Refrigerant detection device

Abstract

[Problem] To provide a refrigerant detection device capable of shortening the time required to detect leakage of a refrigerant. [Solution] According to an embodiment, this refrigerant detection device comprises: a housing that is attached to a wall surface of an indoor space, which is a space to be air-conditioned by an air conditioner, and has a bottom surface facing a floor surface of the indoor space; and a refrigerant sensor that is housed inside the housing and detects leakage of a refrigerant. The housing has a first opening that is provided on the bottom surface and allows the inside and the outside of the housing to communicate with each other, and a second opening that is provided on a surface different from the bottom surface and allows the inside and the outside of the housing to communicate with each other. The first opening is provided at a position opposing the refrigerant sensor when viewed from below in the vertical direction.

Description

Refrigerant detection device

[0001] The present invention relates to a refrigerant detection device.

[0002] It is known to provide a refrigerant sensor unit (refrigerant detection device) to detect refrigerant leaks in air conditioners. For example, Patent Document 1 describes a refrigerant sensor unit having a housing attached to a wall surface of an indoor space and a refrigerant sensor housed inside the housing, with an opening provided on one side of the housing to connect the inside and outside of the housing.

[0003] Japanese Patent Application Laid-Open No. 2022-129916

[0004] Air conditioners use a mildly flammable refrigerant such as R32. If this mildly flammable refrigerant leaks from the air conditioner, it is necessary to shorten the time until the refrigerant leak is detected as short as possible so that the amount of refrigerant leakage does not reach the lower flammability limit.

[0005] In view of the above circumstances, an object of the present invention is to provide a refrigerant detection device that can shorten the time required to detect a refrigerant leak.

[0006] To achieve the above object, one aspect of the present invention provides a refrigerant detection device comprising: a housing attached to a wall of an indoor space that is a conditioned space of an air conditioner and having a bottom surface facing the floor of the indoor space; and a refrigerant sensor housed within the housing for detecting refrigerant leakage. The housing has a first opening provided on the bottom surface that connects the inside of the housing to the outside, and a second opening provided on a surface different from the bottom surface that also connects the inside of the housing to the outside, the first opening being located at a position facing the refrigerant sensor when viewed from below in the vertical direction.

[0007] According to the refrigerant detection device, the first opening of the housing is located on the bottom surface, facing the refrigerant sensor from a vertical perspective, and the second opening of the housing is located on a different surface from the bottom surface. This allows refrigerant leaking from the first opening located on the bottom surface to easily flow into the housing. Furthermore, because the first opening and the refrigerant sensor are facing each other vertically, the distance from the first opening to the refrigerant sensor is minimized, shortening the time it takes for the refrigerant to reach the refrigerant sensor. Furthermore, the second opening allows air equivalent to the refrigerant that has flowed in through the first opening to be expelled, allowing the refrigerant to flow smoothly into the housing.

[0008] The second opening may be provided at a position whose height from the bottom surface is equal to or greater than the height of the refrigerant sensor from the bottom surface.

[0009] The second opening may be provided on a first side surface that is closer to the refrigerant sensor when viewed from the first direction, of a pair of side surfaces that are erected from the bottom surface and face each other in a horizontal direction parallel to the wall surface and perpendicular to the vertical direction.

[0010] The second opening may be rectangular in shape with a long side in the vertical direction when viewed from the horizontal direction.

[0011] The first opening may be rectangular in shape, with a long side extending in a horizontal direction parallel to the wall surface and perpendicular to the vertical direction.

[0012] The housing may further include a substrate provided along the wall surface parallel to the vertical and horizontal directions inside the housing and supporting the refrigerant sensor in a front-to-rear direction perpendicular to the vertical and horizontal directions, the refrigerant sensor being cylindrical and having a substrate-side end on one side provided on the substrate side in the front-to-rear direction and a tip-side end on the other side, and the first opening may be located on the tip-side end side of the refrigerant sensor in the front-to-rear direction.

