Method for evaluating influence of setting off of fireworks and crackers on atmospheric PM2.5 (Particulate Matter 2.5)

Abstract

The invention belongs to the technical field of environmental atmospheric pollutant assessment, and discloses a method for assessing the influence of fireworks and crackers on atmospheric PM2.5, which is suitable for assessing the particulate matter pollution influence of a fireworks setting-off point source in a specific area on a surrounding environmental air quality monitoring station, and realizes PM2.5 emission diffusion simulation and traceability of centralized setting-off of fireworks and crackers. The characteristics of Gaussian diffusion, puff diffusion and computational fluid mechanics theories are integrated, PM2.5 influence evaluation of areas and cities can be achieved, firework and cracker pollution contribution key areas can be recognized, rapid response of pollution emission reduction measures can be achieved, and then more effective supervision and control over centralized setting-off of fireworks and crackers can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental air pollutant assessment, and particularly relates to an evaluation method of the effect of fireworks and firecrackers on atmospheric PM. 2.5 Impact assessment methods. Background Art

[0002] Existing studies have evaluated the impact of fireworks and firecrackers on atmospheric PM 2.5 The impact is mainly based on the relative ratio method of pollutants. In the process of setting off fireworks, different pollutants in the atmosphere will be affected in various ways, with the greatest impact being on PM 10 , while PM 2.5 In PM 10 The proportion of pollutants in the atmosphere also increased significantly, reaching 90%, and CO had the least impact. Therefore, during the fireworks and firecrackers period, CO was used as the reference standard pollutant concentration, and PM 2.5 Analysis of the effect of fireworks and firecrackers on PM 2.5 contribution.

[0003] In the current assessment model, concentrated fireworks and firecrackers may still release a small amount of CO, which will cause the calculated fireworks impact on PM 2.5 In addition, this assessment method cannot conduct detailed assessments for specific areas or specific activities (such as large-scale fireworks displays in public amusement parks), nor can it assess the impact of PM2.5 on monitoring sites. 2.5 Therefore, a method for the effect of fireworks and firecrackers on atmospheric PM 2.5 Impact assessment methods. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a method for treating the atmospheric PM 2. 2.5 An impact assessment method is provided to solve the problems pointed out in the above background technology.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted is as follows:

[0006] Effect of fireworks and firecrackers on atmospheric PM 2.5 The impact assessment method includes the following steps:

[0007] S1. Collect emission source information in the study area and establish an emission source information database, including parameter information such as the type, size, launch time and launch location coordinates of fireworks, as well as data such as the launch height and amount of various types of fireworks;

[0008] S2. Obtain the distribution of monitoring sites in the study area and the continuous monitoring data of the sites (pollutant concentration data and meteorological data), and determine the detection sites and research time;

[0009] S3. Obtain high-resolution digital elevation data (DEM) of the area where fireworks are set off from NASA as terrain data; use the mesoscale weather forecast model to simulate the sounding meteorological data of the area to be evaluated, including atmospheric pressure, altitude, dry bulb temperature, dew point temperature, wind direction and wind speed, etc.; obtain ground meteorological data from the China Meteorological Data Network and local meteorological monitoring departments, including precipitation, cloud height, cloud conditions, temperature, relative humidity, wind direction and wind speed, etc.; and obtain building parameters based on the planning and investigation, including the distribution of the firing locations and their length, width and height;

[0010] S4, PM based on nearby detection points 2.5 Real-time concentration monitoring data, analysis of PM2.5 emission sources 2.5 The emission characteristics and preliminary calculation of dynamic emission source strength were used to further calculate PM based on the total amount of fireworks and firecrackers. 2.5 Total emissions, and matching analysis of the results of the two calculation methods;

[0011] S5. Based on computational fluid dynamics theory, simulate and calculate the impact of low-rise buildings in the firing area on airflow movement, determine the transmission path of pollutants from the emission source, and combine PM 2.5 The diffusion distribution and receptor sensitive point concentration prediction results can identify the impact points and impact levels to achieve pollutant supervision and control.

