Indoor unit of air conditioner

Abstract

To enable more immediate detection of leakage of a combustible refrigerant, in particular leakage in a cross direction of an indoor unit in the indoor unit of an air conditioner using the combustible refrigerant.SOLUTION: An indoor unit 10 includes: a housing 18; a heat exchange unit 15 housed in the housing 18; a power source line 22 drawn into the housing 18 from a back surface side of the housing 18; a power source line guide 23 guiding an arrangement of the power source line 22 in the housing 18; and a refrigerant leakage sensor 24 detecting leakage of a combustible refrigerant. The refrigerant leakage sensor 24 is located on a front side of the housing 18 when viewed from the power source line guide 23. The power source line guide 23 is provided with a communication hole 25 communicating an area in which the refrigerant leakage sensor 24 is located, with an area which is on the back surface side when viewed from the power source line guide 23.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an indoor unit of an air conditioner, and more particularly to an indoor unit of an air conditioner that uses a flammable (including slightly flammable) refrigerant. [Background technology]

[0002] In recent years, refrigerants for air conditioners have been chosen that have as low an ozone depletion potential (ODP) and global warming potential (GWP) as possible in order to minimize their impact on the environment. A typical example is difluoromethane (R32). Difluoromethane has an ODP of 0, a relatively low GWP, and good refrigerant performance.

[0003] However, difluoromethane is flammable. According to ISO 817:2014, the flammability classification of difluoromethane is slightly flammable (Class 2L), but it is not non-flammable (Class 1). Therefore, if difluoromethane leaks from the refrigeration cycle of an air conditioner for any reason, it is necessary to consider the possibility of it catching fire.

[0004] Therefore, in air conditioners that use a flammable refrigerant such as difluoromethane, a configuration is known in which a refrigerant leakage sensor is provided particularly in the indoor unit.

[0005] For example, Patent Document 1 discloses a configuration in which a refrigerant leakage sensor is attached to the outer surface of the housing of an indoor unit, and a communication hole that connects the inside and outside of the housing is formed in the sensor attachment part.Alternatively, Patent Document 2 discloses a configuration in which, in a user-side heat exchange unit that can be used as an indoor unit, an electrical component (electrical equipment) is assumed to be an ignition source, and a gas detection sensor that detects the presence or absence of refrigerant gas is located below this electrical component.

[0006] Both the indoor unit described in Patent Document 1 and the user-side heat exchange unit described in Patent Document 2 are floor-standing types, and use difluoromethane as a flammable refrigerant. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2019-027662 [Patent Document 2] Japanese Patent Publication No. 2020-051734 Summary of the Invention [Problem to be solved by the invention]

[0008] Recently, natural refrigerants with lower GWP have been attracting attention in order to further reduce the impact on the environment. Typical natural refrigerants include hydrocarbons such as propane (R290), isobutane (R600a), and ethane (R170). These hydrocarbons are more flammable than difluoromethane, and many are classified as highly flammable (Class 3). Therefore, if a flammable refrigerant leaks, it is necessary to detect the leak as quickly as possible.

[0009] As mentioned above, the configurations disclosed in Patent Document 1 or Patent Document 2 are intended to detect leakage of difluoropropane, which is slightly flammable, and are intended to detect leakage of flammable (slightly flammable) refrigerant in the vertical direction of the indoor unit, as exemplified by a floor-standing indoor unit.

[0010] For example, Patent Document 1 gives an example in which a refrigerant leakage sensor is placed further below a dew tray placed below a heat exchanger. Also, Patent Document 2 gives an example in which a gas detection sensor is placed below electrical components (electrical equipment), as mentioned above. Therefore, with the configurations disclosed in these patent documents, there is a possibility that a flammable refrigerant leak in the depth direction (front-to-back direction) of the indoor unit cannot be promptly detected.

[0011] The present invention has been made to solve such problems, and aims to make it possible to more quickly detect leakage of flammable refrigerant, particularly leakage in the forward and backward directions of the indoor unit, in the indoor unit of an air conditioner that uses a flammable refrigerant. [Means for solving the problem]

[0012] In order to solve the above-mentioned problems, the indoor unit of an air conditioner according to the present invention is an indoor unit provided in an air conditioner that uses a flammable refrigerant, and comprises a housing, a power supply line that is drawn into the housing from the rear side thereof, a power supply line guide that guides the placement of the power supply line within the housing, and a refrigerant leakage sensor that detects leakage of the flammable refrigerant, wherein the refrigerant leakage sensor is located on the front side of the housing as viewed from the power supply line guide, and the power supply line guide is provided with a communication hole that connects the area where the refrigerant leakage sensor is located with the area on the rear side as viewed from the power supply line guide.