[0013] The second opening may be provided at a position facing the refrigerant sensor when viewed in a horizontal direction that is perpendicular to the vertical direction among directions parallel to the wall surface.

[0014] According to the present invention, it is possible to provide a refrigerant detection device that can shorten the time until a refrigerant leak is detected.

[0015] FIG. 1 is a diagram illustrating the arrangement of a refrigerant detection device according to an embodiment of the present invention. FIG. 2 is a front view of the refrigerant detection device. FIG. 3 is a diagram of the refrigerant detection device as seen from the bottom side. FIG. 4 is a perspective view of the refrigerant detection device as seen from the bottom side. FIG. 5 is a cross-sectional view of the refrigerant detection device as seen from the bottom side. FIG. 6 is a cross-sectional view of the refrigerant detection device as seen from the side side. FIG. 7 is a diagram illustrating the refrigerant detection device and the location of refrigerant leakage. FIG. 8 is a diagram illustrating the flow of the refrigerant. FIG. 9 is a diagram illustrating the refrigerant detection device and refrigerant. FIG. 10 is a diagram illustrating the refrigerant flowing through the refrigerant detection device, where (A) a rectangular second opening with long sides in the Z-axis direction is provided, and (B) a rectangular second opening with short sides in the Z-axis direction is provided. FIG. 11 is a side cross-sectional view of the refrigerant detection device. FIG. 12 is a diagram illustrating a refrigerant detection device according to a modified example of the present invention.

[0016] Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and may differ from the actual product. Therefore, specific components should be determined by taking the following description into consideration.

[0017] Furthermore, the embodiments shown below are merely examples of devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention does not limit the shape, structure, arrangement, etc. of the components to those described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims.

[0018] FIG. 1 is a diagram showing the arrangement of a refrigerant detection device 10 according to an embodiment of the present invention, and FIG. 2 is a front view of the refrigerant detection device 10. Also, FIG. 3 is a diagram of the refrigerant detection device 10 viewed from the bottom surface 15, FIG. 4 is a perspective view of the refrigerant detection device 10 viewed from the bottom surface 15, and FIG. 5 is a cross-sectional view of the refrigerant detection device 10 viewed from the bottom surface 15. FIG. 6 is a cross-sectional view of the refrigerant detection device 10 viewed from the side surface 13. In the following description, the vertical direction perpendicular to the floor surface 102 of the indoor space 100, the front-to-rear direction perpendicular to the wall surface 101, and the horizontal direction perpendicular to the vertical direction and the front-to-rear direction are referred to as the Z direction, the Y direction, and the X direction, respectively. Of course, these directions are not limited to these.

[0019] Refrigerant Detection Device The refrigerant detection device 10 is a detection device provided in the air conditioning apparatus 1, and includes a housing 10A, a refrigerant sensor 20, and a substrate 30.

[0020] The air conditioning apparatus 1 includes a refrigerant circuit formed by a heat exchanger housed in the indoor unit 5, which is the indoor unit, a pressure reducing device such as a compressor and an electronic expansion valve housed in the outdoor unit, and an outdoor heat exchanger provided in the outdoor unit. The air conditioning apparatus 1 conditions an indoor space 100, which is the space to be air-conditioned, by circulating a refrigerant through this refrigerant circuit. The indoor space 100 is a space used by people.

[0021] As shown in Figure 1, the air outlet 6 of the indoor unit 5 is provided on a wall surface 101 of the indoor space 100, but of course the air outlet 6 of the indoor unit 5 is not limited to being provided on the wall surface 101. Air conditioned by the air conditioning device 1 is blown out from the air outlet 6.

