In-situ gas sampling device and gas sampling method for soil hydrogen content

Abstract

The invention provides a soil hydrogen content in-situ gas sampling device and a gas sampling method, and relates to the technical field of soil gas collection. The device comprises a base, a pile casing, a drill rod, a sealing cylinder, an isolating cylinder and a driving structure, a ventilation pipeline is arranged in the drill rod and used for directly collecting soil gas in the drilling process. A storage cavity is formed between the protective cylinder and the isolation cylinder, external miscellaneous gas is prevented from entering a sampling hole to interfere with sampling gas, in-situ gas collection with measurement while drilling or fixed-point depth gas collection can be achieved through the structure, and dissipation or pollution of gas in the transfer process is reduced; in-situ collection of soil gas is realized, and the primitiveness and authenticity of a gas sample are maintained to the greatest extent, so that the accuracy of detection data is improved.

Description

Technical Field

[0001] This invention relates to the field of soil gas sampling technology, and more specifically, to a device and method for in-situ sampling of soil hydrogen content. Background Technology

[0002] In-situ detection and analysis of soil gases (especially hydrogen) are of great significance in mineral resource exploration, environmental monitoring, geological disaster early warning, and scientific research. Obtaining authentic, undisturbed soil gas samples is a crucial prerequisite for ensuring the accuracy of analytical data. Traditional soil gas sampling methods mainly suffer from the following technical bottlenecks:

[0003] Shallow pre-buried pipe method: A gas sampling pipe is pre-buried at a predetermined depth, and gas sampling is performed after the soil environment stabilizes. This method cannot obtain gas from newly exposed depths during drilling, and the pre-buried pipe may alter the local soil structure and gas transport state, resulting in response lag and sample distortion. Core sampling method: Soil cores are obtained through drilling, and the cores are placed in sealed containers for degassing analysis. During this process, gases are easily exposed to the atmosphere, leading to escape and pollution, especially for highly reactive and rapidly diffusing light gases such as hydrogen, resulting in severely insufficient sample representativeness.

[0004] While some existing in-situ gas sampling equipment strives to achieve "testing while drilling," it often faces two major challenges in practical applications. First, borehole clogging and discontinuous operation: Firstly, drilling debris easily accumulates inside the borehole or near the sampling channel, leading to borehole clogging and burying of the sampling pipeline, forcing operation interruptions for cleaning and severely impacting efficiency. Secondly, during the rotating drilling process, effectively sealing the annular space between the drill rod and the outer casing (or borehole wall) to prevent the target gas from escaping upwards and external air from seeping in is a technical challenge. Simple static seals cannot adapt to the dynamic rotation of the drill rod, easily leading to gas sample dilution or contamination. Summary of the Invention

[0005] The purpose of this invention is to provide an in-situ gas extraction device for soil hydrogen content, which addresses the shortcomings of existing technologies and solves the problems mentioned in the background.

[0006] The technical solution of this invention is implemented as follows: The present invention provides an in-situ gas sampling device for soil hydrogen content, including a base, an installation hole on the side wall of the base, and a protective sleeve passing through the installation hole; A drill rod is inserted inside the casing, and a drilling tool is installed at the end of the drill rod. A sealing sleeve is fitted on the outer wall of the drill rod and is installed at the top of the casing. The outer wall of the drill pipe is provided with spiral-shaped cutting blades along its axial direction; the outer edge of the cutting blades abuts against the inner wall of the sealing cylinder. A sealing cap is provided on the outer side wall of the drill pipe. The outer side wall of the sealing cap abuts against the inner wall of the sealing cylinder. A sealing structure is installed on the outer edge of the sealing cap. The sealing structure abuts against the inner wall of the sealing cylinder. An isolation cylinder is fitted onto the outer wall of the casing, and the isolation cylinder is connected to the side wall of the base facing the surface being explored; There is a storage chamber between the isolation cylinder and the protective cylinder. The side wall of the protective cylinder is provided with a discharge port that communicates with the storage chamber. The outer side wall of the isolation cylinder is provided with a slag discharge structure that communicates with the storage chamber. When the storage chamber is filled and compacted by soil debris, the slag discharge structure is opened. After the soil debris continues to enter the storage chamber from the discharge port, the excess soil debris in the storage chamber will be discharged from the slag discharge structure. The side wall of the base is equipped with a drive structure for driving the drill rod to rotate. An inlet and outlet channel is opened inside the drill rod along its extension direction. The inlet and outlet channel is provided with a ventilation pipe that communicates with the detection equipment. The ventilation pipe passes through the outer side wall of the drill rod and extends outward.

[0007] In some technical solutions of the present invention, an annular drill bit is installed at the end of the casing, a sealing cylinder is fixedly set on the base, a portion of the sealing cylinder is embedded in the casing, a guide groove is provided on the inner side wall of the casing along its axial direction, a guide block is slidably provided in the guide groove, the guide block is connected to the outer side wall of the sealing cylinder, a sealing ring is provided on the inner side wall of the casing, the inner ring of the sealing ring abuts against the outer side wall of the sealing cylinder, and a transmission structure connected to the drill rod is provided on the sealing cylinder.

