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

Background Art

[0002] It is known to provide a refrigerant sensor unit (refrigerant detection device) in order to detect leakage of a refrigerant of an air conditioning device. For example, Patent Literature 1 describes a refrigerant sensor unit that includes a casing to be attached to a wall surface of an indoor space and a refrigerant sensor housed in the casing, the refrigerant sensor unit having a structure in which an opening that allows the inside and the outside of the casing to communicate with each other is provided on one side surface of the casing. Citation List Patent Literature

[0003] Patent Literature 1: Japanese Patent Application Laid-open No. 2022-129916 Disclosure of Invention Technical Problem

[0004] For example, a low-flammability refrigerant such as R32 is used in an air conditioning device. If such a low-flammability refrigerant leaks from the air conditioning device, the time taken to detect the leakage of the refrigerant needs to be as short as possible such that the amount of leakage of the refrigerant does not reach a lower flammability limit.

[0005] In view of the circumstances as described above, it is an object of the present invention to provide a refrigerant detection device capable of shortening the time taken to detect leakage of a refrigerant. Solution to Problem

[0006] In order to achieve the object described above, a refrigerant detection device according to an embodiment of the present invention includes: a casing that is to be attached to a wall surface of an indoor space as a space to be air-conditioned by an air conditioning device and has a bottom surface facing a floor surface of the indoor space; and a refrigerant sensor that is housed inside the casing and detects leakage of a refrigerant. The casing includes a first opening that is provided to the bottom surface and allows an inside and an outside of the casing to communicate with each other, and a second opening that is provided to a surface different from the bottom surface and allows the inside and the outside of the casing to communicate with each other. The first opening is provided at a position facing the refrigerant sensor when viewed from below in a vertical direction.

[0007] According to the refrigerant detection device, the first opening of the casing is provided to the bottom surface and provided at the position facing the refrigerant sensor when viewed from below in the vertical direction, and the second opening of the casing is provided to a surface different from the bottom surface. In other words, the leaked refrigerant easily flows into the casing from the first opening provided to the bottom surface. In addition, since the first opening and the refrigerant sensor face each other when viewed from the vertical direction, a distance from the first opening to the refrigerant sensor is the shortest, which makes it possible to shorten the time taken for the refrigerant to reach the refrigerant sensor. Further, since the second opening is provided, air corresponding to the amount of refrigerant that has flowed into from the first opening can be discharged, so that the refrigerant can be caused to flow into the casing smoothly.

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

[0009] The second opening may be provided to a first side surface closer to the refrigerant sensor when viewed from the first direction, the first side surface being one of a pair of side surfaces erected from the bottom surface and facing each other in a horizontal direction orthogonal to the vertical direction in directions parallel to the wall surface.

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

[0011] The first opening may have a rectangular shape having a long side in a horizontal direction orthogonal to the vertical direction in directions parallel to the wall surface.

[0012] The refrigerant detection device may further include a circuit board that is provided inside the casing along the wall surface parallel to the vertical direction and the horizontal direction and supports the refrigerant sensor in a front-back direction orthogonal to the vertical direction and the horizontal direction. The refrigerant sensor may have a columnar shape and includes a circuit-board-side end portion on one side and a tip-side end portion on another side in the front-back direction, the circuit-board-side end portion being provided on a side of the circuit board. The first opening may be located on a side of the tip-side end portion of the refrigerant sensor in the front-back direction.

[0013] The second opening may be provided at a position facing the refrigerant sensor when viewed from the horizontal direction orthogonal to the vertical direction in the directions parallel to the wall surface. Advantageous Effects of Invention

[0014] According to the present invention, it is possible to provide a refrigerant detection device capable of shortening the time taken to detect leakage of a refrigerant. Brief Description of Drawings

