Refrigeration cycle device and control method

Abstract

A refrigeration cycle device (1) comprises: a compressor (4); a condenser (7); an expansion valve (6); an evaporator (5); an indoor fan (3); a control device (2) that controls the rotation speed of the indoor fan (3) and the frequency of the compressor (4); an indoor temperature detection unit (11) that detects the indoor temperature; and an evaporation temperature detection unit (12) that detects the evaporation temperature of a refrigerant in the evaporator (5). The control device (2) comprises: an indoor temperature control unit (211) that calculates the rotation speed of the indoor fan (3) which causes the indoor temperature to approach a preset indoor temperature; and an evaporation temperature control unit (212) that calculates the frequency of the compressor (4) which causes the evaporation temperature to approach a preset refrigerant temperature. The indoor temperature is individually controlled by the indoor fan (3), and the evaporation temperature is individually controlled by the compressor (4).

Description

[Technical Field]

[0001] The present disclosure relates to a refrigeration cycle device and a control method. [Background technology]

[0002] BACKGROUND ART Generally, a refrigeration cycle device that configures a refrigerant circuit for circulating a refrigerant is known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-14724 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional technologies use a technique for switching between cooling operation to maintain a comfortable indoor temperature and dehumidification operation to maintain a comfortable indoor humidity, but it is difficult to maintain a comfortable indoor temperature and humidity with conventional technologies.

[0005] An object of the present disclosure is to independently control the indoor temperature and the indoor humidity to maintain a comfortable indoor temperature and indoor humidity. [Means for solving the problem]

[0006] A refrigeration cycle device according to one aspect of the present disclosure includes: a compressor that compresses a refrigerant; A condenser; An expansion valve; an evaporator; Indoor fan and a control device for controlling the rotation speed of the indoor fan and the frequency of the compressor; an indoor temperature detection unit that detects the indoor temperature; an evaporation temperature detection unit that detects the evaporation temperature of the refrigerant in the evaporator; Equipped with The control device an indoor temperature control unit having a controller that calculates the rotation speed of the indoor fan so that the temperature in the room approaches a preset indoor temperature; an evaporation temperature control unit having a controller that calculates the frequency of the compressor so that the evaporation temperature approaches a preset refrigerant temperature; and the temperature in the room of Individually controlled indoor fans death , The evaporation temperature of Individually controlled by the compressor death , The control device further includes a compressor decoupling control unit that calculates the frequency of the compressor so as to increase the frequency of the compressor when the rotation speed of the indoor fan increases, and to decrease the frequency of the compressor when the rotation speed of the indoor fan decreases. A refrigeration cycle device according to another aspect of the present disclosure includes: a compressor that compresses a refrigerant; A condenser; An expansion valve; an evaporator; Indoor fan and a control device for controlling the rotation speed of the indoor fan and the frequency of the compressor; an indoor temperature detection unit that detects the indoor temperature; an evaporation temperature detection unit that detects the evaporation temperature of the refrigerant in the evaporator; Equipped with The control device an indoor temperature control unit having a controller that calculates the rotation speed of the indoor fan so that the temperature in the room approaches a preset indoor temperature; an evaporation temperature control unit having a controller that calculates the frequency of the compressor so that the evaporation temperature approaches a preset refrigerant temperature; and the temperature in the room of Individually controlled indoor fans death , The evaporation temperature ofIndividually controlled by the compressor death , The control device further includes an indoor fan decoupling control unit that calculates the rotation speed of the indoor fan to reduce the rotation speed of the indoor fan when the frequency of the compressor increases, and to increase the rotation speed of the indoor fan when the frequency of the compressor decreases. A refrigeration cycle device according to another aspect of the present disclosure includes: a compressor that compresses a refrigerant; A condenser; An expansion valve; an evaporator; Indoor fan and a control device for controlling the rotation speed of the indoor fan and the frequency of the compressor; an indoor temperature detection unit that detects the indoor temperature; an evaporation temperature detection unit that detects the evaporation temperature of the refrigerant in the evaporator; Equipped with The control device an indoor temperature control unit having a controller that calculates the rotation speed of the indoor fan so that the temperature in the room approaches a preset indoor temperature; an evaporation temperature control unit having a controller that calculates the frequency of the compressor so that the evaporation temperature approaches a preset refrigerant temperature; and the temperature in the room of Individually controlled indoor fans death , The evaporation temperature of Individually controlled by the compressor death , The control device an evaporation temperature upper limit protection control unit having a controller that calculates the rotation speed of the indoor fan so that the evaporation temperature follows a predetermined evaporation temperature upper limit value; a primary indoor fan speed selection unit that selects the minimum value of the output value of the indoor temperature control unit and the output value of the evaporation temperature upper limit protection control unit; It further has: A refrigeration cycle device according to another aspect of the present disclosure includes: a compressor that compresses a refrigerant; A condenser; An expansion valve; an evaporator; Indoor fan and a control device for controlling the rotation speed of the indoor fan and the frequency of the compressor; an indoor temperature detection unit that detects the indoor temperature; an evaporation temperature detection unit that detects the evaporation temperature of the refrigerant in the evaporator; Equipped with The control device an indoor temperature control unit having a controller that calculates the rotation speed of the indoor fan so that the temperature in the room approaches a preset indoor temperature; an evaporation temperature control unit having a controller that calculates the frequency of the compressor so that the evaporation temperature approaches a preset refrigerant temperature; and the temperature in the room of Individually controlled indoor fans death , The evaporation temperature of Individually controlled by the compressor death , The control device a thermo-off control unit having a controller that calculates the frequency of the compressor so that the temperature in the room follows a predetermined thermo-off temperature; a compressor frequency selection unit that selects the minimum value of the output value of the evaporation temperature control unit and the output value of the thermo-off control unit; It further has: The control method of the present disclosure includes: A control method for a refrigeration cycle device having a compressor that compresses a refrigerant, a condenser, an expansion valve, an evaporator, an indoor fan, a control device that controls a rotation speed of the indoor fan and a frequency of the compressor, an indoor temperature detection unit that detects an indoor temperature, and an evaporation temperature detection unit that detects an evaporation temperature of the refrigerant in the evaporator, Calculating the rotation speed of the indoor fan that brings the temperature in the room closer to a preset indoor temperature; calculating the frequency of the compressor such that the evaporation temperature approaches a preset refrigerant temperature so as to maintain a target indoor humidity; 、 calculating a frequency of the compressor such that the frequency of the compressor is increased when the rotation speed of the indoor fan increases, and the frequency of the compressor is decreased when the rotation speed of the indoor fan decreases; Equipped with The temperature in the room is individually controlled by the indoor fan, and the evaporation temperature is individually controlled by the compressor; The indoor temperature and the indoor humidity are set separately. [Effects of the Invention]

