Indoor unit and air conditioning system

Abstract

This disclosure provides an indoor unit and an air conditioning system that facilitate the detection of refrigerant leaks. [Solution] The indoor unit in this disclosure comprises a heat exchanger, a housing for the heat exchanger, a cover member that covers a header portion connected to the heat exchanger and has a lower end opening at its lower end, a refrigerant sensor provided at a position that overlaps with the lower end opening in a plan view, and a sensor cover that covers the refrigerant sensor from at least one of the directions of upward and horizontal. The heat exchanger is provided in a position in which the header portion is inclined in a direction in which the upper side is located in the first direction, the cover member has an inclined portion that extends upward from the lower end opening along the header portion, and the sensor cover has an opening on the first direction side of the refrigerant sensor.

Description

Technical Field

[0001] The present disclosure relates to an indoor unit and an air conditioning apparatus.

Background Art

[0002] Patent Document 1 discloses a refrigeration apparatus unit capable of improving detection accuracy for leaked refrigerant. This refrigeration apparatus unit includes a resin cover that forms an isolated space containing a connecting U-shaped tube or the like of an outdoor heat exchanger, and a refrigerant sensor that detects refrigerant flowing out into the isolated space.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of Invention

Problem to be Solved by the Invention

[0004] The present disclosure provides an indoor unit and an air conditioning apparatus that facilitate detection of refrigerant leakage.

Means for Solving the Problem

[0005] The indoor unit according to the present disclosure includes a heat exchanger, a housing that accommodates the heat exchanger, a cover member that covers a header portion connected to the heat exchanger and has a lower end opening at a lower end thereof, a refrigerant sensor provided at a position overlapping the lower end opening in a plan view, and a sensor cover that covers the refrigerant sensor from at least one of an upward direction and a horizontal direction, wherein the heat exchanger is provided in such a posture that the header portion is inclined in a direction where an upper side is located on a first direction side, the cover member has an inclined portion that extends inclining along the header portion upward from the lower end opening, and the sensor cover is open on the first direction side of the refrigerant sensor.

[0006] An air conditioning system in another aspect of this disclosure comprises the indoor unit and the outdoor unit described above. [Effects of the Invention]

[0007] In the indoor unit and air conditioning system described herein, the refrigerant flowing along the inclined section from the first direction towards the refrigerant sensor can easily reach the refrigerant sensor without being obstructed by the sensor cover. Therefore, an indoor unit and air conditioning system that can easily detect refrigerant leakage can be provided. [Brief explanation of the drawing]

[0008] [Figure 1] Perspective view of the indoor unit according to Embodiment 1 [Figure 2] Front view of the indoor unit [Figure 3] Perspective view showing the internal configuration of the indoor unit. [Figure 4] Front view showing the internal configuration of the indoor unit. [Figure 5] Figure 4: VV cross-sectional view [Figure 6] Enlarged perspective view showing the internal structure of the indoor unit. [Figure 7] Perspective view of the first sensor unit and fixing device 70 [Figure 8] Perspective view of the first sensor unit [Figure 9] Plan view showing the internal configuration of the enclosure [Figure 10] Perspective view of the second sensor unit [Figure 11] Perspective view of the first sensor unit according to Embodiment 2 [Figure 12] This diagram shows the arrangement of the first sensor unit according to Embodiment 2, viewed along the left-right direction. [Figure 13] This figure shows the arrangement of the first sensor unit according to Embodiment 2 as viewed along the front-to-back direction. [Figure 14] Figure 11 shows the simulation results in the XIV section view. [Figure 15] Concentration contour diagram showing the simulation results in a vertical cross-section of the enclosure perpendicular to the left-right direction. [Figure 16]Chart showing changes in the mole fraction of refrigerant at the position of the refrigerant sensor in simulation [Figure 17] Perspective view showing a first sensor cover according to another embodiment

Mode for Carrying Out the Invention

[0009] (Findings etc. that Form the Basis of the Present Disclosure) At the time when the inventors arrived at the concept of the present disclosure, the technology of air conditioners was in a situation where the use of refrigerants with a low global warming potential was required for environmental response. Therefore, in the relevant industry, it was common to design products with a refrigerant sensor for detecting refrigerant leakage, addressing the issue that such refrigerants are unstable and many of them have flammability or slight flammability. Under such circumstances, the inventors discovered that providing a sensor cover to protect the refrigerant sensor from condensed water and the like has a problem in that the sensor cover may impede the refrigerant from reaching the refrigerant sensor, and arrived at the subject matter of the present disclosure in order to solve this problem. The present disclosure provides an indoor unit and an air conditioning apparatus that facilitate detection of refrigerant leakage.

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

[0011] (Embodiment 1) Hereinafter, Embodiment 1 will be described with reference to the drawings. [1-1. Configuration] FIG. 1 is a perspective view of an indoor unit 1 according to Embodiment 1. FIG. 2 is a front view of the indoor unit 1, showing the indoor unit 1 as viewed from the front side. In the drawings, reference sign X indicates the left direction of the indoor unit 1, reference sign Y indicates the front direction of the indoor unit 1, and reference sign Z indicates the upward direction of the indoor unit 1. In an air conditioner, the indoor unit 1 is disposed in a conditioned space that is a space to be air-conditioned. In the present embodiment, the indoor unit 1 is a so-called floor-standing ducted indoor unit, which is mainly placed on the floor surface of the conditioned space and blows air into the conditioned space via a duct.

[0012] The indoor unit 1 forms a refrigerant circuit by being connected to an outdoor unit (not shown) including a compressor, an outdoor heat exchanger and the like, and performs air conditioning using a refrigerant circulating in the refrigerant circuit. The air conditioner includes any number of one or more indoor units 1 and any number of one or more outdoor units (not shown).

[0013] Further, the refrigerant used in the air conditioner including the indoor unit 1 is a refrigerant having a higher specific gravity than air. In the present embodiment, the refrigerant used in the indoor unit 1 and the air conditioner is R32 refrigerant. R32 refrigerant is a refrigerant that has a higher specific gravity than air and is slightly flammable. Note that any refrigerant other than R32 that has a higher specific gravity than air may be used as the refrigerant of the air conditioner. Further, any refrigerant having a specific gravity equal to that of air or lower than that of air may be used as the refrigerant of the air conditioner.

[0014] The indoor unit 1 includes a housing 10. The housing 10 is a hollow substantially rectangular parallelepiped and is formed of sheet metal. The housing 10 is provided with a suction port 11 and an air outlet 13. The suction port 11 is constituted by a plurality of holes that allow air to pass through from the outside to the inside of the housing 10.

[0015] The suction port 11 is formed at lower portions of a front surface and a rear surface of the housing 10. The air outlet 13 is an opening that allows air to pass through from the inside to the outside of the housing 10. The air outlet 13 opens upward on an upper surface of the housing 10. A duct (not shown) is attached to the air outlet 13.

[0016] The indoor unit 1 has an operating unit 14 at the top of the front of the housing 10. The operating unit 14 accepts user operations such as turning the indoor unit 1 on or off, or setting the set temperature during operation of the indoor unit 1.

[0017] The housing 10 includes an upper maintenance panel 15, a middle maintenance panel 16, and a lower maintenance panel 17. The upper maintenance panel 15 is a plate-shaped member that constitutes the upper part of the front surface of the housing 10. The middle maintenance panel 16 is a plate-shaped member that constitutes the middle part of the front surface of the housing 10. The middle maintenance panel 16 is located below the upper maintenance panel 15. The lower maintenance panel 17 is a plate-shaped member that constitutes the lower part of the front surface of the housing 10. The lower maintenance panel 17 is located below the middle maintenance panel 16. Each maintenance panel 15, 16, and 17 is detachable from the housing 10. The middle maintenance panel 16 and the lower maintenance panel 17 correspond to examples of "maintenance panels" in this disclosure.

[0018] Figure 3 is a perspective view showing the internal configuration of the indoor unit 1, with the maintenance panels 15, 16, and 17 removed. Figure 4 is a front view showing the internal configuration of the indoor unit 1, with the maintenance panels 15, 16, and 17 removed.

[0019] As shown in Figures 3 and 4, the housing 10 has an upper opening 18 and a lower opening 19. The upper opening 18 is an opening formed in the upper part of the front surface of the housing 10. The upper opening 18 is closed by an upper maintenance panel 15. The lower opening 19 is an opening formed in the lower part of the front surface of the housing 10. The lower opening 19 is located below the upper opening 18. The lower opening 19 is closed by a middle maintenance panel 16 and a lower maintenance panel 17. The lower opening 19 corresponds to an example of an "opening" in this disclosure.

