Air conditioner and air conditioning system

Abstract

To provide an air conditioner and an air conditioning system capable of avoiding an intermittent operation even when air conditioning capacity exceeds a load during a low-capacity operation.SOLUTION: An air conditioner includes: an outdoor unit; a plurality of indoor units each provided in each room; a control device; a suction temperature sensor of a compressor; a discharge temperature sensor; an evaporation temperature sensor for sensing an evaporation temperature; and an indoor temperature sensor in each room. In the case where there is an indoor unit in normal operation out of the plurality of indoor units, if a difference between operation frequency of the compressor and lower limit frequency that is a lower limit value of the operation frequency is a preset first threshold value or lower and a difference between a set temperature preset by a user, etc. in the room where the indoor unit in normal operation is installed and the indoor temperature is a preset second threshold value or lower, the control device executes a first low-capacity operation for increasing an opening of a restriction device so that a difference between a discharge temperature and a suction temperature becomes a preset target suction temperature difference, or increasing the opening of the restriction device so that the evaporation temperature becomes a preset target evaporation temperature.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an air conditioning device and an air conditioning system. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is a multi-room air conditioner that adjusts an indoor unit to an appropriate operating capacity when the indoor unit is forcibly operated without an operation command from a user (see, for example, Patent Document 1).

[0003] In Patent Document 1, in a partial operation mode in which the first indoor unit that has received an operation command is operated and the second indoor unit that has not received an operation command is stopped, if the operating load of the first indoor unit is small, the system transitions to a distribution operation mode in which the first indoor unit is operated and the second indoor unit is operated. In the distribution operation mode, the control unit adjusts the capacity of the second indoor unit according to the operating load of the first indoor unit. In this way, even after transitioning to the distribution operation mode, if the operating capacity supplied to the first indoor unit is excessive, the operating capacity distributed to the second indoor unit is increased, and if the operating capacity supplied to the first indoor unit is insufficient, the operating capacity distributed to the second indoor unit is reduced, so that the first indoor unit can be operated at an optimal operating capacity. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-146188 A Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, when the difference between the compressor operating frequency and its lower limit frequency is equal to or less than a preset first threshold value, and the air conditioning capacity exceeds the load during low-capacity operation, the unit operates intermittently. However, intermittent operation can cause temperature fluctuations in the room and make it difficult to adjust the indoor humidity.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an air conditioning device and air conditioning system that avoids intermittent operation even when the air conditioning capacity exceeds the load during low-capacity operation. [Means for solving the problem]

[0007] The air conditioner according to the present disclosure includes an outdoor unit having a compressor, a flow path switching device, an outdoor heat exchanger, a throttling device, and an accumulator, and being provided outdoors; a plurality of indoor units having indoor heat exchangers and being provided in each room; a refrigerant circuit in which the compressor, the flow path switching device, the outdoor heat exchanger, the throttling device, the plurality of indoor heat exchangers, and the accumulator are connected by piping and in which a refrigerant circulates; a control device for controlling the refrigerant circuit; an intake temperature detection device that detects an intake temperature of the compressor; a discharge temperature detection device that detects a discharge temperature of the compressor; an evaporation temperature detection device that detects an evaporation temperature; and an indoor temperature detection device that is provided in each room and detects the indoor temperature. and a temperature detection device, and the control device executes a first low-capacity operation in which, when there is an indoor unit among the multiple indoor units that is in normal operation, the difference between the operating frequency of the compressor and its lower limit frequency, which is its lower limit, is equal to or less than a predetermined first threshold value, and the difference between a predetermined set temperature of the room in which the indoor unit is installed during normal operation and the indoor temperature is equal to or less than a predetermined second threshold value, thereby increasing the opening of the throttling device so that the difference between the discharge temperature and the suction temperature becomes a predetermined target suction temperature difference, or increasing the opening of the throttling device so that the evaporation temperature becomes a predetermined target evaporation temperature.

[0008] An air conditioning system according to the present disclosure includes an outdoor unit having a compressor, a flow path switching device, an outdoor heat exchanger, a throttling device, and an accumulator, and being provided outdoors; a plurality of indoor units having indoor heat exchangers and being provided in each room; a refrigerant circuit in which the compressor, the flow path switching device, the outdoor heat exchanger, the throttling device, the plurality of indoor heat exchangers, and the accumulator are connected by piping and in which a refrigerant circulates; a control device for controlling the refrigerant circuit; an intake temperature detection device that detects an intake temperature of the compressor; a discharge temperature detection device that detects a discharge temperature of the compressor; an evaporation temperature detection device that detects an evaporation temperature; and an indoor temperature detection device that is provided in each room and detects the indoor temperature. The air conditioning apparatus includes a cooling device and a communication device capable of communicating with the air conditioning apparatus, and when an indoor unit among the plurality of indoor units is in normal operation, the communication device instructs the air conditioning apparatus to perform a first low-capacity operation in which, when the difference between the operating frequency of the compressor and its lower limit frequency which is its lower limit is equal to or less than a predetermined first threshold value and the difference between a predetermined set temperature and the indoor temperature is equal to or less than a predetermined second threshold value, the communication device instructs the air conditioning apparatus to perform a first low-capacity operation in which the opening of the throttling device is increased so that the difference between the discharge temperature and the suction temperature becomes a predetermined target suction temperature difference, or the opening of the throttling device is increased so that the evaporation temperature becomes a predetermined target evaporation temperature. Effect of the Invention

[0009] According to the air conditioner and air conditioning system of the present disclosure, when the difference between a preset temperature and the room temperature is equal to or less than a preset second threshold during low capacity operation, the throttling device is controlled to reduce the target temperature difference and make the difference between the discharge temperature and the intake temperature the target temperature difference, or the target evaporation temperature is increased and the throttling device is controlled to make the evaporation temperature the target evaporation temperature. This makes it possible to reduce the air conditioning capacity without reducing the operating frequency of the compressor, thereby making it possible to avoid intermittent operation even when the air conditioning capacity exceeds the load during low capacity operation. [Brief description of the drawings]

[0010] [Figure 1]1 is a schematic configuration diagram of an air conditioning system according to a first embodiment. [Diagram 2] 1 is a schematic configuration diagram of an air conditioner of an air conditioning system according to a first embodiment. [Diagram 3] 1 is a schematic configuration diagram of a ventilation device of an air conditioning system according to a first embodiment. [Figure 4] FIG. 4 is a schematic configuration diagram of a modified example of a ventilation device of the air conditioning system according to the first embodiment. [Diagram 5] FIG. 4 is a diagram showing a control flow during normal cooling operation of the air conditioning system according to the first embodiment. [Figure 6] 4 is a Ph diagram before and after changing the opening degree of the throttling device of the air conditioning system according to the first embodiment. FIG. [Figure 7] FIG. 4 is a Ph diagram before and after changing the air volume of an outdoor blower fan of the air conditioning system according to the first embodiment. [Figure 8] FIG. 4 is a diagram showing a control flow during normal heating operation of the air conditioning system according to the first embodiment. [Figure 9] FIG. 4 is a diagram showing a control flow during low capacity operation of the air conditioning system according to the first embodiment. [Figure 10] FIG. 4 is a Ph diagram before and after changing the air volume of an indoor blower fan of the air conditioning system according to the first embodiment. [Figure 11] FIG. 4 is a diagram showing temperatures versus time in each of a plurality of rooms during normal cooling operation of the air conditioning system according to the first embodiment. [Figure 12] FIG. 4 is a diagram showing temperatures versus time in each of a plurality of rooms during thermo-off suppression operation of the air conditioning system according to Embodiment 1. [Figure 13] FIG. 4 is a diagram showing a control flow during low capacity operation of the air conditioning system according to the first embodiment. [Figure 14] FIG. 4 is a diagram showing a control flow during low-capacity cooling and dehumidification operation of the air conditioning system according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the embodiments described below. In addition, the size relationships of the components in the drawings may differ from the actual ones.

[0012] Embodiment 1 1 is a schematic configuration diagram of an air conditioning system according to Embodiment 1. The air conditioning system according to Embodiment 1 includes an air conditioning device 100, a ventilation device 200, and a communication device 300.

[0013] FIG. 2 is a schematic configuration diagram of an air conditioner 100 of an air conditioning system according to the first embodiment. The air conditioner 100 includes an outdoor unit 10 installed outside a room (air-conditioned space) and indoor units 20a to 20c installed inside the room (air-conditioned space). In the first embodiment, as shown in FIG. 2, a total of three indoor units 20a to 20c are provided in each room, but the present invention is not limited to this and any number of indoor units may be provided. The outdoor unit 10 includes a compressor 11, a flow switching device 12, an outdoor heat exchanger 13, an outdoor blower fan 14, a throttling device 15, and an accumulator 16. The indoor units 20a to 20c include indoor heat exchangers 21a to 21c, indoor blower fans 22a to 22c, and air deflectors 23a to 23c.

[0014] The air-conditioning apparatus 100 includes a refrigerant circuit 1 in which a refrigerant circulates by sequentially connecting a compressor 11, a flow switching device 12, an outdoor heat exchanger 13, a throttling device 15, and indoor heat exchangers 21a to 21c by refrigerant piping. The indoor heat exchangers 21a to 21c are connected in parallel to one another.

[0015] In the following description, when there is no need to distinguish between the indoor units 20a, 20b, and 20c, they will be simply referred to as the "indoor units 20" as appropriate. When there is no need to distinguish between the indoor heat exchangers 21a, 21b, and 21c, they will be simply referred to as the "indoor heat exchangers 21" as appropriate. When there is no need to distinguish between the indoor blower fans 22a, 22b, and 22c, they will be simply referred to as the "indoor blower fans 22" as appropriate. When there is no need to distinguish between the wind direction vanes 23a, 23b, and 23c, they will be simply referred to as the "wind direction vanes 23" as appropriate.

[0016] The compressor 11 draws in a low-temperature, low-pressure refrigerant, compresses the drawn refrigerant, and discharges a high-temperature, high-pressure refrigerant. The compressor 11 is, for example, an inverter compressor whose capacity, which is the amount of discharge per unit time, is controlled by changing the operating frequency.

[0017] The flow path switching device 12 is, for example, a four-way valve, and switches between cooling operation and heating operation by switching the direction of the refrigerant flow. Note that the flow path switching device 12 is not limited to this example, and may be configured by combining other valves such as a two-way valve or a three-way valve.

[0018] The outdoor heat exchanger 13 exchanges heat between the outdoor air and the refrigerant. Specifically, during cooling operation, the outdoor heat exchanger 13 functions as a condenser that releases heat of the refrigerant to the outdoor air and condenses and liquefies the refrigerant. During heating operation, the outdoor heat exchanger 13 functions as an evaporator that evaporates and gasifies the refrigerant and absorbs heat from the outdoor air as heat of vaporization.

[0019] The outdoor blower fan 14 is provided near the outdoor heat exchanger 13 and supplies outdoor air to the outdoor heat exchanger 13. The amount of air blown by the outdoor blower fan 14 is adjusted, for example, by controlling the rotation speed.

