How to set up an ultraviolet irradiation device

Abstract

To provide a setting method of an ultraviolet ray irradiation device capable of efficiently irradiating the ultraviolet ray suitable for treatment of the inside of a room.SOLUTION: According to an embodiment, a method for setting an ultraviolet irradiation device is a method for setting one or more ultraviolet irradiation devices each including a one or more ultraviolet irradiation section that irradiates ultraviolet rays. The method comprises setting one or more ultraviolet ray irradiation devices such that a ratio of a region where intensity of the ultraviolet ray to a virtual cubic space having one side of 1 m that is set such that the one side where a center of one ultraviolet irradiation section of the ultraviolet irradiation device and a face center match each other is 5 μW / cm2 or more, is 49.8% or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a method for setting an ultraviolet irradiation device. [Background technology]

[0002] Ultraviolet irradiation devices are used to treat bacteria, viruses, and the like present indoors by irradiating them with ultraviolet light. Ultraviolet light is effective in treating bacteria, viruses, and the like. However, prolonged irradiation with ultraviolet light can also have an adverse effect on the human body. Therefore, when an ultraviolet irradiation device is used in a room where people are present, it is required that ultraviolet light suitable for treatment of the room be efficiently irradiated. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-36703 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide a method for setting an ultraviolet irradiation device that efficiently irradiates ultraviolet rays suitable for indoor treatment. [Means for solving the problem]

[0005] According to an embodiment, the setting method of the ultraviolet irradiation device is a setting method of one or more ultraviolet irradiation devices each having an ultraviolet irradiation unit that irradiates ultraviolet rays, and the ultraviolet intensity for a virtual cubic space having a side of 1 m and configured so as not to include one ultraviolet irradiation unit inside, the virtual cubic space having a side of 1 m and configured so as not to include one ultraviolet irradiation unit inside, is 5 μW / cm 2 One or more ultraviolet irradiation devices are set so that the ratio of the area where the ultraviolet light intensity is equal to or greater than 49.8%. [Effects of the Invention]

[0006] According to the present invention, a method for setting an ultraviolet irradiation device that efficiently irradiates ultraviolet rays suitable for indoor treatment is provided. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing an example of a method for arranging an ultraviolet irradiation device, as an example of a method for setting an ultraviolet irradiation device. [Figure 2A] FIG. 2A is a diagram showing the relationship between the amount of ultraviolet light irradiation, irradiation time, and intensity. [Figure 2B] FIG. 2B is a diagram showing the relationship between the amount of ultraviolet light irradiation, irradiation time, and intensity. [Figure 2C] FIG. 2C is a diagram showing the relationship between the amount of ultraviolet light irradiation, irradiation time, and intensity. [Figure 3] FIG. 3 is a diagram showing an example of the arrangement of one ultraviolet irradiation device. [Figure 4A] FIG. 4A is a diagram showing the intensity for each small space on a virtual plane at a vertical distance of 0 cm from the ultraviolet ray irradiation unit. [Figure 4B] FIG. 4B is a diagram showing the intensity for each small space on a virtual plane 50 cm vertically away from the ultraviolet ray irradiation unit. [Figure 4C] FIG. 4C is a diagram showing the intensity for each small space on a virtual plane 100 cm vertically away from the ultraviolet irradiating unit. [Figure 5] FIG. 5 is a diagram showing an example of the relationship between the threshold value and the ratio in the example of arrangement in FIG. [Figure 6] FIG. 6 is a graph showing the relationship of FIG. [Figure 7] FIG. 7 is a diagram showing an example of an arrangement in which two ultraviolet irradiation units are arranged at a horizontal and vertical interval of 1 m. [Figure 8] FIG. 8 is a diagram showing the intensity for each small space on a virtual plane 50 cm vertically away from the ultraviolet irradiating unit. [Figure 9] FIG. 9 is a diagram showing an example of the relationship between the threshold value and the ratio in the example of arrangement in FIG. [Figure 10]FIG. 10 is a graph showing the relationship of FIG. [Figure 11] FIG. 11 is a diagram showing an example of an arrangement in which nine ultraviolet irradiation units are arranged. [Figure 12A] FIG. 12A is a diagram showing the intensity for each small space on a virtual plane 50 cm vertically away from the ultraviolet ray irradiation unit. [Figure 12B] FIG. 12B is a diagram showing the intensity for each small space on a virtual plane 100 cm vertically away from the ultraviolet irradiating unit. [Figure 13] FIG. 13 is a diagram showing an example of the relationship between the threshold value and the ratio in the example of arrangement in FIG. [Figure 14] FIG. 14 is a graph showing the relationship of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] The ultraviolet irradiation device according to the embodiment can disinfect, remove bacteria, or sterilize an object to be irradiated (for example, a location where at least one bacteria, virus, etc. is attached) by irradiating the object with ultraviolet light. Here, the term "disinfection" in the following embodiments can be replaced with the term "sterilization" or "disinfection."

