JP2021050907A - Air conditioner - Google Patents

Abstract

To provide an air conditioner which performs a dehumidification operation by using indoor humidity detected by a humidity sensor.SOLUTION: An air conditioner includes a refrigerant circuit, an indoor fan and a control part. The control part has a thermo-off temperature condition by an indoor temperature and a thermo-off humidity condition by indoor humidity as a determination element for determining whether the thermo-off condition is satisfied during a dehumidification operation. In the case where the thermo-off humidity condition is not satisfied when the thermo-off temperature condition is satisfied during the dehumidification operation, the control part controls the capacity of a compressor and the air volume of the indoor fan so that the refrigerant evaporation temperature in an indoor heat exchanger is lower than a dew-point temperature of the indoor air without stopping the compressor. In the case where a predetermined thermo-on condition is satisfied during thermo-off, the control part starts the compressor and performs the dehumidification operation. The control part includes a thermo-on temperature condition by the indoor temperature as a determination element for determining whether the thermo-on condition is satisfied.SELECTED DRAWING: Figure 7

Description

Air conditioner for dehumidifying operation

Conventionally, there is an air conditioner having a refrigerant circuit configured by connecting a compressor, an outdoor heat exchanger, an expansion mechanism, and an indoor heat exchanger. Then, in this air conditioner, as shown in Patent Document 1 (Japanese Unexamined Patent Publication No. 2002-333186), the refrigerant sealed in the refrigerant circuit is exchanged with a compressor using the indoor humidity detected by the humidity sensor. There is a dehumidifying operation that circulates in the order of the vessel, expansion mechanism, and indoor heat exchanger.

The air conditioner according to the first aspect includes a refrigerant circuit, an indoor fan, and a control unit. The refrigerant circuit is configured by connecting a compressor, an outdoor heat exchanger, an expansion mechanism, and an indoor heat exchanger. The indoor fan sends indoor air to the indoor heat exchanger. The control unit performs a dehumidifying operation in which the refrigerant sealed in the refrigerant circuit is circulated in the order of the compressor, the outdoor heat exchanger, the expansion mechanism, and the indoor heat exchanger. During the dehumidifying operation, the control unit performs thermo-off to stop the compressor when a predetermined thermo-off condition is satisfied. The control unit has a thermo-off temperature condition based on the room temperature and a thermo-off humidity condition based on the room humidity as a determination element for determining whether or not the thermo-off condition is satisfied during the dehumidifying operation. During the dehumidifying operation, if the thermo-off humidity condition is not satisfied when the thermo-off temperature condition is satisfied, the evaporation temperature of the refrigerant in the indoor heat exchanger determines the dew point temperature of the indoor air without stopping the compressor. The capacity of the compressor and the air volume of the indoor fan are controlled so as to be lower than that. The control unit activates the compressor to perform a dehumidifying operation when a predetermined thermo-on condition is satisfied during the thermo-off. The control unit has a thermo-on temperature condition based on the room temperature as a determination element for determining whether or not the thermo-on condition is satisfied.

In the air conditioner according to the second aspect, in the air conditioner according to the first aspect, the control unit selectively performs a dehumidifying operation and a cooling operation different from the dehumidifying operation.

The air conditioner according to the third aspect is the air conditioner according to the second aspect. In the air conditioner according to the second aspect, the control unit stops the compressor when a predetermined thermo-off condition is satisfied during the cooling operation. .. Further, the control unit has only the thermo-off temperature condition based on the room temperature as a determination element for determining whether or not the thermo-off condition is satisfied during the cooling operation.

The air conditioner according to the fourth aspect is the air conditioner according to the third aspect, when the control unit continues to reach the temperature below the thermo-off temperature for a predetermined time during the dehumidifying operation. , It is judged that the thermo-off temperature condition is satisfied. Further, the control unit determines that the thermo-off temperature condition is satisfied when the room temperature reaches the thermo-off temperature or less during the cooling operation.

In the air conditioner according to the fifth aspect, in the air conditioner according to the third or fourth aspect, the thermooff temperature under the thermooff temperature condition during the dehumidifying operation is lower than the thermooff temperature under the thermooff temperature condition during the cooling operation. The value.

In the air conditioner according to the sixth aspect, in the air conditioner according to the second to fifth viewpoints, the rotation speed of the indoor fan during the dehumidifying operation is limited to the rotation speed of the indoor fan that can be set during the cooling operation. Has been done.

In the air conditioner according to the seventh aspect, in the air conditioner according to the sixth aspect, the rotation speed of the indoor fan during the dehumidifying operation is equal to or less than the minimum rotation speed among the rotation speeds that can be set during the cooling operation.

The air conditioner according to the eighth aspect is the air conditioner according to the second to seventh aspects, and the evaporation temperature during the dehumidification operation is operated at a temperature equal to or lower than the evaporation temperature during the cooling operation.

The air conditioner according to the ninth aspect is configured in the air conditioner according to the first to eighth aspects so that the control unit can select a plurality of dehumidification operation modes having different dehumidification levels as the dehumidification operation. ..

In the air conditioner according to the tenth aspect, the evaporation temperature of the air conditioner according to the ninth aspect changes according to the dehumidification level of the selected dehumidification operation mode.

The air conditioner according to the eleventh aspect further includes an indoor humidity sensor for detecting the indoor humidity in the air conditioner according to the first to tenth aspects. When the indoor humidity sensor is abnormal, the control unit performs a dehumidifying operation by using a substitute value as the indoor humidity instead of the detected value of the indoor humidity sensor.

The air conditioner according to the twelfth aspect includes a refrigerant circuit, an indoor fan, and a control unit. The refrigerant circuit is configured by connecting a compressor, an outdoor heat exchanger, an expansion mechanism, and an indoor heat exchanger. The indoor fan sends indoor air to the indoor heat exchanger. The control unit selectively performs a dehumidifying operation and a cooling operation different from the dehumidifying operation. During the dehumidifying operation, the control unit performs thermo-off to stop the compressor when a predetermined thermo-off condition is satisfied. The control unit has a thermo-off temperature condition based on the room temperature and a thermo-off humidity condition based on the room humidity as a determination element for determining whether or not the thermo-off condition is satisfied during the dehumidifying operation. During the dehumidifying operation, if the thermo-off humidity condition is not satisfied when the thermo-off temperature condition is satisfied, the evaporation temperature of the refrigerant in the indoor heat exchanger determines the dew point temperature of the indoor air without stopping the compressor. The capacity of the compressor and the air volume of the indoor fan are controlled so as to be lower than that.

It is a schematic block diagram of the air conditioner which concerns on one Embodiment of this disclosure. It is an external perspective view of the indoor unit which constitutes an air conditioner. It is a schematic side sectional view of the indoor unit, and is the IOI sectional view of FIG. It is a control block diagram of an air conditioner. It is a control flowchart at the time of a cooling operation. It is a control flowchart (mode selection) at the time of dehumidifying operation. It is a control flowchart (dehumidifying operation mode L, M, H) at the time of a dehumidifying operation. It is a flowchart which shows the process at the time of an abnormality of an indoor humidity sensor.

Hereinafter, embodiments of the air conditioner will be described with reference to the drawings.

(1) Equipment Configuration FIG. 1 is a schematic configuration diagram of an air conditioner 1 according to an embodiment of the present disclosure.

<Overall>
The air conditioner 1 is a device that air-conditions the interior of a building or the like by a vapor compression refrigeration cycle. The air conditioner 1 mainly has an outdoor unit 2, an indoor unit 3, a liquid refrigerant connecting pipe 4 and a gas refrigerant connecting pipe 5 for connecting the outdoor unit 2 and the indoor unit 3. The vapor compression type refrigerant circuit 10 of the air conditioner 1 is configured by connecting the outdoor unit 2 and the indoor unit 3 via the liquid refrigerant connecting pipe 4 and the gas refrigerant connecting pipe 5.

<Outdoor unit>
The outdoor unit 2 is installed outdoors (on the roof of a building, near the outer wall surface of a building, etc.). As described above, the outdoor unit 2 is connected to the indoor unit 3 via the liquid refrigerant connecting pipe 4 and the gas refrigerant connecting pipe 5, and constitutes a part of the refrigerant circuit 10. The outdoor unit 2 mainly includes a compressor 21, a four-way switching valve 23, an outdoor heat exchanger 24, and an expansion valve 25.

