Air Conditioning Equipment

Abstract

To provide an air conditioning device that can suppress rapid leakage of refrigerant when a refrigerant piping system is provided with multiple indoor units, and secure time to take countermeasures and evacuate in the event of refrigerant leakage and guarantee safety of users.SOLUTION: A control device 50, when a refrigerant leakage sensor 40 detects refrigerant leakage from an indoor unit 20, controls a liquid shut-off valve 34 and a gas shut-off valve 36 to be closed, drives a blower of the indoor unit 20 from which refrigerant leakage is detected, and controls an indoor throttle device 22 of an indoor unit 20 from which refrigerant leakage is not detected to be closed when the indoor unit 20 operates cooling, and to be open when the indoor unit 20 operates heating.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Conventionally, in a refrigeration cycle device equipped with a refrigeration cycle that circulates a refrigerant, a heat exchanger unit that houses at least a heat exchanger of the refrigeration cycle device, and a control unit that controls the heat exchanger unit, the heat exchanger unit has a blower fan and a refrigerant detection means that detects the refrigerant concentration and sends a detection signal to the control unit, and the control unit operates the blower fan when it detects the refrigerant, and stops the blower fan when the change over time in the refrigerant concentration turns from positive to negative (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-197006 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional technology, when a refrigerant leak occurs, the fan of only the indoor unit determined to have a refrigerant leak is operated to agitate the leaked refrigerant. Therefore, in a refrigerant piping system with multiple indoor units, the refrigerant present in the system suddenly leaks into the room from the leakage point, making it impossible to ensure sufficient time for countermeasures and evacuation in the event of a leak, and thus failing to guarantee the safety of users. The present invention has been made in consideration of the above-mentioned points, and has an object to provide an air conditioning apparatus that can suppress sudden refrigerant leakage when multiple indoor units are installed in a refrigerant piping system, ensure countermeasures and evacuation time in the event of a refrigerant leakage, and ensure the safety of users. [Means for solving the problem]

[0005] In order to achieve the above object, the air conditioner of the present disclosure includes an outdoor unit having at least a compressor and an outdoor heat exchanger, a plurality of indoor units having at least an indoor heat exchanger, a blower and a throttling device, and liquid refrigerant piping and gas refrigerant piping connecting the outdoor unit and each of the indoor units, the air conditioner including an opening and closing device provided in the middle of the liquid refrigerant piping and the gas refrigerant piping for blocking the flow of refrigerant in the liquid refrigerant piping and the gas refrigerant piping, each The indoor unit Each of the indoor units Refrigerant leakage from Each of these detects multiple The indoor unit is provided with a refrigerant leakage sensor and a control device that performs opening and closing control of the opening and closing device based on a detection signal from each of the refrigerant leakage sensors. When the control device detects a refrigerant leakage from the indoor unit by the refrigerant leakage sensor, the control device controls the opening and closing device to close, and Corresponding to the refrigerant leak sensor The indoor unit's fan is driven and no refrigerant leakage is detected. Corresponding to the refrigerant leak sensor The throttling device of the indoor unit is controlled to be closed when the indoor unit is in cooling operation, and is controlled to be open when the indoor unit is in heating operation. Effect of the Invention

[0006] According to the present invention, in both cooling and heating operation, the pressure difference with the atmospheric pressure can be reduced, and a sudden refrigerant leakage from an indoor unit where a refrigerant leakage has been detected can be suppressed. As a result, measures and evacuation time can be secured in the event of a refrigerant leakage, and the safety of users can be guaranteed. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing an air conditioning device according to a first embodiment of the present invention. [Diagram 2] Block diagram showing a control configuration of the first embodiment. [Diagram 3] Flowchart showing the operation of the first embodiment [Figure 4] FIG. 11 is a schematic diagram showing an air conditioning apparatus according to a second embodiment. [Diagram 5]A block diagram showing a control configuration of the second embodiment. [Figure 6] Flowchart showing the operation of the second embodiment [Figure 7] A schematic configuration diagram showing an air conditioning device according to a third embodiment. [Figure 8] A block diagram showing a control configuration of the third embodiment. [Figure 9] Flowchart showing the operation of the third embodiment DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A first invention is an air conditioning apparatus comprising an outdoor unit having at least a compressor and an outdoor heat exchanger, a plurality of indoor units each having at least an indoor heat exchanger, a blower and a throttling device, and a liquid refrigerant piping and a gas refrigerant piping connecting the outdoor unit and the indoor units, the air conditioning apparatus further comprising an opening and closing device provided midway through the liquid refrigerant piping and the gas refrigerant piping for blocking the flow of refrigerant in the liquid refrigerant piping and the gas refrigerant piping, a refrigerant leakage sensor for detecting refrigerant leakage from the indoor units, and a control device for controlling the opening and closing of the opening and closing device based on a detection signal from the refrigerant leakage sensor, wherein when the control device detects refrigerant leakage from the indoor units by the refrigerant leakage sensor, the control device controls the opening and closing device to close and drives the blower of the indoor unit that detected the refrigerant leakage, and controls the throttling device of the indoor units that did not detect a refrigerant leakage to close when the indoor unit is in cooling operation, and to open when the indoor unit is in heating operation. This makes it possible to reduce the pressure difference with the atmospheric pressure in both cooling and heating operation, and to prevent a sudden refrigerant leak from an indoor unit where a refrigerant leak has been detected. This makes it possible to secure time for countermeasures and evacuation in the event of a refrigerant leak, and ensures the safety of users.

