A variable pressure coal pillar microbial reaction in-situ nuclear magnetic testing device and method thereof

Abstract

The application discloses a variable-pressure high-pressure coal column microbial reaction in-situ nuclear magnetic testing device and method, which comprises a PEEK pressure-resistant nuclear magnetic tube base body and a PEEK three-way integrated joint base body, an inner part of the PEEK pressure-resistant nuclear magnetic tube base body is provided with an intracanal reaction cavity, and one end of the PEEK three-way integrated joint base body is fixedly provided with a conical high-pressure sealing pair; the application is provided with a multi-channel structure of vacuum and methane channels, bacteria liquid injection, and air valve inflation, integrates vacuum extraction, bacteria liquid injection, and high-pressure inflation, and can sequentially dock corresponding channel equipment during test operation, and step-by-step cavity vacuum extraction, negative pressure bacteria liquid quantitative injection, methane high-pressure inflation, nitrogen inflation for providing confining pressure, and axial pressure are realized, multi-process integrated continuous closed operation is realized, sample pretreatment, medium injection and high-pressure preparation processes can be completed without repeatedly disassembling pipeline equipment, test operation process is simplified, system pollution and test errors caused by repeated disassembly are avoided, and test operation convenience and test data repeatability are improved.

Description

Technical Field

[0001] This invention relates to a variable-pressure coal pillar microbial reaction in-situ nuclear magnetic resonance testing device and method, belonging to the technical field of microbial reaction testing equipment. Background Technology

[0002] In experimental studies on microbial degradation of coalbed methane and high-pressure microbial metabolic mechanisms, it is often necessary to place the bacterial solution and methane gas together in a closed high-pressure environment to simulate different formation pressure conditions, restore the real environment of the underground reservoir, and then use nuclear magnetic resonance equipment to conduct in-situ detection of fluid distribution, microbial activity and changes in media structure inside the sample.

[0003] In the existing technology, most high-pressure microbial reaction testing devices adopt a split pipeline structure. The processes of vacuuming, bacterial liquid injection, and gas pressurization require repeated disassembly and reassembly of multiple pipelines. Repeated disassembly and reassembly can easily introduce contaminants and cause media leakage. The repeatability of the test is poor, and it is impossible to achieve integrated closed continuous test operation.

[0004] Therefore, it is necessary to propose a variable-pressure high-pressure coal pillar microbial reaction in-situ NMR testing device and method to solve or at least alleviate the above-mentioned defects. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a variable pressure high-pressure coal column microbial reaction in-situ nuclear magnetic resonance testing device. This testing device realizes multi-process integrated continuous closed operation, and can complete the sample pretreatment, medium injection and high pressure preparation processes without repeated disassembly and assembly of pipeline equipment. It simplifies the test operation process, avoids system contamination and test errors caused by repeated disassembly and assembly, and improves the convenience of test operation and the repeatability of test data.

[0006] To solve the above problems, the specific technical solution of the present invention is as follows: A variable-pressure coal column microbial reaction in-situ NMR testing device, comprising a PEEK pressure-resistant NMR tube substrate and a PEEK tee integrated connector substrate, wherein the PEEK pressure-resistant NMR tube substrate has an internal reaction chamber for placing coal column samples and carrying out microbial reactions, and a perfluororubber spacer and several support rods are fixedly installed inside the internal reaction chamber; a valve is fixedly installed on the outer surface of the PEEK pressure-resistant NMR tube substrate, and the valve is connected to the internal reaction chamber; the PEEK tee integrated connector substrate... It is equipped with a sealing structure and is sealed and connected to the PEEK pressure-resistant nuclear magnetic tube substrate; the PEEK three-way integrated connector substrate is equipped with a vacuum and methane injection channel, a bacterial liquid injection channel and a high-pressure gauge. The vacuum and methane injection channel is equipped with connector one at the end and the bacterial liquid injection channel is equipped with connector two at the end, which are used to connect to external vacuum equipment, high-pressure methane gas source and microbial liquid injection equipment, respectively. Both channels are equipped with control valve groups. The outside of the channel is fixed with a mounting shell. The mounting shell is equipped with a blocking structure and a limiting structure, which can realize valve opening adjustment, mechanical limit and dual valve interlock function.

