JPWO2017208438A1 - Air conditioning system - Google Patents

Abstract

The first air conditioner (1) has a first refrigerant circuit and supplies air to the indoor space. The second air conditioner (2) has a second refrigerant circuit and supplies air to the indoor space. The control device (30) controls the first and second air conditioners (1, 2). Each of the first and second refrigerant circuits includes a compressor, a condenser, an expansion valve, and an evaporator, and is configured to circulate the refrigerant in the order of the compressor, the condenser, the expansion valve, and the evaporator. During the cooling operation of the first and second air conditioners (1, 2), when the first refrigerant evaporation temperature of the first refrigerant circuit is higher than the second refrigerant evaporation temperature of the second refrigerant circuit, The control device (30) increases the operating frequency of the compressor in the first refrigerant circuit and decreases the operating frequency of the compressor in the second refrigerant circuit, thereby reducing the first refrigerant evaporation temperature and the second refrigerant frequency. Reduce the difference from the refrigerant evaporation temperature.

Description

  The present invention relates to an air conditioning system.

  Conventionally, an air conditioning system including a refrigerant circuit for performing a vapor compression refrigeration cycle is known. In such an air conditioning system, an air conditioner for adjusting the temperature of the indoor space and a humidity control device for adjusting the humidity of the indoor space supply air to the same indoor space. (For example, see Patent Documents 1 to 3).

  For example, Japanese Patent No. 4513380 (Patent Document 1) discloses an air rhyowa system including a latent heat system refrigerant circuit for processing an indoor latent heat load and a sensible heat system refrigerant circuit for processing an indoor sensible heat load. It is disclosed. In Patent Document 1, a generated sensible heat treatment capacity value corresponding to the processing capacity of a sensible heat load processed together with a latent heat treatment is calculated in a latent heat system refrigerant circuit, and the sensible heat system compression mechanism Control the operating capacity. Thereby, the sensible heat processing capability in the sensible heat system refrigerant circuit is prevented from becoming excessive.

Japanese Patent No. 4513380 Japanese Patent No. 4525465 JP 2010-151421 A

  In the air conditioning system described in Patent Document 1, a latent heat load exists to some extent in the room, and the arrangement of a refrigerant circuit that can process the latent heat load with high efficiency is a prerequisite. For this reason, there is a problem that the above-described effects cannot be sufficiently exhibited when the latent heat load is small. Further, in order to perform the latent heat treatment with high efficiency, a device such as a desiccant is required, and there is a problem that the initial cost is expensive.

  Moreover, in the said patent document 1, the operating capacity | capacitance of a sensible heat system | strain compression mechanism is controlled in the direction which reduces sensible heat processing capability by making refrigerant | coolant evaporation temperature high according to the generated sensible heat processing stress value. However, since the air conditioning capacity per air volume decreases in the sensible heat system refrigerant circuit by increasing the refrigerant evaporation temperature, the air volume supplied to the indoor space is increased. As a result, there is a possibility that the occupant's comfort is impaired due to the direct hit of the occupants.

  Further, in an air conditioning system including an air conditioner and a ventilator, conventionally, the capacity of the air conditioner is set according to the indoor load, and the capacity of the ventilator is set according to the ventilator load. However, there is a demand for higher efficiency of the entire air conditioning system. Moreover, it is required that such a highly efficient air conditioning system can be easily constructed with an existing system configuration.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide high operating efficiency and occupancy in an air conditioning system including a plurality of air conditioners targeting the same indoor space. Is to realize the comfort of the elderly.

  The air conditioning system according to the present invention includes a first air conditioner, a second air conditioner, and a control device. The first air conditioner has a first refrigerant circuit and is configured to supply air to the indoor space. The second air conditioner has a second refrigerant circuit and is configured to supply air to the indoor space. The control device is configured to control the first and second air conditioners. Each of the first and second refrigerant circuits includes a compressor, a condenser, an expansion valve, and an evaporator, and is configured to circulate the refrigerant in the order of the compressor, the condenser, the expansion valve, and the evaporator. During the cooling operation of the first and second air conditioners, when the first refrigerant evaporation temperature of the first refrigerant circuit is higher than the second refrigerant evaporation temperature of the second refrigerant circuit, the control device By increasing the operating frequency of the compressor in the first refrigerant circuit and decreasing the operating frequency of the compressor in the second refrigerant circuit, the difference between the first refrigerant evaporation temperature and the second refrigerant evaporation temperature is reduced. To do.

  According to the present invention, in an air conditioning system including a plurality of air conditioners targeting the same indoor space, high operating efficiency and comfort for occupants can be realized.

It is a block diagram of the air conditioning system according to embodiment of this invention. It is the schematic of the refrigerant circuit of an air conditioner. It is the schematic of the refrigerant circuit of a ventilator. It is the schematic of the control structure of an air conditioning system. It is a flowchart explaining the process sequence of the cooperation control (evaporation temperature difference control) performed at the time of air_conditionaing | cooling operation. It is a flowchart explaining the process sequence of the cooperation control (high-low pressure temperature difference control) performed at the time of air_conditionaing | cooling operation. It is a flowchart explaining the process sequence of the cooperation control (discharge superheat degree difference control) performed at the time of air_conditionaing | cooling operation. It is a figure which shows the relationship between the power consumption of an air conditioning system, and evaporation temperature. It is a figure which shows the relationship between the power consumption of an air conditioning system, and evaporation temperature. It is a figure which shows the relationship between the power consumption of an air conditioning system, and evaporation temperature. It is a figure explaining the example of a change of cooperation control performed at the time of air_conditionaing | cooling operation. It is a flowchart explaining the process sequence of cooperation control (condensation temperature difference control) performed at the time of heating operation.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

(Configuration of air conditioning system)
FIG. 1 is a configuration diagram of an air conditioning system 100 according to an embodiment of the present invention. Air conditioning system 100 according to the embodiment includes two air conditioners (a first air conditioner and a second air conditioner) that air-condition the same indoor space. In the example of FIG. 1, the air conditioning system 100 includes an air conditioner 1 and a ventilator 2 and is configured to air-condition the same room R. In the air conditioning system according to the present invention, one of the two air conditioners does not need to be a ventilator, and both may be air conditioners. That is, the attributes of the two air conditioners are not limited.

  With reference to FIG. 1, an air conditioning system 100 includes an air conditioner 1, a ventilator 2, and a controller 30. The air conditioner 1 includes a plurality of indoor units 11 and 12 and an outdoor unit 10 provided corresponding to the indoor units 11 and 12. The ventilation device 2 includes an external air conditioner 21 and an outdoor unit 20 provided corresponding to the external air conditioner 21. In the example shown in FIG. 1, there are a plurality of indoor units and a single external air conditioner, but there may be a single indoor unit and a plurality of external air conditioners.

  The plurality of indoor units 11 and 12 and the outdoor unit 10 are connected by a refrigerant pipe 13. The indoor units 11 and 12 are arranged inside the room R, and the outdoor unit 10 is arranged outside the room R.

  The external air conditioner 21 and the outdoor unit 20 are connected by a refrigerant pipe 22. The external air conditioner 21 and the outdoor unit 20 are disposed outside the room R. The external air conditioner 21 is arrange | positioned at the ceiling back of the room R, for example. The external air conditioner 21 may be disposed inside the room R.

  The controller 30 is connected to each of the indoor units 11 and 12, the outdoor unit 10, the external air conditioner 21, and the outdoor unit 20 by a transmission line 40. The controller 30 includes a display and operation switches. The controller 30 can be configured by a microcomputer. The operation switch is generally constituted by a push switch that can be operated by a user (for example, a person M in the room R). Alternatively, when the display is configured by a touch panel, the display and the operation switch can be provided integrally.

(Air conditioning system refrigerant system)
Next, the refrigerant system of the air conditioning system 100 will be described with reference to FIGS. 2 and 3. The refrigerant system of the air conditioning system 100 includes a refrigerant circuit 1000 (see FIG. 2) that is a refrigerant system of the air conditioner 1 and a refrigerant circuit 2000 (see FIG. 3) that is a refrigerant system of the ventilation device 2.

FIG. 2 is a schematic diagram of the refrigerant circuit 1000 of the air conditioner 1.
Referring to FIG. 2, a refrigerant circuit 1000 includes a compressor 10a, a four-way valve 10d, an outdoor heat exchanger 10b, expansion valves (throttle devices or flow rate adjusting devices) 11c and 12c, indoor heat exchangers 11b and 12b, outdoor heat. The fan 10g for the exchanger 10b and the fans 11g and 12g for the indoor heat exchangers 11b and 12b are included.

  The compressor 10a, the four-way valve 10d, the outdoor heat exchanger 10b, the expansion valves 11c and 12c, and the indoor heat exchangers 11b and 12b are sequentially connected by a refrigerant pipe to constitute a refrigeration cycle in which the refrigerant circulates.

  The outdoor unit 10 includes a compressor 10a, a four-way valve 10d, an outdoor heat exchanger 10b, a blower 10g, an accumulator 10e, and an outdoor unit controller 10f. The outdoor heat exchanger 10b is a condenser that condenses the refrigerant or an evaporator that evaporates the refrigerant. The blower 10g sends air toward the outdoor heat exchanger 10b. The compressor 10a compresses the refrigerant. The four-way valve 10d reverses the flow of the refrigerant flowing through the outdoor heat exchanger 10b.

  The indoor unit 11 includes an indoor heat exchanger 11b, a blower 11g, an expansion valve 11c, and an indoor unit control unit 11f. The indoor heat exchanger 11b is a condenser that condenses the refrigerant or an evaporator that evaporates the refrigerant. The blower 11g sends air toward the indoor heat exchanger 11b. The expansion valve 11c depressurizes the condensed refrigerant.

  The indoor unit 12 includes an indoor heat exchanger 12b, a blower 12g, an expansion valve 12c, and an indoor unit controller 12f. The indoor heat exchanger 12b is a condenser that condenses the refrigerant or an evaporator that evaporates the refrigerant. The blower 12g sends air toward the indoor heat exchanger 12b. The expansion valve 12c depressurizes the condensed refrigerant.

  The refrigeration cycle can be switched between a heating path and a cooling path. The heating refrigeration cycle returns the refrigerant to the compressor 10a through the compressor 10a, the indoor heat exchangers 11b and 12b, the expansion valves 11c and 12c, and the outdoor heat exchanger 10b in this order. The cooling refrigeration cycle returns the refrigerant to the compressor 10a through the compressor 10a, the outdoor heat exchanger 10b, the expansion valves 11c and 12c, and the indoor heat exchangers 11b and 12b in this order.

FIG. 3 is a schematic diagram of the refrigerant circuit 2000 of the ventilation device 2.
Referring to FIG. 3, a refrigerant circuit 2000 includes a compressor 20a, a four-way valve 20d, an outdoor heat exchanger 20b, an expansion valve 21c, a ventilation heat exchanger 21b, a blower 20g for the outdoor heat exchanger 20b, and a ventilation heat exchange. A blower 21g for the device 21b is included.

  The compressor 20a, the four-way valve 20d, the outdoor heat exchanger 20b, the expansion valve 21c, and the ventilation heat exchanger 21b are sequentially connected by a refrigerant pipe to constitute a refrigeration cycle in which the refrigerant circulates.

  The outdoor unit 20 includes a compressor 20a, a four-way valve 20d, an outdoor heat exchanger 20b, a blower 20g, an accumulator 20e, and an outdoor unit controller 20f. The outdoor heat exchanger 20b is a condenser that condenses the refrigerant or an evaporator that evaporates the refrigerant. The blower 20g sends air toward the outdoor heat exchanger 20b. The compressor 20a compresses the refrigerant. The four-way valve 20d reverses the flow of the refrigerant flowing through the outdoor heat exchanger 20b.

  The external air conditioner 21 includes a ventilation heat exchanger 21b, a blower 21g, an expansion valve 21c, and an external air conditioner control unit 21f. The ventilation heat exchanger 21b is a condenser that condenses the refrigerant or an evaporator that evaporates the refrigerant. The blower 21g sends air toward the ventilation heat exchanger 21b. The expansion valve 21c depressurizes the condensed refrigerant.

  The refrigerant circuit 2000 can be switched between a heating path and a cooling path. The refrigeration cycle for heating returns the refrigerant to the compressor 20a through the compressor 20a, the ventilation heat exchanger 21b, the expansion valve 21c, and the outdoor heat exchanger 20b in this order. The cooling refrigeration cycle returns the refrigerant to the compressor 20a via the compressor 20a, the outdoor heat exchanger 20b, the expansion valve 21c, and the ventilation heat exchanger 21b in this order.