[0020] As shown in Figures 3 and 4, the indoor unit 1 has an indoor blower 21 and an indoor heat exchanger 30 inside the housing 10. The indoor blower 21 is a device that blows air from inside the housing 10 to a duct (not shown) via an outlet 13. The indoor blower 21 is located at the top inside the housing 10. When the upper maintenance panel 15 is removed, the indoor blower 21 is exposed to the front through the upper opening 18. In this embodiment, the indoor blower 21 is a so-called fan belt type sirocco fan, but any type of blower, such as an axial flow fan, may be used as the indoor blower 21. The indoor blower 21 corresponds to an example of a "blower". The indoor heat exchanger 30 corresponds to an example of a "heat exchanger" in this disclosure.

[0021] The indoor heat exchanger 30 is a heat exchanger that exchanges heat between the refrigerant flowing inside and the air inside the housing 10. The indoor heat exchanger 30 has a roughly rectangular, plate-like outer shape and is positioned inside the housing 10 to partition the space between the intake port 11 and the outlet port 13. The indoor heat exchanger 30 is also exposed forward from the lower opening 19 when the middle maintenance panel 16 and the lower maintenance panel 17 are removed. In this embodiment, the indoor heat exchanger 30 is a so-called plate fin tube type heat exchanger.

[0022] The indoor heat exchanger 30 has a main body 31. The main body 31 has a plurality of fins 32 and a plurality of heat transfer tubes 33. The fins 32 are plate-shaped members that are positioned substantially perpendicular to the left-right direction. The fins 32 are arranged at substantially equal intervals in the left-right direction. The heat transfer tubes 33 are tubes that extend substantially linearly along the left-right direction, and a refrigerant flows inside them. Each heat transfer tube 33 is arranged to penetrate each fin 32 in the left-right direction and is fixed to each fin 32.

[0023] Bend sections 35 are provided at both ends of the indoor heat exchanger 30 in the left-right direction. The bend section 35 has a plurality of U-bend pipes 36. The U-bend pipes 36 are pipes curved in a U shape. Each U-bend pipe 36 connects the right ends of two heat transfer tubes 33, or the left ends of two heat transfer tubes 33, which have two ends at each end. In this way, the heat transfer tubes 33 are connected to each other via the U-bend pipes 36. In this embodiment, the indoor heat exchanger 30 has a plurality of refrigerant flow paths formed by the connection of the interiors of the plurality of heat transfer tubes 33 and the plurality of U-bend pipes 36. In this embodiment, both ends of the plurality of flow paths composed of the heat transfer tubes 33 and U-bend pipes 36 are provided on the left side of the main body 31.

[0024] Figure 5 is a cross-sectional view of section VV of Figure 4. As shown in Figure 5, a partition plate 38 is provided on the left side of the indoor heat exchanger 30. The partition plate 38 is a plate-shaped member that seals the gap between the left end of the main body 31 of the indoor heat exchanger 30 and the left inner surface of the housing 10. The partition plate 38 prevents air drawn into the housing 10 from passing through the gap between the left end of the main body 31 and the left inner surface of the housing 10 without passing through the main body 31 of the indoor heat exchanger 30.

[0025] Furthermore, a drain pan 39 is provided inside the housing 10 to receive condensed water generated in the indoor heat exchanger 30. The drain pan 39 includes an upper drain pan 39A and a lower drain pan 39B. The upper drain pan 39A has a concave structure that extends in the left-right direction and is recessed downwards. The lower end of the indoor heat exchanger 30 is positioned inside the upper drain pan 39A. That is, the upper drain pan 39A is provided at approximately the same height as the lower end of the indoor heat exchanger 30.

[0026] The lower drain pan 39B is located at a position spaced downward from the upper drain pan 39A. The lower drain pan 39B extends over substantially the entire interior of the housing 10 in a plan view.

[0027] As shown in Figure 5, a header section 41 is provided on the left side of the indoor heat exchanger 30. The header section 41 is piping that extends along the left end of the main body 31 of the indoor heat exchanger 30. The header section 41 is connected to one end of a plurality of flow paths composed of heat transfer tubes 33 and U-bend tubes 36. In the flow of refrigerant, the header section 41 is located downstream of the indoor heat exchanger 30 during cooling operation when the indoor heat exchanger 30 functions as an evaporator, and upstream of the indoor heat exchanger 30 during heating operation when the indoor heat exchanger 30 functions as a condenser. In other words, gaseous refrigerant mainly flows inside the header section 41.

[0028] As shown in Figure 5, the indoor heat exchanger 30 is installed at an inclination with respect to the vertical. More specifically, the indoor heat exchanger 30 is inclined so that its upper side is facing forward with respect to the vertical. Similarly, the header section 41 is installed at an inclination with respect to the vertical in the same direction as the indoor heat exchanger 30. More specifically, the header section 41 is inclined so that its upper side is facing forward with respect to the vertical.

[0029] As shown in Figure 5, a distributor 43 is provided below the header section 41. The distributor 43 has a main pipe 43A which extends vertically, and branch pipes 43B which are multiple pipes branching off from the upper end of the main pipe 43A. The branch pipes 43B are connected to the other end, i.e., the end opposite to the connection to the header section 41, of the multiple flow paths composed of heat transfer tubes 33 and U-bend pipes 36. When the indoor heat exchanger 30 functions as an evaporator, the distributor 43 distributes the gas-liquid two-phase refrigerant flowing into the main pipe 43A to each flow path of the indoor heat exchanger 30 in a substantially equal manner by flowing the gas-liquid two-phase refrigerant so that the ratio of gas phase to liquid phase is substantially equal among each branch pipe 43B. In this embodiment, two distributors 43 are provided side by side in the left-right direction (see Figure 6).

[0030] The lower end of the main pipe 43A of each distributor 43 is connected to a refrigerant pipe 44 that extends approximately horizontally. The refrigerant pipe 44 is a pipe that extends in the front-rear direction, and its front end is closed by crushing. The lower end of the main pipe 43A is connected to a position behind the front end of the refrigerant pipe 44. Of the two refrigerant pipes 44, an expansion valve 45 is connected to the rear end behind the connection point with the main pipe 43A. In this embodiment, the expansion valve 45 is configured to allow adjustment of its opening degree by electronic control. The two expansion valves 45 are provided side by side.

[0031] A branch pipe 46 is connected to the connection port of the expansion valve 45 on the side opposite to the refrigerant piping 44. The branch pipe 46 is roughly Y-shaped in plan view and has a branch section 46A that branches into two and a confluence section 46B where the branch sections 46A merge. Each of the branch sections 46A is connected to the expansion valve 45. The confluence section 46B extends rearward from the point where the branch sections 46A merge. The rear end of the confluence section 46B curves downward and is connected to the upper end of the receiver 47. The receiver 47 is a tank that absorbs fluctuations in the amount of refrigerant circulated. The branch pipe 46 corresponds to an example of "refrigerant piping" in this disclosure.

[0032] As described above, refrigerant that has flowed through the indoor heat exchanger 30, or refrigerant flowing into the indoor heat exchanger 30, flows through the header section 41, distributor 43, refrigerant piping 44, expansion valve 45, branch piping 46, and receiver 47, etc. Hereinafter, the parts of the housing 10 through which refrigerant flows other than through the indoor heat exchanger 30 will be referred to as refrigerant flow paths 40. The refrigerant flow paths 40 are particularly concentrated to the left of the main body 31 of the indoor heat exchanger 30 and below the partition plate 38. This concentrated area of ​​refrigerant flow paths 40 will be specifically referred to as the flow path concentration section 40A. The flow path concentration section 40A includes the header section 41, distributor 43, refrigerant piping 44, expansion valve 45, branch piping 46, and receiver 47. The flow path concentration section 40A is located above the lower drain pan 39B.

[0033] As shown in Figures 3 to 5, the indoor unit 1 is provided with a cover member 50. The cover member 50 is made of a flexible thin plate. More specifically, in this embodiment, the cover member 50 is made of a resin film. Therefore, for example, when attaching or detaching the cover member 50 to the indoor unit 1, the cover member 50 can be temporarily deformed to avoid other parts, making it easier to position the cover member 50.

[0034] The cover member 50 covers the left end bend portion 35, header portion 41, and distributor 43 of the indoor heat exchanger 30 from the front. Furthermore, as shown in Figure 5, the cover member 50 partitions the internal space of the housing 10, forming space S1. Space S1 is the space inside the cover member 50. Space S1 is also partitioned by the cover member 50 towards the header portion 41. More specifically, space S1 is partitioned by the cover member 50 on the front, the left side of the housing 10 on the left, the partition plate 38 on the rear and top, and the cover member 50 and the main body portion 31 of the indoor heat exchanger 30 on the right. Space S1 is closed at the top by the partition plate 38. Since the space S1 is open downwards through the lower end opening 50A, which is an opening formed at the lower end of the cover member 50, gas inside the space S1 can flow out of the space S1 downwards, and gas outside the space S1 can flow into the space S1 from below. The lower end opening 50A is formed over the entire lower surface of the cover member 50.

