Air conditioning system, control device, and control method

Abstract

An air conditioning system (100) comprises: a refrigerant circuit (10, 120, 20) through which a refrigerant flows; a plurality of open / close valves (V1, V2) which each adjust the flow rate of the refrigerant that flows into the refrigerant circuit; a main power source (40) which supplies main power to the plurality of open / close valves (V1, V2); at least one standby power source (55) which supplies standby power to the plurality of open / close valves (V1, V2) when the supply of main power has stopped; and at least one control device (C10) which controls the supply of power to the plurality of open / close valves (V1, V2). When the supply of main power has stopped, the at least one control device (C10) controls the supply of standby power to the plurality of open / close valves (V1, V2) in accordance with the power capacity of the at least one standby power source.

Description

Air conditioning system, control device, and control method

[0001] The present disclosure relates to an air conditioning system, a control device, and a control method.

[0002] Conventionally, in an air conditioning system that circulates a refrigerant, when the supply of main power from the main power source is stopped due to a power outage or the like, a system exists in which an on-off valve is transitioned from an open state to a closed state using backup power supplied from a backup power source. For example, Patent Document 1 (JP 2021-191980 A) discloses a heat pump device that closes an on-off valve using an electric double layer capacitor as a backup power source in the event of a power outage.

[0003] Japanese Patent Application Laid-Open No. 2021-191980

[0004] An air conditioning system may be equipped with multiple on-off valves that adjust the flow rate of refrigerant through a refrigerant circuit. Furthermore, there is also a limit to the power capacity of backup power sources in case of power outages. Therefore, if the air conditioning system attempts to close all of the on-off valves at once using backup power from the backup power source when the main power supply is cut off, there is a risk that the backup power from the backup power source will be insufficient and all of the on-off valves will not be able to be closed.

[0005] Here, it is also possible to provide a backup power supply for each on-off valve in case of a power outage. For example, it is possible to provide a large-capacity backup power supply and use the backup power supplied from the large-capacity backup power supply to close all on-off valves, but in this case, the cost of installing the large-capacity backup power supply increases.

[0006] The present disclosure has been made to solve such problems, and its purpose is to provide technology that can appropriately close multiple on-off valves when the supply of main power is stopped, while suppressing increases in the cost of constructing an air conditioning system.

[0007] The air conditioning system of the present disclosure includes a refrigerant circuit through which a refrigerant flows, a plurality of on-off valves that adjust the flow rate of the refrigerant flowing in the refrigerant circuit, a main power source that supplies main power to the plurality of on-off valves, at least one standby power source that supplies backup power to the plurality of on-off valves when the supply of main power is stopped, and at least one control device that controls the supply of power to the plurality of on-off valves in accordance with the power capacity of the at least one standby power source when the supply of main power is stopped.

[0008] The control device according to the present disclosure controls the supply of power to a plurality of on-off valves that adjust the flow rate of refrigerant through a refrigerant circuit. The control device includes a storage unit that stores a control program for controlling the supply of power to the plurality of on-off valves, and a control unit that controls the supply of power to the plurality of on-off valves in accordance with the control program. The control unit determines whether the supply of main power from a main power source to the plurality of on-off valves has stopped, and, if the supply of main power has stopped, controls the supply of backup power from at least one backup power source to the plurality of on-off valves in accordance with the power capacity of the at least one backup power source.

[0009] A control method according to the present disclosure is a control method for controlling, by a computer, the supply of power to a plurality of on-off valves that adjust the flow rate of refrigerant flowing through a refrigerant circuit. The control method includes, as processing executed by the computer, a step of determining whether the supply of main power from a main power source to the plurality of on-off valves has stopped, and a step of controlling the supply of backup power from at least one backup power source to the plurality of on-off valves in accordance with the power capacity of the at least one backup power source when the supply of main power has stopped.

[0010] According to the present disclosure, it is possible to appropriately close a plurality of on-off valves included in an air conditioning system during a power outage while suppressing increases in the cost of constructing the air conditioning system.

[0011] 1 is a diagram illustrating a configuration of an air conditioning system according to an embodiment. FIG. 1 is a diagram illustrating the positional relationship between an indoor unit, a shutoff unit, and a remote controller. FIG. 2 is a block diagram illustrating the configurations of an outdoor unit, an indoor unit, and a shutoff unit according to embodiment 1. FIG. 3 is a diagram illustrating the power capacity of a standby power supply according to embodiment 1. FIG. 4 is a sequence diagram illustrating a processing flow when the occurrence of a power outage is detected according to embodiment 1. FIG. 5 is a block diagram illustrating the configurations of an outdoor unit, an indoor unit, and a shutoff unit according to a comparative example. FIG. 6 is a sequence diagram illustrating a processing flow when the occurrence of a power outage is detected according to a comparative example. FIG. 7 is a diagram illustrating the power capacity of a standby power supply according to embodiment 2. FIG. 8 is a sequence diagram illustrating a processing flow when the occurrence of a power outage is detected according to embodiment 2. FIG. 9 is a block diagram illustrating the configurations of an outdoor unit, an indoor unit, and a shutoff unit according to embodiment 3. FIG. 10 is a sequence diagram illustrating a processing flow when the occurrence of a power outage is detected according to embodiment 3. FIG. 11 is a block diagram illustrating the configurations of an outdoor unit, an indoor unit, and a shutoff unit according to embodiment 4. FIG. 12 is a sequence diagram illustrating a processing flow when the occurrence of a power outage is detected according to embodiment 4. FIG. 13 is a block diagram illustrating the configurations of an outdoor unit, an indoor unit, and a shutoff unit according to embodiment 5.

[0012] Hereinafter, embodiments of the technical concept according to the present disclosure will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. The names and functions of the components are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0013] Embodiment 1. [Overall configuration of air conditioning system] 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, 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.

