A laser-induced fluorescence ultraviolet reactor integrated system and an ultraviolet reaction online monitoring method

Abstract

The application discloses a laser-induced fluorescence ultraviolet reactor integrated system and an ultraviolet reaction online monitoring method. The system comprises an ultraviolet reactor, ring optical windows arranged at two ends of an outer pipe of the reactor, a laser light source unit, two sheet-shaped light beam shaping modules, laser sheet light, a fluorescence detection unit and a data processing unit. The laser light source unit modulates laser light into a pair of opposite incident and spatially collinear laser sheet lights through the two sheet-shaped light beam shaping modules. The light path of the laser sheet light is perpendicular to the axis of the ultraviolet reactor. The fluorescence detection unit is used for collecting excitation fluorescence signals of fluid in the ring-shaped reaction flow channel. The data processing unit is used for receiving and processing the excitation fluorescence signals, reconstructing and synthesizing a three-dimensional concentration field. The synchronous control unit is used for synchronously working the laser light source unit and the fluorescence detection unit. The application can meet the demand of high-precision online monitoring in a complex reaction-flow coupling field through double-mode differential measurement, and can realize real-time and accurate quantitative monitoring and closed-loop optimization of the concentration field in the reactor, and has the characteristics of visualization, high precision and intelligence.

Description

Technical Field

[0001] This invention relates to the field of ultraviolet photochemical reaction and fluid measurement technology, and specifically to a system and method for monitoring photochemical reaction processes. Background Technology

[0002] Ultraviolet (UV) radiation is widely used in water treatment, such as municipal drinking water production, industrial ultrapure water systems, and secondary purification of semiconductor plant water. Disinfection using UV radiation relies on inactivating microorganisms by altering their DNA, preventing them from multiplying. Simultaneously, advanced UV-based oxidation technologies utilize UV ​​radiation with chemicals (such as hydrogen peroxide, ozone, and persulfate) or vacuum ultraviolet (VUV) to generate highly oxidizing hydroxyl radicals, which degrade / mineralize organic pollutants in water.

[0003] However, the design optimization and operation control of UV degradation reactors have long faced a core dilemma: the complex physicochemical processes inside the reactor are difficult to directly observe and quantify. Current technologies primarily rely on inlet and outlet sampling analysis to evaluate reactor performance, i.e., calculating degradation efficiency by measuring the concentration changes of pollutants at the reactor inlet and outlet. This method is simple and easy to implement, but it only reflects the overall effect of the system, completely ignoring the non-uniform distribution and interactions of the flow field, light field, and concentration field inside the reactor. Therefore, it cannot reveal potential problems such as dead zones, short-circuit flows, or insufficient light intensity in local areas, nor can it provide direct internal information support for the refined structural optimization of the reactor. To compensate for the shortcomings of experimental observation, computational fluid dynamics (CFD) numerical simulations are widely used to study the transport and reaction processes inside the reactor. However, the accuracy of CFD models highly depends on precise boundary conditions, reliable reaction kinetic models, and effective experimental verification. In the absence of measured data on the internal field distribution, the verification of CFD simulations often only involves comparing them with macroscopic inlet and outlet data, which significantly reduces the reliability of the simulation results and makes it difficult to ensure that they can truly reproduce the internal processes of the reactor, especially the highly dynamic and transient local changes.

[0004] The basic principle of laser-induced fluorescence (LIF) is to use a laser of a specific wavelength to excite a tracer or target substance in a flow field, causing it to emit fluorescence. By collecting and analyzing the intensity of the fluorescence signal, scalar field information such as concentration and temperature in the flow field can be retrieved. Currently, LIF technology has been successfully applied in fields such as microscale mixing, combustion diagnostics, and biomedicine. However, its direct application in industrial-scale ultraviolet degradation reactors to measure pollutant concentration fields still faces a series of challenges. The strong ultraviolet light source on which the reactor operates generates severe background interference. The cylindrical curved surface structure of industrial reactors causes complex refraction and distortion of the incident sheet laser and the emitted fluorescence signal as they pass through the curved surface. At the same time, the ultraviolet degradation process is a complex process in which photochemical reactions and fluid flow are highly coupled. How to effectively decouple the fluid mixing effect and the photochemical reaction effect in experiments, so as to accurately resolve the concentration changes caused by the reaction, is also a challenge that has never been encountered in current LIF applications.

