WO2024176421A1

WO2024176421A1 - Air-conditioning device

Info

Publication number: WO2024176421A1
Application number: PCT/JP2023/006658
Authority: WO
Inventors: 周平水谷
Original assignee: 三菱電機株式会社
Priority date: 2023-02-24
Filing date: 2023-02-24
Publication date: 2024-08-29

Abstract

This air-conditioning device comprises: an outdoor unit having a compressor and an outdoor heat exchanger; a plurality of indoor units connected to the outdoor unit, each of the plurality of indoor units having an indoor expansion unit and an indoor heat exchanger; bypass piping that connects sites between the outdoor heat exchanger and the indoor expansion valves to the intake side of the compressor, the bypass piping having an opening/closing valve; and a control device that, in cases in which a high-pressure-side pressure is higher than a high-pressure pressure threshold value, opens the opening/closing valve and increases the opening degree of at least one of the indoor expansion units so that no sense of discomfort is imparted to people.

Description

Air Conditioning Equipment

This disclosure relates to an air conditioning device equipped with a control device.

Conventionally, air conditioners equipped with a control device are known. When low-volume heating operation is performed when the indoor and outdoor temperatures are relatively high, the pressure on the high-pressure side tends to rise. When the pressure on the high-pressure side exceeds the reference pressure, the air conditioner needs to be stopped, and operation cannot be continued. Here, low-volume heating operation refers to operation with a small capacity indoor unit and the minimum number of indoor units in operation, for example, one. When the indoor temperature is high as a temperature environment, the pressure on the high-pressure side is likely to rise, resulting in severe operation. Patent Document 1 discloses an air conditioner in which a constant speed compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are connected by piping. Patent Document 1 is configured so that the refrigerant is bypassed from the discharge side to the suction side of the constant speed compressor via an on-off valve and a pressure reducing device. Patent Document 1 aims to reduce the pressure value on the high-pressure side in this way.

JP 2006-170529 A

However, the air conditioning system disclosed in Patent Document 1 requires the provision of a pressure reducing device such as a solenoid valve on the bypass circuit, which increases costs. Also, when an attempt is made to reduce the pressure on the high-pressure side by increasing the opening of the expansion section connected to the stopped indoor unit, refrigerant flow noise is generated and the indoor temperature rises excessively. This can cause discomfort to people.

This disclosure has been made to solve the problems described above, and provides an air conditioner that reduces the pressure on the high-pressure side without causing discomfort to people or increasing costs.

The air conditioner disclosed herein comprises an outdoor unit having a compressor and an outdoor heat exchanger, a number of indoor units connected to the outdoor unit and each having an indoor expansion section and an indoor heat exchanger, a bypass pipe having an on-off valve connecting between the outdoor heat exchanger and the indoor expansion section and the suction side of the compressor, and a control device that opens the on-off valve when the pressure on the high-pressure side is higher than the high-pressure threshold, and increases the opening degree of at least one indoor expansion section so as not to cause discomfort to people.

According to the present disclosure, when the pressure on the high pressure side is higher than the high pressure threshold, the opening degree of at least one indoor expansion section is increased so as not to cause discomfort to people. Therefore, the pressure on the high pressure side can be reduced without providing a pressure reducing device such as an electromagnetic valve in the bypass piping. In addition, there is no risk of causing discomfort to people. In this way, the pressure on the high pressure side can be reduced without causing discomfort to people and without increasing costs.

1 is a schematic diagram showing an air conditioning apparatus according to a first embodiment. 1 is a circuit diagram showing an air conditioning apparatus according to a first embodiment. 4 is a table showing a high pressure suppression operation according to the first embodiment. 4 is a flowchart showing the operation of the control device according to the first embodiment. 5 is a flowchart showing selection of an operation of the control device according to the first embodiment.

Below, an embodiment of the air conditioning apparatus of the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the embodiment described below. Furthermore, in the following drawings, including FIG. 1, the size relationships of the components may differ from the actual ones. Furthermore, in the following description, terms indicating directions are used as appropriate to facilitate understanding of the present disclosure, but these terms are for the purpose of explaining the present disclosure and do not limit the present disclosure. Examples of terms indicating directions include "up", "down", "right", "left", "front" and "rear".

