UV irradiation device

Abstract

To provide a UV irradiation device capable of precisely and appropriately controlling a UV irradiation amount of a UV lamp to satisfy the target irradiation amount while compensating for differences in UV irradiation efficiency due to an illumination location of the UV lamp.SOLUTION: A UV irradiation device 1 irradiates a fluid (primary pure water W) with UV light, which includes a plurality of UV lamps arranged within a cylinder to irradiate the fluid with UV, a lamp-on-point control unit 13 and a current value control unit 14, each controlling a lamp-on-point P and a current value VC of the UV lamps, respectively, a correction coefficient setting unit 11 that sets a correction coefficient KUV for each irradiation pattern A to E, defined by the number of lit UV lamps N and the positional relation between the lamp-on-points P, to correct the UV irradiation efficiency, and an illumination condition determination unit 12 that determines the lamp-on-point P and the current value VC of the UV lamp such that an effective UV irradiation amount AUVef, calculated using a UV irradiation amount AUVa from the UV lamps and the correction coefficient KUV, satisfies a target irradiation amount AUVtg.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a UV irradiation device that irradiates UV (ultraviolet) rays. [Background technology]

[0002] A conventional UV irradiation device is known that oxidatively decomposes TOC (organic matter) in water by irradiating the water with UV from the UV lamps, for example, by arranging multiple UV lamps in a cylinder and introducing target water into the cylinder (see, for example, Patent Document 1). In such UV irradiation devices, it is known that the number of UV lamps turned on and the current value passed through the UV lamps are controlled to obtain an appropriate TOC decomposition effect. Furthermore, the UV irradiation device of Patent Document 1 measures the TOC concentration of the water at the outlet side of the UV irradiation device, and when the TOC concentration exceeds a set value, the current value of the UV lamps is increased, thereby appropriately controlling the UV irradiation amount. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-263643 Summary of the Invention [Problem to be solved by the invention]

[0004] However, among the above-mentioned conventional technologies, when controlling UV irradiation by the number of lit UV lamps, for example, reducing the number of lit lamps is likely to cause uneven UV irradiation within the cylinder, reducing the actual UV irradiation efficiency on the water in the cylinder, which may result in the expected TOC decomposition efficiency not being achieved. Furthermore, even if the number of lit lamps is the same, if the lit locations (positions) are different, the UV irradiation efficiency on the water in the cylinder will change accordingly, and the expected TOC decomposition efficiency will also not be achieved. Furthermore, UV lamps generally have the characteristic of becoming unstable as the current value decreases. Therefore, when controlling UV irradiation by the current value of the UV lamp as described above, if the current value is reduced too much, the UV lamp operation will become unstable and the expected TOC decomposition efficiency will not be achieved.

[0005] Furthermore, in the method of controlling the current value of the UV lamp according to the measurement results of the actual TOC concentration at the outlet side of the UV irradiation device, there is a time lag after the TOC concentration exceeds the set value until the expected TOC decomposition efficiency is restored, and during that time the TOC decomposition efficiency decreases.

[0006] The present invention has been made to solve such problems, and aims to provide a UV irradiation device that can accurately and appropriately control the UV irradiation amount of the UV lamp so that the target irradiation amount is met, while compensating for differences in UV irradiation efficiency depending on the location where the UV lamp is lit. [Means for solving the problem]

[0007] In order to achieve this object, the invention of claim 1 is a UV irradiation device that irradiates UV onto a fluid, characterized in that it comprises: a plurality of UV lamps that are arranged in a cylinder filled with fluid and that irradiate the fluid with UV while lit; a lighting location control unit that controls the lighting locations of the plurality of UV lamps; a current value control unit that controls the current value of the lit UV lamps; an irradiation efficiency parameter setting unit that sets irradiation efficiency parameters that represent the UV irradiation efficiency for the fluid in the cylinder for each lighting pattern defined by the number of lit UV lamps and the positional relationship between the lighting locations; and a lighting condition determination unit that determines the lighting locations and current values ​​of the UV lamps as lighting conditions for the UV lamps so that the UV irradiation amount irradiated from the UV lamps and the effective UV irradiation amount calculated using the irradiation efficiency parameters satisfy a target irradiation amount.

