Fracture gas collection system

Abstract

This application relates to a rock fracture gas collection system, belonging to the field of rock mechanics experimental technology. It includes a pressure chamber; a medium loading chamber disposed within the pressure chamber, the medium loading chamber having a medium inlet and outlet; a heat-shrinkable sleeve disposed within the medium loading chamber, forming a sample loading space; a pressure head disposed within the medium loading chamber and connected to the first end of the heat-shrinkable sleeve, the pressure head having a first gas collection hole communicating with the medium loading chamber; a pressure base disposed within the medium loading chamber and connected to the second end of the heat-shrinkable sleeve, having a second gas collection hole communicating with the medium loading chamber; and a gas detection device, the gas detection device being connected to both the first and second gas collection holes. This application can completely capture gas parameters throughout the entire cycle from rock loading to fracture, and can reveal the law of rock stress fracture-gas release, providing reliable data support for tunnel gas hazard risk assessment, early warning, and the formulation of prevention and control measures, thereby improving the level of engineering safety.

Description

Technical Field

[0001] This application relates to the field of rock mechanics experimental technology, and in particular to a rock fracture gas collection system. Background Technology

[0002] The construction of long, deep-buried tunnels at high altitudes in plateau regions faces severe challenges from gas outburst hazards. These tunnels are located in areas with complex geological structures, influenced by intense tectonic movements and hydrothermal activity throughout geological history. During excavation, they frequently encounter harmful and asphyxiating gas outbursts. These gas outburst hazards are highly concealed and sudden, directly threatening the lives of construction workers, the operational safety of equipment, and the long-term stability of the tunnel structure. The key to accurate prevention and control of gas hazards lies in the real-time and accurate acquisition of gas composition and flow information during rock fracturing. Current technological shortcomings in real-time gas monitoring have become a core bottleneck restricting the effectiveness of disaster prevention and control. Existing experimental systems struggle to effectively collect, reliably seal, and identify the released gases without interference during the dynamic process of rock loading and fracturing. Common problems during experiments include oil leaks disrupting the gas collection environment, blockages affecting monitoring continuity, and changes or escape of gas components due to detection delays. These issues directly contribute to the inability to accurately capture key gas parameters at the moment of rock fracturing and throughout the entire process. Furthermore, while commonly used handheld multi-functional gas detectors offer advantages such as compact size and high detection efficiency, the data exhibits significant fluctuations, making it difficult to meet the rigorous requirements of subsequent data analysis and processing. This casts doubt on the scientific validity of the data, further complicating the accuracy of real-time gas monitoring and hindering the provision of timely and reliable technical support for tunnel gas hazard prevention and control. Summary of the Invention

[0003] This application provides a rock fracture gas collection system to solve the technical problems that existing experimental systems cannot accurately capture key gas parameters at the moment of rock fracture and throughout the entire process, and that commonly used handheld multi-function gas detectors monitor data with large fluctuations, which cannot provide timely and reliable technical support for tunnel gas disaster prevention and control.

[0004] This application provides a rock fracture gas collection system, comprising: Pressure chamber; A medium loading chamber is disposed within the pressure chamber, and the medium loading chamber is provided with a medium inlet and outlet; A heat shrink sleeve is disposed in the medium loading chamber, and a sample loading space is formed inside the heat shrink sleeve; A pressure head is disposed in the medium loading chamber and connected to the first end of the heat shrink sleeve. The pressure head is provided with a first air collection hole communicating with the medium loading chamber. A pressure seat, wherein the pressure seat is disposed within the medium loading chamber and connected to the second end of the heat shrink sleeve, the pressure seat having a second air collection hole communicating with the medium loading chamber; and A gas detection device, wherein the gas detection device is connected to the first gas collection port and the second gas collection port respectively.

[0005] In an optional embodiment, the pressure head has a first working surface, a first end of the first gas collecting hole extends to the first working surface, and one or more first gas collecting grooves communicating with the first gas collecting hole are also provided on the first working surface of the pressure head. The pressure base has a second working surface, the first end of the second gas collecting hole extends to the second working surface, and one or more second gas collecting grooves communicating with the second gas collecting hole are also provided on the second working surface of the pressure base.

