air conditioner

Abstract

We provide air conditioners with improved safety features. [Solution] The air conditioner of this disclosure is an air conditioner that uses a flammable refrigerant and comprises an outdoor unit having an outdoor heat exchanger, a compressor, and an expansion valve; an indoor unit having a housing positioned with its rear facing the interior wall, an indoor heat exchanger that exchanges heat with indoor air, and an indoor fan that draws indoor air to the indoor heat exchanger; and refrigerant piping connecting the outdoor heat exchanger, compressor, expansion valve, and indoor heat exchanger, through which the refrigerant circulates, wherein the housing of the indoor unit is provided with an air passage that flows from the space inside the housing toward the indoor fan.

Description

Technical Field

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

Background Art

[0002] A refrigeration cycle device using a flammable refrigerant is known. For example, Patent Document 1 discloses a refrigeration cycle device including a refrigerant circuit that circulates a flammable refrigerant, an indoor unit having a housing that houses a load-side heat exchanger of the refrigerant circuit, and a control unit that controls the indoor unit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The refrigeration cycle device of Patent Document 1 has problems in terms of safety.

[0005] The present disclosure provides an air conditioner with improved safety.

Means for Solving the Problems

[0006] The air conditioner of the present disclosure is an air conditioner using a flammable refrigerant, comprising an outdoor unit having an outdoor heat exchanger, a compressor, and an expansion valve, an indoor unit having a housing whose back faces the indoor wall surface, an indoor heat exchanger that exchanges heat with indoor air, and an indoor fan that draws the indoor air to the indoor heat exchanger, a refrigerant pipe that connects the outdoor heat exchanger, the compressor, the expansion valve, and the indoor heat exchanger and through which the refrigerant circulates, and The inside of the indoor unit's casing is provided with an airflow path that allows air to flow from the internal space of the casing toward the indoor fan. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide an air conditioner with improved safety. [Brief explanation of the drawing]

[0008] [Figure 1] Schematic diagram of an air conditioner according to Embodiment 1 of this disclosure [Figure 2] Figure 1 is a perspective view showing the exterior of the indoor unit of an air conditioner. [Figure 3] Figure 2 shows a cross-sectional view of the indoor unit (AA). [Figure 4] Schematic diagram showing the internal configuration of the indoor unit of the air conditioner according to Embodiment 2. [Figure 5] Perspective view showing the indoor unit of the air conditioner according to Embodiment 3. [Figure 6] Figure 5 is a cross-sectional perspective view showing the BB cross-section of the indoor unit. [Figure 7] Enlarged view of region A1 in Figure 6. [Figure 8] Figure 5 shows a cross-sectional view of the indoor unit's CC (Cross-Cross Section). [Figure 9] Perspective view showing the indoor unit of an air conditioner according to Embodiment 4 [Figure 10] Figure 9 shows a cross-sectional view of the indoor unit (DD). [Figure 11] Block diagram showing an air conditioner according to Embodiment 5 [Modes for carrying out the invention]

[0009] (Background leading to this disclosure) Air conditioners widely use refrigerants such as R410A or R32. However, from the perspective of preventing global warming, there is a need to use refrigerants with a lower global warming potential (GWP).

[0010] As a refrigerant with a low GWP, for example, propane or the like is being considered. Since refrigerants such as propane are flammable, there is a risk that a flammable concentration region may be formed indoors if the refrigerant leaks in the indoor unit, and there are issues in terms of safety. Therefore, even if the refrigerant leaks, measures are required to prevent the formation of a flammable concentration region indoors. The flammable concentration region is a region where a mixture of refrigerant and air that has the potential to burn exists.

[0011] The inventor(s) considered that when the refrigerant leaks inside the indoor unit, by diffusing the refrigerant into the room by the indoor fan, it is possible to suppress the formation of a flammable concentration region indoors and improve safety, and arrived at the following invention.

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings in some cases. However, the following embodiments are examples for explaining the present disclosure, and are not intended to limit the present disclosure to the following contents (for example, the shape, dimensions, arrangement, etc. of each component). The positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings unless otherwise specified. Each drawing described in the following embodiments is a schematic drawing, and the ratios of the sizes and thicknesses of each component in each drawing do not necessarily reflect the actual dimensional ratios. Also, the dimensional ratios of each element are not limited to the ratios shown in the drawings.

