Method and equipment for monitoring gas migration in soil

Abstract

The invention relates to a method and equipment for monitoring gas migration in soil, and relates to the technical field of soil respiration monitoring. According to the method and the equipment for monitoring the gas migration in the soil, the direction, the magnitude and the fluctuation frequency of surface wind in a natural state can be simulated by manufacturing the wind flow with the preset wind speed, the preset wind direction and the preset fluctuation frequency. By means of the gas sensor and the pressure difference sensing assembly, gas pressure changes of shallow soil at different depths and carbon dioxide concentration changes caused by the gas pressure changes can be monitored at the same time, and the carbon dioxide concentration change rule of the shallow soil under different wind speed characteristic conditions can be accurately reflected. Data verification is provided for establishing a mathematical physical model of gas migration of shallow soil under the condition of wind speed change, and development of key technologies such as carbon dioxide safety monitoring and early warning and risk assessment is promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of soil respiration monitoring, and particularly to a method and device for monitoring gas migration in soil. Background Art

[0002] When a buried combustible gas pipeline leaks or when carbon dioxide is stored in a geological layer through carbon capture technology, underground high-pressure gas may migrate along underground faults, fractures, and microfractures to the soil surface. High concentrations of combustible gas or carbon dioxide are likely to accumulate on the surface, affecting vegetation growth. When the concentration of such gases is too high, it will also pose a hazard to animals and humans. Since the mass and energy exchange between shallow soil and the external environment is relatively active, the gas concentration in shallow soil is most affected by the surface wind speed. Studying the diffusion law of gas in soil under changing surface wind speed conditions has important application value for key technologies such as the safety monitoring and early warning and risk assessment of combustible gas or carbon dioxide. However, there is currently a lack of experimental methods and equipment for simulating the gas concentration change law in shallow soil under different wind speed characteristics. Summary of the Invention

[0003] The present invention provides a method and device for monitoring gas migration in soil to solve the technical problem in the prior art that the gas concentration change law in shallow soil under different wind speed characteristics cannot be simulated.

[0004] In the first aspect of the present invention, a method for monitoring gas migration in soil is provided, including the following steps:

[0005] At least two gas sensors for monitoring the concentration of the gas to be measured are arranged at different depths in the test soil, at least one differential pressure sensing component is arranged in the test soil, the first end of the differential pressure sensing component is located in the test soil, the depth where the first end of the differential pressure sensing component is located is the same as the depth where at least one of the gas sensors is located, and the second end of the differential pressure sensing component is communicated with the atmosphere;

[0006] A wind flow satisfying a predetermined parameter range is created on the surface of the test soil;

[0007] The gas to be measured is introduced into the test soil;

[0008] The concentration of the gas to be measured in the test soil and the difference between the internal pressure of the test soil and the atmospheric pressure are respectively obtained, and the migration law of the gas to be measured in the test soil is analyzed.

[0009] In one embodiment, the wind direction at least includes a first direction, a second direction, and a third direction parallel to the surface of the test soil, the second direction is perpendicular to the first direction, and the third direction is not perpendicular to the first direction;

[0010] The wind direction further includes a fourth direction perpendicular to the surface of the test soil.

[0011] In one embodiment, the test soil is contained in a container, the gas to be measured is introduced from the bottom of the container, and a buffer chamber capable of storing the gas to be measured is provided at the bottom of the container. The gas to be measured flows into the test soil after passing through the buffer chamber.

[0012] In one embodiment, the number of the differential pressure sensing components is one, and by moving the differential pressure sensing component, the first end of the differential pressure sensing component is successively located at each depth where the gas sensor is located;

[0013] Or, the number of the differential pressure sensing components is greater than one, and at least one first end of the differential pressure sensing component is provided at each depth where the gas sensor is located.

[0014] In one embodiment, at least two of the gas sensors are provided at the same depth.

[0015] In one embodiment, the gas sensor is first placed in a waterproof and breathable device, and then the waterproof and breathable device containing the gas sensor is placed in the test soil.

