Sterilization system, air conditioner, sterilization method, and sterilization program

Abstract

To provide a sterilization system, an air conditioner, a sterilization method and a sterilization program capable of suppressing prolonging a service life of a UV irradiation device and suppressing microbes in drain water.SOLUTION: A sterilization system comprises an irradiation control unit that when an LED 6 continuously irradiates drain water in a drain pan 3 of an air conditioner 1 with UV light, with a time when a predetermined sterilization rate is reached as a reference time, irradiates the drain water for an irradiation time that is 22% or less of the reference time, and after the irradiation time, stops the irradiation for a predetermined rest time, and controls intermittent irradiation in which the irradiation is performed after the rest time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a sterilization system, an air conditioner, a sterilization method, and a sterilization program. [Background technology]

[0002] In an air conditioner, a drain pan is provided in the indoor unit, and drain water accumulated in the drain pan is discharged by a drain pump (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-190753 Summary of the Invention [Problem to be solved by the invention]

[0004] Drain water remaining in the drain pan is prone to the proliferation of microorganisms (bacteria, mold, etc.), and their metabolites can turn into slime. In such cases, the drain water flow path can become blocked or the drain pump can become clogged.

[0005] One approach under consideration is to reduce the number of microorganisms by irradiating drain water with UV-C (LED) light. However, LEDs often have a short lifespan. For example, if the air conditioner is operated 24 hours a day and UV-C light is constantly irradiated, the LEDs may reach the end of their lifespan in about a year. When the LED reaches the end of its lifespan, it must be replaced.

[0006] The present disclosure has been made in consideration of these circumstances, and aims to provide a sterilization system and air conditioner, as well as a sterilization method and a sterilization program, that can extend the life of a UV irradiation device and suppress microorganisms in drain water. [Means for solving the problem]

[0007] A first aspect of the present disclosure is a sterilization system including an irradiation control unit that controls intermittent irradiation by irradiating drain water in a drain pan of an air conditioner with UV light continuously for a time period that is 22% or less of a reference time, where the time period is set to be a time at which a predetermined sterilization rate is achieved when the drain water is continuously irradiated with UV light by a UV irradiation device, and suspending irradiation for a predetermined pause time after the irradiation time, and then irradiating again after the pause time.

[0008] A second aspect of the present disclosure is a sterilization method in which, using a reference time as the time at which a predetermined sterilization rate is achieved when UV light is continuously irradiated onto drain water in a drain pan of an air conditioner using a UV irradiation device, irradiation is performed for an irradiation time that is 22% or less of the reference time, irradiation is stopped for a predetermined rest time after the irradiation time, and irradiation is then performed again after the rest time.

[0009] A third aspect of the present disclosure is a sterilization program that causes a computer to execute a process of irradiating for an irradiation time that is 22% or less of a reference time, where the time at which a predetermined sterilization rate is achieved when UV light is continuously irradiated onto drain water in a drain pan of an air conditioner by a UV irradiation device, stopping irradiation for a predetermined rest time after the irradiation time, and then performing irradiation after the rest time. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to achieve an effect of extending the life of the UV irradiation device and suppressing microorganisms in drain water. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing a schematic configuration of an air conditioner equipped with a sterilization system according to a first embodiment of the present disclosure. FIG. [Figure 2] 2 is a schematic configuration diagram illustrating an example of a hardware configuration of a control device according to the first embodiment of the present disclosure. FIG. [Figure 3] 2 is a functional block diagram showing functions of a control device according to the first embodiment of the present disclosure. FIG. [Figure 4]FIG. 4 is a diagram showing the relationship between irradiation time and the number of remaining bacteria according to the first embodiment of the present disclosure. [Figure 5] FIG. 10 is a diagram showing the relationship between irradiation time and the number of remaining bacteria in a reference example. [Figure 6] 4 is a flowchart showing an example of a procedure of a sterilization process according to the first embodiment of the present disclosure. [Figure 7] FIG. 10 is a functional block diagram showing functions of a control device according to a third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] (First embodiment) A first embodiment of a sterilization system, an air conditioner, a sterilization method, and a sterilization program according to the present disclosure will be described below with reference to the drawings.