[0007] According to the present disclosure, the indoor temperature and indoor humidity can be controlled separately, so that comfortable indoor temperature and indoor humidity can be maintained. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram schematically illustrating an example of the configuration of a refrigeration cycle device according to a first embodiment. [Figure 2] FIG. 2 is a block diagram schematically illustrating the configuration of a control device shown in FIG. [Figure 3] 2 is a functional block diagram showing functions of the control device shown in FIG. 1. FIG. [Figure 4] 4 is a flowchart illustrating an example of a control method for controlling an indoor temperature and an evaporation temperature in a refrigeration cycle device. [Figure 5] FIG. 10 is a functional block diagram showing another example of the control device. [Figure 6] FIG. 10 is a functional block diagram showing yet another example of the control device. [Figure 7] FIG. 10 is a functional block diagram showing yet another example of the control device. [Figure 8] 4 is a graph showing a comparison between the operation of a conventional refrigeration cycle device and the operation of the refrigeration cycle device according to the first embodiment. [Figure 9] FIG. 2 is a diagram showing an operating range of the refrigeration cycle device. [Figure 10] FIG. 10 is a block diagram showing yet another example of a control device. [Figure 11] 1 is a flowchart illustrating an example of a method for controlling a compressor frequency so that an evaporation temperature approaches an evaporation temperature target value. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a refrigeration cycle device 1 according to the present disclosure will be described with reference to the drawings. Note that components denoted by the same reference numerals in the drawings correspond to the same or corresponding components, and this applies throughout the entire specification.

[0010] Embodiment 1 FIG. 1 is a diagram schematically illustrating an example of the configuration of a refrigeration cycle device 1 according to the first embodiment. As shown in Fig. 1, the refrigeration cycle device 1 includes a control device 2, an indoor fan 3, a compressor 4 that compresses a refrigerant, an evaporator 5, an electronic expansion valve 6 as an expansion valve, a condenser 7, an indoor temperature detection unit 11, and an evaporation temperature detection unit 12. The compressor 4, the evaporator 5, the electronic expansion valve 6, and the condenser 7 are connected by piping 9 to form a refrigerant circuit 10. A refrigerant flows through the refrigerant circuit 10. In Fig. 1, solid arrows indicate the direction in which the refrigerant flows.

[0011] The refrigeration cycle apparatus 1 may further include a four-way valve, an accumulator (also called a "liquid reservoir"), an injection circuit, a receiver circuit, or a power receiver circuit. The four-way valve is provided in pipes connected to the suction port and discharge port of the compressor 4, respectively, and switches the flow of refrigerant gas. The accumulator is provided between the compressor 4 and the evaporator 5 and prevents refrigerant that has not been completely gasified by the evaporator from being drawn into the compressor. The injection circuit suppresses an increase in the discharge temperature of the compressor 4. The receiver circuit or power receiver circuit is provided between the condenser 7 and the evaporator 5, and excess refrigerant is stored in the receiver circuit or power receiver circuit. Below, an example in which the refrigeration cycle apparatus 1 is an air conditioner will be described, but the refrigeration cycle apparatus 1 is not limited to an air conditioner.

[0012] The indoor fan 3 draws indoor air into the refrigeration cycle device 1 (for example, the indoor unit of an air conditioner) and sends the cooled or warm air that has undergone heat exchange into the room. The indoor fan speed (i.e., the driving rotation speed) of the indoor fan 3 is controlled by a control circuit such as an inverter circuit. In this case, the control circuit can change the indoor fan speed of the indoor fan 3. As a result, the air volume of the indoor fan 3 changes. In other words, the amount of air sent out by the indoor fan 3 per unit time changes. The indoor fan speed resolution of the indoor fan 3 may be 100 rpm or less.

[0013] The compressor 4 compresses and discharges the refrigerant. The drive frequency of the compressor 4 may be changed by a control circuit such as an inverter circuit. In this case, the capacity of the compressor 4 changes. In other words, the amount of refrigerant delivered by the compressor 4 per unit time changes.

[0014] The evaporator 5 exchanges heat between the refrigerant and the air, evaporating and vaporizing the refrigerant and cooling the air.

[0015] The electronic expansion valve 6 is, for example, a variable opening expansion valve. The electronic expansion valve 6 controls the discharge temperature at the outlet of the compressor 4 and the suction superheat of the compressor 4, but does not control the evaporation temperature by setting a specific target value.

[0016] The condenser 7 exchanges heat between the refrigerant and the air, condensing and liquefying the refrigerant and heating the air.

[0017] As shown in FIG. 1, the refrigeration cycle device 1 includes, for example, an indoor temperature detection unit 11 and an evaporation temperature detection unit 12.

[0018] The indoor temperature detection unit 11 is disposed, for example, at the air intake port of the indoor unit of the air conditioner. The indoor temperature detection unit 11 detects the temperature of the room. Specifically, the indoor temperature detection unit 11 detects the temperature of the indoor air drawn into the indoor unit. The temperature of the indoor air drawn into the indoor unit is also referred to as the "indoor temperature."

[0019] The temperature detected by the indoor temperature detection unit 11 may be, for example, the ambient temperature of a remote controller for operating the air conditioner. In this case, for example, the air temperature detected by the remote controller is sent to the indoor temperature detection unit 11.

[0020] The temperature detected by the indoor temperature detection unit 11 may be, for example, the temperature of the air detected by a temperature sensor installed in the room. In this case, for example, the temperature of the air detected by the temperature sensor is sent to the indoor temperature detection unit 11.

[0021] The temperature detected by the indoor temperature detection unit 11 may be, for example, the temperature of the air detected by an infrared sensor provided in the indoor unit of the air conditioner. In this case, for example, thermal image information indicating the air temperature acquired by the infrared sensor is sent to the indoor temperature detection unit 11.

