JPWO2017002216A1 - Refrigerant leak detector - Google Patents

Abstract

A highly reliable refrigerant leak detection device is provided. The refrigerant leakage detection device is configured to determine whether or not there is a refrigerant leak based on a plurality of detection circuits that detect the output of the refrigerant sensor, and outputs from the plurality of detection circuits, and to determine whether or not there is an abnormality in the plurality of detection circuits Means.

Description

  The present invention relates to a refrigerant leakage detection device that detects refrigerant leakage in a refrigeration apparatus.

  2. Description of the Related Art Conventionally, it is known that a refrigerant leakage detection device is provided in a cooling device such as an air conditioner or a refrigerator in order to detect refrigerant leakage from the cooling device. For example, in Patent Document 1, the presence or absence of a refrigerant leak is determined from the refrigerant concentration detected by a sensor. When it is determined that the refrigerant is leaking, an alarm sound is emitted from an alarm buzzer and a shut-off valve is closed. It describes that the refrigerant flow is cut off and the ventilation fan is turned to lower the refrigerant concentration in the room.

JP 2012-193484 A

  Here, the refrigerant leakage detection function is an important function related to safety. However, if the refrigerant leakage detection device or the refrigerant sensor fails, refrigerant leakage cannot be detected.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a highly reliable refrigerant leak detection device.

  The refrigerant leakage detection device according to the present invention determines the presence or absence of refrigerant leakage based on a plurality of detection circuits that detect the output of the refrigerant sensor and the outputs from the plurality of detection circuits, and whether or not there is an abnormality in the plurality of detection circuits. And a control means for determining.

  According to the refrigerant leakage detection device according to the present invention, the presence or absence of refrigerant leakage is determined based on the outputs from the plurality of detection circuits, and the presence or absence of abnormality in the plurality of detection circuits is determined. Even when an abnormality occurs, the refrigerant leakage can be determined, and the detection circuit where the abnormality has occurred can be specified, so that the reliability is improved.

1 is a schematic configuration diagram of an air conditioning system according to Embodiment 1. FIG. It is a figure which shows the apparatus connected to the internal structure of the refrigerant | coolant leak detection apparatus in Embodiment 1, and a refrigerant | coolant leak detection apparatus. 3 is a flowchart showing a flow of a refrigerant leakage detection process in the first embodiment. 3 is an example of a layout diagram displayed on the centralized controller according to the first embodiment. FIG. It is a figure which shows the apparatus arrange | positioned in the living room in the modification of Embodiment 1. FIG. 6 is a schematic configuration diagram of an air-conditioning system according to Embodiment 2. FIG. It is a figure which shows the apparatus connected to the internal structure of a refrigerant | coolant leak detection apparatus in Embodiment 3, and a refrigerant | coolant leak detection apparatus. 10 is a flowchart showing a flow of processing in an inspection mode according to the third embodiment. It is the schematic diagram which looked at the state by which the refrigerant | coolant sensor and the refrigerant | coolant leak detection apparatus were accommodated in the indoor unit in Embodiment 3 from the side surface. It is a figure which shows the apparatus connected to the internal structure of a refrigerant | coolant leak detection apparatus in Embodiment 4, and a refrigerant | coolant leak detection apparatus. 10 is a graph showing transition of output values of two refrigerant sensors in the fourth embodiment. It is a figure which shows the apparatus connected to the internal structure of the refrigerant | coolant leak detection apparatus in Embodiment 5, and a refrigerant | coolant leak detection apparatus. It is a figure which shows the apparatus connected to the internal structure of a refrigerant | coolant leak detection apparatus in Embodiment 6, and a refrigerant | coolant leak detection apparatus. It is a figure which shows the apparatus connected to the internal structure of a refrigerant | coolant leak detection apparatus in Embodiment 7, and a refrigerant | coolant leak detection apparatus. It is a schematic diagram at the time of connecting the contact of the some refrigerant | coolant detection apparatus in a modification in series.

  Embodiments of a refrigerant leakage detection system according to the present invention will be described below in detail with reference to the drawings. Below, the refrigerant | coolant leakage detection system which detects the refrigerant | coolant leakage in an air conditioning system is demonstrated as an example of a cooling-heat system. In the drawings of the embodiments, the same components are denoted by the same reference numerals.

Embodiment 1 FIG.
FIG. 1 is a schematic configuration diagram of an air-conditioning system 10 according to Embodiment 1 of the present invention. The air conditioning system 10 of the present embodiment performs cooling and heating in the building 100 by performing a vapor compression refrigeration cycle operation. As shown in FIG. 1, the air conditioning system 10 includes an outdoor unit 1 installed outside the building 100, a shunt controller 2 installed inside the building 100, and a plurality of indoor units 31, 32, and 33. . In FIG. 1, a solid line connecting the components indicates a refrigerant pipe, and a broken line indicates a communication line.

  The outdoor unit 1 supplies cold or warm heat into the building 100 and is installed outside the building 100. The outdoor unit 1 constitutes a part of a refrigerant circuit, and includes a compressor 11, an outdoor heat exchanger (not shown), a four-way valve (not shown), an expansion valve (not shown), and outdoor heat. A fan 12 for supplying air to the exchanger and a control device 13 are provided. The operation capacity of the compressor 11 and the rotational speed of the fan 12 are controlled by the control device 13. The control device 13 is communicably connected to a control device (not shown) and the centralized controller 40 provided in the branch controller 2 and the indoor units 31 to 33, respectively.

  The diversion controller 2 is disposed between the outdoor unit 1 and the indoor units 31 to 33, and controls the flow of the refrigerant to the indoor units 31 to 33. The shunt controller 2 is disposed, for example, in the back of the ceiling of the monitoring room 101 of the building 100.

  The indoor units 31 to 33 constitute a refrigerant circuit together with the outdoor unit 1, and each include an indoor heat exchanger (not shown) and a fan (not shown) for supplying air to the indoor heat exchanger. The indoor unit 31 is embedded in the ceiling of the living room 102 and cools and heats the living room 102. The indoor unit 32 is installed by being embedded in the ceiling of the living room 103, and performs cooling and heating of the living room 103. The indoor unit 33 is installed on the floor of the living room 103 and performs cooling and heating of the living room 103 together with the indoor unit 32.

