Indoor unit of air conditioner

Abstract

The invention provides an indoor unit of an air conditioner, which can ensure the contact time of drained water flowing reversely due to self weight and a sterilizing substance when a draining pump is in a stopped state, and improve the sterilizing effect of the drained water. An indoor unit (2) is provided with: a heat exchanger (3) housed in a main body; a drain pan (6) for storing drain water accompanying heat exchange by the heat exchanger (3); a drain pump (8) that drains the drain accumulated in the drain pan (6); a drain hose (9) for discharging the drain water discharged from the drain pump (8) to the outside of the main body; a degerming unit (10) for degerming the discharged water; and a control unit (4) that performs output control of the drainage pump (8) from driving of the drainage pump (8) to stopping of the drainage pump (8) so as to reduce the output in stages.

Description

TECHNICAL FIELD

[0001] The present application relates to an indoor unit of an air conditioner. BACKGROUND

[0002] An indoor unit of an air conditioner is known that includes: an indoor unit main body installed to a ceiling of an air-conditioned room; a heat exchanger housed in the indoor unit main body; a drain pan that accumulates drain water discharged in association with heat exchange by the heat exchanger; a drain pump that draws the drain water accumulated in the drain pan in order to guide the drain water to a drain system; and a semi-rigid drain hose having a corrugated shape that guides the drain water discharged from the drain pump to an outside of the indoor unit main body.

[0003] Further, an indoor unit of an air conditioner is known that, in association with stopping of the drain pump, drain water present in the drain hose and the drain pump and the like flows backward due to gravity, and the drain water contacts an antibacterial agent when the drain water flows from a suction port of the drain pump in the stopped state to the drain pan, whereby sterilization of the drain water is performed.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT DOCUMENTS

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-257622

[0007] Patent Document 2: Japanese Patent Application Publication No. 2017-122526 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] In the conventional indoor unit of an air conditioner, in association with stopping of the drain pump, the antibacterial agent contacts the drain water flowing from the suction port of the drain pump, whereby sterilization of the drain water is performed, but the drain water flowing from the suction port of the drain pump is fast, and there is a concern that sufficient sterilization effect cannot be exerted.

[0010] Therefore, an object of the present application is to provide an indoor unit of an air conditioner that can improve sterilization effect of drain water.

[0011] SOLUTION TO THE PROBLEM

[0012] The indoor unit of an air conditioner according to an embodiment of the present application includes: a main body that can be installed to a ceiling of an air-conditioned room; a heat exchanger housed in the main body; a drain pan that accumulates drain water discharged in association with heat exchange by the heat exchanger; a drain pump that draws the drain water accumulated in the drain pan; a drain hose that discharges the drain water discharged from the drain pump to an outside of the main body; a sterilization section that performs sterilization of the drain water; and a control section that performs output control of the drain pump that makes the output of the drain pump stagewise decrease from driving to stopping.

[0013] Further, in the indoor unit, preferably, the sterilization section is arranged at a position capable of irradiating sterilization substance toward all or a part of a lower region of a suction port of the drain pump, and sterilizes the drain of the all or the part. Furthermore, in the indoor unit, preferably, the sterilization section irradiates ultraviolet rays as the sterilization substance toward the drain accumulated in the drain pan. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a perspective view of an indoor unit of an air conditioner according to an embodiment of the present invention.

[0015] Figure 2 is a plan view of an indoor unit of an air conditioner according to an embodiment of the present invention.

[0016] Figure 3 is a front view of an indoor unit of an air conditioner according to an embodiment of the present invention.

[0017] Figure 4 is an enlarged view of an inclined plate of a left front side of an indoor unit of an air conditioner according to the present embodiment.

[0018] Figure 5 is a schematic view showing an enlarged side surface of a drain pump and a control section arranged in the vicinity of the drain pump of an indoor unit of an air conditioner according to the present embodiment.

[0019] Figure 6 is a flowchart showing a part of an operation of an indoor unit of an air conditioner according to the present embodiment.