[0013] FIG. 1 is a diagram showing the schematic configuration of an air conditioner (air conditioner) 1 equipped with a sterilization system according to a first embodiment of the present disclosure. As shown in FIG. 1, the air conditioner 1 according to this embodiment mainly comprises a heat exchanger 2, a drain pan 3, a drain pump 4, piping 5, and a UV irradiation device (hereinafter referred to as "LED") 6. The air conditioner 1 is also provided with a control device 10. In this embodiment, the air conditioner 1 is, as an example, a type in which an indoor unit and an outdoor unit are separated, and the configuration shown in FIG. 1 is assumed to be installed in an indoor unit such as a ceiling-mounted type. The heat exchanger 2 is also assumed to be connected to a compressor (not shown), another heat exchanger (not shown), an expansion valve (not shown), and the like to form a refrigeration cycle.

[0014] The heat exchanger 2 functions as an evaporator, and air is guided into the heat exchanger 2 by a blower (not shown). Heat is exchanged between the refrigerant flowing through heat transfer tubes provided in the heat exchanger 2 and the air passing through the heat exchanger 2 (around the heat transfer tubes), thereby cooling the passing air. Since the heat exchanger 2 absorbs heat from the air, moisture in the air may condense and liquefy. This liquefied water (hereinafter referred to as "drain water") drips due to gravity into a drain pan 3 provided below.

[0015] The drain pan 3 stores the drain water generated in the heat exchanger 2 and is installed below the heat exchanger 2 to store dripping drain water. The drain pan 3 is provided with a water level gauge. This water level gauge detects the level of the drain water stored in the drain pan 3. The water level gauge prevents overflow. For example, the cooling operation or dehumidification operation may be forcibly stopped based on the result of the water level gauge.

[0016] The drain pump 4 is, for example, a centrifugal pump, and has rotating impellers (not shown) housed within a pump housing. It has a suction port 7 formed at the bottom of the pump housing for sucking in drain water, and a discharge port 8 for discharging the sucked drain water. A motor 9 for driving the rotating impeller is also connected to the drain pump 4. The motor 9 drives the rotating impeller, generating centrifugal force to suck up drain water through the suction port 7, and discharges the drain water from the discharge port 8.

[0017] The piping 5 is connected to the discharge port 8 of the drain pump 4. The drain water sucked up by the drain pump 4 is discharged outside the indoor unit via the discharge port 8 and the piping 5. The piping 5 also extends upward to guide the drain water outside the indoor unit. That is, the drain pump 4 pumps up the drain water stored in the drain pan 3, thereby discharging the drain water outside the indoor unit.

[0018] The UV irradiation device (LED) 6 is a device that irradiates UV light (ultraviolet light). Specifically, the LED 6 is a UV-C LED that irradiates UV-C light (deep ultraviolet light). The LED 6 is attached, for example, near the suction port of the drain pump 4.

[0019] The control device 10 performs overall control of the air conditioner 1. The control device 10 also has a function of controlling the LEDs 6 to suppress microorganisms in the drain water (sterilization system).

[0020] Fig. 2 is a schematic diagram showing an example of a hardware configuration of a control device 10 according to an embodiment of the present disclosure. As shown in Fig. 1, the control device 10 is a so-called computer, and includes, for example, a CPU (Central Processing Unit) 11, a main memory 12, a storage unit 13, an external interface 14, a communication interface 15, an input unit 16, and a display unit 17. These units are connected to each other directly or indirectly via a bus, and cooperate with each other to execute various processes.

[0021] The CPU 11 controls the entire control device 10 using, for example, an OS (Operating System) stored in a memory unit 13 connected via a bus, and performs various processes by executing various programs stored in the memory unit 13.

[0022] The main memory 12 is composed of writable memory such as cache memory or RAM (Random Access Memory), and is used as a working area for reading out programs executed by the CPU 11 and writing data processed by the programs.

[0023] The storage unit 13 is a non-transitory computer readable storage medium, such as a read only memory (ROM), a hard disk drive (HDD), or a flash memory. The storage unit 13 stores, for example, an OS for controlling the entire device, such as Windows (registered trademark), iOS (registered trademark), or Android (registered trademark), a basic input / output system (BIOS), various device drivers for operating peripheral devices as hardware, various application software, and various data and files. The storage unit 13 also stores programs for implementing various processes and various data required for implementing the various processes.

