The indoor unit and air conditioning unit include this indoor unit.

Abstract

The invention relates to an indoor unit (20) comprising a shell (50), a heat exchanger (23), a fan (24), an air guide (70), a duct (75) and a refrigerant sensor (60). The shell (50) has an inlet (51). The fan (24) draws indoor air through the inlet (51) and delivers the thus drawn indoor air to the heat exchanger (23). The air guide (70) directs the drawn indoor air into the fan (24). The air guide (70) divides the interior space of the shell (50) into a first space (77) and a second space (78). The second space (78) is arranged behind the first space (77) in the airflow. The duct (75) is arranged in the air guide (70). Path (75) allows refrigerant (R) to pass from the second space (78) to the first space (77). The refrigerant sensor (60) is positioned closer to the first space (77) on path (75).The refrigerant sensor (60) is configured to detect that refrigerant (R) has passed through the path (75).

Description

Indoor unit and air conditioner equipped with same

[0001] The present disclosure relates to an air conditioner, and more particularly to an indoor unit provided with a refrigerant sensor for detecting refrigerant leaking from a refrigerant circuit.

[0002] Patent Document 1 (International Publication No. WO2019-234902) discloses an indoor unit embedded in a ceiling. This indoor unit has a refrigerant sensor for detecting leaked refrigerant. The refrigerant sensor is located near the air intake of the indoor unit and detects refrigerant components contained in the air drawn into the indoor unit. These refrigerant components are refrigerant that has leaked from the refrigerant circuit and moved into the indoor space, and then diluted by the indoor air.

[0003] Once a leaking refrigerant has passed through the indoor space, it takes time to be detected.

[0004] Furthermore, to detect leaking refrigerant without passing through the indoor space, the refrigerant leaking from the refrigerant circuit outside the bell mouth must reach the refrigerant sensor inside the bell mouth. However, when a refrigerant that is heavier than air is used, the refrigerant leaking from the refrigerant circuit must overcome the height of the bell mouth to reach the refrigerant sensor, which again takes time to detect.

[0005] The indoor unit of a first aspect is a ceiling-mounted type. The indoor unit includes a housing, a heat exchanger, a fan, an air guide member, a passage, and a refrigerant sensor. The housing has an intake port. The fan draws indoor air through the intake port and sends it to the heat exchanger. The air guide member guides the indoor air drawn into the fan. The air guide member divides the space inside the housing into a first space and a second space. The second space is downstream of the first space in the air flow. The passage portion is provided in the air guide member. The passage portion allows refrigerant to pass from the second space to the first space. The refrigerant sensor is arranged on the passage portion on the side of the first space. The refrigerant sensor is configured to detect refrigerant that has passed through the passage portion.

[0006] With this configuration, refrigerant leaking near the heat exchanger passes through the passage and reaches the refrigerant sensor. Therefore, the leaking refrigerant does not need to go over the upper end of the air guide member to be detected, so the refrigerant leak is detected quickly. The refrigerant sensor is located in an easily replaceable position, making maintenance easy.

[0007] An indoor unit according to a second aspect is the indoor unit according to the first aspect, wherein the refrigerant sensor is disposed below the passage portion and facing upward.

[0008] With this configuration, the leaking refrigerant falls toward the refrigerant sensor facing upward, so that the detection of the refrigerant leak can be performed more quickly.

[0009] The indoor unit according to a third aspect is the indoor unit according to the first or second aspect, further comprising a drain pan. The drain pan is adjacent to the air guide member. The drain pan is disposed to face the lower end of the heat exchanger. The bottom of the drain pan is located lower than the upper end of the passage portion.

[0010] With this configuration, the bottom of the drain pan is located lower than the passage, which reduces the risk of drain water leaking from near the bottom in the event of a crack in the drain pan reaching the passage, thereby reducing the risk of the refrigerant sensor being damaged by drain water.

[0011] An indoor unit according to a fourth aspect is the indoor unit according to any one of the first aspect to the third aspect, further comprising a seal material. The seal material seals a gap between the refrigerant passing portion and the refrigerant sensor.

[0012] With this configuration, the gap between the passage portion and the refrigerant sensor is sealed, thereby suppressing leakage of conditioned air and maintaining air conditioning efficiency.

[0013] An indoor unit according to a fifth aspect is the indoor unit according to any one of the first to fourth aspects, further comprising a filter. The filter is provided at the air inlet.

[0014] This configuration makes it difficult for dust in the indoor air drawn in through the air inlet to enter the housing, thereby preventing dust from accumulating on the refrigerant sensor.

[0015] An air conditioning apparatus according to a sixth aspect includes the indoor unit according to any one of the first to fifth aspects.

[0016] According to this configuration, refrigerant leakage can be quickly detected in the air conditioner. Because the refrigerant sensor is located in a position that makes it easy to replace, maintenance of the air conditioner is easy.

