Indoor unit of air conditioner

Abstract

To provide an indoor unit of an air conditioner which enables easy removal of a refrigerant leakage sensor during periodic inspection and replacement.SOLUTION: An indoor unit 1 includes: a housing 1a which houses a heat exchanger, a fan, and a refrigerant pipe; a liquid side refrigerant pipe joint 8 and a gas side refrigerant pipe joint 9 disposed at the outer side of the housing 1a. The housing 1a has, below the liquid side refrigerant pipe joint 8 and the gas side refrigerant pipe joint 9, a maintenance hole M in the form of an opening. The maintenance hole M (the opening) is covered with a removable cover 20b. A refrigerant leakage sensor 20a is attached to a surface at the side of the cover 20b where the liquid side refrigerant pipe joint 8 and the gas side refrigerant pipe joint 9 are disposed.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an indoor unit of an air conditioner. [Background technology]

[0002] In recent air conditioners, which require refrigerants with both low GWP (Global Warming Potential) and low ODP (Ozone Depletion Potential), flammable refrigerants (e.g., R290: propane) are being put to practical use. Conventionally, there is known an air conditioner in which a refrigerant leakage sensor is provided facing a refrigerant pipe inside the main body case (housing) of the indoor unit (see, for example, Patent Document 1). Specifically, this refrigerant leakage sensor has a refrigerant detection unit at its tip located inside the housing, and a lead portion at its rear end extending to the outside of the housing through a hole formed in the housing. According to such an air conditioner, a safety measure can be taken by detecting refrigerant leaking inside the housing of the indoor unit with the refrigerant leakage sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7004836 Summary of the Invention [Problem to be solved by the invention]

[0004] However, safety standards stipulate that refrigerant leak sensors must be inspected and replaced periodically, so it is desirable for the refrigerant leak sensor to be easily removable from the indoor unit for periodic inspection and replacement. However, in conventional indoor units (see, for example, Patent Document 1), the rear end of the refrigerant leak sensor is fixed from inside the housing to a sensor holder attached to the housing. Therefore, when removing the refrigerant leak sensor from a conventional indoor unit, it is necessary to remove the refrigerant leak sensor together with the sensor holder from the housing, and then remove the refrigerant leak sensor from the sensor holder. In other words, with conventional indoor units, the process of removing the refrigerant leak sensor during periodic inspection or replacement is complicated.

[0005] An object of the present invention is to provide an indoor unit for an air conditioner in which a refrigerant leakage sensor can be easily removed for periodic inspection and replacement. [Means for solving the problem]

[0006] The indoor unit of the air conditioner of the present invention comprises a housing that houses a heat exchanger, a fan, and refrigerant piping, and a refrigerant piping fitting arranged on the outside of the housing, the housing having an opening below the refrigerant piping fitting, the opening being covered by a removable cover, and a refrigerant leakage sensor attached to the surface of the cover on the side where the refrigerant piping fitting is arranged. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an indoor unit for an air conditioner in which the refrigerant leakage sensor can be easily removed for periodic inspection and replacement. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an overall perspective view of an indoor unit of an air conditioner according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Figure 3] FIG. 4 is a partially enlarged perspective view showing the vicinity of the piping chamber of the indoor unit. [Figure 4] FIG. 2 is an exploded perspective view of the sensor unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description will be given of an embodiment (or mode) of an indoor unit for an air conditioner according to the present invention, with reference to the accompanying drawings as appropriate. In this embodiment, the present invention will be specifically described using a ceiling cassette type four-way air outlet indoor unit as an example. Note that the up and down directions in the following description are based on the up and down directions in Figure 1, which correspond to the vertical up and down directions of the indoor unit when placed on the ceiling.

