Method and system for measuring reaction activity of ozone

Abstract

The invention provides an ozone reaction activity measurement method and system, and the method comprises the steps: sampling and filtering the atmosphere in the environment, dividing the filtered to-be-measured atmosphere flow into a first branch flow and a second branch flow, providing ozone with known concentration, mixing the ozone with the first branch flow to obtain a mixed gas, detecting the total ozone reaction activity, namely first ozone reaction activity, in the mixed gas by using an ozone on-line measurement system; synchronously detecting second ozone reaction activity corresponding to ozone existing in the second branch gas flow; the difference value between the first ozone reaction activity and the second ozone reaction activity is the ozone reaction activity of the atmospheric airflow to be detected. According to the technical scheme provided by the invention, the ozone reaction activity of the atmosphere can be directly measured, the result resolution is high, and the accuracy is good.

Description

Technical Field

[0001] The invention relates to the technical field of atmospheric environment monitoring, and in particular to a method and a system for measuring ozone reaction activity. Background Art

[0002] Ozone is a highly oxidizing gas, and its presence in the atmosphere is potentially harmful to human health and the environment. It has a strong irritating effect on human respiratory tract and lungs. Studies have shown that ozone exposure is closely related to death, respiratory and cardiovascular diseases, and can cause premature death, asthma, respiratory tract infection, stroke, arrhythmia and other cardiovascular diseases, as well as neurological diseases such as autism in children and Alzheimer's disease in the elderly.

[0003] The ozone in the ambient atmosphere is all secondary, coming from the photochemical reaction of NOx and VOCs. There is a close relationship between the generation of ozone and atmospheric oxidation. In order to protect human health and the environment, ozone needs to be monitored and controlled. Ozone reactivity is an important indicator to measure the ability of ozone to react with other substances in the atmosphere. It is crucial to evaluate the overall reactivity of ozone with other components in the atmosphere. This indicator helps us understand the chemical behavior of ozone in the atmosphere, predict ozone pollution events, and develop effective atmospheric pollution control strategies.

[0004] Ozone reactivity (k) is the sum of all substances Xi in the atmosphere that can react with ozone multiplied by the product of their reaction rate constants with ozone (as shown below). This parameter is a comprehensive evaluation value of all atmospheric components involved in the ozone reaction, rather than the concentration of a certain chemical component or a certain type of chemical component.

[0005] k=∑k xi *Xi;

[0006] Assuming that the ozone reactivity measurement conforms to the assumption of pseudo-first-order reaction kinetics, the above equation can be integrated as:

[0007] O t＝ O 0* e -k*t ;

[0008] Further changes to:

[0009] k=(O t -O0) / O 0* △t;

[0010] Where:

[0011] O t ——O3 concentration at time t

[0012] O0——the concentration of O3 at the initial moment

[0013] k——O3 reactivity, unit is s -1

[0014] △t——the time difference between time t and the initial time.

[0015] From the above, it can be seen that if we want to directly measure the ozone reaction activity k, we need to measure the concentration difference at different times after the ozone reacts with the atmosphere to obtain k. By comparing the result data of ozone reaction activity with the VOCs measurement data in the prior art, we can test and evaluate the integrity of olefins, especially natural olefins, and quantify the composition of olefins in components that cannot be measured by existing monitoring methods, and explore the contribution of unknown olefins to urban ozone generation.

[0016] In the prior art, the measurement of ozone reactivity is mostly indirect measurement, that is, the ozone generation curve is simulated by the existing model to infer the ozone reactivity, or the ratio of the concentration of certain species obtained by measurement is used to preliminarily determine the sensitive area of ​​ozone generation, etc. Since these technical means are indirect measurements, the accuracy of the measurement results is questionable. Although patent CN 118010927B discloses a method for measuring ozone reactivity k, it ignores the ozone contained in the atmosphere itself, and the device is complicated. Therefore, the ozone reactivity k obtained thereby is still inaccurate.

[0017] Therefore, in view of the problems existing in the prior art, it is necessary to provide a high-resolution and high-accuracy online measurement system and method for atmospheric ozone reactivity activity. Summary of the invention

[0018] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a method and system for measuring ozone reactivity, so as to solve the problems in the prior art.

[0019] To achieve the above objectives and other related objectives, the present invention is achieved through the following technical solutions.

[0020] The first aspect of the present invention provides a method for measuring the ozone reactivity of the atmosphere, wherein the atmosphere in the environment is sampled to obtain an atmospheric airflow to be measured, wherein the atmospheric airflow to be measured is divided into a first branch airflow and a second branch airflow, and a mixed gas is obtained by mixing ozone of known concentration with the first branch airflow, and an ozone online measurement system is used to detect the total ozone reactivity in the mixed gas, i.e., the first ozone reactivity;

[0021] synchronously detecting a second ozone reaction activity corresponding to the ozone contained in the second branch airflow;

[0022] The difference between the first ozone reactivity and the second ozone reactivity is the ozone reactivity of the atmosphere;

[0023] The first ozone reaction activity or the second ozone reaction activity is calculated according to the following formula I:

[0024] k=(O t -O0) / O 0* △t

[0025] Formula I;

[0026] Where k is the ozone reaction activity, unit is s -1 , O t is the concentration of O3 at time t, O0 is the concentration of O3 at the initial time, and △t is the time difference between time t and the initial time.

