Photocatalysis automobile exhaust treatment method

Abstract

A photocatalytic automobile tail gas treatment method comprises the following steps: firstly, establishing a tail gas component detection system, and installing various sensors at the tail part of an automobile to monitor the concentration of tail gas pollutants in real time; a photocatalytic reaction kinetic model is constructed, and the optimal photocatalytic treatment condition is determined through numerical simulation by integrating multiple factors. A photocatalyst activity control and illumination condition optimization strategy is implemented, and key parameters including load capacity, particle size, illumination intensity, wavelength, irradiation time and the like are dynamically adjusted by using an intelligent control system. Meanwhile, the tail gas components are monitored and fed back in real time, the treatment conditions are dynamically adjusted in combination with an intelligent control system, and real-time monitoring and adjustment are achieved through a wireless communication system, so that an operator can remotely optimize the treatment effect, and the tail gas treatment efficiency is improved to the maximum extent.

Description

Technical Field

[0001] The present invention relates to the automotive field, and in particular to a photocatalytic automobile exhaust treatment method. Background Art

[0002] With the rapid development of the automobile industry, the number of cars has continued to increase, and the environmental pollution caused by automobile exhaust emissions has become increasingly serious. Automobile exhaust contains a variety of pollutants such as carbon monoxide, hydrocarbons, and nitrogen oxides, which have caused great harm to air quality, human health, and the ecological environment. At present, the treatment technologies for automobile exhaust mainly include in-engine purification and out-engine purification. In-engine purification technology reduces the generation of pollutants by improving the combustion process of the engine, but this method has certain limitations in reducing pollutant emissions. Out-of-engine purification technology mainly includes catalytic converters, particulate filters, etc. However, when traditional catalytic converters treat exhaust, there is often a problem that the catalyst activity is easily affected by factors such as temperature and exhaust composition, resulting in poor exhaust treatment effects under certain working conditions.

[0003] In terms of exhaust gas component detection, the existing detection systems still need to be improved in terms of accuracy, real-time and reliability. Some detection equipment may not be able to accurately detect the concentration changes of various pollutants in the exhaust gas, or may be interfered by external environmental factors during the detection process, resulting in inaccurate detection results. In addition, the research and application of photocatalytic exhaust treatment technology is still in a stage of continuous development. In practical applications, existing photocatalytic technology faces problems such as low photocatalytic activity, low light energy utilization, and difficulty in accurately controlling photocatalytic reaction conditions. For example, there is a lack of scientific and effective methods for the selection and optimization of parameters such as photocatalyst loading, particle size, light intensity, wavelength and irradiation time, which affects the efficiency and stability of photocatalytic exhaust treatment technology.

[0004] In summary, the existing automobile exhaust treatment technology has many shortcomings in terms of the accuracy and real-time detection of exhaust components, the control of photocatalytic reaction conditions, and the overall treatment efficiency. It is urgent to develop a more efficient, accurate and reliable automobile exhaust treatment technology. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a photocatalytic automobile exhaust treatment method.

[0006] Step 1: Establish an exhaust gas composition detection system, install sensors at the rear of the car, and monitor the concentration of pollutants such as carbon monoxide, hydrocarbons and nitrogen oxides in the exhaust gas in real time.

[0007] Step 2: Construct a photocatalytic reaction kinetic model, comprehensively consider multiple factors such as light absorption, excitation, free radical generation, and diffusion and reaction of exhaust components, and determine the optimal photocatalytic treatment conditions through numerical simulation.

[0008] Step 3: Implement photocatalyst activity control and light condition optimization strategies, and use intelligent control systems to dynamically adjust key parameters such as photocatalyst loading, particle size, light intensity, wavelength, and irradiation time to maximize exhaust gas treatment efficiency.

[0009] Step 4: Implement real-time monitoring and feedback of exhaust gas composition, use sensors to provide real-time feedback of exhaust gas information, and combine with intelligent control systems to dynamically adjust photocatalysts and lighting conditions to adapt to changes in exhaust gas composition.

[0010] Step 5: Real-time monitoring and adjustment. The wireless communication system provides real-time exhaust treatment monitoring capabilities, allowing the operator to remotely adjust the photocatalyst and lighting conditions according to the exhaust treatment situation to achieve the optimal exhaust treatment effect.

[0011] As a further improvement of the present invention, the process of establishing the exhaust gas component detection system in step 1 is expressed as follows:

[0012] Step 1.1: Install the carbon monoxide sensor, hydrocarbon sensor, and nitrogen oxide sensor; for the carbon monoxide sensor, select an electrochemical carbon monoxide sensor, which uses the redox reaction of carbon monoxide on the electrode surface to generate an electrical signal to measure the concentration; for the hydrocarbon sensor, select a sensor based on the semiconductor principle, which detects the concentration by the change of its electrical properties caused by the adsorption of hydrocarbon gas on the semiconductor surface; for the nitrogen oxide sensor, select an electrochemical nitrogen oxide sensor based on zirconium oxide, which relies on the electrochemical activity of nitrogen oxides in a specific electrode and electrolyte environment to measure the concentration;

[0013] Step 1.2: When installing the sensor, the installation position should be able to fully contact the exhaust gas, and avoid excessive interference from external environmental factors and the movement of the vehicle's own mechanical parts; choose to install it in a relatively flat area near the exhaust pipe outlet, and ensure that the sensor's detection head is accurately aligned with the exhaust direction, so that the most representative exhaust gas sample can be obtained in real time for concentration monitoring;

[0014] Step 1.3: Build a data acquisition and transmission module. The data acquisition module is responsible for receiving the electrical signals from the sensor and converting these analog electrical signals into digital signals for subsequent processing and analysis. It also transmits the collected exhaust pollutant concentration data to the corresponding processing system in real time, thereby realizing real-time monitoring of the concentrations of pollutants such as carbon monoxide, hydrocarbons and nitrogen oxides in the exhaust gas.