[0010] Fig. 1 is an overall perspective view of an indoor unit 1 of an air conditioner A according to this embodiment. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. As shown in FIG. 1, the indoor unit 1 of the air conditioner A includes a housing 1a and a decorative panel 2. The housing 1a in this embodiment has a substantially rectangular parallelepiped shape. 2, a heat exchanger 10 and a fan 6 are disposed inside the housing 1a. A piping chamber 18 is defined by a partition plate 12 inside the housing 1a. The piping chamber 18 is formed in one of the four corners of the housing 1a in the plan view shown in FIG. 2, where a liquid-side refrigerant piping joint 8 to which a liquid refrigerant piping extending from the outdoor unit side (not shown) is connected and a gas-side refrigerant piping joint 9 to which a gas refrigerant piping extending from the outdoor unit side (not shown) is connected are arranged. The liquid side refrigerant pipe joint 8 and the gas side refrigerant pipe joint 9 correspond to "refrigerant pipe joints." As will be described in detail later, a liquid refrigerant distribution pipe 21 and a gas refrigerant distribution pipe 22 are arranged in this piping chamber 18. The liquid refrigerant distribution pipe 21 and the gas refrigerant distribution pipe 22 arranged in the housing 1a correspond to "refrigerant pipes."

[0011] As shown in Fig. 2, the decorative panel 2 in this embodiment is square with a perimeter longer than that of the housing 1a. Although not shown, an opening to which an intake grille is attached is formed in the center of the decorative panel 2. Furthermore, as shown in Fig. 2, four air outlets 4 are formed in the decorative panel 2 inside the housing 1a and outside the heat exchanger 10 so as to extend along the four sides of the decorative panel 2.

[0012] The decorative panel 2 (see Figure 1) is positioned so that the portion corresponding to the housing 1a (see Figure 1) abuts against the underside of the ceiling (the indoor side) when embedded in the space formed above the ceiling. The decorative panel 2 (see Figure 1) hides the gap between the ceiling and the mounting portion of the indoor unit 1 (see Figure 1). In this way, the decorative panel 2 improves the design of the indoor unit 1 on the indoor side. 1, the indoor unit 1 is provided with support portions 31 for suspension bolts (not shown) at the four corners of the upper surface of the decorative panel 2. The indoor unit 1 is suspended from the upper wall surface inside the ceiling via suspension bolts (not shown) supported by the support portions 31. By extending the suspension bolts (not shown), the indoor unit 1 can be moved below the ceiling.

[0013] FIG. 3 is a partially enlarged perspective view showing the vicinity of the piping chamber 18 of the indoor unit 1. As shown in FIG. For convenience of drawing, the partition plate 12 (see FIG. 2) is omitted in Fig. 3. Fig. 3 shows the state where the end of the heat exchanger 10, which will be described next, faces the piping chamber 18. 3, the heat exchanger 10 includes aluminum stacked fins 10a and a plurality of heat transfer tubes 10b arranged to penetrate the stacked fins 10a in the stacking direction of the fins. As will be described later, a refrigerant flows through the heat transfer tubes 10b.

[0014] As shown in FIG. 2, the heat exchanger 10 is formed so as to extend continuously along the side wall 1a1 of the housing 1a, except for the portion where a piping chamber 18, which will be described in detail later, is formed. That is, heat exchanger 10 extends inside housing 1a in the circumferential direction of housing 1a, except for the portion where piping chamber 18 is formed. That is, heat exchanger 10 has a substantially rectangular tubular shape. The four side surfaces of heat exchanger 10 having a substantially rectangular tubular shape are arranged to face the inner surfaces of the four side walls 1a1 of housing 1a shown in FIG. 1, respectively. The upper opening of the heat exchanger 10, which has a substantially rectangular cylindrical shape, is closed by the housing 1a, and the lower opening faces the inner surface of the intake grille (not shown).

[0015] The fan 6 shown in Fig. 2 is configured by, for example, a turbofan, and is disposed inside the heat exchanger 10, which has a substantially rectangular cylindrical shape. When the fan 6 rotates, indoor air is drawn into the heat exchanger 10 through the intake grille (not shown). The air drawn into the heat exchanger 10 passes between the fins of the stacked fins 10a (see Fig. 3) and is then sent out again into the room through the air outlet 4 (see Fig. 2) formed in the decorative panel 2 (see Fig. 2).