[0017] It is a schematic diagram of an air conditioning apparatus 100. It is a schematic diagram of an indoor unit 20. It is a perspective view of the indoor unit 20. It is a cross-sectional view of the indoor unit 20. It is a schematic diagram of a refrigerant sensor 60. It is a perspective view showing the refrigerant sensor 60 fixed to an air guide member 70.

[0018] <Embodiment> (1) Overall Configuration (1-1) Components Constituting the Refrigerant Circuit Fig. 1 shows an air conditioning apparatus 100 according to one embodiment. The air conditioning apparatus 100 is composed of an outdoor unit 10, an indoor unit 20, and a refrigerant piping group 30 that connects the outdoor unit 10 and the indoor unit 20. Refrigerant R circulates in the refrigerant circuit of the air conditioning apparatus 100.

[0019] The outdoor unit 10 has a compressor 11, a four-way switching valve 12, an outdoor heat exchanger 13, an outdoor expansion valve 15, an accumulator 16, a liquid shut-off valve 17, and a gas shut-off valve 18 as components that make up the refrigerant circuit.

[0020] The indoor unit 20 has an indoor heat exchanger 23 as a component that constitutes the refrigerant circuit.

[0021] The refrigerant pipe group 30 has a liquid connection pipe 31 and a gas connection pipe 32 as components that constitute the refrigerant circuit.

[0022] (1-2) Cooling Operation Cooling operation is an operation in which the air conditioning apparatus 100 provides cold to the user.

[0023] The compressor 11 draws in low-pressure gas refrigerant through the suction pipe 11a, compresses it, generates high-pressure gas refrigerant, and discharges it from the discharge pipe 11b. During cooling operation, the four-way selector valve 12 forms the connection shown by the solid lines. The outdoor heat exchanger 13 condenses the high-pressure gas refrigerant to generate high-pressure liquid refrigerant. The outdoor fan 14 promotes heat exchange between the refrigerant and air in the outdoor heat exchanger 13. The outdoor expansion valve 15 reduces the pressure of the high-pressure liquid refrigerant to generate low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant reaches the indoor heat exchanger 23 via the liquid shut-off valve 17 and the liquid connection pipe 31.

[0024] The indoor heat exchanger 23 generates low-pressure gas refrigerant by evaporating the gas-liquid two-phase refrigerant, and in the process generates cold to be provided to users. The indoor fan 24 promotes heat exchange between the refrigerant and air in the indoor heat exchanger 23 and delivers the cold to users in the form of cold air. The low-pressure gas refrigerant reaches the accumulator 16 via the gas connection pipe 32, the gas shut-off valve 18, and the four-way selector valve 12.

[0025] The accumulator 16 separates and stores the liquid component that is mixed in the low-pressure gas refrigerant. After leaving the accumulator 16, the low-pressure gas refrigerant is sucked into the compressor 11 through the suction pipe 11a.

[0026] (1-3) Heating Operation Heating operation is an operation in which the air conditioning apparatus 100 provides heat to the user.

[0027] The compressor 11 draws in low-pressure gas refrigerant through the suction pipe 11a, compresses it, generates high-pressure gas refrigerant, and discharges it from the discharge pipe 11b. During heating operation, the four-way switching valve 12 forms the connections shown by the dashed lines. The high-pressure gas refrigerant passes through the four-way switching valve 12, the gas shut-off valve 18, and the gas connection pipe 32 and reaches the indoor heat exchanger 23.

[0028] The indoor heat exchanger 23 condenses the high-pressure gas refrigerant to produce high-pressure liquid refrigerant, generating heat to be provided to users in the process. The indoor fan 24 promotes heat exchange between the refrigerant and air in the indoor heat exchanger 23 and delivers the heat to users in the form of warm air. The high-pressure liquid refrigerant reaches the outdoor expansion valve 15 via the liquid connection pipe 31 and the liquid shut-off valve 17.

[0029] The outdoor expansion valve 15 reduces the pressure of the high-pressure liquid refrigerant to produce low-pressure gas-liquid two-phase refrigerant. The outdoor heat exchanger 13 evaporates the low-pressure gas-liquid two-phase refrigerant to produce low-pressure gas refrigerant. The outdoor fan 14 promotes heat exchange between the refrigerant and air in the outdoor heat exchanger 13. The low-pressure gas refrigerant reaches the accumulator 16 via the four-way selector valve 12. The accumulator 16 separates and stores the liquid component mixed in the low-pressure gas refrigerant. After leaving the accumulator 16, the low-pressure gas refrigerant is sucked into the suction pipe 11a by the compressor 11.