[0009] The ultraviolet irradiation device setting method of the embodiment is a setting method for one or more ultraviolet irradiation devices each having an ultraviolet irradiation section (11) that irradiates ultraviolet rays, and the ultraviolet intensity for a virtual cubic space (VS) having a side of 1 m and configured so as not to include one ultraviolet irradiation section (11) inside, the virtual cubic space (VS) having a side of 1 m and configured so as not to include one ultraviolet irradiation section (11) inside, is 5 μW / cm 2 One or more ultraviolet irradiation devices are set so that the ratio of the area where the ultraviolet light intensity is equal to or greater than 49.8%.

[0010] The ultraviolet irradiation device of the embodiment is set so that the ultraviolet intensity for the virtual cubic space (VS) is 5 μW / cm 2Two or more ultraviolet irradiation units (11-19) are arranged so that the ratio of the area where the ultraviolet rays are equal to or greater than 49.8% is 49.8% or more. This allows efficient irradiation of ultraviolet rays suitable for treatment in the room.

[0011] In the method for setting up an ultraviolet irradiation device according to the embodiment, two or more ultraviolet irradiation units (11-19) are arranged so that the ultraviolet rays emitted from each of them enter the virtual cubic space (VS), thereby efficiently irradiating ultraviolet rays suitable for treatment in the room.

[0012] The ultraviolet irradiation device setting method of the embodiment is a setting method for two or more ultraviolet irradiation devices each equipped with an ultraviolet irradiation unit (11-19) for irradiating ultraviolet light, in which the two or more ultraviolet irradiation devices are set so that a first ratio, which is the ratio of an area in a predetermined virtual cubic space (VS) where the ultraviolet intensity is equal to or greater than a threshold, is greater than a second ratio, which is the ratio of an area when only one ultraviolet irradiation device is installed, and the threshold is determined by the degree of sterilization in the virtual cubic space and the operating mode of the ultraviolet irradiation device. This allows efficient irradiation of ultraviolet light suitable for treatment in a room.

[0013] Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an example of a method for installing an ultraviolet irradiation device, as an example of a method for setting up an ultraviolet irradiation device. The ultraviolet irradiation device according to the embodiment is installed in a room R. The room R is not particularly limited as long as it has a space larger than a cubic space with one meter on each side. The room R may be installed in a place such as an office environment, a cafe, a rental conference room, or a family restaurant. Furthermore, although the word "room" is used here, the room R according to the embodiment may also be a space such as a stadium, a sports arena, or a concert venue.

[0014] As shown in FIG. 1, a person H may be staying in room R. The person H can enter and exit room R. Places in room R that the person H has touched may become contaminated with bacteria, viruses, etc. that have been attached to the person H. It is preferable that such contaminated places be sterilized appropriately and quickly. It is also preferable that bacteria, viruses, etc. that the person H has brought into room R and that are residing (floating) in the air of room R be sterilized appropriately and quickly.

[0015] In this embodiment, an ultraviolet irradiation device is disposed, for example, on the ceiling of room R. The ultraviolet irradiation device is disposed so that an ultraviolet irradiation unit 11 included in the ultraviolet irradiation device faces or is exposed to the space within room R. The ultraviolet irradiation unit 11 is disposed so as to irradiate ultraviolet rays downward from the ceiling of room R, i.e., toward the floor of room R. The ultraviolet irradiation unit 11 includes a light source and a power supply. The light source may be a non-LED (Light Emitting Diode) lamp (e.g., a mercury lamp, a metal halide lamp, a fluorescent ultraviolet lamp, an excimer lamp, etc.) or an LED. The light source includes, for example, a light-emitting circuit using a UV-LED and is configured to irradiate ultraviolet rays with a wavelength of at least 380 nm or less. The ultraviolet irradiation unit 11 can irradiate ultraviolet rays whether or not person H is present in room R. Here, the ultraviolet irradiation device does not necessarily have to be disposed on the ceiling of room R and may be disposed anywhere in room R.