[0014] As shown in FIG. 1 , the air conditioning system 100 includes a plurality of indoor units 20, shutoff units 30, and remote controllers 50. In each embodiment described below, in order to distinguish between these multiple components, the indoor units 20, shutoff units 30, and remote controllers 50 may be referred to as indoor units 20a, 20b..., shutoff units 30a, 30b..., and remote controllers 50a, 50b..., respectively. In other words, the indoor units 20 are a general term for the indoor units 20a, 20b.... The shutoff units 30 are a general term for the shutoff units 30a, 30b.... The remote controllers 50 are a general term for the remote controllers 50a, 50b....

[0015] An indoor unit 20 and a remote controller 50 are disposed in each of rooms A and B. The indoor unit 20a is equipped with an on-off valve V2 for adjusting the flow rate of the circulating refrigerant. The indoor unit 20b is equipped with an on-off valve V4 for adjusting the flow rate of the circulating refrigerant. The remote controller 50 is attached, for example, to a wall of the room. The remote controller 50 has a function of transmitting setting information such as the air conditioning temperature to the indoor unit 20.

[0016] A remote controller 60 is placed in the manager's room. For example, a manager who manages the air-conditioned space resides in the manager's room. The manager's room may be a night security room or the like. The remote controller 60 has a function of transmitting setting information such as the air conditioning temperatures of rooms A and B to the indoor units 20a and 20b, respectively.

[0017] The outdoor unit 10, the indoor unit 20, and the shutoff unit 30 are connected by refrigerant pipes 120 through which a refrigerant flows. The refrigerant pipes 120 include a pair of refrigerant pipes 121 that connect the indoor unit 20a and the shutoff unit 30a, and a pair of refrigerant pipes 122 that connect the indoor unit 20b and the shutoff unit 30b.

[0018] A refrigerant circulates between the outdoor unit 10 and the indoor unit 20a via a refrigerant pipe 120 that passes through the shutoff unit 30a. The outdoor unit 10, the indoor unit 20a, the shutoff unit 30a, and the refrigerant pipe 120 form a refrigerant circulation flow path through which the refrigerant circulates. Similarly, a refrigerant circulates between the outdoor unit 10 and the indoor unit 20b via a refrigerant pipe 120 that passes through the shutoff unit 30b. The outdoor unit 10, the indoor unit 20b, the shutoff unit 30b, and the refrigerant pipe 120 form a refrigerant circulation flow path through which the refrigerant circulates. The indoor units 20a, 20b exchange heat with the outdoor unit 10 via the refrigerant that flows through the refrigerant circulation flow path, thereby air-conditioning rooms A and B, respectively.

[0019] 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 refrigerant pipe 121. Specifically, the shutoff unit 30a has an on-off valve V1. 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 refrigerant pipe 122. Specifically, the shutoff unit 30b has an on-off valve V3.

[0020] The outdoor unit 10, the shutoff units 30a, and the shutoff units 30b communicate with each other via communication paths. Similarly, the shutoff units 30a and 30b communicate with the indoor units 20a and 20b, respectively, via communication paths. The indoor unit 20a communicates with the remote controller 50a via a communication path. The indoor unit 20b communicates with the remote controllers 50b and 60 via communication paths. The communication paths connecting the components included in the air conditioning system 100 may be wired or wireless.

[0021] In the air conditioning system 100 of the first embodiment, the outdoor unit 10, the shutoff unit 30, and the indoor unit 20 each have a mechanism for detecting refrigerant leaks (not shown). When any of the outdoor unit 10, the shutoff unit 30, and the indoor unit 20 detects a refrigerant leak, it notifies each component included in the air conditioning system 100 other than the component that detected the refrigerant leak via a communication path.

[0022] Based on the refrigerant leak notification, the indoor units 20a and 20b control the on-off valves V2 and V4 to a closed state. Based on the refrigerant leak notification, the shutoff units 30a and 30b control the on-off valves V1 and V3 to a closed state. Furthermore, if a refrigerant leak is detected, the indoor units 20a and 20b notify the remote controllers 50a, 50b, and 60 of the refrigerant leak. The remote controllers 50a, 50b, and 60 are configured to issue an alert based on the refrigerant leak notification. In this way, in the air conditioning system 100 of embodiment 1, if a refrigerant leak is detected, the on-off valves V1 to V4 are controlled to a closed state, thereby preventing leakage of all refrigerant from the refrigerant pipes 120, 121, and 122.

[0023] The on-off valves V1 to V4 are, for example, electronic linear expansion valves (LEVs). A linear expansion valve is an expansion valve whose opening degree can be variably controlled by supplying electric power. In the air conditioning system 100, when no abnormality such as a power outage has occurred, the opening degree of each of the on-off valves V1 to V4 is adjusted using main electric power supplied from a commercial power source 40.

[0024] 1, each of the outdoor unit 10, the shutoff unit 30, and the indoor unit 20 of the first embodiment is supplied with main power from a commercial power source 40. The commercial power source 40 may correspond to the "main power source" in the present disclosure. In the air conditioning system 100 of the first embodiment, each of the on-off valves V1 to V4 is controlled to a closed state not only when a refrigerant leak is detected but also when a power outage occurs.

[0025] In the present disclosure, a power outage refers to a complete or partial interruption of the main power supply from the commercial power source 40. After a power outage occurs in which the main power supply from the commercial power source 40 is completely interrupted, the main power from the commercial power source 40 is no longer supplied to the components included in the air conditioning system 100, and therefore the air conditioning system 100 may not be able to detect a refrigerant leak even if one occurs.

[0026] Therefore, the air conditioning system 100 of Embodiment 1 controls each of the on-off valves V1 to V4 to a closed state in response to the occurrence of a power outage. As shown in Fig. 1, the outdoor unit 10 has a standby power supply 55, a closure instruction unit 15, and a power outage detection unit 16. The power outage detection unit 16 monitors whether main power is being supplied appropriately from the commercial power supply 40, and detects the occurrence of a power outage when all or part of the power supply is stopped.

