Urban nitrogen oxide absorption coating dynamic environment regulation detection device and method

Abstract

This invention provides a dynamic environmental control and detection device and method for urban outdoor nitrogen oxide absorbing coatings. Through multi-dimensional dynamic environmental simulation and in-situ surface chemical analysis, this invention systematically analyzes the absorption effect of coatings on nitrogen oxides in the environment. This invention not only constructs a dynamic simulation system based on the synergistic effects of spectroscopy, pollutants, and mechanical stress, employing a spectrally adjustable LED array, a NOx pulse injection module, and a temperature, humidity, and wind speed composite cavity to achieve coupled simulation of dynamic adjustment of ultraviolet intensity, pollutant pulse input, and rapid switching of temperature and humidity, but also innovatively introduces real-time monitoring technology for surface adsorption states. By analyzing the intensity ratio of characteristic peaks of nitrate and nitrite using a miniature FTIR probe, a micropore blockage early warning mechanism for the coating layer is established.

Description

Technical Field

[0001] This invention belongs to the field of environmental functional material testing technology, specifically relating to a method for dynamic environmental regulation testing of urban outdoor nitrogen oxide absorbing coatings, which is particularly suitable for testing the anti-pollution performance of photocatalytic, adsorption and other environmental functional coating layers. Background Technology

[0002] Nitrogen oxide (NOx) absorbing coatings are functional materials used for urban air pollution control. They degrade NOx (mainly NO and NO2) in the environment into low-toxicity or harmless products (such as nitrates and nitrites) through mechanisms such as photocatalytic oxidation, physical adsorption, or chemical conversion.

[0003] Traditional nitrogen oxide absorbing coating detection technology has significant limitations: First, the environmental simulation is static, and laboratories often use single conditions such as constant temperature, constant humidity, and fixed light intensity, which cannot reproduce the dynamic composite stresses such as ultraviolet intensity fluctuations, sudden changes in temperature and humidity, and NOx concentration pulses in urban environments.

[0004] Secondly, traditional methods rely on gas chromatography to determine changes in gaseous NOx concentration, but they cannot capture the accumulation process of adsorbed species on the coating surface, leading to distorted assessments of the material's resistance to poisoning. For example, existing testing devices typically only support constant NOx concentration input, and their temperature and humidity control accuracy is insufficient, resulting in significant deviations from real-world conditions. Summary of the Invention

[0005] The purpose of this invention is to provide a standardized dynamic testing method for the anti-pollution performance of coatings, addressing the problems of static environmental simulation, lack of surface adsorption state monitoring, and distortion of anti-pollution ability assessment in traditional nitrogen oxide absorption coating testing technologies. This method is used to simulate extreme dynamic stress in open urban road environments.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A dynamic environmental control and testing device for urban exterior nitrogen oxide absorbing coatings is used to provide a test environment for a type of coating with nitrogen oxide absorption function. The device includes a test hood, the interior of which is defined as a test space. The top of the test space is equipped with a spectrum-tunable LED array module, which is used to provide a simulated alternating scenario of strong daytime ultraviolet radiation and weak nighttime visible light in a road environment within the test space.

[0008] The bottom of the test space is equipped with an operating table, and a paint fixing platform is embedded in the operating table. The paint layer is placed on the paint fixing platform and is located below the spectrally tunable LED array module.

[0009] The two sides of the test hood are connected to the test space through NOx (different proportions of NO and NO2 gas) gas injection units and integrated control units, which are used to simulate the short-term high concentration impact of motor vehicle exhaust during peak traffic hours and the alternating scenario of high humidity in the rainy season and low humidity in the dry season, respectively.

