Disinfection equipment and air conditioning equipment

Abstract

To provide a sterilization device capable of sterilizing water in a drain pan.SOLUTION: A sterilization device (60) comprises a branch flow path (63A) that branches off from a drain pipe (62) for sending water transported from inside a drain pan (43) by a pump (51) to the outside and returns the water to the drain pan (43), and an irradiation unit (70) that irradiates the water in the branch flow path (63A) with ultraviolet light.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a sterilization device and an air conditioner.

Background Art

[0002] Patent Document 1 discloses a sterilization device provided with a UV light source. In the configuration of FIG. 7 of the same document, water flowing out from a branch pipe branched from a drain drain pipe passes through a dirt collection portion outside the branch pipe. The dirt collection portion collects dirt of a relatively large size. The UV light source irradiates ultraviolet rays toward the dirt collected by the dirt collection portion. As a result, the dirt collected by the dirt collection portion is sterilized.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The sterilization device disclosed in Patent Document 1 only considers the sterilization of the dirt collected by the dirt collection portion, and does not consider the sterilization of the water in the drain pan at all.

[0005] The present disclosure is to provide a sterilization device capable of sterilizing the water in the drain pan.

Means for Solving the Problems

[0006] A first aspect is a sterilization device including a branch flow path (63A) that branches from a drain pipe (62) for sending water conveyed from inside a drain pan (43) of an air conditioner (10) to the outside back into the drain pan (43), and an irradiation unit (70) that irradiates ultraviolet rays onto the water in the branch flow path (63A).

[0007] In the first embodiment, water from the drain pipe (62) returns to the drain pan (43) via the branch channel (63A). The irradiation unit (70) irradiates the water in the branch channel (63A) with ultraviolet light, thereby sterilizing the water. As a result, sterilized water can be returned to the drain pan (43), thus suppressing the growth of bacteria in the drain pan (43).

[0008] The second embodiment includes a first control unit (90) that turns on the irradiation unit (70) when the pump (51) is operating and water flows through the branch channel (63A), in the first embodiment.

[0009] In the second embodiment, the pump (51) operates, causing the water in the drain pan (43) to flow through the branch channel (63A). The irradiation unit (70) irradiates the water flowing through the branch channel (63A) with ultraviolet light. As a result, the water flowing through the branch channel (63A) is sterilized by the ultraviolet light and returns to the drain pan (43). The water in the drain pan (43) then flows through the branch channel (63A) again and is sterilized by the irradiation unit (70). Thus, in the second embodiment, the water in the drain pan (43) circulates through the branch channel (63A), and the circulating water is sterilized by the irradiation unit (70).

[0010] A third embodiment includes, in the first or second embodiment, a filter (71) for purifying the water before it passes through the irradiation unit (70).

[0011] In the third embodiment, the water that has passed through the filter (71) flows through the irradiation unit (70). As a result, turbidity of the water flowing through the irradiation unit (70) can be suppressed, making it easier for ultraviolet light to penetrate the water. Consequently, the sterilization effect of ultraviolet light on water can be improved.

[0012] In the fourth embodiment, the filter (71) is positioned upstream of the irradiation unit (70) in the branched channel (63A) of the water flow.

[0013] In the fourth embodiment, since the filter (71) is located in the branch channel (63A), when water in the drain pan (43) is sent to the outside from the drain pipe (62), the water does not pass through the filter (71). This extends the lifespan of the filter (71).

[0014] The fifth embodiment includes a flow path switching valve (73) that switches between a first state in which the discharge side of the pump (51) is connected to the outside via the drain pipe (62) and a second state in which the discharge side of the pump (51) is connected to the branch flow path (63A), in any one of the second to fourth embodiments, and the first control unit (90) performs a first operation in which the flow path switching valve (73) is set to the first state and the irradiation unit (70) is turned OFF while the pump (51) is operating, and a second operation in which the flow path switching valve (73) is set to the second state while the pump (51) is operating, the pump (51) is operated and the irradiation unit (70) is turned ON.

[0015] In the fifth embodiment, the first control unit (90) switches between the first operation and the second operation. In the first operation, water transported from the drain pan (43) by the pump (51) passes through the flow path switching valve (73) and is then discharged to the outside via the drain pipe (62). In the first operation, the irradiation unit (70) is in the OFF state, which extends the lifespan of the irradiation unit (70).

[0016] In the second operation, the water transported by the pump (51) passes through the flow path switching valve (73) and is returned to the drain pan (43) via the branched flow path (63A). By turning on the irradiation unit (70), the water in the drain pan (43) can be sterilized while being circulated.

[0017] In the sixth aspect, in the fifth aspect, the first control unit (90) causes the first operation to be performed when the water level in the drain pan (43) reaches a predetermined value during the second operation.

[0018] When the second operation is performed, the water in the drain pan (43) is not discharged to the outside, causing the water level in the drain pan (43) to rise. In the sixth embodiment, when the water level in the drain pan (43) reaches a predetermined value during the second operation, the first operation is performed. This allows the water in the drain pan (43) to be discharged to the outside, thereby suppressing the rise in the water level in the drain pan (43).

[0019] In the seventh aspect, the first control unit (90) causes the first operation to be executed when a predetermined time has elapsed during the second operation.

[0020] In the seventh embodiment, the first operation is performed when a predetermined time has elapsed in the second operation, thereby preventing the water level in the drain pan (43) from rising due to the second operation.

