EP4656956A1

EP4656956A1 - Indoor unit of air-conditioner

Info

Publication number: EP4656956A1
Application number: EP25176025.2A
Authority: EP
Inventors: Ryusuke ODA
Original assignee: Hitachi Johnson Controls Air Conditioning Inc
Current assignee: Hitachi Johnson Controls Air Conditioning Inc
Priority date: 2024-05-30
Filing date: 2025-05-13
Publication date: 2025-12-03
Also published as: JP2025180325A

Abstract

Provided is an indoor unit of an air-conditioner including: a housing that houses a heat exchanger, a fan and a refrigerant pipe; and a refrigerant pipe joint disposed outside the housing, in which the housing has an opening on a lower side of the refrigerant pipe joint, the opening is covered with a detachable cover, and a refrigerant leakage sensor is attached to a surface of the cover on a side on which the refrigerant pipe joint is disposed.

Description

BACKGROUND

1. Technical Field

The present disclosure relates to an indoor unit of an air-conditioner.

2. Related Art

Nowadays, for an air-conditioner, both reduction in the global warming potential (GWP) of refrigerant and reduction in the ozone depletion potential (ODP) of refrigerant have been demanded. For this reason, an air-conditioner using flammable refrigerant (for example, R290: propane) has been in practical use.
In a generally-known air-conditioner (see, for example, Japanese Patent No. 7004836 ), a refrigerant leakage sensor is provided so as to face a refrigerant pipe in a body case (housing) of an indoor unit. Specifically, a refrigerant sensor at the tip end of the refrigerant leakage sensor is disposed in the housing. In addition, a lead at the back end of the refrigerant leakage sensor is pulled out of the housing through a hole formed in the housing.
According to this air-conditioner, refrigerant having leaked in the housing of the indoor unit is detected by the refrigerant leakage sensor. In this manner, safety measures can be taken.

SUMMARY

An indoor unit of an air-conditioner according to the present embodiment includes: a housing that houses a heat exchanger, a fan and a refrigerant pipe; and a refrigerant pipe joint disposed outside the housing. In the indoor unit, the housing has an opening on a lower side of the refrigerant pipe joint, the opening is covered with a detachable cover, and a refrigerant leakage sensor is attached to a surface of the cover on a side on which the refrigerant pipe joint is disposed.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 is a perspective view of the entirety of an indoor unit of an air-conditioner according to the present embodiment;
Fig. 2 is a sectional view of Fig. 1;
Fig. 3 is a partial enlarged perspective view showing a state in the vicinity of a piping chamber of the indoor unit; and
Fig. 4 is an exploded perspective view of a sensor unit.

