Air conditioning system

Abstract

An air conditioning system (100) is provided with: a heat source machine (10); a first indoor unit (20a); a first shutoff unit (30a) having a first shutoff valve (34); an alarm device (50a); an alarm unit (40a); a first refrigerant sensor (23) provided in the first indoor unit (20a); and an indoor refrigerant sensor (43) provided in the alarm unit (40a). The heat source machine (10) and the first indoor unit (20a) are connected by a first piping (121). The alarm device (50a) issues an alarm when a refrigerant leak is detected by the first refrigerant sensor (23), and the alarm unit (40a) issues an alarm when a refrigerant leak is detected by the indoor refrigerant sensor (43). The first shutoff unit (30a) closes the first piping with a first shutoff valve in each of the cases in which a refrigerant leak is detected by the first refrigerant sensor (23) and in which a refrigerant leak is detected by the indoor refrigerant sensor (43).

Description

air conditioning system

[0001] The present disclosure relates to air conditioning systems.

[0002] Air conditioning systems are required to have sufficient safety measures against refrigerant leaks. JP 2018-77040 A (Patent Document 1) discloses an air conditioning system configured such that, when a refrigerant sensor detects a refrigerant leak in an indoor unit, the indoor unit transmits sensor information to a relay-side control unit, which receives the sensor information and outputs an alarm, while also blocking the flow of refrigerant from the outdoor unit to the indoor unit.

[0003] JP 2018-77040 A

[0004] The configuration disclosed in JP 2018-77040 A does not output an alarm indicating a refrigerant leak if a communication error occurs between the indoor unit and the relay-side control unit. Furthermore, a single refrigerant sensor and alarm are not sufficient safety measures.

[0005] The present disclosure has been made to explain an embodiment that solves the above-mentioned problems, and its purpose is to strengthen safety measures against refrigerant leakage compared to conventional methods.

[0006] The present disclosure relates to an air conditioning system. The air conditioning system includes a heat source unit, a first indoor unit having a first heat exchanger that exchanges heat with the heat source unit via a refrigerant and that blows conditioned air into a first air-conditioned space, a first shutoff unit having a first shutoff valve, an alarm device disposed in the first air-conditioned space, a first alarm unit disposed in the first air-conditioned space, a first refrigerant sensor provided in the first indoor unit that detects a refrigerant leak, and an indoor refrigerant sensor connected to the first alarm unit that detects a refrigerant leak, the heat source unit and the first indoor unit are connected by a first pipe through which a refrigerant flows, the alarm device issues an alarm when the first refrigerant sensor detects a refrigerant leak, the first alarm unit issues an alarm when the indoor refrigerant sensor detects a refrigerant leak, and the first shutoff unit closes the first pipe with the first shutoff valve when the first refrigerant sensor detects a refrigerant leak and when the indoor refrigerant sensor detects a refrigerant leak, respectively.

[0007] According to the air conditioning system of the present disclosure, safety measures against refrigerant leaks can be strengthened compared to conventional systems.

[0008] 1 is a diagram illustrating the configuration of an air conditioning system according to a first embodiment. FIG. 1 is a diagram illustrating the positional relationship between an indoor unit, a shutoff unit, an alarm unit, and a remote controller. FIG. 2 is a diagram illustrating an overview of the configuration of the shutoff unit. FIG. 3 is a block diagram illustrating the configurations of an outdoor unit, an indoor unit, the shutoff unit, and the alarm unit. FIG. 4 is a sequence diagram illustrating the flow of processing when a refrigerant leak is detected by a refrigerant sensor provided in an indoor unit. FIG. 5 is a sequence diagram illustrating the flow of processing when a refrigerant leak is detected by a refrigerant sensor provided in the alarm unit. FIG. 6 is a flowchart illustrating the processing by which the shutoff unit closes the shutoff valve in the event of a power outage. FIG. 7 is a flowchart illustrating the processing by which the indoor unit disables and enables the function of the refrigerant sensor in accordance with operation of the sensor setting switch. FIG. 8 is a diagram illustrating the configuration of an air conditioning system according to a second embodiment. FIG. 9 is a flowchart illustrating the processing executed by the shutoff unit when a refrigerant leak occurs. FIG. 10 is a diagram illustrating the configuration of an air conditioning system according to a third embodiment. FIG. 11 is a diagram illustrating the configuration of an air conditioning system according to a fourth embodiment. FIG. 12 is a diagram illustrating the configuration of an air conditioning system according to a fifth embodiment.

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. While several embodiments will be described below, it was originally intended that the configurations described in each embodiment be combined as appropriate. Note that identical or corresponding parts in the drawings will be designated by the same reference numerals, and their description will not be repeated.

[0010] Embodiment 1. Fig. 1 is a diagram showing the configuration of an air conditioning system 100 according to embodiment 1. The air conditioning system 100 includes an outdoor unit 10, an indoor unit 20, a shutoff unit 30, an alarm unit 40, and remote controllers 50 and 60. In the explanation of embodiment 1, an example will be described in which the air conditioning system 100 is applied to rooms A and B, which are examples of air-conditioned spaces, and a manager's room.

[0011] 1 , the air conditioning system 100 includes a plurality of indoor units 20, shutoff units 30, alarm units 40, and remote controllers 50. In the embodiments described below, in order to distinguish between these multiple components, the indoor units 20, shutoff units 30, alarm units 40, and remote controllers 50 may be referred to as indoor units 20a, 20b..., shutoff units 30a, 30b..., alarm units 40a, 40b..., and remote controllers 50a, 50b..., respectively.

[0012] An indoor unit 20, an alarm unit 40, and a remote controller 50 are disposed in each of rooms A and B. The indoor unit 20 is equipped with a refrigerant sensor 23 that detects refrigerant leaks. The alarm unit 40 has the function of detecting refrigerant leaks and the function of sounding an alarm in response to a refrigerant leak. The alarm unit 40 is disposed in a location where it is considered easy to detect refrigerant leaking from the indoor unit 20. The alarm unit 40 may be disposed, for example, on the floor, wall, or ceiling. Multiple alarm units 40 may be disposed in one room. By detecting refrigerant leaks with the alarm unit 40 in addition to the refrigerant sensor 23 possessed by the indoor unit 20, refrigerant leaks in the indoor unit 20 can be more reliably detected.

[0013] The remote controller 50 is attached to, for example, a wall of a room. The remote controller 50 has a function of transmitting setting information such as the air conditioning temperature to the indoor unit 20, as well as a function of sounding an alarm in case of a refrigerant leak. The remote controller 50 is an example of an alarm device.

[0014] A remote controller 60 is placed in the manager's room. For example, a manager who manages the air-conditioned space is stationed in the manager's room. The manager's room may be a night security room or the like. The remote controller 60 is an example of a management alarm device. If a refrigerant leak occurs in either room A or B, the remote controller 60 issues an alarm about the refrigerant leak. The manager takes appropriate measures in response to the alarm issued by the remote controller 60.

[0015] The outdoor unit 10, the indoor unit 20, and the shutoff unit 30 are connected by piping 120 through which a refrigerant flows. The piping 120 includes a pair of piping 121 that connects the indoor unit 20a and the shutoff unit 30a, and a pair of piping 122 that connects the indoor unit 20b and the shutoff unit 30b.

[0016] A refrigerant circulates between the outdoor unit 10 and the indoor unit 20a via piping 120 passing through the shutoff unit 30a. A refrigerant circulates between the outdoor unit 10 and the indoor unit 20b via piping 120 passing through the shutoff unit 30b. The outdoor unit 10, the indoor unit 20a, the shutoff unit 30a, and the piping 120 form a refrigerant circulation flow path through which the refrigerant circulates. Similarly, the outdoor unit 10, the indoor unit 20b, the shutoff unit 30b, and the piping 120 form a refrigerant circulation flow path through which the refrigerant circulates. Here, the outdoor unit 10 is an example of a heat source unit.

[0017] The indoor units 20a and 20b exchange heat with the outdoor unit 10 via the refrigerant circulating through the refrigerant circulation flow path, thereby air-conditioning the rooms A and B, respectively. If a refrigerant leak occurs in room A, the shutoff unit 30a has the function of shutting off the flow of refrigerant to the indoor unit 20a by closing the pipe 121. Similarly, if a refrigerant leak occurs in room B, the shutoff unit 30b has the function of shutting off the flow of refrigerant to the indoor unit 20b by closing the pipe 122.