[0015] As a further improvement of the present invention, the photocatalyst activity control strategy in step 3 is expressed as follows:

[0016] Load optimization formula:

[0017] r=k1·m n

[0018] Among them, r represents the photocatalytic reaction rate, k1 is a constant related to the properties of the photocatalyst itself and the reaction conditions, m is the photocatalyst loading, and n is an index. In practical applications, the intelligent control system continuously changes the value of m, monitors the changes in r, and optimizes the loading.

[0019] Particle size adjustment formula:

[0020]

[0021] Among them, r is the photocatalytic reaction rate, k2 is a constant, d represents the photocatalyst particle size, and m is an index related to light scattering and quantum size effect; the intelligent control system maximizes r by adjusting the value of d to achieve optimal adjustment of particle size.

[0022] Intensity adjustment formula:

[0023] r=k3·I

[0024] Among them, r represents the photocatalytic reaction rate, k3 is a constant related to the quantum efficiency of the photocatalyst and the reaction system, and I is the light intensity. The intelligent control system monitors the change of r by changing the value of I, maximizes r, and optimizes the light intensity.

[0025] Wavelength selection formula:

[0026] r=k4·f(λ)

[0027] Where f(λ) is a wavelength function that must satisfy r is the photocatalytic reaction rate, k4 is a constant, λ is the wavelength of light, h is Planck's constant, c is the speed of light, E g is the bandgap width of the photocatalyst; the intelligent control system selects the appropriate λ according to the absorption spectrum and photon energy of the photocatalyst to make the f(λ) value larger, thereby improving the efficiency of the photocatalytic reaction and optimizing the illumination wavelength;

[0028] Time control formula:

[0029]

[0030] Wherein, C represents the pollutant concentration in the exhaust gas, C0 is the initial pollutant concentration, k5 is the reaction rate constant, and t is the irradiation time; the intelligent control system monitors the change of C in real time, adjusts the value according to the specific situation, and makes it reach the minimum in the shortest time, thereby optimizing the irradiation time.

[0031] As a further improvement of the present invention, the application of the photocatalyst activity control strategy in step 3 is expressed as follows:

[0032] Load optimization: The controller uses the preset photocatalytic reaction rate formula r = k1·m n In the early stage of system operation, the loading amount m of the photocatalyst is gradually changed, while the change of the photocatalytic reaction rate r is monitored; the gas sensor in the sensor module is used to detect the change of the pollutant concentration in the exhaust gas in real time, thereby indirectly reflecting the photocatalytic reaction rate r; after multiple experiments and data collection, the optimal loading amount range that makes the reaction rate r reach the maximum value is determined, and in the subsequent operation process, the loading amount m is dynamically adjusted within this range according to the actual situation;

[0033] On the vehicle, the load adjustment actuator integrates a catalyst storage tank, a metering pump and a spraying device, etc.; if the carbon monoxide concentration is high and the current photocatalytic treatment efficiency is low, the control system needs to increase the photocatalyst load, and vice versa, if the pollutant concentration is low, the load needs to be reduced; when the intelligent control system issues an instruction to adjust the load, the metering pump accurately extracts an appropriate amount of catalyst solution from the storage tank according to the instruction, and then sprays the solution evenly on the carrier surface of the photocatalytic reactor through the spraying device; the spraying device uses a micro nozzle, and by adjusting the nozzle aperture, spraying pressure, spraying time and other parameters, the photocatalyst load can be precisely controlled;

[0034] Particle size adjustment: Based on the formula The controller first determines the constant k2 and exponent m under specific photocatalyst materials and reaction conditions through experiments; during operation, the particle size d information of the photocatalyst is obtained in real time according to the preparation process parameters of the photocatalyst; then, the expected reaction rate r under different particle sizes d is calculated according to the formula and compared with the actual measured reaction rate; the particle size d of the photocatalyst is kept within the optimal range that can maximize the reaction rate r through graded screening;

[0035] Photocatalysts of different particle sizes may have different treatment effects on different exhaust gas components. Through the exhaust gas composition information fed back by the sensor, the intelligent control system can analyze which particle size of photocatalyst has the best treatment effect on the main pollutants, and thus adjust the particle size optimization actuator to keep the particle size of the photocatalyst within the range that is most conducive to treating the current exhaust gas components. Due to the limited space in the vehicle, the particle size optimization actuator adopts a combination of a miniaturized ultrasonic disperser and a micro-nano particle classifier. The ultrasonic disperser continues to operate after the vehicle is started, and performs real-time ultrasonic dispersion of the photocatalyst to prevent particle agglomeration and refine the particles. The micro-nano particle classifier performs real-time classification and screening of the photocatalyst particles after ultrasonic dispersion according to the particle size range set by the intelligent control system, separates the particles that do not meet the particle size requirements and returns them to the ultrasonic disperser for further processing, ensuring that the particle size of the photocatalyst particles entering the photocatalytic reactor is always maintained within the optimal range.

