Air conditioner and control method

Abstract

This air conditioner comprises a wall-mounted indoor unit through which a flammable refrigerant flows. The air conditioner comprises: a refrigerant leakage detection sensor that detects leakage of the refrigerant; an indoor unit fan that generates an airflow for blowing out, from a blowout port, air sucked from a suction port in the indoor unit; a wind direction adjustment unit that changes the wind direction of the air blown out from the blowout port at least vertically from a first direction on the horizontal direction side to a second direction on the vertical direction side; and a control unit that controls the indoor unit fan and the wind direction adjustment unit to control stirring operation for stirring leaked refrigerant in the event of refrigerant leakage. When refrigerant leakage is detected by the refrigerant leakage detection sensor, the control unit performs control such that the air is blown out from the blowout port toward the first direction only for a preset first time, and after the first time has elapsed, controls the wind direction of the air blown out from the blowout port to the side of the second direction.

Description

Air conditioner and control method

[0001] The present disclosure relates to an air conditioner and a control method.

[0002] Conventionally, an air conditioner has been disclosed in which when leakage of a flammable refrigerant is detected, the indoor unit first blows air toward the floor side (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2015-94566

[0004] However, when air is blown toward the floor side as in the technique disclosed in Patent Document 1, if there are desks, chairs, shelves, etc. placed on the floor, they become obstacles and the leaked refrigerant stays, creating a concern that a flammable concentration range may be formed.

[0005] The present disclosure has been made in view of the above circumstances, and one of its objects is to provide an air conditioner and a control method that reduce the possibility of a flammable concentration range being formed indoors when a flammable refrigerant leaks indoors.

[0006] The air conditioner according to the present disclosure is an air conditioner including a wall-mounted indoor unit through which a flammable refrigerant flows, and includes a refrigerant leakage detection sensor that detects leakage of the refrigerant, an indoor unit fan that generates an air flow for blowing out the air sucked from the suction port in the indoor unit from the blowout port, a wind direction adjustment unit that vertically changes the wind direction of the air blown out from the blowout port from a first direction on at least the horizontal direction side to a second direction on the vertical direction side, and a control unit that controls the indoor unit fan and the wind direction adjustment unit to control a stirring operation for stirring the leaked refrigerant when the refrigerant leaks. When the control unit detects leakage of the refrigerant by the refrigerant leakage detection sensor, it controls so that air blows out from the blowout port in the first direction for a preset first time, and after the first time has elapsed, it controls the wind direction of the air blown out from the blowout port to the side of the second direction.

[0007] Furthermore, the present disclosure relates to an air conditioner equipped with a wall-mounted indoor unit through which a flammable refrigerant flows, comprising: a refrigerant leak detection sensor for detecting leakage of the refrigerant; an indoor unit fan that generates an airflow for blowing out air drawn in from an intake port in the indoor unit; an airflow direction adjustment unit that vertically changes the airflow direction of the air blown out from the outlet from at least a first direction on the horizontal side to a second direction on the vertical side; and a control unit that controls the indoor unit fan and the airflow direction adjustment unit to control a stirring operation for stirring the refrigerant when it leaks, the control unit comprising the steps of: when the refrigerant leak detection sensor detects leakage of the refrigerant, controlling the airflow so that air is blown out from the outlet in the first direction for a preset first time; and after the first time has elapsed, controlling the airflow direction of the air blown out from the outlet to the second direction.

[0008] According to this disclosure, it is possible to reduce the possibility of a flammable concentration range being formed in a room when a flammable refrigerant leaks into the room.

[0009] A schematic diagram showing the refrigerant circuit of the air conditioner according to the first embodiment. A perspective view showing an example of an indoor unit according to the first embodiment. A cross-sectional view showing an example of an indoor unit according to the first embodiment. A schematic diagram showing an example of refrigerant flow due to airflow direction during stirring operation. A schematic diagram showing an example of airflow direction control during stirring operation according to the first embodiment. A schematic block diagram showing an example of the configuration of the indoor unit according to the first embodiment. A flowchart showing an example of airflow direction control processing during stirring operation according to the first embodiment. A schematic diagram showing an example of airflow direction control during stirring operation according to the second embodiment. A schematic diagram showing an example of airflow direction control processing during stirring operation according to the second embodiment. A schematic diagram showing an example of left-right control of airflow direction during stirring operation according to the third embodiment. A schematic diagram showing another example of left-right swing control of airflow direction during stirring operation according to the third embodiment. A schematic diagram showing an example of left-right control of airflow direction during stirring operation according to the fourth embodiment. A schematic block diagram showing an example of the configuration of the indoor unit according to the fifth embodiment.

[0010] The embodiments will be described below with reference to the drawings. <First Embodiment> First, the first embodiment will be described. [Overview of the Air Conditioner] Figure 1 is a diagram showing a schematic of the refrigerant circuit in the air conditioner according to this embodiment. The air conditioner 100 according to this embodiment is a refrigeration cycle device having a refrigerant circuit for circulating a flammable refrigerant. The air conditioner 100 includes a sealed compressor 101, an intake muffler 102, a four-way switching valve 103, an outdoor heat exchanger 104, a pressure reducer 105, and an indoor heat exchanger 106 as the refrigerant circuit. By switching the four-way switching valve 103 to switch the direction of refrigerant circulation, heating operation and cooling operation can be switched.

[0011] In heating operation, the refrigerant circulation direction is as shown by the solid arrow in Figure 1. For example, in heating operation, the refrigerant, compressed in a gaseous state by the sealed compressor 101, flows through the four-way switching valve 103 to the indoor heat exchanger 106. The refrigerant in the indoor heat exchanger 106 exchanges heat with the surrounding air, warming it. The refrigerant, now in a liquid state due to heat exchange, flows through the pressure reducer 105 to the outdoor heat exchanger 104. The refrigerant in the outdoor heat exchanger 104 exchanges heat with the surrounding air. The refrigerant, now in a gaseous state due to heat exchange, returns to the sealed compressor 101 through the four-way switching valve 103 and the intake muffler.