The compressor 21 is a mechanism that compresses the low-pressure refrigerant in the refrigeration cycle until it reaches a high pressure. Here, as the compressor 21, a compressor having a closed structure in which a positive displacement compression element (not shown) such as a rotary type or a scroll type is rotationally driven by a compressor motor 22 is used. Further, here, the compressor motor 22 can control the rotation speed (frequency) by an inverter or the like, whereby the capacity of the compressor 21 can be controlled.

The four-way switching valve 23 is a valve for switching the direction of the refrigerant flow when switching between the cooling operation or the dehumidifying operation and the heating operation. The four-way switching valve 23 connects the discharge side of the compressor 21 and the gas side of the outdoor heat exchanger 24 during the cooling operation or the dehumidifying operation, and also connects the indoor heat exchanger 31 (described later) via the gas refrigerant connecting pipe 5. ) Can be connected to the suction side of the compressor 21 (see the solid line of the four-way switching valve 23 in FIG. 1). Further, the four-way switching valve 23 connects the discharge side of the compressor 21 and the gas side of the indoor heat exchanger 31 via the gas refrigerant connecting pipe 5 during the heating operation, and also connects the gas side of the outdoor heat exchanger 24. Can be connected to the suction side of the compressor 21 (see the broken line of the four-way switching valve 23 in FIG. 1).

The outdoor heat exchanger 24 is a heat exchanger that functions as a refrigerant radiator during a cooling operation or a dehumidifying operation and as a refrigerant evaporator during a heating operation. The liquid side of the outdoor heat exchanger 24 is connected to the expansion valve 25, and the gas side is connected to the four-way switching valve 23.

The expansion valve 25 decompresses the high-pressure liquid refrigerant radiated by the outdoor heat exchanger 24 before sending it to the indoor heat exchanger 31 during cooling operation or dehumidifying operation, and decompresses the high-pressure liquid radiated by the indoor heat exchanger 31 during heating operation. It is an expansion mechanism capable of depressurizing the refrigerant before sending it to the outdoor heat exchanger 24. Here, as the expansion valve 25, an electric expansion valve capable of controlling the opening degree is used.

Further, the outdoor unit 2 is provided with an outdoor fan 26 for sucking outdoor air into the unit, supplying outdoor air to the outdoor heat exchanger 24, and then discharging the outdoor air to the outside of the unit. That is, the outdoor heat exchanger 24 is a heat exchanger that dissipates heat and evaporates the refrigerant by using the outdoor air as a cooling source or a heating source. The outdoor fan 26 is rotationally driven by the outdoor fan motor 27.

Further, the outdoor unit 2 is provided with various sensors. Specifically, the outdoor unit 2 is provided with a suction pressure sensor 28 that detects the suction pressure Ps of the compressor 21.

<Refrigerant connecting pipe>
The refrigerant connecting pipes 4 and 5 are refrigerant pipes to be installed on-site when the air conditioner 1 is installed at an installation location such as a building. One end of the liquid-refrigerant connecting pipe 4 is connected to the expansion valve 25 side of the indoor unit 2, and the other end of the liquid-refrigerant connecting pipe 4 is connected to the liquid side of the indoor heat exchanger 31 of the indoor unit 3. One end of the gas refrigerant connecting pipe 5 is connected to the four-way switching valve 23 side of the indoor unit 2, and the other end of the gas refrigerant connecting pipe 5 is connected to the gas side of the indoor heat exchanger 31 of the indoor unit 3. ..

<Indoor unit>
The indoor unit 3 is installed indoors (inside the building). As described above, the indoor unit 3 is connected to the outdoor unit 2 via the liquid refrigerant connecting pipe 4 and the gas refrigerant connecting pipe 5, and constitutes a part of the refrigerant circuit 10. The indoor unit 3 mainly has an indoor heat exchanger 31 and an indoor fan 32.

Here, as the indoor unit 3, a type of indoor unit called a ceiling-embedded type is adopted. As shown in FIGS. 2 and 3, the indoor unit 3 has a casing 41 for accommodating constituent devices inside. The casing 41 is composed of a casing main body 41a and a decorative panel 42 arranged under the casing main body 41a. As shown in FIG. 2, the casing main body 41a is inserted and arranged in the opening formed in the ceiling U. The decorative panel 42 is arranged so as to be fitted into the opening of the ceiling U. Here, FIG. 2 is an external perspective view of the indoor unit 3. FIG. 3 is a schematic side sectional view of the indoor unit 3, and is a sectional view taken along the line IOI of FIG.

The casing main body 41a is a substantially octagonal box-shaped body in which long sides and short sides are alternately formed in a plan view, and the lower surface thereof is open. The casing main body 41a has a substantially octagonal top plate 43 in which long sides and short sides are alternately and continuously formed, and a side plate 44 extending downward from the peripheral edge portion of the top plate 43.

The decorative panel 42 is a plate-like body having a substantially polygonal shape (here, a substantially square shape) in a plan view, which constitutes the lower surface of the casing 41, and is mainly a panel main body fixed to the lower end portion of the casing main body 41a. It is composed of 42a. The panel main body 42a has a suction port 45 for sucking indoor air at a substantially center thereof, and an air outlet 46 for blowing air into the room formed so as to surround the suction port 45 in a plan view. The suction port 45 is a substantially square opening. The suction port 45 is provided with a suction grill 47 and a suction filter 48 for removing dust in the air sucked from the suction port 45. The outlets 46 are a plurality of (here, four) side outlets 46a formed along each side of the quadrangle of the panel body 42a, and a plurality (here) formed at the corners of the panel body 42a. Then, it has four) corner outlets 46b. Then, at each side outlet 46a, a plurality of (here, four) wind direction changing blades 49 capable of changing the vertical wind direction angle of the air blown into the room from each side outlet are provided. It is provided. The wind direction changing blade 49 is a plate-shaped member that extends elongated along the longitudinal direction of the side outlet 46a. The wind direction changing blade 49 is rotated around an axis in the longitudinal direction so that the wind direction angle in the vertical direction can be changed.

Inside the casing main body 41a, an indoor heat exchanger 31 and an indoor fan 32 are mainly arranged.

The indoor heat exchanger 31 is a heat exchanger that functions as a refrigerant evaporator during a cooling operation or a dehumidifying operation and as a refrigerant radiator during a heating operation. The liquid side of the outdoor heat exchanger 31 is connected to the liquid-refrigerant connecting pipe 4, and the gas side is connected to the gas-refrigerant connecting pipe 5. The indoor heat exchanger 31 is a heat exchanger that is bent and arranged so as to surround the periphery of the indoor fan 32 in a plan view. The indoor heat exchanger 31 exchanges heat between the indoor air sucked into the casing main body 41a by the indoor fan 32 and the refrigerant. Further, below the indoor heat exchanger 31, a drain pan 31a for receiving the drain water generated by condensing the moisture in the indoor air by the indoor heat exchanger 31 is arranged. The drain pan 31a is attached to the lower part of the casing main body 41a.

The indoor fan 32 is a fan that sucks indoor air into the casing main body 41a through the suction port 45 of the decorative panel 42 and blows it into the room from the inside of the casing main body 41a through the air outlet 46 of the decorative panel 42. That is, the indoor heat exchanger 31 is a heat exchanger that dissipates heat and evaporates the refrigerant by using the indoor air as a cooling source or a heating source. Here, as the indoor fan 32, a centrifugal fan that sucks indoor air from below and blows it out toward the outer peripheral side in a plan view is used. The indoor fan 32 is rotationally driven by an indoor fan motor 33 provided in the center of the top plate 43 of the casing main body 41a. Further, here, the rotation speed (frequency) of the indoor fan motor 33 can be controlled by an inverter or the like, whereby the air volume of the indoor fan 32 can be controlled. Specifically, as the air volume of the indoor fan 32, the maximum air volume H, the medium air volume M smaller than the air volume H, the small air volume L smaller than the air volume M, and the minimum air volume smaller than the air volume L. Four air volumes, LL, are prepared. Here, the air volume LL is an air volume that cannot be set by the occupant by the remote controller 60 (described later).