[0016] In one embodiment, the gas to be measured is carbon dioxide, hydrogen or natural gas.

[0017] The second aspect of the present invention provides a device for monitoring gas migration in soil, including:

[0018] A container capable of containing test soil;

[0019] At least two gas sensors for monitoring gas concentration, which are arranged at different depths in the test soil;

[0020] At least one differential pressure sensing component for monitoring the change of gas pressure in the test soil, the depth where the first end of the differential pressure sensing component is located is the same as the depth where at least one of the gas sensors is located, and the second end of the differential pressure sensing component is communicated with the atmosphere;

[0021] At least one wind speed monitoring device, which is arranged on the surface of the test soil for monitoring wind speed;

[0022] A fan for generating an air flow meeting a predetermined parameter range, which is arranged on one side of the container;

[0023] A gas cylinder for supplying the gas to be measured to the test soil, and the gas cylinder is connected to the container through a pipeline;

[0024] A data recorder, and the wind speed monitoring device, the gas sensor, and the differential pressure sensing assembly are all electrically connected to the data recorder.

[0025] In one embodiment, the soil gas migration monitoring device further includes at least two windshields disposed above the test soil, and the opening end of the container is circular or rectangular.

[0026] The first windshield includes an outer frame and at least two baffles. The outer frame is disposed on the opening end of the container, the outer frame is circular or rectangular, and at least two of the baffles are disposed inside the outer frame and are parallel to each other.

[0027] The second windshield includes an outer frame and a grid-like frame. The outer frame is disposed on the opening end of the container, the outer frame is circular or rectangular, and the grid-like frame is disposed inside the outer frame.

[0028] In one embodiment, the differential pressure sensing assembly includes a differential pressure sensor, a first connecting pipe, a second connecting pipe, and a waterproof and breathable membrane. Two ends of the differential pressure sensor are respectively connected to the first connecting pipe and the second connecting pipe, and the waterproof and breathable membrane is disposed at one end of the first connecting pipe away from the differential pressure sensor to seal the first connecting pipe.

[0029] In one embodiment, the diameter of one end of the first connecting pipe away from the differential pressure sensor is larger than the diameter of the end thereof connected to the differential pressure sensor, and the diameter of one end of the second connecting pipe away from the differential pressure sensor is larger than the diameter of the end thereof connected to the differential pressure sensor.

[0030] In one embodiment, the height of one end of the second connecting pipe away from the differential pressure sensor is higher than the top of the blower.

[0031] In one embodiment, the container includes a side wall, a bottom plate, and a partition. The partition is parallel to the bottom plate, and a plurality of air-permeable holes are provided on the partition. A waterproof and breathable membrane is laid on the air-permeable holes. An air inlet for gas to enter is provided on the bottom plate or the side wall. The test soil is filled on the partition, and a buffer cavity capable of storing gas is formed between the partition and the bottom plate. The gas in the buffer cavity flows into the test soil through the air-permeable holes.

[0032] Compared with the prior art, the advantages of the present invention are as follows: by creating an air flow that meets a predetermined parameter range, it is possible to simulate the direction, magnitude, and fluctuation frequency of the surface wind in the natural state. With the help of gas sensors and differential pressure sensing components, it is possible to simultaneously monitor the gas pressure changes at different depths in the shallow soil and the changes in the concentration of the gas to be measured caused by the gas pressure changes, accurately reflecting the variation law of the concentration of the gas to be measured under different wind speed characteristics in the shallow soil, providing data verification for establishing a mathematical and physical model of gas migration in the shallow soil under changing wind speeds, and promoting the development of key technologies such as the safety monitoring and early warning and risk assessment of combustible gases or carbon dioxide and other gases. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Hereinafter, the present invention will be described in more detail based on embodiments with reference to the drawings.

