air conditioning equipment

Abstract

To provide an air conditioner capable of: curbing performance deterioration due to aging; detecting a leakage of a coolant without erroneous detection; and improving safety against the leakage of the coolant.SOLUTION: In an air conditioner, an indoor heat exchanger 14 installed in an indoor unit 10, an outdoor heat exchanger installed in an outdoor unit 30, a compressor, and a reducer are connected to each other through coolant piping and a flammable coolant is used as a cooling medium. The air conditioner has a first coolant detection sensor 40 and a second coolant detection sensor which detect a leakage of the coolant. The second coolant detection sensor is provided with: an external air blocking unit 45 which blocks a sensor section of the second coolant detection sensor 41 from external air; and a lifting mechanism 48 which lifts external air blocking with the external air blocking unit 45.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an air conditioning apparatus. [Background technology]

[0002] Conventionally, Patent Document 1 describes an air conditioner equipped with a detection sensor that detects the concentration of a refrigerant, in which multiple refrigerant detection sensors that detect the leakage of flammable refrigerant are provided in the same location. As a result, one of two detection sensors with a relatively short lifespan is used, and if the other refrigerant detection sensor breaks down, the other is used, thereby extending the lifespan (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-224612 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides an air conditioner that can suppress performance degradation due to aging, detect refrigerant leaks without false detection, and improve safety against refrigerant leaks. [Means for solving the problem]

[0005] In order to achieve the above object, the air conditioning apparatus of the present disclosure is an air conditioning apparatus that connects an indoor heat exchanger of an indoor unit and an outdoor heat exchanger, compressor, and throttling device of an outdoor unit via refrigerant piping, and uses a flammable refrigerant as the refrigerant.The air conditioning apparatus is equipped with a first refrigerant detection sensor and a second refrigerant detection sensor that detect refrigerant leakage, and the second refrigerant detection sensor is equipped with an outside air blocking device that blocks outside air from reaching the sensor section of the second refrigerant detection sensor, and a release mechanism that releases the blockage of outside air by the outside air blocking device. [Effects of the Invention]

[0006] According to the present disclosure, by blocking outside air with an outside air blocking device while the first refrigerant detection sensor is operating, deterioration of the second refrigerant detection sensor over time can be suppressed. As a result, when the second refrigerant detection sensor is operated, refrigerant leaks can be detected without false detection due to deterioration over time, thereby improving safety against refrigerant leaks. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a side cross-sectional view of an indoor unit showing an embodiment of an air conditioning apparatus according to Embodiment 1. [Figure 2] FIG. 1 is a schematic diagram illustrating a refrigerant detection sensor according to a first embodiment of the present invention; [Figure 3] Block diagram showing a control configuration of the first embodiment. [Figure 4] Graph showing an example of deterioration determination of the refrigerant detection sensor according to the first embodiment DETAILED DESCRIPTION OF THE INVENTION

[0008] (Findings that formed the basis of this disclosure) At the time the inventors came up with the idea for this disclosure, there was a technology in place that provided multiple refrigerant detection sensors in the same location to detect leaks of flammable refrigerant, with one of the two detection sensors having a relatively short lifespan being used, and the other refrigerant detection sensor being used in the event that it failed, thereby extending the lifespan of the refrigerant detection sensor.

[0009] However, when using a semiconductor-type refrigerant detection sensor in the prior art, even if the refrigerant detection sensor is not operating, there is a risk of false detection occurring due to deterioration of the adsorption capacity of the miscellaneous gas filter or deterioration of the catalytic activity of the sensor material. Therefore, even if multiple refrigerant detection sensors are provided, the performance of the refrigerant detection sensor used after one fails is not fully demonstrated, and the effect of extending the sensor's lifespan is limited. The inventors discovered this problem, and have come to form the subject of the present disclosure in order to solve this problem. The present disclosure provides an air conditioner that can suppress performance degradation due to aging, detect refrigerant leaks without false detection, and improve safety against refrigerant leaks.

