WO2023223496A1

WO2023223496A1 - Ultraviolet light irradiation device and air conditioning device including same

Info

Publication number: WO2023223496A1
Application number: PCT/JP2022/020818
Authority: WO
Inventors: 彰守川; 典亮勝又
Original assignee: 三菱電機株式会社
Priority date: 2022-05-19
Filing date: 2022-05-19
Publication date: 2023-11-23
Also published as: JPWO2023223496A1; JP7286034B1

Abstract

Provided are an ultraviolet light irradiation device that achieves a reduction in the frequency of replacement of light emitting elements that emit ultraviolet light, and thus is usable for a long period of time, and an air conditioning device including the ultraviolet light irradiation device. An ultraviolet light irradiation device (5) comprises: a long-wavelength LED element (6) that emits ultraviolet light having a first wavelength; a short-wavelength LED element (7) that emits ultraviolet light having a second wavelength different from that of the long-wavelength LED element (6); a power supply circuit (51) that supplies current to the long-wavelength LED element (6) and the short-wavelength LED element (7); and a control circuit (52) that controls the power supply circuit (51), and adjusts the lighting timing and the lighting duration of the long-wavelength LED element (6) and the short-wavelength LED element (7). The control circuit (52) lights the short-wavelength LED element (7) after lighting the long-wavelength LED element (6), so that the lighting duration of the long-wavelength LED element (6) is longer than the lighting duration of the short-wavelength LED element (7).

Description

Ultraviolet light irradiation device and air conditioner using the same

The present disclosure relates to an ultraviolet light irradiation device that treats microorganisms such as bacteria, mold, and viruses, and an air conditioner using the same.

Ultraviolet light with a wavelength of 200 to 350 nm not only acts on nucleic acids, which are the protoplasm of bacteria, inhibiting DNA replication and depriving them of their ability to proliferate, but also destroys the cytoplasm and proteins that form the cell membrane. It is known to have the effect of killing bacteria and viruses. Ultraviolet light irradiation devices have been put into practical use that utilize the action of such ultraviolet light to sterilize microorganisms such as bacteria, mold, and viruses, or to inactivate viruses (sterilization and inactivation treatment).

For example, an ultraviolet light irradiation device disclosed in Japanese Patent Application Publication No. 2018-069029 (Patent Document 1) includes a UV light assembly that irradiates a structure with ultraviolet light and a control unit that controls the UV light assembly. . The control unit controls the UV light assembly to separately irradiate the structure with ultraviolet light of a first band and ultraviolet light of a second band different from the first band.

In addition, the ultraviolet light irradiation device disclosed in Japanese Patent Application Laid-open No. 2010-275841 (Patent Document 2) includes a plurality of ultraviolet light LEDs that irradiate ultraviolet light into the interior of a drainage section that discharges water, and a plurality of ultraviolet light a lighting circuit unit that pulse-lights the LED; a control circuit unit that controls the lighting circuit unit so as to reduce the amount of ultraviolet light irradiation from the ultraviolet LED within a predetermined time as the number of times the ultraviolet LED is lit increases; It is equipped with

Japanese Patent Application Publication No. 2018-069029 JP2010-275841A

However, light-emitting elements that can emit ultraviolet light with a short wavelength (for example, 280 nm or less) that efficiently sterilizes microorganisms or inactivates viruses have a short lifespan. Therefore, in an ultraviolet light irradiation device that employs the light emitting element, the light emitting element needs to be replaced frequently due to its lifespan, which may increase the maintenance cost of the device.

Therefore, the present disclosure is intended to solve the above-mentioned problems, and provides an ultraviolet light irradiation device that reduces the frequency of replacement of light emitting elements that emit ultraviolet light and can be used for a long period of time, and an air conditioner using the same. is intended to provide.

The ultraviolet light irradiation device according to the present disclosure is an ultraviolet light irradiation device that treats microorganisms such as bacteria, mold, and viruses. The ultraviolet light irradiation device includes a first light emitting element that emits ultraviolet light of a first wavelength, a second light emitting element that emits ultraviolet light of a second wavelength different from the first wavelength, and a first light emitting element that emits ultraviolet light of a second wavelength different from the first wavelength. The device includes a power supply circuit that supplies current to the element and the second light emitting element, and a control circuit that controls the power supply circuit and adjusts the lighting timing and lighting time of the first light emitting element and the second light emitting element. The control circuit lights up the second light emitting element after lighting the first light emitting element, and makes the lighting time of the first light emitting element longer than the lighting time of the second light emitting element.

According to the present disclosure, the ultraviolet light irradiation device lights up the second light emitting element after lighting the first light emitting element, and makes the lighting time of the first light emitting element longer than the lighting time of the second light emitting element. Therefore, while microorganisms such as bacteria, mold, and viruses are sterilized and inactivated, the frequency of replacing the second light emitting element that emits ultraviolet light can be reduced, and it can be used for a long period of time.