[0020] The throttling device 15 is, for example, an electronic expansion valve, and has the functions of a pressure reducing valve and an expansion valve, and reduces the pressure of the refrigerant and expands it by adjusting the flow rate of the refrigerant. The throttling device 15 is, for example, configured with a valve capable of controlling the opening degree, such as an electronic expansion valve. Note that the throttling device 15 is not limited to this example, and may be, for example, configured with a capillary tube.

[0021] The accumulator 16 is provided on the suction side of the compressor 11, and serves to store surplus refrigerant generated due to the difference in operating state between cooling operation and heating operation, or surplus refrigerant due to transient changes in operation.

[0022] The indoor heat exchanger 21 exchanges heat between the indoor air and the refrigerant. Specifically, during cooling operation, the indoor heat exchanger 21 functions as an evaporator that evaporates and gasifies the refrigerant and absorbs heat from the outdoor air as heat of vaporization. During heating operation, the indoor heat exchanger 21 functions as a condenser that releases heat from the refrigerant to the indoor air and condenses and liquefies the refrigerant.

[0023] The indoor blower fan 22 is provided near the indoor heat exchanger 21 and supplies indoor air to the indoor heat exchanger 21a. For example, the rotation speed is controlled to adjust the amount of air blown by the indoor blower fan 22a.

[0024] The airflow direction vane 23 is provided at the air outlet of the indoor unit 20, and changes the direction of air blown into the space in which the indoor unit 20 is installed (i.e., the air-conditioned space). The airflow direction vane 23 may change the direction of air in the vertical direction, or the horizontal direction, or both.

[0025] The air conditioner 100 also includes a control device 50 that controls the entire air conditioner 100. The control device 50 switches the operation mode in response to an instruction from the communication device 300, for example. Here, the operation modes include normal cooling operation, first low-capacity cooling operation, second low-capacity cooling operation, normal heating operation, first low-capacity heating operation, second low-capacity heating operation, and low-capacity cooling and dehumidification operation. Note that the normal cooling operation, the first low-capacity cooling operation, the second low-capacity cooling and dehumidification operation, and the thermo-off suppression operation are types of cooling operation, and the normal heating operation, the first low-capacity heating operation, and the second low-capacity heating operation are types of heating operation. In the following, the normal cooling operation and the normal heating operation are collectively referred to as normal operation, the first low-capacity cooling operation and the first low-capacity heating operation are collectively referred to as first low-capacity operation, and the second low-capacity cooling operation and the second low-capacity heating operation are collectively referred to as second low-capacity operation.

[0026] The control device 50 controls the operating frequency of the compressor 11, the switching of the flow path switching device 12, the rotation speed of the outdoor blower fan 14, the opening degree of the throttling device 15, the rotation speed of the indoor blower fan 22, and the inclination of the air deflector 23, for example, according to the operation mode of the air conditioner 100. The control device 50 is composed of, for example, dedicated hardware, or a CPU (also called a central processing unit, processing device, arithmetic device, microprocessor, or processor) that executes a program stored in a storage unit (not shown). When the control device 50 is dedicated hardware, the control device 50 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 50 may be realized by individual hardware, or each of the functional units may be realized by one piece of hardware. When the control device 50 is a CPU, each function executed by the control device 50 is realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in the storage unit. The CPU realizes each function of the control device 50 by reading and executing the programs stored in the storage unit. Here, the storage unit stores various information, and includes, for example, a non-volatile semiconductor memory in which data can be rewritten, such as a flash memory, an EPROM, and an EEPROM. Note that some of the functions of the control device 50 may be realized by dedicated hardware, and some may be realized by software or firmware.

[0027] The air conditioning apparatus 100 is also provided with a discharge temperature detector 31, an intake temperature detector 32, a first outdoor temperature detector 33, a second outdoor temperature detector 34, an outdoor humidity detector 35, a first indoor temperature detector 36, second indoor temperature detectors 37a-37c, indoor humidity detectors 38a-38c, and occupancy detectors 39a-39c.

[0028] In the following description, when there is no need to distinguish between the indoor second temperature detector 37a, the indoor second temperature detector 37b, and the indoor second temperature detector 37c, they will be referred to simply as the "indoor second temperature detector 37" as appropriate. When there is no need to distinguish between the indoor humidity detector 38a, the indoor humidity detector 38b, and the indoor humidity detector 38c, they will be referred to simply as the "indoor humidity detector 38" as appropriate. When there is no need to distinguish between the occupancy detector 39a, the occupancy detector 39b, and the occupancy detector 39c, they will be referred to simply as the "occupancy detector 39" as appropriate.

[0029] The discharge temperature detector 31 is provided on the discharge side of the compressor 11 and detects a discharge temperature Tdc, which is the temperature of the refrigerant discharged from the compressor 11. The suction temperature detector 32 is provided on the suction side of the compressor 11 and detects a suction temperature Tsu, which is the temperature of the refrigerant suctioned into the compressor 11. The outdoor-side first temperature detector 33 is attached, for example, near the middle position of the entire piping length in the outdoor heat exchanger 13 and detects an evaporation temperature Tev during heating operation and a condensation temperature Tcd during cooling operation. The outdoor-side second temperature detector 34 is provided, for example, at the air intake of the outdoor unit 10 and detects an outdoor air temperature Tot, which is the temperature of the space in which the outdoor unit 10 is provided (i.e., the outdoor space). The outdoor-side humidity detector 35 is provided, for example, at the air intake of the outdoor unit 10 and detects an outdoor air humidity Hot, which is the humidity of the space in which the outdoor unit 10 is provided. The indoor first temperature detection device 36 is attached, for example, to the outer periphery of the piping near the middle position of the entire piping length in the indoor heat exchanger 21, and detects the condensation temperature Tcd during heating operation and the evaporation temperature Tev during cooling operation. The indoor second temperature detection device 37 is provided, for example, at the air intake of the indoor unit 20, and detects the indoor temperature Trm, which is the temperature of the space in which the indoor unit 20 is provided (i.e., the indoor space). The indoor humidity detection device 38 is provided, for example, at the air intake of the indoor unit 20, and detects the indoor humidity Hrm, which is the humidity of the space in which the indoor unit 20 is provided. The presence detection device 39 is provided, for example, at the bottom of the indoor unit 20, and detects the presence or absence of a person in the space in which the indoor unit 20 is provided. In the following, the indoor second temperature detection device 37 will also be referred to as the indoor temperature detection device, the outdoor first temperature detection device 33 and the indoor first temperature detection device 36 will also be referred to as the evaporating temperature detection devices, the outdoor second temperature detection device 34 will also be referred to as the outdoor air temperature detection device, the indoor humidity detection device 38 will also be referred to as the indoor humidity detection device, and the outdoor humidity detection device 35 will also be referred to as the outdoor humidity detection device.

[0030] Next, the flow of refrigerant in the air conditioner 100 during cooling operation and heating operation will be described.

[0031] In cooling operation, the flow path switching device 12 is switched so that the discharge side of the compressor 11 is connected to the outdoor heat exchanger 13 and the suction side of the compressor 11 is connected to the indoor heat exchanger 21, as shown by the solid lines in Fig. 2. The high-temperature, high-pressure refrigerant compressed by the compressor 11 flows through the flow path switching device 12 to the outdoor heat exchanger 13, condenses and liquefies, is then throttled by the throttle device 15 to become a two-phase state of low temperature and low pressure, flows to the indoor heat exchanger 21, evaporates, gasifies, and returns to the compressor 11 again through the flow path switching device 12. By circulating the refrigerant as described above, the indoor heat exchanger 21, which is an evaporator, exchanges heat with the indoor air and absorbs heat from the indoor air, i.e., cools the indoor air, and the refrigerant that has absorbed heat is sent to the outdoor heat exchanger 13, which is a condenser, exchanges heat with the outdoor air, and releases heat to the outdoor air.

[0032] In the heating operation, the flow path switching device 12 is switched so that the discharge side of the compressor 11 is connected to the indoor heat exchanger 21 and the suction side of the compressor 11 is connected to the outdoor heat exchanger 13, as shown by the dashed lines in Fig. 2. The high-temperature, high-pressure refrigerant compressed by the compressor 11 flows through the flow path switching device 12 to the indoor heat exchanger 21, condenses and liquefies, is then throttled by the throttle device 15 to become a two-phase state of low temperature and low pressure, flows to the outdoor heat exchanger 13, evaporates, gasifies, and returns to the compressor 11 again through the flow path switching device 12. By circulating the refrigerant as described above, the outdoor heat exchanger 13, which is an evaporator, exchanges heat with the outdoor air, and the refrigerant sent to the outdoor heat exchanger 13 absorbs heat, and the refrigerant that has absorbed heat is sent to the indoor heat exchanger 21, which is a condenser, and exchanges heat with the indoor air to warm the indoor air.

[0033] FIG. 3 is a schematic configuration diagram of a ventilation device 200 of the air conditioning system according to the first embodiment. The ventilation device 200 includes an air supply device 210 that supplies outdoor air to the inside of the room R in which the indoor unit 20 is installed, and an exhaust device 220 that exhausts indoor air from the inside of the room R to the outside. The air supply device 210 is composed of an air supply port 211 provided in a wall of the room R, and an air supply fan 212. The air supply fan 212 is provided near the air supply port 211 and supplies outdoor air from the air supply port 211 to the inside of the room R. The exhaust device 220 is composed of an exhaust port 221 provided in a wall of the room R, and an exhaust fan 222. The exhaust fan 222 is provided near the exhaust port 221 and exhausts indoor air from the inside of the room R through the exhaust port 221. The ventilation device 200 adjusts the ventilation air volume by controlling the rotation speed of the air supply fan 212 and the exhaust fan 222, for example. In the following, the air supply fan 212 and the exhaust fan 222 are also referred to as ventilation fans.

[0034] The ventilation device 200 also includes a ventilation-side control device 230 that controls the entire ventilation device 200. The ventilation-side control device 230 switches the operation mode in response to, for example, an instruction from the communication device 300. Here, the operation modes include a first low-load ventilation operation in which the rotation speed of the ventilation fan is increased, and a second low-load ventilation operation in which the rotation speed of the ventilation fan is increased.

[0035] In the first embodiment, a ventilation device 200 is provided in each room R in which the indoor units 20a to 20c are provided, so that a total of three ventilation devices 200 are provided.

[0036] Fig. 4 is a schematic configuration diagram of a modified example of the ventilation device 200 of the air conditioning system according to Embodiment 1. As shown in Fig. 4, the ventilation device 200 may include an air supply device 210A consisting only of an air supply port 211 provided in a wall of the room R, and an exhaust device 220 consisting of an exhaust port 221 and an exhaust fan 222. In this case, the ventilation device 200 adjusts the ventilation air volume by controlling the rotation speed of the exhaust fan 222, for example.

[0037] The communication device 300 is configured, for example, by a smartphone on which a dedicated application is installed, and is capable of two-way communication with the air conditioning device 100 and the ventilation device 200. The communication device 300 receives, for example, operation information of the air conditioning device 100 and the ventilation device 200, and transmits various instructions to the air conditioning device 100 and the ventilation device 200 based on the operation information. The communication device 300 is also connected to a network N such as the Internet, and is capable of acquiring external information such as weather information via the network N.