[0010] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters or redundant description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0011] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to the drawings. [1-1.Configuration] FIG. 1 is a cross-sectional view showing an indoor unit of an air conditioner according to Embodiment 1. As shown in FIG. As shown in Fig. 1, the air conditioner 1 includes an indoor unit 10. The indoor unit 10 includes a housing 11 that is attached to a wall surface inside a room. An air intake 12 that draws in air from inside the room is provided on the top surface of the housing 11. An air outlet 13 that blows air into the room is provided on the bottom surface of the housing 11. Both the air intake 12 and the air outlet 13 are formed across the entire width of the housing 11. An indoor heat exchanger 14 is housed inside the housing 11. The indoor heat exchanger 14 is formed in a generally inverted V shape when viewed from the side, and is arranged so as to separate the space between the air intake 12 and the air outlet 13 inside the housing 11. This ensures that the indoor air drawn in through the air intake 12 always passes through the indoor heat exchanger 14 before reaching the air outlet 13.

[0012] An indoor blower 15 is disposed inside the indoor heat exchanger 14. The indoor blower 15 is configured to be driven to rotate by a blower drive motor (not shown) to draw in indoor air through the intake port 12, pass the air through the indoor heat exchanger 14 to exchange heat, and then blow the air out of the air outlet 13 into the room. A filter 16 is also disposed in the air intake 12. The filter 16 is made of a flexible material and serves to remove dust and other particles from the air drawn in through the air intake 12.

[0013] A cleaning drive roller 17 is provided in front of the filter 16 so as to be rotatable, and is configured so that dirt such as dust adhering to the filter 16 can be cleaned by rotating and driving this cleaning drive roller 17 to wind up the filter 16.

[0014] A left-right air deflector 18 that adjusts the left-right direction of the air being blown out is provided near the air outlet 13 so as to be able to swing left and right. The left-right air deflector 18 is capable of manually adjusting the air direction. Below the left and right airflow direction vanes 18, vertical airflow direction vanes 19 are provided so as to be able to swing freely, for adjusting the vertical direction of the air being blown out. The vertical airflow direction vane 19 can automatically adjust the vertical airflow direction by an airflow direction vane drive motor (not shown).

[0015] The air conditioner 1 also includes an outdoor unit 30. The outdoor unit 30 includes a compressor 31, an outdoor heat exchanger (not shown), an outdoor blower 32 that sends outside air to the outdoor heat exchanger, an expansion mechanism 33, and a four-way valve 34 (all of which are shown in FIG. 3). The outdoor unit 30 and the indoor unit 10 are connected by refrigerant piping (not shown) to form a predetermined refrigeration cycle circuit. In this embodiment, the indoor unit 10 is equipped with a refrigerant shutoff valve 20. The refrigerant shutoff valve 20 is closed to shut off the refrigerant flowing through the refrigerant piping in the event of a refrigerant leak in the indoor unit 10. The refrigerant shutoff valve 20 may also be installed in the outdoor unit 30.

[0016] Furthermore, inside the housing 11 and near the indoor heat exchanger 14, a first refrigerant detection sensor 40 and a second refrigerant detection sensor 41 are arranged. The first refrigerant detection sensor 40 is a sensor that is used from the start of use of the indoor unit 10, and the second refrigerant detection sensor 41 is a sensor that is used when the first refrigerant detection sensor 40 becomes unusable.

[0017] In this embodiment, the first refrigerant detection sensor 40 is disposed near a location where one end of a refrigerant pipe connected to the outdoor unit 30 is connected to the indoor heat exchanger 14 of the indoor unit 10. This is because the connection between the indoor heat exchanger 14 and the refrigerant pipe is more likely to cause refrigerant leakage in the early stages of use of the indoor unit 10 than other locations. The second refrigerant detection sensor 41 is disposed near a bend position where the refrigerant piping in the indoor heat exchanger 14 turns back. This is because the bend position is a location where refrigerant leakage is likely to occur due to deterioration of the refrigerant piping of the indoor heat exchanger 14 over time. By arranging the first refrigerant detection sensor 40 and the second refrigerant detection sensor 41 in this manner, the first refrigerant detection sensor 40 can detect refrigerant leakage due to initial use of the indoor unit 10, and the second refrigerant detection sensor 41 can detect refrigerant leakage due to deterioration over time.

[0018] The second refrigerant detection sensor 41 may be installed in the same location as the first refrigerant detection sensor 40. In this case, the first refrigerant detection sensor 40 becomes unusable, and when switching to refrigerant leakage detection using the second refrigerant detection sensor 41, detection is possible under the same conditions, thereby suppressing the occurrence of detection errors due to differences in installation location.