[0034] Figure 1 is a flowchart of the method for monitoring gas migration in soil in an embodiment of the present invention;

[0035] Figure 2 is a schematic structural diagram of the device for monitoring gas migration in soil in an embodiment of the present invention;

[0036] Figure 3 is a top view of the first windbreak frame in an embodiment of the present invention;

[0037] Figure 4 is a top view of the second windbreak frame in an embodiment of the present invention;

[0038] Figure 5 is a top view of the third windbreak frame in an embodiment of the present invention;

[0039] Figure 6 is a top view of the fourth windbreak frame in an embodiment of the present invention;

[0040] Figure 7 is a top view of the fifth windbreak frame in an embodiment of the present invention;

[0041] Figure 8 is a top view of the sixth windbreak frame in an embodiment of the present invention;

[0042] Figure 9 is a top view of the partition in an embodiment of the present invention.

[0043] Reference numerals:

[0044] 1. Container; 11. Side wall; 12. Bottom plate; 13. Partition board; 100. Buffer chamber; 200. Ventilation hole; 2. Gas sensor; 3. Differential pressure sensing assembly; 31. Differential pressure sensor; 32. First connecting pipe; 33. Second connecting pipe; 4. Wind speed monitoring device; 5. Fan; 61. Gas cylinder; 62. Pipeline; 63. Flowmeter; 7. Windshield frame; 71. Outer frame; 72. Baffle; 73. Mesh frame. Detailed implementation mode

[0045] The present invention will be further described below with reference to the accompanying drawings.

[0046] As Figure 1 and Figure 2 shown, according to the first aspect of the present invention, a method for monitoring gas migration in soil is provided. In this embodiment, carbon dioxide is used as the gas to be measured, and it includes the following steps:

[0047] S1. Gradually fill the test soil into the container 1. During the process of filling the test soil into the container 1, at least two gas sensors 2 for monitoring gas concentration are set at different depths in the test soil, and at least one differential pressure sensing assembly 3 for monitoring gas pressure change is set in the test soil until the container 1 is filled with the test soil, and the first end of the differential pressure sensing assembly 3 is located inside the test soil, the depth where the first end of the differential pressure sensing assembly 3 is located is the same as the depth where at least one gas sensor 2 is located, and the second end of the differential pressure sensing assembly 3 is located outside the test soil.

[0048] Specifically, after the test soil is filled into the container 1, its surface should be flush with the top of the container 1 to make the thickness of the test soil at each part of the container 1 consistent. In order to make the gas concentration measured by the gas sensor 2 more accurate, at least two gas sensors 2 are set at the same depth, and the error is reduced by calculating the average value. Each gas sensor 2 should also be evenly distributed in the test soil, that is, the gas sensors 2 should be set relatively evenly both in the depth direction and the horizontal direction of the test soil.

[0049] If the gas sensors 2 are distributed at three different depths, three differential pressure sensing assemblies 3 can be correspondingly set, that is, there is a first end of a differential pressure sensing assembly 3 at each depth. Of course, two or more first ends of the differential pressure sensing assembly 3 can also be set at the same depth to obtain more accurate data. When considering the test cost factor, only one differential pressure sensing assembly 3 can also be set. After obtaining the data at a certain depth under a certain wind speed characteristic, the position of the first end of the differential pressure sensing assembly 3 can be adjusted to measure the change of soil gas pressure at another depth.

[0050] S2. A wind speed monitoring device 4 for monitoring the wind speed is arranged on the surface of the test soil. More than two wind speed monitoring devices 4 can be arranged and placed in different areas above the test soil to more accurately reflect the wind speed above the test soil. The wind speed monitoring device 4 can be a wind speed sensor.