  The indoor units 31, 32 and 33 are provided with remote controllers 41, 42 and 43, respectively. By operating the remote controllers 41 to 43, the operation / stop of the indoor units 31 to 33, the operation mode, the set temperature, and the like can be controlled. In the monitoring room 101, a centralized controller 40 that manages the entire air conditioning system 10 is disposed. The centralized controller 40 communicates with the branch controller 2 and the control devices (not shown) of the indoor units 31 to 33 via the outdoor unit 1, and information such as the operation state of the branch controller 2 and the indoor units 31 to 33. To get.

  Next, the refrigerant leak detection system in the air conditioning system 10 of the present embodiment will be described. As shown in FIG. 1, a plurality of refrigerant sensors 51, 52, 53, and 54 for detecting refrigerant are arranged in a building 100. The plurality of refrigerant sensors 51 to 54 are, for example, semiconductor-type gas detection sensors, and detect the same or equivalent gas as the refrigerant used in the refrigerant circuit of the air conditioning system 10. The refrigerant sensor 51 is incorporated in the flow dividing controller 2 and is disposed in or around the product, such as a pipe joint. The refrigerant sensor 52 is installed on the floor of the living room 102 or a wall near the floor. The refrigerant sensor 53 is incorporated in the indoor unit 32 of the living room 103 and is disposed, for example, in the vicinity of the indoor heat exchanger. The refrigerant sensor 54 is installed on the floor of the living room 103 or a wall near the floor. In addition, the refrigerant | coolant sensors 51-54 may be installed so that removal is possible. As a result, it can be exchanged in the event of a failure or when the reaction has deteriorated due to prolonged use.

  Detection signals of the refrigerant sensors 51, 52, 53, and 54 are output to the refrigerant leakage detection devices 61, 62, 63, and 64, respectively. The refrigerant leakage detection devices 61 to 64 determine the presence or absence of refrigerant leakage based on the detection signals of the refrigerant sensors 51 to 54, and activate the safety device when it is determined that refrigerant leakage has occurred. The refrigerant leak detection device 61 is disposed in the monitoring chamber 101 and determines whether or not there is a refrigerant leak from the branch controller 2 based on the detection signal of the refrigerant sensor 51. The refrigerant leak detection device 62 is arranged in the living room 102 and determines whether or not there is a refrigerant leak from the indoor unit 31 based on the detection signal of the refrigerant sensor 52. The refrigerant leak detection device 63 is disposed in the living room 103 and determines whether or not there is a refrigerant leak from the indoor unit 32 based on the detection signal of the refrigerant sensor 53. The refrigerant leak detection device 64 is arranged in the living room 103 and determines whether or not there is a refrigerant leak from the indoor unit 33 based on the detection signal of the refrigerant sensor 54. In addition, the refrigerant | coolant leak detection apparatuses 61-64 may be provided independently of the branch controller 2 and the indoor units 31-33, or may be integrated in the branch controller 2 or the indoor units 31-33.

  In addition, alarm devices 71, 72, and 73 are installed in the monitoring room 101 and the living rooms 102 and 103 to notify the user of refrigerant leakage. The alarm device 71 is installed in the monitoring room 101 and emits an alarm sound when refrigerant leakage is detected by the refrigerant leakage detection device 61. The alarm device 72 is installed in the living room 102 and emits an alarm sound when refrigerant leakage is detected by the refrigerant leakage detection device 62. The alarm device 73 is installed in the living room 103 and emits an alarm sound when refrigerant leakage is detected by the refrigerant leakage detection device 63 or 64. Here, the alarm device 73 may be set to emit a different alarm sound for each refrigerant sensor in which refrigerant leakage is detected. Specifically, the alarm device 73 may vary the level of the alarm sound between when the refrigerant leak is detected by the refrigerant sensor 53 and when the refrigerant leak is detected by the refrigerant sensor 54. Thereby, even when a plurality of refrigerant sensors are arranged in the living room 103, the occurrence location of the refrigerant leakage can be estimated by the pitch of the alarm 73. The alarm devices 71 to 73 may be incorporated in the refrigerant leak detection devices 61 to 64, respectively.

  In addition, shut-off valves 81, 82, and 83 are arranged as safety devices in the refrigerant pipes that connect the diversion controller 2 and the indoor units 31, 32, and 33, respectively. The shut-off valve 81 is disposed between the branch controller 2 and the indoor unit 31 and is closed when refrigerant leakage is detected by the refrigerant leakage detection device 62. The shut-off valve 82 is disposed between the branch controller 2 and the indoor unit 32, and is closed when refrigerant leakage is detected by the refrigerant leakage detection device 63. The shut-off valve 83 is disposed between the flow dividing controller 2 and the indoor unit 33, and is closed when refrigerant leakage is detected by the refrigerant leakage detection device 64.

  Furthermore, ventilation devices 90, 91 and 92 are installed in the monitoring room 101 and the living rooms 102 and 103 as safety devices, respectively. The ventilators 90 to 92 are propeller fans driven by, for example, a fan motor (not shown). The ventilation device 90 is installed on the wall surface between the monitoring room 101 and the living room 102 and is activated when refrigerant leakage is detected by the refrigerant leakage detection device 61 to ventilate the refrigerant in the monitoring room 101. The ventilator 90 may be disposed on the wall facing the outside of the monitoring room 101 and discharge the refrigerant in the monitoring room 101 to the outside. The ventilation device 91 is installed on the wall surface of the living room 102 and is activated when refrigerant leakage is detected by the refrigerant leakage detection device 62, and discharges the refrigerant in the living room 102 to the outdoors. The ventilation device 92 is installed on the wall surface of the living room 103 and is activated when refrigerant leakage is detected by the refrigerant leakage detection device 63 or 64, and discharges the refrigerant in the living room 103 to the outdoors.

  FIG. 2 is a diagram illustrating an internal configuration of the refrigerant leak detection device 62 and devices connected to the refrigerant leak detection device 62. The internal configuration of the refrigerant leak detection devices 61, 63 and 64 is substantially the same as that of the refrigerant leak detection device 62, and here, the refrigerant leak detection device 62 will be described as a representative. As shown in FIG. 2, the refrigerant leakage detection device 62 includes a detection circuit 621 that detects an output from the refrigerant sensor 52, a control unit 622 that controls the entire refrigerant leakage detection device 62, and a drive circuit 623 that drives a safety device. And a power supply circuit 624 that supplies power to each unit, a storage unit 625, a communication unit 626 that communicates with the indoor unit 31, and signal output units 627, 628, and 629 connected to the safety device.

