air conditioning

Abstract

Air conditioning system that uses a flammable refrigerant, including: an outdoor unit with an outdoor heat exchanger, a compressor and an expansion valve; an indoor unit comprising a housing having a rear surface facing a wall surface of a room in which it is to be installed, an internal heat exchanger that exchanges heat with indoor air, and an internal fan that draws the indoor air into the internal heat exchanger; and a refrigerant line that connects the outdoor heat exchanger, the compressor, the expansion valve and the indoor heat exchanger, and through which a refrigerant circulates, wherein a flow path for air is provided from a space inside the housing towards the internal fan inside the housing of the indoor unit.

Description

TECHNICAL AREA

[0001] The present disclosure relates to an air conditioning system. STATE OF THE ART

[0002] A refrigeration circuit device using a flammable refrigerant is known. For example, patent document 1 discloses a refrigeration circuit device comprising a refrigeration circuit circulating a flammable refrigerant, an indoor unit with a housing that accommodates a load-side heat exchanger of the refrigeration circuit, and a control device that controls the indoor unit. DOCUMENT ON THE STATUS OF THE TECHNICAL PATENT PUBLICATION

[0003] Patent specification 1: WO 2017 / 187618 A SUMMARY Problems to be solved by the invention

[0004] The refrigeration circuit device of patent document 1 has a safety problem.

[0005] The present disclosure offers an air conditioning system with improved safety. Solutions to the problems

[0006] An air conditioning system according to one aspect of the present air conditioning system, which uses a flammable refrigerant, comprises: an outdoor unit having an outdoor heat exchanger, a compressor and an expansion valve; an indoor unit having an enclosure with a rear surface facing a wall surface of a room in which it is to be installed, an indoor heat exchanger exchanging heat with indoor air, and an indoor fan drawing the indoor air into the indoor heat exchanger; and a refrigerant line connecting the outdoor heat exchanger, the compressor, the expansion valve and the indoor heat exchanger, and through which a refrigerant circulates, providing a flow path for air from a space within the enclosure towards the indoor fan within the enclosure of the indoor unit. Effects of the invention

[0007] According to the present disclosure, it is possible to equip the air conditioning system with improved safety. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic diagram of an air conditioning system according to a first embodiment of the present disclosure; Fig. Figure 2 is a perspective view showing the appearance of an indoor unit of the air conditioner. Fig. 1 shows; Fig. 3 is a sectional view AA of the indoor unit in Fig. 2; Fig. Figure 4 is a schematic diagram showing an internal configuration of an indoor unit of an air conditioner according to a second embodiment; Fig. Figure 5 is a perspective view showing an indoor unit of an air conditioning system of a third embodiment; Fig. 6 is a perspective sectional view showing section BB of the indoor unit in Fig. 5 shows; Fig. Figure 7 is an enlarged view of segment A1 in Fig. 6; Fig. 8 is a sectional view CC of the indoor unit in Fig. 5; Fig. Figure 9 is a perspective view showing an indoor unit of an air conditioning system of a fourth embodiment; Fig. 10 is a sectional view DD of the indoor unit in Fig. 9; and Fig. Figure 11 is a block diagram showing an air conditioning system according to a fifth embodiment. DETAILED DESCRIPTION (Background to the present disclosure)

[0008] Air conditioning systems, for example, often use refrigerants such as R410A and R32. However, from the perspective of preventing global warming, it is necessary to use refrigerants with a lower global warming potential (GWP).

[0009] For example, the use of propane and similar refrigerants with a low GWP is being investigated. Since refrigerants like propane are flammable, a leak in an indoor unit, for instance, can create a flammable concentration in a room, which is problematic from a safety perspective. Therefore, a measure is needed to prevent the formation of a region with a flammable concentration in the room following a refrigerant leak. A region of flammable concentration is an area where a gas mixture of refrigerant and air is present that can cause combustion.

[0010] The inventor(s) of the present disclosure have concerned themselves with improving the safety by which, in the event of a refrigerant leak in the indoor unit, the refrigerant is distributed (diffused) into the room by means of an indoor fan in order to limit the formation of the region with flammable concentration in the room, and have thus arrived at the following invention.