[0015] [Fig. 1] Fig. 1 is a view illustrating an arrangement state of a refrigerant detection device according to an embodiment of the present invention. [Fig. 2]  Fig. 2 is a front view of the refrigerant detection device. [Fig. 3]  Fig. 3 is a view of the refrigerant detection device when viewed from a bottom surface side. [Fig. 4]  Fig. 4 is a perspective view of the refrigerant detection device when viewed from the bottom surface side. [Fig. 5] Fig. 5 is a cross-sectional view of the refrigerant detection device when viewed from the bottom surface side. [Fig. 6] Fig. 6 is a cross-sectional view of the refrigerant detection device when viewed from a side surface side. [Fig. 7] Fig. 7 is a view illustrating the refrigerant detection device and a position from which a refrigerant is leaked. [Fig. 8]  Fig. 8 is a view illustrating a flow of the refrigerant. [Fig. 9]  Fig. 9 is a view of the refrigerant detection device and the refrigerant. [Fig. 10] Fig. 10 is a view of the refrigerant flowing inside the refrigerant detection device, in (A) of which a second opening having a rectangular shape having a long side in a Z-axis direction is provided, and in (B) of which a second opening having a rectangular shape having a short side in the Z-axis direction is provided. [Fig. 11] Fig. 11 is a cross-sectional side view of the refrigerant detection device. [Fig. 12] Fig. 12 is a view of a refrigerant detection device according to a modified example of the present invention. Mode(s) for Carrying Out the Invention

[0016] Next, an embodiment of the present invention will be described with reference to the drawings. In the following description about the drawings, the same or similar portions will be denoted by the same or similar reference symbols. It should be noted that the drawings are schematic ones and may differ from reality. Therefore, specific constituent parts should be determined by referring to the following description.

[0017] Further, an embodiment to be described below exemplifies apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention does not specify the shape, structure, arrangement, and the like of the constituent parts to those to be described below. Various modifications can be made to the technical idea of the present invention within the technical scope defined by the claims described in the Claims.

[0018] Fig. 1 is a view illustrating an arrangement state of a refrigerant detection device 10 according to an embodiment of the present invention. Fig. 2 is a front view of the refrigerant detection device 10. In addition, Fig. 3 is a view of the refrigerant detection device 10 when viewed from a bottom surface 15 side. Fig. 4 is a perspective view of the refrigerant detection device 10 when viewed from the bottom surface 15 side. Fig. 5 is a cross-sectional view of the refrigerant detection device 10 when viewed from the bottom surface 15 side. Fig. 6 is a cross-sectional view of the refrigerant detection device 10 when viewed from a side surface 13 side. Hereinafter, a vertical direction orthogonal to a floor surface 102 of an indoor space 100, a front-back direction orthogonal to a wall surface 101, and a horizontal direction orthogonal to the vertical direction and the front-back direction will be respectively described as a Z- direction, a Y-direction, and an X-direction orthogonal to each other. The present invention is not limited to those directional settings as a matter of course.

[0019] [Refrigerant Detection Device] The refrigerant detection device 10 is a detection device included in an air conditioning device 1 and includes a casing 10A, a refrigerant sensor 20, and a circuit board 30.

[0020] The air conditioning device 1 includes a refrigerant circuit that is formed of a heat exchanger housed in an indoor unit 5 as an indoor device, a compressor or a pressure reducing device such as an electronic expansion valve housed in an outdoor unit, an outdoor heat exchanger included in an outdoor device, and the like. In the air conditioning device 1, a refrigerant is circulated in the refrigerant circuit to air-condition the indoor space 100 that is an airconditioned space. The indoor space 100 is a space used by a person.

[0021] As illustrated in Fig. 1, an outlet 6 of the indoor unit 5 is provided to the wall surface 101 of the indoor space 100, but of course, the outlet 6 of the indoor unit 5 is not limited to be provided to the wall surface 101. Air harmonized by the air conditioning device 1 is blown out from the outlet 6.

[0022] The air conditioning device 1 includes a control section (not illustrated). The control section includes a computer including a processor such as a CPU and memory devices such as a ROM and a RAM. The control section is connected to the outdoor device, the sections that form the refrigerant circuit such as the indoor unit 5, the refrigerant detection device 10, and the like via signal lines. The control section receives various signals transmitted from the respective sections of the air conditioning device 1 via the signal lines, and also transmits signals to the respective sections of the air conditioning device 1. Thus, the control section controls the operation of the sections of the air conditioning device 1.  Note that the control section and the sections of the air conditioning device 1 may be connected not only by wires such as signal lines, but also by wireless connection through a communication section.