  The detection circuit 621 detects the detection signal of the refrigerant sensor 52, performs A / D conversion, and outputs it to the control means 622 as an output value such as a DC voltage value. The control means 622 controls each part of the refrigerant leakage detection device 62, and is constituted by a microcomputer, for example. In another embodiment, the detection circuit 621 may be included in the control unit 622. The drive circuit 623 drives the signal output means 627, 628 and 629 in response to the control signal from the control means 622. An alarm device 72 is connected to the signal output means 627, a cutoff valve 81 is connected to the signal output means 628, and a ventilator 91 is connected to the signal output means 629. In addition, you may further provide the signal output means connected to apparatuses other than the alarm device 72, the cutoff valve 81, and the ventilation apparatus 91. FIG.

  The power supply circuit 624 converts, for example, an AC power supply AC, which is a commercial power supply, into a DC power supply such as DCI2V and DC5V, and supplies it to the drive circuit 623 and the control means 622. In the present embodiment, the refrigerant leakage detection device 62 is supplied with power independently of the indoor unit 31 and always operates. However, in another embodiment, the power supply circuit for the indoor unit 31 is used. May be configured to operate in conjunction with the indoor unit 31. The storage means 625 is constituted by, for example, a semiconductor memory and stores various data and programs used for controlling the refrigerant leakage detection device 62. The communication unit 626 transmits and receives data to and from the control device (not shown) of the indoor unit 31 by wired or wireless communication. The communication unit 626 can communicate with the remote controller 41 and the centralized controller 40 via the indoor unit 31. The communication unit 626 may be configured to directly communicate with the centralized controller 40 or the remote controller 41.

  FIG. 3 is a flowchart showing the flow of the refrigerant leakage detection process by the refrigerant leakage detection device 62. In this process, first, the detection signal of the refrigerant sensor 52 is acquired by the detection circuit 621, converted into an output value, and output to the control means 622 (S1). Next, the control means 622 compares the output value with a set value that serves as a criterion for refrigerant leakage (S2). The set value is a value defined in an industry standard or the like, and is stored in the storage unit 625. However, the setting value may be variably adjusted according to the installation situation at the site. In addition, a mechanism that cannot be adjusted by a general user prevents easy relaxation of refrigerant leakage detection. If the output value is less than the set value (S2: NO), it is determined that no refrigerant leakage has occurred, and the process returns to step S1.

  On the other hand, when the output value is greater than or equal to the set value (S2: YES), it is determined that refrigerant leakage has occurred, and a leakage signal is transmitted from the control means 622 to the drive circuit 623. Then, the signal output means 627 is driven by the drive circuit 623 that has received the leakage signal, and the alarm device 72 is activated (S3). Thereby, an alarm sound is emitted from the alarm device 72. Further, the signal output means 628 and 629 are driven by the drive circuit 623, and the safety device is activated (S4). Specifically, the shutoff valve 81 connected to the signal output means 628 is closed, and the ventilator 91 connected to the signal output means 629 is driven. Here, since the shutoff valve is not connected to the refrigerant leak detection device 61, a signal instructing the outdoor unit 1 to stop the compressor 11 is transmitted instead of operating the shutoff valve. Thereby, the flow of the refrigerant to the diversion controller 2 can be stopped.

  And the signal which notifies that the refrigerant | coolant leakage generate | occur | produced by the control means 622 is transmitted to the indoor unit 31 via the communication means 626 (S5). The notification signal is transmitted from the indoor unit 31 to the centralized controller 40 via the outdoor unit 1. Further, the date and time when the refrigerant leakage occurred and the output value of the refrigerant sensor 52 at that time are stored in the storage means 625 by the control means 622 (S6).

  As a result, when the refrigerant leak is detected by the refrigerant sensor 52, an alarm sound is emitted from the alarm device 72 to notify the user of the refrigerant leak, and the shutoff valve 81 and the ventilation device 91 are operated to operate the indoor unit 31. It is possible to stop the flow of the refrigerant into the room and discharge the refrigerant leaking into the living room 102 to the outside.

  In addition, the central controller 40 grasps the occurrence of the refrigerant leak by transmitting a signal notifying that the refrigerant leak has been detected by the refrigerant leak detection device 62 to the central controller 40 via the indoor unit 31. Can do. Here, in the air conditioning system 10 of the present embodiment, in addition to the outdoor unit 1, the shunt controller 2, and the indoor units 31 to 33, the refrigerant sensors 51 to 54, the refrigerant leak detection devices 61 to 64, the alarm devices 71 to 73, Unique addresses are also set for the shut-off valves 81 to 83 and the ventilators 90 to 92, respectively. And in the centralized controller 40, with the driving | running state of each indoor unit 31-33, the refrigerant | coolant sensors 51-54, the refrigerant | coolant leak detection apparatuses 61-64, the alarm devices 71-73, the cutoff valves 81-83, and the ventilation apparatuses 90-92. The state can be grasped, and these can be displayed on the layout diagram.

  FIG. 4 is an example of a layout diagram displayed on the centralized controller 40. The centralized controller 40 includes display means 410 configured with a liquid crystal display or the like. And on the display means 410, the layout of the building 100, the refrigerant leak detection devices 61 to 64 arranged in each room, the refrigerant sensors 51 to 54, the alarm devices 71 to 73, the shutoff valves 81 to 83, and the ventilation devices 90 to An icon indicating 92 is displayed. When the centralized controller 40 receives the signal notifying that the refrigerant leak has been detected, the centralized controller 40 identifies the refrigerant sensor in which the refrigerant leak has been detected, and the alarm device, the shut-off valve, and the ventilator that are activated by the refrigerant leak. Change the color so that it can be displayed or blink. Thereby, the area where the refrigerant leaked is displayed on the display unit 410 so as to be identifiable. As a result, the area at the time of refrigerant leakage can be specified, which can be used for evacuation guidance and quick repair work at the time of refrigerant leakage. The display means 410 includes at least one of refrigerant leakage detection devices 61 to 64, refrigerant sensors 51 to 54, alarm devices 71 to 73, shutoff valves 81 to 83, and ventilation devices 90 to 92 disposed in each room. One should be displayed.

  As described above, according to the present embodiment, even when the plurality of refrigerant sensors 51 to 54 and the refrigerant leak detection devices 61 to 64 are arranged in the building 100, the location or the scale of occurrence of the refrigerant leak is quickly detected. I can grasp it. Thereby, appropriate evacuation guidance etc. can be performed and safety can be improved.