[0022] The air conditioning apparatus 1 includes a control unit (not shown). The control unit includes a computer having a processor such as a CPU and memory devices such as ROM and RAM. The control unit is connected via signal lines to the outdoor unit, the indoor unit 5, and other components that form the refrigerant circuit, as well as the refrigerant detection device 10. The control unit receives various signals sent from the components of the air conditioning apparatus 1 via the signal lines, and also sends signals from the control unit to the components of the air conditioning apparatus 1. In this way, the control unit controls the operation of the components of the air conditioning apparatus 1. Note that the control unit and the components of the air conditioning apparatus 1 may be connected not only via a wired connection such as a signal line, but also wirelessly via a communication unit.

[0023] The control unit is connected to an operation unit 7, which is configured by a remote control having operation buttons, etc., via a signal line. The operation unit 7 of this embodiment is attached to a wall surface 101 of the indoor space 100.

[0024] The operation unit 7 is provided with a display panel in addition to operation buttons. The display panel displays the operation status of the operation buttons of the operation unit 7 and the operating status of the air conditioning device 1. The operation unit 7 can input temperature settings, etc. In other words, the operation unit 7 functions as an input unit.

[0025] In this embodiment, the refrigerant used in the air conditioning apparatus 1 including the indoor unit 5 is a mildly flammable or flammable refrigerant, such as a mixed refrigerant containing R32 or the like. In the event of a leak of a mildly flammable or flammable refrigerant, it is necessary to shorten the time until the refrigerant leak is detected so that the refrigerant concentration in the indoor space 100 does not reach the lower flammability limit (LFL). In particular, it is desirable to shorten the time until the refrigerant leak from the indoor unit 5 installed in the indoor space 100 is detected. Furthermore, the refrigerant leaking from the air conditioning apparatus 1 into the indoor space 100 is in a gas state having a specific gravity greater than that of air.

[0026] A refrigerant detection device 10 is disposed near the indoor unit 5. The refrigerant detection device 10 detects the concentration of refrigerant in the indoor space 100 and emits an alarm to alert people in the indoor space 100 of a refrigerant leak. The refrigerant detection device 10 also detects the concentration of refrigerant in the indoor space 100 and transmits a detection signal via a signal line to the control unit. The refrigerant detection device 10 of this embodiment is connected to the control unit via the operation unit 7. Of course, the method of alerting people in the indoor space 100 of a refrigerant leak is not limited to the alarm sound described above; light, for example, may also be used.

[0027] Furthermore, the refrigerant detection device 10 is capable of transmitting and receiving signals via a signal line to and from a control center or other location outside the air conditioning apparatus 1. For example, the refrigerant detection device 10 can detect the concentration of refrigerant in the indoor space 100 and transmit a detection signal to the control center via the signal line.

[0028] The refrigerant detection device 10 is attached to a wall surface 101. As described above, if the refrigerant used in the air conditioning apparatus 1 is a gas with a specific gravity greater than that of air, the refrigerant detection device 10 is desirably installed in the lower part of the indoor space 100, below the indoor unit 5. In this embodiment, the top surface 16 of the refrigerant detection device 10 is attached at a position 30 cm or less above the floor surface 102 of the indoor space 100.

[0029] The refrigerant detection device 10 is powered by the indoor unit 5, which is the indoor unit, but of course this is not limited to this and power may also be supplied from a commercial power source via a switch box 105 provided on the wall surface 101.

[0030] (Housing) As shown in FIGS. 2 to 5, the housing 10A of the refrigerant detection device 10 is attached to a wall surface 101 and is formed in a rectangular parallelepiped shape with an internal space W. The housing 10A has a front surface 11, a back surface 12, multiple side surfaces 13 and 14, a bottom surface 15, and a top surface 16. In this embodiment, the housing 10A is a rectangular parallelepiped with its long sides in the X-axis direction, but this is not limited to this. It may also be a rectangular parallelepiped with its short sides in the X-axis direction, or a regular hexahedron. It is also not limited to a rectangular parallelepiped, and may be, for example, a hexagonal prism. In this embodiment, the floor surface 102, the bottom surface 15, and the top surface 16 are parallel to the XY plane and perpendicular to the Z-axis direction (vertical direction). The wall surface 101 and the floor surface 102 are positioned perpendicular to each other.