[0027] In one embodiment, the mixed gas is further divided into a third branch gas flow and a fourth branch gas flow, the third branch gas flow and the ozone of known concentration enter the first ozone online measurement system after △t time, and the fourth branch gas flow directly enters the first ozone online measurement system at the initial moment; the first ozone reaction activity k1=(O t3 -O 04 ) / O 04* △t, where O t3 is the ozone concentration in the third branch airflow detected by the ozone online measurement system, O 04 It is the ozone concentration of the fourth branch airflow detected by the ozone online measurement system.

[0028] In one embodiment, the second branch airflow is further divided into a fifth branch airflow and a sixth branch airflow, the fifth branch airflow and the ozone contained therein enter the second ozone online measurement system after Δt time, and the sixth branch airflow directly enters the second ozone online measurement system at the initial moment; the second ozone reaction activity k2=(O t5 -O 06 ) / O 06* △t, where O t5 is the ozone concentration in the fifth branch airflow detected by the ozone online measurement system, O 06 It is the ozone concentration of the sixth branch airflow detected by the second ozone online measurement system.

[0029] In one embodiment, at the same time, the flow rate of the mixed gas is equal to the total flow rate of the second branch gas flow.

[0030] In one embodiment, at the same time, the flow rate of the third branch airflow is equal to the flow rate of the fifth branch airflow.

[0031] In one embodiment, the Δt of the first ozone reactivity is equal to the Δt of the second ozone reactivity.

[0032] In one embodiment, at the same time, the flow rate of the fourth branch airflow is equal to the flow rate of the sixth branch airflow.

[0033] In one embodiment, the Δt of the first ozone reactivity is equal to the Δt of the second ozone reactivity.

[0034] In one embodiment, the Δt is 100 to 200 s.

[0035] In one embodiment, the known ozone concentration is 80-300 ppb.

[0036] In one embodiment, the temperature of the airflow to be measured in the measurement method is 20-50°C.

[0037] In one embodiment, filtering is further performed after sampling, and the atmospheric airflow to be measured is obtained after filtering.

[0038] A second aspect of the present invention provides a device for measuring the ozone reactivity of the atmosphere, the device comprising at least:

[0039] An atmospheric sampling device, a first airflow branch, a second airflow branch, an ozone supply branch, a first ozone online measurement system, and a second ozone online measurement system;

[0040] The atmospheric sampling device is used to collect the atmosphere in the environment to form an atmospheric airflow to be measured; the air inlets of the first airflow branch and the second airflow branch are respectively connected to the airflow of the air outlet end of the atmospheric sampling device;

[0041] The first airflow branch comprises a first airflow trunk and a third airflow branch and a fourth airflow branch respectively formed by branches thereof; a gas mixing chamber is provided on the first airflow trunk, and the gas outlet end of the ozone supply branch is connected to the gas mixing chamber; the gas outlet ends of the third airflow branch and the fourth airflow branch are in gas communication with the first ozone online measurement system;

[0042] The second air flow branch includes a second air flow trunk and a fifth air flow branch and a sixth air flow branch respectively formed by its branches; the air outlet end of the second air flow trunk is connected with the air inlet ends of the fifth air flow branch and the sixth air flow branch; the air outlet ends of the fifth air flow branch and the sixth air flow branch are gas-connected to the second ozone online measurement system.

[0043] In one embodiment, a first reaction flow tube is provided on the third gas flow branch.

[0044] In one embodiment, a first drying tube is provided on the fourth airflow branch before the airflow enters the first ozone online measurement system.

[0045] In one embodiment, a second drying tube is provided on the third airflow branch before the airflow enters the first ozone online measurement system.

[0046] In one embodiment, a second reaction flow tube is provided on the fifth gas flow branch.

[0047] In one embodiment, a third drying tube is provided on the sixth airflow branch before the airflow enters the second ozone online measurement system.

[0048] In one embodiment, a fourth drying tube is provided on the fifth airflow branch before the airflow enters the second ozone online measurement system.

[0049] In one embodiment, a first temperature control unit is disposed on the first reaction flow tube.

[0050] In one embodiment, a second temperature control unit is disposed on the second reaction flow tube.

[0051] In one embodiment, on the third air flow branch, a first air pump is further provided between the first reaction flow tube and the second drying tube, and the first air pump has a flow control function.

[0052] In one embodiment, a first valve is provided on the fourth air flow branch before the air flow enters the first drying tube.

[0053] In one embodiment, on the fifth air flow branch, a second air pump is further provided between the second reaction flow tube and the fourth drying tube, and the second air pump has a flow control function.

[0054] In one embodiment, a second valve is provided on the sixth air flow branch before the air flow enters the third drying tube.