[0038] Fig. 5 is a diagram showing a control flow during normal cooling operation of the air conditioning system according to embodiment 1. Fig. 6 is a Ph diagram before and after changing the opening degree of the throttling device 15 of the air conditioning system according to embodiment 1. Fig. 7 is a Ph diagram before and after changing the air volume of the outdoor blower fan 14 of the air conditioning system according to embodiment 1. Next, the control flow during normal cooling operation of the air conditioning system will be explained using Figs. 5 to 7.

[0039] (Step S11) The communication device 300 determines whether or not any of the multiple indoor units 20 is in normal cooling operation based on the operation information from the air conditioning device 100. If the communication device 300 determines that any of the multiple indoor units 20 is in normal cooling operation (YES), the process proceeds to step S12. On the other hand, if the communication device 300 determines that any of the multiple indoor units 20 is not in normal cooling operation (NO), the process ends. During normal cooling operation, the control device 50 operates the compressor 11 at an operating frequency fdr calculated based on the difference between the indoor temperature Trm detected by the indoor side second temperature detection device 37 of the indoor unit 20 during normal cooling operation and the set temperature Tst of the room R in which the indoor unit 20 during normal cooling operation is installed, and controls the throttling device 15 so that the suction superheat calculated from the difference between the suction temperature Tsu detected by the suction temperature detection device 32 and the evaporation temperature Tev detected by the indoor side first temperature detection device 36 is 0 or more, in other words, so that the refrigerant sucked into the compressor 11 becomes gas refrigerant.

[0040] (Step S12) The communication device 300 judges whether or not condition 1 is satisfied based on the operation information from the air conditioning device 100. Here, condition 1 is that the difference between the operation frequency fdr of the compressor 11 and the lower limit frequency flw, which is its lower limit, is equal to or less than a first threshold value Th1 (e.g., 5 Hz) set in advance (i.e., low-capacity operation), and the difference between the room temperature Trm detected by the indoor-side second temperature detection device 37 of the indoor unit 20 in normal cooling operation and the set temperature Tst of the room R in which the indoor unit 20 in normal cooling operation is installed is equal to or less than a second threshold value Th2 (e.g., 0.5°C) set in advance. If the communication device 300 judges that condition 1 is satisfied (YES), the process proceeds to step S13. On the other hand, if the communication device 300 judges that condition 1 is not satisfied (NO), the process ends.

[0041] (Step S13) The communication device 300 instructs the air conditioner 100 to perform a first low-capacity cooling operation, and the control device 50 causes the indoor unit 20 in normal cooling operation to perform the first low-capacity cooling operation. After that, the process proceeds to step S14. In the first low-capacity cooling operation, the control device 50 operates the compressor 11 at the lower limit frequency flw, and controls the throttling device 15 so that the difference between the discharge temperature Tdc detected by the discharge temperature detection device 31 and the suction temperature Tsu detected by the suction temperature detection device 32 becomes a preset target suction temperature difference ΔTts. Note that, instead of controlling the throttling device 15 as described above, the control device 50 may be configured to control the throttling device 15 so that the evaporation temperature Tev detected by the indoor side first temperature detection device 36 becomes a preset target evaporation temperature Tte. Here, values ​​are set for the target suction temperature difference ΔTts and the target evaporation temperature Tte such that the opening degree of the throttling device 15 becomes large. In this way, by increasing the opening of the expansion device 15 during cooling operation and storing the refrigerant in the accumulator 16 to reduce the amount of refrigerant circulating, the amount of heat exchange is reduced, realizing low-capacity operation and making it possible to reduce the air conditioning capacity without changing the operating frequency of the compressor 11. As a result, even if the air conditioning capacity exceeds the load during low-capacity operation, intermittent operation can be avoided. The Ph line before and after changing the opening of the expansion device 15 is as shown in Figure 6.

[0042] (Step S14) The communication device 300 determines whether or not condition 2 is satisfied based on the operation information from the air conditioning device 100. Here, condition 2 is that the difference between the set temperature Tst of the room in which the indoor unit 20 in the first low-capacity cooling operation is installed and the outside air temperature Tot detected by the outdoor side second temperature detection device 34 is equal to or greater than a preset third threshold value Th3 (e.g., 10°C). If the communication device 300 determines that condition 2 is satisfied (YES), the process proceeds to step S15. On the other hand, if the communication device 300 determines that condition 2 is not satisfied (NO), the process ends.

[0043] (Step S15) The communication device 300 instructs the air conditioner 100 to perform the second low-capacity cooling operation, and the control device 50 causes the indoor unit 20 in the first low-capacity cooling operation to perform the second low-capacity cooling operation. After that, the process ends. In the second low-capacity cooling operation, the control device 50 reduces the rotation speed of the outdoor blower fan 14. In this way, by reducing the air volume of the outdoor blower fan 14 at low outdoor air temperature, the condensation temperature rises as shown in FIG. 7, the enthalpy at the evaporator inlet during cooling operation increases, and the heat exchange amount decreases, so that low-capacity operation is realized and the air conditioning capacity can be reduced without changing the operating frequency of the compressor 11. As a result, intermittent operation can be avoided even in cases where the air conditioning capacity exceeds the load during low-capacity operation.

[0044] 5 may be performed solely by the air conditioning apparatus 100. In this case, the processing performed by the communication device 300 in each step is performed by the control device 50.

[0045] 8 is a diagram showing a control flow during normal heating operation of the air conditioning system according to Embodiment 1. Next, the control flow during normal heating operation of the air conditioning system will be explained using FIG. 8 and FIG.

[0046] (Step S21) The communication device 300 judges whether or not there is an indoor unit 20 in normal heating operation among the multiple indoor units 20 based on the operation information from the air conditioner 100. When the communication device 300 judges that there is an indoor unit 20 in normal heating operation among the multiple indoor units 20 (YES), the process proceeds to step S22. On the other hand, when the communication device 300 judges that there is no indoor unit 20 in normal heating operation among the multiple indoor units 20 (NO), the process ends. In normal heating operation, the control device 50 determines the operation frequency fd of the compressor 11 from the difference between the indoor temperature Tr detected by the indoor side second temperature detection device 37 of the indoor unit 20 in normal heating operation and the set temperature Ts of the room R in which the indoor unit 20 in normal heating operation is installed, and controls the throttling device 15 so that the suction superheat degree calculated by the difference between the suction temperature Tsu detected by the suction temperature detection device 32 and the evaporation temperature Tev detected by the outdoor side first temperature detection device 33 is 0 or more, that is, so that the refrigerant sucked into the compressor 11 becomes a gas refrigerant.

[0047] (Step S22) The communication device 300 judges whether or not condition 3 is satisfied based on the operation information from the air conditioning device 100. Here, condition 3 is that the difference between the operation frequency fdr of the compressor 11 and the lower limit frequency flw, which is its lower limit, is equal to or less than a first threshold value Th1 (e.g., 5 Hz) set in advance (i.e., low-capacity operation), and the difference between the room temperature Trm detected by the indoor-side second temperature detection device 37 of the indoor unit 20 in normal heating operation and the set temperature Tst of the room R in which the indoor unit 20 in normal heating operation is installed is equal to or less than a second threshold value Th2 (e.g., 0.5°C) set in advance. If the communication device 300 judges that condition 3 is satisfied (YES), the process proceeds to step S23. On the other hand, if the communication device 300 judges that condition 3 is not satisfied (NO), the process ends.

[0048] (Step S23) The communication device 300 instructs the air conditioner 100 to perform a first low-capacity heating operation, and the control device 50 causes the indoor unit 20 in normal heating operation to perform the first low-capacity heating operation. After that, the process proceeds to step S24. In the first low-capacity heating operation, the control device 50 operates the compressor 11 at the lower limit frequency flw, and controls the throttling device 15 so that the difference between the discharge temperature Tdc detected by the discharge temperature detection device 31 and the suction temperature Tsu detected by the suction temperature detection device 32 becomes the target suction temperature difference ΔTts. Note that, instead of controlling the throttling device 15 as described above, the control device 50 may be configured to control the throttling device 15 so that the evaporation temperature Tev detected by the outdoor first temperature detection device 33 becomes the target evaporation temperature Tte. Here, values ​​are set for the target suction temperature difference ΔTts and the target evaporation temperature Ttg such that the opening degree of the throttling device 15 becomes large. In this way, by increasing the opening of the expansion device 15 during heating operation and storing the refrigerant in the accumulator 16 to reduce the amount of refrigerant circulating, the amount of heat exchange is reduced, realizing low-capacity operation and making it possible to reduce the air conditioning capacity without changing the operating frequency of the compressor 11. As a result, even if the air conditioning capacity exceeds the load during low-capacity operation, intermittent operation can be avoided. The Ph line before and after changing the opening of the expansion device 15 is as shown in Figure 6.

[0049] (Step S24) The communication device 300 determines whether or not condition 4 is satisfied based on the operation information from the air conditioning device 100. Here, condition 4 is that the difference between the set temperature Tst of the room R in which the indoor unit 20 performing the first low-capacity heating operation is installed and the outside air temperature Tot detected by the outdoor-side second temperature detection device 34 is equal to or less than a fourth threshold value Th4 (e.g., 5°C) set in advance. If the communication device 300 determines that condition 2 is satisfied (YES), the process proceeds to step S25. On the other hand, if the communication device 300 determines that condition 4 is not satisfied (NO), the process ends.

[0050] (Step S25) The communication device 300 instructs the air conditioner 100 to perform the second low-capacity heating operation, and the control device 50 causes the indoor unit 20 in the first low-capacity heating operation to perform the second low-capacity heating operation. After that, the process ends. The control device 50 reduces the rotation speed of the outdoor blower fan 14 in the second low-capacity heating operation. In this way, by reducing the air volume of the outdoor blower fan 14 when the outdoor air temperature is high, the evaporation temperature decreases, the density of the refrigerant sucked in during heating operation decreases, and the amount of heat exchange decreases, so that low-capacity operation is realized and the air conditioning capacity can be reduced without changing the operating frequency of the compressor 11. As a result, intermittent operation can be avoided even when the air conditioning capacity exceeds the load during low-capacity operation.

[0051] 8 may be performed solely by the air conditioning apparatus 100. In this case, the processing performed by the communication device 300 in each step is performed by the control device 50.

[0052] Fig. 9 is a diagram showing a control flow during low capacity operation of the air conditioning system according to Embodiment 1. Fig. 10 is a Ph diagram before and after changing the air volume of the indoor blower fan 22 of the air conditioning system according to Embodiment 1. Next, the control flow during low capacity operation of the air conditioning system will be explained using Figs. 9 and 10.

[0053] (Step S31) The communication device 300 determines whether or not there is an indoor unit 20 (hereinafter also referred to as indoor unit A) in the first low-capacity cooling operation, the second low-capacity cooling operation, the first low-capacity heating operation, or the second low-capacity heating operation among the multiple indoor units 20 based on the operation information from the air conditioning device 100. If the communication device 300 determines that there is an indoor unit 20 in the first low-capacity cooling operation, the second low-capacity cooling operation, the first low-capacity heating operation, or the second low-capacity heating operation among the multiple indoor units 20 (YES), the process proceeds to step S32. On the other hand, if the communication device 300 determines that there is no indoor unit 20 in the first low-capacity cooling operation, the second low-capacity cooling operation, the first low-capacity heating operation, or the second low-capacity heating operation among the multiple indoor units 20 (NO), the process ends.

