Ultraviolet irradiation device and control method for ultraviolet irradiation device

Abstract

To provide an ultraviolet irradiation device which sets O3 concentration of an indoor space for device installation to be a recommended value or less, in consideration of characteristics of the indoor space.SOLUTION: An ultraviolet irradiation device is a device that is installed and used in an indoor space includes a light source part for emitting ultraviolet light having a main wavelength of 200 nm to 240 nm, a control part for controlling lighting of the light source part, and a storage part for recording information on an indoor characteristic value unique to the indoor space indicting correlation between average illuminance of the light source part and ozone concentration of the indoor space, and information on an upper limit threshold of the ozone concentration of the indoor space, when the ultraviolet light is emitted toward the indoor space. The control part calculates average illuminance in operation in which the ozone concentration of the indoor space is less than the upper limit threshold, on the basis of the indoor characteristic value and the upper limit threshold, and controls lighting of the light source part under the average illuminance in operation.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an ultraviolet irradiation device and a control method thereof. [Background technology]

[0002] The present applicant has previously proposed a technology for inactivating microorganisms present in an indoor space while suppressing adverse effects on the human body by irradiating the space with ultraviolet light from a KrCl excimer lamp or a KrBr excimer lamp (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-170895 Summary of the Invention [Problem to be solved by the invention]

[0004] According to Patent Document 1, the following description is roughly recognized: When ultraviolet light with a wavelength of less than 190 nm is irradiated to an indoor space, oxygen molecules (O2) present in the air in the room are photodecomposed to generate oxygen atoms (O), and these oxygen atoms (O) combine with the oxygen molecules (O2) to generate ozone (O3). Therefore, in order to effectively suppress the generation of O3 in the indoor space, it is desirable to use ultraviolet light with a peak wavelength of 200 nm or more.

[0005] However, ultraviolet light in the wavelength range of 200nm to 240nm, including 222nm, which is the peak wavelength of KrCl excimer lamps, is also absorbed by O2 in the air, albeit to a small extent. Figure 1 is a graph showing the absorption spectra of O2 and O3 together, with the vertical axis expressed in logarithm.

[0006] 1, it is confirmed that the absorption coefficient of O2 for ultraviolet light with a wavelength of less than 200 nm is indeed significantly higher than the absorption coefficient of O2 for ultraviolet light in the wavelength range of 200 nm to 240 nm. The absorption coefficient of O2 for ultraviolet light in the wavelength range of 200 nm to 240 nm is approximately 0.001 to 0.1 times the absorption coefficient of O2 for ultraviolet light with a wavelength of 190 nm, for example.

[0007] When ultraviolet light with a wavelength λ in the wavelength range of 200 nm to 240 nm is absorbed by O2 in the air, O3 is generated through the following formulas (1) and (2). In the following formula, O( 3 P) represents atomic oxygen in the ground state. The left side of equation (1) conveniently represents the absorption of ultraviolet light with a wavelength of λ by O2. O2+ hν(λ) → O( 3 P) + O( 3 P) …(1) O( 3 P) + O2 → O3…(2)

[0008] The amount of O3 produced is O( 3 P) production, and O( 3 The amount of P produced is affected by the amount of UV rays absorbed by O2. The effect of the amount of UV rays absorbed by O2 depends on the amount of O2, and the amount of O2 increases as the volume of the indoor space increases.

[0009] In many cases, the target recommended value for O3 concentration in indoor spaces is set according to national standards, the target environment, the purpose of work, etc. For example, at the time of filing this application, the Japan Society for Occupational Health has set the permissible concentration of O3 as a work environment standard at 100 ppb or less. In addition, the Japan Air Cleaning Association recommends that the average permissible concentration of O3 in indoor spaces be 500 ppb or less.

[0010] Indeed, according to Figure 1, the absorption coefficient of O2 for ultraviolet light with a wavelength λ in the wavelength range of 200 nm to 240 nm is low, so the amount of O3 generated through equations (1) and (2) is very small. However, as long as ultraviolet light continues to be irradiated and O2 is present in the indoor space, the reactions of equations (1) and (2) above continue, and O3 is generated.

[0011] In particular, when ultraviolet rays are irradiated for the purpose of inactivating microorganisms (bacteria, fungi, viruses, etc.) present in an indoor space, ultraviolet rays may be irradiated for a long period of time. In this case, the amount of O3 generated in the indoor space may increase. In particular, it is expected that the larger the volume of the indoor space, the higher the amount of O3 generated, although it is difficult for the O3 concentration to become high.