[0013] In the following description, when it is necessary to distinguish between a plurality of components from each other, prefixes such as "first" and "second" are attached to the names of the components. However, when the components can be distinguished from each other by the reference numerals attached to the components, the prefixes such as "first" and "second" may be omitted in consideration of the readability of the text.

[0014] (Embodiment 1) [Overall Configuration] FIG. 1 is a schematic view of an air conditioner 10 according to Embodiment 1 of the present disclosure. FIG. 2 is a perspective view showing the appearance of the indoor unit 20 of the air conditioner 10 in FIG. 1. FIG. 3 is a cross-sectional view taken along the line A-A of the indoor unit 20 in FIG. 2. Note that the X-Y-Z orthogonal coordinate system shown in the figures is for facilitating the understanding of the present disclosure and does not limit the embodiments of the present disclosure. The X-axis direction indicates the lateral direction of the indoor unit 20, the Y-axis direction indicates the depth direction of the indoor unit 20, and the Z-axis direction indicates the height direction of the indoor unit 20.

[0015] As shown in FIG. 1, the air conditioner 10 according to the present embodiment includes an indoor unit 20 disposed in the indoor space Rin to be air-conditioned, an outdoor unit 30 disposed in the outdoor space Rout, and a refrigerant pipe 50.

[0016] The outdoor unit 30 has an outdoor heat exchanger 32, a compressor 36, and an expansion valve 38. The indoor unit 20 has a housing 21, an indoor heat exchanger 22, and an indoor fan 24. The indoor unit 20 is arranged such that the rear surface 21a of the housing 21 faces the wall surface W1 of the indoor space Rin. The refrigerant pipe 50 connects the outdoor heat exchanger 32, the compressor 36, the expansion valve 38, and the indoor heat exchanger 22. Refrigerant circulates in the refrigerant pipe 50. In the present embodiment, a flammable refrigerant composed of, for example, propane (R290), isobutane (R600a), ethane (R170), etc. is used as the refrigerant.

[0017] As shown in FIG. 2, the housing 21 of the indoor unit 20 has a rear surface 21a facing the wall surface W1, a front surface 21b opposite to the rear surface 21a, and first and second side surfaces 21c and 21d connecting the rear surface 21a and the front surface 21b. Further, the housing 21 has an upper surface 21e and a bottom surface 21f and is formed in a box shape. Inside the housing 21 of the indoor unit 20, as shown in FIG. 1, there are provided an indoor heat exchanger 22 that exchanges heat with the indoor air A1, and an indoor fan 24 that draws the indoor air A1 into the indoor unit 20 and blows out the indoor air A1 that has exchanged heat with the indoor heat exchanger 22 into the indoor space Rin.

[0018] The outdoor unit 30 is equipped with an outdoor heat exchanger 32 that exchanges heat with the outdoor air A2, and a fan 34 that draws the outdoor air A2 into the outdoor unit 30 and blows the outdoor air A2, which has exchanged heat with the outdoor heat exchanger 32, out to the outdoor Rout. The outdoor unit 30 is also equipped with an indoor heat exchanger 22 and an outdoor heat exchanger 32, a compressor 36, an expansion valve 38, and a four-way valve 40 that execute the refrigeration cycle.

[0019] Each of the indoor heat exchanger 22, outdoor heat exchanger 32, compressor 36, expansion valve 38, and four-way valve 40 is connected by refrigerant piping 50 through which the refrigerant circulates.