(Refrigerant)
Examples of the refrigerant used in the refrigerant circuits 1000 and 2000 include HFC refrigerants such as R410A, R407C, and R404A, HCFC refrigerants such as R22 and R134a, or natural refrigerants such as carbon dioxide, hydrocarbon, and helium.

(Compressor)
The compressors 10a and 20a suck in and compress the refrigerant, and discharge it as a high-temperature and high-pressure gas refrigerant. The compressors 10a and 20a are, for example, mounted with an inverter, and are positive displacement compressors driven by a motor (not shown) controlled by the inverter. As the compressor, for example, various types of compressors such as a reciprocating type, a rotary type, a scroll type, and a screw type can be applied. The number of compressors is not limited to one, and a plurality of compressors may be connected in parallel or in series.

  The outdoor unit controller 10f controls the operating frequency (rotational speed) of the compressor 10a. Thereby, the operating capacity (amount of refrigerant discharged per unit time) of the compressor 10a is controlled. The outdoor unit controller 20f controls the operating frequency of the compressor 20a. Thereby, the operating capacity of the compressor 20a is controlled.

(Heat exchanger)
Both the outdoor heat exchangers 10b and 20b operate as an evaporator during heating. The outdoor heat exchanger 10b performs heat exchange between the refrigerant sent from the expansion valves 11c and 12c and the outdoor air, and evaporates the refrigerant. The outdoor heat exchanger 20b performs heat exchange between the refrigerant sent from the expansion valve 21c and the outdoor air, and evaporates the refrigerant.

  The outdoor heat exchangers 10b and 20b operate as condensers during cooling. The outdoor heat exchanger 10b performs heat exchange between the refrigerant discharged from the compressor 10a and the outdoor air, and condenses the refrigerant. The outdoor heat exchanger 20b performs heat exchange between the refrigerant discharged from the compressor 20a and the outdoor air, and condenses the refrigerant.

  The indoor heat exchangers 11b and 12b and the ventilation heat exchanger 21b operate as a condenser during heating. The indoor heat exchangers 11b and 12b perform heat exchange between the refrigerant discharged from the compressor 10a and the indoor air blown by the blowers 11g and 12g, respectively, and condense the refrigerant. The ventilation heat exchanger 21b performs heat exchange between the refrigerant discharged from the compressor 20a and the outdoor air taken in by the blower 21g, and condenses the refrigerant.

  The indoor heat exchangers 11b and 12b and the ventilation heat exchanger 21b operate as an evaporator during cooling. The indoor heat exchangers 11b and 12b perform heat exchange between the refrigerant sent from the expansion valves 11c and 12c and the indoor air blown by the blowers 11g and 12g, respectively, and evaporate the refrigerant. The ventilation heat exchanger 21b performs heat exchange between the refrigerant sent from the expansion valve 21c and the outdoor air taken in by the blower 21g, and evaporates the refrigerant.

  The heat exchangers 10b, 11b, 12b, 20b, and 21b are, for example, cross-fin type fin-and-tube heat exchangers configured by heat transfer tubes and a large number of fins.

(Expansion valve)
The expansion valves 11c, 12c, and 21c can adjust the flow rate of the refrigerant flowing in the refrigeration cycle. The expansion valves 11c, 12c, and 21c are composed of, for example, an electronic expansion valve that can adjust the opening degree of a valve by a stepping motor (not shown), a mechanical expansion valve that employs a diaphragm as a pressure receiving portion, or a capillary tube. Is done.

  In the present embodiment, the expansion valves 11c, 12c, and 21c are arranged in the indoor units 11 and 12 and the outdoor conditioner 21, respectively, but may be arranged on the refrigerant pipe or in the outdoor unit. That is, each expansion valve should just be arrange | positioned between the condenser and the evaporator.

  The indoor unit control unit 11f controls the opening degree of the expansion valve 11c with a stepping motor. The indoor unit control unit 12f controls the opening degree of the expansion valve 12c. The external air conditioner control unit 21f controls the opening degree of the expansion valve 21c. Thereby, the pressure reduction amount of the refrigerant is controlled.

(Four-way valve)
The four-way valve 10d is a valve for switching the direction of the refrigerant flowing through the heat exchangers 10b, 11b, and 12b by sliding a member inside. When the room is cooled, the four-way valve 10d constitutes a refrigeration cycle in which the refrigerant flows in the order of the compressor 10a, the outdoor heat exchanger 10b, the expansion valves 11c and 12c, and the indoor heat exchangers 11b and 12b. When the room is heated, the four-way valve 10d forms a refrigeration cycle in which the refrigerant flows in the order of the compressor 10a, the indoor heat exchangers 11b and 12b, the expansion valves 11c and 12c, and the outdoor heat exchanger 10b. The four-way valve 10d switches the direction of the refrigerant between cooling and heating according to an instruction from the outdoor unit control unit 10f.

  The four-way valve 20d is a valve for switching the direction of the refrigerant flowing through the heat exchangers 20b and 21b by sliding the member inside. When the room is cooled, the four-way valve 20d forms a refrigeration cycle in which the refrigerant flows in the order of the compressor 20a, the outdoor heat exchanger 20b, the expansion valve 21c, and the ventilation heat exchanger 21b. When the room is heated, the four-way valve 10d constitutes a refrigeration cycle in which refrigerant flows in the order of the compressor 20a, the ventilation heat exchanger 21b, the expansion valve 21c, and the outdoor heat exchanger 20b. The four-way valve 20d switches the direction of the refrigerant between cooling and heating according to an instruction from the outdoor unit control unit 20f.

(Blower)
The blower 10g can change the flow rate of the air supplied to the outdoor heat exchanger 10b. The blowers 11g and 12g can change the flow rate of air supplied to the indoor heat exchangers 11b and 12b, respectively. The blower 20g can change the flow rate of the air supplied to the outdoor heat exchanger 20b. The blower 21g can change the flow rate of the air supplied to the ventilation heat exchanger 21b. The blowers 10g, 11g, 12g, 20g, and 21g are, for example, a centrifugal fan or a multiblade fan driven by a driving motor such as a DC motor.

(accumulator)
The accumulators 10e and 20e are tanks for preventing liquid refrigerant from passing through and preventing liquid refrigerant from flowing into the compressors 10a and 20a.

(Configuration of air path of air conditioner 1)
The structure of the air path in the air conditioner 1 will be described with reference to FIG. When the outdoor unit 10 takes in outdoor air from a suction port (not shown), the air exchanged with the refrigerant through the outdoor heat exchanger 10b is discharged to the outside using the blower 10g. When the indoor units 11 and 12 take in indoor air, the air exchanged through the indoor heat exchangers 11b and 12b is supplied to the room using the blowers 11g and 12g.

(Configuration of the air path of the ventilation device 2)
The structure of the air path in the ventilator 2 will be described with reference to FIG. When the outdoor unit 20 takes in outdoor air from a suction port (not shown), the air exchanged with the refrigerant through the outdoor heat exchanger 20b is discharged to the outside using the blower 20g. When the outdoor air conditioner 21 takes in outdoor air, the air that has undergone heat exchange through the ventilation heat exchanger 21b is supplied to the room using the blower 21g.

(Cooling operation of refrigerant circuit 1000)
The cooling operation of the refrigerant circuit 1000 will be described with reference to FIG. The refrigerant discharged from the compressor 10a passes through the four-way valve 10d and flows to the outdoor heat exchanger 10b. The outdoor heat exchanger 10b operates as a condenser. The refrigerant is condensed and liquefied when exchanging heat with air and flows to the expansion valves 11c and 12c. The refrigerant is depressurized by the expansion valves 11c and 12c. The indoor heat exchangers 11b and 12b operate as an evaporator. The refrigerant evaporates by taking heat from the air in the room R in the indoor heat exchangers 11b and 12b. As a result, the temperature of the room R decreases. Thereafter, the refrigerant passes through the four-way valve 10d and is sucked into the compressor 10a again.

(Heating operation of refrigerant circuit 1000)
Next, the heating operation of the refrigerant circuit 1000 will be described. The refrigerant discharged from the compressor 10a passes through the four-way valve 10d and flows to the indoor heat exchangers 11b and 12b. The indoor heat exchangers 11b and 12b operate as condensers. The refrigerant gives heat to the air in the room R to be condensed and liquefied. Thereby, the temperature of the room R rises. Thereafter, the refrigerant flows to the expansion valves 11c and 12c. The refrigerant is depressurized by the expansion valves 11c and 12c. The outdoor heat exchanger 10b operates as an evaporator. The refrigerant exchanges heat with air and evaporates, and then passes through the four-way valve 10d and is sucked into the compressor 10a again.

(Cooling operation of refrigerant circuit 2000)
The cooling operation of the refrigerant circuit 2000 will be described with reference to FIG. The refrigerant discharged from the compressor 20a flows through the four-way valve 20d to the outdoor heat exchanger 20b. The outdoor heat exchanger 20b operates as a condenser. The refrigerant condenses and liquefies when exchanging heat with air and flows to the expansion valve 21c. The refrigerant is decompressed by the expansion valve 21c. The ventilation heat exchanger 21b operates as an evaporator. The refrigerant evaporates by taking heat from outdoor air in the ventilation heat exchanger 21b. This outdoor air is supplied to the room R. Thereafter, the refrigerant passes through the four-way valve 20d and is sucked into the compressor 20a again.

(Heating operation of refrigerant circuit 2000)
Next, the heating operation of the refrigerant circuit 2000 will be described. The refrigerant discharged from the compressor 20a flows through the four-way valve 20d to the ventilation heat exchanger 21b. The ventilation heat exchanger 21b operates as a condenser. The refrigerant gives heat to the outdoor air and condensates. This outdoor air is supplied to the room R. Thereafter, the refrigerant flows to the expansion valve 21c. The refrigerant is decompressed by the expansion valve 21c. The outdoor heat exchanger 20b operates as an evaporator. The refrigerant exchanges heat with air and evaporates, and then passes through the four-way valve 20d and is sucked into the compressor 20a again.

(Detector)
Next, the detection part installed in the air conditioning system 100 is demonstrated.

  The room temperature detection part 1a is arrange | positioned inside the room R which is air-conditioning object, and detects the room temperature T of the room R. The indoor temperature detection part 1a is arrange | positioned near the suction inlet of the indoor units 11 and 12, for example, and can detect intake air temperature as indoor temperature. A detection value by the room temperature detection unit 1 a is input to the controller 30.

  The room temperature detection unit 1a may be arranged inside the controller 30 or inside each indoor unit as long as the room temperature in the room R can be detected. Moreover, the number of arrangement | positioning of the indoor temperature detection part 1a is not specifically limited.

  The outdoor temperature detection part 1b is arrange | positioned inside the outdoor unit 10, and detects the air temperature around the outdoor unit 10 as outdoor temperature. The detection value by the outdoor temperature detection unit 1 b is input to the controller 30. The outdoor temperature detection part 1b acquires outdoor temperature using a temperature sensor. Or outdoor temperature detection part 1b can also acquire outdoor temperature by receiving weather information via the Internet or other networks.

  The control target detection unit 1 c detects the control target of the ventilation device 2. This control object includes the temperature of the air blown from the air outlet of the external air conditioner 21, the dew point temperature of the blown air, and the absolute humidity.

  The pipe temperature detector 11h is arranged in a refrigerant pipe connected to the gas side of the indoor heat exchanger 11b. The pipe temperature detection part 11i is arrange | positioned at the refrigerant | coolant piping connected to the liquid side of the indoor heat exchanger 11b. The pipe temperature detector 12h is arranged in a refrigerant pipe connected to the gas side of the indoor heat exchanger 12b. The pipe temperature detection part 12i is arrange | positioned at the refrigerant | coolant piping connected to the liquid side of the indoor heat exchanger 12b. The pipe temperature detectors 11h and 12h detect the temperature of the refrigerant at the evaporator outlet when the indoor heat exchangers 11b and 12b operate as an evaporator. The pipe temperature detectors 11i and 12i detect the temperature of the refrigerant at the outlet of the condenser when the indoor heat exchangers 11b and 12b operate as a condenser. Detection values by the pipe temperature detection units 11h, 12h, 11i, and 12i are input to the controller 30.