[0023] An operation section 7 formed of a remote controller including operation buttons and the like is connected to the control section via a signal line. The operation section 7 of this embodiment is attached to the wall surface 101 of the indoor space 100.

[0024] The operation section 7 includes a display panel in addition to the operation buttons. An operation state of the operation section 7 by the operation buttons or a drive state of the air conditioning device 1 is displayed on the display panel. The operation section 7 can be used to input temperature settings and the like.  In other words, the operation section 7 functions as an input section.

[0025] In this embodiment, the refrigerant used in the air conditioning device 1 including the indoor unit 5 is, for example, a refrigerant with low flammability or flammability, such as a mixed refrigerant containing R32 or the like. If the refrigerant with low flammability or flammability leaks, it is required to shorten the time taken to detect the leakage of the refrigerant such that a concentration of the refrigerant in the indoor space 100 does not reach a lower flammability limit (LFL). In particular, it is desired to shorten the time taken to detect the leakage of the refrigerant from the indoor unit 5 installed in the indoor space 100. In addition, the state of the refrigerant leaking from the air conditioning device 1 to the indoor space 100 is a gas having a higher specific gravity than air.

[0026] The refrigerant detection device 10 is disposed in the vicinity of the indoor unit 5. The refrigerant detection device 10 detects the concentration of the refrigerant in the indoor space 100 and issues an alert to inform a person in the indoor space 100 of the leakage of the refrigerant. In addition, the refrigerant detection device 10 detects the concentration of the refrigerant in the indoor space 100 and transmits a detection signal to the control section via a signal line. The refrigerant detection device 10 of this embodiment is connected to the control section via the operation section 7. In this case, the method of informing a person in the indoor space 100 of the leakage of the refrigerant is not limited to the alert described above as a matter of course, but the method may also be performed using light, for example.

[0027] Further, the refrigerant detection device 10 is capable of transmitting and receiving signals to and from the outside of the air conditioning device 1, such as a control center, via a signal line. For example, the refrigerant detection device 10 is capable of detecting the concentration of the refrigerant in the indoor space 100 and transmitting a detection signal to the control center via a signal line.

[0028] The refrigerant detection device 10 is attached to the wall surface 101. As described above, if the refrigerant used in the air conditioning device 1 is a gas having a higher specific gravity than air, it is desirable that the refrigerant detection device 10 is installed below the indoor unit 5 and at a lower portion of the indoor space 100. A top surface 16 of the refrigerant detection device 10 of this embodiment is located at a position of 30 cm or less from the floor surface 102 of the indoor space 100.

[0029] The refrigerant detection device 10 is fed from the indoor unit 5 that is an indoor device, but it is not limited thereto as a matter of course. The power may be supplied from a commercial power source via a switch box 105 provided on the wall surface 101.

[0030] (Casing) As illustrated in Figs. 2 to 5, the casing 10A of the refrigerant detection device 10 is formed in a rectangular parallelepiped shape having an inner space W and is attached to the wall surface 101. The casing 10A has a front surface 11, a back surface 12, a plurality of side surfaces 13 and 14, a bottom surface 15, and the top surface 16. In this embodiment, the casing 10A is a rectangular parallelepiped having a long side in an X-axis direction, but of course it is not limited to this. The casing 10A may be a rectangular parallelepiped having a short side in the X-axis direction or may be a regular hexahedron or the like. In addition, the casing 10A is not limited to a rectangular parallelepiped, but may also have a hexagonal prism shape, for example.  In addition, in this embodiment, the floor surface 102, the bottom surface 15, and the top surface 16 are parallel to the XY-plane and orthogonal to a Z-axis direction (vertical direction). In addition, the wall surface 101 and the floor surface 102 have a positional relationship orthogonal to each other.