[0019] FIG. 2 is a diagram showing the schematic configuration of the first refrigerant detection sensor 40 and the second refrigerant detection sensor 41. As shown in FIG. As shown in Fig. 2, the first refrigerant detection sensor 40 and the second refrigerant detection sensor 41 each include a predetermined sensor substrate 42. A sensor unit (not shown) made of semiconductor is mounted on the sensor substrate 42. A substantially cylindrical sensor case 43 that covers the sensor unit is attached around the sensor unit. A mesh-like opening 44 is formed at the tip of the sensor case 43. The sensor unit is configured to detect leaking refrigerant that enters through the opening 44. In order for the sensor section to operate, it is necessary to heat the sensor section to a predetermined temperature, and therefore a heater (not shown) is disposed near the sensor section.

[0020] The second refrigerant detection sensor 41 is provided with an outside air blocking device 45 that closes the opening 44 . The outside air blocking device 45 is composed of, for example, a cover member 46 that blocks the opening 44, an elastic member 47 such as a spring that biases the cover member 46 and the opening 44 to open, and a cover holding member (not shown) that holds the cover member 46 in a blocking state of the opening 44. The outside air blocking device 45 also includes a release mechanism 48 that releases the outside air blocking device 45 .

[0021] In this embodiment, the lid holding member of the outside air blocking device 45 is configured to hold the lid member 46 to the sensor case 43 with, for example, a resin that melts at a predetermined temperature. In this case, the release mechanism 48 is configured with a heater that melts the resin. In addition, if the lid holding member of the outside air blocking device 45 has a structure in which, for example, the lid member 46 is engaged and held on the sensor case 43 by a holding claw or the like, the release mechanism 48 is composed of a solenoid or the like that electrically releases the engagement of the holding claw.

[0022] As other examples of the release mechanism 48, for example, a structure may be adopted in which the elastic member 47 is not provided and the lid member 46 can be opened and closed electrically, or, for example, the lid member 46 and the opening 44 may be made of a shape memory metal that memorizes the open state, and the lid member 46 may be heated and deformed by a release mechanism 48 such as a heater, thereby opening the opening 44. When the lid holding member of the outside air blocking device 45 is released by the release mechanism 48, the elastic force of the elastic member 47 moves the lid member 46 to a position away from the sensor case 43, thereby making it possible to detect refrigerant leakage through the opening 44 of the sensor case 43.

[0023] Furthermore, the outside air blocking device 45 may be provided with a moisture-proof material on the inside of the cover member 46. This allows moisture that may accelerate deterioration of the second refrigerant detection sensor 41 to be removed when the second refrigerant detection sensor 41 is not in use, thereby suppressing deterioration of the second refrigerant detection sensor 41. Furthermore, the cover member 46 of the outside air blocking device 45 may be made of a material that blocks light and heat. This allows light and heat that may accelerate deterioration of the second refrigerant detection sensor 41 to be blocked when the second refrigerant detection sensor 41 is not in use, thereby suppressing deterioration of the second refrigerant detection sensor 41.

[0024] Next, the control configuration of the first embodiment will be described. FIG. 3 is a block diagram showing the control configuration of this embodiment. As shown in FIG. 3, the indoor unit 10 includes a control unit 50. The control unit 50 controls each device of the air conditioning apparatus 1. The control unit 50 includes a processor and a memory. The control of the control unit 50 is executed by the processor processing a program stored in the memory. The control unit includes a timer 51. The control unit 50 is connected to a first refrigerant detection sensor 40 and a second refrigerant detection sensor 41.

[0025] The control unit 50 includes a communication unit 52, and the communication unit 52 is capable of communicating with a remote control 53 operated by a user. That is, the control unit 50 controls the operation of the compressor 31, outdoor blower 32, expansion mechanism 33, four-way valve 34 of the outdoor unit 30, the indoor blower 15 of the indoor unit 10, and the upper and lower air deflectors 19 based on the set temperature input via the remote control 53 by the user operating the remote control 53. Furthermore, when the first refrigerant detection sensor 40 or the second refrigerant detection sensor 41 detects a refrigerant leak, the control unit 50 controls the refrigerant shutoff valve 20 to close.

