An in-situ simulation system and experimental method for liquid-phase chemical processes of particulate matter in ambient atmosphere

Abstract

The present invention belongs to the fields of atmospheric science and environmental engineering technology, and discloses an in-situ simulation system and experimental method for liquid-phase chemical processes of particulate matter in the ambient atmosphere. The system comprises a first real-environment smoke chamber 1, a second real-environment smoke chamber 2, a zero-gas system 3, a seed aerosol generating system 4, a humidification system 5, a sheath gas system 6, and a measurement system 7. The first real-environment smoke chamber 1 and the second real-environment smoke chamber 2 are each connected to the zero-gas system 3, the seed aerosol generating system 4, the sheath gas system 6, and the measurement system 7. The present invention utilizes two identical real-environment smoke chambers to simultaneously simulate gas-phase and liquid-phase reactions of particulate matter under varying humidity and solar radiation conditions. This overcomes the bottleneck of conventional smoke chamber simulations, which suffer from significant discrepancies between actual atmospheric reaction processes and the resulting poor applicability of the conclusions. The system provides a method for revealing the liquid-phase chemical processes and reaction mechanisms of particulate matter in the atmospheric environment.

Description

Technical Field

[0001] The present invention belongs to the fields of atmospheric science and environmental engineering technology, and in particular to an in-situ simulation system and experimental method for liquid-phase chemical processes of particulate matter in ambient atmosphere. Background Art

[0002] In-depth research on atmospheric chemical processes has become one of the keys to promoting my country's air pollution prevention and control work. 2.5 Secondary components are prominent in the pollution process, and secondary transformation processes are the primary driving force. Atmospheric liquid-phase reactions are considered a key secondary transformation process, contributing significantly to the formation of severe regional pollution. Liquid-phase reactions are chemical reactions using liquid water as a medium. Research has found that incorporating liquid-phase reactions can significantly bridge the gap between simulated particulate matter concentrations using gas-phase reactions and ambient atmospheric observations. Therefore, in-depth research on the liquid-phase chemical reaction mechanisms of atmospheric particulate matter is essential.

[0003] Laboratory simulation is one of the primary methods for studying the liquid-phase chemical reaction mechanisms of atmospheric particulate matter. However, currently commonly used laboratory simulation methods, such as reaction chamber experiments, still have significant limitations. Reactor chamber simulations use zero air or artificially inject one or more gaseous pollutants as the simulated gaseous environment. The single reaction system cannot reflect the complex gas components found in the real atmospheric environment. Furthermore, reaction conditions such as temperature, humidity, and ultraviolet radiation vary significantly. As a result, the liquid-phase chemical process simulation results from laboratory reaction chambers cannot fully interpret the actual particulate matter reaction processes in the ambient atmosphere. This limits in-depth research on atmospheric liquid-phase reaction mechanisms using laboratory simulations, and the applicability and accuracy of the obtained mechanisms are also controversial.

[0004] In summary, there is an urgent need to develop an in situ simulation system and experimental method for the liquid-phase chemical process of particulate matter in the ambient atmosphere, which can simulate liquid-phase chemical reactions under conditions close to the real atmospheric environment, and simultaneously carry out comparative studies of simulations of controllable key parameters and ambient atmospheric observations, which will help to clarify the reaction mechanism of atmospheric liquid-phase chemistry. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide an in-situ simulation system and experimental method for the liquid phase chemical process of ambient atmospheric particulate matter.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A system for in-situ simulation of liquid-phase chemical processes of particulate matter in the ambient atmosphere, the system comprising a first real-environment smoke chamber 1, a second real-environment smoke chamber 2, a zero gas system 3, a seed aerosol generating system 4, a humidification system 5, a sheath gas system 6, and a measurement system 7. The first real-environment smoke chamber 1 and the second real-environment smoke chamber 2 are respectively connected to the zero gas system 3, the seed aerosol generating system 4, the sheath gas system 6, and the measurement system 7. The first real-environment smoke chamber 1 and the second real-environment smoke chamber 2 are also connected to the ambient atmosphere. The second real-environment smoke chamber 2 is also connected to the humidification system 5. The zero gas system 3 is directly connected to the first real-environment smoke chamber 1 and the second real-environment smoke chamber 2. The zero gas system 3 is also connected to the first real-environment smoke chamber 1 and the second real-environment smoke chamber 2 via the sheath gas system 6.

[0008] The zero gas system 3 can provide zero gas to the first real environment smoke box 1 and the second real environment smoke box 2 before and after the experiment for internal purging and cleaning to ensure the clean state of the smoke box before the experiment; the zero gas system 3 can also provide zero gas to the sheath gas system 6 during the experiment, so that the sheath gas system 6 can provide sheath gas to the first real environment smoke box 1 and the second real environment smoke box 2 to reduce wall loss during the experiment;

[0009] The seed aerosol generating system 4 can provide a monodisperse aerosol with surface water molecules removed as a seed aerosol for the simulation experiment inside the first real environment smoke box 1 and the second real environment smoke box 2;

[0010] The humidification system 5 can provide a controllable high-humidity airflow to the second real environment smoke box 2, thereby adjusting the reaction environment humidity in the second real environment smoke box 2 and differentiating the reaction humidity from the first real environment smoke box 1;

[0011] The sheath gas system 6 can provide sheath gas to the first real environment smoke box 1 and the second real environment smoke box 2 to reduce the wall loss of the real environment smoke box;

[0012] The measurement system 7 can measure the concentration, chemical composition, and temperature and humidity parameters of gases and particulate matter in the first real environment smoke chamber 1 and the second real environment smoke chamber 2 online during the experiment, capture the changes in the physical and chemical characteristics of the pollution and the reaction conditions with high time resolution, and realize comparative studies of the reactions between the two real environment smoke chambers and with the atmospheric environment.

[0013] Furthermore, the device also includes an air pump 1-11, which can be tightly connected to the first real environment smoke box 1 and the second real environment smoke box 2. The air pump 1-11 can enable the gas in the first real environment smoke box 1 and the second real environment smoke box 2 to be continuously and quickly exchanged with the atmosphere, so that the gaseous environment in the first real environment smoke box 1 and the second real environment smoke box 2 is close to the ambient atmosphere during the entire simulation process.

[0014] Furthermore, the structures of the first real environment smoke box 1 and the second real environment smoke box 2 are completely consistent. The first real environment smoke box 1 and the second real environment smoke box 2 both include an outer supporting layer 1-1, an inner membrane layer 1-2, a semipermeable membrane 1-3, a reaction chamber 1-4, a flow chamber 1-5 and a sheath gas space 1-6. The inner membrane layer 1-2 is closely spaced and connected and arranged in the outer supporting layer 1-1. A sealed space sheath gas space 1-6 is formed between the inner membrane layer 1-2 and the outer supporting layer 1-1. The sheath gas space 1-6 is used for sheath gas circulation; a closed space is formed in the inner membrane layer 1-2, and the semipermeable membrane 1-3 is arranged in the horizontal direction and is tightly and detachably connected and arranged in the middle and lower part of the inner membrane layer 1-2. The semipermeable membrane 1-3 separates the closed space of the inner membrane layer 1-2 into a reaction chamber 1-4 and a flow chamber 1-5. The reaction chamber 1-4 is arranged above the flow chamber 1-5.

