A precise calculation method and system for RTO air volume of a color coating production line

Abstract

The application discloses a kind of RTO air volume accurate calculation method and system of color coating production line, the method is first according to the process parameters of color coating production line Calculation solvent usage per hour, combined with paint solvent component proportion accounting LEL value, then collect each process exhaust key parameters, get real-time operating condition air volume by standard condition-process dynamic conversion model, combined with the national standard requirement of RTO entrance LEL≤25% And RTO thermal efficiency requirement carries out double check, finally output optimal air volume control value;Matching system includes parameter acquisition module, calculation processing module and execution adjustment module, can realize the real-time dynamic optimization of quantity;The application has high calculation precision, can ensure that RTO exhaust gas treatment efficiency is greater than or equal to 98.5%, while reducing fan energy consumption by more than 30%, meet the requirement of GB 16297-1996 revised edition VOCs emission≤30mg / m³ And RTO entrance LEL≤25%, applicable to the design and operation control of various color coating production line RTO system.

Description

Technical Field

[0001] This invention belongs to the field of industrial waste gas treatment technology, specifically relating to a method and system for accurate calculation of RTO air volume in a color coating production line. Background Technology

[0002] Color coating production lines generate a large amount of VOC-containing waste gas during pretreatment, coating, and baking processes. The main pollutants include toluene, xylene, ethyl acetate, and non-methane hydrocarbons. This type of waste gas needs to be treated by high-temperature oxidation (RTO) equipment to meet environmental emission requirements. The treatment effect and operating energy consumption of the RTO equipment directly depend on the accuracy of the air volume calculation. Excessive air volume can lead to a decrease in furnace temperature, insufficient waste gas residence time, and a decline in VOC removal efficiency; insufficient air volume may cause VOC concentrations to exceed standards, local overheating of the furnace, and even safety hazards.

[0003] In existing technologies, the calculation of RTO airflow in color coating production lines has several shortcomings: First, there is a common problem of confusing standard conditions with operating conditions. The standard airflow used for environmental accounting is directly used as the basis for equipment selection and operation, ignoring the impact of exhaust gas temperature and pressure on the actual operating airflow. This leads to a mismatch between the RTO's processing capacity and actual needs. For example, a coating company selected an RTO based on a standard airflow of 20,000 Nm³ / h. Because the volume expansion of exhaust gas at 80°C was not considered, the actual operating airflow reached 25,900 m³ / h, causing the VOCs removal efficiency to plummet from 98% to below 85%. Second, the calculation process does not fully consider the differences in exhaust gas characteristics among various color coating processes. The exhaust gas concentration in the coating room is high, but the airflow is large, while the exhaust gas in the baking oven has a large airflow but a low concentration. Traditional weighted averaging... The method is difficult to achieve precise coupling; third, it does not meet the national standard requirements for RTO design, lacks precise verification of the LEL concentration at the RTO inlet ≤25%, and does not calculate the mixed LEL value of paint solvents based on the characteristics of paint solvents in the color coating line, resulting in deviations in the calculation of safety thresholds and potential safety hazards; fourth, it does not consider the dynamic changes in solvent usage in the color coating production line, ignores the changes in the solid-solid mass ratio caused by the addition of thinner when the paint is applied to the machine, and cannot dynamically adjust the air volume according to the amount of solvent used, resulting in poor adaptability; fifth, the existing calculation methods are mostly static calculations, which cannot adapt to the dynamic changes in exhaust gas parameters caused by fluctuations in production line load. The fans are often in a full-load operation state, resulting in high energy consumption. The electricity and natural gas costs of the fans account for more than 60% of the company's environmental protection costs.