[0007] The sealing structure includes a conical high-pressure sealing pair, a threaded sealing sleeve, and a sealing ring. The conical high-pressure sealing pair is located at the end of the PEEK tee integrated connector base and is connected to the inner conical thread at the end of the PEEK pressure-resistant nuclear magnetic tube base. The threaded sealing sleeve is coaxially fitted on the outer circumference of the PEEK tee integrated connector base and is threadedly engaged with the PEEK pressure-resistant nuclear magnetic tube base. The sealing ring is installed inside the threaded sealing sleeve and is pressed tightly against the outer wall of the conical high-pressure sealing pair and the inner wall of the end of the PEEK pressure-resistant nuclear magnetic tube base, forming a double high-pressure sealing structure.

[0008] The control valve assembly includes two sets of plugs, connecting holes, a linkage shaft, and a knob. The two sets of plugs are rotatably installed inside the vacuum and methane injection channel and the bacterial liquid injection channel, respectively. The plugs have connecting holes inside that match the inner diameter of the channels. The plugs are rotatably assembled inside the mounting housing via the linkage shaft, and the outer end of the linkage shaft is synchronously connected to the knob on the mounting housing.

[0009] The mounting shell has arc-shaped grooves on both sides, and an arc-shaped slider that is fixedly connected to the knob is slidably installed inside the arc-shaped groove. The rotation trajectory of the knob is restricted by the sliding cooperation between the arc-shaped groove and the arc-shaped slider.

[0010] The limiting structure includes a turntable, a slot, an arc surface, a limiting rod, a slider, and a spring. Two sets of turntables are respectively fixedly sleeved on two linkage shafts. The turntables are provided with slots and arc surfaces. The limiting rod is slidably assembled inside the mounting shell through the slider and spring, and can slide elastically in both directions. When any one of the control valves is rotated open, the corresponding turntable rotates and pushes the limiting rod to slide through the arc surface, so that the limiting rod is locked into the slot of the other set of turntables, thereby mechanically locking the other control valve.

[0011] The blocking structure includes a fixed shaft, an L-shaped stop bar, a baffle plate, a stop seat, an arc-shaped rack, and a conical screw. The fixed shaft is fixedly located at the center of the knob, and the L-shaped stop bar is rotatably sleeved on the fixed shaft. The end of the L-shaped stop bar is connected to the baffle plate, and the stop seat is fixedly located at the end of the mounting shell. The rotating baffle plate and the stop seat are mechanically limited. An arc-shaped rack is fixed to the outside of the knob, and a conical screw is threaded onto the L-shaped stop bar. The tip of the conical screw meshes with the arc-shaped rack and locks in place.

[0012] The angle detection structure includes an angle sensor and a linkage gear. The angle sensor is fixedly installed on the upper end of the stop, and the linkage gear is assembled at the detection end of the angle sensor. The linkage gear meshes with the arc rack for transmission.

[0013] A method for using the above-mentioned variable-pressure high-pressure coal pillar microbial reaction in-situ NMR testing device includes the following steps: S1. Place the pretreated coal pillar sample in the reaction chamber, assemble the conical high-pressure sealing pair to complete the primary seal, and tighten the threaded sealing sleeve to form a double-layer high-pressure seal with the sealing pressure ring. S2. Connect the connector to the vacuum equipment, rotate the corresponding knob to open the channel, adjust the valve opening through the knob, and use the blocking structure to limit the valve stroke to prevent over-rotation and loss of control. The cooperation between the turntable and the limit rod realizes the mechanical interlock of the two valves to avoid gas leakage and liquid leakage during the test. Start the vacuum equipment to evacuate the reaction chamber and remove the internal air impurities. After the evacuation is completed, close the corresponding valve group. S3. Close valve group one of the connectors and connect the bacterial liquid equipment to connector two. Slowly open the valve and use the negative pressure of the chamber to quantitatively draw the prepared microbial liquid into the chamber. Control the injection volume. After the injection is completed, close the valve to maintain the chamber in a sealed and sterile state. S4. Connect the methane cylinder to connector one, slowly adjust the valve to fill with gas to prevent sudden changes in cavity pressure. Check the pressure through the high pressure gauge. After the pressure reaches the preset value, close the valve. Nitrogen can be filled through the valve to make the perfluororubber septum expand inward and squeeze the inner coal column, providing confining pressure and axial pressure to the coal column, simulating the formation conditions, and completing the sealed preparation of the sample. S5. Throughout the test, valve position and pressure data are collected by angle sensors and high-pressure gauges and uploaded to the terminal for storage. When the equipment identifies violations or abnormal operating conditions such as valve over-travel opening, double valve mis-opening, or abnormal fluctuations in cavity pressure, it triggers an audible and visual warning to remind operators to investigate and handle the situation in a timely manner. S6. Place the assembled device into the nuclear magnetic resonance spectrometer to complete in-situ nuclear magnetic resonance testing. After the test, depressurize step by step, disassemble the pipeline, clean and disinfect the cavity and channel, and reposition and tidy up to ensure that the equipment is clean and can be reused for testing.

