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; an indoor unit; a control device that controls a refrigerant circuit; a suction temperature sensor for sensing a suction temperature of a compressor; a discharge temperature sensor for sensing a discharge temperature of the compressor; an evaporation temperature sensor for sensing an evaporation temperature; and an indoor temperature sensor for sensing an indoor temperature. In a normal operation, when 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. 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 the difference between the discharge temperature and the 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] Conventionally, there have been air conditioners that fully satisfy the basic performance requirements of air conditioners, namely cooling and heating, while being quiet and capable of freely controlling the indoor temperature and humidity under a wider range of load conditions (including cases where higher cooling capacity is required) to improve the comfort of the room where the user is located (see, for example, Patent Document 1).

[0003] In Patent Document 1, the outdoor air temperature is determined based on the detection signals from the evaporating temperature sensor and the condensing temperature sensor. If the outdoor air temperature is determined to be low, the on-off valve is prohibited from being closed in order to prevent frost from forming in the indoor unit. Even when the on-off valve is open, the operating frequency of the compressor is reduced and the rotation speed of the outdoor blower is also reduced, thereby achieving low capacity by performing an operation that reduces the condensing capacity. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-090977 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 conditioning apparatus according to the present disclosure includes an outdoor unit having a compressor, a flow path switching device, and an outdoor heat exchanger and installed outdoors, an indoor unit having an indoor heat exchanger and installed indoors, a refrigerant circuit to which the compressor, the flow path switching device, the outdoor heat exchanger, the throttling device, and the indoor heat exchanger are connected by piping and through which a refrigerant circulates, a control device for controlling the refrigerant circuit, an suction temperature detection device for detecting an suction temperature of the compressor, a discharge temperature detection device for detecting a discharge temperature of the compressor, and an indoor temperature detection device for detecting an indoor temperature, and during normal operation, when a difference between the operating frequency of the compressor and a lower limit frequency which is its lower limit value is equal to or less than a predetermined first threshold value and a difference between a predetermined set temperature and the indoor temperature is equal to or less than a predetermined second threshold value, the control device performs 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.

[0008] Furthermore, an air conditioning system according to the present disclosure includes an air conditioning device having an outdoor unit having a compressor, a flow path switching device, and an outdoor heat exchanger and provided outdoors, an indoor unit having an indoor heat exchanger and provided indoors, a refrigerant circuit in which the compressor, the flow path switching device, the outdoor heat exchanger, a throttling device, and the indoor heat exchanger 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 detects an indoor temperature, and the air conditioning device and a communication device capable of communicating with the air conditioning apparatus, wherein when the difference between the operating frequency of the compressor and a lower limit frequency which is its lower limit value 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 during normal operation of the air conditioning apparatus, 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 cooling 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 a control flow during low capacity operation of the air conditioning system according to the first embodiment. [Figure 12] 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

[0013] 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.

[0014] 2 is a schematic configuration diagram of an air conditioner 100 of the 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 an indoor unit 20 installed inside the room (air-conditioned space). The outdoor unit 10 includes a compressor 11, a flow path switching device 12, an outdoor heat exchanger 13, an outdoor blower fan 14, and an expansion device 15. The indoor unit 20 includes an indoor heat exchanger 21, an indoor blower fan 22, and an air direction plate 23. The expansion device 15 may be provided in the indoor unit 20 instead of the outdoor unit 10.

[0015] The air conditioner 100 includes a refrigerant circuit 1 in which a refrigerant circulates, with a compressor 11, a flow switching device 12, an outdoor heat exchanger 13, a throttling device 15, and an indoor heat exchanger 21 being connected in sequence by refrigerant piping.

[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 fdr.

[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 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.

[0022] The indoor blower fan 22 is provided near the indoor heat exchanger 21 and supplies indoor air to the indoor heat exchanger 21. The amount of air blown by the indoor blower fan 22 is adjusted, for example, by controlling the rotation speed.

[0023] 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.