[0026] Furthermore, the control unit 50 counts the drive time of the first refrigerant detection sensor 40 using a timer 51 of the control unit 50. Then, the control unit 50 counts, for example, until the drive time of the first refrigerant detection sensor 40 reaches five years, which is the lifespan of the first refrigerant detection sensor 40, and when the drive time reaches five years, the control unit 50 drives the release mechanism 48 to release the lid member 46, thereby enabling refrigerant leakage detection by the second refrigerant detection sensor 41.

[0027] Furthermore, the control unit 50 determines whether the first refrigerant detection sensor 40 has deteriorated based on the output of the first refrigerant detection sensor 40 . FIG. 4 is a graph showing an example of determining deterioration of the first refrigerant detection sensor 40. In FIG. 4, at the time of shipment, the sensor output of the first refrigerant detection sensor 40 increases in proportion to the refrigerant concentration from 0. In this case, the control unit 50 is controlled to issue an alarm indicating that a refrigerant is leaking when the concentration of the leaking refrigerant falls between 1 / 100 LFL (LFL: minimum flammable concentration) and 1 / 4 LFL.

[0028] When first refrigerant detection sensor 40 deteriorates, the sensor output tends to become higher than when it was shipped. Therefore, the control unit 50 sets a threshold value for determining deterioration to the sensor output at point 0, and if the sensor output at point 0 exceeds the threshold value for determining deterioration and the state in which the sensor output exceeds the threshold value for determining deterioration continues for more than 24 hours, it determines that the sensor is deteriorated. In this case, if the sensor output exceeds the threshold for determining deterioration for 24 hours or more, the sensor is determined to be deteriorated. This is because, although the sensor output changes slightly due to the daily temperature cycle, if the condition continues for 24 hours, it is considered that the daily temperature cycle has no effect.

[0029] The threshold for determining sensor degradation is set to a value lower than the sensor output that triggers a refrigerant leak alarm, thereby preventing false alarms from being issued even if the sensor is deteriorated.

[0030] [1-2. Operation] Next, the operation of the first embodiment will be described. In this embodiment, when the air conditioning apparatus 1 is installed, the first refrigerant detection sensor 40 is operated, and the control unit 50 determines whether or not there is a refrigerant leak based on the output value of the first refrigerant detection sensor 40. At the same time, the control unit 50 causes the timer 51 to count the driving time of the first refrigerant detection sensor 40 from the time of installation.

[0031] The control unit 50 drives the compressor 31, the outdoor blower 32, the expansion mechanism 33, the four-way valve 34, and the indoor blower 15, respectively, to perform heating or cooling operation according to the indoor temperature set by the remote control 53. The control unit 50 monitors the indoor unit 10 for refrigerant leakage using the first refrigerant detection sensor 40, and when the first refrigerant detection sensor 40 detects refrigerant leakage, controls the refrigerant shutoff valve 20 to close. At this time, second refrigerant detection sensor 41 is not operating, and outside air is blocked by outside air blocking device 45, so that deterioration of second refrigerant detection sensor 41 over time when it is not operating can be suppressed.

[0032] When the control unit 50 determines using the timer 51 of the control unit 50 that the operating time of the first refrigerant detection sensor 40 has reached one year, it activates the release mechanism 48 to release the lid member 46, thereby enabling the second refrigerant detection sensor 41 to detect refrigerant leakage.

[0033] Furthermore, the control unit 50 determines whether the first refrigerant detection sensor 40 has deteriorated based on the output of the first refrigerant detection sensor 40 . Therefore, the control unit 50 sets a threshold value for determining deterioration to the sensor output at point 0, and if the sensor output at point 0 exceeds the threshold value for determining deterioration and the state in which the sensor output exceeds the threshold value for determining deterioration continues for more than 24 hours, it determines that the sensor is deteriorated. If the control unit 50 determines that the sensor has deteriorated, it drives the release mechanism 48 to release the cover member 46, thereby enabling the second refrigerant detection sensor 41 to detect refrigerant leakage.

[0034] The earlier of switching to the second refrigerant detection sensor 41 based on the count value of the accumulated driving time by the timer 51 of the first refrigerant detection sensor 40 and switching to the second refrigerant detection sensor 41 based on the deterioration determination of the first refrigerant detection sensor 40 is given priority. That is, if a deterioration determination is made before the count value of the drive time by timer 51 reaches five years, switching to second refrigerant detection sensor 41 is made based on the deterioration determination. In addition, when switching to the second refrigerant detection sensor 41 is performed based on the count value of the accumulated driving time by the timer 51 or a deterioration judgment, the control unit 50 may notify the remote control 53 or a maintenance management company, etc., that driving of the first refrigerant detection sensor 40 has been stopped and switching to the second refrigerant detection sensor 41 has been performed.

