Sampling device and method for BVOCs flux measurement based on relaxed eddy accumulation

Abstract

The present invention relates to the field of environmental monitoring technology, and in particular to a sampling device and method for measuring BVOCs flux based on relaxed vortex accumulation. The method comprises: obtaining the temperature and light quantity of the environment in which the measurement is performed during a measurement period; calculating the temperature measurement coefficient based on the temperature of the environment in which the measurement is performed during the measurement period, calculating the light quantity measurement coefficient based on the light quantity of the environment in which the measurement is performed during the measurement period, recording the sum of the temperature measurement coefficient and the light quantity measurement coefficient as the measurement activation value of the measurement period; and obtaining the measurement value based on the measurement activation value, analyzing the environment in which the measurement is performed based on the measurement value, accurately reflecting the actual situation of the natural environment, and obtaining a more accurate BVOCs flux measurement result with a high measurement accuracy. Furthermore, based on the wind speed data of the environment, the BVOCs flux measurement of the environment is completed based on the wind speed data through a relaxed vortex accumulation acquisition system, thereby improving the sampling efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental monitoring, and in particular to a sampling device and method for measuring BVOCs flux based on relaxed eddy accumulation. Background Art

[0002] Biogenic Volatile Organic Compounds (BVOCs) are the main components of volatile organic compounds (VOCs) in the atmosphere, and their emissions account for more than 90% of the total VOCs emissions. BVOCs not only participate in atmospheric photochemical reactions, but are also key precursors of ozone and secondary organic aerosols (SOA), which have an important impact on the atmospheric environment and climate. Therefore, accurate and efficient measurement of BVOCs flux is of great significance for understanding atmospheric chemical processes, assessing environmental quality, and formulating emission reduction strategies.

[0003] In the prior art, when measuring BVOCs flux, the measurement environment is often not analyzed or studied, which makes it difficult to accurately reflect the actual situation of the natural environment, resulting in inaccurate BVOCs flux measurement results and low measurement accuracy.

[0004] Therefore, there is an urgent need for a sampling device and method for measuring BVOCs flux based on relaxed eddy accumulation to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a sampling device and method for BVOCs flux measurement based on relaxed eddy accumulation: to solve the technical problem that existing solutions often do not analyze and study the measurement environment, resulting in difficulty in accurately reflecting the actual situation of the natural environment, resulting in inaccurate BVOCs flux measurement results and low measurement accuracy.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] On the one hand, a sampling method for measuring BVOCs flux based on relaxed eddy accumulation comprises:

[0008] Generate a measurement cycle and divide the measurement cycle into a number of measurement periods, and obtain the temperature and light quantity of the measurement environment within the measurement period;

[0009] Calculate the temperature measurement coefficient based on the temperature of the environment in which the measurement is performed during the measurement period, calculate the light measurement coefficient based on the light amount of the environment in which the measurement is performed during the measurement period, and record the sum of the temperature measurement coefficient and the light measurement coefficient as the measurement activation value of the measurement period;

[0010] Obtain all measured activation values ​​of the measurement period, establish a rectangular coordinate system with the execution time of the measurement period as the X-axis and the measured activation value corresponding to the measurement period as the Y-axis, draw an activation curve of the measurement period in the rectangular coordinate system through the measured activation value of the measurement period, draw two perpendicular lines from the two end points of the activation curve to the X-axis to obtain two truncation line segments, form an activation graph by the activation curve, the two truncation line segments and the X-axis, and mark the area value of the activation graph as the measurement value;

[0011] Based on the measured values, it is determined whether the environment within the measurement period meets the BVOCs flux measurement requirements. If so, the relaxed eddy accumulation acquisition system is activated; the wind speed data of the environment within the measurement period is obtained, and the BVOCs flux measurement of the environment is completed through the relaxed eddy accumulation acquisition system based on the wind speed data.