[0020] An air passage 60 is provided inside the housing 21 of the indoor unit 20, which flows from the internal space of the housing 21 toward the indoor fan 24. The air passage 60 is a space provided from the inside of the housing 21 toward the indoor fan 24, and is an air passage for guiding the air inside the housing 21 toward the indoor fan 24. In this embodiment, as shown in Figure 3, a first air passage 61 is provided in the gap between the housing 21 of the indoor unit 20 and the indoor heat exchanger 22. In this embodiment, the first air passage 61 includes a first portion 61a provided in the gap between the indoor heat exchanger 22 and the front surface 21b of the housing 21, and a second portion 61b provided in the gap between the indoor heat exchanger 22 and the rear surface 21a of the housing 21. The first air passage 61 is formed such that, when viewed from the axial direction (X direction) of the indoor fan 24, the cross-sectional area decreases from top to bottom. The airflow from the indoor fan 24 is greater on the upper side of the indoor fan 24 compared to the lower side, so the air inside the housing 21 can be efficiently discharged into the indoor Rin.

[0021] The first airflow channel 61 can guide air from the internal space of the housing 21 of the indoor unit 20 toward the indoor fan 24. The first airflow channel 61 is an airflow channel from the space between the indoor heat exchanger 22 and the front surface 21b of the housing 21, and from the space between the indoor heat exchanger 22 and the rear surface 21a of the housing 21 toward the indoor fan 24. In the first airflow channel 61, as shown by arrows m1 to m3, air flows through the indoor heat exchanger 22 toward the indoor fan 24. With the provision of the first airflow channel 61, even if refrigerant is leaking inside the housing 21, air containing the refrigerant can be drawn toward the indoor fan 24 and discharged from inside the housing 21 toward the indoor Rin by the indoor fan 24. When the refrigerant is discharged toward the indoor Rin, it is mixed with the airflow from the indoor fan 24, which has the effect of reducing the concentration of the discharged refrigerant. By discharging air containing the refrigerant toward the indoor Rin, the refrigerant can be diffused into the air of the indoor Rin, further reducing the refrigerant concentration. Therefore, the formation of a flammable concentration region can be suppressed.

[0022] In this embodiment, the first portion 61a is formed to be larger than the second portion 61b. Since the airflow from the indoor fan 24 inside the housing 21 is greatest on the front 21b side of the housing 21, by forming the first portion 61a larger than the second portion 61b, more air inside the housing 21 can be drawn to the indoor fan 24 and discharged into the indoor Rin. As a result, more refrigerant can be discharged into the indoor Rin and diffused in the indoor Rin, thereby reducing the concentration of the refrigerant.

[0023] [effect] According to the above-described embodiment, the following effects can be achieved.

[0024] The air conditioner 10 is an air conditioner that uses a flammable refrigerant and comprises an outdoor unit 30, an indoor unit 20, and refrigerant piping 50. The outdoor unit 30 has an outdoor heat exchanger 32, a compressor 36, and an expansion valve 38. The indoor unit 20 has a housing 21 whose rear surface 21a faces the wall surface W1 of the indoor Rin, an indoor heat exchanger 22 that exchanges heat with indoor air A1, and an indoor fan 24 that draws indoor air A1 to the indoor heat exchanger 22. The refrigerant piping 50 connects the outdoor heat exchanger 32, the compressor 36, the expansion valve 38, and the indoor heat exchanger 22, and the refrigerant circulates through it. Inside the housing 21 of the indoor unit 20, there is an air passage 60 that flows from the space inside the housing 21 toward the indoor fan 24.

[0025] This configuration makes it possible to provide an air conditioner with improved safety. Because a flow path 60 is provided inside the housing 21, even if refrigerant leaks inside the housing 21, the air containing the refrigerant can be guided to the indoor fan 24 via the flow path 60 and discharged into the indoor Rin. By discharging and diffusing the refrigerant into the indoor Rin, the formation of a flammable concentration area can be suppressed.

[0026] The flow path 60 may include a first flow path 61 provided in the gap between the housing 21 and the indoor heat exchanger 22.

[0027] With this configuration, the indoor fan 24 can guide more air from inside the housing 21, thereby allowing more refrigerant leaking from inside the housing 21 to be discharged into the indoor Rin.

[0028] The first flow path 61 may include a first portion 61a between the front surface 21b of the housing 21 and the indoor heat exchanger 22, and a second portion 61b between the rear surface 21a of the housing 21 and the indoor heat exchanger 22. The first portion 61a may be larger than the second portion 61b.