[0024] The external interface 14 is an interface for connecting to an external device. Examples of external devices include an external monitor, a USB memory, an external HDD, etc. Although only one external interface is shown in the example shown in FIG. 1, multiple external interfaces may be provided.

[0025] The communication interface 15 functions as an interface for connecting to a network to communicate with other devices and sending and receiving information. For example, the communication interface 15 communicates with other devices via wired or wireless communication. Examples of wireless communication include Bluetooth (registered trademark), Wi-Fi, and communication using a dedicated communication protocol. An example of wired communication is a wired LAN (Local Area Network).

[0026] The input unit 16 is a user interface for giving instructions, such as a keyboard, a mouse, or a touchpad.

[0027] The display unit 17 is, for example, a liquid crystal display, an organic EL (Electroluminescence) display, etc. Furthermore, the display unit 17 may be a touch panel display on which a touch panel is superimposed.

[0028] Fig. 3 is a functional block diagram showing the functions of the control device 10. As shown in Fig. 3, the control device 10 includes an air conditioning control unit 21 and a sterilization control unit (sterilization system) 22. The sterilization control unit 22 includes an irradiation control unit 23. In this embodiment, the control device 10 is configured to include the sterilization control unit 22, but the sterilization control unit 22 may be provided separately from the control device 10. For example, the sterilization control unit 22 and the LED 6 may be configured as a single module.

[0029] The functions realized by these units are realized, for example, by processing circuitry. For example, a series of processes for realizing the functions shown below are stored in the storage unit 13 in the form of a program (for example, a route teaching data creation program), and the CPU 11 reads this program into the main memory 12 and executes information processing and calculation processing to realize various functions.

[0030] The program may be pre-installed in the storage unit 13, provided in a state stored in another computer-readable storage medium, or distributed via wired or wireless communication means, etc. Examples of computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

[0031] The air conditioning control unit 21 performs various controls on the air conditioner 1. Specifically, the air conditioning control unit 21 controls the refrigeration cycle by switching between operation modes such as heating operation, cooling operation, and dehumidifying operation.

[0032] The irradiation control unit 23 controls the irradiation of the LED 6 to suppress microorganisms in the drain water. Specifically, the irradiation control unit 23 sets the time at which a predetermined sterilization rate (bactericidal rate) is achieved when UV light is continuously irradiated onto the drain water as a reference time, and irradiates for an irradiation time that is 22% or less of the reference time. After the irradiation time, the irradiation is stopped for a predetermined rest time, and irradiation is resumed after the rest time. In other words, the irradiation control unit 23 controls the intermittent irradiation of UV light. The predetermined sterilization rate is, for example, 99%, but can be set arbitrarily.

[0033] Since drain water is likely to be generated when the cooling operation or dehumidifying operation is performed, the intermittent irradiation process is started during the cooling operation or dehumidifying operation or after the operation is stopped.

[0034] FIG. 4 is a diagram showing the relationship between irradiation time and the number of residual bacteria in this embodiment. FIG. 4 shows an example of intermittent irradiation, and specific processing such as irradiation time is not limited to FIG. 4. As shown in FIG. 4, the irradiation control unit 23 performs intermittent irradiation of UV light. In particular, the irradiation control unit 23 repeats irradiation during the irradiation period and stopping irradiation during the pause period. The number of repetitions in the intermittent irradiation is not limited. Furthermore, although the same irradiation period and pause period are repeated, irradiation periods and pause periods of different lengths may also be repeated. FIG. 4 shows the change in the number of residual bacteria with irradiation and the change in the number of residual bacteria without irradiation. The number of residual bacteria without irradiation indicates a case where microorganisms do not increase and naturally disappear.

[0035] 4 shows an example in which the irradiation time is 10 minutes and the rest time is 50 minutes. In this way, the irradiation control unit 23 repeats the process of irradiating for 10 minutes, then stopping irradiation for 50 minutes, and then irradiating for 10 minutes. The total number of irradiations is 7, and the total irradiation time is 70 minutes.