  In the first embodiment, one refrigerant sensor is connected to one refrigerant leak detection device. However, the present invention is not limited to this, and one refrigerant leak detection device includes a plurality of refrigerant leak detection devices. The refrigerant sensor may be connected. FIG. 5 is a diagram illustrating devices arranged in the living room 102 according to the modification of the first embodiment. In the example of FIG. 5, a refrigerant sensor 55 incorporated in the indoor unit 31 is provided in addition to the refrigerant sensor 52 arranged near the floor of the living room 102. The refrigerant leak detection device 62 receives the detection signals of the refrigerant sensor 52 and the refrigerant sensor 55, respectively, compares the detection signals with the set values, and determines that the refrigerant leak has occurred when either of them exceeds the set value. .

  In addition, when refrigerant sensors are arranged on the ceiling and the floor as in the example of FIG. 5, it is possible to estimate the refrigerant leakage speed and amount by calculating the time difference at which each refrigerant sensor operates. . For example, when the time difference during which the refrigerant sensors 52 and 55 are operated is small, the refrigerant leakage speed is fast and there is a possibility that a large amount of leakage occurs. Therefore, in this case, it is determined that immediate evacuation is necessary, and an alarm is issued from the alarm device 72 so as to perform immediate evacuation. On the other hand, if the time difference between the operation of the refrigerant sensors 52 and 55 is large, or if only one of the detection signals of the refrigerant sensors 52 and 55 is greater than or equal to the set value, the refrigerant leakage speed is slow and a small amount of leakage occurs. There is a possibility. Therefore, in this case, it is determined that there is no need for immediate evacuation, and instead of issuing an alarm sound from the alarm device 72, a display indicating that maintenance is to be performed or an instruction by voice may be performed. Further, the sound and volume of the alarm device 72 may be changed according to the leakage speed and leakage amount of the refrigerant.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described. 10 A of air conditioning systems of Embodiment 2 differ from Embodiment 1 in the point provided with 1 A of heat source units instead of the outdoor unit 1. FIG. FIG. 6 is a schematic configuration diagram of an air conditioning system 10A in the present embodiment. As shown in FIG. 6, the heat source machine 1 </ b> A is arranged in a machine room 104 in the building 100. The heat source machine 1A supplies cold or warm heat into the building 100, and includes a compressor 11, a water heat exchanger 14, a four-way valve (not shown), an expansion valve (not shown), and a control. And a device 13. In addition, a cooling tower 15 and a water pump 16 for supplying water to the water heat exchanger 14 are disposed outside the room.

  The machine room 104 is provided with a refrigerant sensor 56, a refrigerant leak detection device 65, an alarm device 74, and a ventilation device 93 in order to detect refrigerant leakage from the heat source unit 1A. The configuration of the refrigerant sensor 56, the refrigerant leak detection device 65, the alarm device 74, and the ventilation device 93 includes the refrigerant sensors 51 to 54, the refrigerant leak detection devices 61 to 64, the alarm devices 71 to 73, and the ventilation devices 90 to 90 in the first embodiment. 92. In the refrigerant leakage detection device 65, the same refrigerant leakage detection process as that in FIG. 3 of the first embodiment is performed. However, the refrigerant leakage detection device 65 activates the ventilation device 93 and stops the operation of the compressor 11 in step S4 of FIG.

  Further, addresses are also set for the refrigerant sensor 56, the refrigerant leakage detection device 65, the alarm device 74, and the ventilation device 93, respectively, and the states of the refrigerant sensor 56, the refrigerant leakage detection device 65, the alarm device 74, and the ventilation device 93 are the centralized controller. It is displayed in 40 layout diagrams.

  As described above, according to the present embodiment, when the heat source unit 1A is provided in the building 100, the central controller 40 can quickly grasp the occurrence of refrigerant leakage in the heat source unit 1A.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described. In the third embodiment, the control unit of the refrigerant leak detection device executes a normal mode for detecting a refrigerant leak at normal times and an inspection mode for checking whether or not the refrigerant leak detection system is operating normally. This is different from the first embodiment. In the following description, the case where the refrigerant leakage detection device 62A in the third embodiment and the refrigerant sensor 52, the alarm device 72, the shut-off valve 81, and the ventilation device 91 connected to the refrigerant leakage detection device 62A are inspected will be described as an example. To do.

  FIG. 7 is a diagram showing an internal configuration of the refrigerant leak detection device 62A and devices connected to the refrigerant leak detection device 62A in the present embodiment. As shown in FIG. 7, the refrigerant leakage detection device 62A includes a detection circuit 621, a control unit 622, a drive circuit 623, a power supply circuit 624, a storage unit 625, and a communication unit 626 similar to those in the first embodiment. In addition to the signal output means 627 to 629, a display means 631 and an operation means 632 are provided. The display means 631 is composed of, for example, an LED. The operation means 632 is constituted by, for example, a slide switch.

  In this embodiment, detection signals from the flow sensor 810 and the wind speed sensor 910 are input to the detection circuit 621 in addition to the detection signal from the refrigerant sensor 52. The flow sensor 810 is attached to the downstream side of the cutoff valve 81 and detects the flow rate of the refrigerant on the downstream side of the cutoff valve 81. The wind speed sensor 910 is attached to the ventilator 91 and detects the wind speed of the ventilator 91.

  The control means 622 executes a normal mode for detecting refrigerant leakage at normal times and an inspection mode for checking whether or not the refrigerant leakage detection system is operating normally. In the normal mode, the refrigerant leakage detection procedure (FIG. 3) of the first embodiment is performed. The control unit 622 includes a mode switching unit 21, an inspection instruction unit 22, a determination unit 23, a display control unit 24, and a time measuring unit 25 that are displayed in FIG. Each of the above units is a functional unit realized by software, and is realized by executing a program by the control unit 622.

  The mode switching unit 21 switches between the normal mode and the inspection mode according to the operation of the operation unit 632. Note that the mode switching unit 21 may switch between the normal mode and the inspection mode based on the operation signal from the centralized controller 40 or the remote controller 41 received via the communication unit 626. In addition, when the mode switching unit 21 is switched to the inspection mode, the mode switching unit 21 transmits a signal instructing the stop of the fan 310 of the indoor unit 31 to the indoor unit 31 via the communication unit 626.