[0051] S3. A wind flow that meets a predetermined parameter range, including wind speed, wind direction, and fluctuation frequency, is generated on the surface of the test soil. The wind in nature not only often changes in wind speed, but also often changes in wind direction, and gusts with a certain fluctuation frequency will also be generated, and the situation is very complex. In order to simulate the real natural wind on the ground surface, a fan 5 or other similar devices need to be used to generate a wind flow with a predetermined wind speed, wind direction, and fluctuation frequency. The fan 5 can be a variable-frequency fan, so that the adjustment of the wind speed is more delicate, and gusts with a certain fluctuation frequency can also be simulated. As for the change of the wind direction, it can be achieved by moving the fan 5, or a rotary vane fan can be arranged in front of the fan 5 to change the wind direction to a certain extent.

[0052] S4. Carbon dioxide gas with a predetermined flow rate is introduced into the test soil, and the wind speed on the surface of the test soil, the carbon dioxide concentration in the test soil, and the gas pressure fluctuation in the test soil are monitored and recorded in real time, and the migration law of the gas in the test soil is analyzed. The principle is as follows: when the surface of the test soil is blown by the wind, the air pressure on the surface of the test soil will change. The test soil has pores inside. Under the action of the air pressure difference inside and outside the soil, part of the gas (including carbon dioxide and other gases) migrates from the inside of the test soil to the air, causing the carbon dioxide concentration inside the test soil to change. The second end of the differential pressure sensing component 3 is always connected to the outside atmosphere, and the air pressure remains relatively stable, so that the differential pressure sensing component 3 can monitor the change of this air pressure difference.

[0053] In summary, the method for monitoring gas migration in soil according to the present invention can simulate the direction, magnitude, and fluctuation frequency of the surface wind in the natural state by generating a wind flow with a predetermined wind speed, wind direction, and fluctuation frequency. With the help of the gas sensor 2 and the differential pressure sensing component 3, the gas pressure changes at different depths in the shallow soil and the change of the carbon dioxide concentration caused by the gas pressure change can be monitored simultaneously, accurately reflecting the change law of the carbon dioxide concentration in the shallow soil under different wind speed characteristics, providing data verification for establishing a mathematical and physical model of gas migration in the shallow soil under wind speed changes, and promoting the development of key technologies such as carbon dioxide safety monitoring and early warning and risk assessment. In some other embodiments, the gas to be measured is hydrogen, natural gas or other combustible gases to simulate the migration law of combustible gases in the soil when an underground gas pipeline leaks.

[0054] Furthermore, the wind direction includes at least a first direction, a second direction and a third direction parallel to the test soil surface, the second direction is perpendicular to the first direction, and the third direction is not perpendicular to the first direction. The differences between these three wind directions are large. By changing the wind direction to monitor the data, it can be closer to the real state of natural wind, and the obtained test data is more valuable for reference.

[0055] In addition, the wind direction also includes a fourth direction perpendicular to the test soil surface. This wind direction is difficult to generate only by the fan 5, and requires the use of additional tools to simulate the airflow in the vertical direction, so as to more comprehensively reflect the influence of natural wind on the gas migration in the soil.

[0056] like Figure 2 As shown, the gas to be tested is introduced from the bottom of the container 1, and a buffer chamber 100 capable of storing the gas to be tested is provided at the bottom of the container 1. The gas to be tested flows into the test soil after passing through the buffer chamber 100. The provision of the buffer chamber 100 not only makes the pressure of carbon dioxide more stable, but also allows the gas to enter various parts of the test soil more evenly. At the same depth, the gas pressure at various parts of the test soil and the concentration of the gas to be tested can be relatively close, making the data monitored by the gas sensor 2 and the differential pressure sensor assembly 3 more credible.

[0057] In some embodiments, the gas sensor 2 may be placed in a waterproof breathable device (not shown), and then the waterproof breathable device with the gas sensor 2 may be placed in the test soil to prevent the moisture in the test soil from damaging the gas sensor 2.