[0006] In an optional embodiment, the rock fracture gas collection system further includes an air passage pad, which is attached to the first working surface of the pressure head and / or the second working surface of the pressure base. The air passage pad is provided with a plurality of air passage holes, which communicate with the first gas collection groove or the second gas collection groove.

[0007] In one alternative embodiment, the first end of the heat shrink sleeve is fitted over the outside of the pressure head and fixed by a first clamping ring; The second end of the heat shrink sleeve is fitted onto the outside of the pressure seat and fixed by the second hoop.

[0008] In an optional embodiment, a first sealing ring is provided between the heat shrink sleeve and the first clamping ring, and a second sealing ring is provided between the heat shrink sleeve and the second clamping ring.

[0009] In an optional embodiment, the medium loading chamber includes a base, on which an air passage is provided, and the outlet of the air passage is connected and communicates with the gas detection device; The first gas collecting hole and the second gas collecting hole are connected and communicated through a pipeline; The pressure seat is mounted on the base, and the second air collection hole is connected and communicates with the air inlet of the air passage.

[0010] In one optional embodiment, the gas detection device includes: Gas chromatograph; A first gas path, one end of which is connected to and communicates with the gas chromatograph, and the other end of which is connected to and communicates with the outlet of the gas passage, wherein a gas pressure gauge and a gas flow meter are connected in series on the first gas path; and The second gas path has one end connected to the gas chromatograph and the other end connected to the outlet of the gas passage. A micro gas pump is installed on the second gas path.

[0011] In an optional embodiment, the gas detection device further includes a gas phase data acquisition instrument, which is connected to the gas pressure gauge and the gas chromatograph, respectively.

[0012] In one alternative embodiment, the gas chromatograph is connected to a carrier gas cylinder, a hydrogen generator, and an air generator.

[0013] In an optional embodiment, the rock fracture gas collection system further includes a heating rod and a thermometer, both of which are disposed in the medium loading chamber.

[0014] The technical solutions provided in this application have the following advantages compared with the prior art: The rock fracture gas collection system provided in this application uses a heat-shrinkable sleeve in conjunction with an indenter and a pressure seat to create a closed sample loading space within the medium loading chamber. This prevents gas escape throughout the rock fracture process, ensuring a solid foundation for detection. Furthermore, the gas collection holes of the indenter and pressure seat directly connect the medium loading chamber and the detection device, forming a short-path transmission channel. This reduces the clogging problems of traditional complex flow paths, ensures continuous monitoring, shortens transmission time, and prevents changes in gas composition due to delays, achieving synchronized detection. Simultaneously, this application replaces traditional handheld detection with in-situ fixed monitoring, reducing operational errors and data jumps, improving the scientific rigor of the collected data, and meeting research and analysis needs. Relying on the synergy of multiple structures, the rock fracture gas collection system of this application can completely capture gas parameters throughout the entire cycle from rock loading to fracture, and can reveal the law of rock stress fracture-gas release. This provides reliable data support for tunnel gas hazard risk assessment, early warning, and the formulation of prevention and control measures, improving engineering safety. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0018] Figure 1 This is a schematic diagram of one embodiment of a rock fracture gas collection system provided in this application. Figure 2 This is a partial structural schematic diagram of the medium loading chamber provided in an embodiment of this application; Figure 3 A schematic diagram of one embodiment of the air-permeable pad provided in this application; Figure 4 This is a cross-sectional structural schematic diagram of one embodiment of the first gas collection tank provided in this application; Figure 5 yes Figure 4 A schematic diagram of the cross-sectional structure of the first gas collection trough.

