Air conditioning system

Abstract

To provide an air conditioning system capable of securing energy saving performance.SOLUTION: An air conditioning system includes: a ventilation device that ventilates an object space; an air conditioner having a heat exchanger functioning as a condenser or an evaporator and a compressor for compressing a refrigerant, sucking air in the object space and blowing out air that has undergone heat exchange with the refrigerant flowing in the heat exchanger to the object space; and a control section that lowers first capacity of the ventilation device for regulating the temperature of the object space and increases second capacity of the air conditioner for regulating the temperature when a first operation mode in which the temperature of the object space is not regulated by the air conditioner and is regulated by the ventilation device is transferred to a second operation mode in which the temperature is regulated by the air conditioner and the ventilation device.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an air conditioning system.

Background Art

[0002] Conventionally, an air conditioning system has been used that includes an outdoor air treatment device that ventilates and air - conditions a target space by heating or cooling outdoor air and supplying it to the target space, and an air conditioner that conditions the air in the target space (indoor air) by heating or cooling it and sending it to the target space.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an air conditioning system including a ventilation device and an air conditioner, there may be a case where the mode is shifted from a mode in which the temperature of the target space is adjusted by the ventilation device without using the air conditioner to a mode in which the temperature of the target space is adjusted by both the air conditioner and the ventilation device. In the mode after the shift, the air conditioner and the ventilation device share the processing of the heat load in the target space.

[0005] However, in the mode after the shift, if the amount of heat load in the target space processed by the air conditioner is small, the air conditioner operates at a low load, and thus the air conditioner may repeatedly start and stop. Repeated start - stop of the air conditioner reduces the energy - saving performance of the air conditioning system.

[0006] The present disclosure provides an air conditioning system capable of ensuring energy - saving performance.

Means for Solving the Problems

[0007] The air conditioning system according to the first aspect is A ventilation device that ventilates the target space, An air conditioning system having a heat exchanger that functions as a condenser or evaporator and a compressor that compresses a refrigerant, which draws in air from the target space and blows out air that has exchanged heat with the refrigerant flowing through the heat exchanger back into the target space, The air conditioning system includes a control unit that, when transitioning from a first operating mode in which the temperature of the target space is adjusted by the ventilation device without adjustment by the air conditioning device, to a second operating mode in which the temperature is adjusted by both the air conditioning device and the ventilation device, reduces the first capacity of the ventilation device to adjust the temperature of the target space and increases the second capacity of the air conditioning device to adjust the temperature.

[0008] According to the first embodiment, compared to a control that increases the second capacity without reducing the first capacity when transitioning from the first operating mode to the second operating mode, the frequency of the air conditioning system starting and stopping after the mode transition is suppressed, thereby ensuring energy savings.

[0009] The air conditioning system of the second embodiment is the air conditioning system of the first embodiment, When the control unit transitions from the first operating mode to the second operating mode, it reduces the first capacity to the capacity that minimizes the power consumption of the ventilation device, and increases the second capacity.

[0010] According to the second embodiment, the power consumption of the ventilation device in the second operating mode is minimized, and the frequency of the air conditioning device starting and stopping after the mode transition is suppressed, thereby ensuring energy saving.

[0011] The third embodiment of the air conditioning system is the first or second embodiment of the air conditioning system, When the control unit transitions from the first operating mode to the second operating mode, it reduces the first capacity to a level where the difference between the temperature of the air supplied from the ventilation device to the target space and the temperature of the target space is within a predetermined range, and increases the second capacity.

[0012] According to the third embodiment, in the second operating mode, the difference between the temperature of the air supplied from the ventilation device to the target space and the temperature of the target space is within a predetermined range, thereby suppressing a decrease in comfort due to a large difference. In addition, the frequency of the air conditioning device starting and stopping after the mode transition is suppressed, thus ensuring energy saving.

[0013] The fourth embodiment of the air conditioning system is an air conditioning system according to any one embodiment of the first to third embodiments, When the control unit transitions from the first operating mode to the second operating mode, it switches between reducing the first capacity to the capacity that minimizes the power consumption of the ventilation device, and reducing it to the capacity that brings the difference between the temperature of the air supplied from the ventilation device to the target space and the temperature of the target space within a predetermined range.

[0014] According to the fourth embodiment, in the second operating mode, it is possible to select whether to prioritize minimizing the power consumption of the ventilation device or keeping the difference between the temperature of the air supplied from the ventilation device to the target space and the temperature of the target space within a predetermined range.

[0015] The fifth embodiment of the air conditioning system is the fourth embodiment of the air conditioning system, When the control unit transitions from the first operating mode to the second operating mode, it selects, based on user input, whether to reduce the first capacity to the capacity that minimizes the power consumption of the ventilation device, or to the capacity that brings the difference between the temperature of the air supplied from the ventilation device to the target space and the temperature of the target space within a predetermined range.

[0016] According to the fifth embodiment, in the second operating mode, the user can choose whether to prioritize minimizing the power consumption of the ventilation device or keeping the difference between the temperature of the air supplied from the ventilation device to the target space and the temperature of the target space within a predetermined range.

[0017] The sixth embodiment of the air conditioning system is an air conditioning system according to any one embodiment of the first to fifth embodiments, When the control unit shifts from the first operation mode to the second operation mode, it decreases the first capacity and increases the second capacity to the capacity at which the power consumption of the air conditioner is minimized.

[0018] According to the sixth aspect, the power consumption of the air conditioner after mode transition is minimized, and the frequency of start and stop of the air conditioner after mode transition is suppressed, so energy conservation is ensured.

[0019] The air conditioning system according to the seventh aspect is the air conditioning system according to any one of the first to sixth aspects, When the temperature does not reach the set temperature in the first operation mode, the control unit shifts from the first operation mode to the second operation mode.

[0020] According to the seventh aspect, when the ability to bring the temperature of the target space close to the set temperature is insufficient in the first operation mode, the ability to bring the temperature of the target space close to the set temperature can be increased by adding the second capacity by shifting from the first operation mode to the second operation mode.