[0031] The back surface 12 has a rectangular shape having a long side in the X-axis direction (horizontal direction) when viewed from a Y-axis direction (front-back direction), and is attached so as to face the wall surface 101 in the Y-axis direction. In addition, the front surface 11 has a rectangular shape having a long side in the X-axis direction when viewed from the Y- axis direction and facing the back surface 12 in the Y- axis direction, and is installed to face toward the indoor space 100. In other words, the front surface 11 and the back surface 12 function as a pair of side surfaces that are erected from the bottom surface 15, which will be described later, and face each other in the direction orthogonal to the wall surface 101 (Y- axis direction). The front surface 11 includes, at the substantially center thereof, sound emission holes 111 that are through-holes penetrating from the inside of the casing 10A to the outside (indoor space 100). An alert issued when a refrigerant is detected is emitted from the sound emission holes 111.

[0032] In addition, the back surface 12 includes an insertion hole (not illustrated) through which various wires such as power supply lines and signal lines to be installed in the casing 10A are inserted.

[0033] As illustrated in Figs. 4 and 5, the plurality of side surfaces 13 and 14 each have a rectangular shape having a long side in the Z-axis direction when viewed from the X-axis direction and come into contact with both ends in the X-axis direction of the front surface 11 and the back surface 12 and also the bottom surface 15 and the top surface 16 to be descried later, thus functioning as side surfaces of the casing 10A. In other words, the plurality of side surfaces 13 and 14 are erected from the bottom surface 15 and face each other in a direction (the X-axis direction) orthogonal to the Z- axis direction in the directions parallel to the wall surface 101. In addition, one side surface (first side surface) 13 in the plurality of side surfaces is provided to a side closer to the refrigerant sensor 20, which will be described later, when viewed from the Y- axis direction or the Z-axis direction. Another side surface (second side surface) 14 in the plurality of side surfaces is provided at a position farther from the refrigerant sensor 20, which will be described later, (than the first side surface 13) when viewed from the Y-axis direction or the Z-axis direction, the position being one of both ends in the X-axis direction. In addition, in this embodiment, the plurality of side surfaces 13 and 14 are provided (to be orthogonal) from the bottom surface 15 along the Z-axis direction, but are not limited thereto as a matter of course. The plurality of side surfaces 13 and 14 may be tilted with respect to the Z-axis direction. The first side surface 13 includes a second opening 18 as will be described later.

[0034] As illustrated in Fig. 3, the bottom surface 15 has a rectangular shape having a long side in the X- axis direction when viewed from the Z-axis direction and is provided to face the floor surface 102 in the Z- axis direction. The bottom surface 15 functions as the bottom of the casing 10A. In addition, the top surface 16 has a rectangular shape having a long side in the X- axis direction when viewed from the Z-axis direction and is provided to face the floor surface 102 and the bottom surface 15 in the Z-axis direction. The top surface 16 is located on a positive direction (upward) side relative to the bottom surface 15 in the Z-axis direction. In this embodiment, the bottom surface 15 and the top surface 16 are provided parallel to the floor surface 102, but are not limited thereto as a matter of course. The bottom surface 15 and the top surface 16 may be tilted with respect to the XY-plane. The bottom surface 15 includes a first opening 17 as will be described later.

[0035] As illustrated in Figs. 2 and 5, the casing 10A has the inner space W surrounded by the front surface 11, the back surface 12, the plurality of side surfaces 13 and 14, the bottom surface 15, and the top surface 16 described above. The refrigerant detection device 10 includes, within its inner space W, the refrigerant sensor 20 to be described later, the circuit board 30 having a plate shape parallel to the wall surface 101 (parallel to the XZ-plane), on which the refrigerant sensor 20 is mounted to be supported along the Y-axis direction, and a space (not illustrated) in which an alert is issued when the refrigerant sensor 20 detects a refrigerant or a detection signal for reporting that the refrigerant has been detected is transmitted to the control section through a signal line. The circuit board 30 is provided on the front surface 11 side in the Y-axis direction, and is electrically connected to the control chamber described above. In the refrigerant detection device 10, when the concentration of the refrigerant, which has been detected by the refrigerant sensor 20, is a predetermined value or more, an alert is issued by the control chamber, and in addition, a detection signal for reporting that the refrigerant has been detected is transmitted to the control section through the signal line.

