Air conditioning and ventilation system

Abstract

A communication line is required between the indoor unit and the ventilation system. [Solution] The air conditioning and ventilation system (1a) comprises an air conditioning unit (2a), ventilation units (3a, 3b), and a detection unit (4). The air conditioning unit sends conditioned air generated by heat exchange with a refrigerant to the air-conditioned space (R1, R2). The ventilation units ventilate the air-conditioned space. The detection unit (4) detects the refrigerant concentration in the air-conditioned space. The air conditioning unit includes a first unit (10) located outdoors and having a first control unit (16), and a second unit (20a, 20b, 20c, 20d) located indoors and having second control units (24a, 24b, 24c, 24d). When the refrigerant concentration detected by the detection unit exceeds a predetermined value, the second control unit transmits a refrigerant leakage signal to the first control unit, and the first control unit, upon receiving the signal, transmits an instruction to the ventilation unit to operate.

Description

Technical Field

[0001] It relates to an air-conditioning and ventilation system.

Background Art

[0002] Patent Document 1 (Japanese Patent Application Laid-Open No. 2016-223643) discloses an air-conditioning and ventilation system including an air-conditioning apparatus that has a refrigerant circuit in which a refrigerant circulates and performs air-conditioning of an air-conditioned space, and a ventilation apparatus that ventilates the air-conditioned space. In the air-conditioning and ventilation system of Patent Document 1, when a refrigerant leakage detection device responsible for detecting the refrigerant in area S1 detects the refrigerant, the air-conditioning control device that receives the signal via the indoor control device instructs the indoor control device of the indoor unit responsible for air-conditioning in area S1 and the ventilation control device of the ventilation apparatus responsible for ventilation in area S1 to perform a refrigerant discharge operation. The instruction for the refrigerant discharge operation to the ventilation control device is given from the indoor control device (paragraph 0070).

Summary of the Invention

Problems to be Solved by the Invention

[0003] Since the air-conditioning and ventilation system of the above Patent Document 1 includes a plurality of indoor units, when a refrigerant leak occurs, an instruction for a refrigerant discharge operation is individually sent from the indoor units to the ventilation apparatus. In order to individually send an instruction for a refrigerant discharge operation from the indoor units to the ventilation apparatus, a communication line is required between each indoor unit and the ventilation apparatus.

Means for Solving the Problems

[0004] The first aspect of the air conditioning and ventilation system comprises an air conditioning unit, a ventilation unit, and a detection unit. The air conditioning unit has a heat exchanger. The heat exchanger generates conditioned air through heat exchange with a refrigerant. The air conditioning unit sends the conditioned air to the conditioned space. The ventilation unit ventilates the conditioned space. The detection unit detects the concentration of the refrigerant in the conditioned space. The air conditioning unit includes a first unit and a second unit. The first unit is located outdoors. The first unit has a first control unit. The second unit is located indoors. The second unit has a second control unit. When the concentration of the refrigerant detected by the detection unit exceeds a predetermined value, the second control unit transmits a refrigerant leak signal to the first control unit, and the first control unit, upon receiving the signal, transmits an instruction to the ventilation unit to operate.

[0005] According to the first aspect of the air conditioning and ventilation system, when the concentration of refrigerant detected by the detection unit exceeds a predetermined value, and refrigerant leakage is detected in the air-conditioned space, the second control unit of the second unit sends a refrigerant leakage signal to the first control unit of the first unit, and the first control unit sends an instruction to the ventilation device to operate. Therefore, even if a communication line is omitted between the second unit and the ventilation device, the first unit can operate the ventilation device in the event of refrigerant leakage.

[0006] The air conditioning and ventilation system relating to the second aspect is the air conditioning and ventilation system relating to the first aspect, further comprising a first communication line, a second communication line, and a third communication line. The first communication line is connected to a first unit. The second communication line branches off from the first communication line and is connected to a second unit. The third communication line branches off from the first communication line and is connected to a ventilation device.

[0007] In the second aspect of the air conditioning and ventilation system, the first unit, the second unit, and the ventilation device are connected via a common first communication line. This allows for a simplification of the communication lines.

[0008] The third aspect of the air conditioning and ventilation system is an air conditioning and ventilation system according to the first or second aspect, wherein the ventilation device has a first fan that discharges the air from the conditioned space to the outside. The first control unit, upon receiving a signal, transmits an instruction to the ventilation device to set the airflow of the first fan to its maximum airflow.

[0009] In the third-party air conditioning and ventilation system, by setting the airflow of the first fan to its maximum, the time required to expel the air from the conditioned space where the refrigerant has leaked to the outside can be reduced.

[0010] The air conditioning and ventilation system relating to the fourth perspective is an air conditioning and ventilation system relating to the third perspective, wherein the maximum airflow exceeds the largest airflow that can be set during normal operation of the air conditioning unit.

[0011] In the fourth aspect of the air conditioning system, when a refrigerant leak occurs, the airflow of the first fan can be increased to a level greater than that that can be set during normal operation. This allows for a shorter time to expel the air from the conditioned space where the refrigerant has leaked to the outside.

[0012] The air conditioning and ventilation system relating to the fifth perspective is an air conditioning and ventilation system relating to any of the first, second, or fourth perspectives, wherein the air conditioning device includes a plurality of second units. The first unit has a storage unit that stores ventilation devices corresponding to each second unit.

[0013] In the fifth aspect of the air conditioning system, the first unit stores the ventilation device corresponding to each second unit. Therefore, the first unit can send an operation command to the ventilation device linked to the second unit that is leaking refrigerant.

[0014] The air conditioning and ventilation system relating to the sixth viewpoint is an air conditioning and ventilation system relating to either the first viewpoint or the fifth viewpoint, wherein the ventilation device has a first fan and a second fan. The first fan discharges the air from the conditioned space to the outside. The second fan supplies outside air to the conditioned space. The first control unit, upon receiving a signal, transmits an instruction to the ventilation device to increase the airflow rate of the first fan to be greater than the airflow rate of the second fan.

[0015] In the sixth aspect of the air conditioning and ventilation system, it is possible to facilitate the discharge of air from the conditioned space where refrigerant leakage has occurred to the outside.

[0016] The air conditioning and ventilation system relating to the seventh perspective is an air conditioning and ventilation system relating to either the first perspective or the sixth perspective, and the first control unit that receives the signal instructs the ventilation device to operate for a set period of time.

[0017] In the seventh aspect of the air conditioning and ventilation system, the first control unit instructs the operating time of the ventilation device when a refrigerant leak occurs, making it easy to ventilate the air in the air-conditioned space. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic diagram showing an air conditioning and ventilation system according to one embodiment of the present disclosure. [Figure 2] This is a schematic diagram showing a building to which an air conditioning and ventilation system according to one embodiment of this disclosure is applied. [Figure 3] A perspective view showing a total heat exchanger included in a ventilation system according to one embodiment of this disclosure. [Figure 4] This is a control block diagram of an air conditioning and ventilation system according to one embodiment of the present disclosure. [Figure 5] This is a flowchart showing an air conditioning and ventilation method according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0019] An air conditioning and ventilation system according to one embodiment of this disclosure will be described with reference to the drawings.

[0020] (1) Overall structure As shown in FIG. 1, an air-conditioning and ventilation system 1a according to an embodiment of the present disclosure includes an air conditioner 2a, ventilation devices 3a and 3b, and a detection unit 4. The air conditioner 2a generates conditioned air by heat exchange with a refrigerant and sends the conditioned air to air-conditioned spaces R1 and R2. The ventilation devices 3a and 3b ventilate the air-conditioned spaces R1 and R2. The detection unit 4 detects the concentration of the refrigerant in the air-conditioned spaces R1 and R2.

