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 a refrigerant sensor positioned below the space partitioned off by the cover member towards the header portion. The cover member is made of a resin film and is fixed by a metal fixing member.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a refrigeration unit capable of improving the detection accuracy of refrigerant leakage. This refrigeration unit has a resin cover that forms an isolation space enclosing a connecting U-shaped pipe of an outdoor heat exchanger, and a refrigerant sensor that detects refrigerant flowing out into the isolation space.

[0003] Patent Document 2 discloses an indoor unit of an air conditioner capable of accurately detecting refrigerant leakage. This indoor unit of the air conditioner has a refrigerant leakage detection sensor disposed together with a refrigerant distributor, refrigerant pipes, etc. in a sealed space formed by a partition plate, a main body heat insulating material, and a drain pan.

[0004] Patent Document 3 discloses a showcase capable of quickly detecting refrigerant leakage occurring at a folded-back portion of a heat transfer pipe. This showcase has a shielding plate that partitions the U-shaped portion of the heat transfer pipe and a refrigerant sensor inside.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006]

Patent Document 2

[0007]

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0008] This disclosure provides an indoor unit and an air conditioning system that can facilitate rapid detection of refrigerant leaks. [Means for solving the problem]

[0009] The indoor unit in this disclosure comprises a housing, a heat exchanger disposed within the housing, a first refrigerant sensor, and a second refrigerant sensor, and uses a refrigerant with a specific gravity greater than that of air, wherein the first refrigerant sensor and the second refrigerant sensor are respectively installed near the bends at both ends of the heat exchanger in a plan view.

[0010] An air conditioning system in another aspect of this disclosure comprises an outdoor unit and the indoor unit described above. [Effects of the Invention]

[0011] In the indoor unit and air conditioning system described herein, refrigerant leaking from a bend where refrigerant leakage is likely to occur can quickly reach the first or second refrigerant sensor, which is located near the bends at both ends of the heat exchanger in a plan view. Therefore, refrigerant leakage can be detected quickly. [Brief explanation of the drawing]

[0012] [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 [Mode for Carrying Out the Invention]

[0013] (Knowledge, etc. Underlying the Present Disclosure) When the inventors arrived at the present disclosure, in the technology of air conditioners, in order to respond to the environment, there was a situation where it was required to use a refrigerant with a low global warming potential. Therefore, in this industry, as a problem that such refrigerants are unstable and many have flammability or weak flammability, it was common to design products with a sensor for detecting refrigerant leakage. Under such circumstances, in order to make it easier to detect refrigerant leakage, when providing a member for partitioning the header portion, bend portion, etc. of the heat exchanger, the inventors found that there is a problem that it is difficult to arrange the member because the refrigerant pipes are likely to be intertwined in the vicinity of the header portion and bend portion, and in order to solve that problem, they arrived at constituting the subject matter of the present disclosure. The present disclosure provides an indoor unit that can easily detect refrigerant leakage and an air conditioner.

[0014] Hereinafter, embodiments will be described in detail with reference to the drawings. However, a more detailed description than necessary may be omitted. For example, a detailed description of well-known matters or a redundant description of substantially the same configuration may be omitted. This is to avoid making the following description overly redundant and to facilitate the understanding of those skilled in the art. Note that the attached drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0015] [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 figure, reference symbol X indicates the left direction of the indoor unit 1, reference symbol Y indicates the front direction of the indoor unit 1, and reference symbol Z indicates the upward direction of the indoor unit 1. The indoor unit 1 is arranged in a conditioned space, which is a space to be air-conditioned, in an air conditioner. In this embodiment, the indoor unit 1 is a so-called floor-mounted duct-type indoor unit, which is mainly placed on the floor surface of the conditioned space and blows air into the conditioned space through a duct.

[0016] The indoor unit 1 is connected to an outdoor unit (not shown) equipped with a compressor and an outdoor heat exchanger, etc., to form a refrigerant circuit, and performs air conditioning using the refrigerant circulating in the refrigerant circuit. Note that the air conditioner has one or more indoor units 1 and one or more outdoor units (not shown).