[0008] In some technical solutions of the present invention, the transmission structure includes a mounting sleeve installed on the drill pipe, a limiting groove is formed on the outer side wall of the mounting sleeve along its axial direction, a connecting frame connected to the sealing cylinder is slidably provided in the limiting groove, and an annular groove is formed on the outer side wall of the mounting sleeve along its circumference, and the limiting groove is in communication with the annular groove. A locking block is installed on the outer wall of the casing, and a locking groove matching the locking block is opened on the outer wall of the base along the circumference of the mounting hole.

[0009] In some technical solutions of the present invention, a limiting ring is provided on the inner wall of the casing, the installation height of the limiting ring is lower than the horizontal height of the discharge port, and the outer diameter of the chisel blade is smaller than the inner diameter of the limiting ring.

[0010] In some technical solutions of the present invention, a blocking ring is provided at the connection between the casing and the sealing cylinder, which is used to restrict the sealing cover from moving along the drill rod axial direction into the casing and to block the discharge port.

[0011] In some technical solutions of the present invention, a ring-shaped baffle is provided in the storage chamber, and the baffle is slidably disposed on the outer side wall of the protective cylinder along the axial direction of the protective cylinder; an isolation ring is provided on the inner wall of the isolation cylinder, and the outer edge of the baffle abuts against the inner side wall of the isolation ring.

[0012] In some technical solutions of the present invention, a through groove is provided on the outer side wall of the casing along the vertical direction, a support frame is provided in the through groove, the support frame is connected to the baffle plate in a driving connection, a sealing sleeve is provided in the through groove, the support frame extends outward after passing through the sealing sleeve, and the inner side wall of the sealing sleeve abuts against the outer side wall of the support frame.

[0013] In some technical solutions of the present invention, an annular groove is formed on the outer wall of the casing along its axial direction. The groove is connected to the through groove. A guide rod is installed in the groove along the axial direction of the casing. A displacement seat connected to the baffle plate is slidably provided on the guide rod. A return spring that abuts against the displacement seat is sleeved on the outer wall of the guide rod. Both ends of the baffle plate are provided with sealing telescopic sleeves connected to the inner wall of the groove. The displacement seat is connected to the support frame in a transmission connection.

[0014] In some technical solutions of the present invention, a push rod is rotatably provided on the displacement seat, a torsion spring is provided between the push rod and the displacement seat, and the angle between the reverse extension line of the push rod and the displacement seat is an acute angle; a number of toothed grooves are opened on the outer side wall of the support frame along the vertical direction, and a portion of the push rod is embedded in the toothed grooves.

[0015] A rotating frame is installed inside the sealed cylinder, and several blades are arranged around the rotating frame. The drill rod passes through the rotating frame and extends outward. The rotating frame is slidably installed inside the sealed cylinder along the extension direction of the drill rod, and the drill rod is connected to the rotating frame by transmission.

[0016] Compared with existing technologies, this invention has at least the following advantages or beneficial effects: By integrating a ventilation pipe at the center of the drill rod, gas can be directly extracted from undisturbed soil pores while the drill rod is continuously drilling or staying at the target depth, ensuring the in-situ and real-time nature of sampling and effectively avoiding gas escape and contamination during the transfer process; the spiral-shaped cutting blades transport the cuttings upwards, and the cuttings enter the casing and isolation cylinder to form an external storage chamber for temporary storage. The casing and isolation cylinder that constitute the storage chamber, as well as the sealing layer formed by the compacted cuttings in the storage chamber, prevent external impurities from entering the sampling hole and interfering with the sampled gas. Through the above structure, in-situ gas collection can be carried out by drilling and testing or by sampling at a fixed depth, reducing gas escape or contamination during the transfer process; in-situ collection of soil gases (especially hydrogen) is achieved, maximizing the originality and authenticity of the gas samples and improving the accuracy of the detection data. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the working state of the in-situ soil hydrogen content sampling device in this invention.

[0018] Figure 2 This is a three-dimensional structural diagram of the soil hydrogen content in-situ gas extraction device of the present invention.

[0019] Figure 3This is a half-section schematic diagram of the soil hydrogen content in-situ gas extraction device of the present invention.

[0020] Figure 4 This is a cross-sectional view of the mounting sleeve and shaft in this invention.

[0021] Figure 5 This is a schematic diagram of the installation structure of the sealing cap and sealing cylinder of the present invention.

[0022] Figure 6 This is a schematic diagram of the installation structure of the sealing cylinder and the protective cylinder of the present invention.

[0023] Figure 7 for Figure 6 A magnified schematic diagram of the structure at point A in the middle.

[0024] Figure 8 This is a three-dimensional structural diagram of the sleeve and base in this invention.

[0025] Figure 9 This is a half-sectional view of the casing and base in this invention.

[0026] Figure 10 This is a schematic diagram of the installation structure of the baffle plate of the present invention.

[0027] Figure 11 for Figure 10 A magnified schematic diagram of the structure at point B in the middle.

[0028] Figure 12 This is a schematic diagram of the assembly structure between the support frame and the baffle plate of the present invention.