[0012] Further, calculating the temperature measurement coefficient based on the temperature of the environment in which the measurement is performed during the measurement period includes the following process:

[0013] ;

[0014] in, is the temperature measurement coefficient, The temperature of the environment measured during the measurement period. is the standard temperature, which is 303K. , is the temperature constant coefficient, and its values ​​are 90000 J / mol and 200000 J / mol respectively. is the temperature constant, its value is 314K, is the number of moles of gas, its value is 8J / Kmol, and the value of e is 2.72.

[0015] Further, calculating the light quantity measurement coefficient based on the light quantity of the environment measured during the measurement period includes the following process:

[0016] ;

[0017] in, is the light quantity measurement coefficient, The light quantity in the environment is measured during the measurement period, where the light quantity is the light radiation energy received per unit area per unit time. , are the light intensity constant coefficients, and their values ​​are 1.066 and 0.0027 respectively.

[0018] Furthermore, judging whether the environment in the measurement period meets the BVOCs flux measurement requirements based on the measured values ​​includes the following process:

[0019] Loading a measurement value threshold, wherein the measurement value threshold is stored in a relaxation vortex accumulation acquisition system;

[0020] Determine whether the measured value exceeds the preset measurement value threshold. If so, it is determined that the environment within the measurement period meets the BVOCs flux measurement requirements. If not, it is determined that the environment within the measurement period does not meet the BVOCs flux measurement requirements.

[0021] Furthermore, the relaxed vortex accumulation collection system includes an anemometer and a collector, wherein the anemometer is used to obtain wind speed data of the environment during the measurement period, and the collector is composed of a gas mass flow controller, a pump, a filter, a solenoid valve, an air outlet and a sampling tube.

[0022] Furthermore, the following steps are included to complete the BVOCs flux measurement of the environment based on the wind speed data through the relaxed eddy accumulation acquisition system:

[0023] Step 1: After turning on the gas mass flow controller for 15 minutes, start the pump to collect the BVOCs flux in the environment;

[0024] Step 2: Obtain wind speed and direction based on wind speed data, and obtain the standard deviation of wind speed perpendicular to the collector. , standard deviation Set by the relaxed vortex accumulation collection system and stored in the relaxed vortex accumulation collection system;

[0025] Step 3: When the wind speed is greater than 0.6 The wind direction relative to the collector is horizontal and upward, and the sample is collected into the UP sampling tube through the control of the solenoid valve. When the wind speed is greater than 0.6 The wind direction relative to the collector is horizontal and downward, and the sample is collected into the down sampling tube through the solenoid valve control. When the wind speed is less than 0.6 , the sample is collected into the NeUtral collection tube through the control of the solenoid valve, wherein the sampling tube includes the UP sampling tube, the down sampling tube and the NeUtral collection tube;

[0026] Step 4: When all sampling is completed, cut to the gas outlet without collecting any samples;

[0027] Step five, calculate the BVOCs flux of the samples in the collection tube.

[0028] Furthermore, the calculation of BVOCs flux for the sample in the collection tube includes the following process:

[0029] ;

[0030] in, is the flux of a certain BVOCs component, is the number of the BVOCs component, is the concentration of BVOCs components in the UP sampling tube, is the concentration of BVOCs components in the down sampling tube, It is a measurement constant whose value is set by the relaxed vortex accumulation acquisition system.

[0031] Furthermore, the collection cycle of the relaxed vortex accumulation collection system is 30 minutes, and the filter cartridge in the filter is replaced at a cycle of 90 minutes.