[0036] By irradiating intermittently, the number of remaining bacteria is significantly reduced by the first irradiation, and the sterilization rate reaches 99% by the second irradiation (70 minutes after the start) after a pause, as shown in Figure 4. Then, by repeating short-term irradiation intermittently thereafter, the number of remaining bacteria is effectively reduced.

[0037] FIG. 5 shows the relationship between irradiation time and residual bacterial count in a reference example. In the reference example, UV light is irradiated continuously for 70 minutes. FIG. 5 shows the change in residual bacterial count with and without irradiation. As shown in FIG. 5, even when irradiating continuously for 70 minutes, a 99% sterilization rate can be achieved. However, in this embodiment, as shown in FIG. 4, a 99% sterilization rate can be achieved by performing two 10-minute irradiation sessions with a rest period (50 minutes) between them. That is, while continuous irradiation requires 70 minutes of irradiation to achieve a 99% sterilization rate, intermittent irradiation reduces this to a total of 20 minutes. As shown in FIG. 4, intermittent irradiation can achieve even greater sterilization with a total irradiation time of 70 minutes. In particular, continuous irradiation of the LED 6 for a long period of time can potentially reduce output due to its own temperature rise. However, intermittent irradiation suppresses temperature rise during rest periods, allowing for effective use of high-output periods.

[0038] By performing intermittent irradiation in this way, it is possible to effectively sterilize while reducing the UV irradiation time. Since the lifespan of the LED 6 is determined by the total irradiation time, intermittent operation can extend the lifespan of the LED 6.

[0039] Furthermore, compared to continuous irradiation, intermittent irradiation has rest periods during which the drain water undergoes natural convection, enabling effective sterilization.

[0040] Next, the setting of the irradiation time will be described. The irradiation time is set based on a reference time. The reference time is the time required for a predetermined sterilization rate to be achieved when UV light is continuously irradiated. In the reference example shown in FIG. 5, continuous irradiation of UV light for 70 minutes results in a sterilization rate of 99%. In other words, if the sterilization rate is 99%, the reference time is 70 minutes. Note that the sterilization rate when setting the reference time is not limited to 99% and can be applied.

[0041] Here, as shown in Fig. 4, the sterilization effect can be obtained without continuous irradiation. For this reason, the irradiation time is set to 22% or less of the reference time. Specifically, if the reference time is 70 minutes, the irradiation time is preferably set to 5 minutes or more and 15 minutes or less (10 minutes in the example of Fig. 4).

[0042] When performing intermittent operation, the pause time is set to be longer than the irradiation time. Specifically, it is set to be at least three times the irradiation time. In the example of Figure 4, the pause time is set to 50 minutes. Even when the pause time is longer than the irradiation time, a sufficient sterilization effect can be obtained.

[0043] Next, the useful life of the LED 6 will be described. The service life is, for example, the rated life. The rated life may be the irradiation time at which the output is 70% of the initial output, or the irradiation time at which the output is 50% of the initial output. In other words, the rated life is set as a criterion for replacing the LED 6.

[0044] The service life of the LED 6 is between 5 and 10, assuming that the service life of the air conditioner 1 is 10. The service life of the air conditioner 1 is the service life of the air conditioner 1 in a configuration other than the LED 6 (if the LED 6 is not provided).

[0045] For example, the lower limit of the service life of the LED 6 is set assuming that the LED 6 will be replaced once within the service life of the air conditioner 1. For example, the upper limit of the service life of the LED 6 is set assuming that the LED 6 will not be replaced even once within the service life of the air conditioner 1.

[0046] This makes it possible to prevent frequent replacement of the LEDs 6 before the end of the service life of the air conditioner 1. For example, it is possible to reduce the need to replace the LEDs 6 to one time (or zero times) before the end of the service life of the air conditioner 1.

[0047] Next, the light intensity of the LED 6 over a predetermined period of time will be described.