[0011] The following describes embodiments of the present disclosure, with reference in some cases to the drawings. However, the following embodiments are merely examples used to describe the present disclosure and are not intended to limit the present disclosure to the following content (e.g., shapes, dimensions, arrangement, and the like of components). The positional relationship between top, bottom, left, right, and the like is based on the positional relationship shown in the drawings, unless otherwise specified. The drawings used to describe the following embodiments are schematic. The size and thickness ratios of the components shown in the drawings do not necessarily correspond to the actual size ratios. The size ratios of the components are not limited to those shown in the drawings.

[0012] It should be noted that in the following description, if it is necessary to distinguish between several components, prefixes such as 'first' and 'second' are appended to the names of the components; however, if the components can be distinguished from one another by reference marks attached to the components, the prefixes such as 'first' and 'second' may be omitted for the sake of readability. (First embodiment) [Overall configuration]

[0013] Fig. Figure 1 is a schematic diagram of an air conditioning system 10 according to a first embodiment of the present disclosure. Fig. Figure 2 is a perspective view showing the appearance of an indoor unit 20 of the air conditioner 10 in Fig. 1 shows. Fig. 3 is a sectional view AA of the indoor unit 20 in Fig. 2. It should be noted that the Cartesian XYZ coordinate system shown in the drawings serves to better understand the present disclosure and does not limit the embodiments of the present disclosure. An X-axis direction indicates a lateral direction of the indoor unit 20, a Y-axis direction indicates a depth direction of the indoor unit 20, and a Z-axis direction indicates a height direction of the indoor unit 20.

[0014] As in Fig. As shown in Figure 1, the air conditioning system 10 according to the present embodiment comprises the indoor unit 20, which is arranged in a room Rin to be air-conditioned, an outdoor unit 30, which is arranged in an outdoor room Rout, and refrigerant lines 50.

[0015] The outdoor unit 30 comprises an outdoor heat exchanger 32, a compressor 36, and an expansion valve 38. The indoor unit 20 comprises a housing 21, an indoor heat exchanger 22, and an indoor fan 24. The indoor unit 20 is arranged such that a rear surface 21a of the housing 21 faces a wall surface W1 of room Rin. The refrigerant lines 50 connect the outdoor heat exchanger 32, the compressor 36, the expansion valve 38, and the indoor heat exchanger 22. A refrigerant circulates through the refrigerant lines 50. In the present embodiment, a flammable refrigerant such as propane (R290), isobutane (R600a), ethane (R170), or the like is used as the refrigerant.

[0016] As in Fig. As shown in Figure 2, the housing 21 of the indoor unit 20 has a rear surface 21a facing the wall surface W1, a front surface 21b opposite the rear surface 21a, and a first side surface 21c and a second side surface 21d connecting the rear surface 21a and the front surface 21b. The housing 21 also has a top surface 21e and a bottom surface 21f and is box-shaped. As shown in Fig. As shown in Figure 1, the housing 21 of the indoor unit 20 is equipped inside with the indoor heat exchanger 22, which exchanges heat with the indoor air A1, and the indoor fan 24, which draws the indoor air A1 into the indoor unit 20 and blows the indoor air A1 into the room Rin after heat exchange with the indoor heat exchanger 22.

[0017] The outdoor unit 30 is equipped with an outdoor heat exchanger 32, which exchanges heat with the outside air A2, and with a fan 34, which draws the outside air A2 into the outdoor unit 30 and blows the outside air A2 into the outdoor room Rout after heat exchange with the outdoor heat exchanger 32. The outdoor unit 30 is also equipped with the compressor 36, the expansion valve 38 and a four-way valve 40, which together with the indoor heat exchanger 22 and the outdoor heat exchanger 32 form a refrigeration circuit.

[0018] The internal heat exchanger 22, the external heat exchanger 32, the compressor 36, the expansion valve 38 and the four-way valve 40 are connected by the refrigerant lines 50 through which the refrigerant circulates.