Further, the indoor unit 3 is provided with various sensors. Specifically, the indoor unit 3 is provided with an indoor temperature sensor 34 and an indoor humidity sensor 35 that detect the temperature (indoor temperature Tr) and humidity (indoor humidity Hr) of the indoor air sucked into the indoor unit 3. ing.

(2) Control configuration FIG. 4 is a control block diagram of the air conditioner 1.

<Overall>
The air conditioner 1 as a refrigerating device is a control unit 6 in which an outdoor control unit 20, an indoor control unit 30, and a remote controller 60 are connected via a transmission line or a communication line in order to control the operation of constituent equipment. have. The outdoor control unit 20 is provided in the indoor unit 2. The indoor side control unit 30 is provided in the indoor unit 3. The remote controller 60 is provided in the room. Here, the control units 20 and 30 and the remote controller 60 are connected by wire via a transmission line or a communication line, but may be wirelessly connected.

<Outdoor control unit>
As described above, the outdoor control unit 20 is provided in the outdoor unit 2, and mainly has an outdoor CPU 20a, an outdoor transmission unit 20b, and an outdoor storage unit 20c. The indoor control unit 20 can receive the detection signal of the suction pressure sensor 28.

The outdoor CPU 20a is connected to the outdoor transmission unit 20b and the outdoor storage unit 20c. The heat source side transmission unit 20b transmits control data and the like to and from the indoor side control unit 30a. The outdoor storage unit 20c stores control data and the like. Then, the outdoor CPU 20a transmits and reads / writes control data and the like via the outdoor transmission unit 20b and the outdoor storage unit 20c, and the constituent devices 21, 23, 25, 26 and the like provided in the outdoor unit 2 and the like. Operation control is performed.

<Indoor control unit>
The indoor side control unit 30 is provided in the indoor unit 3 as described above, and mainly includes an indoor side CPU 30a, an indoor side transmission unit 30b, an indoor side storage unit 30c, and an indoor side communication unit 30d. Have. The indoor control unit 30 can receive the detection signals of the indoor temperature sensor 34 and the indoor humidity sensor 35.

The indoor CPU 30a is connected to the indoor transmission unit 30b, the indoor storage unit 30c, and the indoor storage unit 30d. The indoor side transmission unit 30b transmits control data and the like to and from the outdoor side control unit 20. The indoor storage unit 30b stores control data and the like. The indoor communication unit 30c transmits and receives control data and the like to and from the remote controller 60. Then, the indoor CPU 30a transmits, reads, writes, and transmits / receives control data and the like via the indoor transmission unit 30b, the indoor storage unit 30c, and the indoor communication unit 30d, and is a component device provided in the indoor unit 3. Operation control such as 32 and 49 is performed.

<Remote control>
The remote controller 60 is provided indoors as described above, and mainly includes a remote controller CPU 61, a remote controller storage unit 62, a remote controller communication unit 63, a remote controller operation unit 64, and a remote controller display unit 65. There is.

The remote control CPU 61 is connected to the remote control communication unit 62, the remote control storage unit 63, the remote control operation unit 64, and the remote control display unit 65. The remote control communication unit 62 transmits and receives control data and the like to and from the indoor communication unit 30c. The remote control storage unit 63 stores control data and the like. The remote control operation unit 64 receives an input such as a control command from the user. The remote control display unit 65 displays the operation and the like. Then, the remote controller CPU 61 receives inputs such as an operation command and a control command via the remote controller operation unit 64, reads and writes control data and the like to the remote controller storage unit 63, and displays the operation state and the control state on the remote controller display unit 65. Etc., and a control command or the like is given to the indoor control unit 30 via the remote controller communication unit 62.

As described above, the air conditioner 1 as a refrigerating device has a control unit 6 that controls the operation of the constituent devices. Then, the control unit 6 controls the constituent devices 21, 23, 25, 26, 32, 49, etc. based on the detection signals of the suction pressure sensor 28, the indoor temperature sensor 34, the indoor humidity sensor 35, etc. It is possible to perform air conditioning operation such as dehumidification operation and heating operation, and various controls.

(3) Basic operation Next, the basic operation (heating operation, cooling operation, and dehumidifying operation) of the air conditioner 1 will be described.

<Heating operation>
In the air conditioner 1, a heating operation as an air conditioning operation can be performed. In the heating operation, the control unit 6 that receives the heating operation command via the remote control operation unit 64 controls the operation of the outdoor unit 2 and the constituent devices 21, 23, 25, 26, 32, 49, etc. of the outdoor unit 3. Is done by.

In the heating operation, the outdoor heat exchanger 24 functions as a refrigerant evaporator and the indoor heat exchanger 31 functions as a refrigerant radiator (that is, indicated by the broken line of the four-way switching valve 23 in FIG. 1). The four-way switching valve 23 is switched so as to be in a state where it can be operated.

In the refrigerant circuit 10 in such a state, the low-pressure refrigerant in the refrigeration cycle is sucked into the compressor 21, compressed to the high pressure in the refrigeration cycle, and then discharged. The high-pressure refrigerant discharged from the compressor 21 is sent to the indoor heat exchanger 31 through the four-way switching valve 23 and the gas refrigerant connecting pipe 5. The high-pressure refrigerant sent to the indoor heat exchanger 31 exchanges heat with the indoor air supplied by the indoor fan 32 in the indoor heat exchanger 31 to dissipate heat. As a result, the indoor air is heated and blown into the room. The high-pressure refrigerant radiated by the indoor heat exchanger 31 is sent to the expansion valve 25 through the liquid-refrigerant connecting pipe 4 and is depressurized to the low pressure in the refrigeration cycle. The low-pressure refrigerant decompressed by the expansion valve 25 is sent to the outdoor heat exchanger 24. The low-pressure refrigerant sent to the outdoor heat exchanger 24 undergoes heat exchange with the outdoor air supplied by the outdoor fan 26 in the outdoor heat exchanger 24 and evaporates. The low-pressure refrigerant evaporated in the outdoor heat exchanger 24 is sucked into the compressor 21 again through the four-way switching valve 23. As described above, in the heating operation, the control unit 6 circulates the refrigerant sealed in the refrigerant circuit 10 in the order of the compressor 21, the indoor heat exchanger 31, the expansion valve 25, and the outdoor heat exchanger 24. It has become like.

<Cooling operation>
In the air conditioner 1, a cooling operation as an air conditioning operation can be performed. In the cooling operation, the control unit 6 that receives the cooling operation command via the remote control operation unit 64 controls the operation of the outdoor unit 2 and the constituent devices 21, 23, 25, 26, 32, 49, etc. of the outdoor unit 3. Is done by.

In the cooling operation, the outdoor heat exchanger 24 functions as a refrigerant radiator and the indoor heat exchanger 31 functions as a refrigerant evaporator (that is, shown by the solid line of the four-way switching valve 23 in FIG. 1). The four-way switching valve 23 is switched so as to be in a state where it can be operated.

In the refrigerant circuit 10 in such a state, the low-pressure refrigerant in the refrigeration cycle is sucked into the compressor 21, compressed to the high pressure in the refrigeration cycle, and then discharged. The high-pressure refrigerant discharged from the compressor 21 is sent to the outdoor heat exchanger 24 through the four-way switching valve 23. The high-pressure refrigerant sent to the outdoor heat exchanger 24 exchanges heat with the outdoor air supplied by the outdoor fan 26 in the outdoor heat exchanger 24 to dissipate heat. The high-pressure refrigerant dissipated in the outdoor heat exchanger 24 is sent to the expansion valve 25 to reduce the pressure to the low pressure in the refrigeration cycle. The low-pressure refrigerant decompressed by the expansion valve 25 is sent to the indoor heat exchanger 31 through the liquid refrigerant connecting pipe 4. The low-pressure refrigerant sent to the indoor heat exchanger 31 evaporates by exchanging heat with the indoor air supplied by the indoor fan 32 in the indoor heat exchanger 31. As a result, the indoor air is cooled and blown into the room. The low-pressure refrigerant evaporated in the indoor heat exchanger 31 is sucked into the compressor 21 again through the gas refrigerant connecting pipe 5 and the four-way switching valve 23. As described above, in the cooling operation, the control unit 6 circulates the refrigerant sealed in the refrigerant circuit 10 in the order of the compressor 21, the outdoor heat exchanger 24, the expansion valve 25, and the indoor heat exchanger 31. It has become like.