[0032] On the other hand, a sampling device for measuring BVOCs flux based on relaxed eddy accumulation includes an environmental data acquisition module, a measurement activation value calculation module, a measurement value calculation module and a relaxed eddy accumulation acquisition system;

[0033] The environmental data acquisition module is used to generate a measurement cycle and divide the measurement cycle into several measurement periods, and obtain the temperature and light amount of the environment in which the measurement is performed during the measurement period;

[0034] A measurement activation value calculation module, used to calculate a temperature measurement coefficient based on the temperature of the environment in which the measurement is performed during the measurement period, calculate a light quantity measurement coefficient based on the light quantity of the environment in which the measurement is performed during the measurement period, and record the sum of the temperature measurement coefficient and the light quantity measurement coefficient as the measurement activation value of the measurement period;

[0035] A measurement value calculation module is used to obtain all measurement activation values ​​of the measurement period, establish a rectangular coordinate system with the execution time of the measurement period as the X-axis and the measurement activation value corresponding to the measurement period as the Y-axis, draw an activation curve of the measurement period in the rectangular coordinate system through the measurement activation value of the measurement period, draw two perpendicular lines from the two end points of the activation curve to the X-axis to obtain two truncation line segments, form an activation graph by the activation curve, the two truncation line segments and the X-axis, and mark the area value of the activation graph as the measurement value;

[0036] The relaxed eddy accumulation acquisition system is used to determine whether the environment within the measurement period meets the BVOCs flux measurement requirements based on the measurement values. If so, the relaxed eddy accumulation acquisition system is activated; the wind speed data of the environment within the measurement period is obtained, and the BVOCs flux measurement of the environment is completed through the relaxed eddy accumulation acquisition system based on the wind speed data.

[0037] Compared with the existing solutions, the present invention achieves the following beneficial effects:

[0038] The present invention can obtain the temperature and light quantity of the measurement environment during a measurement period; calculate the temperature measurement coefficient based on the temperature of the measurement environment during the measurement period, calculate the light quantity measurement coefficient based on the light quantity of the measurement environment during the measurement period, and record the sum of the temperature measurement coefficient and the light quantity measurement coefficient as the measurement activation value of the measurement period; and obtain the measurement value based on the measurement activation value, analyze the measurement environment based on the measurement value, accurately reflect the actual situation of the natural environment, and obtain a more accurate BVOCs flux measurement result with a high measurement accuracy.

[0039] The present invention can complete the BVOCs flux measurement of the environment based on the wind speed data of the environment through a relaxed eddy accumulation acquisition system based on the wind speed data, thereby improving the sampling efficiency.

[0040] This device has the advantages of a wide range of applications and no loss of species for the collection of vegetation source volatile organic compounds. It can be used to measure various types of tree species such as broad-leaved forests and coniferous forests, and then determine the emission flux, providing a reliable basis for accurately evaluating the emission of vegetation source volatile organic compounds. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0042] Figure 1 It is a workflow diagram of a sampling method for measuring BVOCs flux based on relaxed eddy accumulation according to an embodiment of the present invention;

[0043] Figure 2 is a structural block diagram of a collector according to an embodiment of the present invention;

[0044] Figure 3 It is a workflow diagram of another sampling method for measuring BVOCs flux based on relaxed eddy accumulation according to an embodiment of the present invention;

[0045] Figure 4 It is a device block diagram of a sampling device for measuring BVOCs flux based on relaxed eddy accumulation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] In addition, the described features, structures or characteristics may be combined in one or more example embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the example embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced while omitting one or more of the specific details, or other methods, components, steps, etc. may be adopted. In other cases, well-known structures, methods, implementations or operations are not shown or described in detail to avoid obscuring various aspects of the present disclosure.