[0014] The variable-pressure high-pressure coal pillar microbial reaction in-situ NMR testing device of this application adopts the above-mentioned technical solution and has the following advantages: 1. This invention features a multi-channel structure with vacuum and methane channels, bacterial liquid injection, and valve inflation, integrating vacuuming, bacterial liquid injection, and high-pressure inflation functions. During the experiment, the corresponding channel equipment can be connected sequentially to complete the cavity vacuuming, negative pressure bacterial liquid quantitative injection, high-pressure methane inflation, nitrogen inflation to provide confining pressure and axial pressure, realizing multi-process integrated continuous closed operation. Sample pretreatment, medium injection, and high-pressure preparation can be completed without repeated disassembly and reassembly of pipeline equipment, simplifying the experimental operation process, avoiding system contamination and experimental errors caused by repeated disassembly and reassembly, and improving the convenience of experimental operation and the repeatability of experimental data. 2. This invention features a conical high-pressure sealing pair combined with a threaded sealing sleeve and a sealing ring to form a double-sealing structure, replacing the traditional single-sealing method. During assembly, the conical high-pressure sealing pair is screwed on to complete the primary seal, and then the threaded sealing sleeve is tightened to drive the sealing ring to press the sealing contact surface, improving the overall sealing performance and pressure-bearing stability of the nuclear magnetic tube cavity. The entire process of vacuuming, bacterial solution injection, and high-pressure pressurization can maintain the cavity in a sealed state, eliminating the problems of gas leakage, media leakage, and external bacterial invasion during the test, ensuring the purity and stability of the coal pillar microbial reaction system, and improving the reliability and detection accuracy of the high-pressure reaction test. 3. This invention is equipped with a control valve assembly, a blocking and limiting structure, and a dual-valve interlocking limiting structure. Operators can adjust the valve opening using a knob, and the blocking structure limits the maximum rotation stroke of the valve. At the same time, relying on the dual-valve interlocking structure, the other channel is automatically locked when a single channel is open, avoiding gas leakage and sudden pressure changes caused by valve over-rotation or accidental opening of both valves. Throughout the test, valve position and pressure data can be collected in real time through an angle sensor and a high-pressure gauge. In case of abnormal conditions, an audible and visual warning is triggered, which facilitates timely troubleshooting and rectification by operators, ensuring a stable high-pressure microbial reaction environment and improving test safety and equipment controllability. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0016] Figure 2 This is a cross-sectional structural diagram of the present invention.

[0017] Figure 3 This is a schematic diagram of the knob structure of the present invention.

[0018] Figure 4 This is a schematic cross-sectional view of the mounting shell structure of the present invention.

[0019] Figure 5 This is a schematic diagram of the arc-shaped groove structure of the present invention.

[0020] In the diagram, 100 is the PEEK pressure-resistant NMR tube substrate; 101 is the internal reaction chamber; 102 is the perfluororubber septum; 103 is the support rod; 104 is the valve; 200 is the PEEK tee integrated connector substrate; 201 is the conical high-pressure sealing pair; 202 is the threaded sealing sleeve; 203 is the sealing pressure ring; 300 is the vacuum and methane injection channel; 301 is the bacterial solution injection channel; 302 is connector one; 303 is connector two; 304 is the high-pressure gauge; and 400 is the plug. Block; 401, connecting hole; 402, mounting shell; 403, knob; 404, fixed shaft; 405, L-shaped stop bar; 406, baffle; 407, stop seat; 408, arc-shaped rack; 409, conical screw; 410, angle sensor; 411, linkage gear; 412, linkage shaft; 413, arc-shaped groove; 414, arc-shaped slider; 500, turntable; 501, slot; 502, arc surface; 503, limit rod; 504, slider; 505, spring. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0022] Example 1: As Figures 1 to 5 As shown, the present invention provides a technical solution: a variable-pressure coal column microbial reaction in-situ NMR testing device, comprising a PEEK pressure-resistant NMR tube substrate 100 and a PEEK tee-connector substrate 200. The PEEK pressure-resistant NMR tube substrate 100 has an internal reaction chamber 101 for placing coal column samples and conducting microbial reactions. A perfluororubber spacer 102 and several support rods 103 are fixedly installed inside the internal reaction chamber 101. A valve 104 is fixedly installed on the outer surface of the PEEK pressure-resistant NMR tube substrate 100, and the valve 104 is connected to the internal reaction chamber 101. A conical high-pressure sealing pair is provided at the end of the PEEK tee-connector substrate 200. The 201 is threaded onto the PEEK pressure-resistant nuclear magnetic tube base 100 to achieve basic sealing of the tube opening. The PEEK tee integrated connector base 200 is equipped with a sealing structure, a vacuum and methane injection channel 300, a bacterial liquid injection channel 301, and a high-pressure gauge 304. The vacuum and methane injection channel 300 is equipped with a connector 1 302 at its end, and the bacterial liquid injection channel 301 is equipped with a connector 2 303 at its end, which are used to connect to external vacuum equipment, high-pressure methane gas source, and microbial liquid injection equipment, respectively. Both channels are equipped with control valve groups. An installation shell 402 is fixed on the outside of the channel. The installation shell 402 is equipped with a blocking structure and a limiting structure inside, which can realize valve opening adjustment, mechanical limit and dual valve interlocking functions.