[0010] A miniature FTIR probe is positioned above the coating mounting platform. This probe is connected to an FTIR spectrometer via optical fiber to analyze in real time the intensity ratio of characteristic peaks of nitrate and nitrite on the coating surface. Nitrate (NO3) - The characteristic absorption peak of nitrite (NO2) is generated by the symmetric stretching vibration of the NO bond. - The characteristic absorption peaks of the NO bond are selected based on the antisymmetric stretching vibration of the NO bond, so that the absorption peaks of the two components in the same system can be distinguished and easily observed. The absorbance values ​​at these locations can be extracted by acquiring the infrared spectrum of the coating surface using a miniature FTIR probe. Calculate the characteristic peak intensity ratio R (calculation formula: Coating absorbs NO x Nitrate (NO3) is then produced. - ) and nitrite (NO2) - NO3 - It has low solubility and easily crystallizes and deposits within micropores; when photocatalytic activity decreases, NO2... - To NO3 - A decrease in conversion rate leads to a decrease in the R value. An R > 2.5 indicates NO3- - An increased proportion of the generated product will accelerate the clogging of micropores (pore size ≤15nm) through crystallization and deposition. Based on TiO2-supported polyurethane resin (specific surface area 120m²), 2 / g) In a simulated road environment, the micropore blockage rate was verified to be ≥15% when R>2.5. Therefore, this threshold was set as an early warning condition, and the threshold was allowed to be adjusted by ±0.5 to adapt to different coating systems, thereby quantifying the dynamic accumulation of micropore adsorbed nitrogen oxides under the coupled effect of humidity and heat in the road environment. A laser-induced fluorescence sensor was set on the side wall of the test space to capture the concentration of hydroxyl radicals and sulfate radicals in the coating layer in real time, thereby correlating the decay law of motor vehicle exhaust pulse input and photocatalytic reaction efficiency.

[0011] Preferably, the NOx gas injection unit includes an inlet pipe and an outlet pipe connecting both sides of the test space. One end of the inlet pipe is connected to the test space, and the other end is connected to the outside air. The inlet pipe is provided with a NOx inlet port with a pulse valve for introducing NOx gas.

[0012] One end of the gas outlet pipe is connected to the test space, and the other end is connected to a gas analyzer for analyzing the gas in the test space.

[0013] Preferably, the integrated control unit includes a temperature and humidity control unit and a wind speed coupling control unit; the temperature and humidity control unit includes a humidification circulation system, a temperature control base, and a humidity sensor; the temperature control base is embedded in the operating platform, and the coating layer is placed on the temperature control base to simulate a heated environment; the humidification circulation system is connected to the air inlet pipe and the air outlet pipe through pipes to connect the test space and realize the humidification circulation mode.

[0014] The wind speed coupling control unit includes several fans; the fans are evenly distributed in the test space and on the side walls of the test space to precisely control the airflow speed and distribution, simulating the multi-scale wind field effect in a real road environment.

[0015] Preferably, the laser-induced fluorescence sensor includes a laser module and an RMT detection probe, which are disposed opposite to each other on the inner wall of the test space to capture the concentration of hydroxyl radicals and sulfate radicals in the coating layer.

[0016] Preferably, the laser module is configured to output dual-wavelength lasers of 308nm and 355nm to excite the analyte.

[0017] Preferably, the spectrally tunable LED array module covers a wavelength range of 280-800nm, and the band gap of the photocatalytic material is 3.2eV, covering the response band.

[0018] This invention also provides an application method for a dynamic environmental control and detection device for urban outdoor nitrogen oxide absorbing coatings, comprising the following steps:

[0019] Step S1: Composite stress loading stage:

[0020] Simulated road environment day-night cycle:

[0021] Simulated daytime scenario: Applying 280-400nm ultraviolet light through a spectrally tunable LED array module, with an irradiance of 50-100W / m². 2 Continuous irradiation for 12 hours, with simultaneous NOx pulse injection of 0→10ppm / 5min every 2 hours; synchronously coupled daytime temperature and humidity conditions of 30-50℃ / RH30%-50% to simulate a high-temperature dry road;

[0022] Simulated nighttime scenario: Switching to visible light at night, with irradiance ≤30W / m². 2 The NOx concentration was maintained at 2 ppm; the nighttime temperature and humidity were 10-25℃ / RH 70%-80% to simulate a condensing and humid environment; and the wind speed fluctuated randomly from 1 to 10 m / s to simulate natural wind load.

[0023] Step S2: In-situ reaction monitoring stage:

[0024] The ratio of nitrate to nitrite intensity at characteristic peaks on the surface of the coating layer is collected every 10 minutes using a miniature FTIR probe. When the ratio is greater than 2.5 for three consecutive times, a micropore blockage warning is triggered.