[0015] The top and bottom outer support layers 1-1 of the sheath gas space 1-6 are tightly connected to form sheath gas ventilation ports 1-12, which can inject or discharge sheath gas to maintain the sheath gas circulation in the sheath gas space 1-6;

[0016] A plurality of sample inlets / sampling ports 1-9 are tightly connected to the center of the side walls of the reaction chamber 1-4. In this embodiment, two sample inlets / sampling ports 1-9 are provided on each side. The sample inlets / sampling ports 1-9 are tightly connected to the interior of the reaction chamber 1-4. The sample inlets / sampling ports 1-9 pass tightly through the outer support layer 1-1 and the inner film layer 1-2 to ensure a sealed interface. The sample inlets / sampling ports 1-9 are used to inject seed aerosols into the reaction chamber 1-4 or collect samples from the reaction chamber 1-4. The sample inlets / sampling ports 1-9 are also used to connect to the zero gas system 3 to purge and clean the interior of the smoke chamber before and after the experiment.

[0017] A plurality of gas flow ports 1-10 are tightly connected at the center positions of the horizontal side walls of the flow chamber 1-5, and the gas flow ports 1-10 are tightly connected with the inside of the flow chamber 1-5; the gas flow ports 1-10 tightly pass through the outer support layer 1-1 and the inner membrane layer 1-2; the gas flow ports 1-10 on the horizontal side of the flow chamber 1-5 of the first real environment smoke box 1 are tightly connected with the air pump 1-11; the gas flow ports 1-10 on the horizontal side of the flow chamber 1-5 of the second real environment smoke box 2 are tightly connected with one end of the humidification system 5, and the other end of the humidification system 5 is tightly connected with the air pump 1-11; the gas flow ports 1-10 on the other horizontal side of the flow chamber 1-5 are fully opened and connected with the ambient atmosphere, and when the air pump 1-11 is turned on, the air in the flow chamber 1-5 is quickly exchanged with the ambient atmosphere.

[0018] Furthermore, the humidification system 5 includes a heating device 5-1, a humidification cavity 5-2 and a connecting pipe, the connecting pipe includes a pipe body 5-3, a water vapor input end 5-4, a humidification gas output end 5-5 and a gas input end 5-6, the water vapor input end 5-4, the humidification gas output end 5-5 and the gas input end 5-6 are all closely connected with the pipe body 5-3, the heating device 5-1 can adjust the heating power, the humidification cavity 5-2 is connected and arranged in the heating device 5-1, and the humidification cavity 5-2 is connected and arranged in the heating device 5-1. The interior of the humidifying chamber 5-2 can contain water, and the heating device 5-1 can heat the water contained in the humidifying chamber 5-2 and generate water vapor. The water vapor input end 5-4 is connected to the upper portion of the humidifying chamber 5-2, and the water vapor generated in the humidifying chamber 5-2 can be input into the pipe body 5-3 through the water vapor input end 5-4. The amount of water vapor generated in the humidifying chamber 5-2 can be controlled by adjusting the heating power of the heating device 5-1, and the water vapor output to the pipe body 5-3 can be adjusted through the water vapor input end 5-4 at its upper portion.

[0019] The output end of the air pump 1-11 is tightly connected to the gas input end 5-6 of the connecting pipe, and the humidified gas output end 5-5 of the connecting pipe is tightly connected to the flow chamber 1-5 of the second real environment smoke box 2 through the gas flow port 1-10.

[0020] The water vapor input end 5-4 is connected to the upper part of the humidification chamber 5-2. The water vapor generated in the humidification chamber 5-2 can be input into the pipe body 5-3 through the water vapor input end 5-4. The air pump 1-11 outputs a specified flow of air flow through the pipe body 5-3 of the humidification system 5, carrying a large amount of water vapor. After being injected into the second real environment smoke box 2, the water vapor diffuses into its reaction chamber 1-4 through the semipermeable membrane 1-3, thereby increasing the humidity in the reaction chamber 1-4. By adjusting the heating power of the heating device 5-1, the humidity in the reaction chamber 1-4 meets the experimental design humidity requirements of the liquid phase reaction simulation.

[0021] Furthermore, the sheath gas system 6 includes a neutralizer 6-1, the output end of the zero gas system 3 is connected to the input end of the neutralizer 6-1, and the output end of the neutralizer 6-1 is closely connected to the sheath gas space 1-6 via the sheath gas ventilation port 1-12; the zero gas system 3 outputs a specified flow of zero gas through the neutralizer 6-1 to charge the gas molecules, and then the zero gas is passed into the sheath gas ventilation port 1-12 as sheath gas to neutralize the static electricity of the inner membrane layer 1-2; the sheath gas system 6 continuously injects sheath gas into the sheath gas spaces 1-6 of the two real environment smoke chambers throughout the simulation experiment to reduce the wall loss of particles during the experiment;

[0022] The measuring system 7 includes a temperature and humidity sensor 7-1, an online measuring instrument system for gases and particulate matter 7-2, and a switching valve 7-3. The switching valve 7-3 includes multiple input ends and one output end. The sampling ports / sampling ports 1-9 of the first real environment smoke box 1 and the second real environment smoke box 2 and the ambient atmosphere are respectively connected to the input ends of the switching valve 7-3. The output end of the switching valve 7-3 is connected to the temperature and humidity sensor 7-1 and the online measuring instrument system for gases and particulate matter 7-2. The temperature and humidity sensor 7-1 can measure temperature and humidity in real time. The online measuring instrument system 7-2 includes a carbon monoxide (CO) meter, a nitric oxide-nitrogen dioxide-nitrogen oxide (NO-NO2-NOx) meter, a sulfur dioxide (SO2) meter, an ozone (O3) meter, an aerosol number spectrometer, and an aerosol mass spectrometer. The online measuring instrument system 7-2 can measure the chemical components and index parameters of gases and particulate matter in real time.

[0023] Alternatively, three gas flow ports 1-10 are provided on each side.

[0024] Furthermore, the measurement system 7 switches channels through the switching valve 7-3 to realize the switching collection and measurement of samples in the reaction chambers 1-4 of the two real-environment smoke boxes and the ambient atmosphere; the temperature and humidity sensor 7-1 can measure temperature and humidity in real time; the online measurement instrument system 7-2 includes a carbon monoxide (CO) meter, a nitric oxide-nitrogen dioxide-nitrogen oxide (NO-NO2-NOx) meter, a sulfur dioxide (SO2) meter, an ozone (O3) meter, an aerosol number spectrometer, and an aerosol mass spectrometer, which can measure parameters such as the chemical composition and concentration of gases and particulate matter in real time, track the changing characteristics of the physical and chemical properties of gases and particles during the reaction process, and provide important information for revealing the liquid phase chemical process and mechanism of particulate matter.

[0025] Furthermore, the outer support layer 1-1 is made of polyacrylate plastic with a thickness of 5.6 mm and a height of 140 cm and a volume of 1.2 m 3The inner film layer 1-2 is made of fluorinated ethylene propylene copolymer Teflon material with a thickness of 0.13 mm. The outer support layer 1-1 and the inner film layer 1-2 have good ultraviolet light penetration performance in the range of UV-B of 280-315 nm and UV-A of 315-400 nm, ensuring the basic consistency of the ultraviolet band of sunlight in the smog box and in the ambient atmosphere, and realizing a simulation close to the photochemical reaction of the ambient atmosphere.

[0026] Alternatively, the semipermeable membrane 1-3 is made of a heat-treated expanded polytetrafluoroethylene membrane with a microporous structure, with a thickness of 0.12 mm, which allows gaseous molecules to pass through and has an excellent filtering effect on particulate matter, with an interception efficiency of 96% for particles with a diameter greater than 10 nm.