[0021] As shown in FIG. 2, the air-conditioning and ventilation system 1a is applied to a building such as a building. Note that FIG. 2 shows a state in which two air-conditioning and ventilation systems 1a and 1b are applied to a building. Although the air-conditioning and ventilation systems 1a and 1b are of different systems, they have the same configuration. Therefore, here, only the configuration of the air-conditioning and ventilation system 1a will be described, and for the configuration of the air-conditioning and ventilation system 1b, the same reference numerals as those of the air-conditioning and ventilation system 1a will be used, and the description of each part will be omitted.

[0022] In this specification, the inside of a building is referred to as the indoor, and the outside of the building is referred to as the outdoor. The "outdoor" includes the rooftop of the building, the vicinity of the outer wall surface of the building, etc. Also, the "indoor" includes air-conditioned spaces R1, R2, R3, R4, etc. to which conditioned air is supplied. In FIG. 2, the four air-conditioned spaces R1, R2, R3, R4 in the building have ceiling spaces C1, C2, C3, C4 between the ceiling material and the ceiling surface.

[0023] The air conditioner 2a includes a first unit 10 disposed outdoors and second units 20a, 20b, 20c, 20d disposed indoors. In FIGS. 1 and 2, the air conditioner 2a includes one first unit 10 and a plurality of second units 20a, 20b, 20c, 20d (here, four) connected in parallel to each other.

[0024] In this embodiment, the first unit 10 is arranged on the roof. The second units 20a, 20b and the ventilation device 3a are arranged in the air-conditioned space R1 (ceiling space C1 in FIG. 2). The second units 20c, 20d and the ventilation device 3b are arranged in the air-conditioned space R2 (ceiling space C2). Two second units 20a, 20b send conditioned air to the air-conditioned space R1, and one ventilation device 3a ventilates the air-conditioned space R1. Similarly, two second units 20c, 20d send conditioned air to the air-conditioned space R2, and one ventilation device 3b ventilates the air-conditioned space R2. The detection unit 4 is arranged in the air-conditioned spaces R1, R2 (ceiling spaces C1, C2 in FIG. 2).

[0025] Note that the second units 20a, 20b of the air conditioner 2b and the ventilation device 3a are arranged in the air-conditioned space R3 (ceiling space C3 in FIG. 2), and the second units 20c, 20d and the ventilation device 3b are arranged in the air-conditioned space R4 (ceiling space C4 in FIG. 2).

[0026] The air-conditioning and ventilation system 1a further includes a communication line 5. The first unit 10, the second units 20a, 20b, 20c, 20d, and the ventilation devices 3a, 3b are connected by the communication line 5. The first unit 10, the second units 20a, 20b, 20c, 20d, and the ventilation devices 3a, 3b use the same communication protocol.

[0027] The first unit 10 has a first control unit 16. The second units 20a, 20b, 20c, 20d have second control units 24a, 24b, 24c, 24d. The ventilation devices 3a, 3b have third control units 44a, 44b. When the concentration of the refrigerant detected by the detection unit 4 exceeds a predetermined value, the second control units 24a, 24b, 24c, 24d send a refrigerant leakage signal to the first control unit 16, and the first control unit 16 that receives this signal sends an instruction to operate the ventilation devices 3a, 3b.

[0028] (2) Detailed configuration (2-1) Air conditioner The air conditioning system 2a is capable of providing air conditioning, such as cooling and heating, to the air-conditioned spaces R1 and R2 using a vapor compression type refrigeration cycle. The air conditioning system 2a mainly includes a first unit 10, second units 20a, 20b, 20c, and 20d, and connecting pipes 31 and 32 that connect the first unit 10 and the second units 20a, 20b, 20c, and 20d. The vapor compression type refrigerant circuit of the air conditioning system 2a is configured by connecting the first unit 10 and the second units 20a, 20b, 20c, and 20d via connecting pipes 31 and 32.

[0029] (2-1-1) Unit 1 The first unit 10 mainly comprises a compressor 11, a four-way switching valve 12, a first heat exchanger 13, a first expansion valve 14, and a first fan 15. The compressor 11, the four-way switching valve 12, the first heat exchanger 13, and the first expansion valve 14 constitute a refrigerant circuit.

[0030] The compressor 11 is a mechanism that compresses the low-pressure refrigerant in the refrigeration cycle until it reaches high pressure. The compressor 11 is a positive displacement compressor, such as a scroll type, whose operating capacity can be varied by controlling the compressor motor with an inverter.

[0031] The four-way diverter valve 12 is a mechanism for switching the direction of refrigerant flow in the refrigerant circuit. During cooling operation, as shown by the solid line in Figure 1, the four-way diverter valve 12 connects the discharge side of the compressor 11 to the gas side of the first heat exchanger 13, and also connects the suction side of the compressor 11 to the gas side of the second heat exchanger 22a. During heating operation, as shown by the dashed line in Figure 1, the four-way diverter valve 12 connects the discharge side of the compressor 11 to the gas side of the second heat exchanger 22a, and also connects the gas side of the first heat exchanger 13 to the suction side of the compressor 11.

[0032] The first heat exchanger 13 is an outdoor heat exchanger that functions as a refrigerant radiator during cooling operation and as a refrigerant evaporator during heating operation. The liquid side of the first heat exchanger 13 is connected to the first expansion valve 14, and the gas side is connected to the four-way switching valve 12.

[0033] The first expansion valve 14 is an expansion mechanism that, during cooling operation, reduces the pressure of the high-pressure liquid refrigerant released in the first heat exchanger 13 before sending it to the second heat exchanger 22a, and during heating operation, reduces the pressure of the high-pressure liquid refrigerant released in the second heat exchangers 22a, 22b, 22c, and 22d before sending it to the first heat exchanger 13. Here, an electrically operated expansion valve with adjustable opening degree is used as the first expansion valve 14.

[0034] The first fan 15 draws in outdoor air into the first unit 10, supplies the outdoor air to the first heat exchanger 13, and then discharges it outside the first unit 10. Therefore, the first heat exchanger 13 uses the outdoor air as a cooling or heating source to dissipate heat or evaporate the refrigerant. The first fan 15 is rotationally driven by a fan motor.

[0035] The first unit 10 further includes a first control unit 16. The first control unit 16 will be described later.

[0036] (2-1-2) Unit 2 Since each of the second units 20a, 20b, 20c, and 20d has a similar configuration, only the configuration of the second unit 20a will be described here. For the configurations of the second units 20b, 20c, and 20d, the subscripts "b," "c," and "d" will be used instead of the subscript "a" that indicates the parts of the second unit 20a, and the descriptions of each part will be omitted.

[0037] The second unit 20a mainly comprises a second expansion valve 21a, a second heat exchanger 22a, and a second fan 23a. The second expansion valve 21a and the second heat exchanger 22a constitute part of the refrigerant circuit. Here, the second unit 20a is an indoor unit of a type called a ceiling-mounted type.

[0038] The second expansion valve 21a is an expansion mechanism that adjusts the flow rate of refrigerant flowing through the second heat exchanger 22a while reducing the pressure of the refrigerant. The second expansion valve 21a is installed corresponding to the liquid side of the second heat exchanger 22a. Here, the second expansion valve 21a is an electrically operated expansion valve with adjustable opening degree.

[0039] The second heat exchanger 22a is an indoor heat exchanger that functions as a refrigerant evaporator during cooling operation and as a refrigerant radiator during heating operation. The liquid side of the second heat exchanger 22a is connected to the second expansion valve 21a, and the gas side is connected to the connecting pipe 32.