[0020] Figure 7 is a flowchart showing another part of an operation of an indoor unit of an air conditioner according to the present embodiment.

[0021] Figure 8 is a view for explaining a first sterilization method of drain accumulated in a drain pump arranged in an indoor unit of an air conditioner according to the present embodiment.

[0022] Figure 9 is a view for explaining a second sterilization method of drain accumulated in a drain pump arranged in an indoor unit of an air conditioner according to the present embodiment. DETAILED DESCRIPTION

[0023] REFERENCE Figures 1 to 9 Embodiments of an indoor unit of an air conditioner according to the present invention will be described. In the drawings, like or equivalent components are designated by like reference numerals.

[0024] Figure 1 is a perspective view of an indoor unit of an air conditioner according to an embodiment of the present invention.

[0025] Figure 2 This is a top view of the indoor unit of an air conditioner according to an embodiment of the present invention.

[0026] Figure 3 This is a front view of the indoor unit of the air conditioner according to an embodiment of the present invention.

[0027] The air conditioner 1 according to this embodiment includes an outdoor unit installed outdoors as a heat source and... Figure 1 The indoor unit 2 shown is installed indoors as the user side.

[0028] In addition, the air conditioner 1 has a refrigeration cycle. The refrigeration cycle includes a heat exchanger on the heat source side, a compressor, a heat exchanger 3 on the user side, an expander, and refrigerant pipes through which the refrigerant flows. The air conditioner 1 may also have a four-way valve, which switches between cooling and heating operation of the air conditioner 1 by changing the flow direction of the refrigerant in the refrigerant pipes.

[0029] Indoor unit 2 houses the heat exchanger 3 on the user side of the refrigeration cycle. Outdoor unit houses the heat exchanger, compressor, and four-way valve on the heat source side of the refrigeration cycle. An electric expansion valve, acting as an expander, can be housed in either indoor unit 2 or outdoor unit. The outdoor and indoor units are connected via a bridging pipe, which is part of the refrigerant piping. Air conditioner 1 regulates indoor air by circulating refrigerant between the heat exchanger on the outdoor unit side and the heat exchanger 3 on the indoor unit 2 side.

[0030] The indoor unit 2 is installed in the air-conditioned room, such as a room in a building. The indoor unit 2 is embedded in the back of the ceiling of the air-conditioned room. That is, the indoor unit 2 is a so-called embedded type indoor unit.

[0031] like Figures 1 to 3 As shown, the indoor unit 2 according to this embodiment includes: a housing 5 as the main body; a heat exchanger 3 disposed inside the housing 5; an air supply device 7 disposed inside the housing 5; a drain pan 6 disposed inside the housing 5 and below the heat exchanger 3; and a decorative panel 19 covering the bottom surface of the housing 5. The air supply device 7 includes an annular flared opening disposed in the housing 5 and a fan that draws in air from the flared opening and blows the air to the heat exchanger 3.

[0032] The housing 5 has a roughly quadrilateral top surface and four rectangular sides, and is an open-bottom box. The top surface of the housing 5 is blocked by a top plate 11. A fan is provided on the lower surface of the top plate 11. The front, right, left, and back sides of the housing 5 are blocked by side plates 12. The corners between adjacent pairs of side surfaces of the housing 5 are chamfered without sharp angles. These chamfered corners are blocked by inclined plates 13. The inclined plates 13 are inclined at 45 degrees relative to the adjacent side plates 12. In other words, the angle between the adjacent inclined plates 13 and the side plates 12 is 135 degrees.

[0033] In addition, the housing 5 has support fittings 15 provided on each inclined plate 13. The support fittings 15 are hooked on nuts to support the entire indoor unit 2, and the nuts are screwed into double-ended bolts that are mounted on the back of the ceiling in a downward manner.