[0029] Figure 13 for Figure 12 A magnified schematic diagram of the structure at point C.

[0030] Reference numerals: 1. Base; 101. Mounting hole; 102. Locking groove; 2. Casing; 201. Discharge port; 202. Annular drill bit; 203. Guide groove; 204. Sealing ring; 205. Locking block; 206. Limiting ring; 207. Blocking ring; 208. Through groove; 209. Support frame; 210. Sealing sleeve; 211. Countersink; 212. Guide rod; 213. Guide block; 214. Return spring; 215. Push rod; 216. Torsion spring; 217. Tooth groove; 3. Drill rod; 301. Drilling tool; 302. Through groove 303. Gas pipeline; 304. Chisel blade; 305. Sealing cover; 306. Sealing structure; 307. Guide groove; 308. Guide strip; 4. Sealing cylinder; 401. Displacement seat; 402. Transmission structure; 403. Mounting sleeve; 404. Limiting groove; 405. Connecting frame; 406. Ring groove; 5. Isolation cylinder; 501. Storage chamber; 502. Slag discharge structure; 503. Material baffle; 504. Isolation ring; 505. Sealing telescopic sleeve; 506. Through port; 6. Drive structure; 7. Blocking sleeve; 701. Inlet and outlet; 702. Sealing strip. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0033] Example 1 This invention provides a device for in-situ sampling of hydrogen content in soil, such as... Figures 1-13As shown, the system includes a base 1, with a mounting hole 101 on the side wall of the base 1, through which a protective sleeve 2 is inserted; a drill rod 3 is inserted inside the protective sleeve 2, with a drilling tool 301 installed at the end of the drill rod 3; a sealing sleeve 4 is fitted on the outer side wall of the drill rod 3, and the sealing sleeve 4 is installed at the top of the protective sleeve 2; a spiral-shaped chisel blade 303 is provided along the axial direction on the outer side wall of the drill rod 3, and the outer edge of the chisel blade 303 abuts against the inner wall of the sealing sleeve 4; a drive structure 6 for driving the drill rod 3 to rotate is installed on the side wall of the base 1; the drill rod 3 rotates under the drive of the drive structure 6 and drives the drilling tool 301 to break the soil, while the spiral-shaped chisel blade 303 plays the role of conveying debris and scraping the inner wall of the protective sleeve 2, so as to avoid the accumulation of soil debris on the inner wall of the protective sleeve 2 and affect the discharge.

[0034] A sealing cap 304 is provided on the outer wall of the drill pipe 3. The sealing cap 304 is a semi-circular shell or disc. The outer wall of the sealing cap 304 abuts against the inner wall of the sealing cylinder 4. A sealing structure 305 is installed on the outer edge of the sealing cap 304, and the sealing structure 305 abuts against the inner wall of the sealing cylinder 4. The sealing structure 305 can be a hollow O-ring rubber ring, which can dynamically seal the gap between the sealing cap 304 and the sealing cylinder 4 when pressurized inside. In addition, a spiral groove can be opened on the outer wall of the O-ring rubber ring to form a multiple seal between the sealing cylinder 4 and the sealing cap 304, minimizing gas escape. The sealing cylinder 4, sealing cover 304, and sealing structure 305 are tightly fitted with the drill rod 3 and the inner wall of the casing 2. Under the dynamic rotation of the drill rod 3, a relatively sealed annular space is formed around the drill rod 3 and the top of the casing 2, preventing gas from escaping from there and ensuring the sealing of the gas collection path; and changing the discharge path of soil debris, and guiding the soil debris to be discharged from the discharge port 201, so that the soil debris forms an isolation layer around the casing 2.

[0035] An isolation cylinder 5 is fitted onto the outer wall of the casing 2, and the isolation cylinder 5 is connected to the side wall of the base 1 facing the exploration surface. A discharge port 201 communicating with the storage chamber 501 is provided on the side wall of the casing 2. The casing 2 and the isolation cylinder 5 form a double-layer structure to create the storage chamber 501. Soil debris generated during drilling is forcibly transported upwards and temporarily stored in the storage chamber 501 through the discharge port 201 under the guidance of the sealing cover 304. When the storage chamber 501 is fully filled and compressed, the debris layer, together with the casing 2 and the isolation cylinder 5, forms an isolation layer to prevent external gas from entering the sampling hole, effectively avoiding gas escape and improving detection efficiency and data accuracy. A slag discharge structure 502 communicating with the storage chamber 501 is provided on the outer wall of the isolation cylinder 5. The slag discharge structure 502 can be a blocking sleeve 7 installed around the isolation cylinder 5, with an inlet / outlet 701 on the outer wall of the blocking sleeve 7, and corresponding openings on the outer wall of the isolation cylinder 5. When the inlet / outlet 701 is misaligned with the passage, the passage is covered by the blocking sleeve 7, and the storage chamber 501 is in a sealed state. Sealing strips 702 are installed at both the upper and lower ends of the blocking sleeve 7, and annular sealing rings 204 can be installed around the inlet / outlet 701. After the storage chamber 501 is filled and compacted by soil debris, the slag discharge structure 502 can be opened. Soil debris continues to enter the storage chamber 501 from the discharge port 201, and excess soil debris in the storage chamber 501 will be discharged from the slag discharge structure 502. Drilling debris is again forcibly conveyed upwards and, guided by the isolation cover, re-enters the storage chamber 501 from the discharge port 201. Utilizing the pressure generated by the filling of soil debris as power, through a "fill-compact-overflow" mechanism, excess soil debris is automatically discharged from the slag discharge structure 502. This enables the continuous containment and cleaning of large amounts of debris without stopping drilling, ensuring that the slag discharge operation can be completed during non-sampling phases and avoiding borehole blockage and equipment interruption.