[0048] This embodiment provides a sampling method for measuring BVOCs flux based on relaxed eddy accumulation. Figure 1 : is a workflow diagram of a sampling method for measuring BVOCs flux based on relaxed eddy accumulation according to an embodiment of the present invention, such as Figure 1 As shown, the method comprises the following steps:

[0049] Step S101: Generate a measurement cycle and divide the measurement cycle into several measurement time periods, and obtain the temperature and light intensity of the measurement environment within the measurement time period;

[0050] Step S102: calculating a temperature measurement coefficient based on the temperature of the environment in which the measurement is performed during the measurement period, calculating a light quantity measurement coefficient based on the light quantity of the environment in which the measurement is performed during the measurement period, and recording the sum of the temperature measurement coefficient and the light quantity measurement coefficient as the measurement activation value of the measurement period;

[0051] Step S103: Obtain all measured activation values ​​of the measurement period, establish a rectangular coordinate system with the execution time of the measurement period as the X-axis and the measured activation value corresponding to the measurement period as the Y-axis, draw an activation curve of the measurement period in the rectangular coordinate system through the measured activation value of the measurement period, draw two perpendicular lines from the two end points of the activation curve to the X-axis to obtain two truncated line segments, and form an activation graph with the activation curve, the two truncated line segments and the X-axis, and mark the area value of the activation graph as the measurement value;

[0052] Step S104: judging whether the environment in the measurement period meets the BVOCs flux measurement requirements based on the measured value, if so, proceeding to step S105, if not, proceeding to step S107;

[0053] Step S105: activating the relaxation vortex accumulation collection system;

[0054] Step S106: obtaining wind speed data of the environment within the measurement period, and completing the BVOCs flux measurement of the environment through the relaxed eddy accumulation acquisition system based on the wind speed data;

[0055] Step S107: deactivating the relaxation vortex accumulation collection system.

[0056] In summary, the present invention can obtain the temperature and light quantity of the environment where the measurement is performed during the measurement period; calculate the temperature measurement coefficient based on the temperature of the environment where the measurement is performed during the measurement period, calculate the light quantity measurement coefficient based on the light quantity of the environment where the measurement is performed during the measurement period, and record the sum of the temperature measurement coefficient and the light quantity measurement coefficient as the measurement activation value of the measurement period; and obtain the measurement value based on the measurement activation value, analyze the environment where the measurement is performed based on the measurement value, accurately reflect the actual situation of the natural environment, and obtain a more accurate BVOCs flux measurement result with a high measurement accuracy. Furthermore, based on the wind speed data of the environment, the BVOCs flux measurement of the environment is completed based on the wind speed data through the relaxed vortex accumulation acquisition system, thereby improving the sampling efficiency.

[0057] In some embodiments, calculating the temperature measurement coefficient based on the temperature of the environment in which the measurement is performed during the measurement period includes the following process:

[0058] ;

[0059] in, is the temperature measurement coefficient, The temperature of the environment measured during the measurement period. is the standard temperature, which is 303K. , is the temperature constant coefficient, and its values ​​are 90000 J / mol and 200000 J / mol respectively. is the temperature constant, its value is 314K, is the number of moles of gas, its value is 8J / Kmol, and the value of e is 2.72.

[0060] In some embodiments, calculating the light quantity measurement coefficient based on the light quantity of the environment measured during the measurement period includes the following process:

[0061] ;

[0062] in, is the light quantity measurement coefficient, The light quantity in the environment is measured during the measurement period, where the light quantity is the light radiation energy received per unit area per unit time. , are the light intensity constant coefficients, and their values ​​are 1.066 and 0.0027 respectively.

[0063] In some embodiments, judging whether the environment in the measurement period meets the BVOCs flux measurement requirements based on the measured value includes the following process:

[0064] Loading a measurement value threshold, wherein the measurement value threshold is stored in a relaxation vortex accumulation acquisition system;

[0065] Determine whether the measured value exceeds the preset measurement value threshold. If so, it is determined that the environment within the measurement period meets the BVOCs flux measurement requirements. If not, it is determined that the environment within the measurement period does not meet the BVOCs flux measurement requirements.

[0066] In some embodiments, the relaxed vortex accumulation collection system includes an anemometer and a collector, wherein the anemometer is used to obtain wind speed data of the environment within a measurement period. Figure 2 is a structural block diagram of a collector according to an embodiment of the present invention, such as Figure 3 As shown, the collector consists of a gas mass flow controller, a pump, a filter, a solenoid valve, a gas outlet and a sampling tube.