[0018] Hereinafter, the indoor unit connected to the shutoff unit 30a by piping 121 may be referred to as the indoor unit subordinate to the shutoff unit 30a, and the indoor unit connected to the shutoff unit 30b by piping 122 may be referred to as the indoor unit subordinate to the shutoff unit 30b. In this case, the indoor unit 20a is the indoor unit subordinate to the shutoff unit 30a, and the indoor unit 20b is the indoor unit subordinate to the shutoff unit 30b.

[0019] The outdoor unit 10, the indoor units 20a, 20b, the shutoff units 30a, and the shutoff units 30b communicate with each other via a communication path L1 established by wire or wirelessly. The communication path L1 is an example of a communication path for establishing communication between the outdoor unit 10, the indoor units 20a, 20b, the shutoff units 30a, and the shutoff units 30b.

[0020] The cutoff unit 30a and the alarm unit 40a communicate with each other via a communication path L2, which may be established by wire or wireless communication. Similarly, the cutoff unit 30b and the alarm unit 40b communicate with each other via a communication path L2, which may be established by wire or wireless communication. The communication path L2 is an example of a communication path for establishing communication between the cutoff unit 30 and the alarm unit 40.

[0021] The indoor unit 20a and the remote controller 50a communicate via a communication path L3 established by wire or wirelessly. Similarly, the indoor unit 20b and the remote controller 50b communicate via a communication path L3 established by wire or wirelessly. Communication path L3 is an example of a communication path for establishing communication between the indoor unit 20 and the remote controller 50. In particular, in the first embodiment, the indoor unit 20b and the remote controller 60 located in the manager's room communicate via communication path L3.

[0022] The indoor unit 20a and the alarm unit 40a notify the shutoff unit 30a of the refrigerant leak. Based on the notification of the refrigerant leak, the shutoff unit 30a closes the piping 121. Similarly, the indoor unit 20b and the alarm unit 40b notify the shutoff unit 30b of the refrigerant leak. Based on the notification of the refrigerant leak, the shutoff unit 30b closes the piping 122.

[0023] If a refrigerant leak is detected in the indoor unit 20a or the alarm unit 40a, the alarm unit 40a and the remote controller 50a issue an alarm. Similarly, if a refrigerant leak is detected in the indoor unit 20b or the alarm unit 40b, the alarm unit 40b and the remote controller 50b issue an alarm. The remote controller 60 located in the manager's room issues an alarm when a refrigerant leak is detected in the indoor unit 20a or the alarm unit 40a, and when a refrigerant leak is detected in the indoor unit 20b or the alarm unit 40b.

[0024] In this way, in the air conditioning system 100, a configuration for detecting a refrigerant leak and a configuration for reporting a refrigerant leak are redundantly arranged in each of rooms A and B. Therefore, with the air conditioning system 100, safety measures against refrigerant leaks can be strengthened compared to systems that do not employ such redundant configurations.

[0025] Furthermore, in the air conditioning system 100, the communication paths (communication paths L1, L2) used to notify the shutoff unit 30 of a refrigerant leak are different between the indoor unit 20 and the alarm unit 40. Therefore, even if a communication failure occurs on one of the two communication paths (L1, L2), the refrigerant leak can be reliably notified to the shutoff unit 30 via the other communication path.

[0026] Furthermore, in the air conditioning system 100, the communication path L2 for reporting a refrigerant leak via the alarm unit 40 is different from the communication path L3 for reporting a refrigerant leak via the remote controllers 50 and 60. Therefore, even if a communication failure occurs on one of the two communication paths (L2, L3), the refrigerant leak alarm can be reliably issued on the other communication path.

[0027] Furthermore, in the air conditioning system 100, the blocking units 30a and 30b separate the areas where the refrigerant flow is stopped. Therefore, for example, even if a refrigerant leak is detected in room A and operation of the indoor unit 20a in room A is stopped, operation of the indoor unit 20b in room B can continue.

[0028] 2 is a diagram for explaining the positional relationship between the indoor unit 20, the shutoff unit 30, the alarm unit 40, and the remote controller 50. Here, the positional relationship between the indoor unit 20 (20a) and the like will be explained using room A as a representative example.

[0029] The indoor unit 20a is embedded in the ceiling of room A, which is the space to be air-conditioned. The shutoff unit 30a is placed in the attic of room A. The alarm unit 40a is placed on the floor of room A, for example. The alarm unit 40a is equipped with an LED (Light Emitting Diode) 45 for displaying an alarm. The alarm unit 40a is communicatively connected to the shutoff unit 30a via a communication path L2. Power is supplied from the shutoff unit 30a to the alarm unit 40a. The alarm unit 40a and the shutoff unit 30a may be configured to be wirelessly connected. The shutoff unit 30 is an example of a shutoff device, the alarm unit 40 is an example of an alarm sensor device, and the remote controllers 50 and 60 are examples of alarm devices.

[0030] The remote controller 50a is placed on the wall of the room A for user convenience. The remote controller 50a is communicatively connected to the cutoff unit 30a via a communication path L3. The remote controller 50a includes a display 51 and an operation unit 52. The user operates the operation unit 52 to input setting information, including the room temperature setting, into the remote controller 50a. The display 51 displays the room temperature and various other information.

[0031] The shutoff unit 30a and the indoor unit 20a are connected by a pair of pipes 121 through which the refrigerant flows. The refrigerant sensor 23 is disposed near the pipes 121 that pass through the indoor unit 20a. If the refrigerant sensor 23 detects a refrigerant leak, the refrigerant leak is notified to the remote controller 50a via the communication path L3. Based on the notification of the refrigerant leak, the remote controller 50a emits an alarm sound and displays alarm information on the display 51. The remote controller 50a may be equipped with an LED for displaying the alarm. When displaying alarm information on the display 51, the remote controller 50a may turn on the backlight of the display 51.

[0032] Here, the layout relationship of the indoor unit 20 (20a) and the like has been explained using room A as a representative example. In room B, an indoor unit 20b, a shutoff unit 30b, an alarm unit 40b, and a remote controller 50b are arranged in the same manner as in room A.

[0033] 3 is a diagram showing an outline of the configuration of the shutoff unit 30. Here, an outline of the configuration of the shutoff unit 30 (30a) will be described using room A as a representative example. The shutoff unit 30a includes a shutoff valve 34 that shuts off a pair of pipes 121, and a substrate 300 that opens and closes the shutoff valve 34.

[0034] The pair of pipes 121 includes a pipe 121a through which refrigerant flows from the outdoor unit 10 to the indoor unit 20a, and a pipe 121b through which refrigerant flows from the indoor unit 20a to the outdoor unit 10. Liquid refrigerant flows through one of the pipes 121a, 121b, and gas refrigerant flows through the other. When the outdoor unit 10 functions as a condenser and the indoor unit 20a functions as an evaporator, room A is cooled. When the outdoor unit 10 functions as an evaporator and the indoor unit 20a functions as a condenser, room A is heated.

[0035] The shutoff valves 34 include a shutoff valve 34a attached to the pipe 121a and a shutoff valve 34b attached to the pipe 121b. The shutoff valves 34 are, for example, linear expansion valves.

[0036] The circuit board 300 communicates with the outdoor unit 10 and the indoor unit 20a via communication path L1, and with the alarm unit 40a via communication path L2. The circuit board 300 is provided with a plurality of connection terminals for connecting a plurality of alarm units 40. The circuit board 300 closes the shutoff valves 34a and 34b when a refrigerant leak is notified from the indoor unit 20a and when a refrigerant leak is notified from the alarm unit 40a. This closes the pipes 121a and 121b.

[0037] Fig. 4 is a block diagram showing the configurations of the outdoor unit 10, indoor unit 20, shutoff unit 30, and alarm unit 40. Fig. 4 shows the outdoor unit 10, indoor units 20a and 20b, shutoff units 30a and 30b, and alarm units 40a and 40b. The indoor units 20a and 20b have a common configuration, the shutoff units 30a and 30b have a common configuration, and the alarm units 40a and 40b have a common configuration. Fig. 4 shows the details of the configurations of the indoor unit 20a, shutoff unit 30a, and alarm unit 40a, while omitting the details of the configurations of the indoor unit 20b, shutoff unit 30b, and alarm unit 40b.