[0021] The eighth aspect is an air conditioning system comprising a drain pan (43), a pump (51) for transporting water in the drain pan (43), a drain pipe (62) for sending the water transported by the pump (51) to the outside, a branch channel (63A) branching off from the drain pipe (62) for returning the water to the drain pan (43), and an irradiation unit (70) for irradiating ultraviolet light towards the water in the branch channel (63A).

[0022] The ninth aspect is the eighth aspect, further comprising a second control unit (80) that turns on the irradiation unit (70) when the pump (51) is operating and water flows through the branch channel (63A).

[0023] The tenth embodiment includes a flow path switching valve (73) that switches between a first state in which the discharge side of the pump (51) is connected to the outside via the drain pipe (62), and a second state in which the discharge side of the pump (51) is connected to the branch flow path (63A). The second control unit (80) performs a first operation in which the flow path switching valve (73) is set to the first state and the irradiation unit (70) is turned OFF while the pump (51) is operating, and a second operation in which the flow path switching valve (73) is set to the second state and the irradiation unit (70) is turned ON while the pump (51) is operating.

[0024] In the 11th aspect, in the 10th aspect, when the water level in the drain pan (43) reaches a predetermined value during the second operation, the second control unit (80) causes the first operation to be executed.

Brief Description of the Drawings

[0025] [Figure 1] FIG. 1 is a piping system diagram of an air conditioner according to an embodiment. [Figure 2] FIG. 2 is a longitudinal sectional view of an indoor unit. [Figure 3] FIG. 3 is a schematic configuration diagram of a drain pan and a water pipe. [Figure 4] FIG. 4 is a block diagram showing main devices of an air conditioning system. [Figure 5] FIG. 5 is a flowchart relating to control of switching between the first operation and the second operation. <� [Figure 6] FIG. 6 is a timing chart relating to control of switching between the first operation and the second operation. [Figure 7] FIG. 7 is a flowchart relating to control of switching between the first operation and the second operation according to Modification 2. [Figure 8] FIG. 8 is a block diagram of an air conditioner according to Modification 11.

Modes for Carrying Out the Invention

[0026] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below, and various modifications are possible without departing from the technical idea of the present disclosure. Since each drawing is for conceptually explaining the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for easy understanding.

[0027] The air conditioning system (S) of this embodiment includes an air conditioning unit (10) and a sterilization unit (60). The sterilization unit (60) is incorporated into the air conditioning system (S) together with the air conditioning unit (10). The sterilization unit (60) may also be an additional device installed on the site in addition to the air conditioning unit (10).

[0028] (1) Overview of the air conditioning system The air conditioning system (10) adjusts the temperature of the air in the indoor space, which is the target space. As shown in Figure 1, the air conditioning system (10) comprises an outdoor unit (20) and an indoor unit (30). The outdoor unit (20) and the indoor unit (30) are connected to each other via a pair of connecting pipes (12). In the air conditioning system (10), the outdoor unit (20), the indoor unit (30), and the connecting pipes (12) constitute a refrigerant circuit (11) that performs a vapor compression refrigeration cycle. The air conditioning system (10) may be an indoor multi-type with multiple indoor units (30) or an outdoor multi-type with multiple outdoor units (20).

[0029] (1-1) Outdoor unit The outdoor unit (20) is installed outdoors. The outdoor unit (20) includes a compressor (21), a four-way switching valve (22), an outdoor heat exchanger (23), an outdoor fan (25), an expansion valve (24), a liquid side shut-off valve (26), and a gas side shut-off valve (27).

[0030] The compressor (21) is, for example, a scroll or rotary type fully enclosed compressor. The compressor (21) draws in and compresses the low-pressure refrigerant. The compressor (21) discharges the compressed high-pressure refrigerant.

[0031] The four-way diverter valve (22) is a valve for switching the flow of refrigerant in the refrigerant circuit (11). The four-way diverter valve (22) switches between a first state, shown by a solid line in Figure 1, and a second state, shown by a dashed line in Figure 1. In the first state, the high-pressure refrigerant discharged by the compressor (21) is sent to the outdoor heat exchanger (23), and the low-pressure refrigerant flowing in from the indoor unit (30) is sent to the compressor (21). In the second state, the high-pressure refrigerant discharged by the compressor (21) is sent to the indoor unit (30), and the low-pressure refrigerant that has passed through the outdoor heat exchanger (23) is sent to the compressor (21).

[0032] The outdoor heat exchanger (23) is a heat exchanger that exchanges heat between the refrigerant and the outdoor air. The outdoor heat exchanger (23) is, for example, a fin-and-tube heat exchanger. The outdoor fan (25) is a fan that supplies outdoor air to the outdoor heat exchanger (23). The expansion valve (24) is an electrically operated expansion valve with a variable opening. The expansion valve (24) may be installed in the indoor unit (30).

[0033] (1-2) Indoor unit The indoor unit (30) is installed in the room that is the target space for air conditioning. The indoor unit (30) has an indoor heat exchanger (31) and an indoor fan (32).

[0034] As shown in Figure 2, the indoor unit (30) in this embodiment is a ceiling-mounted indoor unit. The indoor unit (30) may also be of other types, such as ceiling-suspended, wall-mounted, ducted, or floor-standing. The indoor unit (30) comprises a casing (40), an indoor fan (32), an indoor heat exchanger (31), a drain pan (33), and a bell mouth (34).