Embodiment 1.
FIG. 1 is a schematic diagram showing an air conditioning device 1 according to embodiment 1. The air conditioning device 1 is a device that adjusts the air in a space to be air-conditioned, and as shown in FIG. 1, an outdoor unit 2 and a plurality of indoor units 3 are connected by a refrigerant pipe 5. In this embodiment 1, an example is shown in which an indoor unit 3 is provided in each of four rooms, but the number of rooms and the number of indoor units 3 can be changed as appropriate. Each room is provided with a human detection unit 20 that detects the presence or absence of a person in the room. Here, the first room 15a and the second room 15b are provided with a built-in human detection unit 21 built into the indoor unit 3, and the third room 15c and the fourth room 15d are provided with a separate human detection unit 22 installed separately from the indoor unit 3.

FIG. 2 is a circuit diagram showing an air conditioner 1 according to the first embodiment. As shown in FIG. 2, the air conditioner 1 includes an outdoor unit 2 and an indoor unit 3. The outdoor unit 2 includes, for example, a compressor 6, a flow path switching device 7, an outdoor heat exchanger 8, an outdoor blower 9, an outdoor expansion section 10a, an accumulator 13, a bypass piping 40, and a control device 30. Each indoor unit 3 includes, for example, an indoor expansion section 10b, an indoor heat exchanger 11, and an indoor blower 12. Note that FIG. 2 illustrates an example in which two indoor units 3 are provided, but the number of indoor units 3 can be changed as appropriate. In addition, each room includes a human detection section 20 and an indoor temperature detection section 23. Furthermore, a discharge pressure detection section 24 is provided on the discharge side of the compressor 6.

The compressor 6, the flow path switching device 7, the outdoor heat exchanger 8, the outdoor expansion section 10a, the indoor expansion section 10b, the indoor heat exchanger 11, and the accumulator 13 are connected by the refrigerant piping 5 to form the refrigerant circuit 4. The compressor 6 draws in a refrigerant in a low-temperature and low-pressure state, compresses the drawn refrigerant, and discharges it as a refrigerant in a high-temperature and high-pressure state. The compressor 6 is, for example, a capacity-controllable inverter compressor. The flow path switching device 7 switches the direction in which the refrigerant flows in the refrigerant circuit 4, and is, for example, a four-way valve. The outdoor heat exchanger 8 exchanges heat between, for example, the outdoor air and the refrigerant. The outdoor heat exchanger 8 acts as a condenser during cooling operation and as an evaporator during heating operation. The outdoor expansion section 10a is a pressure reducing valve or an expansion valve that reduces the pressure of the refrigerant and expands it. The outdoor expansion section 10a is, for example, an electronic expansion valve whose opening is adjustable. The outdoor expansion section 10a may be omitted. The accumulator 13 stores liquid refrigerant and sends only gaseous refrigerant to the compressor 6. The accumulator 13 may be omitted.

The indoor expansion section 10b is a pressure reducing valve or expansion valve that reduces the pressure of the refrigerant to expand it. The indoor expansion section 10b is, for example, an electronic expansion valve whose opening degree is adjustable. The indoor heat exchanger 11 exchanges heat between, for example, indoor air and the refrigerant. The indoor heat exchanger 11 acts as an evaporator during cooling operation and as a condenser during heating operation. The indoor blower 12 is a device that sends indoor air to the indoor heat exchanger 11.

(Bypass piping 40)
The bypass pipe 40 connects between the outdoor expansion section 10a and the indoor expansion section 10b and the suction side of the accumulator 13. If the outdoor expansion section 10a or the accumulator 13 is not provided, the bypass pipe 40 may connect between the outdoor heat exchanger 8 and the indoor expansion section 10b and the suction side of the compressor 6. The bypass pipe 40 is provided with an on-off valve 41. Since the on-off valve 41 is normally closed, refrigerant does not flow into the bypass pipe 40 under normal conditions. On the other hand, the on-off valve 41 is opened when the pressure on the high pressure side increases. As a result, refrigerant flows into the bypass pipe 40.