1 is a side sectional view of an indoor unit of an air conditioner according to Embodiment 1. FIG. 1 is a block diagram showing the configuration of an ultraviolet light irradiation device according to Embodiment 1. FIG. FIG. 3 is a diagram for explaining sterilization and inactivation processing of the ultraviolet light irradiation device in the indoor unit of the air conditioner according to the first embodiment. It is a figure for explaining an example of the lighting pattern of an ultraviolet light irradiation device. It is a graph showing experimental results when irradiating light from a long wavelength LED element. It is a graph showing experimental results when irradiating light from a short wavelength LED element. FIG. 3 is a side cross-sectional view of an indoor unit of an air conditioner according to a second embodiment. FIG. 7 is a side sectional view of an indoor unit of an air conditioner according to Embodiment 3;

Embodiment 1.
<Configuration of indoor unit of air conditioner>
FIG. 1 is a side sectional view of an indoor unit 1 of an air conditioner according to a first embodiment. The air conditioner is composed of an indoor unit 1 and an outdoor unit (not shown), and refrigerant is exchanged between the

heat exchangers

8, 9, 10 of the indoor unit 1 and the heat exchanger of the outdoor unit via piping. Flowing. The

heat exchangers

8, 9, and 10 of the indoor unit 1 function as an evaporator when performing a cooling operation, and function as a condenser when performing a heating operation.

The indoor unit 1 includes a suction port 2, a filter 3, a rotating gear 4, an ultraviolet light irradiation device 5,

heat exchangers

8, 9, and 10, a blower fan 11, a drain pan 12, and an air outlet 13. , and a brush 15. The suction port 2 sucks indoor air as shown by the arrow. The filter 3 cleans the sucked air.

Heat exchangers

8, 9, and 10 cool or heat the sucked air. The air outlet 13 discharges cooled or heated air into the room as shown by the arrow. The blower fan 11 creates a flow of air from the inlet 2 to the outlet 13.

The rotating gear 4 and the brush 15 are provided to clean the filter 3, and by winding up the filter 3 with the rotating gear 4, the brush 15 removes deposits on the filter 3. Drain pan 12 receives condensed water from heat exchanger 8 . When performing cooling operation or heating operation, the air conditioner adjusts the temperature of the air blown out from the outlet 13 by cooling or heating the

heat exchangers

8, 9, and 10 to maintain an appropriate indoor temperature. It is kept in

The filter 3 employs a mesh structure made of polypropylene resin, for example. When air passes through this filter 3, bacteria, mold, viruses, floating particles, etc. in the air are captured and become deposits on the filter 3.

The indoor unit 1 of the air conditioner according to the first embodiment is provided with an ultraviolet light irradiation device 5 that treats microorganisms such as bacteria, mold, and viruses contained in the deposits on the filter 3. The ultraviolet light irradiation device 5 includes a long wavelength LED element 6 with a center wavelength of 370 nm and a short wavelength LED element 7 with a center wavelength of 260 nm. The ultraviolet light irradiation device 5 sterilizes microorganisms such as bacteria, mold, and viruses or inactivates viruses by irradiating the object to be treated with ultraviolet light from a long wavelength LED element 6 and a short wavelength LED element 7. let In addition, in this disclosure, the process of sterilizing microorganisms such as bacteria, molds, and viruses or inactivating viruses is also referred to as sterilization and inactivation treatment.

The ultraviolet light irradiation device 5 employs an LED (Light Emitting Diode) element as a light emitting element that emits ultraviolet light. However, the present invention is not limited thereto, and other light emitting elements such as semiconductor lasers may be employed in the ultraviolet light irradiation device 5 as long as they emit ultraviolet light.

In the ultraviolet light irradiation device 5 shown in FIG. 1, a long wavelength LED element 6 is installed on the left side of the figure, and a short wavelength LED element 7 is installed on the right side of the figure. However, the ultraviolet light irradiation device 5 is not limited to this, and the short wavelength LED element 7 may be installed on the left side of the figure, and the long wavelength LED element 6 may be installed on the right side of the figure. Further, although one long wavelength LED element 6 and one short wavelength LED element 7 are each installed in FIG. 1, a plurality of each may be installed. For example, when the filter 3 has a flat plate shape, a plurality of long wavelength LED elements 6 and short wavelength LED elements 7 are provided in the short side direction of the filter 3 so that light can be irradiated along the short side direction of the filter 3. Install.

The long wavelength LED element 6 is a first light emitting element that emits ultraviolet light (UV-A) with a center wavelength (first wavelength) of 370 nm. Note that although the long wavelength LED element 6 emits ultraviolet light at the center wavelength, the wavelength range in which it emits light may include visible light. The short wavelength LED element 7 is a second light emitting element that emits ultraviolet light (UV-C) with a center wavelength (second wavelength) of 260 nm. Although the short wavelength LED element 7 emits ultraviolet light at the center wavelength, the wavelength range in which it emits light may include visible light. Further, the center wavelength (second wavelength) of the short wavelength LED element 7 is shorter than the center wavelength (first wavelength) of the long wavelength LED element 6.

It is generally known that a light-emitting element that emits light at a shorter wavelength has a shorter lifespan than a light-emitting element that emits light at a longer wavelength. Therefore, the lifespan of the short wavelength LED element 7 (second light emitting element) is shorter than that of the long wavelength LED element 6 (first light emitting element). When the short wavelength LED element 7 and the long wavelength LED element 6 are turned on for the same period of time, the short wavelength LED element 7 reaches the end of its life first and needs to be replaced. Therefore, in the ultraviolet light irradiation device 5 according to the present disclosure, as will be described later, the lighting timing and lighting time of the long wavelength LED element 6 and the short wavelength LED element 7 are devised to reduce the frequency of replacing the short wavelength LED element 7. It is designed to be used for a long period of time.