  When the inspection instruction unit 22 is switched to the inspection mode, the inspection instruction unit 22 transmits an inspection signal instructing the driving circuit 623 to perform the inspection. The determination unit 23 determines whether or not each unit is operating normally based on the output value from the detection circuit 621. The inspection result in the determination unit 23 is stored in the storage unit 625 together with the inspection date and time. The display control unit 24 controls the display means 631 to perform a display for prompting inspection and a display indicating the inspection mode state. The timer 25 measures the time after switching to the inspection mode.

  The refrigerant leak detection device 62A and the refrigerant sensor 52, the alarm device 72, the shut-off valve 81, and the ventilation device 91 connected to the refrigerant leak detection device 62A are regularly inspected. For example, the alarm warning inspection of the alarm device 72 is performed at least once a month, and other devices are inspected at least once a year. Therefore, in the present embodiment, when the inspection deadline is approaching, the display control unit 24 displays the display unit 631 to prompt the inspection. It should be noted that the timing at which the display for prompting the inspection is variable, for example, two weeks before the legal inspection deadline, so that it is possible to remember to ask the inspector. In addition, the display control unit 24 may instruct the remote controller 41 or the centralized controller 40 to perform a display for prompting inspection via the communication unit 626, or may transmit it by e-mail through the Internet line. If the e-mail destination is a maintenance inspection company, it is possible to place an order automatically.

  FIG. 8 is a flowchart showing the flow of processing in the inspection mode. This process is started when the mode switching unit 21 switches to the inspection mode. In this process, first, in accordance with an instruction from the display control unit 24, the centralized controller 40 or the remote controller 41 displays the inspection mode (S21). Specifically, “inspection” may be displayed on the remote controller 41 or the centralized controller 40, or an LED indicating the inspection mode may be turned on. Thereby, it can notify outside that it is in inspection mode. When the centralized controller 40 or the remote controller 41 is not connected, it may be displayed on a display unit of a device such as the indoor unit 31 or may be displayed on the display unit 631 of the refrigerant leakage detection device 62A. Further, in addition to the display, the inspection mode may be notified by voice or the like.

  Next, the fan 310 of the indoor unit 31 is stopped by an instruction from the mode switching unit 21 (S22). When the fan 310 of the indoor unit 31 is operating, the refrigerant diffuses and the concentration decreases, so that the refrigerant is difficult to detect. Therefore, the refrigerant is easily detected by stopping the fan 310 in the inspection mode.

  Then, the refrigerant leakage detection device 62A, the refrigerant sensor 52, the alarm device 72, the shutoff valve 81, and the ventilation device 91 are inspected (S23). These inspections may be performed individually for each device, or may be performed in conjunction with all devices. For example, when a large number of refrigerant sensors are connected to the refrigerant leakage detection device 62A, the alarm device 72, the shut-off valve 81, and the ventilation device 91 are separated and individually inspected to reduce the number of inspections. it can. Moreover, since it is not necessary to operate the shut-off valve 81 every time the refrigerant sensor is inspected, the operation of the indoor unit 31 can be continued. Hereinafter, a case where the refrigerant leakage detection device 62A, the refrigerant sensor 52, the alarm device 72, the shut-off valve 81, and the ventilation device 91 are individually checked will be described.

(Inspection of refrigerant sensor 52)
In the inspection of the refrigerant sensor 52, the refrigerant is blown onto the refrigerant sensor 52, and when the determination unit 23 determines that the output value of the refrigerant sensor 52 is equal to or higher than the reference value, the refrigerant sensor 52 and the refrigerant leakage detection device 62A are normal. It is determined to operate. At this time, the output value of the refrigerant sensor 52 may be displayed on the display means 631, the remote controller 41, the centralized controller 40, or the like to determine whether or not the value is an appropriate value. Note that the refrigerant blown to the refrigerant sensor 52 is the same or equivalent refrigerant as the refrigerant used in the refrigerant circuit of the air conditioning system 10. However, in the inspection mode, the operation of the refrigerant sensor 52 may be confirmed using a refrigerant having a low concentration.

  Here, when the refrigerant sensor to be inspected is installed in the indoor unit 32 as in the refrigerant sensor 53 shown in FIG. 1, a tool or the like is used to spray the refrigerant on the refrigerant sensor 53. It is necessary to remove the exterior panel of the indoor unit 32, which is very troublesome. Therefore, an opening for blowing gas to the refrigerant sensor 53 may be provided in a housing (for example, an exterior panel) of the indoor unit 32. FIG. 9 is a schematic view of the state in which the refrigerant sensor 53 and the refrigerant leakage detection device 63 are accommodated in the indoor unit 32 as viewed from the side. In the example shown in FIG. 9, the casing 321 of the indoor unit 32 is the casing of the refrigerant leakage detection device 63 and the refrigerant sensor 53. The indoor unit 32 is arranged with a casing 321 embedded in the ceiling. An opening 322 is formed at a position of the housing 321 facing the refrigerant sensor 53. The opening 322 may be a small hole into which a nozzle for blowing refrigerant gas is inserted. The opening 322 is normally closed, and can be opened without a tool during inspection. Thereby, even when the refrigerant sensor 53 is incorporated in the indoor unit 32, the inspection can be performed without removing the exterior panel of the indoor unit 32, and the working efficiency is improved.

(Inspection of alarm device 72)
In the inspection of the alarm device 72, an inspection signal is transmitted from the inspection instruction unit 22 to the drive circuit 623, and whether or not the alarm device 72 and the refrigerant leakage detection device 62A are normally operated based on the alarm device 72 is notified. Check. Specifically, the drive circuit 623 that has received the inspection signal drives the alarm device 72 by driving the signal output means 627. When the alarm device 72 emits an alarm sound, it is determined that the alarm device 72 is operating normally. Note that a microphone may be attached to the alarm device 72, connected to the refrigerant leakage detection device 62A, and the operation of the alarm device 72 may be confirmed by the determination unit 23 based on the output value of the microphone. Furthermore, an operation switch may be provided in the alarm device 72 and it may be confirmed whether or not the alarm is issued by operating the operation switch. In this case, the inspection can be performed independently from the refrigerant leakage detection device 62A.

  Further, the drive circuit 623 may operate the alarm device 72 at a lower volume in the inspection mode than in the normal mode. As a result, it is possible to prevent reporting at a volume higher than necessary during the inspection.