[0035] The cover member 50 has an inclined portion 51. The inclined portion 51 is a planar portion that is substantially parallel to the left-right direction. The inclined portion 51 is inclined with respect to the vertical direction. More specifically, the inclined portion 51 is inclined in a direction in which the upper side is located forward with respect to the vertical direction. That is, the inclined portion 51 is inclined in the same direction as the inclination of the indoor heat exchanger 30 and the header portion 41 with respect to the vertical direction. In other words, the inclined portion 51 is inclined along the indoor heat exchanger 30 and the header portion 41. In this embodiment, the inclined portion 51 extends in a direction closer to the vertical direction compared to the indoor heat exchanger 30 and the header portion 41. The lower end of the inclined portion 51 extends downward to the height of the main piping 43A of the distributor 43. Also, the inclined portion 51 is located forward of the distributor 43 and the header portion 41 and rearward of the expansion valve 45. The lower end of the inclined portion 51 forms the front edge of the lower end opening 50A. In other words, the inclined portion 51 extends upward from the lower end opening 50A, inclined along the header portion 41. Furthermore, the inclined portion 51 is located below the header portion 41. The forward direction corresponds to an example of the "first direction" in this disclosure.

[0036] The cover member 50 has a partitioned section 53. The partitioned section 53 has a planar structure that is bent backward from the right end of the inclined section 51. The partitioned section 53 contacts the left end of the main body 31 of the indoor heat exchanger 30 from the left side. In addition, the lower end 53A of the partitioned section 53 is bent to the right and is fixed to the upper drain pan 39A by screws while in contact with the upper drain pan 39A from above.

[0037] The cover member 50 has a bent portion 55. The bent portion 55 has a planar structure that is bent backward from the left end of the inclined portion 51. The bent portion 55 contacts the inner surface of the left side of the housing 10 from the right side.

[0038] The cover member 50 has a front portion 57. The front portion 57 has a planar structure that is bent vertically upward from the upper end of the inclined portion 51.

[0039] The cover member 50 is fixed to the housing 10 by a metal fixing member 59. The fixing member 59 is attached to a support column 12 that forms the upper edge of the lower opening 19 of the housing 10. The support column 12 is a columnar member that spans the front of the housing 10 in the left-right direction. The support column 12 is made of sheet metal and is bent into an L-shape in a cross section perpendicular to the left-right direction. The support column 12 is also installed at a height approximately equal to the height of the upper end of the indoor heat exchanger 30.

[0040] The fixing member 59 has a front portion 59A and an inclined portion 59B. The front portion 59A has a planar structure that is substantially perpendicular to the front-rear direction. The front portion 59A is provided overlapping the front portion 57 of the cover member 50 from the rear side. The fixing member 59 is fixed to the housing 10 by fastening the upper end of the front portion 59A to the support column 12.

[0041] The inclined portion 59B has a planar structure that is inclined in a direction where the upper side is located towards the front with respect to the vertical direction. The inclined portion 59B extends downward from the lower end of the front portion 59A towards the rear. The inclined portion 59B is installed overlapping the inclined portion 51 of the cover member 50 from the rear side. The inclined portion 59B is also fixed to the inclined portion 51 of the cover member 50 by screw fastening.

[0042] In this way, by using a metal fixing member 59 to secure the cover member 50, the cover member 50 can be firmly fixed. Therefore, vibrations of the cover member 50 when the indoor blower 21 is driven can be suppressed. In addition, since the fixing member 59 is fixed to the support column 12 of the housing 10, which tends to have high strength, the cover member 50 can be fixed more firmly.

[0043] Figure 6 is an enlarged perspective view showing the internal configuration of the indoor unit 1, and shows the area near the dense flow path 40A with the cover member 50 removed. As shown in Figures 5 and 6, a first sensor unit 60 is provided inside the housing 10. As shown in Figure 5, the first sensor unit 60 is provided at the same height as the drain pan 39, or at a height greater than the drain pan 39. More specifically, the first sensor unit 60 is provided at the same height as the upper drain pan 39A, or at a height greater than the upper drain pan 39A. The first sensor unit 60 detects the refrigerant used in the indoor unit 1 and the air conditioning system.

[0044] Furthermore, as shown in Figure 5, the first sensor unit 60 is provided near the inclined portion 51. More specifically, the first sensor unit 60 is provided above the extension line L1 that extends downward from the inclined portion 51. The first sensor unit 60 is also provided below the space S1 that is partitioned by the cover member 50 and opened downward.

[0045] The first sensor unit 60 is located inside the housing 10 near the refrigerant flow path 40. Furthermore, the first sensor unit 60 is located inside the housing 10 near the dense flow section 40A of the refrigerant flow path 40. The first sensor unit 60 is attached to the housing 10 via a fixing device 70.

[0046] Figure 7 is a perspective view of the first sensor unit 60 and the fixing device 70. The fixing device 70 is a component made of sheet metal. The fixing device 70 has a housing fixing portion 71 that is fixed to the housing 10. The housing fixing portion 71 has a flat plate structure that is substantially perpendicular to the left-right direction. The housing fixing portion 71 has a hook-shaped claw portion 72 that protrudes toward the lower left. The fixing device 70 is supported by the housing 10 by the claw portion 72 catching on a hole formed on the left side surface of the housing 10. The housing fixing portion 71 is fastened from the inside of the housing 10, that is, from the right side to the left side surface of the housing 10. In this way, the housing fixing portion 71 is detachably fixed to the housing 10 by the claw portion 72 and fastening from the inside of the housing 10.

[0047] The fixing device 70 has an arm portion 73. The arm portion 73 is structured to extend upward from the housing fixing portion 71 toward the refrigerant flow path 40. The cross-sectional shape of the arm portion 73 is L-shaped. A wiring holder 74 is attached to the arm portion 73 by fastening. The wiring holder 74 has a roughly C-shaped structure. The arm portion 73 holds wiring such as signal lines or power lines connected to the first sensor unit 60 inside the wiring holder 74.

[0048] The fixing device 70 has a sensor fixing portion 75. The sensor fixing portion 75 fixes the first sensor unit 60. The sensor fixing portion 75 has a flat plate-like structure that is substantially perpendicular to the front-rear direction and is located at the front end of the arm portion 73. The sensor fixing portion 75 has an opening 75A that extends in the left-right direction. In this embodiment, the fixing device 70 is a component in which the housing fixing portion 71, the arm portion 73, and the sensor fixing portion 75 are integrally formed.

[0049] A first sensor cover 77 is attached to the sensor fixing part 75. The first sensor cover 77 is fastened and fixed to the upper end of the sensor fixing part 75. The first sensor cover 77 has a top surface part 77A and a front surface part 77B. The top surface part 77A has a substantially horizontal planar structure that covers the first sensor unit 60 from above. Therefore, water droplets dripping from above are shielded by the top surface part 77A and are unlikely to reach the first sensor unit 60. The front surface part 77B bends downward from the front end of the top surface part 77A and has a planar structure that is substantially perpendicular to the front-to-back direction. The front surface part 77B covers the first sensor unit 60 from the front side. In addition, the first sensor cover 77 does not have a surface perpendicular to the left-to-right direction and is configured not to cover the left-to-right sides of the first sensor unit 60. In other words, the first sensor cover 77 is configured not to cover the first refrigerant sensor 62A, described later, from the horizontal direction, that is, from both the left and right directions, and from the front and back directions.

[0050] Figure 8 is a perspective view of the first sensor unit 60. The first sensor unit 60 includes a sensor substrate 61 and a substrate holder 63. The sensor substrate 61 is a substrate that includes a refrigerant sensor 62 for detecting refrigerant. The substrate holder 63 is a cover that covers the sensor substrate 61 and the refrigerant sensor 62 from the left and right, up and down, and from the front. The substrate holder 63 is made of resin. In this embodiment, the substrate holder 63 has ventilation holes formed on the front, right side, and left side. In addition, no holes are formed on the top surface of the substrate holder 63, so that water droplets dripping from above are less likely to reach the sensor substrate 61. The sensor substrate 61 is an example of a "refrigerant sensor substrate".

[0051] Furthermore, the substrate holder 63 has a claw portion 65 and a fastening portion 67. The claw portion 65 is a projection that protrudes rearward and upward from the rear end of the upper surface of the substrate holder 63. The fastening portion 67 is provided at the lower end of the substrate holder 63 and has a fastening hole formed therein. The first sensor unit 60 is fixed to the sensor fixing portion 75 by fastening the fastening portion 67 to the sensor fixing portion 75 while the claw portion 65 of the substrate holder 63 is inserted into the opening 75A of the sensor fixing portion 75.

