Device and experimental method for simulating atmospheric chemical reaction in actual environment in real time

Abstract

The invention provides a device for real-time simulation of a chemical reaction in an actual ambient atmosphere, the device comprises a main reactor, the main reactor sequentially comprises an outer negative-pressure cooling cavity, a middle transverse reaction cavity and an inner sample gas permeation and diffusion cavity from outside to inside, the outer negative-pressure cooling cavity is provided with a polymethylacrylic acid plate and a reflection light plate, and the middle transverse reaction cavity is provided with an inner sample gas permeation and diffusion cavity. A negative-pressure pump, an electrostatic eliminating meter, a heat exchanger and a turbulent flow fan are arranged in the outer-layer negative-pressure cooling cavity, a cylindrical membrane cabin made of polytetrafluoroethylene is arranged on the middle-layer transverse reaction cavity, a driving assembly for driving the middle-layer transverse reaction cavity to rotate is mounted in the axial direction of the middle-layer transverse reaction cavity, and a permeable membrane is arranged on the inner-layer sample gas permeation and diffusion cavity. The permeable membrane is in contact with the middle-layer transverse reaction cavity, the front end and the rear end of the inner-layer sample gas permeation and diffusion cavity are connected with an airflow assembly, and the main reactor is connected with a refrigeration system, a detection system, a seed aerosol injection system and a control box. The three-layer structural design solves the problem that the atmospheric chemical reaction cannot be continuously simulated in real time in the prior art, the gas exchange rate is remarkably improved, the aerosol wall loss is reduced, and the chemical reaction process of the ambient atmosphere is fully and truly simulated.

Description

Technical Field

[0001] The invention relates to the field of atmospheric science and technology, and in particular to a device and an experimental method for simulating atmospheric chemical reactions in real time. Background Art

[0002] In recent years, my country's air pollution has eased, but it still faces huge challenges. The average annual ozone concentration in many cities is still far from the standard. With the advancement of pollution control, the characteristics of air pollution have changed significantly. Recent studies have shown that the contribution of particulate matter generated by secondary transformation to winter haze has continued to increase, and ozone chemically transformed from nitrogen oxides and volatile organic compounds in summer has also become the primary pollutant in my country's urban areas. Therefore, it is particularly important to identify complex atmospheric chemical mechanisms. At present, although my country has established a complete observation system, such as fine particulate matter (PM 2.5 ), nitrogen dioxide (NO 2 ), ozone (O 3 ), but the detection of these species is difficult to meet the needs of exploring complex atmospheric chemical reactions. The atmosphere contains thousands of organic and inorganic gases that can undergo chemical reactions, especially under conditions of high radiative forcing, generating a large number of secondary aerosols, ozone and other secondary pollutants, which in turn aggravate air pollution. Therefore, clarifying the mechanism of atmospheric chemical reactions is of great guiding significance for the scientific management of the environment and atmosphere.

[0003] At present, there are few studies on the mechanism of real atmospheric chemical reactions, mainly due to the lack of stable simulation devices and methods. The technology of atmospheric chemical simulation at home and abroad is mainly carried out with the help of smoke box devices, mainly indoor smoke boxes. The ultraviolet lamps or xenon lamps of indoor smoke boxes irradiate and artificially produce strong ultraviolet light sources. The oxidizing property in the reaction chamber is 1-3 orders of magnitude higher than the real atmosphere, which will cause the cracking of some gas chemical molecules and produce additional chemical reactions that do not conform to the actual atmosphere, causing a lot of uncertainty. The parameters obtained in the experiment lack real representativeness, which in turn causes uncertainty in the simulation of air quality models. In addition, the existing outdoor smoke box technology methods are single, lack the collection and control of fluid airflow, and cannot achieve continuous atmospheric chemical simulation and observation.

[0004] In summary, existing research has many shortcomings in the device technology for simulating real atmospheric chemical reactions, which limits the in-depth understanding of atmospheric chemical mechanisms. Therefore, it is urgent to develop outdoor smoke chamber simulation technology in order to obtain real and effective atmospheric chemical parameters and make up for the shortcomings of existing technologies. It is urgent to develop a device and method for real-time simulation of real atmospheric chemical reactions. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a device and an experimental method for real-time simulation of atmospheric chemical reactions in an actual environment in view of the deficiencies of the above-mentioned prior art. The device can effectively solve the problems of inaccurate test results due to particulate matter adhering to the inner wall and the inability to simulate and detect the real atmospheric environment in real time for a long time.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a device for simulating atmospheric chemical reactions in real time, characterized in that it includes a main reactor, which includes an outer negative pressure refrigeration chamber, a middle transverse reaction chamber and an inner sample gas penetration diffusion chamber from the outside to the inside, a polymethyl methacrylate plate and a reflective light plate are arranged on the outer negative pressure refrigeration chamber, a negative pressure pump, an electrostatic eliminator, a heat exchanger and a turbulent fan are arranged in the outer negative pressure refrigeration chamber, a cylindrical membrane cabin made of polytetrafluoroethylene is arranged on the middle transverse reaction chamber, a driving component for driving the middle transverse reaction chamber to rotate is installed axially in the middle transverse reaction chamber, a permeable membrane is arranged on the inner sample gas penetration diffusion chamber, the permeable membrane is in contact with the inside of the middle transverse reaction chamber, the front and rear ends of the inner sample gas penetration diffusion chamber are connected to the airflow component, and the main reactor is connected to a refrigeration system, a detection system, a seed injection aerosol system and a control box.