[0019] An airflow path 60 from a space within the housing 21 towards the internal fan 24 is provided within the housing 21 of the indoor unit 20. The airflow path 60 is a space provided from the interior of the housing 21 towards the internal fan 24 and is a flow path that directs air within the housing 21 to the internal fan 24. In the present embodiment, as shown in Fig. Figure 3 shows a first flow path 61 provided in gaps (free spaces) between the housing 21 of the indoor unit 20 and the internal heat exchanger 22. In the present embodiment, the first flow path 61 comprises a first section 61a, which is provided in a gap between the internal heat exchanger 22 and the front surface 21b of the housing 21, and a second section 61b, which is provided in a gap between the internal heat exchanger 22 and the rear surface 21a of the housing 21. The first flow path 61 is designed such that the cross-sectional areas decrease downwards from the axial direction (X-direction) of the internal fan 24. Since the airflow caused by the internal fan 24 is greater at the top of the internal fan 24 than at the bottom, the air inside the housing 21 can be efficiently discharged into the space Rin.

[0020] The first flow path 61 can direct air from spaces within the housing 21 of the indoor unit 20 towards the indoor fan 24. The first flow path 61 is an airflow path towards the indoor fan 24 from a space between the indoor heat exchanger 22 and the front surface 21b of the housing 21, and is a flow path towards the indoor fan 24 from a space between the indoor heat exchanger 22 and the rear surface 21a of the housing 21. In the first flow path 61, air flows through the indoor heat exchanger 22 towards the indoor fan 24, as indicated by arrows m1 to m3. The first flow path 61 is designed so that even if the refrigerant escapes inside the housing 21, the air containing the refrigerant can be drawn into the internal blower 24 and discharged from inside the housing 21 through the internal blower 24 into the space Rin.As the refrigerant is discharged into room Rin, it is mixed with an airflow generated by the internal fan 24, thus reducing its concentration. The air containing the refrigerant is then discharged into room Rin, and the refrigerant diffuses into the air within room Rin, further reducing its concentration. This helps to prevent the formation of a region with a flammable concentration.

[0021] In the present embodiment, the first section 61a is larger than the second section 61b. The airflow generated by the internal fan 24 inside the housing 21 is greatest at the front surface 21b of the housing 21, and the first section 61a is larger than the second section 61b. This allows more air inside the housing 21 to be drawn into the internal fan 24 and discharged into space Rin. Thus, the refrigerant concentration can be reduced while more refrigerant is discharged into space Rin and distributed within it. [Effects]

[0022] According to the embodiment described above, the following effects can be achieved.

[0023] The air conditioner 10 is an air conditioner that uses a flammable refrigerant and comprises the outdoor unit 30, the indoor unit 20, and the refrigerant lines 50. The outdoor unit 30 includes the outdoor heat exchanger 32, the compressor 36, and the expansion valve 38. The indoor unit 20 comprises the housing 21, which has the rear surface 21a facing the wall surface W1 of room Rin, the indoor heat exchanger 22, which exchanges heat with the indoor air A1, and the indoor fan 24, which draws the indoor air A1 into the indoor heat exchanger 22. The refrigerant lines 50 connect the outdoor heat exchanger 32, the compressor 36, the expansion valve 38, and the indoor heat exchanger 22, and the refrigerant circulates through them. The airflow path 60 from the space inside the housing 21 towards the indoor fan 24 is provided inside the housing 21 of the indoor unit 20.

[0024] With such a configuration, air conditioning systems with improved safety can be provided. The flow path 60 is located within the housing 21, so that even if the refrigerant escapes within the housing 21, the air containing the refrigerant can be guided through the flow path 60 to the internal fan 24 and discharged into space Rin. The refrigerant is discharged into space Rin and distributed there, thus suppressing the formation of a region with a flammable concentration.

[0025] The flow path 60 can include the first flow path 61, which is provided in the gaps between the housing 21 and the internal heat exchanger 22.

[0026] With such a configuration, the air inside the housing 21 can be directed more towards the internal blower 24, so that the refrigerant escaping inside the housing 21 can be discharged more into the room Rin.

[0027] The first flow path 61 can comprise the first section 61a between the front surface 21b of the housing 21 and the internal heat exchanger 22, and the second section 61b between the rear surface 21a of the housing 21 and the internal heat exchanger 22. The first section 61a can be larger than the second section 61b.