[0027] Upon detecting the occurrence of a power outage, the outdoor unit 10 begins supplying standby power from the standby power supply 55 to each component included in the air conditioning system 100. The closure instruction unit 15 issues an instruction to control the on-off valves V1 to V4 to a closed state based on the standby power supplied from the standby power supply 55. As a result, in the air conditioning system 100 of the first embodiment, the on-off valves V1 to V4 can be closed in advance at the time a power outage occurs, in preparation for the occurrence of a refrigerant leak after the power outage.

[0028] 2 is a diagram for explaining the positional relationship between the indoor unit 20, the shutoff unit 30, and the remote controller 50. Here, the positional relationship of 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, for example. The shutoff unit 30a is placed, for example, above the ceiling of room A. The remote controller 50a is placed, for example, on a wall surface of room A, taking into consideration the convenience of the user. The remote controller 50a is communicatively connected to the shutoff unit 30a via a communication path. 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.

[0030] The shutoff unit 30a and the indoor unit 20a are connected by a pair of refrigerant pipes 121 through which a refrigerant flows. A refrigerant sensor (not shown) is disposed near the refrigerant pipe 121 that passes through the indoor unit 20a. If the refrigerant sensor detects a refrigerant leak, the refrigerant leak is notified to the remote controller 50a via a communication path. Based on the notification of the refrigerant leak, the remote controller 50a emits an alert sound and displays alert information on the display 51. The remote controller 50a may be equipped with an LED for displaying the alert. When displaying alert information on the display 51, the remote controller 50a may turn on the backlight of the display 51.

[0031] Here, the layout relationship of the indoor unit 20 (20a) and the like has been described using room A as a representative example. In room B, an indoor unit 20b, a shutoff unit 30b, and a remote controller 50b are arranged in the same manner as in room A.

[0032] [Configuration of Functional Blocks] Fig. 3 is a block diagram showing the configurations of the outdoor unit 10, indoor unit 20, and shutoff unit 30 in Embodiment 1. Fig. 3 shows the outdoor unit 10, indoor units 20a and 20b, and shutoff units 30a and 30b. The indoor units 20a and 20b have a common configuration, and the shutoff units 30a and 30b have a common configuration. Fig. 3 shows the details of the configurations of the indoor unit 20a and the shutoff unit 30a, while omitting the details of the configurations of the indoor unit 20b and the shutoff unit 30b.

[0033] The outdoor unit 10 includes a control device C10 and an air conditioning mechanism 14. The control device C10 has a processor 11, a memory 12, and a communication interface (I / F) 13. The air conditioning mechanism 14 includes a compressor 141, a heat exchanger 142, a fan 144, and a four-way valve 145. The processor 11 may correspond to the "controller" in this disclosure. The memory 12 may correspond to the "storage unit" in this disclosure.

[0034] In the first embodiment, the processor 11 is typically configured with a CPU (Central Processing Unit) or an MPU (Multi-Processing Unit). The processor 11 is a computing entity that executes various processes by executing various programs. The processor 11 may be configured with, for example, a microcontroller, a CPU (Central Processing Unit), or an MPU (Micro-Processing Unit). The processor 11 has the function of executing various processes by executing programs, but some or all of these functions may be implemented using dedicated hardware circuits such as an ASIC (Application Specific Integrated Circuit), a GPU (Graphics Processing Unit), or an FPGA (Field-Programmable Gate Array). The term "processor" is not limited to a processor in the narrow sense that executes processes using a stored program, such as a CPU or an MPU, but may also include hardwired circuits such as an ASIC, a GPU, or an FPGA. Therefore, the processor 11 may also be interpreted as a processing circuitry in which processes are predefined by computer-readable code and / or hardwired circuits.

[0035] The processor 11 may be configured as a single chip or multiple chips. Furthermore, the processor 11 and related processing circuits may be configured as multiple computers interconnected by wire or wirelessly via a local area network or a wireless network. The processor 11 and related processing circuits may be configured as a cloud computer that performs calculations remotely based on input data and outputs the calculation results to another device in a remote location.

[0036] The memory 12 is a memory that provides a storage area for temporarily storing program code, work memory, etc. when the processor 11 executes various programs. Furthermore, the memory 12 includes one or more non-transitory computer-readable media. Examples of the memory 12 include volatile memory such as dynamic random access memory (DRAM) and static random access memory (SRAM), or non-volatile memory such as read-only memory (ROM) and flash memory. Furthermore, the memory 12 may be a storage device such as a solid-state drive (SSD) or a hard disk drive (HDD).

[0037] The processor 11 has a communication function. The processor 11 communicates with the shutoff units 30 (30a, 30b) via a communication interface (I / F) 13. Furthermore, the processor 11 can communicate with the indoor units 20 (20a, 20b) via the communication interface 13 and the shutoff unit 30. The processor 11 can also communicate with the remote controllers 50a, 50b, 60 located in the manager's room via the communication interface 13, the shutoff units 30a, 30b, and the indoor unit 20b. In this way, the processor 11, the memory 12, and the communication interface 13 constitute a control device C10 provided in the outdoor unit 10.

[0038] The control device C10 cooperates with a sensor (not shown) that detects a power outage and functions as the power outage detection unit 16 shown in Fig. 1. The control device C10 also functions as the closure instruction unit 15. That is, when the processor 11 detects a power outage of the commercial power source 40, it controls the on-off valves V1 to V4 to close.

[0039] The outdoor unit 10 includes a standby power supply 55 for supplying standby power to the shutoff unit 30 and the indoor unit 20. The standby power supply 55 is a power supply circuit with a power capacity of, for example, 100 W. That is, the rated output of the standby power supply 55 is 100 W. In the event of a power outage, the standby power supply 55 supplies power not only to the on-off valves V1 to V4 but also to other components in order to maintain the operation of each component included in the air conditioning system 100. That is, in the event of a power outage, the outdoor unit 10, the indoor unit 20, and the shutoff unit 30 each operate using power supplied from the standby power supply 55.