[0022] The evaporation temperature detection unit 12 is disposed, for example, in the pipe 9 on the outlet side of the evaporator 5. The evaporation temperature detection unit 12 detects the evaporation temperature of the refrigerant in the evaporator 5. The evaporation temperature detection unit 12 is composed of, for example, a thermocouple, a thermistor, or a pressure sensor. In the case of a thermocouple or a thermistor, the temperature of the two-phase portion (i.e., the portion where gas and liquid are mixed) in the heat exchanger of the indoor unit is detected. In the case of a pressure sensor, the pressure in the heat exchanger of the indoor unit is detected, and the pressure is converted to a saturation temperature and treated as the evaporation temperature. The evaporation temperature detection unit 12 may detect information equivalent to the evaporation temperature, such as low pressure, instead of the evaporation temperature.

[0023] FIG. 2 is a block diagram schematically showing the configuration of the control device 2 shown in FIG. As shown in FIG. 2, the various sensors described above are connected to the control device 2, and temperature data is input from the various sensors to the control device 2. Furthermore, commands and the like from the user of the refrigeration cycle apparatus 1 are input to the control device 2 via an operation unit (not shown). The control device 2 is provided in at least one of the indoor unit or outdoor unit of the air conditioner. That is, the control device 2 may be provided in both the indoor unit and the outdoor unit of the air conditioner, or in either the indoor unit or the outdoor unit. For example, if a component (e.g., a first control unit) that controls the rotation speed of the indoor fan 3 is provided in the indoor unit of the air conditioner, and a component (e.g., a second control unit) that controls the frequency of the compressor 4 is provided in the outdoor unit of the air conditioner, these components (the first control unit and the second control unit) are collectively defined as the "control device 2."

[0024] As shown in Fig. 2, the control device 2 has a control processing device 21, a storage device 23, and a timing device 22. The control processing device 21 performs processes such as calculations and judgments based on input temperature information, and controls the devices of the refrigeration cycle device 1, such as the indoor fan 3 and the compressor 4. The storage device 23 has a volatile storage device (not shown) such as a random access memory (RAM) that can temporarily store data, and a hard disk, a non-volatile auxiliary storage device (not shown) such as a flash memory that can store data for the long term. The timing device 22 is composed of, for example, a timer, and is used to measure time. The timing device 22 is used for judgments, etc. by the control processing device 21.

[0025] The control processing device 21 can be configured, for example, by a microcomputer having a control arithmetic processing device such as a CPU (Central Processing Unit). The storage device 23 has data in the form of a program that describes the processing procedures to be performed by the control processing device 21. The control arithmetic processing device executes processing based on the program data to realize control. Each device can be configured by dedicated equipment (hardware).

[0026] The control device 2 controls the rotation speed of the indoor fan 3 and the frequency of the compressor 4. When calculating the indoor fan speed of the indoor fan 3, the control device 2 refers to the indoor temperature detected by the indoor temperature detection unit 11 and the indoor temperature set by the user of the refrigeration cycle device 1, and uses a predetermined control gain. When calculating the frequency of the compressor 4, the control device 2 refers to the temperature of the evaporator 5 and a target value stored in advance in the storage device 23, and uses a predetermined control gain.

[0027] The operation of the refrigeration cycle device 1 will be described below with reference to FIG. The gaseous refrigerant, which has been compressed by the compressor 4 and has become high temperature and high pressure, is discharged from the discharge port of the compressor 4 and flows into the condenser 7. The gaseous refrigerant that has flowed into the condenser 7 releases heat in the condenser 7, liquefies under high pressure, and flows out of the condenser 7. The liquid refrigerant that has flowed out of the condenser 7 is decompressed by the electronic expansion valve 6, becomes a low-temperature two-phase refrigerant, and flows into the evaporator 5. The low-temperature two-phase refrigerant that has flowed into the evaporator 5 absorbs heat in the evaporator 5, vaporizes under low pressure, and flows out of the evaporator 5. The refrigerant that has flowed out of the evaporator 5 is drawn into the compressor 4 and compressed again. By repeating these operations, the refrigeration cycle of the refrigeration cycle device 1 is realized.

[0028] Next, dehumidifying operation will be described with reference to Fig. 1. When the indoor fan 3 blows indoor air onto the pipe through which the low-temperature two-phase refrigerant that has flowed into the evaporator 5 passes, the inflowing low-temperature two-phase refrigerant absorbs heat from the temperature of the indoor air and vaporizes under low pressure. At this time, if the temperature of the pipe through which the low-temperature two-phase refrigerant that has flowed into the evaporator 5 passes is lower than the dew point of the indoor air, moisture contained in the air blown by the indoor fan 3 condenses, and the condensed moisture is released outside the room via a drain (not shown). In this way, the dehumidifying operation of the refrigeration cycle device 1 is realized.

[0029] 1 is the minimum configuration required to realize the refrigeration cycle in the refrigeration cycle apparatus 1 according to the present disclosure, and the refrigeration cycle apparatus 1 may include, as necessary, a four-way valve for switching the refrigerant flow path, an accumulator for suppressing the intake of liquid refrigerant into the compressor 4, and the like. In addition, in the present disclosure, heat exchange occurs between the air and the refrigerant in the condenser 7 and the evaporator 5, but heat exchange does not necessarily have to occur between the refrigerant and the air. For example, heat exchange may occur between the refrigerant and water.

[0030] FIG. 3 is a functional block diagram showing the functions of the control device 2 shown in FIG. As shown in FIG. 3, the control device 2 has an indoor temperature control unit 211 and an evaporation temperature control unit 212.

[0031] The indoor temperature control unit 211 controls the indoor temperature so that it approaches a preset indoor temperature (also referred to as the "set indoor temperature"). For example, the indoor temperature control unit 211 has a controller that calculates the rotation speed of the indoor fan 3 that brings the indoor temperature closer to the set indoor temperature. The rotation speed of the indoor fan 3 is also referred to as the "indoor fan speed." The controller of the indoor temperature control unit 211 includes at least an integrator. In this application, the term "integrator" refers to an integrator that performs integral calculations.

[0032] The controller of the indoor temperature control unit 211 is configured, for example, by a feedback controller. In the example shown in FIG. 3, the design response of the feedback controller of the indoor temperature control unit 211 is a first-order lag system. More specifically, when the model of the controlled object for controller design is a first-order lag system or a dead time + first-order lag system, the indoor temperature control unit 211 is configured by a PI controller. In this case, as shown in equation (1), the predetermined set indoor temperature Tr set [degC] and the room temperature Tr [degC] obtained from the room temperature detection unit 11 (i.e., ΔTr = Tr set -Tr) is input to the PI controller, which calculates the indoor fan speed that makes the indoor temperature follow the set indoor temperature, and sets the indoor fan speed to the calculated value U ifanIn this application, the term "PI controller" refers to a controller composed of a P controller and an I controller, where the P controller refers to a proportional controller and the I controller refers to an integrator.