[0036] The drill rod 3 has an inlet / outlet channel along its axial direction. Within this channel is a ventilation pipe 302 connected to the testing equipment. The ventilation pipe 302 extends outwards after penetrating the outer wall of the drill rod 3. Integrated at the center of the drill rod 3, the ventilation pipe 302 has its inlet located at the end or side wall of the drill rod 3 (depending on the actual design), allowing direct contact with the soil at the target depth. Within the borehole formed by the drill rod 3, gas is directly extracted from the soil pores through this pipe, enabling in-situ gas collection—either "drilling and testing" or fixed-depth gas sampling—reducing gas escape or contamination during transfer. This improves the in-situ collection of soil gases (especially hydrogen), maintains the originality and authenticity of gas samples, and enhances the accuracy of the testing data.

[0037] The working process of this structure is as follows: The base 1 is placed on the exploration surface. First, the isolation cylinder 5 is inserted into the formation, and then the drive structure 6 is activated to rotate the drill rod 3. At this time, the sealing cylinder 4 drives the casing 2 to rotate first. The casing 2 enters the formation before the drilling tool 301, providing initial support for the drilled borehole. Simultaneously, the drill rod 3 drives the drilling tool 301 and the spiral cutting blade 303 to work together to drill downwards into the soil to form a borehole (inspection hole). After moving a certain distance, the casing 2 disengages from the drill rod 3, and the drill rod 3 can continue to drill downwards. The soil debris (sand and gravel) generated during drilling is transported upwards along the annular space between the drill rod 3 and the casing 2 under the spiral guidance and rotation of the cutting blade 303. When the upwardly transported soil debris reaches the discharge port 201 on the side wall of the casing 2, it is discharged into the storage chamber 501 formed by the casing 2 and the isolation cylinder 5 for temporary storage under the combined action of the sealing cover 304 and the cutting blade 303. As drilling continues, the storage chamber 501 is gradually filled and compacted with soil debris. As more soil debris enters the storage chamber 501, the internal pressure increases. At this point, the slag discharge structure 502 is activated (manually operated), allowing more soil debris to enter through the discharge port 201. This pushes the accumulated soil debris in the chamber out through the slag discharge structure 502 on the isolation cylinder 5, achieving continuous slag discharge. As subsequent soil debris continues to enter the storage chamber 501, it is further compressed as it fills. After drilling to the target depth, the outer diameter detection equipment can be connected to the ventilation pipe 302 inside the drill pipe 3, allowing for in-situ extraction of gases (such as hydrogen) from the soil. These gases are then guided through the pipe penetrating the drill pipe 3 to external detection equipment for analysis.

[0038] Preferably, in order to ensure sealing performance, a sealing ring that contacts the outer wall of the casing 2 can be installed in the mounting hole 101 to enhance the sealing performance.

[0039] Preferably, a cutting tool is mounted on the front end of the cutting blade 303 by a screw, which is used to extend the service life of the cutting blade 303.

[0040] Preferably, negative pressure can be applied to the borehole through the ventilation pipe 302 to expel as much impurity gas as possible from the borehole, which is beneficial for in-situ collection of hydrogen content. Before sampling, the ventilation pipe 302 can be backflushed through the gas supply equipment to remove any possible blockages in the pipe.

[0041] Preferably, in order to further ensure the sealing effect of the sealing layer formed by the soil, casing 2 and isolation casing 5, a highly viscous slurry can be injected into the storage chamber and mixed with debris to form a dense and fluid sealing medium, which is used to improve the sealing effect of this structure.

[0042] In some technical solutions of the present invention, an annular drill bit 202 is installed at the end of the casing 2, which is used to assist the casing 2 in cutting into the soil to provide initial support for the inner wall of the borehole to be drilled. The annular drill bit 202 cooperates with the drilling tool 301 on the central drill rod 3 to form a more stable and efficient annular cutting surface, which is conducive to forming a regular borehole and reducing soil disturbance, and avoiding the collapse of the gas collection port in sandy geology caused by drilling. Preferably, the sealing cylinder 4 is rotatably mounted on the base 1 by the mounting bracket, and a portion of the sealing cylinder 4 is embedded in the casing 2. A guide groove 203 is formed on the inner side wall of the casing 2 along its axial direction, and a guide block 213 is slidably arranged in the guide groove 203. The guide block 213 is connected to the outer side wall of the sealing cylinder 4. When the drive structure 6 drives the drill rod 3 to rotate through the transmission structure 402, the guide block 213 on the sealing cylinder 4 and the guide groove 203 in the casing 2 slide together to achieve relative fixation between them. That is, the casing 2 can rotate with the sealing cylinder 4. At the same time, the casing 2 can slide along the drilling direction of the drill rod 3 on the outside of the sealing cylinder 4 and enter the borehole, thereby providing initial support for the borehole.