<Dehumidifying operation>
The air conditioner 1 can perform a dehumidifying operation as an air conditioning operation. In the dehumidifying operation, the control unit 6 that receives the dehumidifying operation command via the remote control operation unit 64 controls the operation of the outdoor unit 2 and the constituent devices 21, 23, 25, 26, 32, 49, etc. of the outdoor unit 3. Is done by.

In the dehumidifying operation, as in the cooling operation, the outdoor heat exchanger 24 functions as a refrigerant radiator and the indoor heat exchanger 31 functions as a refrigerant evaporator (that is, the four-way switching in FIG. 1). The four-way switching valve 23 is switched so as to be in the state shown by the solid line of the valve 23).

In the refrigerant circuit 10 in such a state, the low-pressure refrigerant in the refrigeration cycle is sucked into the compressor 21, compressed to the high pressure in the refrigeration cycle, and then discharged. The high-pressure refrigerant discharged from the compressor 21 is sent to the outdoor heat exchanger 24 through the four-way switching valve 23. The high-pressure refrigerant sent to the outdoor heat exchanger 24 exchanges heat with the outdoor air supplied by the outdoor fan 26 in the outdoor heat exchanger 24 to dissipate heat. The high-pressure refrigerant dissipated in the outdoor heat exchanger 24 is sent to the expansion valve 25 to reduce the pressure to the low pressure in the refrigeration cycle. The low-pressure refrigerant decompressed by the expansion valve 25 is sent to the indoor heat exchanger 31 through the liquid refrigerant connecting pipe 4. The low-pressure refrigerant sent to the indoor heat exchanger 31 evaporates by exchanging heat with the indoor air supplied by the indoor fan 32 in the indoor heat exchanger 31. As a result, the indoor air is dehumidified and blown into the room. The low-pressure refrigerant evaporated in the indoor heat exchanger 31 is sucked into the compressor 21 again through the gas refrigerant connecting pipe 5 and the four-way switching valve 23. As described above, in the dehumidifying operation, the control unit 6 circulates the refrigerant sealed in the refrigerant circuit 10 in the order of the compressor 21, the outdoor heat exchanger 24, the expansion valve 25, and the indoor heat exchanger 31. It has become like.

(4) Control during cooling operation In the above cooling operation, the following control is performed. FIG. 5 is a flowchart of the cooling operation.

<Step ST1 (Thermoon)>
In step ST1, that is, during the cooling operation (during the operation of operating the compressor 21 to circulate the refrigerant, during thermo-on), the control unit 6 sets the target evaporation temperature Te of the refrigerant in the refrigerant circuit 10 as the target evaporation temperature. Capacity control is performed to control the capacity of the compressor 21 so as to be Tecs. Further, the control unit 6 sets the air volume selected by the occupant inputting the air volume of the indoor fan 32 from the remote control operation unit 64 of the remote controller 60 during the thermo-on of step ST1 (here, the air volume L, the air volume). It is controlled to either M or air volume H).

In the capacity control of the compressor 21, when the evaporation temperature Te of the refrigerant is higher than the target evaporation temperature Tecs, the capacity of the compressor 21 is increased by increasing the rotation speed (frequency) of the compressor 21 to increase the capacity of the refrigerant. When the evaporation temperature Te is lower than the target evaporation temperature Tecs, the capacity of the compressor 21 is reduced by reducing the rotation speed (frequency) of the compressor 21.

Here, the control unit 6 determines the target evaporation temperature Tecs based on the temperature difference ΔTr obtained by subtracting the target indoor temperature Trs from the indoor temperature Tr. Specifically, the control unit 6 determines that the larger the temperature difference ΔTr, the lower the target evaporation temperature Tecs. The target room temperature Trs is set by being input by a resident from the remote control operation unit 64 of the remote control 60. Further, the evaporation temperature Te of the refrigerant is obtained by converting the suction pressure Ps into the saturation temperature of the refrigerant. The refrigerant evaporation temperature Te represents a low-pressure refrigerant in a refrigeration cycle that flows from the outlet of the expansion valve 25 to the suction side of the compressor 21 via the indoor heat exchanger 31 during the cooling operation. It means the temperature obtained by converting the pressure (refrigerant evaporation pressure Pe in the refrigerant circuit 10) into the refrigerant saturation temperature, or the refrigerant saturation temperature in the indoor heat exchanger 31 that functions as a refrigerant evaporator. Therefore, when the indoor heat exchanger 31 is provided with a temperature sensor, the temperature of the refrigerant detected by the temperature sensor may be set as the evaporation temperature Te of the refrigerant.

Here, the state quantity of the controlled object in the capacity control is set to the evaporation temperature Te, but it may be the evaporation pressure Pe. In this case, the target evaporation pressure Pecs corresponding to the target evaporation temperature Tecs may be used as the control target value. Using the evaporation pressure Pe and the target evaporation pressure Pecs in this capacity control is the same as using the evaporation temperature Te and the target evaporation temperature Tecs.

<Step ST2 (determination of whether or not the thermo-off condition is satisfied)>
The control unit 6 determines whether or not the thermo-off condition is satisfied in step ST2 during the thermo-on in step ST1.

The control unit 6 has a thermo-off temperature condition based on the room temperature Tr as a determination element for determining whether or not the thermo-off condition is satisfied. Then, the control unit 6 determines that the thermo-off temperature condition is satisfied when the thermo-off temperature condition is satisfied, and determines that the thermo-off condition is not satisfied when the thermo-off temperature condition is not satisfied. Specifically, the control unit 6 determines that the thermo-off temperature condition is satisfied when the room temperature Tr becomes low and the room temperature Tr reaches the thermo-off temperature Trcf or less during the thermo-on, and the room temperature Tr is the thermo-off temperature. If it is higher than Trcf, it is determined that the thermo-off temperature condition is not satisfied. Here, the thermo-off temperature Trcf is a value obtained by adding the thermo-off temperature difference ΔTrcf to the target room temperature Trs. The thermo-off temperature difference ΔTrcf is set to a value of about -1 degree to +1 degree.

Here, whether or not the thermo-off condition is satisfied is determined by whether or not the room temperature Tr has reached the thermo-off temperature Trcf, but the present invention is not limited to this. For example, it may be determined by whether or not the temperature difference ΔTr obtained by subtracting the target indoor temperature Trs from the indoor temperature Tr reaches the thermo-off temperature difference ΔTrcf. In the determination by this temperature difference ΔTr, the indoor temperature Tr reaches the thermo-off temperature Trcf. It is the same as judging by whether or not it has been done.

<Step ST3 (thermo off)>
When the control unit 6 determines in step ST2 that the thermo-off temperature satisfies the thermo-off condition when the room temperature Tr reaches the thermo-off temperature Trcf or lower, the compressor 21 is stopped in step ST3 to stop the circulation of the refrigerant. Pauses the cooling operation (thermo off).

<Step ST4 (determination of whether or not the thermo-on condition is satisfied)>
The control unit 6 determines whether or not the thermo-on condition is satisfied in step ST4 during the thermo-off in step ST3.

The control unit 6 has a thermo-on temperature condition based on the room temperature Tr as a determination element for determining whether or not the thermo-on condition is satisfied. Then, the control unit 6 determines that the thermoon condition is satisfied when the thermoon temperature condition is satisfied, and determines that the thermoon condition is not satisfied when the thermoon temperature condition is not satisfied. Specifically, the control unit 6 determines that the thermo-on temperature condition is satisfied when the room temperature Tr becomes high and the room temperature Tr reaches the thermo-on temperature Trcn or higher during the thermo-off, and the room temperature Tr is the thermo-on temperature. If it is lower than Trcn, it is determined that the thermoon temperature condition is not satisfied. Here, the thermoon temperature Trcn is a value obtained by adding the thermoon temperature difference ΔTrcn to the target room temperature Trs. The thermo-on temperature difference ΔTrcn is set to a value of about 0 to +2 degrees.