[0012] In cooling operation, the refrigerant circulation direction is as shown by the dashed arrow in Figure 1. For example, in cooling operation, the refrigerant, compressed in a gaseous state by the sealed compressor 101, flows into the outdoor heat exchanger 104 through the four-way switching valve 103. The refrigerant in the outdoor heat exchanger 104 exchanges heat with the surrounding air. The refrigerant, now in a liquid state due to heat exchange, flows into the indoor heat exchanger 106 through the pressure reducer 105. The refrigerant in the indoor heat exchanger 106 exchanges heat with the surrounding air, cooling the surrounding air. The refrigerant, now in a gaseous state due to heat exchange, returns to the sealed compressor 101 through the four-way switching valve 103.

[0013] Here, the sealed compressor 101, intake muffler 102, four-way switching valve 103, outdoor heat exchanger 104, and pressure reducer 105 are components of the outdoor unit of the air conditioner 100. The indoor heat exchanger 106 is a component of the indoor unit of the air conditioner 100.

[0014] Next, the configuration of the indoor unit 20 in the air conditioner 100 will be described with reference to Figures 2 and 3. Figure 2 is a perspective view showing an example of the indoor unit 20 according to this embodiment. Figure 3 is a cross-sectional view showing an example of the indoor unit 20 according to this embodiment. Note that the same reference numerals are used in Figures 2 and 3 to indicate the components corresponding to the parts shown in Figure 1.

[0015] The indoor unit 20 is a wall-mounted indoor unit installed on the wall of a room. Here, in the room where the indoor unit 20 is installed, the direction of the ceiling is up and the direction of the floor is down, and the vertical direction in that room is referred to as the up-down direction. The direction that intersects the up-down direction (i.e., the vertical direction) is referred to as the left-right direction. Here, right and left are defined and explained in terms of the direction when looking from the rear side of the indoor unit 20 towards the front (the direction in which the indoor unit 20 blows air).

[0016] The indoor unit 20 has a roughly rectangular parallelepiped housing 21 that is long in the left-right direction. An intake port 21a is formed on the upper side of the housing 21. In addition, an air outlet 21b is formed on the lower side of the front of the housing 21 (the side opposite to the wall when it is installed on a wall).

[0017] An indoor unit fan 22 and an indoor heat exchanger 106 are provided inside the housing 21 of the indoor unit 20. The indoor unit fan 22 generates an airflow in the indoor unit 20 that draws in air from the intake port 21a and blows it out from the outlet port 21b. As the indoor unit fan 22 rotates, the air drawn in from the intake port 21a passes through the indoor heat exchanger 106, exchanges heat with the refrigerant in the indoor heat exchanger 106, and is blown out from the outlet port 21b.

[0018] The air outlet 21b is provided with flaps 23. The flaps 23 are airflow adjustment plates (airflow adjustment units) that can adjust the direction of the air blown out from the air outlet 21b. For example, the air outlet 21b is provided with two types of flaps 23: upper and lower flaps 23a and left and right flaps 23b.

[0019] The upper and lower flaps 23a change the direction of the air blown out from the outlet 21b in the vertical direction. For example, the upper and lower flaps 23a change the direction (wind direction) of the air blown out from the outlet 21b within a range between the horizontal and vertical directions, or within at least a part of that range. The left and right flaps 23b change the direction of the air blown out from the outlet 21b in the left and right directions.

[0020] Furthermore, a refrigerant leak detection sensor 26 is provided inside the housing 21 of the indoor unit 20. The refrigerant leak detection sensor 26 detects refrigerant leakage in the indoor unit 20. The refrigerant leak detection sensor 26 may be provided as part of the indoor unit 20, or it may be a separate unit that can be attached to the indoor unit 20.

[0021] Furthermore, an LED 27 is provided on the lower side of the housing 21 of the indoor unit 20, excluding the air outlet 21b. The LED 27 is a light that illuminates according to the status of the indoor unit 20. For example, the LED 27 lights up when the unit is in operation and turns off when the unit stops. The LED 27 may also light up or blink when a refrigerant leak is detected.

[0022] When the indoor unit 20 detects a refrigerant leak, it performs an agitation operation by rotating the indoor unit fan 22 to agitate the leaked refrigerant. Referring to Figure 4, the movement of the leaked refrigerant within the room will be explained based on the direction of the airflow from the outlet 21b during the agitation operation.

[0023] Figure 4 is a schematic diagram showing an example of refrigerant flow depending on the airflow direction during agitation operation. Figure 4(A) shows an example of refrigerant flow in the room 200 when the airflow direction is downward (i.e., towards the floor). Reference numeral 210 indicates the ceiling, reference numeral 220 indicates the floor, and reference numeral 230 indicates the wall on the front side as seen from the indoor unit 20. Also, "×" indicates a refrigerant leakage point (inside the indoor unit 20), and "〇" indicates the distribution of leaked refrigerant.

[0024] In the room 200, the refrigerant leaking inside the indoor unit 20 moves towards the floor 220 in accordance with the downward airflow (illustrated by lines). At this time, the leaked refrigerant tends to accumulate on the floor 220 where obstacles to the airflow, such as the desk 250 and chair 255, are placed, raising concerns that flammable concentration zones (illustrated by triangles) may form under the desk 250 and chair 255.

[0025] Figure 4(B) shows an example of refrigerant flow in the room 200 when the wind direction is horizontal (i.e., towards the wall). Similar to Figure 4(A), "×" indicates the location of refrigerant leakage (inside the indoor unit 20), and "〇" indicates the distribution of leaked refrigerant. In the room 200, refrigerant leaked inside the indoor unit 20 moves towards the front wall 230 according to the horizontal airflow (illustrated by lines). Because the leaked refrigerant is diffused into the upper space with fewer obstacles, it is less likely to accumulate.

[0026] Therefore, in the air conditioner 100 according to this embodiment, when the indoor unit 20 detects a refrigerant leak, it performs a stirring operation by rotating the indoor unit fan 22, but first it controls the airflow direction to the horizontal direction (i.e., towards the wall). Then, after controlling the airflow direction to the horizontal direction (i.e., towards the wall), the indoor unit 20 changes it to the downward direction (i.e., towards the floor).

[0027] Figure 5 is a schematic diagram showing an example of airflow direction control during agitation operation according to this embodiment. Reference numeral 11 denotes the air blown out from the indoor unit 20 (discharge outlet 21b). When performing agitation operation, the indoor unit 20 first controls the airflow direction of the air blown out from the discharge outlet 21b in the horizontal direction V1, as shown in Figure 5(A) (horizontal blowing). The V1 direction is the direction corresponding to the horizontal direction. For example, the V1 direction may be the horizontal direction, or it may be a direction at an angle of about 5 degrees downward with respect to the horizontal direction.