[0040] The second fan 23a passes air, which serves as a heat source, to the second heat exchanger 22a. Specifically, the second fan 23a draws air from the conditioned space R1 into the second unit 20a, supplies the air from the conditioned space R1 to the second heat exchanger 22a, and then discharges it outside the second unit 20a. As a result, the second heat exchanger 22a uses the indoor air as a cooling or heating source to dissipate heat or evaporate the refrigerant. The second fan 23a is rotationally driven by a fan motor.

[0041] The second unit 20a further includes a second control unit 24a. The second control unit 24a will be described later.

[0042] (2-1-3) Connecting piping The connecting pipes 31 and 32 are refrigerant pipes that are installed on-site when the air conditioning unit 2a is installed in a building or other location. One end of the liquid connecting pipe 31 is connected to the first expansion valve 14 side of the first unit 10, and the other end of the liquid connecting pipe 31 is connected to the liquid side of the second expansion valves 21a, 21b, 21c, and 21d of the second units 20a, 20b, 20c, and 20d. One end of the gas connecting pipe 32 is connected to the four-way switching valve 12 side of the first unit 10, and the other end of the gas connecting pipe 32 is connected to the gas side of the second heat exchangers 22a, 22b, 22c, and 22d of the second units 20a, 20b, 20c, and 20d.

[0043] (2-1-4) Shut-off valve The shut-off valves 33 and 34 are installed in accordance with one second unit 20a, 20b, 20c, and 20d. By being closed, the shut-off valves 33 and 34 suppress the inflow of refrigerant into the corresponding second units 20a, 20b, 20c, and 20d.

[0044] Shut-off valve 33 is located in the liquid communication pipe 31. Shut-off valve 34 is located in the gas communication pipe 32. Note that one of the shut-off valves 33 or 34 may be omitted.

[0045] A liquid communication pipe 31, which is connected to the first unit 10, is connected to one end of the shut-off valve 33. The second expansion valves 21a, 21b, 21c, and 21d of the corresponding second units 20a, 20b, 20c, and 20d are connected to the other end of the shut-off valve 33.

[0046] A gas communication pipe 32, which is connected to the first unit 10, is connected to one end of the shut-off valve 34. The gas side of the second heat exchangers 22a, 22b, 22c, and 22d of the corresponding second units 20a, 20b, 20c, and 20d is connected to the other end of the shut-off valve 34.

[0047] The shut-off valves 33 and 34 are valves that suppress refrigerant leakage into the air-conditioned spaces R1 and R2 when refrigerant leakage occurs in the second units 20a, 20b, 20c, and 20d. The shut-off valves 33 and 34 are, for example, solenoid valves that can be switched between a closed state (fully closed) and an open state (fully open). Note that the shut-off valves 33 and 34 are not limited to solenoid valves, but may also be, for example, motorized valves.

[0048] The shut-off valves 33 and 34 are normally open. "Normally" here refers to the time when the second control units of the corresponding second units 20a, 20b, 20c, and 20d are not transmitting signals to instruct the closing of the shut-off valves 33 and 34.

[0049] (2-2) Detection unit The detection unit 4 detects the concentration of refrigerant leaking from refrigerant piping, etc. The detection unit 4 is a semiconductor sensor, an infrared sensor, etc. Here, the detection unit 4 continuously or intermittently outputs an electrical signal to the second control unit according to the detected value. The voltage of this electrical signal changes according to the concentration of refrigerant detected by the detection unit 4. The detection unit 4 transmits the output electrical signal to the second control units 24a, 24b, 24c, and 24d.

[0050] The detection unit 4 is installed in a location where it can detect leaked refrigerant. Preferably, the detection unit 4 is placed near locations where refrigerant leakage is likely to occur, such as joints between refrigerant pipes, bends in refrigerant pipes of 90 degrees or more, and thin sections of pipe. Here, the detection unit 4 is located inside the second units 20a, 20b, 20c, and 20d. However, the detection unit 4 may also be located outside the second units 20a, 20b, 20c, and 20d. In this case, the detection unit 4 may be mounted on a remote controller for setting room temperature, airflow, etc., or it may be placed at any location such as on a wall in the room.

[0051] (2-3) Ventilation system Ventilation systems 3a and 3b are employed, each having a third heat exchanger 41a and 41b. In the following explanation, the configuration of ventilation system 3a will be described, and the configuration of ventilation system 3b will be omitted by replacing the subscript "a" with "b".

[0052] The ventilation device 3a ventilates the air-conditioned space R1 by discharging the air from the air-conditioned space R1 to the building's external space (outdoor space). The ventilation device 3a in this embodiment includes a first duct D1a, a second duct D2a, a third duct D3a, a fourth duct D4a, a third heat exchanger 41a, an exhaust fan 42a, and a supply fan 43a.

[0053] The first duct D1a is an intake duct connected to an intake for bringing outdoor air OA into the air-conditioned space R1. The second duct D2a is a supply duct connected to an air supply port that supplies outdoor air OA to the air-conditioned space R1 as supply air SA. The third duct D3a is an outlet duct connected to an outlet for taking out the air RA from the air-conditioned space R1. The fourth duct D4a is an exhaust duct connected to an outlet for discharging the air RA from the air-conditioned space R1 to the outside as exhaust air EA.

[0054] In this embodiment, the third heat exchanger 41a is a total heat exchanger that simultaneously exchanges latent and sensible heat between the air in the conditioned space R1 and the outside air. As shown in Figure 3, the third heat exchanger 41a includes an element E and a spacer. The element E is made up of a number of flat heat transfer sheets stacked at intervals via spacers. The heat transfer sheets are made of a material that has heat transfer and moisture permeability. The heat transfer sheets transfer sensible heat while simultaneously allowing moisture to pass through. The element E has gas barrier properties. The element E is configured such that the air passage in the conditioned space R1 and the air passage in the outside air are in contact via the heat transfer sheets, and the air in the conditioned space R1 and the outside air do not mix.

[0055] The exhaust fan 42a generates an airflow in the conditioned space R1 so that the air RA in the conditioned space R1 is discharged to the outside as exhaust air EA. The exhaust fan 42a is positioned downstream of the third heat exchanger 41a with respect to the airflow.

[0056] The exhaust fan 42a is driven by a fan motor. The fan motor's rotational speed (frequency) can be controlled by an inverter or the like, and by controlling the rotational speed while considering resistance, the airflow of the exhaust fan 42a can be controlled. Specifically, four airflows are available for the exhaust fan 42a: a minimum airflow L, a medium airflow M that is greater than L, an airflow H that is greater than M, and a maximum airflow HH that is greater than H. Here, the maximum airflow HH is an airflow that exceeds the largest airflow that can be set during normal operation of the air conditioning unit 2a. The maximum airflow HH is an airflow that cannot be set by an occupant using the remote controller and can be used in the event of a refrigerant leak.

[0057] The supply fan 43a generates an airflow of outdoor air so as to supply outdoor air OA to the air-conditioned space R1 as supply air SA. The supply fan 43a is positioned downstream of the third heat exchanger 41a with respect to the airflow.

[0058] The supply air fan 43a is driven by a fan motor. The fan motor's rotational speed (frequency) can be controlled by an inverter or the like, and the airflow of the supply air fan 43a can be controlled by controlling the rotational speed while considering resistance, etc. Specifically, four airflows are available for the supply air fan 43a: a minimum airflow L, a medium airflow M that is greater than airflow L, an airflow H that is greater than airflow M, and a maximum airflow HH that is greater than airflow H. Here, the maximum airflow HH is an airflow that exceeds the largest airflow that can be set during normal operation of the air conditioning unit 2a. The maximum airflow HH is an airflow that cannot be set by an occupant using a remote controller and can be used in the event of a refrigerant leak.