[0025] The concentrations of hydroxyl and sulfate radicals in the coating layer were monitored in real time using a laser-induced fluorescence sensor. The radical concentrations at the initial stage of the test were recorded as A0 (unit: ppb), and the radical concentrations at the end of the test were recorded as A... t The unit is ppb; when the daytime peak concentration is <100ppb or the nighttime baseline concentration is <20ppb, the photocatalytic activity of the coating is deemed substandard.

[0026] Step S3: Performance Evaluation Phase

[0027] Based on the monitoring data from the 7-day continuous step S2, the NOx dynamic degradation rate was calculated as 1 - (average residual concentration during the pulse cycle / 10 ppm) and the free radical activity decay rate was calculated using the following formulas:

[0028] Free radical activity decay rate = (A0 - A) t ) / A0, Unit: %;

[0029] Combined with the accumulation rate of adsorbed states, in mg / cm³ 2 The ·d ratio and the free radical activity decay rate are used to comprehensively evaluate the anti-aging level of the coating in an open road environment.

[0030] Preferably, the anti-aging level of step S3 is graded according to the following standards:

[0031] Grade A: Simultaneously meeting the requirement of a NOx dynamic degradation rate ≥85%, indicating that the above coating possesses highly efficient NOx purification capabilities and an adsorption accumulation rate ≤0.15mg / cm³. 2 •d indicates that the microporous structure of the above coating has an extremely low risk of clogging;

[0032] Grade B: A NOx dynamic degradation rate reduced to 70-85% indicates that the above coating still maintains a high NOx purification efficiency, with the adsorption accumulation rate moderately increased to 0.15-0.3 mg / cm³. 2 •d indicates that the risk of microporous blockage in the above coating is controllable, and the free radical activity decay rate ≤30% indicates that the photocatalytic activity of the above coating has not significantly declined;

[0033] Grade C: NOx dynamic degradation rate <70% indicates that the above coating has insufficient NOx purification efficiency or free radical activity decay rate >30% (indicating that the photocatalytic activity of the above coating has seriously degraded).

[0034] Preferably, in step S1, the parameters adjusted for winter operating conditions are: daytime temperature and humidity 10±2℃ / RH40±5%, and nighttime temperature and humidity -2±1℃ / RH85±5%.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] This invention systematically analyzes the absorption effect of coatings on nitrogen oxides in the environment through multi-dimensional dynamic environmental simulation and in-situ surface chemical analysis. This invention not only constructs a dynamic simulation system for the synergistic effects of spectroscopy, pollutants, and mechanical stress, employing a spectrally tunable LED array, a NOx pulse injection module, and a temperature, humidity, and wind speed composite cavity to achieve coupled simulation of dynamic adjustment of ultraviolet intensity, pollutant pulse input, and rapid switching of temperature and humidity, but also innovatively introduces real-time monitoring technology for surface adsorption states. By analyzing the intensity ratio of characteristic peaks of nitrate and nitrite using a miniature FTIR probe, a micropore blockage early warning mechanism for the coating layer is established. Attached Figure Description

[0037] Figure 1 A schematic diagram of the structure of a dynamic environmental control and detection device for urban outdoor nitrogen oxide absorbing coatings provided as an embodiment of the present invention. Figure 1 ;

[0038] Figure 2 A schematic diagram of the structure of a dynamic environmental control and detection device for urban outdoor nitrogen oxide absorbing coatings provided as an embodiment of the present invention. Figure 2 ;

[0039] Figure 3 A flowchart illustrating the application method of a dynamic environmental control and detection device for urban outdoor nitrogen oxide absorbing coatings, provided as an embodiment of the present invention;

[0040] Figure 4 The peak points to be found for LINO3 in the public spectral database;

[0041] Figure 5 The peak point that needs to be found for CH3NO2 in the public spectral database.