[0016] On the other hand, the heat exchanger 10 shown in Fig. 3 cools or heats air by exchanging heat between the air passing between the fins of the stacked fins 10a (see Fig. 3) and the refrigerant flowing through the heat transfer tubes 10b. The indoor air that has undergone heat exchange is then blown out into the room as described above. The indoor unit 1 (see Fig. 1) thereby cools or heats the room.

[0017] The refrigerant used in this embodiment may be, for example, a single hydrocarbon (HC) refrigerant such as R290, R170, R1270, or R600a, or a mixture of these HC refrigerants. The refrigerant may also be a fluorine-based refrigerant such as HFO-1234yf or R-32. Alternatively, a mixture of these refrigerants may be used. Flammable refrigerants include mildly flammable and highly flammable refrigerants. Furthermore, in this embodiment, a refrigerant with a higher specific gravity than air is preferably used as the refrigerant.

[0018] Next, the piping chamber 18 (see FIG. 2) will be described. As described above, the piping chamber 18 (see Figure 2) is formed in a corner of the housing 1a (see Figure 2) where the liquid side refrigerant piping joint 8 (see Figure 2) and the gas side refrigerant piping joint 9 (see Figure 2) are connected. As shown in Figure 2, the piping chamber 18 is formed as an enclosed space (sealed space) so as to be blocked off from the air flow path passing through the heat exchanger 10 by a partition plate 12 that is installed to isolate it from the ventilation path of indoor air by the fan 6.

[0019] As shown in FIG. 3, the piping chamber 18 is provided with an expansion valve 13, a liquid refrigerant distributor 14, and a gas refrigerant distributor 15. The expansion valve 13 is connected to a liquid-side refrigerant pipe joint 8 attached to the side wall 1a1 of the housing 1a via a predetermined connecting pipe (not shown). The expansion valve 13 is connected to a liquid refrigerant distributor 14 via a predetermined connecting pipe (not shown). A plurality of liquid refrigerant distribution pipes 21 are connected to the liquid refrigerant distributor 14. The gas refrigerant distributor 15 is connected to a gas side refrigerant pipe joint 9 attached to the side wall 1a1 of the housing 1a via a predetermined connecting pipe (not shown). A plurality of gas refrigerant distribution pipes 22 are connected to the gas refrigerant distributor 15.

[0020] The circumferential end of the heat exchanger 10 faces the inside of the piping chamber 18 . Furthermore, within the piping chamber 18, a plurality of return bend portions of the heat transfer tubes 10b formed at the end of the heat exchanger 10 and the ends of the plurality of heat transfer tubes 10b face. A corresponding one of the plurality of liquid refrigerant distribution pipes 21 is connected to one end of each of the plurality of heat transfer pipes 10b. Furthermore, a plurality of gas refrigerant distribution pipes 22 are connected to the other ends of the plurality of heat transfer pipes 10b, respectively.

[0021] In addition, the connection between the expansion valve 13 and the liquid side refrigerant pipe joint 8 within the piping chamber 18, the connection between the expansion valve 13 and the liquid refrigerant distributor 14, the connection between the liquid refrigerant distributor 14 and the liquid refrigerant distribution pipe 21, and the connection between the liquid refrigerant distribution pipe 21 and the heat transfer pipe 10b are all made by welding. Furthermore, the connection between the gas refrigerant distributor 15 and the gas side refrigerant pipe joint 9 in the piping chamber 18, the connection between the gas refrigerant distributor 15 and the gas refrigerant distribution pipe 22, and the connection between the gas refrigerant distribution pipe 22 and the heat transfer tube 10b are all welded.

[0022] Next, the mounting structure of the refrigerant leakage sensor 20a (see FIG. 1) in the indoor unit 1 (see FIG. 1) will be described. As shown in FIG. 1, the indoor unit 1 is provided with a sensor unit 20 on a side wall 1a1 of a housing 1a. The sensor unit 20 includes a refrigerant leakage sensor 20a and a cover 20b.