[0040] The standby power supply 55 may be connected to the shutoff unit 30 and the indoor unit 20 using, for example, PLC (Power Line Communications) communication. In this case, the standby power supply 55 starts supplying power when the power supply in part of the air conditioning system 100 is cut off. The standby power supply 55 may also be configured using a capacitor, a storage battery, or the like. In this case, even if all power sources in the air conditioning system 100 are cut off, the power stored in the standby power supply 55 itself can be supplied to the shutoff unit 30 and the indoor unit 20.

[0041] The indoor units 20 (20a, 20b) include a control device C2 and an air conditioning mechanism 24. The control device C2 includes a processor 21, a memory 22, and a communication interface (I / F) 23. The air conditioning mechanism 24 includes a heat exchanger 242, an on-off valve V2, and a fan 244. The air conditioning mechanism 14 of the outdoor unit 10, the air conditioning mechanism 24 of the indoor unit 20, and the refrigerant pipe 120 (FIG. 1) form a refrigerant circulation path and a refrigerant circuit through which the refrigerant circulates. The on-off valve V2 is configured to be able to adjust the flow rate of the refrigerant flowing through the refrigerant pipe 121. The heat exchanger 242 is a heat exchanger that exchanges heat with the heat source unit.

[0042] 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. The processor 21 has a communication function. The processor 21 communicates with the shutoff unit 30 and the remote controller 50 via the communication interface 23. The control device C2 controls the open / closed state of the on-off valve V2.

[0043] The shutoff unit 30 (30a, 30b) includes a control device C1 and an on-off valve V1. The control device C1 has a processor 31, a memory 32, and a communication interface (I / F) 33. 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 will not be described again here.

[0044] The processor 31 has a communication function. The processor 31 communicates with the outdoor unit 10 and the indoor unit 20 via the communication interface 33. The control device C2 controls the open / close state of the on-off valve V1. The on-off valve V1 in the first embodiment may correspond to the "first on-off valve" in the present disclosure. The on-off valve V2 in the first embodiment may correspond to the "second on-off valve" in the present disclosure. The on-off valve V3 in the first embodiment may correspond to the "third on-off valve" in the present disclosure. The control device C10 in the first embodiment may correspond to the "at least one control device" in the present disclosure.

[0045] [Power Supply Capacity] Fig. 4 is a diagram illustrating the power supply capacity of the standby power supply 55 in Embodiment 1. The upper part of Fig. 4 shows the power consumption required to close the on-off valves V1 to V4, which are electronic linear expansion valves. Fig. 4 shows an example in which 9 W of power is required to control the on-off valves V1 and V3 from an open state to a closed state when the on-off valves are closed. Fig. 4 also shows an example in which 7 W of power is required to control the on-off valves V2 and V4 from an open state to a closed state when the on-off valves are closed.

[0046] That is, to switch all of the on-off valves V1 to V4 from an open state to a closed state at once, a total of 32 W of power is required. Note that the on-off valves V1 to V4 require power when switching from an open state to a closed state, but once they are controlled to the closed state, no power is required.

[0047] The bottom of Figure 4 shows an example of the power capacity when the standby power supply 55 is supplying power. In the event of a power outage, the standby power supply 55 supplies power to, for example, the control devices C1, C2, and C10 to maintain operation of the air conditioning system 100. In the example of Figure 4, the standby power supply 55 uses 85 W of its 100 W power capacity to operate the control devices C1, C2, and C10. More specifically, the control devices C1, C2, and C1 use the standby power to provide standby power for the boards included in the control devices C1, C2, and C1, as well as for sensor operation and microcomputer operation. Therefore, in the example of Figure 4, the air conditioning system 100 must use the remaining 15 W to close the on-off valves V1 to V4. The power capacity available to the standby power supply 55 during a power outage varies depending on the circumstances, including the scale, location, and scope of the power outage. The standby power supply 55 of embodiment 1 is pre-configured so that even if a power outage occurs anywhere within the air conditioning system 100, there will be enough remaining power to close each of the on-off valves V1 to V4 one by one.

[0048] [Processing Flow During Power Outage] Fig. 5 is a sequence diagram showing the flow of processing when the occurrence of a power outage is detected in embodiment 1. In the sequence diagram, the flow of processing will be described below with reference to Fig. 5 .

[0049] As described above, the power capacity of the standby power supply 55 is 15 W, and the power that can be used to close the on-off valves V1 to V4 is 15 W. To simultaneously supply power to all of the on-off valves V1 to V4, 32 W would be required. Therefore, in this example, it is not possible to simultaneously supply power to all of the on-off valves V1 to V4 using the standby power supply 55 and control the on-off valves V1 to V4 to a closed state. Therefore, in the air conditioning system 100 of embodiment 1, even with a relatively small-capacity standby power supply 55, the on-off valves V1 to V4 can be appropriately controlled to a closed state by executing the process flow shown below. The control device C10 executes the control program stored in the memory 12 to perform the sequence shown in FIG. 5 .

[0050] The outdoor unit 10 detects a power outage in the commercial power source 40 (step S1). For example, the outdoor unit 10 detects a power outage by the power outage detection unit 16 detecting the power outage. The outdoor unit 10 may also detect the power outage by receiving a power outage signal indicating the occurrence of a power outage from another component included in the air conditioning system 100. Upon detecting the power outage, the control device C10 of the outdoor unit 10 transmits a close signal to the shutoff unit 30a (step S2). The close signal is a signal instructing the shutoff unit 30a to control the on-off valve of the component to a closed state. Upon receiving the close signal from the control device C10 of the outdoor unit 10, the shutoff unit 30a executes a closing process (step S3). The shutoff unit 30a transitions the state of the on-off valve V1 from an open state to a closed state over a period D1. The period D1 is, for example, 60 seconds. The period D1 may be a period other than 60 seconds, such as 40 seconds, 80 seconds, 100 seconds, 120 seconds, or 140 seconds. The shutoff unit 30a transmits a completion signal to the outdoor unit 10 based on the fact that the on-off valve V1 has been controlled to the closed state (step S4). The completion signal indicates that the closing process has been completed.