[0048] When performing intermittent irradiation, the irradiation control unit 23 irradiates a predetermined light intensity of 5,000 mW·sec or more and 90,000 mW·sec or less per unit time. The light intensity may be the light intensity from a single LED or the total light intensity from multiple LEDs, and the configuration is not limited as long as the predetermined light intensity is irradiated. For example, if irradiation is performed at 10 mW (min) for 10 minutes followed by a 60-minute break, the light intensity is 5,143 mW·sec per unit time (60 minutes). For example, if irradiation is performed at 50 mW (min) for 15 minutes followed by a 45-minute break, the light intensity is 90,000 mW·sec per unit time (60 minutes).

[0049] When performing intermittent irradiation, a light intensity of 5000 mW·sec or more and 90000 mW·sec or less per unit time can be used to irradiate a sufficient amount of light for sterilization.

[0050] Next, an example of the sterilization process performed by the control device 10 will be described with reference to Fig. 6. Fig. 6 is a flowchart showing an example of the procedure for the sterilization process according to this embodiment. The flow shown in Fig. 6 is executed repeatedly, for example, at a predetermined control cycle. In the example of Fig. 6, a case where irradiation is performed seven times as intermittent irradiation will be described as an example.

[0051] First, it is determined whether the cooling operation or the dehumidifying operation has stopped (S101). In S101, it may be determined whether a predetermined timing (for example, the operation duration) has occurred during the cooling operation or the dehumidifying operation. That is, in S101, a YES determination may be made when the cooling operation or the dehumidifying operation has stopped (intermittent irradiation after the operation has stopped), or a YES determination may be made when a predetermined timing has occurred during the operation (intermittent irradiation during the operation).

[0052] If the determination in S101 is NO, the process ends. If the cooling operation or dehumidification operation has stopped (if the determination in S101 is YES), the intermittent irradiation process starts. First, the number of irradiations is set to 1 (S102). Then, irradiation is performed for the irradiation time (S103).

[0053] Next, irradiation is stopped during the pause time (S104). Next, it is determined whether the number of irradiations has reached a predetermined value (number of irradiations = 7) (S105). If the determination in S105 is NO, 1 is added to the number of irradiations (S106), and S103 is executed. If the determination in S105 is YES, it is determined that seven irradiations have been completed, and the process ends.

[0054] In the flow of Fig. 6, the case where irradiation is performed seven times is described, but the number of times is not limited. Also, in the flow of Fig. 6, the end determination is made based on the number of times, but the process may be ended when the total time of intermittent irradiation reaches a predetermined time, and the ending method is not limited.

[0055] As described above, the sterilization system, air conditioner, sterilization method, and sterilization program according to this embodiment define a reference time as the time required for a predetermined sterilization rate to be achieved when UV light is continuously irradiated onto drain water, and irradiate the drain water for an irradiation time that is 22% or less of this reference time. The irradiation is then stopped for a rest period, after which irradiation is resumed. This allows for effective sterilization without irradiating UV light continuously for the reference time. Furthermore, shortening the UV light irradiation time can extend the life of the UV irradiation device.

[0056] (Second embodiment) Next, a sterilization system, an air conditioner, a sterilization method, and a sterilization program according to a second embodiment of the present disclosure will be described. In this embodiment, a case where the intermittent operation process is executed again will be described. The sterilization system, air conditioner, sterilization method, and sterilization program according to this embodiment will be described below, focusing on the differences from the first embodiment.

[0057] During long vacations, etc., the air conditioner 1 is not operated for a long period of time, and microorganisms are likely to grow in a high-temperature, high-humidity environment. For this reason, the irradiation control unit 23 in this embodiment performs intermittent irradiation when a predetermined standby time has elapsed after the end of intermittent irradiation. In other words, the irradiation control unit 23 performs intermittent irradiation as shown in FIG. 4 again after the standby time has elapsed.

[0058] In particular, when the air conditioner 1 is not in cooling or dehumidifying operation, microorganisms are likely to grow in the drain pan 3. For this reason, the irradiation control unit 23 performs intermittent irradiation when the air conditioner 1 is not in cooling or dehumidifying operation during a standby time after the end of intermittent irradiation. The standby time is set to be longer than the time during which the intermittent irradiation process is performed. For example, the standby time is set to 24 hours. The process of intermittent irradiation and the standby time is repeated for a predetermined period of time. The predetermined period is set to, for example, 7 days, which is the expected time for the drain water to evaporate.