[0038] The outdoor unit 10 includes a processor 11, a memory 12, a communication interface (I / F) 13, and an air conditioning mechanism 14. The air conditioning mechanism 14 includes a compressor 141, a heat exchanger 142, a fan 144, and a four-way valve 145.

[0039] The processor 11 is typically configured by a CPU (Central Processing Unit) or an MPU (Multi-Processing Unit), etc. The processor 11 is an example of a computing device.

[0040] The memory 12 includes an area in which programs executed by the processor 11 are stored, an area in which the processor 11 temporarily stores program code, work memory, etc., and an area in which an ID is stored to identify the outdoor unit 10 by other devices such as the shutoff unit 30. The memory 12 includes volatile memory such as dynamic random access memory (DRAM) and static random access memory (SRAM), read only memory (ROM), and non-volatile memory such as flash memory. The memory 12 may also be a solid state drive (SSD) or a hard disk drive (HDD), etc.

[0041] The processor 11 has a communication function. The processor 11 transmits data including an ID stored in the memory 12 to the communication destination, thereby allowing the communication destination to identify the source of the communication. The processor 11 communicates with the cutoff units 30 (30a, 30b) via a communication interface (I / F) 13. The processor 11 also communicates with the indoor units 20 (20a, 20b) via the communication interface 13 and the cutoff unit 30. The processor 11 also communicates with a remote controller 60 located in the manager's room via the communication interface 13, the cutoff units 30a, 30b, and the indoor unit 20b.

[0042] The processor 11, memory 12, and communication interface 13 constitute a control device provided in the outdoor unit 10. The control device is also an example of processing circuitry. The processor 11 controls various devices according to a program. This control is not limited to software processing, and can also be processed by dedicated hardware (electronic circuitry).

[0043] The indoor units 20 (20a, 20b) include a processor 21, a memory 22, a refrigerant sensor 23, an air conditioning mechanism 24, a sensor setting switch 25, and communication interfaces (I / F) 26, 27. The air conditioning mechanism 24 includes a heat exchanger 242, an expansion valve 243, and a fan 244. The heat exchanger 242 is an example of a heat exchanger that exchanges heat with a heat source unit. The air conditioning mechanism 14 of the outdoor unit 10, the air conditioning mechanism 24 of the indoor unit 20, and the piping 120 (FIG. 1) form a refrigerant circulation path and a refrigerant circuit through which the refrigerant circulates.

[0044] The memory 22 includes an area for storing an ID that allows other devices, such as the shutoff unit 30, to identify the indoor unit 20. The detailed configurations of the processor 21 and the memory 22 are similar to those of the processor 11 and the memory 12 already described, and therefore will not be described again here.

[0045] The refrigerant sensor 23 detects refrigerant leakage in the indoor unit 20. The sensor setting switch 25 is a switch for switching the sensor function of the refrigerant sensor 23 between on and off. The sensor setting switch 25 is operated, for example, by a worker performing maintenance on the indoor unit 20.

[0046] When the sensor function of the refrigerant sensor 23 is set to on by the sensor setting switch 25 , the processor 21 acquires sensor information from the refrigerant sensor 23 .

[0047] The processor 21 has a communication function. The processor 21 allows the communication destination to identify the source of the communication by transmitting data including the ID stored in the memory 22 to the communication destination. The processor 21 communicates with the blocking unit 30 via the communication interface 26. The processor 21 communicates with the remote controller 50 via the communication interface 27.

[0048] The shutoff unit 30 (30a, 30b) includes a processor 31, a memory 32, a shutoff valve 34 (34a, 34b), a backup power supply 35, and communication interfaces (I / F) 33, 36, 37.

[0049] The memory 32 includes an area for storing an ID that allows other devices such as the outdoor unit 10 to identify the shutoff unit 30. The detailed configurations of the processor 31 and the memory 32 are similar to those of the processor 11 and the memory 12 already described, and therefore the description thereof will not be repeated here.

[0050] The processor 31 has a communication function. The processor 31 transmits data including the ID stored in the memory 32 to the communication destination, thereby allowing the communication destination to identify the communication source. The processor 31 communicates with the outdoor unit 10 via the communication interface 33. The processor 31 communicates with the indoor unit 20 via the communication interface 36. The processor 31 communicates with the alarm unit 40 via the communication interface 37.

[0051] The processor 31 closes the shutoff valves 34a and 34b when a refrigerant leak is notified from the indoor unit 20 and when a refrigerant leak is notified from the alarm unit 40. This closes the pipes 121a and 121b. In the event of a power outage, the shutoff unit 30 switches the power supply source from the main power source to the standby power source 35. The standby power source 35 is configured, for example, by a secondary battery. In the event of a power outage, the processor 31 operates using power supplied from the standby power source 35 and closes the shutoff valves 34a and 34b. This stops the supply of refrigerant to the indoor unit 20 during the power outage.

[0052] The alarm unit 40 includes a processor 41 , a memory 42 , a refrigerant sensor 43 , a speaker 44 , an LED 45 , and a communication interface (I / F) 47 .

[0053] The memory 42 includes an area for storing an ID that allows other devices, such as the cutoff unit 30, to identify the alarm unit 40. The detailed configurations of the processor 41 and the memory 42 are similar to those of the processor 11 and the memory 12 already described, and therefore the description thereof will not be repeated here.

[0054] The refrigerant sensor 43 detects a refrigerant leak. The refrigerant sensor 43 is an example of an indoor refrigerant sensor. The processor 41 acquires sensor information from the refrigerant sensor 43. When a refrigerant leak is detected, the processor 41 generates an alarm sound from the speaker 44 and turns on the LED 45.

[0055] The processor 41 has a communication function. The processor 41 allows the communication destination to identify the source of the communication by transmitting data including the ID stored in the memory 42 to the communication destination. The processor 41 communicates with the blocking unit 30 via the communication interface 47.

[0056] 5 is a sequence diagram showing the processing flow when a refrigerant leak is detected by the refrigerant sensor 23 of the indoor unit 20a. In the sequence diagram, the alarm unit 40b and remote controller 50b arranged in room B are omitted from the illustration. The processing flow will be explained below with reference to FIG.

[0057] The refrigerant sensor 23 detects a refrigerant leak in the indoor unit 20a (step S1). In this case, the indoor unit 20a notifies the remote controller 50a of the refrigerant leak (step S2), notifies the shutoff unit 30a of the refrigerant leak (step S4), and notifies the outdoor unit 10 of the refrigerant leak (step S8). The indoor unit 20a then saves the refrigerant leak history in the memory 22 (see FIG. 4) (step S13) and stops air conditioning operation (step S14). The order in which steps S2, S4, S8, S13, and S14 are performed may be changed.

[0058] The remote controller 50a issues an alarm based on the notification from the indoor unit 20a (step S3). More specifically, the remote controller 50a issues an alarm sound and displays alarm information based on the notification of the refrigerant leak. This allows the user in room A to become aware of the refrigerant leak. The remote controller 50a then saves the refrigerant leak history (step S18).

[0059] The shutoff unit 30a closes the shutoff valves 34a and 34b based on the notification from the indoor unit 20a (step S5). By closing the shutoff valves 34a and 34b, the shutoff unit 30a closes the pipes 121a and 121b, thereby preventing the refrigerant leak from spreading. The shutoff unit 30a then notifies the alarm unit 40a of the refrigerant leak (step S6). The shutoff unit 30a then stores the refrigerant leak history in the memory 32 (see FIG. 4) (step S15).

[0060] The order in which steps S5, S6, and S15 are executed may be changed. As shown in Fig. 5, the blocking unit 30a may notify the outdoor unit 10 of the refrigerant leakage (step S8a).

[0061] The alarm unit 40a issues an alarm based on the notification from the shutoff unit 30a (step S7). More specifically, the alarm unit 40a issues an alarm sound and turns on the LED 45 (see FIG. 4) based on the notification of the refrigerant leak. This allows the user in room A to become aware of the refrigerant leak.

[0062] Based on the notification from the indoor unit 20a, the outdoor unit 10 notifies the remote controller 60 located in the manager's room of the refrigerant leak (step S9). Based on the notification from the indoor unit 20a, the outdoor unit 10 further notifies the shutoff unit 30b and the indoor unit 20b located in room B of the refrigerant leak in room A. More specifically, the outdoor unit 10 notifies the shutoff unit 30b and the indoor unit 20b of a "maintenance abnormality" message (steps S11 and S12). The order in which steps S9, S11, and S12 are performed may be changed. Thereafter, the outdoor unit 10 saves the refrigerant leak history in memory 12 (see FIG. 4) (step S19).