[0029] With this configuration, the first section 61a, which has a larger airflow path, is positioned in the part of the housing 21 where the airflow from the indoor fan 24 is greater, so that the air inside the housing 21 can be discharged to the indoor Rin more efficiently.

[0030] (Embodiment 2) Embodiment 2 will be described with reference to Figure 4. In Embodiment 2, components that are the same as or equivalent to those in Embodiment 1 will be denoted by the same reference numerals. Also, in Embodiment 2, descriptions that are redundant with Embodiment 1 will be omitted.

[0031] Figure 4 is a schematic diagram showing the internal configuration of the indoor unit 20A of the air conditioner according to Embodiment 2. As shown in Figure 4, this embodiment differs from Embodiment 1 in that a second flow path 62 and a third flow path 63 are provided inside the housing 21.

[0032] In this embodiment, as shown in Figure 4, the refrigerant piping 50 includes a plurality of heat transfer tubes 52 arranged inside the housing 21 of the indoor unit 20A, a plurality of first bend tubes 54 connecting one end 52a of the plurality of heat transfer tubes, and a plurality of second bend tubes 56 connecting the other ends 52b of the plurality of heat transfer tubes 52. The first bend tubes 54 and the second bend tubes 56 are components that connect the plurality of heat transfer tubes 52. The bend tubes 54 and 56 have a curved shape, for example, in a U shape.

[0033] The flow path 60 includes a second flow path 62 provided in a first space R1 where a plurality of first bend pipes 54 are located, and a third flow path 63 provided in a second space R2 where a plurality of second bend pipes 56 are located. In other words, when the indoor unit 20A is viewed from the front, the inside of the housing 21 is provided with a first space R1 provided on the left side of the indoor heat exchanger 22 and a first space R2 provided on the right side. The first spaces R1 and R2 form the second flow path 62 and the third flow path 63 for guiding air to the indoor fan 24. The second flow path 62 is provided between the indoor heat exchanger 22 and the second side surface 21d of the housing 21. Similarly, the third flow path 63 is provided between the indoor heat exchanger 22 and the first side surface 21c of the housing 21.

[0034] The connections between the bend pipes 54 and 56 and the ends 52a and 52b of the heat transfer pipes 52 are more prone to refrigerant leakage compared to other parts of the refrigerant piping 50, and the leaked refrigerant tends to accumulate in the first space R1 and the second space R2. Therefore, by providing flow paths 62 and 63 toward the indoor fan 24 in the first space R1 and the second space R2, when refrigerant leaks, the air containing the refrigerant can be quickly guided toward the indoor fan 24.

[0035] [effect] According to the above-described embodiment, the following effects can be achieved.

[0036] The refrigerant piping may include a plurality of heat transfer tubes 52 arranged inside the housing 21 of the indoor unit 20A, a plurality of first bend tubes 54 connecting one end 52a of the plurality of heat transfer tubes 52, and a plurality of second bend tubes 56 connecting the other ends 52b of the plurality of heat transfer tubes 52. The flow path 60 may also include a second flow path 62 provided in a first space R1 where the plurality of first bend tubes 54 are arranged, and a third flow path 63 provided in a second space R2 where the plurality of second bend tubes 56 are arranged.

[0037] With this configuration, air can be efficiently supplied from areas R1 and R2, where leaked refrigerant tends to accumulate inside the housing 21, to the indoor fan 24, thereby suppressing the formation of flammable concentration areas.

[0038] In the embodiments described above, an example was described in which the flow path 60 includes both the second flow path 62 and the third flow path 63, but the invention is not limited to this. The flow path 60 only needs to include at least one of the second flow path 62 provided in the first space R1, or the third flow path 63 provided in the second space R2.

[0039] (Embodiment 3) Embodiment 3 will be described with reference to Figures 5 to 8. In Embodiment 3, components identical or equivalent to those in Embodiment 1 will be denoted by the same reference numerals. Also, in Embodiment 3, descriptions that overlap with those in Embodiment 1 will be omitted.