[0034] exist Figure 2 In the air conditioner 1 shown, the bottom side is designated as the front, and the top side as the back, relative to the paper. Furthermore, the left side is designated as the left side, and the right side as the right side. Figure 3 In the air conditioner 1 shown, the lower side is designated as the bottom surface and the upper side as the top surface relative to the plane of the paper. Furthermore, the left side is designated as the left side and the right side as the right side. The indoor unit 2 is positioned with the top surface facing upwards and the bottom surface facing downwards. Therefore, in the indoor unit 2, the vertical direction extends through both the top and bottom surfaces. The top, bottom, front, back, right, and left sides of the indoor unit 2 are defined by… Figure 2 and Figure 3 Based on.

[0035] The chamfer between the front and right sides of the housing 5 has an inclined portion 13a and a stepped portion 13b that is offset toward the rear side of the housing 5 when viewed from above.

[0036] The stepped portion 13b is blocked by the right-side side plate 12fr and the front-side side plate 12rf. Specifically, the right-side side plate 12fr is arranged parallel to the front side plate 12f, offset towards the rear side, and faces the front of the housing 5. The front-side side plate 12rf is arranged to connect the front side plate 12f to the right-side side plate 12fr, which is offset from the front side plate 12f, and faces the right side of the housing 5. In the example shown, the front-side side plate 12rf is arranged at an angle, facing the right side of the housing 5 and slightly towards the front side.

[0037] The inclined portion 13a is blocked by the inclined plate 13fr on the right front side. The inclined plate 13fr on the right front side is configured to connect the side plate 12fr on the right side of the front of the stepped portion 13b to the side plate 12 on the right side.

[0038] On the right-side side panel 12fr of the front panel, there are connectors 16 and 17 for connecting refrigerant pipes. Connectors 16 and 17 are part of the refrigerant pipes that allow refrigerant to flow in the heat exchanger 3, connecting the external refrigerant pipes of the indoor unit 2 to the internal heat exchanger 3 of the indoor unit 2. Connectors 16 and 17 extend substantially straight toward the front of the housing 5 (hereinafter also referred to as the front), which is a direction parallel to the normal of the front side panel 12f and along the normal of the right-side side panel 12fr of the front panel.

[0039] The side of the air-conditioned chamber opposite the bottom opening of the housing 5 is covered by a decorative panel 19. The decorative panel 19 includes: an intake grille 21 disposed at the center of the decorative panel 19 for drawing air in from the air-conditioned chamber; and a plurality of outlets 22 disposed at the outer edge of the decorative panel 19 for blowing air out to the air-conditioned chamber. The intake grille 21, for example, covers an annular flared opening provided at the center of the bottom surface of the housing 5, opposite the intake opening of the housing 5. The plurality of outlets 22 opposite the plurality of outlet openings of the housing 5. Each outlet 22 has a fin for adjusting the airflow direction.

[0040] The fan comprises: a fan motor with a rotating shaft extending vertically at approximately the center of the housing 5; and an impeller integrally fixed to the rotating shaft. The fan motor drives the impeller to rotate. The fan motor is fixed to the inner surface of the top plate 11 of the housing 5 via a fastener. The rotating impeller draws in air from the air-conditioned chamber through the intake port 21 of the decorative panel 19 and blows the air out radially in a direction intersecting the rotating shaft. The blown air exchanges heat with the refrigerant flowing in the heat exchanger 3 and is blown out from multiple outlet ports of the housing 5, through the outlet ports 22 of the decorative panel 19, into the air-conditioned chamber. The rotation centerline of the impeller is aligned with the rotation shaft of the fan motor and extends vertically when the indoor unit 2 is installed.

[0041] The heat exchanger 3 is fixed to the top plate 11 of the housing 5. In this embodiment, the heat exchanger 3 is, for example, a finned tube type, having a plurality of aluminum alloy fins arranged in a row and refrigerant pipes passing through the fins.

[0042] The heat exchanger 3 is disposed inside the housing 5 and surrounds the radially outer side of the fan. The inner circumferential surface of the heat exchanger 3 faces the fan, and the outer circumferential surface of the heat exchanger 3 faces the inner surface of the side plate 12. The heat exchanger 3 has flat plate portions facing each side plate 12 of the housing 5 and corner portions connecting two adjacent flat plate portions. For example, there are four flat plate portions and three corner portions.