[0028] With such a configuration, the first section 61a, which serves as a larger flow path, is arranged in a section with a larger airflow caused by the internal blower 24 inside the housing 21, so that the air inside the housing 21 can be discharged more efficiently into the space Rin. (Second embodiment)

[0029] A second embodiment is described with reference to Fig. 4. In the second embodiment, identical or equivalent components as in the first embodiment are designated with the same reference numerals as in the first embodiment. In the second embodiment, any description that overlaps with that of the first embodiment is omitted.

[0030] Fig. Figure 4 is a schematic diagram showing an internal configuration of an indoor unit 20A of an air conditioner according to the second embodiment. As shown in Fig. As shown in Figure 4, the present embodiment differs from the first embodiment in that a second flow path 62 and a third flow path 63 are provided within a housing 21.

[0031] In the present embodiment, as in Fig. As shown in Figure 4, the refrigerant lines 50 comprise several heat transfer tubes 52 arranged in the housing 21 of the indoor unit 20A, several first curved tubes 54 connecting one end 52a of the several heat transfer tubes, and several second curved tubes 56 connecting the other end 52b of the several heat transfer tubes 52. The first curved tubes 54 and the second curved tubes 56 are components that connect the several heat transfer tubes 52. The curved tubes 54 and 56 each have, for example, a U-shaped bend.

[0032] A flow path 60 comprises the second flow path 62, which is provided in a first chamber R1 in which several first curved tubes 54 are arranged, and the third flow path 63, which is provided in a second chamber R2 in which several second curved tubes 56 are arranged. In other words, when the indoor unit 20A is viewed from the front, the first chamber R1, which is provided on the left side of an internal heat exchanger 22, and the second chamber R2, which is provided on the right side, are located within the housing 21. The first chamber R1 and the second chamber R2 form the second flow path 62 and the third flow path 63, which direct air to an internal fan 24. The second flow path 62 is provided between the internal heat exchanger 22 and a second side surface 21d of the housing 21. Similarly, the third flow path 63 is provided between the internal heat exchanger 22 and a first side surface 21c of the housing 21.

[0033] In the connecting sections between the curved tubes 54 and the ends 52a of the heat transfer tubes 52, as well as between the curved tubes 56 and the ends 52b of the heat transfer tubes 52, refrigerant is more likely to leak in the refrigerant lines 50 compared to other sections. Consequently, any escaping refrigerant is more likely to accumulate in the first chamber R1 and the second chamber R2. Here, flow paths 62 and 63 are provided in the direction of the internal fan 24 in the first chamber R1 and the second chamber R2, respectively, so that air containing refrigerant can be immediately directed towards the internal fan 24 in the event of a refrigerant leak. [Effects]

[0034] According to the embodiment described above, the following effects can be achieved.

[0035] The refrigerant lines can comprise the multiple heat transfer tubes 52 arranged in the housing 21 of the indoor unit 20A, wherein the multiple first curved tubes 54 connect one end 52a of the multiple heat transfer tubes 52 to one another, and the multiple second curved tubes 56 connect the other end 52b of the multiple heat transfer tubes 52 to one another. The flow path 60 can comprise the second flow path 62, which is provided in the first space R1 in which the multiple first curved tubes 54 are arranged, and the third flow path 63, which is provided in the second space R2 in which the multiple second curved tubes 56 are arranged.

[0036] With such a configuration, air can be efficiently supplied from spaces R1 and R2, where escaping refrigerant can accumulate, into the housing 21 to the internal blower 24, thus suppressing the formation of a region with flammable concentration.

[0037] In the embodiment 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; however, the present embodiment is not limited to this. The flow path 60 can also include at least one of the two flow paths, namely the second flow path 62, which is provided in the first chamber R1, and the third flow path 63, which is provided in the second chamber R2. (Third embodiment)

[0038] A third embodiment is described with reference to the Fig. Sections 5 to 8 are described. In the third embodiment, the same or equivalent components as in the first embodiment are identified with the same reference numerals as those in the first embodiment. In the third embodiment, any description that overlaps with that of the first embodiment is omitted.