[0035] The casing (40) comprises a casing body (41) and a decorative panel (42). The casing (40) houses an indoor fan (32), an indoor heat exchanger (31), a drain pan (43), and a bell mouth (44).

[0036] The indoor fan (32) is a so-called turbo fan. The indoor fan (32) draws in air from below and blows it out radially outward. The indoor fan (32) is located in the center inside the casing body (41).

[0037] The bell mouth (44) is positioned below the indoor fan (32). The bell mouth (44) is a component that guides the air flowing into the casing (40) to the indoor fan (32).

[0038] The indoor heat exchanger (31) is a so-called cross-fin type fin-and-tube heat exchanger. The indoor heat exchanger (31) exchanges heat with the refrigerant in the refrigerant circuit (11) as air passes from the inside to the outside.

[0039] The drain pan (43) is positioned below the indoor heat exchanger (31). The drain pan (43) is positioned to cover the lower end of the casing body (41). The drain pan (43) receives the drain water generated in the indoor heat exchanger (31).

[0040] A discharge passage (45) is formed in the drain pan (43). The discharge passage (45) is a passage through which air that has passed through the indoor heat exchanger (31) flows. The discharge passage (45) penetrates the drain pan (43) in the vertical direction.

[0041] The decorative panel (42) is a resin component formed in the shape of a thick, rectangular plate. The decorative panel (42) is positioned to cover the lower surface of the casing body (41). A single square-shaped intake port (46) is formed in the center of the decorative panel (42). The intake port (46) penetrates the decorative panel (42) vertically. A grid-like intake grille (47) is provided in the intake port (46). An air filter (48) is positioned above the intake grille (47).

[0042] Multiple air outlets (49) are formed in the decorative panel (42) so as to surround the intake port (46). The air outlets (49) penetrate the decorative panel (42) vertically. The air outlets (49) communicate with the air outlet passage (45). Air direction adjustment vanes (50) are provided inside the air outlets (49).

[0043] (1-3) Pump The air conditioning unit (10) includes a pump (51). As schematically shown in Figure 3, the pump (51) is located inside the drain pan (43). The pump (51) is located inside a recess (43b) formed in the bottom plate (43a) of the drain pan (43). The pump (51) pumps up the water accumulated in the drain pan (43) and discharges it. The water transported by the pump (51) is discharged to the outside via a water pipe (61).

[0044] (1-4) Water level detection unit The air conditioning unit (10) includes a water level detection unit (52). The water level detection unit (52) is located inside the drain pan (43). The water level detection unit (52) detects the water level in the drain pan (43). In this embodiment, the water level detection unit (52) is a float switch, but it may also be an ultrasonic, capacitive, or pressure-type water level detection unit. The water level detection unit (52) outputs a signal when the water level in the drain pan (43) reaches a predetermined value. The predetermined value is the upper limit height of the water in the drain pan (43).

[0045] (2) Operating The air conditioning system (10) performs cooling and heating operations.

[0046] (2-1) Cooling operation In cooling operation, the four-way switching valve (22) is set to the first state, and the refrigerant circulates in the refrigerant circuit (11). In the refrigerant circuit (11), the outdoor heat exchanger (23) functions as a heat radiator, and the indoor heat exchanger (31) functions as an evaporator. The indoor unit (30) cools the air drawn in from the indoor space in the indoor heat exchanger (31), and blows the cooled air back into the indoor space.

[0047] (2-2) Heating operation During heating operation, the four-way switching valve (22) is set to the second state, and the refrigerant circulates in the refrigerant circuit (11). In the refrigerant circuit (11), the indoor heat exchanger (31) functions as a radiator, and the outdoor heat exchanger (23) functions as an evaporator. The indoor unit (30) heats the air drawn in from the indoor space in the indoor heat exchanger (31), and blows the heated air back into the indoor space.

[0048] (2-3) Airflow in the indoor unit While the indoor unit is operating, the indoor fan (25) rotates. When the indoor fan (25) rotates, indoor air from the indoor space is drawn into the casing (40) through the intake port (46). The air inside the casing (40) is cooled or heated as it passes through the indoor heat exchanger (65). The cooled or heated air is blown out into the indoor space through the discharge passage (45) and the discharge outlet (49).

[0049] (3) Disinfection device The sterilization device (60) sterilizes and disinfects the water in the drain pan (43). In other words, the sterilization device (60) purifies the water in the drain pan (43). The sterilization device (60) comprises water piping (61), an irradiation unit (70), a filter (71), and a flow path switching valve (73).

[0050] (3-1) Water Piping The water piping (61) is the piping through which water flows in the drain pan (43). The water piping (61) comprises a drain pipe (62) and a branch channel (63A). The drain pipe (62) constitutes a channel for sending water transported from the drain pan (43) by the pump (51) to the outside. The branch channel (63A) branches off from the drain pipe (62) and is a channel for returning water to the drain pan (43). The branch channel (63A) is formed inside the branch pipe (63).

[0051] The inlet end of the drain pipe (62) is connected to the discharge side of the pump (51). The outlet end of the drain pipe (62) is connected to the outside of the air conditioning unit (10). The drain pipe (62) has a first pipe (P1), a second pipe (P2), a third pipe (P3), and a fourth pipe (P4) running from upstream to downstream. The first pipe (P1) extends upward from the pump (51) side. The second pipe (P2) extends horizontally from the outlet end of the first pipe (P1). The third pipe (P3) extends downward from the flow control valve (73) connected to the second pipe (P2). The fourth pipe (P4) extends diagonally downward from the outlet end of the third pipe (P3).