[0027] Alternatively, the reaction chamber 1-4 is 110 cm high and the flow chamber 1-5 is 30 cm high;

[0028] Alternatively, the semipermeable membrane 1-3 is tightly and detachably connected to the outer support layer 1-1 and the inner membrane layer 1-2 through a plurality of sealing clips, and the outer support layer 1-1, the inner membrane layer 1-2 and the semipermeable membrane 1-3 are sealed at the insertion position of the semipermeable membrane 1-3 by a plurality of sealing clips (1-7) and gaskets;

[0029] Alternatively, casters 1-8 are installed at the bottom of the outer supporting layer 1-1 of the first real environment smoke box 1 and the second real environment smoke box 2;

[0030] Alternatively, the concentrations of SO2, NOx and O3 in the zero gas provided by the zero gas system 3 are lower than 1 ppb, and the number of particles is lower than 0.01# / cm 3 The zero gas system 3 provides a maximum flow rate of zero gas of at least 10 L / min and is equipped with a flow regulation control system.

[0031] Furthermore, the seed aerosol generating system 4 includes an aerosol generator 4-1, a dry diffusion tube 4-2 and a differential mobility analyzer 4-3 which are tightly connected in sequence. The aerosol generator 4-1 can generate aerosol of a specified concentration, the dry diffusion tube 4-2 can remove water molecules on the surface of the aerosol, and the differential mobility analyzer 4-3 can screen monodisperse aerosols. The output end of the aerosol generator 4-1 is tightly connected to the input end of the dry diffusion tube 4-2, the input end of the differential mobility analyzer 4-3 is tightly connected to the output end of the dry diffusion tube 4-2, and the output end of the differential mobility analyzer 4-3 is tightly connected to the reaction chamber 1-4. The aerosol generator 4-1 can generate aerosol of a specified concentration, remove water molecules on the surface of the aerosol through the drying diffusion tube 4-2, and then screen the monodisperse aerosol through the differential mobility analyzer 4-3, and finally inject it into the reaction chamber 1-4. After the seed aerosol concentration in the reaction chamber 1-4 reaches the experimental set value, the system is disconnected and the injection is stopped.

[0032] Preferably, the concentration of the seed aerosol in the smoke chamber before the start of the simulation reaction is about 10000# / cm 3 .

[0033] Furthermore, ultraviolet shading covers 1-13 are detachably and tightly connected to the outer surfaces of the first real environment smoke box 1 and the second real environment smoke box 2, and are used to cover the surface to block all solar radiation and form an environment without solar radiation inside.

[0034] An experimental method using the above-mentioned in-situ simulation device for the liquid-phase chemical process of atmospheric particulate matter comprises the following steps:

[0035] S1: Use analytical grade anhydrous ethanol and ultrapure water to clean the inner membrane layer 1-2 of the first real environment smoke box 1 and the second real environment smoke box 2 in turn, wipe them dry with dust-free paper, replace the new semipermeable membrane 1-3 and assemble the smoke box, ensure the smoke box is airtight, and cover the UV light shield 1-13; then connect one of the injection port / sampling port 1-9 to zero gas, close the others, and open all the gas flow ports 1-10 to achieve zero gas purging of the air inside the smoke box. The zero gas flow rate is not less than 10 L / min, and the purging time is not less than 10 hours;

[0036] S2: Stop zero gas purge and close the sampling port 1-9 connected to the zero gas; turn on the air pump 1-11 to allow the gas in the flow chambers 1-5 of the two smoke boxes to exchange rapidly with the atmosphere, and the gas in the reaction chamber 1-4 is continuously exchanged with the flow chamber 1-5 through the semipermeable membrane 1-3 due to diffusion, while the particulate matter is filtered and does not enter the reaction chamber 1-4, so that the gaseous environment of the two real environment smoke box reaction chambers 1-4 remains close to the ambient atmosphere; the measurement system 7 is respectively connected to the sampling port 1-9 of the two smoke boxes and the ambient atmosphere, and switches to collect and measure the first real environment smoke box 1 reaction chamber 1-4, the second real environment smoke box 2 reaction chamber 1-4 and the ambient atmosphere every 15 minutes, so as to simultaneously track the gas and particulate matter concentration, chemical composition and RH change law of the above three;

[0037] S3: After the air pump 1-11 continuously introduces ambient air for approximately 1 hour in step S2, the sheath gas system is turned on to continuously inject sheath gas into the sheath gas spaces 1-6 of the first real environment smoke box 1 and the second real environment smoke box 2 to reduce wall loss during the experiment; at the same time, a seed aerosol generating system 4 is used to generate a 50 nm monodisperse sodium chloride aerosol of a specified concentration and inject it into the reaction chambers 1-4 of the first real environment smoke box 1 and the second real environment smoke box 2 as seed aerosols for subsequent simulated chemical reactions; the total number concentration of NaCl aerosols in the reaction chambers 1-4 reaches approximately 10,000 # / cm 3 Then stop the injection, disconnect the seed aerosol generating system 4 and close the injection port / sampling port 1-9;

[0038] S4: Turn on the heating device 5-1 of the humidification system 5. The airflow from the air pump 1-11 carries a large amount of water vapor and is injected into the flow chamber 1-5 of the second real environment smoke chamber 2. The airflow then passes through the semipermeable membrane 1-3 and enters the reaction chamber 1-4. The power of the heating device 5-1 is adjusted so that the RH of the reaction chamber 1-4 of the second real environment smoke chamber 2 reaches at least 90% within 15 minutes and remains stable.

[0039] S5: Open the UV hood 1-13 of the first real environment smoke box 1, and the UV hood 1-13 of the second real environment smoke box 2 remains covered. This time is recorded as the start time of the simulation experiment; through the collection and measurement results of the measurement system 7, the differences in the particle generation of the in-situ simulation of the gas phase reaction and the liquid phase reaction in the two smoke boxes under the conditions of only differences in humidity and solar radiation conditions are compared, and compared with the evolution characteristics of the ambient atmospheric particles, the determining factors of the liquid phase reaction are revealed, and the liquid phase reaction rate is quantitatively analyzed.

[0040] The advantages and effects achieved by the present invention are:

[0041] 1. The real-environment smoke chamber device in the system of the present invention uses a unique semi-permeable membrane structure to ensure that the gas, temperature, humidity and other conditions in the reaction chamber where liquid phase simulation is carried out are basically consistent with the ambient atmosphere, solving the problem of large differences between the simulated experimental environment and the real atmosphere in the past, and improving the applicability and accuracy of the simulation results.

[0042] 2. The method of the present invention utilizes two real-environment smog chambers with the same structure as above. By controlling the two key parameters of humidity and solar radiation, the method simultaneously simulates the liquid-phase chemical process and photochemical process of particulate matter in a close-to-real atmospheric environment, thereby achieving in-situ simulation of the liquid-phase chemical reaction of atmospheric particulate matter. Based on direct quantitative comparison with gas-phase chemical reactions and synchronous ambient atmospheric observation results, it can be used to reveal the key factors and mechanisms of liquid-phase reactions.

[0043] 3. The core device of the present invention's in-situ atmospheric particulate matter liquid-phase chemical simulation system, the real-environment smog chamber, is physically small and equipped with casters for easy mobility and transportation. This facilitates in-situ simulation of liquid-phase chemical reactions in various atmospheric environments (e.g., urban, rural, and background). The system is simple to operate and highly automated.