(Operation mode, cooling operation)
Next, the operation modes of the air conditioner 1 will be described. First, the cooling operation will be described. In the cooling operation, the refrigerant sucked into the compressor 6 is compressed by the compressor 6 and discharged in a high-temperature, high-pressure gas state. The high-temperature, high-pressure gas state refrigerant discharged from the compressor 6 passes through the flow switching device 7 and flows into the outdoor heat exchanger 8 acting as a condenser, where it is heat exchanged with the outdoor air sent by the outdoor blower 9, and condensed and liquefied. The condensed liquid state refrigerant flows into the outdoor expansion section 10a, where it is expanded and decompressed. The refrigerant then flows into each indoor unit 3, where it is expanded and decompressed in each indoor expansion section 10b, and becomes a low-temperature, low-pressure gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant then flows into the indoor heat exchanger 11 acting as an evaporator, where it is heat exchanged with the indoor air sent by the indoor blower 12, and evaporates and gasifies. At this time, the indoor air is cooled, and cooling is performed in the room. The evaporated low-temperature and low-pressure gaseous refrigerant flows out of each indoor unit 3, merges with the other refrigerants, passes through the flow path switching device 7, and reaches the accumulator 13. The liquid refrigerant is stored in the accumulator 13, and only the gaseous refrigerant is drawn into the compressor 6.

(Operation mode, heating operation)
Next, the heating operation will be described. In the heating operation, the refrigerant sucked into the compressor 6 is compressed by the compressor 6 and discharged in a high-temperature, high-pressure gas state. The high-temperature, high-pressure gas state refrigerant discharged from the compressor 6 passes through the flow switching device 7 and flows into each indoor unit 3. The refrigerant flows into each indoor heat exchanger 11 acting as a condenser, where it is heat exchanged with the indoor air sent by the indoor blower 12, condensed, and liquefied. At this time, the indoor air is warmed, and heating is performed in the room. The condensed liquid state refrigerant flows into each indoor expansion section 10b, where it is expanded and decompressed. The refrigerant flows out of each indoor unit 3, merges, and becomes a low-temperature, low-pressure gas-liquid two-phase refrigerant in the outdoor expansion section 10a. The refrigerant in the gas-liquid two-phase state then flows into the outdoor heat exchanger 8 acting as an evaporator, where it exchanges heat with outdoor air sent by an outdoor blower 9, evaporating and gasifying. The evaporated low-temperature, low-pressure gaseous refrigerant passes through the flow switching device 7 and reaches the accumulator 13. The liquid refrigerant is stored in the accumulator 13, and only the gaseous refrigerant is drawn into the compressor 6.

The air conditioner 1 does not have to have a flow path switching device 7. In this case, the air conditioner 1 becomes a dedicated cooling or heating unit.

(Human detection unit 20)
The human detection unit 20 detects the presence or absence of a person in the room, and is, for example, a human presence sensor. As described above, the human detection unit 20 is composed of a built-in human detection unit 21 and a separately installed human detection unit 22. As shown in FIG. 1, the built-in human detection unit 21 is provided in the indoor unit 3 and is integrated with the indoor unit 3. As shown in FIG. 1, the separately installed human detection unit 22 is provided in a location separate from the indoor unit 3, for example, on a wall of a room. In this way, the human detection unit 20 is linked to the air conditioning device 1, and is not limited to a location where it is installed as long as it is installed indoors.

(Indoor temperature detection unit 23)
The indoor temperature detection unit 23 detects the room temperature and is, for example, a temperature sensor. The indoor temperature detection unit 23 may be provided in the indoor unit 3, or may be provided in a location separate from the indoor unit 3. In this way, the indoor temperature detection unit 23 is also linked to the air conditioning device 1, and is not limited to a location where it is provided, so long as it is provided indoors.

(Discharge pressure detection unit 24)
The discharge pressure detection unit 24 detects the pressure of the refrigerant discharged from the compressor 6, and is provided on the discharge side of the compressor 6. In the first embodiment, the pressure of the refrigerant discharged from the compressor 6 is referred to as the high-pressure side pressure.

(Control device 30)
The control device 30 is a CPU (also called a central processing unit, processing device, arithmetic device, microprocessor, microcomputer, or processor) that executes a program stored in dedicated hardware or a storage device. When the control device 30 is dedicated hardware, the control device 30 corresponds to, for example, a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination of these. Each of the functional units realized by the control device 30 may be realized by individual hardware, or each functional unit may be realized by a single piece of hardware.