[0021] The air conditioning system according to the eighth aspect is the air conditioning system according to the seventh aspect, <00000​​​​​​​​​​The ventilation device is a device that recovers the exhaust heat from the target space to the outside and reuses it for the supply air to the target space.

[0024] According to the ninth aspect, since the exhaust heat from the target space to the outside is reused for temperature adjustment of the supply air to the target space, energy efficiency is improved.

Brief Description of the Drawings

[0025] [Figure 1] It is a diagram showing a configuration example of an air conditioning system according to an embodiment. [Figure 2] It is an example showing changes in the processing capabilities of each of the ventilation device and the air conditioning device when shifting from the first operation mode to the second operation mode. [Figure 3] It is two control examples showing changes in the processing capabilities of each of the ventilation device and the air conditioning device when shifting from the first operation mode to the second operation mode. [Figure 4] It is a state transition diagram showing an example of transition conditions between the first operation mode and the second operation mode.

Modes for Carrying Out the Invention

[0026] Hereinafter, embodiments will be described.

[0027] FIG. 1 is a diagram showing a configuration example of an air conditioning system according to an embodiment. The air conditioning system 201 shown in FIG. 1 is a system that realizes air conditioning in a target space SP included in a building such as a house, building, factory, or facility. The target space SP is, for example, an indoor space such as a living room space in a building BL. The air conditioning system 201 includes a ventilation device 1, an air conditioning device 2, and a control device 3.

[0028] The air conditioning system 201 switches the operating states of the ventilation device 1 and the air conditioning device 2, for example, when a command is input to a remote control 4 installed inside or outside the target space SP. The control device 3 controls the operating states of the ventilation device 1 and the air conditioning device 2 according to the commands input to the remote control 4 (commands related to start / stop, operation type, set temperature, set air volume, etc.).

[0029] Next, we will explain the configuration of the air conditioning system 201 in more detail.

[0030] Ventilation device 1 ventilates the target space SP. Ventilation device 1 adjusts the temperature of the outside air OA taken in from outside and supplies it to the target space SP as supply air SA, and also discharges the air taken in from the target space SP (return air RA) to the outside as exhaust air EA. Ventilation device 1 is also called an outside air treatment device.

[0031] In the example shown in Figure 1, the ventilation system 1 is a device that recovers the heat (exhaust heat) from the exhaust EA from the target space SP to the outdoors and reuses it for supplying air to the target space SP. The ventilation system 1 recovers the waste heat during disposal instead of simply discarding it and reuses it to adjust the temperature of the air supplied to the target space SP, thus improving energy efficiency. The ventilation system 1 includes, for example, an air supply unit 20, an air supply duct P1, a return air duct P2, an exhaust unit 10, refrigerant circuits F1, F2, F3, F4, a compressor unit 50, and a ventilation control unit 23.

[0032] The air supply unit 20 takes in outside air OA from an air intake provided in the outer wall of the building BL. The air supply unit 20 cools or heats the taken-in outside air OA, or dehumidifies or humidifies it, and supplies it as supply air SA to the target space SP from the air intake 92 via the air supply duct P1. The air supply unit 20 includes, for example, an outside air heat exchanger 22, an air supply fan 21, and a sensor 24.

[0033] The outside air heat exchanger 22 exchanges heat between the incoming outside air OA and the refrigerant flowing through the refrigerant circuits F1 and F2. The outside air heat exchanger 22 functions as either a condenser or an evaporator.

[0034] The supply air fan 21 is a blower that takes in outside air OA into the supply air unit 20 and sends it to the supply air duct P1 via the outside air heat exchanger 22. The supply air fan 21 has a fan motor. The rotation speed of the supply air fan 21 is adjusted by inverter control of the fan motor, so the airflow rate of the supply air SA to the target space SP is variable.

[0035] Sensor 24 includes, for example, an outside air temperature sensor, an outside air humidity sensor, or a supply air temperature sensor. The outside air temperature sensor detects the temperature of the outside air OA taken into the supply air unit 20. The outside air humidity sensor detects the humidity of the outside air OA taken into the supply air unit 20. The supply air temperature sensor detects the temperature of the supply air SA (supply air temperature) sent from the supply air unit 20 to the target space SP via the supply air duct P1. Sensor 24 may also detect the surface temperature of the outside air heat exchanger 22 or the temperature of the refrigerant flowing into the outside air heat exchanger 22.

[0036] The air supply duct P1 is an air supply passage for supplying outside air OA, taken in from outdoors, through the air supply unit 20, and then to the target space SP through the air supply port 92. The air supply port 92 is not limited to being installed in the ceiling, but may also be installed in other parts such as walls or floors.

[0037] One end of the air supply duct P1 is connected to the air supply unit 20 so that outside air OA flows into the air supply unit 20 when the air supply fan 21 is driven. The other end of the air supply duct P1 is connected to an air supply port 92 formed in the target space SP so as to communicate with the target space SP. A damper for adjusting the airflow is provided in the air supply port 92. There may be one or more air supply ports 92.

[0038] The return air duct P2 is a return air passage for exhausting air (return air RA) taken in from the return air port 91 of the target space SP to the outside after passing it through the exhaust unit 10. The return air port 91 is not limited to being installed in the ceiling, but may also be installed in other parts such as walls or floors. There may be one or more return air ports 91.

[0039] The exhaust unit 10 uses an exhaust fan 11 to discharge exhaust EA from the return air port 91 of the target space SP through the return air duct P2 to the outside of the building BL. The exhaust unit 10 includes, for example, a return air heat exchanger 12, an exhaust fan 11, and a sensor 14.

[0040] The return air heat exchanger 12 exchanges heat between the incoming return air RA and the refrigerant flowing through the refrigerant circuits F3 and F4. The return air heat exchanger 12 functions as either a condenser or an evaporator.

[0041] The exhaust fan 11 is a blower that takes in return air RA into the exhaust unit 10 and sends it to the exhaust port via the return air heat exchanger 12. Exhaust air EA is discharged from the exhaust port. The exhaust fan 11 has a fan motor. The exhaust fan 11 rotates when the fan motor is inverter controlled.