[0039] Fig. Figure 5 is a perspective view showing an indoor unit 20B of an air conditioner in the third embodiment. Fig. Figure 6 is a perspective sectional view showing section BB of indoor unit 20B in Fig. 5 shows. Fig. Figure 7 is an enlarged view of segment A1 in Fig. 6. Fig. 8 is a sectional view CC of the indoor unit 20B in Fig. 5. As in the Fig. As shown in Figures 5 to 7, the present embodiment differs from the first embodiment in that the indoor unit 20B further comprises a blower motor 71 and a housing 72. Furthermore, the present embodiment differs from the first embodiment in that a flow path includes a fourth flow path 64, which is provided between an inner wall defining a through-hole 74 of the housing 72 and a shaft 73 of the blower motor 71.

[0040] As in the Fig. As shown in Figures 5 to 7, the indoor unit 20B comprises the blower motor 71, which is arranged in a housing 21 and drives an indoor blower 24, as well as the housing in which the blower motor 71 is located. In the present embodiment, the blower motor 71, viewed from the front of the indoor unit 20B, is located on the right side of the indoor blower 24. The blower motor 71 includes the shaft 73, which is connected to a shaft of the indoor blower 24. Thus, the indoor blower 24 can be set in rotation by turning the blower motor 71. The housing 72 is provided with a through-hole 74 for receiving the shaft 73. As shown in Fig. As shown in Figure 7, the through hole 74 is shaped such that a dimension d2 on its inside is larger than a diameter d1 of the shaft 73.

[0041] In the present embodiment, as in Fig. As shown in Figure 7, the flow path includes the fourth flow path 64. The fourth flow path 64 is defined by the shaft 73 and an inner wall 74a of the housing 72, which has the through-hole 74. The fourth flow path 64 is a path that directs air from a section in which the blower motor 71 is located inside the housing 21 towards the inner blower 24. Because of the blower motor 71, the space between an inner blower 22 and a first side surface 21c of the housing 21 is wider than the space between the inner blower 22 and a second side surface 21d of the housing 21. The fourth flow path 64 is designed to direct the air between the inner heat exchanger 22 and the first side surface 21c to the inner blower 24.

[0042] As in Fig. As shown in Figure 8, the fourth flow path 64 has a shape that, in a section perpendicular to the shaft 73, is enclosed by a straight line and a curved line. The fourth flow path 64 is shaped such that the air can be directed more effectively to the internal blower 24. [Effects]

[0043] According to the embodiment described above, the following effects can be achieved.

[0044] The indoor unit 20B comprises the blower motor 71, which is arranged in the housing 21 and drives the indoor blower 24, and the housing 72 in which the blower motor 71 is located. The blower motor 71 includes the shaft 73, which is connected to the shaft of the indoor blower 24. The housing 72 is provided with the through-hole 74 in which the shaft 73 is arranged. The dimension d2 of the through-hole 74 is larger than the diameter d1 of the shaft 73. The flow path includes the fourth flow path 64, which is provided between the inner wall 74a of the housing 72, which defines the through-hole 74, and the shaft 73.

[0045] With such a configuration, the air in the section where the blower motor 71 is located can be directed to the internal blower 24, so that the air inside the housing 21 can be efficiently discharged into a space Rin. (Fourth embodiment)

[0046] A fourth embodiment is described with reference to the Fig. 9 and Fig. 10. In the fourth embodiment, the same or equivalent components as those of the first embodiment are identified with the same reference numerals as those of the first embodiment. In the fourth embodiment, a description that overlaps with that of the first embodiment is omitted.

[0047] Fig. Figure 9 is a perspective view showing an indoor unit 20C of an air conditioner in the fourth embodiment. Fig. 10 is a sectional view DD of the indoor unit 20C in Fig. 9. As in Fig. 9 and Fig. As shown in Figure 10, the present embodiment differs from the first embodiment in that a housing 21 is provided with openings 75. The present embodiment also differs from the first embodiment in that a flow path comprises five flow paths 65 from the openings 75 in the direction of an internal fan 24.

[0048] As in the Fig. 9 and Fig. As shown in Figure 10, several openings 75 are provided in a rear surface 21a of the housing 21. The openings 75 allow the interior and exterior of the housing 21 to communicate with each other. In the present embodiment, the multiple openings 75 are located at positions in the rear surface 21a of the housing 21 that face the internal fan 24.