[0023] The sealing structure includes a conical high-pressure sealing pair 201, a threaded sealing sleeve 202, and a sealing ring 203. The conical high-pressure sealing pair 201 is located at the end of the PEEK tee integrated connector base 200 and is connected to the inner conical thread at the end of the PEEK pressure-resistant nuclear magnetic tube base 100. The threaded sealing sleeve 202 is coaxially fitted on the outer circumference of the PEEK tee integrated connector base 200 and is threadedly engaged with the PEEK pressure-resistant nuclear magnetic tube base 100. The sealing ring 203 is installed inside the threaded sealing sleeve 202 and is pressed tightly against the outer wall of the conical high-pressure sealing pair 201 and the inner wall of the end of the PEEK pressure-resistant nuclear magnetic tube base 100, forming a double high-pressure sealing structure, which improves the overall pressure bearing capacity and sealing stability of the device and prevents air and liquid leakage during high-pressure testing.

[0024] The control valve assembly includes two sets of plugs 400, a connecting hole 401, a linkage shaft 412, and a knob 403. The two sets of plugs 400 are rotatably installed inside the vacuum and methane injection channel 300 and the bacterial liquid injection channel 301, respectively. The plugs 400 have connecting holes 401 that match the inner diameter of the channel. The flow rate and opening degree can be controlled by changing the channel cross-sectional area through rotation angle. The plugs 400 are rotatably assembled inside the mounting shell 402 through the linkage shaft 412. The knob 403 is fixed at the outer end of the linkage shaft 412, which is convenient for manual rotation to open and close the valve and adjust the valve opening degree.

[0025] Specifically, the mounting housing 402 is provided with arc-shaped grooves 413 on both sides. The position of the arc-shaped grooves 413 is consistent with the opening and closing stroke of the connecting hole 401. An arc-shaped slider 414 fixedly connected to the knob 403 is slidably installed inside the arc-shaped grooves 413. The rotation trajectory of the knob 403 is restricted by the sliding cooperation between the arc-shaped grooves 413 and the arc-shaped slider 414.

[0026] Example 2: Figure 3-5 As shown, in order to further improve the valve adjustment accuracy of the device, realize mechanical limit of opening, and angle data acquisition, avoid the problems of gas leakage and liquid leakage during the test, and ensure the safety and data accuracy of the high-pressure microbial reaction test, a blocking structure and an angle detection structure are added to the mounting shell 402.

[0027] The blocking structure includes a fixed shaft 404, an L-shaped stop bar 405, a baffle 406, a stop seat 407, an arc-shaped rack 408, and a conical screw 409. The fixed shaft 404 is fixed at the center of the knob 403. The end of the L-shaped stop bar 405 is connected to the baffle 406. The stop seat 407 is fixedly installed at the end of the mounting shell 402. The rotating baffle 406 and the stop seat 407 cooperate to form a limiting range, which rigidly blocks the rotation stroke of the L-shaped stop bar 405, thereby mechanically limiting the maximum opening of the valve. The arc-shaped rack 408 is fixed on the outside of the knob 403. The conical screw 409 is threaded onto the L-shaped stop bar 405. The tip of the conical screw 409 engages and locks with the arc-shaped rack 408, which can fix the initial angle of the L-shaped stop bar 405, so that the valve opening and closing range can be adjusted and locked, effectively preventing the uncontrolled inflation and liquid injection flow caused by valve over-rotation.