[0042] Sensor 14 includes, for example, a return air temperature sensor, a return air humidity sensor, or an exhaust air temperature sensor. The return air temperature sensor detects the temperature of the return air RA taken into the exhaust unit 10. The return air humidity sensor detects the humidity of the return air RA taken into the exhaust unit 10. The exhaust air temperature sensor detects the temperature of the exhaust air EA taken into the exhaust unit 10 (exhaust air temperature). Sensor 14 may also detect the surface temperature of the return air heat exchanger 12 or the temperature of the refrigerant flowing into the return air heat exchanger 12.

[0043] Refrigerant circuits F1, F2, F3, and F4 are circuits that connect the compressor unit 50, the outside air heat exchanger 22 of the supply air unit 20, and the return air heat exchanger 12 of the exhaust unit 10 by refrigerant piping, and circulate refrigerant through them.

[0044] The compressor unit 50 controls the circulation of refrigerant in refrigerant circuits F1, F2, F3, and F4 by compressing the refrigerant in one of the refrigerant circuits F1, F2, F3, and F4. For example, when the return air heat exchanger 12 in the exhaust unit 10 functions as an evaporator, the compressor unit 50 circulates the refrigerant in refrigerant circuits F1, F2, F3, and F4 by compressing the refrigerant in refrigerant circuit F2. The compressor unit 50 includes, for example, a compressor that compresses the refrigerant in refrigerant circuits F1, F2, F3, and F4, and a motor that drives the compressor.

[0045] The ventilation control unit 23 controls the operation of each part included in the ventilation device 1. The ventilation control unit 23 is communicatively connected to the control device 3 or the remote control 4. The ventilation control unit 23 may also be communicatively connected to the air conditioning control unit 76, which will be described later. The ventilation control unit 23 consists of one or more control units. The ventilation control unit 23 may be located inside or outside the ventilation device 1, or it may be located in one place or distributed.

[0046] The ventilation control unit 23 sets a target value for the supply air temperature according to the set temperature, etc. The ventilation control unit 23 controls the state of each part of the ventilation system 1 (for example, the capacity of the compressor unit 50 and the airflow of the exhaust fan 11) based on the target value for the supply air temperature. This adjusts the operating capacity (air conditioning capacity) of the ventilation system 1. The target value for the supply air temperature may also be set by the control device 3.

[0047] The ventilation control unit 23 includes, for example, memory and a processor (e.g., a CPU (Central Processing Unit)), and each function of the ventilation control unit 23 is realized by the processor operating according to a program stored in memory. Each function of the ventilation control unit 23 may be realized by an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). The program is recorded on a computer-readable recording medium.

[0048] The air conditioning unit 2 draws in air from the target space SP, exchanges heat with the refrigerant flowing through the heat exchanger, and blows the resulting air back into the target space SP to adjust the temperature of the air (indoor air) in the target space SP. The air conditioning unit 2 is a device that performs a vapor compression type refrigeration cycle to cool or heat the target space SP. The air conditioning unit 2 may be a device that performs only cooling, only heating, or both cooling and heating. For example, the air conditioning unit 2 has an outdoor unit 70, a plurality (two in this example) of indoor units 81, 82, and an air conditioning control unit 76.

[0049] In the air conditioning system 2, the outdoor unit 70 and a plurality of indoor units 81, 82 are connected by a connecting pipe F5. The connecting pipe F5 includes liquid refrigerant connecting pipes and gaseous refrigerant connecting pipes. This realizes a refrigerant circuit in which refrigerant circulates between the outdoor unit 70 and the plurality of indoor units 81, 82. When refrigerant circulates within this refrigerant circuit, a vapor compression type refrigeration cycle is performed in the air conditioning system 2. The control mode of the air conditioning system 2 is not particularly limited. For example, the air conditioning system 2 performs variable refrigerant flow rate control.

[0050] The outdoor unit 70 is located outside the target space SP (in this example, outside the building BL). The outdoor unit 70 is equipped with a heat exchanger and discharges air that has exchanged heat with the refrigerant flowing through the heat exchanger to the outside. The outdoor unit 70 includes, for example, a compressor 71, a four-way switching valve 72, an outdoor heat exchanger 73, an outdoor expansion valve 74, and an outdoor fan 75.

[0051] The compressor 71 is a device that compresses the low-pressure refrigerant in the refrigeration cycle until it reaches high pressure.

[0052] The four-way switching valve 72 is a flow path switching means for switching the direction of refrigerant flow in the refrigerant circuit.

[0053] The outdoor heat exchanger 73 is a heat exchanger that exchanges heat between the refrigerant and the airflow passing through it (outdoor airflow generated by the outdoor fan 75). During forward cycle operation (heating operation), the outdoor heat exchanger 73 functions as a refrigerant evaporator, and during reverse cycle operation (cooling operation or defrosting operation), it functions as a refrigerant condenser or radiator.

[0054] The outdoor expansion valve 74 is a valve that functions as a means of reducing the pressure or adjusting the flow rate of the refrigerant, and is, for example, an electrically operated expansion valve with controllable opening. The outdoor expansion valve 74 is located between the outdoor heat exchanger 73 and the liquid-side refrigerant connecting pipe.

[0055] The outdoor fan 75 is a blower that generates an outdoor airflow. The outdoor airflow is the flow of outside air that flows into the outdoor unit 70, passes through the outdoor heat exchanger 73, and flows out of the outdoor unit 70. The outdoor airflow is a heating source for the refrigerant in the outdoor heat exchanger 73 during forward cycle operation and a cooling source for the refrigerant in the outdoor heat exchanger 73 during reverse cycle operation. The outdoor fan 75 has a fan motor. The rotational speed of the outdoor fan 75 is adjusted by inverter control of the fan motor, so the amount of airflow to the outside of the outdoor unit 70 is variable.

[0056] Furthermore, various sensors are installed on the outdoor unit 70. For example, the outdoor unit 70 is equipped with an intake pressure sensor to detect the pressure of the refrigerant drawn into the compressor 71, and a discharge pressure sensor to detect the pressure of the refrigerant discharged from the compressor 71.