[0067] It is worth noting that the Relaxed Eddy Accumulation Collection System separates the air into different storage containers based on the instantaneous direction of vertical air velocity. In effect, this replaces the need for rapid concentration measurements (EC technology) with rapid valves and flow controls. When using REA, air samples are accumulated in two storage reservoirs for a specific period of time (the flow averaging period - usually 15-60 minutes). One for the upgoing air and one for the downgoing air. At the end of this period, the two reservoirs are analyzed to obtain a regional average flux that is proportional to the difference in concentration in the "upgoing" and "downgoing" air.

[0068] In some embodiments, Figure 3 FIG. 4 is a flowchart of another sampling method for measuring BVOCs flux based on relaxed eddy accumulation according to an embodiment of the present invention. Figure 3 As shown, the following steps are included to complete the BVOCs flux measurement of the environment based on wind speed data through the relaxed eddy accumulation acquisition system:

[0069] Step 1: After turning on the gas mass flow controller for 15 minutes, start the pump to collect the BVOCs flux in the environment;

[0070] Step 2: Obtain wind speed and direction based on wind speed data, and obtain the standard deviation of wind speed perpendicular to the collector. , standard deviation Set by the relaxed vortex accumulation collection system and stored in the relaxed vortex accumulation collection system;

[0071] Step 3: When the wind speed is greater than 0.6 The wind direction relative to the collector is horizontal and upward, and the sample is collected into the UP sampling tube through the control of the solenoid valve. When the wind speed is greater than 0.6 The wind direction relative to the collector is horizontal and downward, and the sample is collected into the down sampling tube through the solenoid valve control. When the wind speed is less than 0.6 , the sample is collected into the NeUtral collection tube through the control of the solenoid valve, wherein the sampling tube includes the UP sampling tube, the down sampling tube and the NeUtral collection tube;

[0072] Step 4: When all sampling is completed, cut to the gas outlet without collecting any samples;

[0073] Step five, calculate the BVOCs flux of the samples in the collection tube.

[0074] In some embodiments, calculating the BVOCs flux of the sample in the collection tube includes the following process:

[0075] ;

[0076] in, is the flux of a certain BVOCs component, is the number of the BVOCs component, is the concentration of BVOCs components in the UP sampling tube, is the concentration of BVOCs components in the down sampling tube, It is a measurement constant whose value is set by the relaxed vortex accumulation acquisition system.

[0077] In some embodiments, the collection cycle of the relaxed vortex accumulation collection system is 30 minutes, and the filter cartridge in the filter is replaced at a cycle of 90 minutes.

[0078] The present invention also provides a sampling device for measuring BVOCs flux based on relaxed vortex accumulation. Figure 4 is a device block diagram of a sampling device for measuring BVOCs flux based on relaxed eddy accumulation according to an embodiment of the present invention, such as Figure 4 As shown, the device includes an environmental data acquisition module, a measurement activation value calculation module, a measurement value calculation module and a relaxation vortex accumulation acquisition system;

[0079] The environmental data acquisition module is used to generate a measurement cycle and divide the measurement cycle into several measurement periods, and obtain the temperature and light amount of the environment in which the measurement is performed during the measurement period;

[0080] A measurement activation value calculation module, used to calculate a temperature measurement coefficient based on the temperature of the environment in which the measurement is performed during the measurement period, calculate a light quantity measurement coefficient based on the light quantity of the environment in which the measurement is performed during the measurement period, and record the sum of the temperature measurement coefficient and the light quantity measurement coefficient as the measurement activation value of the measurement period;

[0081] A measurement value calculation module is used to obtain all measurement activation values ​​of the measurement period, establish a rectangular coordinate system with the execution time of the measurement period as the X-axis and the measurement activation value corresponding to the measurement period as the Y-axis, draw an activation curve of the measurement period in the rectangular coordinate system through the measurement activation value of the measurement period, draw two perpendicular lines from the two end points of the activation curve to the X-axis to obtain two truncation line segments, form an activation graph by the activation curve, the two truncation line segments and the X-axis, and mark the area value of the activation graph as the measurement value;