[0028] The indoor unit 20 controls the airflow so that air is blown out from the outlet 21b in the direction of V1 for a preset time Th (horizontal blowing). After time Th has elapsed, as shown in Figure 5(B), the airflow direction of the air blown out from the outlet 21b is changed to the vertical direction V3 (downward blowing). The V3 direction corresponds to the vertical direction. For example, the V3 direction may be the vertical direction, or it may be a direction at an angle of about 30 degrees relative to the vertical direction.

[0029] The indoor unit 20 may control the airflow direction of the air blown out from the outlet 21b in the V3 direction for a predetermined time Tv, and after the time Tv has elapsed, it may return the airflow direction of the air blown out from the outlet 21b to the V1 direction, as shown in Figure 5(A). After that, the indoor unit 20 may continue to alternately control the airflow direction of the air blown out from the outlet 21b between the V1 direction and the V3 direction.

[0030] Next, with reference to Figure 6, the configuration of the indoor unit 20 that detects refrigerant leakage and performs stirring operation will be described. Figure 6 is a schematic block diagram showing an example of the configuration of the indoor unit 20 according to this embodiment. Note that in Figure 6, the same reference numerals are used for the components corresponding to the parts shown in Figures 2 and 3.

[0031] The indoor unit 20 includes an indoor unit fan 22, a flap 23, a refrigerant leak detection sensor 26, an LED 27 (illumination unit), and a control unit 28.

[0032] As described with reference to Figures 2 and 3, the flap 23 includes an upper and lower flap 23a and a left and right flap 23b. In this embodiment, at least the upper and lower flap 23a is controlled by the control unit 28. The left and right flap 23b may or may not be controlled by the control unit 28. If the left and right flap 23b is not controlled by the control unit 28, its orientation can be changed manually.

[0033] The refrigerant leak detection sensor 26 detects refrigerant leakage in the indoor unit 20 and outputs the detection result to the control unit 28.

[0034] The control unit 28 controls the stirring operation in the event of a refrigerant leak by controlling the indoor unit fan 22 and the flap 23. For example, when the refrigerant leak detection sensor 26 detects a refrigerant leak, the control unit 28 controls the air to be blown out from the outlet 21b in the direction of V1 (see Figure 5(A)) for a preset time Th. After the above time Th has elapsed, the control unit 28 controls the airflow direction of the air blown out from the outlet 21b to the direction of V3 (see Figure 5(B)).

[0035] Furthermore, if the control unit 28 controls the airflow direction of the air blown out from the outlet 21b to the V3 direction (see Figure 5(B)), it controls it to the V3 direction for a preset time Tv, and after the time Tv has elapsed, it returns the airflow direction of the air blown out from the outlet 21b to the V1 direction (see Figure 5(A)). After that, the control unit 28 may alternately repeat the airflow direction of the air blown out from the outlet 21b between the V1 direction and the V3 direction. Also, the control unit 28 may make the LED 27 blink during the stirring operation.

[0036] [Operation of airflow direction control processing during stirring operation] Next, referring to Figure 7, the operation of the airflow direction control processing during stirring operation, which controls the airflow direction when the indoor unit 20 detects a refrigerant leak and performs stirring operation, will be explained. Figure 7 is a flowchart showing an example of the airflow direction control processing during stirring operation according to this embodiment.

[0037] (Step S101) The control unit 28 acquires the detection result from the refrigerant leak detection sensor 26. Then, the process proceeds to step S103.

[0038] (Step S103) The control unit 28 determines whether or not a refrigerant leak has been detected based on the detection result of the refrigerant leak detection sensor 26. If the control unit 28 determines that no refrigerant leak has been detected (NO), it returns to step S101. On the other hand, if the control unit 28 determines that a refrigerant leak has been detected (YES), it proceeds to step S105.

[0039] (Step S105) The control unit 28 controls the upper and lower flaps 23a so that the airflow direction of the air blown out from the outlet 21b is in the horizontal direction V1 (see Figure 5(A)). Then proceed to step S107.

[0040] (Step S107) The control unit 28 rotates the indoor unit fan 22 and starts the stirring operation. As a result, air is blown out from the outlet 21b in the direction of V1 on the horizontal side, and the leaked refrigerant is diffused into the upper space of the room (see Figure 4(B)). Then, the process proceeds to step S109.

[0041] (Step S109) The control unit 28 determines whether time Th has elapsed since the start of the stirring operation in step S107. If the control unit 28 determines that time Th has elapsed (YES), it proceeds to step S111. On the other hand, if the control unit 28 determines that time Th has not elapsed (NO), it does not proceed to step S111 and remains in step S109. In other words, the control unit 28 controls the air to be blown out from the outlet 21b in the direction of V1 for time Th, and after time Th has elapsed, it proceeds to step S111.

[0042] (Step S111) The control unit 28 controls the upper and lower flaps 23a so that the airflow direction of the air blown out from the outlet 21b is in the vertical direction V3 (see Figure 5(B)). As a result, the air blown out from the outlet 21b is changed from the horizontal direction to the vertical direction, which changes the airflow in the room space and further diffuses the leaked refrigerant. Then, the process proceeds to step S113.

[0043] (Step S113) The control unit 28 determines whether time Tv has elapsed since the direction of the air blown out from the outlet 21b was changed to the V3 direction in step S111. If the control unit 28 determines that time Tv has elapsed (YES), it returns to step S105. On the other hand, if the control unit 28 determines that time Tv has not elapsed (NO), it remains in step S113.

[0044] In other words, the control unit 28 controls the air to blow out from the outlet 21b in the direction of V3 for a time Tv, and after time Tv has elapsed, it returns to step S105 and controls the upper and lower flaps 23a so that the airflow direction of the air blown out from the outlet 21b is in the horizontal direction of V1. As a result, the air blown out from the outlet 21b returns from the vertical direction to the horizontal direction again, changing the airflow in the indoor space and further diffusing the leaked refrigerant.