[0036] Intensity adjustment: The controller monitors the light intensity I in real time through the light sensor according to the formula r=k3·I; during the operation of the system, the power of the light source and other parameters are gradually adjusted to change the light intensity I; in actual operation, the controller automatically adjusts the light source power according to the comparison result between the real-time monitored light intensity I and the optimal range, so that the light intensity is always kept within the optimal range;

[0037] When the sensor detects that the concentration of pollutants in the exhaust gas is high, the light intensity needs to be increased to stimulate more photocatalysts to produce free radicals, thereby increasing the rate of the photocatalytic reaction; the intensity adjustment actuator adopts a closed-loop control system consisting of an LED light source with adjustable power and a light intensity sensor; the LED light source is installed around the photocatalytic reactor to provide light for the photocatalytic reaction; the light intensity sensor monitors the light intensity in real time and feeds the monitoring data back to the intelligent control system; the intelligent control system changes the light intensity by adjusting the driving current of the LED light source according to the exhaust gas treatment situation and the preset light intensity requirements;

[0038] Wavelength selection: For the formula r = k4·f(λ), f(λ) must satisfy The controller first determines the bandgap E of the selected photocatalyst according to its material properties. g ; Then, the light absorption at different wavelengths λ, i.e., the value of f(λ), is obtained through the pre-stored photocatalyst absorption spectrum data; the expected reaction rate r at different wavelengths is calculated according to the formula, and the optimal wavelength λ that can maximize the reaction rate r is selected in combination with the actual experimental results;

[0039] Different exhaust gas components have different absorption and reaction efficiencies for light of different wavelengths; the sensor monitors the exhaust gas composition in real time, and the intelligent control system selects the most suitable illumination wavelength according to the changes in the exhaust gas composition; the wavelength selection actuator can use a liquid crystal tunable filter LCTF to achieve the selection of the illumination wavelength; the LCTF is installed in the light path between the light source and the photocatalytic reactor, and the intelligent control system sends a control signal to the LCTF according to the absorption spectrum of the photocatalyst and the optimal wavelength requirements for exhaust gas treatment, adjusts the transmission wavelength of the LCTF, and allows light of a specific wavelength to pass through and irradiate the photocatalyst, which can quickly and flexibly achieve wavelength switching;

[0040] Time control: According to the formula The controller records the initial concentration C0 of pollutants in the exhaust gas when the system is started, and monitors the changes in the pollutant concentration C in real time through the gas sensor; during operation, the irradiation time t required to achieve the expected treatment effect is calculated using the formula based on the real-time monitored pollutant concentration C and the known reaction rate constant k5; at the same time, the optimal irradiation time t is comprehensively determined in combination with factors such as the activity change and energy consumption of the photocatalyst; the controller controls the on and off time of the light source based on the calculation results to ensure that the best exhaust gas treatment effect is achieved in the shortest time, while avoiding problems such as deactivation of the photocatalyst or side reactions due to long-term irradiation;

[0041] The irradiation time optimization actuator is composed of a timer and a light switch in the vehicle's electronic control unit ECU; the intelligent control system sends the preset irradiation time parameters to the vehicle ECU, and the timer in the ECU controls the opening and closing of the light switch according to these parameters; when the vehicle starts and stops, the timer automatically adjusts the illumination time according to the actual situation to ensure that the irradiation time of the photocatalytic reaction is always kept within the optimal range during the operation of the vehicle, while avoiding unnecessary energy consumption and loss of photocatalyst when the vehicle stops.

[0042] The present invention provides a photocatalytic automobile exhaust treatment method, with beneficial effects: the technical effects of the present invention are:

[0043] 1. In terms of exhaust gas component detection, the present invention can obtain the concentration information of pollutants in the exhaust gas in real time and accurately by installing a variety of high-precision sensors and selecting suitable installation locations, as well as building an efficient data acquisition and transmission module, providing a reliable data basis for subsequent processing and helping to promptly discover abnormal exhaust emissions.

[0044] 2. The photocatalyst activity control and illumination condition optimization strategy implemented in the present invention dynamically adjusts key parameters such as loading amount, particle size, light intensity, wavelength and irradiation time through an intelligent control system, so that the photocatalytic reaction can be carried out under optimal conditions, greatly improving the effect and stability of exhaust gas treatment.

[0045] 3. The real-time monitoring and adjustment function realized by the wireless communication system of the present invention enables the operator to remotely and flexibly optimize the photocatalyst and lighting conditions, which not only improves the convenience of operation, but also ensures that the optimal exhaust gas treatment effect is always achieved, thereby effectively reducing the pollution of automobile exhaust to the environment and protecting human health and ecological balance. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a flow chart of the present invention.