[0005] Therefore, designing an online monitoring and optimization control system for the ultraviolet reaction process based on LIF to capture the three-dimensional spatial distribution information of pollutant concentration field inside the ultraviolet degradation reactor is of great significance for a deeper understanding of the reaction mechanism and the optimized design of the reactor structure. Summary of the Invention

[0006] Therefore, the present invention provides an integrated system for a laser-induced fluorescence ultraviolet reactor and a method for online monitoring of ultraviolet reactions to solve the problems in the prior art.

[0007] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions: I. An integrated system for a laser-induced fluorescence ultraviolet reactor, characterized in that it comprises: The ultraviolet reactor includes an ultraviolet lamp, an inner reactor tube, and an outer reactor tube arranged sequentially from the inside to the outside. An annular reaction flow channel is formed between the inner reactor tube and the outer reactor tube, and annular optical windows are provided at both ends of the outer reactor tube. The laser source unit includes a pair of sheet-shaped beam shaping modules. The two sheet-shaped beam shaping modules are used to modulate the laser into a pair of opposing incident, spatially collinear laser sheet beams. The optical path of the laser sheet beams is perpendicular to the axis of the ultraviolet reactor and covers the annular reaction channel. The fluorescence detection unit is used to collect the excitation fluorescence signal at the laser sheet scanning position within the annular reaction channel; The data processing unit is used to receive and process the excitation fluorescence signal, and reconstruct the synthetic three-dimensional concentration field and / or three-dimensional degradation rate distribution; The synchronization control unit is used to synchronize the operation of the laser source unit and the fluorescence detection unit.

[0008] The laser source unit also includes a laser, a beam splitter, and several sets of reflectors; the laser emitted by the laser is split by the beam splitter to generate a transmitted beam and a reflected beam; at least one of the transmitted beam and the reflected beam is adjusted in direction by the reflector set, and then passes through the corresponding sheet beam shaping module to form a pair of opposing incident, spatially collinear laser sheet beams.

[0009] The ultraviolet reactor integrated system also includes a linear motion platform; the linear motion platform is communicatively connected to the synchronous control unit; the linear motion platform includes several linear guide rails, which are parallel to the axis of the ultraviolet reactor; the sheet-like beam shaping module and the fluorescence detection unit are slidably arranged on their corresponding linear guide rails.

[0010] The sheet-like beam shaping module includes several optical elements arranged sequentially along the optical path. The optical elements include one or more combinations of cylindrical concave lenses, cylindrical convex lenses, beam splitters, variable circular apertures, and ultraviolet quartz prisms.

[0011] The fluid in the ultraviolet reactor contains a fluorescent tracer that can be excited by laser but cannot be excited and degraded by 254nm single-wavelength ultraviolet light, while it can be degraded under dual-wavelength ultraviolet light.

[0012] II. An online monitoring method for ultraviolet reactions applied to the above-mentioned laser-induced fluorescence ultraviolet reactor integrated system. The online monitoring method for ultraviolet reaction includes the following steps: Step S1) A single-wavelength ultraviolet lamp is selected, and an inert tracer is used to perform hydrodynamic field calibration to obtain calibration information; the calibration information is the relationship curve between the two-dimensional fluorescence intensity distribution and the spatial concentration corresponding to each scanning position.

[0013] Step S1 includes: A single-wavelength ultraviolet lamp is used as the ultraviolet lamp; Start the ultraviolet reactor; Start the laser source unit, fluorescence detection unit, and data processing unit; Tracers of different concentrations are continuously injected into the mainstream of the ultraviolet reactor; At each concentration, the annular reaction channel is linearly scanned along the axial direction of the UV reactor; at each scanning position, the laser source unit is controlled by the synchronous control unit to emit laser sheet light, and the fluorescence detection unit is controlled to capture a two-dimensional image of the reactor cross-section illuminated by the laser sheet light. The data processing unit is used to correct the image and obtain the two-dimensional fluorescence intensity distribution at the scanning position. For each scanning position, the corresponding relationship curve is obtained by fitting the two-dimensional fluorescence intensity distribution and spatial concentration at each concentration.

[0014] Step S2) Use a dual-wavelength ultraviolet lamp and use a reaction tracer to couple and measure the fluorescence distribution to obtain fluorescence distribution information; where the coupling measurement means that the reaction tracer is both a reaction pollutant and a tracer.

[0015] Step S2 includes: A dual-wavelength ultraviolet lamp is used as the ultraviolet lamp; Start the ultraviolet reactor; Start the laser source unit, fluorescence detection unit, and data processing unit; A tracer of a specific concentration is continuously injected into the mainstream of the ultraviolet reactor; A linear scan is performed on the annular reaction channel along the axial direction of the ultraviolet reactor. At each scan position, the laser light source unit is controlled by the synchronous control unit to emit laser sheet light, and the fluorescence detection unit is controlled to capture a two-dimensional image of the reactor cross-section illuminated by the laser sheet light. The data processing unit is used to correct the image and obtain the two-dimensional fluorescence intensity distribution at the scan position.