[0042] The serial numbers in the diagram are as follows:

[0043] 1. Test hood; 2. LED array module; 3. Fan; 4. Laser module; 5. Paint fixing platform; 6. Operating table; 7. Miniature FTIR probe; 8. Inlet pipe; 9. Outlet pipe; 10. Pulse valve; 11. NOx inlet; 12. Humidification circulation system; 13. Temperature control base; 14. Humidity sensor; 15. RMT detection probe; 16. Insulation layer; 17. Gas analyzer; 18. Fiber optic cable; 19. FTIR spectrometer. Detailed Implementation

[0044] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0045] like Figure 1 and Figure 2 As shown in this embodiment, a dynamic environmental control and testing device for urban exterior nitrogen oxide absorbing coatings is provided to provide a testing environment for the coating layer. It includes a test hood 1, model: a customized sealed test chamber (dimensions: 1.23m × 1.23m × 0.59m, material: 316 stainless steel anti-corrosion coating). Its function is to simulate the multi-physics coupling conditions (light, temperature, humidity, air, wind) of a road environment. The interior of the test hood 1 is defined as the test space. A spectrally tunable LED array module 2 is installed at the top of the test space to provide a simulated alternating scenario of strong daytime ultraviolet radiation and weak nighttime visible light in a road environment. The LED array module model is a MicroMoore Technology L4 / L8-3040 multi-channel tunable LED light source.

[0046] The bottom of the test space is equipped with an operating table 6, and the operating table 6 is embedded with a paint fixing table 5. The paint layer is placed on the paint fixing table 5 and is located below the spectrally adjustable LED array module 2.

[0047] The two sides of the test hood 1 are connected to the test space through the NOx gas injection unit (Shanghai Yixian Environmental Protection YX-NOX-100 conversion device) and the integrated control unit, respectively used to simulate the short-term high concentration impact of motor vehicle exhaust during peak traffic hours and the alternating scenario of high humidity in the rainy season and low humidity in the dry season.

[0048] A miniature FTIR probe 7 is positioned above the coating mounting platform 5. The miniature FTIR probe 7 is connected to an FTIR spectrometer 19 (ARCoptix FTIR-FC fiber optic coupling system) via an optical fiber 18. This is used to analyze the intensity ratio of nitrate and nitrite on the coating surface in real time, thereby quantifying the dynamic accumulation of microporous adsorbed nitrogen oxides under the combined effects of humidity and heat in the road environment. A laser-induced fluorescence sensor is installed on the side wall of the test space to capture the concentration of hydroxyl radicals and sulfate radicals in the coating layer in real time, thereby correlating the decay law of vehicle exhaust pulse input with photocatalytic reaction efficiency.

[0049] Furthermore, in this embodiment, an insulation layer 16 (material: rigid polyurethane foam) is laid on the inner wall of the test cover 1 to maintain the temperature inside the test space.

[0050] Furthermore, the NOx gas injection unit includes an inlet pipe 8 and an outlet pipe 9 connecting the two sides of the test space. One end of the inlet pipe 8 is connected to the test space, and the other end is connected to the outside air. The inlet pipe 8 is equipped with a NOx inlet 11 with a pulse valve 10 for introducing NOx gas.

[0051] One end of the gas outlet pipe 9 is connected to the test space, and the other end is connected to an external gas analyzer 17 (model: Gasmet Dx4000) for analyzing the gas in the test space.

[0052] Furthermore, in this embodiment, the integrated control unit includes a temperature and humidity control unit and a wind speed coupling control unit; the temperature and humidity control unit includes a humidification circulation system 12, a temperature control base 13 (constant temperature and humidity chamber model: HZ-1000) and a humidity sensor 14 (model: Honeywell capacitive humidity sensor); the temperature control base 13 is embedded in the operating platform, and the coating layer is placed on the temperature control base 13 to simulate a heated environment; the humidification circulation system 12 is connected to the air inlet pipe 8 and the air outlet pipe 9 through pipes to connect to the test space and realize the humidification circulation mode.

[0053] The wind speed coupling control unit includes several fans 3; the fans 3 are evenly distributed in the test space and on the side wall of the test space to precisely control the airflow speed and distribution, and simulate the multi-scale wind field effect in a real road environment.