[0063] The remote controller 60 issues an alarm based on the notification from the outdoor unit 10 (step S10). More specifically, the remote controller 60 issues an alarm sound and displays alarm information based on the notification of a refrigerant leak. This allows the caretaker to become aware of the refrigerant leak. The remote controller 60 then saves the refrigerant leak history (step S20).

[0064] The shutoff unit 30b arranged in room B stores the refrigerant leak history information in memory 32 (see FIG. 4) based on the notification from the outdoor unit 10 (step S16). The indoor unit 20b arranged in room B stores the refrigerant leak history information in memory 22 (see FIG. 4) based on the notification from the outdoor unit 10 (step S17).

[0065] It is desirable that the outdoor unit 10 transmits the ID of the indoor unit 20a in which a refrigerant leak has been detected in each of steps S9, S11, and S12. This allows the remote controller 60, the shutoff unit 30b, and the indoor unit 20b to identify the indoor unit 20 in which a refrigerant leak has occurred. In this case, the remote controller 60 may issue an alarm including the ID of the indoor unit 20 in which a refrigerant leak has occurred. In addition, the shutoff unit 30b and the indoor unit 20b may each save a history including the ID of the indoor unit 20 in which a refrigerant leak has occurred.

[0066] Here, the processing flow when a refrigerant leak is detected by the refrigerant sensor 23 of the indoor unit 20a has been described. The processing flow when a refrigerant leak is detected by the refrigerant sensor 23 of the indoor unit 20b overlaps with the above description, except that the reference numerals of the components are different. Therefore, the description will not be repeated here.

[0067] 6 is a sequence diagram showing the flow of processing when a refrigerant leak is detected by the refrigerant sensor 43 of the alarm unit 40a. In the sequence diagram, the alarm unit 40b and remote controller 50b arranged in room B are omitted from the illustration. The flow of processing will be described below with reference to FIG.

[0068] The refrigerant sensor 43 detects a refrigerant leak in room A (step S31). In this case, the alarm unit 40a issues an alarm (step S32). More specifically, the alarm unit 40a issues an alarm sound and turns on the LED 45 (see FIG. 4) based on the notification of the refrigerant leak. This allows a user in room A to become aware of the refrigerant leak. The alarm unit 40a further notifies the shutoff unit 30a of the refrigerant leak (step S33). The order in which steps S31 and S32 are performed may be changed.

[0069] The shutoff unit 30a closes the shutoff valves 34a and 34b based on the notification from the alarm unit 40a (step S34). By closing the shutoff valves 34a and 34b, the shutoff unit 30a closes the pipes 121a and 121b, thereby preventing the refrigerant leak from spreading. The shutoff unit 30a further notifies the indoor unit 20a and the outdoor unit 10 of the refrigerant leak (steps S35 and S38). The shutoff unit 30a then stores the refrigerant leak history in the memory 32 (see FIG. 4) (step S45). The order in which steps S33, S34, S38, and S45 are performed may be changed.

[0070] Based on the notification from the shutoff unit 30a, the indoor unit 20a notifies the remote controller 50a of the refrigerant leak (step S36). Thereafter, the indoor unit 20a stores the refrigerant leak history in the memory 22 (see FIG. 4) (step S43) and stops air conditioning operation (step S44). The order in which steps S36, S43, and S44 are performed may be changed.

[0071] The remote controller 50a issues an alarm based on the notification from the indoor unit 20a (step S37). More specifically, the remote controller 50a issues an alarm sound and displays alarm information based on the notification of the refrigerant leak. This allows the user in room A to become aware of the refrigerant leak. The remote controller 50a then saves the refrigerant leak history (step S48).

[0072] Based on the notification from the shutoff unit 30a, the outdoor unit 10 notifies the remote controller 60 located in the caretaker's room of the refrigerant leak (step S39). Based on the notification from the shutoff unit 30a, the outdoor unit 10 further notifies the shutoff unit 30b and the indoor unit 20b located in room B of the refrigerant leak in room A. More specifically, the outdoor unit 10 notifies the shutoff unit 30b and the indoor unit 20b of the refrigerant leak (steps S41 and S42) with a message stating "maintenance abnormality." The order in which steps S39, S41, and S42 are performed may be changed. Thereafter, the outdoor unit 10 saves the refrigerant leak history in memory 12 (see FIG. 4) (step S49).

[0073] The remote controller 60 issues an alarm based on the notification from the outdoor unit 10 (step S40). More specifically, the remote controller 60 issues an alarm sound and displays alarm information based on the notification of a refrigerant leak. This allows the caretaker to become aware of the refrigerant leak. The remote controller 60 then saves the refrigerant leak history (step S50).

[0074] The shutoff unit 30b arranged in room B stores the refrigerant leak history information in memory 32 (see FIG. 4) based on the notification from the outdoor unit 10 (step S46). The indoor unit 20b arranged in room B stores the refrigerant leak history information in memory 22 (see FIG. 4) based on the notification from the outdoor unit 10 (step S47).

[0075] It is desirable that the outdoor unit 10 transmits the ID of the indoor unit 20a in which a refrigerant leak has been detected in each of steps S39, S41, and S42. The reason for this has already been made clear when explaining steps S9, S11, and S12 in Fig. 5, so the explanation will not be repeated here.

[0076] Here, the processing flow when a refrigerant leak is detected by the refrigerant sensor 43 of the alarm unit 40a has been described. The processing flow when a refrigerant leak is detected by the refrigerant sensor 43 of the alarm unit 40b (see FIG. 1) overlaps with the above description, except that the reference numerals of the components are different. Therefore, the description will not be repeated here.

[0077] 7 is a flowchart for explaining the process by which the shutoff unit 30 closes the shutoff valves 34 (34a, 34b) in the event of a power outage. The process executed by the shutoff unit 30 will be explained below based on the flowchart.

[0078] When a power outage occurs (step S101), the shutoff unit 30 detects the power outage (step S102). Next, the shutoff unit 30 starts supplying power from the backup power supply 35 before the power supplied from the main power supply drops below a threshold (step S103). Next, the shutoff unit 30 closes the shutoff valve 34 using the power supplied from the backup power supply 35 (step S104).

[0079] In this way, when a power outage occurs, the shutoff unit 30 starts supplying power from the standby power supply 35 and closes the shutoff valve 34 before the power supplied from the main power supply falls below the threshold (step S104). Therefore, the air conditioning system 100 can prevent refrigerant leakage in the event of a power outage.

[0080] 8 is a flowchart for explaining the process by which the indoor unit 20 disables and enables the function of the refrigerant sensor 23 in response to operation of the sensor setting switch 25. The process executed by the indoor unit 20 will be explained below based on the flowchart.

[0081] First, the indoor unit 20 determines whether or not an operation to turn off the sensor function of the refrigerant sensor 23 has been detected (step S201). If an operation to turn off the sensor function of the refrigerant sensor 23 has been detected, the indoor unit 20 disables the sensor function of the refrigerant sensor 23 (step S202).

[0082] If the indoor unit 20 does not detect an operation to turn off the sensor function of the refrigerant sensor 23, it determines whether or not it has detected an operation to turn on the sensor function of the refrigerant sensor 23 (step S203). If the indoor unit 20 detects an operation to turn on the sensor function of the refrigerant sensor 23, it enables the sensor function of the refrigerant sensor 23 (step S204). If the indoor unit 20 does not detect an operation to turn on the sensor function of the refrigerant sensor 23, it ends the processing based on this flowchart.

[0083] By executing the processing described above, the refrigerant sensor 23 of the indoor unit 20 is enabled or disabled. If sufficient safety measures against refrigerant leaks have been implemented depending on the air-conditioning environment of the room, the designer may turn off the function of the refrigerant sensor 23 of the indoor unit 20. For example, if multiple alarm units 40 are installed in a room, or if a ventilation device with high ventilation capacity is installed in the room, the function of the refrigerant sensor 23 may be turned off in each case.

[0084] Here, an example has been described in which the blocking unit 30 is disposed as a separate device from the indoor unit 20. However, the blocking unit 30 may be built into the indoor unit 20. For example, in FIG. 1 , the blocking unit 30a may be built into the indoor unit 20a, and the blocking unit 30b may be built into the indoor unit 20b. This modification discloses a configuration in which the blocking unit 30 is built into the indoor unit 20 in the air conditioning system 100 that includes the indoor unit 20 and the blocking unit 30.