[0013] According to the above configuration, the power supply line guide has a communication hole, which allows air to flow between the rear area of ​​the indoor unit separated by the power supply line guide and the front area of ​​the indoor unit where the refrigerant leak sensor is located. This allows the refrigerant to pass through the communication hole and reach the refrigerant leak sensor even if a flammable refrigerant leaks behind the indoor unit. This allows the refrigerant leak sensor to detect the flammable refrigerant leak more quickly. As a result, in an air conditioner that uses a flammable refrigerant, flammable refrigerant can be detected more quickly, particularly in the front-to-rear direction (depth direction) of the indoor unit, improving the reliability of the indoor unit. [Effects of the Invention]

[0014] The present invention, with the above configuration, has the effect of being able to more quickly detect leakage of flammable refrigerant, particularly leakage in the front-to-rear direction of the indoor unit, in an indoor unit of an air conditioner that uses a flammable refrigerant. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1A is a perspective view showing an example of the external configuration of the front side of an indoor unit of an air conditioner according to a representative embodiment of the present disclosure, and FIG. 1B is a perspective view showing an example of the external configuration of the rear side of the indoor unit shown in FIG. [Figure 2]FIG. 2 is a vertical cross-sectional view of the indoor unit shown in FIGS. 1(A) and 1(B), showing an example of the configuration from the front to the back near the center. [Figure 3] (A) is a vertical cross-sectional view showing an example of the configuration of the indoor unit shown in Figures 1(A) and (B) near the side where the power line is located, and (B) is an enlarged cross-sectional view of the part surrounded by the thick dotted line in (A). [Figure 4] 4(A) and 4(B) are partial perspective views of the indoor unit shown in FIG. 3, showing examples of the configuration of communication holes that the indoor unit has. [Figure 5] 4(A) and 4(B) are rear views of the indoor unit shown in FIG. 3, showing examples of the configuration of communication holes that the indoor unit has. [Figure 6] (A) is a cross-sectional view of a power line guide provided in the indoor unit shown in Figure 3, (B) is a partial cross-sectional view showing an example of the configuration of a communication hole provided in the power line guide shown in (A), (C) is a partial oblique view showing another example of the configuration of a power line guide provided in the indoor unit shown in Figure 3, (D) is a cross-sectional view showing the configuration of a communication hole provided in the power line guide shown in (C), (E) is a partial oblique view showing yet another example of the configuration of a power line guide provided in the indoor unit shown in Figure 3, and (F) is a cross-sectional view showing the configuration of a communication hole provided in the power line guide shown in (C). DETAILED DESCRIPTION OF THE INVENTION

[0016] [Knowledge and other information that formed the basis of this disclosure] When a flammable refrigerant is used as the refrigerant for an air conditioner, if the flammable refrigerant leaks from the indoor unit, it is important to quickly detect the leak. 、 It is known that a part of an air conditioner's indoor unit that is prone to refrigerant leakage is the pipe connection that connects the indoor unit's heat exchanger unit with the outdoor unit's heat exchanger unit. Because the pipe connection is installed at the site where the indoor unit is installed, there is a possibility of refrigerant leakage due to human error by the installer. This pipe connection is usually located on the back of the indoor unit.

[0017] On the other hand, in consideration of maintenance after installation of the indoor unit, the refrigerant leak sensor equipped in the indoor unit of an air conditioner is usually installed in a position that is easy to maintain from the front (front face) of the indoor unit, for example, on the lower front side. In this case, when a flammable refrigerant leaks on the rear side of the indoor unit, it is anticipated that the refrigerant leak sensor located on the front side of the indoor unit may not be able to quickly detect refrigerant leaks, especially in the front-to-rear direction (depth direction).

[0018] After extensive research, the inventors independently discovered that by providing a communication hole in the power supply wire guide of the indoor unit, the refrigerant leakage sensor can quickly detect refrigerant leakage in the front-to-back direction (depth direction), and thus completed the present invention.

[0019] In other words, the indoor unit of an air conditioner according to the present disclosure is an indoor unit provided in an air conditioner that uses a flammable refrigerant, and comprises a housing, a power supply line that is drawn into the housing from the rear side thereof, a power supply line guide that guides the placement of the power supply line within the housing, and a refrigerant leakage sensor that detects leakage of the flammable refrigerant, wherein the refrigerant leakage sensor is located on the front side of the housing as viewed from the power supply line guide, and the power supply line guide is provided with a communication hole that connects the area where the refrigerant leakage sensor is located with the area on the rear side as viewed from the power supply line guide.