Here, whether or not the thermoon condition is satisfied is determined by whether or not the room temperature Tr has reached the thermoon temperature Trcn, but the present invention is not limited to this. For example, it may be determined by whether or not the temperature difference ΔTr obtained by subtracting the target indoor temperature Trs from the indoor temperature Tr reaches the thermoon temperature difference ΔTrcn, and the determination by this temperature difference ΔTr also shows that the indoor temperature Tr reaches the thermoon temperature Trcn. It is the same as judging by whether or not it has been done.

Then, when the control unit 6 determines in step ST4 that the thermo-on condition is satisfied, the control unit 6 returns to step ST1 and starts the compressor 21 to perform the cooling operation operation (thermo-on).

(5) Control during dehumidifying operation In the above dehumidifying operation, the following control is performed. FIG. 6 is a flowchart of the dehumidifying operation (mode selection), and FIG. 7 is a flowchart of the dehumidifying operation (dehumidifying operation modes L, M, H).

<Step ST11 (mode selection)>
Here, in order to meet the needs of the dehumidification level of the occupants, a plurality of dehumidification operation modes having different dehumidification levels are prepared as the dehumidification operation. Here, the dehumidification level means the degree of the indoor humidity Hr obtained by the dehumidification operation, and the lower the indoor humidity Hr obtained by the dehumidification operation, the higher the dehumidification level. Specifically, as the dehumidification operation mode, the dehumidification operation mode L having the lowest dehumidification level, the dehumidification operation mode M having a medium dehumidification level higher than the dehumidification operation mode L, and the dehumidification operation mode M having a higher dehumidification level than the dehumidification operation mode M. Three high-level dehumidifying operation modes H are prepared in the control unit 6. Here, the selection of the dehumidifying operation mode is selected by inputting from the remote controller operation unit 64 of the remote controller 60 by a resident in the room in step ST11.

<Step ST12 (dehumidifying operation mode L)>
When the dehumidifying operation mode L is selected in step ST11, the control unit 6 controls steps ST12 (that is, steps ST21 to ST27).

-Step ST21 (Thermoon)-
In step ST21, that is, during the operation of the dehumidifying operation (during the operation of operating the compressor 21 to circulate the refrigerant, during thermo-on), the control unit 6 sets the target evaporation temperature Te of the refrigerant in the refrigerant circuit 10 as the target evaporation temperature. Capacity control is performed to control the capacity of the compressor 21 so as to be Teds. Further, the control unit 6 performs air volume control during the thermo-on of step ST21 to limit the air volume of the indoor fan 32 to the air volume L or the air volume LL, unlike the step ST1 during the cooling operation.

The capacity control of the compressor 21 is the same as in step ST1 during the cooling operation, except that the target evaporation temperature Tecs is set as the target evaporation temperature Teds. Therefore, the description of the capacity control of the compressor 21 will be omitted here. Here, the target evaporation temperature Teds is set to a value equal to or less than the target evaporation temperature Tecs.

-Step ST22 (Judgment 1 to determine whether the thermo-off condition is satisfied)-
The control unit 6 determines whether or not the thermo-off condition is satisfied in step ST22 during the thermo-on in step ST21.

The control unit 6 has a first thermo-off temperature condition based on the room temperature Tr and a thermo-off humidity condition based on the room humidity Hr as a determination element for determining whether or not the thermo-off condition is satisfied. Then, when the control unit 6 satisfies both the first thermo-off temperature condition and the thermo-off humidity condition, the control unit 6 determines that the thermo-off condition is satisfied, and satisfies one or both of the first thermo-off temperature condition and the thermo-off humidity condition. If not, it is determined that the thermo-off condition is not satisfied. That is, in the dehumidifying operation mode L, unlike step ST2 during the cooling operation, it is determined whether or not the thermo-off condition is satisfied in consideration of not only the thermo-off temperature condition but also the thermo-off humidity condition.

Specifically, the control unit 6 sets the first thermo-off temperature when the room temperature Tr becomes low and the room temperature Tr reaches the first thermo-off temperature TrdfL1 or less continuously for a predetermined time tL during the thermo-on. It is determined that the condition is satisfied, and the first thermo-off occurs when the room temperature Tr is higher than the first thermo-off temperature TrdfL1 or when the room temperature Tr reaches the first thermo-off temperature TrdfL1 or less for a predetermined time tL continuously. It is determined that the temperature condition is not satisfied. Here, the first thermo-off temperature TrdfL1 is a value obtained by adding the first thermo-off temperature difference ΔTrdfL1 to the target room temperature Trs. The first thermo-off temperature difference ΔTrdfL1 is set to a value of about -1 degree to +1 degree, and the predetermined time tL is set to a value of about several tens of seconds to several minutes. Further, the first thermo-off temperature TrdfL1 (= target room temperature Trs + first thermo-off temperature difference ΔTrdfL1) may be the same value as the thermo-off temperature Trcf (= target room temperature Trs + thermo-off temperature difference ΔTrcf) during the cooling operation. It may be a low value.

Further, the control unit 6 determines that the thermo-off humidity condition is satisfied when the indoor humidity Hr becomes low and the indoor humidity Hr reaches the target indoor humidity HrsL during the thermo-on, and the indoor humidity Hr is higher than the target indoor humidity HrsL. If it is also high, it is judged that the thermo-off humidity condition is not satisfied. Here, the target indoor humidity HrsL is set to a low dehumidification level (that is, a high relative humidity value) of about 60% to 70% when the dehumidification operation mode L is selected in step ST11.

Here, whether or not the thermo-off condition is satisfied is determined by whether or not the indoor temperature Tr has reached the first thermo-off temperature TrdfL1 and whether or not the indoor humidity Hr has reached the target indoor humidity HrsL. It is not limited to this. For example, whether or not the temperature difference ΔTr obtained by subtracting the target indoor temperature Trs from the indoor temperature Tr reaches the first thermooff temperature difference ΔTrdfL1, and the humidity difference ΔHr obtained by subtracting the target indoor humidity Hrs from the indoor humidity Hr is 0 (zero). It may be judged by whether or not it has reached. The determination based on these temperature difference ΔTr and humidity difference ΔHr is also the same as the determination based on whether the indoor temperature Tr has reached the first thermo-off temperature TrdfL1 and whether the indoor humidity Hr has reached the target indoor humidity HrsL. Is.

-Step ST23 (thermo off)-
In step ST22, the control unit 6 satisfies the thermo-off condition by reaching the target indoor humidity HrsL when the indoor humidity Hr reaches the target indoor humidity HrsL when the state in which the indoor temperature Tr reaches the first thermo-off temperature TrdfL1 or less continues for a predetermined time tL continuously. If it is determined, in step ST23, the compressor 21 is stopped, the circulation of the refrigerant is stopped, and the operation of the dehumidifying operation is stopped (thermo-off). Further, the control unit 6 also performs thermo-off when it is determined in step ST27 (described later) that the thermo-off condition is satisfied when the room temperature Tr reaches the second thermo-off temperature TrdfL2 or less.

-Step ST24 (determination of whether or not the thermo-on condition is satisfied)-
The control unit 6 determines whether or not the thermo-on condition is satisfied in step ST24 during the thermo-off in step ST23.

The control unit 6 has a thermo-on temperature condition based on the room temperature Tr as a determination element for determining whether or not the thermo-on condition is satisfied, as in step ST4 during the cooling operation. Then, the control unit 6 determines that the thermoon condition is satisfied when the thermoon temperature condition is satisfied, and determines that the thermoon condition is not satisfied when the thermoon temperature condition is not satisfied. Specifically, the control unit 6 determines that the thermo-on temperature condition is satisfied when the room temperature Tr becomes high and the room temperature Tr reaches the thermo-on temperature TrdnL or higher during the thermo-off, and the room temperature Tr is the thermo-on temperature. When it is lower than TrdnL, it is determined that the thermoon temperature condition is not satisfied. The thermoon temperature TrdnL is a value obtained by adding the thermoon temperature difference ΔTrdnL to the target room temperature Trs. The thermoon temperature difference ΔTrdnL may be the same value as the thermoon temperature Trcn (= target room temperature Trs + thermoon temperature difference ΔTrcn) during the cooling operation, or may be a lower value.

Here, whether or not the thermoon condition is satisfied is determined by whether or not the room temperature Tr has reached the thermoon temperature TrdnL, but the present invention is not limited to this. For example, it may be determined by whether or not the temperature difference ΔTr obtained by subtracting the target indoor temperature Trs from the indoor temperature Tr reaches the thermoon temperature difference ΔTrdnL, and the determination by this temperature difference ΔTr also shows that the indoor temperature Tr reaches the thermoon temperature TrdnL. It is the same as judging by whether or not it has been done.

