature Ts. If the control unit 90 determines that the room temperature Tr is lower than the set temperature Ts, the process proceeds to step S40. If the control unit 90 determines that the room temperature Tr is not lower than the set temperature Ts, the process returns to step S30.

[0110] In the example shown in Fig. 11, when the room temperature Tr reaches a temperature Tr1 that is 1°C lower than the set temperature Ts, that is, at the timing tmg1 shown in Fig. 11, the control unit 90 determines that the room temperature Tr is lower than the set temperature Ts. If the room temperature Tr is higher than the temperature Tr1, the control unit 90 determines that the room temperature Tr is not lower than the set temperature Ts.

[0111] In step S40, the control unit 90 performs dehumidification operation control, which includes supplying the outdoor air A3 to the indoor unit 20. The dehumidification operation control repeats the regeneration operation control in step S50 and the adsorption operation control in step S60 (see FIG. 5).

[0112] Next, the adsorption operation control in this embodiment will be described with reference to FIG.

[0113] As shown in Fig. 10, when the adsorption operation control is started, in step S61, the control unit 90 controls the opening degree of the expansion valve 38. Specifically, as shown in Fig. 11, the control unit 90 reduces the opening degree of the expansion valve 38 compared to during cooling operation. For example, the control unit 90 controls the opening degree of the expansion valve 38 to be equal to or greater than 0% and less than 7%.

[0114] In step S62, the control unit 90 controls the frequency of the compressor 36. Specifically, as shown in Fig. 11, the control unit 90 reduces the frequency of the compressor 36 compared to that during cooling operation. For example, the control unit 90 controls the frequency of the compressor 36 to be equal to or higher than 0 Hz and equal to or lower than 20 Hz.

[0115] By carrying out steps S61 and S62, in the indoor heat exchanger 22, a cooling section is formed on the upstream side and a superheating section is formed on the downstream side.

[0116] In this embodiment, the cooling section is formed on the outer surface side of the central portion of the first portion 22a of the indoor heat exchanger 22 and on the outer surface side of the central portion of the second portion 22b. In other words, the cooling section is formed in the first refrigerant flow path "(A) → (B)" and the second refrigerant flow path "(B) → (C1, C2, C3)". The superheating section is formed from the top to the bottom of the first portion 22a and from the top to the bottom of the second portion 22b, excluding the outer surface side of the central portion of the first portion 22a of the indoor heat exchanger 22. In addition, the superheating section is formed from the top to the bottom of the second portion 22b, excluding the outer surface side of the central portion of the second portion 22b of the indoor heat exchanger 22. In other words, the superheating section is formed in the third to ninth refrigerant flow paths.

[0117] The first temperature sensor 26 is disposed near the boundary between the cooling section and the superheating section. The second temperature sensor 27 is disposed upstream of the cooling section in the direction of refrigerant flow. The third temperature sensor 28 is disposed downstream of the superheating section in the direction of refrigerant flow.

[0118] In the example shown in Fig. 11, the second temperature T2 indicates the temperature of the cooling section, and has dropped from 17°C to about 5°C. The first temperature T1 indicates the temperature near the boundary between the superheating section and the cooling section, and has risen from 17°C to 22°C. That is, in the indoor heat exchanger 22, the inlet of the first refrigerant flow path "(A) → (B)", which is the inlet of the wet path PA1, is cooled from 17°C to 5°C, and the outlet of the second refrigerant flow path "(B) → (C1, C2, C3)", which is the outlet of the wet path PA1, is heated from 17°C to 22°C.

[0119] In step S63, the control unit 90 determines whether the first temperature T1 is equal to or greater than the first threshold L1. If the control unit 90 determines that the first temperature T1 is equal to or greater than the first threshold L1, the process proceeds to step S64. If the control unit 90 determines that the first temperature T1 is smaller than the first threshold L1, the process repeats steps S61 and S62. The first threshold L1 is, for example, 22°C.

