Air conditioning system

Abstract

To appropriately make a notification about replacement of a refrigerant detection sensor.SOLUTION: An air conditioning system 10 includes: a refrigerant circuit 20 that circulates a refrigerant; a refrigerant detection sensor 30 that detects leakage of the refrigerant from the refrigerant circuit 20; a notification device 32 that makes a notification about replacement of the refrigerant detection sensor 30; and a controller 31 that controls the notification device 32. The controller 31 makes a first notification through the notification device 32 when a first period related to a service life of the refrigerant detection sensor 30 elapses, and makes a second notification through the notification device 32 when a second period shorter than the first period elapses. The controller 31 stops the second notification when a predetermined condition other than replacement of the refrigerant detection sensor 30 is satisfied, and maintains the first notification even when the predetermined condition is satisfied.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] The following Patent Document 1 discloses an air conditioner that uses a slightly flammable refrigerant. This air conditioner is equipped with a refrigerant detection sensor that detects leaked refrigerant, and issues a warning when or before the refrigerant detection sensor reaches the end of its expected lifespan, urging the user to replace the refrigerant detection sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 116437 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described in Patent Document 1 has the advantage that the user can prepare to replace the refrigerant detection sensor in good time by notifying the user before the expected lifespan is reached. However, continuing to notify the user before the lifespan is reached may cause discomfort to the user. An object of the present disclosure is to appropriately provide notification regarding the replacement of a refrigerant detection sensor. [Means for solving the problem]

[0005] (1) The air conditioning system of the present disclosure comprises: a refrigerant circuit for circulating a refrigerant; a refrigerant detection sensor that detects leakage of refrigerant from the refrigerant circuit; An alarm device that issues an alarm regarding replacement of the refrigerant detection sensor; A controller for controlling the notification device, the controller causes the notification device to make a first notification when a first period related to the life of the refrigerant detection sensor has elapsed, and causes the notification device to make a second notification when a second period shorter than the first period has elapsed; The controller stops the second notification when a predetermined condition other than replacement of the refrigerant detection sensor is satisfied, and maintains the first notification even when the predetermined condition is satisfied.

[0006] According to the above configuration, the second notification by the notification device can be regarded as a preliminary notification to encourage replacement before the refrigerant detection sensor reaches the end of its life, and by stopping this second notification under a predetermined condition, it is possible to alleviate the discomfort of the user caused by the second notification being continued. On the other hand, since the first notification is intended to inform the user of the need for immediate replacement, by maintaining the first notification even under a predetermined condition, it is possible to continue encouraging the user to replace the refrigerant detection sensor.

[0007] (2) In the air conditioning system of (1) above, preferably, the predetermined condition is that a predetermined period of time has elapsed after the notification by the notification device.

[0008] According to the above configuration, the second notification can be automatically stopped without bothering the user.

[0009] (3) The air conditioning system of (1) above preferably further includes a reception unit that receives an instruction to stop the notification, The predetermined condition is that the instruction is accepted by the accepting unit.

[0010] According to the above configuration, the second notification can be stopped at the will of the user or the like.

[0011] (4) In the air conditioning system described in any one of (1) to (3) above, preferably, after the second notification is stopped, the controller issues a third notification by the notification device before the first period is reached.

[0012] According to the above configuration, by performing the third notification, it is possible to reduce the risk that the refrigerant detection sensor will be left without being replaced after the second notification has stopped.

[0013] (5) In the air conditioning system of (4) above, the controller preferably stops the third notification when a second predetermined condition other than replacement of the refrigerant detection sensor is met.

[0014] According to the above configuration, it is possible to alleviate the discomfort felt by the user due to the third notification being continuously issued.

[0015] (6) In the air conditioning system described in any one of (1) to (5) above, preferably, the controller performs the third notification at predetermined intervals from the time when the second period has elapsed until the time when the first period is reached.

[0016] (7) The air conditioning system according to any one of (1) to (6) above, preferably further comprising a storage unit that stores a history of notifications made by the notification device.