[0052] The inlet end of the branch pipe (63) is connected to the flow path switching valve (73). The outlet end of the branch pipe (63) opens towards the inside of the drain pan (43). The overall shape of the branch pipe (63) is roughly U-shaped. The curved portion of the branch pipe (63) is located laterally. The branch pipe (63) is composed of piping that extends downwards along its entire length. Here, "downward" includes both "vertically downwards" and "diagonally downwards". The branch pipe (63) may also have a horizontally extending portion. With this configuration, even when the pump (51) is stopped, the water in the branch pipe (63) can be discharged into the drain pan (43) by gravity.

[0053] Specifically, the branch pipe (63) has a fifth pipe (P5), a sixth pipe (P6), and a seventh pipe (P7) running from the upstream side to the downstream side. The fifth pipe (P5) extends diagonally downward from the flow path switching valve (73) side. The sixth pipe (P6) extends downward from the outlet end of the fifth pipe (P5). The seventh pipe (P7) extends diagonally downward from the outlet end of the sixth pipe (P6).

[0054] The diameter of the branch pipe (63) is the same as the diameter of the drain pipe (62), but the diameter of the branch pipe (63) may be smaller than the diameter of the drain pipe (62).

[0055] (3-2) Irradiation area The irradiation unit (70) is provided in the branched channel (63A). Specifically, in this embodiment, the irradiation unit (70) is provided in the seventh pipe (P7) downstream of the branched pipe (63). The irradiation unit (70) irradiates ultraviolet light toward the water in the branched channel (63A). The irradiation unit (70) has a UV light source, a lens, a control circuit for the UV light source, and a case to house them. Preferably, the peak wavelength of the ultraviolet light irradiated by the irradiation unit (70) is 255 nm or more and 275 nm or less. This can improve the sterilization effect of the water.

[0056] For example, the irradiation unit (70) is provided in the branch channel (63A) so as to close the opening formed in the peripheral wall of the branch pipe (63). The irradiation unit (70) irradiates ultraviolet light towards the water inside the branch pipe (63). The branch pipe (63) is preferably made of a material with excellent resistance to ultraviolet light, such as an inorganic material. This makes it possible to suppress the deterioration of the branch pipe (63) caused by ultraviolet light.

[0057] A tank may be connected to the branch pipe (63) midway, and the irradiation unit (70) may irradiate ultraviolet light towards the water in the tank. In this case, the flow path inside the tank constitutes part of the branch flow path (63A). The tank is preferably made of a material with excellent resistance to ultraviolet light, such as an inorganic material. This suppresses the deterioration of the tank due to ultraviolet light. In this configuration, the ultraviolet light irradiated from the irradiation unit (70) can be prevented from hitting the branch pipe (63), thus suppressing the deterioration of the branch pipe (63) due to ultraviolet light. Therefore, the branch pipe (63) can be made of polyvinyl chloride or a general metal material.

[0058] The irradiation unit (70) may be an integrated unit with the channel forming member that forms the water channel. The water channel is connected to the middle section of the branch pipe (63). The irradiation unit (70) irradiates ultraviolet light towards the water in the water channel within the channel forming member. In this case, the water channel constitutes a part of the branch channel (63A). The channel forming member is preferably made of a material with excellent resistance to ultraviolet light, such as an inorganic material. This suppresses deterioration of the channel forming member due to ultraviolet light. In this configuration, ultraviolet light irradiated from the irradiation unit (70) can be avoided from hitting the branch pipe (63), thus suppressing deterioration of the branch pipe (63) due to ultraviolet light. Therefore, the branch pipe (63) can be made of polyvinyl chloride or a general metal material.

[0059] (3-3) Filter The filter (71) is positioned upstream of the irradiation unit (70) in the water piping (61). The filter (71) purifies the water before it passes through the irradiation unit (70). The filter (71) is positioned upstream of the irradiation unit (70) in the branched channel (63A). Specifically, the filter (71) in this embodiment is provided in the fifth pipe (P5). The filter (71) captures solid components in the water. Specifically, the filter (71) reduces the turbidity of the water by capturing insoluble substances in the water. The filter (71) is composed of, for example, a filtration type filter or a strainer.

[0060] (3-4) Flow switching valve The flow path switching valve (73) is installed in the middle of the drain pipe (62). The flow path switching valve (73) is composed of a three-way valve. The flow path switching valve (73) has a first port (73a), a second port (73b), and a third port (73c). The first port (73a) communicates with the discharge side of the pump (51). The second port (73b) communicates with the outside of the air conditioning unit (10). The third port (73c) communicates with the branch flow path (63A). The flow path switching valve (73) switches between a first state and a second state. In the first state of the flow path switching valve (73), the first port (73a) and the second port (73b) communicate, and the first port (73a) and the third port (73c) communicate intermittently. In the second state of the flow path switching valve (73), the first port (73a) and the third port (73c) are in communication, and the first port (73a) and the second port (73b) are disconnected. In the first state of the flow path switching valve (73), the discharge side of the pump (51) is connected to the outside of the air conditioning unit (10) via the drain pipe (62). In the second state of the flow path switching valve (73), the discharge side of the pump (51) is connected to the branch flow path (63A).