[0007] Preferably, the outer negative pressure refrigeration chamber is a sealed box in the shape of a cube, and the outer negative pressure refrigeration chamber includes a main frame, and the main frame includes a stainless steel frame and an outer frame flange. A polymethacrylate plate is installed on the stainless steel frame through the outer frame flange to achieve a sealing effect. The polymethacrylate plate has a UV-transmitting property. A reflective plate is arranged at the bottom and the lower part of the side wall of the outer negative pressure refrigeration chamber, and the reflective plate includes a reflective aluminum plate, an expanded polytetrafluoroethylene reflective pad and a polytetrafluoroethylene film arranged from the inside to the outside.

[0008] Preferably, the middle-layer transverse reaction chamber includes a circular frame and a membrane cabin, the membrane cabin is fixed on the circular frame, the driving assembly includes a motor, a rotating shaft and a fixed shaft, the fixed shaft is fixedly mounted on the main frame, the rotating shaft is connected to the fixed shaft through a slewing bearing, the rotating shaft is fixedly connected to the circular frame, and the rotating shaft is transmission-connected to the output shaft of the motor. The rotating shaft and the fixed shaft are both hollow structures for connecting the seed injection aerosol system and the middle-layer transverse reaction chamber.

[0009] Preferably, the inner layer sample gas infiltration diffusion cavity is provided with an airflow component for the actual ambient atmosphere to enter, the inner layer sample gas infiltration diffusion cavity comprises a diffusion support frame and a diffusion film, the diffusion film is an expanded polytetrafluoroethylene film, the diffusion film is arranged on a cylindrical diffusion support frame, the airflow component comprises a rainproof sleeve, a filter cartridge and an air intake guide pipe, the filter cartridge is vertically fixed on the main frame, a sampling hole is provided on the filter cartridge, a rainproof sleeve is arranged on the top of the filter cartridge, and the filter cartridge is connected to the inner layer sample gas infiltration diffusion cavity through the air intake guide pipe.

[0010] Preferably, one end of the inner layer sample gas permeation diffusion chamber is connected to the air inlet guide tube, and the other end of the inner layer sample gas permeation diffusion chamber is connected to the sampling air pump through the air outlet guide tube, and a low pressure drop flow meter is provided on the air outlet guide tube.

[0011] Preferably, the middle-layer transverse reaction chamber has a positive pressure with a pressure difference of less than 30 Pa relative to the outer-layer negative-pressure refrigeration chamber.

[0012] Preferably, a controller is arranged in the control box, and the control box is connected to a motor, a negative pressure pump, a sampling air pump, a seed-injected particle system, a refrigeration system and a detection system; a cold air sheet connected to the refrigeration system is arranged in the outer negative pressure refrigeration cavity; the seed-injected particle system includes an aerosol generator, a drying tube and a particle sifter; and the detection system includes a nitrogen oxide, sulfur dioxide and ozone analyzer, a photon flux detector, an aerosol generator, an ozone generator, a scanning mobility particle size spectrometer, and an atmospheric pressure soft ionization ionization mass spectrometer.

[0013] Preferably, the rotating shaft is connected to the fixed shaft through a bearing, the rotating shaft is fixedly connected to the diffusion support frame through a diffusion support frame fixing groove, a bearing support cylinder for limiting the bearing is arranged on the inner side of the rotating shaft, a sealing gasket is arranged on the rotating shaft, and a particle outlet is opened on the rotating shaft; one end of the fixed shaft is fixedly mounted on a stainless steel frame through a fixed shaft base, a reaction gas channel, a seed particle channel and an environmental sample gas channel are opened on the fixed shaft base, an environmental sample gas channel outlet is arranged on the fixed shaft, and an O-ring is arranged on the fixed shaft.

[0014] A method for simulating a real atmospheric chemical reaction in real time using a device for simulating a real atmospheric chemical reaction in real time comprises the following steps:

[0015] S1. Select observation points: Select atmospheric observation points. The points need sufficient light. Debug and determine the detailed test plan to ensure that the points of the sample gas to be tested meet the representative requirements of the real atmospheric environment.