[0052] Figure 9 is a plan view showing the internal configuration of the housing 10, schematically illustrating the arrangement of the first refrigerant sensor, the second refrigerant sensor, the indoor heat exchanger 30, and the refrigerant flow path 40.

[0053] As shown in Figure 9, in the fixing device 70, the housing fixing portion 71 is located further away from the refrigerant flow path 40 and the dense flow path portion 40A than the sensor fixing portion 75. In other words, the sensor fixing portion 75 is located closer to the refrigerant flow path 40 and the dense flow path portion 40A than the housing fixing portion 71, making it easier to detect refrigerant leaking in the refrigerant flow path 40 and the dense flow path portion 40A.

[0054] The first sensor unit 60 and the sensor fixing part 75 are configured such that, from any point in the lower opening 19, at least a portion of them overlap with the refrigerant flow path 40 and the dense flow path area 40A on the front side. In other words, the first sensor unit 60 is located further back than the refrigerant flow path 40 and the dense flow path area 40A when viewed through the lower opening 19. On the other hand, as shown by the dashed line in Figure 9, the housing fixing part 71 can be seen, for example, from near the right end of the lower opening 19 without overlapping with the refrigerant flow path 40 and the dense flow path area 40A. For this reason, for example, when performing maintenance on the first sensor unit 60, the worker can easily access the housing fixing part 71 and remove the first sensor unit 60 together with the fixing device 70.

[0055] Furthermore, the first sensor unit 60 is located near the left bend portion 35 of the indoor heat exchanger 30 in a plan view. More specifically, the first sensor unit 60 is positioned between the left bend portion 35 of the indoor heat exchanger 30 and the inner surface of the left side of the housing 10 in a plan view. Also, since the first sensor unit 60 is positioned below the bend portion 35 (see Figure 5), when refrigerant leaks at the bend portion 35 and flows downward due to gravity, the first sensor unit 60 can easily detect the leaked refrigerant.

[0056] As shown in Figure 9, in a plan view, a second sensor unit 80 is provided near the right-side bend 35 of the indoor heat exchanger 30. The second sensor unit 80 detects the refrigerant used in the indoor unit 1 and the air conditioning system. In detail, in a plan view, the second sensor unit 80 is positioned between the right-side bend 35 of the indoor heat exchanger 30 and the inner surface of the right side of the housing 10. The second sensor unit 80 is also positioned at the bottom of the housing 10. That is, since the second sensor unit 80 is positioned below the bend 35, the first sensor unit 60 can easily detect the leaked refrigerant when it flows downward due to gravity at the bend 35.

[0057] In detail, the second sensor unit 80 is installed at a position where its height from the lower end of the housing 10 is a height specified by laws or standards. In this embodiment, the second sensor unit 80 is positioned at a height of 30 cm or less from the lower end of the housing 10. Furthermore, the second sensor unit 80 is installed at a height that is less than or equal to the height of the upper drain pan 39A and greater than or equal to the height of the lower drain pan 39B.

[0058] Figure 10 is a perspective view of the second sensor unit 80. The second sensor unit 80 has a sensor substrate 61 and a substrate holder 63 similar to those of the first sensor unit 60. The second sensor unit 80 is positioned in a orientation where the first sensor unit 60 is rotated 90° clockwise in a plan view. Hereinafter, the refrigerant sensor 62 provided on the sensor substrate 61 of the first sensor unit 60 will be referred to as the first refrigerant sensor 62A. The refrigerant sensor 62 provided on the sensor substrate 61 of the second sensor unit 80 will be referred to as the second refrigerant sensor 62B. The substrate holder 63 covering the first refrigerant sensor 62A is an example of the "first holder" in this embodiment. The substrate holder 63 covering the second refrigerant sensor 62B is an example of the "second holder" in this embodiment.

[0059] The second sensor unit 80 is attached to the inner side of the right side of the housing 10 via a base 90. The base 90 is formed by bending sheet metal. The base 90 has housing fixing parts 91 that are fixed to the housing 10. The housing fixing parts 91 are planar structures that are substantially perpendicular to the left-right direction and have fastening holes formed therein. The housing fixing parts 91 are formed at the upper end and the lower end of the base 90, respectively.

[0060] A bulge 93 is formed on the base 90. The bulge 93 is a roughly rectangular parallelepiped structure that bulges out to the left between the two housing fixing parts 91. An opening (not shown) is formed on the left side of the bulge 93 for inserting the claw part 65 of the second sensor unit 80. The second sensor unit 80 is fixed to the base 90 by inserting the claw part 65 of the second sensor unit 80 into the opening of the bulge 93 and fastening the fastening part 67 to the bulge 93.

[0061] A second sensor cover 95 is attached to the base 90. The second sensor cover 95 is a cover that covers the second sensor unit 80 from above, to the left, and from the front and back. A fastening surface 95A is formed on the second sensor cover 95. The fastening surface 95A has a planar structure perpendicular to the left-right direction. The fastening surface 95A is fastened to the left side of the bulge 93 above the second sensor unit 80.

[0062] A first top surface 95B is formed on the second sensor cover 95. The first top surface 95B is a surface bent to the right from the upper end of the fastening surface 95A and has a horizontal planar structure. The first top surface 95B is superimposed on the upper surface of the bulge 93 from above. Therefore, the first top surface 95B can prevent water droplets dripping from above from passing between the fastening surface 95A and the bulge 93 and reaching the second sensor unit 80.

[0063] The second sensor cover 95 has a second top surface 95C. The second top surface 95C is a surface bent to the left from the lower end of the fastening surface 95A and has a horizontal planar structure. The second top surface 95C covers the second sensor unit 80 from above. The second sensor cover 95 also has a pair of front and rear first side surfaces 95D. The first side surfaces 95D are formed by bending downwards from both ends in the front-rear direction of the second top surface 95C and have a planar structure that is substantially perpendicular to the front-rear direction. The pair of first side surfaces 95D cover the second sensor unit 80 from both the front and rear outer sides.

[0064] A second side surface 95E is formed on the second sensor cover 95. The second side surface 95E is formed by folding downwards from the left end of the second top surface 95C and has a planar structure that is approximately perpendicular to the left-right direction. The second side surface 95E covers the second sensor unit 80 from the left. In addition, a pair of front and rear third side surfaces 95F are formed on the second sensor cover 95. The third side surfaces 95F are formed by folding to the right from both ends in the front-rear direction of the second side surface 95E and have a planar structure that is approximately perpendicular to the front-rear direction. The third side surfaces 95F are provided overlapping with the first side surface 95D. Specifically, the third side surfaces 95F are provided inside the first side surface 95D in the front-rear direction, with the second sensor unit 80 as the reference. Therefore, water droplets that drip onto the second top surface 95C from above flow smoothly along the first side surface 95D to the outer surface of the second side surface 95E and are less likely to reach the second sensor unit 80. Thus, the second sensor cover 95 is configured to cover the second refrigerant sensor 62B from above and in almost all directions horizontally.

[0065] [1-2. Operation] The operation of the air conditioning system and indoor unit 1, configured as described above, will be explained below.

[0066] [1-2-1. Operation during driving] When the air conditioning system is operating and the indoor unit 1 is running, the indoor blower 21 drives an airflow from bottom to top inside the housing 10. At this time, if refrigerant leaks from the header section 41 or the distributor 43, which are particularly prone to refrigerant leakage in the indoor unit 1, the refrigerant flows into the space S1 partitioned by the cover member 50.

[0067] As described above, an airflow from bottom to top occurs inside the housing 10, but since the upper side of space S1 is closed by the partition plate 38, the refrigerant in space S1 is not easily carried away by the airflow and tends to remain in space S1. Also, since the refrigerant in this embodiment has a higher specific gravity than air, the refrigerant remaining in space S1 easily reaches the first sensor unit 60 below due to gravity. For this reason, the first refrigerant sensor 62A provided in the first sensor unit 60 can easily detect refrigerant leaking from the header section 41 or the distributor 43.

[0068] Furthermore, during cooling operation of the air conditioning system, the indoor heat exchanger 30 of the indoor unit 1 functions as an evaporator and becomes cold. In this state, humid air reaches the indoor heat exchanger 30, making it easy for condensation to form on the indoor heat exchanger 30. However, the space S1 partitioned by the cover member 50 is closed at the top by the partition plate 38. Therefore, humid air is less likely to flow into space S1, and condensation is less likely to form on the left end bend 35, header 41, and distributor 43 of the indoor heat exchanger 30 located within space S1. Consequently, condensation is less likely to drip onto the first sensor unit 60 and the first refrigerant sensor 62A located below space S1. This allows the first sensor cover 77 to be configured not to cover the first sensor unit 60 and the first refrigerant sensor 62A from both the left and right sides, making it easier to detect refrigerant leakage.