[0028] The angle detection structure includes an angle sensor 410 and a linkage gear 411. The angle sensor 410 is fixedly installed on one side of the stop 407. The linkage gear 411 is assembled at the detection end of the angle sensor 410. The linkage gear 411 meshes with the arc-shaped rack 408 for transmission. During the rotation of the knob 403, the arc-shaped rack 408 can be driven to rotate in real time. Through gear meshing, the valve rotation angle and actual opening are accurately fed back, realizing digital acquisition and monitoring of the valve position. The angle sensor 410 and the high-pressure gauge 304 are electrically connected to the control terminal. The control terminal is equipped with a data storage module and an audible and visual alarm, which can record pressure data and valve position data. When abnormal conditions such as abnormal pressure or valve overtravel occur, an audible and visual alarm is triggered to promptly remind the operator to check and handle the situation.

[0029] Example 3: As Figure 4-5 To achieve the dual-valve interlocking function to prevent misoperation and avoid the problem of valves being opened accidentally during the test, a limit structure was added.

[0030] The limiting structure includes a turntable 500, a slot 501, an arc surface 502, a limiting rod 503, a slider 504, and a spring 505. Two sets of turntables 500 are respectively fixedly sleeved on two linkage shafts 412. The turntable 500 is provided with a slot 501 and an arc surface 502. The limiting rod 503 is slidably assembled inside the mounting shell 402 through the slider 504 and the spring 505, and can slide elastically in both directions. When any one of the control valves is rotated open, the corresponding turntable 500 rotates and pushes the limiting rod 503 to slide through the arc surface 502, so that the limiting rod 503 is locked into the slot 501 of the other set of turntables 500, thereby mechanically locking the other valve and preventing it from rotating open.

[0031] A method for using a variable-pressure high-pressure coal pillar microbial reaction in-situ nuclear magnetic resonance testing device includes the following steps: S1. Place the pretreated coal column sample in the reaction chamber 101 inside the tube, assemble the conical high-pressure sealing pair 201 to complete the primary seal, and tighten the threaded sealing sleeve 202 to cooperate with the sealing pressure ring 203 to form a double-layer high-pressure seal. S2. Connect the vacuum equipment to the connector 302, rotate the corresponding knob 403 to open the channel, adjust the valve opening through the knob 403, and use the blocking structure to limit the valve stroke to prevent over-rotation and loss of control. The mechanical interlock of the two valves is achieved by the cooperation of the turntable 500 and the limit rod 503 to avoid gas leakage and liquid leakage during the test. Start the vacuum equipment to evacuate the reaction chamber 101 to remove the internal air impurities. After the evacuation is completed, close the corresponding valve group. S3. Close the valve group at connector 1 302 and connect the bacterial liquid equipment to connector 2 303. Slowly open the valve and use the negative pressure of the chamber to quantitatively draw the prepared microbial liquid into the chamber. Control the injection volume. After the injection is completed, close the valve to maintain the chamber in a closed and sterile state. S4. Connect the methane cylinder to connector 302 and slowly adjust the valve to fill the cylinder with gas to prevent sudden changes in pressure. Check the pressure through the high-pressure gauge 304. Once the pressure reaches the preset value (maximum 5MPa), close the valve. Nitrogen gas can then be introduced through the valve 104 to cause the perfluororubber septum 102 to expand inward and compress the inner coal pillar, providing confining pressure and axial pressure to the coal pillar to simulate geological conditions and complete the sealed preparation of the sample. S5. Throughout the test, valve position and pressure data are collected by angle sensor 410 and high pressure gauge 304 and uploaded to the terminal for storage. When the equipment identifies violations or abnormal operating conditions such as valve over-travel opening, double valve mis-opening, or abnormal fluctuation of cavity pressure, it triggers an audible and visual warning to remind the operator to investigate and handle the situation in a timely manner. S6. Place the assembled device into the nuclear magnetic resonance spectrometer to complete in-situ nuclear magnetic resonance testing. After the test, depressurize step by step, disassemble the pipeline, clean and disinfect the cavity and channel, and reposition and tidy up to ensure that the equipment is clean and can be reused for testing.

[0032] The working principle is as follows: The reaction chamber 101 inside the tube is divided into two spaces by a perfluororubber spacer 102. Several support rods 103 are set on the inner wall of the reaction chamber 101 inside the tube to support the perfluororubber spacer 102 during vacuuming. During the test assembly stage, the coal column sample to be tested is placed in the reaction chamber 101 inside the PEEK pressure-resistant nuclear magnetic tube base 100, so that it is located inside the perfluororubber spacer 102. The conical high-pressure sealing pair 201 is screwed into the PEEK pressure-resistant nuclear magnetic tube base 100 to complete the primary seal. Then, the threaded sealing sleeve 202 is rotated to push the internal sealing ring 203 to press between the conical high-pressure sealing pair 201 and the inner wall of the PEEK pressure-resistant nuclear magnetic tube base 100 to achieve a secondary seal and improve the overall pressure-bearing sealing effect. After the pipeline is connected, the corresponding gas supply and liquid supply equipment can be connected to the outside through connector 1 302 and connector 2 303 respectively.