[0085] As described above, according to the first embodiment, it is possible to provide an air conditioning system 100 that can strengthen safety measures against refrigerant leakage compared to conventional systems.

[0086] Embodiment 2 Next, embodiment 2 will be described with reference to Fig. 9 and Fig. 10. Fig. 9 is a diagram showing the configuration of an air conditioning system 100A according to embodiment 2. Fig. 10 is a flowchart for explaining the processing executed by the blocking unit 30 when a refrigerant leak occurs.

[0087] Embodiment 2 differs from Embodiment 1 in the number of indoor units 20 subordinate to the shutoff unit 30a. In Embodiment 1, an example was described in which one indoor unit 20 was connected subordinate to the shutoff unit 30a. In Embodiment 2, an example is described in which two indoor units 20a, 20c are connected in parallel subordinate to the shutoff unit 30a. Embodiment 2 has the same configuration as Embodiment 1, except for the number of indoor units 20 subordinate to the shutoff unit 30a.

[0088] In the second embodiment, the indoor units 20a and 20c are connected in parallel to the pipe 121. Therefore, the refrigerant flows between the outdoor unit 10 and the indoor unit 20a through the pipe 121, and the refrigerant flows between the outdoor unit 10 and the indoor unit 20c through the pipe 121. As shown in Fig. 9, the indoor units 20a and 20c are placed in, for example, room A. The indoor unit 20c has a common configuration with the indoor units 20a and 20b. The outdoor unit 10, the shutoff unit 30a, the shutoff unit 30b, the indoor unit 20a, the indoor unit 20b, and the indoor unit 20c communicate with each other through a communication path L1.

[0089] Similar to the indoor unit 20a, a remote controller 50 (50c) is communicatively connected to the indoor unit 20c. Two alarm units 40 (40a, 40c) are arranged in room A. The shutoff unit 30a and the alarm units 40a, 40c communicate with each other via a communication path L2.

[0090] The alarm units 40a and 40b may be placed in any location considered optimal for detecting refrigerant leaks. For example, the alarm unit 40a may be placed near the indoor unit 20a, and the alarm unit 40b may be placed near the indoor unit 20b. A third alarm unit 40 may be placed in room A.

[0091] As explained in the first embodiment, the indoor unit 20a notifies the shutoff unit 30a of a refrigerant leak when the refrigerant sensor 23 detects a refrigerant leak. Similarly, the indoor unit 20c notifies the shutoff unit 30a of a refrigerant leak when the refrigerant sensor 23 detects a refrigerant leak. When the shutoff unit 30a is notified of a refrigerant leak from either the indoor unit 20a or the indoor unit 20c, it closes the piping 121 with the shutoff valve 34 and stops the air conditioning operation of the indoor unit 20a and the indoor unit 20c.

[0092] The air conditioning system 100A according to the second embodiment executes the same processes as those shown in Figures 5 to 8, which have been described as the details of the processes according to the first embodiment. In particular, in the second embodiment, when the shutoff unit 30a receives a refrigerant leak notification from one or both of the indoor units 20a and 20c, it notifies both the alarm units 40a and 40c of the refrigerant leak. The alarm units 40a and 40c issue an alarm based on the notification from the shutoff unit 30a.

[0093] When the outdoor unit 10 is notified of a refrigerant leak from the indoor unit 20b in room B, it notifies the indoor units 20a and 20c in room A of a maintenance abnormality. That is, in the second embodiment, the processing of step S12 in Fig. 5 is executed for the indoor units 20a and 20c.

[0094] When the outdoor unit 10 is notified of a refrigerant leak from the shutoff unit 30b in room B, it notifies the indoor units 20a, 20c in room A of a maintenance abnormality. That is, in the second embodiment, the process of step S42 in Fig. 6 is executed for the indoor units 20a, 20c.

[0095] Next, a process executed by the shutoff unit 30 when a refrigerant leak occurs will be described with reference to Fig. 10. Here, the process will be described using the shutoff unit 30a shown in Fig. 9 as a representative example of the shutoff unit 30.

[0096] First, the shutoff unit 30a determines whether or not a refrigerant leak has been notified from either of the indoor units 20a, 20c subordinate to the shutoff unit 30a (step S301). If the indoor units 20a, 20c detect a refrigerant leak, they notify the shutoff unit 30a of the refrigerant leak together with their IDs. Based on this notification, the shutoff unit 30a identifies the indoor unit 20 in which the refrigerant leak is occurring.

[0097] When the shutoff unit 30a receives a notification of a refrigerant leak from either of the indoor units 20a, 20c subordinate to the shutoff unit 30a, the shutoff unit 30a closes the shutoff valve 34 (step S302). This stops the supply of refrigerant to the indoor units 20a, 20c. As a result, the refrigerant leak in room A is prevented from expanding.

[0098] Next, the shutoff unit 30a transmits an operation stop command to all indoor units 20a, 20c subordinate to the shutoff unit 30a (step S303). As a result, the air conditioning operation of the indoor units 20a, 20c stops. Next, the shutoff unit 30a notifies the outdoor unit 10 of the indoor unit 20 in which a refrigerant leak has been detected (step S304). If a refrigerant leak has occurred in, for example, the indoor unit 20a of the indoor units 20a, 20c, the shutoff unit 30a notifies the outdoor unit 10 of the ID of the indoor unit 20a. As a result, the outdoor unit 10 identifies the indoor unit 20 in which a refrigerant leak has occurred.

[0099] The outdoor unit 10 that has identified the indoor unit 20 in which a refrigerant leak has occurred executes steps S39, S41, and S42 in Fig. 6. As a result, the remote controller 60 located in the manager's room issues an alarm, and the shutoff unit 30b and indoor unit 20b located in room B store the history of the refrigerant leak.

[0100] If the determination in step S301 is NO, the shutoff unit 30a determines whether or not a refrigerant leak has been notified from any of the alarm units 40a, 40b (step S305). If the shutoff unit 30a determines that a refrigerant leak has not been notified from any of the alarm units 40a, 40b, the shutoff unit 30a ends the processing based on this flowchart.

[0101] If the shutoff unit 30a determines that a refrigerant leak has been notified by one of the multiple alarm units 40a, 40b, it stops driving the fans 244 (see Figure 4) of all indoor units 20a, 20c under the control of the shutoff unit 30a (step S306).

[0102] The process of step S306 is executed to identify the indoor unit 20 in which a refrigerant leak is occurring. In other words, if a refrigerant leak is not notified from either indoor unit 20a or indoor unit 20c (NO in step S301), but a refrigerant leak is notified from either indoor unit 20a or indoor unit 20c, this means that a refrigerant leak occurring in either indoor unit 20a or indoor unit 20c has not been detected. One possible reason why a refrigerant leak is not detected in either indoor unit 20a or indoor unit 20c is that the concentration of the refrigerant leaking from indoor unit 20 is rapidly diluted due to the fast air flow in room A. If the concentration of the refrigerant leaking from indoor unit 20 is rapidly diluted, the refrigerant leak may not be detected depending on the detection accuracy of refrigerant sensor 23.

[0103] Therefore, the shutoff unit 30a temporarily stops or slows the air flow within room A by stopping the driving of the fans 244 of all indoor units 20a, 20c. This makes it easier for the leaking refrigerant to remain in the indoor unit 20 where the refrigerant leak is occurring. In other words, by executing the process of step S306, the shutoff unit 30a creates a situation in which the refrigerant sensor 23 can easily detect a refrigerant leak.

[0104] In step S306, the shutoff unit 30a creates a situation in which a refrigerant leak can be easily detected by the refrigerant sensor 23, and then returns to step S301. The shutoff unit 30a then determines whether or not a refrigerant leak has been notified from either of the indoor units 20a, 20b subordinate to the shutoff unit 30a. Thereafter, the shutoff unit 30a repeats the processes of steps S301, S305, and S306 until a refrigerant leak has been notified from either of the indoor units 20a, 20b subordinate to the shutoff unit 30a.

[0105] As a result, the shutoff unit 30a can identify the indoor unit 20 in which the refrigerant leak is occurring. When the shutoff unit 30a identifies the indoor unit 20 in which the refrigerant leak is occurring, the shutoff unit 30a determines YES in step S301. Thereafter, the shutoff unit 30a executes the processing of steps S302 to S304 already described.