[0012] The reason for this is considered to be as follows. According to FIG. 1, ultraviolet rays in the wavelength range of 200nm to 240nm have a significantly lower absorption coefficient for O2 than ultraviolet rays with a wavelength of less than 190nm. This means that ultraviolet rays in the wavelength range of 200nm to 240nm travel a longer distance in the indoor space without being absorbed by O2 than ultraviolet rays with a wavelength of less than 190nm. In other words, when the volume of the indoor space is large, ultraviolet rays in the wavelength range of 200nm to 240nm irradiated from the ultraviolet irradiation device travel a longer distance in the air in the indoor space before reaching the wall surface or the surface of an object. This means that the time it takes for ultraviolet rays to travel in the air in the indoor space becomes longer, leading to a slight increase in the total amount of ultraviolet rays absorbed by O2 during this time. As a result, O3 is generated throughout the indoor space, albeit in small amounts, and the total amount of O3 generated increases as the volume of the indoor space increases.

[0013] On the other hand, because O3 is highly reactive, it is decomposed when it comes into contact with the surfaces of objects and walls in indoor spaces. However, the manner in which this occurs depends on the materials and installation of the objects and walls in the indoor space. The concentration of O3 in indoor spaces is also affected by the volume of the indoor space, the ventilation capacity of the indoor space, and the frequency of ventilation.

[0014] In other words, when installing a light source to irradiate ultraviolet light in an indoor space to inactivate microorganisms, in order to keep the O3 concentration in the indoor space below the recommended value, strictly speaking, it is necessary to take into consideration the characteristics of the indoor space in which the light source is installed. However, the type of indoor space in which the light source is installed depends on the circumstances of the user, and is not an element that can be controlled by the light source.

[0015] Therefore, assuming that a light source is installed in an indoor space (hereinafter referred to as the "reference space") where the volume of the space is small, the ventilation capacity and the decomposition rate of O3 are relatively low, and the O3 concentration is relatively likely to increase, it is possible to control the average illuminance of ultraviolet light on the light source side so that the O3 concentration in the reference space is below the recommended value even when the light source is operated for the purpose of inactivating microorganisms in this reference space. However, with this control method, even though the O3 concentration in the indoor space where the light source is actually installed is less likely to increase than in the reference space, ultraviolet light will be irradiated at a low average illuminance, and it is expected that the inactivation performance of microorganisms in the indoor space will be reduced.

[0016] In view of the above problems, the present invention aims to provide an ultraviolet irradiation device and a control method thereof that can keep the O3 concentration in an indoor space below a recommended value, taking into consideration the characteristics of the indoor space in which the device is installed. [Means for solving the problem]

[0017] The ultraviolet irradiation device according to the present invention is an ultraviolet irradiation device that is installed and used in an indoor space, A light source unit that emits ultraviolet light having a dominant wavelength within a range of 200 nm to 240 nm; A control unit that controls the lighting of the light source unit; a storage unit configured to record information on an indoor specific value specific to the indoor space, the indoor specific value indicating a correlation between an average illuminance of the light source unit and an O3 concentration in the indoor space when the ultraviolet light is emitted toward the indoor space, and information on an upper limit threshold of the O3 concentration in the indoor space; The control unit calculates an average operating illuminance at which the ozone concentration in the indoor space is less than the upper threshold based on the indoor characteristic value and the upper threshold, and controls the lighting of the light source unit under the average operating illuminance.

[0018] According to the above configuration, the storage unit of the ultraviolet irradiation device records information about an indoor specific value that is specific to the indoor space in which the ultraviolet irradiation device is installed and indicates a correlation between the average illuminance of the light source unit and the ozone concentration in the indoor space. The storage unit also records information about an upper threshold value of the ozone concentration in the indoor space. For this upper threshold value, for example, a recommended value set by a country can be adopted, or a value that takes into account a predetermined safety likelihood with respect to the recommended value can be adopted.

[0019] Therefore, the control unit can calculate the average operating illuminance at which the ozone concentration in the indoor space is less than the upper threshold based on the indoor specific value and the upper threshold. Therefore, by the control unit controlling the lighting of the light source unit under this average operating illuminance, the indoor space can be irradiated with ultraviolet light from the ultraviolet irradiation device while keeping the ozone concentration in the indoor space less than the upper threshold, thereby inactivating microorganisms present in the indoor space.

[0020] According to the above configuration, the average illuminance during operation is set based on the indoor specific value. Therefore, it is possible to increase the value of the average illuminance during operation to be higher than the average illuminance (hereinafter referred to as "reference illuminance") for making the ozone concentration below the upper threshold when the ultraviolet irradiation device is installed in the "reference space" described above in the section "Problem to be solved by the invention". As a result, while maintaining the ozone concentration in the indoor space below the upper threshold, the performance of inactivating microorganisms in the indoor space is improved compared to the case where the ultraviolet irradiation device is operated under the reference illuminance.

[0021] As used herein, "inactivation" refers to a concept that encompasses killing or rendering infectivity or toxicity of one or more microorganisms, including bacteria, fungi, and viruses, ineffective.

[0022] In this specification, the term "indoor space" is not limited to rooms in buildings such as buildings, houses, and warehouses, but also includes living spaces in vehicles such as automobiles, trains, buses, airplanes, and ships.