[0054] Furthermore, in this embodiment, the laser-induced fluorescence sensor includes a laser module 4 (model: DualWavelength) and an RMT detection probe 15 (model: RMT-15S-UV). The laser module 4 and the RMT detection probe 15 are arranged opposite each other on the inner wall of the test space to capture the concentration of hydroxyl radicals and sulfate radicals in the coating layer. The laser module 4 is configured to output dual-wavelength lasers of 308nm and 355nm. The spectrally tunable LED array module 2 covers a wavelength range of 280-800nm, and the photocatalyst material is TiO2-supported polyurethane resin (specific surface area 120m²). 2 The bandgap of the light (with an aperture of 15 nm) is 3.2 eV, covering the response wavelength range. The adjustable light intensity range is 0-100 W / m. 2 It supports the dynamic ratio of ultraviolet and visible light according to the diurnal rhythm.

[0055] like Figure 3 As shown, this embodiment also provides an application method for the dynamic environmental control and detection device for urban outdoor nitrogen oxide absorbing coatings, including the following steps:

[0056] Step S1: Composite stress loading stage:

[0057] Simulated road environment day-night cycle:

[0058] Simulating daytime scenarios: Applying 280-400nm ultraviolet light (50-100W / m²) via a spectrally tunable LED array module. 2 ) Continuous irradiation for 12 hours, with simultaneous NOx pulse injection of 0→10ppm / 5min every 2 hours; synchronously coupled daytime temperature and humidity conditions of 30-50℃ / RH30%-50% to simulate a high-temperature dry road;

[0059] Simulated nighttime scene: Switch to visible light (≤30W / m) at night. 2 The NOx concentration was maintained at 2 ppm; the nighttime temperature and humidity were 10-25℃ / RH 70%-80% to simulate a condensing and humid environment; and the wind speed fluctuated randomly from 1 to 10 m / s to simulate natural wind load.

[0060] Step S2: In-situ reaction monitoring stage:

[0061] The ratio of nitrate to nitrite intensity on the coating surface is collected every 10 minutes using a miniature FTIR probe 7. When the ratio is greater than 2.5 for three consecutive times, a micropore blockage warning is triggered.

[0062] By real-time monitoring of the concentrations of hydroxyl and sulfate free radicals in the coating layer, the free radical concentrations of the coating at the initial stage of the test (expressed as A0, unit: ppb) and at the end of the test (expressed as A) were recorded. t (Unit: ppb). When the daytime peak concentration is <100 ppb or the nighttime baseline concentration is <20 ppb, the photocatalytic activity of the coating is deemed substandard.

[0063] Step S3: Performance Evaluation Phase

[0064] Based on the monitoring data from the 7-day continuous step S2, the NOx dynamic degradation rate was calculated as 1 - (average residual concentration during the pulse cycle / 10 ppm) and the free radical activity decay rate was calculated using the following formulas:

[0065] Free radical activity decay rate = (A0 - A) t ) / A0, Unit: %;

[0066] Accumulation rate of adsorbed states (mg / cm) 2 •d) Combined with the free radical activity decay rate, the anti-aging level of the coating in an open road environment is comprehensively evaluated.

[0067] Preferably, the anti-aging grade of step S3 is graded according to the following criteria:

[0068] Grade A: Simultaneously meets the requirements of NOx dynamic degradation rate ≥85% and adsorption accumulation rate ≤0.15mg / cm³. 2 ·d.

[0069] Grade B: NOx dynamic degradation rate decreases to 70-85%, and adsorption accumulation rate moderately increases to 0.15-0.3 mg / cm³. 2 •d, free radical activity decay rate ≤30%.

[0070] Grade C: NOx dynamic degradation rate <70% or free radical activity decay rate >30%.

[0071] In step S1, the parameters are adjusted for winter operating conditions as follows: daytime temperature and humidity 10±2℃ / RH40±5%, nighttime temperature and humidity -2±1℃ / RH85±5%.

[0072] The following details specific embodiments:

[0073] Taking the typical environment of Yan'an Elevated Road in Shanghai as an example, the actual testing using the dynamic environmental control and detection device for urban exterior nitrogen oxide absorbing coatings adopted in the specific implementation method includes the following steps:

[0074] Dynamic environmental parameter settings

[0075] (1) Spectral Simulation: Based on meteorological data and road illumination characteristics in Shanghai, the daytime (6:00-18:00) ultraviolet (280-400nm) intensity of an tunable LED array is 80±5W / m. 2 (Simulating strong ultraviolet radiation in summer), visible light (400-800nm) intensity 20±3W / m 2 Switch to visible light intensity of 10±2W / m² at night (18:00-6:00). 2 UV intensity is off.