[0016] In this embodiment, a virtual cubic space VS is defined when determining the settings (installation) of the ultraviolet irradiation device. The virtual cubic space VS is a space for evaluating the level of ultraviolet irradiation in the ultraviolet irradiation unit 11, and is a virtual cubic space with a side of 1 m that has a virtual surface whose center coincides with the ultraviolet irradiation center of the ultraviolet irradiation unit 11 and is set so as not to include the ultraviolet irradiation unit 11 inside, i.e., so that the ultraviolet irradiation unit 11 is circumscribed on the virtual surface.

[0017] The degree of sterilization by ultraviolet irradiation is generally determined by the amount of ultraviolet irradiation. For example, the amount of irradiation that can sterilize approximately 99.99% of viruses is 4000 μJ / cm2 The irradiation dose required to eliminate approximately 99.90% of viruses is 3000 μJ / cm 2 The irradiation dose required to eliminate approximately 99.00% of viruses is 2000 μJ / cm 2 The irradiation dose required to eliminate approximately 90.00% of viruses is 1000 μJ / cm 2 It is said that this is the case.

[0018] The amount of ultraviolet radiation (illuminance) is determined by the product of the intensity of ultraviolet radiation and the duration of exposure. Therefore, the stronger the intensity and the longer the exposure time, the greater the sterilization effect of ultraviolet radiation. On the other hand, ultraviolet radiation also affects the human body. For this reason, from a safety perspective, an upper limit is set for the amount of ultraviolet radiation that a person can be exposed to. For example, the American Conference of Governmental Industrial Hygienists (ACGIH) and the Japanese Industrial Standards (JIS Z 8812) prescribe threshold limited values ​​(TLV) for the amount of ultraviolet radiation that a person can be exposed to per day. For example, the TLV for ultraviolet radiation with a wavelength of 222 nm is 22 mJ / cm. 2 Thus, in order to sterilize in an environment where people are present, it is necessary to set the intensity and irradiation time of ultraviolet light so that it does not exceed the TLV.

[0019] In addition, from the perspective of air sterilization, it is recommended that indoor ventilation be performed twice an hour. In other words, ventilation should be performed once every 30 minutes on average. Therefore, it is desirable to irradiate ultraviolet light so that air sterilization is completed within this 30-minute period.

[0020] Figures 2A, 2B, and 2C are diagrams showing the relationship between the amount of ultraviolet light irradiation, irradiation time, and intensity. Here, the "definition" in Figures 2A, 2B, and 2C indicates the degree of sterilization that is the target. Also, the "irradiation amount" in Figures 2A, 2B, and 2C indicates the amount of ultraviolet light irradiation required to achieve the sterilization of the "definition." The unit of irradiation amount is μJ / cm. 2The "irradiation time" in Figures 2A, 2B, and 2C indicates the ultraviolet irradiation time required to achieve the "definition" sterilization. The unit of irradiation time is seconds. The "threshold" in Figures 2A, 2B, and 2C indicates the ultraviolet intensity required to achieve the "definition" sterilization. The unit of threshold, i.e., intensity, is μW / cm 2 is.

[0021] 2A is a diagram showing the relationship when the first mode, which continuously irradiates ultraviolet rays for 30 minutes, is available as an operating mode of the ultraviolet irradiation unit 11. When continuous ultraviolet irradiation for 30 minutes is possible, the irradiation time can be fixed at 1800 seconds. As mentioned above, the irradiation amount that can sterilize approximately 99.99% of viruses is 4000 μJ / cm 2 Therefore, the threshold of irradiation intensity per unit time that can eliminate approximately 99.99% of viruses is 4000 / 1800 ≒ 2.22 μW / cm 2 Similarly, the threshold for eliminating approximately 99.90% of viruses is 3000 / 1800 ≒ 1.67 μW / cm 2 The threshold for eliminating approximately 99.00% of viruses is 2000 / 1800 ≒ 1.11 μW / cm 2 The threshold for eliminating approximately 90.00% of viruses is 1000 / 1800 ≒ 0.56 μW / cm 2 If ultraviolet light is irradiated for 30 minutes according to these thresholds, the desired virus sterilization can be achieved while the ultraviolet light irradiation dose is 22 mJ / cm. 2 It will never exceed.