[0024] 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, for example, the communication device 300. 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 operation, and the low-capacity cooling and dehumidification 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 general term for the normal cooling operation and the normal heating operation is normal operation, the general term for the first low-capacity cooling operation and the first low-capacity heating operation is first low-capacity operation, and the general term for the second low-capacity cooling operation and the second low-capacity heating operation is second low-capacity operation.

[0025] The control device 50 controls the operating frequency fdr 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 functional unit 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.

[0026] 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, a second indoor temperature detector 37, and an indoor humidity detector 38.

[0027] 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 detector 36 is attached to the outer periphery of the piping near the middle position of the entire piping length in the indoor heat exchanger 21, for example, and detects the condensation temperature Tcd during heating operation and the evaporation temperature Tev during cooling operation. The indoor second temperature detector 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 installed (i.e., the indoor space). The indoor humidity detector 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 installed. In the following, the indoor second temperature detector 37 is also referred to as the indoor temperature detector, the outdoor first temperature detector 33 and the indoor first temperature detector 36 are also referred to as the evaporation temperature detector, the outdoor second temperature detector 34 is also referred to as the outdoor air temperature detector, the indoor humidity detector 38 is also referred to as the indoor humidity detector, and the outdoor humidity detector 35 is also referred to as the outdoor humidity detector.

[0028] Next, the flow of refrigerant in the air conditioner 100 during cooling operation and heating operation will be described.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] (Step S11) The communication device 300 judges whether the air conditioner 100 is in normal cooling operation based on the operation information from the air conditioner 100. When the communication device 300 judges that the air conditioner 100 is in normal cooling operation (YES), the process proceeds to step S12. On the other hand, when the communication device 300 judges that the air conditioner 100 is not in normal cooling operation (NO), the process ends. Note that, in normal cooling operation, the control device 50 operates the compressor 11 at an operation frequency fdr calculated based on the difference between the room temperature Trm detected by the indoor side second temperature detection device 37 and the room set temperature Tst previously set by a user or the like, 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 indoor side first temperature detection device 36 is 0 or more, that is, so that the refrigerant suctioned into the compressor 11 becomes a gas refrigerant.

[0037] (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 and the lower limit frequency flw of the compressor 11 is equal to or less than a preset first threshold value Th1 (e.g., 5 Hz) (i.e., low capacity operation), and the difference between the room temperature Trm detected by the indoor side second temperature detection device 37 and the set temperature Tst is equal to or less than a preset second threshold value Th2 (e.g., 0.5°C). 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.

[0038] (Step S13) The communication device 300 instructs the air conditioner 100 to perform the first low-capacity cooling operation, and the control device 50 performs 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 throttling device 15 during cooling operation, the enthalpy at the evaporator inlet during cooling operation increases as shown in Fig. 6, and the amount of heat exchange decreases, realizing low-capacity operation and making it possible to reduce the air conditioning capacity without changing the operating frequency fdr of the compressor 11. As a result, it is possible to avoid intermittent operation even in cases where the air conditioning capacity exceeds the load during low-capacity operation.

[0039] (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 and the outside air temperature Tot detected by the outdoor 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.

[0040] (Step S15) The communication device 300 instructs the air conditioner 100 to perform the second low-capacity cooling operation, and the control device 50 performs 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 the time of low outdoor air temperature, the condensation temperature Tcd increases as shown in FIG. 7, the enthalpy at the evaporator inlet during cooling operation increases, 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 fdr 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.

[0041] 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.

[0042] Fig. 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 Figs. 8, 6, and 7.

[0043] (Step S21) The communication device 300 determines whether the air conditioning device 100 is in normal heating operation based on the operation information from the air conditioning device 100. When the communication device 300 determines that the air conditioning device 100 is in normal heating operation (YES), the process proceeds to step S22. On the other hand, when the communication device 300 determines that the air conditioning device 100 is not in normal heating operation (NO), the process ends. Note that, in normal heating operation, the control device 50 determines the operation frequency fd of the compressor 11 from the difference between the indoor temperature Trm detected by the indoor-side second temperature detection device 37 and the set temperature Tst, 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 suctioned into the compressor 11 becomes a gas refrigerant.

[0044] (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 its 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 and the set temperature Tst 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.