[0076] (2) NOx pulse injection: The NO to NO2 ratio is 3:1 to simulate the exhaust emissions of motor vehicles during the morning peak (7:00-9:00) and evening peak (17:00-19:00). A 0→10ppm concentration pulse injection is performed every 2 hours (completed within 5 minutes), and the basic concentration is maintained at 3±0.5ppm during off-peak periods.

[0077] (3) Temperature and humidity-wind speed coupling:

[0078] Daytime: Temperature 35±2℃ (simulating high temperature of asphalt pavement), humidity RH 45±5%, wind speed 3±1m / s (simulating vehicle driving disturbance);

[0079] Nighttime: Temperature 20±2℃, humidity RH 75±5% (simulating condensation), wind speed 1±0.5m / s;

[0080] The cycle repeats every 24 hours for 7 days.

[0081] In-situ monitoring and data acquisition

[0082] (4) Surface adsorption state analysis: Nitrate (NO3) in the coating was collected every 10 minutes using a miniature FTIR probe. - The symmetric stretching vibration of the NO bond produces peak positions and nitrite (NO2). - The NO bond antisymmetric stretching vibration generates peak positions; the absorbance values ​​at these positions are extracted. And calculate the characteristic peak intensity ratio R (calculation formula: When the ratio of three consecutive detections is >2.5, a micropore blockage warning is triggered and the cumulative rate (mg / cm³) is recorded. 2 ·d).

[0083] like Figure 4 and Figure 5 The image shows the peak points needed to locate the specific substances LINO3 and CH3NO2. SDBS is a public spectral database maintained by the National Institute of Advanced Industrial Science and Technology (AIST) in Japan, containing experimentally verified standard spectra of organic compounds. This embodiment combines measured spectral data from the SDBS database (Spectral Database for Organic Compounds, https: / / sdbs.db.aist.go.jp, published by the National Institute of Advanced Industrial Science and Technology, AIST, Japan) and provides the following explanation: The key to this embodiment is distinguishing nitrate (NO3) ions by using characteristic infrared spectral peaks. - ) and nitrite (NO2) - The existence forms and relative abundances of the two ions were determined. Based on standard spectral data from the SDBS database, the vibrational modes of the two ions showed significant differences:

[0084] 1. Nitrate (NO3) - )

[0085] Symmetrical stretching vibration: located at approximately 1040-1060 cm -1 Place

[0086] Asymmetric stretching vibration: located at approximately 1350-1380 cm -1 Place

[0087] 2. Nitrite (NO2) - )

[0088] Symmetrical stretching vibration: located at approximately 820-860 cm -1 Place

[0089] Asymmetric stretching vibration: located at approximately 1210-1260 cm -1 Place

[0090] Nitrate (NO3) -The characteristic absorption peak of nitrite (NO2) is generated by the symmetric stretching vibration of the NO bond. - The characteristic absorption peaks of nitrate (NO3) are selected based on the antisymmetric stretching vibration of the NO bond to differentiate the absorption peaks of the two substances in the same system and facilitate observation. Accurate data sources are available. However, in practical applications, specific data are influenced by various factors, such as the type of coating, the type of photocatalyst, and the adsorption time. Based on the data to be detected: "nitrate (NO3)..." - The symmetric stretching vibration of the NO bond produces peak positions and nitrite (NO2). - The NO bond antisymmetric stretching vibration generates peak positions; the absorbance values ​​at these positions are extracted. And calculate the characteristic peak intensity ratio R (calculation formula: The approximate locations of the two peaks can be determined from the aforementioned website; therefore, the ratio of the characteristic peak intensities can certainly be obtained during the implementation of the specific experiment.

[0091] (5) Free radical activity monitoring: The concentrations of ·OH and SO4· free radicals were captured in real time using a 308nm / 355nm dual-wavelength laser-induced fluorescence sensor. The daytime ·OH concentration threshold was set to ≥100ppb (photocatalytic activity meets the standard) and the nighttime threshold was set to ≥20ppb (weak light response capability).