[0031] The rear surface 12 has a rectangular shape with a long side in the X-axis direction (horizontal direction) when viewed from the Y-axis direction (front-rear direction), and is attached to face the wall surface 101 in the Y-axis direction. The front surface 11 also has a rectangular shape with a long side in the X-axis direction when viewed from the Y-axis direction, faces the rear surface 12 in the Y-axis direction, and is provided facing the indoor space 100. In other words, the front surface 11 and the rear surface 12 stand upright from a bottom surface 15 (described later) and function as a pair of side surfaces facing each other in a direction perpendicular to the wall surface 101 (the Y-axis direction). The front surface 11 has a sound emission hole 111, which is a through-hole that penetrates the inside and outside of the housing 10A (the indoor space 100), at approximately the center, and emits an alarm sound when the refrigerant is detected.

[0032] The rear surface 12 is also provided with insertion holes (not shown) for inserting various wires such as power supply lines and signal lines that are wired inside the housing 10A.

[0033] As shown in FIGS. 4 and 5 , the side surfaces 13 and 14 are rectangular with their long sides in the Z-axis direction when viewed from the X-axis direction. The side surfaces 13 and 14 are in contact with both ends of the front surface 11 and the back surface 12 and the bottom surface 15 and the top surface 16 (described later) in the X-axis direction, and function as side surfaces of the housing 10A. That is, the side surfaces 13 and 14 extend upright from the bottom surface 15 and face each other in a direction parallel to the wall surface 101 and perpendicular to the Z-axis direction (the X-axis direction). One side surface 13 (first side surface) of the side surfaces is located closer to the refrigerant sensor 20 (described later) when viewed from the Y-axis direction or the Z-axis direction. The other side surface 14 (second side surface) of the side surfaces is located farther from the refrigerant sensor 20 (described later) when viewed from the Y-axis direction or the Z-axis direction (relative to the first side surface 13). In this embodiment, the side surfaces 13 and 14 are arranged along the Z-axis direction from the bottom surface 15 (orthogonal to the Z-axis direction). However, this is not a limitation, and the side surfaces 13 and 14 may be inclined with respect to the Z-axis direction. The first side surface 13 has a second opening 18 as will be described later.

[0034] As shown in FIG. 3 , the bottom surface 15 has a rectangular shape with its long side in the X-axis direction as viewed from the Z-axis direction, and is disposed opposite the floor surface 102 in the Z-axis direction. The bottom surface 15 functions as the bottom of the housing 10A. The top surface 16 also has a rectangular shape with its long side in the X-axis direction as viewed from the Z-axis direction, and is disposed opposite the floor surface 102 and the bottom surface 15 in the Z-axis direction. The top surface 16 is located in the positive direction (upward) of the bottom surface 15 in the Z-axis direction. In this embodiment, the bottom surface 15 and the top surface 16 are disposed parallel to the floor surface 102, but this is not a limitation, and the bottom surface 15 and the top surface 16 may be inclined with respect to the XY plane. The bottom surface 15 has a first opening 17, as described below.

[0035] As shown in FIGS. 2 and 5 , the housing 10A has an internal space W surrounded by the front surface 11, rear surface 12, multiple side surfaces 13 and 14, bottom surface 15, and top surface 16. The refrigerant detection device 10 includes within the internal space W: a refrigerant sensor 20 (described later); a board 30 that is parallel to the wall surface 101 (parallel to the XZ plane) and on which the refrigerant sensor 20 is mounted so as to be supported along the Y-axis; and a space (not shown) that emits an alarm when the refrigerant sensor 20 detects a refrigerant concentration and transmits a detection signal to the controller via a signal line. The board 30 is located on the front surface 11 side in the Y-axis direction and is electrically connected to the control room. When the refrigerant concentration detected by the refrigerant sensor 20 exceeds a predetermined value, the control room emits an alarm and transmits a detection signal to the controller via a signal line.