[0023] In this specification, the term "dominant wavelength" refers to a wavelength that exhibits an intensity of 50% or more of the peak intensity in a spectrum. Naturally, the peak wavelength in a spectrum corresponds to the "dominant wavelength."

[0024] Information regarding the indoor eigenvalue may be input to the ultraviolet irradiation device from outside, or the ultraviolet irradiation device itself may be equipped with a function for calculating the indoor eigenvalue.

[0025] In the latter configuration, For example, the ultraviolet irradiation device is an input receiving unit that receives input of information regarding a test ozone concentration, which is the ozone concentration in the indoor space when the light source unit is turned on under a predetermined test illuminance; an inherent value calculation unit that calculates the indoor inherent value based on the test illuminance and the test ozone concentration, The indoor eigenvalue calculated by the eigenvalue calculation unit may be recorded in the storage unit.

[0026] There are several methods available for changing the average illuminance of ultraviolet light emitted from the ultraviolet irradiation device. The first method is a method of continuously turning on the light source unit with the illuminance changed. The second method is a method of repeatedly controlling the light source unit to be continuously turned on at a predetermined first illuminance P1 for a first predetermined time T1, and then to be continuously turned on at a second illuminance P2 lower than the first illuminance P1 for a second predetermined time T2. The third method is a method of repeatedly controlling the light source unit to be continuously turned on at a predetermined first illuminance P1 for a first predetermined time T1, and then to be turned off for a second predetermined time T2. The first, second, and third methods can be combined as appropriate.

[0027] As a more specific example, the input receiving unit is configured to receive input of information for specifying either continuous lighting or intermittent lighting as an operation mode, When the operation mode corresponds to the continuous lighting, the control unit may perform control to adjust the illuminance per unit time of the ultraviolet light emitted from the light source unit so that the average illuminance becomes the average illuminance during operation, and when the operation mode corresponds to the intermittent lighting, the control unit may perform control to adjust the duty of the light source unit when it is turned on so that the average illuminance becomes the average illuminance during operation.

[0028] When an ultraviolet irradiation device is installed in an indoor space for the purpose of inactivating microorganisms in the indoor space, the desired level of inactivation performance may vary from user to user. Therefore, the ultraviolet irradiation device may be configured to be able to accept input of information regarding the level of inactivation performance desired by the user, in other words, the illuminance level of ultraviolet light emitted from the ultraviolet irradiation device.

[0029] In more detail, the input receiving unit is configured to receive input of information for specifying an illuminance level, When the specified illuminance level is relatively low, the control unit may calculate the average driving illuminance based on the upper limit threshold value that is lower than when the specified illuminance level is relatively high.

[0030] As described above, the ultraviolet irradiation device records information about an indoor specific value that indicates the correlation between the average illuminance of the light source unit and the ozone concentration in the indoor space, which is information specific to the indoor space in which the ultraviolet irradiation device is installed. Therefore, even if the ultraviolet irradiation device itself does not have a means for measuring the ozone concentration in the indoor space, it is possible to inactivate microorganisms present in the indoor space by irradiating the indoor space with ultraviolet rays from the ultraviolet irradiation device while keeping the ozone concentration in the indoor space below the upper threshold. In addition, there is no need to separately install a measuring device for measuring the ozone concentration in the indoor space and monitor the ozone concentration.

[0031] The control method for an ultraviolet irradiation device according to the present invention is a control method for an ultraviolet irradiation device installed and used in an indoor space, A step (a) of reading out information on an indoor specific value specific to the indoor space, which indicates a correlation between an average illuminance of the light source unit and an ozone concentration in the indoor space when ultraviolet light having a main wavelength within a range of 200 nm to 240 nm is emitted from the light source unit toward the indoor space, and information on an upper limit threshold of the ozone concentration in the indoor space; (b) calculating an average driving illuminance at which the ozone concentration in the indoor space becomes the upper limit threshold based on the indoor specific value and the upper limit threshold; and (c) controlling the lighting of the light source unit under the average driving illuminance.

[0032] The control method includes a step (d) of turning on the light source unit under a predetermined test illuminance to measure a test ozone concentration, which is an ozone concentration in the indoor space; and (e) calculating the indoor specific value based on the test illuminance and the test ozone concentration; The step (b) may be a step of calculating the average driving illuminance based on the indoor characteristic value calculated in the step (e).

