A photocatalytic automobile exhaust treatment method

Abstract

A photocatalytic vehicle exhaust treatment method first establishes an exhaust composition detection system and installs multiple sensors at the rear of the vehicle to monitor exhaust pollutant concentrations in real time. A photocatalytic reaction kinetic model is constructed, and optimal photocatalytic treatment conditions are determined through numerical simulation, integrating multiple factors. A strategy for controlling photocatalyst activity and optimizing illumination conditions is implemented, utilizing an intelligent control system to dynamically adjust key parameters, including loading, particle size, illumination intensity, wavelength, and illumination time. Simultaneously, exhaust composition is monitored and feedback is provided in real time. The intelligent control system is used to dynamically adjust treatment conditions. Real-time monitoring and adjustment are achieved through a wireless communication system, enabling operators to remotely optimize treatment results and maximize exhaust treatment efficiency.

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 automotive industry and the continuous increase in the number of cars on the road, the environmental pollution caused by automobile exhaust emissions is becoming increasingly serious. Automobile exhaust contains a variety of pollutants such as carbon monoxide, hydrocarbons, and nitrogen oxides, which pose a significant threat to air quality, human health, and the ecological environment. Currently, automobile exhaust treatment technologies mainly include in-engine purification and off-engine purification. In-engine purification technology reduces pollutant generation by improving the engine's combustion process, but this method has certain limitations in reducing pollutant emissions. Off-engine purification technologies mainly include catalytic converters and particulate filters. However, when treating exhaust gas, traditional catalytic converters often have the problem that the catalyst activity is easily affected by factors such as temperature and exhaust gas composition, resulting in poor exhaust treatment results under certain operating 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 with by external environmental factors during the detection process, resulting in inaccurate detection results. In addition, the research and application of photocatalytic exhaust gas treatment technology is still in a stage of continuous development. In practical applications, existing photocatalytic technologies face 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 gas 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 the photocatalyst 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 gas treatment monitoring capabilities, allowing operators to remotely adjust the photocatalyst and lighting conditions according to the exhaust gas treatment situation to achieve the optimal exhaust gas 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, choose 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, choose a sensor based on semiconductor principles, which detects the concentration by changing the electrical properties caused by hydrocarbon gas adsorption on the semiconductor surface. For the nitrogen oxide sensor, choose a zirconium oxide-based electrochemical nitrogen oxide sensor, 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, ensure that it is fully exposed to exhaust gases while avoiding excessive interference from external environmental factors and the movement of the vehicle's mechanical components. Select a relatively flat area near the exhaust pipe outlet and ensure that the sensor's probe is accurately aligned with the exhaust gas discharge direction to obtain the most representative exhaust gas sample 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 electrical signals from sensors 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] Where 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 exponent. 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] 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 maximizes r by adjusting the value of d to achieve optimal adjustment of particle size.

[0022] Intensity adjustment formula:

[0023] r=k3·I

[0024] Where 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 optimizes light intensity by changing the value of I and monitoring the changes in r to maximize r.

[0025] Wavelength selection formula:

[0026] r=k4·f(λ)

[0027] Where f(λ) is the wavelength function and 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 band gap width of the photocatalyst; the intelligent control system selects the appropriate λ according to the absorption spectrum of the photocatalyst and the photon energy, so that the f(λ) value is larger, thereby improving the efficiency of the photocatalytic reaction and optimizing the illumination wavelength;

[0028] Time control formula:

[0029]

[0030] 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 reaches the lowest value in the shortest time to achieve optimization of 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 initial stage of system operation, the photocatalyst loading amount m is gradually changed while monitoring the changes in the photocatalytic reaction rate r. The gas sensor in the sensor module detects the changes in the concentration of pollutants 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 for achieving the maximum reaction rate r is determined. During subsequent operation, the loading amount m is dynamically adjusted within this range according to actual conditions.

[0033] 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 onto the carrier surface of the photocatalytic reactor through the spraying device. The spraying device uses a micro nozzle, and by adjusting parameters such as the nozzle aperture, spraying pressure, and spraying time, precise control of the photocatalyst load is achieved.