[0009] In a second aspect of the present invention, when the control device detects a refrigerant leak in the indoor unit by the refrigerant leak sensor, the control device controls the blower of the indoor unit to operate when the indoor unit in which a refrigerant leak has not been detected is in cooling operation. This allows the refrigerant to be gasified by absorbing heat from the outside air while maintaining low pressure, reducing the density of the refrigerant. This makes it possible to prevent sudden leakage of refrigerant from indoor units that have a refrigerant leak in the same system, ensuring time for measures and evacuation in the event of a refrigerant leak and ensuring the safety of users.

[0010] In a third invention, when the control device detects a refrigerant leak in the indoor unit by the refrigerant leak sensor, if the refrigerant temperature in the indoor unit where refrigerant leakage is not detected is higher than the indoor temperature of the indoor unit, it controls the throttling device to open, and if the refrigerant temperature is lower than the indoor temperature of the indoor unit, it controls the throttling device to close and operates the blower of the indoor unit. This makes it possible to reduce the pressure difference with the atmosphere regardless of the refrigerant temperature, and to prevent a sudden refrigerant leak from an indoor unit where a refrigerant leak has been detected. This makes it possible to secure time for countermeasures and evacuation in the event of a refrigerant leak, and ensures the safety of users.

[0011] In a fourth aspect of the present invention, when a refrigerant leakage sensor detects a refrigerant leakage, the control device notifies that the blower is in operation. According to this, when a refrigerant leak is detected and the indoor blower is operated, the user is notified that the indoor blower is operating, making it possible to inform the user that the indoor blower is operating normally at the time of the refrigerant leak, thereby improving the operational reliability of the air conditioning unit.

[0012] (Embodiment 1) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic diagram showing a first embodiment of an air conditioner according to the present invention. Note that the air conditioner to which the present invention is applied is not limited to this, and various air conditioners are applicable.

[0013] As shown in Fig. 1, the air conditioner 1 includes an outdoor unit 10 and multiple indoor units 20. The outdoor unit 10 houses a compressor 11, a four-way valve 12 that switches the refrigerant flow path, an outdoor heat exchanger 13, and an outdoor throttling device 14, which are connected in sequence by refrigerant piping 15. The indoor unit 20 accommodates an indoor heat exchanger 21, an indoor throttling device 22, and an indoor blower 23, and the indoor heat exchanger 21 and the indoor throttling device 22 are connected via a refrigerant piping 24. The compressor 11 of the outdoor unit 10 and the indoor heat exchanger 21 of the indoor unit 20 are connected by a liquid refrigerant piping 30 and a gas refrigerant piping 32.

[0014] In this embodiment, an example is shown in which two rooms, a room A and a room B, are provided as rooms in which the indoor units 20 are installed. One indoor unit 20 is installed in each of rooms A and B.

[0015] The liquid refrigerant piping 30 and the gas refrigerant piping 32 are connected in parallel to the indoor unit 20 in room A and the indoor unit 20 in room B, respectively. A liquid cutoff valve 34 serving as an opening and closing device is provided in the middle of the liquid refrigerant pipe 30. A gas cutoff valve 36 serving as an opening and closing device is provided in the middle of the gas refrigerant pipe 32. Further, each indoor unit 20 is provided with a refrigerant leakage sensor 40. The refrigerant leakage sensor 40 detects refrigerant leaking from each indoor unit 20, and in this embodiment, is provided inside each indoor unit 20. The refrigerant leakage sensor 40 may be provided outside the indoor unit 20, or may be provided on a remote control (not shown) for operating the indoor unit 20 installed in the room, or at a predetermined location inside the room separately from the indoor unit 20.