[0017] According to the above configuration, even if the second or third notification stops without the user noticing the second or third notification, the user can later read and check the notification history. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram of an air conditioning system according to one embodiment of the present disclosure. [Diagram 2] 1 is a schematic diagram showing a refrigerant circuit of an air conditioner in an air conditioning system. [Diagram 3] FIG. 1 is a block diagram of an air conditioning system. [Figure 4] 5 is a flowchart showing a process performed by a controller for notifying a refrigerant detection sensor of a time to replace the refrigerant detection sensor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Fig. 1 is a schematic diagram of an air conditioning system according to an embodiment of the present disclosure, Fig. 2 is a schematic diagram showing a refrigerant circuit of an air conditioner in the air conditioning system. As shown in FIG. 1, an air conditioning system 10 includes an air conditioner 11. The air conditioner 11 of this embodiment is installed in a building B that includes a computer room R, such as a server room. This air conditioner 11 adjusts the temperature inside the computer room R to a predetermined range throughout the year. This air conditioner 11 is dedicated to cooling. However, the air conditioner 11 may adjust the temperature of any room where people are present, not limited to computer rooms. The air conditioner 11 may perform both cooling and heating, or may be dedicated to heating.

[0020] The air conditioner 11 includes an indoor unit (utilization unit) 12 installed indoors, and an outdoor unit (heat source unit) 13 installed outdoors. The outdoor unit 13 and the indoor unit 12 are connected by refrigerant connection pipes 14, 15. The indoor unit 12, the outdoor unit 13, and the refrigerant connection pipes 14, 15 constitute a refrigerant circuit 20 that circulates the refrigerant. The refrigerant circuit 20 performs a vapor compression refrigeration cycle operation.

[0021] A computer 100 such as a server is installed in the computer room R. The indoor unit 12 is disposed in a separate indoor area partitioned from the computer room R. When the air conditioner 11 is operated, air blown out from the indoor unit 12 passes under the floor A of the computer room R and is blown out from under the floor A into the computer room R to cool the computer room R. The air in the computer room R flows into the ceiling space C of the computer room R and is sucked into the indoor unit 12. The indoor unit 12 cools the air sucked in from the ceiling space C by heat exchange with a refrigerant and blows it out into the floor space A.

[0022] The refrigerant circuit 20 includes a compressor 21, a heat source side heat exchanger 22, an expansion valve 23, and a utilization side heat exchanger 24. The compressor 21 sucks in a low pressure refrigerant and discharges a high pressure refrigerant. The compressor 21 is driven by a motor. The capacity of the compressor 21 can be changed by varying the operating frequency (rotation speed) of the motor via an inverter device. The suction side of the compressor 21 is connected to the outlet of the utilization side heat exchanger 24, and the discharge side of the compressor 21 is connected to the outdoor unit 13 (particularly the inlet of the heat source side heat exchanger 22) via a refrigerant connection pipe 15. The compressor 21 in this embodiment is provided in the indoor unit 12, but may be provided in the outdoor unit 13.

[0023] For example, a cross-fin type heat exchanger or a microchannel type heat exchanger composed of a heat transfer tube and multiple fins is used as the heat source side heat exchanger 22. In a cooling-only air conditioner 11, the heat source side heat exchanger 22 functions as a condenser that condenses high-pressure refrigerant using outdoor air as a heat source. However, when the air conditioner 11 performs both cooling and heating operations, the heat source side heat exchanger 22 functions as a condenser during cooling operation and as an evaporator during heating operation.

[0024] An outlet of the heat source side heat exchanger 22 is connected to the indoor unit 12 (in particular, the expansion valve 23) via a refrigerant communication pipe 14. The expansion valve 23 is an electric valve whose opening degree can be controlled. The expansion valve 23 reduces the pressure of the refrigerant condensed in the heat source side heat exchanger 22 and expands it. The expansion valve 23 in this embodiment is provided in the indoor unit 12, but may be provided in the outdoor unit 13.