[0035] The control unit 50 may be configured to determine whether the second refrigerant detection sensor 41 has deteriorated after the switch from the first refrigerant detection sensor 40 to the second refrigerant detection sensor 41 has been completed. In this case, if it is determined that both the first refrigerant detection sensor 40 and the second refrigerant detection sensor 41 have deteriorated and continued use is no longer possible, the control unit 50 closes the refrigerant shutoff valve 20 to disable use of the air conditioning apparatus 1. This improves safety against refrigerant leakage.

[0036] As described above, in this embodiment, the indoor heat exchanger 14 of the indoor unit 10 and the outdoor heat exchanger, compressor, and throttling device of the outdoor unit 30 are connected via refrigerant piping, and the air conditioning apparatus 1 uses a flammable refrigerant as the refrigerant.The air conditioning apparatus 1 is equipped with a first refrigerant detection sensor 40 and a second refrigerant detection sensor for detecting refrigerant leakage, and the second refrigerant detection sensor is equipped with an outside air blocking device 45 that blocks outside air from reaching the sensor portion of the second refrigerant detection sensor 41, and a release mechanism 48 that releases the blockage of outside air by the outside air blocking device 45. As a result, by blocking outside air with the outside air blocking device 45 while the first refrigerant detection sensor 40 is operating, it is possible to suppress deterioration over time of the second refrigerant detection sensor 41. Therefore, when the second refrigerant detection sensor 41 is operated, it is possible to detect a refrigerant leak without false detection due to deterioration over time, and safety against refrigerant leaks can be improved.

[0037] In this embodiment, the first refrigerant detection sensor 40 and the second refrigerant detection sensor 41 are installed in the same location. This allows detection under the same conditions when switching from refrigerant leakage detection using first refrigerant detection sensor 40 to second refrigerant detection sensor 41, thereby reducing the occurrence of detection errors due to differences in installation location.

[0038] In addition, in this embodiment, the first refrigerant detection sensor 40 is installed near the connection point of the refrigerant piping between the indoor unit 10 and the outdoor unit 30, and the second refrigerant detection sensor 41 is installed near the bend position of the indoor heat exchanger 14. As a result, the first refrigerant detection sensor 40 can detect refrigerant leakage due to initial use of the indoor unit 10, and the second refrigerant detection sensor 41 can detect refrigerant leakage due to deterioration over time.

[0039] In addition, this embodiment is provided with a control unit 50 to which the sensor outputs of the first refrigerant detection sensor 40 and the second refrigerant detection sensor 41 are input, and the control unit 50 sets a deterioration determination threshold value to a value lower than the sensor output at which the first refrigerant detection sensor 40 detects a refrigerant leak and issues an alarm, and when it determines that the first refrigerant detection sensor has exceeded the deterioration determination threshold value for 24 hours or more, it operates the release mechanism 48 to remove the outside air shut-off device 45 and switches to refrigerant leak monitoring using the second refrigerant detection sensor. This makes it possible to determine whether the first refrigerant detection sensor 40 has deteriorated, and prevents a refrigerant leak from being detected by a deteriorated first refrigerant detection sensor 40, thereby reducing false detections due to deterioration over time by the first refrigerant detection sensor 40. This improves safety against refrigerant leaks.

[0040] Furthermore, in this embodiment, the control unit 50 is equipped with a timer 51, and the control unit 50 counts the operating time of the first refrigerant detection sensor 40 using the timer 51. When the control unit 50 determines that the operating time of the first refrigerant detection sensor 40 has elapsed a predetermined time, the control unit 50 operates the release mechanism 48 to remove the outside air blocking device 45 and switches to monitoring for refrigerant leakage using the second refrigerant detection sensor. This prevents a refrigerant leak from being detected by the first refrigerant detection sensor 40 that has reached the end of its life, and reduces false detection by the first refrigerant detection sensor 40. Therefore, safety against refrigerant leaks can be improved.