[0082] The relaxed eddy accumulation acquisition system is used to determine whether the environment within the measurement period meets the BVOCs flux measurement requirements based on the measurement values. If so, the relaxed eddy accumulation acquisition system is activated; the wind speed data of the environment within the measurement period is obtained, and the BVOCs flux measurement of the environment is completed through the relaxed eddy accumulation acquisition system based on the wind speed data.

[0083] The above embodiments can be implemented in whole or in part by software, hardware, firmware or any other combination. When implemented by software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that contains one or more available media sets. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state hard disk.

[0084] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0085] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0086] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only some logical function divisions. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0087] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0088] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A sampling method for measuring BVOCs flux based on relaxed eddy accumulation, characterized in that: Methods include: Generate a measurement cycle and divide the measurement cycle into a number of measurement periods, and obtain the temperature and light intensity of the measurement environment within the measurement period; Calculate the temperature measurement coefficient based on the temperature of the environment in which the measurement is performed during the measurement period, calculate the light measurement coefficient based on the light amount of the environment in which the measurement is performed during the measurement period, and record the sum of the temperature measurement coefficient and the light measurement coefficient as the measurement activation value of the measurement period; The calculation of the temperature measurement coefficient based on the temperature of the environment in which the measurement is performed during the measurement period includes the following process: ； in, is the temperature measurement coefficient, The temperature of the environment measured during the measurement period. is the standard temperature, which is 303K. , is the temperature constant coefficient, and its values ​​are 90000 J / mol and 200000 J / mol respectively. is the temperature constant, its value is 314K, is the number of gas moles, its value is 8J / Kmol, and the value of e is 2.72; Calculating the light measurement coefficient based on the light amount in the environment during the measurement period includes the following process: ； in, is the light quantity measurement coefficient, The light quantity in the environment is measured during the measurement period, where the light quantity is the light radiation energy received per unit area per unit time. , is the constant coefficient of light quantity, and its values ​​are 1.066 and 0.0027 respectively; Obtain all measured activation values ​​of the measurement period, establish a rectangular coordinate system with the execution time of the measurement period as the X-axis and the measured activation value corresponding to the measurement period as the Y-axis, draw an activation curve of the measurement period in the rectangular coordinate system through the measured activation value of the measurement period, draw two perpendicular lines from the two end points of the activation curve to the X-axis to obtain two truncation line segments, form an activation graph by the activation curve, the two truncation line segments and the X-axis, and mark the area value of the activation graph as the measurement value; Based on the measured values, it is determined whether the environment within the measurement period meets the BVOCs flux measurement requirements. If so, the relaxed eddy accumulation acquisition system is activated; the wind speed data of the environment within the measurement period is obtained, and the BVOCs flux measurement of the environment is completed through the relaxed eddy accumulation acquisition system based on the wind speed data.

2. The BVOCs flux measurement sampling method based on relaxed eddy accumulation according to claim 1, characterized in that: Judging whether the environment within the measurement period meets the BVOCs flux measurement requirements based on the measured values ​​includes the following processes: Loading a measurement value threshold, wherein the measurement value threshold is stored in a relaxation vortex accumulation acquisition system; Determine whether the measured value exceeds the preset measurement value threshold. If so, it is determined that the environment within the measurement period meets the BVOCs flux measurement requirements. If not, it is determined that the environment within the measurement period does not meet the BVOCs flux measurement requirements.

3. The sampling method for measuring BVOCs flux based on relaxed eddy accumulation according to claim 1, characterized in that: The relaxed vortex accumulation collection system includes an anemometer and a collector, wherein the anemometer is used to obtain the wind speed data of the environment during the measurement period, and the collector is composed of a gas mass flow controller, a pump, a filter, a solenoid valve, an air outlet and a sampling tube.