[0055] In one embodiment, the first reaction flow tube and the second reaction flow tube are low wall loss reaction flow tubes, preferably, glass tubes.

[0056] In one embodiment, the ozone supply branch is provided with a zero air machine, a mass flow controller and an ozone generator in sequence, and the zero air machine, the mass flow controller and the ozone generator are connected to each other by airflow.

[0057] In one embodiment, the first ozone online measurement system is provided with a first calculation module, and the first calculation module calculates the first ozone reaction activity according to the following formula II:

[0058] k1=(O t3 -O 04 ) / (O 04 *△t)

[0059] Formula II,

[0060] Where k1 is the first ozone reaction activity, unit is s -1 , O t3 is the concentration of O3 in the third airflow branch at time t, O 04 is the concentration of O3 in the fourth airflow branch at the initial moment, and △t is the time difference between moment t and the initial moment.

[0061] In one embodiment, the second ozone online measurement system is provided with a second calculation module, and the second calculation module calculates the second ozone reaction activity according to the following formula III:

[0062] k2=(O t5 -O 06 ) / (O 06 *△t)

[0063] Formula III,

[0064] Where, k2 is the second ozone reaction activity, unit is s-1, O t5 is the concentration of O3 in the fifth airflow branch at time t, O 06 is the concentration of O3 in the sixth airflow branch at the initial moment, and △t is the time difference between moment t and the initial moment.

[0065] The third aspect of the present invention provides a system for measuring ozone reactivity, comprising the measuring device and a measuring module as described above, wherein the measuring module is in information communication with the measuring device and is used to calculate the ozone reactivity of the atmosphere based on the measurement data of the measuring device. The measurement is performed using the system for measuring ozone reactivity as described above.

[0066] In one embodiment, the ozone reactivity of the atmosphere is obtained by subtracting the second ozone reactivity from the first ozone reactivity.

[0067] The technical solution of the present invention provides a new solution to the problem of inaccurate ozone reactivity testing in the atmosphere in the prior art. The method is to react the atmosphere to be tested with ozone gas of known concentration to obtain a corresponding first ozone reactivity, and simultaneously detect a second ozone reactivity corresponding to the ozone contained in the atmosphere to be tested. The difference between the two is the high-resolution and high-accuracy ozone reactivity of the atmosphere provided by the present application.

[0068] In addition, the present application also provides a system for measuring the ozone reactivity of the atmosphere, which creatively sets up a dual reaction flow tube and a dual ozone online measurement system, thereby being able to remove the original ozone in the atmosphere and further provide more accurate ozone reactivity measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 Shown is a schematic diagram of the structure of the ozone reactivity measurement system provided by the present invention.

[0070] Figure 1 Component number description

[0071] 11 Zero Air Machine

[0072] 12 Mass Flow Controller

[0073] 13. Ozone Generator

[0074] 2 Atmospheric sampling device

[0075] 3 Gas mixing chamber

[0076] 41 First reaction flow tube

[0077] 42. Second reaction flow tube

[0078] 51 The first ozone online measurement system

[0079] 52. Second ozone online measurement system

[0080] 6 Measurement module

[0081] 71 Ozone supply branch

[0082] 72 First airflow branch

[0083] 721 Third airflow branch

[0084] 722 Fourth airflow branch

[0085] 73 Second air flow branch

[0086] 731 Fifth airflow branch

[0087] 732 Sixth airflow branch

[0088] 81 First temperature control unit

[0089] 82 Second temperature control unit

[0090] 91 First Valve

[0091] 92 First Air Pump

[0092] 93 Second Valve

[0093] 94 Second Air Pump

[0094] 95 First drying tube

[0095] 96 Second drying tube

[0096] 97 Third drying tube

[0097] 98 Fourth drying tube DETAILED DESCRIPTION

[0098] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0099] Before further describing the specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terms used in the examples of the present invention are intended to describe specific embodiments, rather than to limit the scope of protection of the present invention. The test methods in the following examples without specifying specific conditions are generally carried out under conventional conditions or under conditions recommended by the manufacturers.

[0100] When the embodiments give numerical ranges, it should be understood that, unless otherwise specified in the present invention, both endpoints of each numerical range and any numerical value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those generally understood by those skilled in the art. In addition to the specific methods, equipment, and materials used in the embodiments, according to the grasp of the prior art by those skilled in the art and the record of the present invention, any methods, equipment, and materials of the prior art similar or equivalent to the methods, equipment, and materials described in the embodiments of the present invention can also be used to realize the present invention.

[0101] See also Figure 1 It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0102] The present application provides a specific method for measuring the ozone reactivity of the atmosphere. The atmosphere in the environment is sampled to obtain the atmospheric airflow to be measured, which is divided into a first branch airflow and a second branch airflow. A mixed gas is obtained by providing ozone of a known concentration and mixing it with the first branch airflow. An ozone online measurement system is used to detect the total ozone reactivity in the mixed gas, i.e., the first ozone reactivity; the second ozone reactivity corresponding to the ozone contained in the second branch airflow is simultaneously detected; the difference between the first ozone reactivity and the second ozone reactivity is the ozone reactivity of the atmosphere.