[0040] Figure 5 is a perspective view showing the indoor unit 20B of the air conditioner according to Embodiment 3. Figure 6 is a cross-sectional perspective view showing the BB cross section of the indoor unit 20B in Figure 5. Figure 7 is an enlarged view of area A1 in Figure 6. Figure 8 is a cross-sectional view CC of the indoor unit 20B in Figure 5. As shown in Figures 5 to 7, this embodiment differs from Embodiment 1 in that the indoor unit 20 further includes a fan motor 71 and a housing 72. It also differs from Embodiment 1 in that the flow path includes a fourth flow path 64 provided between the inner wall defining the through hole 74 of the housing 72 and the shaft 73 of the fan motor 71.

[0041] As shown in Figures 5 to 7, the indoor unit 20B includes a fan motor 71 that is located inside the housing 21 and drives the indoor fan 24, and a housing that accommodates the fan motor 71. In this embodiment, when viewed from the front of the indoor unit 20B, the fan motor 71 is located to the right of the indoor fan 24. The fan motor 71 has a shaft 73 that is connected to the rotation axis of the indoor fan 24. Therefore, the indoor fan 24 can be rotated by the rotation of the fan motor 71. The housing 72 is provided with a through hole 74 for arranging the shaft 73. As shown in Figure 6, the through hole 74 is formed such that its inner dimension d2 is larger than the diameter d1 of the shaft 73.

[0042] In this embodiment, as shown in Figure 7, the flow path includes a fourth flow path 64. The fourth flow path 64 is defined by the inner wall 74a of the housing 72 defining the through hole 74 and the shaft 73. The fourth flow path 64 is a flow path that guides air from the part of the housing 21 where the fan motor 71 is located toward the indoor fan 24. Because the fan motor 71 is located there, the space between the indoor heat exchanger 22 and the first side surface 21c of the housing 21 is wider than the space between the indoor heat exchanger 22 and the second side surface 21d of the housing 21. By providing the fourth flow path 64, the air between the housing 21 and the first side surface 21c can be guided toward the indoor fan 24.

[0043] As shown in Figure 8, in a cross-section perpendicular to the shaft 73, the fourth flow path 64 has a shape enclosed by a straight line and a curve. This shape of the fourth flow path 64 allows more air to be guided to the indoor fan 24.

[0044] [effect] According to the above-described embodiment, the following effects can be achieved.

[0045] The indoor unit 20B is located within the enclosure 21 and further comprises a fan motor 71 that drives the indoor fan 24, and a housing 72 that houses the fan motor 71. The fan motor 71 has a shaft 73 connected to the rotating shaft of the indoor fan 24. The housing 72 is provided with a through hole 74 into which the shaft 73 is located. The dimension d2 of the through hole 74 is larger than the diameter d1 of the shaft 73. The flow path includes a fourth flow path 64 provided between the inner wall 74a of the housing 72 defining the through hole 74 and the shaft 73.

[0046] With this configuration, the air in the area where the fan motor 71 is located is guided to the indoor fan 24, and the air inside the housing 21 can be efficiently discharged into the indoor Rin.

[0047] (Embodiment 4) Embodiment 4 will be described with reference to Figures 9 to 10. In Embodiment 4, components identical or equivalent to those in Embodiment 1 will be denoted by the same reference numerals. Also, in Embodiment 4, descriptions that overlap with those in Embodiment 1 will be omitted.

[0048] Figure 9 is a perspective view showing the indoor unit 20C of the air conditioner according to Embodiment 4. Figure 10 is a cross-sectional view of the indoor unit 20C of Figure 9. As shown in Figures 9 to 10, this embodiment differs from Embodiment 1 in that an opening 75 is provided in the housing 21. This embodiment also differs from Embodiment 1 in that the flow path includes a fifth flow path 65 that goes from the opening 75 to the indoor fan 24.

[0049] As shown in Figures 9 and 10, a plurality of openings 75 are provided on the rear surface 21a of the housing 21. The openings 75 allow the inside of the housing 21 to communicate with the outside of the housing 21. In this embodiment, the plurality of openings 75 are provided on the rear surface 21a of the housing 21, facing the indoor fan 24.