[0004] Furthermore, with increasingly stringent environmental regulations, the revised "Integrated Emission Standard of Air Pollutants" (GB 16297-1996) requires VOCs emission concentrations in the color coating process to be ≤30mg / m³. Simultaneously, the national standard for RTO design explicitly requires that the LEL concentration of the RTO inlet exhaust gas be controlled below 25%. Existing airflow calculation methods can no longer meet compliance and safety requirements. Therefore, there is an urgent need to develop a method and system for calculating RTO airflow in color coating production lines that balances accuracy, safety, and energy efficiency, and can integrate LEL calculation and dynamic calculation of solvent usage. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for accurately calculating the RTO air volume of a color coating production line, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for accurately calculating the RTO air volume of a color coating production line, the specific steps of which include: S1: Solvent usage calculation: According to the process parameters of the color coating production line, the hourly solvent usage M is calculated according to the formula: M = B×V×δ×(1-ω) / ω, where B is the board width (m), V is the production speed (m / h), δ is the dry film thickness (m), ω is the solid-solution mass ratio when the paint is applied to the machine (%), and ω is the actual solid-solution mass ratio after adding thinner to adjust the viscosity before the paint is applied to the machine, and is the solid-solution mass ratio of non-original can paint; S2: LEL Calculation: Collect the content of each component of the paint solvent used in the color coating line and the corresponding lower explosive limit of each component. Calculate the mixed lower explosive limit Pm of the paint solvent by weighting the mass percentage of each component. The formula is: Pm = 1 / Σ(Wi / Pi), where Wi is the mass percentage (%) of the i-th solvent component and Pi is the lower explosive limit (%) of the i-th solvent component. At the same time, determine the lower explosive limit Pe of the most explosive component in the solvent. S3: Multi-source parameter acquisition: Collect exhaust gas parameters from the pretreatment section, coating process, and baking oven of the color coating production line. These parameters include the standard exhaust gas flow rate Q0 (Nm³ / h), VOCs concentration C (mg / m³), exhaust gas temperature T (°C), exhaust gas pressure P (kPa), humidity φ (%), and particulate matter concentration P for each process. m (mg / m³); S4: Standard Condition-Operating Condition Dynamic Conversion: Based on the ideal gas law and combined with the temperature fluctuation characteristics of the exhaust gas in the color coating production line, an operating condition air volume conversion model is established: Q = Q0×(273+T) / 273×(101.325 / P)×(1-φ / 100), where Q is the real-time operating condition air volume (m³ / h). S5: Coupled calculation of process air volume: According to the exhaust gas emission characteristics of each process, weighted summation is carried out according to the painting process weight of 0.4, the baking oven weight of 0.5, and the pretreatment section weight of 0.1, and the total operating air volume Q total = 0.4Q painting + 0.5Q baking + 0.1Q pretreatment is obtained; S6: Safety threshold verification: According to the RTO design standard, it is required that the LEL concentration of the exhaust gas at the RTO inlet ≤ 25%. Combining the Pe and Pm calculated in the above steps, calculate the safety air volume threshold Q safety = Q total × [min(Pe, Pm) × 25%] / C to ensure that the LEL value corresponding to the VOCs concentration entering the RTO is lower than 25% of the lower explosion limit; S7: Thermal efficiency matching optimization: Combining the RTO heat recovery efficiency η (≥ 95%) and the VOCs self-sustaining combustion concentration threshold C self (≥ 500 mg / m³), optimize and adjust the safety air volume. When C < C self, the concentrated air volume compensation is carried out according to Q optimized = Q safety × (C self / C). When C ≥ C self, Q optimized = Q safety; S8: Output control value: Take the optimized air volume Q optimized as the target control value for the operation of the RTO fan, and reserve a 10% dynamic adjustment margin at the same time.

[0007] Preferably, in S1, the parameter acquisition frequency is 1 time per second, and continuous monitoring is realized by using high-precision sensors. Among them, the measurement accuracy of VOCs concentration ≤ ±5 mg / m³, the measurement accuracy of temperature ≤ ±0.5 °C; the measurement accuracy of plate width B ≤ ±0.01 m, the measurement accuracy of production speed V ≤ ±0.1 m / h, and the measurement accuracy of dry film thickness δ ≤ ±1 μm.

[0008] Preferably, when the particulate matter concentration P in the exhaust gas m > 5 mg / m³, correct Q safety, and the correction coefficient K = 1 + (P m - 5) / 10, and after correction, Q safety' = Q safety × K.

[0009] [[ID=第十九条]]Preferably, the paint solvent components include but are not limited to toluene, xylene, ethyl acetate, methyl ethyl ketone, cyclohexanone, and the lower explosion limit values of each component adopt the standard values specified in GB / T 16483-2008 "Content and Order of Chemical Safety Technical Specification".