[0033] During the test, the vacuum pump equipment pipeline is first connected to connector 302 at the end of the vacuum and methane injection channel 300. The corresponding high-pressure control valve group is then opened to evacuate the internal cavity of the PEEK pressure-resistant NMR tube substrate 100, removing residual air and eliminating interference from air impurities on the microbial reaction and NMR detection. During the evacuation process, the perfluororubber septum 102 will deform. Several support rods 103 are used to provide auxiliary support to prevent the perfluororubber septum 102 from completely collapsing. After the evacuation process is completed, the corresponding control valve group is closed to cut off the vacuum passage. Then, a sterile syringe containing microbial bacterial solution is connected to connector 303 at the end of the bacterial solution injection channel 301. The corresponding control valve group is slowly opened, and the bacterial solution is quantitatively injected into the reaction chamber 101 inside the tube using the negative pressure inside the cavity. The amount of bacterial solution injected is controlled. After the bacterial solution injection process is completed, the valve is closed again to ensure... The chamber is sealed throughout. Finally, the high-pressure methane cylinder pipeline is connected to the connector 302 of the vacuum and methane injection channel 300. The corresponding valve is slowly opened to fill the chamber with methane gas, allowing the perfluororubber septum 102 to recover. During the test, the pressure change inside the chamber is monitored in real time using the high-pressure gauge 304. The filling volume is adjusted according to the test gradient requirements. Once the internal pressure reaches the maximum test set value of 5 MPa, all valves are closed. Nitrogen gas can be filled into the reaction chamber 101 inside the tube through the valve 104. The nitrogen gas compresses the perfluororubber septum 102, causing it to expand inward and compress the inner coal column, providing confining pressure and axial pressure to the coal column, thus completing the sealed preparation of the entire test sample. The entire assembly is then directly placed into the nuclear magnetic resonance (NMR) probe for in-situ detection. After the test, the pressure can be released step by step, the pipeline components can be disassembled, and the pressure-resistant NMR tube and the inside of the pipeline can be cleaned and disinfected. The device can be reused for testing.

[0034] During the test, the pressure value inside the reaction chamber 101 can be continuously collected by the high-pressure gauge 304. The pressure state inside the chamber can be flexibly adjusted according to different test requirements to realize multi-gradient pressure variation test conditions, accurately simulate the microbial reaction conditions of coal pillar under different formation pressure environments, and upload the pressure data of the whole process to the control terminal in real time, providing complete data support for the recording, analysis and traceability of test pressure parameters.

[0035] During operation, rotating knob 403 drives the linkage shaft 412 and the plug 400 to rotate synchronously. Utilizing the fit between the connecting hole 401 inside the plug 400 and the inner diameter of the channel, the corresponding pipeline can be opened and closed, and its opening degree adjusted. This controls the vacuum extraction rate, methane pressurization rate, and bacterial solution injection flow rate, preventing sudden changes in flow rate that could cause abrupt changes in chamber pressure or bacterial solution impacting and disturbing the sample. As knob 403 rotates, the arc-shaped rack 408 rotates synchronously, meshing with and driving the linkage gear 411. This, in conjunction with the angle sensor 410, collects the valve rotation angle and opening status, determining the valve's fully open, fully closed, partially open, and overtravel rotation states. On the other hand, the L-shaped stop 405 is locked and limited by the conical screw 409. The L-shaped stop 405 can rotate together with the knob 403. With the help of the baffle 406, the stop seat 407, the arc groove 413 and the arc slider 414, the knob 403 is blocked and limited, which can limit the maximum rotation stroke of the knob 403, realize the mechanical limit of the valve opening, and prevent the valve from over-rotating or being opened too large, resulting in abnormal liquid injection and gas filling. Furthermore, by rotating the conical screw 409, it can be disengaged from the arc rack 408 through the threaded engagement with the L-shaped stop 405. The initial position of the L-shaped stop 405 can be adjusted by rotating it, thereby adjusting the valve opening and closing range.