[0050] In this embodiment, the flow path includes a fifth flow path 65 that flows from the opening 75 toward the indoor fan 24. In this embodiment, the fifth flow path 65 is provided from the opening 75 located on the back surface 21a of the housing 21 toward the indoor fan 24. If refrigerant leaks inside the housing 21, it tends to accumulate near the back surface 21a of the housing 21. Therefore, by providing the fifth flow path 65 on the back surface 21a side of the housing 21, if refrigerant leaks, the air containing the refrigerant can be efficiently guided toward the indoor fan 24, thereby suppressing the formation of a flammable concentration region.

[0051] [effect] According to the above-described embodiment, the following effects can be achieved.

[0052] The housing 21 of the indoor unit 20C is provided with an opening 75 located facing the indoor fan 24 and communicating with the outside of the housing 21. The flow path includes a fifth flow path 65 that flows from the opening 75 to the indoor fan 24.

[0053] This configuration allows for more efficient discharge of air from inside the housing 21 to the indoor Rin, thereby suppressing the formation of a flammable concentration region. Since the opening 75 communicates with the outside of the housing 21, the fifth flow path 65 can guide air from outside the housing 21 towards the indoor fan 24. Therefore, even if refrigerant leaks inside the housing 21, air from outside the housing 21 can be taken in and guided to the indoor fan 24, thereby further reducing the refrigerant concentration in the air.

[0054] The fifth flow path 65 may be provided from an opening 75 on the rear surface 21a of the housing 21 toward the indoor fan 24.

[0055] This configuration allows air to be guided from the rear surface 21a of the housing 21, where refrigerant tends to accumulate, to the indoor fan 24, thereby suppressing the formation of a flammable concentration region.

[0056] In the above-described embodiment, an example was given in which the opening 75 is located on the rear surface 21a of the housing 21 and faces the indoor fan 24, but the invention is not limited to this. The opening 75 may be located on any part of the housing 21, and may be located in a position facing the indoor heat exchanger 22. For example, the opening 75 may be located on the front surface 21b or top surface 21e of the housing 21, or in a position facing the indoor heat exchanger 22.

[0057] Furthermore, although the above-described embodiment described an example in which multiple openings 75 are provided in the housing 21, the invention is not limited to this. It is sufficient to provide one or more openings 75.

[0058] (Embodiment 5) Embodiment 5 will be described with reference to Figure 11. In Embodiment 5, components that are the same as or equivalent to those in Embodiment 1 will be denoted by the same reference numerals. Also, in Embodiment 5, descriptions that overlap with those in Embodiment 1 will be omitted.

[0059] Figure 11 is a block diagram showing an air conditioner 10A according to Embodiment 5. As shown in Figure 11, this embodiment differs from Embodiment 1 in that the air conditioner 10A is equipped with a control unit 80 and the indoor unit 20C has a sensor 81 that detects refrigerant gas within the housing 21.

[0060] The control unit 80 controls the outdoor unit 30 and the indoor unit 20C. The control unit 80 includes, for example, a memory that stores a program and a processing circuit corresponding to a processor such as a CPU (Central Processing Unit). The functions of the control unit 80 may be composed solely of hardware, or they may be realized by a combination of hardware and software. The control unit 80 realizes predetermined functions by reading data and programs stored in memory and performing various calculations.

[0061] Sensor 81 is a sensor capable of detecting the refrigerant gas inside the housing 21. For example, a gas sensor capable of detecting the concentration of refrigerant gas in the air can be used as sensor 81.

[0062] The control unit 80 activates the indoor fan 24 when the sensor 81 detects refrigerant gas inside the housing 21. By activating the indoor fan 24 when the sensor 81 detects refrigerant gas, the leaked refrigerant can be diffused into the indoor Rin. Alternatively, the control unit 80 may increase the airflow of the indoor fan 24 when the sensor 81 detects refrigerant gas. By increasing the airflow of the indoor fan 24, the refrigerant gas inside the housing 21 can be efficiently diffused into the indoor Rin.

[0063] [effect] According to the above-described embodiment, the following effects can be achieved.

[0064] The system may further include a control unit 80 that controls the outdoor unit 30 and the indoor unit 20. The indoor unit 20 may further include a sensor 81 that detects refrigerant gas inside the housing 21. The control unit 80 may operate the indoor fan 24 when the sensor 81 detects refrigerant gas.