[0010] A precise calculation system for the RTO air volume of a color coating production line implementing the above method, including: Parameter acquisition module: It consists of an air volume sensor, a VOCs concentration monitor, a temperature and humidity sensor, a pressure sensor, and a particulate matter detector installed in the exhaust gas pipelines of each process, as well as a plate width measuring instrument, a speed sensor, and a dry film thickness gauge installed on the production line, and is used to collect multi-source exhaust gas parameters and production line process parameters in real time and transmit them to the calculation and processing module; The calculation and processing module includes a built-in solvent usage calculation model, LEL accounting model, standard condition-operating condition conversion model, process airflow coupling algorithm, safety threshold verification program, and thermal efficiency optimization model. It receives data from the parameter acquisition module, executes the calculation method steps, and outputs the optimal airflow control value. The execution adjustment module includes a variable frequency fan, a damper controller, and a linkage control unit. Based on the Q-optimization output by the calculation and processing module, it adjusts the fan speed and damper opening in real time to achieve dynamic matching of air volume. Feedback correction module: Real-time acquisition of RTO outlet VOCs concentration and furnace temperature. When the outlet concentration is >15mg / m³ or the furnace temperature deviates from 760±50℃, a correction signal is sent to the calculation and processing module to adjust the air volume calculation parameters. At the same time, the solid-solvent mass ratio when the paint is applied to the machine is acquired in real time, and the solvent usage and LEL calculation results are dynamically corrected.

[0011] Preferably, the calculation and processing module supports linkage with the PLC system of the color coating production line, and can obtain production line operating load data and paint dilution process parameters to achieve coordinated adaptation of air volume calculation with production conditions and paint process; at the same time, it has a built-in database of common paint solvent components and their lower explosive limits, which can quickly complete LEL calculation.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] High calculation accuracy: This invention adds precise calculation of solvent usage and LEL accounting steps, combined with standard condition-operating condition dynamic conversion and process air volume coupling calculation, which solves the problems of confusion between standard condition and operating condition, insufficient consideration of the characteristics of exhaust gas in each process, and failure to calculate safety thresholds in combination with paint solvent characteristics in traditional methods. The air volume calculation error is ≤5%, ensuring that the RTO exhaust gas treatment efficiency is ≥98.5%, meeting the environmental protection requirement of VOCs emission ≤30mg / m³;

[0014] Safe and reliable operation: Strictly adhering to the standard of LEL ≤ 25% at the RTO inlet, by accurately calculating the LEL value of paint solvent mixture and the LEL value of the most explosive component, combined with safety threshold verification and particulate matter concentration correction, the system avoids concentration exceeding the standard and safety hazards caused by insufficient air volume, ensuring the long-term stable operation of the RTO system;

[0015] Highly adaptable: It can collect the solid-solid mass ratio and production line process parameters in real time when the paint is applied to the machine, dynamically calculate the amount of solvent used, adapt to changes in paint dilution process and production line load fluctuations, and support linkage with the PLC system of the color coating production line. It is suitable for color coating production line RTO systems of different scales and processes, and has a wide range of application prospects.

[0016] Significant energy-saving effect: Through thermal efficiency matching optimization and dynamic air volume adjustment, the fan power is precisely matched with the actual treatment needs. Compared with traditional static air volume control, the fan energy consumption is reduced by more than 30%, and natural gas consumption is reduced by 25% to 40%, significantly reducing the environmental protection costs of enterprises. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the calculation method of the present invention;

[0018] Figure 2 This is a schematic diagram of the system composition of the present invention; Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0020] A certain color coating production line adopts the process of "pretreatment + zeolite rotor concentration + RTO". The paint used is polyester-based color coating paint. Xylene thinner is added before the paint is loaded to adjust the viscosity. The solid-solution mass ratio of the paint when loaded is ω=45%. The width of the color coating line is B=1.2m, the production speed is V=60m / h, and the dry film thickness is δ=20μm (2×10). -5 m); The paint solvent composition and parameters are as follows: xylene (60% by mass, lower explosive limit Pi=1.0%), ethyl acetate (30% by mass, lower explosive limit Pi=2.0%), methyl ethyl ketone (10% by mass, lower explosive limit Pi=1.8%); The exhaust gas parameters for each process are as follows: Pretreatment section: Standard air volume Q0pre = 8000 Nm3 / h, VOCs concentration Cpre = 120 mg / m3, temperature Tpre = 45℃, pressure Ppre = 101.325 kPa, humidity φpre = 60%, particulate matter concentration Ppre m Precipitation rate = 3 mg / m³; Coating process: Standard airflow Q0 = 15000 Nm³ / h, VOCs concentration C = 750 mg / m³, temperature T = 60℃, pressure P = 101.325 kPa, humidity φ = 50%, particulate matter concentration P m The concentration of the coating is 4 mg / m³. Baking Oven: Standard airflow Q0_baking = 60000 Nm³ / h, VOCs concentration C_baking = 280 mg / m³, temperature T_baking = 120℃, pressure P_baking = 101.325 kPa, humidity φ_baking = 30%, particulate matter concentration P_baking = 100 mg / m³. mBaking = 6mg / m³; Given: RTO heat recovery efficiency η = 96%, VOCs self-sustaining combustion concentration threshold Cself = 500 mg / m³.