[0020] Typically, the electrical components (terminals) of the indoor unit are installed on the front of the unit, and the power cables that supply power to the electrical components are introduced into the indoor unit from the rear side and connected to the electrical components. In this case, a power cable guide is used to guide the power cable to an appropriate position inside the indoor unit. This power cable guide is a component installed so that it extends from the rear of the indoor unit to the front of the indoor unit.

[0021] Therefore, by providing a communication hole in the power supply line guide, air can flow between the area (space) on the rear side of the indoor unit where the pipe connection is located and the area (space) in front where the refrigerant leak sensor is located. This allows flammable refrigerant to quickly pass through the communication hole and reach the area (space) where the refrigerant leak sensor is located, even if flammable refrigerant leaks from the pipe connection on the rear side of the indoor unit. This allows the refrigerant leak sensor to detect flammable refrigerant leaks more quickly. As a result, in air conditioners that use flammable refrigerants, flammable refrigerant can be more quickly detected, especially in the front-to-rear direction (depth direction) of the indoor unit, improving the reliability of the indoor unit.

[0022] Furthermore, because the power line guide is shaped like a flow passage to guide the power line inside the indoor unit, leaked flammable refrigerant is more easily guided to the communication holes. This not only makes it easier for flammable refrigerant to reach the refrigerant leak sensor, but also prevents the flammable refrigerant from diffusing inside the indoor unit. This allows for faster detection of refrigerant leaks, further improving the reliability of air conditioners that use flammable refrigerants.

[0023] Representative embodiments of the present disclosure will be described below with reference to the drawings. Note that the same or corresponding elements will be designated by the same reference numerals throughout the drawings, and redundant description thereof will be omitted.

[0024] [Configuration example of air conditioner and indoor unit] The air conditioner according to the present disclosure includes an indoor unit and an outdoor unit, which are connected by a refrigerant pipe. In this embodiment, the indoor unit of the air conditioner according to the present disclosure is a wall-mounted type that is attached to a wall surface inside a room, but it goes without saying that the present disclosure is not limited to this. In this embodiment, a wall-mounted indoor unit is used as an example to explain an example of its specific configuration.

[0025] As shown schematically in FIG. 1(A), the indoor unit 10 according to this embodiment has a rectangular parallelepiped shape that is longer in the left-right direction than in the up-down and front-to-back directions, with an upper surface forming an upper surface opening 18b, a front panel 11 on the front surface, and an air outlet 12 at the bottom of the front surface. Furthermore, as shown in FIG. 1(B), the rear surface of the indoor unit 10 is provided with a pipe connection part 13. Refrigerant piping 14 is connected to the pipe connection part 13. Refrigerant piping 14 is piping that circulates refrigerant between a heat exchanger unit provided in the indoor unit 10 and a heat exchanger unit provided in the outdoor unit. Note that in this embodiment, for ease of explanation, the left-right direction may be referred to as the "horizontal direction" and the up-down direction as the "vertical direction."

[0026] As shown in the vertical cross section of Figure 2, the indoor unit 10 includes, in addition to the front panel 11, a heat exchanger unit 15, an indoor fan 16, a frame 17, a housing (casing) 18, upper and lower airflow direction vanes 19, and an auxiliary airflow direction vane 20. Note that the vertical cross section of Figure 2 shows a schematic representation of the main internal configuration of the indoor unit 10, with various known components or mechanisms being included in the blank areas depending on the specific configuration of the indoor unit 10.

[0027] 2 is the front surface of the indoor unit 10, the right side of the page is the back surface (or rear surface) of the indoor unit 10, the upper side of the page is the top surface of the indoor unit 10, and the lower side of the page is the bottom surface of the indoor unit 10. The members, mechanisms, etc. shown in FIG. 2 are also representative examples, and the present disclosure is not limited to this illustration.

[0028] The housing 18 constitutes the outer shape of the main body of the indoor unit 10, and the heat exchanger unit 15 is housed within the housing 18. The indoor unit 10 according to this embodiment is equipped with, as the heat exchanger unit 15, a front heat exchanger 15a located at the front inside the indoor unit 10 and a rear heat exchanger 15b located at the rear inside the indoor unit 10. An indoor fan 16 is located below and between the front heat exchanger 15a and the rear heat exchanger 15b.