[0043] A sealing ring 204 is provided on the inner wall of the casing 2. The inner ring of the sealing ring 204 abuts against the outer wall of the sealing cylinder 4. The sealing cylinder 4 is provided with a transmission structure 402 that is connected to the drill rod 3 to strengthen the static seal between the sealing cylinder 4 and the casing 2.

[0044] Preferably, the sealing ring 204 can be an inflatable airbag, which can dynamically enhance the sealing effect between the sealing cylinder 4 and the protective cylinder 2 after being inflated and pressurized.

[0045] In some technical solutions of the present invention, the transmission structure 402 includes a mounting sleeve 403 mounted on the drill pipe 3. A limiting groove 404 is formed on the outer side wall of the mounting sleeve 403 along its axial direction. A connecting frame 405 connected to the sealing cylinder 4 is slidably provided in the limiting groove 404. An annular groove 406 is formed on the outer side wall of the mounting sleeve 403 along its circumference. The limiting groove 404 is in communication with the annular groove 406.

[0046] A locking block 205 is installed on the outer side wall of the casing 2, and a locking groove 102 matching the locking block 205 is provided on the outer side wall of the base 1 along the circumference of the mounting hole 101.

[0047] A guide groove 306 is provided on the inner wall of the mounting sleeve 403, and a guide strip 307 is provided on the outer wall of the drill rod 3. The length of the guide strip 307 corresponds to the depth to which the casing 2 enters the drilled ground. When the casing 2 enters the designated position of the soil debris, the guide strip 307 on the drill rod 3 exits from the guide groove 306, and the transmission between the mounting sleeve 403 and the drill rod 3 fails. At this time, the mounting sleeve 403 no longer moves along the drilling direction of the drill rod 3 or rotates with the drill rod 3. The torque applied to the drill rod 3 by the drive structure 6 is transmitted to the sealing cylinder 4 through the mounting sleeve 403 and the connecting frame 405, which then drives the casing 2 to rotate into the formation. The limiting groove 404 on the mounting sleeve 403 allows the sealing cylinder 4 to rotate under the drive of the drill rod 3 during a certain distance of the drilling process. This rotation drives the casing 2 to enter the formation to be sampled for initial support of the borehole. When the upper end of the casing 2 moves to be flush with the base 1, the locking block 205 at the top of the casing 2 is embedded in the locking groove 102 on the base 1. At this time, the connecting frame 405 moves from the limiting groove 404 to the annular groove 406. The drill rod 3 no longer applies rotational driving force to the sealing sleeve through the mounting sleeve 403 and the connecting frame 405. Instead, the sealing sleeve and the connecting frame 405, together with the gravity generated by the sealing cylinder 4, apply thrust to the casing 2 to prevent the casing 2 from floating up. This avoids problems such as borehole wall collapse caused by the casing 2 floating up during drilling, as well as affecting the sealing effect during gas collection.

[0048] In some technical solutions of this invention, a limiting ring 206 is provided on the inner wall of the casing 2. The installation height of the limiting ring 206 is lower than the horizontal height of the discharge port 201, and the outer diameter of the chisel blade 303 is smaller than the inner diameter of the limiting ring 206. When the drill rod 3 is lowered, the chisel blade 303 rotates with the drill rod 3. When the drill rod 3 is raised, since the outer diameter of the chisel blade 303 is smaller than the inner diameter of the limiting ring 206, the blade can pass smoothly through the limiting ring 206. The soil debris is transported by the spiral-shaped chisel blade 303 to the dynamic downward pressure chamber formed by the sealing cover 304 and the limiting ring 206, and the downward-moving sealing cover 304 pushes the soil debris lifted by the chisel blade 303 downward into the discharge port 201, thereby sending the soil debris into the storage chamber 501. At this point, the soil debris, casing 2, and isolation casing 5 form a sealing layer to prevent external hydrogen from entering the borehole through the gap between casing 2 and soil debris, thus interfering with the measurement of hydrogen content in the formation.

[0049] In some technical solutions of the present invention, a blocking ring 207 is provided at the connection between the casing 2 and the sealing cylinder 4. This ring is used to restrict the sealing cover 304 from entering the casing 2 and blocking the discharge port 201 after it moves axially along the drill rod 3. During the axial movement of the drill rod 3 (e.g., descending into the borehole), the sealing cover 304 moves with the drill rod 3. When the sealing cover 304 moves close to the connection between the casing 2 and the sealing cylinder 4, it is blocked by the blocking ring 207 at that location and cannot continue to move downwards (into the casing 2), thus stopping at a predetermined position. The blocking ring 207 restricts the travel path of the sealing cover 304, ensuring that it does not descend excessively and prevents the sealing cover 304 from obstructing the discharge port 201 on the side wall of the casing 2. This ensures that the channel for debris to enter the storage chamber 501 remains unobstructed, preventing interference or damage to other internal structures of the casing 2.