[0012] As a further improvement of the present invention, in step S3, using a mesoscale weather forecast model to simulate the sounding meteorological data of the required assessment area specifically includes the following steps:

[0013] (1) Collection and collation of basic meteorological data: using initial meteorological field data from multiple channels across the country or a larger area to drive, assimilate meteorological field data, and substitute them into the mesoscale weather forecast (WRF) model;

[0014] (2) Determine the simulation grid accuracy of the mesoscale weather forecast model: the accuracy can be set from a few hundred meters to tens of kilometers according to the actual forecast requirements;

[0015] (3) Select the required simulation area: Establish a reasonable simulation nesting scheme and select the appropriate simulation area;

[0016] (4) Data processing and analysis: Output the simulation results of the meteorological field in the specified simulation area; establish a numerical meteorological data system based on the mesoscale weather forecast model (WRF) to simulate weather conditions and meteorological elements accurately.

[0017] As a further improvement of the present invention, in step S4, the calculation of the dynamic emission source strength specifically includes the following steps:

[0018] (1) Formula method

[0019] The aerosol number concentration decreases in the vertical direction according to the negative exponential law. Fireworks and firecrackers have a significant impact on PM 2.5 The contribution decreases with height according to the negative exponential law, and the calculation formula is as follows:

[0020] C Z =C0×e (-n×z)

[0021] Where Z is the height and Cz is the PM at the height Z. 2.5 Concentration, C0 is ground PM 2.5 concentration, n is a constant, take n = 0.015;

[0022] PM 2.5 Mix evenly in the horizontal direction, PM emitted by fireworks 2.5 The calculation formula of the total amount M is as follows:

[0023]

[0024] Where S is the area, t1 and t2 are the start and end time of the fireworks, Z is the height, and Cz is the PM at the height Z. 2.5 concentration;

[0025] (2) Material balance method

[0026] The main chemical components of fireworks and firecrackers include combustible substances (such as sulfur, charcoal, magnesium powder, red phosphorus), oxidants (such as nitrates, chlorates, etc.), flame colorants (such as barium salts, strontium salts, sodium salts, copper salts) and other chemicals (such as potassium picrate, polyvinyl chloride resin, hexachloroethane, various oils and fats, nitro compounds), etc.; under the high temperature and high pressure conditions after being triggered, the substances in fireworks and firecrackers undergo a series of chemical reactions, releasing sulfur dioxide, nitrogen oxides, heavy metals and organic matter, and producing a large amount of smoke particles, causing the air quality to deteriorate significantly.

[0027] The explosion reaction after fireworks are ignited is mainly:

[0028] S+2KNO3+3C→K2S+N2+3CO2; △H=-707KJ / mol

[0029] The PM generated was estimated by K ion material balance. 2.5 Total amount;

[0030] (3) Result fitting

[0031] The calculation results of the formula method and the material balance method are fitted to more accurately estimate the PM generated. 2.5 Total amount, that is, the emission source strength.

[0032] As a further improvement of the present invention, in step S5, based on the theory of computational fluid dynamics, the influence of low-rise buildings in the firing area on the airflow movement is simulated and calculated to determine the transmission path of the emission source pollutants. 2.5 The prediction results of diffusion distribution and receptor sensitive point concentration include the following steps: combining terrain data, real-time meteorological data and building parameters, constructing PM based on Gaussian plume diffusion theory and smoke puff diffusion theory 2.5 The diffusion model calculates the pollutant diffusion distribution characteristics of the emission source based on real-time meteorological data and predicts the pollutant concentration at sensitive points; the calculation equation for the pollutant concentration at any point in space is:

[0033]

[0034]

[0035] Where Q is the emission source strength calculated in step S4, u is the average wind speed, and σ x , σ y , σ z are the diffusion parameters in the x, y and z directions respectively, H is the effective source height, and T is the time.