[0029] As described above, the top of the indoor unit 10 is the top opening 18b, and the front panel 11 is provided on the front of the indoor unit 10. The front panel 11 closes the front opening 18a in an openable and closable manner. Therefore, the housing 18 has the front opening 18a in its front part and the top opening 18b above it. Furthermore, with the heat exchanger unit 15 as the reference point, the front opening 18a is located in front of the heat exchanger unit 15, and the top opening 18b is located above the heat exchanger unit 15.

[0030] The heat exchanger unit 15 (front heat exchanger 15a and rear heat exchanger 15b) is supported by a frame 17 inside a housing 18. The indoor fan 16 exchanges heat in the front heat exchanger 15a and rear heat exchanger 15b with the indoor air taken in through the front opening 18a and top opening 18b, and then blows the air into the room from the air outlet 12 at the bottom front of the indoor unit 10.

[0031] As described above, the front panel 11 is provided in an openable and closable manner at the front opening 18a. The front panel 11 closes the front opening 18a when the air conditioner is stopped, and moves away from the housing 18 to open the front opening 18a when the air conditioner is operating. Note that Fig. 2 schematically illustrates the state in which the front panel 11 closes the front opening 18a. The back surface of the housing 18, i.e., the back surface of the indoor unit 10, is the surface that is attached to the wall inside the room.

[0032] An air outlet 12 is provided on the underside of the housing 18 at a position below the indoor fan 16. In the example shown in Fig. 2, the air outlet 12 is provided with air direction vanes such as an up-down air deflector 19 and an auxiliary air deflector 20. The up-down air deflector 19 and the auxiliary air deflector 20 open and close the air outlet 12 and enable the direction in which air is blown out from the air outlet 12 to be changed up or down. The air outlet 12 may also be provided with left-right air deflectors. The left-right air deflectors enable the direction in which air is blown out from the air outlet 12 to be changed left or right.

[0033] As shown in the vertical cross-sectional view of FIG. 3(A), the indoor unit 10 further includes an electrical component section 21, a power supply line 22, a power supply line guide 23, a refrigerant leakage sensor 24, and the like. The vertical cross-sectional view of FIG. 2 corresponds to a cross-section of the horizontal center of the indoor unit 10 shown in FIG. 1(A). In contrast, the vertical cross-sectional view of FIG. 3(A) corresponds to a cross-section of the portion where the power supply line 22 is disposed. In this embodiment, for example, as shown in FIG. 1(B), the power supply line 22 is disposed at the left end on the rear surface of the indoor unit 10. Therefore, when viewed from the front side of the indoor unit 10 shown in FIG. 1(A), the power supply line 22 is disposed at the right end. Therefore, in this embodiment, the vertical cross-sectional view of FIG. 3(A) corresponds to a cross-section of the indoor unit 10 shown in FIG. 1(A) near the right end in the horizontal direction. Also, FIGS. 3(A) and 3(B) schematically illustrate the fan motor 16a of the indoor fan 16.

[0034] As shown in Fig. 3(A), at the end of the indoor unit 10 where the power cord 22 is arranged, similar to the central portion, the front panel 11 is provided at the front opening 18a, an upper opening 18b is provided on the top surface, and an air outlet 12 is provided at the lower front portion, and air direction plates such as an upper and lower air deflector 19 and an auxiliary air deflector 20 are provided at the air outlet 12. Also, at the position of the vertical cross section shown in Fig. 3(A) (a position near the right end in the horizontal direction), the fan motor 16a of the indoor fan 16 is located above the air outlet 12, and the pipe connection part 13 is located below the back surface as viewed from the fan motor 16a.

[0035] In the example shown in Figure 3(A), the power supply line 22 runs from the lower part of the rear surface of the indoor unit 10, passing below the fan motor 16a, and reaching the front opening 18a. The power supply line 22 may run above the fan motor 16a or at another location. For convenience, the power supply line 22 is shown schematically in Figures 3(A) and 3(B) using thick dashed lines. An electrical component section 21 is provided on the front surface of the indoor unit 10. The electrical component section 21 includes electrical components such as a control board that controls electric components such as a drain pump and a float switch, and a terminal block that connects the power supply line 22 or internal electrical wiring, and these electrical components are usually housed in dedicated housings.