[0008] In this UV irradiation device, multiple UV lamps are arranged in a cylinder filled with fluid, and the lit UV lamps irradiate the fluid with UV light. The lighting locations (number and lighting positions) of the multiple UV lamps are controlled by a lighting location control unit, and the current values ​​of the lit UV lamps are controlled by a current value control unit. As described above, the UV irradiation efficiency for the fluid in the cylinder changes depending on the number and lighting positions of the UV lamps. In contrast, according to the present invention, lighting patterns are defined based on the number of lit UV lamps and the positional relationship between the lighting locations, and an irradiation efficiency parameter representing the difference in irradiation efficiency for the fluid in the cylinder is set for each lighting pattern. The lighting locations and current values ​​of the UV lamps are then determined as UV lamp lighting conditions so that the effective UV irradiation amount, calculated based on the UV irradiation amount irradiated from the UV lamps and the set irradiation efficiency parameter, meets the target irradiation amount. By determining the UV lamp lighting conditions in this manner, the UV irradiation amount can be accurately and appropriately controlled to meet the target irradiation amount while compensating for differences in irradiation efficiency depending on the number of lit UV lamps and their lighting positions.

[0009] The invention of claim 2 is characterized in that, in the UV irradiation device described in claim 1, the lighting condition determination unit selects the lighting pattern with the greater number of lighting patterns when the effective irradiation amount satisfies the target irradiation amount and there are multiple lighting patterns with different numbers of lighting patterns.

[0010] As mentioned above, the fewer the number of UV lamps that are turned on, the more likely it is that uneven UV irradiation will occur inside the cylinder, and the lower the irradiation efficiency for the fluid inside the cylinder.With this configuration, when there are multiple lighting patterns that satisfy the target irradiation amount and have different numbers of lamps turned on, the lighting pattern with the largest number of lamps turned on is selected, thereby achieving higher irradiation efficiency.

[0011] The invention of claim 3 is characterized in that, in the UV irradiation device described in claim 1, the irradiation efficiency parameter reflects the UV irradiation efficiency and is a correction coefficient for calculating the effective irradiation amount by multiplying it by the UV irradiation amount.

[0012] According to this configuration, a correction coefficient that reflects the UV irradiation efficiency is set as the irradiation efficiency parameter for each lighting pattern, and by multiplying this by the UV irradiation amount of the UV lamp, it is possible to accurately calculate the effective irradiation amount that appropriately reflects differences in irradiation efficiency.

[0013] The invention according to claim 4 is the UV irradiation device according to claim 1, wherein the lighting condition determination unit determines the current value so that the current value does not fall below a predetermined lower limit value.

[0014] According to this configuration, by determining the current value of the UV lamp so that it does not fall below the lower limit, it is possible to prevent the operation of the UV lamp from becoming unstable and ensure a stable amount of UV irradiation.

[0015] The invention of claim 5 is characterized in that, in the UV irradiation device described in claim 1, it further comprises an operation history storage unit that stores at least one of the operating time since the UV lamp was installed and the number of times it has been turned on / off as operation history for each UV lamp, and when there are multiple selectable UV lamps or combinations of multiple UV lamps in the determined lighting pattern, the lighting condition determination unit selects the UV lamp or combination of UV lamps with the shorter operating history as the lighting location.

[0016] In this configuration, at least one of the operating (illumination) time and the number of on / off cycles since the UV lamp was installed is stored as an operating history for each UV lamp. The longer the operating history of a UV lamp (the longer the operating time or the more on / off cycles), the shorter the remaining lifespan of the UV lamp and the greater the need for replacement or maintenance. According to the present invention, when there are multiple selectable UV lamps or combinations of UV lamps in a determined lighting pattern, the UV lamp or combination with the shortest operating history is selected as the lighting location. This allows multiple UV lamps to be used so that their operating histories are as even as possible, thereby reducing the frequency of UV lamp replacement and maintenance.