[0044] 4. The present invention controls the humidification system 5 and the detachable UV hood 1-13 to enable two real-environment smoke chambers with the same structure to simultaneously simulate the gas-phase and liquid-phase reactions of particulate matter under different humidity and solar radiation conditions. This overcomes the bottleneck of the poor applicability of the conclusions drawn due to the large difference between the traditional smoke chamber simulation and the actual atmospheric reaction process, and provides a method for revealing the liquid-phase chemical process and reaction mechanism of particulate matter in the atmospheric environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a structural connection diagram and usage flow chart of the system of the present invention; wherein the direction of the arrow represents the direction of airflow;

[0046] Figure 2 for Figure 1 A schematic diagram of a structural connection between the first real environment smoke box 1 and the second real environment smoke box 2;

[0047] Figure 3 Schematic diagram of the airflow direction in the first real environment smoke box 1 and the second real environment smoke box 2 when the system of the present invention is in use. DETAILED DESCRIPTION

[0048] The present invention will be further described in detail below with reference to specific examples. The following examples are merely illustrative and non-restrictive, and should not be used to limit the scope of protection of the present invention.

[0049] The raw materials used in the present invention, unless otherwise specified, are all conventional commercial products. The methods used in the present invention, unless otherwise specified, are all conventional methods in the art. The quality of each substance used in the present invention is the quality of conventional use. The structures, connections, etc. not described in detail in the present invention are understood to be conventional technical means in the art.

[0050] A system for in situ simulation of liquid phase chemical processes of particles in ambient atmosphere, e.g. Figures 1 to 3 As shown, the system includes a first real environment smoke box 1, a second real environment smoke box 2, a zero gas system 3, a seed aerosol generating system 4, a humidification system 5, a sheath gas system 6 and a measurement system 7. The first real environment smoke box 1 and the second real environment smoke box 2 are respectively connected to the zero gas system 3, the seed aerosol generating system 4, the sheath gas system 6 and the measurement system 7. The first real environment smoke box 1 and the second real environment smoke box 2 are also connected to the ambient atmosphere. The second real environment smoke box 2 is also connected to the humidification system 5. The zero gas system 3 is directly connected to the first real environment smoke box 1 and the second real environment smoke box 2 (not shown in the figure). The zero gas system 3 is also connected to the first real environment smoke box 1 and the second real environment smoke box 2 through the sheath gas system 6;

[0051] The zero gas system 3 can provide zero gas to the first real environment smoke box 1 and the second real environment smoke box 2 before and after the experiment, for internal purging and cleaning, to ensure the clean state of the smoke box before the experiment; in addition, the zero gas system 3 can also provide zero gas to the sheath gas system 6 during the experiment, so that the sheath gas system 6 can provide sheath gas to the first real environment smoke box 1 and the second real environment smoke box 2, so as to reduce wall loss during the experiment;

[0052] The seed aerosol generating system 4 can provide a monodisperse aerosol with surface water molecules removed as a seed aerosol for the simulation experiments inside the first real environment smoke chamber 1 and the second real environment smoke chamber 2; the seed aerosol can increase the surface area of the particles in the smoke chamber, promote the adsorption, condensation and chemical reaction of gaseous pollutants thereon, and better simulate the liquid phase reaction in the ambient atmosphere;

[0053] The humidification system 5 can provide a controllable high-humidity airflow to the second real environment smoke box 2, thereby adjusting the reaction environment humidity in the second real environment smoke box 2 and differentiating the reaction humidity from the first real environment smoke box 1;

[0054] The sheath gas system 6 can provide sheath gas to the first real environment smoke box 1 and the second real environment smoke box 2 to reduce the wall loss of the real environment smoke box;

[0055] The measurement system 7 can measure parameters such as the concentration, chemical composition, temperature and humidity of gases and particulate matter in the first real environment smoke chamber 1 and the second real environment smoke chamber 2 online during the experiment, capture the changes in the physical and chemical characteristics of the pollution and the reaction conditions with high time resolution, and realize comparative studies of the reactions between the two real environment smoke chambers and with the atmospheric environment.

[0056] The system of the present invention includes a first real environment smoke chamber 1, a second real environment smoke chamber 2, a zero gas system 3, a seed aerosol generating system 4, a humidifying system 5, a sheath gas system 6 and a measuring system 7. When in use, the present invention uses an experimental method in which two real environment smoke chambers with identical structures simultaneously perform simulated reactions under different humidity and solar radiation environmental conditions. This not only overcomes the bottleneck of poor applicability of the conclusions due to the large difference between traditional smoke chamber simulation and atmospheric reaction processes, but also provides a method for revealing the liquid phase chemical process and reaction mechanism of particulate matter in the atmospheric environment through comparative studies under controlled simulation conditions.

[0057] In this embodiment, the device also includes an air pump 1-11, which can be tightly connected to the first real environment smoke box 1 and the second real environment smoke box 2. The air pump 1-11 can enable the gas in the first real environment smoke box 1 and the second real environment smoke box 2 to be continuously and quickly exchanged with the atmosphere, so that the gaseous environment in the first real environment smoke box 1 and the second real environment smoke box 2 is close to the ambient atmosphere during the entire simulation process.

[0058] In this embodiment, the structures of the first real environment smoke box 1 and the second real environment smoke box 2 are exactly the same. The first real environment smoke box 1 and the second real environment smoke box 2 both include an outer supporting layer 1-1, an inner membrane layer 1-2, a semipermeable membrane 1-3, a reaction chamber 1-4, a flow chamber 1-5 and a sheath gas space 1-6. The inner membrane layer 1-2 is closely spaced and connected and arranged in the outer supporting layer 1-1. A sealed space sheath gas space 1-6 is formed between the inner membrane layer 1-2 and the outer supporting layer 1-1. The sheath gas space 1-6 is used for sheath gas circulation; a closed space is formed in the inner membrane layer 1-2, and the semipermeable membrane 1-3 is arranged in the horizontal direction and is tightly and detachably connected and arranged in the middle and lower part of the inner membrane layer 1-2. The semipermeable membrane 1-3 separates the closed space of the inner membrane layer 1-2 into a reaction chamber 1-4 and a flow chamber 1-5. The reaction chamber 1-4 is arranged above the flow chamber 1-5.

[0059] The top and bottom outer support layers 1-1 of the sheath gas space 1-6 are tightly connected to form sheath gas ventilation ports 1-12, which can inject or discharge sheath gas to maintain the sheath gas circulation in the sheath gas space 1-6;

[0060] The center of the side wall of the reaction chamber 1-4 is closely connected to set a plurality of injection ports / sampling ports 1-9. In this embodiment, there are two injection ports / sampling ports 1-9 on each side. The injection ports / sampling ports 1-9 are closely connected with the reaction chamber 1-4. Figure 1 As shown; the injection port / sampling port 1-9 passes tightly through the outer support layer 1-1 and the inner film layer 1-2 to ensure that the interface is sealed, and is used to inject seed aerosols, etc. into the reaction chamber 1-4 (that is, the seed aerosol generating system 4 is connected to the injection port / sampling port 1-9 through a pipeline to inject seed aerosols), or to collect samples from the reaction chamber 1-4, and is also used to connect the zero gas system 3 to purge and clean the inside of the smoke box before and after the experiment (that is, the zero gas system 3 is directly connected to the injection port / sampling port 1-9 through a pipeline, that is, step S1).