[0054] (Step S32) The communication device 300 determines whether or not condition 5 is satisfied based on the operation information from the air conditioning device 100. Here, condition 5 is that among the multiple indoor units 20, there is an indoor unit 20 in first low-capacity cooling operation or second low-capacity cooling operation, and there is a request for defrosting, such as the set humidity Hst of room R being set by a user or the like, for the room R in which that indoor unit 20 is installed. If the communication device 300 determines that condition 5 is satisfied (YES), the process proceeds to step S33. On the other hand, if the communication device 300 determines that condition 5 is not satisfied (NO), the process proceeds to step S34.

[0055] (Step S33) The communication device 300 instructs the air conditioner 100 to perform a low-capacity cooling and dehumidification operation, and the control device 50 causes the indoor unit A to perform a low-capacity cooling and dehumidification operation. After that, the process ends. In the low-capacity cooling and dehumidification operation, the control device 50 controls the air direction plate 23 so that the amount of air blown out from the air outlet of the indoor unit A decreases, and controls the throttling device 15 so that the target evaporation temperature Tte is set to a value equal to or lower than the dew point temperature Tdp in the room in which the indoor unit A is installed, and the evaporation temperature Tev detected by the indoor side first temperature detection device 36 of the indoor unit A becomes the target evaporation temperature Tte. Here, the indoor dew point temperature Tdp can be obtained from the indoor temperature Trm detected by the indoor side second temperature detection device 37 and the indoor humidity Hrm detected by the indoor side humidity detection device 28, or from the set temperature Tst and the set humidity Hst. In this way, by controlling the airflow direction plate 23 of the indoor unit 20 when defrosting is required, the air volume can be reduced without changing the rotation speed of the indoor blower fan 22, and as shown in Fig. 10, the evaporation temperature Tev decreases and the amount of latent heat processing increases, so that the dehumidification amount can be increased without changing the operation frequency fdr of the compressor 11. And, because the operation frequency fdr of the compressor 11 is not changed, intermittent operation can be avoided and continuous operation can be continued.

[0056] (Step S34) The communication device 300 determines whether or not condition 6 is satisfied based on the operation information from the air conditioning device 100. Here, condition 6 is that the indoor temperature Trm in the room R with an air conditioning operation instruction (i.e., the room in which the indoor unit A is installed) remains at or below the set temperature Tst for a preset time tst, and there is no air conditioning operation instruction in any other room R, and no one is present. If the communication device 300 determines that condition 6 is satisfied (YES), the process proceeds to step S35. On the other hand, if the communication device 300 determines that condition 6 is not satisfied (NO), the process ends.

[0057] (Step S35) The communication device 300 instructs the air conditioner 100 to perform a thermo-off suppression operation, and the control device 50 performs the thermo-off suppression operation. After that, the process ends. In the thermo-off suppression operation, the control device 50 operates the indoor unit 20 in the other room R, and controls the air deflector 23 so that the amount of air blown out from the air outlet of the indoor unit 20 in the room R with the air conditioning operation instruction is reduced. In this way, the indoor unit 20 in the room R with no air conditioning operation instruction and no occupants is operated, and the air deflector 23 of the indoor unit 20 with the operation instruction is controlled, so that the air volume can be reduced without changing the rotation speed of the indoor blower fan 22, and as shown in FIG. 10, the evaporation temperature Tev is reduced and the amount of latent heat processing is increased, so that the amount of dehumidification can be increased without changing the operating frequency of the compressor 11. And, because the operating frequency of the compressor 11 is not changed, intermittent operation can be avoided and continuous operation can be continued.

[0058] Fig. 11 is a diagram showing the temperature versus time in each of a plurality of rooms during normal cooling operation of the air conditioning system according to embodiment 1. Fig. 12 is a diagram showing the temperature versus time in each of a plurality of rooms during thermo-off suppression operation of the air conditioning system according to embodiment 1. Note that room A in Figs. 11 and 12 indicates room R for which an air conditioning operation instruction has been issued, and rooms B and C indicate room R for which an air conditioning operation instruction has not been issued and no one is present.

[0059] During the thermo-off suppression operation, the control device 50 sets the set temperature Tst (set temperature B in FIG. 12) of the indoor unit 20 in the other room R lower during cooling operation and higher during heating operation than the set temperature Tst (set temperature A in FIG. 12) of the indoor unit 20 in the room R with an air-conditioning operation instruction, and sets the rotation speed of the indoor blower fan 22 of the indoor unit 20 in the other room R higher than the rotation speed of the indoor blower fan 22 of the indoor unit 20 in the room R with an air-conditioning operation instruction. In this way, by setting the set temperature Tst so that the air-conditioning load is large in the room R with no air-conditioning operation instruction and no occupants (rooms B and C in FIG. 12), thermo-off is suppressed in the room R with an air-conditioning operation instruction (room A in FIG. 12), so that intermittent operation can be avoided and continuous operation can be continued.

[0060] Furthermore, during thermo-off suppression operation, when there is no air-conditioning operation command and there are multiple rooms R with no occupants, the control device 50 determines the indoor unit 20 to be operated as follows. Note that the control device 50 has information regarding the heat exchange area of ​​the indoor heat exchanger 21 of each of the multiple indoor units 20.

[0061] (1) When there is no dehumidification request for a room R for which an air conditioning operation instruction has been issued, priority is given to operation of the indoor unit 20 with a larger heat exchange area of ​​the indoor heat exchanger 21. In addition, when there are multiple indoor heat exchangers 21 with the same heat exchange area, priority is given to operation of the indoor unit 20 of the room R with a higher indoor temperature Trm if the room R for which an air conditioning operation instruction has been issued is in cooling operation, and priority is given to operation of the indoor unit 20 of the room R with a lower indoor temperature Trm if the room R for which an air conditioning operation instruction has been issued is in heating operation. (2) When there is a dehumidification request for a room R for which an air conditioning operation instruction has been issued, priority is given to operation of the indoor unit 20 with a smaller heat exchange area of ​​the indoor heat exchanger 21. In addition, when there are multiple indoor heat exchangers 21 with the same heat exchange area, priority is given to operation of the indoor unit 20 of the room R with a higher indoor temperature Trm if the room R for which an air conditioning operation instruction has been issued is in cooling operation, and priority is given to operation of the indoor unit 20 of the room R with a lower indoor temperature Trm if the room R for which an air conditioning operation instruction has been issued is in heating operation.

[0062] In this way, when there is no air conditioning operation command, there are multiple rooms R with no occupants, and there is no request for dehumidification, the indoor unit 20 with the large heat exchange area of ​​the indoor heat exchanger 21 is operated preferentially, which increases the evaporation temperature Tev and the density of the suctioned refrigerant, thereby increasing the amount of refrigerant circulating, thereby enabling high efficiency and improving energy conservation. Also, when there is no air conditioning operation command, there are multiple rooms R with no occupants, and there is a request for dehumidification, the indoor unit 20 with the small heat exchange area of ​​the indoor heat exchanger 21 is operated preferentially, and by prioritizing achievement of the target evaporation temperature Tte, the required amount of refrigerant circulating can be reduced, enabling high efficiency and improving energy conservation.

[0063] 9 may be performed solely by the air conditioning apparatus 100. In this case, the processing performed by the communication device 300 in each step is performed by the control device 50.

[0064] 13 is a diagram showing a control flow during low capacity operation of the air conditioning system according to Embodiment 1. Next, the control flow during low capacity operation of the air conditioning system will be explained using FIG.

[0065] (Step S41) The communication device 300 determines whether or not there is an indoor unit 20 (hereinafter also referred to as indoor unit B) in the first low-capacity cooling operation, the second low-capacity cooling operation, the first low-capacity heating operation, the second low-capacity heating operation, or the thermo-off suppression operation among the multiple indoor units 20 based on the operation information from the air conditioning device 100. If the communication device 300 determines that there is an indoor unit 20 in the first low-capacity cooling operation, the second low-capacity cooling operation, the first low-capacity heating operation, the second low-capacity heating operation, or the thermo-off suppression operation among the multiple indoor units 20 (YES), the process proceeds to step S42. On the other hand, if the communication device 300 determines that there is no indoor unit 20 in the first low-capacity cooling operation, the second low-capacity cooling operation, the first low-capacity heating operation, the second low-capacity heating operation, or the thermo-off suppression operation among the multiple indoor units 20 (NO), the process ends.

[0066] (Step S42) The communication device 300 judges whether or not condition 7 is satisfied based on the operation information from the air conditioning device 100. Here, condition 7 is that the difference between the outdoor air temperature Tot detected by the outdoor side second temperature detection device 34 and the indoor temperature Trm detected by the indoor side second temperature detection device 37 of the indoor unit B is greater than the set temperature Tst preset by the user or the like of the room R in which the indoor unit B is installed, and the difference between the outdoor air temperature Tot detected by the outdoor side second temperature detection device 34 and the indoor temperature Trm detected by the indoor side second temperature detection device 37 of the indoor unit B is equal to or greater than a fifth threshold value Th5 (for example, 5°C) set in advance. If the communication device 300 judges that condition 7 is satisfied (YES), the process proceeds to step S43. On the other hand, if the communication device 300 judges that condition 7 is not satisfied (NO), the process ends.

[0067] (Step S43) The communication device 300 instructs the air conditioner 100 to perform the first low-load ventilation operation, and the control device 50 performs the first low-load ventilation operation. After that, the process ends. In the first low-load ventilation operation, the control device 50 increases the rotation speed of the ventilation fan of the ventilation device 200 of the room R in which the indoor unit B is installed. In this way, when the air conditioning load increases due to ventilation, the ventilation air volume is increased, and the air conditioning load is increased, so that the indoor temperature Trm can be prevented from falling below the set temperature Tst during cooling operation, and the indoor temperature Trm can be prevented from rising above the set temperature Tst during heating operation, and intermittent operation can be avoided. In addition, since the transition to normal operation with high operating efficiency can be promoted, energy saving can be improved, and the indoor air quality can be improved by improving the air quality due to the reduction in CO2 concentration.

[0068] 14 is a diagram showing a control flow during low-capacity cooling and dehumidification operation of the air conditioning system according to Embodiment 1. Next, the control flow during low-capacity cooling and dehumidification operation of the air conditioning system will be described with reference to FIG.

[0069] (Step S51) The communication device 300 determines whether or not there is an indoor unit 20 (hereinafter also referred to as indoor unit C) in low-capacity cooling and dehumidification operation among the multiple indoor units 20, based on the operation information from the air conditioning apparatus 100. If the communication device 300 determines that there is an indoor unit 20 in low-capacity cooling and dehumidification operation among the multiple indoor units 20 (YES), the process proceeds to step S52. On the other hand, if the communication device 300 determines that there is no indoor unit 20 in low-capacity cooling and dehumidification operation among the multiple indoor units 20 (NO), the process ends.