[0017] The invention of claim 6 is characterized in that, in the UV irradiation device of claim 3, it further comprises an operation history storage unit that stores at least one of the operating time and the number of times the UV lamp has been turned on / off since installation of the UV lamp as an operation history for each UV lamp, and the irradiation efficiency parameter setting unit sets the correction coefficient to a smaller value as the operation history becomes longer.

[0018] In this configuration, similar to claim 5 described above, the operation history of each UV lamp is stored. As the operation history becomes longer, the performance of the UV lamp deteriorates, and the actual UV irradiation amount decreases. According to the present invention, the longer the operation history of the UV lamp, the smaller the correction coefficient is set to, thereby compensating for the decrease in UV irradiation amount according to the operation history and making it possible to appropriately calculate the effective irradiation amount.

[0019] The invention of claim 7 is characterized in that, in the UV irradiation device of claim 1, it further comprises a lighting condition presentation unit that presents the lighting conditions of the UV lamp determined by the lighting condition determination unit, and a lighting condition input unit that allows the presented lighting conditions to be input by manual operation.

[0020] In this configuration, the lighting conditions of the UV lamp determined by the lighting condition determination unit are presented to the lighting condition presentation unit, so that, for example, an operator in charge of the UV irradiation device can input the lighting conditions by manually operating the lighting condition input unit while checking this presentation.

[0021] The invention according to claim 8 is characterized in that the UV irradiation device according to claim 7 further comprises a target irradiation amount input unit capable of inputting a target irradiation amount of the UV lamp.

[0022] In this configuration, the operator can manually input the predetermined target irradiation amount of the UV lamp or the target irradiation amount set appropriately depending on the situation by operating the target irradiation amount input unit.

[0023] The invention of claim 9 is characterized in that, in the UV irradiation device according to any one of claims 1 to 8, the UV irradiation device is used as a UV oxidation device in an ultrapure water production system that produces ultrapure water with reduced organic matter, for oxidatively decomposing organic matter in the water by irradiating the water with UV.

[0024] According to this configuration, the UV irradiation device is used as a UV oxidation device in an ultrapure water production system, which oxidizes and decomposes organic matter in water by irradiating water with UV. Therefore, this UV oxidation device can achieve the same effects as those of the UV irradiation devices of claims 1 to 8, and in particular, by precisely controlling the UV irradiation amount of the UV lamp to meet the target irradiation amount, it is possible to reliably achieve the expected organic matter decomposition efficiency. [Brief explanation of the drawings]

[0025] [Figure 1]1 is a block diagram showing a schematic diagram of a UV irradiation device according to a first embodiment of the present invention and an ultrapure water production system including a UV oxidation device using the same. [Figure 2] FIG. 1 shows the arrangement of V lamps within the cylinder of a UV oxidation device. [Figure 3] FIG. 10 is a diagram showing an example of calculation of the effective UV irradiation dose. [Figure 4] FIG. 10 is a block diagram schematically showing a UV irradiation device according to a second embodiment of the present invention and an ultrapure water production system including a UV oxidation device using the same. [Figure 5] FIG. 10 is a block diagram schematically showing a UV irradiation device according to a third embodiment of the present invention and an ultrapure water production system including a UV oxidation device using the same. DETAILED DESCRIPTION OF THE INVENTION

[0026] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. A UV irradiation device 1 according to a first embodiment shown in FIG.