[0030] (2) Detailed Configuration of the Indoor Unit 20 Fig. 2 is a diagram showing a schematic diagram of the structure of the indoor unit 20. The indoor unit 20 is designed to be embedded in the ceiling. The indoor unit 20 has a housing 50, an indoor heat exchanger 23, an indoor fan 24, an air guide member 70, a refrigerant sensor 60, and a drain pan 73.

[0031] (2-1) Housing 50 Figure 3 is a perspective view of the indoor unit 20. The bottom surface of the indoor unit 20 is visible at the top of the figure. The bottom surface of the indoor unit 20 is the top surface of the indoor unit 20, which is embedded in the ceiling.

[0032] The housing 50 houses the indoor heat exchanger 23, the indoor fan 24, and other components of the indoor unit 20. The housing 50 is provided with one air inlet 51 for taking in air from the room and four air outlets 52 for supplying conditioned air to the room. As shown in Fig. 2, the air inlet 51 is provided with a filter 53 for removing dust or dirt from the taken-in air. The filter 53 is omitted from Fig. 3.

[0033] (2-2) Indoor Heat Exchanger 23 The indoor heat exchanger 23 shown in Fig. 2 functions as an evaporator of the refrigerant R during cooling operation, and as a condenser of the refrigerant R during heating operation. The indoor heat exchanger 23 has, for example, a plurality of heat transfer tubes and fins. The air flow passing through the indoor heat exchanger 23 exchanges heat with the refrigerant R.

[0034] (2-3) Indoor Fan 24 By the action of the indoor fan 24, indoor air is drawn in through the air inlet 51, passing through the filter 53 in the process. The air flow then passes through the indoor heat exchanger 23 and is conditioned by heat exchange with the refrigerant R. The conditioned air travels from the indoor heat exchanger 23 to the air outlet 52 and is blown out into the room.

[0035] (2-4) Air Guide Member 70 The air guide member 70 shown in FIG. 2 guides indoor air that is drawn into the indoor fan 24. The air guide member 70 includes a bell mouth 71 and a plate 72. The bell mouth 71 is a cylindrical member provided to concentrate the air flow path toward the indoor fan 24. The plate 72 is a flat or cone-shaped plate member provided to protect the components of the indoor unit 20 that are arranged in an area that may be exposed through the air outlet 52. The plate 72 is disposed adjacent to the bell mouth 71 and is connected to the bell mouth 71.

[0036] The air guide member 70 divides the internal space of the housing 50 into a first space 77 and a second space 78. The first space 77 is located on the upstream side of the air flow and occupies the area from the air inlet 51 to the indoor fan 24. The second space 78 is located on the downstream side of the air flow and occupies the area from the indoor fan 24 to the air outlet 52.

[0037] FIG. 4 is a cross-sectional view of the indoor unit 20. It can be seen from this drawing that the inclined surface of the bell mouth 71 and the horizontal surface of the plate 72 are connected. The air guide member 70 has a passage 75 that connects the first space 77 and the second space 78. The actual form of the passage 75 may be a hole or notch provided in the bell mouth 71 or the plate 72. The passage 75 allows refrigerant R leaking from the refrigerant circuit, such as the indoor heat exchanger 23, to pass from the second space 78 to the first space 77. The upper end 75a of the passage 75 shown in FIG. 4 is the surface of the air guide member 70 facing the second space 78.

[0038] (2-5) Refrigerant Sensor 60 The refrigerant sensor 60 shown in FIG. 4 detects refrigerant R leaking from the refrigerant circuit. The refrigerant sensor 60 is disposed on the first space 77 side of the passing portion 75. The refrigerant sensor 60 is disposed below the passing portion 75 and faces upward. The refrigerant sensor 60 detects the refrigerant R that has passed through the passing portion 75.

[0039] The height of the upper end of the air guide member 70 is approximately the same as the height of the upper end of the indoor heat exchanger 23. In addition, the height of the lower end of the air guide member 70 is approximately the same as the height of the lower end of the indoor heat exchanger 23. Therefore, the air guide member 70 can act as a barrier to refrigerant R leaking from the indoor heat exchanger 23 from reaching the refrigerant sensor 60. The passage portion 75 provided in the air guide member 70 enables the refrigerant R to quickly reach the refrigerant sensor 60.

[0040] Components that constitute the refrigerant circuit, such as the indoor heat exchanger 23 and the piping connected thereto, are mainly disposed in the second space 78. Therefore, refrigerant R that leaks from the refrigerant circuit first drifts in the second space 78. Refrigerant R has a specific gravity heavier than air, such as R32. Therefore, the refrigerant R drifting in the second space 78 then passes through the passage portion 75 due to the action of gravity and other factors, and reaches the refrigerant sensor 60. A sealant 76 is disposed in the air guide member 70 to seal the gap between the vicinity of the passage portion 75 and the refrigerant sensor 60.