[0033] The control method includes a preparation step including the step (d) and the step (e); A using step including the steps (a), (b), and (c), The preparation step is performed at an initial stage when the ultraviolet irradiation device is installed in the indoor space, When the using step is performed, the steps (d) and (e) may not be performed. Effect of the Invention

[0034] According to the present invention, it is possible to inactivate microorganisms present in an indoor space while maintaining the O3 concentration in the indoor space at or below the recommended value, taking into consideration the characteristics of the indoor space in which the ultraviolet irradiation device is installed. [Brief description of the drawings]

[0035] [Figure 1] This is a graph showing the absorption spectra of oxygen molecules (O2) and ozone (O3). [Diagram 2] 1 is a diagram showing a schematic example of a process for inactivating microorganisms present in an indoor space using an ultraviolet irradiation device. [Diagram 3] FIG. 2 is a functional block diagram illustrating a configuration of an ultraviolet irradiation device. [Figure 4] 10 is a flowchart showing a process executed before the ultraviolet irradiation device is operated; [Diagram 5] 4 is a flowchart showing a typical process executed during operation of the ultraviolet irradiation device. [Figure 6] FIG. 11 is a functional block diagram illustrating a configuration of another embodiment of an ultraviolet irradiation device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an ultraviolet irradiation device and a control method thereof according to the present invention will be described with reference to the accompanying drawings. Note that the drawings are schematic illustrations, and the dimensional ratios in the drawings do not necessarily correspond to the actual dimensional ratios.

[0037] Fig. 2 is a diagram showing a schematic example of a state in which microorganisms present in an indoor space are inactivated using an ultraviolet irradiation device. In the example shown in Fig. 2, an ultraviolet irradiation device 1 of the present embodiment is installed in a room 50 as an indoor space. The ultraviolet irradiation device 1 is installed in the space of the room 50 and at least one of a desk 51, a chair 52, wallpaper 53, and a floor 54 installed in the room 50 for the purpose of inactivating microorganisms present in the area.

[0038] 2 shows an example in which the ultraviolet irradiation device 1 is attached to the ceiling 55 of the room 50. However, in the present invention, when inactivating microorganisms present in an indoor space, the installation position of the ultraviolet irradiation device 1 in the indoor space is not limited.

[0039] The ultraviolet irradiation device 1 emits ultraviolet light L1 whose dominant wavelength falls within the range of 200 nm to 240 nm. The ultraviolet light L1 in this wavelength range has an inactivating effect on microorganisms.

[0040] 3 is a functional block diagram illustrating an example of the configuration of the ultraviolet irradiation device 1. The ultraviolet irradiation device 1 illustrated in FIG. 3 includes a light source unit 3, a control unit 5, a storage unit 7, an input receiving unit 9, and an eigenvalue calculation unit 11.

[0041] The light source unit 3 emits ultraviolet light L1. The light source unit 3 is typically an excimer lamp, more specifically, an excimer lamp in which KrCl or KrBr is sealed as a light emitting gas. However, the light source unit 3 provided in the ultraviolet irradiation device 1 is not limited to this configuration as long as it is a light source that emits ultraviolet light L1 whose main wavelength falls within the range of 200 nm to 240 nm. For example, the light source unit 3 may be a lamp in which a light emitting gas other than the above-mentioned light emitting gas species is sealed, or may be a solid light source such as an LED. Furthermore, the light source unit 3 may be configured to emit ultraviolet light L1 whose main wavelength falls within the range of 200 nm to 240 nm by including a phosphor or a wavelength conversion element.

[0042] The control unit 5 is a functional means for controlling the power supply to the light source unit 3 to control the light emission state of the light source unit 3, and typically includes a power supply circuit. In this embodiment, the control unit 5 includes a calculation function for calculating the average illuminance during operation. In other words, the control unit 5 is a concept that encompasses the power supply circuit and the calculation processing unit.

[0043] The storage unit 7 is a storage area for recording information on an indoor specific value Vr specific to the room 50 and information on an upper threshold Cf of the ozone concentration in the room 50, which will be described later, and is configured, for example, with a storage medium such as a non-volatile memory.

[0044] The input receiving unit 9 is a functional means for receiving various information input to the ultraviolet irradiation device 1 from outside the ultraviolet irradiation device 1. In Fig. 3, information on a test ozone concentration Cr is illustrated as one piece of information input to the ultraviolet irradiation device 1. The test ozone concentration Cr will be described later.

[0045] The characteristic value calculation unit 11 is a functional means for calculating an indoor characteristic value Vr, which is a value specific to the room 50, using the test ozone concentration Cr, and is configured, for example, with a processor such as a CPU.

[0046] The ultraviolet irradiation device 1 in this embodiment performs a process of calculating an indoor characteristic value Vr specific to the room 50 at the time of installation in the room 50, and a process of inactivating microorganisms in the room 50 by irradiating ultraviolet light L1 under an average illuminance during operation calculated based on the calculated indoor characteristic value Vr. Typically, the former process is performed at the initial time when the ultraviolet irradiation device 1 is installed in the room 50, and is not performed thereafter as a rule. The latter process corresponds to a process of operating the ultraviolet irradiation device 1 to inactivate microorganisms in the room 50.

[0047] Hereinafter, the processing contents of the ultraviolet irradiation device 1 will be described with reference to the flowcharts shown in Figures 4 and 5. Figure 4 is a flowchart showing typically the processing contents executed before the ultraviolet irradiation device 1 is operated, and corresponds to the flowchart of the preparation step. Figure 5 is a flowchart showing typically the processing contents executed when the ultraviolet irradiation device 1 is operated, and corresponds to the flowchart of the use step.