[0061] (4) Configuration of the control unit As shown in Figure 4, the air conditioning system (S) includes an air conditioning control unit (80) provided in the air conditioning device (10) and a sterilization control unit (90) provided in the sterilization device (60). The air conditioning control unit (80) includes an outdoor control unit (81) provided in the outdoor unit (20) and an indoor control unit (82) provided in the indoor unit (30). The sterilization control unit (90) corresponds to the first control unit, and the air conditioning control unit (80) corresponds to the second control unit.

[0062] Each of the air conditioning control unit (80) and the sterilization control unit (90) includes an MCU (Micro Control Unit), electrical circuits, and electronic circuits. The MCU includes a CPU (Central Processing Unit), memory, and a communication interface. The memory stores various programs for the CPU to execute.

[0063] The outdoor control unit (81) and the indoor control unit (82) transmit and receive signals bidirectionally via a first communication line (W1). The air conditioning control unit (80) and the sterilization control unit (90) transmit and receive signals bidirectionally via a second communication line (W2). The first communication line (W1) and the second communication line (W2) can be wired or wireless. In this embodiment, the indoor control unit (82) and the sterilization control unit (90) are connected to each other via the second communication line (W2).

[0064] (4-1) Air Conditioning Control Unit The air conditioning control unit (80) controls the operation of the air conditioning system (10) and the various components of the air conditioning system (10).

[0065] The outdoor control unit (81) controls the ON / OFF status and rotation speed of the compressor (21). The outdoor control unit (81) controls the state of the four-way switching valve (22) and the opening degree of the expansion valve (24). The outdoor control unit (81) controls the ON / OFF status and rotation speed of the outdoor fan (25). The indoor control unit (82) controls the rotation speed of the indoor fan (32). The indoor control unit (82) controls the ON / OFF status of the pump (51). The indoor control unit (82) receives a signal output from the water level detection unit (52) when the water level in the drain pan (43) reaches the upper limit.

[0066] (4-2) Disinfection Control Unit The sterilization control unit (90) controls the ON / OFF status of the irradiation unit (70). The sterilization control unit (90) may also adjust the intensity of the ultraviolet light emitted from the irradiation unit (70). The sterilization control unit (90) controls the irradiation unit (70) in accordance with the signal output from the air conditioning unit (10). The sterilization control unit (90) controls the state of the flow path switching valve (73). Specifically, the sterilization control unit (90) controls the flow path switching valve (73) in accordance with the signal output from the air conditioning unit (10).

[0067] The signal output from the air conditioning unit (10) to the sterilization control unit (90) is a signal output from the air conditioning control unit (80), but it may also be a signal output directly from each device. This signal includes signals related to the operating status of the air conditioning unit (10), signals related to the operating status of the pump (51), and signals related to the water level detected by the water level detection unit (52).

[0068] (5) Control operation The control operation related to the drainage of the drain pan (43) will be explained in detail with reference to Figures 3 to 6. The sterilization device (60) of this embodiment performs a first operation and a second operation based on the determination result of the air conditioning control unit (80). In Figure 3, solid arrows indicate the water flow in the first operation, and dashed arrows indicate the water flow in the second operation.

[0069] (5-1) 1st action The first operation is a drainage operation to discharge the water in the drain pan (43) to the outside. In the first operation, the sterilization control unit (90) sets the flow path switching valve (73) to the first state and turns off the irradiation unit (70) while the pump (51) is operating. In the first operation, the irradiation unit (70) is in the OFF state, so the water is not sterilized by the irradiation unit (70).

[0070] In the first operation, the pump (51) draws up the water from the drain pan (43). The water discharged from the pump (51) flows through the drain pipe (62) and is discharged outside the air conditioning unit (10). Specifically, the water discharged from the pump (51) passes through the first pipe (P1), the second pipe (P2), the flow path switching valve (73), the third pipe (P3), and the fourth pipe (P4), and is sent to a drainage channel outside the air conditioning unit (10) system.

[0071] (5-2)Second operation The second operation is a circulating operation in which the water in the drain pan (43) is circulated and sterilized. In the second operation, the flow path switching valve (73) is set to the second state while the pump (51) is operating, and the irradiation unit (70) is turned ON. In the second operation, the irradiation unit (70) is turned ON, so the water is sterilized by the irradiation unit (70).

[0072] In the second operation, the pump (51) draws up the water from the drain pan (43). The water discharged from the pump (51) passes through the first pipe (P1), the second pipe (P2), and the flow path switching valve (73) of the drain pipe (62) before flowing into the branched flow path (63A). In the branched flow path (63A), the water is purified by the filter (71) located in the fifth pipe (P5). As a result, the turbidity of the water decreases. In other words, the water that passes through the filter (71) becomes clearer.

[0073] The water that has passed through the filter (71) passes through the irradiation unit (70) in the seventh pipe (P7). The irradiation unit (70) irradiates ultraviolet light towards the water flowing through the branch channel (63A). This sterilizes the water. Because the turbidity of this water has been reduced by the filter (71), the transmittance of ultraviolet light in the water increases. Therefore, the sterilization effect by ultraviolet light is improved. The water that has passed through the irradiation unit (70) returns to the drain pan (43).

[0074] As described above, sterilization of the water in the drain pan (43) suppresses the growth of bacteria in the drain pan (43). As a result, the formation of mold and slime that accompanies bacterial growth can be suppressed.