[0103] Furthermore, the mixed gas is further divided into a third branch gas flow and a fourth branch gas flow. After the third branch gas flow and the ozone of known concentration are subjected to △t time, they enter the first ozone online measurement system at time t, and the fourth branch gas flow directly enters the first ozone online measurement system at the initial time. Through the first ozone online measurement system, according to k1=(O t3 -O 04 ) / O 04* △t (where k1 is the first ozone reaction activity, O t3 is the ozone concentration of the third branch airflow at time t, O 04 is the ozone concentration of the fourth branch airflow at the initial moment, △t is the time difference between moment t and the initial moment), and then the first ozone reaction activity is obtained.

[0104] The second branch airflow is further divided into a fifth branch airflow and a sixth branch airflow. The fifth branch airflow and the ozone contained therein enter the second ozone online measurement system at time t after a period of △t. The sixth branch airflow directly enters the second ozone online measurement system at the initial time. Through the second ozone online measurement system, according to k2=(O t5 -O 06 ) / O 06* △t (where k2 is the second ozone reaction activity, O t5 is the ozone concentration of the fifth branch airflow at time t, O 06 is the ozone concentration of the sixth branch airflow at the initial moment, △t is the time difference between moment t and the initial moment), and then the second ozone reaction activity is obtained.

[0105] Finally, the ozone reactivity of the atmosphere is obtained by calculating the difference between the first ozone reactivity and the second ozone reactivity.

[0106] In a specific embodiment, at the same time, the flow rate of the mixed gas is equal to the total flow rate of the second branch gas flow. Further, at the same time, the flow rate of the mixed gas and the total flow rate of the second branch gas flow are preferably 1 to 10L, more preferably 2 to 6L. For example, the flow rate of the mixed gas and the total flow rate of the second branch gas flow can be 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L. Specifically, as an example, the flow rate of the mixed gas and the total flow rate of the second branch gas flow are 4L respectively.

[0107] In a specific embodiment, at the same time, the flow rate of the third branch airflow is equal to the flow rate of the fifth branch airflow. Further, the flow rate of the third branch airflow and the flow rate of the fifth branch airflow are preferably 1 to 8L, more preferably 2 to 5L. For example, the flow rate of the third branch airflow and the flow rate of the fifth branch airflow can be 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L. Specifically, as an example, the flow rate of the third branch airflow and the flow rate of the fifth branch airflow are 3L.

[0108] In a specific embodiment, at the same time, the flow rate of the fourth branch airflow is equal to the flow rate of the sixth branch airflow. Further, the flow rate of the fourth branch airflow and the flow rate of the sixth branch airflow are preferably 0.5 to 2L, more preferably 1L. For example, the flow rate of the fourth branch airflow and the flow rate of the sixth branch airflow can be 0.5L, 1L, 1.5L, 2L. Specifically, as an example, the flow rate of the fourth branch airflow and the flow rate of the sixth branch airflow are 1L.

[0109] In a specific embodiment, the Δt of the first ozone reaction activity is equal to the Δt of the second ozone reaction activity, so as to ensure that the reaction time of the gas to be tested and ozone is equal, thereby ensuring the effectiveness and accuracy of the test results.

[0110] In a specific embodiment, the △t is 100-200s. For example, it can be 100-120s, 120-200s, 100-150s, 150-180s. The duration of the △t is not arbitrarily limited. If the duration of △t is too short, the measurement time of the airflow is too short, and the ozone concentration at time t is too close to the ozone concentration at the initial time, and the first ozone reaction activity cannot be measured; if the duration of △t is too long, wall loss will occur due to the diffusion effect, which is not conducive to the accuracy of the measurement result. Specifically, as an example, the △t is 120s.

[0111] In a specific embodiment, the concentration of the known ozone concentration is 80-300 ppb. For example, it can be 80-100 ppb, 100-300 ppb. Specifically, as an example, the concentration of the known ozone concentration is 100 ppb. If the concentration of ozone is too low, an incomplete reaction may occur. If the concentration of ozone is too high, due to the small consumption during the reaction, the measurement fluctuation of the excessively high concentration of ozone itself may be greater than the actual measurement difference, which is not conducive to the accurate measurement of the reaction result.

[0112] In a specific embodiment, the temperature of the airflow to be measured in the measuring method is 20-50° C. For example, it may be 20-40° C. or 40-50° C. Specifically, as an example, the temperature of the airflow to be measured in the measuring method is 40° C.

[0113] In a specific embodiment, filtration is further performed after sampling to obtain the atmospheric airflow to be measured, and most of the particulate matter contained in the atmospheric airflow is removed by filtration.

[0114] The method for measuring the ozone reactivity of the atmosphere provided in the present application further takes into account the ozone reactivity corresponding to the ozone already existing in the atmospheric airflow to be measured, and by diverting the flow to synchronously measure the ozone reactivity of ozone of known concentration and the atmospheric airflow to be measured, as well as the ozone reactivity corresponding to the ozone contained in the atmospheric airflow to be measured, and then taking the difference between the two, it is possible to obtain a more accurate atmospheric ozone reactivity with high resolution.