[0016] Step S3) Based on the fluorescence distribution information and calibration information, obtain the three-dimensional concentration field information, and based on the three-dimensional concentration field information, obtain the three-dimensional degradation rate distribution information.

[0017] Step S3 includes: using a data processing unit to obtain a two-dimensional concentration distribution based on the calibration information of each scanning position and the acquired two-dimensional image; and combining the two-dimensional concentration distributions of all scanning positions to obtain a three-dimensional concentration distribution.

[0018] Furthermore, step S3 may also include: generating a three-dimensional degradation rate distribution map based on the tracer concentration and three-dimensional concentration distribution at the inlet of the ultraviolet reactor.

[0019] The beneficial effects of this invention are as follows: This invention provides an integrated system for a laser-induced fluorescence ultraviolet reactor, which enables online detection of the internal three-dimensional concentration field during the degradation reaction of the ultraviolet degradation reactor. This provides a visualization method for studying the internal flow field and concentration field of the reactor, and provides direct internal information support for the refined structural optimization of the reactor.

[0020] This invention proposes a method for reconstructing the three-dimensional spatial distribution information of pollutant concentration field inside an ultraviolet degradation reactor, which is of great significance for a deeper understanding of the reaction mechanism and the optimized design of the reactor structure.

[0021] This invention is highly systematic and integrated, and simultaneously achieves feedback-optimized control. Attached Figure Description

[0022] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0023] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0024] Figure 1 This is a schematic diagram of the integrated system of laser-induced fluorescence ultraviolet reactor provided in the embodiments of this application; Figure 2 A flowchart of a gray-scale-concentration calibration curve calibration method provided in this application embodiment; Figure 3 A flowchart illustrating a method for differential calculation and measurement of the concentration field in a dual-mode operation of an ultraviolet degradation reactor, as provided in this application embodiment; The diagram shows: 1. Laser; 2. Beam splitter; 3. Sheet beam shaping module; 4. Linear guide rail; 5. Ultraviolet reactor; 6. Reactor inner tube; 7. Ultraviolet lamp; 8. Inlet component; 9. Outlet component; 10. Reactor outer tube; 11. Reflector; 12. Reactor control unit; 13. Data processing unit; 14. Fluorescence detection unit; 15. Filter; 16. ICCD camera; 17. Synchronization control unit; 18. Motion platform. Detailed Implementation

[0025] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0026] This invention provides an integrated system for a laser-induced fluorescence ultraviolet reactor.

[0027] The laser-induced fluorescence ultraviolet reactor integrated system provided by this invention includes: The ultraviolet reactor 5 includes an ultraviolet lamp 7, an inner reactor tube 6 and an outer reactor tube 10 arranged sequentially from the inside to the outside. An annular reaction channel is formed between the inner reactor tube 6 and the outer reactor tube 10. The fluid flows in the annular reaction channel and is irradiated by the ultraviolet lamp 7 to carry out the pollutant degradation reaction. Annular optical windows are provided on the end faces of both ends of the outer reactor tube 10. The laser source unit includes a pair of sheet beam shaping modules 3. The two sheet beam shaping modules 3 are used to modulate the laser into at least a pair of opposing incident, spatially collinear laser sheet beams. The optical path of the laser sheet beams is perpendicular to the axis of the ultraviolet reactor 5 and covers the radial width of the annular reaction channel. The fluorescence detection unit 14 is arranged on the outside of one axial end of the ultraviolet reactor 5, with the acquisition end aligned with the annular optical window on the outer tube 10 of the reactor, and is used to acquire the excitation fluorescence signal of the laser sheet light scanning position in the annular reaction channel, that is, the radial section illuminated by the laser sheet light. Data processing unit 13 is communicatively connected to fluorescence detection unit 14 and is used to receive and process excitation fluorescence signals to reconstruct the synthetic three-dimensional concentration field and / or three-dimensional degradation rate distribution map; The synchronization control unit 17 is used to synchronize the operation of the laser source unit and the fluorescence detection unit 14.

[0028] Specifically, the fluid in the ultraviolet reactor 5 contains fluorescent tracers or pollutants that can be excited by lasers but cannot be excited and degraded by 254nm single-wavelength ultraviolet light, but can be degraded under dual-wavelength ultraviolet light.