[0049] In the present embodiment, the flow path comprises the fifth flow paths 65 extending from the openings 75 towards the internal fan 24. In this embodiment, the fifth flow paths 65 extend from the openings 75 provided in the rear surface 21a of the housing 21 towards the internal fan 24. If a refrigerant leaks inside the housing 21, the refrigerant can accumulate near the rear surface 21a of the housing 21. Therefore, the fifth flow paths 65 are provided on the side of the rear surface 21a of the housing 21, so that, in the event of a refrigerant leak, air containing the refrigerant can be efficiently directed towards the internal fan 24, thus suppressing the formation of a region with a flammable concentration. [Effects]

[0050] According to the embodiment described above, the following effects can be achieved.

[0051] The openings 75, which are connected to the exterior of the housing 21, are provided at the positions in the housing 21 of the indoor unit 20C that face the indoor fan 24. The flow path comprises the fifth paths 65 from the openings 75 towards the indoor fan 24.

[0052] With this configuration, the air inside the housing 21 can be more efficiently discharged into space Rin, and the formation of a region with a flammable concentration can be suppressed. Since the openings 75 are connected to the exterior of the housing 21, air from outside the housing 21 can be directed towards the internal fan 24 via the fifth flow paths 65. Thus, even in the event of a refrigerant leak inside the housing 21, air from outside the housing 21 can be drawn in and directed to the internal fan 24, further reducing the refrigerant concentration in the air.

[0053] The fifth flow paths 65 can be provided from the openings 75, which are provided in the rear surface 21a of the housing 21, in the direction of the internal blower 24.

[0054] With such a configuration, the air from the rear surface 21a of the housing 21, where the refrigerant can accumulate, can be directed to the internal blower 24, so that the formation of the region with flammable concentration can be suppressed.

[0055] In the embodiment described above, an example was provided in which the openings 75 are located in the rear surface 21a of the housing 21 facing the internal fan 24; however, the present embodiment is not limited to this. Each of the openings 75 can be located in any section of the housing 21 or in a position facing an internal heat exchanger 22. For example, the openings 75 can be located in positions facing the internal heat exchanger 22, such as on a front surface 21b or an upper surface 21e of the housing 21.

[0056] The embodiment described above is an example in which several openings 75 are provided in the housing 21; however, the present embodiment is not limited to this. It may suffice to provide one or more openings 75. (Fifth embodiment)

[0057] A fifth embodiment is described with reference to Fig. 11. In the fifth embodiment, the same or equivalent components as in the first embodiment are identified with the same reference numerals as those in the first embodiment. In the fifth embodiment, a description that overlaps with that of the first embodiment is omitted.

[0058] Fig. Figure 11 is a block diagram showing an air conditioner 10A according to the fifth embodiment. As in Fig. As shown in Figure 11, the present embodiment differs from the first embodiment in that the air conditioning system 10A comprises a control device 80 and an indoor unit 20C contains a sensor 81 which detects a refrigerant gas in a housing 21.

[0059] The control unit 80 controls an outdoor unit 30 and an indoor unit 20C. The control unit 80 includes, for example, a memory in which a program is stored and a processing circuit corresponding to a processor such as a central processing unit (CPU). A function of the control unit 80 can be configured using only hardware or implemented by a combination of hardware and software. The control unit 80 reads data and the program stored in memory and performs various arithmetic operations to implement a predetermined function.

[0060] Sensor 81 is a sensor that can detect a refrigerant gas inside the housing 21. For example, a gas sensor that can detect the concentration of a refrigerant gas in the air can be used as sensor 81.

[0061] The control unit 80 operates an internal fan 24 when the sensor 81 detects refrigerant gas inside the housing 21. The internal fan 24 is operated when the sensor 81 detects the refrigerant gas, thereby distributing any escaping refrigerant into a space Rin. Alternatively, the control unit 80 can increase the air volume (or airflow rate) of the internal fan 24 when the sensor 81 detects the refrigerant gas. The air volume of the internal fan 24 is increased, thereby efficiently distributing the refrigerant gas in the housing 21 into the space Rin. [Effects]

[0062] The following effects can be achieved according to the implementation method described above.