[0059] Note that the maximum airflow HH of the exhaust fan 42a and the maximum airflow HH of the supply fan 43a may be different, but in this case they are the same. Also, the supply fan 43a does not necessarily need to have a maximum airflow HH.

[0060] The ventilation device 3a further includes a third control unit 44a. The third control unit 44a will be described later.

[0061] (2-4) Communication lines The air conditioning and ventilation system 1a includes a first communication line 51, a second communication line 52, and a third communication line 53 as communication lines 5.

[0062] The first communication line 51 is connected to the first unit 10. The second communication line 52 branches off from the first communication line 51 and is connected to the second units 20a, 20b, 20c, and 20d. The third communication line 53 branches off from the first communication line 51 and is connected to the ventilation devices 3a and 3b.

[0063] In other words, the first communication line 51 is shared between the first unit 10 and the second units 20a, 20b, 20c, and 20d, and between the first communication line 51 and the second communication line 52 connecting the first unit 10 and the ventilation devices 3a and 3b. To put it another way, the second units 20a, 20b, 20c, and 20d and the ventilation devices 3a and 3b are connected to the first unit 10 by a common first communication line 51.

[0064] (2-5) Control Configuration As shown in Figure 1, the air conditioning and ventilation system 1a comprises a first control unit 16 and second control units 24a, 24b, 24c, and 24d for controlling the operation of the air conditioning unit 2a, and a third control unit 44a and 44b for controlling the operation of the ventilation unit 3a. The first control unit 16, the second control units 24a, 24b, 24c, and 24d, and the third control units 44a and 44b are connected via a communication line 5.

[0065] The first control unit 16, second control units 24a, 24b, 24c, 24d, and third control units 44a, 44b of the air conditioning and ventilation system 1a perform various calculations and processes, and are implemented by, for example, a processing unit such as a CPU.

[0066] (2-5-1) First Control Unit As described above, the first control unit 16 is provided in the first unit 10 and, as shown in Figure 4, mainly comprises a CPU 17, a storage unit 18, and a communication unit 19.

[0067] The CPU 17 is connected to the memory unit 18 and the communication unit 19. The memory unit 18 stores control data, etc. The communication unit 19 communicates control data, etc. with the second control units 24a, 24b, 24c, 24d and the third control units 44a, 44b. The CPU 17 then transmits and reads / writes control data, etc. via the memory unit 18 and the communication unit 19, while controlling the operation of the components of the first unit 10, such as the compressor 11, four-way switching valve 12, first expansion valve 14, and first fan 15.

[0068] (2-5-2) Second Control Unit Since each of the second control units 24a, 24b, 24c, and 24d has a similar configuration, only the configuration of the second control unit 24a will be described here. For the configurations of the second control units 24b, 24c, and 24d, the subscripts "b," "c," and "d" will be used instead of the subscript "a" that indicates each part of the second control unit 24a, and the descriptions of each part will be omitted.

[0069] As described above, the second control unit 24a is provided in the second unit 20a and mainly comprises a CPU 25a, a storage unit 26a, and a communication unit 27a. The second control unit 24a is configured to receive detection signals from the detection unit 4.

[0070] The CPU 25a is connected to the memory unit 26a and the communication unit 27a. The memory unit 26a stores control data, etc. The communication unit 27a transmits control data, etc. to and from the first control unit 16. The CPU 25a then transmits, reads, writes, and sends / receives control data, etc. via the memory unit 26a and the communication unit 27a, while also controlling the operation of components provided in the second unit 20a, such as the second expansion valve 21a, the second fan 23a, and the shut-off valve 33.

[0071] (2-5-3) Third Control Unit Since the third control units 44a and 44b have similar configurations, only the configuration of the third control unit 44a will be described here. For the configuration of the third control unit 44b, the subscript "b" will be used instead of the subscript "a" used to indicate each part of the third control unit 44a, and the description of each part will be omitted.

[0072] The third control unit 44a is provided in the ventilation device 3a as described above, and mainly comprises a CPU 45a, a storage unit 46a, and a communication unit 47a.

[0073] The CPU 45a is connected to the memory unit 46a and the communication unit 47a. The memory unit 46a stores control data, etc. The communication unit 47a transmits control data, etc. to the first control unit 16. The CPU 45a then transmits, reads, writes, and sends / receives control data, etc. via the memory unit 46a and the communication unit 47a, while controlling the operation of components of the ventilation system 3a, such as the exhaust fan 42a and the supply fan 43a.

[0074] (2-5-4) Control in case of refrigerant leakage This section explains the control of the air conditioning and ventilation system 1a when refrigerant leaks into the air-conditioned spaces R1 and R2.

[0075] The second control units 24a, 24b, 24c, and 24d receive electrical signals related to the concentration of the refrigerant detected by the corresponding detection unit 4 via the communication units 27a, 27b, 27c, and 27d. The storage units 26a, 26b, 26c, and 26d of the second control units 24a, 24b, 24c, and 24d contain: A predetermined value for the refrigerant leakage concentration is stored. The predetermined value is the value (refrigerant concentration) at which refrigerant leakage is considered to have occurred in the second units 20a, 20b, 20c, and 20d. The second control units 24a, 24b, 24c, and 24d determine whether the refrigerant concentration detected by the detection unit 4 is below the predetermined value. If the second control units 24a, 24b, 24c, and 24d determine that the refrigerant concentration in at least one of the air-conditioned spaces R1 and R2 is below the predetermined value, they determine that there is no refrigerant leakage in the air-conditioned spaces R1 and R2. On the other hand, if the second control units 24a, 24b, 24c, and 24d determine that the refrigerant concentration in at least one of the air-conditioned spaces R1 and R2 exceeds the predetermined value, they transmit a refrigerant leakage signal to the first control unit 16. The first control unit 16, having received the refrigerant leakage signal via the communication unit 19, transmits an instruction to the ventilation devices 3a and 3b to operate them.

[0076] In this embodiment, the first control unit 16 operates all ventilation devices 3a and 3b connected to the first unit 10 by communication lines 5. In other words, the first control unit 16 operates all ventilation devices 3a and 3b of the same system. Specifically, when the concentration of refrigerant detected by at least one of the multiple detection units 4 exceeds a predetermined value, the communication units 27a, 27b, 27c, and 27d of the second control units 24a, 24b, 24c, and 24d corresponding to that detection unit 4 transmit a refrigerant leak signal to the first control unit 16. The first control unit 16, having received the signal via the communication unit 19, transmits an instruction to the ventilation devices 3a and 3b to operate. For example, when the concentration of refrigerant detected by a detection unit 4 located in the second unit 20a exceeds a predetermined value, the corresponding second control unit 24a transmits a refrigerant leak signal to the first control unit 16, and the first control unit 16 transmits an instruction to the ventilation devices 3a and 3b to operate. Therefore, if a refrigerant leak occurs in the air-conditioned space R1, the ventilation devices 3a and 3b will operate, ventilating both the air-conditioned space R1 where the refrigerant leak occurred and the air-conditioned space R2 where no refrigerant leak occurred. On the other hand, the first control unit of the air-conditioned ventilation system 1b, which is on a different system from the air-conditioned ventilation system 1a, does not receive a signal indicating a refrigerant leak, and therefore does not receive an instruction to operate the ventilation devices that ventilate the air-conditioned spaces R3 and R4.

[0077] In this embodiment, the first control unit 16, upon receiving a signal indicating refrigerant leakage, transmits an instruction to set the airflow of the exhaust fans 42a and 42b to their maximum airflow HH. Furthermore, the first control unit 16 transmits an instruction to set the airflow of the supply fans 43a and 43b to their maximum airflow HH.