[0017] Also, the refrigerant used in the air conditioner having the indoor unit 1 is a refrigerant having a specific gravity greater than that of air. In this embodiment, the refrigerant used in the indoor unit 1 and the air conditioner is R32 refrigerant. The R32 refrigerant has a specific gravity greater than that of air and is a slightly flammable refrigerant. Note that any refrigerant other than R32 refrigerant having a specific gravity greater than that of air may be used as the refrigerant of the air conditioner. Also, any refrigerant having the same specific gravity as air or a specific gravity smaller than that of air may be used as the refrigerant of the air conditioner.

[0018] The indoor unit 1 has a housing 10. The housing 10 has a hollow substantially rectangular parallelepiped shape and is made of sheet metal. The housing 10 is provided with a suction port 11 and a blowout port 13. The suction port 11 is composed of a plurality of holes that allow air to pass from the outside to the inside of the housing 10.

[0019] The suction port 11 is formed at the lower parts of the front and rear surfaces of the housing 10. The blowout port 13 is an opening that allows air to pass from the inside to the outside of the housing 10. The blowout port 13 opens upward on the upper surface of the housing 10. A duct (not shown) is attached to the blowout port 13.

[0020] 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 and off, or setting the set temperature during operation of the indoor unit 1.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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).

[0034] 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.

[0035] A branch pipe 46 is connected to the connection port of the expansion valve 45 on the side opposite to the refrigerant pipe 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.

[0036] 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.

[0037] 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.

[0038] 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. Also, as shown in Figure 5, the cover member 50 partitions the space inside the housing 10, forming space S1. Space S1 is the space inside the cover member 50. Space S1 is also formed by the cover member 50 partitioning it towards the header portion 41. In detail, space S1 is partitioned on the front side by the cover member 50, on the left side by the left side surface of the housing 10, on the rear and upper sides by the partition plate 38, and on the right side by the cover member 50 and the main body portion 31 of the indoor heat exchanger 30. Space S1 is closed at the top by the partition plate 38. Since space S1 is open at the bottom, gas inside space S1 can flow out of space S1 downwards, and gas outside space S1 can flow into space S1 from below.

[0039] 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 in front of the distributor 43 and the header portion 41 and behind the expansion valve 45.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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".

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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 19. 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] [1-2. Operation] The operation of the air conditioning system and indoor unit 1, configured as described above, will be explained below.

[0070] [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.

[0071] 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.

[0072] 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.

[0073] [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.

[0074] 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.

[0075] [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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] As in this embodiment, the sensor fixing portion 75 may be configured to have a 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] (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.

[0094] In Embodiment 1, as an example of a fixing device 70 for fixing the first refrigerant sensor 62A, a fixing device 70 was described in which a housing fixing part 71, an arm part 73, and a sensor fixing part 75 are integrally formed, but this is just one example. For example, the fixing device 70 may be constructed by connecting the housing fixing part 71, the arm part 73, and the sensor fixing part 75 as separate components by fastening or the like. In this case, for example, by manufacturing arm parts 73 of multiple lengths and constructing the fixing device 70 using an arm part 73 of the appropriate length, the first refrigerant sensor 62A can be placed in the appropriate position even in multiple types of indoor units 1 with different dimensions. Therefore, the housing fixing part 71 and the sensor fixing part 75 can be standardized among indoor units 1 with different dimensions, making it possible to reduce manufacturing costs.

[0095] In Embodiment 1, the configuration described was such that the first refrigerant sensor 62A is covered by a circuit board holder 63 and a first sensor cover 77, and the second refrigerant sensor 62B is covered by a circuit board holder 63 and a second sensor cover 95, but this is just one example. As described above, the first refrigerant sensor 62A is located below the space S1 in which moist air is less likely to flow in and condensation is less likely to occur. For this reason, unlike in this embodiment, the indoor unit 1 may not have a first sensor cover 77, and the first refrigerant sensor 62A may be covered only by the circuit board holder 63 inside the housing 10, while the second refrigerant sensor 62B may be covered by the circuit board holder 63 and a second sensor cover 95.