  Detection values obtained by the pipe temperature detection units 11h, 11i, 12h, and 12i are used to calculate the degree of superheat and the degree of supercooling of the refrigerant flowing through the refrigerant circuit 1000. The degree of superheat of the refrigerant is the difference between the evaporation temperature ET and the refrigerant temperature at the evaporator outlet. The degree of supercooling of the refrigerant is the difference between the condensation temperature CT and the temperature of the refrigerant at the condenser outlet.

  The pipe temperature detector 21h is arranged in a refrigerant pipe connected to the gas side of the ventilation heat exchanger 21b. The pipe temperature detection part 21i is arrange | positioned at the refrigerant | coolant piping connected to the liquid side of the ventilation heat exchanger 21b. The pipe temperature detector 21h detects the temperature of the refrigerant at the evaporator outlet when the ventilation heat exchanger 21b operates as an evaporator. The pipe temperature detector 21i detects the temperature of the refrigerant at the condenser outlet when the ventilation heat exchanger 21b operates as a condenser. The detection values by the pipe temperature detection units 21h and 21i are used to calculate the degree of superheat and the degree of supercooling of the refrigerant flowing through the refrigerant circuit 2000.

  The discharge temperature detector 10j detects the discharge temperature Td of the refrigerant discharged from the compressor 10a. The discharge temperature detector 20j detects the discharge temperature Td of the refrigerant discharged from the compressor 20a. In the following description, the discharge temperature Td of the compressor 10a is expressed as “Td1”, and the discharge temperature Td of the compressor 20a is expressed as “Td2”.

  The condensing temperature detector 10k detects the condensing temperature CT of the refrigerant flowing through the refrigerant circuit 1000. The condensation temperature detection unit 20k detects the condensation temperature CT of the refrigerant flowing through the refrigerant circuit 2000. The detection values by the condensation temperature detection units 10k and 20k are input to the controller 30.

  The evaporating temperature detection unit 101 detects the evaporating temperature ET of the refrigerant flowing through the refrigerant circuit 1000. The evaporating temperature detector 20l detects the evaporating temperature ET of the refrigerant flowing through the refrigerant circuit 2000. Detection values by the evaporation temperature detection units 10 l and 20 l are input to the controller 30.

  In the following description, the condensation temperature CT of the refrigerant flowing through the refrigerant circuit 1000 of the air conditioner 1 is expressed as “CT1”, and the evaporation temperature ET is expressed as “ET1”. Further, the condensation temperature CT of the refrigerant flowing through the refrigerant circuit 2000 of the ventilation device 2 is expressed as “CT2”, and the evaporation temperature ET is expressed as “ET2”.

(controller)
Next, the controller 30 will be described. The controller 30 includes a CPU (Central Processing Unit), a storage device, an input / output buffer, and the like (all not shown). The controller 30 controls the air conditioner 1 (the outdoor unit 10 and the indoor units 11 and 12) and the ventilation device 2 (the external air conditioner 21 and the outdoor unit 20). Note that these controls are not limited to processing by software, and can be processed by dedicated hardware (electronic circuit).

  The controller 30 and each of the outdoor unit 10, the indoor units 11 and 12, the outdoor conditioner 21, and the outdoor unit 20 are connected to each other via a transmission line 40. The detection value of each detection unit and the control instructions to the outdoor unit 10, the indoor units 11 and 12, the external air conditioner 21 and the outdoor unit 20 are transmitted through the transmission line 40. The transmission line 40 need not be wired. The communication through the transmission line 40 may be wireless communication such as infrared communication.

  The controller 30 does not have to be arranged in the room R. The controller 30 is arranged outside the room R, and uses, for example, a wireless communication system such as LTE (Long Term Evolution), CDMA (Code Division Multiple Access), or Bluetooth (registered trademark), the outdoor unit 10, the indoor unit. 11, 12, the external air conditioner 21, and the outdoor unit 20 may communicate with each other.

(Control configuration of the air conditioning system 100)
Next, the control configuration of the air conditioning system 100 will be described with reference to FIG.

  Detection values obtained by the various detection units described above are input to the controller 30. The controller 30 generates a control instruction for controlling the air conditioner 1 and the ventilator 2 based on the detection values by the various detection units. The controller 30 transmits the generated control instructions to the control units (the outdoor unit control units 10f and 20f, the indoor unit control units 11f and 12f, and the external air conditioner control unit 21f) of the air conditioner 1 and the ventilation device 2.

  The outdoor unit control unit 10f changes the operating capacity of the compressor 10a by controlling the operating frequency (rotational speed) of the compressor 10a. The outdoor unit control unit 10f acquires a target value (target temperature T *) of the indoor temperature set by the controller 30. Further, the outdoor unit control unit 10 f acquires a target value (target evaporation temperature ET1 *) of the evaporation temperature ET1 of the refrigerant circuit 1000 from the controller 30. The outdoor unit control unit 10f controls the amount of air blown from the blower 10g.

  The indoor unit controllers 11f and 12f adjust the flow rate of the refrigerant flowing through the refrigerant circuit 1000 by controlling the opening degrees of the expansion valves 11c and 12c, respectively. Moreover, the indoor unit control parts 11f and 12f respectively control the air volume of the blowers 11g and 12g.

  The outdoor unit control unit 20f changes the operating capacity of the compressor 20a by controlling the operating frequency of the compressor 20a. The outdoor unit control unit 20 f acquires the target value to be controlled set by the controller 30. Moreover, the outdoor unit control part 20f controls the ventilation volume of the air blower 20g.

  The external air conditioner control unit 21 f adjusts the flow rate of the refrigerant flowing in the refrigerant circuit 2000 by controlling the opening degree of the expansion valve 21. In addition, the external air conditioner control unit 21f controls the amount of air blown by the blower 21g.

  The controller 30, the outdoor unit control unit 10f, the indoor unit control units 11f and 12f, the outdoor unit control unit 20f, and the external air conditioner control unit 21f can also be realized by hardware such as a circuit device that realizes these functions. However, it can also be realized as software executed on an arithmetic device such as a microcomputer or CPU. The controller 30, the outdoor unit control unit 10f, the indoor unit control units 11f and 12f, the outdoor unit control unit 20f, and the external air conditioner control unit 21f correspond to an example of the “control device” in the present invention.

  The outdoor unit control unit 10f, the indoor unit control units 11f and 12f, the outdoor unit control unit 20f, and the outdoor conditioner control unit 21f may be provided in the controller 30. Or you may provide the function of the controller 30 in either the outdoor unit control part 10f, the indoor unit control parts 11f and 12f, the outdoor unit control part 20f, and the external air conditioner control part 21f.

  The air conditioning system 100 includes “normal control” and “cooperative control” as control modes for controlling the air conditioner 1 and the ventilator 2.

  In the normal control, the air conditioner 1 is controlled so that the room temperature T of the room R matches the target temperature T * set by the controller 30, and the control target of the ventilator 2 is set by the controller 30. The ventilator 2 is controlled so as to match the value. In addition, as above-mentioned, the control object of the ventilation apparatus 2 contains the blowing air temperature of the external air conditioner 21, the dew point temperature of blowing air, and absolute humidity. In the normal control, the operation capacity of the compressor 10a in the air conditioner 1 and the operation capacity of the compressor 20a in the ventilation device 2 are controlled independently of each other.

  On the other hand, the cooperative control controls the operation of the air conditioner 1 and the operation of the ventilation device 2 in cooperation. In the present embodiment, as described later, cooperative control of the air conditioner 1 and the ventilator 2 is executed so that the power consumption of the entire air conditioning system is reduced.

  In the cooperative control, information indicating the operating state of the air conditioner 1 and information indicating the operating state of the ventilator 2 are shared by the control unit of the air conditioner 1 and the control unit of the ventilator 2 through the controller 30. Based on this shared information, the operating capacity of the compressor 10a in the air conditioner 1 and the operating capacity of the compressor 20a in the ventilation device 2 are controlled in cooperation.

<Normal control>
First, normal control executed in the air conditioning system 100 will be described.

(1) Cooling operation Control of the air conditioner 1 and the ventilator 2 when the air conditioning system 100 performs the cooling operation will be described.

(Control of air conditioner 1)
The outdoor unit control unit 10f and the indoor unit control units 11f and 12f control the air conditioner 1 based on the indoor temperature T detected by the indoor temperature detection unit 1a.

  The outdoor unit controller 10f calculates the target evaporation temperature ET1 * based on the deviation α1 (α1 = T−T *) of the indoor temperature T with respect to the target temperature T *. Then, the outdoor unit controller 10f controls the operating frequency of the compressor 10a so that the evaporation temperature ET1 detected by the evaporation temperature detector 10l matches the target evaporation temperature ET1 *.

  The indoor unit controllers 11f and 12f adjust the opening degrees of the expansion valves 11c and 12c so that the degree of superheat in the indoor units 11 and 12 becomes a predetermined value, respectively. The indoor unit control units 11f and 12f further control the rotation speeds of the blowers 11g and 12g so that the blown amount of the blowers 11g and 12g becomes the set air volume. The set air volume is set according to the deviation α1, for example. When the deviation α1 is equal to or less than the threshold value, the indoor unit control units 11f and 12f set the air flow rate so as to reduce the air flow rate or stop the air flow.

  When the outdoor unit controller 10f sets the target value (target condensing temperature CT1 *) of the condensing temperature CT1 based on the outdoor temperature detected by the outdoor temperature detecting unit 1b, the outdoor unit controller 10f sets the target air temperature of the blower 10g based on the target condensing temperature CT1 *. Set the air flow. And the outdoor unit control part 10f controls the rotational speed of the air blower 10g so that the air flow rate of the air blower 10g becomes the set air volume.

  When the absolute value of the deviation α1 becomes smaller than a preset threshold value in the air conditioning ranges of the indoor units 11 and 12, the outdoor unit control unit 10f increases the target evaporation temperature ET1 *. Since the work amount (power consumption) of the compressor 10a is reduced by increasing the target evaporation temperature ET1 *, the operating efficiency of the air conditioner 1 can be increased.

(Control of ventilation device 2)
The outdoor unit control unit 20f and the outdoor conditioner control unit 21f control the ventilator 2 based on the detection value of the control target detection unit 1c.

  The outdoor unit control unit 20f is configured so that the blown air temperature SA detected by the controlled object detection unit 1c matches the target value (target blown air temperature SA *) set by the controller 30. 2 is controlled. Specifically, the outdoor unit control unit 20f determines the necessary air conditioning capacity based on the deviation β1 (β1 = SA * −SA) of the blown air temperature SA with respect to the target blown air temperature SA * and a preset ventilation air volume. Is calculated. And the outdoor unit control part 20f controls the operating frequency of the compressor 20a based on the calculated air conditioning capability so that the target blown air temperature SA * can be reached.

  The external air conditioner control unit 21f adjusts the opening degree of the expansion valve 21c so that the degree of superheat in the external air conditioner 21 becomes a predetermined value. The external air conditioner control unit 21f further controls the rotational speed of the blower 21g so that the blown air volume of the blower 21g becomes a preset ventilation air volume.

  When the outdoor unit control unit 20f sets the target value (target condensation temperature CT2 *) of the condensation temperature CT2 based on the detection value of the outdoor temperature detection unit 1b, the outdoor unit control unit 20f sets the blowing amount of the blower 20g based on the target condensation temperature CT2 *. To do. And the outdoor unit control part 20f controls the rotational speed of the air blower 20g so that the air flow rate of the air blower 20g becomes the set air volume.

(2) Heating operation Control of the air conditioner 1 and the ventilator 2 when the air conditioning system 100 performs the heating operation will be described.

(Control of air conditioner 1)
The outdoor unit control unit 10f and the indoor unit control units 11f and 12f control the air conditioner 1 based on the indoor temperature T detected by the indoor temperature detection unit 1a.

  The outdoor unit controller 10f calculates a target condensation temperature CT1 * based on the deviation α1 of the room temperature T with respect to the target temperature T *. Then, the outdoor unit control unit 10f controls the operating frequency of the compressor 10a so that the condensation temperature CT1 detected by the condensation temperature detection unit 10k matches the target condensation temperature CT1 *.

  The indoor unit controllers 11f and 12f adjust the opening degree of the expansion valves 11c and 12c so that the degree of supercooling in the indoor units 11 and 12 becomes a predetermined value, respectively. The indoor unit control units 11f and 12f further control the rotation speeds of the blowers 11g and 12g so that the blown amount of the blowers 11g and 12g becomes the set air volume. The set air volume is set according to the deviation α1, for example. When the deviation α1 is equal to or less than the threshold value, the indoor unit control units 11f and 12f set the air flow rate so as to reduce the air flow rate or stop the air flow.