[0045] (Step S23) The communication device 300 instructs the air conditioner 100 to perform the first low-capacity heating operation, and the control device 50 performs 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 Tte such that the opening degree of the throttling device 15 becomes large. In this way, by increasing the opening of the throttling device 15 during heating operation, as shown in Fig. 6, the enthalpy at the condenser inlet during heating operation decreases, reducing the amount of heat exchange, thereby realizing low-capacity operation and making it possible to reduce the air conditioning capacity without changing the operating frequency fdr of the compressor 11. As a result, even if the air conditioning capacity exceeds the load during low-capacity operation, it is possible to avoid intermittent operation.

[0046] (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 and the outside air temperature Tot detected by the outdoor 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 4 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.

[0047] (Step S25) The communication device 300 instructs the air conditioner 100 to perform the second low-capacity heating operation, and the control device 50 performs the second low-capacity heating operation. After that, the process ends. In the second low-capacity heating 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 when the outdoor air temperature is high, as shown in FIG. 7, the evaporation temperature Tev decreases, the intake refrigerant density during heating operation decreases, 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 fdr 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.

[0048] 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.

[0049] Fig. 9 is a diagram showing a control flow during low-capacity cooling 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 cooling operation of the air conditioning system will be described with reference to Figs. 9 and 10.

[0050] (Step S31) The communication device 300 determines whether the air conditioning device 100 is in first low capacity cooling operation or second low capacity cooling operation based on the operation information from the air conditioning device 100. If the communication device 300 determines that the air conditioning device 100 is in first low capacity cooling operation or second low capacity cooling operation (YES), the processing proceeds to step S32. On the other hand, if the communication device 300 determines that the air conditioning device 100 is not in first low capacity cooling operation or second low capacity cooling operation (NO), the processing ends.

[0051] (Step S32) The communication device 300 determines whether or not condition 5 is met based on the operation information from the air conditioning device 100. Here, condition 5 is that there is a request for defrosting, such as when the indoor humidity setting Hst is set by a user or the like. If the communication device 300 determines that condition 5 is met (YES), the process proceeds to step S33. On the other hand, if the communication device 300 determines that condition 5 is not met (NO), the process ends.

[0052] (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 performs the 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 as to reduce the amount of air blown out from the air outlet of the indoor unit 20, and controls the throttling device 15 so as to set the target evaporation temperature Tte to a value equal to or lower than the indoor dew point temperature Tdp and to make the evaporation temperature Tev detected by the indoor side first temperature detection device 36 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.

[0053] 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.

[0054] 11 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.

[0055] (Step S41) The communication device 300 determines whether the air conditioning device 100 is in first low-capacity cooling operation, second low-capacity cooling operation, first low-capacity heating operation, or second low-capacity heating operation based on the operation information from the air conditioning device 100. If the communication device 300 determines that the air conditioning device 100 is in first low-capacity cooling operation, second low-capacity cooling operation, first low-capacity heating operation, or second low-capacity heating operation (YES), the process proceeds to step S42. On the other hand, if the communication device 300 determines that the air conditioning device 100 is not in first low-capacity cooling operation, second low-capacity cooling operation, first low-capacity heating operation, or second low-capacity heating operation (NO), the process ends.

[0056] (Step S42) The communication device 300 judges whether or not condition 6 is satisfied based on the operation information from the air conditioning device 100. Here, condition 6 is that the difference between the outdoor air temperature Tot detected by the outdoor side second temperature detection device 34 and the room temperature Trm detected by the indoor side second temperature detection device 37 is greater than the preset temperature Tst, and the difference between the outdoor air temperature Tot detected by the outdoor side second temperature detection device 34 and the room temperature Trm detected by the indoor side second temperature detection device 37 is equal to or greater than a fifth threshold value Th5 (for example, 5°C) that is set in advance. If the communication device 300 judges that condition 6 is satisfied (YES), the process proceeds to step S43. On the other hand, if the communication device 300 judges that condition 6 is not satisfied (NO), the process ends.

[0057] (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. 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.

[0058] 12 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.