[0027] The ultrapure water production system 2 produces ultrapure water with significantly reduced TOC (organic matter) and DO (dissolved oxygen), and includes a sub-tank 2a, a UV oxidation device 2b, an ion exchange device 2c, and a use point 2d. In the ultrapure water production system 2, primary pure water delivered from the sub-tank 2a is irradiated with UV light from UV lamps L (see FIG. 2) in the UV oxidation device 2b, whereby TOC in the primary pure water is oxidized and decomposed into organic acids and CO2. Furthermore, the organic acids and CO2 are removed from the water effluent from the UV oxidation device 2b in the ion exchange device 2c, producing ultrapure water. Most of the produced ultrapure water is delivered to the use point 2d, and a portion is returned to the sub-tank 2a.

[0028] As shown in FIG. 1, the UV irradiation device 1 includes a correction coefficient setting unit 11, a lighting condition determination unit 12, a lighting location control unit 13, and a current value control unit 14 in addition to a UV oxidation device 2b.

[0029] 2, the UV oxidation device 2b has a cylinder C filled with water (primary pure water) W and, for example, four UV lamps L (L1 to L4) installed inside the cylinder C. The UV lamps L1 to L4 are arranged at predetermined positions spaced 90 degrees apart in the circumferential direction near the peripheral wall of the cylinder C, and each extends in the same axial direction as the cylinder C (the depth direction of the paper).

[0030] The on / off of the UV lamps L1 to L4 is controlled independently by a lighting location control unit 13, and the current values ​​of the UV lamps L1 to L4 are controlled independently by a current value control unit 14, thereby controlling the amount of UV irradiation emitted from the lit UV lamps L. The UV irradiation amount AUVa means the sum of the UV irradiation amounts from each UV lamp L (total UV irradiation amount) and is expressed as an absolute amount (unit: kWh / m3), but in this control it is also expressed as a relative amount (unit: %), with the UV irradiation amount when all UV lamps L are operated at full current being 100%.

[0031] Similarly, the current value VC of each UV lamp L is expressed as a relative amount (duty rate) (%), with the current value when operated at full current being 100%. When the UV irradiation amount AUVa and the current value VC are expressed as relative amounts, the UV irradiation amount AUVa is calculated using the following formula (1). AUVa = VC (N / 4) (1) For example, when the number of lit lamps N=3 and the current value VC of each UV lamp L=80%, the UV irradiation amount AUVa is calculated as follows: AUVa=80×(3 / 4)=60(%).

[0032] A correction coefficient KUV is set in the correction coefficient setting unit 11. This correction coefficient KUV reflects differences in UV irradiation efficiency depending on the number and lighting positions of the UV lamps L, and is set for each lighting pattern of the UV lamps L.

[0033] This lighting pattern is defined by the number N of lit UV lamps L and the positional relationship between the lit locations, and is classified into five patterns A to E. Specifically, as shown in FIGS. 2 and 3, when the number N of lit UV lamps L is 1, the lighting pattern is classified into pattern A regardless of their positions within the cylinder C. When the number N of lit UV lamps L is 2 and two lit locations are adjacent in the circumferential direction (90 degrees apart in the circumferential direction), the lighting pattern is classified into pattern B regardless of their positions within the cylinder C. When N=2 and two lit locations are opposite in the radial direction (180 degrees apart in the circumferential direction), the lighting pattern is classified into pattern C regardless of their positions within the cylinder C. When the number N=3 and all UV lamps L are lit, the lighting pattern is classified into pattern D regardless of their positions within the cylinder C. When N=4 and all UV lamps L are lit, the lighting pattern is classified into pattern E.

[0034] When multiple UV lamps L are arranged inside a cylinder C, if the number N of lit lamps is small, or if the number N is the same but the lit locations are not well balanced, uneven UV irradiation is likely to occur inside the cylinder C, reducing the actual UV irradiation efficiency on the water W inside the cylinder C. For this reason, as shown in Figure 3, the correction coefficient KUV is set to its maximum value in lighting pattern E, which has the highest number N of lit lamps, and is set to decrease toward lighting pattern A (KUV = 1.0, 0.95, 0.93, 0.85, 0.7 for lighting patterns E to A).