[0019] Explanation of reference numerals in the attached figures: 100, Pressure chamber; 200, Medium loading chamber; 210, Medium inlet / outlet; 220, Base; 221, Air passage; 230, Heating rod; 240, Thermometer; 300, Heat shrink sleeve; 310, First hoop ring; 320, Second hoop ring; 330, First sealing ring; 340, Second sealing ring; 400, Pressure head; 410, First air collection hole; 420, First air collection groove; 500, Pressure base; 510, Second air collection hole; 520, Second air collection groove; 600, Air passage gasket; 610, Air passage hole; 7 00. Gas detection device; 710. Gas chromatograph; 711. Carrier gas cylinder; 712. Hydrogen generator; 713. Air generator; 720. First gas path; 721. Gas pressure gauge; 722. Gas flow meter; 730. Second gas path; 731. Miniature vacuum pump; 740. First three-way solenoid valve; 750. Second three-way solenoid valve; 760. Gas phase data acquisition instrument; 800. Pressure loading system; 810. Axial pressure loading system; 820. Confining pressure loading system; 830. TP coupling control system. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0022] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0023] To address the technical problems of existing experimental systems' inability to accurately capture key gas parameters during and throughout the rock fracture process, and the significant data fluctuations observed by commonly used handheld multi-functional gas detectors, which fail to provide timely and reliable technical support for tunnel gas hazard prevention and control, this application provides a rock fracture gas collection system. This system can comprehensively capture gas parameters throughout the entire cycle from rock loading to fracture, and can reveal the pattern of rock stress fracture and gas release. This provides reliable data support for tunnel gas hazard risk assessment, early warning, and the formulation of prevention and control measures, thereby improving engineering safety.

[0024] Figures 1-5 A rock fracture gas collection system provided in this application embodiment includes: Pressure chamber 100; The medium loading chamber 200 is located inside the pressure chamber 100, and the medium loading chamber 200 is provided with a medium inlet / outlet 210; Heat shrink sleeve 300 is installed inside medium loading chamber 200, and sample loading space is formed inside heat shrink sleeve 300. The pressure head 400 is disposed inside the medium loading chamber 200 and connected to the first end of the heat shrink sleeve 300. The pressure head 400 is provided with a first air collection hole 410 communicating with the medium loading chamber 200. Pressure seat 500, disposed within medium loading chamber 200 and connected to the second end of heat shrink sleeve 300, pressure seat 500 having a second air collection hole 510 communicating with medium loading chamber 200; and Gas detection device 700 is connected to the first gas collecting port 410 and the second gas collecting port 510 respectively.

[0025] Specifically, such as Figures 1 to 2 As shown, the pressure chamber 100 can be connected to multiple pressure loading systems 800. In this embodiment, the pressure chamber 100 is a triaxial pressure chamber 100, and is respectively connected to an axial pressure loading system 810 and a confining pressure loading system 820. The ends of the axial pressure loading system 810 and the confining pressure loading system 820 away from the pressure chamber 100 are connected to a TP coupling control system 830 (temperature-pressure coupling control system). Through the axial pressure loading system 810 and the confining pressure loading system 820, axial pressure and confining pressure can be provided to the sample through the triaxial pressure chamber 100, that is, to simulate vertical and lateral geostress. Compared with the limitations of traditional uniaxial loading, which can only simulate stress in a single direction, the rock fracture gas collection system of this application is more in line with the actual state of underground rocks subjected to multi-directional stress, laying the foundation for studying the gas release law of rock fracture under real geological conditions.

[0026] Simultaneously, the axial compression loading system 810 and the confining pressure loading system 820 can be linked in real time with the TP coupling control system 830 to precisely adjust their loading rates, magnitude ratios, and dynamic responses. This avoids the problems of asynchronous stress loading and stress field imbalance caused by traditional separate control, ensuring that the rock is stably stressed under the preset stress path and guaranteeing the consistency between the experimental process and actual geological stress changes. Furthermore, the TP coupling control system 830 can flexibly set different stress combinations, such as different axial compression-confining pressure ratios, enabling systematic research on the coupled effects of stress field parameters on rock fracture strength and gas release characteristics. This provides controllable experimental conditions for revealing the intrinsic relationship between stress, fracture, and gas release.

[0027] The medium can enter the medium loading chamber 200 through the medium inlet / outlet 210. As mentioned above, in this embodiment, the pressure chamber 100 is connected to the confining pressure loading system 820. Therefore, the confining pressure loading system 820 can inject hydraulic oil into the medium loading chamber 200 through the medium inlet / outlet 210. The injected hydraulic oil can fill the internal space of the medium loading chamber 200, providing a confining pressure environment that meets the testing requirements for the sample, thus realizing confining pressure loading and maintenance. Hydraulic oil has good fluidity, and after being injected into the medium loading chamber 200, it can evenly wrap the heat shrink sleeve 300 and the internal sample, avoiding the problem of uneven local pressure that is prone to occur in traditional rigid confining pressure devices. This makes the confining pressure on the rock closer to the lateral stress environment of the underground rock, ensuring the authenticity of the experimental conditions. In addition, during the hydraulic oil injection process, the TP coupling control system 830 can be used to achieve precise adjustment of the confining pressure magnitude and loading rate, meeting the experimental requirements under different geological conditions and breaking through the adjustment limitations of traditional fixed confining pressure devices.