[0016] Next, the control configuration of this embodiment will be described. FIG. 2 is a block diagram showing a control configuration of this embodiment. As shown in FIG. 2, the air conditioner 1 is equipped with a control device 50. The control device 50 is equipped with a processor such as a CPU or MPU that executes programs, and memory such as a ROM or RAM, and performs various processes through cooperation between hardware and software, such as the processor reading out a control program stored in the memory and executing processing.

[0017] The control device 50 controls the compressor of the outdoor unit 10, the outdoor throttling device 14, the indoor blower 23 of the indoor unit 20, and the indoor throttling device 22 based on a control program. The control device 50 controls the opening and closing of the liquid cutoff valve 34 , the gas cutoff valve 36 , and the indoor throttle device 22 based on the detection signal of the refrigerant leakage sensor 40 of each indoor unit 20 .

[0018] Next, the operation of this embodiment will be described with reference to the flowchart shown in FIG. In this embodiment, when the cooling operation or heating operation is being performed, the control device 50 monitors whether or not the refrigerant leakage sensor 40 has detected a refrigerant leakage from the indoor unit 20 (ST1). Then, if the refrigerant leakage sensor 40 detects a refrigerant leakage from an indoor unit 20 (for example, the indoor unit 20 in room A) (ST1: YES), the control device 50 controls the liquid cut-off valve 34 and the gas cut-off valve 36 corresponding to the indoor unit 20 in which the refrigerant leakage sensor 40 detected a refrigerant leakage to be switched to "closed" based on the detection signal of the refrigerant leakage sensor 40 (ST2).

[0019] If the indoor unit 20 in the room where the refrigerant leakage has been detected (ST3: YES), the control device 50 controls the indoor blower 23 of the indoor unit 20 to operate (ST4). This allows the air in the room to be agitated in the indoor unit 20 where the refrigerant has leaked.

[0020] In addition, if the control device 50 has not detected a refrigerant leak in an indoor unit 20 (for example, the indoor unit 20 in room B) (ST3: NO), and the indoor unit 20 is performing cooling operation (ST5: YES), the control device 50 switches the indoor throttling device 22 to "closed" (ST6). Then, the control device 50 switches the indoor throttle device 22 to "closed" and then operates the indoor blower 23 (ST7). As a result, the refrigerant downstream of the indoor throttling device 22 is maintained at a low pressure, reducing the pressure difference with atmospheric pressure, and the refrigerant is gasified by absorbing heat from the outside air while maintaining its low pressure, thereby reducing the refrigerant density.

[0021] On the other hand, if the indoor unit 20 in which no refrigerant leakage has been detected is performing heating operation (ST5: NO), the indoor throttle device 22 is controlled to be open (ST8). As a result, by opening the indoor throttling device 22, the refrigerant pressure is equalized on the upstream and downstream sides of the indoor throttling device 22, and the pressure difference with respect to atmospheric pressure can be reduced.

[0022] In this way, by switching the indoor throttling device 22 to "closed" during cooling operation and switching the indoor throttling device 22 to "open" during heating operation, the pressure difference with atmospheric pressure can be reduced in both cooling and heating operating conditions, and as a result, it is possible to suppress sudden refrigerant leakage from the indoor unit 20 in which a refrigerant leakage has been detected.

[0023] When the refrigerant leakage sensor 40 detects a refrigerant leakage, the control device 50 may be configured to notify that the indoor blower 23 is in operation. In this case, the notification may be made by, for example, providing a display device on the indoor unit 20 or a remote control, and displaying the information on the display device, or by audio. In this way, when a refrigerant leak is detected and the indoor blower 23 is operated, the user is notified that the indoor blower 23 is operating, so that it is possible to inform the user that the indoor blower 23 is operating normally at the time of the refrigerant leak, thereby improving the operational reliability of the air conditioning apparatus.