[0036] Furthermore, the refrigerant detection device 10 detects the concentration of refrigerant in the indoor space 100 and transmits a detection signal to the control unit via a signal line. Upon receiving the detection signal, the control unit may, for example, cause a predetermined display to be displayed on the display panel of the operation unit 7 or cause the indoor unit 5 to perform air blowing operation. This allows the air conditioning apparatus 1 to suppress an increase in refrigerant concentration in the indoor space 100.

[0037] The control unit may receive a detection signal from the refrigerant detection device 10 and determine whether or not a refrigerant leak has occurred in the indoor space 100. Alternatively, the refrigerant detection device 10 may determine whether or not a refrigerant leak has occurred in the indoor space 100. Furthermore, the refrigerant detection device 10 may cause a predetermined display to be displayed on the display panel of the operation unit 7, or cause the indoor unit 5 to perform a fan operation, etc.

[0038] 5, the refrigerant sensor 20 is a sensor component that detects the concentration of refrigerant that has flowed into the internal space W. The refrigerant sensor 20 is cylindrical. The refrigerant sensor 20 is mounted on a substrate 30, and when the substrate 30 is incorporated into the housing 10A and the housing 10A is attached to the wall surface 101, the refrigerant sensor 20 is positioned so as to extend in the Y-axis direction. In this embodiment, the diameter of the refrigerant sensor 20 is shorter than the height of the refrigerant sensor 20, but this is not necessarily limited to this.

[0039] 5 , the refrigerant sensor 20 has a substrate-side end portion 20B on one side, which is located on the substrate 30 side in the Y-axis direction and has a terminal (not shown) electrically connected to the substrate 30, and a tip-side end portion 20A on the other side, which is located on the front surface 11. In this embodiment, the substrate 30 is located on the front surface 11 side, but this is not limiting, and the substrate 30 may also be located on the back surface 12 side.

[0040] In this embodiment, the refrigerant sensor 20 is a semiconductor gas sensor, but is not limited to this and may be an NDIR (Non Dispersive InfraRed) type or an electrochemical type. In this embodiment, the refrigerant sensor 20 detects the refrigerant as it flows into the refrigerant sensor 20 from the tip end 20A.

[0041] 5 , first opening 17 is a through-hole that connects the inside and outside of housing 10A in the Z-axis direction, and has a rectangular shape with its long side in the X-axis direction when bottom surface 15 is viewed in the Z-axis direction from below (vertically below) housing 10A. First opening 17 is located opposite refrigerant sensor 20 when viewed in the Z-axis direction.

[0042] 5, in this embodiment, the first opening 17 is located on the tip end 20A side of the refrigerant sensor 20 as viewed in the Z-axis direction. In particular, in this embodiment, the first opening 17 is provided at a position opposite the tip end 20A as viewed in the Z-axis direction. Of course, this is not limitative, and the first opening 17 may be provided at the substrate end 20B side opposite the refrigerant sensor 20.

[0043] 6 , second opening 18 is a through-hole that connects the inside and outside of housing 10A in the X-axis direction and has a rectangular shape with its long side in the Z-axis direction as viewed from the X-axis direction. In this embodiment, second opening 18 is provided at a position whose height in the Z-axis direction from bottom surface 15 is equal to or greater than the height of refrigerant sensor 20 from bottom surface 15. However, this is not limiting, and second opening 18 may also be provided at a position facing refrigerant sensor 20 as viewed from the X-axis direction.