[0059] (Step S51) The communication device 300 determines whether the air conditioning device 100 is in low-capacity cooling and dehumidification operation based on the operation information from the air conditioning device 100. If the communication device 300 determines that the air conditioning device 100 is in low-capacity cooling and dehumidification operation (YES), the process proceeds to step S52. On the other hand, if the communication device 300 determines that the air conditioning device 100 is not in low-capacity cooling and dehumidification operation (NO), the process ends.

[0060] (Step S52) 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 is smaller than the preset set temperature Tst, and the difference between the outdoor air humidity Hot detected by the outdoor side humidity detection device 35 and the indoor humidity Hrm detected by the indoor side humidity detection device 28 is equal to or smaller than a sixth threshold value Th6 that is set in advance. If the communication device 300 judges that condition 7 is satisfied (YES), the process proceeds to step S53. On the other hand, if the communication device 300 judges that condition 7 is not satisfied (NO), the process ends.

[0061] (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. 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.

[0062] 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, and an outdoor heat exchanger 13 and installed outdoors, an indoor unit 20 having an indoor heat exchanger 21 and installed indoors, a refrigerant circuit 1 in which the compressor 11, the flow path switching device 12, the outdoor heat exchanger 13, the throttling device 15, and the indoor heat exchanger 21 are connected by piping and in which the 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 an indoor temperature and an indoor temperature detection device for detecting the indoor temperature Trm, and during normal operation, when the difference between the operating frequency fdr of the compressor 11 and its lower limit frequency flw, which is its lower limit value, 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.

[0063] The air conditioning system according to the first embodiment includes an outdoor unit 10 having a compressor 11, a flow path switching device 12, and an outdoor heat exchanger 13 and installed outdoors, an indoor unit 20 having an indoor heat exchanger 21 and installed indoors, a refrigerant circuit 1 in which the compressor 11, the flow path switching device 12, the outdoor heat exchanger 13, the throttling device 15, and the indoor heat exchanger 21 are connected by piping and in which the refrigerant circulates, a control device 50 that controls the refrigerant circuit 1, an air conditioner 100 having an intake temperature detection device 32 that detects an intake 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 an indoor temperature detection device that detects an indoor temperature Trm, and and a communication device 300 capable of communicating with the air conditioning apparatus 100. When the difference between the operating frequency fdr 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 during normal operation of the air conditioning apparatus 100, the communication device 300 instructs the air conditioning apparatus 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.

[0064] 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.

[0065] 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 in which the rotation speed of the outdoor blower fan 14 is reduced when, during first low-capacity operation, the difference between the set temperature Tst and the outdoor air temperature Tot is equal to or greater than a predetermined third threshold value during cooling operation, or when, during heating operation, the difference between the set temperature Tst and the outdoor air temperature Tot is equal to or less than a predetermined fourth threshold value.

[0066] 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 the difference between the set temperature Tst and the outdoor air temperature Tot is equal to or greater than a predetermined third threshold value during cooling operation, or when the difference between the set temperature Tst and the outdoor air temperature Tot is equal to or less than a predetermined fourth threshold value during heating operation, when the air conditioning apparatus 100 is in first low-capacity operation.

[0067] 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.

[0068] Furthermore, the air conditioning apparatus 100 according to embodiment 1 has an air deflector 23 that changes the direction of air blown out from the air outlet of the indoor unit 20, and when cooling operation and first low capacity operation or second low capacity operation are in progress and there is a demand for dehumidification, the control device 50 controls the air deflector 23 so as to reduce the amount of air blown out from the air outlet of the indoor unit 20, and also performs a low-capacity cooling and dehumidification operation in which the target evaporation temperature Tte is set to a value below the indoor dew point temperature and the throttling device 15 is controlled so that the evaporation temperature Tev becomes the target evaporation temperature Tte.

[0069] Furthermore, in the air conditioning system according to embodiment 1, the air conditioning apparatus 100 has an air deflector 23 that changes the direction of air blown out from the air outlet of the indoor unit 20, and when the air conditioning apparatus 100 is in cooling operation and in first low capacity operation or second low capacity operation and there is a request for dehumidification, the communication device 300 controls the air deflector 23 so as to reduce the amount of air blown out from the air outlet of the indoor unit 20, and instructs the air conditioning apparatus 100 to perform low-capacity cooling and dehumidification operation in which the target evaporation temperature Tte is set to a value below the indoor dew point temperature and the throttling device 15 is controlled so that the evaporation temperature Tev becomes the target evaporation temperature Tte.