[0024] As described above, according to this embodiment, the system includes the liquid shutoff valve 34 and the gas shutoff valve 36 (opening / closing devices) that are provided in the middle of the liquid refrigerant piping 30 and the gas refrigerant piping 32 and shut off the flow of refrigerant in the liquid refrigerant piping 30 and the gas refrigerant piping 32, the refrigerant leakage sensor 40 that detects refrigerant leakage from the indoor unit 20, and the control device 50 that controls the opening and closing of the liquid shutoff valve 34 and the gas shutoff valve 36 based on a detection signal from the refrigerant leakage sensor 40. When the control device 50 detects refrigerant leakage from the indoor unit 20 by the refrigerant leakage sensor 40, it controls the liquid shutoff valve 34 and the gas shutoff valve 36 to "closed" and drives the blower of the indoor unit 20 in which refrigerant leakage has been detected, and controls the indoor throttling device 22 (throttling device) of the indoor unit 20 in which refrigerant leakage has not been detected to "closed" when the indoor unit 20 is in cooling operation, and controls it to "open" when the indoor unit 20 is in heating operation.

[0025] This makes it possible to reduce the pressure difference with the atmospheric pressure in both cooling and heating operation, and to suppress sudden refrigerant leakage from the indoor unit 20 in which a refrigerant leakage has been detected. This makes it possible to secure time for countermeasures and evacuation in the event of a refrigerant leakage, and ensures the safety of users.

[0026] Furthermore, in this embodiment, when the control device 50 detects a refrigerant leak in an indoor unit 20 by the refrigerant leak sensor 40, the control device 50 controls the indoor blower 23 of the indoor unit 20 to operate when the indoor unit 20 that has not detected a refrigerant leak is in cooling operation. This allows the refrigerant to be gasified by absorbing heat from the outside air while maintaining a low pressure, reducing the density of the refrigerant. This makes it possible to prevent a sudden leakage of refrigerant from an indoor unit 20 in the same system that has a refrigerant leak, ensuring time for measures and evacuation in the event of a refrigerant leak and ensuring the safety of users.

[0027] (Embodiment 2) Next, a second embodiment of the present invention will be described. FIG. 4 is a schematic diagram showing a configuration according to a second embodiment of the present invention. As shown in FIG. 4, in this embodiment, each indoor unit 20 is provided with a refrigerant temperature sensor 42 that detects the refrigerant temperature, and an indoor temperature sensor 44 that detects the indoor temperature.

[0028] FIG. 5 is a block diagram showing a control configuration according to the second embodiment. In this embodiment, the control device 50 controls the opening and closing of the liquid shutoff valve 34, the gas shutoff valve 36, and the indoor throttling device 22 based on the detection signal from the refrigerant leakage sensor 40 of each indoor unit 20, the detection signal from the refrigerant temperature sensor 42, and the detection signal from the indoor temperature sensor 44. The other configurations are the same as those in the first embodiment, so the same parts are given the same reference numerals and the description thereof is omitted.

[0029] Next, the operation of the second embodiment will be described with reference to the flowchart shown in FIG. In this embodiment, when the cooling operation or heating operation is being performed, the control device 50 monitors whether or not the refrigerant leakage sensor 40 has detected a refrigerant leakage from the indoor unit 20 (ST11). Then, if the refrigerant leakage sensor 40 detects a refrigerant leakage from an indoor unit 20 (for example, the indoor unit 20 in room A) (ST11: YES), the control device 50 controls the liquid cut-off valve 34 and the gas cut-off valve 36 corresponding to the indoor unit 20 in which the refrigerant leakage sensor 40 detected a refrigerant leakage to be switched to "closed" based on the detection signal of the refrigerant leakage sensor 40 (ST12).

[0030] If the indoor unit 20 in the room where the refrigerant leakage has been detected (ST13: YES), the control device 50 controls the indoor blower 23 of the indoor unit 20 to operate (ST14). This makes it possible to agitate the air in the room in the indoor unit 20 where the refrigerant has leaked.

[0031] In addition, in the case of an indoor unit 20 in which a refrigerant leak has not been detected (for example, the indoor unit 20 in room B) (ST13: NO), the control device 50 compares the refrigerant temperature detected by the refrigerant temperature sensor 42 in that indoor unit 20 with the indoor temperature detected by the indoor temperature sensor 44 (ST15). If it is determined that the refrigerant temperature is lower than the indoor temperature (ST15: YES), the indoor throttle device 22 is switched to "closed" (ST16). Then, the control device 50 switches the indoor throttle device 22 to "closed" and then operates the indoor blower 23 (ST17). As a result, the refrigerant downstream of the indoor throttling device 22 is maintained at a low pressure, reducing the pressure difference with atmospheric pressure, and the refrigerant is gasified by absorbing heat from the outside air while maintaining its low pressure, thereby reducing the refrigerant density.