[0029] Alternatively, the fluorescent tracer can be a fluorescent dye, such as rhodamine 6G.

[0030] Specifically, the ultraviolet reactor 5 also includes an inlet component 8 and an outlet component 9. The ultraviolet lamp 7, serving as the degradation radiation source, is built into the inner tube 6 of the reactor and is horizontally fixed inside the ultraviolet reactor 5. The inner tube 6 and the outer tube 10 of the reactor form an annular flow channel. The inlet component 8 and the outlet component 9 are connected to the optical quartz hollow tube 10 via flanges, respectively. Both the inlet and outlet components 8 and 9 are equipped with annular optical quartz windows for collecting fluorescence signals.

[0031] Preferably, the ultraviolet lamp 7 can be a dual-wavelength low-pressure amalgam ultraviolet lamp capable of emitting 185nm (VUV) and 254nm (UV) ultraviolet light, generating an advanced oxidation reaction based on UV / VUV, producing highly reactive hydroxyl radicals, etc., for the degradation of pollutants.

[0032] Specifically, the laser source unit also includes a laser 1, a beam splitter 2, and several reflector groups 11; the laser emitted by the laser 1 is split by the beam splitter 2 to generate a transmitted beam and a reflected beam; at least one of the transmitted beam and the reflected beam is adjusted in propagation direction by the reflector group 11, and then passes through the corresponding sheet beam shaping module 3 to form a pair of opposing incident, spatially collinear laser sheet beams.

[0033] Preferably, laser 1 is an Nd:YAG laser, particularly a double-frequency 532nm green laser. This type of laser has high power, good beam quality, and can effectively excite commonly used fluorescent tracers.

[0034] Specifically, the two sheet-like beam shaping modules 3 have identical design parameters. By bidirectionally shaping the laser beam, a bidirectional sheet beam perpendicular to the axis of the ultraviolet reactor 5 and symmetrically incident is formed, eliminating the influence of the ultraviolet lamp tube blocking the laser distribution at the central axis of the reactor.

[0035] The thickness of the laser sheet is about 0.5 mm, and its height is sufficient to cover the entire radial width of the annular flow channel.

[0036] Furthermore, the sheet beam shaping module 3 can employ a Gaussian beam shaper or a variable aperture to attenuate the energy at both ends of the laser sheet, thereby smoothing the connection area between the two laser beams in the camera's field of view and reducing or eliminating splicing bright or dark band artifacts.

[0037] Furthermore, the sheet-like beam shaping module 3 can be equipped with a beam quality analyzer and an energy meter in the optical path to monitor and provide feedback on the symmetry, uniformity, and energy consistency of the laser sheets on both sides in real time.

[0038] Specifically, the fluorescence detection unit 14 includes an ICCD camera 16 and a narrowband filter 15 mounted in front of the lens of the ICCD camera 16. The transmission band of the narrowband filter 15 matches the fluorescence emission spectrum of the tracer in the fluid.

[0039] Specifically, the sheet-like beam shaping module 3 includes several optical elements arranged sequentially along the optical path. The optical elements include one or more combinations of cylindrical concave lenses, cylindrical convex lenses, beam splitters, variable circular apertures, and ultraviolet quartz prisms.

[0040] Specifically, the ultraviolet reactor integrated system also includes a linear motion platform 18; the linear motion platform 18 is communicatively connected to the synchronization control unit 17 and is controlled by the synchronization control unit 17, thereby realizing the synchronous motion control of the laser light source unit and the fluorescence detection unit 14.

[0041] Specifically, the linear motion platform 18 includes several linear guide rails 4, which are parallel to the axis of the ultraviolet reactor 5. The sheet-like beam shaping module 3 and the fluorescence detection unit 14 are both slidably arranged on their corresponding linear guide rails 4.

[0042] Specifically, the fluorescence detection unit 14 can slide along the linear guide rail 4, and its focal plane is precisely aligned with the light plane of the laser sheet.

[0043] Furthermore, the fluorescence detection unit 14 and the two sheet beam shaping modules 3 can move synchronously along their respective sheet beam shaping modules 3 to maintain this common alignment relationship, thereby avoiding the impact of changes in object distance or rapid focusing on image clarity.

[0044] Preferably, the stepping distance of the linear guide 4 is matched with the thickness of the laser sheet, such as 0.5 mm, to achieve axial layer-by-layer scanning.