[0051] The control device C10 of the outdoor unit 10 transmits a close signal to the shutoff unit 30b based on receiving the completion signal from the shutoff unit 30a (step S5). The shutoff unit 30b executes a close process based on receiving the close signal from the control device C10 of the outdoor unit 10 (step S6). The shutoff unit 30b transitions the state of the on-off valve V3 from an open state to a closed state over a period D3. The shutoff unit 30b transmits a completion signal to the outdoor unit 10 based on the on-off valve V3 being controlled to the closed state (step S7).

[0052] The control device C10 of the outdoor unit 10 transmits a close signal to the indoor unit 20a based on receiving the completion signal from the shutoff unit 30b (step S8). The indoor unit 20a executes the close process based on receiving the close signal from the control device C10 of the outdoor unit 10 (step S9). The indoor unit 20a transitions the state of the on-off valve V2 from the open state to the closed state over a period D2. The indoor unit 20a transmits a complete signal to the outdoor unit 10 based on the on-off valve V2 being controlled to the closed state (step S10).

[0053] The control device C10 of the outdoor unit 10 transmits a close signal to the indoor unit 20b based on receiving a completion signal from the indoor unit 20a (step S11). The indoor unit 20b executes a close process based on receiving a close signal from the control device C10 of the outdoor unit 10 (step S12). The indoor unit 20b transitions the state of the on-off valve V4 from an open state to a closed state over a period D4. The indoor unit 20b transmits a complete signal to the outdoor unit 10 based on the on-off valve V4 being controlled to a closed state (step S13). Similar to period D1, each of periods D2 to D4 may be any period between 40 seconds and 140 seconds, for example.

[0054] In this way, in the air conditioning system 100 of Embodiment 1, the on-off valves V1 to V4 are closed one by one in order so as not to exceed the power supply capacity available in the standby power supply 55. In other words, in the air conditioning system 100 of Embodiment 1, it is not necessary to provide a standby power supply 55 large enough to simultaneously close the on-off valves V1 to V4. This allows the cost of configuring the air conditioning system 100 to be reduced.

[0055] In this air conditioning system 100, when a power outage occurs, there is little need to quickly close the on-off valves V1 to V4 because a refrigerant leak has not yet occurred. Therefore, it is sufficient for all of the on-off valves V1 to V4 to be closed between the time the power outage occurs and the time a refrigerant leak occurs. In the first embodiment, as shown in FIG. 5 , the on-off valves V1 to V4 are closed one by one in sequence. This allows the air conditioning system 100 of the first embodiment to appropriately close the multiple on-off valves V1 to V4 included in the air conditioning system 100 during a power outage while suppressing increases in the cost of constructing the air conditioning system 100.

[0056] More specifically, when the control device C10 detects a power outage, it acquires the power capacity of the standby power source 55 that can be used to close the on-off valves V1 to V4. In the example of FIG. 4, the control device C10 acquires 15 W as the power capacity that can be used to close the on-off valves V1 to V4. The control device C10 acquires the power required to execute a predetermined closing process for each of the on-off valves V1 to V4. If the remaining power capacity of the standby power source 55 is less than the power required to close the on-off valves, the control device C10 closes the on-off valves.

[0057] In the first embodiment, the control device C10 gives priority to closing the on-off valves included in the shutoff unit 30. That is, in the first embodiment, the on-off valves V1 and V3 included in the shutoff units 30a and 30b, respectively, are closed with priority over the on-off valves V2 and V4 included in the indoor units 20a and 20b, respectively. That is, the on-off valves V1 and V3 are controlled to a closed state earlier than the on-off valves V2 and V4. In other words, the start timing of the period D1 during which the on-off valve V1 is closed is earlier than the start timing of the period D2 during which the on-off valve V2 is closed.

[0058] 1, when the shutoff unit 30a is closed, the refrigerant is isolated between the refrigerant pipe 120 and the refrigerant pipe 121. In other words, if a refrigerant leak occurs, the risk of all refrigerant leaking can be efficiently reduced when the shutoff unit 30a is closed. The order in which the on-off valves V1 to V4 are closed is not limited to the example shown in FIG. 5. For example, the on-off valves V1 to V4 may be closed in order starting with the valve that requires the most power to perform the closing process.

[0059] [Comparative Example] In the above-described first embodiment, it has been explained that by providing only the standby power supply 55, which has a small power supply capacity compared to a standby power supply having a power supply capacity large enough to simultaneously close the on-off valves V1 to V4 even during a power outage, it is possible to reduce the construction costs of the air conditioning system 100. Below, a comparative example in which a standby power supply is provided in each of the indoor units 20a, 20b and the shutoff units 30a, 30b will be used for comparison with the first embodiment.

[0060] Fig. 6 is a block diagram showing the configurations of the outdoor unit 10, indoor unit 20, and shutoff unit 30 in the comparative example. As shown in Fig. 6, the air conditioning system 100Z in the comparative example is equipped with standby power supplies 51Z to 54Z. The standby power supplies 51Z to 54Z are provided as external components independent of the outdoor unit 10, indoor unit 20, and shutoff unit 30. The standby power supplies 51Z and 52Z supply power to the shutoff unit 30a and indoor unit 20a, respectively. The standby power supplies 53Z and 54Z supply power to the shutoff unit 30b and indoor unit 20b, respectively. Unlike in the first embodiment, the outdoor unit 10 in the comparative example does not have a standby power supply.

[0061] 7 is a sequence diagram showing the flow of processing when a power outage is detected in the comparative example. The outdoor unit 10 detects the occurrence of a power outage in the commercial power source 40 (step S1). Upon detection of the power outage, the control device C10 of the outdoor unit 10 in the comparative example simultaneously transmits a close signal to each of the shutoff units 30a, 30b and the indoor units 20a, 20b (step S2Z).

[0062] The shutoff units 30a, 30b and the indoor units 20a, 20b each start the closing process at the same time based on receiving a closing signal from the control device C10 of the outdoor unit 10. Specifically, the indoor unit 20a starts the closing process (step S3Z). The shutoff unit 30a starts the closing process (step S4Z). The indoor unit 20b starts the closing process (step S5Z). The shutoff unit 30b starts the closing process (step S6Z).