[0036] In addition, the refrigerant detection device 10 detects the concentration of the refrigerant in the indoor space 100 and transmits the detection signal to the control section through the signal line. When receiving the detection signal, the control section may cause the display panel of the operation section 7 to perform predetermined display or may cause the indoor unit 5 to perform an air blowing operation, for example. This makes it possible for the air conditioning device 1 to suppress an increase in the concentration of the refrigerant in the indoor space 100.

[0037] Note that the control section may receive the detection signal from the refrigerant detection device 10 and determine whether or not leakage of the refrigerant is caused in the indoor space 100. In addition, the refrigerant detection device 10 may determine whether or not leakage of the refrigerant is caused in the indoor space 100. Further, the refrigerant detection device 10 may cause the display panel of the operation section 7 to perform predetermined display or may cause the indoor unit 5 to perform an air blowing operation or the like.

[0038] (Refrigerant Sensor) As illustrated in Fig. 5, the refrigerant sensor 20 is a sensor component that detects the concentration of the refrigerant that has flowed into the inner space W. This refrigerant sensor 20 has a columnar shape. In addition, the refrigerant sensor 20 is mounted on the circuit board 30, the mounted circuit board 30 is incorporated into the casing 10A, and the refrigerant sensor 20 is disposed to extend in the Y-axis direction when the casing 10A is attached to the wall surface 101. In this embodiment, a diameter direction of the refrigerant sensor 20 is shorter than a height direction of the refrigerant sensor 20, but is not limited thereto as a matter of course.

[0039] As illustrated in Fig. 5, the refrigerant sensor 20 includes a circuit-board-side end portion 20B on one side and a tip-side end portion 20A on the front surface 11 side as another side in the Y-axis direction. The circuit-board-side end portion 20B includes a terminal (not illustrated) provided on the circuit board 30 side and electrically connected to the circuit board 30. In this embodiment, the circuit board 30 is provided on the front surface 11 side, but is not limited thereto as a matter of course. The circuit board 30 may be provided on the back surface 12 side.

[0040] The refrigerant sensor 20 is a semiconductortype gas sensor in this embodiment, but is not limited thereto as a matter of course and may be of a non- dispersive infrared absorption (NDIR) type or electrochemical type. In addition, in this embodiment, the refrigerant sensor 20 detects a refrigerant when the refrigerant flows into the refrigerant sensor 20 from the tip-side end portion 20A.

[0041] (Positional Relationship between First and Second Openings and Refrigerant Sensor) As illustrated in Fig. 5, the first opening 17 is a through-hole that communicates with the inside and the outside of the casing 10A in the Z-axis direction, and has a rectangular shape having a long side in the X-axis direction when the bottom surface 15 is viewed from the Z-axis direction from below the casing 10A (downward in the vertical direction). The first opening 17 is provided at a position facing the refrigerant sensor 20 when viewed from the Z-axis direction.

[0042] As illustrated in Fig. 5, in this embodiment, the first opening 17 is located on the tip-side end portion 20A side of the refrigerant sensor 20 when viewed from the Z-axis direction. In particular, in this embodiment, the first opening 17 is provided at a position facing the tip-side end portion 20A when viewed from the Z-axis direction. The first opening 17 is not limited to the above as a matter of course and may be provided to face the refrigerant sensor 20 on the circuit-board-side end portion 20B side.

[0043] As illustrated in Fig. 6, the second opening 18 is a through-hole that communicates with the inside and the outside of the casing 10A in the X-axis direction, and has a rectangular shape having a long side in the Z-axis direction when viewed from the X- axis direction. In this embodiment, the second opening 18 is provided at a position at which the height of the second opening 18 from the bottom surface 15 in the Z- axis direction is higher than the height of the refrigerant sensor 20 from the bottom surface 15. The second opening 18 is not limited to the above as a matter of course and may be provided at a position facing the refrigerant sensor 20 when viewed from the X-axis direction.