[0069] [1-2-2. Operation while stopped] When the air conditioning system is stopped and the indoor unit 1 is not operating, if refrigerant leakage occurs inside the indoor unit 1, the leaked refrigerant will flow downward due to gravity. Also, inside the indoor unit 1, the refrigerant flow path 40 and the indoor heat exchanger 30 are located above the lower drain pan 39B. Therefore, the leaked refrigerant tends to accumulate on top of the lower drain pan 39B. In this embodiment, the second sensor unit 80 and the second refrigerant sensor 62B are located at a height between the lower drain pan 39B and the upper drain pan 39A. Therefore, the second refrigerant sensor 62B can easily detect the leaked refrigerant.

[0070] Furthermore, the first refrigerant sensor 62A and the second refrigerant sensor 62B are located below the indoor heat exchanger 30 and are positioned near the bend section 35 of the indoor heat exchanger 30, where refrigerant is prone to leakage in a plan view. Therefore, refrigerant leaking from the bend section 35 easily reaches the first refrigerant sensor 62A and the second refrigerant sensor 62B, making it easy for the first refrigerant sensor 62A and the second refrigerant sensor 62B to detect refrigerant leakage.

[0071] [1-3. Effects, etc.] As described above, in this embodiment, the indoor unit 1 comprises an indoor heat exchanger 30, a housing 10 that houses the indoor heat exchanger 30, a cover member 50 that covers a header portion 41 connected to the indoor heat exchanger 30, and a first refrigerant sensor 62A positioned below the space S1 partitioned off by the cover member 50 towards the header portion 41. The cover member 50 is made of a resin film and is fixed by a metal fixing member 59. This allows the cover member 50 to be temporarily deformed when positioning it, making it easier to position the cover member 50 in a location that covers the header portion 41. As a result, it is easier to allow leaked refrigerant in the space S1 partitioned by the cover member 50 to reach the first refrigerant sensor 62A, making it easier to detect refrigerant leakage. In addition, fixing the cover member 50 with the metal fixing member 59 makes it easier to suppress vibration and rattle of the cover member 50.

[0072] As in this embodiment, in the indoor unit 1, the indoor heat exchanger 30 may be configured such that the header portion 41 is inclined so that the upper side is located forward with respect to the vertical direction, the cover member 50 has an inclined portion 51 that is inclined along the header portion 41 so that the upper side is located forward with respect to the vertical direction, and the first refrigerant sensor 62A is positioned near the inclined portion 51. This allows the refrigerant leaking near the header section 41 to be guided by the inclined section 51 and more easily reach the first refrigerant sensor 62A. Therefore, refrigerant leakage can be easily detected.

[0073] As in this embodiment, in the indoor unit 1, the fixing member 59 may be configured to be fixed to the support column 12 stretched across the housing 10 and to the cover member 50. This allows the cover member 50 to be fixed to the support column 12, which is a part of the housing 10 that tends to have high strength, via the fixing member 59. As a result, the cover member 50 can be more firmly fixed, and vibration and rattle of the cover member 50 can be more easily suppressed.

[0074] As in this embodiment, the indoor unit 1 may have a configuration in which the housing 10 has an intake port 11 located below the air outlet 13, and the space S1 is closed at the top and open at the bottom. As a result, even when air flows upward inside the housing 10, leaked refrigerant is more likely to accumulate in space S1, and the leaked refrigerant is more likely to reach the first refrigerant sensor 62A located below space S1. Therefore, it is easier to detect refrigerant leaks.

[0075] As in this embodiment, the indoor unit 1 may be configured such that the cover member 50 has an inclined portion 51 that is inclined vertically along the header portion 41 and a bent portion 55 that is bent from the inclined portion 51, and is in contact with the upper drain pan 39A and the bent portion 55 is in contact with the housing 10. This makes it less likely for gaps to form in space S1 and makes it easier to fix the cover member 50. As a result, it is easier to get the refrigerant to the first refrigerant sensor 62A and easier to suppress vibration and rattle of the cover member 50.

[0076] As in this embodiment, the indoor unit 1 may be configured to have a first sensor cover 77 that covers the first refrigerant sensor 62A from above but does not cover the first refrigerant sensor 62A from at least one direction in the horizontal direction. This protects the first refrigerant sensor 62A, which is located below the space S1 where condensation is less likely to occur, from condensation, while making it easier for leaked refrigerant to reach the first refrigerant sensor 62A. Therefore, it is possible to protect the first refrigerant sensor 62A while making it easier to detect refrigerant leaks.

[0077] In this embodiment, the air conditioning system comprises the indoor unit 1 described above and an outdoor unit. This allows the cover member 50 to be temporarily deformed when positioning it, making it easier to position the cover member 50 in a location that covers the header portion 41. As a result, it is easier to allow leaked refrigerant in the space S1 partitioned by the cover member 50 to reach the first refrigerant sensor 62A, making it easier to detect refrigerant leakage. In addition, fixing the cover member 50 with the metal fixing member 59 makes it easier to suppress vibration and rattle of the cover member 50.

[0078] Furthermore, as described above, in this embodiment, the indoor unit 1 comprises a housing 10 that houses the indoor heat exchanger 30 and the indoor blower 21, a first refrigerant sensor 62A, and a fixing device 70 for fixing the first refrigerant sensor 62A. The fixing device 70 comprises a sensor fixing part 75 to which the first refrigerant sensor 62A is fixed, and a housing fixing part 71 that is fixed to the housing 10 at a position further away from the refrigerant flow path 40 than the sensor fixing part 75. As a result, the fixing device 70 allows the first refrigerant sensor 62A to be positioned near the refrigerant flow path 40, and the first refrigerant sensor 62, along with the fixing device 70, can be removed from the housing 10 at the housing fixing part 71, which is away from the refrigerant flow path 40. Therefore, refrigerant leakage can be easily detected and maintenance of the first refrigerant sensor 62A can be easily performed.

[0079] As in this embodiment, the housing 10 may be configured to include a lower opening 19 for maintenance, a middle maintenance panel 16 and a lower maintenance panel 17 that cover the lower opening 19, the first refrigerant sensor 62A being located behind the refrigerant flow path 40 when viewed through the lower opening 19, and the housing fixing part 71 being provided in a position that is visible through the lower opening 19 without overlapping with the refrigerant flow path 40. This makes it easier to access the housing fixing portion 71 of the fixing device 70 from the lower opening 19 of the housing 10, and makes it easier to remove the first refrigerant sensor 62A together with the fixing device 70. Therefore, maintenance of the first refrigerant sensor 62A can be easily performed.

[0080] As in this embodiment, the fixing device 70 may have an arm portion 73 that connects the housing fixing portion 71 and the sensor fixing portion 75, and the arm portion 73 may be configured to hold the wiring connected to the sensor board 61 of the first refrigerant sensor 62A. This allows the wiring to be positioned along the arm portion 73, making it easier to remove the first refrigerant sensor 62A together with the fixing device 70. Therefore, maintenance of the first refrigerant sensor 62A can be easily performed.

[0081] As in this embodiment, the sensor fixing portion 75 may be configured to have a first sensor cover 77 that covers the first refrigerant sensor 62A from above. This makes it easier to protect the first refrigerant sensor 62A from water droplets such as condensed water. Therefore, the fixing device 70 can protect the first refrigerant sensor 62A.

[0082] In this embodiment, the air conditioning system comprises an outdoor unit and the indoor unit 1 described above. As a result, the fixing device 70 allows the first refrigerant sensor 62A to be positioned near the refrigerant flow path 40, and the first refrigerant sensor 62, along with the fixing device 70, can be removed from the housing 10 at the housing fixing part 71, which is away from the refrigerant flow path 40. Therefore, refrigerant leakage can be easily detected and maintenance of the first refrigerant sensor 62A can be easily performed.

[0083] Furthermore, as described above, in this embodiment, the indoor unit 1 comprises a housing 10, an indoor heat exchanger 30 disposed within the housing 10, a first refrigerant sensor 62A, and a second refrigerant sensor 62B. It uses a refrigerant with a specific gravity greater than air, and the first refrigerant sensor 62A and the second refrigerant sensor 62B are respectively installed near the bends 35 at both ends of the indoor heat exchanger 30 in a plan view. As a result, refrigerant leaking from the bend section 35, where refrigerant leakage is likely to occur, can quickly reach the first refrigerant sensor 62A or the second refrigerant sensor 62B, which are positioned near the bend sections 35 at both ends of the indoor heat exchanger 30 in a plan view. Therefore, refrigerant leakage can be detected quickly.