[0070] 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.

[0071] Moreover, the air conditioning system according to embodiment 1 includes a ventilation device 200 having a ventilation fan that takes in outdoor air into the room and exhausts indoor air to the outside, and when the air conditioning device 100 is operating at a first low capacity or a second low capacity, if the difference between the outdoor air temperature Tot and the set temperature Tst is greater than the indoor temperature Trm and the difference between the outdoor air temperature Tot and the indoor temperature Trm is equal to or greater than a predetermined fifth threshold, the communication device 300 instructs the ventilation device 200 to increase the rotation speed of the ventilation fan.

[0072] 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.

[0073] Moreover, the air conditioning system according to embodiment 1 includes a ventilation device 200 having a ventilation fan that 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 the communication device 300 instructs the ventilation device 200 to increase the rotation speed of the ventilation fan when the difference between the outdoor humidity Hot and the predetermined set humidity Hst is smaller than that of the indoor humidity Hrm and the difference between the outdoor humidity Hot and the indoor humidity Hrm is equal to or less than a predetermined sixth threshold value when the air conditioning device 100 is in low-capacity cooling and dehumidification operation.

[0074] 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.

[0075] Various aspects of the present disclosure are described below.

[0076] (Appendix 1) an outdoor unit having a compressor, a flow path switching device, and an outdoor heat exchanger and provided outside the room; an indoor unit having an indoor heat exchanger and installed in the room; a refrigerant circuit in which the compressor, the flow switching device, the outdoor heat exchanger, the throttling device, and the indoor heat exchanger 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 that detects an indoor temperature, The control device includes: During normal operation, 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, 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: During the first low capacity operation, During cooling operation, when the difference between the set temperature and the outside air temperature is equal to or greater than a preset third threshold value, During heating operation, if the difference between the set temperature and the outside air temperature 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 wind direction plate is provided to change the direction of the wind blown out from the air outlet of the indoor unit, The control device includes: During cooling operation and the first low capacity operation or the second low capacity operation, If you need dehumidification, 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 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. 3. An air conditioning apparatus according to claim 1 or 2. (Appendix 4) an outdoor unit having a compressor, a flow path switching device, and an outdoor heat exchanger and provided outside the room; an indoor unit having an indoor heat exchanger and installed in the room; a refrigerant circuit in which the compressor, the flow switching device, the outdoor heat exchanger, the throttling device, and the indoor heat exchanger 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 that detects an indoor temperature; A communication device capable of communicating with the air conditioning device, The communication device includes: When the air conditioning apparatus is in normal operation, 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 5) 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 the air conditioning apparatus is in the first low capacity operation, During cooling operation, when the difference between the set temperature and the outside air temperature is equal to or greater than a preset third threshold value, During heating operation, if the difference between the set temperature and the outside 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. 5. An air conditioning system as described in claim 4. (Appendix 6) The air conditioning device includes: A wind direction plate is provided to change the direction of the wind blown out from the air outlet of the indoor unit, The communication device includes: When the air conditioning apparatus is in cooling operation and in the first low capacity operation or the second low capacity operation, If you need dehumidification, 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 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. 6. An air conditioning system according to claim 4 or 5. (Appendix 7) A 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 the air conditioning apparatus is in the first low capacity operation or the second low capacity operation, When the difference between the outdoor temperature and the indoor temperature is larger than the set temperature, and the difference between the outdoor temperature and the indoor temperature is equal to or greater than a fifth threshold value set in advance, Instruct the ventilation device to increase the rotation speed of the ventilation fan. An air conditioning system according to any one of claims 4 to 6. (Appendix 8) A 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 is An indoor humidity detection device that detects indoor humidity; An outdoor air humidity detection device that detects outdoor air humidity, The communication device includes: When the air conditioning apparatus is in the low-capacity cooling and dehumidification operation, When the difference between the outdoor air humidity and the indoor humidity is smaller than the predetermined set humidity and the difference between the outdoor air humidity and the indoor humidity is equal to or smaller than a sixth threshold value set in advance, Instruct the ventilation device to increase the rotation speed of the ventilation fan. 10. An air conditioning system according to claim 6 or claim 7 which is dependent on claim 6. [Explanation of symbols]