[0033]

number

[0034] In equation (1), K pr represents the proportional gain for PI control, and K Ir represents the integral gain for PI control. The control performed by the indoor temperature control unit 211 may be PID control depending on the design response or the model of the controlled object for design. Furthermore, if the only purpose is to simply control the indoor temperature without deviation from the set indoor temperature, the control performed by the indoor temperature control unit 211 may be I control.

[0035] These control gains, such as the proportional gain and integral gain, are designed using methods such as the pole placement method, the CHR method, the Ziegler-Nichols method (ZN method), etc. The indoor temperature control unit 211 needs to be discretized using a microcomputer or DSP when implemented, and the calculation method may be either position type or velocity type.

[0036] The evaporation temperature control unit 212 controls the evaporation temperature so that it approaches a preset refrigerant temperature (also referred to as an "evaporation temperature target value"). For example, the evaporation temperature control unit 212 has a controller that calculates the frequency of the compressor 4 that brings the evaporation temperature closer to the evaporation temperature target value. The frequency of the compressor 4 is also referred to as a "compressor frequency." The controller of the evaporation temperature control unit 212 includes at least an integrator.

[0037] The controller of the evaporation temperature control unit 212 is configured, for example, by a feedback controller. The feedback controller of the evaporation temperature control unit 212 brings the evaporation temperature closer to the evaporation temperature target value. For example, the design response of the feedback controller of the evaporation temperature control unit 212 shown in FIG. 3 is a first-order lag system. More specifically, when the model of the controlled object for controller design is a first-order lag system or a dead time + first-order lag system, the evaporation temperature control unit 212 is configured by a PI controller. In this case, as shown in equation (2), the predetermined evaporation temperature target value ET tgt The deviation between the evaporation temperature ET [degC] obtained from the evaporation temperature detection unit 12 and the evaporation temperature ET [degC] (i.e., ΔET = ET tgt -ET) is input to the PI controller, and the PI controller calculates the compressor frequency that makes the evaporation temperature follow the evaporation temperature target value, and sets the compressor frequency to the calculated value U comp Control to [Hz].

[0038]

number

[0039] In equation (2), K pe represents the proportional gain for PI control, and K Ie represents the integral gain for PI control. The control performed by the evaporation temperature control unit 212 may be PID control depending on the design response or the model of the control object for design. Also, if the control is simply to be performed without deviation from the evaporation temperature target value, the control performed by the evaporation temperature control unit 212 may be I control.

[0040] These control gains, such as the proportional gain and integral gain, are designed using methods such as the pole placement method, CHR method, and ZN method. The evaporation temperature control unit 212 must be discretized using a microcomputer or DSP when implemented, but its calculation method may be either position-based or velocity-based. For example, the evaporation temperature target value may be a fixed value of 0 [degC] or higher, or it may vary in accordance with the set indoor temperature, or it may vary in accordance with the difference between the indoor temperature and the set indoor temperature.

[0041] Each of the controllers of the indoor temperature control unit 211 and the evaporation temperature control unit 212 does not necessarily have to be a PI controller. For example, each of the controllers of the indoor temperature control unit 211 and the evaporation temperature control unit 212 may be a controller including at least an integrator (for example, a feedback controller), such as an I controller or a PID controller.

[0042] Each of the controllers of the indoor temperature control unit 211 and the evaporating temperature control unit 212 may have an anti-reset windup function to prevent the windup phenomenon. The anti-reset windup function is a function that stops the function of the integrator when not selected by the selector, and may perform processing such as maintenance or automatic matching type on the value immediately before the limit. Each of the controllers of the indoor temperature control unit 211 and the evaporating temperature control unit 212 may be configured as a speed-type PI controller.

[0043] As described above, the indoor temperature control unit 211 and the evaporation temperature control unit 212 operate independently of each other. As a result, the indoor temperature is individually controlled by the indoor fan (3), and the evaporation temperature is individually controlled by the compressor (4).

[0044] FIG. 4 is a flowchart schematically showing an example of a control method for controlling the indoor temperature and the evaporation temperature in the refrigeration cycle device 1. As described above, the control method for controlling the indoor temperature and the evaporation temperature includes the following steps.

[0045] That is, the control method for controlling the indoor temperature and the evaporation temperature includes calculating an indoor fan speed that brings the indoor temperature closer to a set indoor temperature (step S1) and calculating a compressor frequency that brings the evaporation temperature closer to a target evaporation temperature value (step S2). The control device 2 controls the indoor fan 3 and the compressor 4 in accordance with the indoor fan speed and the compressor frequency calculated in these steps (step S3). As a result, the indoor temperature is controlled individually by the indoor fan (3), and the evaporation temperature is controlled individually by the compressor (4). The order of steps S1 and S2 is not limited to the example shown in FIG. 4. Furthermore, the processing in step S1 and the processing in step S2 may proceed simultaneously.

[0046] Advantages of the First Embodiment In the first embodiment, the indoor fan speed is controlled to maintain a comfortable indoor temperature, and the compressor frequency is controlled to an evaporation temperature that maintains a comfortable indoor humidity. That is, the indoor temperature is controlled independently by the indoor fan (3), and the evaporation temperature is controlled independently by the compressor (4). Therefore, since the indoor temperature and the indoor humidity can be controlled independently, a comfortable indoor temperature and indoor humidity can be maintained not only at low loads but also in medium or high load operation with ventilation.

[0047] Furthermore, according to the first embodiment, not only the ratio of latent heat to sensible heat but also the air conditioning capacity itself can be increased, thereby making it possible to further increase latent heat processing (ie, dehumidification).

[0048] Variation 1. FIG. 5 is a functional block diagram showing another example of the control device 2. As shown in FIG. The control device 2 in Modification 1 differs from the control device 2 shown in Fig. 1 to Fig. 3 in that it further includes a compressor non-interference control unit 219. The compressor non-interference control unit 219 controls the compressor frequency to reduce in advance the effect of the indoor fan 3 on the evaporation temperature. Specifically, the compressor non-interference control unit 219 calculates the compressor frequency so that when the indoor fan speed of the indoor fan 3 increases, the compressor frequency of the compressor 4 is increased, and when the rotation speed of the indoor fan 3 decreases, the compressor frequency of the compressor 4 is decreased.