[0023] The refrigerant leakage sensor 20a is not particularly limited as long as it can detect the refrigerant, and examples thereof include a semiconductor gas sensor, an infrared gas sensor, and a thermal conduction gas sensor. As will be described later, the refrigerant leakage sensor 20a in this embodiment has a substantially rectangular parallelepiped shape. The sensor unit 20 is disposed below and adjacent to the liquid side refrigerant pipe joint 8 and the gas side refrigerant pipe joint 9 which are arranged side by side on the side wall 1a1 of the housing 1a. That is, the refrigerant leakage sensor 20a of the sensor unit 20 is located lower than the liquid side refrigerant pipe joint 8 and the gas side refrigerant pipe joint 9, and is disposed between these two joints.

[0024] FIG. 4 is an exploded perspective view of the sensor unit 20. As shown in FIG. As shown in FIG. 4, the cover 20b constituting the sensor unit 20 is formed of a plate-like body that is substantially rectangular (including square) in plan view. The planar shape of the cover 20b is formed to correspond to the maintenance hole M formed in the side wall 1a1 of the housing 1a. The maintenance hole M corresponds to an "opening".

[0025] As shown in FIG. 4, the cover 20b is configured to close the maintenance hole M (first opening) from the outside of the housing 1a when fastened to the side wall 1a1 of the housing 1a with the screw S1. As long as the cover 20b can be detachably attached to the side wall 1a1, it is not limited to fastening, and it can also be configured to be supported on the side wall 1a1 by a locking claw. The cover 20b has an upper edge with a pair of curved surfaces 20b2 that fit along the outer peripheral surfaces of the liquid side refrigerant pipe joint 8 and the gas side refrigerant pipe joint 9.

[0026] The cover 20b is also formed with a sensor mounting hole 20b1 into which the refrigerant leakage sensor 20a is fitted. The sensor mounting hole 20b1 is formed as a hole having a rectangular (including square) planar shape in which the sensor mounting hole 20b1 is fitted.

[0027] When the refrigerant leakage sensor 20a is fastened to the cover 20b from the outside of the housing 1a with a screw S2 provided on its flange, the refrigerant leakage sensor 20a fits within the sensor mounting hole 20b1, thereby blocking the sensor mounting hole 20b1. As long as the refrigerant leakage sensor 20a can be attached to and detached from the cover 20b, it is not limited to fastening, and it can also be configured to be supported on the cover 20b by a locking claw. The refrigerant leakage sensor 20a is disposed so as to close the sensor mounting hole 20b1, and faces the piping chamber 18 (see FIG. 3). In FIG. 4, reference numeral 2 denotes a decorative panel, and reference numeral 31 denotes a support portion for a hanging bolt (not shown).

[0028] <Action and effect> Next, the effects and advantages achieved by the indoor unit 1 of the air conditioner A according to this embodiment will be described. The indoor unit 1 of the air conditioner A of this embodiment comprises a housing 1a that houses a heat exchanger 10, a fan 6, and refrigerant piping (liquid refrigerant distribution pipe 21, gas refrigerant distribution pipe 22), and liquid side refrigerant piping fittings 8 and gas side refrigerant piping fittings 9 that are refrigerant piping fittings arranged on the outside of the housing 1a, the housing 1a has a maintenance hole M which is an opening below the liquid side refrigerant piping fittings 8 and the gas side refrigerant piping fittings 9, the maintenance hole M (opening) is covered with a removable cover 20b, and a refrigerant leakage sensor 20a is attached to the surface of the cover 20b on the side where the liquid side refrigerant piping fittings 8 and gas side refrigerant piping fittings 9 are arranged.

[0029] In conventional air conditioner indoor units (see, for example, Patent Document 1), as described above, when removing a refrigerant leakage sensor from the indoor unit, it is necessary to remove the refrigerant leakage sensor together with the sensor holder from the housing, and then remove the refrigerant leakage sensor from the sensor holder. In contrast to this, in the indoor unit 1 of this embodiment, the refrigerant leakage sensor 20a is attached to the cover 20b from the outside of the housing 1a, so that it is possible to remove just the refrigerant leakage sensor 20a from the housing 1a.