[0035] As shown in the following equation (2), the effective UV irradiation amount AUVef that is effectively irradiated onto the water W in the cylinder C is calculated by multiplying the UV irradiation amount AUVa by the correction coefficient KUV set as described above and correcting it. AUVef = AUVa KUV (2) Figure 3 shows an example of calculating the effective UV dose AUVef when the UV dose AUVa is expressed in absolute terms. Furthermore, from equation (2) and the above equation (1), when it is based on a relative amount, the effective irradiation amount AUVef is expressed by the following equation (3) using the current value VC of the UV lamp L and the number N of lamps that are lit. AUVef = VC (N / 4) KUV (3)

[0036] The lighting condition determination unit 12 determines the lighting location P and current value VC of the UV lamp L so that the effective irradiation dose AUVef calculated by equation (3) matches the target irradiation dose AUVtg. This target irradiation dose AUVtg is a target value of the UV irradiation dose that is effectively irradiated onto the water W in the syringe C, and in this example, is set to a fixed value in advance.

[0037] The current value VC is calculated for each lighting pattern using the target irradiation amount AUVtg, the number of lighting lamps N, and the correction coefficient KUV according to the following equation (4). VC = AUVtg / ((N / 4)·KUV) ···(4) This equation (4) is obtained by replacing the effective dose AUVef on the left side of the above equation (3) with the target dose AUVtg, thereby obtaining the following equation (5), which is also expressed in terms of the current value VC. AUVtg = VC (N / 4) KUV (5)

[0038] As described above, the effective irradiation amount AUVef is controlled to match the target irradiation amount AUVtg for each lighting pattern by calculating the current value VC of the UV lamps L. In this way, the UV irradiation amount AUVa of the UV lamps L can be accurately and appropriately controlled so as to satisfy the target irradiation amount AUVtg while compensating for differences in UV irradiation efficiency due to the number N of lit UV lamps L and their lighting positions.

[0039] Furthermore, the lighting condition determination unit 12 determines the lighting conditions for the UV lamps L as follows: First, when there are multiple lighting patterns in which the effective UV irradiation amount AUVef matches the target irradiation amount AUVtg and the number of lamps N that are lit is different, the lighting pattern with the larger number of lamps N that are lit is selected. For example, as shown in FIG. 2, if there are four UV lamps L and a UV irradiation amount AUVa = 75% is to be achieved, there are two possible methods (1) (lighting pattern E) in which the number of lamps N is 4 and each current value VU is 75%, and (2) (lighting pattern D) in which the number of lamps N is 3 and each current value VU is 100%, and method (1) in which the number of lamps N that is lit is larger is selected.

[0040] This is because, as mentioned above, the fewer the number of lit lamps N, the more likely it is that uneven UV irradiation will occur within the cylinder C, reducing the efficiency of UV irradiation on the water W within the cylinder C. Also, the fewer the number of lit lamps N, the more likely it is that the operating time and frequency of use of the UV lamps L will be uneven. From this perspective, by selecting a lighting pattern with a larger number of lit lamps N, high UV irradiation efficiency can be ensured, and the operating time of the UV lamps L can be made as equal as possible, reducing the burden of maintenance.

[0041] Second, when the current value VC calculated by equation (4) is less than a predetermined lower limit LMTL, the lighting condition determination unit 12 switches to a lighting pattern with a smaller number of lit lamps N to prevent the current value VC from falling below the lower limit LMTL. This lower limit LMTL is a value below which the operation of the UV lamp L becomes significantly unstable if the current value VC falls below this value, and is set to, for example, 70%. From this perspective, by maintaining the current value VC of the UV lamp L at or above the lower limit LMTL, it is possible to prevent the operation of the UV lamp L from becoming unstable and ensure a stable UV irradiation amount AVUa and UV irradiation efficiency.

[0042] The lighting condition determination unit 12 determines the lighting conditions (lighting pattern, lighting location P, and current value VC) of the UV lamp L as described above, and outputs a signal representing the lighting conditions to the lighting location control unit 13 and the current value control unit .