[0120] In the example shown in FIG. 11, at time tmg2 when the first temperature T1 becomes temperature T11 indicating the first threshold value L1, the control unit 90 determines that the first temperature T1 is greater than or equal to the first threshold value L1, and the processing proceeds to step S64.

[0121] In step S64, the control unit 90 controls the ventilation device 50 to supply the outdoor air A3 to the indoor heat exchanger 22. Specifically, the control unit 90 controls the first fan 62, the motor 54, and the damper device 64 to supply the dry outdoor air A3 from the outdoor Rout to the indoor heat exchanger 22 of the indoor unit 20.

[0122] For example, the control unit 90 turns on the heaters 58, 60 to heat and dry the absorbent material 52. After turning off the heaters 58, 60, the control unit 90 rotates the first fan 62 to pass the outdoor air A3 through the absorbent material 52. As a result, moisture in the outdoor air A3 is absorbed by the absorbent material 52, and the outdoor air A3 is dried. The outdoor air A3 is also warmed by the absorbent material 52 heated by the heaters 58, 60. The control unit 90 opens the damper device 64 to distribute the dried outdoor air A3 to the indoor unit 20. As a result, the outdoor air A3 passes through the ventilation duct 56 and is supplied to the indoor heat exchanger 22 of the indoor unit 20.

[0123] The outdoor air A3 is supplied to the area DP1 located downstream of the superheating portion of the indoor heat exchanger 22, i.e., the lower part of the second portion 22b. The superheating portion is hotter and drier than the cooling portion. For this reason, condensation is less likely to occur in the superheating portion. As a result, when the outdoor air A3 is blown toward the superheating portion, the outdoor air A3 is blown out of the room Rin without becoming humid.

[0124] In step S65, the control unit 90 controls the aperture of the expansion valve 38 based on the first temperature T1 acquired by the first temperature sensor 26. For example, the control unit 90 increases the aperture of the expansion valve 38 when the first temperature T1 decreases, and decreases the aperture of the expansion valve 38 when the first temperature T1 increases. The control unit 90 adjusts the aperture of the expansion valve 38 to adjust the first temperature T1 to a desired temperature. For example, the control unit 90 adjusts the aperture of the expansion valve 38 to adjust the first temperature T1 to approximately 22°C. In this way, the temperature of the superheating unit is prevented from decreasing.

[0125] In step S66, the control unit 90 controls the frequency of the compressor 36 based on the room temperature Tr. For example, the control unit 90 increases the frequency of the compressor 36 when the room temperature Tr increases, and decreases the frequency of the compressor 36 when the room temperature Tr decreases. For example, the control unit 90 adjusts the frequency of the compressor 36 to keep the room temperature Tr below the set temperature Ts. In this way, the room temperature Tr is prevented from rising.

[0126] In step S67, the control unit 90 determines whether the first temperature T1 is equal to or less than the second threshold value L2. If the control unit 90 determines that the first temperature T1 is equal to or less than the second threshold value L2, the process proceeds to step S66. If the control unit 90 determines that the first temperature T1 is greater than the second threshold value L2, the process repeats step S64. For example, the second threshold value L2 is 18°C.

[0127] In step S68, the control unit 90 controls the ventilation device 50 to stop the supply of the outdoor air A3. Specifically, the control unit 90 closes the damper device 64 to stop the supply of the dry outdoor air A3 to the indoor heat exchanger 22 of the indoor unit 20.

[0128] In the example shown in FIG. 11, at timing tmg3 when the first temperature T1 reaches temperature T12 which indicates the second threshold value L2, the control unit 90 controls the ventilation device 50 to stop the supply of outdoor air A3.

[0129] In this embodiment, the control unit 90 switches from dehumidifying operation control to cooling operation control after stopping the supply of the outdoor air A3.

[0130] According to the present embodiment as described above, it is possible to prevent condensation from occurring in the region DP1 to which the outdoor air A3 is supplied in the indoor heat exchanger 22. This makes it possible to prevent a decrease in dehumidification efficiency in the air conditioner 10.