(Inspection of shut-off valve 81)
In the inspection of the shut-off valve 81, an inspection signal is transmitted from the check instructing unit 22 to the drive circuit 623, and whether or not the shut-off valve 81 and the refrigerant leakage detection device 62A operate normally is determined based on the output value of the flow sensor 810. Check. Specifically, the drive circuit 623 that has received the inspection signal drives the signal output means 628 to operate the shut-off valve 81. When the shutoff valve 81 is normally closed, the flow rate detected by the flow sensor 810 decreases. The determination unit 23 determines whether the cutoff valve 81 operates normally based on the output value of the flow sensor 810 by opening / closing the cutoff valve 81.

  As another embodiment, a pressure sensor may be attached to the downstream side of the shutoff valve 81 instead of the flow sensor 810, and the operation of the shutoff valve 81 may be confirmed based on a change in pressure. Further, a flow sensor or a pressure sensor may be attached before and after the shutoff valve 81, and the operation of the shutoff valve 81 may be confirmed based on a difference in flow rate or pressure before and after the shutoff valve 81.

(Inspection of ventilation device 91)
In the inspection of the ventilation device 91, an inspection signal is transmitted from the inspection instruction unit 22 to the drive circuit 623, and whether or not the ventilation device 91 and the refrigerant leakage detection device 62A operate normally based on the output value of the wind speed sensor 910. Check. Specifically, the drive circuit 623 that has received the inspection signal drives the signal output means 629 to operate the ventilation device 91. When the ventilation device 91 operates normally, the wind speed detected by the wind speed sensor 910 increases. The determination unit 23 determines whether the ventilator 91 operates normally based on the output value of the wind speed sensor 910.

  As another embodiment, an inspection signal may be transmitted from the inspection instruction unit 22 to the drive circuit 623, and it may be visually confirmed whether or not the ventilation device 91 rotates. Moreover, it replaces with the wind speed sensor 910, a flow sensor may be attached to the ventilator 91, and operation | movement confirmation of the ventilator 91 may be performed from the change of flow volume.

  In addition, the inspection method of each apparatus is not limited to the above, and various changes are possible. Further, it is not necessary to inspect all of the refrigerant sensor 52, the alarm device 72, the shutoff valve 81, and the ventilation device 91. May be checked. In addition, when performing inspection with all the devices linked, the alarm device 72, the shut-off valve 81, and the ventilation device 91 are activated when the refrigerant is sprayed on the refrigerant sensor 52 and the output value reaches a predetermined concentration. You can confirm.

  The inspection result in the determination unit 23 and the output value of each sensor may be displayed on the display means 631, the remote controller 41 or the centralized controller 40.

  Next, it is determined whether or not to end the inspection mode (S24). Here, it is determined whether or not the inspection mode has been switched to the normal mode based on the operation of the operation means 632, the centralized controller 40, or the remote controller 41. When the inspection mode is ended (S24: YES), the inspection date or inspection date and time and the inspection result are stored in the storage means 625 (S26). The inspection result stored here is the pass / fail of the operation check of the refrigerant sensor 52, the alarm device 72, the shutoff valve 81, and the ventilation device 91, or the refrigerant sensor 52, the flow sensor 810, the wind speed sensor 910, and the output value of the microphone. . Further, by storing the concentration of the refrigerant gas used for the inspection in association with the actually measured value of the refrigerant sensor 52, it is possible to record the sensing accuracy.

  Further, the inspection date and time and the inspection result may be stored not only in the storage unit 625 but also in an external memory such as an SD card (registered trademark). Alternatively, the inspection result and the inspection date / time may be transmitted to the remote controller 41, the centralized controller 40, or other external devices via the communication unit 626. Further, the inspection date and the inspection result may be output as a form. As a form output method, the refrigerant leakage detection device 62A may be provided with a form output means, or the inspection date and result and the inspection result are transmitted to an external device having a form output function via the communication means 626, and the external device You may instruct to output the check date and the check result.

  On the other hand, when the inspection mode is not terminated (S24: NO), it is determined whether or not the inspection time has elapsed (S25). And when inspection time has not passed (S25: NO), it returns to step S24. Here, the inspection time is a time required for performing the inspection, and is set in advance and stored in the storage unit 625. If the inspection time has elapsed (S25: YES), the process proceeds to step S26, and the inspection date and result and the inspection result are stored in the storage means 625 (S26). In this way, when the predetermined time has elapsed, the inspection mode is automatically terminated, so that it is possible to prevent forgetting to switch to the normal mode. It should be noted that when the inspection time has elapsed, the return to the normal mode may be notified by display or sound. Furthermore, the user may be prompted to input an extension of the inspection time, and when there is an input of an extension of the inspection time, the inspection time may be extended and the inspection may be continued.

  Then, the fan 310 of the indoor unit 31 is activated (S27), the display indicating the inspection mode of the remote controller 41, the centralized controller 40 or the display means 631 is turned off (S28), and the inspection mode is terminated. Note that the display indicating the inspection mode may be turned off, and the return to the normal mode may be notified by display or sound. Thereby, it can be recognized that the inspector has returned to the normal mode.

  Moreover, you may complete | finish inspection mode in the middle of the inspection of step S23. In this case, how far the inspection has been performed may be stored in the storage unit 625, and the inspection may be continued from the next time the inspection mode is selected.

  As described above, according to the present embodiment, the inspection date and time and the inspection result in the inspection mode can be stored and displayed as data, or the form can be output to confirm that the inspection has been carried out reliably and its contents. be able to.

  In the second embodiment, the single refrigerant sensor 52 is inspected. However, the present invention is not limited to this. For example, the refrigerant sensors 51 to 54 in the air conditioning system 10 may be removed, put together in a container, and the reaction may be confirmed by spraying a refrigerant for inspection. With such a configuration, when there are a large number of refrigerant sensors, the inspection work can be performed efficiently.

  Further, the refrigerant sensor 52 may be calibrated based on the output value of the refrigerant sensor 52. Specifically, the concentration of the refrigerant sprayed on the refrigerant sensor 52 and the measured value of the refrigerant sensor 52 are displayed on the remote controller 41, the centralized controller 40, or the display means 631. Then, while watching the display, the refrigerant sensor 52 can be calibrated by operating the remote controller 41, the centralized controller 40 or the operating means 632 to increase or decrease the detection level of the refrigerant sensor 52. Alternatively, the refrigerant sensor 52 may be calibrated by bringing a separately calibrated densitometer and comparing and adjusting the values. Furthermore, two refrigerant | coolant sensors arrange | positioned at the same place may be connected to the refrigerant | coolant leak detection apparatus 62A, and these output values may be compared and comprised.