DETAILED DESCRIPTION

In the following detailed description, for purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.
According to safety standards, regular inspection and replacement of a refrigerant leakage sensor are required. Thus, there has been demanded a refrigerant leakage sensor easily detachable from an indoor unit upon the regular inspection and replacement.
However, in the general indoor unit (see, for example, Japanese Patent No. 7004836 ), the back end of the refrigerant leakage sensor is fixed, from the inside of the housing, to a sensor holder attached to the housing. For this reason, when the refrigerant leakage sensor is detached from the general indoor unit, the refrigerant leakage sensor needs to be detached from the housing together with the sensor holder. Thereafter, the refrigerant leakage sensor is detached from the sensor holder. That is, a step of detaching the refrigerant leakage sensor upon regular inspection and replacement of the general indoor unit is complicated.
An object of the present embodiment is to provide an indoor unit of an air-conditioner configured such that a refrigerant leakage sensor is easily detachable upon regular inspection and replacement.
An indoor unit of an air-conditioner according to the present embodiment includes: a housing that houses a heat exchanger, a fan and a refrigerant pipe; and a refrigerant pipe joint disposed outside the housing. In the indoor unit, the housing has an opening on a lower side of the refrigerant pipe joint, the opening is covered with a detachable cover, and/or a refrigerant leakage sensor is attached to a surface of the cover on a side on which the refrigerant pipe joint is disposed.
According to the present embodiment, the indoor unit of the air-conditioner can be provided, which is configured such that the refrigerant leakage sensor is easily detachable upon the regular inspection and replacement.
Hereinafter, a mode (embodiment) for carrying out the indoor unit of the air-conditioner of the present disclosure will be described in detail with reference to the drawings.
In the description of the present embodiment, a ceiling cassette type four-direction blowing indoor unit will be specifically described as an example. Note that an up-down direction in the description below is defined with reference to the up-down direction of Fig. 1 coincident with the vertical direction of the indoor unit disposed above the ceiling.
Fig. 1 is a perspective view of the entirety of an indoor unit 1 of an air-conditioner A according to the present embodiment. Fig. 2 is a sectional view of 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 the present embodiment is substantially in a rectangular parallelepiped shape.
As shown in Fig. 2, a heat exchanger 10 and a fan 6 are arranged in the housing 1a. Moreover, a piping chamber 18 is defined by a partition plate 12 in the housing 1a.
The piping chamber 18 is defined at one corner at which a liquid-side refrigerant pipe joint 8 and a gas-side refrigerant pipe joint 9 among four corners of the housing 1a in plan view as shown in Fig. 2. Here, a liquid refrigerant pipe extending from an outdoor unit side (not shown) is connected to the liquid-side refrigerant pipe joint 8. Moreover, a gas refrigerant pipe extending from the outdoor unit side (not shown) is connected to the gas-side refrigerant pipe joint 9.
The liquid-side refrigerant pipe joint 8 and the gas-side refrigerant pipe joint 9 are equivalent to a "refrigerant pipe joint".
As described in detail later, a liquid refrigerant distribution pipe 21 and a gas refrigerant distribution pipe 22 are arranged in the piping chamber 18. The liquid refrigerant distribution pipe 21 and the gas refrigerant distribution pipe 22 arranged in the housing 1a are equivalent to a "refrigerant pipe".
As shown in Fig. 2, the decorative panel 2 of the present embodiment is in a square shape. This square shape has a longer circumferential length than the circumferential length of the housing 1a. Although not shown in the figure, the decorative panel 2 has, in a center portion thereof, an opening to which a suction grille is to be attached. Moreover, as shown in Fig. 2, the decorative panel 2 is formed with four blow ports 4 inside the housing 1a and outside the heat exchanger 10. These four blow ports 4 extend along four sides of the decorative panel 2.
Note that the decorative panel 2 (see Fig. 1) is positioned such that a portion of the decorative panel 2 corresponding to the housing 1a (see Fig. 1) contacts the lower surface (surface in a room) of the ceiling when the housing 1a (see Fig. 1) is embedded in a space formed above the ceiling. Thus, the decorative panel 2 (see Fig. 1) can hide a gap between the ceiling and an attachment portion of the indoor unit 1 (see Fig. 1). Consequently, the decorative panel 2 improves the design of the indoor unit 1 as viewed from the inside of the room.