[0070] (Step S52) The communication device 300 judges whether or not condition 8 is satisfied based on the operation information from the air conditioning device 100. Here, condition 8 is that the difference between the outdoor air temperature Tot detected by the outdoor side second temperature detection device 34 and the indoor air temperature Trm detected by the indoor side second temperature detection device 37 of the indoor unit C is smaller than the set temperature Tst preset by the user of the room R in which the indoor unit C is installed, and the difference between the outdoor air humidity Hot detected by the outdoor side humidity detection device 35 and the indoor air humidity Hrm detected by the indoor side humidity detection device 28 of the indoor unit C is equal to or smaller than a sixth threshold value Th6 set in advance. If the communication device 300 judges that condition 8 is satisfied (YES), the process proceeds to step S53. On the other hand, if the communication device 300 judges that condition 8 is not satisfied (NO), the process ends.

[0071] (Step S53) The communication device 300 instructs the air conditioning device 100 to perform the second low-load ventilation operation, and the control device 50 performs the second low-load ventilation operation. After that, the process ends. In the second low-load ventilation operation, the control device 50 increases the rotation speed of the ventilation fan of the ventilation device 200 of the room R in which the indoor unit C is installed. In this way, when the dehumidification load is reduced by ventilation, the ventilation air volume is increased, that is, the ventilation volume is increased in the direction in which the dehumidification load is reduced, thereby reducing the sensible heat load and promoting a transition to the first cooling load operation or the second cooling load operation, which have a high evaporation temperature Tev and are more efficient, thereby improving energy conservation.

[0072] As described above, the air conditioning apparatus 100 according to the first embodiment includes an outdoor unit 10 having a compressor 11, a flow path switching device 12, an outdoor heat exchanger 13, a throttling device 15, and an accumulator 16 and installed outdoors, a plurality of indoor units 20 having an indoor heat exchanger 21 and installed in each room, a refrigerant circuit 1 in which the compressor 11, the flow path switching device 12, the outdoor heat exchanger 13, the throttling device 15, the plurality of indoor heat exchangers 21, and the accumulator 16 are connected by piping and in which a refrigerant circulates, a control device 50 that controls the refrigerant circuit 1, a suction temperature detection device 32 that detects a suction temperature Tsu of the compressor 11, a discharge temperature detection device 31 that detects a discharge temperature Tdc of the compressor 11, an evaporation temperature detection device that detects an evaporation temperature Tev, and a refrigeration circuit 111 in which the refrigerant circulates. and an indoor temperature detection device provided in the indoor unit 20 for detecting the indoor temperature Trm. When the difference between the operating frequency fdv of the compressor 11 and its lower limit frequency flw is equal to or less than a predetermined first threshold value and the difference between the predetermined set temperature Tst and the indoor temperature Trm is equal to or less than a predetermined second threshold value, the control device 50 executes a first low-capacity operation in which the opening of the throttling device 15 is increased so that the difference between the discharge temperature Tdc and the suction temperature Tsu becomes a predetermined target suction temperature difference ΔTts, or the opening of the throttling device 15 is increased so that the evaporation temperature Tev becomes a predetermined target evaporation temperature Tte.

[0073] The air conditioning system according to the first embodiment includes an outdoor unit 10 having a compressor 11, a flow path switching device 12, an outdoor heat exchanger 13, a throttling device 15, and an accumulator 16 and installed outdoors, a plurality of indoor units 20 having an indoor heat exchanger 21 and installed in each room, a refrigerant circuit 1 in which the compressor 11, the flow path switching device 12, the outdoor heat exchanger 13, the throttling device 15, the plurality of indoor heat exchangers 21, and the accumulator 16 are connected by piping and in which the refrigerant circulates, a control device 50 that controls the refrigerant circuit 1, an intake temperature detection device 32 that detects the intake temperature Tsu of the compressor 11, a discharge temperature detection device 31 that detects the discharge temperature Tdc of the compressor 11, an evaporation temperature detection device that detects the evaporation temperature Tev, and an indoor temperature detection device that is installed in each room and detects the indoor temperature Trm. and a communication device 300 capable of communicating with the air conditioning device 100. When there is an indoor unit 20 in normal operation among the multiple indoor units 20, the communication device 300 instructs the air conditioning device 100 to perform a first low-capacity operation in which, when the difference between the operating frequency fdv of the compressor 11 and its lower limit frequency flw is equal to or less than a predetermined first threshold value and the difference between a predetermined set temperature Tst and an indoor temperature Trm is equal to or less than a predetermined second threshold value, the communication device 300 instructs the air conditioning device 100 to perform a first low-capacity operation in which the opening of the throttling device 15 is increased so that the difference between the discharge temperature Tdc and the suction temperature Tsu becomes a predetermined target suction temperature difference ΔTts, or the opening of the throttling device 15 is increased so that the evaporation temperature Tev becomes a predetermined target evaporation temperature Tte.

[0074] According to the air conditioner 100 and the air conditioning system according to the first embodiment, during low capacity operation in which the difference between the operating frequency fdr of the compressor 11 and the lower limit frequency flw, which is its lower limit, is equal to or less than a preset first threshold, if the difference between the preset set temperature Tst and the room temperature Trm is equal to or less than a preset second threshold, the air conditioner 100 is instructed to perform a first low capacity operation in which the opening degree of the throttling device 15 is increased so that the difference between the discharge temperature Tdc and the suction temperature Tsu becomes the preset target suction temperature difference ΔTts, or the opening degree of the throttling device 15 is increased so that the evaporation temperature Tev becomes the preset target evaporation temperature Tte. By doing so, the air conditioning capacity can be reduced without reducing the operating frequency fdr of the compressor 11, so that intermittent operation can be avoided even in cases where the air conditioning capacity exceeds the load during low capacity operation.

[0075] Furthermore, the air conditioning apparatus 100 according to embodiment 1 includes an outdoor blower fan 14 that supplies air to the outdoor heat exchanger 13, and an outdoor air temperature detection device that detects the outdoor air temperature Tot, and the control device 50 executes a second low-capacity operation to reduce the rotation speed of the outdoor blower fan 14 when, among the multiple indoor units 20, there is an indoor unit 20 that is operating in a first low-capacity mode, and when, during cooling operation, the difference between the set temperature Tst of the room R in which the indoor unit 20 is installed during the first low-capacity mode and the outdoor air temperature Tot is equal to or greater than a preset third threshold value, and when, during heating operation, the difference between the set temperature Tst of the room R in which the indoor unit 20 is installed during the first low-capacity mode and the outdoor air temperature Tot is equal to or less than a preset fourth threshold value.

[0076] Furthermore, in the air conditioning system according to embodiment 1, the air conditioning apparatus 100 has an outdoor blower fan 14 that supplies air to the outdoor heat exchanger 13, and an outdoor air temperature detection device that detects the outdoor air temperature Tot, and the communication device 300 instructs the air conditioning apparatus 100 to perform a second low-capacity operation to reduce the rotation speed of the outdoor blower fan 14 when, among the multiple indoor units 20, there is an indoor unit 20 that is operating in a first low capacity, and when, during cooling operation, the difference between the set temperature Tst of the room R in which the indoor unit 20 is installed during the first low capacity operation and the outdoor air temperature Tot is equal to or greater than a preset third threshold, and when, during heating operation, the difference between the set temperature Tst of the room R in which the indoor unit 20 is installed during the first low capacity operation and the outdoor air temperature Tot is equal to or less than a preset fourth threshold.

[0077] According to the air conditioner 100 and the air conditioning system according to the first embodiment, during cooling operation, the air volume of the outdoor blower fan 14 is reduced when the outdoor air temperature is low, thereby increasing the condensation temperature Tcd, increasing the enthalpy at the evaporator inlet, and reducing the amount of heat exchange. Also, during heating operation, the air volume of the outdoor blower fan 14 is reduced when the outdoor air temperature is high, thereby decreasing the evaporation temperature Tev, decreasing the density of the suction refrigerant, and reducing the amount of heat exchange. Therefore, low capacity operation is realized, and the air conditioning capacity can be reduced without changing the operating frequency fdr of the compressor 11. As a result, even when the air conditioning capacity exceeds the load during low capacity operation, intermittent operation can be avoided.

[0078] Furthermore, the air conditioning apparatus 100 according to the first embodiment is provided with an occupancy detection device 39 that is provided in each room R to detect the presence or absence of a person in the room, and an air deflector 23 that is provided at the air outlet of each of the multiple indoor units 20 to change the direction of the air blown out from the air outlet. When the indoor temperature Trm of a first indoor unit, which is an indoor unit 20 among the multiple indoor units 20 and which is performing first low-capacity operation or second low-capacity operation, is equal to or lower than a preset fifth threshold, if there is a second indoor unit, which is an indoor unit 20 other than the first indoor unit, for which no operation instruction has been issued and which is installed in a room R where no person is present, the control device 50 executes a thermo-off suppression operation in which it operates the second indoor unit and controls the air deflector 23 so as to reduce the amount of air blown out from the air outlet of the first indoor unit.

[0079] Furthermore, in the air conditioning system according to embodiment 1, the air conditioning apparatus 100 has an occupancy detection device 39 provided in each room R for detecting the presence or absence of a person in the room, and an air deflector 23 provided at each air outlet of the multiple indoor units 20 for changing the direction of the air blown out from the air outlet, and when the indoor temperature Trm of a first indoor unit, which is an indoor unit 20 among the multiple indoor units 20 and which is performing first low-capacity operation or second low-capacity operation, is equal to or lower than a preset fifth threshold, the communication device 300 instructs the air conditioning apparatus 100 to operate the second indoor unit and perform a thermo-off suppression operation to control the air deflector 23 so as to reduce the amount of air blown out from the air outlet of the first indoor unit when the indoor temperature Trm of a first indoor unit, which is an indoor unit 20 performing first low-capacity operation or second low-capacity operation, is equal to or lower than a preset fifth threshold, and when there is a second indoor unit, which is an indoor unit 20 other than the first indoor unit, for which no operation instruction has been issued and which is installed in a room R where no person is present.

[0080] According to the air conditioner 100 and air conditioning system of the first embodiment, by operating the indoor unit 20 in room R where there is no air conditioning operation command and no one is present, and controlling the air direction vane 23 of the indoor unit 20 where an operation command is given, it is possible to reduce the air volume without changing the rotation speed of the indoor blower fan 22, and since the evaporation temperature falls and the latent heat processing amount increases, it is possible to increase the dehumidification amount without changing the operating frequency of the compressor 11. And because the operating frequency of the compressor 11 is not changed, intermittent operation is avoided and continuous operation can be continued.

[0081] Furthermore, in the air conditioning apparatus 100 according to embodiment 1, the multiple indoor units 20 have indoor blower fans 22 that supply air to the indoor heat exchanger 21, and when there is an indoor unit 20 among the multiple indoor units 20 that is in thermo-off suppression operation, the control device 50 sets the set temperature Tst of the second indoor unit lower than the set temperature Tst of the first indoor unit during cooling operation, and sets the set temperature Tst of the second indoor unit higher than the set temperature Tst of the first indoor unit during heating operation, and sets the rotation speed of the indoor blower fan 22 of the second indoor unit higher than the rotation speed of the indoor blower fan 22 of the first indoor unit.