[0096] In other words, in other embodiments, the first refrigerant sensor 62A may be covered by the substrate holder 63 inside the housing 10, and the second refrigerant sensor 62B may be covered by the substrate holder 63 and the second sensor cover 95. This protects the first refrigerant sensor 62A, located below the space S1 where condensation is less likely to occur, from condensation, while also allowing leaked refrigerant to easily reach the first refrigerant sensor 62A. In addition, the second refrigerant sensor 62B, which is more easily reached by condensation, can be protected by both the substrate holder 63 and the second sensor cover 95.

[0097] Furthermore, while Embodiment 1 described that a first sensor cover 77 and a second sensor cover 95 are provided separately from the substrate holder 63 that covers the first refrigerant sensor 62A and the second refrigerant sensor 62B, this is merely an example. For example, the indoor unit 1 may not be provided with the first sensor cover 77 and the second sensor cover 95, and the first refrigerant sensor 62A and the second refrigerant sensor 62B may be protected from water droplets by the substrate holder 63 alone by adjusting the number and position of holes formed in the substrate holder 63 that covers the first refrigerant sensor 62A and the substrate holder 63 that covers the second refrigerant sensor 62B. In this case, the substrate holder 63 that covers the first refrigerant sensor 62A and the second refrigerant sensor 62B function as the "first sensor cover" and the "second sensor cover," respectively.

[0098] In Embodiment 1, the indoor unit 1 was described as a floor-standing ducted type, but this is just one 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.

[0099] Since the embodiments described above are for illustrative purposes only, various modifications, substitutions, additions, omissions, etc., can be made within the claims or their equivalents.

[0100] (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 covering a header portion connected to the heat exchanger, and a refrigerant sensor positioned below the space partitioned off by the cover member toward the header portion, wherein the cover member is made of a resin film and fixed by a metal fixing member. This allows the cover member to be temporarily deformed when positioning it, making it easier to position the cover member to cover the header section. As a result, leaked refrigerant in the space partitioned by the cover member can be more easily reached by the refrigerant sensor, making it easier to detect refrigerant leaks. In addition, fixing the cover member with a metal fixing member makes it easier to suppress vibration and rattle of the cover member.

[0101] (Technology 2) The indoor unit according to Technology 1, characterized in that the heat exchanger has a header portion that is inclined with respect to the vertical direction, the cover member has an inclined portion that is inclined with respect to the vertical direction along the header portion, and the refrigerant sensor is arranged near the inclined portion. This allows leaked refrigerant near the header to be guided by the inclined section, making it easier to reach the refrigerant sensor. Therefore, refrigerant leaks can be more easily detected.

[0102] (Technical 3) The indoor unit according to Technical 1 or 2, characterized in that the fixing member is fixed to the support column stretched across the housing and the cover member. This allows the cover member to be fixed to the support column, which tends to have higher strength within the housing, via a fixing member. As a result, the cover member can be more securely fixed, and vibration and rattle of the cover member can be more easily suppressed.

[0103] (Technology 4) The indoor unit according to any one of Techniques 1 to 3, characterized in that the housing has an intake port located below the air outlet, and the space is closed at the top and open at the bottom. This makes it easier for leaked refrigerant to accumulate in the space partitioned by the cover member, even when air flows upward inside the enclosure, and for the leaked refrigerant to reach the refrigerant sensor located below that space. Therefore, it becomes easier to detect refrigerant leaks.

[0104] (Technical 5) The indoor unit according to any one of Technical 1 to 4, characterized in that the cover member has an inclined portion that is inclined vertically along the header portion and a bent portion that is bent from the inclined portion, and is provided in a state in which it is in contact with the drain pan and the bent portion is in contact with the housing. This reduces the likelihood of gaps forming in the space partitioned by the cover member and makes it easier to fix the cover member in place. As a result, it becomes easier to deliver the refrigerant to the refrigerant sensor and easier to suppress vibration and rattle of the cover member.

[0105] (Technology 6) An indoor unit according to any one of Techniques 1 to 5, characterized in that it has a sensor cover that covers the refrigerant sensor from above and does not cover the refrigerant sensor from at least one direction in the horizontal direction. This protects the refrigerant sensor, located below a space partitioned by a cover member that is less prone to condensation, from condensation while allowing leaked refrigerant to easily reach the sensor. Therefore, it is possible to protect the refrigerant sensor while making it easier to detect refrigerant leaks.