[0034] Particle size adjustment: Based on the formula The controller first experimentally determines the constant k2 and exponent m for specific photocatalyst materials and reaction conditions. During operation, it obtains information on the photocatalyst particle size d in real time based on the photocatalyst preparation process parameters. It then calculates the expected reaction rate r for different particle sizes d using a formula and compares it with the actual measured reaction rate. Through graded screening, the photocatalyst particle size d is maintained within the optimal range that maximizes the reaction rate r.

[0035] 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 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 components. Due to limited vehicle space, 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, performing 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 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.

[0036] Intensity adjustment: The controller uses the formula r = k3·I to monitor the light intensity I in real time through the light sensor. During system operation, the controller gradually adjusts the power of the light source and other parameters to change the light intensity I. In actual operation, the controller automatically adjusts the light source power based on the comparison between the real-time monitored light intensity I and the optimal range to ensure that the light intensity always remains within the optimal range.

[0037] When the sensor detects a high concentration of pollutants in the exhaust gas, it needs 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 uses a closed-loop control system consisting of an adjustable-power LED light source 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 status 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 band gap 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 by using 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 maximizes the reaction rate r is selected based on the actual experimental results.

[0039] Different exhaust gas components have different absorption and reaction efficiencies for light of different wavelengths. Sensors monitor exhaust gas composition in real time, and the intelligent control system selects the most suitable illumination wavelength based on changes in exhaust gas composition. A wavelength selection actuator can use a liquid crystal tunable filter (LCTF) to select the illumination wavelength. The LCTF is installed in the light path between the light source and the photocatalytic reactor. Based on the absorption spectrum of the photocatalyst and the optimal wavelength requirements for exhaust gas treatment, the intelligent control system sends a control signal to the LCTF, adjusting the LCTF's transmission wavelength to allow light of a specific wavelength to pass through and illuminate the photocatalyst, enabling rapid and flexible wavelength switching.

[0040] Time control: According to the formula When the system starts, the controller records the initial concentration C0 of pollutants in the exhaust gas and monitors the changes in the pollutant concentration C in real time through gas sensors. During operation, the controller uses a formula to calculate the irradiation time t required to achieve the desired treatment effect 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 based on factors such as the activity change of the photocatalyst and energy consumption. The controller controls the on and off time of the light source based on the calculated results to ensure the best exhaust gas treatment effect in the shortest time while avoiding problems such as photocatalyst deactivation or side reactions due to long-term irradiation.

[0041] 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 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 actual conditions, ensuring that the irradiation time of the photocatalytic reaction always remains within the optimal range during vehicle operation, while avoiding unnecessary energy consumption and loss of photocatalyst when the vehicle is stopped.

[0042] The present invention provides a photocatalytic automobile exhaust treatment method, which has the following beneficial effects:

[0043] 1. In terms of exhaust gas composition 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 proceed under optimal conditions, greatly improving the effect and stability of exhaust gas treatment.

[0045] 3. The real-time monitoring and adjustment functions achieved by the wireless communication system of the present invention allow operators to remotely and flexibly optimize the photocatalyst and lighting conditions. This not only improves the convenience of operation, but also ensures that the optimal exhaust 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 Flowchart of the present invention.

[0047] Figure 2 Schematic diagram of the test equipment of the present invention. DETAILED DESCRIPTION

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

[0049] The present invention aims at automobile exhaust treatment, establishes an accurate and real-time exhaust gas component detection system, constructs a photocatalytic reaction kinetic model, implements a photocatalyst and light condition optimization strategy, monitors and provides feedback on exhaust gas components in real time, effectively improves exhaust gas 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, choose an electrochemical carbon monoxide sensor. This uses the redox reaction of carbon monoxide on the electrode surface to generate an electrical signal to measure concentration. For the hydrocarbon sensor, choose a semiconductor-based sensor. This detects concentration by observing changes in the electrical properties of the semiconductor surface caused by hydrocarbon gas adsorption. For the nitrogen oxide sensor, choose a zirconium oxide-based electrochemical nitrogen oxide sensor. This sensor uses the electrochemical activity of nitrogen oxides in a specific electrode and electrolyte environment to measure concentration.