[0057] The indoor units 81 and 82 are placed in the target space SP. The indoor units 81 and 82 are equipped with heat exchangers and blow air that has exchanged heat with the refrigerant flowing through the heat exchangers into the target space SP. In this embodiment, the indoor units 81 and 82 are ceiling-mounted units installed on the ceiling of the target space SP. In particular, the indoor units 81 and 82 of this embodiment are ceiling-embedded air conditioning indoor units, and the heat-exchanged air is blown out from the air outlets 93A and 93B. In this embodiment, an example in which the air outlets 93A and 93B are installed on the ceiling is described, but the position in which the air outlets 93A and 93B are installed is not particularly limited. Note that the indoor units 81 and 82 are not limited to ceiling-embedded units, but may also be ceiling-suspended units. In addition, the indoor units 81 and 82 may be wall-mounted or floor-standing units, or other types other than ceiling-mounted units. The indoor units 81 and 82 have, for example, an indoor heat exchanger 83, an indoor expansion valve 84, and an indoor fan 85.

[0058] The indoor heat exchanger 83 is a heat exchanger that exchanges heat between the refrigerant and the airflow passing through it (the indoor airflow generated by the indoor fan 85). During forward cycle operation, the indoor heat exchanger 83 functions as a refrigerant condenser or radiator, and during reverse cycle operation, it functions as a refrigerant evaporator.

[0059] The indoor expansion valve 84 is a valve that functions as a means of reducing the pressure or adjusting the flow rate of the refrigerant, and is, for example, an electrically operated expansion valve with controllable opening. The indoor expansion valve 84 is located between the indoor heat exchanger 83 and the liquid-side refrigerant connecting pipe.

[0060] The indoor fan 85 is a blower that generates indoor airflow. The indoor airflow is the flow of air that flows into the indoor units 81 and 82, passes through the indoor heat exchanger 83, and flows out of the indoor units 81 and 82. The indoor airflow is a cooling source for the refrigerant in the indoor heat exchanger 83 during forward cycle operation and a heating source for the refrigerant in the indoor heat exchanger 83 during reverse cycle operation. The indoor fan 85 has a fan motor. The rotational speed of the indoor fan 85 is adjusted by inverter control of the fan motor, so the amount of air blown from the indoor units 81 and 82 to the target space SP is variable.

[0061] Furthermore, various sensors are installed in each of the indoor units 81 and 82. For example, each of the indoor units 81 and 82 is equipped with an indoor temperature sensor to detect the temperature of the indoor airflow (internal air) drawn into the indoor unit, an indoor humidity sensor to detect the humidity of the indoor airflow drawn into the indoor unit, and a carbon dioxide concentration sensor to detect the carbon dioxide concentration of the indoor airflow drawn into the indoor unit. For example, each of the indoor units 81 and 82 is equipped with a refrigerant temperature sensor to detect the temperature of the refrigerant in the indoor heat exchanger 83.

[0062] The air conditioning control unit 76 controls the operation of each part included in the air conditioning system 2. The air conditioning control unit 76 is communicatively connected to the control device 3 or the remote control 4. The air conditioning control unit 76 may also be communicatively connected to the ventilation control unit 23. The air conditioning control unit 76 consists of one or more control units. The air conditioning control unit 76 may be located inside or outside the air conditioning system 2, and may be located in one place or distributed.

[0063] The air conditioning control unit 76 sets target values ​​for the evaporation temperatures of each of the indoor units 81 and 82 according to the set temperature and the room temperature. The air conditioning control unit 76 controls the state of each part of the air conditioning system 2 (for example, the capacity of the compressor 71 and the airflow of the outdoor fan 75) based on the target values ​​for evaporation temperatures. This adjusts the operating capacity (air conditioning capacity) of the air conditioning system 2. The target values ​​for evaporation temperatures may also be set by the control device 3.

[0064] The air conditioning control unit 76 includes, for example, memory and a processor (e.g., CPU), and each function of the air conditioning control unit 76 is realized by the processor operating according to a program stored in memory. Each function of the air conditioning control unit 76 may be realized by an FPGA or ASIC. The program is recorded on a computer-readable recording medium.

[0065] The control device 3 is an example of a control unit and comprehensively controls the operation of the air conditioning system 201. The control device 3 is electrically connected to the ventilation control unit 23 and the air conditioning control unit 76 and transmits and receives signals to each other. The control device 3 controls the operation of the ventilation unit 1 and the air conditioning unit 2 by transmitting predetermined signals (for example, control signals to set the target supply air temperature and target evaporation temperature) to the ventilation control unit 23 and the air conditioning control unit 76. The control device 3 acquires detection values ​​from various sensors located in the ventilation unit 1 and the air conditioning unit 2, as well as information that identifies the operating status of the ventilation unit 1 and the air conditioning unit 2.

[0066] The control device 3 includes, for example, memory and a processor (e.g., a CPU (Central Processing Unit)), and each function of the control device 3 is realized by the processor operating according to a program stored in memory. Each function of the control device 3 may be realized by an FPGA or ASIC. The program is recorded on a computer-readable recording medium.

[0067] Remote control 4 is an input device for the user to input various commands to individually switch the operating status of ventilation system 1 and air conditioning system 2 (start / stop, operation type, set temperature, set humidity, set airflow, etc.). Remote control 4 also functions as a display device to show predetermined information (for example, the operating status of ventilation system 1 and air conditioning system 2, the indoor and outdoor temperatures, and the indoor and outdoor humidity).

[0068] Next, the control in the air conditioning system 201 of this embodiment will be described in more detail.

[0069] In this embodiment, the ability of the ventilation device 1 to adjust the temperature of the target space SP is defined as the first capacity Av, and the ability of the air conditioning device 2 to adjust the temperature of the target space SP is defined as the second capacity Ac. The units of the first capacity Av and the second capacity Ac are expressed, for example, in kW (kilowatts).