[0032] On the other hand, if it is determined that the refrigerant temperature in the indoor unit 20 in which no refrigerant leakage has been detected is higher than the room temperature (ST15: NO), the indoor throttle device 22 is controlled to be open (ST18). In this case, the indoor blower 23 is not operated. As a result, by opening the indoor throttling device 22, the refrigerant pressure is equalized on the upstream and downstream sides of the indoor throttling device 22, and the pressure difference with respect to atmospheric pressure can be reduced.

[0033] That is, while embodiment 1 determines whether cooling or heating operation is being performed and controls the opening and closing of the indoor throttling device 22, in this embodiment, the refrigerant temperature is compared with the indoor temperature to indirectly determine whether cooling or heating operation is being performed. In this way, by switching the indoor throttling device 22 to "closed" during cooling operation and switching the indoor throttling device 22 to "open" during heating operation, the pressure difference with atmospheric pressure can be reduced in both cooling and heating operating conditions, and as a result, it is possible to suppress sudden refrigerant leakage from the indoor unit 20 in which a refrigerant leakage has been detected.

[0034] As described above, according to this embodiment, when the control device 50 detects a refrigerant leak in the indoor unit 20 by the refrigerant leak sensor 40, if the refrigerant temperature in the indoor unit 20 where refrigerant leakage has not been detected is higher than the indoor temperature of that indoor unit 20, it controls the indoor throttling device 22 to open, and if the refrigerant temperature is lower than the indoor temperature of that indoor unit 20, it controls the indoor throttling device 22 to close and operates the indoor blower 23 of that indoor unit 20. This makes it possible to reduce the pressure difference with the atmospheric pressure regardless of the refrigerant temperature, and to suppress sudden refrigerant leakage from the indoor unit 20 in which a refrigerant leakage has been detected. This makes it possible to secure countermeasures and evacuation time in the event of a refrigerant leakage, and ensures the safety of users.

[0035] (Embodiment 3) Next, a third embodiment of the present invention will be described. FIG. 7 is a schematic diagram showing a configuration according to the second embodiment of the present invention. As shown in FIG. 7, this embodiment shows an example in which four rooms, Room A to Room D, are provided as rooms in which indoor units 20 are installed. One indoor unit 20 is installed in each of the rooms A, B, and D. In addition, two indoor units 20 are installed in the room C.

[0036] The liquid refrigerant pipe 30 branches into a first liquid refrigerant pipe 30a and a second liquid refrigerant pipe 30b. The gas refrigerant pipe 32 branches into a first gas refrigerant pipe 32a and a second gas refrigerant pipe 32b. The first liquid refrigerant pipe 30a and the first gas refrigerant pipe 32a are connected to the indoor unit 20 in room A and the indoor unit 20 in room B, respectively. The second liquid refrigerant piping 30b and the second gas refrigerant piping 32b are connected to the two indoor units 20 in room D and the indoor unit 20 in room D, respectively.

[0037] A first liquid cutoff valve 34a serving as an opening / closing device is provided in the middle of the first liquid refrigerant pipe 30a. A first gas cutoff valve 36a serving as an opening / closing device is provided in the middle of the first gas refrigerant pipe 32a. The first liquid cutoff valve 34a is provided upstream of the chamber A of the first liquid refrigerant pipe 30a, and the first gas cutoff valve 36a is provided upstream of the chamber A of the first gas refrigerant pipe 32a. A second liquid cutoff valve 34b and a third liquid cutoff valve 34c are provided as opening / closing devices in the middle of the second liquid refrigerant pipe 30b. A second gas cutoff valve 36b and a third gas cutoff valve 36c are provided as opening / closing devices in the middle of the second gas refrigerant pipe 32b.

[0038] The second liquid cutoff valve 34b is provided upstream of the chamber C of the second liquid refrigerant pipe 30b, and the second gas cutoff valve 36b is provided upstream of the chamber C of the second gas refrigerant pipe 32b. The third liquid shutoff valve 34c is provided on the second liquid refrigerant piping 30b upstream of room D and downstream of room C, and the third gas shutoff valve 36c is provided on the second gas refrigerant piping 32b upstream of room D and downstream of room C.