[0078] Therefore, when the ventilation devices 3a and 3b are stopped, the third control units 44a and 44b, which receive information from the first control unit 16 via the communication units 47a and 47b, start the fan motors so that the airflow of the exhaust fans 42a and 42b and the supply fans 43a and 43b reaches the maximum airflow HH. When the ventilation devices 3a and 3b are operating, the third control units 44a and 44b, which receive information from the first control unit 16 via the communication units 47a and 47b, increase the rotation speed of the fan motors so that the airflow of the exhaust fans 42a and 42b and the supply fans 43a and 43b reaches the maximum airflow HH. If the ventilation devices 3a and 3b have dampers that switch the airflow path to allow air to pass through element E and not pass through it (bypass path), the third control units 44a and 44b, which receive information from the first control unit 16, control the rotation speed of the fan motors considering resistance, etc., without switching the dampers.

[0079] Furthermore, the second control units 24a, 24b, 24c, and 24d, which correspond to the detection unit 4 that detects that the refrigerant concentration exceeds a predetermined value, close the corresponding shut-off valves 33 and 34. When the shut-off valves 33 and 34 are closed, the inflow of refrigerant from the piping connecting the first unit 10 and the shut-off valves 33 and 34 to the corresponding second units 20a, 20b, 20c, and 20d is suppressed.

[0080] Furthermore, the second control units 24a, 24b, 24c, and 24d corresponding to the detection unit 4 that detects that the refrigerant concentration exceeds a predetermined value stop the corresponding second fans 23a, 23b, 23c, and 23d. This suppresses the diffusion of refrigerant leakage in the air-conditioned spaces R1 and R2. Also, the second control units 24a, 24b, 24c, and 24d corresponding to the detection unit 4 that have not detected that the refrigerant concentration exceeds a predetermined value continue operation of the corresponding second fans 23a, 23b, 23c, and 23d if they are already operating.

[0081] Furthermore, the first control unit 16 controls the components of the first unit 10 when it stops the operation of the second units 20a, 20b, 20c, and 20d corresponding to the detection unit 4 that detects that the refrigerant concentration exceeds a predetermined value. For example, the first control unit 16 reduces the rotational speed of the compressor 11.

[0082] Furthermore, the first control unit 16 controls the components of the first unit 10 in response to an increase in the airflow of the ventilation devices 3a and 3b. For example, the first control unit 16 varies the opening degree of the first expansion valve 14.

[0083] Furthermore, if the ventilation devices 3a and 3b are of a type that have coils that use refrigerant, and refrigerant leakage occurs in the ventilation devices 3a and 3b, the third control units 44a and 44b will stop the operation of their exhaust fans 42a and 42b and supply fans 43a and 43b.

[0084] (3) Operation This section will explain the normal operation of the air conditioning and ventilation system 1a, as well as its operation in the event of a refrigerant leak.

[0085] (3-1) Normal operation The air conditioning unit 2a performs heating and cooling operations as part of its air conditioning operation. In this embodiment, the air conditioning unit 2a allows multiple second units 20a, 20b, 20c, and 20d to individually perform either cooling or heating operations. The ventilation unit 3a performs exhaust and supply air operations. The air conditioning and ventilation system 1a can perform air conditioning and ventilation operations simultaneously, or perform either air conditioning or ventilation operations individually.

[0086] (3-1-1) Cooling operation In full cooling operation, the second control units 24a, 24b, 24c, and 24d, upon receiving a cooling operation command, transmit this information to the first control unit 16. The first control unit 16 and the second control units 24a, 24b, 24c, and 24d control the operation of the constituent equipment, including the compressor 11, four-way switching valve 12, first expansion valve 14, first fan 15, second expansion valves 21a, 21b, 21c, and 21d, and second fans 23a, 23b, 23c, and 23d.

[0087] During cooling operation, the four-way switching valve 12 is switched so that the first heat exchanger 13 functions as a refrigerant radiator and the second heat exchangers 22a, 22b, 22c, and 22d function as refrigerant evaporators (as shown by the solid line of the four-way switching valve 12 in Figure 1).

[0088] In this type of refrigerant circuit, the low-pressure refrigerant in the refrigeration cycle is drawn into the compressor 11, compressed to the high pressure of the refrigeration cycle, and then discharged. The high-pressure refrigerant discharged from the compressor 11 is sent to the first heat exchanger 13 through the four-way switching valve 12. The high-pressure refrigerant sent to the first heat exchanger 13 dissipates heat by exchanging heat with the outdoor air supplied by the first fan 15. The high-pressure refrigerant that has dissipated heat in the first heat exchanger 13 is sent to the second units 20a, 20b, 20c, and 20d through the first expansion valve 14 and the connecting pipe 31.

[0089] The refrigerant sent to the second units 20a, 20b, 20c, and 20d is reduced to the low pressure in the refrigeration cycle by the second expansion valves 21a, 21b, 21c, and 21d, and then sent to the second heat exchangers 22a, 22b, 22c, and 22d. The refrigerant sent to the second heat exchangers 22a, 22b, 22c, and 22d is heated by heat exchange with the indoor air supplied from the conditioned spaces R1 and R2 by the second fans 23a, 23b, 23c, and 23d in the second heat exchangers 22a, 22b, 22c, and 22d, which function as refrigerant evaporators, and evaporates. This refrigerant then flows out from the second units 20a, 20b, 20c, and 20d. Meanwhile, the indoor air cooled in the second heat exchangers 22a, 22b, 22c, and 22d is sent to the air-conditioned spaces R1 and R2, thereby cooling the air-conditioned spaces R1 and R2.

[0090] The refrigerant flowing out from the second units 20a, 20b, 20c, and 20d is sent to the first unit 10 via the connecting pipe 32. The refrigerant sent to the first unit 10 is drawn into the compressor 11 via the four-way switching valve 12.

[0091] (3-1-2) Heating operation For full heating operation, the second control units 24a, 24b, 24c, and 24d, upon receiving a heating operation command, transmit this information to the first control unit 16. The first control unit 16 and the second control units 24a, 24b, 24c, and 24d control the operation of the constituent equipment, including the compressor 11, the four-way switching valve 12, the first expansion valve 14, the first fan 15, the second expansion valves 21a, 21b, 21c, and 21d, and the second fans 23a, 23b, 23c, and 23d.

[0092] During heating operation, the four-way switching valve 12 is switched so that the first heat exchanger 13 functions as a refrigerant evaporator and the second heat exchangers 22a, 22b, 22c, and 22d function as refrigerant radiators (as shown by the dashed line of the four-way switching valve 12 in Figure 1).

[0093] In this type of refrigerant circuit, the low-pressure refrigerant in the refrigeration cycle is drawn into the compressor 11, compressed to the high pressure of the refrigeration cycle, and then discharged. The high-pressure refrigerant discharged from the compressor 11 flows out of the first unit 10 through the four-way switching valve 12.

[0094] The refrigerant flowing out of the first unit 10 is branched and sent to the second units 20a, 20b, 20c, and 20d via the connecting pipe 32. The refrigerant sent to the second units 20a, 20b, 20c, and 20d is then sent to the second heat exchangers 22a, 22b, 22c, and 22d. The high-pressure refrigerant sent to the second heat exchangers 22a, 22b, 22c, and 22d is cooled and condensed by the second fans 23a, 23b, 23c, and 23d, which function as refrigerant radiators, by exchanging heat with the air supplied from the conditioned spaces R1 and R2. This refrigerant is depressurized by the second expansion valves 21a, 21b, 21c, and 21d and flows out of the second units 20a, 20b, 20c, and 20d. Meanwhile, the indoor air heated in the second heat exchangers 22a, 22b, 22c, and 22d is sent to the conditioned space R1, thereby heating the conditioned spaces R1 and R2.