[0044] (Operation) The operation of the refrigerant detection device 10 configured as described above will now be described. In the air conditioning apparatus 1, refrigerant may leak into the indoor space 100 via the indoor unit 5. In this embodiment, the refrigerant used in the air conditioning apparatus 1 is a gas with a specific gravity greater than that of air, and so refrigerant that leaks into the indoor space 100 accumulates in the indoor space 100, accumulating on the floor surface 102. If refrigerant continues to leak into the indoor space 100, the refrigerant that has accumulated on the floor surface 102 eventually flows into the refrigerant detection device 10 via the first opening 17 and the second opening 18.

[0045] The refrigerant sensor 20 detects the concentration of refrigerant that has flowed into the housing 10A. When the refrigerant concentration detected by the refrigerant sensor 20 reaches or exceeds a predetermined value, the refrigerant detection device 10 emits an alarm sound. In this manner, the refrigerant detection device 10 alerts people in the indoor space 100 to a refrigerant leak. In this embodiment, an alarm sound has been described as an example of a method for alerting people in the indoor space 100 to a refrigerant leak, but this is not limiting and light or other means may also be used to alert people.

[0046] As described above, the refrigerant detection device 10 detects that the refrigerant concentration is equal to or greater than a predetermined value, thereby alerting people in the indoor space 100 to a refrigerant leak. The flow of the leaked refrigerant will now be described. FIG. 7 is a diagram showing the refrigerant detection device 10 and the location of the leaked refrigerant R, and FIG. 8 is a diagram showing the flow of refrigerant R. FIG. 9 is a diagram showing the refrigerant detection device 10 and refrigerant R, and FIG. 10 is a diagram showing the refrigerant R flowing through the refrigerant detection device 10. (A) shows a rectangular second opening 18 with its long side in the Z-axis direction, and (B) shows a rectangular second opening 18' with its short side in the Z-axis direction. Furthermore, FIG. 11 is a side cross-sectional view of the refrigerant detection device 10.

[0047] As shown in Figure 7, the refrigerant detection device 10 is installed in an indoor space 100. The refrigerant (R32) R is sprayed from a ceiling 103. The refrigerant R is sprayed toward a floor surface 102.

[0048] FIG. 8 shows the flow of refrigerant R when refrigerant (R32) R is sprayed from ceiling 103 into indoor space 100 similar to that shown in FIG. 7 . As shown in FIG. 8 , refrigerant R flows from ceiling 103 toward floor 102 along wall surface 101 in the negative direction of the Z axis. Next, refrigerant R that reaches floor 102 flows toward the opposing wall surface 101 along floor 102 in the negative direction of the Y axis. Next, refrigerant R that collides with wall surface 101 flows toward ceiling 103 along wall surface 101 in the positive direction of the Z axis. Because refrigerant R rising toward ceiling 103 is a gas with a higher specific gravity than air, it loses speed and moves toward floor 102 as shown in FIG. 8 . As a result, refrigerant R gradually accumulates on floor 102 as shown in FIG. 9 .

[0049] That is, as shown in Figure 9, by providing the first opening 17 on the bottom surface 15 of the refrigerant detection device 10 mounted on the wall surface 101 as in this embodiment, the refrigerant R that gradually accumulates from the floor surface 102 can more easily flow into the housing 10A, allowing the refrigerant sensor 20 to detect a leak of refrigerant R more quickly. Furthermore, when air convection occurs in the air-conditioned space due to the indoor unit fan running or people moving around in the air-conditioned space, a flow of air (refrigerant R) occurs within the housing 10A as shown in Figure 10, allowing the refrigerant sensor 20 to detect the leak more quickly. By providing the first opening 17 in a position facing the refrigerant sensor 20 in the Z-axis direction, the distance between the refrigerant sensor 20 and the first opening 17 is minimized, allowing for faster detection.

[0050] As shown in Fig. 5, the first opening 17 has a rectangular shape with the longitudinal direction in the X-axis direction when viewed from the Z-axis direction. This increases the width (in the X-axis direction) through which the refrigerant R passes, making it easier for the refrigerant R to come into contact with the refrigerant sensor 20. This shortens the time until a leak of the refrigerant R is detected. Furthermore, in this embodiment, the first opening 17 is provided on the tip end 20A side of the refrigerant sensor 20, particularly at a position opposite the tip end 20A. This makes it easier for the refrigerant R to come into contact with the refrigerant sensor 20, making it shorter the time until a leak of the refrigerant R is detected.