As shown in Fig. 1, support portions 31 for hanging bolts (not shown) are provided at four corners of the upper surface of the decorative panel 2 of the indoor unit 1. The indoor unit 1 is hung from an upper wall surface above the ceiling with the hanging bolts (not shown) supported by the support portions 31. Note that the indoor unit 1 is movable downward from the ceiling by extension of the hanging bolts (not shown).
Fig. 3 is a partial enlarged perspective view showing a state in the vicinity of the piping chamber 18 of the indoor unit 1. In Fig. 3, the partition plate 12 (see Fig. 2) is omitted for the sake of convenience in illustration. Fig. 3 shows a state when an end portion of the heat exchanger 10 described next faces the piping chamber 18.
As shown in Fig. 3, the heat exchanger 10 includes aluminum laminated fins 10a and a plurality of heat transfer pipes 10b arranged so as to penetrate the laminated fins 10a in a fin lamination direction. Refrigerant flows in the heat transfer pipes 10b as described later.
As shown in Fig. 2, the heat exchanger 10 is formed so as to continuously extend along side walls 1a1 of the housing 1a, except for a portion formed in the piping chamber 18 described in detail later.
That is, the heat exchanger 10 extends along the circumferential direction of the housing 1a in the housing 1a, except that the heat exchanger 10 is disconnected at the portion formed in the piping chamber 18. That is, the heat exchanger 10 is substantially in a rectangular tubular shape. Four side surfaces of the heat exchanger 10 in the substantially rectangular tubular shape are arranged so as to face the inner surfaces of the four side walls 1a1 of the housing 1a shown in Fig. 1, respectively.
An upper opening of the heat exchanger 10 in the substantially rectangular tubular shape is closed with the housing 1a. Moreover, a lower opening of the heat exchanger 10 faces the inner surface of the suction grille (not shown).
The fan 6 shown in Fig. 2 includes, for example, a turbofan, and is disposed inside the substantially rectangular tubular heat exchanger 10. When the fan 6 rotates, air in the room is sucked into the heat exchanger 10 through the above-described suction grille (not shown). The air sucked into the heat exchanger 10 passes between the laminated fins 10a (see Fig. 3), and is sent into the room again through the blow ports 4 (see Fig. 2) formed in the decorative panel 2 (see Fig. 2).
Meanwhile, the heat exchanger 10 shown in Fig. 3 exchanges heat between the air passing between the laminated fins 10a (see Fig. 3) and the refrigerant flowing in the heat transfer pipes 10b. Accordingly, the air is cooled or heated. Then, the indoor air having exchanged heat is blown into the room as described above. The indoor unit 1 (see Fig. 1) cools or heats the inside of the room in this manner.
Note that examples of the refrigerant used in the present embodiment include single hydrocarbon-based (HC-based) refrigerants including R290, R170, R1270, and R600a and an HC refrigerant mixture thereof. Alternatively, the refrigerant may be, for example, fluorine-based refrigerants including HFO-1234yf and R-32. Alternatively, a refrigerant mixture thereof may be used. Examples of flammable refrigerant include mildly flammable refrigerant and highly flammable refrigerant. Further, in the present embodiment, refrigerant having a greater specific weight than that of air is suitably used as the refrigerant.
Next, the piping chamber 18 (see Fig. 2) will be described.
As described above, the piping chamber 18 (see Fig. 2) is formed at the corner of the housing 1a (see Fig. 2). At this corner, the liquid-side refrigerant pipe joint 8 (see Fig. 2) and the gas-side refrigerant pipe joint 9 (see Fig. 2) are connected to each other.
The piping chamber 18 is defined as a closed space by the partition plate 12. As shown in Fig. 2, the partition plate 12 is provided so as to isolate the piping chamber 18 from an air passage for the indoor air from the fan 6. In this manner, the piping chamber 18 is blocked from the flow path for the air passing through the heat exchanger 10.
As shown in Fig. 3, an expansion valve 13, a liquid refrigerant distributor 14, and a gas refrigerant distributor 15 are provided in the piping chamber 18.
The expansion valve 13 is connected, through a predetermined joint pipe (not shown), to the liquid-side refrigerant pipe joint 8 attached to the side wall 1a1 of the housing 1a.
The liquid refrigerant distributor 14 is connected to the expansion valve 13 through a predetermined joint pipe (not shown).
A plurality of liquid refrigerant distribution pipes 21 is connected to the liquid refrigerant distributor 14.
The gas refrigerant distributor 15 is connected, through a predetermined joint pipe (not shown), to the gas-side refrigerant pipe joint 9 attached to the side wall 1a1 of the housing 1a.
A plurality of gas refrigerant distribution pipes 22 is connected to the gas refrigerant distributor 15.