[0059] As described above, according to the sterilization system, air conditioner, sterilization method, and sterilization program of this embodiment, even if there is a possibility that microorganisms will grow after intermittent irradiation has ended, intermittent irradiation is performed after a predetermined standby time has elapsed, making it possible to suppress the growth of microorganisms. Microorganisms are likely to grow when the air conditioner 1 is not in cooling or dehumidifying operation, but since intermittent irradiation is performed after the standby time has elapsed, it is possible to suppress the growth of microorganisms.

[0060] (Third embodiment) Next, a sterilization system, an air conditioner, a sterilization method, and a sterilization program according to a third embodiment of the present disclosure will be described. In this embodiment, a case will be described where the drain pump 4 is driven. The sterilization system, air conditioner, sterilization method, and sterilization program according to this embodiment will be described below, focusing on differences from the first and second embodiments.

[0061] 7, the sterilization control unit 22 in this embodiment includes a pump control unit 24. The pump control unit 24 controls the drain pump 4 that sucks out drain water from the drain pan 3 to operate for a certain period of time. Operation To make.

[0062] For example, the pump control unit 24 may operate the drain pump 4 for a predetermined time (about one minute) after the cooling operation or dehumidifying operation of the air conditioner 1 is stopped and before the UV light is irradiated. Operation To make.

[0063] When the drain pump 4 is driven, drain water is sucked into the drain pump 4. When the driving of the drain pump 4 is stopped, the drain water that was sucked into the drain pump 4 and not discharged to the outside flows back into the drain pan 3. This allows the drain water to be agitated.

[0064] As described above, according to the sterilization system, air conditioner, sterilization method, and sterilization program of the present embodiment, the drain pump 4 that sucks out drain water from the drain pan 3 is operated for a certain period of time. Operation By doing so, drain water is sucked from the drain pan 3 into the drain pump 4, and then any drain water that could not be completely sucked out flows back into the drain pan 3, thereby agitating the drain water. This improves the sterilization effect of UV light.

[0065] (Fourth embodiment) Next, a sterilization system, an air conditioner, a sterilization method, and a sterilization program according to a fourth embodiment of the present disclosure will be described. In this embodiment, a case where the presence or absence of drain water is determined will be described. The sterilization system, air conditioner, sterilization method, and sterilization program according to this embodiment will be described below, focusing on differences from the first, second, and third embodiments.

[0066] In this embodiment, the air conditioner 1 is provided with a sensor that detects the presence of drain water in the drain pan 3. The sensor is, for example, an electrostatic sensor or a float switch. In other words, the sensor detects the presence of drain water in the drain pan 3.

[0067] The irradiation control unit 23 then performs irradiation when the sensor detects that drain water is present in the drain pan 3. That is, after the sensor confirms that drain water is present, intermittent irradiation is performed.

[0068] The sensor may be provided as a separate device, or may be configured as an integral part of the module of the LED 6. For example, the sensor may also be incorporated into a module incorporating the sterilization control unit 22 and the LED 6. In this way, by adding the module to an existing air conditioner 1, it is possible to add the functionality of a sterilization system.

[0069] As described above, the sterilization system and air conditioner, sterilization method, and sterilization program of this embodiment can suppress unnecessary UV light irradiation by irradiating when the sensor detects that drain water is in the drain pan 3.

[0070] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the invention. It is also possible to combine the various embodiments. That is, the above-described first, second, third, and fourth embodiments can be combined with each other.

[0071] The sterilization system and air conditioner, as well as the sterilization method and sterilization program described in each of the above-described embodiments, can be understood, for example, as follows. The sterilization system (22) according to the present disclosure includes an irradiation control unit (23) that controls intermittent irradiation, in which irradiation is performed for an irradiation time that is 22% or less of a reference time that is a time at which a predetermined sterilization rate is achieved when UV light is continuously irradiated by a UV irradiation device (6) onto drain water in a drain pan (3) of an air conditioner (1), and irradiation is stopped for a predetermined pause time after the irradiation time, and irradiation is performed after the pause time.