[0106] Embodiment 2 has been described above using Figures 9 and 10. According to the air conditioning system 100A of Embodiment 2, similar to the air conditioning system 100 of Embodiment 1, it is possible to strengthen safety measures against refrigerant leakage compared to conventional systems. Note that here, an example has been shown in which two indoor units 20a, 20c are connected to the shutoff unit 30a. However, three or more indoor units 20 may be connected under the shutoff unit 30a.

[0107] Third Embodiment Next, a third embodiment will be described with reference to Fig. 11. Fig. 11 is a diagram showing the configuration of an air conditioning system 100B according to the third embodiment.

[0108] Embodiment 3 differs from Embodiment 2 in that a configuration for making room C a space to be air-conditioned is added. In room C, an indoor unit 20d is arranged as the indoor unit 20 subordinate to the blocking unit 30a. In room C, an alarm unit 40d and a remote controller 50d are also arranged. Embodiment 3 has the same configuration as Embodiment 2, except for the addition of a configuration for making room C a space to be air-conditioned.

[0109] In the third embodiment, three indoor units 20a, 20c, and 20d are connected in parallel under the shutoff unit 30a. That is, in the third embodiment, the indoor units 20a, 20c, and 20c are connected in parallel to the pipe 121. Therefore, the refrigerant flows between the outdoor unit 10 and the indoor unit 20a through the pipe 121, the refrigerant flows between the outdoor unit 10 and the indoor unit 20b through the pipe 121, and the refrigerant flows between the outdoor unit 10 and the indoor unit 20c through the pipe 121.

[0110] The indoor unit 20d is capable of communicating with the outdoor unit 10 and the shutoff unit 30a via communication path L1. The indoor unit 20d is equipped with a refrigerant sensor 23, just like the indoor unit 20a. If a refrigerant leak is detected by the refrigerant sensor 23, the indoor unit 20d notifies the shutoff unit 30a of the refrigerant leak. Just like the indoor unit 20a, a remote controller 50d is communicatively connected to the indoor unit 20d. An alarm unit 40d is disposed in room C. The shutoff unit 30a and the alarm unit 40d communicate with each other via communication path L2.

[0111] When a refrigerant leak is notified from any of the indoor units 20a, 20c, and 20d, the shutoff unit 30a closes the shutoff valve 34. This blocks the flow of refrigerant to the indoor units 20a, 20c, and 20d. As a result, the refrigerant leak occurring in either room A or C is prevented from expanding.

[0112] The process executed by the shutoff unit 30a in the third embodiment is the same as that shown in the flowchart of FIG. 10, which has already been described. Therefore, the description will not be repeated here. However, if the alarm unit 40d notifies the shutoff unit 30a of a refrigerant leak when the indoor unit 20d has not notified the shutoff unit 30a of a refrigerant leak, the shutoff unit 30a does not need to execute the process of stopping the fan drive (step S306). This is because in this case, it is assumed that the refrigerant leak has occurred in the indoor unit 20d.

[0113] When a refrigerant leak occurs in any of rooms A to C, the outdoor unit 10 receives a notification of the refrigerant leak from the shutoff units 30a, 30b or the indoor units 20a to 20d. In this case, the outdoor unit 10 notifies the remote controller 60 located in the manager's room of the refrigerant leak. Based on the notification of the refrigerant leak, the remote controller 60 issues a refrigerant leak alarm.

[0114] According to the air conditioning system 100B of the third embodiment, similar to the air conditioning system 100 of the first embodiment, it is possible to strengthen safety measures against refrigerant leakage compared to conventional methods. Note that here, an example is shown in which one indoor unit 20d is placed in room C. However, multiple indoor units 20 may be placed in room C. In that case, the multiple indoor units 20 placed in room C may be added to the control of the shutoff unit 30a. For example, the shutoff unit 30 may be designed so that a maximum of about eight indoor units 20 can be placed under the control of the shutoff unit 30.

[0115] Fourth Embodiment Next, a fourth embodiment will be described with reference to Fig. 12. Fig. 12 is a diagram showing the configuration of an air conditioning system 100C according to the fourth embodiment.

[0116] The fourth embodiment differs from the third embodiment in that a configuration for designating room D as a space to be air-conditioned is added. In the fourth embodiment, it is assumed that the spatial size of room D is significantly larger than the spatial sizes of rooms A to C. Room D is, for example, a large hall.

[0117] An indoor unit 20e and a remote controller 50e communicatively connected to the indoor unit 20e are disposed in room D. The indoor unit 20e communicates with the outdoor unit 10 and the shutoff units 30a and 30b via a communication path L1.

[0118] No alarm unit 40 is installed in room D. The indoor unit 20e is equipped with a refrigerant sensor 23. When the refrigerant sensor 23 detects a refrigerant leak, the indoor unit 20e notifies the outdoor unit 10 and the remote controller 50e of the refrigerant leak. The remote controller 50e issues a refrigerant leak alarm based on the notification from the indoor unit 20e. The outdoor unit 10 executes processing such as notifying the remote controller 60 in the manager's room of the refrigerant leak based on the notification from the indoor unit 20e. The details of the processing by the outdoor unit 10 at this time are the same as those already described using FIG. 5.

[0119] In the fourth embodiment, the indoor unit 20e and the remote controller 60 arranged in the manager's room communicate with each other via a communication path L3 established between the indoor unit 20e and the remote controller 60. If a refrigerant leak occurs in any of the rooms A to D, the remote controller 60 issues a refrigerant leak alarm.

[0120] The indoor unit 20e is directly connected to the outdoor unit 10 by the piping 120 without going through the shutoff unit 30. Therefore, if a refrigerant leak is detected in room D, the piping 120 between the outdoor unit 10 and the indoor unit 20e will not be closed by the shutoff unit 30.

[0121] Assuming that room D is a large room, even if a refrigerant leak occurs in indoor unit 20e, the leaked refrigerant will diffuse throughout the large space of room D, making it unlikely that the refrigerant leak will immediately have a negative impact on the air-conditioning environment. Therefore, room D is not provided with a mechanism for shutting off piping 120 or an alarm unit 40 as a safety measure against refrigerant leaks. According to embodiment 4, by taking into account the size of room D, costs can be reduced while safety measures against refrigerant leaks can be strengthened compared to conventional methods. However, if necessary, indoor unit 20e may be subordinate to shutoff unit 30b or shutoff unit 30a, and an alarm unit 40 may be provided in room D.

[0122] The outdoor unit 10 may detect a refrigerant leak occurring in room D by monitoring the pressure of the refrigerant supplied to the indoor unit 20e. If the outdoor unit 10 detects a refrigerant leak occurring in room D by such a method, it may instruct the indoor unit 20e to close a valve of a refrigerant pipe arranged inside the indoor unit 20e.

[0123] Fifth Embodiment Next, a fifth embodiment will be described with reference to Fig. 13. Fig. 13 is a diagram showing the configuration of an air conditioning system 100D according to the fifth embodiment.

[0124] The fifth embodiment differs from the fourth embodiment in that a branch controller 90 is provided between the outdoor unit 10 and the shutoff units 30a, 30b. Furthermore, the configuration of the devices arranged in rooms A to C in the fifth embodiment differs from that in the fourth embodiment. The fifth embodiment can be said to be a variation of the fourth embodiment.

[0125] The flow division controller 90 is connected to the outdoor unit 10 by a pair of pipes 123. The flow division controller 90 includes a flow division mechanism 91 for dividing the refrigerant. The flow division mechanism 91 is composed of an expansion valve, a heat exchanger, a refrigerant branch path, etc. The flow division controller 90 is connected to the shutoff unit 30a by a pair of pipes 124. The flow division controller 90 is connected to the shutoff unit 30b by a pair of pipes 125. The flow division controller 90 is connected to the indoor unit 20e by a pair of pipes 126.

[0126] 13, indoor unit 20a under the control of shutoff unit 30a is arranged in room A, indoor unit 20b under the control of shutoff unit 30b is arranged in room B, and indoor units 20c and 20d under the control of shutoff unit 30b are arranged in room C. Indoor unit 20e is arranged in room D, as in embodiment 4.