[0043] The drain pan 6 is located below the heat exchanger 3 and receives the drainage generated during heat exchange in the heat exchanger 3. When the heat exchanger 3 is operating as an evaporator for refrigeration, moisture contained in the air passing through the heat exchanger 3, i.e., indoor humidity, condenses on the surface of the heat exchanger 3, adhering to the heat exchanger 3 as drainage and dripping from it. The drain pan 6 receives and collects the drainage dripping from the heat exchanger 3. The drainage stored in the drain pan 6 is pumped, for example, by a drain pump 8 located within the housing 5. Figure 5 Extracted through the drain hose 9 (as shown in the diagram) Figure 5 (As shown in the diagram) Discharges to the outside of the indoor unit 2.

[0044] Viewed from above, the center of the essentially annular heat exchanger 3, the rotation center of the fan, the center of the suction inlet 21 of the decorative panel 19, and the center of the annular flared mouth are essentially the same.

[0045] When air conditioner 1 is operating in cooling mode, the compressor of the outdoor unit discharges high-temperature, high-pressure gaseous refrigerant, which is then delivered to the outdoor heat exchanger (condenser). The outdoor heat exchanger exchanges heat between the refrigerant flowing inside and the outdoor air, causing the refrigerant to condense. The condensed liquid refrigerant is then delivered to the indoor unit 2 through refrigerant pipes. The indoor unit 2 uses an electric expansion valve to expand the liquid refrigerant flowing from the refrigerant pipes, delivering the low-temperature gas-liquid mixture to the heat exchanger 3 (evaporator). The heat exchanger 3 exchanges heat between the low-temperature refrigerant flowing inside and the indoor air, causing the refrigerant to vaporize. At this time, the indoor air is cooled by the low-temperature air blown out from the indoor unit 2.

[0046] When the air conditioner 1 is operating in heating mode, the compressor of the outdoor unit discharges high-temperature, high-pressure gaseous refrigerant, which is then delivered to the heat exchanger 3 (condenser) of the indoor unit 2. The heat exchanger 3 exchanges heat between the refrigerant flowing inside and the indoor air, causing the refrigerant to condense. At this time, the room is heated by the high-temperature air blown out from the indoor unit 2.

[0047] Figure 4 This is an enlarged view of the inclined plate on the left front side of the indoor unit of the air conditioner according to this embodiment.

[0048] like Figure 4 As shown, the housing 5 of the indoor unit 2 in this embodiment has a drain pipe inlet 31 provided on the left front side of the inclined plate 13fl.

[0049] The drain pipe inlet 31 extends substantially straight along the normal to the inclined plate 13fl on the left front side. Thus, the drain pipe inlet 31 protrudes at a 45-degree angle to the left relative to the front of the housing 5. Consequently, the protruding direction of the drain pipe inlet 31 is inclined relative to the extending direction of the connectors 16 and 17. The drain pipe inlet 31 connects the inside and outside of the housing 5, allowing drainage accumulated inside the housing 5, for example, drawn by a drain pump, to be discharged outside the housing 5.

[0050] Figure 5 This is a schematic diagram showing an enlarged side view and a control section surrounding the drain pump of the indoor unit of the air conditioner according to this embodiment. Figure 5 The water level of the drain W is the water level during the period of output control described later (during the period of backflow of the drain from the drain pump 8).

[0051] like Figure 5 As shown, the indoor unit 2 according to this embodiment, in addition to the drain pan 6, also includes a control unit 4, a drain pump 8, a drain hose 9, and a sterilization unit 10. The control unit 4 controls various parts of the air conditioner 1 based on pre-programmed content in the microcomputer of the control unit 4 and content set before operation. The drain pan 6 accumulates the drain water W that accompanies the heat exchange of the heat exchanger 3. The drain pump 8 draws the drain water W accumulated in the drain pan 6 from the lower suction port 8a. The drain hose 9 discharges the drain water discharged by the drain pump 8 to the outside of the housing 5 through the drain pipe inlet 31 and guides it to a drain pipe (not shown) provided on the back of the ceiling of the air-conditioned room.