[0016] S2. Cleaning and installing the reactor: In the early stage of installation, bake the membrane cabin of the middle horizontal reaction chamber at 180°C for 12 hours to remove the volatile organic matter remaining on the surface of the material; in the early stage of the experiment, use ultrapure water to clean the inside and outside of the polymethyl methacrylate plate, and use dust-free paper soaked in alcohol to wipe the surface of the polytetrafluoroethylene film of the reflective light plate to increase the light transmittance; regularly introduce high-concentration ozone into the middle horizontal reaction chamber through the air flow duct to make the ozone concentration reach more than 5ppm, and continue for 12 hours or more to oxidize and clean the chemical substances attached to the wall surface in the middle horizontal reaction chamber; after cleaning, install the reactor at the observation point;

[0017] S3. Check the air tightness of the main reactor: block the air inlet and outlet, and continuously inject 1L / min of gas into the middle horizontal reaction chamber. The membrane cabin gradually swells, indicating that the air tightness is good;

[0018] S4. Connect the pipeline and adjust the flow rate: adjust the voltage of the sampling pump to achieve the set sampling flow rate;

[0019] S5, temperature control and adjustment: using a temperature sensor to detect the device temperature, turning on the refrigeration system (6) and adjusting the temperature so that the reactor temperature reaches the target value;

[0020] S6. Control and adjust the pressure difference: adjust the pressure difference between the middle horizontal reaction chamber and the outer negative pressure refrigeration chamber to reach the set threshold, so as to ensure that the membrane cabin of the middle horizontal reaction chamber is in a drum-like full state and the volume reaches a constant state;

[0021] S7. Determine the gas exchange rate: inject a high concentration of identification gas (such as carbon monoxide) into the air intake guide tube, use a gas detector to measure the concentration change in the middle horizontal reaction chamber, quantitatively calculate the gas diffusion exchange rate by the differential of concentration with respect to time, adjust the gas exchange rate, and analyze the reaction process under different oxidizing conditions;

[0022] S8. Determine the residence time: introduce a signature gas (such as carbon monoxide), detect the real-time change of the signature gas in the middle horizontal reaction chamber by a gas analyzer corresponding to the signature gas, perform curve fitting with time, obtain the residence time of the gas, and further calculate the half-life;

[0023] S9, driving the middle-layer lateral reaction chamber to rotate through the control box, with a rotation speed of less than 10 revolutions per minute;

[0024] S10, the main reactor continuously extracts atmospheric ambient air at a constant flow rate, and the extracted sample gas passes through the rainproof sleeve, the filter cartridge and the air inlet guide tube in turn, enters the inner layer sample gas penetration diffusion cavity, and is diffused to the middle layer transverse reaction cavity after the particles are filtered by the diffusion membrane; the atmospheric chemical simulation is divided into two modes, one is not adding additional reaction gas, and the second is adding additional reaction gas, and the additional reaction gas is directly introduced into the middle layer transverse reaction cavity through the air inlet guide tube;

[0025] S11. Simulate daytime atmospheric chemistry: Place the main reactor under sunlight, filter out particulate matter from the ambient air through the filter cartridge, and the particulate-free gas enters the inner layer sample gas penetration diffusion chamber. Further, the gas diffuses into the middle layer transverse reaction chamber. Due to light radiation, hydroxyl and peroxyhydroxyl free radicals are generated. The gas entering the middle layer transverse reaction chamber undergoes multi-generation oxidation reactions to generate reaction oxidation products and secondary oxidation products, and new particulate matter is generated along with the physical process.

[0026] S12. Detection of reactants and reaction products: The detection system is connected to the middle-layer transverse reaction chamber, and the detection system detects the components and concentrations of the reactants and products of atmospheric chemistry occurring in the membrane cabin in real time;

[0027] S13. Calculate the reaction process: Based on the chemical molecular formula of the reaction products detected by the detection system, identify and screen the species, incorporate them into the chemical theoretical calculation model, input the parameters measured in the experiment into the chemical theoretical calculation model, and use the chemical theoretical calculation model to calculate the concentration of free radicals in the middle-level lateral reaction cavity, oxidation products, reaction products of different pathways, and oxidation process parameters. Explain the measured results of laboratory simulation and explore the characteristics of the chemical mechanism.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] 1. The present invention sets a micro-positive pressure to drive the membrane cabin of the middle-layer horizontal reaction chamber to be full and constant in volume, thereby enhancing circulation and eliminating dead-angle airflow, which is conducive to rotation to generate laminar flow.

[0030] 2. The present invention diffuses gas axially to the middle-layer horizontal reaction chamber through the inner-layer horizontal sample gas penetration chamber. The gas undergoes a photochemical reaction under natural light. A flow reactor is used to continuously collect a large amount of ambient air to simulate and detect atmospheric chemical reactions. The design is scientific and reasonable, the use effect is good, and the detection effect is accurate.

[0031] 3. The present invention drives the middle-layer horizontal reaction chamber to rotate slowly through a driving component, so that the airflow in the chamber produces axial laminar flow, thereby reducing the wall loss of particles caused by gravity, and evenly eliminates the static electricity generated at the interface of the polytetrafluoroethylene membrane and the polymethacrylic acid plate through an anti-static meter, thereby reducing the wall loss of nano-scale particles caused by electrostatic adsorption.

[0032] 4. The present invention can operate 24 hours a day to comprehensively observe the atmospheric chemical reaction process during the day and at night. The device has good sealing performance, is wind-proof and rain-proof, and can operate all year round to further simulate and compare the differences in atmospheric chemical reactions in different seasons.