  When the outdoor unit control unit 10f sets a target value (target evaporation temperature ET1 *) of the evaporation temperature ET1 based on the outdoor temperature detected by the outdoor temperature detection unit 1b, the outdoor unit control unit 10f sets the fan 10g based on the target evaporation temperature ET1 *. Set the air flow. And the outdoor unit control part 10f controls the rotational speed of the air blower 10g so that the air flow rate of the air blower 10g becomes the set air volume.

  When the absolute value of the deviation α1 becomes smaller than a preset threshold in the air conditioning ranges of the indoor units 11 and 12, the indoor unit control units 11f and 12f control the indoor unit 11 in order to suppress excessive heating. , 12 is stopped.

(Control of ventilation device 2)
The outdoor unit control unit 20f and the outdoor conditioner control unit 21f control the ventilator 2 based on the detection value of the control target detection unit 1c.

  The outdoor unit control unit 20f is configured so that the blown air temperature SA detected by the controlled object detection unit 1c matches the target value (target blown air temperature SA *) set by the controller 30. 2 is controlled. Specifically, the outdoor unit control unit 20f calculates the necessary air conditioning capacity based on the deviation β1 of the detected temperature SA of the controlled object detection unit 1c with respect to the target blown air temperature SA * and a preset ventilation air volume. . And the outdoor unit control part 20f controls the operating frequency of the compressor 20a based on the calculated air conditioning capability so that the target blown air temperature SA * can be reached.

  The external air conditioner control unit 21f adjusts the opening degree of the expansion valve 21c so that the degree of supercooling in the external air conditioner 21 becomes a predetermined value. The external air conditioner control unit 21f further controls the rotational speed of the blower 21g so that the blown air volume of the blower 21g becomes a preset ventilation air volume.

  When the outdoor unit control unit 20f sets the target value (target evaporation temperature ET2 *) of the evaporation temperature ET2 based on the detection value of the outdoor temperature detection unit 1b, the outdoor unit control unit 20f sets the blowing amount of the blower 20g based on the target evaporation temperature ET2 *. To do. And the outdoor unit control part 20f controls the rotational speed of the air blower 20g so that the air flow rate of the air blower 20g becomes the set air volume.

<Cooperation control>
Next, cooperative control executed in the air conditioning system 100 will be described. In the present embodiment, cooperative control executed during cooling operation will be described.

  The transition from the normal control to the cooperative control described above is executed based on the operating states of the air conditioner 1 and the ventilator 2. First, transition from normal control to cooperative control will be described with reference to FIG. Steps S01 to S04 in FIG. 5 indicate processing for determining whether or not to shift from normal control to cooperative control.

(S01: Normal control)
In step S01, the normal control described above is executed in the air conditioning system 100. In the normal control, the evaporation temperature ET1 of the air conditioner 1 changes by controlling the operating frequency of the compressor 10a according to the indoor load. Moreover, the evaporation temperature ET2 of the ventilator 2 changes by controlling the operating frequency of the compressor 20a according to the ventilation load.

(S02: Determination of continuous operation)
In step S02, it is determined whether or not the operating state of the compressor is stable in each of the air conditioner 1 and the ventilator 2. Specifically, it is determined whether each of the compressors 10a and 20a is continuously operated for a predetermined time (referred to as A time) set in advance.

  For example, the operation time (continuous operation time) of the compressor 10a from the time when the compressor 10a is most recently activated to the present is compared with the A time. When the continuous operation time of the compressor 10a is longer than the A time, it is determined that the operation state of the compressor 10a is stable. On the other hand, when the continuous operation time of the compressor 10a is A hours or less, it is determined that the operation state of the compressor 10a is not stable. In this case, normal control is continued without changing to cooperative control.

  Similarly to the compressor 10a, when the continuous operation time of the compressor 20a is longer than the A time (when YES is determined in S02), it is determined that the operation state of the compressor 20a is stable. On the other hand, when the continuous operation time of the compressor 20a is equal to or shorter than A time (NO in S02), it is determined that the operation state of the compressor 20a is not stable. In this case, normal control is continued without changing to cooperative control.

  The “A time” used for the determination in step S02 is a time set for determining whether or not each of the air conditioner 1 and the ventilator 2 is in a start / stop state in which the operation and the stop are repeated. is there. When setting the A time, it is necessary to consider the time until the operation state of the compressor is stabilized when the operation frequency of the compressor or the opening of the expansion valve is changed. For example, the A time is set to about 30 minutes.

(S03: Determination of achievement of control target of air conditioner)
If it is determined that the operation state of the compressor 10a is stable (YES in S02), it is subsequently determined whether the control of the air conditioner 1 has achieved the control target value. Specifically, it is determined whether or not the deviation α1 of the detected temperature T by the indoor temperature detector 1a with respect to the target indoor temperature T * is equal to or less than a first threshold value (± B ° C.). When deviation α1 is ± B ° C. or less (when YES is determined in S03), it is determined that the control of air conditioner 1 has achieved the control target value.

  On the other hand, when the deviation α1 is larger than ± B ° C. (NO determination in S03), it is determined that the control of the air conditioner 1 has not yet achieved the control target value, and the normal control is continued.

  Note that “B ° C.” (first threshold) used in the determination in step S03 is an index for determining whether or not the operating state of the air conditioner 1 is stable. The unit and size of this index can be freely set according to the control target value of the air conditioner 1. For example, when the control target value is the room temperature of the room R, B ° C. is an allowable temperature difference with respect to the target room temperature T *. Normally, the controller 30 can set the target room temperature T * in increments of 0.5 ° C. or 1.0 ° C. The allowable temperature difference with respect to the target room temperature T * is preferably set to about 1.0 ° C. in accordance with the temperature setting interval of the controller 30. According to this, since cooperation control can be performed in a state where the room temperature is stable, the user's comfort can be maintained.

(S04: Determination of achievement of control target of ventilator)
When the control of the air conditioner 1 has achieved the control target value (when YES is determined in S03), it is further determined whether or not the control of the ventilator 2 has achieved the control target value. Specifically, it is determined whether or not a deviation β1 of a detection value (blow air temperature SA) detected by the control target detection unit 1c with respect to the target blown air temperature SA * is equal to or smaller than a second threshold value (± C ° C.). The When deviation β1 is ± C ° C. or less (when YES is determined in S04), it is determined that the control of ventilator 2 has achieved the control target value.

  On the other hand, when the deviation β1 is larger than ± C ° C. (NO determination in S04), it is determined that the control of the ventilator 2 has not achieved the control target value, and the normal control is continued.

  Note that “C ° C.” (second threshold) used in the determination in step S04 is an index for determining whether or not the operating state of the ventilator 2 is stable. This index can be set freely according to the control target value of the ventilator 2 (the blown air temperature of the external air conditioner 21, the dew point temperature of the blown air, the dry bulb temperature of the blown air, etc.) of the ventilator 2. it can. For example, when the control target value is the blown air temperature SA of the external air conditioner 21, C ° C. is an allowable temperature difference with respect to the target blown air temperature SA *. Normally, the controller 30 can set the blown air temperature in increments of 0.5 ° C. or 1.0 ° C. The allowable temperature difference with respect to the target blown air temperature SA * is preferably set to about 1.0 ° C. in accordance with the temperature setting interval of the controller 30. According to this, cooperation control can be executed while maintaining user comfort.

  In this way, during the execution of the normal control, it is determined that both the operating states of the compressors 10a and 20a are stable and that the control of the air conditioner 1 and the ventilation device 2 has achieved the control target value. Then, the air conditioning system 100 transitions from normal control to cooperative control. In the cooperative control, the operation state is shared between the air conditioner 1 and the ventilator 2. By controlling the air conditioner 1 and the ventilator 2 in a coordinated manner based on the shared operating state, the power consumption of the entire air conditioning system 100 can be reduced. As a result, the operating efficiency of the air conditioning system 100 can be improved.

  Specifically, the cooperative control during the cooling operation includes “evaporation temperature difference control”, “high / low pressure temperature difference control”, and “discharge superheat degree difference control”. “Evaporation temperature difference control” is control for reducing the difference between the evaporation temperature ET1 in the air conditioner 1 and the evaporation temperature ET2 in the ventilation device 2. “High / low pressure temperature difference control” refers to the difference between the temperature difference between the condensation temperature CT1 and the evaporation temperature ET1 (high and low pressure temperature difference) in the air conditioner 1 and the temperature difference between the condensation temperature CT2 and the evaporation temperature ET2 in the ventilation device 2. This is control for reducing the size. “Discharge superheat degree difference control” means that the difference between the temperature difference (discharge superheat degree) between the discharge temperature Td1 and the condensation temperature CT1 in the air conditioner 1 and the temperature difference between the discharge temperature Td2 and the condensation temperature CT2 in the ventilator 2 is reduced. It is control to do.

  In the cooperative control during the heating operation, “condensation temperature difference control” is executed instead of the above-described evaporation temperature difference control. “Condensation temperature difference control” is control for reducing the difference between the condensation temperature CT1 in the air conditioner 1 and the condensation temperature CT2 in the ventilation device 2.

  As will be described below, the evaporation temperature difference control (or condensation temperature difference control), the high / low pressure temperature difference control and the discharge superheat degree difference control are performed by suppressing the uneven distribution of processing loads in the air conditioner 1 and the ventilator 2. The power consumption of the entire air conditioning system is reduced.

  Here, in the cooperative control during the cooling operation, priorities are given in the order of the evaporation temperature difference control, the high / low pressure temperature difference control, and the discharge superheat degree difference control, and are executed in descending order of priority. This is because during the cooling operation, the evaporation temperature changes to other characteristic values such as the intake air temperature / humidity of the indoor heat exchanger, the blower volume, the capacity of the outdoor heat exchanger, and the compressor performance (compressor efficiency). By comparison, the effect on the power consumption of the air conditioning system is greater. Therefore, in the cooperative control during the cooling operation, the power consumption of the air conditioning system can be effectively reduced by preferentially executing the evaporation temperature difference control.

  Hereinafter, the processing procedure of the cooperation control executed at the time of cooling operation will be described. First, evaporation temperature difference control is executed as the first mode of the cooperative control executed during the cooling operation.

[Evaporation temperature difference control]
In the evaporation temperature difference control, the difference between the evaporation temperature ET1 in the air conditioner 1 and the evaporation temperature ET2 in the ventilation device 2 is reduced. Therefore, in the apparatus with the higher evaporation temperature, the operating frequency of the compressor is lowered to lower the evaporation temperature. On the other hand, in the device having the lower evaporation temperature, the operating frequency of the compressor is increased in order to increase the evaporation temperature.

  FIG. 8 is a diagram showing the relationship between the evaporation temperature ET in the air conditioner 1 and the ventilator 2 and the power consumption of the entire air conditioning system 100. In FIG. 8, the horizontal axis indicates the evaporation temperature ET, and the vertical axis indicates the power consumption of the entire air conditioning system.

  The relationship indicated by k1 in FIG. 8 is that between the air conditioner 1 and the ventilator 2, the amount of air supplied to the room, the condensation temperature, the heat exchanger performance (heat exchange efficiency), the performance of the compressor (compressor efficiency) and The case where the intake air temperature and humidity are equivalent is assumed. The power consumption of the entire air conditioning system can be calculated from the inverse Carnot cycle in each of the refrigerant circuit 1000 and the refrigerant circuit 2000.

  Referring to FIG. 8, the power consumption of the entire air conditioning system changes in a quadratic function with respect to the evaporation temperature. When the compressor efficiency is equal between the air conditioner 1 and the ventilator 2, when the evaporation temperature ET1 and the evaporation temperature ET2 are equal (ET1 = ET2), the power consumption of the entire air conditioning system is minimized.

  In FIG. 8, the lower temperature side than the state where ET1 = ET2 indicates a state where the evaporation temperature ET1 is lower than the evaporation temperature ET2 (ET1 <ET2), and the higher temperature side indicates a state where the evaporation temperature ET2 is lower than the evaporation temperature ET1. (ET2 <ET1) is shown. When the evaporation temperature ET2 becomes lower than the evaporation temperature ET1, the power consumption increases in a quadratic function with respect to the change in the evaporation temperature ET2. This is because, when the evaporation temperature ET2 is lowered, in the refrigerant circuit 2000, the amount of heat acquired by the refrigerant in the evaporator increases, so that the processing capacity per air volume increases, but the coefficient of performance (COP) of the compressor decreases. Further, when the evaporation temperature ET1 becomes lower than the evaporation temperature ET2, the power consumption increases in a quadratic function with respect to the change in the evaporation temperature ET1. This is because when the evaporation temperature ET1 is lowered, in the refrigerant circuit 1000, the processing capacity per air volume in the evaporator is increased, but the COP of the compressor is lowered.