[0052] Step 1.2: When installing the sensor, ensure it is in sufficient contact with exhaust gases while avoiding excessive interference from external environmental factors and the movement of the vehicle's mechanical components. Choose a relatively flat area near the exhaust pipe outlet and ensure the sensor's probe is accurately aligned with the exhaust gas discharge direction to obtain the most representative exhaust gas sample 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 electrical signals from sensors 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 photocatalytic reactions, according to the Lambert-Beer law, the following relationship exists between absorbance (A) and the optical path length (l), the concentration of the absorbing substance (c), and the molar absorptivity (ε):

[0056] A=ε×l×c

[0057] In the case of exhaust gas photocatalytic treatment, the photocatalyst acts as a light-absorbing substance, and its concentration is the effective distribution concentration of the photocatalyst in the reaction system. The optical path length is related to the distance that light travels from the catalyst surface to the exhaust gas. Light of different wavelengths (λ) corresponds to different molar absorptivity coefficients (ε).

[0058] When light is absorbed by a photocatalyst, electrons in the photocatalyst jump from the valence band to the conduction band, generating electron-hole pairs. The relationship between photon energy (E), the frequency of light (v), and Planck's 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 band gap 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, generating 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 the surrounding environment to generate free radicals with strong oxidizing properties: hydroxyl radicals (·OH), superoxide radicals etc. Using 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 are 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 ), namely:

[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] Here, r represents the photocatalytic reaction rate, k1 is a constant related to the properties of the photocatalyst and reaction conditions, m is the photocatalyst loading, and n is an exponent. In practical applications, an intelligent control system continuously adjusts the value of m and monitors changes in r to optimize 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] Here, 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 optimizes light intensity by varying the value of I and monitoring changes in r to maximize r.

[0083] Wavelength selection formula:

[0084] r=k4·f(λ)

[0085] Where f(λ) is the wavelength function and 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 The intelligent control system selects the appropriate λ according to the absorption spectrum and photon energy of the photocatalyst to maximize the f(λ) value, thereby improving the efficiency of the photocatalytic reaction and optimizing the illumination wavelength.

[0086] Time control formula:

[0087]

[0088] Where 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 in C in real time and adjusts the value according to the specific situation to achieve the lowest value in the shortest time, thereby optimizing 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 During the initial system operation, the photocatalyst loading m was gradually varied while simultaneously monitoring the photocatalytic reaction rate r. The gas sensor in the sensor module monitored changes in exhaust pollutant concentrations in real time, indirectly reflecting the photocatalytic reaction rate r. After multiple experiments and data collection, the optimal loading range for maximizing the reaction rate r was determined. During subsequent operation, the loading m was dynamically adjusted within this range based on actual conditions.

[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 a command to adjust the load, the metering pump accurately extracts the appropriate amount of catalyst solution from the storage tank according to the command, and then uses the spraying device to evenly spray the solution onto the carrier surface of the photocatalytic reactor. The spraying device uses a micro nozzle, and by adjusting parameters such as the nozzle aperture, spraying pressure, and spraying time, precise control of the photocatalyst load is achieved.

[0092] Particle size adjustment: Based on the formula The controller first experimentally determines the constant k² and exponent m for specific photocatalyst materials and reaction conditions. During operation, it acquires real-time information on the photocatalyst particle size d based on the photocatalyst preparation process parameters. It then calculates the expected reaction rate r for different particle sizes d using a formula and compares it with the actual measured reaction rate. Through graded screening, the photocatalyst particle size d is maintained within the optimal range that maximizes the reaction rate r.

[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 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 components. Due to 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 run after the vehicle is started, performing 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 uses the formula r = k³·I to monitor the light intensity I in real time through a light sensor. During system operation, it gradually adjusts parameters such as the light source power to change the light intensity I. In actual operation, the controller automatically adjusts the light source power based on the comparison of the real-time monitored light intensity I with the optimal range, ensuring that the light intensity remains within the optimal range.