[0045] As described above, the air conditioner 100 according to the present embodiment is an air conditioner including a wall-mounted indoor unit 20 through which a flammable refrigerant flows. The air conditioner 100 (indoor unit 20) includes a refrigerant leak detection sensor 26 that detects refrigerant leakage, an indoor unit fan 22 that generates an air flow for blowing out the air sucked from the suction port 21a in the indoor unit 20 from the blowout port 21b, an up-and-down flap 23a (wind direction adjustment unit) that vertically changes the wind direction of the air blown out from the blowout port 21b from at least the horizontal direction side V1 direction (an example of the first direction) to the vertical direction side V3 direction (an example of the second direction), and a control unit 28 that controls the indoor unit fan 22 and the up-and-down flap 23a to control a stirring operation for stirring the leaked refrigerant when the refrigerant leaks. When the refrigerant leak detection sensor 26 detects refrigerant leakage, the control unit 28 controls the air to blow out from the blowout port 21b in the V1 direction for a preset time Th (an example of the first time), and after the time Th has elapsed, controls the wind direction of the air blown out from the blowout port 21b to the V3 direction side.

[0046] In this way, when the refrigerant leaks, during the stirring operation of the air conditioner 100, in the initial stage of the leakage occurrence, the air is controlled to blow out in the horizontal direction side with fewer obstacles, so that the leaked refrigerant can be diffused into the upper space in the room, and it is difficult for the leaked refrigerant to stay on the floor where furniture such as desks and chairs that serve as obstacles are placed. Also, since the refrigerant that has fallen on the tabletop diffuses along the tabletop, it is superior in terms of stirring performance compared to the case where it blows out toward the floor first. Therefore, the air conditioner 100 can reduce the possibility that a flammable concentration range is formed in the room when a flammable refrigerant leaks into the room.

[0047] In addition, the leaked refrigerant diffused in the room gradually falls toward the floor by gravity. Therefore, after controlling the air to blow out in the horizontal direction side for a predetermined time, the air conditioner 100 can effectively diffuse the leaked refrigerant by changing the wind direction to the vertical direction side, and can reduce the possibility that a flammable concentration range is formed in the room.

[0048] In addition, in the control method of the air conditioner 100 according to the present embodiment, when the control unit 28 detects a refrigerant leak by the refrigerant leak detection sensor 26, it controls the air to blow out from the air outlet 21b in the V1 direction for a preset time Th (an example of the first time), and after the time Th has elapsed, it controls the wind direction of the air blown out from the air outlet 21b to the side in the V3 direction.

[0049] In this way, the control method of the air conditioner 100 controls the air to blow out in the horizontal direction with fewer obstacles at the initial stage of the leak during the stirring operation when the refrigerant leaks, so that the leaked refrigerant can be diffused into the upper space of the room, and it is difficult for the leaked refrigerant to stay on the floor where desks and chairs that become obstacles are placed. Also, since the refrigerant that has fallen on the tabletop also diffuses along the tabletop, it is superior in terms of stirring compared to the case where it blows out toward the floor first. Therefore, the control method of the air conditioner 100 can reduce the possibility of a flammable concentration range being formed in the room when the flammable refrigerant leaks into the room.

[0050] In addition, the leaked refrigerant diffused into the room gradually falls toward the floor by gravity. Therefore, the control method of the air conditioner 100 can effectively diffuse the leaked refrigerant by changing the wind direction to the vertical direction side after controlling the air to blow out in the horizontal direction side for a predetermined time, and can reduce the possibility of a flammable concentration range being formed in the room.

[0051] <Second Embodiment> Next, the second embodiment will be described. In the first embodiment, an example of controlling the wind direction in two directions, the V1 direction on the horizontal direction side and the V3 direction on the vertical direction side, during the stirring operation was described. In this embodiment, an example of controlling also in an intermediate direction between the V1 direction and the V3 direction will be described.

[0052] The configuration of the air conditioner 100 (indoor unit 20) according to the present embodiment is the same as the configuration described in the first embodiment, and the description thereof will be omitted. Here, the point of controlling also in the intermediate direction in addition to the V1 direction and the V3 direction will be described.

[0053] Figure 8 is a schematic diagram showing an example of wind direction control during stirring operation according to this embodiment. The wind direction (V1 direction) shown in Figure 8(A) corresponds to the wind direction (V1 direction) shown in Figure 5(A) (horizontal blowing), and the wind direction (V3 direction) shown in Figure 8(C) corresponds to the wind direction (V3 direction) shown in Figure 5(B) (downward blowing). In Figure 8(B), the wind direction of the air blown out from the indoor unit 20 (see reference numeral 11) is the V2 direction, which is an intermediate direction between the V1 direction corresponding to the horizontal direction and the V3 direction corresponding to the vertical direction (intermediate blowing). Note that the V2 direction can also be considered the vertical direction when viewed from the V1 direction, and the horizontal direction when viewed from the V3 direction.

[0054] In this embodiment, as shown in Figure 8(A), the indoor unit 20 is first controlled to blow air out from the outlet 21b in the direction of V1 for a time Th (horizontal blowing), and after time Th has elapsed, it is changed to the vertical direction, but as shown in Figure 8(B), the airflow direction of the air blown out from the outlet 21b is changed to the intermediate direction, V2 (intermediate blowing).

[0055] Furthermore, the indoor unit 20 controls the airflow direction of the air blown out from the outlet 21b in the V2 direction for a preset time Tm, and after time Tm has elapsed, it changes the airflow direction of the air blown out from the outlet 21b in the vertical direction V3 (downward blowing), as shown in Figure 8(C).

[0056] Alternatively, the indoor unit 20 may control the airflow direction of the air blown out from the outlet 21b in the V3 direction for a time Tv, and after time Tv has elapsed, return the airflow direction of the air blown out from the outlet 21b to the intermediate direction, V2 direction, as shown in Figure 8(B) (intermediate blowing). Furthermore, the indoor unit 20 may control the airflow direction of the air blown out from the outlet 21b in the V2 direction for a time Tm, and after time Tm has elapsed, return the airflow direction of the air blown out from the outlet 21b to the V1 direction, as shown in Figure 8(A).

[0057] For example, the indoor unit 20 controls the direction of the air blown out from the outlet 21b in the order of V1 direction → V2 direction → V3 direction → V2 direction → V1 direction (and so on thereafter).