[0070] The larger the first capacity Av, the greater the amount of heat load that the ventilation system 1 can handle in the target space SP. Similarly, the larger the second capacity Ac, the greater the amount of heat load that the air conditioning system 2 can handle in the target space SP. The heat load of the target space SP is either a cooling load or a heating load.

[0071] The first capacity Av of the ventilation device 1 is the air conditioning capacity adjusted within a predetermined first capacity range by the ventilation control unit 23 controlling the state of each part within the ventilation device 1. The second capacity Ac of the air conditioning device 2 is the air conditioning capacity adjusted within a predetermined second capacity range by the air conditioning control unit 76 controlling the state of each part within the air conditioning device 2.

[0072] When the control device 3 reduces the first capacity Av of the ventilation device 1 during heating operation, the temperature or airflow rate (supply air temperature or supply air volume) of the supply air SA from the ventilation device 1 to the target space SP decreases during heating operation. When the control device 3 increases the first capacity Av of the ventilation device 1 during heating operation, the supply air temperature or supply air volume from the ventilation device 1 to the target space SP increases during heating operation. On the other hand, when the control device 3 reduces the first capacity Av of the ventilation device 1 during cooling operation, the supply air temperature from the ventilation device 1 to the target space SP increases, or the supply air volume from the ventilation device 1 to the target space SP decreases during cooling operation. When the control device 3 increases the first capacity Av of the ventilation device 1 during cooling operation, the supply air temperature from the ventilation device 1 to the target space SP decreases, or the supply air volume from the ventilation device 1 to the target space SP increases during cooling operation.

[0073] When the control device 3 reduces the second capacity Ac of the air conditioner 2 during heating operation, the temperature or airflow rate (discharge temperature or discharge airflow rate) of the air supplied from the air conditioner 2 to the target space SP decreases. When the control device 3 increases the second capacity Ac of the air conditioner 2 during heating operation, the discharge temperature or discharge airflow rate from the air conditioner 2 to the target space SP increases. On the other hand, when the control device 3 reduces the second capacity Ac of the air conditioner 2 during cooling operation, the discharge temperature from the air conditioner 2 to the target space SP increases, or the discharge airflow rate from the air conditioner 2 to the target space SP decreases. When the control device 3 increases the second capacity Ac of the air conditioner 2 during cooling operation, the discharge temperature from the air conditioner 2 to the target space SP decreases, or the discharge airflow rate from the air conditioner 2 to the target space SP increases.

[0074] The ventilation system 1 has an efficiency characteristic in which its energy efficiency (COP) increases as the first capacity Av decreases within the first capacity range. On the other hand, the COP of the air conditioning system 2 may be lower than that of the ventilation system 1, and the air conditioning system 2 may have an efficiency characteristic in which its COP decreases as the second capacity Ac decreases within the second capacity range.

[0075] When the heat load of the target space SP is lower than a predetermined amount L (low heat load condition), the control device 3 executes a first operating mode in which the ventilation device 1 adjusts the temperature of the target space SP without adjusting it with the air conditioning device 2. In the first operating mode, the control device 3 stops the air conditioning device 2 from adjusting the temperature of the target space SP and has the ventilation device 1 adjust the temperature of the target space SP. By executing the first operating mode in the low heat load condition, the control device 3 improves energy efficiency such as COP compared to when both the ventilation device 1 and the air conditioning device 2 adjust the temperature of the target space SP in the low heat load condition. The predetermined amount L is, for example, the amount that the air conditioning device 2 can handle with its minimum second capacity Ac to process the heat load of the target space SP.

[0076] The COP of ventilation unit 1 when operating at a low load is higher than that of air conditioning unit 2 when operating at the same low load. Therefore, by stopping the operation of air conditioning unit 2 under low heat load conditions, control device 3 improves energy efficiency, such as COP.

[0077] As the heat load of the target space SP gradually increases, the first capacity Av of the ventilation device 1 for adjusting the temperature of the target space SP becomes insufficient in the first operating mode. When the ventilation device 1 can no longer handle the heat load of the target space SP with its first capacity Av, the control device 3 switches from the first operating mode, in which the temperature of the target space SP is adjusted by the ventilation device 1 without adjustment by the air conditioning device 2, to the second operating mode, in which the temperature of the target space SP is adjusted by both the air conditioning device 2 and the ventilation device 1.

[0078] For example, if the difference between the amount of heat load that the ventilation device 1 can handle in the target space SP with its first capacity Av and the heat load in the target space SP falls below a predetermined threshold, the control device 3 determines that the condition indicating insufficient first capacity Av has been met. When the condition indicating insufficient first capacity Av is met, the control device 3 switches the operating mode from the first operating mode to the second operating mode.

[0079] Upon transitioning from the first operating mode to the second operating mode, the air conditioning system 201 processes the increased heat load of the target space SP through the first capacity Av of the ventilation device 1, which adjusts the temperature of the target space SP, and the second capacity Ac of the air conditioning device 2, which adjusts the temperature of the target space SP. In the second operating mode, the air conditioning system 201 distributes the processing of the heat load of the target space SP between the air conditioning device 2 and the ventilation device 1.

[0080] However, in the second operating mode, if the amount of heat load that the air conditioning unit 2 handles from the target space SP is small, the air conditioning unit 2 will operate at a low load, which may cause the air conditioning unit 2 (for example, the compressor 71) to repeatedly start and stop. This point will be explained with reference to Figure 2.

[0081] Figure 2 shows an example of the changes in the processing capacity (first capacity Av and second capacity Ac) of the ventilation system and the air conditioning system when transitioning from the first operating mode to the second operating mode. By executing the first operating mode, the control device 3 causes the ventilation system 1 to process the heat load of the target space SP instead of the air conditioning system 2. If the heat load of the target space SP is lower than the amount that the ventilation system 1 can process with its first capacity Av, the ventilation system 1 can process the entire heat load of the target space SP with its first capacity Av.