[0025] For example, a cross-fin type heat exchanger or a microchannel type heat exchanger composed of a heat transfer tube and multiple fins is used as the user-side heat exchanger 24. In an air conditioner 11 that is exclusively for cooling, the user-side heat exchanger 24 functions as an evaporator that evaporates a low-pressure refrigerant and cools the air in the room. However, when the air conditioner 11 performs both cooling and heating operations, the user-side heat exchanger 24 functions as an evaporator during cooling operation and as a condenser during heating operation.

[0026] The outdoor unit 13 further includes an outdoor fan 26. The outdoor fan 26 draws outdoor air into the outdoor unit 13, exchanges heat with the refrigerant in the heat source side heat exchanger 22, and then forms an air flow that blows the air outside.

[0027] The indoor unit 12 further includes an indoor fan 27. The indoor fan 27 draws indoor air into the indoor unit 12, exchanges heat with the refrigerant in the utilization-side heat exchanger 24, and then forms an airflow that blows the air into the room.

[0028] In this embodiment, a flammable refrigerant is used as the refrigerant. Specifically, R32 is used as the refrigerant. However, other flammable refrigerants such as R1234yf, R474a, R600a (isobutane), and R290 (propane) can be used as the refrigerant.

[0029] The air conditioning system 10 of this embodiment is equipped with a refrigerant detection sensor 30 to detect leakage of a flammable refrigerant. The refrigerant detection sensor 30 of this embodiment is provided in the indoor unit 12. The refrigerant detection sensor 30 detects refrigerant leaking from the refrigerant piping in the indoor unit 12 or the user-side heat exchanger 24. When the refrigerant detection sensor 30 detects a refrigerant leak, the air conditioning system 10 performs a predetermined operation. For example, the air conditioning system 10 performs at least one of the following operations: stopping the operation of the air conditioner 11, issuing an alarm, and performing a stirring operation. The stirring operation is an operation in which only the fan of the air conditioner 11 is driven. When the air conditioning system 10 includes a ventilation device, the predetermined operation may include forced ventilation by the ventilation device.

[0030] The refrigerant detection sensor 30 is determined to have reached the end of its life after a predetermined period of time has passed, and replacement is required. In particular, because the refrigerant used in the air conditioner 11 of this embodiment is flammable, it is essential to detect refrigerant leakage, and regular replacement of the refrigerant detection sensor 30 is extremely important. For this reason, when the refrigerant detection sensor 30 has reached or is approaching the end of its life, the air conditioning system 10 of this embodiment notifies the user or maintenance worker (hereinafter also referred to as the user, etc.) of this fact and urges replacement.

[0031] FIG. 3 is a block diagram of the air conditioning system. The indoor unit 12 of the air conditioner 11 has a controller 31, a refrigerant detection sensor 30, and a notification unit 32. The controller 31 controls the operation of the compressor 21, the expansion valve 23, the indoor fan, the outdoor fan, and the like in the air conditioner 11. The controller 31 includes a processor and a memory. The processor is configured with a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), a gate array, an FPGA (Field Programmable Gate Array), and the like. The ASIC, or a programmable logic device such as a gate array or an FPGA is configured to be able to execute the same processing as the control program. The memory of the controller 31 includes volatile memory such as SRAM (Static Random Access Memory) or DRAM (Dynamic Random Access Memory), and non-volatile memory such as a flash memory, a hard disk, and a ROM (Read Only Memory). The non-volatile memory stores a control program, which is a computer program, and control data.

[0032] The controller 31 performs various functions by the processor executing a control program. In this embodiment, the controller 31 executes a notification process to prompt replacement of the refrigerant detection sensor 30. The controller 31 calculates the usage period from when the refrigerant detection sensor 30 started to be used to the present. The usage period can be, for example, the period during which power is supplied to the air conditioner 11 and current is passed through the refrigerant detection sensor 30. When the usage period of the refrigerant detection sensor 30 reaches a predetermined period, it is determined that the refrigerant detection sensor 30 has reached the end of its life. Therefore, the life of the refrigerant detection sensor 30 is set using the usage period as an index.