[0021] The optimal airflow for the RTO is calculated using the method of this invention: Solvent usage calculation: M = B × V × δ × (1 - ω) / ω = 1.2 × 60 × 2 × 10 -5 ×(1-45%) / 45%=1.2×60×2×10 -5 ×0.55 / 0.45≈0.0088t / h (8.8kg / h); LEL calculation: Pm = 1 / Σ(Wi / Pi) = 1 / (60% / 1.0% + 30% / 2.0% + 10% / 1.8%) ≈ 1 / (60 + 15 + 5.56)≈1 / 80.56≈1.24%; the most explosive component is xylene, Pe=1.0%; Standard Condition-Operating Condition Dynamic Conversion: Qpre = 8000 × (273 + 45) / 273 × (101.325 / 101.325) × (1 - 60 / 100) = 8000 × 318 / 273 × 0.4 ≈ 3721 m³ / h; Q_coating = 15000 × (273 + 60) / 273 × 1 × (1 - 50 / 100) = 15000 × 333 / 273 × 0.5 ≈ 9095 m³ / h; Q_drying = 60000 × (273 + 120) / 273 × 1 × (1 - 30 / 100) = 60000 × 393 / 273 × 0.7 ≈ 60740 m³ / h; Process airflow coupling calculation: Qtotal = 0.4 × 9095 + 0.5 × 60740 + 0.1 × 3721 ≈ 3638 + 30370 + 372.1 ≈ 34380.1 m³ / h; Safety threshold verification: min(Pe,Pm)=1.0%, C_average=(0.4×750+0.5×280+0.1×120)=404mg / m³; Q_safe=34380.1×(1.0%×25%) / 404×10 -6 ≈34380.1×0.0025 / 404×10 -6 ≈212278 m³ / h; Due to the use of zeolite rotor concentration with a concentration ratio of 10:1, the actual air volume entering the RTO is the concentrated air volume, and after correction, Q_amp = 21228 m³ / h; At the same time, the particulate matter concentration P in the baking oven m Since the concentration of baking powder is 6 mg / m³ > 5 mg / m³, the correction factor K = 1 + (6 - 5) / 10 = 1.1. Finally, Qan' = 21228 × 1.1 ≈ 23351 m³ / h; Thermal efficiency matching optimization: After concentration, VOCs concentration C = 404 × 10 = 4040 mg / m³ ≥ Cself = 500 mg / m³, therefore Qoptimal = 23351 m³ / h; System performance: After controlling the RTO air volume using the system of this invention, the LEL concentration at the RTO inlet is stable at 20% to 22% (≤25%, which meets the national standard), and the VOCs concentration at the outlet is stable at 12 to 14 mg / m³, with a removal efficiency of 99.7%. The fan energy consumption is reduced by 32% compared with the traditional method, and the natural gas consumption is reduced by 35%. Example 2

[0022] A small-scale color coating production line does not have a zeolite rotor thickener and directly uses an RTO to treat waste gas. The paint used is an epoxy-based color coating paint. Cyclohexanone thinner is added before the paint is applied to adjust the viscosity. The solid-solution mass ratio of the paint at the time of application is ω=50%. The width of the color coating line is B=1.0m, the production speed is V=40m / h, and the dry film thickness is δ=15μm (1.5×10⁻⁶). -5 m); The paint solvent composition and parameters are as follows: cyclohexanone (70% by mass, lower explosive limit Pi=1.1%), xylene (20% by mass, lower explosive limit Pi=1.0%), butyl acetate (10% by mass, lower explosive limit Pi=1.7%); The exhaust gas parameters for each process are as follows: Pretreatment section: Q0pre = 5000 Nm3 / h, Cpre = 80 mg / m3, Tpre = 40℃, Ppre = 100 kPa, φpre = 55%, Ppre m Precipitation rate = 2 mg / m³; Coating process: Q0 coating = 10000 Nm³ / h, C coating = 320 mg / m³, T coating = 55℃, P pre-coating = 100 kPa, φ pre-coating = 45%, P m Precipitation rate = 3 mg / m³; Baking oven: Q0_baking = 30000 Nm³ / h, C_baking = 180 mg / m³, T_baking = 100℃, P_pre = 100 kPa, φ_pre = 25%, P m Precipitation rate = 4 mg / m³; Given: RTO heat recovery efficiency η=95%, VOCs self-sustaining combustion concentration threshold Cself=500mg / m³.