[0050] Preferably, when the sealing cap 304 moves to abut against the blocking ring 207, the drill rod 3 of this structure reaches the maximum drilling depth.

[0051] In some technical solutions of the present invention, a ring-shaped baffle plate 503 is provided inside the storage chamber 501. The baffle plate 503 is slidably disposed on the outer side wall of the protective casing 2 along the axial direction of the casing 2. An isolation ring 504 is provided on the inner wall of the isolation cylinder 5, and the outer edge of the baffle plate 503 abuts against the inner side wall of the isolation ring 504. The baffle plate 503 and the isolation ring 504 constitute the bottom of an axially expandable storage chamber 501, preventing soil debris from directly contacting the outer edge of the upper end of the borehole. As soil debris continuously enters the storage chamber 501 from the discharge port 201, the strata at the casing 2 and the outer edge of the borehole are squeezed, causing the completed borehole to collapse, which blocks the subsequent gas collection path and is not conducive to the collection of gas as much as possible. As the accumulated soil debris pushes the annular baffle 503 downward along the outer wall of the casing 2, until the outer edge of the baffle 503 is always in contact with the isolation ring 504 on the inner wall of the isolation cylinder 5, the soil debris entering the storage chamber 501 is compacted as much as possible under the support of the baffle 503, which improves the sealing effect of the sealing layer formed by the soil debris, casing 2 and isolation cylinder 5, and prevents the measuring gas from escaping from this place or entering the borehole from this area.

[0052] Example 2 Based on Example 1, a support structure is installed to support the strata below the casing 2, thereby increasing the depth of gas collection when drilling continues in the already drilled borehole. This structure allows for monitoring of hydrogen content at different depths in the soil at the same location, improving the accuracy, effectiveness, and continuity of hydrogen content data collection.

[0053] Therefore, the following structural improvements are made. Several vertical slots 208 are formed on the outer wall of the casing 2. Support frames 209 pass through the slots 208 and are connected to the baffle plate 503. A sealing sleeve 210, which is elastic, is provided within the slots 208. The support frame 209 extends outward after passing through the sealing sleeve 210, with the inner wall of the sealing sleeve 210 abutting against the outer wall of the support frame 209. After passing through the slots 208 on the side wall of the casing 2, the support frame 209 enters the drilling area below the casing 2, providing support to this area and preventing borehole collapse during hydrogen measurement in sandy and gravelly strata. Furthermore, the sealing sleeve 210 covers the portion of the support frame 209 that passes through the through groove 208, sealing the annular gap between the support frame 209 and the through groove 208. This prevents external gas, gas from inside the borehole, or fine dust from communicating through this gap, which could cause deviations in the accuracy of hydrogen content data acquisition. The sealing sleeve 210 uses its own clamping force to lock the support frame 209 within the through groove 208, preventing axial movement of the support frame 209 unless subjected to external force.

[0054] Preferably, a ring-shaped support structure is formed by several support frames enclosing each other.

[0055] In some technical solutions of the present invention, an annular groove 211 is formed on the outer wall of the casing 2 along its axial direction. The groove 211 communicates with the through groove 208. A guide rod 212 is installed in the groove 211 along the axial direction of the casing 2. A displacement seat 401 connected to the baffle plate 503 is slidably mounted on the guide rod 212. A return spring 214 abutting against the displacement seat 401 is sleeved on the outer wall of the guide rod 212. Both ends of the baffle plate 503 are provided with sealing telescopic sleeves 505 connected to the inner wall of the groove 211. The displacement seat 401 is connected to the support frame 209 in a transmission connection. When soil debris continues to enter the baffle plate 503, the soil debris squeezes the baffle plate 503 downward, and the displacement seat 401 slides along the guide rod 212 to squeeze the return spring 214. The sealing telescopic sleeve 505 extends and retracts with the movement of the baffle plate 503, always sealing both ends of the settling tank 211. As a flexible sealing cover, the sealing telescopic sleeve 505 extends and retracts with the movement of the baffle plate 503, always isolating the settling tank 211 containing the moving parts (guide rod 212, displacement seat 401) from the storage chamber 501, achieving full-stroke sealing of the components in this area. The support frame 209, in conjunction with the displacement seat 401, is pushed to the drilling area under the casing 2, providing support to this area. This eliminates the need for manual operation when installing the support frame 209, improving the convenience for operators when using this structure.