[0033] The notification unit 32 issues a notification to encourage replacement of the refrigerant detection sensor 30. The notification unit 32 is controlled by the controller 31. The notification unit 32 is composed of a light that emits light, such as an LED, a buzzer that emits sound, etc. The notification unit 32 may be a display panel, such as a liquid crystal or organic electroluminescence (EL) panel, that displays characters and figures.

[0034] A remote controller 34 is connected to the indoor unit 12. The remote controller 34 has an operation unit 35, a display unit 36, and a memory unit 37. The operation unit 35 is used to input various settings related to the operation of the air conditioner 11, such as settings of temperature, air volume, etc., and turning the operation on and off. The operation unit 35 is composed of push buttons, a touch panel, etc. The display unit 36 ​​is used to display the settings and operation of the air conditioner 11. The display unit 36 ​​is composed of a display panel such as liquid crystal or organic EL. The memory unit 37 includes a volatile or non-volatile memory. The memory unit 37 is used to store the notification history of the notification unit 32, as described later.

[0035] In addition to the above, the air conditioning system 10 also has a centralized control device 41 and a management device 42. Both of these include computers with a processor and memory. When multiple air conditioners 11 are installed, the centralized control device 41 is used to centrally monitor the operating status of these air conditioners 11, set the temperature, and control the operation and shutdown of the air conditioners. The management device 42 is installed in a remote location away from the building in which the air conditioners 11 are installed, and is connected to the centralized control device 41 or the air conditioners 11 via a network such as the Internet. The centralized control device 41 and management device 42 may be omitted.

[0036] FIG. 4 is a flowchart showing a process performed by the controller for notifying the user of the timing to replace the refrigerant detection sensor. As described above, when the refrigerant detection sensor 30 has reached the end of its life or is approaching the end of its life, the controller 31 executes a notification process to prompt replacement. Details of this process will be described below with reference to FIG.

[0037] The controller 31 determines whether the period of use of the refrigerant detection sensor 30 has reached a predetermined replacement preparation period (step S1). The replacement preparation period is a period that is shorter than the period during which the refrigerant detection sensor 30 reaches the end of its life and requires replacement (hereinafter also referred to as the "replacement period"), and is a period for encouraging early replacement before the end of its life. For example, if the life (replacement period) of the refrigerant detection sensor 30 is five years, the replacement preparation period can be set to four years and six months, six months earlier.

[0038] If the determination result in step S1 is positive (YES), the controller 31 performs a preliminary notification in step S2. This preliminary notification refers to a notification performed before the refrigerant detection sensor 30 reaches the end of its life, and is a notification in a manner different from the notification performed when the refrigerant detection sensor 30 reaches its end of its life (hereinafter also referred to as "main notification"). For example, when the notification in the notification unit 32 is performed using a light (light), a mode can be adopted in which the light is flashed in the preliminary notification and the light is turned on in the main notification. When the notification in the notification unit 32 is performed using a buzzer (sound), the buzzer can be operated intermittently in the preliminary notification and the buzzer can be operated continuously in the main notification. Also, when the notification in the notification unit 32 is performed using both a light and a buzzer, for example, the light can be turned on or flashed in the preliminary notification and the buzzer can be operated in the main notification. However, these are merely examples, and various modes can be combined and adopted.

[0039] Next, in step S3, the controller 31 determines whether or not the refrigerant detection sensor 30 has been replaced. Replacing the refrigerant detection sensor 30 refers to the task of removing the refrigerant detection sensor 30 from the air conditioner 11 and installing a new refrigerant detection sensor 30. Replacing the refrigerant detection sensor 30 also includes various tasks associated with removing and installing the refrigerant detection sensor 30. For example, replacing the refrigerant detection sensor 30 includes a reset operation that clears the accumulated usage period of the refrigerant detection sensor 30.