[0048] <Preparation steps> First, the preparation step will be described. The preparation step is typically performed in the initial stage after the ultraviolet irradiation device 1 is installed at the installation position in the room 50, but may be performed in a state where the ultraviolet irradiation device 1 has been brought into the room 50 but has not yet been installed at the installation position.

[0049] (Step #11) The ultraviolet irradiation device 1 is operated, and the light source unit 3 is turned on at a predetermined test illuminance Yt. The ultraviolet irradiation device 1 irradiates the room 50 with ultraviolet light L1 at the test illuminance Yt.

[0050] For example, the ultraviolet irradiation device 1 may be configured such that a preparation mode is preregistered, and the light source unit 3 is turned on at the prerecorded test illuminance Yt by instructing to execute the preparation mode. Also, the ultraviolet irradiation device 1 may be configured such that the value of the test illuminance Yt can be input from outside the device.

[0051] (Step #12) An ozone sensor is installed at a predetermined position in the room 50, and the ozone concentration in the room 50 is measured under a condition in which ultraviolet light L1 is irradiated under a test illuminance Yt. Steps #11 to #12 are continuously executed until the measurement value of the ozone sensor becomes stable.

[0052] As described above in the section "Problems to be Solved by the Invention", even if the ultraviolet rays L1 have a dominant wavelength within the range of 200 nm to 240 nm, when the ultraviolet rays L1 are irradiated onto the room 50, a small amount of ozone is generated within the room 50. The rate at which this ozone is generated is affected by the volume of the room 50, the properties related to the shapes, sizes, amounts, and materials of objects (e.g., a desk 51, a chair 52, wallpaper 53, a floor 54, etc.) present in the room 50, the ventilation performance of the room 50, etc.

[0053] The amount of ozone generated by irradiating the room 50 with ultraviolet light L1 is proportional to the irradiation time of the ultraviolet light L1. On the other hand, since ozone is highly reactive, it is decomposed when it comes into contact with the objects present in the room 50. In addition, due to the ventilation capacity of the room 50, the air containing ozone generated in the room 50 is replaced with air not containing ozone at regular intervals. Due to these circumstances, if ultraviolet light L1 is continuously irradiated to the room 50, the ozone concentration in the room 50 will stabilize within a certain range. Step #12 is executed until the ozone concentration in the room 50 stabilizes.

[0054] In step #12, it is preferable to measure the ozone concentration at a height position where a human being may breathe (so-called "breathing zone") in the room 50. As an example, an ozone sensor may be installed at a predetermined position in an area between a height position 75 cm above the floor 54 and a height position 180 cm above the floor 54 to measure the ozone concentration in the room 50.

[0055] Steps #11 and #12 correspond to the process (d).

[0056] (Step #13) In step #12, when it is confirmed that the ozone concentration in the room 50 has stabilized, this stabilized ozone concentration is input to the ultraviolet irradiation device 1 as a test ozone concentration Cr.

[0057] Any method may be used to input information on the test ozone concentration Cr to the ultraviolet irradiation device 1. For example, if the ozone sensor is configured to be able to communicate with the ultraviolet irradiation device 1, the information may be remotely input from the ozone sensor to the ultraviolet irradiation device 1. Alternatively, a specific information terminal may be prepared, and the information on the test ozone concentration Cr from the ozone sensor may be input to the ultraviolet irradiation device 1 via the information terminal.

[0058] As another method, the ultraviolet irradiation device 1 may be provided with an input means for directly inputting a numerical value, and an operator who reads the test ozone concentration Cr from the ozone sensor may operate the input means to input the value of the test ozone concentration Cr to the ultraviolet irradiation device 1. As yet another method, an operator who reads the test ozone concentration Cr from the ozone sensor may operate an operation terminal separate from the ultraviolet irradiation device 1 to input the value of the test ozone concentration Cr, and the input value of the test ozone concentration Cr may be remotely input from the operation terminal to the ultraviolet irradiation device 1.

[0059] (Step #14) The eigenvalue calculation unit 11 calculates an indoor eigenvalue Vr specific to the room 50 based on the test illuminance Yt in step #11 and the test ozone concentration Cr input in step #13.

[0060] When an ozone generating device is operated in a room 50, the amount of ozone released per unit time (release rate) is Z (μg / h), and the volume of the room 50 is V (m 3 ), the deposition rate of ozone in the room 50 is ν (m / h), the air exchange rate (ACH) of the room 50 is ψ (1 / h), and the surface area of ​​the room 50 is A (m 2 ), then the ozone concentration in room 50 is ε (μg / m 3 ) is considered to be defined by the following equation (3).

[0061]

number

[0062] Here, each element of the volume V of the room 50, the air exchange rate ψ of the room 50, the deposition velocity ν of ozone in the room 50, and the surface area A of the room 50 are values ​​specific to the room 50. That is, according to the formula (3), the value α specific to the room 50 is calculated by the following formula (4).