[0065] With this configuration, when refrigerant gas is detected, the airflow of the indoor fan 24 is increased, allowing the refrigerant that has leaked into the inside of the housing 21 to be efficiently diffused into the indoor Rin.

[0066] (Summary of the embodiment) (Note) Based on the above description of embodiments, the following technologies are disclosed.

[0067] (Technology 1) An air conditioner using a flammable refrigerant, comprising: an outdoor unit having an outdoor heat exchanger, a compressor, and an expansion valve; an indoor unit having a housing positioned with its rear facing the interior wall; an indoor heat exchanger that exchanges heat with the indoor air; an indoor fan that draws the indoor air to the indoor heat exchanger; and refrigerant piping connecting the outdoor heat exchanger, compressor, expansion valve, and indoor heat exchanger, through which the refrigerant circulates, wherein the housing of the indoor unit is provided with an air passage that flows from the space inside the housing toward the indoor fan.

[0068] This configuration makes it possible to provide an air conditioner with improved safety. Because a flow path is provided inside the casing, even if refrigerant leaks inside the casing, the air containing the refrigerant can be guided through the flow path to the indoor fan and discharged into the room. By discharging and diffusing the refrigerant into the room, the formation of a flammable concentration zone can be suppressed.

[0069] (Technology 2) The air conditioner according to Technology 1, wherein the flow path includes a first flow path provided in the gap between the housing and the indoor heat exchanger.

[0070] This configuration allows more air to be directed to the indoor fan, thus enabling more refrigerant leaking from inside the enclosure to be discharged into the room.

[0071] (Technical 3) The air conditioner according to Technical 2, wherein the first flow path includes a first portion between the front of the housing and the indoor heat exchanger, and a second portion between the rear of the housing and the indoor heat exchanger, the first portion being larger than the second portion.

[0072] With this configuration, the first section, which has a larger airflow path, is positioned in the part of the enclosure where the airflow from the indoor fan is greater, allowing the air inside the enclosure to be discharged into the room more efficiently.

[0073] (Technology 4) An air conditioner according to any one of Technologies 1 to 3, wherein the refrigerant piping comprises a plurality of heat transfer tubes arranged inside the housing of the indoor unit, a plurality of first bend tubes connecting one end of the plurality of heat transfer tubes to each other, and a plurality of second bend tubes connecting the other ends of the plurality of heat transfer tubes, and the flow path includes at least one of a second flow path provided in a first space where the plurality of first bend tubes are arranged, or a third flow path provided in a second space where the plurality of second bend tubes are arranged.

[0074] This configuration allows for efficient airflow from areas within the enclosure where leaked refrigerant tends to accumulate to the indoor fan, thereby suppressing the formation of flammable concentration zones.

[0075] (Technology 5) An air conditioner according to any one of Technologies 1 to 4, wherein the indoor unit further comprises a fan motor disposed within a casing for driving an indoor fan, and a housing for housing the fan motor, the fan motor having a shaft connected to the rotation axis of the indoor fan, the housing having a through hole in which the shaft is disposed, the dimensions of the through hole being larger than the diameter of the shaft, and the flow path including a fourth flow path provided between the inner wall of the housing defining the through hole and the shaft.

[0076] This configuration allows the air from the area where the fan motor is located to be guided to the indoor fan, enabling efficient exhaust of air from inside the enclosure into the room.

[0077] (Technology 6) An air conditioner according to any one of Technologies 1 to 5, wherein the housing is provided with an opening that is located facing an indoor heat exchanger or an indoor fan and communicates with the outside of the housing, and the flow path includes a fifth flow path that goes from the opening to the indoor fan.

[0078] This configuration allows for more efficient exhaust of air from inside the enclosure into the room, suppressing the formation of a flammable concentration zone. Because the opening communicates with the outside of the enclosure, the fifth flow path can guide air from outside the enclosure towards the indoor fan. Therefore, even if refrigerant leaks inside the enclosure, air from outside the enclosure can be drawn in and guided to the indoor fan, further reducing the refrigerant concentration in the air.