[0061] The center positions of the horizontal side walls of the flow chamber 1-5 are closely connected to each other to set a plurality of gas flow ports 1-10, and the gas flow ports 1-10 are closely connected to the flow chamber 1-5. In this embodiment, three gas flow ports 1-10 are set on each side. Figure 1 As shown; the gas flow port 1-10 tightly passes through the outer support layer 1-1 and the inner membrane layer 1-2; the gas flow port 1-10 on the horizontal side of the flow chamber 1-5 of the first real environment smoke box 1 is tightly connected with the air pump 1-11; the gas flow port 1-10 on the horizontal side of the flow chamber 1-5 of the second real environment smoke box 2 is tightly connected with one end of the humidification system 5, and the other end of the humidification system 5 is tightly connected with the air pump 1-11; the gas flow port 1-10 on the other horizontal side of the flow chamber 1-5 is fully opened and connected to the ambient atmosphere, and when the air pump 1-11 is turned on, the air in the flow chamber 1-5 is quickly exchanged with the ambient atmosphere.

[0062] Preferably, the humidification system 5 includes a heating device 5-1, a humidification cavity 5-2 and a connecting pipe, the connecting pipe includes a pipe body 5-3, a water vapor input end 5-4, a humidified gas output end 5-5 and a gas input end 5-6, the water vapor input end 5-4, the humidified gas output end 5-5 and the gas input end 5-6 are all closely connected to the pipe body 5-3, the heating device 5-1 can adjust the heating power, the humidification cavity 5-2 is connected and arranged in the heating device 5-1, and the humidification cavity 5-2 is connected and arranged in the heating device 5-1. The interior of the humidifying chamber 5-2 can contain water, and the heating device 5-1 can heat the water contained in the humidifying chamber 5-2 and generate water vapor. The water vapor input end 5-4 is connected to the upper portion of the humidifying chamber 5-2, and the water vapor generated in the humidifying chamber 5-2 can be input into the pipe body 5-3 through the water vapor input end 5-4. The amount of water vapor generated in the humidifying chamber 5-2 can be controlled by adjusting the heating power of the heating device 5-1, and the water vapor output to the pipe body 5-3 can be adjusted through the water vapor input end 5-4 at its upper portion.

[0063] The output end of the air pump 1-11 is tightly connected to the gas input end 5-6 of the connecting pipe, and the humidified gas output end 5-5 of the connecting pipe is tightly connected to the flow chamber 1-5 of the second real environment smoke box 2 through the gas flow port 1-10.

[0064] The water vapor input terminal 5-4 is connected to the upper portion of the humidification chamber 5-2. The water vapor generated in the humidification chamber 5-2 can be input into the pipe body 5-3 through the water vapor input terminal 5-4. The air pump 1-11 outputs a specified flow of airflow through the pipe body 5-3 of the humidification system 5, carrying a large amount of water vapor. After being injected into the second real environment smoke chamber 2, the water vapor diffuses into its reaction chamber 1-4 through the semipermeable membrane 1-3, thereby increasing the humidity in the reaction chamber 1-4. By adjusting the heating power of the heating device 5-1, the humidity in the reaction chamber 1-4 meets the experimental design humidity requirements for liquid phase reaction simulation. In this embodiment, the relative humidity (RH) in the reaction chamber 1-4 reaches at least 90%.

[0065] Preferably, the sheath gas system 6 includes a neutralizer 6-1, the output end of the zero gas system 3 is connected to the input end of the neutralizer 6-1, and the output end of the neutralizer 6-1 is closely connected to the sheath gas space 1-6 via the sheath gas ventilation port 1-12; the zero gas system 3 outputs a specified flow of zero gas through the neutralizer 6-1 to charge the gas molecules, and then the zero gas is passed into the sheath gas ventilation port 1-12 as sheath gas to neutralize the static electricity of the inner membrane layer 1-2; the sheath gas system 6 continuously injects sheath gas into the sheath gas spaces 1-6 of the two real environment smoke chambers throughout the simulation experiment to reduce the wall loss of particles during the experiment;

[0066] The measurement system 7 includes a temperature and humidity sensor 7-1, an online measurement instrument system for gases and particulate matter 7-2, and a switching valve 7-3. The switching valve 7-3 includes multiple input ends and one output end. The sampling ports / sampling ports 1-9 of the first real environment smoke box 1 and the second real environment smoke box 2 and the ambient atmosphere are respectively connected to the input end of the switching valve 7-3. The output end of the switching valve 7-3 is connected to the temperature and humidity sensor 7-1 and the online measurement instrument system for gases and particulate matter 7-2. The temperature and humidity sensor 7-1 can measure temperature and humidity in real time; the online measurement instrument system 7-2 includes a carbon monoxide (CO) meter, a nitric oxide-nitrogen dioxide-nitrogen oxide (NO-NO2-NOx) meter, a sulfur dioxide (SO2) meter, an ozone (O3) meter, an aerosol number spectrometer, and an aerosol mass spectrometer. The online measurement instrument system 7-2 can measure the chemical components and index parameters of gases and particulate matter in real time.

[0067] The measurement system 7 of this system switches channels through the switching valve 7-3 to realize the switching collection and measurement of samples in the reaction chambers 1-4 of the two real-environment smoke boxes and the ambient atmosphere; preferably, the measurement system 7 continuously collects and measures during the entire simulation experiment, and switches the sampling channel through the switching valve 7-3 every 15 minutes; the temperature and humidity sensor 7-1 can measure temperature and humidity in real time; the online measurement instrument system 7-2 includes a carbon monoxide (CO) meter, a nitric oxide-nitrogen dioxide-nitrogen oxide (NO-NO2-NOx) meter, a sulfur dioxide (SO2) meter, an ozone (O3) meter, an aerosol number spectrometer, an aerosol mass spectrometer and other instruments, which can measure parameters such as the chemical composition and concentration of gases and particulate matter in real time, track the changing characteristics of the physical and chemical properties of gases and particles during the reaction, and provide important information for revealing the liquid phase chemical process and mechanism of particulate matter.

[0068] Preferably, the outer support layer 1-1 is made of polyacrylate plastic (such as OP-4) with a thickness of 5.6 mm and a height of 140 cm and a volume of about 1.2 m 3 The chamber can be adjusted within a certain range according to experimental needs, ensuring that liquid-phase reaction simulations close to atmospheric conditions can be carried out within it, while also achieving a small device size, making it easy to move and transport, and allowing experimental research to be carried out in different locations. The material of the inner film layer 1-2 is a fluorinated ethylene propylene copolymer Teflon material (such as FEPTeflon), with a thickness of 0.13mm. This material is extremely inert and basically does not absorb gaseous substances. The outer support layer 1-1 and the inner film layer 1-2 both have good ultraviolet light penetration properties in the UV-B (280-315nm) and UV-A (315-400nm) ranges, ensuring the basic consistency of the ultraviolet band of sunlight in the smog chamber and the ambient atmosphere, and achieving simulation of photochemical reactions close to the ambient atmosphere.

[0069] Preferably, the material of the semipermeable membrane 1-3 is an expanded polytetrafluoroethylene membrane material (such as e-PTFE) with a microporous structure that has been extended after heat treatment, with a thickness of 0.12 mm, which can allow gaseous molecules to pass through and has an excellent filtering effect on particulate matter. The interception efficiency for particles with a particle size greater than 10 nm is about 96%; the selected material also has high chemical stability, non-polarity and thermal stability, and it can be used for a long time in the presence of chemicals; in addition, as a hydrophobic material with micropores, when air flows through, droplets can be blocked by the filter membrane.

[0070] Preferably, the reaction chamber 1-4 is 110 cm high, and the flow chamber 1-5 is 30 cm high.