  When the compressor efficiency differs between the air conditioner 1 and the ventilator 2, there is a slight temperature difference between the evaporation temperature ET1 and the evaporation temperature ET2, as shown in FIGS. In this state, the power consumption of the entire air conditioning system is minimized.

  K2 in FIG. 9 indicates the relationship between the evaporation temperature ET and the power consumption of the entire air conditioning system when the compressor efficiency of the air conditioner 1 is higher than the compressor efficiency of the ventilator 2. In FIG. 9, power consumption is minimized when the evaporation temperature ET1 is slightly lower than the evaporation temperature ET2. This is because, even when ET1 = ET2, the ventilator 2 with low compressor efficiency consumes more power than the air conditioner 1 with high compressor efficiency. In such a case, in the air conditioner 1 with high compressor efficiency, a greater load is processed by reducing the evaporation temperature ET1 and increasing the air conditioning capability. Thereby, since the load which the ventilation apparatus 2 with low compressor efficiency should process is reduced, the power consumption of the whole air conditioning system reduces as a result.

  K3 in FIG. 10 indicates the relationship between the evaporation temperature ET and the power consumption of the entire air conditioning system when the compressor efficiency of the ventilation device 2 is higher than the compressor efficiency of the air conditioner 1. In FIG. 10, the power consumption is minimized when the evaporation temperature ET2 is slightly lower than the evaporation temperature ET1. In such a case, the evaporating temperature ET2 is lowered in the ventilator 2 having a high compressor efficiency so that the ventilator 2 handles more load. Thereby, since the load which the air conditioner 1 with low compressor efficiency should process is reduced, the power consumption of the whole air conditioning system reduces as a result.

  Thus, the fluctuation of the evaporation temperature affects the power consumption of the entire air conditioning system in a quadratic function. Note that the compressor efficiency may have a linear function on the COP of the compressor, and the heat exchange efficiency may have a linear function on the air conditioning capacity. The evaporation temperature difference control focuses on the evaporation temperature having the greatest influence on the power consumption of the air conditioning system. The evaporating temperature difference control unit controls the air conditioner 1 and the ventilator 2 so that the difference between the evaporating temperature ET1 and the evaporating temperature ET2 is reduced, thereby realizing a reduction in power consumption of the entire air conditioning system.

  Hereinafter, the processing procedure of the evaporation temperature difference control will be described with reference to steps S05 to S12 of FIG.

(S05: Determination of start of evaporation temperature difference control)
In step S05, the absolute value of the difference between the evaporation temperature ET1 of the air conditioner 1 detected by the evaporation temperature detector 10l and the evaporation temperature ET2 of the ventilation device 2 detected by the evaporation temperature detector 20l (= abs {ET1- ET2}) is calculated. In the following description, the absolute value of the difference between the evaporation temperature ET1 and the evaporation temperature ET2 is also expressed as “evaporation temperature difference ΔET”.

  The calculated evaporation temperature difference ΔET is compared with a third threshold value (D ° C). If the evaporation temperature difference ΔET is greater than D ° C. (when YES is determined in S05), the process proceeds to step S06. On the other hand, if the evaporation temperature difference ΔET is equal to or less than D ° C. (NO determination in S05), the process proceeds to step S13 in FIG.

  Note that “D ° C.” (third threshold) used for the determination in step S05 is an index for determining whether or not to start the evaporation temperature difference control. Even when the operation state of the air conditioner 1 is stable and the operation state of the ventilator 2 is stable (when YES is determined in S03 and S04), the expansion valve operates to stabilize the refrigeration cycle. As a result, the evaporation temperature may fluctuate. By setting the allowable fluctuation range of the evaporation temperature to be slightly larger than the allowable temperature difference shown in steps S03 and S04, it is determined whether or not the evaporation temperature difference control is started taking into account the temporary fluctuation caused by the expansion valve. can do. Furthermore, considering the detection accuracy of the evaporating temperature detectors 10l and 20l, “D ° C.” (third threshold value) is “B ° C.” (first threshold value) in step S03 and “C ° C.” in step S04 ( It is preferable to set a value equal to or greater than (second threshold).

(S06: Comparison of evaporation temperature)
If the evaporation temperature difference ΔET is greater than D ° C. (when YES is determined in S05), the magnitudes of the evaporation temperature ET1 and the evaporation temperature ET2 are compared in step S06. Based on the comparison result, the operating frequencies of the compressor 10a of the air conditioner 1 and the compressor 20a of the ventilation device 2 are changed.

(S07: Operation for increasing the evaporation temperature of the air conditioner)
When the evaporation temperature ET2 is higher than the evaporation temperature ET1 (when YES is determined in S06), the operation frequency of the compressor 10a of the air conditioner 1 is lowered in step S07. Thereby, the evaporation temperature ET1 in the air conditioner 1 is raised.

(S08: Operation for lowering the evaporation temperature of the ventilator)
Further, in step S08, the operating frequency of the compressor 20a of the ventilation device 2 is increased. Thereby, the evaporation temperature ET2 in the ventilator 2 is lowered.

  That is, when the evaporation temperature ET2 is higher than the evaporation temperature ET1 (when YES is determined in S06), the evaporation temperature ET1 is increased (S07), and the evaporation temperature ET2 is decreased (S08). The operation frequency of each of 20a is changed. Thereby, the evaporation temperature difference ΔET is reduced.

  Note that the amount of increase in the evaporation temperature ET1 in step S07 and the amount of decrease in the evaporation temperature ET2 in step S08 can be, for example, the magnitude obtained by distributing the evaporation temperature difference ΔET by the ratio of the operating capacities of the compressors 10a and 20a. Alternatively, both the increase amount and the decrease amount can be set to a magnitude obtained by multiplying the evaporation temperature difference ΔET by a predetermined ratio (for example, about 30%).

(S09: Operation for increasing the evaporation temperature of the ventilator)
On the other hand, when the evaporation temperature ET1 is higher than the evaporation temperature ET2 (when NO is determined in S06), the operation frequency of the compressor 20a of the ventilator 2 is lowered in step S09. Thereby, the evaporation temperature ET2 in the ventilator 2 is raised.

(S10: Operation for lowering the evaporation temperature of the air conditioner)
Further, in step S10, the operating frequency of the compressor 10a of the air conditioner 1 is lowered. Thereby, the evaporation temperature ET1 in the air conditioner 1 is lowered.

  That is, when the evaporation temperature ET1 is higher than the evaporation temperature ET2 (NO in S06), the evaporation temperature ET2 is increased (S09), and the evaporation temperature ET1 is decreased (S10). The operation frequency of each of 20a is changed. Thereby, the evaporation temperature difference ΔET is reduced.

  Note that the amount of increase in the evaporation temperature ET2 in step S09 and the amount of decrease in the evaporation temperature ET1 in step S10 can be, for example, the magnitude obtained by distributing the evaporation temperature difference ΔET by the ratio of the operating capacities of the compressors 10a and 20a. Alternatively, both the increase amount and the decrease amount can be set to a magnitude obtained by multiplying the evaporation temperature difference ΔET by a predetermined ratio (for example, about 30%).

(S11, S12: Determination of continuation of evaporation temperature difference control)
When an operation for reducing the evaporation temperature difference ΔET is performed in steps S07 to S10, the process proceeds to step S11, and it is determined whether or not the operating state setting has been changed for either the air conditioner 1 or the ventilator 2. Is done. Specifically, when the set temperature, the set air volume, or the like is changed in either the air conditioner 1 or the ventilator 2 (YES in S11), it is determined that the evaporation temperature difference control cannot be continued. The Therefore, the air conditioning system 100 transitions from cooperative control to normal control.

  On the other hand, when neither the air conditioner 1 nor the ventilator 2 has been changed (when NO is determined in S11), the process proceeds to step S12, and the deviation of the detected temperature T by the indoor temperature detector 1a from the target indoor temperature T *. It is determined whether α1 is equal to or less than a predetermined threshold value (± E ° C.). When the deviation α1 is ± E ° C. or less (when YES in S12), the process returns to step S05 to continue the evaporation temperature difference control.

  On the other hand, when deviation α1 is larger than ± E ° C. (NO determination in S12), it is determined that the evaporation temperature difference control cannot be continued. Therefore, the air conditioning system 100 transitions from cooperative control to normal control.

  Note that “E ° C.” used for the determination in step S12 is an index for determining whether or not to continue the evaporation temperature difference control. In setting this index, it is necessary to take into account a temporary change in room temperature due to a change in the operating frequency of the compressor. Therefore, “E ° C.” is preferably set to a value larger than “B ° C.” (first threshold) in step S03.

  Further, when changing the operating frequency of the compressors 10a and 20a, an operation of lowering the operating frequency of one compressor (evaporating temperature increasing operation) and then an operation of increasing the operating frequency of the other compressor (evaporating temperature lowering). It is preferable to perform operation. When the operation for increasing the operating frequency of the compressor is first performed, the air conditioning capability of the corresponding air conditioner is rapidly increased, which may cause the room R to be overcooled and induce the start / stop of the compressor. Since such an inconvenience can be suppressed by first performing an operation to lower the operating frequency of the compressor, it is possible to ensure energy saving and user comfort.

[High-low pressure temperature difference control]
If it is determined in step S05 that the evaporation temperature difference ΔET is equal to or lower than D ° C. (at the time of NO determination in S05), next, high / low pressure temperature difference control is executed as a second mode of the cooperative control.

  In the high / low pressure temperature difference control, the difference between the high / low pressure temperature difference (CT1-ET1) in the air conditioner 1 and the high / low pressure temperature difference (CT2-ET2) in the ventilator 2 is reduced. Therefore, the operating frequency of the compressor is lowered in order to reduce the high / low pressure temperature difference in the apparatus having the higher high / low pressure temperature difference. On the other hand, in the apparatus with the lower high-low pressure temperature difference, the operating frequency of the compressor is increased in order to increase the high-low pressure temperature difference.

  Even when the evaporation temperature ET1 and the evaporation temperature ET2 are equal by executing the above evaporation temperature difference control, the condensation temperature CT1 and the condensation temperature CT2 may be different. When the condensation temperature is different between the air conditioner 1 and the ventilator 2, the compression ratio in the compressor is different. As the compression ratio increases, the amount of refrigerant circulating in the compressor decreases and the work of the compressor increases. Therefore, the air conditioning system 100 is not necessarily in an optimal operating state from the viewpoint of operating efficiency.

  On the other hand, the condensation temperature is affected by the condenser performance such as the condenser capacity and the amount of air blown to the condenser. Therefore, if the performance of the condenser differs between the air conditioner 1 and the ventilator 2, the condensation temperature also differs.

  In high-low pressure difference control, the performance of the condenser is compared between the air conditioner 1 and the ventilator 2 by comparing the high-low pressure difference (CT1-ET1) and the high-low pressure difference (CT2-ET2). The performance of the condenser is changed by changing the operating frequency of the compressors 10a and 20a so that the difference between the high-low pressure temperature difference (CT1-ET1) and the high-low pressure temperature difference (CT2-ET2) becomes small. It is possible to execute cooperative control that takes into account these differences.

Hereinafter, the processing procedure of the high / low pressure temperature difference control will be described with reference to FIG.
(S13: High / low pressure temperature difference control start determination)
In step S13, a difference (= high / low pressure temperature difference (CT1-ET1)) between the evaporation temperature ET1 detected by the evaporation temperature detector 10l and the condensation temperature CT1 detected by the condensation temperature detector 10k is calculated. Further, a difference between the evaporation temperature ET2 detected by the evaporation temperature detection unit 20l and the condensation temperature CT2 detected by the condensation temperature detection unit 20k (= high / low pressure temperature difference (CT2-ET2)) is calculated. Subsequently, the absolute value (= abs {(CT1-ET1)-(CT2-ET2)}) between the high-low pressure temperature difference (CT1-ET1) and the high-low pressure temperature difference (CT2-ET2) is calculated.

  The absolute value of the calculated difference is compared with a fourth threshold value (F ° C). If the absolute value of the difference is greater than F ° C. (when YES is determined in S13), the process proceeds to step S14. On the other hand, when the absolute value of the difference is equal to or lower than F ° C. (when NO is determined in S13), the process proceeds to step S21 in FIG.