[0131] Although the present invention has been described above with reference to the above-mentioned embodiments, the present disclosure is not limited to the above-mentioned embodiments.

[0132] In the above-described embodiment, an example has been described in which the control unit 90 controls the compressor 36, the expansion valve 38, and the ventilation device 50 based on the first temperature T1 during dehumidifying operation, but this is not limiting. For example, the control unit 90 may control the compressor 36, the expansion valve 38, and the ventilation device 50 based on the first temperature T1 and the second temperature T2. For example, the control unit 90 may calculate a temperature difference Td1 between the first temperature T1 and the second temperature T2, and control the compressor 36, the expansion valve 38, and the ventilation device 50 based on the temperature difference Td1. With such a configuration, it is possible to further suppress a decrease in dehumidification efficiency.

[0133] In the above embodiment, as shown in steps S67 and S68 in FIG. 10, an example has been described in which the control unit 90 determines to stop the supply of the outdoor air A3 based on the first temperature T1, but the present invention is not limited to this.

[0134] Figures 12 to 14 are flowcharts showing adsorption operation control according to modified examples. The processes in Figures 12 and 13 are similar to the process in Figure 10, except that steps S67A and S67B are different from step S67 in Figure 10. The process in Figure 14 is similar to the process in Figure 10, except that steps S67A and S68A are different from steps S67 and S68 in Figure 10.

[0135] 12, in steps S67A and S68, the control unit 90 may stop the supply of outdoor air A3 from the ventilation device 50 when the temperature difference Td1 between the first temperature T1 and the second temperature T2 becomes equal to or less than a third threshold L3. For example, the third threshold L3 is 5°C. With this configuration, it is possible to further suppress a decrease in dehumidification efficiency.

[0136] 13, in steps S67B and S68, the control unit 90 acquires the room temperature Tr and the set temperature Ts, and may stop the supply of outdoor air A3 from the ventilation device 50 when it determines that the room temperature Tr is higher than the set temperature Ts. Furthermore, the control unit 90 may increase the opening of the expansion valve 38 and the frequency of the compressor 36, for example, to perform cooling operation control. Such a configuration can improve comfort.

[0137] As shown in FIG. 14, in steps S67C and S69, the control unit 90 may control the aperture of the expansion valve 38 and the frequency of the compressor 36 when the second temperature T2 becomes equal to or lower than the fourth threshold L4. Specifically, the control unit 90 may increase the aperture of the expansion valve 38 and the frequency of the compressor 36 when the second temperature T2 becomes equal to or lower than the fourth threshold L4. For example, the fourth threshold L4 is 0°C. This configuration can prevent the refrigerant from falling below the dew point temperature and freezing. Note that the fourth threshold L4 may be greater than the dew point temperature.

[0138] It should be noted that, in this specification, terms such as "first," "second," etc. are used for descriptive purposes only and should not be understood as expressing or implying the relative importance or ranking of technical features. Features qualified as "first" and "second" expressly or imply the inclusion of one or more of such features.

[0139] An air conditioner according to an embodiment of the present disclosure broadly comprises an outdoor unit having an outdoor heat exchanger, a compressor, and an expansion valve; an indoor unit having an indoor heat exchanger; refrigerant piping connecting the outdoor heat exchanger, the compressor, the expansion valve, and the indoor heat exchanger and through which a refrigerant circulates; a first temperature sensor that acquires a first temperature of a portion of the indoor heat exchanger upstream in the flow direction of the refrigerant and downstream of the inlet portion where the refrigerant flows into the indoor heat exchanger; a ventilation device that supplies outdoor air toward a region downstream in the flow direction of the refrigerant in the indoor heat exchanger; and a control unit that controls the compressor, the expansion valve, and the ventilation device based on the first temperature. [Industrial Applicability]

[0140] The present disclosure is applicable to any air conditioner that includes an indoor unit and an outdoor unit. [Explanation of symbols]