[0058] Figure 9 is a flowchart showing an example of the wind direction control process during stirring operation according to this embodiment.

[0059] (Step S201) The control unit 28 acquires the detection result from the refrigerant leak detection sensor 26. Then, the process proceeds to step S203.

[0060] (Step S203) The control unit 28 determines whether or not a refrigerant leak has been detected based on the detection result of the refrigerant leak detection sensor 26. If the control unit 28 determines that no refrigerant leak has been detected (NO), it returns to step S201. On the other hand, if the control unit 28 determines that a refrigerant leak has been detected (YES), it proceeds to step S205.

[0061] (Step S205) The control unit 28 controls the upper and lower flaps 23a so that the airflow direction of the air blown out from the outlet 21b is in the horizontal direction V1 (see Figure 8(A)). Then proceed to step S207.

[0062] (Step S207) The control unit 28 rotates the indoor unit fan 22 and starts the stirring operation. As a result, air is blown out from the outlet 21b in the direction of V1 on the horizontal side, and the leaked refrigerant is diffused into the upper space of the room (see Figure 4(B)). Then, the process proceeds to step S209.

[0063] (Step S209) The control unit 28 determines whether time Th has elapsed since the start of the stirring operation in step S207. If the control unit 28 determines that time Th has elapsed (YES), it proceeds to step S211. On the other hand, if the control unit 28 determines that time Th has not elapsed (NO), it does not proceed to step S211 and remains in step S209. In other words, the control unit 28 controls the air to be blown out from the outlet 21b in the direction of V1 for time Th, and after time Th has elapsed, it proceeds to step S211.

[0064] (Step S211) The control unit 28 controls the upper and lower flaps 23a so that the airflow direction of the air blown out from the outlet 21b is in the vertical direction V2 (see Figure 8(B)). As a result, the air blown out from the outlet 21b is slightly changed from the horizontal direction to the vertical direction, which changes the airflow in the room space and further diffuses the leaked refrigerant. Then, the process proceeds to step S213.

[0065] (Step S213) The control unit 28 determines whether time Tm has elapsed since the direction of the air blown out from the outlet 21b was changed to the V2 direction in step S211. If the control unit 28 determines that time Tm has elapsed (YES), it proceeds to step S215. On the other hand, if the control unit 28 determines that time Tm has not elapsed (NO), it remains in step S213. In other words, the control unit 28 controls the air to blow out from the outlet 21b in the V2 direction for time Tm, and after time Tm has elapsed, it proceeds to step S215.

[0066] (Step S215) The control unit 28 controls the upper and lower flaps 23a so that the airflow direction of the air blown out from the outlet 21b is in the vertical direction V3 (see Figure 8(C)). As a result, the air blown out from the outlet 21b is changed from the intermediate direction to the vertical direction, which changes the airflow in the room space and further diffuses the leaked refrigerant. Then, the process proceeds to step S217.

[0067] (Step S217) The control unit 28 determines whether time Tv has elapsed since the direction of the air blown out from the outlet 21b was changed to the V3 direction in step S215. If the control unit 28 determines that time Tv has elapsed (YES), it proceeds to step S219. On the other hand, if the control unit 28 determines that time Tv has not elapsed (NO), it remains in step S217. In other words, the control unit 28 controls the air to blow out from the outlet 21b in the V3 direction for time Tv, and after time Tv has elapsed, it proceeds to step S219.

[0068] (Step S219) The control unit 28 controls the upper and lower flaps 23a so that the airflow direction of the air blown out from the outlet 21b is in the vertical direction V2 (see Figure 8(B)). As a result, the air blown out from the outlet 21b is slightly changed from the vertical direction to the horizontal direction, which changes the airflow in the room space and further diffuses the leaked refrigerant. Then, the process proceeds to step S221.

[0069] (Step S221) The control unit 28 determines whether time Tm has elapsed since the direction of the air blown out from the outlet 21b was changed to the V2 direction in step S219. The time Tm that serves as the threshold for determining the elapsed time at this time may be the same value as the time Tm in step S213, or it may be a different value. If the control unit 28 determines that time Tm has elapsed (YES), it proceeds to step S223. On the other hand, if the control unit 28 determines that time Tm has not elapsed (NO), it remains in step S221. In other words, the control unit 28 controls the air to blow out from the outlet 21b in the V2 direction for time Tm, and after time Tm has elapsed, it proceeds to step S223.

[0070] (Step S223) The control unit 28 controls the upper and lower flaps 23a so that the airflow direction of the air blown out from the outlet 21b is in the vertical direction V1 (see Figure 8(A)). As a result, the air blown out from the outlet 21b is changed from the intermediate direction to the horizontal direction, which changes the airflow in the room space and further diffuses the leaked refrigerant. Then, the process returns to step S209.

[0071] As described above, in the air conditioner 100 according to this embodiment, the upper and lower flaps 23a (an example of an airflow direction adjustment unit) of the indoor unit 20 can change the direction of the airflow blown out from the outlet vertically in the V1 direction on the horizontal side (an example of a first direction), the V3 direction on the vertical side (an example of a first direction), and the V2 direction between the V1 direction and the V3 direction (an example of an intermediate direction). When a refrigerant leak is detected by the refrigerant leak detection sensor 26, the control unit 28 controls the air to be blown out from the outlet 21b in the V1 direction for a time Th (an example of a first time), and after time Th has elapsed, controls the direction of the airflow blown out from the outlet 21b in the V2 direction for a preset time Tm (an example of a second time).

[0072] Thus, when the air conditioner 100 performs agitation operation in the event of a refrigerant leak, it controls the air to blow out horizontally in the initial stages of the leak, where there are fewer obstacles. Subsequently, when changing the airflow direction to the vertical, it first changes it to the V2 direction, which is between the V1 and V3 directions. Therefore, although the leaked refrigerant diffused in the room gradually falls towards the floor due to gravity, the air conditioner 100 can effectively diffuse the leaked refrigerant by gradually changing the airflow direction towards the floor, thereby reducing the possibility of a flammable concentration zone being formed in the room.

[0073] Furthermore, the control unit 28 controls the airflow direction of the air blown out from the outlet 21b in the V2 direction for a time Tm, and then controls the airflow direction of the air blown out from the outlet 21b in the V3 direction.

