Ozone source analysis method for online monitoring of atmospheric ozone photochemical generation rate

Abstract

The invention provides an ozone source analysis method for online monitoring of the photochemical generation rate of atmospheric ozone, and relates to the field of atmospheric science research. The test aims at monitoring the total concentration of the RO2 * in the environment in real time, evaluating secondary pollution formation under different environmental conditions in typical events in combination with field regional pollutant data and meteorological data, calculating the O3 generation rate based on the concentration of the RO2 *, evaluating the photochemical generation source and consumption of O3 in the environment, and providing a reasonable prevention and control strategy; according to the method, a time sequence of actually monitored precursors such as VOCs, RO2 * and conventional pollutants and meteorological observation data (including air temperature, air pressure, total solar radiation and the like) is used as input parameters, the O3 generation rate is calculated, an F0AM mode is used for nesting MCM to simulate the photochemical reaction of the RO2 * in the environment, photochemical analysis of O3 is carried out, and the result of the photochemical analysis of the O3 is obtained. Comprising RO2 generation daily variation simulation, RO2 key species proportion, O3 photochemical generation source and O3 photochemical consumption process.

Description

Technical Field

[0001] The invention relates to the field of atmospheric science research, and in particular to an ozone source analysis method for online monitoring of atmospheric ozone photochemical generation rate. Background Art

[0002] In recent years, ozone (O 3 ) concentration is on the rise, gradually becoming the main pollutant in ambient air. Human emissions enhance the accumulation of photochemical precursors (such as nitrogen oxides, volatile organic compounds and carbon monoxide). Under sunlight, the precursors undergo photochemical reactions to generate secondary pollutants, which ultimately trigger photochemical O 3 The total peroxyl radicals (RO 2 * =RO 2 +HO 2 ) participates in the conversion of nitric oxide (NO) to nitrogen dioxide (NO 2 ) conversion, NO 2 Produces O under light 3 Therefore, RO 2 * The circulation helps in atmospheric oxidation. 2 * Direct measurements of RO are necessary to fully understand changes in urban atmospheric composition and the impact of such changes on regional air quality changes and health issues. 2 * concentrations, and understand the complex chemical reactions involving these free radicals, 3 The generation rate is monitored online and the source is analyzed.

[0003] MCM (Master Chemical Mechanism) is a detailed chemical mechanism that describes the chemical process of a single VOC species. It details the chemical process of atmospheric gas phase organic matter and is widely used in the field of atmospheric science research. The 0-dimensional atmospheric framework model (F0AM) is a box model used to solve complex atmospheric chemical processes. This model can nest the MCM mechanism to simulate the VOCs, NOx, O in the photochemical reaction process without considering the horizontal and vertical transport of pollutants. 3 The generation and elimination process of free radicals such as OH and ROx, thus reacting with O 3 The process of generation and consumption. Summary of the invention

[0004] In view of the above problems, the present invention provides an ozone source analysis method for online monitoring of atmospheric ozone photochemical generation rate. The purpose of this experiment is to monitor the total RO in the environment in real time. 2 *The concentration of secondary pollution under different environmental conditions in typical events is evaluated by combining the on-site regional pollutant data and meteorological data. 2 * Calculate the concentration of O 3 The generation rate and the effect of O 3 The sources and consumption of photochemical generation are evaluated, and reasonable prevention and control strategies are proposed.

[0005] To solve the above problems, the technical solution adopted by the present invention is:

[0006] The ozone source analysis method for online monitoring of atmospheric ozone photochemical generation rate includes:

[0007] The data input and processing module is used to convert the units of input data, fill in missing values ​​and calculate the daily average;

[0008] O 3 The generation rate calculation module is used to calculate the O after the data input and processing modules are completed. 3 Calculate the generation rate of

[0009] O 3 Photochemical analysis module for RO simulation 2 Diurnal variation of generation and O 3 Generate sources for parsing.

[0010] As a further solution of the present invention, the input and processing module will automatically convert the input precursor species name code and fill the missing data with linear interpolation. If more than 10 hours of data are missing on a single day, the single day will be judged as an invalid day and no subsequent calculations will be performed. The data in this module include: VOCs species concentration, meteorological data and hourly data of atmospheric pollutant concentration, atmospheric RO 2 * Real-time monitoring data also includes the longitude, latitude, altitude, observation year and month of the regional observation location.