The end portion of the heat exchanger 10 in the circumferential direction thereof faces the inside of the piping chamber 18.
Moreover, return vent portions and end portions of the plurality of heat transfer pipes 10b provided at the end portion of the heat exchanger 10 face the inside of the piping chamber 18.
The liquid refrigerant distribution pipe 21 corresponding to one end portion of each of the plurality of heat transfer pipes 10b is connected to the one end portion.
The gas refrigerant distribution pipe 22 corresponding to the other end portion of each of the plurality of heat transfer pipes 10b is connected to the other end portion.
Note that in the piping chamber 18, a connection portion between the expansion valve 13 and the liquid-side refrigerant pipe joint 8, a connection portion between the expansion valve 13 and the liquid refrigerant distributor 14, a connection portion between the liquid refrigerant distributor 14 and the liquid refrigerant distribution pipe 21, and a connection portion between the liquid refrigerant distribution pipe 21 and the heat transfer pipe 10b are formed by welding.
Moreover, in the piping chamber 18, a connection portion between the gas refrigerant distributor 15 and the gas-side refrigerant pipe joint 9, a connection portion between the gas refrigerant distributor 15 and the gas refrigerant distribution pipe 22, and a connection portion between the gas refrigerant distribution pipe 22 and the heat transfer pipe 10b are formed by welding.
Next, a structure for attaching a 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 includes a sensor unit 20 on the side wall 1a1 of the housing 1a.
The sensor unit 20 includes the refrigerant leakage sensor 20a and a cover 20b.
The configuration of the refrigerant leakage sensor 20a is not particularly limited as long as the refrigerant leakage sensor can sense the refrigerant. Examples thereof include a semiconductor gas sensor, an infrared gas sensor, and a thermally conductive gas sensor.
The refrigerant leakage sensor 20a in the present embodiment is substantially in a rectangular parallelepiped shape as described later.
The sensor unit 20 is disposed adjacent to the liquid-side refrigerant pipe joint 8 and the gas-side refrigerant pipe joint 9 arranged on the side wall 1a1 of the housing 1a and below these pipe joints.
That is, the refrigerant leakage sensor 20a of the sensor unit 20 is disposed between the liquid-side refrigerant pipe joint 8 and the gas-side refrigerant pipe joint 9 at a location lower than these two pipe joints.
Fig. 4 is an exploded perspective view of the sensor unit 20.
As shown in Fig. 4, the cover 20b forming the sensor unit 20 is formed of a plate-shaped body in a substantially rectangular shape (including a square shape) in plan view.
The planar shape of the cover 20b is formed corresponding to a maintenance hole M formed in the side wall 1a1 of the housing 1a.
The maintenance hole M is equivalent to an "opening".
As shown in Fig. 4, the cover 20b is fastened to the side wall 1a1 of the housing 1a with a screw S1. The cover 20b is configured such that the maintenance hole M (opening) is closed with the cover 20b from the outside of the housing 1a upon such fastening.
The configuration of the cover 20b is not limited to the fastening as long as the cover is detachably attached to the side wall 1a1. The cover 20b may be supported on the side wall 1a1 with a locking claw.
The cover 20b is provided, at the upper edge thereof, with a pair of curved surfaces 20b2 along the outer peripheral surfaces of the liquid-side refrigerant pipe joint 8 and the gas-side refrigerant pipe joint 9.
Moreover, the cover 20b is formed with a sensor attachment hole 20b1 in which the refrigerant leakage sensor 20a is to be fitted.
The sensor attachment hole 20b1 is formed as a rectangular (including square) hole in plan view such that the refrigerant leakage sensor 20a is fitted therein.
The refrigerant leakage sensor 20a is fastened to the cover 20b with a screw S2, which is provided in a flange of the refrigerant leakage sensor 20a, from the outside of the housing 1a. At this time, the refrigerant leakage sensor 20a is fitted in the sensor attachment hole 20b1. As described above, the refrigerant leakage sensor 20a is configured to close the sensor attachment hole 20b1.
The refrigerant leakage sensor 20a is not limited to the fastening as long as the leakage sensor is detachably attached to the cover 20b. The refrigerant leakage sensor 20a may be supported on the cover 20b with a locking claw.
That is, the refrigerant leakage sensor 20a is disposed so as to close the sensor attachment hole 20b1. As described above, the refrigerant leakage sensor 20a faces the piping chamber 18 (see Fig. 3).
Note that in Fig. 4, reference numeral 2 indicates the decorative panel. Reference numeral 31 indicates the support portion for the hanging bolt (not shown).