[0115] The present invention also provides a specific measuring device for atmospheric ozone reactivity, such as Figure 1 As shown, the measuring device at least includes: an atmospheric sampling device 2, a first airflow branch 72, a second airflow branch 73, an ozone supply branch 71, a first ozone online measuring system 51 and a second ozone online measuring system 52;

[0116] The atmospheric sampling device 2 is used to collect the atmosphere in the environment to form an atmospheric airflow to be measured; the air inlet of the first airflow branch 72 and the second airflow branch 73 are respectively connected to the air outlet end of the atmospheric sampling device 2;

[0117] The first airflow branch 72 includes a first airflow trunk and a third airflow branch 721 and a fourth airflow branch 722 formed by the first airflow trunk; a gas mixing chamber 3 is provided on the first airflow trunk, and the gas outlet end of the ozone supply branch 71 is connected to the gas mixing chamber 3; the gas outlet ends of the third airflow branch 721 and the fourth airflow branch 722 are in gas communication with the first ozone online measurement system 51;

[0118] The second air flow branch 73 includes a second air flow trunk and a fifth air flow branch 731 and a sixth air flow branch 732 respectively formed by its branches; the air outlet end of the second air flow trunk is connected to the air inlet ends of the fifth air flow branch 731 and the sixth air flow branch 732; the air outlet ends of the fifth air flow branch 731 and the sixth air flow branch 732 are gas-connected to the second ozone online measurement system 52.

[0119] The branches mentioned in this application include pipelines.

[0120] In actual use, the atmosphere in the environment forms an atmospheric airflow to be measured after passing through the atmospheric sampling device 2. The atmospheric airflow to be measured is divided into two paths, wherein the first branch airflow enters the first airflow branch 72, and the second branch airflow enters the second airflow branch 73. At the same time, the ozone supply branch 71 is used to provide ozone of known concentration.

[0121] After the first branch airflow enters the first airflow branch 72, it forms a mixed gas with ozone of known concentration in the gas mixing chamber 3, and forms a third branch airflow and a fourth branch airflow respectively, wherein the third branch airflow enters the third airflow branch 721, and enters the first ozone online measurement system 51 after t time; the fourth branch airflow enters the fourth airflow branch 722, and enters the first ozone online measurement system 51 at the initial moment, and obtains the first ozone reaction activity after analysis and detection by the first ozone online measurement system 51. After the second branch airflow enters the second airflow branch 73, it forms a fifth branch airflow and a sixth branch airflow respectively, wherein the fifth branch airflow enters the fifth airflow branch 731, and enters the second ozone online measurement system 52 after t time; the sixth branch airflow enters the sixth airflow branch 732, and enters the second ozone online measurement system 52 at the initial moment, and obtains the second ozone reaction activity after analysis and detection by the second ozone online measurement system 52.

[0122] In the measuring device for atmospheric ozone reactivity provided by the present invention, a dual ozone online measurement system is creatively set up, so that the first ozone reactivity corresponding to the known concentration of ozone in the atmospheric airflow to be measured and the second ozone reactivity corresponding to the ozone contained in the atmospheric airflow to be measured can be measured respectively, and the influence of the second ozone reactivity can be eliminated on the basis of the first ozone reactivity to provide a more accurate atmospheric ozone reactivity measurement result.

[0123] More specifically, the first ozone online measurement system 51 is provided with a first calculation module, and the first calculation module calculates the first ozone reaction activity according to the following formula II:

[0124] k1=(O t3 -O 04 ) / (O 04* △t)

[0125] Formula II,

[0126] Where k1 is the first ozone reaction activity, unit is s -1 , O t3 is the concentration of O3 in the third airflow branch 721 at time t, O 04 is the concentration of O3 in the fourth airflow branch 722 at the initial moment, and Δt is the time difference between moment t and the initial moment.

[0127] More specifically, the second ozone online measurement system 52 is provided with a second calculation module, and the second calculation module calculates the second ozone reaction activity according to the following formula III:

[0128] k2=(O t5 -O 06 ) / (O 06* △t)

[0129] Formula III,

[0130] Where k2 is the second ozone reaction activity, unit is s -1 , O t5 is the concentration of O3 in the fifth airflow branch 731 at time t, O 06 is the concentration of O3 in the sixth air flow branch 732 at the initial moment, and Δt is the time difference between moment t and the initial moment.

[0131] In this application, there are no specific requirements for the model and manufacturer of the ozone online measurement system, as long as it can be used to calculate the ozone reaction activity and meet the requirements of the above-mentioned calculation module. It should be clear that the ozone online measurement systems commonly used on the market have the function of extracting airflow, which can control the flow rate of the airflow entering the ozone online measurement system, and can also provide power to a certain extent for the atmospheric airflow to be measured in the collection environment. Specifically, as an example, the ozone online measurement system in this application is an API T265 ozone analyzer with an extraction range of 0.5L / min±10% / min. It is used to monitor the O3 concentration before and after the reaction flow tube and calculate the ozone reaction activity. At the same time, it can also provide power for the gas entering its measurement system and control the size of the gas flow.