[0041] 5 shows the structure of the refrigerant sensor 60. The refrigerant sensor 60 has an upper case 61, a lower case 62, a circuit board 63, a refrigerant detection element 64, a connector 65, and wiring 66. A detection window 61a is formed in the upper case 61. The detection window 61a allows refrigerant leaking outside the upper case 61 to reach the refrigerant detection element 64. A screw through hole 62a is formed in the lower case 62. The refrigerant detection element 64 and the connector 65 are mounted on the circuit board 63. Wiring 66 extends from the connector 65 to an electrical equipment box (not shown).

[0042] 6 shows the refrigerant sensor 60 fixed to the air guide member 70. The refrigerant sensor 60 is fixed to the air guide member 70 by a screw 67 attached to the screw through hole 62a.

[0043] (2-6) Drain Pan 73 The drain pan 73 shown in FIG. 4 is a container for collecting condensation water generated on the surface of the indoor heat exchanger 23. The collected condensation water is discharged outdoors via a drainage path (not shown). The drain pan 73 is adjacent to the air guide member 70. The drain pan 73 is disposed opposite the lower end of the indoor heat exchanger 23. The drain pan 73 has a recessed shape that is open upward, and surrounds the lower end of the indoor heat exchanger 23. The bottom 73a of the drain pan 73 is located lower than the upper end 75a of the passage portion 75.

[0044] (3) Features (3-1) Refrigerant R that leaks into second space 78 reaches refrigerant sensor 60 by passing through passage 75. Therefore, when detecting leaking refrigerant R, there is no need for the refrigerant R to climb over the upper end of air guide member 70, and refrigerant leakage is quickly detected. In addition, refrigerant sensor 60 is located on the underside of housing 50, in a position that makes it easy to replace, making maintenance easy.

[0045] (3-2) The refrigerant R leaking from the refrigerant circuit flows downward toward the refrigerant sensor 60 facing upward, so that the refrigerant leakage can be detected more quickly.

[0046] (3-3) The bottom 73a of the drain pan 73 is located lower than the upper end 75a of the passage 75. Therefore, when the drain pan 73 cracks, drain water leaking from near the bottom 73a is unlikely to reach the passage 75, which reduces the risk of the refrigerant sensor 60 being damaged by the drain water.

[0047] (3-4) The gap between the passage 75 and the refrigerant sensor 60 is sealed. This prevents conditioned air from leaking out, maintaining air conditioning efficiency.

[0048] (3-5) The filter 53 makes it difficult for dust or dirt in the indoor air drawn in through the air inlet 51 to enter the inside of the housing 50. This prevents dust or dirt from accumulating on the refrigerant sensor 60.

[0049] (4) Modifications The indoor unit 20 in the above-described embodiment is designed to be embedded in the ceiling. Alternatively, the indoor unit 20 may be designed to be suspended from the ceiling. Alternatively, the indoor unit 20 may be a wall-mounted type or a floor-standing type.

[0050] <Conclusion> Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as defined in the claims.

[0051] 10: Outdoor unit 20: Indoor unit 23: Indoor heat exchanger (heat exchanger) 24: Indoor fan (fan) 50: Housing 51: Intake port 52: Outlet port 53: Filter 60: Refrigerant sensor 70: Air guide member 71: Bell mouth 72: Plate 73: Drain pan 73a: Bottom 75: Passage portion 75a: Upper end 76: Sealing material 77: First space 78: Second space 100: Air conditioner R: Refrigerant

[0052] International Publication WO2019-234902

Claims

1. A ceiling-embedded indoor unit (20) comprising: a housing (50) having an intake port (51); a heat exchanger (23); a fan (24) that draws in indoor air from the intake port and sends it to the heat exchanger; an air guide member (70) that guides the indoor air drawn into the fan and divides the space inside the housing into a first space (77) and a second space (78) that is downstream in the air flow relative to the first space; a passage (75) provided in the air guide member and that allows a refrigerant (R) to pass from the second space to the first space; and a refrigerant sensor (60) that is positioned on the side of the passage on the first space side and configured to detect the refrigerant that has passed through the passage.

2. The indoor unit according to claim 1, wherein the refrigerant sensor is disposed below the passage portion and facing upward.

3. An indoor unit as described in claim 1 or claim 2, further comprising a drain pan (73) arranged adjacent to the air guide member and facing the lower end of the heat exchanger, wherein a bottom (73a) of the drain pan is positioned lower than an upper end (75a) of the passage portion.

4. The indoor unit according to claim 1, further comprising a sealant (76) that seals a gap between the passage portion and the refrigerant sensor.

5. The indoor unit according to any one of claims 1 to 4, further comprising a filter (53) provided at the air inlet.

6. An air conditioner (100) comprising an indoor unit according to any one of claims 1 to 5.

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