[0033] 5. The device of the present invention is small in size and convenient to transport and carry. It is suitable for observation of complex points in multiple scenes. It can flexibly adjust the temperature and vacuum degree in the main reactor to simulate real atmospheric chemical reactions in the closest way.

[0034] The present invention is further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0036] Figure 2 It is a schematic diagram of the three-dimensional structure of the main reactor of the present invention.

[0037] Figure 3 It is a side structural schematic diagram of the main reactor in the present invention.

[0038] Figure 4 It is a fixed-axis stereogram of the main reactor in the present invention.

[0039] Figure 5 It is a three-dimensional diagram of the rotating shaft of the main reactor in the present invention.

[0040] Figure 6 It is a comparison chart of volatile organic compounds in the main reactor and the ambient atmosphere in the present invention.

[0041] Description of reference numerals:

[0042] 1—Main frame; 2—Outer negative pressure refrigeration chamber; 3—Middle horizontal reaction chamber; 4—Inner layer sample gas permeation diffusion chamber; 5—Control box; 6—Refrigeration system;

[0043] 7—Detection system; 8—Seed particle injection system; 1-1—Stainless steel frame; 1-2—External frame flange; 1-3—Polymethacrylic plate; 1-4—Inner bracket;

[0044] 1-5—polymethacrylic acid strip; 2-1—static eliminator; 2-2—reflective light plate; 2-3—turbulence fan; 2-4—negative pressure suction pump; 3-1—membrane cabin;

[0045] 3-2—round frame support frame; 3-3—round frame; 3-4—motor;

[0046] 3-5—rotating shaft; 3-6—fixed shaft; 3-7—connecting shaft;

[0047] 4-1—Rainproof sleeve; 4-2—Filter cartridge; 4-3—Flange and air intake guide pipe

[0049] 4-4—Sample gas permeation diffusion chamber; 4-4-1—Diffusion support frame; 4-4-2—Expanded polytetrafluoroethylene membrane

[0051] 4-5—flow meter; 4-5—sample gas pump; 6-1—water chiller;

[0052] 6-2—heat sink; 8-1—particle generator; 8-2—drying tube;

[0053] 8-3—particle sifter; 3-5-1—diffusion support frame fixing groove; 3-5-2—bearing;

[0055] 3-5-3—Bearing support cylinder; 3-5-4—Sealing gasket; 3-5-5—Particle outlet;

[0057] 3-6-1—Environmental sample gas channel; 3-6-2—Seed particle channel; 3-6-3—Reaction gas channel;

[0059] 3-6-4—fixed axis base; 3-6-5—O-ring; 3-6-6—environmental sample gas channel outlet. DETAILED DESCRIPTION

[0061] Example 1

[0062] like Figures 1 to 5 As shown, this embodiment provides a device for simulating atmospheric chemical reactions in an actual environment in real time, including a main reactor, which includes, from the outside to the inside, an outer negative pressure refrigeration chamber 2, a middle transverse reaction chamber 3 and an inner sample gas penetration diffusion chamber 4, a polymethyl methacrylate plate 1-3 and a reflective light plate 2-2 are arranged on the outer negative pressure refrigeration chamber 2, a negative pressure pump 2-4, an electrostatic eliminator 2-1 and a turbulent fan 2-3 are arranged in the outer negative pressure refrigeration chamber 2, a membrane cabin 3-1 made of polytetrafluoroethylene is arranged on the middle transverse reaction chamber 3, a driving component for driving the middle transverse reaction chamber 3 to rotate is installed on the middle transverse reaction chamber 3, an airflow component is arranged on the inner sample gas penetration diffusion chamber 4, and a refrigeration system 6, a detection system 7, a seed injection aerosol system 8 and a control box 5 are connected to the main reactor.

[0063] In this embodiment, the outer negative pressure refrigeration chamber 2 is a sealed box in the shape of a cube, and the outer negative pressure refrigeration chamber 2 includes a main frame 1, and the main frame 1 includes a stainless steel frame 1-1 and an outer frame flange 1-2. A polymethacrylate plate 1-3 is installed on the stainless steel frame 1-1 through the outer frame flange 1-2 to achieve a sealing effect. The polymethacrylate plate 1-3 has an ultraviolet light-transmitting property. A reflective plate 2-2 is set at the bottom and the lower part of the side wall of the outer negative pressure refrigeration chamber 2. The reflective plate 2-2 includes a reflective aluminum plate, an expanded polytetrafluoroethylene reflective pad and a polytetrafluoroethylene film arranged from the inside to the outside.

[0064] In this embodiment, the middle-level transverse reaction chamber 3 includes a circular frame 3-3 and a membrane cabin 3-1, the membrane cabin 3-1 is fixed on the circular frame 3-3, the driving assembly includes a motor 3-4, a rotating shaft 3-5 and a fixed shaft 3-6, the fixed shaft 3-6 is fixedly mounted on the main frame 1, the rotating shaft 3-5 is connected to the fixed shaft 3-6 through a slewing bearing, the rotating shaft 3-5 is fixedly connected to the circular frame 3-3, and the rotating shaft 3-5 is transmission-connected to the output shaft of the motor 3-4. The rotating shaft 3-5 and the fixed shaft 3-6 are both hollow structures for connecting the seed injection aerosol system 8 and the middle-level transverse reaction chamber 3.