[0092] Performance evaluation and rating

[0093] (6) Dynamic degradation rate calculation: Based on 7 days of monitoring data, the NOx degradation rate is calculated as follows: Degradation rate = 1 - (average residual concentration during pulse cycle / 10 ppm). If the degradation rate is ≥85% and the adsorption accumulation rate is ≤0.15 mg / cm³, the NOx degradation rate is calculated. 2 •d, the coating's anti-aging grade is determined to be Grade A; if the degradation rate is 70-85%, the adsorption accumulation rate is 0.15-0.3 mg / cm³. 2 •d. If the free radical activity decay rate is ≤30%, the assessment grade is B; if the degradation rate is <70% or the free radical activity decay rate is >30%, the assessment grade is C (not up to standard).

[0094] Adjustment Implementation

[0095] For winter operating conditions (temperature -5~15℃), the temperature and humidity control unit parameters can be adjusted as follows: daytime temperature and humidity 10±2℃ / RH 40±5%, nighttime temperature and humidity -2±1℃ / RH 85±5%, and the remaining steps remain unchanged.

[0096] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0097] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0098] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A dynamic environmental regulation detection device for urban outdoor nitrogen oxide absorbing coating, used for providing a test environment for a type of coating with nitrogen oxide absorbing function, characterized in that, Includes a test cover (1), the inside of which is defined as a test space, and the top of the test space is provided with a spectrum-tunable LED array module (2) for providing a simulated alternating scene of strong daytime ultraviolet radiation and weak nighttime visible light in a road environment within the test space; The bottom of the test space is provided with an operating table (6), and the operating table (6) is embedded with a paint fixing table (5). The paint layer is placed on the paint fixing table (5) and located below the spectrally adjustable LED array module (2). The two sides of the test hood (1) are connected to the test space through the NOx gas injection unit and the integrated control unit, respectively used to simulate the short-term high concentration impact of motor vehicle exhaust during peak traffic hours and the alternating scenario of high humidity in the rainy season and low humidity in the dry season. A miniature FTIR probe (7) is provided above the coating mounting platform (5). The miniature FTIR probe (7) is connected to an FTIR spectrometer (19) via an optical fiber (18) to analyze the intensity ratio of nitrate and nitrite on the surface of the coating layer in real time, thereby quantifying the dynamic accumulation of microporous adsorbed nitrogen oxides under the coupling effect of road environment humidity and heat. A laser-induced fluorescence sensor is provided on the side wall of the test space to capture the concentration of hydroxyl radicals and sulfate radicals in the coating layer in real time, thereby correlating the decay law of motor vehicle exhaust pulse input and photocatalytic reaction efficiency.

2. The dynamic environmental control and detection device for urban outdoor nitrogen oxide absorbing coatings according to claim 1, characterized in that, The NOx gas injection unit includes an inlet pipe (8) and an outlet pipe (9) connecting the two sides of the test space. One end of the inlet pipe (8) is connected to the test space, and the other end is connected to the outside air. The inlet pipe (8) is provided with a NOx inlet (11) with a pulse valve (10) for introducing NOx gas. One end of the gas outlet pipe (9) is connected to the test space, and the other end is connected to a gas analyzer for analyzing the gas in the test space.

3. The dynamic environmental regulation and detection device for urban outdoor nitrogen oxide absorption paint according to claim 2, characterized in that, The integrated control unit includes a temperature and humidity control unit and a wind speed coupling control unit; the temperature and humidity control unit includes a humidification circulation system (12), a temperature control base (13), and a humidity sensor (14); the temperature control base (13) is embedded in the operating platform, and the coating layer is placed on the temperature control base (13) to simulate a heating environment; the humidification circulation system (12) is connected to the air inlet pipe (8) and the air outlet pipe (9) through pipes to connect the test space and realize the humidification circulation mode; The wind speed coupling control unit includes several fans (3); the fans (3) are evenly distributed in the test space and on the side wall of the test space to precisely control the airflow speed and distribution, and simulate the multi-scale wind field effect in the real road environment.

4. The dynamic environmental regulation and detection device for urban outdoor nitrogen oxide absorption paint according to claim 1, characterized in that, The laser-induced fluorescence sensor includes a laser module (4) and an RMT detection probe (15). The laser module (4) and the RMT detection probe (15) are arranged opposite each other on the inner wall of the test space to capture the concentration of hydroxyl radicals and sulfate radicals in the coating layer.