[0063] The control unit 80, which controls the outdoor unit 30 and the indoor unit 20, may also be included. The indoor unit 20 may also contain a sensor 81 that detects refrigerant gas inside the housing 21. The control unit 80 can operate the indoor fan 24 when the sensor 81 detects the refrigerant gas.

[0064] In such a configuration, the air volume of the internal blower 24 is increased when the refrigerant gas is detected, thereby efficiently distributing any refrigerant escaping from the housing 21 into the space Rin. (Overview of embodiments) (Supplement)

[0065] Based on the above description of the embodiments, the following techniques are disclosed. (Technical Point 1)

[0066] Air conditioning system that uses a flammable refrigerant, including: an outdoor unit with an outdoor heat exchanger, a compressor and an expansion valve; an indoor unit comprising a housing having a rear surface facing a wall surface of a room in which it is to be installed, an internal heat exchanger that exchanges heat with indoor air, and an internal fan that draws the indoor air into the internal heat exchanger; and a refrigerant line that connects the outdoor heat exchanger, the compressor, the expansion valve and the indoor heat exchanger, and through which a refrigerant circulates, wherein a flow path for air is provided from a space inside the housing towards the internal fan inside the housing of the indoor unit.

[0067] With this configuration, the air conditioning system can be provided with improved safety. The airflow path is located within the housing, so that even if refrigerant leaks inside the housing, air containing the refrigerant can be drawn through the airflow path to the internal fan and discharged into a room. The refrigerant is thus dispersed into the room, preventing the formation of an area with a flammable concentration. (Technical point 2)

[0068] Air conditioning system according to technical point 1, wherein the flow path includes a first flow path provided in a gap between the casing and the interior heat exchanger.

[0069] With such a configuration, more air can be directed to the internal fan, so that any refrigerant escaping from the housing can be more effectively vented into the room. (Technical point 3)

[0070] Air conditioning according to technical point 2, whereby the first flow path comprises a first section between a front surface of the casing and the interior heat exchanger and a second section between the rear surface of the casing and the interior heat exchanger, and the first section is larger than the second section.

[0071] With such a configuration, the first section, which serves as a larger flow path, is located in a section with a larger airflow, caused by the internal fan inside the housing, so that the air inside the housing can be more efficiently discharged into the room. (Technical point 4)

[0072] Air conditioning according to one of the technical points 1 to 3, whereby The refrigerant line comprises several heat transfer tubes arranged in the housing of the indoor unit, several first curved tubes connecting one end of the several heat transfer tubes to each other, and several second curved tubes connecting the other ends of the several heat transfer tubes to each other. the flow path comprises at least one of a second flow path, which is provided in a first space in which the several first arc tubes are arranged, and a third flow path, which is provided in a second space in which the several second arc tubes are arranged.

[0073] With such a configuration, air can be efficiently supplied to the internal fan within the housing from a space where escaping refrigerant can accumulate, thus suppressing the formation of a region with flammable concentration. (Technical point 5)

[0074] Air conditioning according to one of the technical points 1 to 4, whereby The indoor unit further comprises a blower motor arranged in the housing and driving the indoor blower, as well as a housing that accommodates the blower motor, the blower motor has a shaft that is connected to a shaft of the internal blower, the housing is provided with a through-hole in which the shaft is arranged, one dimension of the through-hole is larger than the diameter of the shaft, and the flow path includes a fourth flow path, which is provided between an inner wall of the housing, defining the through-hole, and the shaft.

[0075] With such a configuration, the air in a section where the blower motor is located can be directed to the internal blower, allowing the air inside the housing to be efficiently discharged into the room. (Technical point 6)

[0076] Air conditioning according to one of the technical points 1 to 5, whereby the housing is provided with an opening located in a position facing the internal heat exchanger or the internal fan and connected to an outside of the housing, and The flow path includes a fifth flow path from the opening towards the internal blower.

[0077] With this configuration, the air inside the enclosure can be more efficiently discharged into the room, and the formation of a region with a flammable concentration can be suppressed. Since the opening is connected to the outside of the enclosure, air from the outside can be directed towards the internal fan via the fifth flow path. Therefore, even if refrigerant leaks inside the enclosure, air can be drawn in from the outside and directed to the internal fan, further reducing the refrigerant concentration in the air. (Technical point 7)

[0078] Air conditioning according to technical point 6, wherein the fifth flow path is provided from the opening provided in the rear surface of the housing towards the internal blower.