[0082] As the heat load of the target space SP gradually increases, the first capacity Av is insufficient to handle the heat load of the target space SP if the system remains in the first operating mode, resulting in a shortage of the first capacity Av. Therefore, when the conditions indicating a shortage of the first capacity Av are met, the control device 3 switches the operating mode of the air conditioning system 201 from the first operating mode to the second operating mode. As a result, the capacity of the air conditioning system 201 to handle the heat load of the target space SP in the second operating mode (total processing capacity) becomes the sum of the first capacity Av and the second capacity Ac. When this total processing capacity exceeds the start / stop line (the capacity at which the air conditioning unit 2 may start or stop), the frequency of the air conditioning unit 2 starting and stopping increases.

[0083] In the second operating mode, if the ventilation unit 1 handles a large proportion of the heat load of the target space SP, the proportion handled by the air conditioning unit 2 becomes relatively small, resulting in a reduced amount of heat load handled by the air conditioning unit 2. When the amount of heat load handled by the air conditioning unit 2 decreases, the air conditioning unit 2 operates at a low load, which may cause the air conditioning unit 2 (for example, the compressor 71) to repeatedly start and stop. Repeated start and stop of the air conditioning unit 2 reduces the energy efficiency of the air conditioning system 201.

[0084] In contrast, in this embodiment, when the control device 3 transitions from the first operating mode to the second operating mode, it performs control (variable capacity ratio control) that reduces the first capacity Av of the ventilation device 1 and increases the second capacity Ac of the air conditioning device 2, as shown in Figure 3. Energy saving of the air conditioning system 201 is ensured by the variable capacity ratio control.

[0085] Figure 3 shows two control examples illustrating the changes in the respective processing capacities (first capacity Av and second capacity Ac) of the ventilation system and the air conditioning system when transitioning from the first operating mode to the second operating mode. When the control device 3 transitions from the first operating mode to the second operating mode, it performs control (variable capacity ratio control) that reduces the first capacity Av of the ventilation system 1 and increases the second capacity Ac of the air conditioning system 2. Figure 3 shows energy-saving priority control and comfort priority control as examples of variable capacity ratio control.

[0086] Through variable capacity ratio control, in the second operating mode, the proportion of the heat load handled by the ventilation device 1 in the target space SP decreases, while the proportion handled by the air conditioning device 2 in the target space SP increases relatively. As a result, the amount of heat load handled by the air conditioning device 2 in the target space SP increases. When the amount of heat load handled by the air conditioning device 2 in the target space SP increases, the load on the air conditioning device 2 increases, and the frequency of starting and stopping of the air conditioning device 2 (for example, the compressor 71) is suppressed. Consequently, energy saving of the air conditioning system 201 is ensured.

[0087] When the control device 3 transitions from the first operating mode to the second operating mode, it reduces the first capacity Av. If the ventilation device 1 is a device that has an efficiency characteristic in which the COP increases in response to a decrease in the first capacity Av, the COP of the ventilation device 1 increases as a result of the decrease in the first capacity Av, thus ensuring the energy saving of the air conditioning system 201.

[0088] When the control device 3 transitions from the first operating mode to the second operating mode, it may perform energy-saving priority control in the second operating mode (see "Energy-saving priority" in Figure 3). Energy-saving priority control is an example of variable capacity ratio control. Energy-saving priority control is a control that reduces the first capacity Av of the ventilation device 1 to the capacity at which the power consumption of the ventilation device 1 is minimized, and increases the second capacity Ac of the air conditioning device 2.

[0089] Due to the energy-saving priority control, in the second operating mode, the first capacity Av is reduced to the capacity at which the power consumption of the ventilation device 1 is minimized, thereby improving the energy efficiency of the ventilation device 1. Furthermore, due to the energy-saving priority control, in the second operating mode, the proportion of the heat load of the target space SP handled by the ventilation device 1 decreases, while the proportion handled by the air conditioning device 2 increases relatively. As a result, as described above, the load on the air conditioning device 2 increases, and the frequency of starting and stopping of the air conditioning device 2 (for example, the compressor 71) is suppressed. In this way, the energy efficiency of the air conditioning system 201 is ensured by the energy-saving priority control.

[0090] When the control device 3 transitions from the first operating mode to the second operating mode, it may perform comfort-prioritizing control in the second operating mode (see "Comfort Prioritizing" in Figure 3). Comfort-prioritizing control is an example of variable capacity ratio control. When the difference between the temperature of the supply air SA from the ventilation device 1 to the target space SP and the temperature of the target space SP becomes large, the comfort level of the target space SP decreases. Comfort-prioritizing control is a control that reduces the first capacity Av of the ventilation device 1 to a level where the difference between the temperature of the supply air SA from the ventilation device 1 to the target space SP and the temperature of the target space SP is within a predetermined range, and increases the second capacity Ac of the air conditioning device 2.

[0091] The temperature of the supply air SA (supply air temperature) is detected, for example, by sensor 24. The control device 3 uses the value detected by sensor 24 for comfort-prioritizing control. The temperature of the target space SP (indoor air temperature) is detected, for example, by an indoor temperature sensor located in indoor unit 81 or indoor unit 82. The control device 3 uses the value detected by the indoor temperature sensor for comfort-prioritizing control.

[0092] With comfort-prioritizing control, in the second operating mode, the difference between the temperature of the supply air SA from the ventilation device 1 to the target space SP and the temperature of the target space SP is kept within a predetermined range, thus suppressing the decrease in comfort caused by a large difference. Furthermore, with comfort-prioritizing control, in the second operating mode, the proportion of the heat load of the target space SP handled by the ventilation device 1 decreases, while the proportion handled by the air conditioning device 2 increases relatively. As a result, as described above, the load on the air conditioning device 2 increases, and the frequency of starting and stopping of the air conditioning device 2 (for example, the compressor 71) is suppressed. In this way, comfort-prioritizing control ensures both the comfort of the target space SP and the energy efficiency of the air conditioning system 201.

[0093] When the control device 3 transitions from the first operating mode to the second operating mode, it may perform control such as lowering the first capacity Av of the ventilation device 1 and increasing the second capacity Ac of the air conditioning device 2 so that the total processing capacity, which is the sum of the first capacity Av and the second capacity Ac, does not exceed the start / stop line. For example, the control device 3 may perform energy-saving priority control so that the total processing capacity, which is the sum of the first capacity Av and the second capacity Ac, does not exceed the start / stop line.