[0036] The beneficial effects of the present invention are as follows: the present invention is applicable to evaluating the impact of the point source of fireworks setting off in a specific area on the particulate matter pollution of the surrounding environmental air quality monitoring station, and the method of the present invention has the following advantages:

[0037] 1. Carry out quantitative assessment of fireworks point sources in a specific area, and evaluate the impact of a single point source on PM2.5 at surrounding monitoring stations. 2.5 Contribution level of concentration;

[0038] 2. The numerical model simulation method can comprehensively consider various influencing factors such as regional topography and meteorology;

[0039] 3. Centralized assessment of primary particulate matter directly emitted during the fireworks display process. The simulation assessment process is simple and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0041] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0042] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0043] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0044] like Figure 1 As shown in the figure, the effect of fireworks on atmospheric PM 2.5 The impact assessment method includes the following steps:

[0045] S1. Collect emission source information in the study area and establish an emission source information database, including parameter information such as the type, size, launch time and launch location coordinates of fireworks, as well as data such as the launch height and amount of various types of fireworks;

[0046] S2. Obtain the distribution of monitoring sites in the study area and the continuous monitoring data of the sites (pollutant concentration data and meteorological data), and determine the detection sites and research time;

[0047] S3. Obtain high-resolution digital elevation data (DEM) of the area where fireworks are set off from NASA as terrain data; use the mesoscale weather forecast model to simulate the sounding meteorological data of the area to be evaluated, including atmospheric pressure, altitude, dry bulb temperature, dew point temperature, wind direction and wind speed, etc.; obtain ground meteorological data from the China Meteorological Data Network and local meteorological monitoring departments, including precipitation, cloud height, cloud conditions, temperature, relative humidity, wind direction and wind speed, etc.; and obtain building parameters based on the planning and investigation, including the distribution of the firing locations and their length, width and height;

[0048] S4, PM based on nearby detection points 2.5 Real-time concentration monitoring data, analysis of PM2.5 emission sources 2.5 The emission characteristics and preliminary calculation of dynamic emission source strength were used to further calculate PM based on the total amount of fireworks and firecrackers. 2.5 Total emissions, and matching analysis of the results of the two calculation methods;

[0049] S5. Based on computational fluid dynamics theory, simulate and calculate the impact of low-rise buildings in the firing area on airflow movement, determine the transmission path of pollutants from the emission source, and combine PM 2.5 The diffusion distribution and receptor sensitive point concentration prediction results can identify the impact points and impact levels to achieve pollutant supervision and control.

[0050] In step S3, the sounding meteorological data of the required assessment area is simulated using a mesoscale weather forecast model, which specifically includes the following steps:

[0051] (1) Collection and collation of basic meteorological data: using initial meteorological field data from multiple channels across the country or a larger area to drive, assimilate meteorological field data, and substitute them into the mesoscale weather forecast (WRF) model;

[0052] (2) Determine the simulation grid accuracy of the mesoscale weather forecast model: the accuracy can be set from a few hundred meters to tens of kilometers according to the actual forecast requirements;

[0053] (3) Select the required simulation area: Establish a reasonable simulation nesting scheme and select the appropriate simulation area;

[0054] (4) Data processing and analysis: Output the simulation results of the meteorological field in the specified simulation area; establish a numerical meteorological data system based on the mesoscale weather forecast model (WRF) to simulate weather conditions and meteorological elements accurately.