In addition, in the following ultraviolet light irradiation device 5, it will be explained that the second wavelength of the second light emitting element is shorter than the first wavelength of the first light emitting element. The first wavelength and the second wavelength may be different as long as they are shorter than the lifetime of the first light emitting element. Further, FIG. 1 shows the indoor unit 1 in a normal state where the filter 3 is not being cleaned by the rotating gear 4 and the brush 15 and the ultraviolet light irradiation device 5 is not being driven.

<Ultraviolet light irradiation device>
Next, the configuration of the ultraviolet light irradiation device 5 will be explained in detail. FIG. 2 is a block diagram showing the configuration of the ultraviolet light irradiation device 5 according to the first embodiment. The ultraviolet light irradiation device includes a long wavelength LED element 6, a short wavelength LED element 7, a power supply circuit 51, and a control circuit 52. The power supply circuit 51 supplies current to the long wavelength LED element 6 and the short wavelength LED element 7. The control circuit 52 controls the power supply circuit 51 and adjusts the lighting timing and lighting time of the long wavelength LED element 6 and the short wavelength LED element 7.

The control circuit 52 is communicably connected to the control section 100 of the indoor unit 1. Therefore, the control circuit 52 can acquire the operating status of the indoor unit 1 from the control unit 100 of the indoor unit 1, and can also provide the driving status of the ultraviolet light irradiation device 5 to the control unit 100. The ultraviolet light irradiation device 5 can appropriately drive the ultraviolet light irradiation device 5 according to the operating status of the indoor unit 1.

The ultraviolet light irradiation device 5 further includes a memory circuit 53. The storage circuit 53 stores a lighting pattern that defines the lighting timing and lighting time of the long wavelength LED element 6 and the short wavelength LED element 7. Note that the ultraviolet light irradiation device 5 may have a configuration that does not include the storage circuit 53 if there is no need to store the lighting pattern.

<Sterilization and inactivation treatment>
Next, the filter 3 is cleaned by the rotating gear 4 and the brush 15, and the sterilization and inactivation treatment performed by the ultraviolet light irradiation device 5 will be described. FIG. 3 is a diagram for explaining sterilization and inactivation processing of the ultraviolet light irradiation device 5 in the indoor unit 1 of the air conditioner according to the first embodiment. First, when the indoor unit 1 performs cooling operation or heating operation for a set period of time (for example, 10 hours), the indoor unit 1 performs cleaning of the filter 3 (sterilization and inactivation treatment of lighting up the long wavelength LED element 6 and short wavelength LED element 7). including). Specifically, the control unit 100 of the indoor unit 1 operates the rotation gear 4 to move the filter 3 toward the brush 15. By moving the filter 3 toward the brush 15, the filter 3 is rubbed by the brush 15, and bacteria, mold, viruses, and fine particles adhering to the filter 3 are removed. Bacteria, mold, viruses, and particulates that could not be removed by the brush 15 remain in the filter 3.

In order to sterilize microorganisms such as bacteria, mold, and viruses remaining in the filter 3 or to inactivate viruses, the ultraviolet light irradiation device 5 is driven. The ultraviolet light irradiation device 5 starts the sterilization and inactivation process when one end of the filter 3 reaches above the long wavelength LED element 6 in the figure. Note that the rotation gear 4 does not rotate continuously, but rotates in steps. Therefore, each time the rotation gear 4 is rotated by a predetermined angle, the range of the filter 3 located above the long wavelength LED element 6 and the short wavelength LED element 7 moves. The long wavelength LED element 6 and the short wavelength LED element 7 are fixed to the indoor unit 1 at an irradiation angle that is equal to or higher than an appropriate irradiation intensity for the range of the filter 3 located above. That is, the positions of the long wavelength LED element 6 and the short wavelength LED element 7 are fixed so that they can irradiate the range (solid surface) of the filter 3 with ultraviolet light.

First, the ultraviolet light irradiation device 5 performs a sterilization and inactivation process on the filter 3 within a predetermined range from one end. The lighting pattern for the sterilization and inactivation process is stored in advance in the memory circuit 53. FIG. 4 is a diagram for explaining an example of a lighting pattern of the ultraviolet light irradiation device 5. As shown in FIG. The lighting pattern in FIG. 4 shows the lighting timing and lighting time of the long wavelength LED element 6 and the short wavelength LED element 7. The control circuit 52 turns on the long wavelength LED element 6 at the start time _t1 , turns off the long wavelength LED element 6 after the elapse of time Ta, and turns on the short wavelength LED element 7. The control circuit 52 turns on the short wavelength LED element 7 for a time Tc, and then turns off the light at end time _t2 .

Thereafter, the rotation gear 4 rotates counterclockwise by a predetermined angle to send the filter 3 to the range where the filter 3 has newly moved to a position above the long wavelength LED element 6 and the short wavelength LED element 7. On the other hand, sterilization and inactivation treatment is performed using the lighting pattern shown in FIG. The ultraviolet light irradiation device 5 repeats the sterilization and inactivation process in the lighting pattern shown in FIG. 4 until the other end of the filter 3 reaches the upper part of the long wavelength LED element 6 in the figure.