[0022] FIG. 2B is a diagram showing the relationship when the second mode, which performs intermittent irradiation of ultraviolet light every minute (i.e., repeating 1 minute on and 1 minute off) is included as the operating mode of the ultraviolet light irradiation unit 11. In the case of intermittent irradiation every minute, there is a period of 1 minute in which ultraviolet light is not irradiated. Therefore, in order to complete sterilization in 30 minutes, the irradiation time can be fixed at 900 seconds. As a result, the threshold value of the irradiation intensity per unit time that can sterilize approximately 99.99% of viruses is 4000 / 900 ≒ 4.44 μW / cm 2 Similarly, the threshold for eliminating approximately 99.90% of viruses is 3000 / 900 ≒ 3.33 μW / cm 2The threshold for eliminating approximately 99.00% of viruses is 2000 / 900 ≒ 2.22 μW / cm 2 The threshold for eliminating approximately 90.00% of viruses is 1000 / 900 ≒ 1.11 μW / cm 2 If intermittent irradiation is performed every minute according to these thresholds, the desired virus sterilization can be achieved while the ultraviolet irradiation dose is 22 mJ / cm. 2 It will never exceed.

[0023] 2C is a diagram showing the relationship when the ultraviolet irradiation unit 11 has an operating mode in which ultraviolet irradiation is repeated for 1 minute and then stopped for 2 minutes. In this case, the irradiation time can be fixed at 600 seconds to complete sterilization in 30 minutes. As a result, the threshold value of the irradiation intensity per unit time that can sterilize approximately 99.99% of viruses is 4000 / 600 ≒ 6.67 μW / cm 2 Similarly, the threshold for eliminating approximately 99.90% of viruses is 3000 / 600 ≒ 5.00 μW / cm 2 The threshold for eliminating approximately 99.00% of viruses is 2000 / 600 ≒ 3.33 μW / cm 2 The threshold for eliminating approximately 90.00% of viruses is 1000 / 600 ≒ 1.67 μW / cm 2 If irradiation is performed for 1 minute and then stopped for 2 minutes according to these thresholds, the desired virus sterilization can be achieved while the ultraviolet irradiation dose is 22 mJ / cm. 2 It will never exceed.

[0024] Thus, when the goal is to eliminate bacteria in 30 minutes, the threshold value varies depending on the amount of ultraviolet light irradiation that satisfies the required level of sterilization and the operating mode of the ultraviolet light irradiation unit 11. It is desirable to set the ultraviolet light irradiation device so that as a result of ultraviolet light irradiation from the ultraviolet light irradiation unit 11, the area where the value is above the threshold is as large as possible. Evaluation for this setting is performed using a virtual cubic space VS. This will be explained in detail below.

[0025] Fig. 3 is a diagram showing an example of the arrangement of one ultraviolet irradiation device. Here, Fig. 3 is a diagram showing the ultraviolet irradiation unit 11 of the ultraviolet irradiation device as viewed from the ceiling of room R. As shown in Fig. 3, the center of one virtual face of the virtual cubic space VS coincides with the ultraviolet irradiation center of one ultraviolet irradiation unit 11.

[0026] Consider a situation where only one ultraviolet irradiation unit 11 is installed, irradiating ultraviolet light of a certain intensity I at a certain light distribution angle θ. The greater the proportion of areas in the virtual cubic space VS where the intensity is equal to or greater than the threshold, the more areas in the virtual cubic space VS are sterilized, meaning that room R can be sterilized more efficiently. This proportion can be calculated, for example, by dividing the virtual cubic space VS into small spaces measuring 100 mm x 100 mm x 100 mm and counting the number of small spaces with an intensity equal to or greater than the threshold. The number of small spaces to be counted may be the number of small spaces where the average intensity of ultraviolet light irradiated within the small spaces is equal to or greater than the threshold, or the number of small spaces where the maximum intensity (or minimum intensity) of ultraviolet light irradiated within the small spaces is equal to or greater than the threshold. Alternatively, the integrated intensity within the small spaces may be compared with the threshold.