[0063] In this way, in the air conditioning system 100Z of the comparative example, when a power outage is detected, the on-off valves V1 to V4 are simultaneously controlled to a closed state using the standby power supplies 51Z to 54Z, respectively. In the comparative example, it is necessary to provide four standby power supplies 51Z to 54Z, which increases the cost of constructing the air conditioning system 100Z.

[0064] Embodiment 2. In the first embodiment, a configuration was described in which all of the on-off valves V1 to V4 are closed one by one in sequence. In the second embodiment, a configuration will be described in which some of the on-off valves V1 to V4 are closed simultaneously depending on the value of the available power supply capacity of the standby power supply 55. Note that in the second embodiment, the description of the configuration that overlaps with the air conditioning system 100 of the first embodiment will not be repeated.

[0065] 8 is a diagram illustrating the power capacity of the standby power supply 55 in embodiment 2. In embodiment 2, the power consumption required to control the states of the on-off valves V1 to V4 from an open state to a closed state is the same as in embodiment 1. In embodiment 2, unlike embodiment 1, the power capacity of the standby power supply 55 that can be used to close the on-off valves V1 to V4 is 16 W.

[0066] 9 is a sequence diagram showing the flow of processing when the occurrence of a power outage is detected in Embodiment 2. In Embodiment 2, the control device C10 of the outdoor unit 10 transmits a close signal to the indoor unit 20a in addition to the shutoff unit 30b based on receiving a completion signal from the shutoff unit 30a (steps S5A and S8A). That is, steps S5A and S8A are executed simultaneously, and the close signal transmitted to the shutoff unit 30b and the close signal transmitted to the indoor unit 20a are transmitted simultaneously.

[0067] In the example of the second embodiment, the power available for closing the on-off valves V1 to V4 is 16 W, so the on-off valves V2 and V3 can be closed simultaneously. That is, in the control device C10 of the second embodiment, the available power out of the power capacity of the standby power supply 55 is equal to or greater than the total power consumption for closing two of the on-off valves V1 to V4. In this case, the control device C10 closes the two on-off valves simultaneously.

[0068] That is, the control device C10 determines the order in which the on-off valves V1 to V4 are closed and which on-off valves are to be closed simultaneously, depending on the power capacity of the standby power source 55. In the example of Fig. 9, the on-off valves V2 and V3 are closed simultaneously, but in some aspects, the control device C10 may close the on-off valves V2 and V4 simultaneously.

[0069] This makes it possible to shorten the period required for all of the on-off valves V1 to V4 to be closed in embodiment 2. Also, in embodiment 2, similar to embodiment 1, it is possible to appropriately close the multiple on-off valves V1 to V4 included in the air conditioning system 100 during a power outage while suppressing increases in the construction costs of the air conditioning system 100.

[0070] The outdoor unit 10 may appropriately change the order in which the on-off valves V1 to V4 are shut off based on the power capacity of the standby power source 55, the types of the on-off valves V1 to V4, and the like. More specifically, after detecting a power outage, the outdoor unit 10 may change the order in which the on-off valves are shut off depending on the power capacity available from the standby power source 55, the type and number of devices experiencing the power outage, the number and type of open on-off valves, and other conditions. Furthermore, the outdoor unit 10 may change the determined order in which the on-off valves are shut off in response to changes in the above-mentioned conditions during the process of shutting off the on-off valves. Furthermore, if the outdoor unit 10 detects a refrigerant leak from a specified position upon the occurrence of a power outage, it selects and shuts off the on-off valve that minimizes the amount of refrigerant leakage. This allows the amount of refrigerant leakage to be suppressed even when both a power outage and a refrigerant leak occur.

[0071] Embodiment 3 In the first embodiment, a configuration was described in which one standby power source 55 is used to supply power during a power outage. In the third embodiment, a configuration including two standby power sources 55A and 55B will be described. Note that in the third embodiment, the description of the configuration that overlaps with the air conditioning system 100 of the first embodiment will not be repeated.

[0072] FIG. 10 is a block diagram showing the configurations of the outdoor unit 10, indoor unit 20, and shutoff unit 30 according to the third embodiment. As shown in FIG. 10, the air conditioning system 100B according to the third embodiment includes standby power supplies 55A and 55B. The standby power supply 55A supplies power to the outdoor unit 10, indoor unit 20a, and shutoff unit 30a. The standby power supply 55B supplies power to the indoor unit 20b and shutoff unit 30b. The standby power supply 55A according to the third embodiment may correspond to the "first standby power supply" in the present disclosure. The standby power supply 55B according to the third embodiment may correspond to the "second standby power supply" in the present disclosure. Unlike the first embodiment, the outdoor unit 10 according to the third embodiment does not have a standby power supply.

[0073] 11 is a sequence diagram showing the flow of processing when a power outage is detected in Embodiment 3. The outdoor unit 10 detects that a power outage has occurred in the commercial power source 40 (step S1). The detection of the power outage causes the outdoor unit 10 to transmit a close signal to the circuit breaker unit 30a and the circuit breaker unit 30b (steps S2B and S5B). That is, steps S2B and S5B are executed simultaneously, and the close signal transmitted to the circuit breaker unit 30a and the close signal transmitted to the circuit breaker unit 30b are transmitted simultaneously by the control device C10.

[0074] Thereafter, the control device C10 transmits a close signal to the indoor unit 20a based on the completion signal received from the shutoff unit 30a (step S8B).Furthermore, the control device C10 transmits a close signal to the indoor unit 20b based on the completion signal received from the shutoff unit 30b (step S11B).

[0075] In this way, in the air conditioning system 100B of embodiment 3, the on-off valves are closed sequentially for different periods for each of the standby power sources 55A and 55B. This allows the period in which all of the on-off valves V1 to V4 are closed to be shortened in embodiment 3. Furthermore, in embodiment 3, the increase in construction costs of the air conditioning system 100B can be suppressed compared to the comparative example shown in FIG. 6, and the multiple on-off valves V1 to V4 included in the air conditioning system 100B can be appropriately closed during a power outage. Note that in embodiment 3, the outdoor unit 10 may close the on-off valves V1 to V4 so that the periods D1 to D4 do not overlap, as in FIG. 5.