Here, the total lighting time T of the lighting pattern is time Ta + time Tc, which is less than or equal to the time from when the rotating gear 4 rotates at a predetermined angle in the counterclockwise direction to when it rotates at the next predetermined angle. It is. Furthermore, the total lighting time T of the lighting pattern is not the same as the time Ta during which the long wavelength LED element 6 is lit and the time Tc during which the short wavelength LED element 7 is lit; It is shorter than the lighting time T. That is, the long wavelength LED element 6 and the short wavelength LED element 7 are each intermittently lit within the total lighting time T. Note that the long wavelength LED element 6 may be lit continuously within the total lighting time T, and if the short wavelength LED element 7 is lit at least intermittently, the frequency of replacement of the short wavelength LED element 7 can be suppressed. can.

Thereafter, when the other end of the filter 3 reaches above the long wavelength LED element 6, the rotation gear 4 rotates clockwise to return the filter 3 to the state shown in FIG. 1 and cleans the filter 3. The ultraviolet light irradiation device 5 then ends the sterilization and inactivation process. Then, the indoor unit 1 can perform cooling operation or heating operation.

Next, the effect when the object to be processed is irradiated with only the long wavelength LED element 6 will be explained. FIG. 5 is a graph showing experimental results when light from the long wavelength LED element 6 was irradiated. In FIG. 5, the horizontal axis represents the elapsed time when only the long wavelength LED element 6 is continuously lit, and the vertical axis represents the virus inactivation rate. The long wavelength LED element 6 was prepared in two cases, one with a center wavelength of 370 nm and the other with a center wavelength of 410 nm. The virus to be treated was φX174, which is a phage that infects Escherichia coli, and the experiment was conducted by attaching it to the filter 3 in advance.

The virus inactivation rate was determined by washing the filter 3 with sterilized water after the experiment, diluting the washing water appropriately and quantifying it using the plaque method, and the number of virus reductions from the elapsed time of 0 seconds is shown as a logarithm. In FIG. 5, the results of the background without irradiation with the light of the long wavelength LED element 6 are shown with a cross mark (x), and the results of irradiation with the light of the long wavelength LED element 6 with a center wavelength of 370 nm are shown with the triangle mark (△). ), and the results of irradiation with light from the long wavelength LED element 6 having a center wavelength of 410 nm are indicated by circles (◯).

The results shown in Figure 5 show that when irradiated with 370 nm light, the virus inactivation rate decreased by two orders of magnitude, or 99%, by the time 3000 seconds passed, but even after 3000 seconds, the virus inactivation rate decreased by 99%. It can be seen that there is almost no change in the inactivation rate. Furthermore, when irradiated with 410 nm light, the virus inactivation rate decreased by one order of magnitude by the time 5000 seconds passed, but there was almost no change in the virus inactivation rate even after 5000 seconds passed. I understand that.

Such a phenomenon is known as the photorecovery effect of ultraviolet light, and is known to occur not only in LED elements but also in other light sources such as UV lamps. The mechanism is thought to be based on a repair mechanism possessed by microorganisms, but the mechanism has not yet been clearly elucidated. However, it is clear from the results shown in FIG. 5 that it is difficult to reduce the virus inactivation rate even if the elapsed time becomes long. Therefore, it is suggested that if it is desired to further reduce the inactivation rate of the virus, it is necessary to irradiate the virus with light having a shorter wavelength than the light from the long wavelength LED element 6.

Next, the effect when the object to be processed is irradiated with only the short wavelength LED element 7 will be explained. FIG. 6 is a graph showing experimental results when light from a short wavelength LED element is irradiated. In FIG. 6, the horizontal axis represents the elapsed time when only the short wavelength LED element 7 is continuously lit, and the vertical axis represents the virus inactivation rate. The short wavelength LED element 7 has a center wavelength of 260 nm. The virus to be treated was φX174, which is a phage that infects Escherichia coli, and the experiment was conducted by attaching it to the filter 3 in advance.

The virus inactivation rate was determined by washing the filter 3 with sterilized water after the experiment, diluting the washing water appropriately, and quantifying it using the plaque method, and the number of decreases from the elapsed time of 0 seconds is shown as a logarithm. In FIG. 6, the results of irradiation with light from the short wavelength LED element 7 having a center wavelength of 260 nm are indicated by square marks (□).

The results shown in Figure 6 show that when irradiated with 260 nm light, the virus inactivation rate decreases exponentially with the elapsed time, and by the time 30 seconds have passed, the virus inactivation rate has increased by three orders of magnitude or more, i.e. It can be seen that it has decreased by more than 99.9%. In other words, when irradiated with light from a short wavelength LED element, although the photorecovery effect of ultraviolet light is observed, the effect of reducing the virus inactivation rate by more than two orders of magnitude can be obtained, and the lighting time of the short wavelength LED element 7 Experimental results showed that the length can be shortened.

In Figures 5 and 6, the experiment was conducted using a phage that infects Escherichia coli as the object to be treated, but when the target is a different type of virus, bacteria, mold, etc., the virus inactivation rate is It is conceivable that the time required to reduce by more than two orders of magnitude may differ. Therefore, the ultraviolet light irradiation device 5 conducts experiments in advance and sets the lighting times (Ta, Tc) of the long wavelength LED element 6 and the short wavelength LED element 7 depending on the type of the object to be treated.