Then, when the control unit 6 determines in step ST24 that the thermo-on condition is satisfied, the control unit 6 returns to step ST21, starts the compressor 21, and performs a dehumidifying operation (thermo-on).

-Step ST25 (Judgment 2 to determine whether the thermo-off condition is satisfied)-
When the control unit 6 does not satisfy the thermo-off conditions (both the first thermo-off temperature condition and the thermo-off humidity condition) of step ST22 during the thermo-on of step ST21, the control unit 6 satisfies the first thermo-off temperature condition in step ST25, but the thermo-off. It is determined whether or not the humidity condition is not satisfied. That is, the control unit 6 determines whether or not the thermo-off humidity condition is not satisfied when the first thermo-off temperature condition is satisfied. Then, if the thermo-off humidity condition is not satisfied when the first thermo-off temperature condition is satisfied, the control unit 6 performs dehumidification continuation control in step ST26 without performing the thermo-off.

-Step ST26 (Thermoon, continuous dehumidification control)-
In step ST26, the control unit 6 continuously controls the capacity of the compressor 21 and the air volume of the indoor fan 32 so that the evaporation temperature Te of the refrigerant in the refrigerant circuit 10 becomes the target evaporation temperature Teds. However, here, unlike the capacity control and air volume control in step ST21, the control unit 6 has the capacity of the compressor 21 so that the evaporation temperature Te of the refrigerant in the indoor heat exchanger 31 is lower than the dew point temperature Trw of the indoor air. And the air volume of the indoor fan 32 is controlled. Here, the air volume of the indoor fan 32 is controlled to the minimum air volume LL, and the capacity of the compressor 21 is controlled to be reduced within a range where the evaporation temperature Te is lower than the dew point temperature Trw.

Here, the control unit 6 determines the target evaporation temperature Teds based on the dew point temperature Trw. Specifically, the control unit 6 calculates the dew point temperature Trw from the room temperature Tr and the room humidity Hr. Then, the control unit 6 determines the target evaporation temperature Teds by subtracting the predetermined temperature difference ΔTrw from the calculated dew point temperature Trw. That is, the control unit 6 determines the target evaporation temperature Teds to be lower than the dew point temperature Trw.

Then, when the indoor humidity Hr reaches the target indoor humidity HrsL by continuing the dehumidification by such dehumidification continuous control, the control unit 6 sets both the first thermo-off temperature condition and the thermo-off humidity condition in step ST22. It is determined that the thermo-off condition is satisfied by satisfying the condition, and the thermo-off is performed in step ST23.

-Step ST27 (Judgment 3 to determine whether the thermo-off condition is satisfied)-
If the control unit 6 does not satisfy the thermo-off condition (both the first thermo-off temperature condition and the thermo-off humidity condition) of step ST22 during the continuous dehumidification control of step ST26, the control unit 6 does not satisfy the thermo-off humidity condition in step ST27. By satisfying the second thermo-off temperature condition, it is determined whether or not the thermo-off condition is satisfied.

The control unit 6 further has a second thermo-off temperature condition on the lower temperature side than the first thermo-off temperature condition as a determination element for determining whether or not the thermo-off condition is satisfied. Then, the control unit 6 determines that the thermo-off condition is satisfied when the second thermo-off temperature condition is satisfied even if the thermo-off humidity condition is not satisfied, and when the thermo-off humidity condition and the second thermo-off temperature condition are not satisfied. Is determined not to satisfy the thermo-off condition. That is, during the dehumidification continuation control in step ST26, in step ST22, it is determined not only whether or not both the first thermo-off temperature condition and the thermo-off humidity condition are satisfied, but also whether or not the second thermo-off temperature condition is satisfied. ing.

Specifically, the control unit 6 determines that the second thermo-off temperature condition is satisfied when the room temperature Tr becomes lower and the room temperature Tr reaches the second thermo-off temperature TrdfL2 or less during the dehumidification continuous control. When the room temperature Tr is higher than the second thermo-off temperature TrdfL2, it is determined that the second thermo-off temperature condition is not satisfied. Here, the second thermo-off temperature TrdfL2 is a value obtained by adding the second thermo-off temperature difference ΔTrdfL2 to the target room temperature Trs. Then, the second thermo-off temperature difference ΔTrdfL2 is set to a value lower than the first thermo-off temperature TrdfL1 (for example, a value of about -3 degrees to -2 degrees).

Here, whether or not the thermo-off condition is satisfied is determined by whether or not the room temperature Tr has reached the second thermo-off temperature TrdfL2, but the present invention is not limited to this. For example, it may be determined whether or not the temperature difference ΔTr obtained by subtracting the target indoor temperature Trs from the indoor temperature Tr reaches the second thermo-off temperature difference ΔTrdfL2. The determination based on this temperature difference ΔTr is also the same as the determination based on whether or not the room temperature Tr has reached the second thermo-off temperature TrdfL2.

<Step ST13 (dehumidifying operation mode M)>
When the dehumidifying operation mode M is selected in step ST11, the control unit 6 controls steps ST13 (that is, steps ST31 to ST37).

Here, the processing of steps ST31 to ST37 of the dehumidifying operation mode M is the same as the processing of steps ST21 to ST27 of the dehumidifying operation mode L. Therefore, here, the description of steps ST31 to ST37 will be described by replacing the letters "L" in the description of steps ST21 to ST27 of the dehumidifying operation mode L with "M" and replacing steps ST21 to ST27 with ST31 to ST37. Omit.

However, the target indoor humidity HrsM is a value lower than the target indoor humidity HrsL of the dehumidifying operation mode L (for example, a medium relative humidity of about 50% to 60%) when the dehumidifying operation mode M is selected in step ST11. Value).

Further, in the dehumidifying operation mode M, the first thermo-off temperature TrdfM1 (first thermo-off temperature difference ΔTrdfM1) may be set to the same value as the first thermo-off temperature TrdfL1 (first thermo-off temperature difference ΔTrdfL1) in the dehumidifying operation mode L. , A low value (for example, a value in which the first thermo-off temperature difference ΔTrdfM1 is about −1.5 ° C. to + 0.5 ° C.) may be set. The predetermined time tM may be the same value as the predetermined time tL in the dehumidifying operation mode L, but may be a longer value. The thermoon temperature TrdnM (= target room temperature Trs + thermoon temperature difference ΔTrdnM) may be the same value as the thermoon temperature TrdnL (= target room temperature Trs + thermoon temperature difference ΔTrdnL) in the dehumidifying operation mode L, but may be a lower value. .. The second thermo-off temperature TrdfM2 (= target room temperature Trs + second thermo-off temperature difference ΔTrdfM2) may be set to the same value as the second thermo-off temperature TrdfL2 (= target room temperature Trs + second thermo-off temperature difference ΔTrdfL2) in the dehumidifying operation mode L. However, a low value (for example, a value in which the second thermo-off temperature difference ΔTrdfM2 is about −3.5 ° C. to −2.5 ° C.) may be set.

<Step ST14 (dehumidifying operation mode H)>
When the dehumidifying operation mode H is selected in step ST11, the control unit 6 controls steps ST14 (that is, steps ST41 to ST47).

Here, the processing of steps ST41 to ST47 of the dehumidifying operation mode H is the same as the processing of steps ST21 to ST27 of the dehumidifying operation mode L. Therefore, here, the description of steps ST41 to ST47 will be described by replacing the letters "L" in the description of steps ST21 to ST27 of the dehumidifying operation mode L with "H" and replacing steps ST21 to ST27 with ST41 to ST47. Omit.

However, the target indoor humidity HrsH is lower than the target indoor humidity HrsL and HrsM of the dehumidifying operation modes L and M (for example, about 40% to 50% lower) when the dehumidifying operation mode H is selected in step ST11. Relative humidity value).