[0047] Figure 2 It is a schematic diagram of the test equipment of the present invention. DETAILED DESCRIPTION

[0048] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0049] The present invention aims at automobile exhaust treatment, establishes an accurate and real-time exhaust component detection system, constructs a photocatalytic reaction kinetic model, implements a photocatalyst and light condition optimization strategy, monitors and feedbacks exhaust components in real time, effectively improves exhaust treatment efficiency, reduces pollution, and protects the environment and health. The invention flow chart is as follows Figure 1 As shown, the steps of the present invention are described in detail below.

[0050] Step 1: Establish an exhaust gas composition detection system, install sensors at the rear of the car, and monitor the concentration of pollutants such as carbon monoxide, hydrocarbons and nitrogen oxides in the exhaust gas in real time.

[0051] Step 1.1: Install the carbon monoxide sensor, hydrocarbon sensor, and nitrogen oxide sensor. For the carbon monoxide sensor, select an electrochemical carbon monoxide sensor, which uses the redox reaction of carbon monoxide on the electrode surface to generate an electrical signal to measure the concentration. For the hydrocarbon sensor, select a sensor based on the semiconductor principle, which detects the concentration by changing the electrical properties caused by the adsorption of hydrocarbon gas on the semiconductor surface. For the nitrogen oxide sensor, select an electrochemical nitrogen oxide sensor based on zirconium oxide, which relies on the electrochemical activity of nitrogen oxides in a specific electrode and electrolyte environment to measure the concentration.

[0052] Step 1.2: When installing the sensor, the installation position should be able to fully contact the exhaust gas, and avoid excessive interference from external environmental factors and the movement of the vehicle's own mechanical parts. Choose to install it in a relatively flat area near the exhaust pipe outlet, and ensure that the sensor's detection head is accurately aligned with the exhaust direction, so that the most representative exhaust gas sample can be obtained in real time for concentration monitoring.

[0053] Step 1.3: Build a data acquisition and transmission module. The data acquisition module is responsible for receiving the electrical signals from the sensor and converting these analog electrical signals into digital signals for subsequent processing and analysis. It also transmits the collected exhaust pollutant concentration data to the corresponding processing system in real time, thereby realizing real-time monitoring of the concentrations of pollutants such as carbon monoxide, hydrocarbons and nitrogen oxides in the exhaust gas.

[0054] Step 2: Construct a photocatalytic reaction kinetic model, comprehensively consider multiple factors such as light absorption, excitation, free radical generation, and exhaust gas component diffusion and reaction, and determine the optimal photocatalytic treatment conditions through numerical simulation. The schematic diagram of the experimental equipment is shown in the figure. Figure 2 shown.

[0055] In the photocatalytic reaction, according to the Lambert-Beer law, there is the following relationship between absorbance (A) and light path length (l), concentration of absorbing substance (c) and molar absorption coefficient (ε):

[0056] A=ε×l×c

[0057] In the case of exhaust gas photocatalytic treatment, the photocatalyst is used as a light-absorbing substance, and its concentration is used as the effective distribution concentration of the photocatalyst in the reaction system. The optical path is related to the distance that the light irradiates the catalyst surface and propagates in the exhaust gas. The molar absorption coefficient (ε) corresponding to light of different wavelengths (λ) is different.

[0058] When light is absorbed by the photocatalyst, the electrons in the photocatalyst will jump from the valence band to the conduction band, generating electron-hole pairs. The relationship between photon energy (E), light frequency (v) and Planck constant (h) is:

[0059] E=hv

[0060] At the same time, the relationship between the frequency (v) and wavelength (λ) of light is as follows:

[0061]

[0062] Where c0 is the speed of light in vacuum, we can get:

[0063]

[0064] When the photon energy is greater than or equal to the bandgap width of the photocatalyst (E g ), electron-hole pairs can be generated, that is, E ≥ E g , that is When the appropriate light wavelength (λ) is determined, the photocatalyst can be effectively excited to generate sufficient electron-hole pairs to participate in subsequent chemical reactions.

[0065] The electron-hole pairs generated by light excitation will further react with substances adsorbed on the surface of the photocatalyst and in the surrounding environment to generate free radicals with strong oxidizing properties: hydroxyl radicals (·OH), superoxide radicals etc. Photogenerated holes (h + ) with water (H2O) or hydroxide ions (OH - ) reaction can generate hydroxyl radicals, and its generation rate (r ·OH ) and the concentration of photogenerated holes ([h + ]), the concentration of water or hydroxide ions and the related reaction rate constants (k1, k2), etc., which can be described as:

[0066] r ·OH =k1[h + ][H2O]+k2[h + ][OH - ]

[0067] Carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NO x ) need to diffuse to the surface of the photocatalyst to participate in the photocatalytic reaction. The diffusion process is described by Fick's law. For one-dimensional diffusion, the diffusion flux (J) and the diffusion coefficient (D) as well as the concentration gradient The relationship between them is:

[0068]

[0069] On the surface of the photocatalyst, pollutants react chemically with the generated free radicals, and the reaction rate of carbon monoxide and hydroxyl radicals (r CO ) and carbon monoxide concentration ([CO]), hydroxyl radical concentration ([·OH]), and reaction rate constant (k CO ) related to:

[0070] r CO =k CO [CO][·OH]

[0071] When constructing the model, the effects of load optimization, particle size adjustment, intensity regulation, wavelength selection, time control, etc. on the reaction rate should be comprehensively considered.