[0027] For example, in the virtual cubic space VS shown in FIG. 1, the intensities of each small space on virtual planes P0, P50, and P100 at vertical distances of 0 cm, 50 cm, and 100 cm from the ultraviolet irradiation unit 11 are shown in FIGS. 4A, 4B, and 4C, respectively. Region A1 in FIGS. 4A, 4B, and 4C is a small space region where the intensity is equal to or greater than the threshold. Region A2 in FIGS. 4A, 4B, and 4C is a small space region where the intensity is greater than 0 but less than the threshold. Region A3 in FIG. 4A is a small space region where the intensity is 0. Regions where the intensity is 0 are regions where no ultraviolet light is irradiated at all.

[0028] For example, on a virtual plane at 0 cm directly below the ultraviolet irradiation section 11, as shown in Figure 4A, the number of small spaces contained in area A1 is 4, the number of small spaces contained in area A2 is 12, and the number of small spaces contained in area A3 is 84.

[0029] Similarly, on a virtual surface 50 cm from the ultraviolet irradiation unit 11, as shown in Fig. 4B, the number of small spaces included in region A1 is 32, and the number of small spaces included in region A2 is 68. Similarly, on a virtual surface 100 cm from the ultraviolet irradiation unit 11, as shown in Fig. 4C, the number of small spaces included in region A1 is 88, and the number of small spaces included in region A2 is 12. In Figs. 4B and 4C, the reason why the number of small spaces included in region A1 is large is because the ultraviolet light emitted from the ultraviolet irradiation unit 11 is distributed in a wide range.

[0030] The total number of small spaces included in the area A1 counted as described above is divided by the total number of small spaces included in the virtual cubic space VS, that is, by 1000, to calculate the proportion of areas with an intensity equal to or greater than the threshold.

[0031] Fig. 5 is a diagram showing an example of the relationship between the threshold and the ratio in the arrangement example of Fig. 3. Here, the ratio shown in Fig. 5 is a ratio calculated with respect to the threshold in the case of Fig. 2C, that is, when the operation mode of the ultraviolet irradiation unit 11 has a mode in which ultraviolet irradiation for 1 minute and stopping ultraviolet irradiation for 2 minutes are repeated. The unit of the threshold in Fig. 5 is mW / cm 2 That is, FIG. 5 is a diagram showing the proportion of small spaces per unit area that are irradiated with ultraviolet light having an intensity equal to or greater than the threshold. As is clear from FIG. 5, the proportion decreases as the threshold increases. FIG. 6 is a graph showing the relationship shown in FIG. 5. Here, the horizontal axis of FIG. 6 represents the threshold, and the vertical axis of FIG. 6 represents the proportion. As shown in FIG. 6, the threshold and proportion shown in FIG. 5 can be approximated by a linear function of y=-0.0421x+0.703. Therefore, if the ultraviolet light irradiation conditions are the same, the proportion can be determined by determining the threshold.

[0032] For example, it can be determined whether the ultraviolet irradiation conditions are appropriate based on the ratio shown in Fig. 6. That is, if only one ultraviolet irradiation unit 11 is provided and the threshold is 5.00 μW / cm 2When the second ratio calculated at that time is greater than the first ratio of 49.8% shown in FIG. 6, the conditions for ultraviolet irradiation by the ultraviolet irradiation unit 11 at that time are such that the air in the virtual cubic space VS is efficiently sterilized and the room R is efficiently sterilized. Even if the first ratio of 49.8% is not reached, for example, by increasing the intensity I, the ratio of the area where the intensity is equal to or greater than the threshold increases, and the ratio of the small spaces satisfying the threshold becomes 49.8% or more, thereby enabling efficient air sterilization of the room R. The ratio of the area can also be changed, for example, by changing the light distribution angle θ. For example, the area A1 shown in FIG. 4A is an area where no ultraviolet light is irradiated. However, by changing the light distribution angle θ, the intensity of the small spaces in area A1 becomes equal to or greater than the threshold, and the ratio of the small spaces satisfying the threshold becomes 49.8% or more, thereby enabling efficient air sterilization of the room R. The conditions for the intensity I and the light distribution angle θ may be determined by simulation, for example.