[0052] The sterilization section 10 sterilizes the drainage W. For example, the sterilization section 10 is a sterilization unit that irradiates a sterilizing substance toward the drainage W and / or an antibacterial agent provided on the drainage tray 6. Hereinafter, an example of the sterilization section 10 being a sterilization unit will be described. The sterilization section 10 is disposed at a position that can irradiate all or part of the lower region R of the suction port 8a of the drainage pump 8, thereby sterilizing all or part of the drainage W. Figure 5 The irradiation area U of the disinfectant is shown. Preferably, the disinfection unit 10 irradiates the disinfectant over a large area of ​​drainage, including all or part of the lower region R of the suction port 8a of the drainage pump 8, and multiple units may be provided. Examples of disinfection units 10 include ultraviolet irradiation devices that generate and irradiate ultraviolet light (e.g., deep ultraviolet light (UV-C)), ozone irradiation devices that generate and irradiate ozone, devices containing photocatalysts, or devices that combine these disinfection functions.

[0053] Next, use Figure 6 The flowchart shown illustrates the operation of the indoor unit of the air conditioner according to this embodiment.

[0054] Figure 6 and Figure 7This is a flowchart illustrating the operation of the indoor unit of the air conditioner according to this embodiment. Figure 6 and Figure 7 In the flowchart, the "S" symbol with a number indicates each step.

[0055] The indoor unit 2 of the air conditioner 1 has a control unit 4, which controls various parts of the air conditioner 1 based on the content pre-programmed in the microcomputer of the control unit 4 and the content set before operation, thereby operating as follows.

[0056] First, by supplying power to the main power source, air conditioner 1 enters the operation preparation state.

[0057] Next, the control unit 4 determines whether the user has operated the start button of the air conditioner 1 (step S1). If it is determined that the start button has been operated, the control unit 4 starts the air conditioning operation of the air conditioner 1.

[0058] Then, the user selects the desired operating mode from (1) cooling operation mode, (2) dehumidification operation mode, (3) air supply / humidification operation mode, (4) heating / humidification operation mode, (5) air supply operation mode, and (6) heating operation mode, thereby setting the air conditioner 1 to the desired operating mode (step S2). In step S2, when the operating mode is any of the above (1) to (4), the control unit 4 drives the drain pump 8 (step S3) to draw the drain water accumulated in the drain pan 6 from the suction port 8a. Then, the drain hose 9 discharges the drain water discharged by the drain pump 8 to the outside of the housing 5.

[0059] Next, the control unit 4 determines whether the operating time of any of the above-mentioned operating modes (1) to (6) has exceeded the preset time, and determines whether the user has operated the operation stop button of the air conditioner 1 (step S4).

[0060] In step S4, if it is determined that the operating time has exceeded the preset time or the operation stop button has been pressed, the air conditioning operation of the air conditioner 1 stops. Then, the control unit 4 determines whether the previous operating mode was any of the modes mentioned in (1) to (4) above (step S5).

[0061] In step S5, if it is determined that the previous operating mode is not any of the modes (1) to (4) above, the control unit 4 performs an operation end process, and the air conditioner 1 stops and becomes a stopped state (step S6).

[0062] On the other hand, in step S5, if it is determined that the previous operating mode is any of the above (1) to (4), the control unit 4 determines whether the setting after operation of the above (1) to (4) set before the start of operation is the setting of the operation mode with drain pan sterilization (step S7).

[0063] In step S7, if the setting is determined to be a sterilization operation mode without a drain pan, the control unit 4 performs an operation end process, and the air conditioner 1 stops and enters a stopped state (step S6).