[0044] (Operation) The operation of the refrigerant detection device 10 configured as described above will be described. In the air conditioning device 1, the refrigerant may leak into the indoor space 100 via the indoor unit 5. In this embodiment, since the refrigerant used in the air conditioning device 1 is a gas having a higher specific gravity than air, the refrigerant that has leaked into the indoor space 100 is accumulated in the indoor space 100 in a manner that the refrigerant is deposited on the floor surface 102. If the refrigerant is continuously leaking into the indoor space 100, the refrigerant accumulated on the floor surface 102 eventually flows into the refrigerant detection device 10 via the first opening 17 or the second opening 18.

[0045] The refrigerant sensor 20 detects the concentration of the refrigerant that has flowed into the casing 10A. When the concentration of the refrigerant, which has been detected by the refrigerant sensor 20, reaches a predetermined value or more, the refrigerant detection device 10 issues an alert. Thus, the refrigerant detection device 10 informs a person in the indoor space 100 of the leakage of the refrigerant. In this embodiment, the alert has been described as an example of the method of informing a person in the indoor space 100 of the leakage of the refrigerant, but the method is not limited thereto as a matter of course and may be performed using light and the like.

[0046] As described above, the refrigerant detection device 10 detects that the concentration of the refrigerant is a predetermined value or more, and thus informs a person in the indoor space 100 of the leakage of the refrigerant. Here, the flow of the leaking refrigerant will be described. Fig. 7 is a view illustrating the refrigerant detection device 10 and a position from which a refrigerant R is leaking, and Fig. 8 is a view illustrating a flow of the refrigerant R. Fig. 9 is a view of the refrigerant detection device 10 and the refrigerant R, and Fig. 10 is a view of the refrigerant R flowing inside the refrigerant detection device 10, in (A) of which the second opening 18 having a rectangular shape having a long side in the Z-axis direction is provided, and in (B) of which a second opening 18' having a rectangular shape having a short side in the Z-axis direction is provided. Further, Fig. 11 is a cross-sectional side view of the refrigerant detection device 10.

[0047] As illustrated in Fig. 7, the refrigerant detection device 10 is provided in the indoor space 100. In addition, the refrigerant (R32) R is blown out from a ceiling 103. The refrigerant R is blown out toward the floor surface 102.

[0048] Fig. 8 illustrates the flow of the refrigerant R when the refrigerant (R32) R is blown out from the ceiling 103 to the indoor space 100 as in Fig. 7. As illustrated in Fig. 8, the refrigerant R flows to the negative direction side of the Z-axis from the ceiling 103 toward the floor surface 102 along the wall surface 101. Next, the refrigerant R that has reached the floor surface 102 flows to a negative direction side of the Y-axis toward the opposed wall surface 101 along the floor surface 102. Next, the refrigerant R that has collided with the wall surface 101 flows to the positive direction side of the Z-axis toward the ceiling 103 along the wall surface 101. Since the refrigerant R rising toward the ceiling 103 is a gas having a higher specific gravity than air, the refrigerant R loses speed and goes toward the floor surface 102 as illustrated in Fig. 8. As a result, as illustrated in Fig. 9, the refrigerant R is gradually accumulated from the floor surface 102.

[0049] In other words, as illustrated in Fig. 9, the first opening 17 is provided to the bottom surface 15 of the refrigerant detection device 10 provided to the wall surface 101 as in this embodiment, which makes it easy for the refrigerant R gradually accumulated from the floor surface 102 to flow into the casing 10A and makes it possible for the refrigerant sensor 20 to detect the leakage of the refrigerant R in a shorter time. In addition, when air convection occurs in the air-conditioned space due to rotation of a fan of the indoor device or movement of a person in the airconditioned space, the flow of air (refrigerant R) occurs in the casing 10A as illustrated in Fig. 10, and the refrigerant sensor 20 is capable of detecting the leakage earlier. At that time, the first opening 17 is provided at a position facing the refrigerant sensor 20 when viewed from the Z-axis direction, which makes it possible to provide a shortest distance between the refrigerant sensor 20 and the first opening 17 and to detect the leakage earlier.