When the control device 30 is a CPU, each function executed by the control device 30 is realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in a storage device (not shown). The CPU realizes each function by reading and executing the programs stored in the storage device. Note that some of the functions of the control device 30 may be realized by dedicated hardware, and some by software or firmware. The storage device may be configured as a hard disk, or as a volatile storage device such as a random access memory (RAM) that can temporarily store data. The storage device may also be configured as a non-volatile storage device such as a flash memory that can store data for the long term.

As shown in FIG. 2, the control device 30 is provided in the outdoor unit 2. The control device 30 may also be provided in the indoor unit 3, or outside the air conditioning device 1. In this way, the location where the control device 30 is installed is not limited.

When the pressure on the high-pressure side is higher than the high-pressure threshold, the control device 30 opens the on-off valve 41 and increases the opening degree of at least one indoor expansion section 10b so as not to cause discomfort to people. When the on-off valve 41 is opened with the opening degree of the indoor expansion section 10b increased, the pressure of the refrigerant that has passed through the indoor heat exchanger 11 becomes extremely low, and the low-pressure refrigerant passes through the bypass piping 40 and is bypassed to the discharge side of the compressor 6. As a result, the control device 30 reduces the pressure on the high-pressure side. Here, the high-pressure side pressure is the pressure of the refrigerant detected by the discharge pressure detection unit 24. The high-pressure pressure threshold has a first reference value and a second reference value. The first reference value is higher than the second reference value. When the pressure on the high-pressure side exceeds the first reference value, the control device 30 performs an operation to reduce the pressure on the high-pressure side. In this case, even if the pressure on the high-pressure side becomes equal to or lower than the first reference value, the control device 30 continues the operation without stopping. Then, when the pressure on the high-pressure side falls below a second reference value that is lower than the first reference value, the control device 30 stops operation. In this way, by providing a differential for the high-pressure threshold, it is possible to sufficiently reduce the pressure on the high-pressure side while suppressing overshooting when the control device 30 is released from operation.

FIG. 3 is a table showing the high pressure suppression operation according to the first embodiment. Next, the operation of the control device 30 to reduce the pressure on the high pressure side will be described. As shown in FIG. 3, the control device 30 performs three operations, namely, operation A, operation B, and operation C. Here, the control device 30 increases the opening degree of the indoor expansion part 10b selected preferentially from the indoor expansion part 10b of the indoor unit 3 installed in a room where no one is present, the indoor expansion part 10b of the indoor unit 3 in operation, and the indoor expansion part 10b of the indoor unit 3 installed in a room where the room temperature is equal to or lower than the room temperature threshold. In the first embodiment, the control device 30 increases the opening degree preferentially in the order of the indoor expansion part 10b of the indoor unit 3 installed in a room where no one is present, the indoor expansion part 10b of the indoor unit 3 in operation, and the indoor expansion part 10b of the indoor unit 3 installed in a room where the room temperature is equal to or lower than the room temperature threshold. Note that the priority order of operation A, operation B, and operation C can be changed as appropriate. The priority order may be any priority order desired by the user. In addition, operation A, operation B, and operation C may be performed simultaneously.

(Operation A)
As operation A, when the high-pressure side pressure is higher than the high-pressure threshold, the control device 30 increases the opening degree of the indoor expansion section 10b of the indoor unit 3 installed in a room where no one is present. More specifically, the control device 30 increases the opening degree of the indoor expansion section 10b of the indoor unit 3 installed in a room where the absence of a person is confirmed by the human detection section 20. As a result, even if refrigerant flow noise occurs and the indoor temperature rises excessively, no one is present in the room and therefore no one feels uncomfortable. As shown in FIG. 3, operation A has the highest priority among operations A, B, and C.

(Operation B)
As operation B, when the high-pressure side pressure is higher than the high-pressure threshold, the control device 30 increases the opening degree of the indoor expansion section 10b of the indoor unit 3 in operation. In the indoor unit 3 in operation, the indoor blower 12 is driven. Therefore, even if a refrigerant flow sound occurs, the refrigerant flow sound is drowned out by the driving sound of the indoor blower 12 and is not noticeable. As shown in FIG. 3, operation B has the second highest priority among operations A, B, and C.