[0064] On the other hand, in step S7, when it is determined that the drain tray sterilization operation mode is set, the control unit 4 performs output control such that the output is reduced in stages from driving the drain pump 8 to stopping it, and controls the sterilization unit 10 to sterilize the drain by irradiating sterilizing substance during the period of output control (drain backflow first interval) (step S8).

[0065] By controlling this output, the flow rate of the drainage pump 8 is adjusted, thereby causing the drainage pipe outside the housing 5, the drainage hose 9 inside the housing 5, and the drainage pump 8 to slowly flow out from the suction port 8a of the drainage pump 8 to the lower region R. The drainage flowing out from the suction port 8a slowly merges with the drainage W from the drainage tray 6. That is, the drainage flowing out from the suction port 8a slowly passes through the irradiation area U of the sterilization section 10.

[0066] If the sterilization operation of the drain pan in step S8 is completed, the control unit 4 performs an operation termination process, and the air conditioner 1 stops and enters a stopped state (step S6). In step S6, in any of the above (1) to (4) modes, the drain pump 8 driven in step S3 is stopped, and the discharge of drainage to the outside of the housing 5 is stopped.

[0067] On the other hand, when step S1 determines that the start button has not been operated (entering...) Figure 7 When “A” is used, such as Figure 7 As shown, the control unit 4 determines whether the standby time has exceeded a preset time (step S9). If it is determined that the standby time has exceeded the preset time, the control unit 4 determines whether the sterilization operation mode with a drain pan is set (step S7').

[0068] In step S7', it is determined that the setting is a sterilization operation mode without a drain tray (enter). Figure 6 In the case of “B”, the control unit 4 does not perform any processing and re-enters the determination step S1.

[0069] On the other hand, in step S7', if it is determined that the drain tray sterilization operation mode is set, the control unit 4 performs output control that gradually reduces the output from driving the drain pump 8 to stopping, and controls the sterilization unit 10 to sterilize the drain by irradiating sterilizing material during the period of this output control (during the first interval of drain backflow) (step S8'). The gradual reduction of output control in step S8' is related to step S8 (Figure 6 The diagram is different and is unrelated to the previous types of operation modes (1) to (6).

[0070] If the sterilization operation of the drain tray in step S8' is completed (enter...) Figure 6 If the "B" is not found, then the control unit 4 will re-enter the determination step S1.

[0071] Furthermore, in step S9, it was not determined that the standby time had exceeded the preset time (entering...). Figure 6 In the case of “B”, the control unit 4 also re-enters the determination step S1.

[0072] use Figure 8 and Figure 9 The operation of the drainage pump 8 in step S8 (and the same applies to step S8') will be explained. Figure 8 This is a diagram illustrating a first sterilization method for wastewater accumulated in a drain pump installed in the indoor unit of an air conditioner according to this embodiment. Figure 9 This diagram illustrates a second sterilization method for wastewater accumulated in a drain pump installed in the indoor unit of an air conditioner according to this embodiment. Figure 8 (A) and Figure 9 (A) is a diagram showing the operation of the drainage pump involved in the comparative example. Figure 8 (B) and Figure 9 (B) is a diagram showing the operation of the drainage pump 8 according to this embodiment.

[0073] In the indoor unit of the air conditioner (hereinafter referred to as air conditioner 1') involved in the comparative example, such as Figure 8 As shown in (A), the control unit controls the opening and closing of the drain pump 8. In the air conditioner 1', after the operation stop instruction, the control unit 4' starts the sterilization operation of the drain pan in the operation modes (1) to (4) mentioned above. After the operation stop instruction of the air conditioner 1', the drain pump 8 switches from open to closed, thereby causing the drainage present in the drain hose 9 and the drain pump 8 to flow backward due to its own weight, and flow out from the suction port 8a of the drain pump 8 to the drain pan 6. At this time, the drainage flowing out from the suction port 8a of the drain pump 8 in the stopped state is irradiated with a sterilizing substance to sterilize the drainage.