4. The sampling method for measuring BVOCs flux based on relaxed eddy accumulation according to claim 3, characterized in that: The following steps are used to measure the BVOCs flux in the environment based on wind speed data through the relaxed eddy accumulation acquisition system: Step 1: After turning on the gas mass flow controller for 15 minutes, start the pump to collect the BVOCs flux in the environment; Step 2: Obtain wind speed and direction based on wind speed data, and obtain the standard deviation of wind speed perpendicular to the collector. , standard deviation Set by the relaxed vortex accumulation collection system and stored in the relaxed vortex accumulation collection system; Step 3: When the wind speed is greater than 0.6 The wind direction relative to the collector is horizontal and upward, and the sample is collected into the UP sampling tube through the control of the solenoid valve. When the wind speed is greater than 0.6 The wind direction relative to the collector is horizontal and downward, and the sample is collected into the down sampling tube through the solenoid valve control. When the wind speed is less than 0.6 , the sample is collected into the NeUtral collection tube through the control of the solenoid valve, wherein the sampling tube includes the UP sampling tube, the down sampling tube and the NeUtral collection tube; Step 4: When all sampling is completed, cut to the gas outlet without collecting any samples; Step five, calculate the BVOCs flux of the samples in the collection tube.

5. The sampling method for measuring BVOCs flux based on relaxed eddy accumulation according to claim 4, characterized in that: The calculation of BVOCs flux for samples in the collection tube includes the following process: ； in, is the flux of a certain BVOCs component, is the number of the BVOCs component, is the concentration of BVOCs components in the UP sampling tube, is the concentration of BVOCs components in the down sampling tube, It is a measurement constant whose value is set by the relaxed vortex accumulation acquisition system.

6. The sampling method for measuring BVOCs flux based on relaxed eddy accumulation according to claim 3, characterized in that: The collection cycle of the relaxed vortex accumulation collection system is 30 minutes, and the filter cartridge in the filter is replaced every 90 minutes.

7. A sampling device for measuring BVOCs flux based on relaxed eddy accumulation, characterized in that: A sampling method for measuring BVOCs flux based on relaxed eddy accumulation applicable to any one of claims 1 to 6, the device comprising an environmental data acquisition module, a measurement activation value calculation module, a measurement value calculation module and a relaxed eddy accumulation acquisition system; The environmental data acquisition module is used to generate a measurement cycle and divide the measurement cycle into several measurement periods, and obtain the temperature and light amount of the environment in which the measurement is performed during the measurement period; A measurement activation value calculation module, used to calculate a temperature measurement coefficient based on the temperature of the environment in which the measurement is performed during the measurement period, calculate a light quantity measurement coefficient based on the light quantity of the environment in which the measurement is performed during the measurement period, and record the sum of the temperature measurement coefficient and the light quantity measurement coefficient as the measurement activation value of the measurement period; A measurement value calculation module is used to obtain all measurement activation values ​​of the measurement period, establish a rectangular coordinate system with the execution time of the measurement period as the X-axis and the measurement activation value corresponding to the measurement period as the Y-axis, draw an activation curve of the measurement period in the rectangular coordinate system through the measurement activation value of the measurement period, draw two perpendicular lines from the two end points of the activation curve to the X-axis to obtain two truncation line segments, form an activation graph by the activation curve, the two truncation line segments and the X-axis, and mark the area value of the activation graph as the measurement value; The relaxed eddy accumulation acquisition system is used to determine whether the environment within the measurement period meets the BVOCs flux measurement requirements based on the measurement values. If so, the relaxed eddy accumulation acquisition system is activated; the wind speed data of the environment within the measurement period is obtained, and the BVOCs flux measurement of the environment is completed through the relaxed eddy accumulation acquisition system based on the wind speed data.

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