(Operation C)
As operation C, when the pressure on the high-pressure side is higher than the high-pressure threshold, the control device 30 increases the opening degree of the indoor expansion section 10b of the indoor unit 3 installed in a room where the room temperature is equal to or lower than the room temperature threshold. More specifically, the control device 30 increases the opening degree of the indoor expansion section 10b of the indoor unit 3 installed in a room where the room temperature detected by the indoor temperature detection section 23 is equal to or lower than the room temperature threshold. The control device 30 may also be configured to increase the opening degree of the indoor expansion section 10b of the indoor unit 3 installed in a room where the room temperature is low among rooms where people are present and is stopped. As a result, even if the room temperature rises excessively, the temperature of the room, which was originally low, simply rises to an appropriate temperature, and no discomfort is caused. As shown in FIG. 3, operation C has the third highest priority among operations A, B, and C.

FIG. 4 is a flowchart showing the operation of the control device 30 according to the first embodiment. Next, the operation of the control device 30 will be described. As shown in FIG. 4, when the air conditioning device 1 is performing heating operation (step S1), the control device 30 determines whether the pressure on the high-pressure side is greater than the first reference value of the high-pressure threshold (step S2). When the pressure on the high-pressure side is equal to or less than the first reference value of the high-pressure threshold (NO in step S2), step S2 is repeated. When the pressure on the high-pressure side is greater than the first reference value of the high-pressure threshold (YES in step S2), information is received from the human detection unit 20 and a predetermined operation is performed (step S3). The specific content of step S3 will be described later with reference to FIG. 5.

When the specified operation is being performed, the control device 30 determines whether the pressure on the high-pressure side is less than the second reference value of the high-pressure threshold (step S4). If the pressure on the high-pressure side is equal to or greater than the second reference value of the high-pressure threshold (NO in step S4), the control device 30 returns to step S3 and continues the specified operation. If the pressure on the high-pressure side is less than the second reference value of the high-pressure threshold (YES in step S4), the control device 30 releases the operation on the indoor expansion section 10b (step S5). After that, the control device 30 returns to step S2 and continues monitoring the pressure on the high-pressure side.

FIG. 5 is a flowchart showing the selection of the operation of the control device 30 according to the first embodiment. Next, the operation of step S3 in FIG. 4 will be described in detail. As shown in FIG. 5, the control device 30 judges whether there is an empty room (step S10). Specifically, the control device 30 receives information from the human detection unit 20 installed in each room and judges whether there is an empty room. If there is an empty room (YES in step S10), as operation A, the control device 30 increases the opening degree of the indoor expansion section 10b of the indoor unit 3 installed in the room where the absence of a person is confirmed by the human detection unit 20. As a result, even if a refrigerant flow sound is generated and the indoor temperature rises excessively, people will not feel uncomfortable because there is no person in the room.

On the other hand, if there are people in all the rooms (NO in step S10), the control device 30 judges whether the opening degree of the indoor expansion section 10b of the indoor unit 3 that is operating among all the indoor units 3 is fully open (step S11). If the opening degree of the indoor expansion section 10b of the indoor unit 3 that is operating is not fully open (NO in step S11), as operation B, the control device 30 increases the opening degree of the indoor expansion section 10b of the indoor unit 3 that is operating (step S14). At this time, even if a refrigerant flow sound occurs, it is drowned out by the driving sound of the indoor blower 12 and is difficult to notice. On the other hand, if the opening degree of the indoor expansion section 10b of the indoor unit 3 that is operating is fully open (YES in step S11), as operation C, the control device 30 increases the opening degree of the indoor expansion section 10b of the indoor unit 3 installed in a room where the room temperature is equal to or lower than the room temperature threshold (step S12). More specifically, the control device 30 increases the opening of the indoor expansion section 10b of the indoor unit 3 that is installed in a room where the room temperature is low among rooms where people are present and that is stopped. As a result, even if the room temperature rises excessively, the room temperature, which was originally low, simply rises to an appropriate temperature and no discomfort is caused.

According to the first embodiment, when the pressure on the high-pressure side is higher than the high-pressure threshold, the opening degree of at least one indoor expansion section 10b is increased so as not to cause discomfort to people. Therefore, the pressure on the high-pressure side can be reduced without providing a pressure reducing device such as an electromagnetic valve in the bypass piping 40. In addition, there is no risk of causing discomfort to people. In this way, the pressure on the high-pressure side can be reduced without causing discomfort to people and without increasing costs.