[0095] The refrigerants flowing out from the second units 20a, 20b, 20c, and 20d merge through the connecting pipe 31 and are sent to the first unit 10. The refrigerants sent to the first unit 10 are then sent to the first expansion valve 14. The refrigerants sent to the first expansion valve 14 are reduced in pressure to the low pressure in the refrigeration cycle by the first expansion valve 14 and then sent to the first heat exchanger 13. The refrigerants sent to the first heat exchanger 13 are heated by heat exchange with the outdoor air supplied by the first fan 15 and evaporate. This refrigerant is then drawn into the compressor 11 through the four-way switching valve 12.

[0096] (3-1-3) Exhaust operation Upon receiving a command to operate the exhaust system, the third control units 44a and 44b control the operation of the exhaust fans 42a and 42b, etc., as components of the system.

[0097] When the exhaust fans 42a and 42b are driven, the air RA from the conditioned spaces R1 and R2 is sent through the third ducts D3a and D3b to the third heat exchangers 41a and 41b. This air RA passes through element E, where it exchanges heat with the outdoor air OA, and transfers waste heat to the outdoor air OA. The air EA that has exchanged heat with the outdoor air OA is discharged to the outside of the building through the fourth ducts D4a and D4b.

[0098] (3-1-4) Air intake operation Upon receiving a command to operate the air supply unit, the third control units 44a and 44b control the operation of the air supply fans 43a and 43b, etc., as components of the unit.

[0099] When the supply fans 43a and 43b are driven, the outdoor air OA is sent through the first duct D1a to the third heat exchangers 41a and 41b. In the third heat exchangers 41a and 41b, the outdoor air OA exchanges heat with the air RA by passing through element E, and receives waste heat from the air RA. The air SA that has exchanged heat with the air RA is supplied to the conditioned spaces R1 and R2 through the second ducts D2a and D2b.

[0100] (3-2) When refrigerant leaks Referring to Figure 5, the operation in the event of refrigerant leakage will be explained. When the air conditioning and ventilation system 1a is operating normally (step S1), the second control units 24a, 24b, 24c, and 24d receive signals regarding the refrigerant concentration detected by the corresponding detection unit 4 and determine whether or not it is below a predetermined value (step S2).

[0101] In step S2, if the second control units 24a, 24b, 24c, and 24d determine that the value is below a predetermined value, it is determined that no refrigerant leak has occurred, and normal operation continues (step S1). On the other hand, in step S2, if the second control units 24a, 24b, 24c, and 24d determine that the value exceeds the predetermined value, it is determined that a refrigerant leak has occurred in the air-conditioned spaces R1 and R2 corresponding to the detection unit 4 that detected the value exceeding the predetermined value.

[0102] When the second control units 24a, 24b, 24c, and 24d determine that a predetermined value has been exceeded, they transmit a refrigerant leak signal to the first control unit 16 (step S3). Upon receiving the refrigerant leak signal, the first control unit 16 transmits an instruction to the ventilation devices 3a and 3b to operate them (step S4). At this time, the first control unit 16 transmits an instruction to the third control units 44a and 44b to set the airflow of the exhaust fans 42a and 42b to the maximum airflow HH (step S5). In this embodiment, the first control unit 16 transmits an instruction to the third control units 44a and 44b to set the airflow of the supply fans 43a and 43b to the maximum airflow HH.

[0103] Specifically, if the ventilation devices 3a and 3b are stopped, the third control units 44a and 44b, having received instructions from the first control unit 16, start the fan motors of the exhaust fans 42a and 42b and the supply fans 43a and 43b to achieve the maximum airflow HH. If the ventilation devices 3a and 3b are operating, the third control units 44a and 44b, having received instructions from the first control unit 16, increase the rotation speed of the fan motors of the exhaust fans 42a and 42b and the supply fans 43a and 43b to achieve the maximum airflow HH.

[0104] By performing steps S4 and S5, the leaked refrigerant can be discharged from the air-conditioned spaces R1 and R2, thereby reducing the concentration of refrigerant in the air-conditioned spaces R1 and R2. In this state, a service technician or similar person repairs the location of the refrigerant leak. The ventilation systems 3a and 3b continue to operate until the repair is completed. Once the repair is completed (step S6), normal operation is restored (step S1).

[0105] Furthermore, in step S2, if the second control units 24a, 24b, 24c, and 24d determine that the refrigerant concentration detected by the detection unit 4 exceeds a predetermined value, the second control units 24a, 24b, 24c, and 24d that made that determination close the corresponding shut-off valves 33 and 34 (step S7) and stop the corresponding second fans 23a, 23b, 23c, and 23d (step S8). However, if the second control units 24a, 24b, 24c, and 24d determine in step S6 that the refrigerant concentration detected by the detection unit 4 is below a predetermined value, they do not close the corresponding shut-off valves 33 and 34 and continue operating the corresponding second units 20a, 20b, 20c, and 20d.

[0106] Furthermore, if the required load decreases by stopping the operation of at least one of the second units 20a, 20b, 20c, and 20d, the first control unit 16 controls the components of the first unit 10, for example, by lowering the rotational speed of the compressor 11, in accordance with the change in load.

[0107] Furthermore, even if a refrigerant leak occurs in the air conditioning and ventilation system 1a, the air conditioning and ventilation system 1b, which is on a separate system, will continue to operate.

[0108] (4) Features (4-1) The inventors diligently studied the instruction system in the event of refrigerant leakage in the air-conditioned spaces R1 and R2. As a result, they conceived of having the first control unit 16 of the first unit 10 send an instruction to the ventilation devices 3a and 3b to perform refrigerant discharge operation, thereby completing the air conditioning and ventilation system 1a according to this embodiment.

[0109] Specifically, the air conditioning and ventilation system 1a according to this embodiment comprises an air conditioning unit 2a, ventilation units 3a and 3b, and a detection unit 4. The air conditioning unit 2a has heat exchangers (second heat exchangers 22a, 22b, 22c, and 22d). The heat exchangers (second heat exchangers 22a, 22b, 22c, and 22d) generate conditioned air through heat exchange with a refrigerant. The air conditioning unit 2a sends the conditioned air to the conditioned spaces R1 and R2. The ventilation units 3a and 3b ventilate the conditioned spaces R1 and R2. The detection unit 4 detects the concentration of the refrigerant in the conditioned spaces R1 and R2. The air conditioning unit 2a includes a first unit 10 and second units 20a, 20b, 20c, and 20d. The first unit 10 is located outside the room. The first unit 10 has a first control unit 16. The second units 20a, 20b, 20c, and 20d are placed inside the room. The second units 20a, 20b, 20c, and 20d have second control units 24a, 24b, 24c, and 24d. When the concentration of refrigerant detected by the detection unit 4 exceeds a predetermined value, the second control units 24a, 24b, 24c, and 24d transmit a refrigerant leak signal to the first control unit 16. Upon receiving the signal, the first control unit 16 transmits an instruction to the ventilation devices 3a and 3b to operate.

[0110] According to the air conditioning and ventilation system 1a of this embodiment, when the concentration of refrigerant detected by the detection unit 4 exceeds a predetermined value, and refrigerant leakage is detected in the air-conditioned spaces R1 and R2, the second control units 24a, 24b, 24c, and 24d of the second units 20a, 20b, 20c, and 20d send a refrigerant leakage signal to the first control unit 16 of the first unit 10, and the first control unit 16 sends an instruction to the ventilation devices 3a and 3b to operate. Therefore, even if a communication line is omitted between the second units 20a, 20b, 20c, and 20d and the ventilation devices 3a and 3b, the first unit 10 can operate the ventilation devices 3a and 3b in the event of refrigerant leakage.