[0041] Furthermore, in this embodiment, when the control unit 50 determines that all of the first refrigerant detection sensors 40 to 41 have deteriorated and continued use is no longer possible, it controls the refrigerant shut-off valve 20 provided in the refrigerant piping to the indoor unit 10 to close. This makes it impossible to use the air conditioner 1, thereby improving safety against refrigerant leakage.

[0042] (Other embodiments) As described above, the first embodiment has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in the first embodiment above to create new embodiments. For example, the first refrigerant detection sensor 40 and the second refrigerant detection sensor 41 are generally configured by inserting and connecting pins of the sensor board 42 into connectors provided on the control board. Therefore, an insulating film or the like may be inserted at the connection point between the sensor board 42 of the second refrigerant detection sensor 41 and the control board to insulate the sensor board 42. This prevents current from flowing through the sensor board 42 and keeps it isolated from the outside air by the outside air blocking device 45, making it possible to maintain the second refrigerant detection sensor 41 in approximately the same condition as when it was shipped. In this case, when first refrigerant detection sensor 40 reaches the end of its life or deteriorates over time, a notification may be provided to notify the user that the insulating film should be removed. [Industrial Applicability]

[0043] As described above, the air conditioning device of the present invention can suppress performance degradation due to aging, detect refrigerant leaks without false detection, and can be suitably used as an air conditioning device that can improve safety against refrigerant leaks. [Explanation of symbols]

[0044] 1. Air conditioning equipment 10 Indoor unit 11. Housing 12 Air intake 14 Indoor heat exchanger 15 Indoor fan 18 Left and right wind direction plates 19 Upper and lower wind direction plates 20 Refrigerant shutoff valve 30 Outdoor unit 31 Compressor 32 Outdoor blower 33 Expansion mechanism 34 Four-way valve 40 First refrigerant detection sensor 41 Second refrigerant detection sensor 42 Sensor board 43 Sensor case 44 Aperture 45 Outside air shutoff device 46 Lid member 47 Elastic member 48 Release mechanism 50 control section 51 Timer 52 Communications Department 53 Remote Control

Claims

1. In an air conditioner in which an indoor heat exchanger of an indoor unit is connected to an outdoor heat exchanger, a compressor, and a throttling device of an outdoor unit via refrigerant piping, and a flammable refrigerant is used as the refrigerant, a first refrigerant detection sensor and a second refrigerant detection sensor for detecting refrigerant leakage; The second refrigerant detection sensor is provided with an outside air blocking device that blocks outside air from reaching a sensor portion of the second refrigerant detection sensor, and a release mechanism that releases the blocking of outside air by the outside air blocking device. Air conditioning equipment.

2. The first refrigerant detection sensor and the second refrigerant detection sensor are installed in the same location. The air conditioning apparatus according to claim 1.

3. The first refrigerant detection sensor is installed near a connection point of the refrigerant pipe between the indoor unit and the outdoor unit, and the second refrigerant detection sensor is installed near a bend position of the indoor heat exchanger. The air conditioning apparatus according to claim 1.

4. a control unit to which sensor outputs from the first refrigerant detection sensor and the second refrigerant detection sensor are input, The control unit sets a deterioration determination threshold value to a value lower than the sensor output at which the first refrigerant detection sensor detects a refrigerant leak and issues an alarm, and when it determines that the first refrigerant detection sensor has exceeded the deterioration determination threshold value for 24 hours or more, it operates the release mechanism to remove the outside air shutoff device and switches to monitoring for refrigerant leaks using the second refrigerant detection sensor. The air conditioning apparatus according to any one of claims 1 to 3.

5. the control unit includes a timer, The control unit counts the driving time of the first refrigerant detection sensor using the timer, and when it determines that the driving time of the first refrigerant detection sensor has elapsed a predetermined time, it operates the release mechanism to remove the outside air blocking device and switches to monitoring for refrigerant leakage using the second refrigerant detection sensor. The air conditioning apparatus according to claim 4.

6. The outside air blocking device has a moisture-proof material inside. The air conditioning apparatus according to any one of claims 1 to 5.

7. The outside air blocking device is formed of a material that also blocks light and heat. The air conditioning apparatus according to any one of claims 1 to 6.

8. When the control unit determines that both the first refrigerant detection sensor and the second refrigerant detection sensor have deteriorated and continued use is no longer possible, the control unit controls a refrigerant shutoff valve provided in a refrigerant piping to the indoor unit to close. The air conditioning apparatus according to claim 4.

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