[0055] In step S4, the calculation of the dynamic emission source intensity specifically includes the following steps:

[0056] (1) Formula method

[0057] The aerosol number concentration decreases in the vertical direction according to the negative exponential law. Fireworks and firecrackers have a significant impact on PM 2.5 The contribution decreases with height according to the negative exponential law, and the calculation formula is as follows:

[0058] C Z =C0×e (-n×z)

[0059] Where Z is the height and Cz is the PM at the height Z. 2.5 Concentration, C0 is ground PM 2.5 concentration, n is a constant, take n = 0.015;

[0060] PM 2.5 Mix evenly in the horizontal direction, PM emitted by fireworks 2.5 The calculation formula of the total amount M is as follows:

[0061]

[0062] Where S is the area, t1 and t2 are the start and end time of the fireworks, Z is the height, and Cz is the PM at the height Z. 2.5 concentration;

[0063] (2) Material balance method

[0064] The main chemical components of fireworks and firecrackers include combustible substances (such as sulfur, charcoal, magnesium powder, red phosphorus), oxidants (such as nitrates, chlorates, etc.), flame colorants (such as barium salts, strontium salts, sodium salts, copper salts) and other chemicals (such as potassium picrate, polyvinyl chloride resin, hexachloroethane, various oils and fats, nitro compounds), etc.; under the high temperature and high pressure conditions after being triggered, the substances in fireworks and firecrackers undergo a series of chemical reactions, releasing sulfur dioxide, nitrogen oxides, heavy metals and organic matter, and producing a large amount of smoke particles, causing the air quality to deteriorate significantly.

[0065] The explosion reaction after fireworks are ignited is mainly:

[0066] S+2KNO3+3C→K2S+N2+3CO2; △H=-707KJ / mol

[0067] The PM generated was estimated by K ion material balance. 2.5 Total amount;

[0068] (3) Result fitting

[0069] The calculation results of the formula method and the material balance method are fitted to more accurately estimate the PM generated. 2.5 Total amount, that is, the emission source strength.

[0070] In step S5, based on the theory of computational fluid dynamics, the influence of low-rise buildings in the firing area on the airflow movement is simulated and calculated to determine the transmission path of the emission source pollutants. 2.5 The prediction results of diffusion distribution and receptor sensitive point concentration include the following steps: combining terrain data, real-time meteorological data and building parameters, constructing PM based on Gaussian plume diffusion theory and smoke puff diffusion theory 2.5 The diffusion model calculates the pollutant diffusion distribution characteristics of the emission source based on real-time meteorological data and predicts the pollutant concentration at sensitive points; the calculation equation for the pollutant concentration at any point in space is:

[0071]

[0072]

[0073] Where Q is the emission source strength calculated in step S4, u is the average wind speed, and σ x , σ y , σ z are the diffusion parameters in the x, y and z directions respectively, H is the effective source height, and T is the time.

[0074] The applicable premise of the method of the present invention is: (1) the parameter information such as the composition of the fireworks material, the firing time and the location of each fireworks firing point source in the target assessment area is known; (2) the pollution impact of the primary particulate matter generated by the fireworks firing on the ambient air is evaluated in detail.

[0075] The present invention provides a method for controlling the atmospheric PM by burning fireworks and firecrackers. 2.5 The impact assessment method has realized the PM 2.5 Emission diffusion simulation and tracing combines the characteristics of Gaussian diffusion, smoke puff diffusion and computational fluid dynamics theory, which can achieve regional and urban PM 2.5 Impact assessment, identification of key areas contributing to fireworks pollution and rapid response to pollution reduction measures, thereby achieving more effective supervision and control of concentrated fireworks discharge.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, component splitting or combination, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. The effect of fireworks on atmospheric PM 2.5 The impact assessment method is characterized by: The following steps are involved: S1. Collect emission source information in the study area and establish an emission source information database, including the type, size, launch time and launch location coordinate information of fireworks, as well as the launch height and charge data of various types of fireworks; S2. Obtain the distribution of monitoring sites and continuous monitoring data of the sites within the study area, and determine the target receptors and the study time; S3. Obtain high-resolution digital elevation data of the area where fireworks are set off from NASA as terrain data; use the mesoscale weather forecast model to simulate the sounding meteorological data of the area to be evaluated, including atmospheric pressure, altitude, dry bulb temperature, dew point temperature, wind direction and wind speed; obtain ground meteorological data from the China Meteorological Data Network and local meteorological monitoring departments, including precipitation, cloud height, cloud conditions, temperature, relative humidity, wind direction and wind speed; and obtain building parameters based on the planning and survey, including the distribution of the firing locations and their length, width and height; S4, PM based on nearby detection points 2.5 Real-time concentration monitoring data, analysis of PM2.5 emission sources 2.5 The emission characteristics and preliminary calculation of dynamic emission source strength were used to further calculate PM based on the total amount of fireworks and firecrackers. 2.5 Total emissions, and matching analysis of the results of the two calculation methods; S5. Based on computational fluid dynamics theory, simulate and calculate the impact of low-rise buildings in the firing area on airflow movement, determine the transmission path of pollutants from the emission source, and combine PM 2.5 The diffusion distribution and receptor sensitive point concentration prediction results can identify the impact points and impact levels to achieve pollutant supervision and control.