[0071] Preferably, the semipermeable membrane 1-3 is tightly and detachably connected to the outer support layer 1-1 and the inner membrane layer 1-2 through multiple sealing clips. The outer support layer 1-1, the inner membrane layer 1-2 and the semipermeable membrane 1-3 are sealed at the insertion position of the semipermeable membrane 1-3 by multiple sealing clips 1-7 and gaskets to ensure that the interior is a closed space with a simple structure and easy installation, use and cleaning.

[0072] Preferably, casters 1-8 are installed at the bottom of the outer supporting layer 1-1 of the first real environment smoke box 1 and the second real environment smoke box 2 for movement, which improves the mobility of the first real environment smoke box 1 and the second real environment smoke box 2, makes it easy to use this set of equipment to carry out simulation research in different locations, and improves work efficiency.

[0073] In this embodiment, the concentrations of SO2, NOx and O3 in the zero gas provided by the zero gas system 3 are lower than 1 ppb, and the number of particles is lower than 0.01# / cm 3 The zero gas system 3 provides a maximum flow rate of zero gas of at least 10 L / min, and is equipped with a flow regulation control system to meet the needs of providing zero gas with different flow rates.

[0074] In this embodiment, the seed aerosol generating system 4 includes an aerosol generator 4-1, a dry diffusion tube 4-2 and a differential mobility analyzer 4-3 which are tightly connected in sequence. The aerosol generator 4-1 can generate aerosol of a specified concentration, the dry diffusion tube 4-2 can remove water molecules on the surface of the aerosol, and the differential mobility analyzer 4-3 can screen monodisperse aerosols. The output end of the aerosol generator 4-1 is tightly connected to the input end of the dry diffusion tube 4-2, the input end of the differential mobility analyzer 4-3 is tightly connected to the output end of the dry diffusion tube 4-2, and the output end of the differential mobility analyzer 4-3 is tightly connected to the reaction chamber 1-4. The aerosol generator 4-1 can generate aerosol of a specified concentration, remove water molecules on the surface of the aerosol through the drying diffusion tube 4-2, and then screen the monodisperse aerosol through the differential mobility analyzer 4-3, and finally inject it into the reaction chamber 1-4. After the seed aerosol concentration in the reaction chamber 1-4 reaches the experimental set value, the system is disconnected and the injection is stopped.

[0075] Preferably, the concentration of the seed aerosol in the smoke chamber before the start of the simulation reaction is about 10000# / cm 3 .

[0076] In this embodiment, a UV shading cover 1-13 is detachably and tightly connected to the outer surface of the first real environment smoke box 1 and the second real environment smoke box 2, which is used to cover the surface to block all solar radiation and form an environment without solar radiation inside.

[0077] An experimental method using the above-mentioned in-situ simulation device for the liquid-phase chemical process of atmospheric particulate matter comprises the following steps:

[0078] S1: Use analytical grade anhydrous ethanol and ultrapure water to clean the inner membrane layer 1-2 of the first real environment smoke box 1 and the second real environment smoke box 2 in turn, wipe them dry with dust-free paper, replace the new semipermeable membrane 1-3 and assemble the smoke box, ensure the airtightness of the smoke box, and cover the UV light shield 1-13; then connect one of the injection port / sampling port 1-9 to the zero gas (i.e., directly connect to the zero gas system 3), close the others, and open all the gas flow ports 1-10 to achieve zero gas purging of the air inside the smoke box, with a zero gas flow rate of not less than 10 L / min and a purging time of not less than 10 hours;

[0079] S2: Stop zero gas purge and close the sampling port 1-9 connected to the zero gas; turn on the air pump 1-11 to allow the gas in the flow chambers 1-5 of the two smoke boxes to exchange rapidly with the atmosphere, and the gas in the reaction chamber 1-4 is continuously exchanged with the flow chamber 1-5 through the semipermeable membrane 1-3 due to diffusion, while the particulate matter is filtered and does not enter the reaction chamber 1-4, so that the gaseous environment of the two real environment smoke box reaction chambers 1-4 remains close to the ambient atmosphere; the measurement system 7 is respectively connected to the sampling port 1-9 of the two smoke boxes and the ambient atmosphere, and switches to collect and measure the first real environment smoke box 1 reaction chamber 1-4, the second real environment smoke box 2 reaction chamber 1-4 and the ambient atmosphere every 15 minutes, so as to simultaneously track the change patterns of the gas and particulate matter concentration, chemical composition, RH, etc. of the above three;

[0080] S3: After the air pump 1-11 continuously introduces ambient air for about 1 hour in step S2, the sheath gas system is turned on to continuously inject sheath gas into the sheath gas spaces 1-6 of the first real environment smoke box 1 and the second real environment smoke box 2 (i.e., the zero gas system 3 is connected to the two smoke boxes via the sheath gas system 6) to reduce wall loss during the experiment; at the same time, a seed aerosol generating system 4 is used to generate a specified concentration of 50nm monodisperse sodium chloride (NaCl) aerosol, which is injected into the reaction chambers 1-4 of the first real environment smoke box 1 and the second real environment smoke box 2 as seed aerosols for subsequent simulated chemical reactions; the total number concentration of NaCl aerosols in the reaction chambers 1-4 reaches about 10,000# / cm 3 Then stop the injection, disconnect the seed aerosol generating system 4 and close the injection port / sampling port 1-9;

[0081] S4: Turn on the heating device 5-1 of the humidification system 5. The airflow from the air pump 1-11 carries a large amount of water vapor and is injected into the flow chamber 1-5 of the second real environment smoke chamber 2. The airflow then passes through the semipermeable membrane 1-3 and enters the reaction chamber 1-4. The power of the heating device 5-1 is adjusted so that the RH of the reaction chamber 1-4 of the second real environment smoke chamber 2 reaches at least 90% within 15 minutes and remains stable.

[0082] S5: Open the UV hood 1-13 of the first real environment smoke box 1, and the UV hood 1-13 of the second real environment smoke box 2 remains covered. This time is recorded as the start time of the simulation experiment; through the collection and measurement results of the measurement system 7, the differences in the particle generation of the in-situ simulation of the gas phase reaction and the liquid phase reaction in the two smoke boxes under the conditions of only differences in humidity and solar radiation conditions are compared, and compared with the evolution characteristics of the ambient atmospheric particles, the determining factors of the liquid phase reaction are revealed, and the liquid phase reaction rate is quantitatively analyzed.

[0083] Although the embodiments of the present invention are disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments.