[0072] According to the sterilization system of the present disclosure, the time required for achieving a predetermined sterilization rate when UV light is continuously irradiated onto drain water is set as a reference time, and irradiation is performed for an irradiation time that is 22% or less of this reference time. Then, UV light is stopped for a rest period, and irradiation is resumed after that. This allows for effective sterilization without continuously irradiating UV light for the reference time. Furthermore, shortening the UV light irradiation time can extend the life of the UV irradiation device. The predetermined sterilization rate is, for example, 99 percent.

[0073] In the sterilization system according to the present disclosure, the irradiation control unit may repeat irradiation during the irradiation time and stopping irradiation during the pause time.

[0074] According to the sterilization system of the present disclosure, by repeating irradiation during the irradiation time and stopping irradiation during the rest time, it is possible to reduce the burden on the UV irradiation device while suppressing a decrease in the sterilization effect compared to when UV light is continuously irradiated.

[0075] In the sterilization system according to the present disclosure, the rest time may be set to be three times or more the irradiation time.

[0076] According to the sterilization system of the present disclosure, even if irradiation is stopped for a rest period of three or more times the irradiation time, the burden on the UV irradiation device can be reduced while suppressing a decrease in the sterilization effect compared to when UV light is continuously irradiated.

[0077] In the sterilization system according to the present disclosure, the irradiation control unit may irradiate a predetermined amount of light of not less than 5000 mW·sec and not more than 90000 mW·sec per unit time when performing the intermittent irradiation.

[0078] According to the sterilization system of the present disclosure, when performing the intermittent irradiation, a predetermined light amount of 5000 mW·sec or more and 90000 mW·sec or less per unit time is intermittently irradiated, thereby reducing the total light amount when performing intermittent irradiation and enabling sterilization to be performed.

[0079] In the sterilization system according to the present disclosure, the irradiation control unit may perform the intermittent irradiation when a predetermined waiting time has elapsed after the end of the intermittent irradiation.

[0080] According to the sterilization system of the present disclosure, even if there is a possibility that microorganisms may grow after intermittent irradiation has ended, intermittent irradiation is performed after a predetermined waiting time has elapsed, so that the growth of microorganisms can be suppressed.

[0081] In the sterilization system according to the present disclosure, the irradiation control unit may perform the intermittent irradiation if the air conditioner is not performing cooling operation or dehumidification operation during the standby time after the end of the intermittent irradiation.

[0082] According to the sterilization system of the present disclosure, microorganisms tend to grow when an air conditioner is not operating in cooling or dehumidifying mode, but by performing intermittent irradiation after the standby time has elapsed, the growth of microorganisms can be suppressed.

[0083] The sterilization system according to the present disclosure is configured to: operate a drain pump (4) that sucks out drain water from the drain pan for a certain period of time; Operation The pump control unit (24) may be provided to control the pump pressure.

[0084] According to the sterilization system of the present disclosure, the drain pump that sucks out the drain water from the drain pan is operated for a certain period of time. Operation By doing so, drain water is sucked from the drain pan into the drain pump, and any remaining drain water flows back into the drain pan, stirring the drain water and improving the sterilization effect of UV light.

[0085] In the sterilization system according to the present disclosure, the irradiation control unit may perform irradiation when a sensor detects that drain water is present in the drain pan.

[0086] According to the sterilization system of the present disclosure, irradiation is performed when the sensor detects that drain water is present in the drain pan, thereby making it possible to suppress unnecessary UV light irradiation.

[0087] The air conditioner according to the present disclosure includes a drain pan, a UV irradiation device, and the above-described sterilization system.

[0088] In the air conditioner according to the present disclosure, the useful life of the UV irradiation device may be set to be 5 or more and 10 or less, where the useful life of the air conditioner is 10.

[0089] According to the air conditioner of the present disclosure, it is possible to prevent frequent replacement of the UV irradiation device before the end of the service life of the air conditioner. For example, it is possible to reduce the need to replace the UV irradiation device to one time (or zero times) before the end of the service life of the air conditioner.

[0090] In the air conditioner according to the present disclosure, the service life may be a rated life.