  Note that “F ° C.” (fourth threshold) used in the determination in step S13 is an index for determining whether to start the high-low pressure difference control. In one refrigeration cycle, when the operating frequency of the compressor is increased, the condensation temperature increases and the evaporation temperature decreases. Therefore, the high / low pressure temperature difference becomes large. On the other hand, when the operating frequency of the compressor is lowered, the condensation temperature is lowered and the evaporation temperature is raised. Therefore, the high / low pressure temperature difference is reduced. Thus, in the refrigeration cycle, the high-low pressure temperature difference changes by changing the operating frequency of the compressor.

  Therefore, when the evaporating temperature difference control is executed, the operating frequency of the compressors 10a and 20a is changed, so that the high / low pressure temperature difference (CT1-ET1) in the air conditioner 1 and the high / low pressure temperature difference (CT2) in the ventilator 2 are changed. The difference from -ET2) is large. This difference is larger than the evaporation temperature difference ΔET. “F ° C.” is preferably set to a value equal to or higher than “D ° C.” (third threshold value), which is a determination index, as to whether or not to start the steam temperature difference control. In this way, since the evaporation temperature difference control can be preferentially executed as compared with the high and low pressure difference control, the cooperative control can be stabilized.

(S14: Comparison of temperature difference between high and low pressure)
When the absolute value of the difference between the high-low pressure temperature difference (CT1-ET1) and the high-low pressure temperature difference (CT2-ET2) is larger than F ° C. (when YES is determined in S13), the high-low pressure temperature difference (CT1-ET1) is determined in step S14. ET1) and high / low pressure difference (CT2-ET2) are compared in magnitude. Based on the comparison result, the operating frequency of the compressors 10a and 20a is changed.

(S15: High / low pressure temperature difference reduction operation of ventilator)
When the high-low pressure temperature difference (CT2-ET2) is larger than the high-low pressure temperature difference (CT1-ET1) (when YES is determined in S14), the operation frequency of the compressor 20a of the ventilator 2 is lowered in step S15. Thereby, in the ventilator 2, since the condensation temperature CT2 falls, the high-low pressure temperature difference (CT2-ET2) decreases.

(S16: High / low pressure temperature difference increase operation of air conditioner)
Further, in step S16, the operating frequency of the compressor 10a of the air conditioner 1 is increased. Thereby, in the air conditioner 1, since the condensation temperature CT1 rises, the high-low pressure difference (CT1-ET1) increases.

  That is, when the high / low pressure temperature difference (CT2-ET2) is larger than the high / low pressure temperature difference (CT1-ET1) (when YES is determined in S14), the high / low pressure temperature difference (CT2-ET2) is decreased (S15). ), The operating frequency of the compressors 10a and 20a is changed so as to increase the high / low pressure temperature difference (CT1-Et1) (S16). Thereby, the difference of the high-low pressure temperature difference (CT-ET) between the air conditioner 1 and the ventilator 2 is made small.

(S17: High / low pressure temperature difference reduction operation of air conditioner)
When the high / low pressure temperature difference (CT2-ET2) is smaller than the high / low pressure temperature difference (CT1-ET1) (when NO is determined in S14), the operation frequency of the compressor 10a of the air conditioner 1 is lowered in step S17. Thereby, in the air conditioner 1, since the condensation temperature CT1 falls, the high-low pressure temperature difference (CT1-ET1) decreases.

(S18: High / low pressure temperature difference increase operation of the ventilator)
Furthermore, the operating frequency of the compressor 20a of the ventilator 2 is increased in step S18. Thereby, in the ventilator 2, since the condensation temperature CT2 rises, the high-low pressure temperature difference (CT2-ET2) increases.

  That is, when the high / low pressure temperature difference (CT2-ET2) is smaller than the high / low pressure temperature difference (CT1-ET1) (NO determination in S14), the high / low pressure temperature difference (CT1-ET1) is decreased (S17). ), The operating frequency of the compressors 10a and 20a is changed so as to increase the high-low pressure temperature difference (CT2-ET2) (S18). Thereby, the difference of the high-low pressure temperature difference (CT-ET) between the air conditioner 1 and the ventilator 2 is made small.

(S19, S20: Determination of continuation of high-low pressure temperature difference control)
When an operation for reducing the difference in high-low pressure temperature difference (CT-ET) is performed in steps S13 to S18, the process proceeds to step S19, and the operating state setting is changed for either the air conditioner 1 or the ventilator 2. It is determined whether or not an error has occurred. Specifically, when the set temperature, the set air volume, or the like is changed in either the air conditioner 1 or the ventilator 2 (YES in S19), it is determined that the high / low pressure temperature difference control cannot be continued. Is done. Therefore, the air conditioning system 100 transitions from cooperative control to normal control.

  On the other hand, if neither the air conditioner 1 nor the ventilator 2 has been changed (when NO in S19), the process proceeds to step S20, where the deviation α1 of the indoor temperature detector 1a with respect to the target indoor temperature T * is a predetermined value. It is determined whether or not the threshold value (± E ° C.) or less. When the deviation α1 is ± E ° C. or less (when YES is determined in S20), the high / low pressure temperature difference control is continued by returning the process to step S13.

  On the other hand, when deviation α1 is larger than ± E ° C. (NO determination in S20), it is determined that the high / low pressure temperature difference control cannot be continued. Therefore, the air conditioning system 100 transitions from cooperative control to normal control.

  Similarly to the steam temperature difference control, when changing the operating frequency of the compressors 10a and 20a, the operation of lowering the operating frequency of one compressor (high / low pressure temperature difference decreasing operation) is performed, and then the other compressor is operated. It is preferable to perform an operation for increasing the operating frequency (high / low pressure temperature difference increasing operation).

[Discharge superheat difference control]
If it is determined in step S13 that the absolute value of the difference between the high / low pressure temperature difference (CT1-ET1) and the high / low pressure temperature difference (CT2-ET2) is F ° C. or less (NO in S13), then As a third aspect of the cooperative control, discharge superheat degree difference control is executed.

  In the discharge superheat degree difference control, the difference between the discharge superheat degree (Td1-CT1) in the air conditioner 1 and the discharge superheat degree (Td2-CT2) in the ventilator 2 is reduced. Therefore, in the device having the higher discharge superheat degree, the operating frequency of the compressor is lowered in order to lower the discharge temperature. On the other hand, in the apparatus with the lower discharge superheat degree, the operating frequency of the compressor is increased in order to increase the discharge temperature.

  When the high / low pressure temperature difference is equal between the air conditioner 1 and the ventilator 2 by the above high / low pressure temperature difference control, the difference in the discharge superheat degree represents the difference in the discharge temperature of the compressor. Therefore, the discharge superheat degree is an index indicating the performance of the compressor. When the discharge temperatures are different between the air conditioner 1 and the ventilator 2, the air conditioning system 100 is not necessarily in an optimal operating state from the viewpoint of operating efficiency due to the difference in the performance of the compressor.

  In the discharge superheat degree difference control, the performance of the compressor can be compared between the air conditioner 1 and the ventilator 2 by comparing the discharge superheat degree (Td1-CT1) and the discharge superheat degree (Td2-CT2). Then, by changing the operating frequency of the compressors 10a and 20a so as to reduce the difference between the discharge superheat degree (Td1-CT1) and the discharge superheat degree (Td2-CT2), the difference in compressor performance is taken into account. As a result, the operation efficiency of the air conditioning system 100 can be further improved.

  For example, when the discharge superheat degree becomes large, it is considered that the operating frequency of the compressor is high or the compressor efficiency is low. When the operating frequency of the compressor is high, the discharge superheat degree can be reduced and the efficiency can be improved by lowering the operating frequency of the compressor. On the other hand, when the compressor efficiency is low, reducing the operating frequency of the compressor can reduce the amount of work of the compressor and increase the efficiency.

Hereinafter, the processing procedure of the discharge superheat difference control will be described with reference to FIG.
(S21: Start determination of discharge superheat difference control)
In step S21, a difference (= discharge superheat (Td1−CT1)) between the discharge temperature Td1 detected by the discharge temperature detection unit 10j and the condensation temperature CT1 detected by the condensation temperature detection unit 10k is calculated. Further, a difference (= discharge superheat degree (Td2−CT2)) between the discharge temperature Td2 detected by the discharge temperature detection unit 20j and the condensation temperature CT2 detected by the condensation temperature detection unit 20k is calculated. Subsequently, an absolute value (= abs {(Td1−CT1) − (Td2−CT2)}) between the discharge superheat degree (Td1−CT1) and the discharge superheat degree (Td2−CT2) is calculated.

  The absolute value of the calculated difference in discharge superheat degree is compared with a fifth threshold value (G ° C.). If the absolute value of the discharge superheat difference is greater than G ° C. (when YES is determined in S21), the process proceeds to step S22. On the other hand, if the absolute value of the discharge superheat degree difference is G ° C. or less (NO determination in S21), the process proceeds to step S29.

  Here, “G ° C.” (fifth threshold value) used in the determination in step S21 is an index for determining whether or not to start the discharge superheat difference control. In one refrigeration cycle, when the operating frequency of the compressor is increased, the discharge temperature Td of the compressor rises, and as a result, the discharge superheat degree (Td-CT) increases. On the other hand, even when the compressor efficiency is lowered, the discharge superheat degree (Td-CT) is increased. That is, the discharge superheat degree can be changed not only by the operating frequency of the compressor but also by the compressor efficiency. Therefore, even if the operating frequency of the compressor is changed, there are cases where the difference in discharge superheat cannot be reduced due to individual differences in the performance of the compressor.

  The discharge superheat difference control is a control for correcting such individual differences in the performance of the compressor. This individual difference does not change depending on the state of the refrigeration cycle. Since the cooperation control can be executed in consideration of such individual differences in the performance of the compressor, the accuracy of the cooperation control can be improved.

  Note that “G ° C.” (fifth threshold) is preferably set to a value equal to or higher than “F ° C.” (fourth threshold), which is a determination index for determining whether to start high-low pressure difference control. If it does in this way, since it can prevent that the driving | running state which cannot be reached | attained also by control of the air conditioner 1 and the ventilation apparatus 2 is set to a control target value, possibility that erroneous control will be performed can be reduced. .

(S22: Comparison of discharge superheat degree)
When the absolute value of the difference between the discharge superheat degree (Td1−CT1) and the discharge superheat degree (Td2−CT2) is larger than G ° C. (at the time of YES determination in S21), the discharge superheat degree (Td1−ET1) is The magnitude is compared with the discharge superheat degree (Td2-CT2). Based on the comparison result, the operating frequency of the compressors 10a and 20a is changed.

(S23: Operation for reducing discharge superheat degree of ventilation device)
When the discharge superheat degree (Td2-CT2) is larger than the discharge superheat degree (Td1-CT1) (when YES is determined in S22), the operation frequency of the compressor 20a of the ventilator 2 is lowered in step S23. Thereby, in the ventilation apparatus 2, since the discharge temperature Td2 of the compressor 20a falls, discharge superheat degree (Td2-ET2) reduces.

(S24: Operation for increasing discharge superheat of air conditioner)
Further, in step S24, the operating frequency of the compressor 10a of the air conditioner 1 is increased. Thereby, in the air conditioner 1, since discharge temperature Td1 increases, discharge superheat degree (Td1-CT1) increases.

  That is, when the discharge superheat degree (Td2-CT2) is larger than the discharge superheat degree (Td1-CT1) (when YES is determined in S22), the discharge superheat degree (Td2-CT2) is decreased (S23) and the discharge The operating frequency of the compressors 10a and 20a is changed so as to increase the degree of superheat (Td1-CT1) (S24). Thereby, the difference of the discharge superheat degree (Td-CT) between the air conditioner 1 and the ventilation apparatus 2 is made small.

(S25: Operation for decreasing discharge superheat of air conditioner)
When the discharge superheat degree (Td2-CT2) is smaller than the discharge superheat degree (Td1-CT1) (NO determination in S22), the operation frequency of the compressor 10a of the air conditioner 1 is lowered in step S25. Thereby, in the air conditioner 1, since the discharge temperature Td1 of the compressor 10a falls, discharge superheat degree (Td1-CT1) reduces.

(S26: Operation for increasing discharge superheat of ventilator)
Furthermore, the operating frequency of the compressor 20a of the ventilator 2 is increased in step S26. Thereby, in the ventilator 2, since the discharge temperature Td2 rises, the discharge superheat degree (Td2-CT2) increases.