[0074] As a result, the air conditioner 100 can effectively diffuse the leaked refrigerant by gradually changing the airflow direction, which was initially controlled horizontally, towards the floor, thereby reducing the possibility of a flammable concentration zone forming in the room.

[0075] Furthermore, the control unit 28 controls the airflow direction of the air blown out from the outlet 21b in the V3 direction for a preset time Tv (an example of a third time), then controls the airflow direction of the air blown out from the outlet 21b in the V2 direction for a time Tm, and after time Tm has elapsed, returns to controlling the airflow direction of the air blown out from the outlet 21b in the V1 direction for a time Th.

[0076] As a result, the air conditioner 100 can continuously diffuse leaked refrigerant by first controlling the airflow direction to the horizontal side and then swinging the airflow direction between the horizontal and vertical sides, thereby reducing the possibility of a flammable concentration zone forming in the room.

[0077] For example, if the airflow direction is changed from the horizontal direction to the vertical direction V3 (downward blowing), the leaked refrigerant will be blown upward. Therefore, the air conditioner 100 can effectively diffuse the leaked refrigerant by gradually changing the blowing direction upward. After returning to the horizontal direction V1 (horizontal blowing), the air conditioner 100 can further effectively diffuse the leaked refrigerant by repeatedly switching between the horizontal, intermediate, and vertical directions.

[0078] In this embodiment, the control of the airflow direction during stirring operation was described as swinging vertically in three stages: V1, V2, and V3. However, it is also possible to swing in more stages, or to continuously change the direction without any stages between V1 and V3.

[0079] <Third Embodiment> Next, a third embodiment will be described. In this embodiment, an example will be described in which the direction of the air blown out from the outlet 21b during stirring operation is changed not only in the vertical direction but also in the left-right direction. In this embodiment, when the control unit 28 controls the flaps 23 during stirring operation, it controls the left-right flaps 23b in addition to controlling the upper and lower flaps 23a.

[0080] Multiple left and right flaps 23b are provided on the left and right sides of the indoor unit 20. The indoor unit 20 can control the direction of the blown air, such as blowing air only forward, only to the right, only to the left, or only in the left and right directions, by opening some of the multiple left and right flaps 23b and closing the others, and by controlling the opening angle.

[0081] Figure 10 is a schematic diagram showing an example of controlling the airflow direction in the left-right direction during stirring operation according to this embodiment. Reference numeral 11 denotes the air blown out from the indoor unit 20 (discharge outlet 21b). Figure 10(A) shows an example in which the air is controlled to be blown out to the right from the discharge outlet 21b (right blowing). Figure 10(B) shows an example in which the air is controlled to be blown out in the front direction from the discharge outlet 21b (front blowing). Figure 10(C) shows an example in which the air is controlled to be blown out to the left from the discharge outlet 21b (left blowing). Figure 10(D) shows an example in which the air is controlled to be blown out simultaneously to the left and right from the discharge outlet 21b (left and right blowing).

[0082] Furthermore, Figure 10(E) shows an example of control that swings the air blown out from the outlet 21b in the left-right direction (left-right swing). For example, the control may be such that the air swings repeatedly in the order of (A) blowing to the right → (B) blowing straight ahead → (C) blowing to the left → (B) blowing straight ahead → (A) blowing to the right → ... or (E) left-right swing may be added to one cycle of swing.

[0083] Figure 11 is a schematic diagram showing another example of swing control of the airflow direction in the left-right direction during stirring operation according to this embodiment. Figure 11(A) shows an example of blowing air forward from the outlet 21b (forward blowing). Figure 11(B) shows an example of blowing air to the left and right at narrow intervals (left-right blowing (small)).

[0084] Figure 11(B) shows an example of blowing air in the left and right directions at narrow intervals (small left / right blowing). Figure 11(C) shows an example of blowing air in the left and right directions at wider intervals than in (B) (medium left / right blowing). Figure 11(D) shows an example of blowing air in the left and right directions at even wider intervals than in (C) (large left / right blowing).

[0085] For example, the distance between the left and right sides of the small left and right blowers may be set to an angle of approximately ±20 degrees relative to the front; the distance between the left and right sides of the medium left and right blowers may be set to an angle of approximately ±35 degrees relative to the front; and the distance between the left and right sides of the large left and right blowers may be set to an angle of approximately ±45 degrees relative to the front.

[0086] For example, the control could be set to repeatedly swing in the following order: (A) blowing straight ahead → (B) blowing left and right (small) → (C) blowing left and right (medium) → (D) blowing left and right (large) → (C) blowing left and right (medium) → (B) blowing left and right (small) → (A) blowing straight ahead → ...

[0087] During the stirring operation in the first embodiment, the control unit 28 controls the airflow direction of the air blown out from the outlet 21b to one of the vertical directions (direction V1 or direction V3), and during this period, it causes the airflow direction of the air blown out from the outlet 21b to swing in the left-right direction for at least one cycle.

[0088] For example, during stirring operation, the control unit 28 swings at least one cycle in the left-right direction during the time Th in which it is controlled in the V1 direction, and swings at least one cycle in the left-right direction during the time Tv in which it is controlled in the V3 direction.

[0089] Furthermore, during the stirring operation in the second embodiment, the control unit 28 controls the airflow direction of the air blown out from the outlet 21b to one of the vertical directions (direction V1, direction V2, or direction V3), and during this period, it causes the airflow direction of the air blown out from the outlet 21b to swing in the left-right direction for at least one cycle.

[0090] For example, during stirring operation, the control unit 28 swings at least one cycle in the left-right direction during the time Th in which it is controlled in the V1 direction, swings at least one cycle in the left-right direction during the time Tm in which it is controlled in the V2 direction, and swings at least one cycle in the left-right direction during the time Tv in which it is controlled in the V3 direction.

[0091] Thus, in the air conditioner 100 according to this embodiment, the flap 23 of the indoor unit 20 can swing the direction of the air blown out from the outlet 21b not only in the vertical direction but also in the left-right direction which intersects with the vertical direction. When the control unit 28 detects a refrigerant leak by the refrigerant leak detection sensor 26, during the period in which the direction of the air blown out from the outlet 21b is controlled in one of the vertical directions, the control unit 28 swings the direction of the air blown out from the outlet 21b in the left-right direction for at least one cycle.