[0036] Since the electrical components include components that generate heat, they are usually placed on the front side of the indoor unit 10, which has good ventilation. In the example shown in Fig. 3(A), the electrical component section 21 is placed above and in front of the fan motor 16a, but the present disclosure is not limited to this. In the example shown in Fig. 3(A), the power supply line 22 reaches the front side from below the fan motor 16a and then extends upward to be connected to the electrical component section 21.

[0037] [Example of power line guide and communication hole configuration] Thus, in the example shown in FIG. 3(A), a power line guide 23 is provided to extend the power line 22 from the lower rear surface of the indoor unit 10, below the fan motor 16a, and above the front surface. In the example shown in FIG. 3(A), the power line guide 23 is disposed below the fan motor 16a and has a shape that slopes upward from the rear surface to the front surface as a whole. A horizontal portion may be formed in a portion between the rear surface and the front surface. In this embodiment, the rear surface of the power line guide 23 is a rear guide portion 23a that is positioned along the vertical direction.

[0038] As shown in Fig. 3(A), the refrigerant leakage sensor 24 is located below the fan motor 16a and below the power supply line guide 23. As shown in Fig. 3(A), in this embodiment, the rear guide portion 23a is located along the vertical direction so as to divide the interior of the indoor unit 10 (inside the housing 18) into a rear area and a lower front area. The refrigerant leakage sensor 24 is located in front of this rear guide portion 23a. The power supply line 22 is guided by the rear guide portion 23a from near the bottom of the rear surface and extends upward, and then is extended forward by the entire power supply line guide 23.

[0039] FIG. 3(B) is an enlarged view of the portion surrounded by a thick dotted line in the vertical cross-sectional view of FIG. 3(A), i.e., the lower part of the indoor unit 10. In this embodiment, as shown schematically in FIG. 3(B), a communication hole 25 is formed in the rear guide portion 23a of the power line guide 23. As described above, the rear guide portion 23a divides the interior of the indoor unit 10 into a rear region and a lower front region, with the pipe connection portion 13 located above the rear region. In other words, the pipe connection portion 13 is located on the rear side of the housing 18 (indoor unit 10) when viewed from the power line guide 23. The pipe connection portion 13 is a portion from which flammable refrigerant is likely to leak. Meanwhile, a refrigerant leakage sensor 24 is located in the lower front region.

[0040] A rear guide portion 23a is disposed between the rear region, above which the pipe connection portion 13 is located, and the refrigerant leakage sensor 24, located in the lower front region, so as to block the gap between them. However, by providing a communication hole 25 in the rear guide portion 23a, the rear region and the lower front region are communicated to allow air to flow. As a result, even if a flammable refrigerant leaks on the rear side of the indoor unit 10, the flammable refrigerant can pass through the communication hole 25 and successfully reach the position of the refrigerant leakage sensor 24, allowing the refrigerant leakage sensor 24 to detect the flammable refrigerant leakage more quickly.

[0041] The specific configuration of the refrigerant leak sensor 24 is not particularly limited. Typical refrigerant leak sensors 24 include, for example, semiconductor sensors, hot-wire semiconductor sensors, and non-dispersive infrared sensors. Semiconductor sensors detect the change in resistance that occurs when a metal oxide semiconductor comes into contact with a flammable refrigerant as the gas concentration. Hot-wire semiconductor sensors detect the change in resistance that occurs when a metal oxide semiconductor comes into contact with a flammable refrigerant as the gas concentration. Non-dispersive infrared sensors irradiate a measurement cell with infrared rays and detect the amount of change in the infrared rays due to absorption by the flammable refrigerant. Generally, semiconductor sensors or hot-wire semiconductor sensors are used, as they are easy to miniaturize.

[0042] Furthermore, the flammable refrigerants used in air conditioners in this disclosure are not particularly limited. In this disclosure, "flammable" also includes "mildly flammable." Typically, among the flammability classifications in ISO 817:2014, this includes not only flammable (Class 2) and highly flammable (Class 3), but also mildly flammable (Class 2L). In other words, refrigerants that exhibit flammability in the same flammability classification, excluding non-flammable (Class 1), can be considered flammable refrigerants in this disclosure. Note that the definition of "flammable" in this disclosure is not limited to the flammability classifications in ISO 817:2014, and other definitions of flammability or combustibility known in refrigerants or related fields can be referenced.

[0043] Typical flammable refrigerants in the present disclosure include propane (R290), isobutane (R600a), and ethane (R170). Alternatively, slightly flammable refrigerants such as difluoromethane (R32) can be used. These flammable refrigerants may be used alone or in combination. Furthermore, in the present disclosure, flammable refrigerants other than propane, isobutane, ethane, and difluoromethane may be used in combination, or non-flammable refrigerants may be used in combination.