[0030] In addition, in such an indoor unit 1, the piping chamber 18 is an enclosed space, and the first opening is a maintenance hole M for the refrigerant piping (liquid refrigerant distribution pipe 21, gas refrigerant distribution pipe 22). With this indoor unit 1, even if refrigerant leaks from the welded joints of the refrigerant pipes (liquid refrigerant distribution pipe 21, gas refrigerant distribution pipe 22), the refrigerant is contained within the sealed space of the piping chamber 18. Furthermore, because the piping chamber 18 is a sealed space, the refrigerant leakage sensor 20a can quickly detect the leaked refrigerant even if the amount of leaked refrigerant is small.

[0031] Furthermore, according to this indoor unit 1, the cover 20b is attached to the maintenance hole M (opening) that allows easy access to the refrigerant piping (liquid refrigerant distribution pipe 21, gas refrigerant distribution pipe 22), so the refrigerant leakage sensor 20a attached to the cover 20b is positioned in close proximity to the refrigerant piping (liquid refrigerant distribution pipe 21, gas refrigerant distribution pipe 22). This allows the refrigerant leakage sensor 20a to more reliably detect refrigerant leaking from the piping. In other words, this indoor unit 1 can achieve both reliable detection of refrigerant leakage and easy maintenance.

[0032] In addition, in this indoor unit 1, the cover 20b can be removed from the housing 1a together with the refrigerant leakage sensor 20a, so that inspection of the refrigerant / air piping (liquid refrigerant distribution pipe 21, gas refrigerant distribution pipe 22) through the maintenance hole M and inspection of the refrigerant leakage sensor 20a can be carried out in parallel.

[0033] In addition, in such an indoor unit 1, a liquid side refrigerant piping joint 8 and a gas side refrigerant piping joint 9 are arranged side by side in the housing 1a, and the sensor mounting hole 20b1 is formed adjacent to the liquid side refrigerant piping joint 8 and the gas side refrigerant piping joint 9. According to this indoor unit 1, the refrigerant leakage sensor 20a is disposed in a position close to the joint (welded portion) between the liquid side refrigerant pipe fitting 8 side and the liquid refrigerant distribution pipe 21 via a specified connecting pipe (not shown) in the piping chamber 18, and the joint (welded portion) between the gas side refrigerant pipe fitting 9 side and the gas refrigerant distribution pipe 22 via a specified connecting pipe (not shown). This allows the refrigerant leakage sensor 20a to more reliably detect refrigerant leaking from the piping.

[0034] In addition, in such an indoor unit 1, the cover 20b has a curved surface 20b2 that fits along the outer peripheral surfaces of the liquid side refrigerant pipe joint 8 and the gas side refrigerant pipe joint 9. According to this indoor unit 1, when the cover 20b is attached to the housing 1a, the curved surface 20b2 serves as a guide groove, making it easy to position the cover 20b relative to the housing 1a.

[0035] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be embodied in various forms. In the above embodiment, a ceiling cassette type four-way air outlet type indoor unit 1 has been described, but the present invention can also be applied to indoor units such as floor-standing indoor units, wall-mounted indoor units, and ceiling-suspended indoor units. [Explanation of symbols]

[0036] 1 Indoor unit 1a Housing 6 Fans 8 Liquid side refrigerant piping joint (refrigerant piping joint) 9 Gas side refrigerant piping joint (refrigerant piping joint) 10 Heat exchanger 18 Piping room (closed space) 20a Refrigerant leak sensor 20b cover 20b1 Sensor mounting hole 20b2 curved surface 21 Liquid refrigerant distribution piping (refrigerant piping) 22 Gas refrigerant distribution pipe (refrigerant piping) A. Air conditioner M Maintenance hole (opening)

Claims

1. a housing that houses a heat exchanger, a fan, and refrigerant piping; a refrigerant pipe joint disposed outside the housing, the housing has an opening below the refrigerant pipe joint, The opening is covered with a removable cover; An indoor unit for an air conditioner, wherein a refrigerant leakage sensor is attached to the surface of the cover on which the refrigerant pipe joint is disposed.

2. The refrigerant pipe joint is composed of two joints, 2. The indoor unit of an air conditioner according to claim 1, wherein the refrigerant leakage sensor is disposed at a position lower than the refrigerant pipe joints and between the two joints.

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