[0065] In this embodiment, the inner layer sample gas infiltration diffusion chamber 4 is provided with an airflow component for the actual ambient atmosphere to enter, the inner layer sample gas infiltration diffusion chamber 4 includes a diffusion support frame 4-4-1 and a diffusion film 4-4-2, the diffusion film 4-4-2 is an expanded polytetrafluoroethylene film, the diffusion film 4-4-2 is arranged on a cylindrical diffusion support frame 4-4-1, the airflow component includes a rainproof sleeve 4-1, a filter cartridge 4-2 and an air intake guide pipe 4-3, the filter cartridge 4-2 is vertically fixed on the main frame 1, a sampling hole is provided on the filter cartridge 4-2, a rainproof sleeve 4-1 is arranged on the top of the filter cartridge 4-2, and the filter cartridge 4-2 is connected to the inner layer sample gas infiltration diffusion chamber 4 through the air intake guide pipe 4-3.

[0066] In this embodiment, the rotating shaft 3-5 is connected to the fixed shaft 3-6 through the bearing 3-5-2, and the rotating shaft 3-5 is fixedly connected to the diffusion support frame 4-4-1 through the diffusion support frame fixing groove 3-5-1. A bearing support cylinder 3-5-3 for limiting the bearing 3-5-2 is arranged on the inner side of the rotating shaft 3-5, a sealing gasket 3-5-4 is arranged on the rotating shaft 3-5, and a particle outlet 3-5-5 is opened on the rotating shaft 3-5; one end of the fixed shaft 3-6 is fixedly installed on the stainless steel frame 1-1 through a fixed shaft base 3-6-4, and a reaction gas channel 3-6-3, a seed particle channel 3-6-2 and an environmental sample gas channel 3-6-1 are opened on the fixed shaft base 3-6-4, an environmental sample gas channel outlet 3-6-6 is arranged on the fixed shaft 3-6, and an O-ring 3-6-5 is arranged on the fixed shaft 3-6.

[0067] In this embodiment, one end of the inner layer sample gas permeation diffusion chamber 4 is connected to the air inlet guide tube 4-3, and the other end of the inner layer sample gas permeation diffusion chamber 4 is connected to the sampling air pump 4-6 through the air outlet guide tube, and a low pressure drop flowmeter 4-5 is provided on the air outlet guide tube.

[0068] In this embodiment, the middle-layer transverse reaction chamber 3 is at a positive pressure with a pressure difference of less than 30 Pa relative to the outer-layer negative-pressure refrigeration chamber 2 .

[0069] In this embodiment, a controller is arranged in the control box 5, and the control box 5 is connected to the motor 3-4, the negative pressure pump 2-4, the sampling air pump 4-6, the seed particle injection system 8, the refrigeration system 6 and the detection system 7. The outer negative pressure refrigeration chamber 2 is provided with a cold air sheet 6-2 connected to the refrigeration system 6. The seed particle injection system 8 includes an aerosol generator 8-1, a drying tube 8-2 and a particle sifter 8-3. The detection system 7 includes NOx, SO 2 and O 3 Analyzer, photon flux detector, aerosol generator, O 3 Generator, scanning mobility particle size spectrometer, atmospheric pressure soft ionization mass spectrometer.

[0070] Example 2

[0071] This embodiment provides a method for simulating a real atmospheric chemical reaction in real time using a device for simulating a real atmospheric chemical reaction in real time, comprising the following steps:

[0072] S1. Select observation points: Select atmospheric observation points. The points need sufficient light. Debug and determine the detailed test plan to ensure that the points of the sample gas to be tested meet the representative requirements of the real atmospheric environment.

[0073] S2. Cleaning and installing the reactor: In the early stage of installation, the membrane cabin 3-1 of the middle horizontal reaction chamber 3 is baked at 180°C for 12 hours to remove the volatile organic matter remaining on the surface of the material; in the early stage of the experiment, ultrapure water is used to clean the inner and outer sides of the polymethyl methacrylate plate 1-3, and the surface of the polytetrafluoroethylene film of the reflective light plate 2-2 is wiped with dust-free paper soaked in alcohol to increase the light transmittance; high-concentration ozone is regularly introduced into the middle horizontal reaction chamber 3 through the air flow duct 4-3 to make the ozone concentration reach more than 5ppm, and it lasts for 12 hours or more to oxidize and clean the chemical substances attached to the wall surface in the middle horizontal reaction chamber 3; after cleaning, the reactor is installed at the observation point;

[0074] S3. Check the air tightness of the main reactor: block the air inlet and outlet, and continuously inject 1L / min of gas into the middle horizontal reaction chamber 3. The membrane cabin 3-1 gradually swells, indicating that the air tightness is good;