[0023] Calculated using the method of this invention: Solvent usage calculation: M=B×V×δ×(1-ω) / ω=1.0×40×1.5×10 -5 ×(1-50%) / 50%=1.0×40×1.5×10 -5×0.5 / 0.5≈0.0006t / h (0.6kg / h); LEL accounting: Pm = 1 / Σ(Wi / Pi) = 1 / (70% / 1.1%+20% / 1.0%+10% / 1.7%)≈1 / (63.64+20+5.88)≈1 / 89.52≈1.12%; The most explosive component is xylene, Pe = 1.0%; Standard Condition to Operating Condition Conversion: Qpre = 5000×(273+40) / 273×(101.325 / 100)×(1-55 / 100)≈5000×313 / 273×1.01325×0.45≈1042m³ / h; Qcoat = 10000×(273+55) / 273×1.01325×(1-45 / 100)≈10000×328 / 273×1.01325×0.55≈6689m³ / h; Qdry = 30000×(273+100) / 273×1.01325×(1-25 / 100)≈30000×373 / 273×1.01325×0.75≈30568m³ / h; Process airflow coupling: Q_total = 0.4 × 6689 + 0.5 × 30568 + 0.1 × 1042 ≈ 2675.6 + 15284 + 104.2 ≈ 18063.8 m³ / h; Security threshold verification: min(Pe,Pm)=1.0%, C average=(0.4×320+0.5×180+0.1×80)=236mg / m³; Q ampere=18063.8×(1.0%×25%) / 236×10 -6 ≈18063.8×0.0025 / 236×10 -6 ≈191765m³ / h (no adjustment is needed as the actual air volume is less than the safety threshold); the particulate matter concentration in each process is ≤5mg / m³, and no particulate matter correction is required. Thermal efficiency optimization: Caverage = 236 mg / m3 < Cself = 500 mg / m3, Qoptimal = 18063.8 × (500 / 236) ≈ 38238 m3 / h (requires supplementing fresh air or adjusting operating parameters to ensure self-sustaining combustion). Running result: After the system is in operation, the LEL concentration at the RTO inlet is stable at 23% to 24% (≤25%, in line with national standards), the RTO furnace temperature is stable at 780 to 820℃, the VOCs concentration at the outlet is ≤25mg / m³, and the fan energy consumption is reduced by 28%, meeting environmental protection and energy-saving requirements.

[0024] Although embodiments of the invention have been shown and described in detail above, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for accurately calculating the air volume of an RTO (Regenerative Thermal Oxidizer) in a color coating production line, characterized in that, The specific steps include: S1: Solvent usage calculation: Calculate the hourly solvent usage M based on the process parameters of the color coating production line; S2: LEL calculation: Collect the content of each component of the paint solvent used in the color coating line and the corresponding lower explosive limit of each component, and calculate the mixed lower explosive limit Pm of the paint solvent by weighting the mass ratio of each component; S3: Multi-source parameter acquisition: Collect exhaust gas parameters from the pretreatment section, coating process, and baking oven of the color coating production line. These parameters include the standard exhaust gas flow rate Q0, VOCs concentration C, exhaust gas temperature T, exhaust gas pressure P, humidity φ, and particulate matter concentration P for each process. m ; S4: Standard Condition-Operating Condition Dynamic Conversion: Based on the ideal gas law and combined with the temperature fluctuation characteristics of exhaust gas in the color coating production line, an operating condition air volume conversion model is established. S5: Process air volume coupling calculation: Based on the exhaust gas emission characteristics of each process, the total working air volume Q_total is obtained by weighting and summing the data according to the weight of the coating process (0.4), the baking oven (0.5), and the pretreatment section (0.1). S6: Safety threshold verification: According to RTO design standards, the LEL concentration of the exhaust gas at the RTO inlet is required to be ≤25%. Based on the Pe and Pm calculated in the above steps, calculate the safe air volume threshold Q to ensure that the LEL value corresponding to the VOCs concentration entering the RTO is lower than 25% of the lower explosion limit. S7: Thermal efficiency matching optimization: Combining the RTO heat recovery efficiency η (≥95%) and the VOCs self-sustaining combustion concentration threshold Cself (≥500mg / m³), the safe air volume is optimized and adjusted. When C < Cself, the concentrated air volume is compensated according to Qoptimized = Qsafe × (Cself / C). When C ≥ Cself, Qoptimized = Qsafe. S8: Output control value: The optimized air volume Q is used as the target control value for the operation of the RTO fan, while reserving a 10% dynamic adjustment margin.