  That is, when the discharge superheat degree (Td2-CT2) is smaller than the discharge superheat degree (Td1-CT1) (NO determination in S22), the discharge superheat degree (Td1-CT1) is decreased (S25), and the discharge superheat degree. The operating frequency of the compressors 10a and 20a is changed so as to increase the degree (Td2-CT2) (S26). Thereby, the difference of the discharge superheat degree between the air conditioner 1 and the ventilation apparatus 2 is made small.

(S27, S28: Determination of continuation of discharge superheat difference control)
When an operation for reducing the difference in discharge superheat degree is performed in steps S21 to S26, the process proceeds to step S27, and whether or not the operating state setting has been changed for either the air conditioner 1 or the ventilator 2. Determined. Specifically, when the set temperature, the set air volume, or the like is changed in either the air conditioner 1 or the ventilator 2 (YES in S27), it is determined that the discharge superheat difference control cannot be continued. Is done. Therefore, the air conditioning system 100 transitions from cooperative control to normal control.

  On the other hand, if the setting has not been changed in either the air conditioner 1 or the ventilator 2 (NO determination in S27), the process proceeds to step S28, and the deviation of the detected temperature T by the indoor temperature detector 1a with respect to the target indoor temperature T *. It is determined whether α1 is equal to or less than a predetermined threshold (± E ° C.). When the deviation α1 is ± E ° C. or less (when YES is determined in S28), the process returns to step S21 to continue the discharge superheat difference control.

  On the other hand, when deviation α1 is larger than ± E ° C. (NO determination in S28), it is determined that the discharge superheat degree difference control cannot be continued. Therefore, the air conditioning system 100 transitions from cooperative control to normal control.

(S29: Operation state maintenance operation)
When the discharge superheat difference is equal to or lower than G ° C. in step S21 (when NO is determined in S21), the process proceeds to step S29, and the operating states of the air conditioner 1 and the ventilator 2 are maintained.

(S30, 31: normal control return determination)
In step S30, it is determined whether or not the operating state setting has been changed for either the air conditioner 1 or the ventilator 2. Specifically, when the set temperature, the set air volume, and the like are changed in either the air conditioner 1 or the ventilator 2 (YES in S30), it is determined that the discharge superheat difference control cannot be continued. Is done. Therefore, the air conditioning system 100 transitions from cooperative control to normal control.

  On the other hand, when the setting is not changed in either the air conditioner 1 or the ventilator 2 (NO determination in S30), the process proceeds to step S31, and the deviation of the detected temperature T by the indoor temperature detection unit 1a with respect to the target indoor temperature T *. It is determined whether α1 is within a predetermined range (± B ° C.). When the deviation α1 is ± B ° C. or less (when YES is determined in S31), the process returns to step S29 to continue the discharge superheat difference control.

  On the other hand, when deviation α1 is larger than ± B ° C. (NO determination in S31), it is determined that the discharge superheat degree difference control cannot be continued. Therefore, the air conditioning system 100 transitions from cooperative control to normal control.

  Similarly to the steam temperature difference control and the high / low pressure temperature difference control, when changing the operating frequency of the compressors 10a and 20a, the operation of lowering the operating frequency of one of the compressors (discharging superheat degree decreasing operation) is performed. It is preferable to perform an operation for increasing the operating frequency of the other compressor (an operation for increasing the degree of discharge superheat).

  As described above, in the air conditioning system 100 according to the embodiment of the present invention, the evaporation temperature difference control, the high / low pressure temperature difference control, and the discharge are performed as the cooperative control of the two air conditioners (the air conditioner 1 and the ventilator 2). Execute superheat difference control. Thereby, uneven distribution of the processing load between the two air conditioners can be suppressed, and as a result, the operation efficiency of the air conditioning system 100 can be improved.

  For example, in the cooling operation of the air conditioning system 100, a situation is assumed in which the outdoor temperature and humidity are high, but there are few load sources in the room and the heat insulation performance of the room R is high. When normal control is executed in such a situation, the ventilator 2 continues to operate at a high capacity so that the blown air temperature matches the target blown air temperature. On the other hand, the air conditioner 1 performs an operation at a low capacity because the indoor load is small.

  At this time, in the ventilator 2, during high capacity operation, it is necessary to lower the evaporation temperature ET2 in order to increase the capacity per air volume, and as a result, the compressor efficiency tends to decrease. On the other hand, in the air conditioner 1, since the low capacity operation is performed, the evaporation temperature ET1 can be raised, and there is room for improving the compressor efficiency. However, when the evaporation temperature ET1 is increased, the air conditioning capacity per air volume of the air conditioner 1 is reduced, and thus the load that can be processed by the air conditioner 1 is reduced. As a result, the load to be processed by the low-efficiency ventilator 2 further increases, and the operation efficiency of the air conditioning system 100 may be reduced.

  When the evaporating temperature difference control is performed in such a situation, the operating frequency of the compressor 10a is increased so as to decrease the evaporating temperature ET1, while the operating frequency of the compressor 20a is decreased so as to increase the evaporating temperature ET2. Let Thereby, in the air conditioner 1, since the air conditioning capability per air volume increases, the load which can be processed increases. On the other hand, in the ventilator 2, the compressor efficiency is improved due to the increase in the evaporation temperature ET2. Moreover, the load which the ventilation apparatus 2 should process decreases by the load which the air conditioner 1 processes increases. As a result, the power consumption of the entire air conditioning system is reduced compared to the power consumption during normal control. Therefore, the operating efficiency of the air conditioning system 100 is improved.

  Furthermore, according to the cooperative control according to the embodiment of the present invention, the amount of heat processed by each of air conditioner 1 and ventilator 2 and the amount of air supplied to the indoor space are not significantly changed. Thereby, both user comfort and energy saving can be achieved.

  Here, in order to reduce the power consumption of the entire air conditioning system, in addition to the relationship between the evaporating temperature and the condensing temperature, for each of the air conditioner 1 and the ventilator 2, Information indicating the system characteristics calculated in consideration of various characteristic values such as the air volume, the capacity of the outdoor heat exchanger, the air volume control range of the outdoor unit, and the performance of the compressor is required. A complicated calculation is required for the calculation of information indicating system characteristics.

  On the other hand, in the cooperative control according to the present embodiment, it is assumed that characteristic values other than the evaporation temperature having a large influence on power consumption are equivalent between the air conditioner 1 and the ventilator 2. The optimum condition for minimizing the electric power is summarized as the evaporation temperature ET1 and the evaporation temperature ET2 being equivalent (see FIG. 8). Therefore, efficiency can be easily realized by controlling the air conditioner 1 and the ventilator 2 so as to satisfy this condition.

  In addition, since the information necessary for improving the efficiency of the air conditioning system can be limited to information related to the evaporation temperature, even if the characteristics of the devices constituting each air conditioner are not known, it is based on the evaporation temperature. The linkage control can be easily executed. According to this, for example, cooperation control with a device whose characteristic value is unknown, such as a device installed in the past, can be performed. As a result, highly versatile control can be constructed.

  Further, a third threshold value (D ° C.) that is an index for determining whether or not to start the evaporation temperature difference control is determined whether or not the operating states of the air conditioner 1 and the ventilator 2 are stable. By setting the value to be equal to or higher than the first and second threshold values (B ° C., C ° C.), which are indices for that purpose, it is possible to construct a control that takes into account the detection error of the detection unit. This makes it possible to suppress erroneous control.

  Further, a threshold (E ° C.), which is an index for determining whether to continue the cooperative control, is an index (B) for determining whether the operating state of the air conditioner 1 is stable during normal control. By making the value larger than (° C.), it is possible to suppress the return from the cooperative control to the normal control due to the temporary fluctuation of the indoor temperature due to the change of the operating frequency of the compressor. Thereby, since it becomes easy to reach the optimal operating state for efficiency, energy saving can be realized.

  Further, during the cooling operation, by comparing the high and low pressure temperature differences between the air conditioner 1 and the ventilator 2 after the evaporation temperature difference ΔET is reduced by the evaporation temperature difference control, the performance of the heat exchanger that each device has can be Comparison can be made through high and low pressure difference. Thereby, the cooperation control which considered the performance of the heat exchanger can be constructed.

  Furthermore, by performing the discharge superheat degree difference control after the high / low pressure temperature difference control, it is possible to compare the discharge temperatures when the compression ratios of the refrigeration cycles in the air conditioner 1 and the ventilator 2 are equal. Since the discharge temperature in this state is a value that does not depend on the state of the refrigeration cycle, it serves as an index indicating the performance of the compressor. Therefore, cooperative control in consideration of the compressor performance is possible, and as a result, the accuracy of control for efficiency can be improved.

(Example of change)
(1) In the above embodiment, when the operating states of the air conditioner and the ventilator are stable and both the control of the air conditioner and the control of the ventilator have achieved the control target value, Although the configuration of transition from normal control to cooperative control has been described, a configuration in which transition from normal control to cooperative control may be employed when the control target value is not achieved by control of either the air conditioner or the ventilation device.

  FIG. 11 is a diagram illustrating a modification example of the cooperative control executed in the air conditioning system 100 according to the present embodiment. In the air conditioning system 100 shown in FIG. 11, since the number of people M in the room R is large, the indoor load is large. Therefore, the air conditioner 1 is operated at a high capacity so that the room temperature matches the target room temperature. On the other hand, since the ventilation load is smaller than the indoor load, the ventilator 2 is operating at a low capacity. The control target value has not yet been achieved in the air conditioner 1, and the control target value has been achieved in the ventilator 2.

  Thus, cooperation control is performed in the situation where the processing load is unevenly distributed between the air conditioner 1 and the ventilator 2. In the cooperative control, the operating frequency of the compressor 10a is increased so as to increase the evaporation temperature ET1, while the operating frequency of the compressor 20a is increased so as to decrease the evaporation temperature ET2. Thereby, in the ventilation apparatus 2, since the air-conditioning capability per air volume increases, the load which can be processed increases. On the other hand, in the air conditioner 1, the efficiency of the compressor is improved by increasing the evaporation temperature ET1. Moreover, the load which the air conditioner 1 should process decreases by the load which the ventilator 2 processes increases. By suppressing the uneven distribution of the processing load, the power consumption of the entire air conditioning system can be reduced. Thereby, the operating efficiency of the air conditioning system 100 can be improved.

  (2) As the ventilator 2, a total heat exchanger that exchanges sensible heat or total heat between the return air and outside air may be installed. If it does in this way, since the temperature of the air which flows in into the heat exchanger of the ventilation apparatus 2 approaches indoor temperature, it can be brought close to the assumption conditions in evaporation temperature difference control. As a result, it is possible to approach the optimum operating state for efficiency by the evaporation temperature difference control.

  (3) In linked control during heating operation, condensing temperature difference control (see FIG. 12) is executed instead of evaporation temperature difference control (see FIG. 5). Hereinafter, the processing procedure of the condensation temperature difference control will be described with reference to steps S05A to S12 of FIG.

(S05A: Determination of start of condensation temperature difference control)
In step S05A, the absolute value of the difference between the condensation temperature CT1 of the air conditioner 1 detected by the condensation temperature detector 10k and the condensation temperature CT2 of the ventilation device 2 detected by the condensation temperature detector 20k (= abs {CT1- CT2}) is calculated. In the following description, the absolute value of the difference between the condensation temperature CT1 and the condensation temperature CT2 is also expressed as “condensation temperature difference ΔCT”.

  The calculated condensation temperature difference ΔCT is compared with a third threshold value (D ° C.). When the condensation temperature difference ΔCT is greater than D ° C. (when YES is determined in S05A), the process proceeds to step S06A. On the other hand, when the condensation temperature difference ΔCT is equal to or less than D ° C. (when NO is determined in S05A), the process proceeds to step S13 in FIG.

  “D ° C.” (third threshold) used for the determination in step S05A is an index for determining whether or not to start the condensation temperature difference control. “D ° C.” (third threshold) is preferably set to a value equal to or higher than “B ° C.” (first threshold) in step S03 and “C ° C.” (second threshold) in step S04.

(S06A: Comparison of condensation temperature)
When the condensation temperature difference ΔCT is larger than D ° C. (when YES is determined in S05A), the magnitudes of the condensation temperature CT1 and the condensation temperature CT2 are compared in step S06A. Based on the comparison result, the operating frequencies of the compressor 10a of the air conditioner 1 and the compressor 20a of the ventilation device 2 are changed.

(S07A: Operation for lowering the condensation temperature of the ventilator)
When the condensation temperature CT2 is higher than the condensation temperature CT1 (when YES is determined in S06A), the operation frequency of the compressor 20a of the ventilation device 2 is lowered in step S07A. Thereby, condensation temperature CT2 in the ventilator 2 is reduced.