[0141] 10 Air conditioner 20 Indoor unit 22 Indoor heat exchanger 22a First Part 22b Second part 22c Refrigerant inlet 22d Refrigerant outlet 26 First temperature sensor 27 Second temperature sensor 28 Third Temperature Sensor 30 Outdoor unit 32 Outdoor heat exchanger 36 Compressor 38 Expansion valve 40 Four-way valve 42 Refrigerant piping 50 Ventilation Equipment 52 Absorbent material 54 Motor 56 Ventilation duct 57 nozzle 58 First heater 60 Second heater 62 Fan (First Fan) 64 Damper device 66 Fan (Second Fan) 70 Remote Controller 90 Control Unit DP1 area P1 flow path (first flow path) P2 flow path (second flow path) PA1 Wet Pass PA2 Drying Pass

Claims

1. an outdoor unit having an outdoor heat exchanger, a compressor, and an expansion valve; an indoor unit having an indoor heat exchanger; a refrigerant pipe that connects the outdoor heat exchanger, the compressor, the expansion valve, and the indoor heat exchanger and through which a refrigerant circulates; a first temperature sensor that acquires a first temperature of a portion of the indoor heat exchanger that is upstream in a flow direction of the refrigerant and downstream of an inflow portion into the indoor heat exchanger; a ventilation device that supplies outdoor air toward a downstream region of the indoor heat exchanger in a flow direction of the refrigerant; a control unit that controls the compressor, the expansion valve, and the ventilation device based on the first temperature in a dehumidifying operation that includes supplying outdoor air; An air conditioner comprising:

2. The control unit Obtain the indoor temperature and the set temperature, When it is determined that the indoor temperature is lower than the set temperature, the operation mode is switched to the dehumidifying operation, and the opening degree of the expansion valve and the frequency of the compressor are reduced. The air conditioner according to claim 1.

3. the control unit starts supplying the outdoor air from the ventilation device when the first temperature becomes equal to or higher than a first threshold.

3. The air conditioner according to claim 1 or 2.

4. the control unit stops the supply of the outdoor air from the ventilation device when the first temperature becomes equal to or lower than a second threshold value. The air conditioner according to any one of claims 1 to 3.

5. a second temperature sensor configured to acquire a second temperature of the inlet portion; the control unit controls the compressor and the expansion valve based on the second temperature. The air conditioner according to any one of claims 1 to 4.

6. the control unit calculates a temperature difference between the first temperature and the second temperature, and controls the compressor, the expansion valve, and the ventilation device based on the temperature difference. The air conditioner according to claim 5.

7. The control unit stops the supply of the outdoor air from the ventilation device when the temperature difference becomes equal to or less than a third threshold. The air conditioner according to claim 6.

8. The control unit increases the opening degree of the expansion valve and the frequency of the compressor when the second temperature becomes equal to or lower than a fourth threshold value. The air conditioner according to any one of claims 5 to 7.

9. a third temperature sensor configured to acquire a third temperature of a downstream region of the indoor heat exchanger in a flow direction of the refrigerant; the control unit controls the compressor and the expansion valve based on the third temperature during the cooling operation. The air conditioner according to any one of claims 5 to 8.

10. The control unit In the dehumidifying operation, the indoor temperature and the set temperature are acquired, When it is determined that the indoor temperature is higher than the set temperature, the supply of the outdoor air from the ventilation device is stopped, and the opening degree of the expansion valve and the frequency of the compressor are increased. The air conditioner according to any one of claims 1 to 9.

11. The ventilation device includes: an absorbent material that absorbs moisture from the outdoor air; a flow path connecting the outdoor area with the indoor unit and through which the outdoor air flows; a heater disposed upstream of the absorbent material in the flow path; a fan for sending the outdoor air to the flow path; a damper device that distributes the outdoor air flowing through the flow path between the outdoor unit and the indoor unit; Including, The control unit controlling the heater to heat and dry the absorbent material; controlling the fan to pass the outdoor air through the absorbent material to dry it; controlling the damper device to distribute the dried outdoor air to the indoor unit; The air conditioner according to any one of claims 1 to 10.

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