Claims

1. A system for in-situ simulation of liquid-phase chemical processes of particulate matter in ambient atmosphere, characterized by: The system comprises a first real environment smoke box (1), a second real environment smoke box (2), a zero gas system (3), a seed aerosol generating system (4), a humidifying system (5), a sheath gas system (6) and a measuring system (7); the first real environment smoke box (1) and the second real environment smoke box (2) are respectively connected to the zero gas system (3), the seed aerosol generating system (4), the sheath gas system (6) and the measuring system (7); the first real environment smoke box (1) and the second real environment smoke box (2) are also connected to the ambient atmosphere; the second real environment smoke box (2) is also connected to the humidifying system (5); the zero gas system (3) is directly connected to the first real environment smoke box (1) and the second real environment smoke box (2); and the zero gas system (3) is also connected to the first real environment smoke box (1) and the second real environment smoke box (2) through the sheath gas system (6); The zero gas system (3) can provide zero gas to the first real environment smoke box (1) and the second real environment smoke box (2) before and after the experiment, for internal purging and cleaning, to ensure the clean state of the smoke box before the experiment; the zero gas system (3) can also provide zero gas to the sheath gas system (6) during the experiment, so that the sheath gas system (6) can provide sheath gas to the first real environment smoke box (1) and the second real environment smoke box (2), so as to reduce wall loss in the experiment; The seed aerosol generating system (4) can provide a monodisperse aerosol with surface water molecules removed as a seed aerosol for the simulation experiment inside the first real environment smoke chamber (1) and the second real environment smoke chamber (2); The humidification system (5) can provide a controllable high-humidity airflow for the second real environment smoke box (2), thereby adjusting the reaction environment humidity in the second real environment smoke box (2) and differentiating the reaction humidity from the first real environment smoke box (1); The sheath gas system (6) is capable of providing sheath gas to the first real environment smoke box (1) and the second real environment smoke box (2) to reduce the wall loss of the real environment smoke box; The measurement system (7) is capable of online measuring the concentration, chemical composition, and temperature and humidity parameters of gases and particulate matter in the first real environment smoke chamber (1) and the second real environment smoke chamber (2) during the experiment, capturing the changes in the physical and chemical characteristics of the pollution and the reaction conditions with high time resolution, and realizing comparative studies of the reactions between the two real environment smoke chambers and with the atmospheric environment; The structures of the first real environment smoke box (1) and the second real environment smoke box (2) are completely identical. The first real environment smoke box (1) and the second real environment smoke box (2) both comprise an outer support layer (1-1), an inner membrane layer (1-2), a semipermeable membrane (1-3), a reaction chamber (1-4), a flow chamber (1-5) and a sheath gas space (1-6). The inner membrane layer (1-2) is closely spaced and connected to the outer support layer (1-1). (1-1) forms a sealed sheath gas space (1-6), and the sheath gas space (1-6) is used for sheath gas circulation; a closed space is formed in the inner membrane layer (1-2), and the semipermeable membrane (1-3) is arranged in a horizontal direction and is tightly and detachably connected and arranged in the middle and lower part of the inner membrane layer (1-2), and the semipermeable membrane (1-3) divides the closed space of the inner membrane layer (1-2) into a reaction chamber (1-4) and a flow chamber (1-5), and the reaction chamber (1-4) is arranged above the flow chamber (1-5); The top and bottom outer support layers (1-1) of the sheath gas space (1-6) are tightly connected to form sheath gas exchange ports (1-12), which can inject or discharge sheath gas to maintain the circulation of sheath gas in the sheath gas space (1-6); The center of the side wall of the reaction chamber (1-4) is tightly connected to set a plurality of injection ports / sampling ports (1-9), with two injection ports / sampling ports (1-9) on each side, and the injection ports / sampling ports (1-9) are tightly connected with the inside of the reaction chamber (1-4); the injection ports / sampling ports (1-9) tightly pass through the outer support layer (1-1) and the inner film layer (1-2) to ensure the interface is sealed, and are used to inject seed aerosol into the reaction chamber (1-4) or collect samples from the reaction chamber (1-4), and are also used to connect to the zero gas system (3) before and after the experiment to purge and clean the inside of the smoke box; A plurality of gas flow ports (1-10) are tightly connected and arranged at the center positions of the horizontal side walls of the flow chamber (1-5), and the gas flow ports (1-10) are tightly connected with the inside of the flow chamber (1-5); the gas flow ports (1-10) tightly pass through the outer support layer (1-1) and the inner membrane layer (1-2); the gas flow ports (1-10) on the horizontal side of the flow chamber (1-5) of the first real environment smoke box (1) are tightly connected with the air pump (1-11); the gas flow ports (1-10) on the horizontal side of the flow chamber (1-5) of the second real environment smoke box (2) are tightly connected with one end of the humidification system (5), and the other end of the humidification system (5) is tightly connected with the air pump (1-11); the gas flow ports (1-10) on the other horizontal side of the flow chamber (1-5) are fully opened and connected with the ambient atmosphere, and when the air pump (1-11) is turned on, the air in the flow chamber (1-5) is quickly exchanged with the ambient atmosphere; The semipermeable membrane (1-3) is made of expanded polytetrafluoroethylene membrane material with a microporous structure that has been stretched after heat treatment, which can allow gaseous molecules to pass through and has an excellent filtering effect on particulate matter. The interception efficiency for particulate matter with a particle size greater than 10nm is 96%.

2. The system for in-situ simulation of liquid-phase chemical processes of particulate matter in ambient atmosphere according to claim 1, characterized in that: The system further comprises an air pump (1-11), which can be closely connected to the first real environment smoke box (1) and the second real environment smoke box (2). The air pump (1-11) can enable the gas in the first real environment smoke box (1) and the second real environment smoke box (2) to be exchanged with the atmosphere continuously and rapidly, so that the gaseous environment in the first real environment smoke box (1) and the second real environment smoke box (2) is close to the ambient atmosphere during the entire simulation process.

3. The system for in-situ simulation of liquid-phase chemical processes of particulate matter in ambient atmosphere according to claim 2, characterized in that: The humidification system (5) comprises a heating device (5-1), a humidification cavity (5-2) and a connecting pipe. The connecting pipe comprises a pipe body (5-3), a water vapor input end (5-4), a humidification gas output end (5-5) and a gas input end (5-6). The water vapor input end (5-4), the humidification gas output end (5-5) and the gas input end (5-6) are all closely connected to the pipe body (5-3). The heating device (5-1) can adjust the heating power. The humidification cavity (5-2) is connected and arranged in the heating device (5-1). The humidification cavity (5- 2) Water can be contained inside, and the heating device (5-1) can heat the water contained in the humidification cavity (5-2) and generate water vapor; the water vapor input end (5-4) is connected to the upper part of the humidification cavity (5-2), and the water vapor generated in the humidification cavity (5-2) can be input into the pipe body (5-3) through the water vapor input end (5-4); the amount of water vapor generated in the humidification cavity (5-2) can be controlled by adjusting the heating power of the heating device (5-1), and the water vapor output to the pipe body (5-3) can be adjusted through the water vapor input end (5-4) at its upper part; The output end of the air pump (1-11) is tightly connected to the gas input end (5-6) of the connecting pipe, and the humidified gas output end (5-5) of the connecting pipe is tightly connected to the flow chamber (1-5) of the second real environment smoke box (2) through the gas flow port (1-10).

4. The system for in-situ simulation of liquid-phase chemical processes of particulate matter in ambient atmosphere according to claim 1, characterized in that: The sheath gas system (6) includes a neutralizer (6-1), the output end of the zero gas system (3) is connected to the input end of the neutralizer (6-1), and the output end of the neutralizer (6-1) is closely connected to the sheath gas space (1-6) through the sheath gas exchange port (1-12); the zero gas system (3) outputs a specified flow of zero gas through the neutralizer (6-1) to charge the gas molecules, and then the zero gas is passed into the sheath gas exchange port (1-12) as sheath gas to neutralize the static electricity of the inner membrane layer (1-2); the sheath gas system (6) continuously injects sheath gas into the sheath gas space (1-6) of the two real environment smoke boxes during the entire simulation experiment to reduce the wall loss of particles during the experiment; The measuring system (7) includes a temperature and humidity sensor (7-1), an online measuring instrument system for gases and particulate matter (7-2), and a switching valve (7-3). The switching valve (7-3) includes multiple input ends and an output end. The inlet / sampling port (1-9) of the first real environment smoke box (1) and the second real environment smoke box (2) and the ambient atmosphere are respectively connected to the input end of the switching valve (7-3). The output end of the switching valve (7-3) is connected to the temperature and humidity sensor (7-1) and the online measuring instrument system for gases and particulate matter (7-2). The temperature and humidity sensor (7-1) can measure temperature and humidity in real time. The online measuring instrument system (7-2) includes a carbon monoxide (CO) measuring instrument, a nitric oxide-nitrogen dioxide-nitrogen oxide (NO-NO2-NOx) measuring instrument, a sulfur dioxide (SO2) measuring instrument, an ozone (O3) measuring instrument, an aerosol number spectrometer, and an aerosol mass spectrometer. The online measuring instrument system (7-2) can measure the chemical components and index parameters of gases and particulate matter in real time.