  Further, a mechanism for leaking a small amount of the refrigerant of the indoor unit 31 may be provided, and the refrigerant sensor 52 may be inspected using the refrigerant leaked from the indoor unit 31 in the inspection mode. In this case, the inspection can be automatically performed without blowing the refrigerant to the refrigerant sensor 52.

  In the second embodiment, the fan 310 of the indoor unit 31 is stopped in step S22 of the inspection mode. However, the operation of the indoor unit 31 may be stopped. Specifically, in step S22, the shutoff valve 81 may be closed to stop the refrigerant flow to the indoor unit 31. Moreover, you may stop not only the indoor unit 31 but the other indoor units 32 or 33, or the outdoor unit 1, the shunt controller 2, and the indoor units 31-33 of the same refrigerant system. Moreover, when there are a plurality of refrigerant systems with a plurality of outdoor unit heat source units, all the refrigerant systems may be stopped. It may be possible for the inspector to select which unit or system to stop.

Embodiment 4 FIG.
Next, a fourth embodiment of the present invention will be described. The fourth embodiment is different from the first embodiment in that the refrigerant sensor and the detection circuit are duplicated. FIG. 10 is a diagram showing an internal configuration of the refrigerant leak detection device 62B and devices connected to the refrigerant leak detection device 62B in the present embodiment. As shown in FIG. 10, the refrigerant leakage detection device 62B of the present embodiment includes two detection circuits 621a and 621b, and refrigerant sensors 52a and 52b are connected to the two detection circuits 621a and 621b, respectively. The two detection circuits 621a and 621b have the same specifications.

  The refrigerant sensors 52a and 52b are arranged at the same place (for example, the floor of the living room 102 or a wall near the floor). The refrigerant sensor 52a is an expensive high precision sensor, and the refrigerant sensor 52b is an inexpensive low precision sensor. The control means 622 compares the output values of the detection circuits 621a and 621b with the set values, respectively, and determines that refrigerant leakage has occurred when either of them is greater than or equal to the set value. Thus, by doubling the refrigerant sensor and the detection circuit, it is possible to detect refrigerant leakage even when any of the refrigerant sensors or the detection circuit is in an abnormal state.

  FIG. 11 is a graph showing the transition of the output values of the refrigerant sensors 52a and 52b. In FIG. 11, the vertical axis indicates the sensor output value, and the horizontal axis indicates time. The output value of the refrigerant sensor 52a is indicated by a solid line, and the output value of the refrigerant sensor 52b is indicated by a broken line. Here, when an abnormality occurs in the refrigerant sensor 52a or the detection circuit 621a, the output value is in a state where the output value is fixed or only slightly fluctuated. Then, when the output value of the refrigerant sensor 52b fluctuates but the output value of the refrigerant sensor 52a is fixed or slightly fluctuated, it can be determined that an abnormality has occurred in the refrigerant sensor 52a or the detection circuit 621a.

  As described above, according to the present embodiment, it is possible to detect refrigerant leakage even when any refrigerant sensor or detection circuit is in an abnormal state by duplicating the refrigerant sensor and the detection circuit. Reliability is improved. Further, by comparing the output values of the two refrigerant sensors, it is possible to determine which refrigerant sensor or detection circuit is in an abnormal state.

Embodiment 5. FIG.
Next, a fifth embodiment of the present invention will be described. The fifth embodiment is different from the fourth embodiment in that the detection circuit is duplicated for one refrigerant sensor. FIG. 12 is a diagram showing an internal configuration of the refrigerant leak detection device 62C and devices connected to the refrigerant leak detection device 62C in the present embodiment. As shown in FIG. 12, the refrigerant leakage detection device 62 </ b> C of the present embodiment includes two detection circuits 621 a and 621 b corresponding to one refrigerant sensor 52.

  The control means 622 compares the output values of the detection circuits 621a and 621b with the set values, respectively, and determines that refrigerant leakage has occurred when either of them is greater than or equal to the set value. Thus, by doubling the detection circuit, it is possible to detect refrigerant leakage even when any of the refrigerant sensors or the detection circuit is in an abnormal state. Further, as in the fourth embodiment, it is possible to determine in which detection circuit an abnormality has occurred based on fluctuations in the output values from the detection circuits 621a and 621b.

  As described above, according to the present embodiment, it is possible to detect refrigerant leakage even when one of the detection circuits becomes an abnormal state by duplicating the detection circuit, and reliability is improved. Further, by using one refrigerant sensor that is relatively unlikely to cause an abnormality, it is possible to reduce the number of parts and the cost.

Embodiment 6 FIG.
Next, a sixth embodiment of the present invention will be described. The sixth embodiment is different from the first embodiment in that the presence or absence of abnormality of the detection circuit is determined during normal operation. FIG. 13 is a diagram showing an internal configuration of the refrigerant leak detection device 62D and devices connected to the refrigerant leak detection device 62D in the present embodiment. As shown in FIG. 13, the refrigerant leakage detection device 62D of the present embodiment further includes an input switching circuit 630. A detection signal of the refrigerant sensor 52 and a reference voltage (for example, 2.5 V) from the power supply circuit 624 are input to the input switching circuit 630. The input switching circuit 630 periodically switches the detection signal and reference voltage of the refrigerant sensor 52 under the control of the control means 622 and outputs the switching signal to the detection circuit 621.

  The control unit 622 monitors the output value of the detection circuit 621, and determines that the detection circuit 621 has failed when the output value when the reference voltage is input is different from the reference voltage. When it is determined that the detection circuit 621 has failed, the control unit 622 transmits a failure signal to the drive circuit 623. The drive circuit 623 that has received the failure signal drives the signal output means 628 to close the shut-off valve 81, drives the signal output means 627 to operate the alarm device 72, and issues an alarm for notifying the failure.

  As described above, according to the present embodiment, an abnormality in the detection circuit can be quickly found, and the reliability can be improved.