[0072] Step 3: Implement photocatalyst activity control and light condition optimization strategies, and use intelligent control systems to dynamically adjust key parameters such as photocatalyst loading, particle size, light intensity, wavelength, and irradiation time to maximize exhaust gas treatment efficiency.

[0073] Step 3.1: Photocatalyst activity control strategy formula

[0074] Load optimization formula:

[0075] r=k1·m n

[0076] Among them, r represents the photocatalytic reaction rate, k1 is a constant related to the properties of the photocatalyst itself and the reaction conditions, m is the photocatalyst loading, and n is an index. In practical applications, the intelligent control system continuously changes the value of m, monitors the changes in r, and optimizes the loading.

[0077] Particle size adjustment formula:

[0078]

[0079] Where r is the photocatalytic reaction rate, k2 is a constant, d represents the photocatalyst particle size, and m is an index related to light scattering and quantum size effect. The intelligent control system adjusts the value of d to maximize r and achieve optimal adjustment of particle size.

[0080] Intensity adjustment formula:

[0081] r=k3·I

[0082] Among them, r represents the photocatalytic reaction rate, k3 is a constant related to the quantum efficiency of the photocatalyst and the reaction system, and I is the light intensity. The intelligent control system monitors the change of r by changing the value of I, maximizes r, and optimizes the light intensity.

[0083] Wavelength selection formula:

[0084] r=k4·f(λ)

[0085] Where f(λ) is a wavelength function that must satisfy r is the photocatalytic reaction rate, k4 is a constant, λ is the wavelength of light, h is Planck's constant, c is the speed of light, E g is the bandgap width of the photocatalyst. The intelligent control system selects the appropriate λ according to the absorption spectrum and photon energy of the photocatalyst to make the f(λ) value larger, thereby improving the efficiency of the photocatalytic reaction and optimizing the illumination wavelength.

[0086] Time control formula:

[0087]

[0088] Among them, C represents the pollutant concentration in the exhaust gas, C0 is the initial pollutant concentration, k5 is the reaction rate constant, and t is the irradiation time. The intelligent control system monitors the changes of C in real time, adjusts the value according to the specific situation, and makes it reach the minimum in the shortest time to optimize the irradiation time.

[0089] Step 3.2: Application of photocatalyst activity control strategies

[0090] Load optimization: The controller uses the preset photocatalytic reaction rate formula r = k1·m n In the early stage of system operation, the loading amount m of the photocatalyst is gradually changed, and the change of the photocatalytic reaction rate r is monitored at the same time. The gas sensor in the sensor module is used to detect the change of the pollutant concentration in the exhaust gas in real time, thereby indirectly reflecting the photocatalytic reaction rate r. After many experiments and data collection, the optimal loading amount range that makes the reaction rate r reach the maximum value is determined, and in the subsequent operation process, the loading amount m is dynamically adjusted within this range according to the actual situation.

[0091] On the vehicle, the load adjustment actuator integrates a catalyst storage tank, a metering pump, and a spraying device. If the carbon monoxide concentration is high and the current photocatalytic treatment efficiency is low, the control system needs to increase the photocatalyst load. Conversely, if the pollutant concentration is low, the load needs to be reduced. When the intelligent control system issues an instruction to adjust the load, the metering pump accurately extracts an appropriate amount of catalyst solution from the storage tank according to the instruction, and then sprays the solution evenly on the carrier surface of the photocatalytic reactor through the spraying device. The spraying device uses a micro nozzle, and by adjusting the nozzle aperture, spraying pressure, spraying time and other parameters, the photocatalyst load can be precisely controlled.

[0092] Particle size adjustment: Based on the formula The controller first determines the constant k2 and exponent m for specific photocatalyst materials and reaction conditions through experiments. During operation, the particle size d information of the photocatalyst is obtained in real time according to the preparation process parameters of the photocatalyst. Then, the expected reaction rate r under different particle sizes d is calculated according to the formula and compared with the actual measured reaction rate. The particle size d of the photocatalyst is kept within the optimal range that maximizes the reaction rate r through graded screening.

[0093] Photocatalysts of different particle sizes may have different treatment effects on different exhaust components. Through the exhaust composition information fed back by the sensor, the intelligent control system can analyze which particle size of photocatalyst has the best treatment effect on the main pollutants, and then adjust the particle size optimization actuator to keep the particle size of the photocatalyst within the range that is most conducive to treating the current exhaust components. Due to the limited space in the vehicle, the particle size optimization actuator adopts a combination of a miniaturized ultrasonic disperser and a micro-nano particle classifier. The ultrasonic disperser continues to operate after the vehicle is started, and performs real-time ultrasonic dispersion of the photocatalyst to prevent particle agglomeration and refine the particles. The micro-nano particle classifier performs real-time classification and screening of the ultrasonically dispersed photocatalyst particles according to the particle size range set by the intelligent control system, separates the particles that do not meet the particle size requirements and returns them to the ultrasonic disperser for further processing, ensuring that the particle size of the photocatalyst particles entering the photocatalytic reactor always remains within the optimal range.