[0036] When one valve group is rotated open, the linkage shaft 412 within it rotates, which in turn rotates the corresponding turntable 500 inside the mounting housing 402. The turntable 500 slides against the limiting rod 503 through the arc surface 502, causing the limiting rod 503 to insert into the slot 501 of the other turntable 500, locking the other valve group. When the current valve group rotates to reset and closes, the elastic reset action of the springs 505 on both sides causes the limiting rod 503 to disengage from the slot 501 and reset, realizing the mechanical interlock function of the two turntables 500. When any control valve is opened, the limiting rod 503 inserts into the other slot 501, automatically locking the other control valve and preventing it from rotating and opening. This prevents the violation of simultaneous operation of two channels, prevents cross-contamination and leakage during vacuuming, gas injection, and liquid injection processes, and ensures the airtightness, sterility, and pressure stability of the test system.

[0037] The valve position signal of the angle sensor 410 and the pressure signal of the high pressure gauge 304 are transmitted to the control terminal in real time. The data storage module records the pressure change data and valve operation status throughout the process. When violations or abnormal operating conditions such as valve over-travel opening, double valve mis-opening, or abnormal fluctuation of cavity pressure occur, the control terminal triggers the audible and visual alarm to issue a warning, reminding the operator to correct the operation in time and troubleshoot the abnormal pressure problem.

[0038] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A variable-pressure high-pressure coal pillar microbial reaction in-situ NMR testing device, characterized in that: The system includes a PEEK pressure-resistant NMR tube substrate (100) and a PEEK tee integrated connector substrate (200). The PEEK pressure-resistant NMR tube substrate (100) has an internal reaction chamber (101) for placing coal column samples and conducting microbial reactions. A perfluororubber spacer (102) and several support rods (103) are fixedly installed inside the internal reaction chamber (101). A valve (104) is fixedly installed on the outer surface of the PEEK pressure-resistant NMR tube substrate (100), and the valve (104) is connected to the internal reaction chamber (101). The PEEK tee integrated connector substrate (200) has a sealing structure and is connected to the PEEK pressure-resistant NMR tube substrate. The body (100) is sealed and connected; the PEEK three-way integrated connector base (200) is provided with a vacuum and methane injection channel (300), a bacterial liquid injection channel (301) and a high pressure gauge (304). The vacuum and methane injection channel (300) is provided with a connector one (302) at the end, and the bacterial liquid injection channel (301) is provided with a connector two (303) at the end, which are respectively used to connect to external vacuum equipment, methane high pressure gas source and microbial bacterial liquid injection equipment. Both channels are provided with control valve groups. The outside of the channel is fixed with an installation shell (402). The installation shell (402) is provided with a blocking structure and a limiting structure inside, which can realize valve opening adjustment, mechanical limit and double valve interlock function.

2. The variable-pressure high-pressure coal pillar microbial reaction in-situ NMR testing device according to claim 1, characterized in that: The sealing structure includes a conical high-pressure sealing pair (201), a threaded sealing sleeve (202), and a sealing ring (203). The conical high-pressure sealing pair (201) is located at the end of the PEEK tee integrated connector base (200) and is connected to the inner conical thread at the end of the PEEK pressure-resistant nuclear magnetic tube base (100). The threaded sealing sleeve (202) is coaxially fitted on the outer circumference of the PEEK tee integrated connector base (200) and is threadedly engaged with the PEEK pressure-resistant nuclear magnetic tube base (100). The sealing ring (203) is installed inside the threaded sealing sleeve (202) and is pressed tightly against the outer wall of the conical high-pressure sealing pair (201) and the inner wall at the end of the PEEK pressure-resistant nuclear magnetic tube base (100), forming a double high-pressure sealing structure.

3. The variable-pressure high-pressure coal pillar microbial reaction in-situ NMR testing device according to claim 1, characterized in that: The control valve assembly includes two sets of plugs (400), a connecting hole (401), a linkage shaft (412), and a knob (403). The two sets of plugs (400) are rotatably installed inside the vacuum and methane injection channel (300) and the bacterial liquid injection channel (301), respectively. The plugs (400) have connecting holes (401) that match the inner diameter of the channels. The plugs (400) are rotatably assembled inside the mounting housing (402) via the linkage shaft (412). The outer end of the linkage shaft (412) is synchronously rotated and connected to the knob (403) connected to the mounting housing (402).

4. The variable-pressure high-pressure coal pillar microbial reaction in-situ NMR testing device according to claim 3, characterized in that: The mounting shell (402) has arc-shaped grooves (413) on both sides. An arc-shaped slider (414) that is fixedly connected to the knob (403) is slidably installed inside the arc-shaped groove (413). The rotation trajectory of the knob (403) is restricted by the sliding cooperation between the arc-shaped groove (413) and the arc-shaped slider (414).