[0043] The lighting area control unit 13 has switches (not shown) for individually turning on / off the UV lamps L, and controls the lighting areas P by controlling the on / off of each UV lamp L according to the lighting areas P input from the lighting condition determination unit 12.

[0044] The current value control unit 14 has an inverter circuit (not shown) that variably controls the current passed through the UV lamps L, and by controlling the inverter circuit in accordance with the current value VC input from the lighting condition determination unit 12, the current value of each UV lamp L that is turned on is controlled to the determined current value VC, thereby controlling the UV irradiation amount AUVa.

[0045] As described above, according to the UV irradiation device 1 of this embodiment, the lighting position P of the UV lamp L and the current value VC are determined so that the effective irradiation amount AUVef calculated using the UV irradiation amount AUVa irradiated from the UV lamp L and the correction coefficient KUV matches the target irradiation amount AUVtg. This makes it possible to accurately and appropriately control the UV irradiation amount AUVa so that the target irradiation amount AUVtg is achieved while compensating for differences in UV irradiation efficiency depending on the lighting position P of the UV lamp L.

[0046] [Second embodiment] Next, a UV irradiation device 21 according to a second embodiment will be described with reference to Fig. 4. As is clear from a comparison with Fig. 1, this UV irradiation device 21, like the UV irradiation device 1 of the first embodiment, is used in a UV oxidation device 2b of an ultrapure water production system 2, and differs mainly in that an operation history storage unit 22 is added to the UV irradiation device 1. For this reason, in Fig. 4, components that are the same as or equivalent to those of the first embodiment are given the same reference numerals, and descriptions thereof will be omitted.

[0047] The operation history storage unit 22 stores the operation time TL and the number of on / off times NS of the UV lamp L for each UV lamp L as parameters representing the operation history. The operation time TL is the measured and accumulated operation time (lighting time) of each UV lamp L since installation, and is stored as needed in the operation history storage unit 22. The number of on / off times NS is the count of the number of on / off times (number of times of operation) of each UV lamp L since installation, and is stored as needed in the operation history storage unit 22.

[0048] In this embodiment, the operating time TL and the on / off count NS are used to set the correction coefficient KUV and select the lighting location P of the UV lamp L. First, the correction coefficient setting unit 11 sets the correction coefficient KUV according to the operating time TL and the on / off count NS read from the operating history storage unit 22. Specifically, the longer the operating time TL and the greater the on / off count NS, i.e., the longer the operating history, the smaller the value of the correction coefficient KUV is set to.

[0049] This takes into consideration that as the operating history becomes longer, the performance of the UV lamp L deteriorates and the actual UV irradiation amount AUVa decreases. Based on this viewpoint, by setting the correction coefficient KUV as described above according to the operating history of the UV lamp L, it is possible to compensate for the decrease in the UV irradiation amount AUVa according to the operating history and appropriately evaluate the effective irradiation amount AUVef.

[0050] Furthermore, when there are multiple selectable UV lamps L or combinations thereof in the determined lighting pattern, the lighting condition determination unit 12 selects the UV lamp L or combination thereof with the shorter operating history (shorter operating time TL and fewer on / off counts NS) as the lighting location P. This is because the longer the operating history, the shorter the remaining life of the UV lamp L and the greater the need for replacement or maintenance. Based on this perspective, by selecting the lighting location P as described above according to the operating history of the UV lamp L, multiple UV lamps L can be used so that their operating histories are as uniform as possible, thereby reducing the frequency of replacement and maintenance of the UV lamps L.

[0051] Other than the above, the configuration of this embodiment is the same as that of Embodiment 1. Therefore, according to this embodiment, in addition to the above-mentioned effects, the effects of Embodiment 1 can be obtained in the same way.