[0094] Intensity adjustment: The controller monitors the light intensity I in real time through the light sensor according to the formula r=k3·I. During the operation of the system, the power and other parameters of the light source are gradually adjusted to change the light intensity I. In actual operation, the controller automatically adjusts the light source power according to the comparison result of the real-time monitored light intensity I with the optimal range, so that the light intensity is always kept within the optimal range.

[0095] When the sensor detects a high concentration of pollutants in the exhaust gas, it is necessary to increase the light intensity to stimulate more photocatalysts to produce free radicals, thereby increasing the rate of the photocatalytic reaction. The intensity adjustment actuator adopts a closed-loop control system consisting of an LED light source with adjustable power and a light intensity sensor. The LED light source is installed around the photocatalytic reactor to provide light for the photocatalytic reaction. The light intensity sensor monitors the light intensity in real time and feeds the monitoring data back to the intelligent control system. The intelligent control system changes the light intensity by adjusting the driving current of the LED light source according to the exhaust gas treatment situation and the preset light intensity requirements.

[0096] Wavelength selection: For the formula r = k4·f(λ), f(λ) must satisfy The controller first determines the bandgap width E of the selected photocatalyst according to its material properties. g Then, the light absorption at different wavelengths λ, i.e., the value of f(λ), is obtained through the pre-stored photocatalyst absorption spectrum data. The expected reaction rate r at different wavelengths is calculated according to the formula, and the optimal wavelength λ that can maximize the reaction rate r is selected in combination with the actual experimental results.

[0097] Different exhaust gas components have different absorption and reaction efficiencies for light of different wavelengths. The sensor monitors the exhaust gas composition in real time, and the intelligent control system selects the most suitable illumination wavelength according to the changes in the exhaust gas composition. The wavelength selection actuator can use a liquid crystal tunable filter (LCTF) to achieve the selection of the illumination wavelength. The LCTF is installed in the light path between the light source and the photocatalytic reactor. The intelligent control system sends a control signal to the LCTF according to the absorption spectrum of the photocatalyst and the optimal wavelength requirements for exhaust gas treatment, adjusts the transmission wavelength of the LCTF, and allows light of a specific wavelength to pass through and irradiate the photocatalyst, which can quickly and flexibly achieve wavelength switching.

[0098] Time control: According to the formula The controller records the initial concentration C0 of pollutants in the exhaust gas when the system is started, and monitors the changes in the pollutant concentration C in real time through the gas sensor. During operation, the irradiation time t required to achieve the expected treatment effect is calculated using the formula based on the real-time monitored pollutant concentration C and the known reaction rate constant k5. At the same time, the optimal irradiation time t is comprehensively determined in combination with factors such as the activity change and energy consumption of the photocatalyst. The controller controls the on and off time of the light source based on the calculation results to ensure that the best exhaust gas treatment effect is achieved in the shortest time, while avoiding problems such as deactivation of the photocatalyst or side reactions due to long-term irradiation.

[0099] The irradiation time optimization actuator consists of a timer and a light switch in the vehicle's electronic control unit (ECU). The intelligent control system sends the preset irradiation time parameters to the vehicle ECU, and the timer in the ECU controls the opening and closing of the light switch based on these parameters. When the vehicle starts and stops, the timer automatically adjusts the irradiation time according to the actual situation to ensure that the irradiation time of the photocatalytic reaction is always kept within the optimal range during the operation of the vehicle, while avoiding unnecessary energy consumption and loss of photocatalyst when the vehicle stops.

[0100] Step 4: Implement real-time monitoring and feedback of exhaust gas composition, use sensors to provide real-time feedback of exhaust gas information, and combine with intelligent control systems to dynamically adjust photocatalysts and lighting conditions to adapt to changes in exhaust gas composition.

[0101] Step 5: Real-time monitoring and adjustment. The wireless communication system provides real-time exhaust treatment monitoring capabilities, allowing the operator to remotely adjust the photocatalyst and lighting conditions according to the exhaust treatment situation to achieve the optimal exhaust treatment effect.

[0102] The above description is only a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any modification or equivalent change made based on the technical essence of the present invention still falls within the scope of protection required by the present invention.

Claims

1. A photocatalytic automobile exhaust treatment method, comprising the following specific steps, characterized in that: Step 1: Establish an exhaust gas component detection system, install sensors at the rear of the car, and monitor the concentration of pollutants such as carbon monoxide, hydrocarbons and nitrogen oxides in the exhaust gas in real time; Step 2: Construct a photocatalytic reaction kinetic model, comprehensively consider multiple factors such as light absorption, excitation, free radical generation, and exhaust gas component diffusion and reaction, and determine the optimal photocatalytic treatment conditions through numerical simulation; Step 3: Implement photocatalyst activity control and light condition optimization strategies, and use intelligent control systems to dynamically adjust key parameters such as photocatalyst loading, particle size, light intensity, wavelength, and irradiation time to maximize exhaust gas treatment efficiency; Step 4: Implement real-time monitoring and feedback of exhaust gas composition, use sensors to feedback exhaust gas information in real time, and combine with intelligent control systems to dynamically adjust photocatalysts and lighting conditions to adapt to changes in exhaust gas composition; Step 5: Real-time monitoring and adjustment. The wireless communication system provides real-time exhaust treatment monitoring capabilities, allowing the operator to remotely adjust the photocatalyst and lighting conditions according to the exhaust treatment situation to achieve the optimal exhaust treatment effect.