[0050] As illustrated in Fig. 5, the first opening 17 has a rectangular shape whose longitudinal direction is 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, and facilitates contact of the refrigerant R with the refrigerant sensor 20. This makes it possible to shorten the time taken to detect the leakage of the refrigerant R. Further, in this embodiment, the first opening 17 is provided on the tip-side end portion 20A side of the refrigerant sensor 20, particularly at a position facing the tip-side end portion 20A. This facilitates contact of the refrigerant R with the refrigerant sensor 20 and makes it possible to shorten the time taken to detect the leakage of the refrigerant R.

[0051] Further, since the first opening 17 is provided to the bottom surface 15, which makes it possible to prevent dust, dirt, and the like from entering the inner space W (inside the casing 10A).

[0052] In this embodiment, the second opening 18 is provided at a position at which the height of the second opening 18 from the bottom surface 15 in the Z- axis direction is higher than the height of the refrigerant sensor 20 from the bottom surface 15. Thus, the refrigerant sensor 20 detects the refrigerant R more easily. In other words, if the height of the second opening 18 from the bottom surface 15 in the Z- axis direction is lower than that of the refrigerant sensor 20, the refrigerant R that has flowed in from the first opening 17 may escape from the second opening 18 located at a position lower than the refrigerant sensor 20 before the refrigerant R reaches the height of the refrigerant sensor 20. However, if the height of the second opening 18 from the bottom surface 15 in the Z-axis direction is equal to or higher than that of the refrigerant sensor 20 as in this embodiment, as illustrated in Fig. 10, the refrigerant R that has flowed in from the first opening 17 passes through the refrigerant sensor 20 and then escapes though the second opening 18. Thus, the refrigerant R reliably comes into contact with the refrigerant sensor 20, which makes it easier for the refrigerant sensor 20 to detect the refrigerant R.

[0053] The second opening 18 is provided to the first side surface 13. This makes it difficult for dust G to be accumulated as compared to the case where the top surface 16 includes an opening, and makes it possible to prevent the second opening 18 from being closed by the dust G and cause the refrigerant R to smoothly flow into the casing 10A. In addition, the second opening 18 is provided not to the front surface 11 but to the first side surface 13, which makes it less visible to a person in the indoor space 100 and improves the design.

[0054] In addition, in this embodiment, as illustrated in Fig. 11, the second opening 18 has a rectangular shape having a long side in the Z-axis direction when viewed from the X-axis direction. This makes it possible to prevent the entire second opening 18 from being closed by the dust G even if the dust G is accumulated in the second opening 18, as compared to a second opening 18 having a rectangular shape having a short side in the Z-axis direction when viewed from the X-axis direction. In other words, the refrigerant R that has flowed into the casing 10A from the first opening 17 can be smoothly caused to flow out from the second opening 18. In this regard, as illustrated in Fig. 11, the dust G is accumulated on a lower side of the second opening 18. The second opening 18 having a rectangular shape having a long side in the Z-axis direction as in this embodiment has a larger area of a portion where the dust G is not accumulated, and the substantial area of the opening through which the refrigerant R flows into the casing 10A becomes larger, as compared to a rectangular shape having a short side in the Z-axis direction.

[0055] In addition, since the second opening 18 has a rectangular shape having a long side in the Z-axis direction when viewed from the X-axis direction, as illustrated in (A) and (B) of Fig. 10, the width of a flow path through which the refrigerant R passes is wider as compared to a rectangular shape having a short side in the Z-axis direction, and thus the refrigerant R easily comes into contact with the refrigerant sensor 20. In other words, as illustrated in (B) of Fig. 10, when the refrigerant R that has flowed in from the first opening 17 escapes (flows out) through the second opening 18, if the width of the second opening 18 in the Z-axis direction is narrower (shorter), the width of the flow path through which the refrigerant R passes becomes narrower, and the refrigerant R is less likely to come into contact with the refrigerant sensor 20. However, if the second opening 18 has a rectangular shape whose longitudinal direction is the Z-axis direction when viewed from the X-axis direction as in this embodiment, as illustrated in (A) of Fig. 10, the width of the flow path through which the refrigerant R passes becomes wider as compared to a rectangular shape having a short side in the Z-axis direction, and the refrigerant R is more likely to come into contact with the refrigerant sensor 20. This makes it easy for the refrigerant sensor 20 to detect the refrigerant R.