[0051] Furthermore, since the first opening 17 is provided on the bottom surface 15, it is possible to prevent dirt, dust, etc. from entering the internal space W (inside the housing 10A).

[0052] In the present embodiment, the second opening 18 is provided at a position whose height in the Z-axis direction from the bottom surface 15 is equal to or greater than the height of the refrigerant sensor 20 from the bottom surface 15. This allows the refrigerant sensor 20 to more easily detect the refrigerant R. In other words, if the height in the Z-axis direction of the second opening 18 from the bottom surface 15 is lower than that of the refrigerant sensor 20, the refrigerant R flowing in from the first opening 17 may escape through the second opening 18, which is lower than the refrigerant sensor 20, before reaching the height of the refrigerant sensor 20. However, if the height in the Z-axis direction of the second opening 18 from the bottom surface 15 is equal to or greater than that of the refrigerant sensor 20, as in the present embodiment, the refrigerant R flowing in from the first opening 17 passes through the refrigerant sensor 20 and escapes to the second opening 18, as shown in FIG. 10 . This ensures that the refrigerant R comes into contact with the refrigerant sensor 20, making it easier for the refrigerant sensor 20 to detect the refrigerant R.

[0053] The second opening 18 is provided on the first side surface 13. This makes it less likely for dust G to accumulate and block the second opening 18 than when an opening is provided on the top surface 16, allowing the refrigerant R to flow smoothly into the housing 10A. Furthermore, by providing the second opening 18 on the first side surface 13 rather than the front surface 11, it is less visible to people in the indoor space 100, improving the design.

[0054] In this embodiment, as shown in FIG. 11 , the second opening 18 has a rectangular shape with its long side in the Z-axis direction as viewed from the X-axis direction. This prevents dust G from accumulating in the second opening 18 from being blocked entirely by dust G, compared to a rectangular shape with its short side in the Z-axis direction as viewed from the X-axis direction. This allows the refrigerant R that flows into the housing 10A from the first opening 17 to flow smoothly out of the second opening 18. As shown in FIG. 11 , dust G accumulates below the second opening 18. When the second opening 18 has a rectangular shape with its long side in the Z-axis direction as in this embodiment, the area of ​​the portion free of dust G is larger than when the second opening 18 has a rectangular shape with its short side in the Z-axis direction, and the effective opening area through which the refrigerant R flows into the housing 10A is therefore larger.

[0055] Furthermore, because the second opening 18 has a rectangular shape with its long side oriented in the Z-axis direction as viewed from the X-axis direction, as shown in FIGS. 10A and 10B , the width of the flow path through which the refrigerant R passes is wider than in a rectangular shape with its short side oriented in the Z-axis direction, making it easier for the refrigerant R to come into contact with the refrigerant sensor 20. That is, as shown in FIG. 10B , when the refrigerant R flowing in from the first opening 17 flows out (out) of the second opening 18, if the width of the second opening 18 in the Z-axis direction is narrow (its short side is narrow), the width of the flow path through which the refrigerant R passes is narrow, making it difficult for the refrigerant R to come into contact with the refrigerant sensor 20. However, when the second opening 18 has a rectangular shape with its long side oriented in the Z-axis direction as viewed from the X-axis direction as shown in FIG. 10A , the width of the flow path through which the refrigerant R passes is wider than in a rectangular shape with its short side oriented in the Z-axis direction, making it easier for the refrigerant R to come into contact with the refrigerant sensor 20. This makes it easier for the refrigerant sensor 20 to detect the refrigerant R.