[0094] When the control device 3 transitions from the first operating mode to the second operating mode, it may perform control such as lowering the first capacity Av of the ventilation device 1 and increasing the second capacity Ac of the air conditioning device 2 so that the time it takes for the total processing capacity, which is the sum of the first capacity Av and the second capacity Ac, to exceed the start / stop line is delayed. For example, the control device 3 may perform comfort-prioritizing control so that the time it takes for the total processing capacity, which is the sum of the first capacity Av and the second capacity Ac, to exceed the start / stop line is delayed.

[0095] When the control device 3 transitions from the first operating mode to the second operating mode, it may switch between reducing the first capacity Av to the capacity that minimizes the power consumption of the ventilation device 1, or reducing it to the capacity that keeps the difference between the temperature of the supply air SA from the ventilation device 1 to the target space SP and the temperature of the target space SP within a predetermined range. This allows the control device 3 to select whether to prioritize minimizing the power consumption of the ventilation device 1 or keeping the difference between the temperature of the supply air SA from the ventilation device 1 to the target space SP and the temperature of the target space SP within a predetermined range in the second operating mode.

[0096] When the control device 3 transitions from the first operating mode to the second operating mode, it may allow the user to select whether to reduce the first capacity Av to the level at which the power consumption of the ventilation device 1 is minimized, or to reduce it to the level at which the difference between the temperature of the supply air SA from the ventilation device 1 to the target space SP and the temperature of the target space SP is within a predetermined range. This allows the user to choose whether to prioritize minimizing the power consumption of the ventilation device 1 or keeping the difference between the temperature of the supply air SA from the ventilation device 1 to the target space SP and the temperature of the target space SP within a predetermined range in the second operating mode. The user's selection input may also be set by operating the remote control 4.

[0097] Furthermore, when the control device 3 transitions from the first operating mode to the second operating mode, it may automatically select, according to predetermined selection conditions, whether to reduce the first capacity Av to the capacity that minimizes the power consumption of the ventilation device 1, or to the capacity that brings the difference between the supply air temperature from the ventilation device 1 to the target space SP and the temperature of the target space SP within a predetermined range.

[0098] When the control device 3 transitions from the first operating mode to the second operating mode, it may perform control (variable capacity control) that reduces the first capacity Av and increases the second capacity Ac to the capacity that minimizes the power consumption of the air conditioning unit 2. Variable capacity control may be applied to the variable capacity ratio control described above, or to the energy saving priority control or comfort priority control described above.

[0099] With variable capacity control, in the second operating mode, the second capacity Ac is reduced to the capacity that minimizes the power consumption of the air conditioning unit 2, thereby improving the energy efficiency of the air conditioning unit 2. Furthermore, with variable capacity control, in the second operating mode, the proportion of the heat load of the target space SP handled by the ventilation unit 1 decreases, while the proportion handled by the air conditioning unit 2 increases relatively. As a result, as described above, the load on the air conditioning unit 2 increases, and the frequency of starting and stopping of the air conditioning unit 2 (for example, the compressor 71) is suppressed. Energy efficiency of the air conditioning system 201 is ensured by variable capacity control.

[0100] Figure 4 is a state transition diagram showing an example of the transition conditions between the first operating mode and the second operating mode. In the first operating mode, the control device 3 controls the temperature to be controlled (temperature of the target space SP) to approach the set temperature by adjusting the first capacity Av of the ventilation device 1 (room temperature control).

[0101] If the controlled temperature does not reach the set temperature during room temperature control in the first operating mode, the control device 3 determines that a condition indicating insufficient first capacity Av has been met and switches the operating mode of the air conditioning system 201 from the first operating mode to the second operating mode. At this time, the control device 3 performs control (start / stop avoidance control) to suppress the frequency of starting and stopping of the air conditioning unit 2 by the variable capacity ratio control described above. As a result, if the first capacity Av in the first operating mode is insufficient to bring the temperature of the target space SP closer to the set temperature, the ability to bring the temperature of the target space SP closer to the set temperature can be increased by adding the second capacity Ac when switching to the second operating mode.

[0102] If the controlled temperature does not reach the set temperature for a predetermined period of time or longer during room temperature control in the first operating mode, the control device 3 may determine that a condition indicating insufficient first capacity Av has been met and switch the operating mode of the air conditioning system 201 from the first operating mode to the second operating mode. The switch to the second operating mode occurs if the first capacity Av in the first operating mode is insufficient to bring the temperature of the target space SP closer to the set temperature for a predetermined period of time or longer. This increases the ability to bring the temperature of the target space SP closer to the set temperature by adding the second capacity Ac, and also prevents the state in which the temperature of the target space SP does not approach the set temperature from continuing for a long period of time.

[0103] If the compressor 71 of the air conditioning unit 2 remains stopped for a predetermined time t1 or longer during the start / stop avoidance control in the second operating mode, the control device 3 may determine that the condition indicating the sufficiency of the first capacity Av has been met and switch the operating mode of the air conditioning system 201 from the second operating mode to the first operating mode. This allows the first capacity Av to be used to bring the temperature of the target space SP closer to the set temperature, and also prevents the compressor 71 from remaining stopped for an extended period.

[0104] If the rotational speed of the compressor 71 rises to a predetermined rotational speed r1 or higher during the start / stop avoidance control of the second operating mode, or if the operation of the compressor 71 continues for a predetermined time t2 or longer, the control device 3 transitions the control from start / stop avoidance control to coordinated control. Coordinated control is a control that removes the constraint of reducing the first capacity Av by start / stop avoidance control and adjusts the temperature of the target space SP to approach the set temperature by adjusting the first capacity Av and the second capacity Ac. By coordinated control in which the ventilation device 1 and the air conditioning device 2 work together to adjust the temperature of the target space SP, efficient temperature adjustment of the target space SP is achieved.