[0052] [Third embodiment] Next, a UV irradiation device 41 according to a third embodiment will be described with reference to Fig. 5. As is clear from a comparison with Fig. 4, this UV irradiation device 41, like the UV irradiation devices 1 and 21 of the first and second embodiments, is used in a UV oxidation device 2b of an ultrapure water production system 2, and differs from the UV irradiation device 21 of the second embodiment in that it is equipped with a lighting condition presentation unit 42, a lighting condition input unit 43 for manual input by an operator OP, and a target irradiation dose input unit 44. For this reason, in Fig. 5, components that are the same as or equivalent to those of the second embodiment are designated by the same reference numerals, and descriptions thereof will be omitted.

[0053] The lighting condition presentation unit 42 displays the lighting conditions (lighting pattern, lighting location P, current value VC) of the UV lamp L determined by the lighting condition determination unit 12 on a touch panel or the like (not shown), and presents them to an operator OP who manages the UV irradiation device 41. The lighting condition input unit 43 has an operation panel (not shown), and is connected to the lighting location control unit 13 and the current value control unit 14.

[0054] With this configuration, the operator OP can input the lighting location P and the current value VC to the lighting location control unit 13 and the current value control unit 14 by manually operating the operation panel of the lighting condition input unit 43 while checking the lighting conditions of the UV lamp L presented by the lighting condition presentation unit 42. In this case, the lighting conditions may be input as presented by the lighting condition presentation unit 42, or the lighting conditions may be input with some changes based on the presentation.

[0055] The target irradiation amount input unit 44 has an operation panel (not shown) and is connected to the lighting condition determination unit 12. With this configuration, the operator OP can manually operate the operation panel of the target irradiation amount input unit 44 to input the target irradiation amount AUVtg of the UV lamp L to the lighting condition determination unit 12. In this case, the target irradiation amount AUVtg may be a predetermined constant value, or may be set appropriately depending on the situation.

[0056] Other than the above, the configuration of this embodiment is the same as that of Embodiment 2. Therefore, according to this embodiment, in addition to the above-mentioned effects, the same effects as those of Embodiment 2 can be obtained.

[0057] The present invention is not limited to the described embodiment and can be embodied in various forms. For example, in the embodiment, four UV lamps L are arranged at 90-degree intervals in the circumferential direction inside a cylinder C with a circular cross section, and the lighting patterns are classified into five patterns in consideration of UV irradiation efficiency. This configuration is merely an example, and the present invention can be applied to cases where the cross-sectional shape of the cylinder C or the number and arrangement of the UV lamps L are different. In such cases, the lighting patterns are appropriately set to reflect actual differences in UV irradiation efficiency. Furthermore, if the evaluation of UV irradiation efficiency becomes complicated due to the number and arrangement of the UV lamps L, the UV irradiation efficiency may be estimated using a simulation based on flow analysis or a predictive model based on machine learning, and the lighting patterns may be set based on the results.

[0058] In addition, in the second embodiment, both the operating time TL and the number of on / off times NS are used as the operating history of the UV lamp L, but only one of them may be used, or other appropriate parameters representing the operating history may be used.

[0059] Furthermore, in the third embodiment, the target irradiation amount AUVtg is set in advance and input manually. However, the present invention is not limited to this. For example, the water quality in the cylinder C may be detected while the UV lamp L is operating, and the target irradiation amount AUVtg may be automatically changed based on the detection result and input to the lighting condition determination unit 12.

[0060] Furthermore, the lighting condition determination unit 12 may be constructed on-premise or may be set on a server. The lighting condition presentation unit 42 in the third embodiment has been described as displaying the lighting conditions on a touch panel or the like, but is not limited to this, and may be, for example, a unit that displays the lighting conditions on a browser using a web service or that notifies via an email service or the like.