[0049] The compressor decoupling control unit 219 can be designed using, for example, a transfer function from the indoor fan speed to the evaporation temperature and a transfer function from the compressor frequency to the evaporation temperature. The transfer function from the compressor frequency to the evaporation temperature is calculated using the process gain K ETcomp The transfer function from the indoor fan speed to the evaporating temperature is the process gain K ETifan In this case, the calculated value U c_comp is expressed by equation (3).

[0050]

number

[0051] In equation (3), U ifan may be the indoor fan speed itself, or the change in the indoor fan speed ΔU ifan The speed change calculation unit may be a value equivalent to the speed change, such as a calculation by taking the difference from the previous value or a calculation using a low-pass filter. In equation (3), the characteristics of both (i.e., the transfer function) are set to the process gain of the steady-state response, but the influence of interference can be further reduced by using a model that takes into account transients such as a first-order lag system. The transfer function is not limited to this example, and may be any function that reduces interference.

[0052] According to the first modification, it is possible to prevent the compressor frequency from affecting the indoor temperature.

[0053] Variation 2. FIG. 6 is a functional block diagram showing still another example of the control device 2. As shown in FIG. The control device 2 in Modification 2 differs from the control device 2 shown in FIGS. 1 to 3 in that it further includes an indoor fan non-interference control unit 220. Generally, when the indoor fan and the compressor are controlled separately, responsiveness can be degraded due to interference between their operations. For this reason, the indoor fan non-interference control unit 220 in Modification 2 controls the indoor fan speed to mitigate in advance the effect of the compressor 4 on the indoor temperature. Specifically, the indoor fan non-interference control unit 220 calculates the indoor fan speed of the indoor fan 3 so as to decrease the indoor fan speed of the indoor fan 3 when the compressor frequency of the compressor 4 increases, and to increase the indoor fan speed of the indoor fan 3 when the compressor frequency of the compressor 4 decreases.

[0054] The indoor fan decoupling control unit 220 can be designed using, for example, a transfer function from the compressor frequency to the indoor temperature and a transfer function from the indoor fan speed to the indoor temperature. The transfer function from the compressor frequency to the indoor temperature is calculated using the process gain K Trcomp The transfer function from the indoor fan speed to the indoor temperature is the process gain K TrifanIn this case, the calculated value U c_ifan is expressed by equation (4).

[0055]

number

[0056] In equation (4), U comp may be the compressor frequency itself, or the change in the compressor frequency ΔU comp The speed change calculation unit may be any value equivalent to the speed change, such as by calculating the difference from the previous value or by using a low-pass filter. In equation (4), the characteristics of both (i.e., the transfer function) are the process gain of the steady-state response, but the influence of interference can be further reduced by using a model that takes into account transients such as a first-order lag system. The transfer function is not limited to this example, and may be any function that reduces interference.

[0057] According to the second modification, it is possible to prevent the compressor frequency from affecting the indoor temperature.

[0058] Variation 3. FIG. 7 is a functional block diagram showing still another example of the control device 2. As shown in FIG. The control device 2 in Modification 3 differs from the control device 2 shown in Fig. 1 to Fig. 3 in that it further includes a compressor non-interference control unit 219 and an indoor fan non-interference control unit 220. The compressor non-interference control unit 219 calculates the frequency of the compressor 4 by multiplying the calculation result calculated by the evaporation temperature control unit 212 by a constant. The indoor fan non-interference control unit 220 calculates the indoor fan speed by multiplying the calculation result calculated by the indoor temperature control unit 211 by a constant.

[0059] Variation 4. The refrigeration cycle apparatus 1 shown in Fig. 1 may have a liquid reservoir. This liquid reservoir is installed at the inlet of the compressor 4 and separates liquid refrigerant that has not been completely evaporated in the evaporator 5. Furthermore, the refrigeration cycle apparatus 1 shown in Fig. 1 may have an injection circuit. This injection circuit introduces low-pressure refrigerant into the compressor 4 to lower the discharge temperature when the discharge temperature becomes too high.

[0060] FIG. 8 is a graph showing a comparison between the operation of a conventional refrigeration cycle apparatus and the operation of the refrigeration cycle apparatus 1 according to the first embodiment. 8, in a conventional refrigeration cycle device, when the indoor temperature reaches the set temperature, the operation is switched to dehumidification operation and the indoor fan speed is suddenly reduced, which may prevent the compressor frequency from increasing due to freezing prevention. In contrast, in the refrigeration cycle device 1 according to the present disclosure, the indoor fan speed and the compressor frequency are controlled separately, so the capacity is less likely to decrease.

[0061] FIG. 9 is a diagram showing the operating range of the refrigeration cycle device 1. As shown in FIG. As shown in Figure 9, conventional refrigeration cycle devices can only operate in a range where latent heat and sensible heat are low because the airflow rate is reduced during dehumidification operation. In contrast, the refrigeration cycle device 1 according to the present disclosure can operate in a range where latent heat and sensible heat are high, and there is no discontinuity in operation because there is no need to switch between cooling operation and operation. In other words, the refrigeration cycle device 1 according to the present disclosure can operate from the range of conventional cooling operation and conventional dehumidification operation where the latent heat is 0 kW or more to the range where the latent heat and sensible heat are high.

[0062] <Advantages of Refrigeration Cycle Device 1> According to the present disclosure, the indoor temperature and evaporation temperature can be individually controlled to appropriate values ​​by calculating the indoor fan speed using the indoor temperature control unit 211 and calculating the compressor frequency using the evaporation temperature control unit 212. In other words, the controlled object and the control unit can be controlled in a one-to-one relationship. That is, since the target value of the indoor temperature and the target value of the indoor humidity can be individually set, it is possible to prevent a drop in the indoor temperature due to dehumidification operation and quickly achieve comfortable indoor temperature and indoor humidity. Therefore, the operating range of the refrigeration cycle device 1 can be expanded.

[0063] Furthermore, according to the present disclosure, the compressor 4 and indoor fan speed are controlled by the controller through feedback control, which allows the target values ​​to be reached quickly.

[0064] Furthermore, according to the present disclosure, since there is no need to switch between modes, it is possible to avoid the risk of an increase in indoor temperature that occurs when switching between modes and the risk of returning moisture during dehumidification.