As for LED elements, elements that can emit light from infrared light to ultraviolet light have been put into practical use. Historically, development has progressed from elements that can emit long-wavelength infrared light to elements that can emit short-wavelength ultraviolet light. Therefore, when we compare the lifespan of LED elements of each wavelength by continuously irradiating them, we find that elements that can emit long-wavelength infrared light are more durable than elements that can emit short-wavelength ultraviolet light. It is generally known to have a long lifespan.

From the experimental results shown in FIGS. 5 and 6, the virus inactivation rate can be reduced by making the time Ta for lighting the long wavelength LED element 6 shown in FIG. 4 longer than the time Tc for lighting the short wavelength LED element 7. I understand that. For example, the time Ta is the elapsed time (e.g., 3000 seconds) when the long wavelength LED element 6 is turned on and the virus inactivation rate decreases to 99%, and the short wavelength LED element 7 is turned on and the virus inactivation rate is decreased to 99%. The elapsed time (for example, 10 seconds) at which the amount decreases to 99.9% is set as time Tc. Thereby, the life of the ultraviolet light irradiation device 5 as a whole becomes longer, and the frequency of maintenance for replacing the LED elements can be reduced. If you want to shorten the time it takes to reduce the virus inactivation rate to 99.9%, you can achieve this by setting a lighting pattern that shortens the time Ta and lengthens the time Tc. In this case, since the load on the short wavelength LED element 7 increases, the life of the short wavelength LED element 7 is slightly shortened, and the life of the ultraviolet light irradiation device 5 itself is also shortened.

In addition, in the sterilization and inactivation treatment, although it has been explained that the rotation gear 4 rotates in a stepwise manner, it may be rotated continuously. In this case, the ultraviolet light irradiation device 5 needs to adjust the lighting time of the long wavelength LED element 6 and the short wavelength LED element 7 in advance so that the filter 3 can be sufficiently sterilized and inactivated. Further, the ultraviolet light irradiation device 5 performs sterilization and inactivation processing on the filter 3 when the rotation gear 4 is rotating counterclockwise, but when returning the filter 3 to the normal state, that is, when the rotation gear 4 rotates counterclockwise, When the rotation gear 4 is rotating clockwise, the filter 3 may be subjected to sterilization and inactivation treatment. In this case, instead of installing the long wavelength LED element 6 on the left side of the figure and the short wavelength LED element 7 on the right side of the figure as shown in FIG. 1, the ultraviolet light irradiation device 5 should be installed in the opposite position. can perform sterilization and inactivation treatment efficiently.

As described above, the ultraviolet light irradiation device 5 according to Embodiment 1 treats microorganisms such as bacteria, mold, and viruses. The ultraviolet light irradiation device 5 includes a long wavelength LED element 6 that emits ultraviolet light of a first wavelength, and a short wavelength LED element 7 that emits ultraviolet light of a second wavelength that is different from the long wavelength LED element 6. A power supply circuit 51 that supplies current to the long wavelength LED element 6 and the short wavelength LED element 7, and a control circuit that controls the power supply circuit 51 and adjusts the lighting timing and lighting time of the long wavelength LED element 6 and the short wavelength LED element 7. 52. The control circuit 52 turns on the short wavelength LED element 7 after turning on the long wavelength LED element 6, and makes the lighting time of the long wavelength LED element 6 longer than the lighting time of the short wavelength LED element 7.

Thereby, the ultraviolet light irradiation device 5 according to the first embodiment lights up the short wavelength LED element 7 after lighting the long wavelength LED element 6, and changes the lighting time of the long wavelength LED element 6 to the lighting time of the short wavelength LED element 7. Since the time is longer than the time, it is possible to sterilize and inactivate microorganisms such as bacteria, mold, and viruses, while reducing the frequency of replacement of the short wavelength LED element 7 that emits ultraviolet light, and allowing it to be used for a long period of time.

The second wavelength of the ultraviolet light emitted by the short wavelength LED element 7 is preferably shorter than the first wavelength of the light emitted by the long wavelength LED element 6. Thereby, the lighting time of the short wavelength LED element 7, which has a short life span, can be reduced, and the frequency of replacement can be reduced.

It is preferable that the control circuit 52 lights up the short wavelength LED element 7 at least intermittently. Thereby, the lighting time of the short wavelength LED element 7, which has a short life span, can be reduced, and the frequency of replacement can be reduced.

Preferably, the long wavelength LED element 6 and the short wavelength LED element 7 are fixed in position so that they can irradiate light onto the solid surface. Thereby, microorganisms such as bacteria, mold, and viruses attached to the solid surface can be sterilized and inactivated.

The ultraviolet light irradiation device 5 further includes a memory circuit 53 that stores a lighting pattern that defines the lighting timing and lighting time of the long wavelength LED element 6 and the short wavelength LED element 7. It is preferable to change the lighting timing and lighting time of the long wavelength LED element 6 and the short wavelength LED element 7 based on the lighting pattern. Thereby, it is possible to change the lighting timing and lighting time so that the long-wavelength LED element 6 and the short-wavelength LED element 7 can have longer lives while performing sterilization and inactivation treatment.