2. The effect of fireworks and firecrackers on atmospheric PM according to claim 1 2.5 The impact assessment method is characterized by: In step S3, the sounding meteorological data of the required assessment area is simulated using a mesoscale weather forecast model, which specifically includes the following steps: (1) Collection and collation of basic meteorological data: using multiple channels of national or larger meteorological initial field data to drive, assimilate meteorological field data, and substitute them into the mesoscale weather forecast model; (2) Determine the simulation grid accuracy of the mesoscale weather forecast model: the accuracy can be set from hundreds of meters to tens of kilometers according to actual forecast requirements; (3) Select the required simulation area: Establish a reasonable simulation nesting scheme and select the appropriate simulation area; (4) Data processing and analysis: Output the simulation results of the meteorological field in the specified simulation area; establish a numerical meteorological data system based on the mesoscale weather forecast model to simulate weather conditions and meteorological elements accurately.

3. The effect of fireworks and firecrackers on atmospheric PM according to claim 1 2.5 The impact assessment method is characterized by: In step S4, the calculation of the dynamic emission source intensity specifically includes the following steps: (1) Formula method The aerosol number concentration decreases in the vertical direction according to the negative exponential law. Fireworks and firecrackers have a significant impact on PM 2.5 The contribution decreases with height according to the negative exponential law, and the calculation formula is as follows: C Z =C0×e (-n×z) Where Z is the height and Cz is the PM at the height Z. 2.5 Concentration, C0 is ground PM 2.5 concentration, n is a constant, take n = 0.015; PM 2.5 Mix evenly in the horizontal direction, PM emitted by fireworks 2.5 The calculation formula of the total amount M is as follows: Where S is the area, t1 and t2 are the start and end time of the fireworks, Z is the height, and Cz is the PM at the height Z. 2.5 concentration; (2) Material balance method The explosion reaction after fireworks are ignited is mainly: S+2KNO3+3C→K2S+N2+3CO2; △H=-707KJ / mol The PM generated was estimated by K ion material balance. 2.5 Total amount; (3) Result fitting Fit the calculation results of the formula method and material balance method to estimate the PM generated 2.5 Total amount, that is, the emission source strength.

4. The effect of fireworks and firecrackers on atmospheric PM according to claim 1 2.5 The impact assessment method is characterized by: In step S5, based on the theory of computational fluid dynamics, the influence of low-rise buildings in the firing area on the airflow movement is simulated and calculated to determine the transmission path of the emission source pollutants. 2.5 The prediction results of diffusion distribution and receptor sensitive point concentration include the following steps: combining terrain data, real-time meteorological data and building parameters, constructing PM based on Gaussian plume diffusion theory and smoke puff diffusion theory 2.5 The diffusion model calculates the pollutant diffusion distribution characteristics of the emission source based on real-time meteorological data and predicts the pollutant concentration at sensitive points; the calculation equation for the pollutant concentration at any point in space is: Where Q is the emission source strength calculated in step S4, u is the average wind speed, and σ x , σ y , σ z are the diffusion parameters in the x, y and z directions respectively, H is the effective source height, and T is the time.

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