[0091] According to the air conditioner of the present disclosure, the useful life is the rated life, so the relationship between the useful life of the UV irradiation device and the air conditioner can be appropriately set.

[0092] The sterilization method according to the present disclosure sets the time required for a predetermined sterilization rate to be achieved when UV light is continuously irradiated onto drain water in the drain pan of an air conditioner using a UV irradiation device as a reference time, irradiating for an irradiation time that is 22% or less of the reference time, halting irradiation for a predetermined rest time after the irradiation time, and then irradiating again after the rest time.

[0093] The sterilization program of the present disclosure causes a computer to execute a process in which, using a reference time as the time at which a predetermined sterilization rate is achieved when UV light is continuously irradiated onto drain water in an air conditioner's drain pan by a UV irradiation device, irradiation is performed for an irradiation time that is 22% or less of the reference time, irradiation is stopped for a predetermined rest time after the irradiation time, and irradiation is performed again after the rest time. [Explanation of symbols]

[0094] 1:Air conditioner 2: Heat exchanger 3: Drain pan 4: Drain pump 5: Piping 6: LED 7: Suction port 8:Discharge port 9: Motor 10: Control device 11: CPU 12: Main memory 13: Storage section 14: External interface 15: Communication interface 16: Input section 17:Display section 21: Air conditioning control unit 22: Sterilization control section 23: Irradiation control unit 24: Pump control section

Claims

1. A sterilization system comprising an irradiation control unit that controls intermittent irradiation, in which the time required for a predetermined sterilization rate to be achieved when UV light is continuously irradiated onto drain water in a drain pan of an air conditioner by a UV irradiation device is set as a reference time, irradiation is performed for an irradiation time that is 22% or less of the reference time, irradiation is stopped for a predetermined pause time after the irradiation time has elapsed, and irradiation is then resumed after the pause time, and the predetermined sterilization rate is 99%.

2. The sterilization system according to claim 1 , wherein the irradiation control unit repeats irradiation during the irradiation time and stopping irradiation during the pause time.

3. The sterilization system according to claim 2 , wherein the rest time is set to be three times or more the irradiation time.

4. The sterilization system according to any one of claims 1 to 3, wherein the irradiation control unit irradiates a predetermined amount of light of 5000 mW·sec or more and 90000 mW·sec or less per unit time when performing the intermittent irradiation.

5. The sterilization system according to claim 1 , wherein the irradiation control unit performs the intermittent irradiation when a predetermined waiting time has elapsed after the end of the intermittent irradiation.

6. The sterilization system according to claim 5 , wherein the irradiation control unit performs the intermittent irradiation when the air conditioner does not perform a cooling operation or a dehumidifying operation during the standby time after the intermittent irradiation ends.

7. The sterilization system according to any one of claims 1 to 6, further comprising a pump control unit that operates a drain pump that sucks out drain water from the drain pan for a certain period of time.

8. The sterilization system according to claim 1 , wherein the irradiation control unit performs irradiation when a sensor detects that drain water is present in the drain pan.

9. Drain pan and a UV irradiation device; The sterilization system according to any one of claims 1 to 8, An air conditioner equipped with:

10. The air conditioner according to claim 9 , wherein the useful life of the UV irradiation device is 5 to 10, both inclusive, assuming that the useful life of the air conditioner is 10.

11. The air conditioner according to claim 10, wherein the service life is a rated life.

12. A sterilization method in which the time required for a predetermined sterilization rate to be achieved when UV light is continuously irradiated onto drain water in a drain pan of an air conditioner using a UV irradiation device is set as a reference time, irradiation is performed for an irradiation time that is 22% or less of the reference time, irradiation is stopped for a predetermined rest time after the irradiation time, and irradiation is continued after the rest time, and the predetermined sterilization rate is 99%.

13. A sterilization program that causes a computer to execute a process in which, using a time period that results in a predetermined sterilization rate when UV light is continuously irradiated onto drain water in a drain pan of an air conditioner by a UV irradiation device as a reference time, irradiation is performed for an irradiation time that is 22% or less of the reference time, irradiation is stopped for a predetermined rest time after the irradiation time, and irradiation is performed again after the rest time, and the predetermined sterilization rate is 99%.

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