[0058] like Figure 2 As shown, on the other hand, an embodiment of the present invention further provides a soil gas migration monitoring device, comprising:

[0059] Container 1, capable of containing test soil;

[0060] at least two gas sensors 2 for monitoring gas concentration, arranged at different depths in the test soil;

[0061] At least one differential pressure sensing assembly 3 for monitoring gas pressure changes, wherein a first end of the differential pressure sensing assembly 3 is located at the same depth as that of the at least one gas sensor 2, and a second end of the differential pressure sensing assembly 3 is located outside the test soil;

[0062] at least one wind speed monitoring device 4, disposed on the surface of the test soil, for monitoring wind speed;

[0063] The fan 5 is used to produce a wind flow that meets a predetermined parameter range, including wind speed, wind direction, and fluctuation frequency, and the fan 5 is arranged on one side of the container 1;

[0064] A gas cylinder 61 for supplying gas to the test soil, the gas cylinder 61 is connected to the container 1 through a pipeline 62;

[0065] A flowmeter 63 is arranged on the pipeline 62 for measuring the flow rate of the gas introduced into the test soil;

[0066] A data recorder (not shown in the figure), the gas sensor 2, the differential pressure sensing assembly 3 and the wind speed monitoring device 4 are all electrically connected to the data recorder.

[0067] As Figure 2 shown, the soil gas migration monitoring device of the embodiment of the present invention further includes at least two wind shielding frames 7, the wind shielding frames 7 are arranged above the test soil, and the opening end of the container 1 is circular or rectangular.

[0068] As Figure 3 shown, the first wind shielding frame includes an outer frame 71 and at least two baffles 72, the outer frame 71 is arranged on the opening end of the container, the outer frame 71 is circular and has the same shape as the opening end of the container 1 so that the first wind shielding frame can be stably placed on the container 1, and at least two baffles 72 are arranged inside the outer frame 71 and are parallel to each other. The baffle 72 can play a guiding role, so that the wind flow on the surface of the test soil only flows along the direction set by the baffle 72, and a more stable wind flow in a predetermined direction is obtained. Since the outer frame 71 and the opening end of the container 1 have the same shape, both are circular, the first wind shielding frame can be rotated at will, and at the same time, the fan 5 is moved, and wind flows in various different wind directions can be obtained, and the operation is very simple.

[0069] As Figure 4 shown, the second wind shielding frame includes an outer frame 71 and a grid-like frame 73, the outer frame 71 is arranged on the opening end of the container, the outer frame 71 is circular, and the grid-like frame 73 is arranged inside the outer frame 71. When the second wind shielding frame is placed on the opening end of the container 1, due to the blocking of the grid-like frame 73, the wind flow generated by the fan 5 cannot directly blow to the surface of the test soil, so that an air flow in the vertical direction is generated on the surface of the test soil, that is, the flow direction of the air flow is perpendicular to the surface of the test soil, thereby simulating the air flow on the soil surface in a natural state.

[0070] As Figure 5 、 Figure 6 and Figure 7 shown, the outer frames 71 of the third wind shielding frame, the fourth wind shielding frame and the fifth wind shielding frame are all rectangular. Correspondingly, the shape of the opening end of the container 1 is the same as that of the outer frame 71, and the baffles 72 inside the outer frame 71 are all parallel to each other, and can all cooperate with the fan 5 to generate a relatively stable wind flow in a predetermined direction.

[0071] As Figure 8As shown, the outer frame 71 of the sixth windshield frame is rectangular, and the grid-like frame 73 is arranged inside the outer frame 71. The function of the sixth windshield frame is the same as that of the second windshield frame, which can generate an air flow in the vertical direction on the surface of the test soil, except that the shapes of the open ends of the adapted containers 1 are different.

[0072] As Figure 2 shown, the differential pressure sensing assembly 3 includes a differential pressure sensor 31, a first connecting pipe 32, a second connecting pipe 33, and a waterproof and breathable membrane (not shown in the figure). The two ends of the differential pressure sensor 31 are respectively connected to the first connecting pipe 32 and the second connecting pipe 33. The waterproof and breathable membrane is arranged at one end of the first connecting pipe 32 away from the differential pressure sensor 31 and closes the first connecting pipe 32. The waterproof and breathable membrane can prevent soil from entering the inside of the first connecting pipe 32 and causing blockage, but it does not prevent gas from passing through, enabling the differential pressure sensing assembly 3 to work properly and obtain accurate test data.