5. The variable-pressure high-pressure coal pillar microbial reaction in-situ NMR testing device according to claim 3, characterized in that: The limiting structure includes a turntable (500), a slot (501), an arc surface (502), a limiting rod (503), a slider (504), and a spring (505). Two sets of turntables (500) are fixedly sleeved on two linkage shafts (412). The turntable (500) is provided with a slot (501) and an arc surface (502). The limiting rod (503) is slidably assembled inside the mounting shell (402) through the slider (504) and the spring (505), and can slide elastically in both directions. When any one of the control valves is rotated and opened, the corresponding turntable (500) rotates and pushes the limiting rod (503) to slide through the arc surface (502), so that the limiting rod (503) is inserted into the slot (501) of the other set of turntables (500), thereby mechanically locking the other control valve.

6. The variable-pressure high-pressure coal pillar microbial reaction in-situ NMR testing device according to claim 1, characterized in that: The blocking structure includes a fixed shaft (404), an L-shaped stop bar (405), a baffle (406), a stop seat (407), an arc-shaped rack (408), and a conical screw (409). A fixed shaft (404) is fixedly set at the center of the knob (403), and an L-shaped stop bar (405) is rotatably sleeved on the fixed shaft (404); the end of the L-shaped stop bar (405) is connected to a baffle (406), and a stop seat (407) is fixedly set at the end of the mounting shell (402). The rotating baffle (406) and the stop seat (407) are mechanically limited; an arc-shaped rack (408) is fixed on the outside of the knob (403), and a conical screw (409) is threaded onto the L-shaped stop bar (405). The tip of the conical screw (409) meshes and locks with the arc-shaped rack (408).

7. The variable-pressure high-pressure coal pillar microbial reaction in-situ NMR testing device according to claim 6, characterized in that: The angle detection structure includes an angle sensor (410) and a linkage gear (411). The angle sensor (410) is fixedly installed on the upper end of the stop (407). The linkage gear (411) is assembled at the detection end of the angle sensor (410). The linkage gear (411) meshes with the arc rack (408) for transmission.

8. A method of using the above-mentioned variable-pressure high-pressure coal pillar microbial reaction in-situ NMR testing device, characterized in that, Includes the following steps: S1. Place the pretreated coal column sample in the reaction chamber (101), assemble the conical high-pressure sealing pair (201) to complete the primary seal, and tighten the threaded sealing sleeve (202) to cooperate with the sealing pressure ring (203) to form a double-layer high-pressure seal. S2. Connect the vacuum equipment to the connector (302), rotate the corresponding knob (403) to open the channel, adjust the valve opening through the knob (403), and use the blocking structure to limit the valve stroke to prevent over-rotation and loss of control. Relying on the cooperation of the turntable (500) and the limit rod (503) to achieve mechanical interlock of the double valve, avoid the problem of gas leakage and liquid leakage during the test. Start the vacuum equipment to evacuate the reaction chamber (101) and remove the internal air impurities. After the evacuation is completed, close the corresponding valve group. S3. Close the valve group at connector one (302) and connect the bacterial liquid equipment to connector two (303). Slowly open the valve and use the negative pressure of the cavity to quantitatively draw the prepared microbial liquid into the cavity. Control the injection volume. After the injection is completed, close the valve to maintain the cavity in a closed and sterile state. S4. Connect the methane cylinder to connector 1 (302), slowly adjust the valve to fill the cylinder with gas to prevent sudden changes in cavity pressure. Check the pressure through the high pressure gauge (304). After the pressure reaches the preset value, close the valve. Nitrogen gas can be filled through the valve (104) to make the perfluororubber septum (102) expand inward to squeeze the inner coal column, providing confining pressure and axial pressure to the coal column, simulating the formation conditions, and completing the sealed preparation of the sample. S5. Throughout the test, valve position and pressure data are collected by angle sensor (410) and high pressure gauge (304), uploaded to terminal storage, and the equipment triggers audible and visual warnings when it identifies violations or abnormal operating conditions such as valve over-extension opening, double valve mis-opening, and abnormal fluctuation of cavity pressure, reminding operators to investigate and handle them in a timely manner. S6. Place the assembled device into the nuclear magnetic resonance spectrometer to complete in-situ nuclear magnetic resonance testing. After the test, depressurize step by step, disassemble the pipeline, clean and disinfect the cavity and channel, and reposition and tidy up to ensure that the equipment is clean and can be reused for testing.

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