Embodiment 7 FIG.
Next, a seventh embodiment of the present invention will be described. The seventh embodiment is different from the sixth embodiment in that the detection signal from the refrigerant sensor 52 and the reference voltage are two parallel inputs, and the input switching circuit and the detection circuit are duplicated. FIG. 14 is a diagram showing an internal configuration of the refrigerant leak detection device 62E and devices connected to the refrigerant leak detection device 62E in the present embodiment. As shown in FIG. 14, the refrigerant leak detection device 62E of the present embodiment includes two detection circuits 621a and 621b and two input switching circuits 630a and 630b. A detection signal of the refrigerant sensor 52 and a reference voltage (for example, 2.5 V) from the power supply circuit 624 are input to the input switching circuits 630a and 630b, respectively. The input switching circuits 630a and 630b periodically switch the detection signal and reference voltage of the refrigerant sensor 52 under the control of the control means 622 and output them to the detection circuits 621a and 621b, respectively. In FIG. 14, the communication line between the control means 622 and the input switching circuits 630a and 630b is omitted.

  The control unit 622 monitors the output values of the detection circuits 621a and 621b, and determines that the detection circuit 621a or 621b has failed when the output value when the reference voltage is input is different from the reference voltage. When it is determined that the detection circuit 621a or 621b has failed, the control unit 622 transmits a failure signal to the drive circuit 623. The drive circuit 623 that has received the failure signal drives the signal output means 628 to close the shut-off valve 81, drives the signal output means 627 to operate the alarm device 72, and issues an alarm for notifying the failure.

  As described above, according to the present embodiment, an abnormality in the detection circuit can be quickly found. Further, by duplicating the detection circuit, it is possible to detect refrigerant leakage even when a failure occurs in any one of the detection circuits, and it is possible to further improve the reliability.

  The above is the description of the embodiment of the present invention. However, the present invention is not limited to the configuration of the above embodiment, and various modifications or combinations are possible within the scope of the technical idea. For example, in the first and second embodiments, the presence or absence of the refrigerant leakage is determined based on the output value of the refrigerant sensor 52 that directly detects the refrigerant gas. However, instead of the refrigerant sensor 52, the output of a pressure sensor, a temperature sensor, or the like. The presence or absence of refrigerant leakage may be determined based on the value. Specifically, the control unit 622 may determine the presence or absence of refrigerant leakage by a known method based on the refrigerant temperature or the refrigerant pressure detected by the pressure sensor or the temperature sensor.

  Moreover, the refrigerant | coolant leak detection apparatus in Embodiment 3-7 may be used not only for cold-heating systems, such as the air conditioning system 10, but for single-piece | units, such as room air conditioners and refrigerators, for example. In the fourth, fifth and sixth embodiments, the refrigerant sensor or the detection circuit is configured to be duplicated, but it may be tripled or more.

  Moreover, it is good also as a structure which connects the some refrigerant | coolant detection apparatus arrange | positioned in a some room, and manages with a detection system. In the case of connecting a plurality of refrigerant detection devices, conventionally, it is assumed that the contact is “closed” at the time of leakage and failure, and the contact is “open” at the time of normal operation and power failure. However, in this case, it is necessary to use each contact in parallel connection, and workability is deteriorated. Even if there is a connection leak at the time of construction, the logic of signal = “open” = “normal” is obtained. Therefore, the contact logic at the time of leakage may be “open” and a plurality of contacts may be connected in series. FIG. 15 is a schematic diagram when contacts of a plurality of refrigerant leak detection devices 60 are connected in series. In the example of FIG. 15, the contact output is opened at the time of leakage, and the contact Y is energized when the signal output means X in the detection system 500 is not excited. Thereby, the alarm device 510 is turned ON.

DESCRIPTION OF SYMBOLS 1 Outdoor unit, 1A heat source machine, 2 split flow controller, 10, 10A air conditioning system, 11 compressor, 12, 310 fan, 13 control apparatus, 14 water heat exchanger, 15 cooling tower, 16 water pump, 21 mode switching part, 22 inspection instruction unit, 23 determination unit, 24 display control unit, 25 timing unit, 31, 32, 33 indoor unit, 40 centralized controller, 41, 42, 43 remote control, 51, 52, 52a, 52b, 53, 54, 55 , 56 Refrigerant sensor, 60, 61, 62, 62A, 62B, 62C, 62D, 62E, 63, 64, 65 Refrigerant leak detector, 71, 72, 73, 74 Alarm, 81, 82, 83
Shut-off valve, 90, 91, 92, 93 Ventilation device, 100 building, 101 monitoring room, 102, 103 living room, 104 machine room, 321 housing, 322 opening, 410, 631 display means, 500 detection system, 510 alarm, 621, 621a, 621b detection circuit, 622 control means, 623 drive circuit, 624 power supply circuit, 625 storage means, 626
Communication means, 627, 628, 629, X signal output means, 630, 630a, 630b
Input switching circuit, 632 operation means, 810 flow rate sensor, 910 wind speed sensor, AC AC power supply, Y contact.

The refrigerant leakage detection device according to the present invention determines the presence or absence of refrigerant leakage based on a plurality of detection circuits that detect the output of one refrigerant sensor and the outputs from the plurality of detection circuits, and the abnormality of the plurality of detection circuits Control means for determining the presence or absence of.

Claims (5)

A plurality of detection circuits for detecting the output of the refrigerant sensor;
Control means for determining the presence or absence of refrigerant leakage based on outputs from the plurality of detection circuits, and determining the presence or absence of abnormality of the plurality of detection circuits;
A refrigerant leakage detection device comprising: The plurality of detection circuits detect outputs from different refrigerant sensors,
The refrigerant leakage detection device according to claim 1, wherein the control unit determines whether or not there is an abnormality in the plurality of detection circuits or the refrigerant sensor based on outputs from the plurality of detection circuits.   The refrigerant leakage detection device according to claim 2, wherein the refrigerant sensors output to the plurality of detection circuits have different accuracy. A detection circuit that alternately detects the output of the refrigerant sensor and the reference voltage;
Based on the output from the detection circuit, it is determined whether there is an abnormality in the detection circuit, and when it is determined that an abnormality has occurred in the detection circuit, a control means for operating a safety device;
A refrigerant leakage detection device comprising: A plurality of the detection circuits are provided,
The control means determines whether there is an abnormality in the plurality of detection circuits based on outputs from the plurality of detection circuits, and determines that an abnormality has occurred in any of the plurality of detection circuits. The refrigerant leakage detection device according to claim 4, wherein the safety device is operated.

Images