[0061] In addition, in the embodiments, the UV irradiation device is used as a UV oxidation device in an ultrapure water production system, irradiating primary pure water with UV to oxidatively decompose TOC. The present invention is not limited to this, and can be applied to UV irradiation devices in ultrapure water subsystems, UV irradiation devices for disinfection in water purification plants, and a wide range of other UV irradiation devices that require precise control of the amount of UV irradiation from a UV lamp to a fluid (liquid or gas). In addition, the configurations specifically shown in the embodiments are merely examples, and can be modified as appropriate within the spirit and scope of the present invention. [Explanation of symbols]

[0062] 1 UV irradiation device according to the first embodiment 2 Ultrapure water production equipment 2a UV oxidizer 11 Correction coefficient setting unit (irradiation efficiency parameter setting unit) 12 Lighting condition determination unit 13 Lighting location control unit 14 Current value control section 21 UV irradiation device according to the second embodiment 22 Driving history memory unit 41 UV irradiation device according to the third embodiment 42 Lighting condition presentation section 43 Lighting condition input section 44 Target irradiation dose input section UV ultraviolet light C cylinder W Primary pure water (fluid) L UV lamp P UV lamp lighting position VC UV lamp current value N Number of UV lamps lit AUVa UV irradiation amount of UV lamp KUV correction factor (irradiation efficiency parameter) AUVef UV effective dose AUVtg UV target dose LMTL Lower limit of current TL UV lamp operating time (operating history) NS UV lamp on / off count (operation history) TOC organic matter

Claims

1. A UV irradiation device that irradiates a fluid with UV, a plurality of UV lamps disposed within the fluid-filled cylinder, the UV lamps irradiating the fluid with UV light when lit; a lighting location control unit that controls lighting locations of the plurality of UV lamps; a current value control unit that controls a current value of the UV lamp that is turned on; an irradiation efficiency parameter setting unit that sets an irradiation efficiency parameter that represents UV irradiation efficiency for the fluid in the cylinder for each lighting pattern defined by the number of lit UV lamps and the positional relationship between the lit positions; a lighting condition determination unit that determines lighting locations and current values ​​of the UV lamps as lighting conditions for the UV lamps so that the effective UV irradiation amount calculated based on the UV irradiation amount irradiated from the UV lamps and the irradiation efficiency parameter satisfies a target irradiation amount; A UV irradiation device comprising:

2. 2. The UV irradiation device according to claim 1, wherein when there are a plurality of lighting patterns in which the effective irradiation amount satisfies the target irradiation amount and the number of lighting strands is different, the lighting condition determination unit selects the lighting pattern in which the number of lighting strands is greater.

3. 2. The UV irradiation device according to claim 1, wherein the irradiation efficiency parameter reflects the UV irradiation efficiency and is a correction coefficient for calculating the effective irradiation amount by multiplying the UV irradiation amount by the parameter.

4. The UV irradiation device according to claim 1 , wherein the lighting condition determining unit determines the current value so that the current value does not fall below a predetermined lower limit value.

5. an operation history storage unit that stores, for each UV lamp, at least one of the operation time and the number of times the UV lamp has been turned on / off since installation as an operation history; 2. The UV irradiation device according to claim 1, wherein when the determined lighting pattern includes a plurality of selectable UV lamps or a combination of a plurality of UV lamps, the lighting condition determination unit selects the UV lamp or the combination of UV lamps with the shortest operating history as the lighting location.

6. an operation history storage unit that stores, for each UV lamp, at least one of the operation time and the number of times the UV lamp has been turned on / off since installation as an operation history; The UV irradiation device according to claim 3 , wherein the irradiation efficiency parameter setting unit sets the correction coefficient to a smaller value as the operating history becomes longer.

7. 2. The UV irradiation device according to claim 1, further comprising: a lighting condition presentation unit that presents the lighting conditions of the UV lamp determined by the lighting condition determination unit; and a lighting condition input unit that allows the presented lighting conditions to be input by manual operation.

8. The UV irradiation device according to claim 7 , further comprising a target irradiation amount input unit capable of inputting a target irradiation amount of the UV lamp.

9. The UV irradiation device according to any one of claims 1 to 8, characterized in that the UV irradiation device is used as a UV oxidation device for oxidatively decomposing organic matter in water by irradiating the water with UV in an ultrapure water production system that produces ultrapure water with reduced organic matter.

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