[0045] Specifically, the data processing unit 13 is used to store and correct image information and reconstruct the synthetic three-dimensional concentration field. The data processing unit 13 includes corrections for factors such as noise, sheet light attenuation along the optical path, uneven sheet light intensity distribution, laser power variation, and optical distortion.

[0046] Furthermore, the UV reactor integrated system also includes a reactor control unit 12, which is communicatively connected to the data processing unit 13, for controlling the UV reactor 5 based on the data fed back by the data processing unit 13.

[0047] The present invention also provides a method for online monitoring of ultraviolet reactions in the above-mentioned laser-induced fluorescence ultraviolet reactor integrated system.

[0048] The online monitoring method for ultraviolet reaction provided by this invention includes the following steps: Step S1) Select a single-wavelength ultraviolet lamp 7 and use an inert tracer to perform hydrodynamic field calibration to obtain calibration information; the calibration information is the relationship curve between the two-dimensional fluorescence intensity (grayscale) distribution and spatial concentration corresponding to each scanning position.

[0049] This step is specifically as follows: To establish control conditions, the hydraulic parameters of the integrated system, such as flow rate and temperature, were kept constant. A single-wavelength ultraviolet lamp with the same power that emits only 254 nm UV was used as ultraviolet lamp 7 to create an oxidation-free environment. Start the UV reactor 5 and keep the internal flow rate and lamp output of the UV reactor 5 stable; Start the laser source unit, fluorescence detection unit 14 and data processing unit 13; Different concentrations of tracer reagents are continuously injected into the mainstream of UV reactor 5 until the concentration distribution in UV reactor 5 reaches a statistical steady state. At each concentration, the annular reaction channel is linearly scanned along the axial direction (Z-axis direction) of the ultraviolet reactor 5; at each scanning position, the laser light source unit is controlled by the synchronous control unit 17 to emit laser sheet light, and the fluorescence detection unit 14 is controlled to capture a two-dimensional image of the reactor cross-section (XY plane) illuminated by the laser sheet light. The data processing unit 13 is used to correct the acquired two-dimensional image to obtain the two-dimensional fluorescence intensity (grayscale) distribution at the scanning position. For each scanning position, the corresponding relationship curve is obtained by fitting the two-dimensional fluorescence intensity (grayscale) distribution and spatial concentration at each concentration.

[0050] Step S2) Use a dual-wavelength ultraviolet lamp 7 and use a reaction tracer to couple and measure the fluorescence distribution to obtain fluorescence distribution information.

[0051] This step is specifically as follows: A dual-wavelength ultraviolet lamp is used as the ultraviolet lamp 7; Start the UV reactor 5 and keep the internal flow rate and lamp output of the UV reactor 5 stable; Start the laser source unit, fluorescence detection unit 14 and data processing unit 13; A tracer of a specific concentration is continuously injected into the mainstream of the ultraviolet reactor 5. The tracer can be degraded by the dual-wavelength ultraviolet light emitted by the ultraviolet lamp 7 in the annular reaction channel of the ultraviolet reactor 5. A linear scan is performed on the annular reaction channel along the axial direction (Z-axis direction) of the ultraviolet reactor 5. At each scan position, the laser light source unit is controlled by the synchronous control unit 17 to emit laser sheet light, and the fluorescence detection unit 14 is controlled to capture a two-dimensional image of the reactor cross-section (XY plane) illuminated by the laser sheet light. The data processing unit 13 is used to correct the acquired two-dimensional image to obtain the two-dimensional fluorescence intensity (grayscale) distribution at the scan position.

[0052] Step S3) Based on the fluorescence distribution information and calibration information, obtain the three-dimensional concentration field information, and based on the three-dimensional concentration field information, obtain the three-dimensional degradation rate distribution information.

[0053] Specifically, this step involves using the data processing unit 13 to obtain a two-dimensional concentration distribution based on the calibration information of each scanning position and the acquired two-dimensional image; and combining the two-dimensional concentration distributions of all scanning positions to obtain a three-dimensional concentration distribution.

[0054] This step also includes generating a three-dimensional degradation rate distribution map based on the tracer concentration and three-dimensional concentration distribution at the inlet of the UV reactor 5.

[0055] Furthermore, the online monitoring method for ultraviolet reaction also includes: feeding back the three-dimensional degradation rate distribution information to the reactor control unit 12 to determine whether the pollutant concentration conditions at the outlet of the ultraviolet reactor are met, and adjusting the operating parameters of the ultraviolet degradation reaction unit based on the determination results.

[0056] The operating parameters of the ultraviolet reactor 5 include one or more combinations of parameters such as influent flow rate, ultraviolet lamp power, and internal mixer speed.