[0040] If the determination result in step S3 is positive (YES), the controller 31 proceeds to step S4 and ends the notification. That is, the controller 31 stops the preliminary notification and ends the notification regarding the replacement of the old refrigerant detection sensor 30. This makes it possible to move on to managing the usage period of the new refrigerant detection sensor 30 after replacement. If the determination result in step S3 is negative (NO), the controller 31 proceeds to step S5.

[0041] In step S5, the controller 31 determines whether a predetermined period T1 has elapsed after the preliminary notification. This predetermined period T1 may be, for example, 24 hours. If the result of the determination in step S5 is affirmative (YES), the controller 31 proceeds to step S6, and if the result is negative (NO), the controller 31 returns to step S3.

[0042] In step S6, the controller 31 stops the preliminary warning. By automatically stopping the preliminary warning after a predetermined period T1 (e.g., 24 hours) in this manner, it is possible to prevent the preliminary warning from being continuously issued, which may cause discomfort to the user. For example, if the light is constantly on or flashing, or the buzzer is constantly sounding, the user is likely to feel uncomfortable, but this embodiment can eliminate such inconveniences.

[0043] Note that the preliminary warning is issued when the refrigerant detection sensor 30 has not yet reached the end of its life, and therefore there is no need to immediately replace the refrigerant detection sensor 30. Therefore, the disadvantage of not being able to promote replacement of the refrigerant detection sensor 30 by stopping the preliminary warning is small, and conversely, the advantage of being able to eliminate discomfort to the user is great.

[0044] In step S7, the controller 31 determines whether the period of use of the refrigerant detection sensor 30 has passed the replacement period. As described above, the replacement period is the period of use until the refrigerant detection sensor 30 reaches the end of its life. If the result of the determination in step S7 is affirmative (YES), the controller 31 proceeds to step S8, and if the result is negative, the controller 31 proceeds to step S10.

[0045] In step S10, the controller 31 judges whether a predetermined period T2 has elapsed after the preliminary warning. This predetermined period T2 is set to, for example, two months. If the result of the judgment in step S10 is affirmative (YES), the controller 31 returns the process to step S2, and if the result is negative (NO), the controller 31 returns the process to step S7. In step S2, the controller 31 issues a preliminary warning again, and then repeatedly executes the same process as described above.

[0046] Therefore, after the replacement preparation period has been reached, the controller 31 will repeatedly issue a preliminary warning every predetermined period T2 (e.g., every two months) until the replacement period is reached. Therefore, even if the preliminary warning stops after the predetermined period T2 (e.g., 24 hours), the user or the like can be prompted again to replace the refrigerant detection sensor 30.

[0047] If the replacement period is 5 years, the replacement preparation period is 4 years and 6 months, and preliminary notification is repeated every two months, preliminary notification will be performed three times at 4 years and 6 months, 4 years and 8 months, and 4 years and 10 months, after which a main notification will be performed since 5 years have passed. The interval at which preliminary notification is repeated is not limited to 2 months, but may be 1 month, or may be 3 to 5 months. In the latter case, preliminary notification will be performed a maximum of two times in practice.

[0048] If the determination result in step S7 is affirmative (YES), in step S8, the controller 31 issues a "main notification" regarding replacement of the refrigerant detection sensor 30. As described above, the main notification is implemented in a manner different from the preliminary notification in order to distinguish it from the preliminary notification.

[0049] In step S9, the controller 31 determines whether or not the refrigerant detection sensor 30 has been replaced. If the result of this determination is affirmative (YES), the controller 31 proceeds to step S4, and ends the process of notifying the user of the replacement of the refrigerant detection sensor 30.

[0050] If the determination result in step S9 is negative (NO), the controller 31 continues the notification as is. That is, the notification is continued without stopping until the refrigerant detection sensor 30 is replaced. Therefore, the user or the like is more strongly urged to replace the refrigerant detection sensor 30.