[0132] In the present application, there is no specific limitation on the atmospheric sampling device 2, as long as it can collect and capture the atmospheric airflow in the environment. As an example, the atmospheric sampling device 2 is an environmental sampling filter head. Furthermore, the filter pores of the filter head are less than or equal to 5 microns. For example, it can be 1μm, 2μm, 3μm, 4μm, 5μm. In a Figure 1 In the embodiment shown, the environmental sampling filter head is an environmental sampling filter head with a pore size of 5 μm, which is used to capture the atmosphere in the environment and filter most of the particulate matter in the atmosphere.

[0133] The present application has no specific limitation on the gas mixing chamber 3, as long as it can provide a turbulent environment to achieve uniform mixing of the gas flow. Figure 1 As shown, the gas mixing chamber 3 is 24 cm long and 8 mm in diameter, and contains 30 parts. By setting obstacles and changing the flow direction, the complexity of gas flow is increased and the formation of turbulence is promoted. The setting of the gas mixing chamber provides a turbulent environment for the mixed gas to make the gas mixed evenly.

[0134] In a Figure 1 In the specific embodiment shown, a first reaction flow tube 41 is disposed on the third gas flow branch 721 .

[0135] In a Figure 1In the specific embodiment shown, a second reaction flow tube 42 is provided on the fifth gas flow branch 731 .

[0136] More specifically, the first reaction flow tube 41 and the second reaction flow tube 42 are low wall loss reaction flow tubes. As an example, the low wall loss reaction flow tube uses a quartz glass tube wrapped with thermal insulation cotton to ensure the lowest ozone loss, reduce wall loss interference, and further ensure a uniform environment in the reaction flow tube. If other materials such as stainless steel or aluminum reaction flow tubes are used, VOCs in the airflow will be lost, resulting in inaccurate measurement results.

[0137] Furthermore, the shape and size of the reaction flow tube are not particularly limited in the present application. In actual use, the shape and size of the reaction flow tube are adapted to the volume of the gas flow to be measured, and the gas flow to be measured can be ensured to pass smoothly within a time range of 100 to 200 seconds. Figure 1 In the illustrated embodiment, the first reaction flow tube 41 and the second reaction flow tube 42 are two identical quartz glass tubes with a length of 40.0 cm, an inner diameter of 17.8 cm, and a capacity of 10 L.

[0138] In a Figure 1 In the specific embodiment shown, a first temperature control unit 81 is disposed on the first reaction flow tube 41 .

[0139] In a Figure 1 In the specific embodiment shown, a second temperature control unit 82 is disposed on the second reaction flow tube 42 .

[0140] The temperature in the reaction flow tube is kept uniform by a temperature control unit. In the present application, the temperature control unit is not specifically limited, as long as it can provide a constant temperature for the environment of the reaction flow tube. As an example, the temperature control unit can be an integrated module with a thermistor, a thermocouple, or an integrated temperature sensor.

[0141] In a Figure 1 In the specific embodiment shown, a first drying tube 95 is provided on the fourth air flow branch 722 before the air flow enters the first ozone online measurement system 51 to remove moisture from the gas.

[0142] In a Figure 1 In the specific embodiment shown, a second drying tube 96 is provided on the third air flow branch 721 before the air flow enters the first ozone online measurement system 51 to remove moisture from the gas.

[0143] In a Figure 1In the specific embodiment shown, a third drying tube 97 is provided on the sixth airflow branch 732 before the airflow enters the second ozone online measurement system 52 to remove moisture from the gas.

[0144] In a Figure 1 In the specific embodiment shown, a fourth drying tube 98 is provided on the fifth air flow branch 731 before the air flow enters the second ozone online measurement system 52 to remove moisture from the gas.

[0145] In the present application, by providing a first drying tube 95, a second drying tube 96, a third drying tube 97 and a fourth drying tube 98, moisture is removed from the airflow to be measured before it enters the ozone online measurement assembly, thereby avoiding interference of moisture on the accuracy of ozone reaction activity.

[0146] There is no specific limitation on the drying tube in this application, as long as it can only play a drying role. Figure 1 In the specific embodiment shown, the first drying tube 95, the second drying tube 96, the third drying tube 97 and the fourth drying tube 98 are drying tubes filled with color-changing silica gel.

[0147] In a Figure 1 In the specific embodiment shown, a first valve 91 is further provided on the fourth airflow branch 722 before the airflow enters the first drying tube 95. The first valve 91 is used to adjust the gas pressure of the fourth branch airflow entering the first ozone online measurement system 51 to be equal to the gas pressure of the third branch airflow, so as to further improve the accuracy of the measurement result.

[0148] In a Figure 1 In the specific embodiment shown, on the third air flow branch 721, a first air pump 92 is further provided between the first reaction flow tube 41 and the second drying tube 96, and the first air pump 92 has a flow control function. Specifically, the first air pump 92 is a flow pump, which is used to control the flow of the third branch airflow entering the first reaction flow tube 41, and provide power for the gas flow of the entire ozone reaction activity measurement device, including providing power for the atmospheric airflow in the collection environment.