[0092] As a result, the air conditioner 100 can diffuse the leaked refrigerant over a wider area of ​​the room, reducing the possibility of a flammable concentration zone forming in the room.

[0093] <Fourth Embodiment> Next, a fourth embodiment will be described. In the third embodiment, an example was described in which the direction of the air blown out from the outlet 21b is controlled in the left-right direction. However, by making the direction of the air blown out by the indoor unit 20 different in the left-right direction depending on the shape of the room in which the indoor unit 20 is installed, it is possible to effectively diffuse the leaked refrigerant.

[0094] Figure 12 is a schematic diagram showing an example of controlling the airflow direction in the left-right direction during stirring operation according to this embodiment. In the example shown in Figure 12(A), the room 200 in which the indoor unit 20 is installed has a shape in which the space to the right of the indoor unit 20 is larger than the space in front of and to the left of the indoor unit 20. Because the space to the right of the indoor unit 20 is larger, by controlling the airflow direction of the air blown out from the outlet 21b to the right (rightward blowing), leaked refrigerant can be effectively diffused.

[0095] Furthermore, in the example shown in Figure 12(B), the room 200 in which the indoor unit 20 is installed has a long shape in the left-right direction. Because there is ample space in the left-right direction of the indoor unit 20, the airflow direction of the air blown out from the outlet 21b can be controlled simultaneously to the left and right (left-right blowing), thereby effectively diffusing the leaked refrigerant.

[0096] Here, the shape of the room in which the indoor unit 20 is installed may be set according to the operation. For example, the shape of the room may be selected in the initial setup when the indoor unit 20 is installed, and a service technician or user may select the shape of the room using the operating remote control (not shown) of the indoor unit 20. Alternatively, the airflow direction in the left-right direction during mixing operation may be selected in the initial setup when the indoor unit 20 is installed, and a service technician or user may select an appropriate airflow direction according to the shape of the room. In this case, the relationship between the shape of the room and the airflow direction to be selected may be displayed on the display of the operating remote control, or it may be described in the instruction manual of the air conditioner 100.

[0097] Thus, in the air conditioner 100 according to this embodiment, the flap 23 of the indoor unit 20 is capable of changing the direction of the air blown out from the outlet 21b not only in the vertical direction but also in the left-right direction which intersects with the vertical direction. When the control unit 28 detects a refrigerant leak by the refrigerant leak detection sensor 26, it controls the direction of the air blown out from the outlet 21b to either the right side or the left side of the left-right direction, or both, during the period when the air direction is controlled in one of the vertical directions.

[0098] As a result, the air conditioner 100 can more effectively diffuse leaked refrigerant according to the shape of the room, reducing the possibility of a flammable concentration zone forming in the room.

[0099] <Fifth Embodiment> Next, a fifth embodiment will be described. In the fourth embodiment, an example was described in which the user sets the left-right airflow direction of the air blown out by the indoor unit 20 according to the shape of the room in order to effectively diffuse the leaked refrigerant. However, the left-right airflow direction may also be controlled by detecting the shape of the room in which the indoor unit 20 is installed.

[0100] Figure 13 is a schematic block diagram showing an example of the configuration of the indoor unit 20A according to this embodiment. The indoor unit 20A shown differs from the indoor unit 20 shown in Figure 6 in that a distance sensor 29 is added. The control unit 28 uses the distance sensor 29 to detect the shape (spatial shape) of the room.

[0101] The distance sensor 29 is, for example, a sensor that measures distance using the Time of Flight (ToF) method with infrared light. Alternatively, the distance sensor 29 may measure distance using ultrasound instead of infrared light with the ToF method. Furthermore, a LiDAR (Light Detection and Ranging) sensor may be used as the distance sensor 29.

[0102] The control unit 28 controls the left and right flaps 23b according to the shape of the room detected by the distance sensor 29, thereby controlling the left and right airflow direction of the air blown out from the air outlet 21b.

[0103] For example, if the control unit 28 detects that the shape of the room detected using the distance sensor 29 has more space to the right of the indoor unit 20, it controls the airflow direction of the air blown out from the air outlet 21b to the right (rightward blowing) (see Figure 12(A)). Conversely, if the control unit 28 detects that the shape of the room detected using the distance sensor 29 has more space to the left of the indoor unit 20, it controls the airflow direction of the air blown out from the air outlet 21b to the left (leftward blowing). Also, if the shape of the room detected using the distance sensor 29 is longer in the left-right direction, the control unit 28 controls the airflow direction of the air blown out from the air outlet 21b to both the left and right (left-right blowing) simultaneously.

[0104] The detection (determination) of the room shape using the distance sensor 29 is pre-set, for example, by checking whether the difference in the detected distances in the left-right direction is greater than or equal to a threshold, or whether the value of the detected distance in the left-right direction is greater than or equal to a threshold. Then, the setting of the left-right airflow direction is associated and set for each pre-set room shape. The control unit 28 controls the left-right airflow direction based on this setting information and the room shape detected using the distance sensor 29.

[0105] As a result, the air conditioner 100 can detect the shape of the room and more effectively diffuse the leaked refrigerant according to the shape of the room.

[0106] Although the embodiments have been described in detail above with reference to the drawings, the specific configurations are not limited to these embodiments, and each embodiment can be modified or omitted as appropriate.

[0107] For example, if the indoor unit 20 performs a stirring operation when a refrigerant leak occurs, the user or service technician can manually perform a specific operation to terminate the stirring operation after the user determines that ventilation is complete, or after the service technician who came to repair the unit has finished repairing it. Alternatively, if the indoor unit 20 performs a stirring operation when a refrigerant leak occurs, the stirring operation may be terminated after a certain period of time has elapsed since the start of the stirring operation.

[0108] Furthermore, when the indoor unit 20 performs agitation operation in the event of a refrigerant leak, it may first detect the flammable source and control the initial airflow direction during the agitation operation to avoid the flammable source. For example, the indoor unit 20 may detect the flammable source by using a sensor that detects the temperature of a person or the floor (e.g., an infrared sensor) to detect areas where the temperature is above a certain value.