5. The dynamic environmental regulation detection device for urban external nitrogen oxide absorption paint according to claim 4, characterized in that, The laser module (4) is configured to output dual-wavelength lasers of 308nm and 355nm to excite the substance to be tested.

6. The dynamic environmental regulation and detection device for urban outdoor nitrogen oxide absorption paint according to claim 1, characterized in that, The spectrally tunable LED array module (2) covers a wavelength range of 280-800nm, and the band gap of the photocatalytic material is 3.2eV, covering the response band.

7. A method for using the urban nitrogen oxide absorption coating dynamic environment regulation detection device according to any one of claims 1-6, characterized in that, Includes the following steps: Step S1: Composite stress loading stage: Simulated road environment day-night cycle: Simulated daytime scene: 280-400nm ultraviolet light is applied through a spectrally tunable LED array module (2), with an irradiance of 50-100W / m. 2 Continuous irradiation for 12 hours, with simultaneous NOx pulse injection of 0→10ppm / 5min every 2 hours; Synchronous coupling of daytime temperature and humidity conditions is 30-50℃ / RH 30%-50%, simulating high-temperature and dry roads; Simulated nighttime scenario: Switching to visible light at night, with irradiance ≤30W / m². 2 The NOx concentration was maintained at 2 ppm; the nighttime temperature and humidity were 10-25℃ / RH 70%-80% to simulate a condensing and humid environment; and the wind speed fluctuated randomly from 1 to 10 m / s to simulate natural wind load. Step S2: In-situ reaction monitoring stage: The ratio of nitrate to nitrite intensity on the surface of the coating layer is collected every 10 minutes using a miniature FTIR probe (7). When the ratio is greater than 2.5 for three consecutive times, a micropore blockage warning is triggered. The concentrations of hydroxyl and sulfate radicals in the coating layer were monitored in real time using a laser-induced fluorescence sensor. The radical concentrations at the initial stage of the test were recorded as A0 (unit: ppb), and the radical concentrations at the end of the test were recorded as A... t Indicates unit: ppb; When the daytime peak concentration is <100ppb or the nighttime base concentration is <20ppb, the photocatalytic activity of the coating is deemed to be substandard. Step S3: Performance Evaluation Phase Based on the monitoring data from the 7-day continuous step S2, the dynamic NOx degradation rate was calculated using the following formula: Dynamic degradation rate = 1 - (average residual concentration during pulse cycle / 10 ppm) And the free radical activity decay rate, calculated using the following formula: Radical activity decay rate = (A0- A t ) / A0, in %; Combined with the accumulation rate of adsorbed states, unit: mg / cm 2 •d, together with the free radical activity decay rate, comprehensively evaluates the anti-aging level of the coating in an open road environment.

8. The use of the urban dynamic environmental regulation detection device for nitrogen oxide absorption coating according to claim 7, characterized in that, The anti-aging level of step S3 is graded according to the following standards: Grade A: Simultaneously meeting the requirement of a NOx dynamic degradation rate ≥85%, indicating that the above coating possesses highly efficient NOx purification capabilities and an adsorption accumulation rate ≤0.15mg / cm³. 2 •d indicates that the microporous structure of the above coating has an extremely low risk of clogging; Grade B: A NOx dynamic degradation rate reduced to 70-85% indicates that the above coating still maintains a high NOx purification efficiency, with the adsorption accumulation rate moderately increased to 0.15-0.3 mg / cm³. 2 •d indicates that the risk of microporous blockage in the above coating is controllable, and the free radical activity decay rate ≤30% indicates that the photocatalytic activity of the above coating has not significantly declined; Grade C: A NOx dynamic degradation rate of <70% indicates that the above coating has insufficient NOx purification efficiency, or a free radical activity decay rate of >30% indicates that the photocatalytic activity of the above coating has seriously degraded.

9. The use of the urban dynamic environmental regulation detection device for nitrogen oxide absorption coating according to claim 7, characterized in that, In step S1, the parameters are adjusted for winter operating conditions as follows: daytime temperature and humidity 10±2℃ / RH40±5%, nighttime temperature and humidity -2±1℃ / RH85±5%.

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