[0149] In a Figure 1 In the specific embodiment shown, on the sixth air flow branch 732, before the air flow enters the third drying tube 97, a second valve 93 is further provided. The second valve 93 is used to adjust the gas pressure of the sixth branch air flow entering the second ozone online measurement system 52 to be equal to the gas pressure of the fifth branch air flow, so as to further improve the accuracy of the measurement results.

[0150] In a Figure 1In the specific embodiment shown, on the fifth air flow branch 731, a second air pump 94 is further provided between the second reaction flow tube 42 and the fourth drying tube 98, and the second air pump 94 also has a flow control function. Specifically, the second air pump 94 is a flow pump, which is used to control the flow of the fifth branch air flow entering the second reaction flow tube 42 and provide power for the gas flow of the entire ozone reaction activity measurement system.

[0151] like Figure 1 As shown, the ozone supply branch 71 is provided with a zero air machine 11, a mass flow controller 12 and an ozone generator 13 in sequence, and the zero air machine 11, the mass flow controller 12 and the ozone generator 13 are connected to each other by airflow. The mass flow controller 12 is used to control the concentration and flow rate of the zero-level air entering the ozone generator 13, thereby further controlling the concentration and flow rate of the generated ozone.

[0152] There is no particular limitation on the zero air machine 11 and the ozone generator 13 in the present application, as long as they are zero air machines commonly used in the market to generate zero-grade air and ozone generators commonly used in the market to generate ozone. Figure 1 In the preferred embodiment shown, the hydrocarbon content of the zero-level air generated by the zero air machine 11 is less than 0.05 ppm (in terms of methane); the ozone generator 13 adopts a small mercury lamp ozone generator.

[0153] The present invention also provides a specific system for measuring atmospheric ozone reactivity, comprising the measuring device as described above and a measuring module 6, wherein the measuring module 6 is in information communication with the measuring device and is used to calculate atmospheric ozone reactivity based on measurement data of the measuring device.

[0154] In a specific embodiment, the ozone reactivity of the atmosphere is obtained by subtracting the second ozone reactivity from the first ozone reactivity.

[0155] When in use, the measuring module 6 is in information communication with the measuring device. The measuring module 6 collects the first ozone reaction activity and the second ozone reaction activity obtained by the measuring device and calculates the difference between the two to obtain the ozone reaction activity of the atmosphere.

[0156] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for measuring the ozone reactivity of the atmosphere, characterized in that: Sampling the atmosphere in the environment to obtain an atmospheric airflow to be measured, wherein the atmospheric airflow to be measured is divided into a first branch airflow and a second branch airflow, and a mixed gas is obtained by providing ozone of known concentration to mix with the first branch airflow, and an ozone online measurement system is used to detect the total ozone reaction activity in the mixed gas, i.e., the first ozone reaction activity; synchronously detecting a second ozone reaction activity corresponding to the ozone contained in the second branch airflow; The difference between the first ozone reactivity and the second ozone reactivity is the ozone reactivity of the atmosphere; The first ozone reaction activity or the second ozone reaction activity is calculated according to the following formula I: k=(O t -O0) / (O0*△t) Formula I; Where k is the ozone reaction activity, unit is s -1 , O t is the concentration of O3 at time t, O0 is the concentration of O3 at the initial time, and △t is the time difference between time t and the initial time.

2. The measuring method according to claim 1, characterized in that: The mixed gas is further divided into a third branch gas flow and a fourth branch gas flow. The third branch gas flow and the ozone of known concentration enter the first ozone online measurement system after △t time, and the fourth branch gas flow directly enters the first ozone online measurement system at the initial moment; the first ozone reaction activity k1=(O t3 -O 04 ) / (O 04 *△t), where O t3 is the ozone concentration in the third branch airflow detected by the first ozone online measurement system, O 04 The ozone concentration of the fourth branch airflow detected by the first ozone online measurement system; And / or, the second branch airflow is further divided into a fifth branch airflow and a sixth branch airflow, the fifth branch airflow and the ozone contained therein react for a time Δt before entering the second ozone online measurement system, and the sixth branch airflow directly enters the second ozone online measurement system at the initial moment; the second ozone reaction activity k2=(O t5 -O 06 ) / (O 06 *△t), where O t5 is the ozone concentration in the fifth branch airflow detected by the second ozone online measurement system, O 06 It is the ozone concentration of the sixth branch airflow detected by the second ozone online measurement system.

3. The measuring method according to claim 2, characterized in that: At the same time, the flow rate of the mixed gas is equal to the total flow rate of the second branch gas flow; and / or, at the same time, the flow rate of the third branch airflow is equal to the flow rate of the fifth branch airflow; and / or, at the same time, the flow rate of the fourth branch airflow is equal to the flow rate of the sixth branch airflow; and / or, the Δt of the first ozone reactivity is equal to the Δt of the second ozone reactivity; And / or, the Δt is 100 to 200 s; And / or, the known concentration of ozone is 80-300 ppb; And / or, in the measuring method, the temperature of the airflow to be measured is 20 to 50° C.; And / or, filtering is further performed after sampling to obtain the atmospheric airflow to be measured.