[0127] The shunt controller 90 controls the air conditioning mode of the indoor unit 20a subordinate to the shutoff unit 30a, the air conditioning mode of the indoor units 20b to 20d subordinate to the shutoff unit 30b, and the air conditioning mode of the indoor unit 20e by controlling the flow of refrigerant in the pipes 124 to 126. For example, the shunt controller 90 can operate the indoor unit 20a subordinate to the shutoff unit 30a in cooling mode, while operating the indoor unit 20e and the indoor units 20b to 20d subordinate to the shutoff unit 30b in heating mode.

[0128] According to the air conditioning system 100D of the fifth embodiment, it is possible to strengthen safety measures against refrigerant leakage compared to conventional systems, similar to the air conditioning system 100 of the first embodiment. Note that the branch controller 90 introduced as the fifth embodiment may be applied to any of the first to fourth embodiments.

[0129] Here, an example has been described in which the shutoff unit 30 is disposed as a separate device from the diversion controller 90. However, the shutoff unit 30 may be built into the diversion controller 90. For example, in FIG. 13 , the shutoff units 30a and 30b may be built into the diversion controller 90. This modification discloses a configuration in which the shutoff unit 30 is built into the diversion controller 90 in an air conditioning system 100 that includes an indoor unit 20, a shutoff unit 30, and a diversion controller 90.

[0130] (Modification) In each embodiment, an example has been described in which the indoor unit 20 and the remote controller 50 communicate via communication path L3. However, the indoor unit 20 and the remote controller 50 may be configured to communicate via communication path L1 instead of communication path L3. Similarly, the remote controller 60 located in the manager's room may also be configured to communicate via communication path L1 instead of communication path L3.

[0131] The refrigerant sensor 23 connected to the indoor unit 20 may be provided inside the indoor unit 20 or outside the indoor unit 20 .

[0132] In the above embodiments, various pieces of information are sent to the remote controller 60 installed in the manager's room. However, the same information may be sent to a system controller of an air conditioning system instead of the remote controller 60.

[0133] The above embodiments will be summarized. (Item 1) The present disclosure relates to an air conditioning system (100, 100A to 100D), including a heat source unit (10), a first indoor unit (20a) having a first heat exchanger (242) that exchanges heat with the heat source unit via a refrigerant and that blows conditioned air into a first air-conditioned space (A), a first shut-off unit (30a) having a first shut-off valve (34), an alarm device (50a) disposed in the first air-conditioned space (A), a first alarm unit (40a) disposed in the first air-conditioned space (A), a first refrigerant sensor (23) provided in the first indoor unit that detects refrigerant leaks, and a second alarm unit (40a) connected to the first alarm unit that detects refrigerant leaks. The heat source unit and the first indoor unit are connected by a first pipe (121) through which a refrigerant flows, and the alarm device issues an alarm when the first refrigerant sensor detects a refrigerant leak (step S3), the first alarm unit issues an alarm when the indoor refrigerant sensor detects a refrigerant leak (step S7), and the first shutoff unit closes the first pipe with the first shutoff valve when the first refrigerant sensor detects a refrigerant leak and when the indoor refrigerant sensor detects a refrigerant leak (step S5, step S34).

[0134] (Item 2) In the air conditioning system (100, 100A-100D) described in Item 1, when a refrigerant leak is detected by the first refrigerant sensor, the first indoor unit notifies the first shut-off unit and the alarm device of the refrigerant leak (steps S2, S4), the first shut-off unit closes the first piping with the first shut-off valve based on the notification from the first indoor unit (step S5) and notifies the first alarm unit of the refrigerant leak (step S6), the alarm device issues an alarm based on the notification from the first indoor unit (step S3), and the first alarm unit issues an alarm based on the notification from the first shut-off unit (step S7).

[0135] (Item 3) In the air conditioning system (100, 100A-100D) described in Items 1 or 2, when a refrigerant leak is detected by the indoor refrigerant sensor, the first alarm unit notifies the first shutoff unit of the refrigerant leak and issues an alarm (steps S32 and S33), the first shutoff unit closes the first piping with the first shutoff valve based on the notification from the first alarm unit and notifies the first indoor unit of the refrigerant leak (steps S34 and S35), the first indoor unit notifies the alarm device of the refrigerant leak based on the notification from the first shutoff unit (step S36), and the alarm device issues an alarm based on the notification from the first indoor unit (step S37).

[0136] (4) In the air conditioning system (100, 100A to 100D) described in any one of paragraphs 1 to 3, the first indoor unit receives an instruction to disable the sensor function of the first refrigerant sensor (step S202).

[0137] (5) The air conditioning system (100, 100A to 100D) described in any one of paragraphs 1 to 4 further includes a first communication path (L1) for establishing communication between the heat source unit, the first shutoff unit, and the first indoor unit, and a second communication path (L2) for establishing communication between the first shutoff unit and the first alarm unit.

[0138] (Item 6) The air conditioning system (100, 100A to 100D) described in item 5 further comprises a third communication path (L3) for establishing communication between the first indoor unit and the alarm device.

[0139] (7) The air conditioning system (100, 100A-100D) described in any one of paragraphs 1 to 6 further includes a management alarm device (60) arranged in a manager space different from the first target space, wherein the first indoor unit notifies the heat source unit of the refrigerant leak when the first refrigerant sensor detects a refrigerant leak (step S8), the first shut-off unit notifies the heat source unit of the refrigerant leak when the indoor refrigerant sensor detects a refrigerant leak (step S38), the heat source unit notifies the management alarm device of the refrigerant leak based on the notifications from the first indoor unit and the first shut-off unit (steps S9, S39), and the management alarm device issues an alarm based on the notification from the heat source unit (steps S10, S40).

[0140] (Item 8) The air conditioning system (100, 100A to 100D) according to any one of Items 1 to 7 further comprises: a second indoor unit (20b) having a heat exchanger (242) for exchanging heat with a heat source unit and blowing conditioned air into a second air-conditioned space (room B); a second shutoff unit (30b) having a second shutoff valve (34); a second alarm unit (40b) disposed in the second air-conditioned space and connected to an indoor refrigerant sensor for detecting refrigerant leakage; The heat source unit is further provided with a second refrigerant sensor (23) for detecting a leak, and the heat source unit and the second indoor unit are connected by a second pipe (122) through which the refrigerant flows, and the second shut-off unit is configured to close the second pipe with a second shut-off valve when a refrigerant leak is detected by the second refrigerant sensor, and the heat source unit notifies each of the second indoor unit and the second shut-off unit of the refrigerant leak in the first air-conditioned space based on the notification from the first shut-off unit (steps S41 and S42).

[0141] (Item 9) The air conditioning system (100A to 100D) described in any one of Items 1 to 8 further includes a third indoor unit (20c) having a heat exchanger (242) that exchanges heat with the heat source unit and that blows conditioned air into the first air-conditioned space, the first indoor unit and the third indoor unit are connected in parallel to the first piping, the third indoor unit has a third refrigerant sensor (23) that detects a refrigerant leak, and when the third indoor unit detects a refrigerant leak, the third indoor unit notifies the first shut-off unit of the refrigerant leak, and when the first shut-off unit notifies of the refrigerant leak from either the first indoor unit or the third indoor unit, the first shut-off unit closes the first piping with the first shut-off valve (step S302).

[0142] (Section 10) In the air conditioning system (100A to 100D) described in Section 9, if a refrigerant leak is notified from either the first indoor unit or the third indoor unit, the first shut-off unit stops operation of the first indoor unit and the third indoor unit (step S303).

[0143] (Item 11) In the air conditioning system (100A to 100D) described in Items 9 or 10, each of the first indoor unit and the third indoor unit has a fan (244) for blowing air, and when a refrigerant leak is detected by the indoor refrigerant sensor, if neither the first indoor unit nor the third indoor unit has notified the user of the refrigerant leak (Step S305), the first shutoff unit stops driving the fans of the first indoor unit and the third indoor unit (Step S306).

[0144] (Item 12) The air conditioning system (100B) described in any one of Items 9 to 11 further includes a fourth indoor unit (20d) that has a heat exchanger (242) that exchanges heat with the heat source unit and that blows conditioned air into a third air-conditioned space (room C), the first indoor unit, the second indoor unit, and the fourth indoor unit are connected in parallel to the first piping, the fourth indoor unit has a fourth refrigerant sensor (23) that detects refrigerant leakage, and when the fourth indoor unit detects a refrigerant leakage by the fourth refrigerant sensor, the fourth indoor unit notifies the first shut-off unit of the refrigerant leakage, and the first shut-off unit closes the first piping with a first shut-off valve based on the notification from the fourth indoor unit.