[0065] Embodiment 2 FIG. 10 is a block diagram showing yet another example of the control device 2. As shown in FIG. The control device 2 in embodiment 2 differs from the control device 2 shown in Figures 1 to 3 in that, in addition to the indoor temperature control unit 211 and the evaporation temperature control unit 212, it further has an evaporation temperature upper limit protection control unit 213, an evaporation temperature lower limit protection control unit 214, a primary indoor fan speed selection unit 215, a secondary indoor fan speed selection unit 216, a thermo-off control unit 217, and a compressor frequency selection unit 218.

[0066] The evaporation temperature upper limit protection control unit 213 has a controller that calculates an indoor fan speed that causes the evaporation temperature to follow a predetermined evaporation temperature upper limit value. The controller of the evaporation temperature upper limit protection control unit 213 includes at least an integrator. In this case, the controller of the evaporation temperature upper limit protection control unit 213 is configured, for example, by a position-type PI controller. The evaporation temperature upper limit protection control unit 213 calculates the indoor fan speed U ifan[rpm] and outputs the calculation result. The PI controller constituting the evaporation temperature upper limit protection control unit 213 receives the deviation (i.e., ΔETmax=ETmax-ET) between the predetermined evaporation temperature upper limit value ETmax [degC] and the evaporation temperature ET [degC] acquired from the evaporation temperature detection unit 12. The PI controller constituting the evaporation temperature upper limit protection control unit 213 calculates the indoor fan speed U that causes the evaporation temperature to follow the evaporation temperature upper limit value. ifan Calculates [rpm] and outputs the calculation result.

[0067]

number

[0068] In equation (5), K p_ETmax represents the proportional gain for PI control, and K I_ETmax represents the integral gain for PI control. If the target response is regarded as a first-order lag system, the control performed by the evaporating temperature upper limit protection control unit 213 is PI control, and if the target response is regarded as a second-order lag system, the control performed by the evaporating temperature upper limit protection control unit 213 is PID control. These control gains may be designed using the CHR method, ZN method, or the like. The evaporating temperature upper limit protection control unit 213 may be configured as a speed-type PI controller.

[0069] The evaporation temperature lower limit protection control unit 214 has a controller that calculates an indoor fan speed that causes the evaporation temperature to follow a predetermined evaporation temperature lower limit value. The controller of the evaporation temperature lower limit protection control unit 214 includes at least an integrator. In this case, the controller of the evaporation temperature lower limit protection control unit 214 is configured, for example, as a position-type PI controller. The evaporation temperature lower limit protection control unit 214 calculates the indoor fan speed U ifan[rpm] and outputs the calculation result. The PI controller constituting the evaporation temperature lower limit protection control unit 214 receives the deviation (i.e., ΔETmin=ETmin-ET) between a predetermined evaporation temperature lower limit value ETmin [degC] and the evaporation temperature ET [degC] acquired from the evaporation temperature detection unit 12. The PI controller constituting the evaporation temperature lower limit protection control unit 214 calculates the indoor fan speed U that causes the evaporation temperature to follow the evaporation temperature lower limit value. ifan Calculates [rpm] and outputs the calculation result.

[0070]

number

[0071] In equation (6), K p_ETmin represents the proportional gain for PI control, and K I_ETmin represents the integral gain for PI control. If the target response is regarded as a first-order lag system, the control performed by the evaporation temperature lower limit protection control unit 214 is PI control, and if the target response is regarded as a second-order lag system, the control performed by the evaporation temperature lower limit protection control unit 214 is PID control. These control gains may be designed using the CHR method, ZN method, or the like. Furthermore, the evaporation temperature lower limit protection control unit 214 may be configured as a speed-type PI controller. The evaporation temperature lower limit value is, for example, 0 degC or higher and a value lower than the evaporation temperature target value.

[0072] The primary indoor fan speed selection unit 215 is composed of a selector (also referred to as a "minimum selector" or a "first minimum selector") that selects the minimum value among the input values. Specifically, the primary indoor fan speed selection unit 215 selects the minimum value among the output value of the indoor temperature control unit 211 (i.e., the calculation result output from the indoor temperature control unit 211) and the output value of the evaporating temperature upper limit protection control unit 213 (i.e., the calculation result output from the evaporating temperature upper limit protection control unit 213), and outputs the minimum value as a selected value.

[0073] The secondary indoor fan speed selection unit 216 is configured with a selector (also referred to as a "maximum selector") that selects the maximum value of input values. Specifically, the secondary indoor fan speed selection unit 216 selects the maximum value of the output value of the evaporating temperature lower limit protection control unit 214 (i.e., the calculation result output from the evaporating temperature lower limit protection control unit 214) and the output value of the primary indoor fan speed selection unit 215 (i.e., the selected value output from the primary indoor fan speed selection unit 215), and sets the indoor fan speed to that maximum value (i.e., the selected value).

[0074] The thermo-off control unit 217 has a controller that calculates a compressor frequency that causes the indoor temperature to follow a predetermined thermo-off temperature. The controller of the thermo-off control unit 217 includes at least an integrator. In this case, the controller of the thermo-off control unit 217 is configured, for example, as a position-type PI controller. The thermo-off control unit 217 calculates the compressor frequency U comp [Hz] and outputs the calculation result. The PI controller constituting the thermo-off control unit 217 receives the deviation (i.e., ΔTO=TO-Tr) between a predetermined thermo-off temperature TO [degC] and the room temperature Tr [degC] obtained from the room temperature detection unit 11. The PI controller constituting the thermo-off control unit 217 calculates the compressor frequency U that causes the room temperature to follow the thermo-off temperature. comp Calculates [Hz] and outputs the calculation result.

[0075]

number

[0076] In equation (7), K p_to represents the proportional gain for PI control, and K I_torepresents the integral gain for PI control. If the target response is regarded as a first-order lag system, the control performed by the thermo-off control unit 217 is PI control, and if the target response is regarded as a second-order lag system, the control performed by the thermo-off control unit 217 is PID control. These control gains may be designed using the CHR method, ZN method, or the like. Furthermore, the thermo-off control unit 217 may be configured with a speed-type PI controller. The thermo-off temperature may be, for example, a value 3 degrees Celsius lower than the set indoor temperature.