4. A device for measuring the ozone reactivity of the atmosphere, characterized in that: The measuring device comprises at least: An atmospheric sampling device (2), a first airflow branch (72), a second airflow branch (73), an ozone supply branch (71), a first ozone online measurement system (51), and a second ozone online measurement system (52); The atmospheric sampling device (2) is used to collect the atmosphere in the environment to form an atmospheric airflow to be measured; the air inlets of the first airflow branch (72) and the second airflow branch (73) are respectively connected to the airflow of the air outlet end of the atmospheric sampling device (2); The first air flow branch (72) comprises a first air flow trunk and a third air flow branch (721) and a fourth air flow branch (722) formed by branches thereof; a gas mixing chamber (3) is provided on the first air flow trunk, and the gas outlet end of the ozone supply branch (71) is in communication with the gas mixing chamber (3); the gas outlet ends of the third air flow branch (721) and the fourth air flow branch (722) are in gas communication with the first ozone online measurement system (51); The second air flow branch (73) comprises a second air flow trunk and a fifth air flow branch (731) and a sixth air flow branch (732) respectively formed by branches thereof; the air outlet end of the second air flow trunk is connected to the air inlet ends of the fifth air flow branch (731) and the sixth air flow branch (732); the air outlet ends of the fifth air flow branch (731) and the sixth air flow branch (732) are in gas communication with the second ozone online measurement system (52).

5. The measuring device according to claim 4, characterized in that The third air flow branch (721) is provided with a first reaction flow tube (41); And / or, a first drying tube (95) is provided on the fourth airflow branch (722) before the airflow enters the first ozone online measurement system (51); And / or, a second drying tube (96) is provided on the third airflow branch (721) before the airflow enters the first ozone online measurement system (51); and / or, a second reaction flow tube (42) is provided on the fifth gas flow branch (731); And / or, a third drying tube (97) is provided on the sixth airflow branch (732) before the airflow enters the second ozone online measurement system (52); And / or, a fourth drying tube (98) is provided on the fifth airflow branch (731) before the airflow enters the second ozone online measurement system (52).

6. The measuring device according to claim 5, characterized in that The first reaction flow tube (41) is provided with a first temperature control unit (81); and / or, the second reaction flow tube (42) is provided with a second temperature control unit (82); And / or, on the third air flow branch (721), a first air pump (92) is further provided between the first reaction flow tube (41) and the second drying tube (96), and the first air pump (92) has a flow control function; and / or, on the fourth air flow branch (722), before the air flow enters the first drying tube (95), a first valve (91) is provided; and / or, on the fifth air flow branch (731), a second air pump (94) is further provided between the second reaction flow tube (42) and the fourth drying tube (98), and the second air pump (94) has a flow control function; And / or, on the sixth air flow branch (732), a second valve (93) is provided before the air flow enters the third drying tube (97); and / or, the first reaction flow tube (41) and the second reaction flow tube (42) are low wall loss reaction flow tubes, preferably, glass tubes.

7. The measuring device according to claim 4, characterized in that The ozone supply branch (71) is provided with a zero air machine (11), a mass flow controller (12) and an ozone generator (13) in sequence, and the zero air machine (11), the mass flow controller (12) and the ozone generator (13) are connected to each other by airflow.

8. The measuring device according to claim 4, characterized in that The first ozone online measurement system (51) is provided with a first calculation module, and the first calculation module calculates the first ozone reaction activity according to the following formula II: k1=(O t3 -SHE 04 ) / (SHE 04 *△t) Formula II, Where k1 is the first ozone reaction activity, unit is s -1 , O t3 is the concentration of O3 in the third airflow branch (721) at time t, O 04 is the concentration of O3 in the fourth airflow branch (722) at the initial time, Δt is the time difference between time t and the initial time; And / or, the second ozone online measurement system (52) is provided with a second calculation module, and the second calculation module calculates the second ozone reaction activity according to the following formula III: k2=(O t5 -Oh 06 ) / (O 06 *△t) Formula III, Where, k2 is the second ozone reaction activity, unit is s-1, O t5 is the concentration of O3 in the fifth airflow branch (731) at time t, O 06 is the concentration of O3 in the sixth airflow branch (732) at the initial time, and Δt is the time difference between time t and the initial time.

9. A system for measuring atmospheric ozone reactivity, characterized in that: It comprises a measuring device as claimed in any one of claims 4 to 8 and a measuring module (6), wherein the measuring module (6) is in information communication with the measuring device and is used to calculate the ozone reactivity of the atmosphere based on the measurement data of the measuring device.

10. The measuring system according to claim 9, characterized in that The ozone reactivity of the atmosphere is obtained by subtracting the second ozone reactivity from the first ozone reactivity.

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