[0075] S4, connect the pipeline and adjust the flow rate: adjust the voltage of the sampling pump 4-6 to achieve the set sampling flow rate;

[0076] S5, temperature control and adjustment: use the temperature sensor to detect the device temperature, turn on the refrigeration system 6 and adjust the temperature so that the reactor temperature reaches the target value;

[0077] S6, control and adjust the pressure difference: adjust the pressure difference between the middle layer transverse reaction chamber 3 and the outer layer negative pressure refrigeration chamber 2 to reach the set threshold, ensure that the membrane cabin of the middle layer transverse reaction chamber 3 is in a drum-like full state, and the volume reaches a constant state;

[0078] S7, determine the gas exchange rate: inject a high concentration of identification gas such as carbon monoxide into the intake guide pipe 4-3, use a gas detector to measure the concentration change in the middle horizontal reaction chamber 3, quantitatively calculate the gas diffusion exchange rate by the differential of the concentration with respect to time, adjust the gas exchange rate, and analyze the reaction process under different oxidizing conditions;

[0079] S8. Determine the residence time: introduce a signature gas such as carbon monoxide, detect the real-time change of the signature gas in the middle horizontal reaction chamber 3 by a gas analyzer corresponding to the signature gas, perform curve fitting with time, obtain the residence time of the gas, and further calculate the half-life;

[0080] S9, driving the middle-layer horizontal reaction chamber 3 to rotate through the control box 5, with a rotation speed less than 10 rpm;

[0081] S10, the main reactor continuously extracts atmospheric ambient air at a constant flow rate, and the extracted sample gas passes through the rainproof sleeve 4-1, the filter cartridge 4-2 and the air inlet guide tube 4-3, enters the inner layer sample gas penetration diffusion chamber 4, and is diffused to the middle layer transverse reaction chamber 3 after the particles are filtered by the diffusion film 4-4-2; the atmospheric chemical simulation is divided into two modes, one is not adding additional reaction gas, and the second is adding additional reaction gas, and the additional reaction gas is directly introduced into the middle layer transverse reaction chamber 3 by the air inlet guide tube 4-3;

[0082] S11. Simulating daytime atmospheric chemistry: placing the main reactor under sunlight, filtering out particulate matter from the ambient air through the filter cartridge 4-2, and allowing the particulate-free gas to enter the inner layer sample gas penetration diffusion chamber 4. Further, the gas diffuses into the middle layer transverse reaction chamber 3. Due to light radiation, hydroxyl and peroxyhydroxyl free radicals are generated. The gas entering the middle layer transverse reaction chamber 3 undergoes multiple generations of oxidation reactions, generating reaction oxidation products and secondary oxidation products, and generating new particulate matter along with the physical process.

[0083] S12, detection of reactants and reaction products: the detection system 7 is connected to the middle horizontal reaction chamber 3, and the detection system 7 detects the components and concentrations of the reactants and products of atmospheric chemistry occurring in the membrane cabin 3-1 in real time. Figure 6 As shown;

[0084] S13. Calculate the reaction process: Based on the chemical molecular formula of the reaction product detected by the detection system 7, identify and screen the species, incorporate them into the chemical theoretical calculation model, input the parameters measured in the experiment into the chemical theoretical calculation model, use the chemical theoretical calculation model to calculate the concentration of free radicals in the middle-level lateral reaction cavity 3, oxidation products, reaction products of different pathways, oxidation process parameters, explain the actual measurement results of laboratory simulation, and explore the characteristics of chemical mechanisms.

[0085] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A device for simulating chemical reactions in the actual environment in real time, characterized in that: The invention comprises a main reactor, which comprises, from the outside to the inside, an outer negative pressure refrigeration chamber (2), a middle transverse reaction chamber (3) and an inner sample gas permeation diffusion chamber (4); the outer negative pressure refrigeration chamber (2) provides a negative pressure, temperature control, enhanced illumination and static-free environment; a polymethyl methacrylate plate (1-3) and a light reflecting plate (2-2) are arranged on the outer negative pressure refrigeration chamber (2); a negative pressure pump (2-4), an antistatic meter (2-1) and a turbulent fan (2-3) are arranged in the outer negative pressure refrigeration chamber (2); ); a membrane cabin (3-1) made of polytetrafluoroethylene is arranged on the middle-layer transverse reaction chamber (3); a driving component for driving the middle-layer transverse reaction chamber (3) to rotate is installed on the middle-layer transverse reaction chamber (3); the inner-layer sample gas permeation diffusion chamber (4) permeates and diffuses gas into the middle-layer transverse reaction chamber (3); an airflow component is arranged on the inner-layer sample gas permeation diffusion chamber (4); a refrigeration system (6), a detection system (7), a seed injection aerosol system (8) and a control box (5) are connected to the main reactor.