[0033] Furthermore, the ratio can be increased by combining two or more ultraviolet irradiation units, rather than just one. FIG. 7 is a diagram showing an example of an arrangement in which two ultraviolet irradiation units 11 and 12 are arranged with a horizontal and vertical distance of 1 m between them. In FIG. 7, the center of the imaginary surface of the imaginary cubic space VS coincides with the ultraviolet irradiation center of the ultraviolet irradiation unit 11. The ultraviolet irradiation units 11 and 12 both irradiate ultraviolet light with an intensity I at a light distribution angle θ. The ultraviolet irradiation unit 12 is an ultraviolet irradiation unit included in an ultraviolet irradiation device different from the ultraviolet irradiation device that includes the ultraviolet irradiation unit 11, and is arranged in the room R in the same configuration as the ultraviolet irradiation unit 11.

[0034] 8 is a diagram showing the intensity of each small space on a virtual plane P50 that is 50 cm vertically away from the ultraviolet irradiation unit 11. As ultraviolet rays emitted from the ultraviolet irradiation unit 12 in addition to the ultraviolet irradiation unit 11 enter the virtual cubic space VS, the number of small spaces included in the area A1 increases to 49.

[0035] FIG. 9 is a diagram showing an example of the relationship between the threshold and the ratio in the arrangement example of FIG. 7. The ratio shown in FIG. 9 is the ratio calculated for the threshold when the ultraviolet irradiation unit 11 and the ultraviolet irradiation unit 12 have an operating mode in which ultraviolet irradiation is repeated for one minute and then stopped for two minutes, as in FIG. 5. As is clear from FIG. 9, the ratio for each threshold is increased compared to the case of FIG. 5. In other words, the air sterilization efficiency of room R is improved by arranging the ultraviolet irradiation units 11 and 12 as shown in FIG. 8. FIG. 10 is a graph showing the relationship of FIG. 9. As shown in FIG. 10, the threshold and the ratio shown in FIG. 9 can be approximated by a linear function of approximately y = -0.0415x + 0.753.

[0036] FIG. 11 is a diagram showing an example of an arrangement in which nine ultraviolet irradiation units are arranged. In FIG. 11, eight ultraviolet irradiation units 12-19 are arranged around ultraviolet irradiation unit 11 at intervals of 1 m or 1 m vertically and horizontally. In FIG. 11, the center of the imaginary plane of virtual cubic space VS coincides with the ultraviolet irradiation center of ultraviolet irradiation unit 11. Each of ultraviolet irradiation units 11-19 irradiates ultraviolet light of intensity I at a light distribution angle θ. Note that ultraviolet irradiation unit 13-19 is an ultraviolet irradiation unit included in an ultraviolet irradiation device different from the ultraviolet irradiation device including ultraviolet irradiation unit 11 and the ultraviolet irradiation device including ultraviolet irradiation unit 12, and is arranged in room R in the same manner as ultraviolet irradiation unit 11 and ultraviolet irradiation unit 12.

[0037] FIG. 12A shows the intensity of each small space on a virtual surface P50 that is 50 cm vertically away from the ultraviolet irradiation unit 11. Because ultraviolet light emitted from the ultraviolet irradiation unit 12-19, in addition to the ultraviolet light emitted from the ultraviolet irradiation unit 11, also enters the virtual cubic space VS, the number of small spaces included in the region A1 increases to 88. FIG. 12B shows the intensity of each small space on a virtual surface P100 that is 100 cm vertically away from the ultraviolet irradiation unit 11. Because ultraviolet light emitted from the ultraviolet irradiation unit 12-19, in addition to the ultraviolet light emitted from the ultraviolet irradiation unit 11, also enters the virtual cubic space VS, the number of small spaces included in the region A1 increases to 100. In other words, on the 100 cm virtual surface, all small spaces have an intensity above the threshold.

[0038] FIG. 13 is a diagram showing an example of the relationship between the threshold and the ratio in the arrangement example of FIG. 11. The ratio shown in FIG. 13 is the same as in FIG. 5, that is, the ratio calculated for the threshold when the operating mode of ultraviolet irradiation units 11-19 includes a mode in which ultraviolet irradiation is repeated for one minute and then stopped for two minutes. As is clear from FIG. 13, the ratio for each threshold is increased compared to the case of FIG. 9. In other words, by arranging ultraviolet irradiation units 11-19 as shown in FIG. 11, the air sterilization efficiency of room R is further improved. FIG. 14 is a graph showing the relationship shown in FIG. 13. As shown in FIG. 14, the threshold and ratio shown in FIG. 13 can be approximated by a linear function of approximately y = -0.0337x + 0.7755.