2. A photocatalytic automobile exhaust treatment method according to claim 1, characterized in that: The process of establishing the exhaust gas component detection system in step 1 is expressed as: Step 1.1: Install the carbon monoxide sensor, hydrocarbon sensor, and nitrogen oxide sensor; for the carbon monoxide sensor, select an electrochemical carbon monoxide sensor, which uses the redox reaction of carbon monoxide on the electrode surface to generate an electrical signal to measure the concentration; for the hydrocarbon sensor, select a sensor based on the semiconductor principle, which detects the concentration by the change of its electrical properties caused by the adsorption of hydrocarbon gas on the semiconductor surface; for the nitrogen oxide sensor, select an electrochemical nitrogen oxide sensor based on zirconium oxide, which relies on the electrochemical activity of nitrogen oxides in a specific electrode and electrolyte environment to measure the concentration; Step 1.2: When installing the sensor, the installation position should be able to fully contact the exhaust gas, and avoid excessive interference from external environmental factors and the movement of the vehicle's own mechanical parts; choose to install it in a relatively flat area near the exhaust pipe outlet, and ensure that the sensor's detection head is accurately aligned with the exhaust direction, so that the most representative exhaust gas sample can be obtained in real time for concentration monitoring; Step 1.3: Build a data acquisition and transmission module. The data acquisition module is responsible for receiving the electrical signals from the sensor and converting these analog electrical signals into digital signals for subsequent processing and analysis. It also transmits the collected exhaust pollutant concentration data to the corresponding processing system in real time, thereby realizing real-time monitoring of the concentrations of pollutants such as carbon monoxide, hydrocarbons and nitrogen oxides in the exhaust gas.

3. A photocatalytic automobile exhaust treatment method according to claim 1, characterized in that: The photocatalyst activity control strategy in step 3 is expressed as follows: Load optimization formula: r=k1·m n Among them, r represents the photocatalytic reaction rate, k1 is a constant related to the properties of the photocatalyst itself and the reaction conditions, m is the photocatalyst loading, and n is an index. In practical applications, the intelligent control system continuously changes the value of m, monitors the changes in r, and optimizes the loading. Particle size adjustment formula: Among them, r is the photocatalytic reaction rate, k2 is a constant, d represents the photocatalyst particle size, and m is an index related to light scattering and quantum size effect; the intelligent control system maximizes r by adjusting the value of d to achieve optimal adjustment of particle size. Intensity adjustment formula: r=k3·I Among them, r represents the photocatalytic reaction rate, k3 is a constant related to the quantum efficiency of the photocatalyst and the reaction system, and I is the light intensity. The intelligent control system monitors the change of r by changing the value of I, maximizes r, and optimizes the light intensity. Wavelength selection formula: r=k4·f(λ) Where f(λ) is a wavelength function that must satisfy r is the photocatalytic reaction rate, k4 is a constant, λ is the wavelength of light, h is Planck's constant, c is the speed of light, E g is the bandgap width of the photocatalyst; the intelligent control system selects the appropriate λ according to the absorption spectrum and photon energy of the photocatalyst to make the f(λ) value larger, thereby improving the efficiency of the photocatalytic reaction and optimizing the illumination wavelength; Time control formula: Wherein, C represents the pollutant concentration in the exhaust gas, C0 is the initial pollutant concentration, k5 is the reaction rate constant, and t is the irradiation time; the intelligent control system monitors the change of C in real time, adjusts the value according to the specific situation, and makes it reach the minimum in the shortest time, thereby optimizing the irradiation time.