[0056] In some technical solutions of the present invention, a push rod 215 is rotatably mounted on the displacement seat 401, and a torsion spring 216 is provided between the push rod 215 and the displacement seat 401. The angle between the backward extension line of the push rod 215 and the displacement seat 401 is an acute angle. Several toothed grooves 217 are formed vertically on the outer side wall of the support frame 209, and a portion of the push rod 215 is embedded in the toothed grooves 217. Under the action of the torsion spring 216, the end of the push rod 215 is engaged in the toothed grooves 217 of the support frame 209 to achieve one-way locking. When the soil debris enters the storage area and moves downward using the baffle plate 503, the support frame 209 is driven into the stratum to support the drilled area. When the soil debris pressure in the chamber remains constant, the baffle plate 503 cannot move. It pushes the push rod 215 embedded in the toothed groove 217 via the displacement seat 401, applying a continuous thrust to the support frame 209. This creates a one-way ratchet / check mechanism between the push rod 215 and the toothed groove 217, achieving one-way self-locking. When the soil debris pressure in the storage chamber 501 decreases, the return spring 214 pushes the baffle plate 503 back to its original position. The baffle plate 503 pulls the displacement seat 401 and the push rod 215 back to their original positions, preparing the storage chamber 501 to receive a new round of soil debris. During the next compression of the baffle plate 503 (during another drilling process), as the baffle plate 503 moves downward, it again drives the support rod into the formation via the push rod 215, supporting the drilled borehole area and achieving a progressive support effect.

[0057] Example 3 The gas extraction method based on the in-situ gas extraction device for soil hydrogen content involves the following steps: The drive structure 6 is activated, causing the drill rod 3 to rotate. Through the initial engagement of the transmission structure 402, the torque of the drill rod 3 is synchronously transmitted to the sealing cylinder 4 and the casing 2 connected thereto. The annular drill bit 202 at the end of the casing 2 and the drilling tool 301 at the end of the drill rod 3 work together to cut the soil layer. The casing 2 then follows, providing immediate support to the upper section of the borehole. At the same time, the cutting blades 303 on the drill rod 3 transport the cuttings upward. The upward-conveyed debris is blocked by the sealing cap 304 and its sealing structure 305 on the drill pipe 3; during the rotation and downward pressing of the drill pipe 3, the sealing structure 305 and the inner wall of the sealing cylinder 4 maintain a dynamic seal, forcing the debris to change its flow direction and be discharged from the discharge port 201 on the side wall of the casing 2, and enter the annular storage chamber 501 formed by the casing 2 and the isolation cylinder 5; As drilling continues, the debris in the storage chamber 501 gradually accumulates and compacts. Once the chamber is full, the operator activates the slag discharge structure 502 on the isolation cylinder 5. Subsequent incoming debris pushes the compacted debris in the chamber out through the slag discharge structure 502, achieving continuous slag discharge without stopping drilling. When drilling deeper is required in loose formations, the pressure of the continuously accumulating debris in the storage chamber 501 pushes the baffle plate 503 downward. The baffle plate 503 drives the push rod 215 through the displacement seat. The push rod 215 engages with the toothed groove 217 on the support frame 209, gradually pushing the support frame 209 out of the through groove 208 of the casing 2 and pressing it into the borehole wall, forming a support structure for the drilled section and preventing collapse; After drilling to the predetermined sampling depth, the rotation of drill rod 3 is paused or the drill rod is held stationary. Negative pressure is applied through the ventilation pipe 302 at the center of drill rod 3 to directly extract gas from the soil pores at that depth. The gas is guided through the ventilation pipe 302 to external analytical equipment for real-time detection or collection. This process takes place in a relatively sealed environment formed by the casing 2, sealing components, and compacted debris layer, greatly reducing the risk of gas exchange with the atmosphere. After sampling is completed, drive structure 6 reverses to lift drill pipe 3.

[0058] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for in-situ sampling of hydrogen content in soil, characterized in that, Includes a base, on which mounting holes are provided on the side walls, and a protective sleeve is inserted into the mounting holes; A drill rod is inserted inside the casing, and a drilling tool is installed at the end of the drill rod. A sealing cylinder is fitted on the outer side wall of the drill rod and is installed at the top of the casing. The outer wall of the drill rod is provided with spiral-shaped cutting blades along its axial direction; the outer edge of the cutting blades abuts against the inner wall of the sealing cylinder. A sealing cover is provided on the outer side wall of the drill pipe. The outer side wall of the sealing cover abuts against the inner wall of the sealing cylinder. A sealing structure is installed on the outer edge of the sealing cover. The sealing structure abuts against the inner wall of the sealing cylinder. An isolation cylinder is fitted on the outside of the protective casing, and the isolation cylinder is connected to the side wall of the base facing the surface being explored. A storage chamber is provided between the isolation cylinder and the protective cylinder, and a discharge port communicating with the storage chamber is provided on the side wall of the protective cylinder; a slag discharge structure communicating with the storage chamber is provided on the outer side wall of the isolation cylinder; when the soil debris fills the storage chamber tightly, the slag discharge structure is opened, and the subsequently entering soil debris pushes the compacted debris out of the slag discharge structure. The base has a drive structure installed on its side wall for driving the drill rod to rotate; the drill rod has an inlet and outlet channel along its extension direction, and the inlet and outlet channel has a ventilation pipe connected to the testing equipment. The ventilation pipe passes through the outer side wall of the drill rod and extends outward.

2. The in-situ gas extraction device for soil hydrogen content according to claim 1, characterized in that, The end of the casing is equipped with an annular drill bit. The sealing cylinder is rotatably mounted on the base. A portion of the sealing cylinder is embedded inside the casing. A guide groove is formed along the axial direction on the inner side wall of the casing. A guide block is slidably arranged in the guide groove. The guide block is connected to the outer side wall of the sealing cylinder. A sealing ring is provided on the inner side wall of the casing. The inner ring of the sealing ring abuts against the outer side wall of the sealing cylinder. The sealing cylinder is provided with a transmission structure that is connected to the drill pipe drive.