[0063]

number

[0064] Here, when the ultraviolet irradiation device 1 is used as the device for generating ozone, the ozone release rate Z is a value that shows a high correlation with the total luminous flux of the ultraviolet rays L1 irradiated from the ultraviolet irradiation device 1. The illuminance of the ultraviolet rays L1 irradiated from the ultraviolet irradiation device 1 shows a high positive correlation with the total luminous flux of the ultraviolet rays L1, and typically the two are in a proportional relationship. In other words, the value Vr calculated by the following formula (5) based on the value of the test illuminance Yt and the value of the test ozone concentration Cr measured when the ultraviolet rays L1 are irradiated to the room 50 under the test illuminance Yt is recognized as a value specific to the room 50. Hereinafter, this value Vr will be referred to as the "indoor specific value Vr" of the room 50.

[0065]

number

[0066] In view of the above, the method of calculating the indoor eigenvalue Vr is not limited to formula (5), and it is possible to adopt a value calculated as a ratio between a value showing a correlation with the test ozone concentration Cr and a value showing a correlation with the test illuminance Yt. In other words, the indoor eigenvalue Vr is information showing the correlation between the average illuminance of the ultraviolet light L1 irradiated from the light source unit 3 and the ozone concentration in the room 50.

[0067] The eigenvalue calculation unit 11 may be configured to calculate the indoor eigenvalue Vr based on the test ozone concentration Cr and the test illuminance Yt by prerecording an arithmetic formula, such as formula (5), and to calculate the indoor eigenvalue Vr based on this arithmetic formula. The arithmetic formula for calculating the indoor eigenvalue Vr may be recorded in the storage unit 7.

[0068] Step #14 corresponds to process (e).

[0069] (Step #15) Information relating to the indoor eigenvalue Vr calculated in step #14 is recorded in the storage unit 7. When the above steps #11 to #15 are completed, the preparation step ends.

[0070] <Usage steps> Next, the use step will be described. As described above, the use step is a step that is executed after the preparation step is completed, and is executed for the purpose of operating the ultraviolet irradiation device 1 installed in the room 50 to inactivate microorganisms present in the room 50. That is, the use step is executed from the point in time when a signal to start the operation of the ultraviolet irradiation device 1 is input after the ultraviolet irradiation device 1 is installed in the room 50.

[0071] (Step #21) The control unit 5 reads out information on the indoor characteristic value Vr of the room 50 and information on the upper limit threshold Cf of the ozone concentration of the room 50 from the storage unit 7.

[0072] Here, the information on the indoor characteristic value Vr of the room 50 corresponds to the information recorded in the storage unit 7 in step #15. Moreover, the information on the upper threshold Cf of the ozone concentration in the room 50 is information previously recorded in the storage unit 7. For example, the upper threshold Cf may be a recommended value set by the country or the local government to which the room 50 belongs, or a value that takes into account a predetermined safety likelihood with respect to the recommended value may be adopted.

[0073] The information on the upper threshold Cf may be recorded in advance in the storage unit 7 of the ultraviolet irradiation device 1 before the preparation step is performed. Also, the information on the upper threshold Cf may be remotely recorded in the storage unit 7 when the preparation step is performed.

[0074] Step #21 corresponds to process (a).

[0075] (Step #22) The arithmetic processing function included in the control unit 5 calculates the average driving illuminance Y based on the indoor characteristic value Vr of the room 50 and the upper limit threshold Cf of the ozone concentration.

[0076] In view of the above-mentioned formula (5), when the ultraviolet irradiation device 1 is operated in a room 50 having an indoor characteristic value Vr, the average illuminance Yf at which the ozone concentration reaches the upper threshold value Cf can be calculated by the following formula (6).

[0077]

number

[0078] For the same reasons as those mentioned above when explaining equation (5), the method of calculating the average illuminance Yf when the ozone concentration reaches the upper threshold Cf is not limited to the above equation (6), and it is possible to adopt a value calculated as the ratio between a value showing a correlation with the upper threshold Cf of the ozone concentration and a value showing a correlation with the indoor eigenvalue Vr.

[0079] It is considered that by operating the ultraviolet irradiation device 1 under an average illuminance equal to or less than the average illuminance Yf calculated by the above-mentioned calculation, it is possible to make the ozone concentration in the room 50 less than the upper limit threshold Cf.

[0080] The control unit 5 may determine the average illuminance Y during driving using the average illuminance Yf calculated by the above-mentioned calculation, or may determine the average illuminance Y during driving using a value obtained by multiplying the average illuminance Yf by a predetermined safety factor δ.

[0081] For example, when the input receiving unit 9 of the ultraviolet irradiation device 1 is configured to receive input of information on the degree of inactivation performance desired by the user, in other words, information on the illuminance level of the ultraviolet ray L1, the safety factor may be determined according to the relative value of the illuminance level. As a more specific example, when the operation mode of the ultraviolet irradiation device 1 can be selected by the user from three stages, "strong mode", "medium mode", and "weak mode", the average operation illuminance Y may be determined taking into account the safety factor set according to this mode. As an example, in the "strong mode", δ=0.95, in the "medium mode", δ=0.7, and in the "weak mode", δ=0.6.