[0084] As in this embodiment, the indoor unit 1 may be configured to include an air intake port 11 for drawing in air and an air outlet port 13 located above the air intake port 11, and the indoor heat exchanger 30 may be located between the air intake port 11 and the air outlet port 13 and further include a cover member 50 that covers the bend portion 35 on the left end of the indoor heat exchanger 30, and the second refrigerant sensor 62B may be located at the bottom of the housing 10, and the first refrigerant sensor 62A may be located below the space S1 partitioned by the cover member 50. As a result, when the indoor unit 1 is stopped, the second refrigerant sensor 62B located at the bottom of the housing 10 can detect refrigerant leakage, and when the indoor unit 1 is in operation, the first refrigerant sensor 62A can detect refrigerant accumulated inside the cover member 50 covering the bend portion 35. Therefore, refrigerant leakage can be detected quickly and easily.

[0085] As in this embodiment, the first refrigerant sensor 62A may be configured to be installed at a height greater than or equal to the height of the drain pan 39 that receives condensed water from the indoor heat exchanger 30. This allows the first refrigerant sensor 62A to be positioned higher up, making it easier to detect refrigerant accumulating inside the cover member 50 during operation of the indoor unit 1. Therefore, refrigerant leakage can be detected quickly.

[0086] As in this embodiment, the drain pan 39 may include an upper drain pan 39A and a lower drain pan 39B located below the upper drain pan 39A, the second refrigerant sensor 62B may be positioned at a height between the upper drain pan 39A and the lower drain pan 39B, and the first refrigerant sensor 62A may be provided at a height equal to or greater than the height of the upper drain pan 39A. This allows the first refrigerant sensor 62A to be positioned higher up, making it easier to detect refrigerant accumulating inside the cover member 50 while the indoor unit 1 is in operation, and the second refrigerant sensor 52B to be positioned at a height above the lower drain pan 39B, making it easier to detect refrigerant accumulating in the lower drain pan 39B while the indoor unit 1 is stopped. As a result, refrigerant leakage can be detected quickly and easily.

[0087] As in this embodiment, the first refrigerant sensor 62A may be covered by a first sensor cover 77, the second refrigerant sensor 62B may be covered by a second sensor cover 95, the second sensor cover 95 may cover the second refrigerant sensor 62B from above and horizontally, and the first sensor cover 77 may cover the first refrigerant sensor 62A from above and not cover it from at least one direction in the horizontal direction. This allows the first refrigerant sensor 62A, which is less prone to condensation above, to be exposed more than the second refrigerant sensor 62B, protecting both the first and second refrigerant sensors 62A and 62B from condensation, while making it easier for leaked refrigerant to reach the first refrigerant sensor 62A. As a result, refrigerant leaks can be detected quickly.

[0088] In this embodiment, the air conditioning system comprises an outdoor unit and the indoor unit 1 described above. As a result, refrigerant leaking from the bend section 35, where refrigerant leakage is likely to occur, can quickly reach the first refrigerant sensor 62A or the second refrigerant sensor 62B, which are positioned near the bend sections 35 at both ends of the indoor heat exchanger 30 in a plan view. Therefore, refrigerant leakage can be detected quickly.

[0089] (Embodiment 2) The indoor unit 101 according to Embodiment 2 will be described below. Note that the following will describe the differences from Embodiment 1, and explanations of matters similar to those in Embodiment 1 may be omitted.

[0090] [2-1. Structure] The indoor unit 101 according to Embodiment 2 has a first sensor unit 160 in place of the first sensor unit 60 in the indoor unit 1 according to Embodiment 1. The first sensor unit 160 according to Embodiment 2 is arranged in a position where the first sensor unit 60 according to Embodiment 1 has been rotated by 90 degrees.

[0091] Figure 11 is a perspective view of the first sensor unit 160 according to Embodiment 2. The first sensor unit 160 includes a sensor substrate 161 and a substrate holder 163. The sensor substrate 161 is a substrate that includes a refrigerant sensor 162 for detecting refrigerant. The substrate holder 163 is a cover that covers the sensor substrate 161 and the refrigerant sensor 162 from the front-rear, up-down, and right-side directions. The substrate holder 163 is made of resin. In this embodiment, the substrate holder 163 has ventilable openings formed on the front, rear, and right-side. This allows the refrigerant sensor 162 to detect refrigerant flowing into the substrate holder 163 through the front, rear, and right-side. Furthermore, no openings are formed on the top surface of the substrate holder 163, making it difficult for water droplets dripping from above to reach the sensor substrate 161.

[0092] The first sensor unit 160 is fixed to the fixing device 170. The fixing device 170 is made of sheet metal and is a component fixed to the housing 10. The fixing device 170 has a sensor fixing portion 175. The sensor fixing portion 175 fixes the first sensor unit 160. The sensor fixing portion 175 has a flat plate structure that is substantially perpendicular to the left-right direction. The first sensor unit 160 is fixed to the fixing device 170 by attaching a substrate holder 163 to the right side of the sensor fixing portion 175.

[0093] A first sensor cover 177 is attached to the sensor fixing portion 175. The first sensor cover 177 is fixed by fastening it to the upper end of the sensor fixing portion 175. The first sensor cover 177 has a top surface portion 177A and a right side surface portion 177B. The top surface portion 177A has a substantially horizontal planar structure that covers the first sensor unit 160 from above. Therefore, water droplets dripping from above are shielded by the top surface portion 177A and are less likely to reach the first sensor unit 160. The right side surface portion 177B bends downward from the right end of the top surface portion 177A and has a planar structure that is substantially perpendicular to the left-right direction. The right side surface portion 177B covers the first sensor unit 60 from the right side. The right direction corresponds to an example of "at least one of the horizontal directions" in this disclosure. Furthermore, the first sensor cover 177 does not have a surface perpendicular to the front-rear direction, and is configured not to cover the first sensor unit 160 from the front or rear. In other words, the first sensor cover 177 has an open shape on the front and rear sides of the first sensor unit 160 and the refrigerant sensor 162. The first sensor cover 177 corresponds to an example of a "sensor cover" in this disclosure.

[0094] Furthermore, in Embodiment 2, the first sensor unit 160 and the first sensor cover 177 are configured such that the dimension W1 in the front-to-back direction is larger than the dimension W2 in the left-to-right direction. The left-to-right direction corresponds to an example of the "second direction" in this disclosure.

[0095] Figure 12 shows the arrangement of the first sensor unit 160 according to Embodiment 2 as viewed along the left-right direction. Figure 13 shows the arrangement of the first sensor unit 160 according to Embodiment 2 as viewed along the front-back direction.

[0096] As shown in Figures 12 and 13, the first sensor unit 160 is positioned in a location that overlaps with the lower end opening 50A in a plan view, similar to the first sensor unit 60 according to Embodiment 1. That is, on the front side of the first sensor unit 160, there is an inclined portion 51 that is inclined so that its upper side is facing forward. Also, as described above, the first sensor cover 177 has an opening on the front side of the first sensor unit 160. Therefore, refrigerant that leaks in the space S1 inside the cover member 50 flows downwards and backwards along the inclined portion 51 and can easily reach the refrigerant sensor 162 inside the first sensor unit 160 through the opening in the first sensor cover 177.

[0097] More specifically, the first sensor unit 160 is positioned further forward and upward than the first sensor unit 60 according to Embodiment 1. More specifically, the upper end of the first sensor cover 177 covering the first sensor unit 160 according to Embodiment 2 is located above the refrigerant pipes 44 and branch pipes 46, which are refrigerant pipes located below the cover member 50. More specifically, the upper end of the first sensor cover 177 is located above the horizontal portions of the refrigerant pipes 44, branch section 46A, and junction section 46B, which are refrigerant pipes extending in the front-rear direction.

[0098] Furthermore, the first sensor unit 160 is positioned to overlap with the branch pipe 46 when viewed along the left-right direction. More specifically, the first sensor unit 160 is positioned to overlap with the junction 46B of the branch pipe 46 when viewed along the left-right direction.

[0099] Furthermore, as shown in Figure 12, the height H1 of the lower end of the substrate holder 163 is higher than the upper end of the upper drain pan 39A. Therefore, the refrigerant sensor 162, which is installed inside the substrate holder 163, is located above the upper end of the upper drain pan 39A. As a result, the refrigerant sensor 162 can easily detect refrigerant leakage when refrigerant that has leaked in the space S1 inside the cover member 50 accumulates on top of the upper drain pan 39A. In addition, in the second embodiment, the first sensor unit 160 and the refrigerant sensor 162 are installed in front of the upper drain pan 39A.