Further, in the dehumidifying operation mode H, the first thermo-off temperature TrdfH1 (first thermo-off temperature difference ΔTrdfH1) is the same as the first thermo-off temperatures TrdfL1 and TrdfM1 (first thermo-off temperature difference ΔTrdfL1, ΔTrdfM1) in the dehumidifying operation modes L and M. It may be a value, but it may be a low value (for example, a value in which the first thermo-off temperature difference ΔTrdfH1 is about -2 degrees to 0 degrees). The predetermined time tH may be the same value as the predetermined time tL, tM in the dehumidifying operation modes L and M, but may be a longer value. The thermoon temperature TrdnH (= target room temperature Trs + thermoon temperature difference ΔTrdnH) may be set to the same value as the thermoon temperatures TrdnL and TrdnM (= target room temperature Trs + thermoon temperature difference ΔTrdnL, ΔTrdnM) in the dehumidifying operation modes L and M. It may be a low value. The second thermo-off temperature TrdfH2 (= target room temperature Trs + second thermo-off temperature difference ΔTrdfH2) is combined with the second thermo-off temperatures TrdfL2 and TrdfM2 (= target room temperature Trs + second thermo-off temperature difference ΔTrdfL2, ΔTrdfM2) in the dehumidifying operation modes L and M. The same value may be used, but a lower value (for example, a value in which the second thermo-off temperature difference ΔTrdfH2 is about -4 degrees to -3 degrees) may be used.

(6) Processing when the indoor humidity sensor is abnormal When controlling the dehumidifying operation described above, the indoor humidity Hr detected by the indoor humidity sensor 35 is used. Specifically, the control unit 6 uses the indoor humidity Hr detected by the indoor humidity sensor 35 in the determination process of determining whether or not the thermo-off humidity condition of steps ST22, ST32, and ST42 is satisfied, and steps ST26, ST36, It is used to calculate the dew point temperature Trw in the process of continuous dehumidification control of ST46. Therefore, when an abnormality occurs in the indoor humidity sensor 35, the control unit 6 cannot obtain the detected value of the indoor humidity Hr, and cannot perform the dehumidifying operation using the indoor humidity Hr. Here, the abnormality of the indoor humidity sensor 35 includes not only the damage or failure of the indoor humidity sensor 35 but also the case where the connection line between the indoor humidity sensor 35 and the control unit 6 is broken.

Therefore, here, when the indoor humidity sensor 35 is abnormal, the control unit 6 uses a substitute value as the indoor humidity Hr instead of the detected value of the indoor humidity sensor 35 to perform the dehumidifying operation. In particular, here, since a plurality of dehumidifying operation modes having different dehumidifying levels can be selected as the dehumidifying operation, the control unit 6 substitutes the indoor humidity Hr according to the dehumidifying level of the selected dehumidifying operation mode. I am trying to change the value.

Specifically, as shown in FIG. 8, when the control unit 6 detects an abnormality in the indoor humidity sensor 35 in step ST61, the dehumidifying operation mode selected as the indoor humidity Hr in steps ST62 to ST65 is used. The processing using the substitute values HreL, HreM, and HreH according to the above is performed.

Here, the substitute value HreL in the dehumidification operation mode L can be shifted to the dehumidification continuation control process in step ST26 without thermo-off in the determination process of whether or not the thermo-off humidity condition of step ST22 is satisfied. The value is set higher than the target indoor humidity HrsL in the dehumidifying operation mode L. Moreover, the substitute value HreL in the dehumidification operation mode L is higher than the target room humidity HrsL so that the target evaporation temperature Teds is set lower by calculating the dew point temperature Trw lower in the process of dehumidification continuation control in step ST26. Is set to a slightly higher value. The substitute value HreL in the dehumidifying operation mode L is set to be higher than the target indoor humidity HrsL (set to about 60% to 70%) and the difference is small (for example, within 10%). .. Further, the substitute value HreM in the dehumidifying operation mode M and the substitute value HreH in the dehumidifying operation mode H are also set in the same manner as the substitute value HreL in the dehumidifying operation mode L. For example, the substitute value HreM in the dehumidifying operation mode M is set to be higher than the target indoor humidity HrsM (set to about 50% to 60%) and the difference is small (for example, within 10%). The substitute value HreH in the dehumidifying operation mode H is set to be higher than the target indoor humidity HrsH (set to about 40% to 50%) and the difference is small (for example, within 10%). Will be done. In this way, here, as the dehumidification level of the selected dehumidification operation mode increases in the order of L, M, H, the substitute value of the indoor humidity Hr is changed to decrease in the order of HreL, HreM, HreH. It has become so. As a result, in the determination process of whether or not the thermo-off humidity condition of steps ST22, ST32, and ST42 is satisfied, the process can be shifted to the dehumidification continuation control process of steps ST26, ST36, and ST46 without thermo-off. In the dehumidification continuation control, the target evaporation temperature Teds can be set so that the dehumidification level of the selected dehumidification operation mode becomes lower in the order of L, M, H.

Further, here, the control unit 6 is configured to notify the abnormality of the indoor humidity sensor 35 when the abnormality of the indoor humidity sensor 35 is detected.

Specifically, as shown in FIG. 8, when the control unit 6 detects an abnormality in the indoor humidity sensor 35 in step ST61, the control unit 6 performs a process of notifying the abnormality of the indoor humidity sensor 35 in step ST66. I have to.

Here, the abnormality notification may be a sound or a lamp, or a sentence, a word, or a code indicating that the abnormality is displayed on the screen of the remote controller display unit 65 of the remote controller 60. There may be. Further, in the notification by the display on the screen of the remote control display unit 65, it may be displayed on the screen of the remote control display unit 65 at the same time as the occurrence of an abnormality, or the screen may be switched to the remote control operation unit 64. By giving an instruction, the screen of the remote controller display unit 65 may be displayed when the screen is switched to the screen for displaying an abnormality.

(7) Features Next, the features of the air conditioner 1 will be described.

<A>
Here, as described above, in the air conditioner 1 that performs the dehumidifying operation using the indoor humidity sensor 35, when the indoor humidity sensor 35 is abnormal, the indoor humidity Hr is used instead of the detected value of the indoor humidity sensor 35. The dehumidifying operation is performed using the values HreL, HreM, and HreH (see steps ST61 to ST65).

Specifically, during the control of the dehumidifying operation, the control unit 6 uses the substitute values HreL, HreM, and HreH as the indoor humidity Hr in the determination process of whether or not the thermo-off humidity condition of steps ST22, ST32, and ST42 is satisfied. Further, in the process of continuous dehumidification control in steps ST26, ST36, and ST46, the substitute values HreL, HreM, and HreH are used to calculate the dew point temperature Trw, and these processes can be performed without delay. ..

As a result, here, even if the detection value of the indoor humidity sensor 35 cannot be obtained, the same method as when no abnormality has occurred in the indoor humidity sensor 35 (steps ST21 to ST27, ST31 to ST37, ST41). The dehumidifying operation can be performed by the treatment of ~ ST47).

<B>
Further, here, as described above, the control unit 6 is configured to be able to select a plurality of dehumidifying operation modes having different dehumidifying levels as the dehumidifying operation (see steps ST11 to ST14).

Thereby, here, the dehumidifying operation suitable for the needs of the dehumidifying level of the occupants can be performed.

<C>
Further, here, as described above, the control unit 6 changes the substitute values HreL, HreM, and HreH of the indoor humidity Hr according to the dehumidification level of the selected dehumidification operation mode (see steps ST62 to ST65). ).

Specifically, in any of the dehumidifying operation modes L, M, and H, by setting the substitute values HreL, HreM, and HreH to values higher than the corresponding target indoor humiditys HrsL, HrsM, and HrsH, step ST22 In the process of determining whether or not the thermo-off humidity condition of ST32 and ST42 is satisfied, the process shifts to the dehumidification continuation control process of steps ST26, ST36 and ST46 without thermo-off. Further, by setting the substitute values HreL, HreM, and HreH so that the dehumidification level of the selected dehumidification operation mode becomes lower in the order of L, M, and H, in the process of dehumidification continuation control in steps ST26, ST36, and ST46. The target evaporation temperature Teds is set so that the dehumidification level of the selected dehumidification operation mode decreases in the order of L, M, H (that is, the dehumidification capacity increases in the order of L, M, H). ..

Thereby, here, even if the detection value of the indoor humidity sensor 35 cannot be obtained, the dehumidification operation according to the selected dehumidification level can be performed.