[0011] As a further aspect of the present invention, 3 After the generation rate is calculated, the input and processed O 3 and NO 2 Actual observation data, calculate O 3 Photochemical generation and consumption.

[0012] As a further aspect of the present invention, 3 The photochemical analysis module includes:

[0013] RO 2 Generate daily variation simulation, RO 2 Key species proportion, O3 The photochemical generation and consumption process is divided into four zones.

[0014] As a further solution of the present invention, the data input and processing module, 3 Generation rate calculation module and O 3 The operation steps of the photochemical analysis module include:

[0015] Step 1, input data into MATLAB and run [daily, name1] = DailyCal (inpath, outpath), remove outliers, fill invalid values ​​and calculate daily averages for the input precursor hourly data, and temporarily store the processed hourly data under the double type data "DataC" in the MATLAB workspace, and temporarily store the calculated daily average data under the double type data "daily" in the MATLAB workspace;

[0016] Step 2: Call the RO under the double type data "DataC" described in step 1 2 * And NO measured data, calculate, output is O 3 Generation rate (P(O 3 The hourly time series of )) is stored in "P(O3)" of "RO2chem.xlsx" and is calculated as shown in formula (1):

[0017] P(O 3 )=k[NO][RO 2 * ] (1)

[0018] Among them, [NO] and [RO 2 * ] are NO and RO respectively 2 * The volume fraction of NO and RO 2 * The effective reaction rate constant of

[0019] Step 3: Run RO2chem(S,outpath) in MATLAB, call the double type data "daily" described in step 1, compile it into mat format data and input it into F0AM mode, use MCM to simulate atmospheric photochemical reactions, and filter HO in the simulation results according to the daily changes in the concentrations of different chemical species in the simulation results. 2 And the top 10 RO concentrations 2 Key species, and record the daily changes in their concentrations. The results are saved in "Sheet1" of "RO2chem.xlsx" under the output path;

[0020] Step 4: In all MCM chemical reaction equations, screen the reactants that also contain RO 2 and NO, and the product contains NO 2 The chemical reaction formula is recorded, and the reaction rate per hour is recorded. The names of the chemical reaction equations with the top 10 reaction rates and the results of the reaction rates are saved in "G(O3)" of "RO2chem.xlsx" under the output path, which is O 3 The photochemical production rate of

[0021] Step 5: Screen O in all MCM chemical reaction equations 3 Consumption chemical reaction formula, including O 3 Photolysis (O 3 +hv), O 3 Reaction with OH radicals (reactants containing both O 3 and OH), O 3 with HO 2 Free radical reactions (reactants containing both O 3 and HO 2 Reaction formula), NO 2 Consumption (the reactants contain NO 2 The hourly reaction rate result is saved in "L(O3)" of "RO2chem.xlsx" under the output path, which is O 3 The photochemical consumption rate of

[0022] O 3 The photochemical generation rate (G(O3)) and O 3 The difference in the photochemical consumption rate (L(O3)) is O 3 The net photochemical production rate (G(O 3 ) net )

[0023] The beneficial effects of the present invention are:

[0024] Compared with the existing technology, this method is based on the actual monitoring of VOCs, RO 2 * The precursors of conventional pollutants and meteorological observation data (including temperature, air pressure, total solar radiation, etc.) are used as input parameters to calculate O 3 Generation rate, using F0AM mode nested MCM to control RO in the environment 2 *The photochemical reaction is simulated to carry out O 3 Photochemical analysis, including RO 2 Generate daily variation simulation, RO 2 Key species proportion, O 3 The photochemical generation sources and O3 photochemical consumption process.

[0025] The analysis results will be RO 2 * Types: RO 2 and HO 2 , can show the impact of RO on different time scales in the target city or region 2 * The photochemical generation process of O 3 Analyze the generation and consumption sources of the 2 The photolysis products of different VOCs can be used to trace the source, providing support for effective control measures and suggestions; the O 3 The generation rate, combined with O 3 The measured concentration and wind direction can be used to analyze the O 3 Mutual influence. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the overall design diagram of the ozone source analysis method based on online monitoring of the atmospheric ozone photochemical generation rate.

[0027] Figure 2 This is the program diagram for data and parameter input and daily average calculation.

[0028] Figure 3 For HO 2 and RO 2 Simulation results and visualization of daily changes in key species concentrations.