[0079] (Technical 7) The air conditioner described in Technical 6, wherein the fifth flow path is provided from an opening on the back of the housing toward the indoor fan.

[0080] This configuration allows air to be guided from the back of the enclosure, where refrigerant tends to accumulate, to the indoor fan, thereby suppressing the formation of a flammable concentration region.

[0081] (8) An air conditioner according to any one of technologies 1 to 7, further comprising a control unit for controlling an outdoor unit and an indoor unit, wherein the indoor unit further comprises a sensor for detecting refrigerant gas inside the housing, and the control unit operates an indoor fan when the sensor detects refrigerant gas.

[0082] This configuration allows the airflow of the indoor fan to be increased when refrigerant gas is detected, efficiently diffusing any refrigerant that has leaked into the enclosure into the room. [Industrial applicability]

[0083] This disclosure can be broadly applied to air conditioners that use flammable refrigerants. [Explanation of Symbols]

[0084] 10, 10A air conditioner 20, 20A~20C indoor unit 21 cabinets 21a Back 21b Front 22 Indoor heat exchanger 24 Indoor Fan 30 Outdoor unit 32 Outdoor heat exchanger 34 Fans 36 Compressor 38 Expansion valve 40 Square valve 50 Refrigerant piping 52 Heat transfer tubes 54 First Bend Pipe 56. Second bend pipe 60 flow channels 61 First channel 61a Part 1 61b Part 2 62 Second channel 63 Third channel 64 Fourth channel 65 Fifth channel 71 Fan motor 72 Housing 73 Shaft 74 Through holes 74a Internal wall 75 Aperture 80 Control Unit 81 Sensors

Claims

1. An air conditioner that uses a flammable refrigerant, An outdoor unit having an outdoor heat exchanger, a compressor, and an expansion valve, An indoor unit comprising: a housing positioned with its rear facing the interior wall; an indoor heat exchanger that exchanges heat with the interior air; and an indoor fan that draws the interior air to the indoor heat exchanger; The outdoor heat exchanger, the compressor, the expansion valve, and the indoor heat exchanger are connected by refrigerant piping through which the refrigerant circulates, Equipped with, The inside of the indoor unit's casing is provided with an airflow path that directs air from the internal space of the casing toward the indoor fan. Air conditioner.

2. The aforementioned flow path includes a first flow path provided in the gap between the housing and the indoor heat exchanger. The air conditioner according to claim 1.

3. The first flow path includes a first portion between the front of the housing and the indoor heat exchanger, and a second portion between the rear of the housing and the indoor heat exchanger. The first part is larger than the second part. The air conditioner according to claim 2.

4. The refrigerant piping comprises a plurality of heat transfer tubes arranged within the housing of the indoor unit, a plurality of first bend tubes connecting one end of the plurality of heat transfer tubes, and a plurality of second bend tubes connecting the other ends of the plurality of heat transfer tubes. The flow path includes at least one of a second flow path provided in the first space where the plurality of first bend pipes are arranged, or a third flow path provided in the second space where the plurality of second bend pipes are arranged. The air conditioner according to claim 1.

5. The indoor unit further comprises a fan motor that drives the indoor fan and is located within the enclosure, and a housing that accommodates the fan motor. The fan motor has a shaft connected to the rotating shaft of the indoor fan, The housing is provided with a through hole in which the shaft is placed. The dimensions of the through-hole are larger than the diameter of the shaft. The flow path includes a fourth flow path provided between the inner wall of the housing defining the through hole and the shaft, The air conditioner according to claim 1.

6. The housing is provided with an opening that is positioned facing the indoor heat exchanger or the indoor fan and communicates with the outside of the housing. The aforementioned flow path includes a fifth flow path leading from the opening to the indoor fan, The air conditioner according to claim 1.

7. The fifth flow path is provided from an opening on the rear of the housing toward the indoor fan. The air conditioner according to claim 6.

8. The system further comprises a control unit for controlling the outdoor unit and the indoor unit, The indoor unit further includes a sensor for detecting the refrigerant gas inside the housing, The control unit operates the indoor fan when the sensor detects refrigerant gas. The air conditioner according to claim 1.

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