[0077] REFRIGERATION DEVICE, 10 OUTDOOR UNIT, 11 COMPRESSOR, 12 FLOW CHANGER, 13 OUTDOOR HEAT EXCHANGER, 14 OUTDOOR AIR SUPPLY FAN, 15 THROTTLE DEVICE, 20 INDOOR UNIT, 21 INDOOR HEAT EXCHANGER, 22 INDOOR AIR SUPPLY FAN, 23 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, 38 INDOORS' HUMIDITY DETECTOR, 50 CONTROL DEVICE, 100 AIR CONDITIONING APPARATUS, 200 VENTILATION APPARATUS, 210 SUPPLY APPARATUS, 210A SUPPLY APPARATUS, 211 SUPPLY OPEN, 212 SUPPLY FAN, 220 EXTRACTOR APPARATUS, 221 OUTLET OPEN, 222 EXTRACTOR FAN, 230 Ventilation side control device, 300 communication device, N network, R room.

Claims

1. an outdoor unit having a compressor, a flow path switching device, and an outdoor heat exchanger and provided outside the room; an indoor unit having an indoor heat exchanger and installed in the room; a refrigerant circuit in which the compressor, the flow switching device, the outdoor heat exchanger, the throttling device, and the indoor heat exchanger 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 that detects an indoor temperature, The control device includes: During normal operation, 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, 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: During the first low capacity operation, During cooling operation, when the difference between the set temperature and the outside air temperature is equal to or greater than a preset third threshold value, During heating operation, if the difference between the set temperature and the outside air temperature 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 wind direction plate is provided to change the direction of the wind blown out from the air outlet of the indoor unit, The control device includes: During cooling operation and the first low capacity operation or the second low capacity operation, If you need dehumidification, 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 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.

3. An air conditioning apparatus according to claim 1 or 2.

4. an outdoor unit having a compressor, a flow path switching device, and an outdoor heat exchanger and provided outside the room; an indoor unit having an indoor heat exchanger and installed in the room; a refrigerant circuit in which the compressor, the flow switching device, the outdoor heat exchanger, the throttling device, and the indoor heat exchanger 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 that detects an indoor temperature; A communication device capable of communicating with the air conditioning device, The communication device includes: When the air conditioning apparatus is in normal operation, 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.

5. 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 the air conditioning apparatus is in the first low capacity operation, During cooling operation, when the difference between the set temperature and the outside air temperature is equal to or greater than a preset third threshold value, During heating operation, if the difference between the set temperature and the outside 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.

5. The air conditioning system according to claim 4.

6. The air conditioning device includes: A wind direction plate is provided to change the direction of the wind blown out from the air outlet of the indoor unit, The communication device includes: When the air conditioning apparatus is in cooling operation and in the first low capacity operation or the second low capacity operation, If you need dehumidification, The air conditioner is instructed to execute 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 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.

6. An air conditioning system according to claim 4 or 5.

7. A 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 the air conditioning apparatus is in the first low capacity operation or the second low capacity operation, When the difference between the outdoor temperature and the set temperature is larger than the difference between the indoor temperature and the outdoor temperature and the difference between the indoor temperature and the set temperature is equal to or larger than a fifth threshold value set in advance, Instruct the ventilation device to increase the rotation speed of the ventilation fan.

6. The air conditioning system according to claim 5.

8. A 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: When the air conditioning apparatus is in the low-capacity cooling and dehumidification operation, When the difference between the outdoor air humidity and the indoor humidity is smaller than the predetermined set humidity and the difference between the outdoor air humidity and the indoor humidity is equal to or smaller than a sixth threshold value set in advance, Instruct the ventilation device to increase the rotation speed of the ventilation fan.

7. The air conditioning system according to claim 6.

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