[0039] Next, the control configuration of this embodiment will be described. FIG. 8 is a block diagram showing a control configuration of this embodiment. As shown in FIG. 8, the air conditioning apparatus 1 is equipped with a control device 50, which controls the opening and closing of the first liquid shut-off valve 34a, the second liquid shut-off valve 34b, the third liquid shut-off valve 34c, the first gas shut-off valve 36a, the second gas shut-off valve 36b, the third gas shut-off valve 36c, and the indoor throttling device 22, and controls the operation of the indoor blower 23, based on detection signals from the refrigerant leakage sensor 40, the refrigerant temperature sensor 42, and the indoor temperature sensor 44 of each indoor unit 20.

[0040] Next, the operation of this embodiment will be described with reference to the flowchart shown in FIG. In this embodiment, when the cooling operation or heating operation is being performed, the control device 50 monitors whether or not the refrigerant leakage sensor 40 has detected a refrigerant leakage from the indoor unit 20 (ST21).

[0041] If the refrigerant leak sensor 40 detects a refrigerant leak (ST21: YES), the control device 50 controls the liquid cut-off valve 34 and gas cut-off valve 36 of the refrigerant piping corresponding to the indoor unit 20 in which the refrigerant leak sensor 40 detected a refrigerant leak to be switched to "closed" based on the detection signal of the refrigerant leak sensor 40 (ST22). For example, if a refrigerant leak is detected by the refrigerant leak sensor 40 of the indoor unit 20 in room A, the first liquid refrigerant shutoff valve 34a and the gas shutoff valve 36a of the first liquid refrigerant piping 30a and the first gas refrigerant piping 32a, which flow refrigerant to the indoor unit 20 in room A, are each switched to "closed." As a result, no refrigerant is sent to the indoor unit 20 in room B.

[0042] If the refrigerant temperature sensor 42 does not detect a refrigerant leak (ST21: NO) and there is an indoor unit 20 (in this example, the indoor unit 20 in room B) in which the liquid shut-off valve 34 and the gas shut-off valve 36 of the refrigerant piping of the same refrigerant system are "closed" (ST24: YES), the control device 50 compares the refrigerant temperature detected by the refrigerant temperature sensor 42 with the indoor temperature detected by the indoor temperature sensor 44 (ST25). If it is determined that the refrigerant temperature is lower than the indoor temperature (ST25: YES), the indoor throttle device 22 is switched to "closed" (ST26). Then, the control device 50 switches the indoor throttle device 22 to "closed" and then operates the indoor blower 23 (ST27). As a result, the refrigerant downstream of the indoor throttling device 22 is maintained at a low pressure, reducing the pressure difference with atmospheric pressure, and the refrigerant is gasified by absorbing heat from the outside air while maintaining its low pressure, thereby reducing the refrigerant density.

[0043] On the other hand, if it is determined that the refrigerant temperature in the indoor unit 20 in which a refrigerant leak has not been detected is higher than the room temperature (ST25: NO), the indoor throttle device 22 is controlled to be open (ST28). In this case, the indoor blower 23 is not operated. As a result, by opening the indoor throttling device 22, the refrigerant pressure is equalized on the upstream and downstream sides of the indoor throttling device 22, and the pressure difference with respect to atmospheric pressure can be reduced.

[0044] Furthermore, if the refrigerant temperature sensor 42 does not detect a refrigerant leak (ST21: NO) and there is an indoor unit 20 (in this example, the indoor units 20 in rooms C and D) in which the liquid shutoff valve 34 and the gas shutoff valve 36 of the refrigerant piping of the same system are "open" (ST24: NO), this indoor unit 20 performs normal operation control (ST29).

[0045] For example, if a refrigerant leak is detected in one of the indoor units 20 in room C, the second liquid shutoff valve 34b and the second gas shutoff valve 36b of the second liquid refrigerant pipe 30b and the second gas refrigerant pipe 32b are switched to "closed," and the indoor blower 23 of that indoor unit 20 is controlled to operate. Then, for the other indoor unit 20 in room C and the indoor unit 20 in room D, the indoor throttling device 22 is controlled to open or close depending on a comparison between the refrigerant temperature and the indoor temperature.