The air conditioner includes a filter 3 through which air passes,

heat exchangers

8, 9, and 10 that exchange heat between the air and a refrigerant, a drain pan 12 that receives water, and an ultraviolet light irradiation device 5. The light irradiation device 5 fixes the positions of the long wavelength LED element 6 and the short wavelength LED element 7 so that the light can be irradiated toward at least one of the filter 3, the

heat exchangers

8, 9, and 10, and the drain pan 12. It is preferable that the Thereby, microorganisms such as bacteria, mold, and viruses attached to at least one of the filter 3, the

heat exchangers

8, 9, and 10, and the drain pan 12 can be sterilized and inactivated.

It is preferable that the control circuit 52 starts the control of lighting up the long wavelength LED element 6 and the short wavelength LED element 7 after performing the cooling operation or the heating operation for a set time. Thereby, sterilization and inactivation processing can be performed periodically.

Embodiment 2.
It has been explained that the ultraviolet light irradiation device 5 according to the first embodiment sterilizes and inactivates microorganisms such as bacteria, mold, and viruses that adhere to the filter 3. In the ultraviolet light irradiation device according to the second embodiment, a configuration for sterilizing and inactivating microorganisms such as bacteria, mold, and viruses attached not only to the filter but also to the drain pan will be described. FIG. 7 is a side sectional view of the indoor unit 1 of the air conditioner according to the second embodiment. In the indoor unit 1 according to the second embodiment, the same components as the indoor unit 1 according to the first embodiment are given the same reference numerals, and detailed description thereof will not be repeated.

In the ultraviolet light irradiation device 5 shown in FIG. 7, a long wavelength LED element 6a and a short wavelength LED element 7a are added so that light can be irradiated toward the drain pan 12. The long wavelength LED element 6a emits ultraviolet light having the same center wavelength as the long wavelength LED element 6 at 370 nm, and the short wavelength LED element 7a emits ultraviolet light having the same center wavelength as the short wavelength LED element 7 at 260 nm. Since the drain pan 12 has a long shape in the depth direction in the figure, a plurality of long wavelength LED elements 6a and a plurality of short wavelength LED elements 7a are provided in this direction. Thereby, the entire drain pan 12 can be irradiated with ultraviolet light from the long wavelength LED element 6a and the short wavelength LED element 7a.

When the air conditioner is performing cooling operation, the heat exchanger 8 condenses, and the condensed water flows down to the drain pan 12 and stays at the bottom of the drain pan 12. When water accumulates at the bottom of the drain pan 12, bacteria, mold, etc. multiply, and viruses accumulate. Therefore, in the ultraviolet light irradiation device 5, the long wavelength LED element 6a and the short wavelength LED element 7a are fixed to the indoor unit 1 at an irradiation angle that is equal to or higher than the appropriate irradiation intensity with respect to the bottom surface of the drain pan 12. Therefore, the ultraviolet light irradiation device 5 irradiates the bottom part of the drain pan 12 with ultraviolet light from the long wavelength LED element 6a and the short wavelength LED element 7a to sterilize microorganisms such as bacteria, mold, and viruses, or to eliminate viruses. Activation treatment can be performed.

The ultraviolet light irradiation device 5 may perform the sterilization and inactivation treatment on the drain pan 12 at the same time as the sterilization and inactivation treatment on the filter 3 described in the first embodiment. Alternatively, the ultraviolet light irradiation device 5 may perform a sterilization and inactivation process on the drain pan 12 periodically, for example, once a day, in addition to the sterilization and inactivation process on the filter 3.

Even when performing sterilization and inactivation treatment on the drain pan 12 using the long wavelength LED element 6a and the short wavelength LED element 7a, the ultraviolet light irradiation device 5 lights up the short wavelength LED element 7a after lighting the long wavelength LED element 6a. However, the lighting time of the long wavelength LED element 6a is made longer than the lighting time of the short wavelength LED element 7a. Specifically, the control circuit 52 first turns on the long wavelength LED element 6a for a period of time until the virus inactivation rate decreases by two digits (for example, 3000 seconds), then turns off the light, and then turns on the short wavelength LED element 7a. The light is turned on for a period of time (for example, 15 seconds) until the virus inactivation rate decreases to three digits or less, and then the light is turned off.

As described above, the ultraviolet light irradiation device 5 according to the second embodiment can remove microorganisms such as bacteria, mold, and viruses in the drain pan 12 by lighting the long wavelength LED element 6a and the short wavelength LED element 7a as described above. While performing sterilization and inactivation treatment, the frequency of replacement of the short wavelength LED element 7a that emits ultraviolet light can be reduced, and it can be used for a long period of time.

Embodiment 3.
In the ultraviolet light irradiation device according to the third embodiment, a configuration for sterilizing and inactivating microorganisms such as bacteria, mold, and viruses attached not only to the filter but also to the heat exchanger will be described. FIG. 8 is a side sectional view of an indoor unit of an air conditioner according to Embodiment 3. In addition, in the indoor unit 1 according to the third embodiment, the same components as the indoor unit 1 according to the first embodiment are given the same reference numerals, and detailed description thereof will not be repeated.