3. The device for in-situ sampling of soil hydrogen content according to claim 2, characterized in that, The transmission structure includes a mounting sleeve installed on the drill rod, and a limiting groove is formed on the outer side wall of the mounting sleeve along its axial direction. A connecting frame connected to the sealing cylinder is slidably provided in the limiting groove. The outer wall of the mounting sleeve is provided with an annular groove along its circumference, and the limiting groove communicates with the annular groove; A locking block is installed on the outer side wall of the casing, and a locking groove matching the locking block is opened on the outer side wall of the base along the circumference of the mounting hole.

4. A device for in-situ sampling of soil hydrogen content according to any one of claims 1-3, characterized in that, A limiting ring is provided on the inner wall of the casing. The installation height of the limiting ring is lower than the horizontal height of the discharge port, and the outer diameter of the chisel blade is smaller than the inner diameter of the limiting ring.

5. The in-situ gas extraction device for soil hydrogen content according to claim 4, characterized in that, A blocking ring is provided at the connection between the casing and the sealing cylinder, which is used to restrict the sealing cover from moving along the drill rod axial direction into the casing and to block the discharge port.

6. The device for in-situ sampling of soil hydrogen content according to claim 1, characterized in that, The storage chamber is provided with an annular baffle plate, which is slidably disposed on the outer side wall of the protective cylinder along the axial direction of the protective cylinder; the inner wall of the isolation cylinder is provided with an isolation ring, and the outer edge of the baffle plate abuts against the inner side wall of the isolation ring.

7. The in-situ gas extraction device for soil hydrogen content according to claim 6, characterized in that, An annular groove is formed on the outer wall of the casing along its axial direction. A guide rod is installed in the groove along the axial direction of the casing. A displacement seat connected to the baffle plate is slidably mounted on the guide rod. A return spring that abuts against the displacement seat is sleeved on the outer wall of the guide rod. Both ends of the baffle plate are provided with sealing telescopic sleeves that are connected to the inner wall of the groove.

8. A device for in-situ sampling of soil hydrogen content according to claim 7, characterized in that, A through groove is formed on the outer side wall of the casing along the vertical direction. A support frame passes through the through groove and is drivenly connected to the baffle plate. A sealing sleeve is provided in the through groove. The support frame extends outward after passing through the sealing sleeve. The inner side wall of the sealing sleeve abuts against the outer side wall of the support frame. The sink groove is connected to the through groove. The displacement seat is drivenly connected to the support frame.

9. A device for in-situ sampling of soil hydrogen content according to claim 8, characterized in that, A push rod is rotatably mounted on the displacement seat, and a torsion spring is provided between the push rod and the displacement seat. The angle between the reverse extension line of the push rod and the displacement seat is an acute angle. Several toothed grooves are opened on the outer side wall of the support frame along the vertical direction, and a portion of the push rod is embedded in the toothed grooves.

10. A method for gas extraction based on the soil hydrogen content in-situ gas extraction device according to any one of claims 1-9, characterized in that, Includes the following steps: The drive mechanism is activated, causing the drill rod to rotate. Through the initial engagement of the transmission mechanism, the torque of the drill rod is synchronously transmitted to the sealing cylinder and the casing connected to it. The annular drill bit at the end of the casing and the drilling tool at the end of the drill rod work together to cut the soil layer. The casing then follows, providing immediate support to the upper section of the borehole. At the same time, the cutting blades on the drill rod transport the cuttings upward. The upward-flowing debris is blocked by the sealing cap and its sealing structure on the drill pipe; during the rotation and downward pressing of the drill pipe, the sealing structure and the inner wall of the sealing cylinder maintain a dynamic seal, forcing the debris to change its flow direction and be discharged from the discharge port on the side wall of the casing, entering the annular storage chamber formed by the casing and the isolation cylinder; As drilling continues, the debris in the storage chamber gradually accumulates and compacts. Once the chamber is full, the operator activates the slag removal mechanism on the isolation cylinder. Subsequent incoming debris generates thrust, pushing the compacted debris out of the chamber through the slag removal mechanism, thus achieving continuous slag removal without stopping drilling. When drilling deeper is required in loose formations, the pressure of the continuously accumulating debris in the storage chamber pushes the baffle plate downwards; the baffle plate drives the push rod through the displacement seat, and the push rod engages with the toothed groove on the support frame, gradually pushing the support frame out of the through groove of the casing and pressing it into the borehole wall, forming a support structure for the drilled section; After drilling to the predetermined sampling depth, the drill rod can pause rotation or remain stationary; negative pressure is applied through the ventilation pipe at the center of the drill rod to directly extract gas from the soil pores at that depth; the gas is guided through the ventilation pipe to external analysis equipment for real-time detection or collection; this process takes place in a relatively sealed environment formed by the casing, sealing components, and compacted debris layer; After sampling is completed, the drive structure reverses and lifts the drill pipe.

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