[0082] Furthermore, in the air conditioning system according to embodiment 1, the multiple indoor units 20 have indoor blower fans 22 that supply air to the indoor heat exchanger 21, and the communication device 300 instructs the air conditioning device 100, when there is an indoor unit 20 among the multiple indoor units 20 that is in thermo-off suppression operation, to set the set temperature Tst of the second indoor unit lower than the set temperature Tst of the first indoor unit during cooling operation, and to set the set temperature Tst of the second indoor unit higher than the set temperature Tst of the first indoor unit during heating operation, and to set the rotation speed of the indoor blower fan 22 of the second indoor unit higher than the rotation speed of the indoor blower fan 22 of the first indoor unit.

[0083] According to the air conditioner 100 and air conditioning system of the first embodiment, during thermo-off suppression operation, the set temperature Tst of the indoor unit 20 in the other room R is set lower during cooling operation and higher during heating operation than the set temperature Tst of the indoor unit 20 in the room R for which an air-conditioning operation instruction is given, and the rotation speed of the indoor blower fan 22 of the indoor unit 20 in the other room R is set higher than the rotation speed of the indoor blower fan 22 of the indoor unit 20 in the room R for which an air-conditioning operation instruction is given. In this way, by setting the set temperature Tst so that the air-conditioning load is high in the room R for which there is no air-conditioning operation instruction and no occupants, thermo-off is suppressed in the room R for which an air-conditioning operation instruction is given, so that intermittent operation can be avoided and continuous operation can be continued.

[0084] Furthermore, in the air conditioning apparatus 100 according to embodiment 1, the control device 50 has information regarding the heat exchange area of ​​the indoor heat exchanger 21 of each of the multiple indoor units 20, and when there is an indoor unit 20 among the multiple indoor units 20 that is in thermo-off suppression operation, if there are multiple second indoor units, if there is no request for dehumidification, the second indoor unit with the larger heat exchange area is operated with priority, and if there is a request for dehumidification, the second indoor unit with the smaller heat exchange area is operated with priority.

[0085] Furthermore, in the air conditioning system according to embodiment 1, the control device 50 has information regarding the heat exchange area of ​​the indoor heat exchanger 21 of each of the multiple indoor units 20, and the communication device 300 instructs the air conditioning device 100 that, when there is an indoor unit 20 among the multiple indoor units 20 that is in thermo-off suppression operation and there are multiple second indoor units, if there is no request for dehumidification, the second indoor unit with the larger heat exchange area is operated preferentially, and if there is a request for dehumidification, the second indoor unit with the smaller heat exchange area is operated preferentially.

[0086] According to the air conditioner 100 and the air conditioning system according to the first embodiment, when there is no air conditioning operation command, there are multiple rooms R with no occupants, and there is no request for dehumidification, the indoor unit 20 with the large heat exchange area of ​​the indoor heat exchanger 21 is operated preferentially, so that the evaporation temperature Tev rises, the intake refrigerant density rises, and the refrigerant circulation amount increases, making it possible to achieve high efficiency and improve energy saving. Also, when there is no air conditioning operation command, there are multiple rooms R with no occupants, and there is a request for dehumidification, the indoor unit 20 with the small heat exchange area of ​​the indoor heat exchanger 21 is operated preferentially, and by prioritizing the achievement of the target evaporation temperature Tte, the required amount of refrigerant circulation can be reduced, making it possible to achieve high efficiency and improve energy saving.

[0087] Furthermore, in the air conditioning apparatus 100 according to embodiment 1, the control device 50 has information regarding the heat exchange area of ​​the indoor heat exchanger 21 of each of the multiple indoor units 20, and when there is an indoor unit 20 among the multiple indoor units 20 that is in thermo-off suppression operation, if there are multiple second indoor units and the heat exchange area is the same, among the multiple second indoor units, the one with the higher indoor temperature Trm is operated with priority during cooling operation, and the one with the lower indoor temperature Trm is operated with priority during heating operation.

[0088] Furthermore, in the air conditioning system according to embodiment 1, the control device 50 has information regarding the heat exchange area of ​​the indoor heat exchanger 21 of each of the multiple indoor units 20, and when there is an indoor unit 20 among the multiple indoor units 20 that is in thermo-off suppression operation, if there are multiple second indoor units and the heat exchange area is the same, the communication device 300 instructs the air conditioning device 100 to operate preferentially among the multiple second indoor units with the higher indoor temperature Trm during cooling operation, and to operate preferentially with the lower indoor temperature Trm during heating operation.

[0089] According to the air conditioner 100 and the air conditioning system according to the first embodiment, when there is no air conditioning operation command, there are multiple rooms R with no occupants, and there is no request for dehumidification, the indoor unit 20 with the large heat exchange area of ​​the indoor heat exchanger 21 is operated preferentially, so that the evaporation temperature Tev rises, the intake refrigerant density rises, and the refrigerant circulation amount increases, making it possible to achieve high efficiency and improve energy saving. Also, when there is no air conditioning operation command, there are multiple rooms R with no occupants, and there is a request for dehumidification, the indoor unit 20 with the small heat exchange area of ​​the indoor heat exchanger 21 is operated preferentially, and by prioritizing the achievement of the target evaporation temperature Tte, the required amount of refrigerant circulation can be reduced, making it possible to achieve high efficiency and improve energy saving.

[0090] Furthermore, in the air conditioning apparatus 100 according to embodiment 1, when there is a first indoor unit among the multiple indoor units 20 and there is a demand for dehumidification, the control device 50 controls the air direction flap 23 so as to reduce the amount of air blown out from the air outlet of the first indoor unit, and also performs low-capacity cooling and dehumidification operation by setting the target evaporation temperature Tte to a value lower than the indoor dew point temperature Tdp and controlling the throttling device 15 so that the evaporation temperature Tev becomes the target evaporation temperature Tte.

[0091] Furthermore, in the air conditioning system according to embodiment 1, when there is a first indoor unit among the multiple indoor units 20 and there is a request for dehumidification, the communication device 300 instructs the air conditioning device 100 to perform low-capacity cooling and dehumidification operation in which the air direction flap 23 is controlled so as to reduce the amount of air blown out from the air outlet of the first indoor unit, and the target evaporation temperature Tte is set to a value below the indoor dew point temperature Tdp and the throttling device 15 is controlled so that the evaporation temperature Tev becomes the target evaporation temperature Tte.

[0092] According to the air conditioner 100 and air conditioning system of the first embodiment, by controlling the air direction plate 23 of the indoor unit 20 when defrosting is required, the air volume can be reduced without changing the rotation speed of the indoor blower fan 22, and the evaporation temperature Tev falls and the latent heat processing amount increases, so that the dehumidification amount can be increased without changing the operation frequency fdr of the compressor 11. And, because the operation frequency fdr of the compressor 11 is not changed, intermittent operation can be avoided and continuous operation can be continued.

[0093] Moreover, the air conditioning system according to the first embodiment includes a ventilation device 200 that is provided in each room R, has a ventilation fan, and takes in outdoor air into the room and exhausts indoor air to the outside. When there is an indoor unit 20 among the multiple indoor units 20 that is operating in a first low capacity, a second low capacity, or in a thermo-off suppression operation, and when the difference between the outdoor air temperature Tot and the indoor temperature Trm is greater than the set temperature Tst of the room R in which the indoor unit 20 is installed, and when the difference between the outdoor air temperature Tot and the indoor temperature Trm is equal to or greater than a fifth threshold value set in advance, the communication device 300 instructs the ventilation device 200 of the room R in which the indoor unit 20 is operating in the first low capacity, the second low capacity, or in a thermo-off suppression operation to increase the rotation speed of the ventilation fan.

[0094] According to the air conditioning system of the first embodiment, when ventilation increases the air conditioning load, the ventilation air volume is increased to increase the air conditioning load, thereby preventing the indoor temperature Trm from falling below the set temperature Tst during cooling operation, and preventing the indoor temperature Trm from rising above the set temperature Tst during heating operation, thereby avoiding intermittent operation. In addition, since the transition to normal operation with high operating efficiency can be promoted, energy saving can be improved, and indoor air quality can be improved by improving air quality through a reduction in CO2 concentration.

[0095] Moreover, the air conditioning system according to embodiment 1 is provided with a ventilation device 200 that is provided in each room R, has a ventilation fan, takes in outdoor air into the room, and exhausts the indoor air to the outside, and the air conditioning device 100 has an indoor humidity detection device that detects the indoor humidity Hrm and an outdoor humidity detection device that detects the outdoor humidity Hot, and when there is an indoor unit 20 in low-capacity cooling and dehumidification operation among the multiple indoor units 20, the communication device 300 instructs the ventilation device 200 of the room R in which the indoor unit 20 in low-capacity cooling and dehumidification operation is installed to increase the rotation speed of the ventilation fan when the difference between the outdoor humidity Hot and the indoor humidity Hrm is smaller than the preset humidity Hst of the room R in which the indoor unit 20 is installed and the difference between the outdoor humidity Hot and the indoor humidity Hrm is equal to or less than a preset sixth threshold value.

[0096] According to the air conditioning system of embodiment 1, when ventilation reduces the dehumidification load, the ventilation air volume is increased, that is, the ventilation volume is increased in the direction that reduces the dehumidification load, thereby reducing the sensible heat load and promoting a transition to the first cooling load operation or the second cooling load operation, which have a high evaporation temperature Tev and are more efficient, thereby improving energy savings.

[0097] Various aspects of the present disclosure are described below.