[0111] Furthermore, since communication lines between the second units 20a, 20b, 20c, and 20d and the ventilation devices 3a and 3b can be omitted, costs and installation time can be reduced. In particular, as in this embodiment, the effect of reducing costs and installation time is greater when at least one of the second units and ventilation devices is multiple.

[0112] (4-2) The air conditioning and ventilation system 1a according to this embodiment further comprises a first communication line 51, a second communication line 52, and a third communication line 53. The first communication line 51 is connected to the first unit 10. The second communication line 52 branches off from the first communication line 51 and is connected to the second units 20a, 20b, 20c, and 20d. The third communication line 53 branches off from the first communication line 51 and is connected to the ventilation devices 3a and 3b.

[0113] Here, the first unit 10, the second units 20a, 20b, 20c, and 20d, and the ventilation devices 3a and 3b are connected via a common first communication line 51. This allows for the simplification of the communication lines 5.

[0114] Furthermore, since the air conditioning and ventilation system 1a is equipped with a common first communication line 51, the ventilation devices 3a and 3b and the second units 20a, 20b, 20c, and 20d are located in close proximity. Therefore, if a refrigerant leak occurs in the second units 20a, 20b, 20c, and 20d, the nearby ventilation devices 3a and 3b can operate.

[0115] (4-3) In the air conditioning and ventilation system 1a according to this embodiment, the ventilation devices 3a and 3b have first fans (exhaust fans 42a and 42b) that discharge the air from the air-conditioned spaces R1 and R2 to the outside. Upon receiving a signal, the first control unit 16 transmits an instruction to the ventilation devices 3a and 3b to set the airflow of the first fans (exhaust fans 42a and 42b) to the maximum airflow.

[0116] Here, by setting the airflow of the first fan (exhaust fans 42a and 42b) to its maximum, the time required to expel the air from the air-conditioned spaces R1 and R2, where the refrigerant has leaked, to the outside can be shortened.

[0117] (4-4) In this embodiment, the maximum airflow of the air conditioning and ventilation system 1a exceeds the largest airflow that can be set during normal operation of the air conditioning unit 2a. In this embodiment, the normal operation of the air conditioning unit 2a is cooling operation and heating operation.

[0118] In this configuration, when a refrigerant leak occurs, the airflow of the first fan (exhaust fans 42a and 42b) can be increased to a level greater than that achievable during normal operation. This allows for a shorter time to expel the air from the R1 and R2 spaces where the refrigerant has leaked to the outside.

[0119] (5) Variant (5-1) Variation 1 In the above embodiment, when a refrigerant leak occurs, all ventilation devices 3a and 3b connected to the first unit 10 by the communication line 5 are operated (all ventilation devices 3a and 3b belonging to the same system are operated), but the system is not limited to this. In this modified example, when a refrigerant leak occurs, the first control unit 16 operates some of the multiple ventilation devices 3a and 3b connected to the first unit 10 by the communication line 5. In other words, the first control unit 16 operates some of the ventilation devices 3a and 3b belonging to the same system.

[0120] (5-1-1) Overview The memory unit 18 of the first unit 10 stores the ventilation devices 3a and 3b associated with each of the second units 20a, 20b, 20c, and 20d. Specifically, the memory unit 18 stores that the second units 20a and 20b that send the conditioned air generated to the air-conditioned space R1 correspond to the ventilation device 3a that ventilates the air-conditioned space R1, and also stores that the second units 20c and 20d that send the conditioned air generated to the air-conditioned space R2 correspond to the ventilation device 3b that ventilates the air-conditioned space R2.

[0121] When the refrigerant concentration detected by the detection unit 4 exceeds a predetermined value, the second control units 24a, 24b, 24c, and 24d corresponding to the detection unit 4 transmit a refrigerant leak signal to the first control unit 16. Upon receiving the refrigerant leak signal, the first control unit 16 transmits an instruction to operate the ventilation devices 3a and 3b corresponding to the transmitting second control units 24a, 24b, 24c, and 24. For example, when the refrigerant concentration detected by the detection unit 4 located in the second unit 20a exceeds a predetermined value, the corresponding second control unit 24a transmits a refrigerant leak signal to the first control unit 16, and the first control unit 16 transmits an instruction to operate the ventilation device 3a corresponding to the second control unit 24a.

[0122] Therefore, if a refrigerant leak occurs in the air-conditioned space R1, the ventilation device 3a will start operating, ventilating the air-conditioned space R1 where the refrigerant leak occurred. At the same time, no instruction is sent to the ventilation device 3b, so there is no change in the operation of the ventilation device 3b in the air-conditioned space R2 where no refrigerant leak has occurred.

[0123] Here, based on instructions from the first control unit 16, the third control unit 44a controls the fan motors so that the exhaust fan 42a and supply fan 43a of the ventilation system 3a reach the maximum airflow HH. On the other hand, if the ventilation system 3b is stopped, the ventilation systems 3a and 3b remain stopped. If the ventilation system 3b is operating, the third control unit 44b controls the fan motors so that the airflow is set by the occupant using the remote controller.

[0124] (5-1-2) Characteristics In the modified air conditioning and ventilation system 1a, the air conditioning device 2a includes a plurality of second units 20a, 20b, 20c, and 20d. The first unit 10 has a storage unit 18 that stores ventilation devices 3a and 3b corresponding to each of the second units 20a, 20b, 20c, and 20d.

[0125] Here, the first unit 10 stores the ventilation devices 3a and 3b corresponding to each of the second units 20a, 20b, 20c, and 20d. Therefore, the first unit 10 can send instructions to operate the ventilation devices 3a and 3b that are linked to the second units 20a, 20b, 20c, and 20d that have leaked refrigerant.

[0126] (5-2) Modification 2 In the above embodiment, when refrigerant leakage occurs, the first control unit 16 sends an instruction to maximize the airflow of the exhaust fans 42a and 42b and the airflow of the supply fans 43a and 43b, but is not limited to this. In this modified example, when refrigerant leakage occurs, the first control unit 16 sends an instruction to make the airflow of the exhaust fans 42a and 42b greater than the airflow of the supply fans 43a and 43b.

[0127] (5-2-1) Overview When the concentration of refrigerant detected by the detection unit 4 exceeds a predetermined value, the second control units 24a, 24b, 24c, and 24d corresponding to the detection unit 4 transmit a refrigerant leak signal to the first control unit 16. Upon receiving the refrigerant leak signal, the first control unit 16 transmits an instruction to the ventilation devices 3a and 3b to increase the airflow of the exhaust fans 42a and 42b to a level greater than that of the supply fans 43a and 43b. For example, the first control unit 16 transmits an instruction to the ventilation devices 3a and 3b to set the airflow of the exhaust fans 42a and 42b to the maximum airflow HH, and to set the airflow of the supply fans 43a and 43b to either H, M, or L. Alternatively, for example, the first control unit 16 transmits an instruction to the ventilation devices 3a and 3b to set the airflow of the exhaust fans 42a and 42b to the maximum airflow HH, and to stop the supply fans 43a and 43b. In this way, the airflow of the supply fans 43a and 43b in the event of refrigerant leakage is appropriately set based on the relationship between the positions of the ventilation devices 3a and 3b and the positions of the second units 20a, 20b, 20c, and 20d. Specifically, if the ventilation devices 3a and 3b are located near the second units 20a, 20b, 20c, and 20d that are determined to have leaked refrigerant, the third control units 44a and 44b stop the supply fans 43a and 43b.