5. The system for in-situ simulation of liquid-phase chemical processes of particulate matter in ambient atmosphere according to claim 1, characterized in that: The outer support layer (1-1) is made of polyacrylate plastic with a thickness of 5.6 mm and a height of 140 cm and a volume of 1.2 m 3 The inner film layer (1-2) is made of a fluorinated ethylene propylene copolymer Teflon material with a thickness of 0.13 mm. The outer support layer (1-1) and the inner film layer (1-2) both have good ultraviolet light penetration performance in the range of UV-B of 280-315 nm and UV-A of 315-400 nm, ensuring the basic consistency of the ultraviolet band of sunlight in the smog box and in the ambient atmosphere, thereby achieving a simulation close to the photochemical reaction of the ambient atmosphere. Alternatively, the thickness of the semipermeable membrane (1-3) is 0.12 mm; Alternatively, the reaction chamber (1-4) is 110 cm high and the flow chamber (1-5) is 30 cm high; Alternatively, the semipermeable membrane (1-3) is tightly and detachably connected to the outer support layer (1-1) and the inner membrane layer (1-2) via a plurality of sealing clips, and the outer support layer (1-1), the inner membrane layer (1-2) and the semipermeable membrane (1-3) are sealed at the insertion position of the semipermeable membrane (1-3) via a plurality of sealing clips (1-7) and gaskets; Alternatively, casters (1-8) are installed at the bottom of the outer supporting layer (1-1) of the first real environment smoke box (1) and the second real environment smoke box (2); Alternatively, the zero gas provided by the zero gas system (3) has a concentration of SO2, NOx and O3 lower than 1 ppb and a particle number concentration lower than 0.01# / cm 3 , the zero gas system (3) provides a maximum flow rate of zero gas of at least 10 L / min and is equipped with a flow regulation control system; Alternatively, three gas flow ports (1-10) are provided on each side.

6. The system for in-situ simulation of liquid-phase chemical processes of particulate matter in ambient atmosphere according to claim 1, characterized in that: The seed aerosol generating system (4) comprises an aerosol generator (4-1), a dry diffusion tube (4-2) and a differential mobility analyzer (4-3) which are tightly connected in sequence. The aerosol generator (4-1) can generate aerosol of a specified concentration, the dry diffusion tube (4-2) can remove water molecules on the surface of the aerosol, and the differential mobility analyzer (4-3) can screen monodisperse aerosols. The output end of the aerosol generator (4-1) is tightly connected to the input end of the dry diffusion tube (4-2), and the differential mobility analyzer (4-3) is connected to the output end of the aerosol generator (4-1). ) is tightly connected to the output end of the dry diffusion tube (4-2), and the output end of the differential mobility analyzer (4-3) is tightly connected to the reaction chamber (1-4); the aerosol generator (4-1) is capable of generating aerosol of a specified concentration, removing water molecules on the surface of the aerosol through the dry diffusion tube (4-2), and then screening the monodisperse aerosol through the differential mobility analyzer (4-3), and finally injecting it into the reaction chamber (1-4); after the seed aerosol concentration in the reaction chamber (1-4) reaches the experimental set value, the system is disconnected and the injection is stopped; The concentration of seed aerosol in the smoke chamber before the start of the simulation reaction was 10000 # / cm 3 .

7. The system for in-situ simulation of liquid-phase chemical processes of particulate matter in ambient atmosphere according to any one of claims 1 to 6, characterized in that: Ultraviolet light shielding covers (1-13) are detachably and tightly connected to each other on the outer surfaces of the first real environment smoke box 1 and the second real environment smoke box (2), and are used to cover the surfaces to shield all solar radiation, thereby forming an environment without solar radiation inside.

8. An experimental method using the system for in-situ simulation of liquid-phase chemical processes of particulate matter in ambient atmosphere according to any one of claims 1 to 7, characterized in that: The steps include: S1: Use analytically pure anhydrous ethanol and ultrapure water to clean the inner membrane layer (1-2) of the first real environment smoke box (1) and the second real environment smoke box (2) in turn, wipe them dry with dust-free paper, replace the new semipermeable membrane (1-3) and assemble the smoke box, ensure that the smoke box is airtight, and cover it with a UV light shield (1-13); then connect one of the injection port / sampling port (1-9) to zero gas, close the others, and open all the gas flow ports (1-10) to achieve zero gas purging of the air inside the smoke box, with the zero gas flow rate being not less than 10 L / min and the purging time being not less than 10 hours; S2: Stop zero gas purge and close the inlet / sampling port (1-9) connected to zero gas; turn on the air pump (1-11) to allow the gas in the flow chamber (1-5) of the two smoke boxes to exchange rapidly with the atmosphere, and the gas in the reaction chamber (1-4) is continuously exchanged with the flow chamber (1-5) through the semipermeable membrane (1-3) due to diffusion, while the particulate matter is filtered and does not enter the reaction chamber (1-4), so that the gaseous environment of the two real environment smoke box reaction chambers (1-4) remains close to the ambient atmosphere; the measurement system (7) is connected to the inlet / sampling port (1-9) of the two smoke boxes and the ambient atmosphere respectively, and switches to collect and measure the first real environment smoke box (1) reaction chamber (1-4), the second real environment smoke box (2) reaction chamber (1-4) and the ambient atmosphere every 15 minutes, so as to simultaneously track the gas and particulate matter concentration, chemical composition and RH change law of the above three; S3: After the air pump (1-11) in step S2 continuously introduces ambient air for 1 hour, the sheath gas system is turned on and sheath gas is injected into the sheath gas spaces (1-6) of the first real environment smoke box (1) and the second real environment smoke box (2) to reduce wall loss; at the same time, a seed aerosol generating system (4) is used to generate a 50nm monodisperse sodium chloride aerosol of a specified concentration and inject it into the reaction chambers (1-4) of the first real environment smoke box (1) and the second real environment smoke box (2) as seed aerosols for subsequent simulated chemical reactions; the total number concentration of NaCl aerosol in the reaction chambers (1-4) reaches 10,000 # / cm 3 Then stop the injection, disconnect the seed aerosol generating system (4) and close the injection port / sampling port (1-9); S4: Turn on the heating device (5-1) of the humidification system (5), and the airflow of the air pump (1-11) carries a large amount of water vapor and is injected into the flow chamber (1-5) of the second real environment smoke box (2), and enters the reaction chamber (1-4) through the semipermeable membrane (1-3); adjust the power of the heating device (5-1) so that the RH of the reaction chamber (1-4) of the second real environment smoke box (2) reaches at least 90% within 15 minutes and remains stable; S5: The UV hood (1-13) of the first real environment smoke box (1) is opened, and the UV hood (1-13) of the second real environment smoke box (2) remains covered. This time is recorded as the start time of the simulation experiment; through the collection and measurement results of the measurement system (7), the differences in the particle generation of the gas phase reaction and the liquid phase reaction in the two smoke boxes under the condition of only differences in humidity and solar radiation conditions are compared, and compared with the evolution characteristics of the ambient atmospheric particles, the determining factors of the liquid phase reaction are revealed, and the liquid phase reaction rate is quantitatively analyzed.

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