[0098] (Appendix 1) an outdoor unit having a compressor, a flow switching device, an outdoor heat exchanger, a throttling device, and an accumulator and disposed outside the room; A plurality of indoor units each having an indoor heat exchanger and installed in each room; a refrigerant circuit in which the compressor, the flow switching device, the outdoor heat exchanger, the throttling device, the plurality of indoor heat exchangers, and the accumulator are connected by piping, and in which a refrigerant circulates; A control device for controlling the refrigerant circuit; a suction temperature detection device that detects a suction temperature of the compressor; A discharge temperature detection device that detects a discharge temperature of the compressor; An evaporation temperature detection device that detects an evaporation temperature; An indoor temperature detection device is provided in each room and detects an indoor temperature, The control device includes: When there is an indoor unit in normal operation among the plurality of indoor units, When the difference between the operating frequency of the compressor and a lower limit frequency that is a lower limit thereof is equal to or less than a first threshold value set in advance, and the difference between the preset temperature of the room in which the indoor unit is installed during the normal operation and the indoor temperature is equal to or less than a second threshold value set in advance, A first low capacity operation is performed in which the opening degree of the throttling device is increased so that the difference between the discharge temperature and the suction temperature becomes a preset target suction temperature difference, or the opening degree of the throttling device is increased so that the evaporation temperature becomes a preset target evaporation temperature. Air conditioning equipment. (Appendix 2) an outdoor blower fan for supplying air to the outdoor heat exchanger; An outside air temperature detection device that detects an outside air temperature, The control device includes: When there is an indoor unit in a first low capacity operation among the plurality of indoor units, During cooling operation, when the difference between the set temperature of the room in which the indoor unit is installed during the first low capacity operation and the outdoor air temperature is equal to or greater than a preset third threshold value, During heating operation, if the difference between the set temperature of the room in which the indoor unit is installed and the outdoor air temperature during the first low capacity operation is equal to or less than a fourth threshold value set in advance, A second low-capacity operation is performed to reduce the rotation speed of the outdoor blower fan. 2. An air conditioning apparatus as described in claim 1. (Appendix 3) A presence detection device is provided in each room to detect whether or not someone is present; a wind direction plate provided at each of the air outlets of the plurality of indoor units to change the direction of air blown out from the air outlet, The control device includes: When the indoor temperature of a first indoor unit that is an indoor unit performing the first low capacity operation or the second low capacity operation among the plurality of indoor units is equal to or lower than a preset fifth threshold value, If there is a second indoor unit other than the first indoor unit, which is an indoor unit for which an operation instruction has not been issued and which is installed in a room where no one is present, The second indoor unit is operated, and a thermo-off suppression operation is performed to control the air direction plate so that the amount of air blown out from the air outlet of the first indoor unit is reduced. 3. An air conditioning apparatus as described in appendix 2. (Appendix 4) The plurality of indoor units include An indoor blower fan that supplies air to the indoor heat exchanger, The control device includes: When there is an indoor unit in a thermo-off suppression operation among the plurality of indoor units, During cooling operation, the set temperature of the second indoor unit is set lower than the set temperature of the first indoor unit, and during heating operation, the set temperature of the second indoor unit is set higher than the set temperature of the first indoor unit, The rotation speed of the indoor blower fan of the second indoor unit is set to be greater than the rotation speed of the indoor blower fan of the first indoor unit. 4. An air conditioning apparatus as described in appendix 3. (Appendix 5) The control device includes: information regarding the heat exchange area of ​​the indoor heat exchanger of each of the plurality of indoor units; When there is an indoor unit in a thermo-off suppression operation among the plurality of indoor units, When there are multiple second indoor units, When there is no need for dehumidification, among the plurality of second indoor units, the one having a larger heat exchange area is operated preferentially, When there is a demand for dehumidification, the second indoor unit having a smaller heat exchange area is operated preferentially among the plurality of second indoor units. 5. The air conditioning apparatus according to claim 3 or 4. (Appendix 6) The control device includes: information regarding the heat exchange area of ​​the indoor heat exchanger of each of the plurality of indoor units; When there is an indoor unit in a thermo-off suppression operation among the plurality of indoor units, When there are multiple second indoor units and the heat exchange areas are the same, Among the plurality of second indoor units, the one having a higher indoor temperature is operated preferentially during cooling operation, and the one having a lower indoor temperature is operated preferentially during heating operation. 6. An air-conditioning apparatus according to any one of claims 3 to 5. (Appendix 7) The control device includes: When the first indoor unit is present among the plurality of indoor units and dehumidification is required, A low-capacity cooling and dehumidifying operation is performed by controlling the air direction plate so as to reduce the amount of air blown out from the air outlet of the first indoor unit, setting the target evaporation temperature to a value equal to or lower than a dew point temperature in the room, and controlling the throttling device so that the evaporation temperature becomes the target evaporation temperature. 7. The air conditioner according to any one of claims 3 to 6. (Appendix 8) an outdoor unit having a compressor, a flow switching device, an outdoor heat exchanger, a throttling device, and an accumulator and disposed outside the room; A plurality of indoor units each having an indoor heat exchanger and provided in each room; a refrigerant circuit in which the compressor, the flow switching device, the outdoor heat exchanger, the throttling device, the plurality of indoor heat exchangers, and the accumulator are connected by piping, and in which a refrigerant circulates; A control device for controlling the refrigerant circuit; a suction temperature detection device that detects a suction temperature of the compressor; A discharge temperature detection device that detects a discharge temperature of the compressor; An evaporation temperature detection device that detects an evaporation temperature; An air conditioning apparatus having an indoor temperature detection device provided in each room and detecting an indoor temperature; A communication device capable of communicating with the air conditioning device, The communication device includes: When there is an indoor unit in normal operation among the plurality of indoor units, When a difference between the operating frequency of the compressor and a lower limit frequency, which is a lower limit value thereof, is equal to or less than a first threshold value set in advance, and a difference between a preset set temperature and the indoor temperature is equal to or less than a second threshold value set in advance, The air conditioner is instructed to execute a first low capacity operation in which the opening degree of the throttling device is increased so that the difference between the discharge temperature and the suction temperature becomes a preset target suction temperature difference, or the opening degree of the throttling device is increased so that the evaporation temperature becomes a preset target evaporation temperature. Air conditioning system. (Appendix 9) The air conditioning device includes: an outdoor blower fan for supplying air to the outdoor heat exchanger; An outside air temperature detection device that detects an outside air temperature, The communication device includes: When there is an indoor unit in a first low capacity operation among the plurality of indoor units, During cooling operation, if the difference between the set temperature of the room in which the indoor unit is installed during the first low capacity operation and the outdoor air temperature is equal to or greater than a preset third threshold value, During heating operation, if the difference between the set temperature of the room in which the indoor unit is installed during the first low capacity operation and the outdoor air temperature is equal to or less than a fourth threshold value set in advance, Instructing the air conditioner to execute a second low-capacity operation in which the rotation speed of the outdoor blower fan is reduced. 9. The air conditioning system of claim 8. (Appendix 10) The air conditioning device includes: A presence detection device is provided in each room to detect whether or not someone is present; a wind direction plate provided at each of the air outlets of the indoor units to change the direction of air blown out from the air outlets, The communication device includes: When the indoor temperature of a first indoor unit that is an indoor unit performing the first low capacity operation or the second low capacity operation among the plurality of indoor units is equal to or lower than a preset fifth threshold value, If there is a second indoor unit other than the first indoor unit, which is an indoor unit for which an operation instruction has not been issued and which is installed in a room where no one is present, The second indoor unit is operated, and a thermo-off suppression operation is performed to control the air direction plate so as to reduce the amount of air blown out from the air outlet of the first indoor unit. 10. The air conditioning system of claim 9. (Appendix 11) The plurality of indoor units include An indoor blower fan that supplies air to the indoor heat exchanger, The communication device includes: When there is an indoor unit in a thermo-off suppression operation among the plurality of indoor units, During cooling operation, the set temperature of the second indoor unit is set lower than the set temperature of the first indoor unit, and during heating operation, the set temperature of the second indoor unit is set higher than the set temperature of the first indoor unit, Instructing the air conditioner to set the rotation speed of the indoor blower fan of the second indoor unit higher than the rotation speed of the indoor blower fan of the first indoor unit. 11. The air conditioning system of claim 10. (Appendix 12) The control device includes: information regarding the heat exchange area of ​​the indoor heat exchanger of each of the plurality of indoor units; The communication device includes: When there is an indoor unit in a thermo-off suppression operation among the plurality of indoor units, When there are multiple second indoor units, When there is no need for dehumidification, among the plurality of second indoor units, the one having a larger heat exchange area is operated preferentially, When there is a demand for dehumidification, the air conditioner is instructed to operate the second indoor unit having a smaller heat exchange area with priority among the plurality of second indoor units. 12. The air conditioning system according to claim 10 or 11. (Appendix 13) The control device includes: information regarding the heat exchange area of ​​the indoor heat exchanger of each of the plurality of indoor units; The communication device includes: When there is an indoor unit in a thermo-off suppression operation among the plurality of indoor units, When there are multiple second indoor units and the heat exchange areas are the same, Instructing the air conditioner to operate the second indoor units having a higher indoor temperature with priority during cooling operation and to operate the second indoor units having a lower indoor temperature with priority during heating operation. An air conditioning system according to any one of claims 10 to 12. (Appendix 14) The communication device includes: When the first indoor unit is present among the plurality of indoor units and dehumidification is required, Instruct the air conditioner to perform a low-capacity cooling and dehumidifying operation in which the air direction plate is controlled so as to reduce the amount of air blown out from the air outlet of the first indoor unit, the target evaporation temperature is set to a value equal to or lower than the indoor dew point temperature, and the throttling device is controlled so that the evaporation temperature becomes the target evaporation temperature. An air conditioning system according to any one of claims 10 to 13. (Appendix 15) a ventilation device provided in each room, the ventilation device having a ventilation fan, taking in outdoor air into the room and discharging the indoor air to the outside; The communication device includes: When there is an indoor unit in the first low capacity operation, the second low capacity operation, or the thermo-off suppression operation among the plurality of indoor units, and when the difference between the outdoor air temperature and the indoor temperature is greater than the indoor temperature with respect to the set temperature of the room in which the indoor unit is installed, and when the difference between the outdoor air temperature and the indoor temperature is equal to or greater than a fifth threshold value set in advance, An instruction is given to the ventilation device in a room in which an indoor unit in the first low capacity operation, the second low capacity operation, or the thermo-off suppression operation is installed to increase the rotation speed of the ventilation fan. An air conditioning system according to any one of claims 10 to 14. (Appendix 16) a ventilation device provided in each room, the ventilation device having a ventilation fan, taking in outdoor air into the room and discharging the indoor air to the outside; The air conditioning device includes: An indoor humidity detection device that detects indoor humidity; An outdoor air humidity detection device that detects outdoor air humidity, The communication device includes: Among the plurality of indoor units, if there is an indoor unit in low-capacity cooling and dehumidification operation, When the difference between the outdoor air humidity and the indoor humidity is smaller than the indoor humidity with respect to the preset humidity of the room in which the indoor unit is installed, and the difference between the outdoor air humidity and the indoor humidity is equal to or less than a preset sixth threshold value, Instruct the ventilation device in the room in which the indoor unit performing the low-capacity cooling and dehumidification operation is installed to increase the rotation speed of the ventilation fan. An air conditioning system according to any one of claims 10 to 15. [Explanation of symbols]

[0099] REFRIGERATION SYSTEM, 10 OUTDOOR UNIT, 11 COMPRESSOR, 12 FLOW CHANGER, 13 OUTDOOR HEAT EXCHANGER, 14 OUTDOOR AIR SUPPLY FAN, 15 THROTTLE DEVICE, 16 ACCUMULATOR, 20 INDOOR UNIT, 20a-20c INDOOR UNIT, 21 INDOOR HEAT EXCHANGER, 21a-21c INDOOR HEAT EXCHANGER, 22 INDOOR AIR SUPPLY FAN, 22a-22c INDOOR AIR SUPPLY FAN, 23 VENTILATION VAN, 23a-23c VENTILATION VAN, 28 INDOORS' HUMIDITY DETECTOR, 31 DISCHARGE TEMPERATURE DETECTOR, 32 SUPPLY TEMPERATURE DETECTOR, 33 OUTDOOR FIRST TEMPERATURE DETECTOR, 34 OUTDOOR SECOND TEMPERATURE DETECTOR, 35 OUTDOOR HUMIDITY DETECTOR, 36 INDOORS' FIRST TEMPERATURE DETECTOR, 37 INDOORS' SECOND TEMPERATURE DETECTOR, 37a-37c INDOORS' SECOND TEMPERATURE DETECTOR, 38a-38c Indoor humidity detection device, 39 occupancy detection device, 39a to 39c occupancy detection devices, 50 control device, 100 air conditioning device, 200 ventilation device, 210 air supply device, 210A air supply device, 211 air supply port, 212 air supply fan, 220 exhaust device, 221 exhaust port, 222 exhaust fan, 230 ventilation side control device, 300 communication device, N network, R room.