[0029] Figure 4 For different RO 2 O 3 Visualize the generation rate and consumption rate results. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0031] See attached Figure 1 -Attached Figure 4 ,like Figure 1 As shown, the overall design diagram of the ozone source analysis method based on online monitoring of the atmospheric ozone photochemical generation rate.

[0032] Ozone source analysis methods based on online monitoring of atmospheric ozone photochemical generation rate include:

[0033] The data input and processing module is used to convert the units of input data, fill in missing values ​​and calculate the daily average;

[0034] O3 The generation rate calculation module is used to calculate the O after the data input and processing modules are completed. 3 Calculate the generation rate of

[0035] O 3 Photochemical analysis module for simulating HO 2 and RO 2 Diurnal variation of generation and O 3 Generate sources for parsing.

[0036] As a further solution of the present invention, the input precursor species name code will be automatically converted in the input and processing module, and the missing data will be filled in by linear interpolation. If more than 10 hours of data are missing on a single day, the single day will be judged as an invalid day and no subsequent calculations will be performed. The data in this module include: VOCs species concentration, meteorological data and hourly data of atmospheric pollutant concentration, real-time monitoring data of total atmospheric peroxyl radicals, and also the longitude, latitude, altitude, observation year and month of the regional observation site.

[0037] In the embodiment of the present invention, the 3 The generation rate calculation module operation steps include:

[0038] Figure 2 This is a program diagram for data and parameter input and daily average calculation. Input data into MATLAB and run [daily, name1] = DailyCal (inpath, outpath). The input precursor hourly data is subjected to outlier elimination, invalid value filling and daily average calculation. The processed hourly data is temporarily stored in the double type data "DataC" of the MATLAB workspace, and the calculated daily average data is temporarily stored in the double type data "daily" of the MATLAB workspace.

[0039] Call RO under "DataC" 2 * The measured data of NO are calculated using formula (1) to obtain P(O 3 ) is stored in "P(O3)" of "RO2chem.xlsx".

[0040] P(O 3 )=k[NO][RO 2 * ] (1)

[0041] Among them, [NO] and [RO 2 * ] are NO and RO respectively 2 * The volume fraction of NO and RO2 * The effective reaction rate constant.

[0042] In the embodiment of the present invention, the 3 The photochemical analysis module includes:

[0043] HO 2 and RO 2 Generate daily variation simulation, RO 2 Key species proportion, O 3 The photochemical generation and consumption process is divided into four zones, and the operation steps include:

[0044] HO 2 and RO 2 Generate daily variation simulation, RO 2 Key species share:

[0045] Run RO2chem(S,outpath) in MATLAB, call the double type data "daily", compile it into mat format data, input F0AM mode to run, simulate daily changes, and obtain HO 2 , RO with the top 10 concentrations 2 Key species, and record the daily changes in their concentrations. The results are saved in "Sheet1" of "RO2chem.xlsx" under the output path. The data structure is 25 rows (daily changes in concentration) and 14 columns (species categories). The data example is shown in Table 1;

[0046] Figure 3 For HO 2 and RO 2 Simulation results and visualization of daily changes in key species concentrations.

[0047] Table 1

[0048]

[0049]

[0050] Screening RO 2 Species react with NO to generate NO 2 The chemical reaction formula is recorded, and the reaction rate per hour is recorded. The names of the chemical reaction equations with the top 10 reaction rates and the results of the reaction rates are saved in "G(O3)" of "RO2chem.xlsx" under the output path. The data structure is 25 rows (daily change concentration) and 17 columns (chemical equation names). The data example is shown in Table 2.

[0051] Screening O 3 The chemical reaction formula consumed mainly includes O 3 Photolysis, O3 With OH and HO 2 Free radical reaction, NO 2 The consumption of the reaction rate per hour is saved in "L(O3)" of "RO2chem.xlsx" under the output path. The data structure is 25 rows (daily change concentration) and 6 columns (chemical equation name). The data example is shown in Table 3.

[0052] Figure 4 For different RO 2 O 3 Visualize the generation rate and consumption rate results.