[0044] In other words, in the present disclosure, the refrigerant used in the air conditioner is a mixed refrigerant containing a flammable refrigerant, as long as the mixed refrigerant as a whole has a flammability of at least slightly flammable. Therefore, even if the refrigerant used in the air conditioner is a mixed refrigerant containing a non-flammable refrigerant, as long as it is flammable, it falls under the flammable refrigerant definition of the present disclosure. Thus, in the present disclosure, the flammable refrigerant used in the air conditioner is any refrigerant containing at least one refrigerant selected from the group consisting of propane (R290), isobutane (R600a), ethane (R170), and difluoromethane (R32).

[0045] In the air conditioner indoor unit 10 according to the present disclosure, the specific configuration of each component other than the refrigerant leak sensor 24 and the flammable refrigerant is not particularly limited, and components known in the field of air conditioners can be suitably used. For example, the housing 18, the frame 17, the power line guide 23, the wind direction plate, etc. can be suitably made of known resin. The power line 22, the electrical component section 21, etc. can also be suitably made of electrical and electronic components known in the field of air conditioners.

[0046] [Variations] In the indoor unit 10 of the air conditioner according to the present disclosure, the refrigerant leak sensor 24 is located on the front side of the housing 18 as viewed from the power line guide 23, and the power line guide 23 is provided with a communication hole 25 that connects the area where the refrigerant leak sensor 24 is located with an area on the back side as viewed from the power line guide 23. Therefore, as shown in Figures 3(A) and 3(B), for example, the power line guide 23 may be configured without the back side guide portion 23a. The communication hole 25 may be provided in any part of the power line guide 23 as long as it allows air to flow between the area where the refrigerant leak sensor 24 is located and the area on the back side of the housing 18 (indoor unit 10).

[0047] As described above, if the power line guide 23 has the rear guide portion 23a and the communication hole 25 is provided in this portion, the refrigerant leakage sensor 24 can be disposed in front of the rear guide portion 23a and close to the communication hole 25, as shown in Fig. 3(B). Therefore, even if a flammable refrigerant leaks, the refrigerant leakage sensor 24 can detect the leak more quickly.

[0048] Furthermore, in this embodiment, the pipe connection portion 13 is cited as a portion where flammable refrigerant is likely to leak, and therefore the power supply line guide 23 is provided with a communication hole 25 at a position between the pipe connection portion 13 and the refrigerant leakage sensor 24. However, in the present disclosure, the portion where flammable refrigerant is likely to leak is not limited to the pipe connection portion 13. Depending on the more specific configuration of the indoor unit 10, if there is a portion where flammable refrigerant is likely to leak, the power supply line guide 23 may be provided with a communication hole 25 to allow air to flow between that portion and the refrigerant leakage sensor 24.

[0049] Furthermore, in the present disclosure, the specific configuration of the communication hole 25 is not particularly limited. The communication hole 25 may have any shape as long as it allows air to circulate between the area where the refrigerant leakage sensor 24 is located and the area on the back side of the housing 18 (indoor unit 10). For example, as shown in FIG. 4(A), the communication hole 25 may be provided in the power supply line guide 23 as a slit along the horizontal direction. Alternatively, as shown in FIG. 4(B), the communication hole 25 may be provided in the power supply line guide 23 as a slit that is inclined toward the side. The inclination direction of the slit communication hole 25 is not particularly limited.

[0050] Alternatively, as shown in FIG. 5(A), the communication holes 25 may be provided in the power line guide 23 as slits along the vertical direction. Alternatively, as shown in FIG. 5(B), the communication holes 25 may be provided in the power line guide 23 as circular holes. Furthermore, the communication holes 25 may be provided in the power line guide 23 as polygonal holes, or as a combination of slits, circles, and polygonal holes. The number of communication holes 25 provided in the power line guide 23 is not particularly limited. The number of communication holes 25 may be any number that allows air to circulate between the area where the refrigerant leakage sensor 24 is located and the area on the back side of the housing 18 (indoor unit 10).

[0051] Alternatively, in the present disclosure, the communication holes 25 may be configured as gaps rather than through-holes that penetrate the power line guide 23. For example, as shown in Figures 6(A) to 6(F), the communication holes 25 may be configured as gaps that are generated when the power line guide 23 is divided into multiple parts.