Claims

1. an outdoor unit having a compressor, a flow switching device, an outdoor heat exchanger, a throttling device, and an accumulator and disposed outside the room; A plurality of indoor units each having an indoor heat exchanger and installed in each room; a refrigerant circuit in which the compressor, the flow switching device, the outdoor heat exchanger, the throttling device, the plurality of indoor heat exchangers, and the accumulator are connected by piping, and in which a refrigerant circulates; A control device for controlling the refrigerant circuit; a suction temperature detection device that detects a suction temperature of the compressor; A discharge temperature detection device that detects a discharge temperature of the compressor; An evaporation temperature detection device that detects an evaporation temperature; An indoor temperature detection device is provided in each room and detects an indoor temperature, The control device includes: When there is an indoor unit in normal operation among the plurality of indoor units, When the difference between the operating frequency of the compressor and a lower limit frequency that is a lower limit thereof is equal to or less than a first threshold value set in advance, and the difference between the preset temperature of the room in which the indoor unit is installed during the normal operation and the indoor temperature is equal to or less than a second threshold value set in advance, A first low capacity operation is performed in which the opening degree of the throttling device is increased so that the difference between the discharge temperature and the suction temperature becomes a preset target suction temperature difference, or the opening degree of the throttling device is increased so that the evaporation temperature becomes a preset target evaporation temperature. Air conditioning equipment.

2. an outdoor blower fan for supplying air to the outdoor heat exchanger; An outside air temperature detection device that detects an outside air temperature, The control device includes: When there is an indoor unit in a first low capacity operation among the plurality of indoor units, During cooling operation, when the difference between the set temperature of the room in which the indoor unit is installed during the first low capacity operation and the outdoor air temperature is equal to or greater than a preset third threshold value, During heating operation, if the difference between the set temperature of the room in which the indoor unit is installed and the outdoor air temperature during the first low capacity operation is equal to or less than a fourth threshold value set in advance, A second low-capacity operation is performed to reduce the rotation speed of the outdoor blower fan. The air conditioning apparatus according to claim 1.

3. A presence detection device is provided in each room to detect whether or not someone is present; a wind direction plate provided at each of the air outlets of the plurality of indoor units to change the direction of air blown out from the air outlet, The control device includes: When the indoor temperature of a first indoor unit that is an indoor unit performing the first low capacity operation or the second low capacity operation among the plurality of indoor units is equal to or lower than a preset fifth threshold value, If there is a second indoor unit other than the first indoor unit, which is an indoor unit for which an operation instruction has not been issued and which is installed in a room where no one is present, The second indoor unit is operated, and a thermo-off suppression operation is performed to control the air direction plate so that the amount of air blown out from the air outlet of the first indoor unit is reduced. The air conditioning apparatus according to claim 2.

4. The plurality of indoor units include An indoor blower fan that supplies air to the indoor heat exchanger, The control device includes: When there is an indoor unit in a thermo-off suppression operation among the plurality of indoor units, During cooling operation, the set temperature of the second indoor unit is set lower than the set temperature of the first indoor unit, and during heating operation, the set temperature of the second indoor unit is set higher than the set temperature of the first indoor unit, The rotation speed of the indoor blower fan of the second indoor unit is set to be greater than the rotation speed of the indoor blower fan of the first indoor unit. The air conditioning apparatus according to claim 3.

5. The control device includes: information regarding the heat exchange area of ​​the indoor heat exchanger of each of the plurality of indoor units; When there is an indoor unit in a thermo-off suppression operation among the plurality of indoor units, When there are multiple second indoor units, When there is no need for dehumidification, among the plurality of second indoor units, the one having a larger heat exchange area is operated preferentially, When there is a demand for dehumidification, the second indoor unit having a smaller heat exchange area is operated preferentially among the plurality of second indoor units.

5. The air conditioning apparatus according to claim 3 or 4.

6. The control device includes: information regarding the heat exchange area of ​​the indoor heat exchanger of each of the plurality of indoor units; When there is an indoor unit in a thermo-off suppression operation among the plurality of indoor units, When there are multiple second indoor units and the heat exchange areas are the same, Among the plurality of second indoor units, the one having a higher indoor temperature is operated preferentially during cooling operation, and the one having a lower indoor temperature is operated preferentially during heating operation.

5. The air conditioning apparatus according to claim 3 or 4.

7. The control device includes: When the first indoor unit is present among the plurality of indoor units and dehumidification is required, A low-capacity cooling and dehumidifying operation is performed by controlling the air direction plate so as to reduce the amount of air blown out from the air outlet of the first indoor unit, setting the target evaporation temperature to a value equal to or lower than a dew point temperature in the room, and controlling the throttling device so that the evaporation temperature becomes the target evaporation temperature.

5. The air conditioning apparatus according to claim 3 or 4.

8. an outdoor unit having a compressor, a flow switching device, an outdoor heat exchanger, a throttling device, and an accumulator and disposed outside the room; A plurality of indoor units each having an indoor heat exchanger and provided in each room; a refrigerant circuit in which the compressor, the flow switching device, the outdoor heat exchanger, the throttling device, the plurality of indoor heat exchangers, and the accumulator are connected by piping, and in which a refrigerant circulates; A control device for controlling the refrigerant circuit; a suction temperature detection device that detects a suction temperature of the compressor; A discharge temperature detection device that detects a discharge temperature of the compressor; An evaporation temperature detection device that detects an evaporation temperature; An air conditioning apparatus having an indoor temperature detection device provided in each room and detecting an indoor temperature; A communication device capable of communicating with the air conditioning device, The communication device includes: When there is an indoor unit in normal operation among the plurality of indoor units, When a difference between the operating frequency of the compressor and a lower limit frequency, which is a lower limit value thereof, is equal to or less than a first threshold value set in advance, and a difference between a preset set temperature and the indoor temperature is equal to or less than a second threshold value set in advance, The air conditioner is instructed to execute a first low capacity operation in which the opening degree of the throttling device is increased so that the difference between the discharge temperature and the suction temperature becomes a preset target suction temperature difference, or the opening degree of the throttling device is increased so that the evaporation temperature becomes a preset target evaporation temperature. Air conditioning system.

9. The air conditioning device includes: an outdoor blower fan for supplying air to the outdoor heat exchanger; An outside air temperature detection device that detects an outside air temperature, The communication device includes: When there is an indoor unit in a first low capacity operation among the plurality of indoor units, During cooling operation, if the difference between the set temperature of the room in which the indoor unit is installed during the first low capacity operation and the outdoor air temperature is equal to or greater than a preset third threshold value, During heating operation, if the difference between the set temperature of the room in which the indoor unit is installed during the first low capacity operation and the outdoor air temperature is equal to or less than a fourth threshold value set in advance, Instructing the air conditioner to execute a second low-capacity operation in which the rotation speed of the outdoor blower fan is reduced.

9. The air conditioning system according to claim 8.

10. The air conditioning device includes: A presence detection device is provided in each room to detect whether or not someone is present; a wind direction plate provided at each of the air outlets of the indoor units to change the direction of air blown out from the air outlets, The communication device includes: When the indoor temperature of a first indoor unit that is an indoor unit performing the first low capacity operation or the second low capacity operation among the plurality of indoor units is equal to or lower than a preset fifth threshold value, If there is a second indoor unit other than the first indoor unit, which is an indoor unit for which an operation instruction has not been issued and which is installed in a room where no one is present, The second indoor unit is operated, and a thermo-off suppression operation is performed to control the air direction plate so as to reduce the amount of air blown out from the air outlet of the first indoor unit.

10. The air conditioning system according to claim 9.

11. The plurality of indoor units include An indoor blower fan that supplies air to the indoor heat exchanger, The communication device includes: When there is an indoor unit in a thermo-off suppression operation among the plurality of indoor units, During cooling operation, the set temperature of the second indoor unit is set lower than the set temperature of the first indoor unit, and during heating operation, the set temperature of the second indoor unit is set higher than the set temperature of the first indoor unit, Instructing the air conditioner to set the rotation speed of the indoor blower fan of the second indoor unit higher than the rotation speed of the indoor blower fan of the first indoor unit. The air conditioning system according to claim 10.

12. The control device includes: information regarding the heat exchange area of ​​the indoor heat exchanger of each of the plurality of indoor units; The communication device includes: When there is an indoor unit in a thermo-off suppression operation among the plurality of indoor units, When there are multiple second indoor units, When there is no need for dehumidification, among the plurality of second indoor units, the one having a larger heat exchange area is operated preferentially, When there is a demand for dehumidification, the air conditioner is instructed to operate the second indoor unit having a smaller heat exchange area with priority among the plurality of second indoor units.

12. An air conditioning system according to claim 10 or 11.

13. The control device includes: information regarding the heat exchange area of ​​the indoor heat exchanger of each of the plurality of indoor units; The communication device includes: When there is an indoor unit in a thermo-off suppression operation among the plurality of indoor units, When there are multiple second indoor units and the heat exchange areas are the same, Instructing the air conditioner to operate the second indoor units having a higher indoor temperature with priority during cooling operation and to operate the second indoor units having a lower indoor temperature with priority during heating operation.

12. An air conditioning system according to claim 10 or 11.

14. The communication device includes: When the first indoor unit is present among the plurality of indoor units and dehumidification is required, Instruct the air conditioner to perform a low-capacity cooling and dehumidifying operation in which the air direction plate is controlled so as to reduce the amount of air blown out from the air outlet of the first indoor unit, the target evaporation temperature is set to a value equal to or lower than the indoor dew point temperature, and the throttling device is controlled so that the evaporation temperature becomes the target evaporation temperature.

12. An air conditioning system according to claim 10 or 11.

15. a ventilation device provided in each room, the ventilation device having a ventilation fan, taking in outdoor air into the room and discharging the indoor air to the outside; The communication device includes: When there is an indoor unit in the first low capacity operation, the second low capacity operation, or the thermo-off suppression operation among the plurality of indoor units, and when the difference between the outdoor air temperature and the indoor temperature is greater than the indoor temperature with respect to the set temperature of the room in which the indoor unit is installed, and when the difference between the outdoor air temperature and the indoor temperature is equal to or greater than a fifth threshold value set in advance, An instruction is given to the ventilation device in a room in which an indoor unit in the first low capacity operation, the second low capacity operation, or the thermo-off suppression operation is installed to increase the rotation speed of the ventilation fan.

12. An air conditioning system according to claim 10 or 11.

16. a ventilation device provided in each room, the ventilation device having a ventilation fan, taking in outdoor air into the room and discharging the indoor air to the outside; The air conditioning device includes: An indoor humidity detection device that detects indoor humidity; An outdoor air humidity detection device that detects outdoor air humidity, The communication device includes: Among the plurality of indoor units, if there is an indoor unit in low-capacity cooling and dehumidification operation, When the difference between the outdoor air humidity and the indoor humidity is smaller than the indoor humidity with respect to the preset humidity of the room in which the indoor unit is installed, and the difference between the outdoor air humidity and the indoor humidity is equal to or less than a preset sixth threshold value, Instructing the ventilation device in the room in which the indoor unit performing the low-capacity cooling and dehumidification operation is installed to increase the rotation speed of the ventilation fan.

12. An air conditioning system according to claim 10 or 11.

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