[0046] Also, for example, if a refrigerant leak is detected in the indoor unit 20 in room D, the third liquid refrigerant shut-off valve 34c and the third gas refrigerant shut-off valve 36c of the second liquid refrigerant piping 30b and the second gas refrigerant piping 32b are switched to "closed," and the indoor blower 23 of the indoor unit 20 in room D is controlled to operate. In this case, since there are no other indoor units 20 downstream of the third liquid cutoff valve 34c and the third gas cutoff valve 36c, opening and closing control of the indoor throttle device 22 is not performed. As for the indoor unit 20 in room C, since refrigerant is supplied through the second liquid refrigerant piping 30b and the second gas refrigerant piping 32b, normal operation is performed.

[0047] As described above, in this embodiment as well, similarly to the first and second embodiments, the pressure difference with the atmospheric pressure can be reduced regardless of the refrigerant temperature, and a sudden refrigerant leakage can be suppressed in the indoor unit 20 in which a refrigerant leakage has been detected. Therefore, it is possible to secure countermeasures and evacuation time in the event of a refrigerant leakage, and the safety of users can be guaranteed.

[0048] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. [Industrial Applicability]

[0049] As described above, the air conditioning apparatus of the present invention can be suitably used as an air conditioning apparatus that has multiple indoor units connected to an outdoor unit and can suppress sudden refrigerant leakage if a refrigerant leakage is detected in any of the indoor units. [Explanation of symbols]

[0050] 1. Air conditioning equipment 10 Outdoor unit 11 Compressor 12 Four-way valve 13 Outdoor heat exchanger 14 Outdoor throttle device 15 Refrigerant piping 20 Indoor unit 21 Indoor heat exchanger 22 Indoor throttle device 23 Indoor fan 24 Refrigerant piping 30 Liquid refrigerant piping 30a First liquid refrigerant piping 30b 2nd liquid refrigerant piping 32 Gas refrigerant piping 32a First gas refrigerant piping 32b Second gas refrigerant piping 34 Liquid shutoff valve 34a First liquid shutoff valve 34b Second liquid shutoff valve 34c Third liquid shutoff valve 36 Gas shutoff valve 36a First gas shutoff valve 36b Second gas shutoff valve 36c Third gas shutoff valve 40 Refrigerant leak sensor 42 Refrigerant temperature sensor 44 Indoor temperature sensor 50 Control device

Claims

1. an outdoor unit having at least a compressor and an outdoor heat exchanger; A plurality of indoor units each having at least an indoor heat exchanger, a blower, and a throttling device; In an air conditioning apparatus including a liquid refrigerant pipe and a gas refrigerant pipe connecting the outdoor unit and each of the indoor units, An opening and closing device that is provided in an intermediate portion of the liquid refrigerant pipe and the gas refrigerant pipe and blocks the flow of refrigerant in the liquid refrigerant pipe and the gas refrigerant pipe; A plurality of refrigerant leakage sensors are provided in the indoor units, respectively, and each of the indoor units detects leakage of refrigerant; a control device that controls the opening and closing of the opening and closing device based on detection signals from each of the refrigerant leakage sensors; The air conditioning apparatus is characterized in that when the refrigerant leak sensor detects a refrigerant leak in the indoor unit, the control device controls the opening and closing device to close, drives the blower of the indoor unit corresponding to the refrigerant leak sensor that detected the refrigerant leak, and controls the throttling device of the indoor unit corresponding to the refrigerant leak sensor that does not detect a refrigerant leak to close when the indoor unit is in cooling operation, and to open when the indoor unit is in heating operation.

2. The air conditioning apparatus according to claim 1, characterized in that, when the control device detects a refrigerant leak in the indoor unit by the refrigerant leak sensor, the control device controls the blower of the indoor unit to operate when the indoor unit in which a refrigerant leak is not detected is in cooling operation.

3. The air conditioning apparatus of claim 1, characterized in that when the control device detects a refrigerant leak in the indoor unit by the refrigerant leak sensor, if the refrigerant temperature in the indoor unit where no refrigerant leakage has been detected is higher than the indoor temperature of the indoor unit, the control device controls the throttling device to open, and if the refrigerant temperature is lower than the indoor temperature of the indoor unit, the control device controls the throttling device to close and operates the blower of the indoor unit.

4. When the control device detects a refrigerant leak by the refrigerant leak sensor, The air-conditioning apparatus according to claim 2 or 3, characterized in that it notifies that the blower is in operation.

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