[0105] If the starting and stopping of the compressor 71 increases to a predetermined frequency or the rotational speed of the compressor 71 drops below a predetermined rotational speed r2 during coordinated control of the second operating mode, the control device 3 switches the control from coordinated control to start / stop avoidance control. This makes it possible to suppress the decrease in energy efficiency due to repeated starting and stopping of the compressor 71.

[0106] As described above, embodiments have been explained, but these embodiments are presented as examples only, and the present invention is not limited by these embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, and modifications are possible without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents.

[0107] For example, the ventilation method of ventilation device 1 is not limited to the above configuration. For example, ventilation device 1 may be an outside air treatment device equipped with an air handling unit and a chiller unit, or it may be a total heat exchanger that exchanges total heat. [Explanation of symbols]

[0108] 1. Ventilation system 2 Air conditioner 3. Control device 4 Remote control 10 Exhaust Units 11 Exhaust fan 12 Return air heat exchanger 14 sensors 20 Air supply units 21 Intake fan 22 Outdoor air heat exchanger 23 Ventilation Control Unit 24 sensors 50 Compressor Units 70 Outdoor unit 71 Compressor 72 Four-way switching valve 73 Outdoor heat exchanger 74 Outdoor expansion valve 75 Outdoor fan 76 Air Conditioning Control Unit 81,82 Indoor unit 83 Indoor heat exchanger 84 Indoor expansion valve 85 Indoor Fan 91 Return air port 92 Air supply port 93A,93B Air outlet 201 Air Conditioning System

Claims

1. A ventilation device that ventilates the target space, An air conditioning system having a heat exchanger that functions as a condenser or evaporator and a compressor that compresses a refrigerant, which draws in air from the target space and blows out air that has exchanged heat with the refrigerant flowing through the heat exchanger back into the target space, An air conditioning system comprising: a control unit that, when transitioning from a first operating mode in which the temperature of the target space is adjusted by the ventilation device without the air conditioning device, to a second operating mode in which the temperature is adjusted by both the air conditioning device and the ventilation device, reduces the first capacity and increases the second capacity so that the combined total processing capacity of the ventilation device adjusting the temperature and the air conditioning device adjusting the temperature does not exceed the start / stop line of the air conditioning device, or delays the time it takes to exceed it.

2. The air conditioning system according to claim 1, wherein when the control unit transitions from the first operating mode to the second operating mode, it reduces the first capacity to the capacity that minimizes the power consumption of the ventilation device, and increases the second capacity.

3. The air conditioning system according to claim 1, wherein when the control unit transitions from the first operating mode to the second operating mode, it reduces the first capacity to a level within which the difference between the temperature of the air supplied from the ventilation device to the target space and the temperature of the target space is within a predetermined range, and increases the second capacity.

4. The air conditioning system according to claim 1, wherein when the control unit transitions from the first operating mode to the second operating mode, it switches whether to reduce the first capacity to the capacity that minimizes the power consumption of the ventilation device, or to the capacity that brings the difference between the temperature of the air supplied from the ventilation device to the target space and the temperature of the target space within a predetermined range.

5. The air conditioning system according to claim 4, wherein when the control unit transitions from the first operating mode to the second operating mode, it selects, by user input, whether to reduce the first capacity to the capacity that minimizes the power consumption of the ventilation device, or to the capacity that brings the difference between the temperature of the air supplied from the ventilation device to the target space and the temperature of the target space within a predetermined range.

6. The air conditioning system according to claim 1, wherein when the control unit transitions from the first operating mode to the second operating mode, it reduces the first capacity and increases the second capacity to the capacity that minimizes the power consumption of the air conditioning device.

7. The air conditioning system according to claim 1, wherein the control unit transitions from the first operating mode to the second operating mode if the temperature does not reach the set temperature in the first operating mode.

8. The air conditioning system according to claim 7, wherein the control unit transitions from the first operating mode to the second operating mode if the temperature in the first operating mode remains below the set temperature for a predetermined period of time or longer.

9. The air conditioning system according to any one of claims 1 to 8, wherein the ventilation device is a device that recovers exhaust heat from the target space to the outside and reuses it as supply air to the target space.

10. A ventilation device that ventilates the target space, An air conditioning system having a heat exchanger that functions as a condenser or evaporator and a compressor that compresses a refrigerant, which draws in air from the target space and blows out air that has exchanged heat with the refrigerant flowing through the heat exchanger back into the target space, The system includes a control unit that, when transitioning from a first operating mode in which the temperature of the target space is adjusted by the ventilation device without adjustment by the air conditioning device, to a second operating mode in which the temperature is adjusted by both the air conditioning device and the ventilation device, reduces the first capacity of the ventilation device to adjust the temperature of the target space and increases the second capacity of the air conditioning device to adjust the temperature, The control unit, when transitioning from the first operating mode to the second operating mode, switches between reducing the first capacity to the capacity that minimizes the power consumption of the ventilation device, and reducing the capacity to the capacity that brings the difference between the temperature of the air supplied from the ventilation device to the target space and the temperature of the target space within a predetermined range.

11. A ventilation device that ventilates the target space, An air conditioning system having a heat exchanger that functions as a condenser or evaporator and a compressor that compresses a refrigerant, which draws in air from the target space and blows out air that has exchanged heat with the refrigerant flowing through the heat exchanger back into the target space, The system includes a control unit that, when transitioning from a first operating mode in which the temperature of the target space is adjusted by the ventilation device without adjustment by the air conditioning device, to a second operating mode in which the temperature is adjusted by both the air conditioning device and the ventilation device, reduces the first capacity of the ventilation device to adjust the temperature of the target space and increases the second capacity of the air conditioning device to adjust the temperature, After transitioning to the second operating mode, the control unit, upon meeting predetermined conditions during operation in the second operating mode, releases the restriction that reduces the first capacity and adjusts the first and second capacities to bring the temperature of the target space closer to the set temperature. The predetermined conditions include the rotational speed of the compressor increasing to or exceeding a predetermined rotational speed, or the operation of the compressor continuing for a predetermined time or longer.

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