[0100] Furthermore, the height H1 of the lower end of the substrate holder 163 is greater than or equal to the height of the lower end of the cover member 50. More specifically, the height H1 of the lower end of the substrate holder 163 is located above the lower end 53A of the compartment 53 of the cover member 50. Therefore, the refrigerant sensor 162 installed inside the substrate holder 163 is located above the lower end of the compartment 53. As a result, refrigerant leaking in the space S1 inside the cover member 50 is more likely to reach the refrigerant sensor 162 before it flows out of the space S1.

[0101] Furthermore, as described above, the first sensor cover 177 according to Embodiment 2 is configured such that the dimension W2 in the left-right direction is smaller than the dimension W1 in the front-rear direction. Therefore, the first sensor unit 160 covered by the first sensor cover 177 can be easily positioned without interfering with the refrigerant piping 44 and branch piping 46 that extend along the front-rear direction.

[0102] [2-2. Operation] The inventors conducted simulations to verify the behavior of the refrigerant when it leaks in the space S1 within the cover member 50. The simulations are described below. The inventors simulated the behavior of the leaked refrigerant in Embodiment 1 and Embodiment 2 under the condition that the refrigerant leaked from the assumed leak area P1 (see Figure 13) at the top of the space S1, and compared the results. In addition, the inventors set the conditions that the indoor units 1 and 101 were operating and the indoor blower 21 was running in the simulations corresponding to Embodiment 1 and Embodiment 2. Furthermore, in the simulations corresponding to Embodiment 1 and Embodiment 2, the inventors set the condition that the refrigerant leak occurred at 0 seconds, flowed out for up to 60 seconds, and then stopped flowing out after 60 seconds.

[0103] Figure 14 shows the simulation results in the XIV cross-sectional view of Figure 11, and shows the velocity vector diagram and concentration contour diagram of the leaked refrigerant in the horizontal cross-section of each first sensor unit 60, 160, among the simulation results corresponding to Embodiment 1 and Embodiment 2. Note that Figure 14 shows the velocity vector diagram and concentration contour diagram 20 seconds after the occurrence of refrigerant leakage. In the velocity vector diagram, the longer the arrow is closer to black, the greater the refrigerant flow velocity, and the shorter the arrow is closer to white, the smaller the flow velocity. In the concentration contour diagram, the closer the area is to black, the higher the refrigerant concentration, and the closer the area is to white, the lower the refrigerant concentration.

[0104] As shown in the velocity vector diagram in Figure 14, in both Embodiment 1 and Embodiment 2, if a refrigerant leak occurs in the space S1, the refrigerant that has flowed downward along the inclined portion 51 reaches the vicinity of the first sensor units 60 and 160 from the front. In Embodiment 1, the first sensor cover 77 has a front portion 77B that covers the first sensor unit 60 from the front. Therefore, in Embodiment 1, the refrigerant flowing from the front toward the first sensor unit 60 is easily blocked by the front portion 77B. In contrast, in Embodiment 2, the first sensor cover 177 that covers the first sensor unit 160 has an opening on the front side of the first sensor unit 160. Therefore, in Embodiment 2, the refrigerant flowing from the front toward the first sensor unit 160 is less likely to be blocked by the first sensor cover 177 and is more likely to reach the refrigerant sensor 162 inside the first sensor unit 160.

[0105] Figure 15 is a concentration contour plot showing the simulation results in a vertical cross-sectional view perpendicular to the left-right direction of the housing 10, and shows the concentration contour plot 20 seconds after the occurrence of refrigerant leakage. As shown in Figure 15, the refrigerant concentration near the first sensor unit 160 in Embodiment 2 is higher than that near the first sensor unit 60 in Embodiment 1. This is thought to be because the first sensor unit 160 in Embodiment 2 is located above the refrigerant piping 44 and the branch piping 46, and the flow of refrigerant along the inclined section 51 reaches the vicinity of the first sensor unit 160 before it is obstructed and disturbed by the refrigerant piping 44 and the branch piping 46.

[0106] Figure 16 is a graph showing the change in the mole fraction of refrigerant at the locations of refrigerant sensors 62 and 162 in the simulation. In Figure 16, graph G1, shown by a dashed line, shows the mole fraction of refrigerant at the location of refrigerant sensor 62 in the simulation corresponding to Embodiment 1, and graph G2, shown by a solid line, shows the mole fraction of refrigerant at the location of refrigerant sensor 162 in the simulation corresponding to Embodiment 2. As shown in Figure 16, it was confirmed that the mole fraction of refrigerant detected by the refrigerant sensor 162 in Embodiment 2, i.e., the concentration of refrigerant, was greater than or equal to the mole fraction of refrigerant detected by the refrigerant sensor 62 in Embodiment 1, at all times from 0 seconds when the refrigerant outflow begins to 60 seconds when the refrigerant outflow ends, and at subsequent times. Thus, in Embodiment 2, the arrangement of the first sensor unit 160 and the first sensor cover 177 is changed from Embodiment 1 to make it easier to detect refrigerant leakage.

[0107] [2-3. Effects, etc.] As described above, in this embodiment, the indoor unit 101 comprises an indoor heat exchanger 30, a housing 10 housing the indoor heat exchanger 30, a cover member 53 that covers a header portion 41 connected to the indoor heat exchanger 30 and has a lower end opening 50A at its lower end, a refrigerant sensor 162 provided at a position that overlaps with the lower end opening 50A in a plan view, and a first sensor cover 177 that covers the refrigerant sensor 162 from above and from the right in the horizontal direction. The indoor heat exchanger 30 is provided in a position in which the header portion 41 is inclined in a direction in which the upper side is located towards the front, the cover member 50 has an inclined portion 51 that extends upward from the lower end opening 50A along the header portion 41, and the first sensor cover 177 has an opening on the front side of the refrigerant sensor 162. This makes it easier for the refrigerant flowing along the inclined section 51 from the forward side toward the refrigerant sensor 162 to reach the refrigerant sensor 162 without being obstructed by the cover member. Therefore, an indoor unit 1 that makes it easier to detect refrigerant leakage can be provided.

[0108] As in this embodiment, the refrigerant sensor 162 may be configured to be installed at a height greater than or equal to the height of the upper drain pan 39A that receives condensed water from the indoor heat exchanger 30. This makes it easier for the refrigerant sensor 162 to detect refrigerant accumulating on the upper drain pan 39A. Therefore, it is possible to provide an indoor unit 1 that makes it easier to detect refrigerant leaks.

[0109] As in this embodiment, a refrigerant pipe 44 and a branch pipe 46 may be provided below the cover member 50, the refrigerant pipe 44 and the branch pipe 46 may extend along a horizontal direction, and the upper end of the first sensor cover 177 may be provided above the refrigerant pipe 44 and the branch pipe 46. As a result, the refrigerant flow along the inclined section 51 is more likely to reach the refrigerant sensor 162 before it is disturbed by the refrigerant piping 44 and branch piping 46. Therefore, an indoor unit 1 that can easily detect refrigerant leaks can be provided.

[0110] As in this embodiment, the refrigerant piping 44 and branch piping 46 may extend in the front-rear direction along the forward direction, and the first sensor cover 177 may be configured such that the dimension W2 in the left-right direction perpendicular to the forward direction in the horizontal direction is smaller than the dimension W1 in the front-rear direction along the forward direction. This makes it less likely for the first sensor cover 177 to interfere with the refrigerant piping 44 and branch piping 46. As a result, the refrigerant sensor 162 can be easily positioned near the refrigerant piping 44 and branch piping 46.

[0111] As in this embodiment, the refrigerant sensor 162 may be configured to be installed at a height equal to or greater than the lower end 53A of the cover member 50. This makes it easier for leaked refrigerant to reach the refrigerant sensor 162 before it flows out of the partitioned space S1 inside the cover member 50. Therefore, an indoor unit 1 that makes it easier to detect refrigerant leaks can be provided.

[0112] As in this embodiment, the air conditioning system may be configured to include the indoor unit 1 described above and an outdoor unit. This makes it easier for the refrigerant flowing from the front towards the refrigerant sensor 162 along the inclined section 51 to reach the refrigerant sensor 162 without being obstructed by the first sensor cover 177. Therefore, it is possible to provide an air conditioning system that makes it easier to detect refrigerant leaks.

[0113] (Other embodiments) As described above, Embodiment 1 has been explained as an example of the technology disclosed in this application. However, the technology in this disclosure is not limited to this and can be applied to embodiments that have been modified, replaced, added, or omitted. Furthermore, it is possible to create new embodiments by combining the components described in Embodiment 1 above. Therefore, other embodiments are illustrated below.

[0114] In Embodiments 1 and 2, the indoor unit 1 was described as a floor-standing ducted type, but this is just an example. The indoor unit 1 may be, for example, a floor-standing type that is not ducted, or any other type of indoor unit 1 such as an upward-blowing type.