[0095] When the sensor detects high concentrations of pollutants in the exhaust, it increases the light intensity to stimulate more photocatalysts to produce free radicals, thereby increasing the rate of the photocatalytic reaction. The intensity adjustment actuator utilizes a closed-loop control system consisting of an adjustable-power LED light source 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 this data back to the intelligent control system. The intelligent control system adjusts the light intensity by adjusting the LED drive current based on the exhaust treatment status 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 band gap E of the selected photocatalyst according to its material properties. g Then, using pre-stored photocatalyst absorption spectrum data, the light absorption at different wavelengths λ, i.e., the value of f(λ), is obtained. The expected reaction rate r at different wavelengths is calculated using the formula, and combined with actual experimental results, the optimal wavelength λ that maximizes the reaction rate r is selected.

[0097] Different exhaust gas components have different absorption and reaction efficiencies for light of different wavelengths. Sensors monitor exhaust gas composition in real time, and the intelligent control system selects the most suitable illumination wavelength based on changes in exhaust gas composition. The wavelength selection actuator can use a liquid crystal tunable filter (LCTF) to select the illumination wavelength. The LCTF is installed in the light path between the light source and the photocatalytic reactor. Based on the absorption spectrum of the photocatalyst and the optimal wavelength requirements for exhaust gas treatment, the intelligent control system sends a control signal to the LCTF, adjusting the LCTF's transmission wavelength to allow light of a specific wavelength to pass through and illuminate the photocatalyst, enabling rapid and flexible wavelength switching.

[0098] Time control: According to the formula At system startup, the controller records the initial exhaust pollutant concentration, C0, and uses gas sensors to monitor changes in pollutant concentration, C, in real time. During operation, the controller calculates the irradiation time, t, required to achieve the desired treatment effect based on the real-time monitored pollutant concentration, C, and the known reaction rate constant, k5. The optimal irradiation time, t, is determined by combining factors such as the photocatalyst's activity and energy consumption. Based on this calculation, the controller controls the light source's on and off times to ensure optimal exhaust gas treatment results in the shortest possible time while preventing issues such as photocatalyst deactivation or side reactions caused by prolonged 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 transmits preset irradiation time parameters to the vehicle's ECU, and the timer in the ECU uses these parameters to control the light switch's on and off state. When the vehicle starts and stops, the timer automatically adjusts the irradiation time based on actual conditions, ensuring that the irradiation time for the photocatalytic reaction remains within the optimal range while the vehicle is in operation, while also avoiding unnecessary energy consumption and loss of photocatalyst when the vehicle is stopped.

[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 the photocatalyst 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 gas treatment monitoring capabilities, allowing operators to remotely adjust the photocatalyst and lighting conditions according to the exhaust gas treatment situation to achieve the optimal exhaust gas treatment effect.

[0102] The above description is merely a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any modification or equivalent variation based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. A photocatalytic automobile exhaust treatment method, comprising the following steps, characterized in that: Step 1: Establish an exhaust gas composition detection system and install sensors at the rear of the vehicle to 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 considering multiple factors such as light absorption, excitation, free radical generation, and the diffusion and reaction of exhaust components, and determine the optimal photocatalytic treatment conditions through numerical simulation; Step 3: Implement a strategy to control photocatalyst activity and optimize illumination conditions, using an intelligent control system to dynamically adjust key parameters such as photocatalyst loading, particle size, illumination intensity, wavelength, and illumination time to maximize exhaust gas treatment efficiency. Step 4: Implement real-time monitoring and feedback of exhaust gas composition. Sensors provide real-time feedback of exhaust gas information, and combined with an intelligent control system, dynamically adjust the photocatalyst 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 gas treatment monitoring capabilities, allowing operators to remotely adjust the photocatalyst and lighting conditions according to the exhaust gas treatment situation to achieve the optimal exhaust gas treatment effect.