[0077] The compressor frequency selection unit 218 is configured with a selector (also referred to as a "minimum selector" or a "second minimum selector") that selects the minimum value of input values. Specifically, the compressor frequency selection unit 218 selects the minimum value of the output value of the evaporation temperature control unit 212 (i.e., the calculation result output from the evaporation temperature control unit 212) and the output value of the thermo-off control unit 217 (i.e., the calculation result output from the thermo-off control unit 217), and the compressor frequency is set to that minimum value (i.e., the selected value).

[0078] Each of the controllers of the evaporation temperature upper limit protection control unit 213, the evaporation temperature lower limit protection control unit 214, and the thermo-off control unit 217 does not necessarily have to be a PI controller. For example, each of the controllers of the evaporation temperature upper limit protection control unit 213, the evaporation temperature lower limit protection control unit 214, and the thermo-off control unit 217 may be a controller including at least an integrator (e.g., a feedback controller), such as an I controller or a PID controller. In this application, a "PID controller" refers to a controller including a P controller, an I controller, and a D controller, and a "D controller" refers to a differentiator.

[0079] Each of the evaporation temperature upper limit protection control unit 213, evaporation temperature lower limit protection control unit 214, and thermo-off control unit 217 may have an anti-reset windup function to prevent the windup phenomenon. petition This is a function to stop the function of the integrator when the limit is reached or when the integrator is not selected by the selector, and processing such as maintenance or automatic matching may be performed on the value immediately before the limit.

[0080] Advantages of the Second Embodiment The second embodiment has the advantages described in the first embodiment.

[0081] Furthermore, according to the second embodiment, the evaporation temperature upper limit protection control unit 213 calculates the indoor fan speed, and the primary indoor fan speed selection unit 215 selects the minimum value of the output value of the indoor temperature control unit 211 and the output value of the evaporation temperature upper limit protection control unit 213. With this configuration, it is possible to control the indoor temperature while protecting the evaporation temperature upper limit to prevent damage to the refrigeration cycle device 1 (for example, the evaporator 5).

[0082] Furthermore, the evaporation temperature upper limit protection control unit 213 calculates the indoor fan speed, and the secondary indoor fan speed selection unit 216 selects the maximum value from the output value of the primary indoor fan speed selection unit 215 and the output value of the evaporation temperature lower limit protection control unit 214. With this configuration, it is possible to control the indoor temperature while protecting the evaporation temperature lower limit and evaporation temperature upper limit to prevent damage to the refrigeration cycle device 1 (e.g., evaporator 5). In other words, since the evaporation temperature lower limit is controlled to a value lower than the evaporation temperature target value, it is possible to prevent the evaporation temperature from dropping too much due to the influence of the indoor fan 3.

[0083] Furthermore, the compressor frequency is calculated by the thermo-off control unit 217, and the compressor frequency selection unit 218 selects the minimum value of the output value of the evaporation temperature control unit 212 and the output value of the thermo-off control unit 217. With this configuration, the evaporation temperature can be controlled up to the limit of the thermo-off temperature. In other words, dehumidification operation can be performed up to the limit of the thermo-off temperature. This makes it possible to prevent a drop in the indoor temperature or thermo-off due to dehumidification operation, and quickly achieve a comfortable indoor temperature and indoor humidity.

[0084] Furthermore, according to embodiment 2, the target value for indoor temperature and the target value for indoor humidity can be set separately, and the operating range can be expanded while protecting the evaporation temperature so as not to damage the refrigeration cycle device 1 (e.g., evaporator 5).

[0085] Furthermore, according to the second embodiment, not only the ratio of latent heat to sensible heat but also the air conditioning capacity itself can be increased, thereby making it possible to further increase latent heat processing (ie, dehumidification).

[0086] Embodiment 3 FIG. 11 is a flowchart showing an example of a method for controlling the compressor frequency so that the evaporation temperature approaches the evaporation temperature target value. The indoor temperature Tr [degC] is detected by the indoor temperature detection unit 11 (step S11). For example, using the discomfort index DI and the indoor temperature Tr [degC] obtained from the indoor temperature detection unit 11, the relative humidity H [%] at which the user does not feel uncomfortable is calculated by equation (8).

[0087]

number

[0088] Few people will feel uncomfortable if the discomfort index DI is 73 or less. The saturated water vapor pressure Pws [hPa] of the indoor temperature is calculated using the indoor temperature Tr [degC] and Tetens's equation, as shown in equation (9). In equation (9), A, m, and Tn are constants.

[0089]

number

[0090] Using the saturated water vapor pressure Pws [hPa], the non-uncomfortable water vapor partial pressure Pw [hPa] is calculated using equation (10).

[0091]

number

[0092] The dew point Td [degC] of the relative humidity that does not cause discomfort is calculated using the Tetens equation as shown in equation (11).

[0093]

number

[0094] The value obtained by equation (11) may be used as the evaporation temperature target value, or a value obtained by correcting the value obtained by equation (11) may be used as the evaporation temperature target value.

[0095] A saturated water vapor pressure table may be stored in advance in the storage device 23 as an index representing comfort, and the saturated water vapor pressure Pws [hPa] may be calculated using this saturated water vapor pressure table.

[0096] The refrigeration cycle apparatus 1 may further include an indoor humidity detection unit that measures indoor humidity. If the refrigeration cycle apparatus 1 includes this indoor humidity detection unit, the indoor humidity obtained from the indoor humidity detection unit may be used to correct the evaporation temperature target value. Using the above-described method, the evaporation temperature target value is determined using the indoor temperature detected by the indoor temperature detection unit 11 and the index representing comfort (step S12).

[0097] The control device 2 controls the compressor frequency so that the evaporation temperature approaches the evaporation temperature target value (step S13).

[0098] Advantages of the Third Embodiment

[0099] The third embodiment has the advantages described in the first embodiment.

[0100] Furthermore, according to the third embodiment, it is possible to achieve an indoor humidity that does not cause discomfort at any indoor temperature by using the above-described method to calculate the evaporation temperature target value of the evaporation temperature control unit 212. Furthermore, according to the third embodiment, it is possible to achieve an indoor humidity that does not cause discomfort without using an indoor hygrometer.

[0101] When the refrigeration cycle device 1 has this indoor humidity detection unit, the evaporation temperature target value can be corrected so as not to dehumidify too much.