[0115] In Embodiment 2, the first sensor cover 177 was described as having an opening on the rear side of the first sensor unit 160, but this is just one example. Figure 17 is a perspective view showing the first sensor cover 177 according to another embodiment. As shown in Figure 17, the first sensor cover 177 may be provided with a rear portion 177C that covers the first sensor unit 160 from the rear side. As described above, since the first sensor unit 160 is located on the front side of the upper drain pan 39A, even if condensed water drips onto the upper drain pan 39A and water splashes, the rear portion 177C can prevent the water from reaching the refrigerant sensor 162.

[0116] In other words, as in other embodiments, the refrigerant sensor 162 may be provided in front of the upper drain pan 39A, and the first sensor cover 177 may cover the refrigerant sensor 162 from the rear side, which is opposite to the front side. As a result, even if condensed water drips onto the upper drain pan 39A and splashes, the first sensor cover 177 can prevent the splashed water from reaching the refrigerant sensor 162. Therefore, the reliability of the refrigerant sensor 162 can be improved, and an indoor unit 1 that makes it easier to detect refrigerant leaks can be provided.

[0117] In Embodiment 2, the first sensor unit 160 is described as being covered by the first sensor cover 177, but this is just one example. The first sensor unit 160 may also be configured not to be covered by the first sensor cover 177. In this case, the substrate holder 163 functions as the "sensor cover," and the substrate holder 163 only needs to have an opening on the front side of the refrigerant sensor 162, similar to Embodiment 2.

[0118] Since the embodiments described above are for illustrative purposes of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the claims or their equivalents.

[0119] (Note) Based on the above description of embodiments, the following technologies are disclosed. (Technical 1) An indoor unit comprising: a heat exchanger; a housing for housing the heat exchanger; a cover member that covers a header portion connected to the heat exchanger and has a lower end opening at its lower end; a refrigerant sensor provided at a position that overlaps with the lower end opening in a plan view; and a sensor cover that covers the refrigerant sensor from at least one of the upward and horizontal directions, wherein the heat exchanger is provided in a position in which the header portion is inclined in a direction in which the upper side is located toward the first direction, the cover member has an inclined portion that extends upward from the lower end opening toward the header portion and inclined along the header, and the sensor cover has an opening toward the first direction side of the refrigerant sensor. This allows refrigerant flowing along the inclined section from the first direction towards the refrigerant sensor to reach the sensor more easily without being obstructed by the sensor cover. As a result, an indoor unit that makes it easier to detect refrigerant leaks can be provided.

[0120] (Technical 2) The indoor unit according to Technical 1, characterized in that the refrigerant sensor is installed at a height greater than or equal to the height of the drain pan that receives condensed water from the heat exchanger. This makes it easier for the refrigerant sensor to detect refrigerant accumulating on the drain pan. Therefore, it is possible to provide an indoor unit that makes it easier to detect refrigerant leaks.

[0121] (Technology 3) An indoor unit according to Technology 1 or 2, wherein a refrigerant pipe is provided below the cover member, the refrigerant pipe extends in a horizontal direction, and the upper end of the sensor cover is provided above the refrigerant pipe. This allows the refrigerant flow along the inclined section to reach the refrigerant sensor more easily before it is disturbed by the refrigerant piping. As a result, it is possible to provide an indoor unit that makes it easier to detect refrigerant leaks.

[0122] (Technical 4) The indoor unit according to Technical 3, wherein the refrigerant piping extends in a direction along the first direction, and the dimensions of the sensor cover in a second direction perpendicular to the first direction in the horizontal direction are smaller than the dimensions in the direction along the first direction. This reduces the likelihood of the sensor cover interfering with the refrigerant piping. Therefore, it becomes easier to position the refrigerant sensor near the refrigerant piping.

[0123] (Technical 5) The indoor unit according to any one of Technical 1 to 4, wherein the refrigerant sensor is provided at a height equal to or greater than the lower end of the cover member. This makes it easier for leaked refrigerant to reach the refrigerant sensor before it flows out of the partitioned space inside the cover component. Therefore, it is possible to provide an indoor unit that makes it easier to detect refrigerant leaks.

[0124] (Technical 6) The indoor unit according to any one of Technical 2 to 5, wherein the refrigerant sensor is provided on the side of the drain pan in the first direction, and the sensor cover covers the refrigerant sensor from the opposite side of the first direction. This design prevents condensed water from reaching the refrigerant sensor, even if it drips into the drain pan and splashes. Therefore, it improves the reliability of the refrigerant sensor and provides an indoor unit that makes refrigerant leaks easier to detect.

[0125] (Technical 7) An air conditioning system comprising an indoor unit and an outdoor unit as described in any of Technical 1 to 6. This allows refrigerant flowing along the inclined section from the first direction towards the refrigerant sensor to reach the sensor more easily without being obstructed by the sensor cover. Therefore, it is possible to provide an air conditioning system that makes it easier to detect refrigerant leaks. [Industrial applicability]

[0126] This disclosure is applicable to indoor units and air conditioning systems. Specifically, this disclosure is applicable to floor-standing ducted indoor units, or any other type of indoor unit, and air conditioning systems that include such indoor units. [Explanation of Symbols]

[0127] 1 Indoor unit 10 cabinets 11 Inlet 12 pillars 13 Air outlet 14 Control section 15. Upper maintenance panel 16. Middle maintenance panel (maintenance panel) 17. Lower maintenance panel 18 Top opening 19 Lower opening (opening) 21 Indoor fan (blower) 30 Indoor heat exchanger (heat exchanger) 31 Main body 32 fins 33 Heat transfer tubes 35 Bend section 36 U-bend pipe 38 Partition Plates 39 Drain pan 39A Upper drain pan (drain pan) 39B Lower drain pan 40 Refrigerant flow path 40A Congested flow channel section 41 Header section 43 Distributors 43A Main piping 43B Branch piping 44 Refrigerant piping 45 Expansion valve 46 Branch piping (refrigerant piping) 46A Branch section 46B Confluence 47 Receiver 50 Cover component 50A bottom opening 51 Slope 53 Sections 53A bottom end 55 Folded section 57 Front part 59 Fixing member 59A Surface section 59B Inclined section 60 First Sensor Unit 61 Sensor board (refrigerant sensor board) 62 Refrigerant Sensor 62A First Refrigerant Sensor 62B Second Refrigerant Sensor 63. Circuit board holder (first holder, second holder) 65 Nail part 67 Fastening part 70 Fixtures 71 Housing fixing part 72 Nail area 73 Arm section 74 Wire holder 75 Sensor fixing part 75A aperture 77. First Recovery Cover 77A Top section 77B Front part 80 Second Sensor Unit 90 base 91 Housing fixing part 93 Bulge 95 Second sensor cover 95A Fastening surface 95B First Top Surface 95C Second Top Surface 95D First side view 95E Second side 95F 3rd side 101 Indoor unit 160 First Sensor Unit 161 Sensor board 162 Refrigerant Sensor 163 Circuit board holder 170 Fixtures 175 Sensor fixing part 177 First sensor cover (sensor cover) 177A Top section 177B Right side part 177C Rear section L1 extension line S1 space

Claims

1. Heat exchanger, A housing for the aforementioned heat exchanger, A cover member that covers the header portion connected to the heat exchanger and has a lower end opening at its lower end, A refrigerant sensor is provided at a position that overlaps with the lower end opening in a plan view, The device comprises a sensor cover that covers the refrigerant sensor from at least one of the directions of above and horizontal, The heat exchanger is installed in such a position that the header portion is inclined in a direction where the upper side is located towards the first direction. The cover member has an inclined portion that extends upward from the lower end opening and inclined along the header portion, The sensor cover has an opening on the first direction side of the refrigerant sensor. An indoor unit characterized by the following features.

2. The refrigerant sensor is installed at a height greater than or equal to the height of the drain pan that receives condensed water from the heat exchanger. The indoor unit according to feature 1.

3. Below the cover member, a refrigerant pipe is provided. The refrigerant piping extends along a horizontal direction, The upper end of the sensor cover is provided above the refrigerant piping. The indoor unit according to claim 1.

4. The refrigerant piping extends in a direction along the first direction described above, The sensor cover has dimensions in a second direction perpendicular to the first direction in the horizontal direction that are smaller than the dimensions in the direction along the first direction. The indoor unit according to claim 3.

5. The refrigerant sensor is provided at a height greater than or equal to the lower end of the cover member. The indoor unit according to claim 1.

6. The refrigerant sensor is provided on the side of the drain pan in the first direction, The sensor cover covers the refrigerant sensor from the opposite side of the first direction. The indoor unit according to claim 2.

7. An indoor unit according to any one of claims 1 to 6, Equipped with an outdoor unit, An air conditioning system characterized by the following features.

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