[0076] Embodiment 4 In the first embodiment, an example was described in which the control device C10 of the outdoor unit 10 determines the order and timing of transmitting a close signal according to the power capacity of the standby power supply 55. In the fourth embodiment, a configuration in which the control devices C1 and C2 have synchronized timers will be described. Note that in the air conditioning system 100C of the fourth embodiment, description of the configuration that overlaps with the air conditioning system 100 of the first embodiment will not be repeated.

[0077] FIG. 12 is a block diagram showing the configurations of the outdoor unit 10, indoor unit 20, and shutoff unit 30 in embodiment 4. As shown in FIG. 14, the control device C1 of the shutoff unit 30a has a timer T1. Furthermore, the control device C2 of the indoor unit 20a has a timer T2. Furthermore, the control device C1 of the shutoff unit 30b has a timer T3 (not shown). Furthermore, the control device C2 of the indoor unit 20b has a timer T4 (not shown). The timers T1 to T4 are time-synchronized. Furthermore, in embodiment 4, the indoor unit 20 and the shutoff unit 30 each have a power outage detection unit (not shown).

[0078] 13 is a sequence diagram showing the flow of processing when a power outage is detected in embodiment 4. In embodiment 4, the control devices C1 and C2 determine in advance the timing at which the on-off valve closing process is executed when a power outage occurs so as not to overlap with periods D1 to D4. For example, the timers T1 to T4 are synchronized at 10-minute intervals.

[0079] The control device C1 of the shutoff unit 30a executes the process of closing the on-off valve V1 at the start of the 10-minute cycle. The control device C2 of the indoor unit 20a executes the process of closing the on-off valve V2 at 2 minutes 30 seconds into the 10-minute cycle. The control device C1 of the shutoff unit 30b executes the process of closing the on-off valve V3 at 5 minutes into the 10-minute cycle. The control device C2 of the indoor unit 20b executes the process of closing the on-off valve V4 at 7 minutes 30 seconds into the 10-minute cycle.

[0080] In this way, in the fourth embodiment, the shutoff unit 30 and the indoor unit 20 each perform closing processing independently, so even if a power outage occurs and the communication paths between the outdoor unit 10, the shutoff unit 30, and the indoor unit 20 are cut off, the on-off valves V1 to V4 can be closed appropriately. Furthermore, in the fourth embodiment as well, it is possible to suppress an increase in the construction costs of the air conditioning system 100C, and it is possible to properly close the multiple on-off valves V1 to V4 included in the air conditioning system 100C in the event of a power outage.

[0081] Embodiment 5 In Embodiment 5, an example will be described in which the number of blocking units 30 and indoor units 20 is different from that in Embodiment 1. Note that in air conditioning system 100D of Embodiment 5, the description of the configuration that overlaps with air conditioning system 100 of Embodiment 1 will not be repeated.

[0082] Figure 14 is a block diagram showing the configurations of the outdoor unit 10, indoor unit 20, and shutoff unit 30 in embodiment 5. An air conditioning system 100D in embodiment 5 has indoor units 20c, 20d, and 20e in addition to indoor units 20a and 20b. Remote controllers 50c and 50d are connected to indoor units 20c and 20d, respectively. Remote controller 50e is connected to indoor unit 20e. Indoor units 20c and 20d and remote controllers 50c and 50d are located in room C. Indoor unit 20e and remote controller 50e are located in room D. Indoor units 20c, 20d, and 20e have on-off valves V5, V6, and V7, respectively.

[0083] The air conditioning system 100D of the fifth embodiment also includes a flow division controller 90. The flow division controller 90 is a mechanism for dividing the path of the refrigerant flowing from the outdoor unit 10. The flow division controller 90 has a plurality of on-off valves V8 to VN. In the fifth embodiment as well, the control device C1 performs a process of closing the on-off valves V1 to VN so that the periods for which the on-off valves V1 to VN are closed are different.

[0084] In this way, the technology of the present disclosure can also be applied to the configuration shown as embodiment 5. As a result, in embodiment 5 as well, it is possible to suppress an increase in the construction costs of the air conditioning system 100D, and to appropriately close the multiple on-off valves V1 to V4 included in the air conditioning system 100C in the event of a power outage.

[0085] <Modifications> In the example of Embodiment 1, an example has been described in which two indoor units 20a, 20b are provided as the indoor units 20, but the number of indoor units 20 may be one, or may be three or more. Similarly, the number of shutoff units 30 and the number of remote controllers 50 are not limited to two.

[0086] Furthermore, in the first to fifth embodiments, examples have been described in which the on-off valve is included in the indoor unit 20 or the shutoff unit 30, but the on-off valve only needs to be installed on the refrigerant circuit, and may be included in another component such as the outdoor unit 10, or may be provided as a new component outside the outdoor unit 10, the indoor unit 20, and the shutoff unit 30.

[0087] Furthermore, in the example of the first embodiment, an example has been described in which the power outage detection unit 16 is provided inside the outdoor unit 10. However, the power outage detection unit 16 may be provided inside the indoor unit 20 or the shutoff unit 30, or may be provided as a new component outside the outdoor unit 10, the indoor unit 20, and the shutoff unit 30.

[0088] Furthermore, in the above example, a configuration has been described in which one indoor unit 20 includes one on-off valve, but one indoor unit 20 may include multiple on-off valves. Similarly, one shutoff unit 30 may include multiple on-off valves.

[0089] Furthermore, in the first embodiment, the configuration has been described in which the control device C10 that determines the closing order based on the power capacity of the standby power supply 55 is disposed inside the outdoor unit 10. However, the control device C10 may be included in a configuration other than the outdoor unit 10, or may be provided as an independent configuration. Alternatively, the control device C2 included in the indoor unit 20 or the control device C1 included in the circuit breaker unit 30 may function as the control device that determines the closing order based on the power capacity of the standby power supply 55.