In the ultraviolet light irradiation device 5 shown in FIG. 8, a long wavelength LED element 6b and a short wavelength LED element 7b are provided integrally with the heat exchanger 8, and a long wavelength LED element 6c and a short wavelength LED element 7b are provided integrally with the heat exchanger 9. An LED element 7c is provided, and integrated with the heat exchanger 10, a long wavelength LED element 6d and a short wavelength LED element 7d are provided.

The long wavelength LED elements 6b to 6d emit ultraviolet light having the same center wavelength as the long wavelength LED element 6 of 370 nm, and the short wavelength LED elements 7b to 7d emit ultraviolet light having the same center wavelength as the short wavelength LED element 7 of 260 nm. emits light. Since the

heat exchangers

8, 9, and 10 have a long shape in the depth direction in the figure, a plurality of long wavelength LED elements 6b to 6d and a plurality of short wavelength LED elements 7b to 7d are provided in this direction. Furthermore, in order to integrate the long wavelength LED elements 6b to 6d and the short wavelength LED elements 7b to 7d, the

heat exchangers

8, 9, and 10 are made of a highly thermally conductive metal material such as aluminum or iron. Wavelength LED elements 6b to 6d and short wavelength LED elements 7b to 7d are attached. The long wavelength LED elements 6b to 6d and the short wavelength LED elements 7b to 7d are fixed to the

heat exchangers

8, 9, and 10 so that the

entire heat exchangers

8, 9, and 10 can be irradiated with ultraviolet light. ing.

The ultraviolet light irradiation device 5 may perform the sterilization and inactivation treatment on the

heat exchangers

8, 9, and 10 at the same time as the sterilization and inactivation treatment on the filter 3 described in the first embodiment. Alternatively, the ultraviolet light irradiation device 5 may perform sterilization and inactivation processing on the

heat exchangers

8, 9, and 10 periodically, for example, once a day, in addition to the sterilization and inactivation processing on the filter 3.

The ultraviolet light irradiation device 5 also uses the long wavelength LED elements 6b to 6d and the short wavelength LED elements 7b to 7d to sterilize and inactivate the

heat exchangers

8, 9, and 10. 6d are turned on, the short wavelength LED elements 7b to 7d are turned on, and the lighting time of the long wavelength LED elements 6b to 6d is made longer than the lighting time of the short wavelength LED elements 7b to 7d. Specifically, the control circuit 52 first turns on the long wavelength LED elements 6b to 6d for a period of time until the virus inactivation rate decreases by two digits (for example, 3000 seconds), then turns them off, and then turns on the short wavelength LED elements 6b to 6d. 7b to 7d are turned on for a period of time (for example, 15 seconds) until the virus inactivation rate decreases to three digits or less, and then turned off.

Note that when the ultraviolet light irradiation device 5 performs sterilization and inactivation treatment on the

heat exchangers

8, 9, and 10, it is preferable to cool the

heat exchangers

8, 9, and 10 in advance. By cooling the

heat exchangers

8, 9, and 10 in advance, the integrated long wavelength LED elements 6b to 6d and short wavelength LED elements 7b to 7d are also cooled. The long wavelength LED elements 6b to 6d and the short wavelength LED elements 7b to 7d generate heat by emitting light, and the

heat exchangers

8, 9, and 10 generate heat. By cooling, the lifetimes of the long wavelength LED elements 6b to 6d and the short wavelength LED elements 7b to 7d can be extended.

As described above, the ultraviolet light irradiation device 5 according to the third embodiment lights up the

heat exchangers

8, 9, The long wavelength LED elements 6b to 6d and the short wavelength LED elements 7b to 7d are also cooled while sterilizing and inactivating microorganisms such as bacteria, molds, and viruses as described in 10 above. The frequency of replacement of the elements 7b to 7d can be reduced and they can be used for a long period of time. It has been explained that the ultraviolet light irradiation device 5 shown in FIG. 8 has a configuration in which the long wavelength LED elements 6b to 6d and the short wavelength LED elements 7b to 7d are integrated into the

heat exchangers

8, 9, and 10. Even in a configuration in which the long wavelength LED elements 6b to 6d and the short wavelength LED elements 7b to 7d are not integrated into the

heat exchangers

8, 9, and 10, at least one of the long wavelength LED elements 6b to 6d and the short wavelength LED elements 7b to 7d One may be integrated into the

heat exchangers

8, 9, and 10.

Embodiment 4.
It has been explained that in the ultraviolet light irradiation device 5 according to the first embodiment, microorganisms such as bacteria, mold, and viruses adhering to the filter 3 are sterilized and inactivated while the

heat exchangers

8, 9, and 10 are stopped. The ultraviolet light irradiation device according to the fourth embodiment sterilizes microorganisms such as bacteria, mold, and viruses attached to the filter 3 while heating the heat exchanger, focusing on the fact that viruses are sensitive to heat of 50° C. or higher. Inactivate. Note that the configuration of the indoor unit according to Embodiment 4 is the same as the indoor unit 1 shown in FIG. 1, so detailed description will not be repeated.