[0056] <Modification> In the above embodiment, the height of second opening 18 from bottom surface 15 in the Z-axis direction is equal to or greater than the height of refrigerant sensor 20 from bottom surface 15 in the Z-axis direction, but this is not necessarily limited to this, and second opening 18 may be located opposite refrigerant sensor 20 when viewed from the X-axis direction. Figure 12 shows a refrigerant detection device 10' according to a modification of the present invention.

[0057] The height of the housing 10A' of the refrigerant detection device 10' in the Z-axis direction is lower than that of the above-described refrigerant detection device 10. This is because the height of the second opening 18 from the bottom surface 15 in the Z-axis direction is the same as the height of the refrigerant sensor 20 from the bottom surface 15 in the Z-axis direction, so a space equal to or greater than this height can be eliminated. This makes it possible to reduce the size of the refrigerant detection device 10', thereby reducing manufacturing costs.

[0058] <Other Modifications> In the above embodiment, the second opening 18 is provided on the first side surface 13, but of course this is not limited thereto. The second opening 18 may be provided on the front surface 11, which is a surface different from the bottom surface 15, or on the top surface 16. This also makes it easier for the refrigerant sensor 20 to detect the refrigerant R. Furthermore, when the second opening 18 is provided on the top surface 16, it is preferable that the second opening 18 be provided in a position facing the refrigerant sensor 20 when viewed from the Z-axis direction. As a result, the refrigerant R flows from the first opening 17 to the second opening 18 along the Z-axis direction, and the refrigerant sensor 20 is present on that flow path, making it easier for the refrigerant sensor 20 to detect the refrigerant R.

[0059] DESCRIPTION OF SYMBOLS 1... Air conditioning apparatus 10... Refrigerant detection device 10A... Housing 11... Front surface 13... First side surface 14... Second side surface 15... Bottom surface 17... First opening 18... Second opening surface 20... Refrigerant sensor 30... Circuit board 100... Indoor space 101... Wall surface 102... Floor surface R... Refrigerant W... Internal space

Claims

1. A refrigerant detection device comprising a housing attached to a wall surface of an indoor space which is an air-conditioned space of an air conditioner and having a bottom surface facing the floor surface of the indoor space, and a refrigerant sensor housed inside the housing for detecting refrigerant leakage, wherein the housing has a first opening provided in the bottom surface for communicating the inside and the outside of the housing, and a second opening provided in a surface different from the bottom surface for communicating the inside and the outside of the housing, and the first opening is provided at a position facing the refrigerant sensor when viewed from below in the vertical direction.

2. The refrigerant detection device according to claim 1, wherein the second opening is provided at a position where the height from the bottom surface is equal to or higher than the height of the refrigerant sensor from the bottom surface.

3. The refrigerant detection device according to claim 1, wherein the second opening is provided in a first side surface closer to the refrigerant sensor when viewed in the vertical direction among a pair of side surfaces facing each other in a horizontal direction orthogonal to the vertical direction in a direction parallel to the wall surface and standing upright from the bottom surface.

4. The refrigerant detection device according to claim 3, wherein the second opening has a rectangular shape having a long side in the vertical direction when viewed in the horizontal direction.

5. The refrigerant detection device according to claim 1, wherein the first opening has a rectangular shape having a long side in a horizontal direction orthogonal to the vertical direction in a direction parallel to the wall surface.

6. The refrigerant detection device according to claim 5, further comprising a substrate provided inside the housing along the wall surface parallel to the vertical direction and the horizontal direction for supporting the refrigerant sensor in a front-rear direction orthogonal to the vertical direction and the horizontal direction, wherein the refrigerant sensor has a cylindrical shape and has one substrate-side end provided on the substrate side and the other tip-side end in the front-rear direction, and the first opening is located on the tip-side end side of the refrigerant sensor in the front-rear direction.

7. The refrigerant detection device according to claim 3, wherein the second opening is provided at a position facing the refrigerant sensor when viewed in the horizontal direction.

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