[0074] In addition, after the drain pump 8 stops in the third interval, the drain pump 8 is turned on again in the second interval, and then the drain pump 8 is turned off, thereby stirring the drain water accumulated in the drain pan 6 of the air conditioner 1' and sterilizing the drain pan 6.

[0075] However, in this situation, the drainage flow from the bottom of the drainage pump 8 is too fast when the pump is switched off, making it impossible to achieve a sufficient sterilization effect with a single irradiation. When the above-described sterilization operation (sterilization operation based solely on the on / off control of the drainage pump 8) was performed, and a plastic test piece was immersed in the drainage W accumulated in the drainage tray 6 for an anti-biofilm test of the plastic product, a black biofilm formed on the test piece. Microorganisms from the drainage attached to and multiplied on the surface of the test piece.

[0076] On the other hand, in the indoor unit 2 of the air conditioner 1 according to the embodiment, such as Figure 8 As shown in (B), the control unit 4 controls the pump in the following manner: after the operation stop instruction of the operation modes (1) to (4) above, the drain pump 8 is not turned off, but is turned off after a period of phased reduction of the output of the drain pump 8 (the first period). When the drain pump 8 is an AC power driven pump, a high-speed switch based on duty cycle (DUTY) adjustment is used; on the other hand, when the pump is a DC power driven pump, the applied DC voltage is adjusted.

[0077] As a phased control of drainage pump 8, such as Figure 8 As shown in the first interval of (B), the control unit 4 causes the drain pump 8 to reduce its output in stages from drive (duty cycle 100%) to stop (duty cycle 0%). During the period when the output of the drain pump 8 is reduced in stages, that is, during the first interval, the drain pipe outside the housing 5, the drain hose 9 inside the housing 5, and the drain pump 8, etc., flow backward, but slowly flow out from the suction port 8a of the drain pump 8 to the drain pan 6.

[0078] In addition, after the stop interval (third interval) of the drain pump 8, the drain pump 8 is set to open again (second interval), and then the output of the drain pump 8 is set to decrease in stages (first interval) before the drain pump 8 is turned off, thereby stirring the drain accumulated in the drain pan 6 of the air conditioner 1 and sterilizing the drain pan 6.

[0079] During the first interval, drainage flows slowly from the lower part of the drainage pump 8, thereby allowing it to slowly pass through the irradiation area U of the sterilization section, effectively sterilizing the drainage. Therefore, sufficient sterilization effect can be applied with a single irradiation. When performing the sterilization operation of this embodiment (sterilization operation in steps S7 and S7' where the output is reduced in stages from the start to the stop of the drainage pump 8), the drainage accumulated in the drainage tray 6 was used to conduct an anti-biofilm test on plastic products, etc., in the same manner as described above, but no biofilm formed on the test piece.

[0080] In addition, Figure 8In the first interval of (B), the output of the drain pump 8 is reduced in four stages, but this is not a limitation; it can also be reduced in two or three stages, or even in five or more stages. Furthermore, in Figure 8 The first interval of (B) shows an example of the duty cycle percentage for each segment, but it is not limited to this case; any duty cycle percentage can be set. Furthermore, in Figure 8 In the first interval of (B), the time width of each segment is set to be the same (all 30 seconds), but this is not a limitation.

[0081] use Figure 9 The case where the drain pump 8 is reduced in stages from drive to stop when operation stops in any of the modes described above (1) to (4) has been explained, but it is not limited to this case. For example, as Figure 9 As shown in (B), the drain pump 8 can also be gradually reduced from drive to stop after a specified period (120 seconds) following the shutdown of any of the modes described in (1) to (4). In this case, the second interval from the shutdown to the end of the specified period is also sterilized by the same method as the first interval, thereby improving the sterilization effect of the drain.