Features and Effects

Next, the features and effects of the indoor unit 1 of the air-conditioner A according to the present embodiment will be described.
The indoor unit 1 of the air-conditioner A according to the present embodiment includes the housing 1a, the liquid-side refrigerant pipe joint 8, and the gas-side refrigerant pipe joint 9. The housing 1a houses the heat exchanger 10, the fan 6, and the refrigerant pipes (liquid refrigerant distribution pipe 21 and gas refrigerant distribution pipe 22). The liquid-side refrigerant pipe joint 8 and the gas-side refrigerant pipe joint 9 are arranged as the refrigerant pipe joints outside the housing 1a. The housing 1a has the maintenance hole M as the opening on the lower side of the liquid-side refrigerant pipe joint 8 and the gas-side refrigerant pipe joint 9. The maintenance hole M (opening) is covered with the detachable cover 20b. The refrigerant leakage sensor 20a is attached to the surface of the cover 20b on which the liquid-side refrigerant pipe joint 8 and the gas-side refrigerant pipe joint 9 are arranged.
In a general indoor unit of an air-conditioner (see, for example, Japanese Patent No. 7004836 ), a refrigerant leakage sensor needs to be detached from a housing together with a sensor holder when the refrigerant leakage sensor is detached from the indoor unit, as described above. Thereafter, the refrigerant leakage sensor is detached from the sensor holder.
On the other hand, in the indoor unit 1 of the present embodiment, the refrigerant leakage sensor 20a is attached to the cover 20b from the outside of the housing 1a. Thus, only the refrigerant leakage sensor 20a can be detached from the housing 1a.
In the indoor unit 1, the piping chamber 18 is the closed space. The opening is the maintenance hole M for the refrigerant pipes (liquid refrigerant distribution pipe 21 and gas refrigerant distribution pipe 22).
According to the indoor unit 1, even if the refrigerant leaks from the joint portion formed by welding the refrigerant pipes (liquid refrigerant distribution pipe 21 and gas refrigerant distribution pipe 22), the refrigerant stays in the piping chamber 18 which is the closed space. Since the piping chamber 18 is the closed space, the refrigerant leakage sensor 20a can promptly detect even a slight amount of leaked refrigerant.
According to the indoor unit 1, the cover 20b is attached to the maintenance hole M (opening) through which an access to the refrigerant pipes (liquid refrigerant distribution pipe 21 and gas refrigerant distribution pipe 22) is easily made. Thus, the refrigerant leakage sensor 20a attached to the cover 20b is disposed at the location near the refrigerant pipes (liquid refrigerant distribution pipe 21 and gas refrigerant distribution pipe 22).
Thus, the refrigerant leakage sensor 20a can more reliably detect the refrigerant having leaked from the pipes. That is, according to the indoor unit 1, both reliable sensing of the refrigerant leakage and easy maintenance can be achieved.
According to the indoor unit 1, the cover 20b and the refrigerant leakage sensor 20a can be integrally detached from the housing 1a. Thus, inspection of the refrigerant pipes (liquid refrigerant distribution pipe 21 and gas refrigerant distribution pipe 22) through the maintenance hole M and inspection of the refrigerant leakage sensor 20a can be performed in parallel.
On the housing 1a of the indoor unit 1 as described above, the liquid-side refrigerant pipe joint 8 and the gas-side refrigerant pipe joint 9 are provided in parallel. In addition, the sensor attachment hole 20b1 is formed adjacent to the liquid-side refrigerant pipe joint 8 and the gas-side refrigerant pipe joint 9.
According to the indoor unit 1, the liquid-side refrigerant pipe joint 8 side is connected to the liquid refrigerant distribution pipe 21 through a predetermined connection pipe (not shown) at the joint portion (welded portion) in the piping chamber 18. The gas-side refrigerant pipe joint 9 side is connected to the gas refrigerant distribution pipe 22 through a predetermined connection pipe (not shown) at another joint portion (welded portion) in the piping chamber 18. The refrigerant leakage sensor 20a is disposed at the location near these joint portions (welded portions).
Thus, the refrigerant leakage sensor 20a can more reliably detect the refrigerant having leaked from the pipes.
In the indoor unit 1, the cover 20b has the curved surfaces 20b2 along the outer peripheral surface of the liquid-side refrigerant pipe joint 8 and the outer peripheral surface of the gas-side refrigerant pipe joint 9.
According to the indoor unit 1, when the cover 20b is attached to the housing 1a, the cover 20b can be easily positioned on the housing 1a using the curved surfaces 20b2 as guide grooves.
The present embodiment has been described above. Note that the present embodiment is not limited to the embodiment above. The present embodiment may be implemented as various embodiments other than the embodiment above.
In the embodiment above, the ceiling cassette type four-direction blowing indoor unit 1 has been described as an example. However, the present embodiment is also applicable to, for example, a floor-standing indoor unit, a wall-mounted indoor unit, or a ceiling-hanging indoor unit.
The foregoing detailed description has been presented for the purposes of illustration and description. Many modifications and variations are possible in light of the above teaching. It is not intended to be exhaustive or to limit the subject matter described herein to the precise form disclosed. Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims appended hereto.

Claims

An indoor unit of an air-conditioner, comprising:
a housing that houses a heat exchanger, a fan and a refrigerant pipe; and

a refrigerant pipe joint disposed outside the housing,

wherein the housing has an opening on a lower side of the refrigerant pipe joint,

the opening is covered with a detachable cover, and

a refrigerant leakage sensor is attached to a surface of the cover on a side on which the refrigerant pipe joint is disposed.
The indoor unit of the air-conditioner according to claim 1, wherein
the refrigerant pipe joint includes two refrigerant pipe joints, and

the refrigerant leakage sensor is disposed between the two refrigerant pipe joints at a location lower than the two refrigerant pipe joints.