[0075] (5-3) Switching control between the first and second operations The switching control between the first and second operations will be explained with reference to Figures 5 and 6.

[0076] As shown in Figure 5, in step S11, the sterilization control unit (90) determines whether or not there is a command for cooling operation. Here, cooling operation is the operation in which the indoor heat exchanger (31) of the indoor unit (30) cools the air during the cooling operation described above. Cooling operation includes the operation in which the indoor heat exchanger (31) functions as an evaporator due to the so-called thermo-on. The command for cooling operation is output from the air conditioning control unit (80) to the sterilization control unit (90). If it is determined in step S11 that there is a command for cooling operation, the process moves on to step S12.

[0077] In step S12, the first operation is performed. More precisely, in the first operation, the air conditioning control unit (80) operates the pump (51), and the sterilization control unit (90) turns off the irradiation unit (70) and sets the flow path switching valve (73) to the first state. In the first operation, the sterilization control unit (90) may operate the pump (51) directly, or the sterilization control unit (90) may operate the pump (51) indirectly via the air conditioning control unit (80).

[0078] Thus, in this embodiment, the first operation is performed at the start of the cooling operation. At the start of the cooling operation, the air surrounding the indoor heat exchanger (31) is rapidly cooled, causing this air to fall below the dew point temperature, making it easy for condensation to form. For this reason, the water level in the drain pan (43) tends to rise at the start of the cooling operation. By performing the first operation at the start of the cooling operation, the rapid rise in the water level in the drain pan (43) can be suppressed.

[0079] In step S13, the sterilization control unit (90) determines whether or not the first time period ΔT1 has elapsed. The starting point of the first time period is when the command for cooling operation is input to the sterilization control unit (90), that is, the start of the cooling operation. If it is determined in step 13 that the first time period ΔT1 has elapsed, the process proceeds to step S14.

[0080] In step S14, the second operation is performed. More precisely, in the second operation, the pump (51) is operated continuously, the sterilization control unit (90) turns on the irradiation unit (70) and sets the flow path switching valve (73) to the second state. In the second operation, as described above, the water in the drain pan (43) is sterilized. In the second operation, the water in the drain pan (43) is not discharged to the outside, so the water level in the drain pan (43) gradually rises. After that, if the command for cooling operation continues (YES in step S15), the process moves on to step S16.

[0081] In step S16, the sterilization control unit (90) determines whether the water level in the drain pan (43) has reached the upper limit. When the water level detection unit (52) detects that the water level in the drain pan (43) has reached the upper limit, the signal output from the water level detection unit (52) is input to the sterilization control unit (90) via the air conditioning control unit (80). Based on this signal, the sterilization control unit (90) can determine whether the water level in the drain pan (43) has reached the upper limit. Alternatively, the sterilization control unit (90) may directly receive the signal output from the water level detection unit (52) and determine whether the water level in the drain pan (43) has reached the upper limit based on this signal. If it is determined in step S16 that the water level has reached the upper limit, the process proceeds to step S17.

[0082] In step S17, the first operation is performed. This causes the water in the drain pan (43) to be discharged to the outside again. As a result, the water level in the drain pan (43) gradually decreases. If the command for cooling operation continues (YES in step S18), the process proceeds to step S19.

[0083] In step S19, the sterilization control unit (90) determines whether or not the second time ΔT2 has elapsed. The starting point of the second time is the time when the previous first operation began. In this embodiment, the second time ΔT2 is longer than the first time ΔT1. The second time ΔT2 may be the same as the first time Δ1, or shorter than the first time ΔT1. If it is determined in step 19 that the second time ΔT2 has elapsed, the process returns to step S14, and the second operation is executed again. As a result, the water in the drain pan (43) is sterilized again.

[0084] As described above, when a command to operate the air conditioning is given, the first operation and the second operation are repeatedly executed alternately.

[0085] (6) Effects of the Embodiment The sterilization device (60) is equipped with an irradiation unit (70) that irradiates ultraviolet light toward the water in the branch channel (63A). The irradiation unit (70) directly irradiates ultraviolet light toward the water returning from the branch channel (63A) to the drain pan (43), thereby improving the sterilization effect of the water.

[0086] The sterilization control unit (90) turns on the irradiation unit (70) when the pump (51) operates and water flows through the branch channel (63A). This allows for continuous sterilization of the water in the branch channel (63A) while circulating the water in the drain pan (43). In addition, the heat emitted from the irradiation unit (70) when it is turned on can be released into the water. This suppresses the temperature rise of the irradiation unit (70), thereby extending the lifespan of the irradiation unit (70).

[0087] A filter (71) for purifying water is provided upstream of the irradiation unit (70) in the branched channel (63A). This reduces the turbidity of the water flowing through the irradiation unit (70), allowing ultraviolet light emitted from the irradiation unit (70) to penetrate the water more easily. As a result, the sterilization effect of the irradiation unit (70) on the water can be improved. In addition, the filter (71) is located in the branched channel (63A) rather than the drain pipe (62). This shortens the time the water flows through the filter (71), thus extending the lifespan of the filter (71).

[0088] The sterilization control unit (90) performs two actions: a first action, which sets the flow path switching valve (73) to a first state and turns off the irradiation unit (70) while the pump (51) is operating; and a second action, which sets the flow path switching valve (73) to a second state while the pump (51) is operating, operates the pump (51), and turns on the irradiation unit (70). This allows for selective switching between the first action, which discharges the water in the drain pan (43) to the outside, and the second action, which sterilizes the water in the drain pan (43) while circulating it.