[0082] It should be noted that the above is merely an example, and it is possible to set any number of types of modes and the value of the safety factor 6. Also, the ultraviolet irradiation device 1 may be configured so that the value of the safety factor 6 itself can be input.

[0083] Step #22 corresponds to process (b).

[0084] (Step #23) The control unit 5 determines the control content to be actually executed on the light source unit 3 in order to operate the ultraviolet irradiation device 1 under the average operation illuminance Y determined in step #22. The control unit 5 may store information indicating the correlation between the factors that affect the power supplied to the light source unit 3 and the illuminance of the ultraviolet light L1 irradiated from the ultraviolet irradiation device 11. For example, when the light source unit 3 is an excimer lamp and the excimer lamp is controlled to be turned on by a pulse voltage obtained by the control unit 5 performing current control using a switching element, the control unit 5 may store in advance the correlation between the ON / OFF frequency of the switching element and the illuminance of the ultraviolet light L1. The ON / OFF frequency here is an example of a factor that affects the power supplied to the light source unit 3, and other factors include values ​​of the current and voltage supplied to the light source unit 3. The type of factor to be adopted is appropriately set depending on the configuration of the light source unit 3 itself and the configuration of the lighting circuit for controlling the lighting of the light source unit 3.

[0085] In other words, the description that the control unit 5 turns on the light source unit 3 at a predetermined first illuminance P1 means, in detail, that the control unit 5 controls the power supplied to the light source unit 3 based on a correlation stored in advance so that the illuminance of the ultraviolet light L1 irradiated from the light source unit 3 becomes the first illuminance P1.

[0086] As a specific example, the control unit 5 determines the control content to be such that the light source unit 3 is continuously turned on under the average operational illuminance Y. For convenience, this control is referred to as a "first operational mode."

[0087] As another specific example, the control unit 5 determines the control content to be repeated such that the light source unit 3 is continuously turned on at a predetermined first illuminance P1 for a first predetermined time T1, and then the light source unit is continuously turned on at a second illuminance P2 lower than the first illuminance P1 for a second predetermined time T2, so that the average illuminance becomes the average illuminance during operation Y. For convenience, this control is called the "second operation mode."

[0088] As another specific example, the control unit 5 determines the control content to be repeated such that the light source unit 3 is continuously turned on at a predetermined first illuminance P1 for a first predetermined time T1, and then the light source unit is turned off for a second predetermined time T2, so that the average illuminance becomes the average illuminance during operation Y. For convenience, this control is called the "third operation mode." The third operation mode corresponds to intermittent lighting, and the ratio of the time T1 to the total value of the times T1 and T2 corresponds to the lighting duty.

[0089] The input receiving unit 9 of the ultraviolet irradiation device 1 may be configured to receive input of information for specifying the above-mentioned operation mode (hereinafter, referred to as "specified mode information"). In this case, the control unit 5 determines the control content to be actually executed on the light source unit 3 in order to operate the ultraviolet irradiation device 1 under the average operating illuminance Y based on the specified mode information.

[0090] If the ultraviolet irradiation device 1 is not configured to accept input of designated mode information, or if designated mode information is not input, any one of the first to third operation modes may be executed according to the priority order of the modes registered in advance on the ultraviolet irradiation device 1 side. Furthermore, the ultraviolet irradiation device 1 may be configured to be capable of executing only any one of the above-mentioned first to third operation modes.

[0091] (Step #24) Based on the control content determined in step #23, the control unit 5 controls the light source unit 3 to irradiate the ultraviolet ray L1 into the room 50. This makes it possible to maintain the ozone concentration in the room 50 below the upper limit threshold Cf while irradiating the ultraviolet ray L1 with a relatively high illuminance.

[0092] Steps #23 to #24 correspond to the process (c).

[0093] (Step #25) Step #24 is continuously executed until an instruction signal to stop operation is input to the ultraviolet irradiation device 1 (No in step #25), thereby continuing irradiation of the ultraviolet ray L1 to the room 50. When an instruction signal to stop operation is input to the ultraviolet irradiation device 1 (Yes in step #25), operation of the ultraviolet irradiation device 1 is stopped, and the use step ends.

[0094] From the above, it can be seen that it is not necessarily necessary to monitor the ozone concentration in room 50 during the time period when ultraviolet irradiation device 1 is operating (i.e., when the use step is being performed) for the purpose of actually inactivating microorganisms in room 50.

[0095] [Another embodiment] Another embodiment will be described below.