4. A photocatalytic automobile exhaust treatment method according to claim 1, characterized in that: The application of the photocatalyst activity control strategy in step 3 is shown as follows: Load optimization: The controller uses the preset photocatalytic reaction rate formula r = k1·m n In the early stage of system operation, the loading amount m of the photocatalyst is gradually changed, while the change of the photocatalytic reaction rate r is monitored; the gas sensor in the sensor module is used to detect the change of the pollutant concentration in the exhaust gas in real time, thereby indirectly reflecting the photocatalytic reaction rate r; after multiple experiments and data collection, the optimal loading amount range that makes the reaction rate r reach the maximum value is determined, and in the subsequent operation process, the loading amount m is dynamically adjusted within this range according to the actual situation; On the vehicle, the load adjustment actuator integrates a catalyst storage tank, a metering pump and a spraying device, etc.; if the carbon monoxide concentration is high and the current photocatalytic treatment efficiency is low, the control system needs to increase the photocatalyst load, and vice versa, if the pollutant concentration is low, the load needs to be reduced; when the intelligent control system issues an instruction to adjust the load, the metering pump accurately extracts an appropriate amount of catalyst solution from the storage tank according to the instruction, and then sprays the solution evenly on the carrier surface of the photocatalytic reactor through the spraying device; the spraying device uses a micro nozzle, and by adjusting the nozzle aperture, spraying pressure, spraying time and other parameters, the photocatalyst load can be precisely controlled; Particle size adjustment: Based on the formula The controller first experimentally determines the constant k2 and exponent m for a specific photocatalyst material and reaction conditions; During operation, the particle size d of the photocatalyst is obtained in real time according to the preparation process parameters of the photocatalyst; then, the expected reaction rate r under different particle sizes d is calculated according to the formula and compared with the actual measured reaction rate; the particle size d of the photocatalyst is kept within the optimal range that can maximize the reaction rate r through graded screening; Photocatalysts of different particle sizes may have different treatment effects on different exhaust gas components. Through the exhaust gas composition information fed back by the sensor, the intelligent control system can analyze which particle size of photocatalyst has the best treatment effect on the main pollutants, and thus adjust the particle size optimization actuator to keep the particle size of the photocatalyst within the range that is most conducive to treating the current exhaust gas components. Due to the limited space in the vehicle, the particle size optimization actuator adopts a combination of a miniaturized ultrasonic disperser and a micro-nano particle classifier. The ultrasonic disperser continues to operate after the vehicle is started, and performs real-time ultrasonic dispersion of the photocatalyst to prevent particle agglomeration and refine the particles. The micro-nano particle classifier performs real-time classification and screening of the photocatalyst particles after ultrasonic dispersion according to the particle size range set by the intelligent control system, separates the particles that do not meet the particle size requirements and returns them to the ultrasonic disperser for further processing, ensuring that the particle size of the photocatalyst particles entering the photocatalytic reactor is always maintained within the optimal range. Intensity adjustment: The controller monitors the light intensity I in real time through the light sensor according to the formula r=k3·I; During the operation of the system, the power and other parameters of the light source are gradually adjusted to change the light intensity I. In actual operation, the controller automatically adjusts the light source power according to the comparison result between the real-time monitored light intensity I and the optimal range, so that the light intensity is always kept within the optimal range. When the sensor detects that the concentration of pollutants in the exhaust gas is high, the light intensity needs to be increased to stimulate more photocatalysts to produce free radicals, thereby increasing the rate of the photocatalytic reaction; the intensity adjustment actuator adopts a closed-loop control system consisting of an LED light source with adjustable power and a light intensity sensor; the LED light source is installed around the photocatalytic reactor to provide light for the photocatalytic reaction; the light intensity sensor monitors the light intensity in real time and feeds the monitoring data back to the intelligent control system; the intelligent control system changes the light intensity by adjusting the driving current of the LED light source according to the exhaust gas treatment situation and the preset light intensity requirements; Wavelength selection: For the formula r = k4·f(λ), f(λ) must satisfy The controller first determines the bandgap E of the selected photocatalyst according to its material properties. g ; Then, the light absorption at different wavelengths λ, i.e., the value of f(λ), is obtained through the pre-stored photocatalyst absorption spectrum data; the expected reaction rate r at different wavelengths is calculated according to the formula, and the optimal wavelength λ that can maximize the reaction rate r is selected in combination with the actual experimental results; Different exhaust gas components have different absorption and reaction efficiencies for light of different wavelengths; the sensor monitors the exhaust gas composition in real time, and the intelligent control system selects the most suitable illumination wavelength according to the changes in the exhaust gas composition; the wavelength selection actuator can use a liquid crystal tunable filter LCTF to achieve the selection of the illumination wavelength; the LCTF is installed in the light path between the light source and the photocatalytic reactor, and the intelligent control system sends a control signal to the LCTF according to the absorption spectrum of the photocatalyst and the optimal wavelength requirements for exhaust gas treatment, adjusts the transmission wavelength of the LCTF, and allows light of a specific wavelength to pass through and irradiate the photocatalyst, which can quickly and flexibly achieve wavelength switching; Time control: According to the formula The controller records the initial concentration C0 of pollutants in the exhaust gas when the system is started, and monitors the changes in the pollutant concentration C in real time through the gas sensor; during operation, the irradiation time t required to achieve the expected treatment effect is calculated using the formula based on the real-time monitored pollutant concentration C and the known reaction rate constant k5; at the same time, the optimal irradiation time t is comprehensively determined in combination with factors such as the activity change and energy consumption of the photocatalyst; the controller controls the on and off time of the light source based on the calculation results to ensure that the best exhaust gas treatment effect is achieved in the shortest time, while avoiding problems such as deactivation of the photocatalyst or side reactions due to long-term irradiation; The irradiation time optimization actuator is composed of a timer and a light switch in the vehicle's electronic control unit ECU; the intelligent control system sends the preset irradiation time parameters to the vehicle ECU, and the timer in the ECU controls the opening and closing of the light switch according to these parameters; when the vehicle starts and stops, the timer automatically adjusts the illumination time according to the actual situation to ensure that the irradiation time of the photocatalytic reaction is always kept within the optimal range during the operation of the vehicle, while avoiding unnecessary energy consumption and loss of photocatalyst when the vehicle stops.

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