2. The method for accurately calculating the RTO air volume of a color coating production line according to claim 1, characterized in that, In S1, the calculation formula is: M = B×V×δ×(1-ω) / ω, where B is the board width, V is the production speed, δ is the dry film thickness, ω is the solid-solution mass ratio when the paint is applied to the machine, and ω is the actual solid-solution mass ratio after adding thinner to adjust the viscosity before the paint is applied to the machine, and the solid-solution mass ratio of non-original can paint; the parameter acquisition frequency is 1 time / second, and a high-precision sensor is used to achieve continuous monitoring, wherein the VOCs concentration measurement accuracy is ≤±10mg / m³, the temperature measurement accuracy is ≤±2℃; the board width B measurement accuracy is ≤±0.01m, the production speed V measurement accuracy is ≤±1m / h, and the dry film thickness δ measurement accuracy is ≤±1μm.

3. The method for accurately calculating the RTO air volume of a color coating production line according to claim 2, characterized in that, In S2, the formula for LEL calculation is: Pm = 1 / Σ(Wi / Pi), where Wi is the mass percentage of the i-th solvent component and Pi is the lower explosive limit of the i-th solvent component; at the same time, the lower explosive limit Pe of the most explosive component in the solvent is determined.

4. The method for accurately calculating the RTO air volume of a color coating production line according to claim 3, characterized in that, In S4, the working condition air volume conversion model is: Q = Q0×(273+T) / 273×(101.325 / P)×(1-φ / 100), where Q is the real-time working condition air volume.

5. The method for accurately calculating the RTO air volume of a color coating production line according to claim 4, characterized in that, In S5, Q_total = 0.4Q_coating + 0.5Q_baking + 0.1Q_preheating.

6. The method for accurately calculating the RTO air volume of a color coating production line according to claim 5, characterized in that, In S5, Qan = Qtotal × [min(Pe,Pm) × 25%] / C.

7. The method for accurately calculating the RTO air volume of a color coating production line according to claim 6, characterized in that, When the particulate matter concentration P in the waste gas m > 5 mg / m³, correct Qₐₙ, and the correction coefficient K = 1 + (P m - 5) / 10. After correction, Qₐₙ' = Qₐₙ × K.

8. The method for accurately calculating the RTO air volume of a color coating production line according to claim 1, characterized in that, Paint solvent components include, but are not limited to, toluene, xylene, ethyl acetate, butanone, and cyclohexanone.

9. A precise calculation system for RTO air volume in a color coating production line implementing the method of any one of claims 1-8, characterized in that, include: Parameter acquisition module: It consists of air volume sensor, VOCs concentration monitor, temperature and humidity sensor, pressure sensor and particulate matter detector installed in the exhaust gas pipelines of each process, as well as plate width measuring instrument, speed sensor and dry film thickness gauge installed in the production line. It is used to collect multi-source exhaust gas parameters and production line process parameters in real time and transmit them to the calculation and processing module. The calculation and processing module includes a built-in solvent usage calculation model, LEL accounting model, standard condition-operating condition conversion model, process airflow coupling algorithm, safety threshold verification program, and thermal efficiency optimization model. It receives data from the parameter acquisition module, executes the calculation method steps, and outputs the optimal airflow control value. The execution adjustment module includes a variable frequency fan, a damper controller, and a linkage control unit. Based on the Q-optimization output by the calculation and processing module, it adjusts the fan speed and damper opening in real time to achieve dynamic matching of air volume. Feedback correction module: Real-time acquisition of RTO outlet VOCs concentration and furnace temperature. When the outlet concentration is >15mg / m³ or the furnace temperature deviates from 760±50℃, a correction signal is sent to the calculation and processing module to adjust the air volume calculation parameters. At the same time, the solid-solvent mass ratio when the paint is applied to the machine is acquired in real time, and the solvent usage and LEL calculation results are dynamically corrected.

10. A precise calculation system for RTO air volume in a color coating production line according to claim 9, characterized in that, The calculation and processing module supports linkage with the PLC system of the color coating production line, and can obtain production line operating load data and paint dilution process parameters to achieve coordinated adaptation of air volume calculation with production conditions and paint process; at the same time, it has a built-in database of common paint solvent components and their lower explosive limits, which can quickly complete LEL calculation.

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