[0039] Here, when two or more ultraviolet irradiation units are combined and arranged, the spacing between the ultraviolet irradiation units is determined so that the ultraviolet rays emitted from each ultraviolet irradiation unit are incident on the virtual cubic space VS. Preferably, the spacing between the ultraviolet irradiation units is determined so that the ultraviolet rays are incident on a small space where the intensity is less than the threshold value as a result of evaluation under conditions when one ultraviolet irradiation unit 11 is arranged. In this case, the spacing between the ultraviolet irradiation units does not necessarily have to be equal. Such spacing conditions may be determined by simulation, etc. Furthermore, when two or more ultraviolet irradiation units are arranged, the ultraviolet irradiation units may be mounted on a common ultraviolet irradiation device or on separate ultraviolet irradiation devices.

[0040] As described above, according to the embodiment, when ultraviolet light with intensity I is irradiated from one ultraviolet irradiation unit onto the virtual cubic space VS at a light distribution angle θ, the intensity of the ultraviolet light in the virtual cubic space VS is 5 μW / cm 2 The ultraviolet irradiation unit is set so that the ratio increases based on the ratio of the area that is equal to or greater than 5 μW / cm. This allows for efficient irradiation of ultraviolet light suitable for processing within the virtual cubic space VS. Note that the ultraviolet intensity setting of 5 μW / cm 2can be set appropriately depending on the desired degree of space sterilization. Then, depending on the UV intensity setting, the threshold value for the proportion of small spaces that can efficiently sterilize the space R can also be set appropriately in accordance with the relational expressions shown in Figures 6, 10, and 14, for example.

[0041] Furthermore, by combining two or more ultraviolet irradiation units, the intensity can be increased to above the threshold in areas where the intensity would not be increased by a single ultraviolet irradiation unit alone, thereby achieving further efficiency improvements.

[0042] In the above-described embodiment, the virtual cubic space VS is set directly below the ultraviolet irradiation unit 11. However, the virtual cubic space VS may be set, for example, so that the center of one virtual face coincides with the ultraviolet irradiation center of the ultraviolet irradiation unit 11. For example, if the ultraviolet irradiation unit 11 is configured to irradiate ultraviolet rays obliquely, the virtual cubic space VS may also be set so that it is inclined obliquely accordingly. In this case, a virtual cubic space VS is set that includes one face parallel to the irradiation surface of the ultraviolet irradiation unit 11. Furthermore, the center of one virtual face of the virtual cubic space VS does not necessarily have to coincide with the ultraviolet irradiation center of the ultraviolet irradiation unit 11. For example, the virtual cubic space VS may be set at a location away from the ultraviolet irradiation unit 11.

[0043] Furthermore, when two or more ultraviolet irradiation units are used in combination, the intensity, light distribution, and operation mode of the ultraviolet rays emitted from each ultraviolet irradiation unit do not necessarily have to be the same. Furthermore, the arrangement of the ultraviolet irradiation units is not limited to the arrangement shown in Figure 7 or Figure 11.

[0044] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0045] 11, 12, 13, 14, 15, 16, 17, 18, 19...Ultraviolet irradiation area.

Claims

1. A setting method for one or more ultraviolet irradiation devices each including an ultraviolet irradiation unit that irradiates ultraviolet light, comprising: The ultraviolet irradiation device has an imaginary surface with a side of 1 m, the center of which coincides with the center of one of the ultraviolet irradiation units, and the ultraviolet intensity for a virtual cubic space with a side of 1 m, which is set so as not to include one of the ultraviolet irradiation units inside, is 5 μW / cm ２ The one or more ultraviolet irradiation devices are set so that the ratio of the area where the ultraviolet radiation amount is equal to or greater than 49.8%. How to set up an ultraviolet irradiation device.

2. The intensity of the ultraviolet light in the virtual cubic space is 5 μW / cm ２ The percentage of the area that is greater than or equal to Two or more ultraviolet irradiation units are arranged so that the proportion of the ultraviolet rays emitted from the ultraviolet ray irradiation unit is 49.8% or more. A method for setting the ultraviolet irradiation device according to claim 1.

3. The two or more ultraviolet ray irradiation units are arranged so that the ultraviolet rays irradiated from each of them enter the virtual cubic space. A method for setting the ultraviolet irradiation device according to claim 2.

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