2. The device for simulating chemical reactions in the actual environment atmosphere in real time according to claim 1, characterized in that: The outer negative pressure refrigeration chamber (2) is a sealed box in the shape of a cube that is transparent to ultraviolet light. The outer negative pressure refrigeration chamber (2) comprises a main frame (1), and the main frame (1) comprises a stainless steel frame (1-1) and an outer frame flange (1-2). A polymethyl methacrylate plate (1-3) is installed on the stainless steel frame (1-1) through the outer frame flange (1-2) to achieve a sealing effect. The polymethyl methacrylate plate (1-3) has the property of being transparent to ultraviolet light. A reflective plate (2-2) is arranged at the bottom and the lower part of the side wall of the outer negative pressure refrigeration chamber (2). The reflective plate (2-2) comprises a reflective aluminum plate, an expanded polytetrafluoroethylene reflective pad and a polytetrafluoroethylene film arranged from the inside to the outside.

3. The device for simulating chemical reactions in the actual environment atmosphere in real time according to claim 1, characterized in that: The middle-layer transverse reaction chamber (3) comprises a circular frame (3-3) and a membrane cabin (3-1), wherein the membrane cabin (3-1) is fixed on the circular frame (3-3), and the driving assembly comprises a motor (3-4), a rotating shaft (3-5) and a fixed shaft (3-6), wherein the fixed shaft (3-6) is fixedly mounted on the main frame (1), and the rotating shaft (3-5) is connected to the fixed shaft (3-6) via a slewing bearing, and the rotating shaft (3-5) is fixedly connected to the circular frame (3-3), and the rotating shaft (3-5) is transmission-connected to the output shaft of the motor (3-4), and the rotating shaft (3-5) and the fixed shaft (3-6) are both hollow structures for connecting the seed injection aerosol system (8) and the middle-layer transverse reaction chamber (3).

4. The device for simulating chemical reactions in the actual environment atmosphere in real time according to claim 1, characterized in that: The inner layer sample gas penetration diffusion chamber (4) is provided with an airflow component for continuous entry of the actual ambient atmosphere. The inner layer sample gas penetration diffusion chamber (4) comprises a diffusion support frame (4-4-1) and a diffusion film (4-4-2). The diffusion film (4-4-2) is an expanded polytetrafluoroethylene film. The diffusion film (4-4-2) is arranged on a cylindrical diffusion support frame (4-4-1). The airflow component comprises a rainproof sleeve (4-1), a filter cartridge (4-2) and an air intake guide pipe (4-3). The filter cartridge (4-2) is vertically fixed on the main frame (1). A sampling hole is provided on the filter cartridge (4-2). A rainproof sleeve (4-1) is arranged on the top of the filter cartridge (4-2). The filter cartridge (4-2) is connected to the inner layer sample gas penetration diffusion chamber (4) through the air intake guide pipe (4-3).

5. The device for simulating chemical reactions in the actual environment atmosphere in real time according to claim 4, characterized in that: The gas permeates and diffuses from the diffusion film (4-4-2) into the middle-layer transverse reaction chamber (3); one end of the inner-layer sample gas permeation diffusion chamber (4) is connected to the air inlet guide tube (4-3); the other end of the inner-layer sample gas permeation diffusion chamber (4) is connected to the sampling air pump (4-6) through the air outlet guide tube; and a low-pressure drop flow meter (4-5) is provided on the air outlet guide tube.

6. The device for simulating chemical reactions in the actual environment atmosphere in real time according to claim 1, characterized in that: The middle-layer transverse reaction chamber (3) has a positive pressure with a pressure difference of less than 30 Pa relative to the outer-layer negative-pressure refrigeration chamber (2), and the pressure difference drives the membrane cabin (3-1) to be round and full with a constant volume.

7. The device for simulating chemical reactions in the actual environment atmosphere in real time according to claim 3, characterized in that: The control box (5) is provided with a controller, and the control box (5) is connected to a motor (3-4), a negative pressure pump (2-4), a sampling air pump (4-6), a seed particle injection system (8), a refrigeration system (6) and a detection system (7). The outer negative pressure refrigeration chamber (2) is provided with a cold air sheet (6-2) connected to the refrigeration system (6). The seed particle injection system (8) includes an aerosol generator (8-1), a drying tube (8-2) and a particle sifter (8-3). The detection system (7) includes a NOx, SO2 and O3 analyzer, a photon flux detector, an aerosol generator, an O3 generator, a scanning electric mobility particle size spectrometer, and an atmospheric pressure soft ionization mass spectrometer. The rotating shaft (3-5) is connected to the fixed shaft (3-6) through a bearing (3-5-2). The rotating shaft (3-5) is connected to the fixed shaft (3-6) through a bearing (3-5-2). The diffusion support frame fixing groove (3-5-1) is fixedly connected to the diffusion support frame (4-4-1); a bearing support cylinder (3-5-3) for limiting the bearing (3-5-2) is arranged on the inner side of the rotating shaft (3-5); a sealing gasket (3-5-4) is arranged on the rotating shaft (3-5); and a particle outlet (3-5-5) is provided on the rotating shaft (3-5); one end of the fixed shaft (3-6) is fixedly installed on the stainless steel frame (1-1) through a fixed shaft base (3-6-4); a reaction gas channel (3-6-3), a seed particle channel (3-6-2) and an environmental sample gas channel (3-6-1) are provided on the fixed shaft base (3-6-4); an environmental sample gas channel outlet (3-6-6) is provided on the fixed shaft (3-6); and an O-type sealing ring (3-6-5) is provided on the fixed shaft (3-6).