[0106] (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 the cover member to be temporarily deformed when positioning it, making it easier to position the cover member to cover the header section. As a result, leaked refrigerant in the space partitioned by the cover member can be more easily reached by the refrigerant sensor, making it easier to detect refrigerant leaks. In addition, fixing the cover member with a metal fixing member makes it easier to suppress vibration and rattle of the cover member.

[0107] (Technical 8) An indoor unit comprising a housing for a heat exchanger and a blower, a refrigerant sensor, and a fixing device for fixing the refrigerant sensor, wherein the fixing device comprises a sensor fixing portion for which the refrigerant sensor is fixed, and a housing fixing portion fixed to the housing at a position further away from the refrigerant flow path than the sensor fixing portion. This allows the refrigerant sensor to be positioned near the refrigerant flow path using a fixing device, and also allows the refrigerant sensor and its fixing device to be removed from the housing at a point away from the refrigerant flow path. Therefore, refrigerant leaks can be easily detected and the refrigerant sensor can be easily maintained.

[0108] (Technical 9) The indoor unit according to Technical 8, characterized in that the housing comprises a maintenance opening and a maintenance panel that closes the opening, the refrigerant sensor is located behind the refrigerant flow path when viewed through the opening, and the housing fixing part is provided in a position that is visible through the opening without overlapping with the refrigerant flow path. This makes it easier to access the housing fixing part of the fastener through the opening in the housing, and makes it easier to remove the refrigerant sensor together with the fastener. Therefore, maintenance of the refrigerant sensor is made easier.

[0109] (Technical 10) The indoor unit according to Technical 8 or 9, characterized in that the fixing device has an arm portion connecting the housing fixing portion and the sensor fixing portion, and the arm portion holds the wiring connected to the circuit board of the refrigerant sensor. This allows the wiring to be routed along the arm, making it easier to remove the refrigerant sensor along with its mounting bracket. Therefore, maintenance of the refrigerant sensor is made easier.

[0110] (Technical 11) The indoor unit according to any one of Technical 8 to 10, characterized in that the sensor fixing part has a sensor cover that covers the refrigerant sensor from above. This makes it easier to protect the refrigerant sensor from water droplets such as condensed water. Therefore, the refrigerant sensor can be protected by the fixing device.

[0111] (Technical 12) An air conditioning system comprising an outdoor unit and an indoor unit as described in any one of Technical 8 to 11. This allows the refrigerant sensor to be positioned near the refrigerant flow path using a fixing device, and also allows the refrigerant sensor and its fixing device to be removed from the housing at a point away from the refrigerant flow path. Therefore, refrigerant leaks can be easily detected and the refrigerant sensor can be easily maintained.

[0112] (Technical 13) An indoor unit comprising a housing, a heat exchanger disposed within the housing, a first refrigerant sensor, and a second refrigerant sensor, wherein a refrigerant with a specific gravity greater than that of air is used, and the first refrigerant sensor and the second refrigerant sensor are respectively installed near the bends at both ends of the heat exchanger in a plan view. As a result, refrigerant leaking from bends, where leaks are likely to occur, can quickly reach the first or second refrigerant sensors, which are positioned near the bends at both ends of the heat exchanger in a plan view. Therefore, refrigerant leaks can be detected quickly.

[0113] (Technical 14) An indoor unit according to Technical 13, comprising an air intake port for drawing in air and an outlet port provided above the air intake port, wherein the heat exchanger is provided between the air intake port and the outlet port and further comprises a cover member that covers the bend portion on one end of the heat exchanger, the second refrigerant sensor is located in the lower part of the housing, and the first refrigerant sensor is located below the space partitioned by the cover member. As a result, when the indoor unit is stopped, a second refrigerant sensor located at the bottom of the housing can detect refrigerant leakage, and when the indoor unit is operating, the first refrigerant sensor can detect refrigerant accumulated inside the cover member covering the vent section. Therefore, refrigerant leakage can be detected quickly and easily.

[0114] (Technical 15) The indoor unit according to Technical 14, characterized in that the first refrigerant sensor is provided at a height greater than or equal to the height of the drain pan that receives condensed water from the heat exchanger. This allows the first refrigerant sensor to be positioned higher up, making it easier to detect refrigerant accumulating inside the cover during indoor unit operation. Therefore, refrigerant leaks can be detected quickly.