[0053] Table 2

[0054]

[0055]

[0056] Table 3

[0057]

[0058]

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for online monitoring of the photochemical generation rate of atmospheric ozone sources, characterized in that: include: The data input and processing module is used to convert the units of input data, fill in missing values ​​and calculate the daily average; The O3 generation rate calculation module is used to calculate the generation rate of O3 after the data input and processing module are completed; O3 photochemical analysis module, used to simulate the daily variation of RO2 generation and analyze the source of O3 generation; The steps include: S1, collect daily average data and perform calculations to output the hourly time series of O3 generation rate (P(O3)); S2. Use MCM to simulate atmospheric photochemical reactions. Among all MCM chemical reaction equations, screen the chemical reaction equations whose reactants contain both RO2 and NO and whose products contain NO2, record their hourly reaction rates, and obtain the photochemical generation rate of O3. S3. Among all the MCM chemical reaction equations, the chemical reaction equations for O3 consumption are screened to obtain the photochemical consumption rate of O3. The difference between the photochemical generation rate of O3 and the photochemical consumption rate of O3 is the net photochemical generation rate of O3.

2. The ozone source analysis method for online monitoring of atmospheric ozone photochemical generation rate according to claim 1, characterized in that: The input and processing module will automatically convert the input precursor species name code and fill in the missing data using linear interpolation. If more than 10 hours of data are missing on a single day, the day will be judged as an invalid day and no subsequent calculations will be performed.

3. The ozone source analysis method for online monitoring of atmospheric ozone photochemical generation rate according to claim 2, characterized in that: Input and processing module data include: VOCs species concentration, meteorological data and hourly data of atmospheric pollutant concentration, atmospheric RO2 * Real-time monitoring data also includes the longitude, latitude, altitude, observation year and month of the regional observation location.

4. The ozone source analysis method for online monitoring of atmospheric ozone photochemical generation rate according to claim 1, characterized in that: After the O3 generation rate is calculated, the input and processed actual observation data of O3 and NO2 will be called to calculate the photochemical generation and consumption of O3.

5. The ozone source analysis method for online monitoring of atmospheric ozone photochemical generation rate according to claim 1, characterized in that: The O3 photochemical analysis module includes four areas: simulation of daily changes in RO2 generation, proportion of key RO2 species, and photochemical generation and consumption process of O3.

6. The ozone source analysis method for online monitoring of atmospheric ozone photochemical generation rate according to claim 1, characterized in that: The operation steps of the data input and processing module, the O3 generation rate calculation module and the O3 photochemical analysis module include: Step 1, input data into MATLAB and run [daily, name1] = DailyCal (inpath, outpath), remove outliers, fill invalid values ​​and calculate daily averages for the hourly data of the input precursor, and temporarily store the processed hourly data in the double type data "DataC" of the MATLAB workspace, and temporarily store the calculated daily average data in the double type data "daily" of the MATLAB workspace; Step 2: Call RO2 under the double type data "DataC" described in step 1 * The measured data of NO are calculated and the hourly time series of O3 generation rate (P(O3)) is output and stored in "P(O3)" of "RO2chem.xlsx". The calculation method is as follows: P(O3)=k[NO][RO2 * ] (1) Among them, [NO] and [RO2 * ] are NO and RO2 * The volume fraction of NO and RO2 * The effective reaction rate constant of Step 3, run RO2chem(S,outpath) in MATLAB, call the double type data "daily" described in step 1, compile it into mat format data and input the F0AM mode, use MCM to simulate atmospheric photochemical reactions, and select the key species of HO2 and RO2 with the top 10 concentrations in the simulation results according to the daily changes in the concentrations of different chemical species in the simulation results, and record the daily changes in their concentrations. The results are saved in "Sheet1" of "RO2chem.xlsx" under the output path; Step 4: Among all the MCM chemical reaction equations, screen the chemical reaction equations whose reactants contain both RO2 and NO and whose products contain NO2, record their hourly reaction rates, and save the names of the top 10 chemical reaction equations and the results of the reaction rates in "G(O3)" of "RO2chem.xlsx" under the output path, which is the photochemical generation rate of O3; Step 5. In all MCM chemical reaction equations, screen the chemical reaction equations of O3 consumption, including O3 photolysis (O3+hv), the reaction of O3 with OH radicals (reaction equations in which the reactants include both O3 and OH), the reaction of O3 with HO2 radicals (reaction equations in which the reactants include both O3 and HO2), and the consumption of NO2 (chemical formulas in which the reactants include NO2), and save the hourly reaction rate results in "L(O3)" of "RO2chem.xlsx" under the output path, which is the photochemical consumption rate of O3.

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