[0051] The history of the preliminary notification and the main notification performed in the above procedure is stored in the storage unit 37 of the remote controller 34. For example, information such as the type of notification (preliminary notification or main notification), the timing of the notification, and the duration of the notification is stored in the storage unit 37. Then, the user or the maintenance worker can display and check the history information stored in the storage unit 37 on the display unit 36 ​​by operating the operation unit 35 of the remote controller 34. Therefore, for example, if the preliminary notification stops before the user or the like notices it, it is possible to check later whether or not there was a preliminary notification. When the history information stored in the storage unit 37 exceeds a predetermined capacity, the oldest information is deleted. This allows the capacity of the storage unit 37 to be reduced.

[0052] [Other embodiments] In the above embodiment, the refrigerant detection sensor 30 is provided in the indoor unit 12, but this is not limited to this. For example, the refrigerant detection sensor 30 may be provided in the remote controller 34. The refrigerant detection sensor 30 may be provided in a room that is a space to be air-conditioned. The refrigerant detection sensor 30 may also be provided in the outdoor unit 13.

[0053] In the above embodiment, a flammable refrigerant is used as the refrigerant, but the present invention is not limited to this. For example, a toxic refrigerant or a refrigerant with a relatively high global warming potential (GWP) (e.g., a refrigerant with a GWP of 4 or more, which is higher than natural refrigerants) can be used as the refrigerant. Examples of toxic refrigerants include NH 3 As a refrigerant with a high GWP, in addition to R32 exemplified in the above embodiment, R454B, R454C, etc. can be used.

[0054] In the above embodiment, the notification unit 32 is controlled by the controller 31 of the indoor unit 12, but it may be controlled by a controller provided in the outdoor unit 13. The notification unit 32 may be controlled by the remote controller 34, or may be controlled by a controller provided in the centralized control device 41 or the management device 42. The notification unit may be provided in the remote controller 34. In this case, the display unit 36 ​​may function as the notification unit.

[0055] In the above embodiment, the notification history information is stored in the storage unit 37 of the remote controller 34, but it may also be stored in a storage unit (memory) included in the controller 31 of the indoor unit 12. The history information may also be stored in a storage unit of the centralized control device 41 or a storage unit of the management device 42. In this case, the centralized control device 41 or the management device 42 is provided with an operation unit and a display unit, and the history information stored in the storage unit can be displayed on the display unit by operating the operation unit.

[0056] In the above embodiment, the preliminary alert issued after the replacement preparation period has elapsed is automatically stopped after a predetermined period T1 (e.g., 24 hours) has elapsed, but this is not limited to the above. For example, the preliminary alert may be stopped by manual operation by a user or the like. In this case, the preliminary alert can be stopped by operating the operation unit 35 of the remote controller 34, for example. Note that this alert cannot be stopped automatically or manually, and is maintained unless the refrigerant detection sensor 30 is replaced.

[0057] When the notification regarding replacement of the refrigerant detection sensor 30 is made using a display panel, the preliminary notification can include a message indicating that the refrigerant detection sensor 30 needs to be replaced, or that the time for replacement is approaching, and the main notification can include a message indicating that the sensor has reached the end of its life, or that operation will be stopped if the sensor is not replaced, etc.

[0058] [Effects of the embodiment] (1) The air conditioning system 10 of the above embodiment includes a refrigerant circuit 20 that circulates a refrigerant, a refrigerant detection sensor 30 that detects leakage of refrigerant from the refrigerant circuit 20, an alarm device (alarm unit) 32 that issues an alarm regarding replacement of the refrigerant detection sensor 30, and a controller 31 that controls the alarm device 32. The controller 31 issues a first alarm (main alarm) by the alarm device 32 when a first period (replacement period) regarding the life of the refrigerant detection sensor 30 has elapsed, and issues a second alarm (preliminary alarm) by the alarm device 32 when a second period (replacement preparation period) shorter than the first period has elapsed. Furthermore, the controller 31 stops the second alarm when a predetermined condition other than replacement of the refrigerant detection sensor 30 is met, and maintains the first alarm even when the predetermined condition is met. According to this configuration, the second notification can be regarded as a preliminary notification to urge the user to replace the refrigerant detection sensor 30 before it reaches the end of its life, and by stopping this second notification under a predetermined condition, the discomfort felt by the user due to the continuation of the second notification can be alleviated. On the other hand, since the first notification notifies the user that an immediate replacement is required, by maintaining the first notification even under a predetermined condition, the user can be continuously urged to replace the refrigerant detection sensor 30.