[0057] Furthermore, in steps S1 and S2, the UV lamps and VUV / UV lamps are preheated for at least 30 minutes before testing to achieve a stable photon output flux.

[0058] Specific embodiments of the present invention are as follows: Example The structure of the laser-induced fluorescence ultraviolet reactor integrated system proposed in this embodiment is as follows: Figure 1 As shown.

[0059] In this embodiment, the laser source unit uses a double-frequency Nd:YAG 532nm green laser, and the position of the laser is fixed. The design parameters of the two sets of sheet beam shaping modules 3 are exactly the same, each consisting of a cylindrical concave lens and two cylindrical convex lenses. The laser 1 emits laser light, which is split into a transmitted beam and a reflected beam by the beam splitter 2. After the direction of the transmitted beam is adjusted by the reflector group 11, it passes through its corresponding sheet beam shaping module 3 to generate the first laser sheet beam. The reflected beam passes through its corresponding sheet beam shaping module 3 to generate the second laser sheet beam. The two laser sheet beams are incident on each other, spatially collinear, and both are perpendicular to the axis of the ultraviolet reactor 5 and cover the radial width of the annular flow channel of the ultraviolet reactor 5.

[0060] Among them, the sheet beam shaping module 3, the beam splitter 2 and the lower reflector 11 are jointly installed on the corresponding high-precision linear guide rail 4, and the two reflectors 11 are fixed on the left and right upper corners of the linear motion platform 18 respectively; the step distance of the linear guide rail 4 is matched with the thickness of the laser sheet, such as 0.5mm, to realize axial layer-by-layer scanning.

[0061] like Figure 1 As shown, in this embodiment, the fluorescence detection unit 14 is coaxially arranged with the ultraviolet reactor 5. Simultaneously, the fluorescence detection unit 14 is mounted on a corresponding high-precision linear guide rail 4, allowing it to move synchronously with the sheet beam shaping module 3, thereby avoiding the impact of changes in object distance or rapid focusing on image clarity.

[0062] In this embodiment, the reactor control unit 12 judges whether the real-time pollutant degradation efficiency of the ultraviolet reaction unit 5 meets industrial requirements based on the feedback data from the data processing unit 13, and uses this information to control and adjust the control parameters of the ultraviolet reactor 5.

[0063] Figure 2 , Figure 3 A flowchart illustrating a method for real-time measurement of a concentration field in an ultraviolet degradation reactor according to an embodiment of the present disclosure is shown, the method being characterized by dual-mode differential calculation.

[0064] In this embodiment, a specific concentration of fluorescent dye reagent is pre-injected into the mainstream at a certain flow rate at a certain distance upstream of the UV degradation reaction unit 5 (ensuring that it passes through a sufficiently long pipeline before entering the reactor) as a pollutant. The fluorescent dye reagent is prepared using deionized water or ultrapure water with high UV transmittance, and the mainstream fluid is also deionized water or ultrapure water with high UV transmittance. After startup, it runs at a constant flow rate for a sufficient time to ensure that the pollutants at the inlet of the UV degradation reaction unit are in a completely mixed state, while ensuring that the fluid dynamics conditions inside the UV degradation reaction unit remain unchanged.

[0065] In this embodiment, the dual-mode differential calculation includes tracer inert hydrodynamic field calibration (i.e., non-oxidative control group), reaction tracer coupling measurement, and chemical reaction information extraction.

[0066] This embodiment also provides a method for calibrating a tracer inert hydrodynamic field, such as Figure 2 As shown, this includes operations S201 to S204.

[0067] In this embodiment, the tracer inert hydrodynamic field calibration steps include: establishing control conditions, maintaining the system's flow rate, temperature and other hydrodynamic parameters unchanged, and temporarily replacing the central VUV / UV dual-wavelength lamp with a single-wavelength ultraviolet lamp that emits only 254 nm UV and has the same power to create an oxidation-free environment. In this embodiment, operation S201 starts the ultraviolet reaction unit to keep the internal flow rate of the reactor and the output of the lamp tube stable; In this embodiment, S202 is used to start the laser source system, fluorescence detection system, 3D LIF data processing unit and reactor control system; In this embodiment, operation S203 continuously injects tracers of different specific concentrations (e.g., 500 ppb RhB) into the main stream of the system until the concentration distribution in the reactor reaches a statistical steady state; linear scanning acquires the three-dimensional concentration field, and controls the high-precision linear motion platform at certain intervals (determined by the thickness of the laser sheet); the synchronous control unit 17 controls the camera to capture a two-dimensional image of the reactor cross-section (XY plane) illuminated by the sheet light. In this embodiment, the S204 data processing unit 13 is used to correct the acquired image and calibrate the relationship between fluorescence intensity (grayscale) and spatial concentration. In this embodiment, during the tracer inert hydrodynamic field calibration, the tracer is purely dominated by convection and diffusion. Since the tracer at the inlet of the UV degradation reaction unit is in a completely mixed state and its concentration is known, the tracer inert hydrodynamic field calibration can replace the offline calibration device of traditional LIF technology. Fluorescence intensity (grayscale)-concentration calibration curves can be obtained by using tracers of different concentrations.