[0096] <1> In the above embodiment, the preparation step is performed using the ultraviolet irradiation device 1 that is the same as the ultraviolet irradiation device 1 installed in the room 50. However, the preparation step may be performed using a test ultraviolet irradiation device (not shown) that is the same as or substantially the same as the ultraviolet irradiation device 1 to calculate the indoor eigenvalue Vr of the room 50. In this case, since information on the indoor eigenvalue Vr is input from outside to the ultraviolet irradiation device 1 installed in the room 50 and recorded in the storage unit 7, the ultraviolet irradiation device 1 does not necessarily need to include the eigenvalue calculation unit 11 as shown in FIG. 6.

[0097] <2> In the above embodiment, the indoor eigenvalue Vr is calculated in the ultraviolet irradiation device 1. However, even if the preparation step is performed using the same ultraviolet irradiation device 1 as the ultraviolet irradiation device 1 installed in the room 50, the process of calculating the indoor eigenvalue Vr based on the test ozone concentration Cr and the test illuminance Yt may be performed in a calculation processing device (not shown) other than the ultraviolet irradiation device 1. Even in this case, information on the indoor eigenvalue Vr is input from the calculation processing device to the ultraviolet irradiation device 1 and recorded in the storage unit 7, so that the ultraviolet irradiation device 1 does not necessarily have to include the eigenvalue calculation unit 11 as shown in FIG. 6. [Explanation of symbols]

[0098] 1: Ultraviolet irradiation device 3: Light source section 5: Control section 7: Storage section 9: Input reception section 11: Eigenvalue calculation section 50: Room 51: desk 52: Chair 53:Wallpaper 54:Floor 55: Ceiling

Claims

1. An ultraviolet irradiation device that is installed and used in an indoor space, A light source unit that emits ultraviolet light having a dominant wavelength within a range of 200 nm to 240 nm; A control unit that controls the lighting of the light source unit; a storage unit configured to record information on an indoor specific value specific to the indoor space, the indoor specific value indicating a correlation between an average illuminance of the light source unit and an ozone concentration in the indoor space when the ultraviolet light is emitted toward the indoor space, and information on an upper limit threshold of the ozone concentration in the indoor space; The control unit calculates an average operating illuminance at which the ozone concentration in the indoor space is less than the upper threshold based on the indoor specific value and the upper threshold, and controls the lighting of the light source unit under the average operating illuminance.

2. The ultraviolet irradiation device is an input receiving unit that receives input of information regarding a test ozone concentration, which is the ozone concentration in the indoor space when the light source unit is turned on under a predetermined test illuminance; an inherent value calculation unit that calculates the indoor inherent value based on the test illuminance and the test ozone concentration, 2. The ultraviolet irradiation device according to claim 1, wherein the indoor eigenvalue calculated by the eigenvalue calculation unit is recorded in the storage unit.

3. The input reception unit is configured to receive input of information for designating an operation mode of either continuous lighting or intermittent lighting, 3. The ultraviolet irradiation device according to claim 2, wherein the control unit performs control to adjust the illuminance per unit time of the ultraviolet light emitted from the light source unit so that the average illuminance becomes the average operating illuminance when the operation mode corresponds to the continuous lighting, and performs control to adjust the lighting duty of the light source unit so that the average illuminance becomes the average operating illuminance when the operation mode corresponds to the intermittent lighting.

4. the input receiving unit is configured to receive input of information for specifying an illuminance level, 3. The ultraviolet irradiation device according to claim 2, wherein when the specified illuminance level is relatively low, the control unit calculates the average operating illuminance based on the upper limit threshold that is lower than when the specified illuminance level is relatively high.

5. 5. The ultraviolet irradiation device according to claim 1, further comprising no means for measuring an ozone concentration in the indoor space.

6. A method for controlling an ultraviolet irradiation device installed and used in an indoor space, comprising: (a) reading out information on an indoor specific value specific to the indoor space, which indicates a correlation between an average illuminance of the light source unit and an ozone concentration in the indoor space when ultraviolet light having a main wavelength within a range of 200 nm to 240 nm is emitted from the light source unit toward the indoor space, and information on an upper limit threshold of the ozone concentration in the indoor space; (b) calculating an average driving illuminance at which the ozone concentration in the indoor space becomes the upper limit threshold based on the indoor specific value and the upper limit threshold; and (c) controlling the light source unit to be turned on under the average illuminance during operation.

7. (d) turning on the light source unit under a predetermined test illuminance to measure a test ozone concentration, which is an ozone concentration in the indoor space; and (e) calculating the indoor specific value based on the test illuminance and the test ozone concentration; 7. The method for controlling an ultraviolet irradiation device according to claim 6, wherein the step (b) is a step of calculating the average operating illuminance based on the indoor characteristic value calculated in the step (e).

8. A preparation step including the steps (d) and (e); A using step including the steps (a), (b), and (c), The preparation step is performed at an initial stage when the ultraviolet irradiation device is installed in the indoor space, 8. The method for controlling an ultraviolet irradiating device according to claim 7, wherein the steps (d) and (e) are not performed when the using step is performed.

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