[0089] The sterilization control unit (90) executes the first operation if the water level in the drain pan (43) reaches a predetermined value (upper limit) during the second operation. This allows the water in the drain pan (43) to be quickly discharged to the outside, thus reliably preventing the water in the drain pan (43) from overflowing.

[0090] (7) Variant The above-described embodiment may also be configured in the following modified form.

[0091] (7-1) Variation 1 In the above embodiment, the sterilization control unit (90) makes a determination to execute the first and second operations. However, the air conditioning control unit (80) may also make the determination to execute the first and second operations. Specifically, for example, in step S13, the air conditioning control unit (80) may determine that ΔT1 has elapsed, and if ΔT1 has elapsed, the air conditioning control unit (80) may output a signal to the sterilization control unit (90) to control the irradiation unit (70) and the flow path switching valve (73). In this case, the sterilization control unit (90), upon receiving this signal, turns on the irradiation unit (70) and sets the flow path switching valve (73) to the second state, thereby executing the second operation.

[0092] Furthermore, for example, in step S16, the air conditioning control unit (80) may determine that the water level in the drain pan (43) has reached the upper limit, and if the water level has reached the upper limit, the air conditioning control unit (80) may output a signal to the sterilization control unit (90) for controlling the irradiation unit (70) and the flow path switching valve (73). In this case, the sterilization control unit (90), upon receiving this signal, turns off the irradiation unit (70) and sets the flow path switching valve (73) to the first state, thereby executing the first operation.

[0093] (7-2) Variation 2 The air conditioning system (S) of Modified Example 2 differs from the air conditioning system (S) of the above embodiment in its method of determining the switch from the second operation to the first operation. As shown in Figure 7, the sterilization control unit (90) of Modified Example 2 performs the determination in step S26 instead of step S16 of the embodiment.

[0094] In step S26, the sterilization control unit (90) determines whether or not the third time period ΔT3 has elapsed. The starting point of the third time period ΔT3 is the time when the previous second operation began. In other words, the starting point of the third time period ΔT3 is when the sterilization control unit (90) turns on the irradiation unit (70) and switches the flow path switching valve (73) to the second state at the start of the second operation. If it is determined in step S26 that the third time period ΔT3 has elapsed, the process proceeds to step S17. As a result, the first operation is executed again, and the water in the drain pan (43) is discharged to the outside.

[0095] In Modification 2, the first and second operations are repeated alternately at predetermined intervals, starting from the timing when the command to start the cooling operation is input to the sterilization control unit (90). In Modification 2, the output unit for outputting the signal from the water level detection unit (52), the input unit for receiving this signal, and the communication line connecting the output unit and the input unit can be omitted. This simplifies the air conditioning system (S). In particular, existing air conditioning units (10) may not have an output unit for outputting the signal from the water level detection unit (52). Therefore, when adding a sterilization device (60) to an existing air conditioning unit (10) later, the control according to Modification 2 can be easily added.

[0096] (7-3) Modification 3 The sterilization control unit (90) may execute the first operation if either of the following conditions is met during the second operation: the first condition is that the water level in the drain pan (43) reaches a predetermined value (upper limit), or the second condition is that a predetermined time (third time Δ3) has elapsed during the second operation.

[0097] (7-4) Modification 4 In the control shown in Figures 5 and 7, if a cooling operation command is received in step S11, the processing in steps S12 and S13 may be omitted, and the process may proceed to step S14. In other words, when the sterilization control unit (90) receives a command to start the cooling operation, it may execute the second operation without executing the first operation.

[0098] (7-5) Variation 5 The sterilization control unit (90) may execute a second operation if the water level in the drain pan (43), as detected by the water level detection unit (52) during the first operation, reaches a predetermined value (lower limit). This lower limit is set to a predetermined height lower than the upper limit.

[0099] (7-6) Modification 6 The sterilization control unit (90) may perform a second operation when the air conditioner (10) stops operating, immediately after it stops, or during the period it is stopped. The sterilization control unit (90) may perform a first operation when the air conditioner (10) stops operating, immediately after it stops, or during the period it is stopped.

[0100] (7-7) Modification 7 The irradiation unit (70) may irradiate ultraviolet light toward the water in the branch channel (63A) when the pump (51) is stopped. Specifically, the irradiation unit (70) may irradiate ultraviolet light toward the water in the branch channel (63A) immediately after the pump (51) has stopped while in operation. Alternatively, the irradiation unit (70) may irradiate ultraviolet light toward the water flowing in the branch channel (63A) due to its own weight when the pump (51) is stopped.

[0101] (7-8) Variation 8 In this embodiment, the flow path switching valve (73) is provided in the second pipe (P2) of the drain pipe (62). However, the flow path switching valve (73) may also be provided in the first pipe (P1) of the drain pipe (62).

[0102] (7-9) Modification 9 In this embodiment, the filter (71) is provided in the branched flow path (63A). However, the filter (71) may also be provided upstream of the water flow of the irradiation section (70) in the drain pipe (62). Specifically, for example, the filter (71) may be provided in the first pipe (P1) or the second pipe (P2).