[0073] Furthermore, the diameter of the first connecting pipe 32 at the end away from the differential pressure sensor 31 is larger than the diameter of the end where it is connected to the differential pressure sensor 31, and the diameter of the second connecting pipe 33 at the end away from the differential pressure sensor 31 is larger than the diameter of the end where it is connected to the differential pressure sensor 31. Enlarging the ends of the first connecting pipe 32 and the second connecting pipe 33 can effectively increase the cross-section of gas flow, with less resistance to gas flow, making the pressure value collected by the differential pressure sensor 31 more accurate and reducing measurement errors.

[0074] As Figure 1 shown, the height of the end of the second connecting pipe 33 away from the differential pressure sensor 31 is higher than the top of the fan 5. This can prevent the air flow generated by the fan 5 from directly blowing on the open end of the second connecting pipe 33, maintaining the air pressure at the open end of the second connecting pipe 33 relatively stable and enabling the differential pressure sensor 31 to collect more real and accurate data. During the test, the gas pressure change in the soil fluctuates very little, while the pressure change caused by the wind speed on the ground surface may far exceed the pressure change in the soil. If the fan 5 directly blows on the end of the second connecting pipe 33 away from the differential pressure sensor 31, the measured data will be the pressure change on the ground surface, which is not conducive to analyzing the internal pressure change of the soil at different depths and cannot reflect the pressure change characteristics of the soil with different porosities or at different depths.

[0075] As Figure 1 and Figure 9As shown, the container 1 includes a side wall 11, a bottom plate 12 and a partition 13. The partition 13 is parallel to the bottom plate 12. A plurality of air holes 200 are provided on the partition 13. A waterproof air-permeable membrane (not shown in the figure) is laid on the air holes 200. An air inlet (not shown in the figure) is provided on the side wall 11 for gas to enter. The test soil is filled on the partition 13. A buffer cavity 100 capable of storing gas is formed between the partition 13 and the bottom plate 12. The gas in the buffer cavity 100 flows into the test soil after passing through the air holes 200. The air holes 200 are relatively large in number and are relatively evenly distributed at various locations on the partition 13, so that the gas can enter various locations of the test soil. The waterproof air-permeable membrane on the air holes 200 can prevent the soil from falling into the buffer cavity 100 and does not hinder the passage of gas.

[0076] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present invention is not limited to the predetermined embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for monitoring gas migration in soil, characterized in that, it includes the following steps: At least two gas sensors for monitoring the concentration of the gas to be measured are set at different depths in the test soil, at least one differential pressure sensing component is set in the test soil, and the first end of the differential pressure sensing component is located in the test soil, and the depth where the first end of the differential pressure sensing component is located is the same as the depth where at least one of the gas sensors is located, and the second end of the differential pressure sensing component is communicated with the atmosphere; Create a wind flow on the surface of the test soil that meets a predetermined parameter range; Introduce the gas to be measured into the test soil; Respectively obtain the concentration of the gas to be measured in the test soil and the difference between the internal pressure of the test soil and the atmospheric pressure, and analyze the migration law of the gas to be measured in the test soil.

2. The method for monitoring gas migration in soil according to claim 1, characterized in that, The wind direction of the wind flow includes at least a first direction, a second direction and a third direction parallel to the surface of the test soil, the second direction is perpendicular to the first direction, and the third direction is not perpendicular to the first direction; The wind direction also includes a fourth direction perpendicular to the surface of the test soil.

3. The method for monitoring gas migration in soil according to claim 1 or 2, characterized in that, The test soil is contained in a container, the gas to be measured is introduced from the bottom of the container, and a buffer cavity capable of storing the gas to be measured is provided at the bottom of the container, and the gas to be measured flows into the test soil after passing through the buffer cavity.