8. A method for simulating real atmospheric chemical reactions in real time using the device for simulating real atmospheric chemical reactions in real time according to any one of claims 1 to 7, characterized in that: The steps include: S1. Select observation points: Select atmospheric observation points. The points need sufficient light. Debug and determine the detailed test plan to ensure that the points of the sample gas to be tested meet the representative requirements of the real atmospheric environment. S2. Cleaning and installing the main reactor: In the early stage of installation, the membrane cabin (3-1) of the middle horizontal reaction chamber (3) is baked at 180°C for 12 hours to remove the volatile organic matter remaining on the surface of the material; in the early stage of the experiment, ultrapure water is used to clean the inside and outside of the polymethyl methacrylate plate (1-3), and the surface of the polytetrafluoroethylene film of the reflective light plate (2-2) is wiped with dust-free paper soaked in alcohol to increase the light transmittance; high-concentration ozone is regularly introduced into the middle horizontal reaction chamber (3) through the air flow duct (4-3) to make the ozone concentration reach more than 5ppm, and it is continuously for 12 hours or more to oxidize and clean the chemical substances attached to the wall surface in the middle horizontal reaction chamber (3); after cleaning, the main reactor is installed at the observation point; S3. Check the air tightness of the main reactor: block the air inlet and outlet, and continuously inject 1L / min of gas into the middle horizontal reaction chamber (3). The membrane cabin (3-1) gradually swells, indicating that the air tightness is good; S4. Connect the pipeline and adjust the flow rate: adjust the voltage of the sampling pump (4-6) to achieve the set sampling flow rate; S5, temperature control and adjustment: using a temperature sensor to detect the device temperature, turning on the refrigeration system (6) and adjusting the temperature so that the temperature of the main reactor reaches the target value; S6, control and adjust the pressure difference: adjust the pressure difference between the middle layer transverse reaction chamber (3) and the outer layer negative pressure refrigeration chamber (2) to reach the set threshold value, ensure that the membrane cabin of the middle layer transverse reaction chamber (3) is in a drum-like full state, and the volume reaches a constant state; S7, determining the gas exchange rate: injecting a high concentration of identification gas into the air inlet guide tube (4-3), using a gas detector to measure the concentration change in the middle horizontal reaction chamber (3), quantitatively calculating the gas diffusion exchange rate by the differential of the concentration with respect to time, adjusting the gas exchange rate, and analyzing the reaction process under different oxidizing conditions; S8. Determine the residence time: introduce the identification gas, detect the real-time change of the identification gas in the middle horizontal reaction chamber (3) by using a gas analyzer corresponding to the identification gas, perform curve fitting with time, obtain the residence time of the gas, and further calculate the half-life; S9, driving the middle-layer transverse reaction chamber (3) to rotate via the control box (5), with the rotation speed being less than 10 revolutions per minute; S10, the main reactor continuously extracts atmospheric ambient air at a constant flow rate, and the extracted sample gas passes through the rainproof sleeve (4-1), the filter cartridge (4-2) and the air inlet guide tube (4-3) in turn, enters the inner layer sample gas penetration diffusion chamber (4), and is diffused to the middle layer transverse reaction chamber (3) after the particles are filtered by the diffusion film (4-4-2); the atmospheric chemical simulation is divided into two modes, one is not adding additional reaction gas, and the second is adding additional reaction gas, and the additional reaction gas is directly introduced into the middle layer transverse reaction chamber (3) by the air inlet guide tube (4-3); S11. Simulating daytime atmospheric chemistry: placing the main reactor under sunlight, filtering out particulate matter from the ambient air through the filter cartridge (4-2), and allowing the particulate-free gas to enter the inner layer sample gas penetration diffusion chamber (4). Further, the gas diffuses into the middle layer transverse reaction chamber (3). Due to light radiation, hydroxyl and peroxyhydroxyl free radicals are generated. The gas entering the middle layer transverse reaction chamber (3) undergoes multiple generations of oxidation reactions, generating reaction oxidation products and secondary oxidation products, and generating new particulate matter along with the physical process. S12, detecting reactants and reaction products: the detection system (7) is connected to the middle-layer transverse reaction chamber (3), and the detection system (7) detects the components and concentrations of the reactants and products of atmospheric chemistry occurring in the membrane cabin (3-1) in real time; S13. Calculate the reaction process: Based on the chemical molecular formula of the reaction product detected by the detection system (7), identify and screen the species, incorporate them into the chemical theoretical calculation model, input the parameters measured in the experiment into the chemical theoretical calculation model, use the chemical theoretical calculation model to calculate the concentration of free radicals, oxidation products, reaction products of different pathways, and oxidation process parameters in the middle-level lateral reaction cavity (3), explain the actual measurement results of the laboratory simulation, and explore the characteristics of the chemical mechanism.

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