In order to avoid causing discomfort to people, the control device 30 increases the opening degree of the indoor expansion section 10b of the indoor unit 3 installed in a room where no one is present when the pressure on the high-pressure side is higher than the high-pressure threshold. As a result, even if refrigerant flow noise occurs and the indoor temperature rises excessively, people will not feel uncomfortable because there is no one in the room. In addition, when the pressure on the high-pressure side is higher than the high-pressure threshold, the control device 30 increases the opening degree of the indoor expansion section 10b of the indoor unit 3 in operation. As a result, even if refrigerant flow noise occurs, it is drowned out by the driving noise of the indoor blower 12 and is less noticeable. Furthermore, when the pressure on the high-pressure side is higher than the high-pressure threshold, the control device 30 increases the opening degree of the indoor expansion section 10b of the indoor unit 3 installed in a room where the room temperature is equal to or lower than the room temperature threshold. As a result, even if the room temperature rises excessively, the room temperature, which was originally low, simply rises to an appropriate temperature and no discomfort is caused.

1 air conditioner, 2 outdoor unit, 3 indoor unit, 4 refrigerant circuit, 5 refrigerant piping, 6 compressor, 7 flow path switching device, 8 outdoor heat exchanger, 9 outdoor blower, 10a outdoor expansion section, 10b indoor expansion section, 11 indoor heat exchanger, 12 indoor blower, 13 accumulator, 15a first chamber, 15b second chamber, 15c third chamber, 15d fourth chamber, 20 human detection section, 21 built-in human detection section, 22 separately installed human detection section, 23 indoor temperature detection section, 24 discharge pressure detection section, 30 control device, 40 bypass piping, 41 opening and closing valve.

Claims

an outdoor unit having a compressor and an outdoor heat exchanger;
A plurality of indoor units connected to the outdoor unit, each of which has an indoor expansion section and an indoor heat exchanger;
a bypass pipe that connects a portion between the outdoor heat exchanger and the indoor expansion section and a suction side of the compressor and has an on-off valve;
a control device that opens the on-off valve and increases the opening degree of at least one of the indoor expansion parts so as not to cause discomfort to a person when the pressure on the high-pressure side is higher than a high-pressure threshold;
An air conditioning device comprising:
The control device includes:
The air conditioner according to claim 1 , wherein when the pressure on the high-pressure side is higher than the high-pressure threshold, the opening degree of the indoor expansion section of the indoor unit installed in an unoccupied room is increased.
A human detection unit is further provided for detecting the presence or absence of a human in the room,
The control device includes:
The air-conditioning apparatus according to claim 2 , wherein the opening degree of the indoor expansion section of the indoor unit installed in a room in which the absence of a person is confirmed by the human detection section is increased.
The control device includes:
The air conditioner according to any one of claims 1 to 3, wherein when the pressure on the high pressure side is higher than a high pressure threshold value, the degree of opening of the indoor expansion section of the indoor unit in operation is increased.
The control device includes:
The air conditioning apparatus according to any one of claims 1 to 4, wherein when the high-pressure side pressure is higher than the high-pressure threshold, the opening degree of the indoor expansion section of the indoor unit installed in a room whose room temperature is equal to or lower than the room temperature threshold is increased.
Further comprising an indoor temperature detection unit for detecting an indoor temperature,
The control device includes:
The air conditioner according to claim 5 , wherein the degree of opening of the indoor expansion section of the indoor unit is increased when the room temperature detected by the indoor temperature detection section is equal to or lower than a room temperature threshold value.
The control device includes:
The air conditioning apparatus according to any one of claims 1 to 6, wherein, when the pressure on the high-pressure side is higher than the high-pressure threshold, the opening degree of the indoor expansion part that is preferentially selected from the indoor expansion part of the indoor unit installed in an unoccupied room, the indoor expansion part of the indoor unit in operation, and the indoor expansion part of the indoor unit installed in a room whose room temperature is equal to or lower than the room temperature threshold is increased.
The control device includes:
The air conditioning apparatus according to claim 7, wherein the opening degree is increased in the following order: the indoor expansion part of the indoor unit installed in an unoccupied room, the indoor expansion part of the indoor unit in operation, and the indoor expansion part of the indoor unit installed in a room whose room temperature is equal to or lower than a room temperature threshold.