2. The photocatalytic automobile exhaust treatment method according to claim 1, characterized in that: The process of establishing the exhaust gas composition detection system in step 1 is expressed as follows: Step 1.1: Install the carbon monoxide sensor, hydrocarbon sensor, and nitrogen oxide sensor. For the carbon monoxide sensor, choose 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, choose a sensor based on semiconductor principles, which detects the concentration by changing the electrical properties caused by hydrocarbon gas adsorption on the semiconductor surface. For the nitrogen oxide sensor, choose a zirconium oxide-based electrochemical nitrogen oxide sensor, 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, ensure that it is fully exposed to exhaust gases while avoiding excessive interference from external environmental factors and the movement of the vehicle's mechanical components. Select a relatively flat area near the exhaust pipe outlet and ensure that the sensor's probe is accurately aligned with the exhaust gas discharge direction to obtain the most representative exhaust gas sample in real time for concentration monitoring. Step 1.3: Build a data acquisition and transmission module. The data acquisition module is responsible for receiving electrical signals from sensors 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. The 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 Where 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 exponent. 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: 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 maximizes r by adjusting the value of d, thereby optimizing the particle size. Intensity adjustment formula: r=k3·I Where 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 optimizes light intensity by changing the value of I and monitoring the changes in r to maximize r. Wavelength selection formula: r=k4·f(λ) Where f(λ) is the wavelength function and 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 band gap width of the photocatalyst; the intelligent control system selects the appropriate λ according to the absorption spectrum of the photocatalyst and the photon energy, so that the f(λ) value is larger, thereby improving the efficiency of the photocatalytic reaction and optimizing the illumination wavelength; Time control formula: 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 reaches the lowest value in the shortest time to achieve optimization of the irradiation time.

4. The 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 initial stage of system operation, the photocatalyst loading amount m is gradually changed while monitoring the changes in the photocatalytic reaction rate r. The gas sensor in the sensor module detects the changes in the concentration of pollutants 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 for achieving the maximum reaction rate r is determined. During subsequent operation, the loading amount m is dynamically adjusted within this range according to actual conditions. 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 onto the carrier surface of the photocatalytic reactor through the spraying device. The spraying device uses a micro nozzle, and by adjusting parameters such as the nozzle aperture, spraying pressure, and spraying time, precise control of the photocatalyst load is achieved. 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 based on the preparation process parameters of the photocatalyst. Then, the expected reaction rate r at different particle sizes d is calculated according to a formula and compared with the actual measured reaction rate. Through graded screening, the particle size d of the photocatalyst is maintained within the optimal range that maximizes the reaction rate r. 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 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 components. Due to limited vehicle space, 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, performing 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 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. 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 based on the comparison results of the real-time monitored light intensity I with the optimal range, so that the light intensity is always kept within the optimal range. When the sensor detects a high concentration of pollutants in the exhaust gas, it needs 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 uses a closed-loop control system consisting of an adjustable-power LED light source 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 status and the preset light intensity requirements. Wavelength selection: For the formula r = k4·f(λ), f(λ) must satisfy The controller first determines the band gap 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 by using 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 maximizes the reaction rate r is selected based on the actual experimental results. Different exhaust gas components have different absorption and reaction efficiencies for light of different wavelengths. Sensors monitor exhaust gas composition in real time, and the intelligent control system selects the most suitable illumination wavelength based on changes in exhaust gas composition. A wavelength selection actuator can use a liquid crystal tunable filter (LCTF) to select the illumination wavelength. The LCTF is installed in the light path between the light source and the photocatalytic reactor. Based on the absorption spectrum of the photocatalyst and the optimal wavelength requirements for exhaust gas treatment, the intelligent control system sends a control signal to the LCTF, adjusting the LCTF's transmission wavelength to allow light of a specific wavelength to pass through and illuminate the photocatalyst, enabling rapid and flexible wavelength switching. Time control: According to the formula When the system starts, the controller records the initial concentration C0 of pollutants in the exhaust gas and monitors the changes in the pollutant concentration C in real time through gas sensors. During operation, the controller uses a formula to calculate the irradiation time t required to achieve the desired treatment effect 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 based on factors such as the activity change of the photocatalyst and energy consumption. The controller controls the on and off time of the light source based on the calculated results to ensure the best exhaust gas treatment effect in the shortest time while avoiding problems such as photocatalyst deactivation or side reactions due to long-term irradiation. 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 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 actual conditions, ensuring that the irradiation time of the photocatalytic reaction always remains within the optimal range during vehicle operation, while avoiding unnecessary energy consumption and loss of photocatalyst when the vehicle is stopped.

Images