[0145] (Item 13) In the air conditioning system (100, 100A to 100D) described in any one of Items 1 to 12, the first shutoff unit has a backup power supply (35), and when a power outage is detected, the first shutoff unit switches the power supply source from the main power supply to the backup power supply (steps S101 to S103).

[0146] (Item 14) The air conditioning system (100C) described in item 12 or 13 further includes a fifth indoor unit (20e) having a heat exchanger that exchanges heat with the heat source unit and that blows conditioned air into a fourth air-conditioned space (room D), the fourth air-conditioned space being larger in spatial size than any of the first air-conditioned space, the second air-conditioned space, and the third air-conditioned space, the fifth indoor unit being connected to the heat source unit by a third pipe that is different from the first pipe and the second pipe, and no alarm units corresponding to the first alarm unit and the second alarm unit are arranged in the fourth air-conditioned space.

[0147] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims.

[0148] 10 Outdoor unit (heat source unit), 11, 21, 31, 41 Processor, 12, 22, 32, 42 Memory, 13, 26, 27, 33, 36, 37, 47 Communication interface, 14, 24 Air conditioning mechanism, 20, 20a to 20e Indoor unit, 23, 43 Refrigerant sensor, 25 Sensor setting switch, 30, 30a, 30b Shutoff unit, 34, 34a, 34b Shutoff valve, 35 Standby power supply, 40, 40a to 40d Alarm unit, 44 Speaker, 45 LED, 50, 50a to 50e, 60 Remote controller, 51 Display, 52 Operation unit, 90 Diversion controller, 91 Diversion mechanism, 100, 100A to 100D Air conditioning system, 120 to 126, 121a, 121b Piping, L1 to L3 Communication path, 141 compressor, 142, 242 heat exchanger, 243 expansion valve, 144, 244 fan, 145 four-way valve, 300 board, A to D rooms.

Claims

1. An air conditioning system comprising: a heat source unit; a first indoor unit having a heat exchanger that exchanges heat with the heat source unit via a refrigerant, and that blows conditioned air into a first air-conditioned space; a first shutoff unit having a first shutoff valve; an alarm device disposed in the first air-conditioned space; a first alarm unit disposed in the first air-conditioned space; a first refrigerant sensor provided in the first indoor unit that detects refrigerant leaks; and an indoor refrigerant sensor connected to the first alarm unit that detects refrigerant leaks, wherein the heat source unit and the first indoor unit are connected by a first piping through which refrigerant flows, the alarm device issues an alarm when a refrigerant leak is detected by the first refrigerant sensor, the first alarm unit issues an alarm when a refrigerant leak is detected by the indoor refrigerant sensor, and the first shutoff unit closes the first piping with the first shutoff valve when a refrigerant leak is detected by the first refrigerant sensor and when a refrigerant leak is detected by the indoor refrigerant sensor, respectively.

2. The air conditioning system of claim 1, wherein when a refrigerant leak is detected by the first refrigerant sensor, the first indoor unit notifies the first shutoff unit and the alarm device of the refrigerant leak, the first shutoff unit closes the first piping with the first shutoff valve based on the notification from the first indoor unit and notifies the first alarm unit of the refrigerant leak, the alarm device issues an alarm based on the notification from the first indoor unit, and the first alarm unit issues an alarm based on the notification from the first shutoff unit.

3. The air conditioning system of claim 1 or claim 2, wherein when a refrigerant leak is detected by the indoor refrigerant sensor, the first alarm unit notifies the first shutoff unit of the refrigerant leak and issues an alarm, the first shutoff unit closes the first piping with the first shutoff valve based on the notification from the first alarm unit and notifies the first indoor unit of the refrigerant leak, the first indoor unit notifies the alarm device of the refrigerant leak based on the notification from the first shutoff unit, and the alarm device issues an alarm based on the notification from the first indoor unit.

4. An air conditioning system according to any one of claims 1 to 3, wherein the first indoor unit accepts an instruction to disable the sensor function of the first refrigerant sensor.

5. An air conditioning system as described in any one of claims 1 to 4, further comprising: a first communication path for establishing communication between the heat source unit, the first shutoff unit, and the first indoor unit; and a second communication path for establishing communication between the first shutoff unit and the first alarm unit.

6. The air conditioning system according to claim 5, further comprising a third communication path for establishing communication between said first indoor unit and said alarm device.

7. An air conditioning system as described in any one of claims 1 to 6, further comprising a management alarm device arranged in a manager space different from the first air-conditioned space, wherein the first indoor unit notifies the heat source unit of a refrigerant leak when a refrigerant leak is detected by the first refrigerant sensor, the first shut-off unit notifies the heat source unit of a refrigerant leak when a refrigerant leak is detected by the indoor refrigerant sensor, the heat source unit notifies the management alarm device of the refrigerant leak based on notifications from each of the first indoor unit and the first shut-off unit, and the management alarm device issues an alarm based on the notification from the heat source unit.

8. An air conditioning system as described in any one of claims 1 to 7, further comprising: a second indoor unit having a heat exchanger for exchanging heat with the heat source unit, and blowing out conditioned air into a second air-conditioned space; a second shutoff unit having a second shutoff valve; a second alarm unit disposed in the second air-conditioned space, and connected to an indoor refrigerant sensor for detecting refrigerant leakage; and a second refrigerant sensor provided in the second indoor unit for detecting refrigerant leakage, wherein the heat source unit and the second indoor unit are connected by a second piping through which refrigerant flows, and the second shutoff unit is configured to close the second piping with the second shutoff valve when a refrigerant leakage is detected by the second refrigerant sensor, and the heat source unit notifies each of the second indoor unit and the second shutoff unit of the refrigerant leakage in the first air-conditioned space based on the notification from the first shutoff unit.

9. An air conditioning system as described in any one of claims 1 to 8, further comprising a third indoor unit having a heat exchanger for exchanging heat with the heat source unit and blowing out conditioned air to the first air-conditioned space, the first indoor unit and the third indoor unit being connected in parallel to the first piping, the third indoor unit having a third refrigerant sensor for detecting a refrigerant leak, the third indoor unit notifying the first shutoff unit of a refrigerant leak when a refrigerant leak is detected by the third refrigerant sensor, and the first shutoff unit closing the first piping with the first shutoff valve when a refrigerant leak is notified from either the first indoor unit or the third indoor unit.

10. An air conditioning system as described in claim 9, wherein the first shutoff unit stops operation of the first indoor unit and the third indoor unit when a refrigerant leak is notified from either the first indoor unit or the third indoor unit.

11. An air conditioning system as described in claim 9 or claim 10, wherein each of the first indoor unit and the third indoor unit has a fan for blowing air, and the first shutoff unit stops driving the fans of each of the first indoor unit and the third indoor unit when a refrigerant leak is detected by the indoor refrigerant sensor and no refrigerant leak is notified from either the first indoor unit or the third indoor unit.

12. An air conditioning system as described in any one of claims 9 to 11, further comprising a fourth indoor unit having a heat exchanger for exchanging heat with the heat source unit and blowing out conditioned air to a third air-conditioned space, the first indoor unit, the second indoor unit and the fourth indoor unit being connected in parallel to the first piping, the fourth indoor unit having a fourth refrigerant sensor for detecting a refrigerant leak, the fourth indoor unit notifying the first shutoff unit of the refrigerant leak when a refrigerant leak is detected by the fourth refrigerant sensor, and the first shutoff unit closing the first piping with the first shutoff valve based on the notification from the fourth indoor unit.

13. An air conditioning system as described in any one of claims 1 to 12, wherein the first shutoff unit has a standby power supply, and the first shutoff unit switches the power supply source from the main power supply to the standby power supply when a power outage is detected.

14. An air conditioning system as described in claim 12 or claim 13, further comprising a fifth indoor unit having a heat exchanger for exchanging heat with the heat source unit and blowing conditioned air into a fourth air-conditioned space, wherein the fourth air-conditioned space has a larger spatial size than any of the first air-conditioned space, the second air-conditioned space, and the third air-conditioned space, wherein the fifth indoor unit is connected to the heat source unit by a third piping different from the first piping and the second piping, and wherein no alarm unit corresponding to each of the first alarm unit and the second alarm unit is disposed in the fourth air-conditioned space.

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