[0102] The features of the above-described embodiments and modifications can be combined with each other. [Explanation of symbols]

[0103] 1 Refrigeration cycle device, 2 Control device, 3 Indoor fan, 4 Compressor, 5 Evaporator, 6 Electronic expansion valve, 7 Condenser, 8 Outdoor fan, 9 Piping, 10 Refrigerant circuit, 11 Indoor temperature detection unit, 12 Evaporation temperature detection unit, 211 Indoor temperature control unit, 212 Evaporation temperature control unit, 213 Evaporation temperature upper limit protection control unit, 214 Evaporation temperature lower limit protection control unit, 215 Primary indoor fan speed selection unit, 216 Secondary indoor fan speed selection unit, 217 Thermo-off control unit, 218 Compressor frequency selection unit, 219 Compressor non-interference control unit, 220 Indoor fan non-interference control unit.

Claims

1. a compressor that compresses a refrigerant; A condenser; An expansion valve; an evaporator; Indoor fan and a control device for controlling the rotation speed of the indoor fan and the frequency of the compressor; an indoor temperature detection unit that detects the indoor temperature; an evaporation temperature detection unit that detects the evaporation temperature of the refrigerant in the evaporator; Equipped with The control device an indoor temperature control unit having a controller that calculates the rotation speed of the indoor fan so that the temperature in the room approaches a preset indoor temperature; an evaporation temperature control unit having a controller that calculates the frequency of the compressor so that the evaporation temperature approaches a preset refrigerant temperature; and The temperature in the room is individually controlled by the indoor fan; The evaporation temperature is individually controlled by the compressor; The control device further includes a compressor decoupling control unit that calculates the frequency of the compressor so as to increase the frequency of the compressor when the rotation speed of the indoor fan increases and to decrease the frequency of the compressor when the rotation speed of the indoor fan decreases.

2. a compressor that compresses a refrigerant; A condenser; An expansion valve; an evaporator; Indoor fan and a control device for controlling the rotation speed of the indoor fan and the frequency of the compressor; an indoor temperature detection unit that detects the indoor temperature; an evaporation temperature detection unit that detects the evaporation temperature of the refrigerant in the evaporator; Equipped with The control device an indoor temperature control unit having a controller that calculates the rotation speed of the indoor fan so that the temperature in the room approaches a preset indoor temperature; an evaporation temperature control unit having a controller that calculates the frequency of the compressor so that the evaporation temperature approaches a preset refrigerant temperature; and The temperature in the room is individually controlled by the indoor fan; The evaporation temperature is individually controlled by the compressor; The control device further includes an indoor fan decoupling control unit that calculates the rotation speed of the indoor fan to reduce the rotation speed of the indoor fan when the frequency of the compressor increases, and to increase the rotation speed of the indoor fan when the frequency of the compressor decreases.

3. a compressor that compresses a refrigerant; A condenser; An expansion valve; an evaporator; Indoor fan and a control device for controlling the rotation speed of the indoor fan and the frequency of the compressor; an indoor temperature detection unit that detects the indoor temperature; an evaporation temperature detection unit that detects the evaporation temperature of the refrigerant in the evaporator; Equipped with The control device an indoor temperature control unit having a controller that calculates the rotation speed of the indoor fan so that the temperature in the room approaches a preset indoor temperature; an evaporation temperature control unit having a controller that calculates the frequency of the compressor so that the evaporation temperature approaches a preset refrigerant temperature; and The temperature in the room is individually controlled by the indoor fan; The evaporation temperature is individually controlled by the compressor; The control device an evaporation temperature upper limit protection control unit having a controller that calculates the rotation speed of the indoor fan so that the evaporation temperature follows a predetermined evaporation temperature upper limit value; a primary indoor fan speed selection unit that selects the minimum value of the output value of the indoor temperature control unit and the output value of the evaporation temperature upper limit protection control unit; The refrigeration cycle device further comprises:

4. The control device an evaporation temperature lower limit protection control unit having a controller that calculates the rotation speed of the indoor fan so that the evaporation temperature follows a predetermined evaporation temperature lower limit value; a secondary indoor fan speed selection unit that selects the maximum value of the output value of the evaporation temperature lower limit protection control unit and the output value of the primary indoor fan speed selection unit; The refrigeration cycle device according to claim 3, further comprising:

5. a compressor that compresses a refrigerant; A condenser; An expansion valve; an evaporator; Indoor fan and a control device for controlling the rotation speed of the indoor fan and the frequency of the compressor; an indoor temperature detection unit that detects the indoor temperature; an evaporation temperature detection unit that detects the evaporation temperature of the refrigerant in the evaporator; Equipped with The control device an indoor temperature control unit having a controller that calculates the rotation speed of the indoor fan so that the temperature in the room approaches a preset indoor temperature; an evaporation temperature control unit having a controller that calculates the frequency of the compressor so that the evaporation temperature approaches a preset refrigerant temperature; and The temperature in the room is individually controlled by the indoor fan; The evaporation temperature is individually controlled by the compressor; The control device a thermo-off control unit having a controller that calculates the frequency of the compressor so that the temperature in the room follows a predetermined thermo-off temperature; a compressor frequency selection unit that selects the minimum value of the output value of the evaporation temperature control unit and the output value of the thermo-off control unit; The refrigeration cycle device further comprises:

6. The control device further includes a storage device in which an index representing comfort is stored, The refrigeration cycle device according to claim 1 , wherein the preset refrigerant temperature is determined using the temperature in the room and the index representing comfort.

7. 6. The refrigeration cycle device according to claim 1, wherein the indoor temperature control unit and the evaporation temperature control unit are each configured by a feedback controller including an integrator, and operate independently of each other.

8. A control method for a refrigeration cycle device having a compressor that compresses a refrigerant, a condenser, an expansion valve, an evaporator, an indoor fan, a control device that controls a rotation speed of the indoor fan and a frequency of the compressor, an indoor temperature detection unit that detects an indoor temperature, and an evaporation temperature detection unit that detects an evaporation temperature of the refrigerant in the evaporator, Calculating the rotation speed of the indoor fan that brings the temperature in the room closer to a preset indoor temperature; Calculating the frequency of the compressor such that the evaporation temperature approaches a preset refrigerant temperature so as to maintain a target indoor humidity; calculating a frequency of the compressor such that the frequency of the compressor is increased when the rotation speed of the indoor fan increases, and the frequency of the compressor is decreased when the rotation speed of the indoor fan decreases; Equipped with The temperature in the room is individually controlled by the indoor fan, and the evaporation temperature is individually controlled by the compressor; The indoor temperature and the indoor humidity are set separately. Control method.

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