<D>
Further, here, as described above, the control unit 6 is configured to notify the abnormality of the indoor humidity sensor 35 (see step ST66).

Here, it is possible to urge the occupants and the like to repair or replace the indoor humidity sensor 35.

<E>
Here, when the above-mentioned processing at the time of abnormality of the indoor humidity sensor 35 (see steps ST61 to ST65) is performed, the room is dehumidified by continuing the dehumidification after satisfying the first thermo-off temperature condition (thermo-off temperature condition). The temperature Tr may become too low. That is, since the thermo-off humidity condition is not satisfied in steps ST22, ST32, and ST42 due to the processing when the indoor humidity sensor 35 is abnormal, the dehumidifying operation is continued and the indoor temperature Tr becomes too low, so that the occupants in the room It means that you may feel uncomfortable.

Therefore, here, as described above, the control unit 6 further sets the second thermo-off temperature condition on the lower temperature side than the first thermo-off temperature condition (thermo-off temperature condition) as a determination element for determining whether or not the thermo-off condition is satisfied. Have. Then, the control unit 6 determines that the thermo-off condition is satisfied when the second thermo-off temperature condition on the low temperature side is satisfied even if the thermo-off humidity condition is not satisfied (see steps ST27, ST37, and ST47). ..

As a result, here, even when the above-mentioned processing at the time of abnormality of the indoor humidity sensor 35 (see steps ST61 to ST65) is performed, the indoor temperature Tr is continued by continuing the dehumidification after the first thermo-off temperature condition is satisfied. The thermo-off can be performed before the temperature becomes too low (see steps ST23, ST33, ST43). Therefore, as in the case where the indoor humidity sensor 35 does not have an abnormality, the amount of dehumidification is increased by continuing dehumidification after the first thermo-off temperature condition is satisfied, and the room occupants are uncomfortable due to insufficient dehumidification in the room. In addition to reducing the risk of feeling uncomfortable, it is possible to suppress the excessive continuation of dehumidification after the first thermo-off temperature condition is satisfied, and reduce the risk of the occupants feeling uncomfortable due to the room temperature Tr becoming too low. ..

(8) Modification example <A>
In the above embodiment, three dehumidifying operation modes L, M, and H can be selected as a plurality of dehumidifying operation modes having different dehumidification levels, but the present invention is not limited to these, and two dehumidifying operations are performed. It may be a mode, or may be four or more dehumidifying operation modes.

<B>
In the above embodiment and the modified example A, as an example, the air conditioner 1 having a dehumidifying operation performed until the first thermo-off temperature condition is satisfied and a dehumidifying operation performed after satisfying the first thermo-off temperature condition is given as an example. Therefore, the processing when the indoor humidity sensor 35 is abnormal is applied, but the present invention is not limited to this, and if it is an air conditioner that performs a dehumidifying operation using the indoor humidity sensor, the control content during the dehumidifying operation is applied. It is possible to apply according to.

<C>
In the above-described embodiment and the modified examples A and B, an example in which a ceiling-embedded type is adopted as the indoor unit 3 for accommodating the indoor heat exchanger 31 is described, but the present invention is not limited to this. It may be another type of indoor unit such as a wall-mounted type.

Although the embodiments of the present disclosure have been described above, it will be understood that various modifications of the forms and details are possible without departing from the purpose and scope of the present disclosure described in the claims. ..

The present disclosure is widely applicable to an air conditioner that performs a dehumidifying operation using the indoor humidity detected by the humidity sensor.

1 Air conditioner 6 Control unit 10 Refrigerant circuit 21 Compressor 24 Outdoor heat exchanger 25 Expansion valve (expansion mechanism)
31 Indoor heat exchanger 35 Indoor humidity sensor

JP-A-2002-333186

Claims (12)

A refrigerant circuit (10) configured by connecting a compressor (21), an outdoor heat exchanger (24), an expansion mechanism (25), and an indoor heat exchanger (31).
An indoor fan (32) that sends indoor air to the indoor heat exchanger,
A control unit (6) that performs a dehumidifying operation that circulates the refrigerant sealed in the refrigerant circuit in the order of the compressor, the outdoor heat exchanger, the expansion mechanism, and the indoor heat exchanger.
Is equipped with
During the dehumidifying operation, the control unit performs thermo-off to stop the compressor when a predetermined thermo-off condition is satisfied.
The control unit has a thermo-off temperature condition based on the room temperature and a thermo-off humidity condition based on the room humidity as a determination element for determining whether or not the thermo-off condition is satisfied during the dehumidification operation.
If the thermo-off humidity condition is not satisfied when the thermo-off temperature condition is satisfied during the dehumidifying operation, the control unit does not stop the compressor and evaporates the refrigerant in the indoor heat exchanger. Controls the capacity of the compressor and the air volume of the indoor fan so that
When the predetermined thermo-on condition is satisfied during the thermo-off, the control unit activates the compressor to perform the dehumidifying operation.
The control unit has a thermoon temperature condition based on the room temperature as a determination element for determining whether or not the thermoon condition is satisfied.
Air conditioner (1). The control unit selectively performs the dehumidifying operation and a cooling operation different from the dehumidifying operation.
The air conditioner according to claim 1. The control unit is designed to stop the compressor when a predetermined thermo-off condition is satisfied during the cooling operation.
The control unit has only a thermo-off temperature condition based on the room temperature as a determination element for determining whether or not the thermo-off condition is satisfied during the cooling operation.
The air conditioner according to claim 2. The control unit
During the dehumidifying operation, when the state in which the room temperature reaches the thermo-off temperature or lower continues for a predetermined time continuously, it is determined that the thermo-off temperature condition is satisfied.
When the room temperature reaches the thermo-off temperature or lower during the cooling operation, it is determined that the thermo-off temperature condition is satisfied.
The air conditioner according to claim 3. The thermo-off temperature under the thermo-off temperature condition during the dehumidifying operation is a value lower than the thermo-off temperature under the thermo-off temperature condition during the cooling operation.
The air conditioner according to claim 3 or 4. The rotation speed of the indoor fan during the dehumidifying operation is limited to the rotation speed of the indoor fan that can be set during the cooling operation.
The air conditioner according to any one of claims 2 to 5. The rotation speed of the indoor fan during the dehumidifying operation is equal to or less than the minimum rotation speed among the rotation speeds that can be set during the cooling operation.
The air conditioner according to claim 6. The evaporation temperature during the dehumidifying operation is operated below the evaporation temperature during the cooling operation.
The air conditioner according to any one of claims 2 to 7. The control unit is configured to be able to select a plurality of dehumidifying operation modes having different dehumidifying levels as the dehumidifying operation.
The air conditioner according to any one of claims 1 to 8. The evaporation temperature changes according to the dehumidification level of the dehumidification operation mode selected.
The air conditioner according to claim 9. Further equipped with an indoor humidity sensor (35) for detecting the indoor humidity,
When the indoor humidity sensor is abnormal, the control unit performs the dehumidifying operation by using a substitute value as the indoor humidity instead of the detected value of the indoor humidity sensor.
The air conditioner according to any one of claims 1 to 10. A refrigerant circuit (10) configured by connecting a compressor (21), an outdoor heat exchanger (24), an expansion mechanism (25), and an indoor heat exchanger (31).
An indoor fan (32) that sends indoor air to the indoor heat exchanger,
A control unit (6) that performs a dehumidifying operation that circulates the refrigerant sealed in the refrigerant circuit in the order of the compressor, the outdoor heat exchanger, the expansion mechanism, and the indoor heat exchanger.
Is equipped with
The control unit selectively performs the dehumidifying operation and a cooling operation different from the dehumidifying operation.
During the dehumidifying operation, the control unit performs thermo-off to stop the compressor when a predetermined thermo-off condition is satisfied.
The control unit has a thermo-off temperature condition based on the room temperature and a thermo-off humidity condition based on the room humidity as a determination element for determining whether or not the thermo-off condition is satisfied during the dehumidifying operation.
If the thermo-off humidity condition is not satisfied when the thermo-off temperature condition is satisfied during the dehumidifying operation, the control unit does not stop the compressor and evaporates the refrigerant in the indoor heat exchanger. Controls the capacity of the compressor and the air volume of the indoor fan so that
Air conditioner (1).

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