[0052] In the example shown in Figures 6(A) and (B), as shown in Figure 6(A), a cylindrical power line guide 23 is divided into two approximately equal parts, and the thickness of the butt joints of the divided parts is small so that they overlap each other. As shown in Figure 6(B), a communication hole 25 is formed as a gap between the overlapping divided parts. As shown in Figure 6(B), this communication hole 25 is not a straight line but has a labyrinth structure with two bends.

[0053] In the example shown in Figures 6(C) and (D), as shown in Figure 6(C), the groove-shaped power line guide 23 is divided into two approximately equal parts at the center of the bottom, and a communication hole 25 is formed between the butt joints of these parts. Here, as shown in Figure 6(D), the butt joint of one divided part is thick and has a recess formed on the butt joint surface, while the butt joint of the other divided part is thin so that it can be inserted into the recess in the butt joint of the one divided part. As a result, the communication hole 25 has a labyrinth structure with four bends.

[0054] It should be noted that a labyrinth structure is not necessary when the gaps formed when the power line guide 23 is divided into multiple pieces of equipment are used as the communication holes 25. In the example shown in Figures 6(E) and (F), the groove-shaped power line guide 23 is divided into two approximately equal parts at the center of the bottom, as shown in Figure 6(E), and communication holes 25 are formed between the butt joints of these parts. This is similar to the example shown in Figures 6(C) and (D), but as shown in Figure 6(F), communication holes 25 are linear slit-like gaps.

[0055] In this way, the indoor unit of the air conditioner according to the present disclosure uses a flammable refrigerant and comprises a housing, a power supply line drawn into the housing from the rear side thereof, a power supply line guide for guiding the placement of the power supply line within the housing, and a refrigerant leakage sensor for detecting leakage of the flammable refrigerant, wherein the refrigerant leakage sensor is located on the front side of the housing as viewed from the power supply line guide, and the power supply line guide has a communication hole that connects the area where the refrigerant leakage sensor is located with the area on the rear side as viewed from the power supply line guide.

[0056] With this configuration, the power supply line guide has a communication hole, which allows air to flow between the area on the rear side of the indoor unit separated by the power supply line guide and the area on the front side of the indoor unit where the refrigerant leak sensor is located. This allows the flammable refrigerant to pass through the communication hole and reach the refrigerant leak sensor, even if a flammable refrigerant leaks on the rear side of the indoor unit. This allows the refrigerant leak sensor to detect the flammable refrigerant leak more quickly. As a result, in an air conditioner that uses a flammable refrigerant, flammable refrigerant can be detected more quickly, particularly in the front-to-rear direction (depth direction) of the indoor unit, improving the reliability of the indoor unit.

[0057] (Addendum) Based on the description of the above embodiments, the following techniques are disclosed in this specification. (Technology 1) An indoor unit of an air conditioner that uses a flammable refrigerant, comprising: a housing; a power supply line that is drawn into the housing from the rear side of the housing; a power supply line guide that guides the placement of the power supply line within the housing; and a refrigerant leakage sensor that detects leakage of the flammable refrigerant, wherein the refrigerant leakage sensor is located on the front side of the housing as viewed from the power supply line guide, and the power supply line guide is provided with a communication hole that connects the area where the refrigerant leakage sensor is located with the area on the rear side as viewed from the power supply line guide.

[0058] According to the above configuration, the power supply line guide has a communication hole, which allows air to flow between the rear area of ​​the indoor unit separated by the power supply line guide and the front area of ​​the indoor unit where the refrigerant leak sensor is located. This allows the refrigerant to pass through the communication hole and reach the refrigerant leak sensor even if a flammable refrigerant leaks behind the indoor unit. This allows the refrigerant leak sensor to detect the flammable refrigerant leak more quickly. As a result, in an air conditioner that uses a flammable refrigerant, flammable refrigerant can be detected more quickly, particularly in the front-to-rear direction (depth direction) of the indoor unit, improving the reliability of the indoor unit.

[0059] (Technology 2) An indoor unit of an air conditioner according to Technology 1, comprising a heat exchanger unit housed within the housing and a pipe connection part that connects the heat exchanger unit to a refrigerant pipe, the pipe connection part being located on the rear side of the housing as viewed from the power supply line guide, and the communication hole being provided in a position in the power supply line guide between the pipe connection part and the refrigerant leakage sensor.