[0128] Therefore, in this modified example, if refrigerant leakage occurs in the air-conditioned spaces R1 and R2, the third control units 44a and 44b of the ventilation devices 3a and 3b operate the ventilation devices 3a and 3b such that the airflow of the exhaust fans 42a and 42b is greater than the airflow of the supply fans 43a and 43b.

[0129] (5-2-2) Characteristics In the modified air conditioning and ventilation system 1a, the ventilation devices 3a and 3b include a first fan (exhaust fan 42a, 42b) and a second fan (supply fan 43a, 43b). The first fans (exhaust fans 42a, 42b) discharge the air from the conditioned spaces R1 and R2 to the outside. The second fans (supply fans 43a, 43b) supply outside air to the conditioned spaces R1 and R2. Upon receiving a signal, the first control unit 16 transmits an instruction to the ventilation devices 3a and 3b to increase the airflow of the first fans (exhaust fans 42a, 42b) to be greater than the airflow of the second fans (supply fans 43a, 43b).

[0130] This facilitates the discharge of R1 and R2 air from the air-conditioned space where refrigerant leakage has occurred to the outside.

[0131] (5-3) Modification 3 In the above embodiment, when a refrigerant leak occurs, the ventilation devices 3a and 3b are kept running until repairs are completed, but the invention is not limited to this. In this modified example, the first control unit 16 instructs the ventilation devices 3a and 3b on the duration of operation.

[0132] (5-3-1) Overview When the refrigerant concentration detected by the detection unit 4 exceeds a predetermined value, the second control units 24a, 24b, 24c, and 24d corresponding to the detection unit 4 transmit a refrigerant leak signal to the first control unit 16. Upon receiving the refrigerant leak signal, the first control unit 16 instructs the ventilation devices 3a and 3b on the operating time. Thus, in this modified example, one of the specific pieces of information that the first control unit 16 instructs the ventilation devices 3a and 3b on is the operating time. The operating time is calculated from the time the first control unit 16 transmits the refrigerant leak signal to the third control units 44a and 44b, regardless of whether the ventilation devices 3a and 3b are operating or stopped.

[0133] (5-3-2) Characteristics In the modified air conditioning and ventilation system 1a, the first control unit 16, upon receiving a signal, instructs the ventilation devices 3a and 3b on the time to operate.

[0134] In this configuration, the first control unit 16 instructs the operating time of the ventilation devices 3a and 3b when a refrigerant leak occurs, making it easy to ventilate the air in the air-conditioned spaces R1 and R2.

[0135] (5-4) Modification 4 In the above embodiment, the exhaust fans 42a, 42b and supply fans 43a, 43b of the ventilation devices 3a, 3b are configured to operate at the maximum usable airflow HH in the event of refrigerant leakage, but are not limited thereto. In this modified ventilation device, at least one of the exhaust fan and the supply fan is configured to operate within an airflow range that can be set by the occupant using a remote controller.

[0136] (5-5) Variation 5 In the above embodiment, the second control units 24a, 24b, 24c, and 24d of the second units 20a, 20b, 20c, and 20d determine whether the concentration of the refrigerant detected by the detection unit 4 exceeds a predetermined value, but the embodiment is not limited to this. In this modified example, the air conditioning and ventilation system comprises a unit including the detection unit 4 and a control unit, and the control unit of this unit determines whether the concentration exceeds a predetermined value.

[0137] (5-6) Variation 6 In the above embodiment, the ventilation devices 3a and 3b have orthogonal total heat exchangers with perpendicular flow paths as third heat exchangers 41a and 41b, but are not limited to this. The ventilation device may have a rotary total heat exchanger that recovers heat from the air RA of the conditioned space by the rotation of a rotor. Furthermore, the ventilation device may not have a heat exchanger at all.

[0138] (5-7) Variation 7 In the above embodiment, an air conditioning system 2a in which multiple second units 20a, 20b, 20c, and 20d can individually perform cooling or heating operations was described as an example, but the invention is not limited to this. In this modified example, the air conditioning system 2a in which multiple second units 20a, 20b, 20c, and 20d cannot individually perform cooling or heating operations is not possible. In this case, for example, a second expansion valve common to the second units 20a, 20b, 20c, and 20d is provided.

[0139] Furthermore, the air conditioning system described herein may be capable of performing dehumidification operations, etc., or may be used exclusively for cooling.

[0140] (5-8) Variation 8 In the above embodiment, the air conditioning system comprising the air conditioning and ventilation system includes one first unit, a plurality of second units, and a plurality of ventilation devices, but is not limited thereto. The air conditioning system of this disclosure may include a plurality of first units, a plurality of second units, or a plurality of ventilation devices.

[0141] While embodiments of this disclosure have been described above, it should be understood that various modifications to the form and details are possible without departing from the spirit and scope of this disclosure as described in the claims. [Explanation of Symbols]

[0142] 1a,1b: Air conditioning and ventilation system 2a, 2b: Air conditioner 3a,3b: Ventilation system 4: Detection unit 5: Communication lines 51: First communication line 52: Second communication line 53: Third communication line 10: Unit 1 16: First control unit 18: Storage section 20a, 20b, 20c, 20d: Unit 2 22a, 22b, 22c, 22d: Second heat exchanger (heat exchanger) 24a, 24b, 24c, 24d: Second control unit 42a, 42b: Exhaust fan (first fan) 43a, 43b: Intake fan (second fan) R1, R2, R3, R4: Air conditioned space [Prior art documents] [Patent Documents]

[0143] [Patent Document 1] Japanese Patent Publication No. 2016-223643

Claims

1. An air conditioning device (2a) has a heat exchanger (22a) that generates conditioned air by heat exchange with a refrigerant, and supplies the conditioned air to the air-conditioned space (R1), A ventilation device (3a) for ventilating the air-conditioned space, A detection unit (4) for detecting the concentration of the refrigerant in the air-conditioned space, Equipped with, The aforementioned air conditioning system is A first unit (10) is located outdoors and has a first control unit (16), A second unit (20a) is located indoors and has a second control unit (24a), Includes, An air conditioning and ventilation system (1a) in which, when the concentration of the refrigerant detected by the detection unit exceeds a predetermined value, the second control unit transmits a signal of refrigerant leakage to the first control unit, and the first control unit, upon receiving the signal, transmits an instruction to the ventilation device to operate.

2. A first communication line (51) connected to the first unit, A second communication line (52) that branches off from the first communication line and is connected to the second unit, A third communication line (53) is branched from the first communication line and connected to the ventilation device, Furthermore, The air conditioning and ventilation system according to claim 1.

3. The ventilation device has a first fan (42a) that discharges the air from the air-conditioned space to the outside. The air conditioning and ventilation system according to claim 1 or 2, wherein the first control unit, upon receiving the signal, transmits an instruction to the ventilation device to set the airflow of the first fan to its maximum airflow.

4. The aforementioned maximum airflow exceeds the largest airflow that can be set during normal operation of the air conditioning unit. The air conditioning and ventilation system according to claim 3.

5. The air conditioning system includes a plurality of the second units, The first unit has a storage unit (18) that stores the ventilation device corresponding to each of the second units. The air conditioning and ventilation system according to claim 1 or 2.

6. The aforementioned ventilation device is A first fan (42a) that discharges the air from the air-conditioned space to the outside, A second fan (43a) supplies outdoor air to the air-conditioned space, It has, Upon receiving the signal, the first control unit transmits an instruction to the ventilation device to increase the airflow of the first fan to be greater than that of the second fan. The air conditioning and ventilation system according to claim 1 or 2.

7. Upon receiving the signal, the first control unit instructs the ventilation device to operate for a specified time. The air conditioning and ventilation system according to claim 1 or 2.

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