4. The method for monitoring gas migration in soil according to claim 1 or 2, characterized in that, The number of the differential pressure sensing components is one, and the first end of the differential pressure sensing component is successively located at each depth where the gas sensor is located by moving the differential pressure sensing component; Or, the number of the differential pressure sensing components is more than one, and at least one first end of the differential pressure sensing component is provided at each depth where the gas sensor is located.

5. The method for monitoring gas migration in soil according to claim 1 or 2, characterized in that, At least two of the gas sensors at the same depth are provided.

6. The method for monitoring gas migration in soil according to claim 1 or 2, characterized in that, First place the gas sensor in a waterproof and breathable device, and then place the waterproof and breathable device equipped with the gas sensor in the test soil.

7. The method for monitoring gas migration in soil according to claim 1 or 2, characterized in that, The gas to be measured is carbon dioxide, hydrogen or natural gas.

8. A device for monitoring gas migration in soil, characterized in that, it includes: A container capable of containing test soil; At least two gas sensors for monitoring gas concentration, which are arranged at different depths in the test soil; At least one differential pressure sensing component for monitoring the gas pressure change in the test soil, the depth where the first end of the differential pressure sensing component is located is the same as the depth where at least one of the gas sensors is located, and the second end of the differential pressure sensing component is communicated with the atmosphere; At least one wind speed monitoring device, which is arranged on the surface of the test soil and is used for monitoring the wind speed; A fan, which is used for generating an air flow meeting a predetermined parameter range and is arranged on one side of the container; A gas cylinder, which is used for supplying a gas to be measured to the test soil, and the gas cylinder is connected to the container through a pipeline; A data recorder, and the wind speed monitoring device, the gas sensor and the differential pressure sensing assembly are all electrically connected to the data recorder.

9. The soil gas migration monitoring device according to claim 8, wherein, it further includes at least two wind shielding frames, the wind shielding frames are arranged above the test soil, and the opening end of the container is circular or rectangular; The first wind shielding frame includes an outer frame and at least two baffles, the outer frame is arranged on the opening end of the container, the outer frame is circular or rectangular, and at least two of the baffles are arranged inside the outer frame and are parallel to each other; The second wind shielding frame includes an outer frame and a grid-like frame, the outer frame is arranged on the opening end of the container, the outer frame is circular or rectangular, and the grid-like frame is arranged inside the outer frame.

10. The soil gas migration monitoring device according to claim 8 or 9, wherein, The differential pressure sensing assembly includes a differential pressure sensor, a first connecting pipe, a second connecting pipe and a waterproof breathable membrane, two ends of the differential pressure sensor are respectively connected to the first connecting pipe and the second connecting pipe, and the waterproof breathable membrane is arranged at one end of the first connecting pipe away from the differential pressure sensor and closes the first connecting pipe.

11. The soil gas migration monitoring device according to claim 10, wherein, The diameter of one end of the first connecting pipe away from the differential pressure sensor is larger than the diameter of the end thereof connected to the differential pressure sensor, and the diameter of one end of the second connecting pipe away from the differential pressure sensor is larger than the diameter of the end thereof connected to the differential pressure sensor.

12. The soil gas migration monitoring device according to claim 11, wherein, The height of one end of the second connecting pipe away from the differential pressure sensor is higher than the top of the fan.

13. The soil gas migration monitoring device according to claim 8 or 9, wherein, The container includes a side wall, a bottom plate and a partition plate, the partition plate is parallel to the bottom plate, a plurality of air permeable holes are formed in the partition plate, a waterproof breathable membrane is laid on the air permeable holes, an air inlet hole for gas to enter is formed in the bottom plate or the side wall, the test soil is filled on the partition plate, a buffer cavity capable of storing gas is formed between the partition plate and the bottom plate, and the gas in the buffer cavity flows into the test soil through the air permeable holes.

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