[0082] Furthermore, the case where sterilization is performed by irradiating a sterilizing substance during the first interval (i.e., the period during which output control is performed, from the start of the drain pump 8 to its stop, causing a phased decrease in output) after operation in any of the above modes (1) to (4) has been described, is not limited to this case. Sterilization of the sterilization unit 10 can be performed not only during the first interval, but also during the second and / or third intervals (e.g., during...). ​ It can be performed as shown in (B) diagram, or it can be performed in any of the modes described in (1) to (6) above. In addition, it can be performed according to any set time.

[0083] As explained above, the indoor unit 2 of the air conditioner 1 according to this embodiment ensures sufficient contact time between the disinfecting substance and the drainage that flows backward due to its own weight when the drain pump 8 is stopped, thereby improving the disinfection effect of the drainage. Furthermore, because the disinfection effect of the indoor unit 2 of the air conditioner according to this embodiment is improved, it is unnecessary to repeatedly switch from drive to stop to ensure sufficient contact time for the disinfecting substance. Therefore, the drive noise of the drain pump 8 or the suction noise (stirring noise) of the drainage during these switches can be suppressed, minimizing user discomfort.

[0084] Several embodiments of the present invention have been described, but these embodiments are provided by way of example and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, and are included within the scope of the invention as set forth in the claims and its equivalents.

[0085] Explanation of reference numerals in the attached figures

[0086] 1 air conditioner

[0087] 2 indoor units

[0088] 3 heat exchangers

[0089] 4 Control Department

[0090] 5. Shell

[0091] 6 drain trays

[0092] 7. Air supply device

[0093] 8 drainage pumps

[0094] 9. Drain hose

[0095] 10Sterilization Department

[0096] 11 top plate

[0097] 12 side panels

[0098] 12f front side panel

[0099] 12fr front right side panel

[0100] 12rf right front side panel

[0101] 13 Inclined Plate

[0102] 13a Inclined section

[0103] 13b Step Section

[0104] 13fl left front inclined plate

[0105] 13fr right front inclined plate

[0106] 15 Support accessories

[0107] 16 and 17 joints

[0108] 19 base plate

[0109] 21 suction port

[0110] 22 blowout

[0111] 31. Drain pipe inlet.

Claims

1. An indoor unit of an air conditioner, characterized in that, have: The main body can be installed on the ceiling of an air-conditioned room; A heat exchanger is housed within the main body; A drain pan for collecting wastewater generated during heat exchange with the heat exchanger. A drainage pump draws up the drainage accumulated in the drainage pan; A drain hose is used to discharge the drainage pumped by the drain pump to the outside of the main body; The sterilization section sterilizes the drainage. The control unit performs output control of the drainage pump, from driving the drainage pump to stopping it, so that the output is reduced in stages.

2. The indoor unit of the air conditioner as described in claim 1, characterized in that, The sterilization unit is positioned so that it can irradiate all or part of the lower region of the drainage pump's suction inlet with sterilizing material, thereby sterilizing all or part of the drainage.

3. The indoor unit of the air conditioner as described in claim 1, characterized in that, If any of the cooling operation mode, dehumidification operation mode, air supply / humidification operation mode, or heating / humidification operation mode ends, the control unit performs output control by gradually reducing the output of the drain pump from drive to stop.

4. The indoor unit of the air conditioner as described in claim 1, characterized in that, If a predetermined time has elapsed since the air conditioner has stopped operating, the control unit performs output control including a first interval and a second interval. The first interval is the control interval that causes the drain pump to reduce its output in stages from driving to stopping, and the second interval is the driving interval of the drain pump.

5. The indoor unit of the air conditioner as described in claim 4, characterized in that, The control unit controls the output of the drainage pump in such a way that the first interval and the second interval have the same time width.

6. The indoor unit of the air conditioner as described in claim 2, characterized in that, The control unit controls the sterilization unit in such a way that it irradiates the sterilization substance during the first interval of control in which the output of the drainage pump is reduced in stages from driving to stopping.

7. The indoor unit of the air conditioner as described in any one of claims 1 to 6, characterized in that, The sterilization section is a device that irradiates the drain water accumulated in the drain pan with ultraviolet light as a sterilizing agent.

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