[0079] With such a configuration, air can be directed from the rear surface of the housing, where refrigerant can accumulate, to the internal fan, thus suppressing the formation of the region with flammable concentration. (Technical point 8)

[0080] Air conditioning according to one of the technical points 1 to 7, furthermore comprehensive a control unit that controls the outdoor unit and the indoor unit, wherein the indoor unit further comprises a sensor that detects a refrigerant gas inside the housing, and The control unit operates the internal blower when the sensor detects a refrigerant gas.

[0081] With such a configuration, the air volume of the internal blower is increased when a refrigerant gas is detected, thereby efficiently distributing any refrigerant escaping from the housing into the room.

[0082] The present disclosure can be applied extensively to air conditioning systems that use flammable refrigerants. (Description of reference symbols) 10, 10A Air conditioner 20, 20A-20C Indoor unit 21 cases 21a Rear surface 21b Front surface 22 internal heat exchangers 24 internal blowers 30 outdoor units 32 external heat exchangers 34 blowers 36 Compressor 38 Expansion valve 40 Four-way valve 50 refrigerant lines 52 heat transfer pipes 54 First curved pipes 56 Second curved pipes 60 Flow path 61 First flow path 61a First Section 61b Second Section 62 Second flow path 63 Third flow path 64 Fourth flow path 65 Fifth flow path 71 Blower motor 72 cases 73 shaft 74 Through hole 74a Interior wall 75 openings 80 Control unit 81 Sensor

Claims

[1] Air conditioning system which uses a flammable refrigerant, comprising: an outdoor unit with an outdoor heat exchanger, a compressor and an expansion valve; an indoor unit comprising a housing having a rear surface facing a wall surface of a room in which it is to be installed, an internal heat exchanger that exchanges heat with indoor air, and an internal fan that draws the indoor air into the internal heat exchanger; and a refrigerant line that connects the outdoor heat exchanger, the compressor, the expansion valve and the indoor heat exchanger, and through which a refrigerant circulates, wherein a flow path for air is provided from a space inside the housing towards the internal fan inside the housing of the indoor unit. [2] Air conditioning system according to claim 1, wherein the flow path comprises a first flow path which is provided in a gap between the housing and the interior heat exchanger. [3] Air conditioning system according to claim 2, wherein the first flow path comprises a first section between a front surface of the casing and the interior heat exchanger and a second section between the rear surface of the casing and the interior heat exchanger, and the first section is larger than the second section. [4] Air conditioning system according to any one of claims 1 to 3, wherein The refrigerant line comprises several heat transfer tubes arranged in the housing of the indoor unit, several first curved tubes connecting one end of the several heat transfer tubes to each other, and several second curved tubes connecting the other ends of the several heat transfer tubes to each other. the flow path comprises at least one of a second flow path, which is provided in a first space in which the several first arc tubes are arranged, and a third flow path, which is provided in a second space in which the several second arc tubes are arranged. [5] Air conditioning system according to any one of claims 1 to 4, wherein The indoor unit further comprises a blower motor arranged in the housing and driving the indoor blower, as well as a housing that accommodates the blower motor, the blower motor has a shaft that is connected to a shaft of the internal blower, the housing is provided with a through-hole in which the shaft is arranged, one dimension of the through-hole is larger than the diameter of the shaft, and the flow path includes a fourth flow path, which is provided between an inner wall of the housing, defining the through-hole, and the shaft. [6] Air conditioning system according to any one of claims 1 to 5, wherein the housing is provided with an opening located in a position facing the internal heat exchanger or the internal fan and connected to an outside of the housing, and The flow path includes a fifth flow path from the opening towards the internal blower. [7] Air conditioning system according to claim 6, wherein the fifth flow path is provided from the opening provided in the rear surface of the housing towards the internal blower. [8] Air conditioning system according to any one of claims 1 to 7, further comprising a control unit that controls the outdoor unit and the indoor unit, wherein the indoor unit further comprises a sensor that detects a refrigerant gas inside the housing, and The control unit operates the internal blower when the sensor detects a refrigerant gas.

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