[0059] (2) In the above embodiment, the predetermined condition for stopping the second notification (preliminary notification) is that a predetermined period of time T1 has elapsed after the notification by the notification device 32. Therefore, the second notification can be automatically stopped without bothering the user.

[0060] (3) In the above embodiment, the air conditioning system 10 further includes a reception unit (operation unit) 35 that receives an instruction to stop the notification, and the predetermined condition for stopping the second notification (preliminary notification) is that the instruction is received by the reception unit 35. Therefore, the second notification can be stopped at the will of a user, etc.

[0061] (4) In the above embodiment, after the second notification (preliminary notification) has stopped, the controller 31 causes the notification device 32 to issue a third notification (second preliminary notification) before the first period (replacement period) is reached. By issuing the third notification in this manner, it is possible to reduce the risk that the refrigerant detection sensor 30 will be left unreplaced after the second notification has stopped.

[0062] (5) In the above embodiment, the controller 31 stops the third alert (second preliminary alert) when a second predetermined condition is met other than replacement of the refrigerant detection sensor 30. This can alleviate the discomfort felt by the user due to the continuation of the third alert.

[0063] (6) In the above embodiment, the controller 31 issues the third notification (second and subsequent preliminary notifications) at predetermined intervals T2 from the end of the second period (replacement preparation period) until the first period (replacement period). This reduces the risk that the refrigerant detection sensor will be left unreplaced after the third notification stops.

[0064] (7) In the above embodiment, the air conditioning system 10 further includes a storage unit 37 that stores a history of notifications by the notification device 32. Therefore, for example, even if the user does not notice the second and third notifications (preliminary notifications) and these notifications stop, the notification history can be read and checked later.

[0065] Although the embodiments have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. [Explanation of symbols]

[0066] 10: Air conditioning system 20: Refrigerant circuit 30: Refrigerant detection sensor 31: Controller 32: Notification unit (notification device) 35: Operation section (reception section) 37: Storage section

Claims

1. a refrigerant circuit (20) for circulating a refrigerant; a refrigerant detection sensor (30) that detects leakage of refrigerant from the refrigerant circuit (20); an alarm device (32) for notifying the user of replacement of the refrigerant detection sensor (30); A controller (31) for controlling the notification device (32), the controller (31) issues a first notification through the notification device (32) when a first period related to the life of the refrigerant detection sensor (30) has elapsed, and issues a second notification through the notification device (32) when a second period shorter than the first period has elapsed; The controller (31) stops the second notification when a predetermined condition other than replacement of the refrigerant detection sensor (30) is satisfied, and maintains the first notification even when the predetermined condition is satisfied.

2. 2. The air conditioning system according to claim 1, wherein the predetermined condition is that a predetermined period of time (T1) has elapsed after the notification by the notification device (32).

3. A reception unit (35) for receiving an instruction to stop the notification is further provided, The air conditioning system according to claim 1 , wherein the predetermined condition is that the instruction is accepted by the accepting unit (35).

4. The air conditioning system according to any one of claims 1 to 3, wherein the controller (31) issues a third alert by the alert device (32) after the second alert has stopped and before the first period has elapsed.

5. The air conditioning system according to claim 4, wherein the controller (31) stops the third notification when a second predetermined condition other than replacement of the refrigerant detection sensor (30) is satisfied.

6. The air conditioning system according to claim 5, wherein the controller (31) issues the third notification at predetermined intervals (T2) from when the second period has elapsed until when the first period is reached.

7. The air conditioning system according to any one of claims 1 to 3, further comprising a storage unit (37) that stores a history of notifications by the notification device (32).

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