[0115] (Technical 16) The indoor unit according to Technical 15, characterized in that the drain pan includes an upper drain pan and a lower drain pan located below the upper drain pan, the second refrigerant sensor is positioned at a height between the upper drain pan and the lower drain pan, and the first refrigerant sensor is provided at a height equal to or greater than the height of the upper drain pan. This allows the first refrigerant sensor to be positioned higher up, making it easier to detect refrigerant accumulating inside the cover member while the indoor unit is operating, and the second refrigerant sensor to be positioned at a height above the lower drain pan, making it easier to detect refrigerant accumulating in the lower drain pan while the indoor unit is stopped. As a result, refrigerant leaks can be detected quickly and easily.

[0116] (Technical 17) An indoor unit according to any one of Technical 14 to 16, characterized in that the first refrigerant sensor is covered by a first sensor cover, the second refrigerant sensor is covered by a second sensor cover, the second sensor cover covers the second refrigerant sensor from above and horizontally, and the first sensor cover covers the first refrigerant sensor from above and does not cover it from at least one direction in the horizontal direction. This design allows the first refrigerant sensor, which is less prone to condensation above, to be more exposed than the second refrigerant sensor. This protects both sensors from condensation while making it easier for leaked refrigerant to reach the first sensor. As a result, refrigerant leaks can be detected more quickly.

[0117] (Technical 18) An indoor unit according to any one of Technical 14 to 16, characterized in that the first refrigerant sensor is covered by a first holder inside the housing, and the second refrigerant sensor is covered by a second holder and a second sensor cover. This design allows the first refrigerant sensor, which is less prone to condensation above, to be more exposed than the second refrigerant sensor. This protects both sensors from condensation while making it easier for leaked refrigerant to reach the first sensor. As a result, refrigerant leaks can be detected more quickly.

[0118] (Technical 19) An air conditioning system characterized by comprising an outdoor unit and an indoor unit as described in any one of Technical 13 to 18. As a result, refrigerant leaking from bends, where leaks are likely to occur, can quickly reach the first or second refrigerant sensors, which are positioned near the bends at both ends of the heat exchanger in a plan view. Therefore, refrigerant leaks can be detected quickly. [Industrial applicability]

[0119] 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]

[0120] 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 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 46A Branch section 46B Confluence 47 Receiver 50 Cover component 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 L1 extension line S1 Space

Claims

1. An indoor unit comprising a housing, a heat exchanger disposed within the housing, a first refrigerant sensor, and a second refrigerant sensor, using a refrigerant with a specific gravity greater than that of air, The first refrigerant sensor and the second refrigerant sensor are respectively installed near the bends at both ends of the heat exchanger in a plan view. An indoor unit characterized by the following features.

2. The air intake port, It comprises an outlet located above the aforementioned intake port, The heat exchanger is provided between the intake port and the outlet port, The heat exchanger further has a cover member that covers the bend portion on one end side, The second refrigerant sensor is located at the bottom of the housing, The first refrigerant sensor is positioned below the space partitioned by the cover member. The indoor unit according to feature 1.

3. The first 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 2.

4. The drain pan is, Upper drain pan and It includes a lower drain pan located below the upper drain pan, The second refrigerant sensor is positioned at a height between the upper drain pan and the lower drain pan. The first refrigerant sensor is installed at a height greater than or equal to the height of the upper drain pan. The indoor unit according to feature 3.

5. The first refrigerant sensor is covered by the first sensor cover. The second refrigerant sensor is covered by the second sensor cover. The second sensor cover covers the second refrigerant sensor from above and horizontally. The first sensor cover covers the first refrigerant sensor from above and does not cover it from at least one direction in the horizontal direction. The indoor unit according to any one of claims 2 to 4.

6. The first refrigerant sensor is covered by a first holder inside the housing. The second refrigerant sensor is covered by a second holder and a second sensor cover. The indoor unit according to any one of claims 2 to 4.

7. The system comprises an outdoor unit and an indoor unit according to any one of claims 1 to 4. An air conditioning system characterized by the following features.

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