When performing sterilization and inactivation treatment, the ultraviolet light irradiation device 5 according to the fourth embodiment heats the

heat exchangers

8, 9, and 10 to raise the temperature inside the indoor unit 1 to 50° C. or higher, and then irradiates with long wavelength light. The LED element 6 and the short wavelength LED element 7 are turned on to sterilize and inactivate microorganisms such as bacteria, mold, and viruses attached to the filter 3. Note that the long wavelength LED element 6 and the short wavelength LED element 7 have a short lifespan when driven in a high temperature state, so it is desirable to suppress the temperature inside the indoor unit 1 to 60° C. or less.

The ultraviolet light irradiation device 5 according to the fourth embodiment performs sterilization and inactivation treatment on the filter 3 using the long wavelength LED element 6 and the short wavelength LED element 7 while the

heat exchangers

8, 9, and 10 are heated. In this case, the short wavelength LED element 7 is turned on after the long wavelength LED element 6 is turned on, and the lighting time of the long wavelength LED element 6 is made longer than the lighting time of the short wavelength LED element 7. Specifically, the control circuit 52 first turns on the long wavelength LED element 6 for a period of time until the virus inactivation rate decreases by two digits (for example, 3000 seconds), then turns off the light, and then turns on the short wavelength LED element 7. The light is turned on for a period of time (for example, 15 seconds) until the virus inactivation rate decreases to three digits or less, and then the light is turned off.

As described above, the ultraviolet light irradiation device 5 according to the fourth embodiment heats the

heat exchangers

8, 9, and 10 by lighting the long wavelength LED element 6a and the short wavelength LED element 7a as described above. Therefore, the time required to sterilize and inactivate microorganisms such as bacteria, mold, and viruses can be shortened, and the frequency of replacing the short wavelength LED element 7a that emits ultraviolet light can be reduced, allowing long-term use.

In the above-described embodiments, only the filter 3 is irradiated with the ultraviolet light of the LED element, the filter 3 and the drain pan 12 are only irradiated with the ultraviolet light of the LED element, the filter 3 and the heat exchanger 8, A configuration in which only LED

elements

9 and 10 are irradiated with ultraviolet light has been described. However, the present invention is not limited to this, and the ultraviolet light irradiation device 5 may be configured to irradiate at least one of the filter 3, the drain pan 12, and the

heat exchangers

8, 9, and 10 with ultraviolet light from an LED element. .

The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is indicated by the claims rather than the above description, and it is intended that all changes within the meaning and range equivalent to the claims are included.

1 Indoor unit, 2 Suction port, 3 Filter, 4 Rotating gear, 5 Ultraviolet light irradiation device, 6, 6a to 6d Long wavelength LED element, 7, 7a to 7d Short wavelength LED element, 8, 9, 10 Heat exchanger , 11 blower fan, 12 drain pan, 13 air outlet, 15 brush, 51 power supply circuit, 52 control circuit, 53 memory circuit, 100 control unit.

Claims

An ultraviolet light irradiation device that treats microorganisms such as bacteria, mold, and viruses,
a first light emitting element that emits ultraviolet light of a first wavelength;
a second light emitting element that emits ultraviolet light of a second wavelength different from the first wavelength;
a power supply circuit that supplies current to the first light emitting element and the second light emitting element;
a control circuit that controls the power supply circuit and adjusts lighting timing and lighting time of the first light emitting element and the second light emitting element,
The control circuit includes:
lighting the second light emitting element after lighting the first light emitting element;
An ultraviolet light irradiation device, wherein the lighting time of the first light emitting element is longer than the lighting time of the second light emitting element.
The ultraviolet light irradiation according to claim 1, wherein the second wavelength of the ultraviolet light emitted by the second light emitting element is shorter than the first wavelength of the light emitted by the first light emitting element. Device.
The control circuit includes:
The ultraviolet light irradiation device according to claim 1 or 2, wherein the second light emitting element lights up at least intermittently.
The ultraviolet light according to any one of claims 1 to 3, wherein the first light emitting element and the second light emitting element are fixed in position so that they can irradiate light onto a solid surface. Irradiation device.
further comprising a memory circuit that stores a lighting pattern that defines lighting timing and lighting time of the first light emitting element and the second light emitting element,
Any one of claims 1 to 4, wherein the control circuit changes the lighting timing and lighting time of the first light emitting element and the second light emitting element based on a lighting pattern stored in the storage circuit. The ultraviolet light irradiation device according to item 1.
a filter through which air passes;
A heat exchanger that exchanges heat between air and refrigerant;
A drain pan to catch water,
The ultraviolet light irradiation device according to any one of claims 1 to 5,
The ultraviolet light irradiation device includes:
An air conditioner, wherein the positions of the first light emitting element and the second light emitting element are fixed so that light can be irradiated toward at least one of the filter, the heat exchanger, and the drain pan.
The air conditioner according to claim 6, wherein the control circuit starts controlling to light up the first light emitting element and the second light emitting element after performing cooling operation or heating operation for a set time.
At least one of the first light emitting element and the second light emitting element is integrated with the heat exchanger,
8. The air conditioner according to claim 6, wherein when lighting a light emitting element integrated with the heat exchanger, the control circuit cools the light emitting element with the heat exchanger.
Any one of claims 6 to 8, wherein at least one of the filter and the drain pan is heated by the heat exchanger when at least one of the first light emitting element and the second light emitting element is turned on. The air conditioner according to item 1.