[0056] <Modified Example> In the embodiment described above, the height of the second opening 18 from the bottom surface 15 in the Z-axis direction is equal to or higher than that of the refrigerant sensor 20 from the bottom surface 15 in the Z-axis direction, but it is not limited thereto as a matter of course. The second opening 18 may be provided at a position facing the refrigerant sensor 20 when viewed from the X-axis direction. Fig. 12 is a view of a refrigerant detection device 10' according to a modified example of the present invention.

[0057] In the refrigerant detection device 10', the height of a casing 10A' in the Z-axis direction is lower as compared to the refrigerant detection device 10 described above. This is because the height of the second opening 18 from the bottom surface 15 in the Z- axis direction is equal to the height of the refrigerant sensor 20 from the bottom surface 15 in the Z-axis direction, and thus the space located higher than that height can be omitted. This makes it possible to reduce the size of the refrigerant detection device 10', thereby reducing manufacturing costs.

[0058] <Other modified Examples> In the embodiment described above, the second opening 18 is provided to the first side surface 13, but is not limited thereto as a matter of course and may be provided to the front surface 11, which is a different surface from the bottom surface 15, or provided to the top surface 16. This also makes it easier for the refrigerant sensor 20 described above to detect the refrigerant R. In addition, when the second opening 18 is provided to the top surface 16, the second opening 18 is favorably provided at a position facing the refrigerant sensor 20 when viewed from the Z-axis direction. Thus, the refrigerant R flows along the Z-axis direction from the first opening 17 to the second opening 18, and since the refrigerant sensor 20 is present on that flow path, the refrigerant sensor 20 easily detects the refrigerant R. Reference Signs List

[0059] 1    air conditioning device 10   refrigerant detection device 10A  casing 11   front surface 13   first side surface 10 14   second side surface 15   bottom surface 17   first opening 18   second opening 20   refrigerant sensor 30   circuit board 100  indoor space 101  wall surface 102  floor surface R    refrigerant W    inner space

Claims

1. A refrigerant detection device, comprising:a casing that is to be attached to a wall surfaceof an indoor space as a space to be air-conditioned byan air conditioning device and has a bottom surfacefacing a floor surface of the indoor space; anda refrigerant sensor that is housed inside thecasing and detects leakage of a refrigerant, whereinthe casing includesa first opening that is provided to thebottom surface and allows an inside and an outside ofthe casing to communicate with each other, anda second opening that is provided to asurface different from the bottom surface and allowsthe inside and the outside of the casing to communicatewith each other, andthe first opening is provided at a position facingthe refrigerant sensor when viewed from below in avertical direction.

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

3. The refrigerant detection device according toclaim 1, whereinthe second opening is provided to a first sidesurface closer to the refrigerant sensor when viewedfrom the vertical direction, the first side surfacebeing one of a pair of side surfaces erected from thebottom surface and facing each other in a horizontaldirection orthogonal to the vertical direction indirections parallel to the wall surface.

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

5. The refrigerant detection device according to claim 1, whereinthe first opening has a rectangular shape having along side in a horizontal direction orthogonal to thevertical direction in directions parallel to the wall surface.

6. The refrigerant detection device according to claim 5, further comprisinga circuit board that is provided inside the casingalong the wall surface parallel to the verticaldirection and the horizontal direction and supports the refrigerant sensor in a front-back direction orthogonal to the vertical direction and the horizontal direction,whereinthe refrigerant sensor has a columnar shape andincludes a circuit-board-side end portion on one sideand a tip-side end portion on another side in the5     front-back direction, the circuit-board-side endportion being provided on a side of the circuit board,andthe first opening is located on a side of the tipside end portion of the refrigerant sensor in the10     front-back direction.

7. The refrigerant detection device according toclaim 3, whereinthe second opening is provided at a position facing the refrigerant sensor when viewed from the15     horizontal direction.

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