[0068] This embodiment also provides a flowchart of a method for differential calculation of the spatial concentration field of an ultraviolet degradation reactor in dual-mode operation, such as... Figure 3 As shown, this includes operations S301 to S308.

[0069] In this embodiment, the laser-induced fluorescence ultraviolet reactor integrated system is installed by operating S301, and the ultraviolet reaction unit is started to keep the internal flow rate and lamp output of the reactor stable. In this embodiment, operation S302 starts the laser source system, fluorescence detection system, 3D LIF data processing unit and reactor control system; a tracer of a specific concentration (e.g. 500 ppb RhB) is continuously injected into the main stream of the system, and the tracer is degraded in the ultraviolet degradation reaction unit; In this embodiment, operations S303~S304 initiate linear scanning to acquire a three-dimensional concentration field, controlling the linear guide rail 4 at certain intervals (determined by the thickness of the laser sheet); the synchronous control unit 17 controls the camera 16 to capture a two-dimensional image of the reactor cross-section (XY plane) illuminated by the sheet light; the 3D LIF data processing unit 13 corrects the image information to realize the conversion of image grayscale (fluorescence intensity) to concentration, and at the same time converts the pixel coordinates in the image into spatial three-dimensional coordinates, and reconstructs the spatial concentration fields C1(x, y, z) and C2(x, y, z) by calculating the color value of each data point; In this embodiment, after operation S305 converts the original grayscale value of the image into concentration field data using the linear calibration relationship between grayscale value and RhB concentration, the local time average degradation rate D is calculated at any point P(x, y, z) in three-dimensional space. avg (x, y, z) Separate chemical reaction information: D avg (x,y,z)=[C1(x,y,z)-C2(x,y,z)] / C1(x,y,z); In this embodiment, operation S306 calculates the spatial degradation rate distribution to generate a three-dimensional degradation rate distribution map of the entire reactor under stable operating conditions. In this embodiment, operation S307 feeds back the three-dimensional degradation rate distribution information to the reactor control unit 12 to determine whether the pollutant concentration conditions at the outlet of the ultraviolet reactor are met, and operation S308 adjusts the operating parameters of the ultraviolet degradation reaction unit (inlet flow rate, ultraviolet lamp power, internal mixer speed, etc.).

[0070] The above specific embodiments are used to explain and illustrate the present invention, but not to limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

[0071] The above description is only a preferred embodiment of the present invention. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the claims of this patent application are included in the scope of this patent application.

Claims

1. An integrated system for a laser-induced fluorescence ultraviolet reactor, characterized in that, include: The ultraviolet reactor (5) includes an ultraviolet lamp (7), an inner tube (6) and an outer tube (10) arranged sequentially from the inside to the outside. An annular reaction flow channel is formed between the inner tube (6) and the outer tube (10). Annular optical windows are provided at both ends of the outer tube (10). The laser source unit includes a pair of sheet beam shaping modules (3). The two sheet beam shaping modules (3) are used to modulate the laser into a pair of opposing incident, spatially collinear laser sheet beams. The optical path of the laser sheet beams is perpendicular to the axis of the ultraviolet reactor (5) and covers the annular reaction channel. The fluorescence detection unit (14) is used to collect the excitation fluorescence signal at the laser sheet scanning position in the annular reaction channel; The data processing unit (13) is used to receive and process the excitation fluorescence signal, and reconstruct the synthetic three-dimensional concentration field and / or three-dimensional degradation rate distribution; The synchronization control unit (17) is used to synchronize the laser light source unit and the fluorescence detection unit (14).

2. The laser-induced fluorescence ultraviolet reactor integrated system according to claim 1, characterized in that: The laser source unit also includes a laser (1), a beam splitter (2) and several reflector groups (11); the laser emitted by the laser (1) is split by the beam splitter (2) to generate a transmitted beam and a reflected beam; at least one of the transmitted beam and the reflected beam is adjusted in direction by the reflector group (11) and then passes through the corresponding sheet beam shaping module (3) to form a pair of opposing incident, spatially collinear laser sheet beams.