[0109] Furthermore, the indoor unit 20 may be configured to have a ventilation source initially set, or equipped with a sensor for detecting a ventilation source, so that when stirring is performed in the event of a refrigerant leak, the airflow direction is controlled towards the ventilation source. The ventilation source may be, for example, a ventilation fan or a window.

[0110] Furthermore, when the indoor unit 20 performs agitation operation in the event of refrigerant leakage, the airflow rate may be changed during the agitation operation. For example, the indoor unit 20 may initially control the airflow to the maximum airflow rate when controlling the airflow direction to the horizontal V1 direction, and then reduce the airflow rate thereafter.

[0111] Furthermore, the indoor unit 20 may output notifications such as "Turn off the fire" or "Ventilate" when performing agitation operation in the event of refrigerant leakage. The notification may be output by voice or by display. The device for outputting by voice or display may be provided on the indoor unit 20, or on a remote controller (not shown) that remotely operates the indoor unit 20.

[0112] Furthermore, the indoor unit 20 may, in the event of a refrigerant leak, output a notification such as "Please turn off the fire" before starting the stirring operation, and only proceed with the stirring operation (air blowing) after confirming that the fire has been extinguished.

[0113] Alternatively, the program for realizing the functions of the control unit 28 may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be loaded into a computer system and executed to perform the processing of the control unit 28. The term "computer system" here includes hardware such as the operating system and peripheral devices.

[0114] Furthermore, "computer-readable recording media" refers to portable media such as flexible disks, magneto-optical disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into computer systems. Moreover, "computer-readable recording media" includes those that dynamically hold programs for a short period, such as communication lines used when transmitting programs via networks like the Internet or telephone lines, and those that hold programs for a fixed period, such as volatile memory within computer systems acting as servers or clients. The program itself may only implement a portion of the aforementioned functions, and may also be able to implement those functions in combination with programs already recorded in the computer system. Additionally, the program may be stored on a designated server and distributed (downloaded, etc.) via a communication line in response to requests from other devices.

[0115] Furthermore, some or all of the functions of the control unit 28 may be implemented as an integrated circuit such as an LSI (Large Scale Integration). Each function may be individually processorized, or some or all of them may be integrated into a single processor. In addition, the method of implementing the integrated circuit is not limited to LSIs; it may also be implemented using dedicated circuits or general-purpose processors. Furthermore, if advances in semiconductor technology lead to the emergence of integrated circuit technologies that can replace LSIs, integrated circuits using such technologies may be used.

[0116] 20 Indoor unit 21 Housing 21a Intake port 21b Outlet port 22 Indoor unit fan 23 (23a, 23b) Flap 26 Refrigerant leak detection sensor 27 LED 28 Control unit 100 Air conditioner 101 Sealed compressor 102 Intake muffler 103 Four-way switching valve 104 Outdoor heat exchanger 105 Pressure reducer 106 Indoor heat exchanger

Claims

1. An air conditioner comprising a wall-mounted indoor unit through which a flammable refrigerant flows, the air conditioner comprising: a refrigerant leak detection sensor for detecting leakage of the refrigerant; an indoor unit fan that generates an airflow for blowing out air drawn in from an intake port in the indoor unit; an airflow direction adjustment unit that vertically changes the direction of the air blown out from the outlet from at least a first direction on the horizontal side to a second direction on the vertical side; and a control unit that controls the indoor unit fan and the airflow direction adjustment unit to control a stirring operation for stirring the leaked refrigerant when the refrigerant leaks, wherein when the refrigerant leak detection sensor detects leakage of the refrigerant, the control unit controls the air to blow out from the outlet in the first direction for a preset first time, and after the first time has elapsed, controls the direction of the air blown out from the outlet to the second direction.

2. The airflow direction adjustment unit is capable of changing the direction of the air blown out from the outlet vertically to a first direction, a second direction, and an intermediate direction between the first direction and the second direction, and the control unit, when a refrigerant leak is detected by the refrigerant leak detection sensor, controls the airflow from the outlet to blow out in the first direction for a first time, and after the first time has elapsed, controls the direction of the air blown out from the outlet to the intermediate direction for a preset second time, as described in claim 1.

3. The air conditioner according to claim 2, wherein the control unit controls the direction of the air blown out from the outlet to the intermediate direction for the second time, and then controls the direction of the air blown out from the outlet to the second direction.

4. The air conditioner according to claim 3, wherein the control unit controls the direction of the air blown out from the outlet to the second direction for a predetermined third time, then controls the direction of the air blown out from the outlet to the intermediate direction for a second time, and after the second time has elapsed, returns to controlling the direction of the air blown out from the outlet to the first direction for a first time.

5. The airflow direction adjustment unit is capable of swinging the airflow direction of the air blown out from the outlet in a left-right direction intersecting the vertical direction, in addition to changing it in the vertical direction, and the control unit, when a refrigerant leak is detected by the refrigerant leak detection sensor, swings the airflow direction of the air blown out from the outlet in the left-right direction for at least one cycle during the period in which the airflow direction of the air blown out from the outlet is controlled in any one of the vertical directions, according to any one of claims 1 to 4.

6. The airflow direction adjustment unit is capable of changing the direction of the air blown out from the outlet in a left-right direction that intersects with the vertical direction, in addition to changing it in the vertical direction, and the control unit, when a refrigerant leak is detected by the refrigerant leak detection sensor, controls the direction of the air blown out from the outlet to either the right side or the left side of the left-right direction, or both, during the period when it is controlled in one of the vertical directions, the air conditioner according to any one of claims 1 to 4.

7. An air conditioner equipped with a wall-mounted indoor unit through which a flammable refrigerant flows, comprising: a refrigerant leak detection sensor for detecting leakage of the refrigerant; an indoor unit fan that generates an airflow for blowing out air drawn in from an intake port in the indoor unit; an airflow direction adjustment unit that vertically changes the airflow direction of the air blown out from the outlet from at least a first direction on the horizontal side to a second direction on the vertical side; and a control unit that controls the indoor unit fan and the airflow direction adjustment unit to control a stirring operation for stirring the refrigerant when it leaks, the control unit comprising: a step of controlling the airflow direction of the air blown out from the outlet in the first direction for a preset first hour when the refrigerant leak detection sensor detects leakage of the refrigerant; and a step of controlling the airflow direction of the air blown out from the outlet in the second direction after the first hour has elapsed.

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