[0090] In the above example, the shutoff unit 30 and the indoor unit 20 transmit a completion signal to the outdoor unit 10. However, the shutoff unit 30 and the indoor unit 20 do not have to transmit a completion signal. In this case, the outdoor unit 10 may transmit the next close signal by referring to the time elapsed since transmitting the close signal. More specifically, the outdoor unit 10 may transmit the close signal shown in step S5 based on the fact that a predetermined period of time has elapsed since transmitting the close signal shown in step S2.

[0091] In the third embodiment, an example has been described in which the standby power supply 55A supplies power to the shutoff unit 30a and the indoor unit 20a, and the standby power supply 55B supplies power to the shutoff unit 30b and the indoor unit 20b. However, the standby power supply 55A may be configured to supply power to all of the shutoff units 30a, 30b and the indoor units 20a, 20b. In this case, the standby power supply 55B may also be configured to supply power to all of the shutoff units 30a, 30b and the indoor units 20a, 20b, similar to the standby power supply 55A. This allows the other standby power supply 55A, 55B to operate if one of the standby power supplies 55A, 55B fails during a power outage, thereby improving redundancy. Of course, the number of standby power supplies 55 is not limited to two, and the standby power supplies 55A and 55B may be different models.

[0092] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0093] 10 Outdoor unit, 11, 21, 31 Processor, 12, 22, 32 Memory, 13, 23, 33 Communication interface, 14, 24 Air conditioning mechanism, 15 Closure instruction unit, 16 Power outage detection unit, 20, 20a to 20e Indoor unit, 30, 30a, 30b Cutoff unit, 40 Commercial power supply, 50, 50a to 50e, 60 Remote controller, 51Z to 54Z, 55, 55A, 55B Standby power supply, 51 Display, 52 Operation unit, 90 Shunt controller, 100, 100B to 100D, 100Z Air conditioning system, 120, 121, 122 Refrigerant pipe, 141 Compressor, 142, 242 Heat exchanger, 144, 244 Fan, 145 Four-way valve, A, B, C, D Room, C1, C2, C10 control device, D1 to D4 period, T1 to T4 timer, V1 to VN on-off valve.

Claims

1. An air conditioning system comprising a refrigerant circuit through which a refrigerant flows, a plurality of on-off valves for adjusting the flow rate of the refrigerant flowing through the refrigerant circuit, a main power supply for supplying main power to the plurality of on-off valves, at least one backup power supply for supplying backup power to the plurality of on-off valves when the supply of the main power stops, and at least one control device for controlling the power supply to the plurality of on-off valves, wherein the at least one control device controls the supply of the backup power to the plurality of on-off valves according to the power capacity of the at least one backup power supply when the supply of the main power stops.

2. The plurality of on-off valves include a first on-off valve and a second on-off valve, and the at least one control device supplies the backup power to the first on-off valve for a first period when the supply of the main power stops, to shift the first on-off valve from an open state to a closed state, and supplies the backup power to the second on-off valve for a second period different from the first period, to shift the second on-off valve from an open state to a closed state. The air conditioning system according to claim 1.

3. The plurality of on-off valves further include a third on-off valve, and the at least one control device supplies the backup power to the third on-off valve for a third period different from the first period or the second period when the supply of the main power stops, to shift the third on-off valve from an open state to a closed state. The air conditioning system according to claim 2.

4. The third period is the same period as the second period when the backup power available in the at least one backup power supply is equal to or greater than a threshold value. The air conditioning system according to claim 3.

5. The at least one backup power supply includes a first backup power supply for supplying a first backup power and a second backup power supply for supplying a second backup power, and the at least one control device: when the supply of the main power stops, supplies the first backup power to the first on-off valve and the second on-off valve to shift the first on-off valve and the second on-off valve from an open state to a closed state; when the supply of the main power stops, supplies the second backup power to the third on-off valve to shift the state of the third on-off valve from an open state to a closed state. The air conditioning system according to claim 3.

6. The at least one control device includes a first control device that controls power supply to the first on-off valve and a second control device that controls power supply to the second on-off valve. The first control device supplies the standby power to the first on-off valve for a first period determined based on a first timer when the supply of the main power stops. The second control device supplies the standby power to the second on-off valve for a second period determined based on a second timer synchronized with the first timer when the supply of the main power stops. The air conditioning system according to claim 2.

7. The timing at which the first period starts is earlier than the timing at which the second period starts. The air conditioning system according to any one of claims 2 to 6.

8. The refrigerant circuit includes an outdoor unit, at least one indoor unit, and at least one shut-off unit connected between the outdoor unit and the at least one indoor unit. The plurality of on-off valves are provided in either the at least one indoor unit or the at least one shut-off unit. The air conditioning system according to any one of claims 1 to 7.

9. The air conditioning system according to claim 8, further comprising a flow divider that divides the refrigerant flow path between the outdoor unit and the at least one shut-off unit.

10. A control device that controls power supply to a plurality of on-off valves that adjust the flow rate of refrigerant flowing through a refrigerant circuit, the control device comprising: a storage unit that stores a control program for controlling power supply to the plurality of on-off valves; and a control unit that controls power supply to the plurality of on-off valves according to the control program. The control unit determines whether the supply of main power from the main power source to the plurality of on-off valves has stopped, and when the supply of the main power has stopped, controls the supply of standby power from the at least one standby power source to the plurality of on-off valves according to the power capacity of the at least one standby power source.

11. A control method for controlling, by a computer, power supply to a plurality of on-off valves that adjust the flow rate of a refrigerant flowing through a refrigerant circuit, the method comprising, as processing executed by the computer, a step of determining whether or not supply of main power from a main power supply to the plurality of on-off valves has stopped, and a step of controlling supply of standby power from at least one standby power supply to the plurality of on-off valves according to the power supply capacity of the at least one standby power supply when the supply of the main power has stopped.

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