3. The laser-induced fluorescence ultraviolet reactor integrated system according to claim 1, characterized in that: The ultraviolet reactor integrated system also includes a linear motion platform (18); the linear motion platform (18) is communicatively connected to the synchronous control unit (17); the linear motion platform (18) includes several linear guide rails (4), the linear guide rails (4) are parallel to the axis of the ultraviolet reactor (5); the sheet beam shaping module (3) and the fluorescence detection unit (14) are slidably arranged on their corresponding linear guide rails (4).

4. The laser-induced fluorescence ultraviolet reactor integrated system according to any one of claims 1 to 3, characterized in that: The sheet-like beam shaping module (3) includes several optical elements arranged sequentially along the optical path. The optical elements include one or more combinations of cylindrical concave lenses, cylindrical convex lenses, beam splitters, variable circular apertures, and ultraviolet quartz prisms.

5. The laser-induced fluorescence ultraviolet reactor integrated system according to claim 1, characterized in that: The fluid in the ultraviolet reactor (5) contains a fluorescent tracer that can be excited by laser but not by 254nm single-wavelength ultraviolet light, and can be degraded under dual-wavelength ultraviolet light.

6. A method for online monitoring of ultraviolet reactions in an integrated system of laser-induced fluorescence ultraviolet reactors as described in any one of claims 1 to 5, characterized in that, Includes the following steps: Step S1) Ultraviolet lamp (7) Select a single-wavelength ultraviolet lamp and use an inert tracer to perform hydrodynamic field calibration to obtain calibration information; the calibration information is the relationship curve between the two-dimensional fluorescence intensity distribution and spatial concentration corresponding to each scanning position; Step S2) Ultraviolet lamp (7) Select a dual-wavelength ultraviolet lamp and use a reaction tracer to couple and measure the fluorescence distribution to obtain fluorescence distribution information; Step S3) Based on the fluorescence distribution information and calibration information, obtain the three-dimensional concentration field information, and based on the three-dimensional concentration field information, obtain the three-dimensional degradation rate distribution information.

7. The online monitoring method for ultraviolet reaction according to claim 6, characterized in that: Step S1 includes: A single-wavelength ultraviolet lamp was used as the ultraviolet lamp (7); Start the ultraviolet reactor (5); Start the laser source unit, fluorescence detection unit (14) and data processing unit (13); Tracers of different concentrations were continuously injected into the mainstream of the ultraviolet reactor (5); At each concentration, the annular reaction channel is linearly scanned along the axial direction of the ultraviolet reactor (5); at each scanning position, the laser light source unit is controlled by the synchronous control unit (17) to emit laser sheet light, and the fluorescence detection unit (14) is controlled to capture a two-dimensional image of the reactor cross section illuminated by the laser sheet light. The data processing unit (13) is used to correct the two-dimensional fluorescence intensity distribution at the scanning position. For each scanning position, the corresponding relationship curve is obtained by fitting the two-dimensional fluorescence intensity distribution and spatial concentration at each concentration.

8. The online monitoring method for ultraviolet reaction according to claim 6, characterized in that: Step S2 includes: A dual-wavelength ultraviolet lamp was used as the ultraviolet lamp (7); Start the ultraviolet reactor (5); Start the laser source unit, fluorescence detection unit (14) and data processing unit (13); A tracer of a specific concentration is continuously injected into the mainstream of the ultraviolet reactor (5); Linear scanning is performed on the annular reaction channel along the axial direction of the ultraviolet reactor (5); at each scanning position, the laser light source unit is controlled by the synchronous control unit (17) to emit laser sheet light, and the fluorescence detection unit (14) is controlled to capture a two-dimensional image of the reactor cross section illuminated by the laser sheet light. The data processing unit (13) is used to correct the two-dimensional fluorescence intensity distribution at the scanning position.

9. The online monitoring method for ultraviolet reaction according to claim 6, characterized in that: Step S3 includes: using the data processing unit (13) to obtain a two-dimensional concentration distribution based on the calibration information of each scanning position and the acquired two-dimensional image; and combining the two-dimensional concentration distributions of all scanning positions to obtain a three-dimensional concentration distribution.

10. The online monitoring method for ultraviolet reaction according to claim 9, characterized in that: Step S3 further includes generating a three-dimensional degradation rate distribution map based on the tracer concentration and three-dimensional concentration distribution at the inlet of the ultraviolet reactor (5).

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