(S08A: Operation for increasing the condensation temperature of the air conditioner)
Further, in step S08A, the operating frequency of the compressor 10a of the air conditioner 1 is increased. Thereby, the condensation temperature CT1 in the air conditioner 1 is raised.

  That is, when the condensation temperature CT2 is higher than the condensation temperature CT1 (when YES is determined in S06A), the condensation temperature CT2 is decreased (S07A), and the condensation temperature CT1 is increased (S08A). The operation frequency of each of 20a is changed. Thereby, the condensation temperature difference ΔCT is reduced.

  Note that the amount of decrease in the condensation temperature CT2 in step S07A and the amount of increase in the condensation temperature CT1 in step S08A can be, for example, the magnitude obtained by distributing the condensation temperature difference ΔCT by the ratio of the operating capacities of the compressors 10a and 20a. Alternatively, both the increase amount and the decrease amount can be set to a size obtained by multiplying the condensation temperature difference ΔCT by a predetermined ratio (for example, about 30%).

(S09A: Operation for lowering the condensation temperature of the air conditioner)
On the other hand, when the condensation temperature CT1 is higher than the condensation temperature CT2 (when NO is determined in S06A), the operation frequency of the compressor 10a of the air conditioner 1 is lowered in step S09A. Thereby, the condensation temperature CT1 in the air conditioner 1 is lowered.

(S10: Operation for increasing the condensation temperature of the ventilator)
Furthermore, the operating frequency of the compressor 20a of the ventilation device 2 is increased by step S10A. Thereby, the condensation temperature CT2 in the ventilation apparatus 2 is raised.

  That is, when the condensation temperature CT1 is higher than the condensation temperature CT2 (when NO is determined in S06A), the condensation temperature CT1 is decreased (S09A), and the condensation temperature CT2 is increased (S10A). The operation frequency of each of 20a is changed. Thereby, the condensation temperature difference ΔCT is reduced.

  Note that the amount of decrease in the condensation temperature CT1 in step S09A and the amount of increase in the condensation temperature CT2 in step S10A can be, for example, the magnitude obtained by distributing the condensation temperature difference ΔCT by the ratio of the operating capacities of the compressors 10a and 20a. Alternatively, both the increase amount and the decrease amount can be set to a size obtained by multiplying the condensation temperature difference ΔCT by a predetermined ratio (for example, about 30%).

(S11, S12: Continuation determination of condensing temperature difference control)
When an operation for reducing the condensation temperature difference ΔCT is performed in steps S07A to S10A, the process proceeds to step S11, and it is determined whether or not the operating state setting has been changed for either the air conditioner 1 or the ventilator 2. Is done. Specifically, when the set temperature, the set air volume, or the like is changed in either the air conditioner 1 or the ventilator 2 (YES in S11), it is determined that the condensation temperature difference control cannot be continued. The Therefore, the air conditioning system 100 transitions from cooperative control to normal control.

  On the other hand, when neither the air conditioner 1 nor the ventilator 2 has been changed (when NO in S11), the process proceeds to step S12, where the indoor temperature T deviation α1 with respect to the target indoor temperature T * is within a predetermined range (± E It is determined whether or not the temperature is within (° C). When the deviation α1 is ± E ° C. or less (when YES is determined in S12), the process returns to step S05A to continue the condensation temperature difference control.

  On the other hand, when deviation α1 is greater than ± E ° C. (NO determination in S12), it is determined that the condensation temperature difference control cannot be continued. Therefore, the air conditioning system 100 transitions from cooperative control to normal control.

  When changing the operating frequency of the compressors 10a and 20a, an operation for lowering the operating frequency of one compressor (condensation temperature lowering operation) and then an operation for increasing the operating frequency of the other compressor (condensation temperature rise) It is preferable to perform operation. If it does in this way, overheating of room R and starting and stopping of a compressor can be controlled. Thus, energy saving and user comfort can be ensured.

  (4) When reducing the operating frequency of the compressor 10a in the air conditioner 1, it is preferable to increase the flow rate of air supplied to the heat exchanger in the ventilator 2. When the operating frequency of the compressor 10a is lowered in the air conditioner 1, the evaporation temperature ET1 rises, so that the air conditioning capacity of the entire air conditioning system is lowered and the room temperature T may rise as a result. By increasing the amount of air blown to the heat exchanger in the ventilation device 2, it is possible to suppress a decrease in the air conditioning capability of the entire air conditioning system. For the same reason, when the operating frequency of the compressor 20a is lowered in the ventilator 2, it is preferable to increase the flow rate of air supplied to the heat exchanger in the air conditioner 1.

  (5) When the humidity of the indoor space is higher than the sixth threshold value, it is preferable to prohibit a decrease in the operating frequency of the compressors 10a and 20a. In this way, since the increase in the evaporation temperatures ET1, ET2 is suppressed, the humidity of the indoor space can be kept below the sixth threshold value. Therefore, the comfort of the occupants can be ensured.

  Each embodiment disclosed this time is also planned to be implemented in combination as appropriate. The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Air conditioner, 2 Ventilator, 10,20 Outdoor unit, 1a Indoor temperature detection part, 1b Outdoor temperature detection part, 1c Control object detection part, 10a, 20a Compressor, 10b, 20b Outdoor heat exchanger, 21b Ventilation heat exchange 10d, 20d Four-way valve, 10f, 20f Outdoor unit controller, 11c, 12c, 21c Expansion valve, 11f, 12f Indoor unit controller, 21f External controller controller, 10g, 11g, 12g, 20g, 21g 11h, 12h, 21h, 11i, 12i, 21i Piping temperature detection unit, 10j, 20j Discharge temperature detection unit, 10k, 20k Condensation temperature detection unit, 10l, 20l Evaporation temperature detection unit, 11, 12 Indoor unit, 21 External air conditioner 13,22 Refrigerant piping, 30 controller, 40 transmission line, 100 air conditioning system, 1000, 2000 Refrigerant circuit.

Claims (15)

A first air conditioner having a first refrigerant circuit and configured to supply air to the indoor space;
A second air conditioner having a second refrigerant circuit and configured to supply air to the indoor space;
A controller configured to control the first and second air conditioners;
Each of the first and second refrigerant circuits includes a compressor, a condenser, an expansion valve, and an evaporator, and circulates the refrigerant in the order of the compressor, the condenser, the expansion valve, and the evaporator. Configured,
When the first refrigerant evaporation temperature of the first refrigerant circuit is higher than the second refrigerant evaporation temperature of the second refrigerant circuit during the cooling operation of the first and second air conditioners, the control is performed. The apparatus increases the operating frequency of the compressor in the first refrigerant circuit and decreases the operating frequency of the compressor in the second refrigerant circuit, thereby reducing the first refrigerant evaporation temperature and the first refrigerant frequency. An air conditioning system that reduces the difference between the refrigerant evaporation temperature of 2 and the refrigerant. The control device controls the first air conditioner so that the first control target value matches the first control target value, and the second control target value matches the second control target value. Is configured to control the second air conditioner,
During the cooling operation of the first and second air conditioners, a deviation of the first control target value with respect to the first control target value is less than or equal to a first threshold value, and the second control target value 2. The control device reduces the difference between the first refrigerant evaporation temperature and the second refrigerant evaporation temperature when the deviation of the second control target value with respect to is less than or equal to a second threshold value. Air conditioning system as described in.   During the cooling operation of the first and second air conditioners, a deviation of the first control target value with respect to the first control target value is not more than the first threshold value, while the second control target is When the deviation of the second control target value with respect to the value is greater than the second threshold, the control device decreases the operating frequency of the compressor in the second refrigerant circuit, and The air conditioning system according to claim 2, wherein the operating frequency of the compressor in the refrigerant circuit is increased.   The said control apparatus raises the said operating frequency of the said compressor in the said 1st refrigerant circuit, after reducing the said operating frequency of the said compressor in the said 2nd refrigerant circuit. The air conditioning system according to claim 1.   The controller is configured to increase a flow rate of air supplied to the condenser and the evaporator in the first refrigerant circuit when the operating frequency of the compressor in the second refrigerant circuit is decreased. The air conditioning system of any one of 1-4.   When the first refrigerant condensing temperature of the first refrigerant circuit is higher than the second refrigerant condensing temperature of the second refrigerant circuit during the heating operation of the first and second air conditioners, the control is performed. The apparatus reduces the operating frequency of the compressor in the first refrigerant circuit and increases the operating frequency of the compressor in the second refrigerant circuit to thereby increase the first refrigerant condensing temperature. The air conditioning system according to claim 1, wherein a difference from the second refrigerant condensing temperature is reduced. The control device controls the first air conditioner so that the first control target value matches the first control target value, and the second control target value matches the second control target value. Configured to control the second air conditioner,
During the heating operation of the first and second air conditioners, a deviation of the first control target value with respect to the first control target value is equal to or less than a first threshold, and the second control target value The control device reduces a difference between the first refrigerant condensing temperature and the second refrigerant condensing temperature when a deviation of the second control target value with respect to the second threshold value is equal to or smaller than a second threshold value. Air conditioning system as described in.   During the heating operation of the first and second air conditioners, the deviation of the first control target value with respect to the first control target value is larger than the first threshold, while the second control target When the deviation of the second control target value with respect to the value is less than or equal to the second threshold value, the control device decreases the operating frequency of the compressor in the first refrigerant circuit, and The air conditioning system according to claim 7, wherein the operating frequency of the compressor in the refrigerant circuit is increased.   The said control apparatus raises the said operating frequency of the said compressor in the said 2nd refrigerant circuit, after reducing the said operating frequency of the said compressor in the said 1st refrigerant circuit. The air conditioning system according to claim 1.   In the cooling operation of the first and second air conditioners, when the difference between the first refrigerant evaporation temperature and the second refrigerant evaporation temperature is equal to or less than a third threshold value, the control device The first temperature difference between the first refrigerant evaporation temperature and the first refrigerant condensing temperature in the first refrigerant circuit is the second refrigerant evaporating temperature and the second refrigerant condensing temperature in the second refrigerant circuit. When the second temperature difference is greater than the second temperature difference, the operating frequency of the compressor in the first refrigerant circuit is decreased, and the operating frequency of the compressor in the second refrigerant circuit is increased, thereby The air conditioning system according to any one of claims 1 to 5, wherein a difference between the first temperature difference and the second temperature difference is reduced.   In the heating operation of the first and second air conditioners, when the difference between the first refrigerant condensing temperature and the second refrigerant condensing temperature is equal to or less than a third threshold, the control device When the first temperature difference between the first refrigerant evaporation temperature and the first refrigerant condensation temperature is larger than the second temperature difference between the second refrigerant evaporation temperature and the second refrigerant condensation temperature, Lowering the operating frequency of the compressor in one refrigerant circuit and increasing the operating frequency of the compressor in the second refrigerant circuit to thereby increase the first temperature difference and the second temperature difference. The air conditioning system according to any one of claims 6 to 9, wherein a difference between the air conditioning system and the air conditioning system is reduced. The control device reduces the difference between the first temperature difference and the second temperature difference when the difference between the first temperature difference and the second temperature difference is larger than a fourth threshold value. Configured as
The air conditioning system according to claim 10 or 11, wherein the fourth threshold value is equal to or greater than the third threshold value.   When the difference between the first temperature difference and the second temperature difference is less than or equal to the fourth threshold value, the control device causes the first refrigerant discharge temperature in the first refrigerant circuit and the first temperature difference to be A first discharge superheat degree that is a difference from the refrigerant condensation temperature is larger than a second discharge superheat degree that is a difference between the second refrigerant discharge temperature and the second refrigerant condensation temperature in the second refrigerant circuit. Sometimes, the operating frequency of the compressor in the first refrigerant circuit is decreased, and the operating frequency of the compressor in the second refrigerant circuit is increased to increase the first discharge superheat degree and the The air conditioning system according to claim 12, wherein a difference from the second discharge superheat degree is reduced. When the difference between the first discharge superheat degree and the second discharge superheat degree is greater than a fifth threshold, the control device determines whether the first discharge superheat degree and the second discharge superheat degree are Configured to reduce the difference,
The air conditioning system according to claim 13, wherein the fifth threshold is equal to or greater than the fourth threshold.   The said control apparatus prohibits the fall of the said operating frequency of the said compressor in a said 1st refrigerant circuit and a said 2nd refrigerant circuit, when the humidity of the said indoor space is higher than a 6th threshold value. The air conditioning system according to any one of 14.

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