[0103] (7-10) Variation 10 In this embodiment, the water piping (61) may be configured without the flow path switching valve (73). In this case, when the pump (51) is operated, a portion of the water flowing through the drain pipe (62) is diverted to the branch flow path (63A) and returns to the drain pan (43). This allows the water in the drain pan (43) to be discharged to the outside while simultaneously sterilizing the water in the drain pan (43). In this configuration, it is preferable to make the diameter of the branch pipe (63) smaller than the diameter of the drain pipe (62). This prevents the amount of water discharged from the drain pan (43) to the outside from becoming too small when the pump (51) is operating, and prevents the water level in the drain pan (43) from rising.

[0104] (7-11) Variation 11 Modification 11 is an air conditioning system (10) having a configuration corresponding to the embodiment and the sterilization device (60) according to each of the modifications described above.

[0105] The air conditioning system (10) comprises the aforementioned water piping (61), an irradiation unit (70), a filter (71), and a flow path switching valve (73). As shown in Figure 8, the indoor control unit (82) controls the irradiation unit (70) and the flow path switching valve (73) in the same manner as the sterilization control unit (90) of the embodiment.

[0106] The indoor control unit (82) performs a first operation, which sets the flow path switching valve (73) to a first state and turns off the irradiation unit (70) while the pump (51) is operating, and a second operation, which sets the flow path switching valve (73) to a second state and turns on the irradiation unit (70) while the pump (51) is operating.

[0107] The indoor control unit (82) determines the switching between the first operation and the second operation in the same manner as in the above embodiment and each modified example. The air conditioning control unit (80) executes the first operation when the water level in the drain pan (43) reaches a predetermined value during the second operation. The air conditioning control unit (80) executes the first operation when a predetermined time has elapsed during the second operation.

[0108] While embodiments and modifications have been described above, it will be understood that a variety of changes in form and details are possible without departing from the spirit and scope of the claims. Furthermore, the embodiments, modifications, and other embodiments described above may be combined or substituted as appropriate, as long as they do not impair the functions covered by this disclosure.

[0109] The designations "1st," "2nd," "3rd," etc., mentioned above are used to distinguish between the terms to which these designations are attached, and do not limit the number or order of those terms. [Industrial applicability]

[0110] As described above, this disclosure is useful for sterilization devices and air conditioning devices. [Explanation of Symbols]

[0111] 10. Air conditioning system 43 Drain pan 51 Pump 60 Disinfection devices 62 Drain pipe 63A Branch channel 70 Irradiation area 71 Filters 72 Flow path switching valve 80 Air Conditioning Control Unit (Second Control Unit) 90 Disinfection Control Unit (First Control Unit)

Claims

1. A branch channel (63A) branches off from a drain pipe (62) that sends water transported by a pump (51) from the drain pan (43) of the air conditioning unit (10) to the outside, and returns the water to the drain pan (43), The branch channel (63A) includes an irradiation unit (70) that irradiates ultraviolet light toward the water within the branch channel (63A). Disinfection device.

2. The system includes a first control unit (90) that turns on the irradiation unit (70) when the pump (51) is operating and water flows through the branch channel (63A). The sterilization device according to claim 1.

3. The system includes a filter (71) that purifies the water before it passes through the irradiation unit (70). The disinfection device according to claim 2.

4. The filter (71) is positioned upstream of the irradiation unit (70) in the branched channel (63A) of the water flow. The sterilization device according to claim 3.

5. The system includes a flow path switching valve (73) that switches between a first state in which the discharge side of the pump (51) is connected to the outside via the drain pipe (62), and a second state in which the discharge side of the pump (51) is connected to the branch flow path (63A). The first control unit (90) performs a first operation in which the flow path switching valve (73) is set to a first state and the irradiation unit (70) is turned OFF while the pump (51) is operating, and a second operation in which the flow path switching valve (73) is set to a second state, the pump (51) is operated and the irradiation unit (70) is turned ON while the pump (51) is operating. A sterilization device according to any one of claims 2 to 4.

6. The first control unit (90) causes the first operation to be executed when the water level in the drain pan (43) reaches a predetermined value during the second operation. The disinfection device according to claim 5.

7. The first control unit (90) causes the first operation to be executed when a predetermined time has elapsed during the second operation. The disinfection device according to claim 5.

8. Drain pan (43) and A pump (51) for transporting the water in the drain pan (43), A drain pipe (62) for sending the water transported by the pump (51) to the outside, A branch channel (63A) branches off from the drain pipe (62) and returns the water to the drain pan (43), The branch channel (63A) is equipped with an irradiation unit (70) that irradiates ultraviolet light toward the water within the branch channel (63A). Air conditioning system.

9. The system includes a second control unit (80) that turns on the irradiation unit (70) when the pump (51) is operating and water flows through the branch channel (63A). The air conditioning device according to claim 8.

10. The system includes a flow path switching valve (73) that switches between a first state in which the discharge side of the pump (51) is connected to the outside via the drain pipe (62), and a second state in which the discharge side of the pump (51) is connected to the branch flow path (63A). The second control unit (80) causes the pump (51) to operate and perform a first operation, which is to set the flow path switching valve (73) to a first state and turn off the irradiation unit (70), and a second operation, which is to set the flow path switching valve (73) to a second state and turn on the irradiation unit (70) while the pump (51) is operating. The air conditioning device according to claim 9.

11. The second control unit (80) causes the first operation to be executed when the water level in the drain pan (43) reaches a predetermined value during the second operation. The air conditioning device according to claim 10.

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