[0060] According to the above configuration, the pipe connection portion is a location where refrigerant is relatively likely to leak, and is usually located on the rear side of the housing. Therefore, a communication hole is provided in the power line guide at a location located between the pipe connection portion and the refrigerant leakage sensor. This allows flammable refrigerant to pass through the communication hole and reach the refrigerant leakage sensor, allowing the refrigerant leakage sensor to detect flammable refrigerant leakage more quickly.

[0061] (Technology 3) An indoor unit of an air conditioner according to Technology 2, wherein the power supply line guide has a rear guide portion located inside the housing between a rear region and a lower front region along the vertical direction of the housing, the refrigerant leakage sensor is located in front of the rear guide portion, and the communication hole is provided in the rear guide portion.

[0062] According to this configuration, the power line guide has a rear guide portion positioned vertically inside the housing, and by providing a communication hole in this rear guide portion, the refrigerant leak sensor can be positioned in front of and adjacent to the rear guide portion, allowing the refrigerant leak sensor to detect the leak more quickly even if a flammable refrigerant leaks.

[0063] (Technology 4) An indoor unit of an air conditioner described in any one of Technology 1 to Technology 3, wherein the communication hole is at least one of a slit or circular hole formed in the power line guide, a gap formed between the power line guide and an adjacent component, a gap created when the power line guide is divided into multiple components, and a labyrinth structure formed by overlapping between a part of the power line guide and a part of an adjacent component.

[0064] According to the above configuration, by having the communication hole have any of the above configurations, the leaked flammable refrigerant can be made to reach the position of the refrigerant leakage sensor more effectively.

[0065] (Technology 5) The indoor unit of the air conditioner according to any one of Technology 1 to Technology 4, wherein the flammable refrigerant contains at least one refrigerant selected from the group consisting of propane (R290), isobutane (R600a), ethane (R170), and difluoromethane (R32).

[0066] According to the above configuration, if the air conditioner is configured to use a flammable refrigerant containing at least one refrigerant selected from the above group, even if such a flammable refrigerant leaks, the refrigerant leakage sensor can detect the leak more quickly due to the communication hole provided in the power line guide.

[0067] The present invention is not limited to the description of the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments or multiple modified examples are also included in the technical scope of the present invention. [Industrial Applicability]

[0068] The present invention can be widely and suitably used in the field of air conditioners that use flammable (including slightly flammable) refrigerants. [Explanation of symbols]

[0069] 10: Indoor unit 11: Front panel 12:Air outlet 13: Pipe connection part 14: Refrigerant piping 15: Heat exchanger unit 15a: Front heat exchanger 15b: Rear heat exchanger 16: Indoor fan 16a: Fan motor 17: Frame 18: Casing 18a: Front opening 18b: Top opening 19: Upper and lower wind direction plates 20: Auxiliary wind direction plate 21: Electrical Equipment Department 22: Power line 23: Power line guide 23a: Rear guide section 24: Refrigerant leak sensor 25:Communication hole

Claims

1. An indoor unit provided in an air conditioner that uses a flammable refrigerant, The housing and a power supply line drawn into the housing from the rear side thereof; a power line guide that guides the placement of the power line within the housing; a refrigerant leakage sensor that detects leakage of the flammable refrigerant; Equipped with the refrigerant leakage sensor is located on the front side of the housing as viewed from the power line guide, The power supply line guide is provided with a communication hole that communicates an area where the refrigerant leakage sensor is located with an area on the back side as viewed from the power supply line guide. Air conditioner indoor unit.

2. a heat exchanger unit housed within the housing; a pipe connection portion for connecting the heat exchanger unit to a refrigerant pipe; the pipe connection portion is located on the rear side of the housing as seen from the power line guide, The communication hole is provided in the power line guide at a position between the pipe connection portion and the refrigerant leakage sensor. The indoor unit of an air conditioner according to claim 1.

3. the power line guide has a rear guide portion located between a rear region and a lower front region inside the housing along the up-down direction of the housing, The refrigerant leakage sensor is located in front of the rear guide portion, The communication hole is provided in the rear guide portion. The indoor unit of an air conditioner according to claim 2.

4. The communication hole is a slit or a circular hole formed in the power line guide; a gap formed between the power line guide and an adjacent component; a gap that occurs when the power line guide is divided into multiple parts; A labyrinth structure formed by overlapping a part of the power line guide with a part of an adjacent component. At least one of the following is true: The indoor unit of an air conditioner according to claim 1.

5. The flammable refrigerant contains at least one refrigerant selected from the group consisting of propane (R290), isobutane (R600a), ethane (R170), and difluoromethane (R32). The indoor unit of an air conditioner according to claim 1.

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