[0028] The heat shrink sleeve 300 can be made of ultra-thin, high-temperature FEP (fluorinated ethylene propylene copolymer) or PFA (perfluoroalkoxyalkane). The ultra-thin heat shrink sleeve 300 can significantly reduce the interference of the thickness of the heat shrink sleeve 300 itself on the stress on the rock. Axial pressure and confining pressure can be efficiently transferred to the rock sample through the heat shrink sleeve 300, avoiding stress loss or uneven distribution caused by traditional thick-walled heat shrink sleeves 300, ensuring that the rock fractures under the preset stress path, which is closer to the actual stress and fracture process of underground rock strata.

[0029] The FEP and PFA heat shrink sleeves 300 are heat-resistant, capable of handling frictional heat generation during rock loading and fracturing or high-temperature experimental scenarios. This prevents the heat shrink sleeves 300 from softening, deforming, or even failing due to high temperatures. Simultaneously, under high-temperature environments, both materials maintain excellent shrinkage and sealing performance, preventing the escape of gases released from the rock through the gaps in the heat shrink sleeves 300, ensuring the integrity of gas collection. Furthermore, both materials possess strong chemical inertness, will not react with acidic, alkaline, or corrosive gases that may be released during rock fracturing, nor will they dissolve or contaminate the hydraulic oil in the medium loading chamber 200. This prevents material degradation products from mixing into the gas being tested, or oil contamination from affecting loading stability, ensuring the accuracy and reliability of the test results for parameters such as gas composition and concentration.

[0030] Of course, in situations where temperature requirements are not extreme, the heat shrink sleeve 300 can be replaced with a heat shrink sleeve 300 made of perfluoroether high-performance plastic. The upper temperature resistance limit of perfluoroether high-performance plastics is typically -50 to 150°C, therefore, in non-extreme temperature scenarios, it still possesses extremely strong chemical stability and does not react with corrosive gases released from rock fractures or the hydraulic oil in the hydraulic chamber of the media loading chamber 200. Furthermore, the production cost and processing difficulty of perfluoroether high-performance plastics are lower than those of PFA and FEP, which can reduce the cost of experimental consumables.

[0031] like Figures 1 to 2 As shown, within the medium loading chamber 200, the pressure head 400 and the pressure base 500 are arranged vertically in a corresponding manner. They are respectively tightly connected to the first and second ends of the heat shrink sleeve 300 to fix the position of the heat shrink sleeve 300 and the sample inside the heat shrink sleeve 300. The first gas collecting hole 410 penetrates the pressure head 400, and the second gas collecting hole 510 penetrates the pressure base 500. One end of both the first gas collecting hole 410 and the second gas collecting hole 510 communicates with the internal space of the medium loading chamber 200, while the other end extends to the outside of the pressure head 400 and the pressure base 500 and connects to the inlet pipe of the gas detection device 700.

[0032] The pressure head 400 and pressure base 500 can prevent sample leakage within the heat shrink sleeve 300 while providing a diffusion channel for the gas released from the rupture of the sample within the heat shrink sleeve 300. This released gas can diffuse freely and quickly enter the gas detection device 700 through the first gas collecting hole 410 and the second gas collecting hole 510. This shortens the time from gas release to detection, reduces compositional changes caused by prolonged gas residence, and ensures that the detection data accurately reflects the gas state during rock fracture. Furthermore, when pressure is applied by the axial compression loading system 810, the pressure head 400 transmits axial force downwards, while the pressure base 500 provides bottom support. Both components, through tight connection to both ends of the heat shrink sleeve 300, fix its position, preventing displacement, wrinkling, or deformation under pressure. This fixing effect maintains the fit between the heat shrink sleeve 300 and the rock sample, preventing new gaps from being created due to changes in the shape of the heat shrink sleeve 300, further ensuring the airtightness of the sample loading space, preventing gas leakage from the connection between the heat shrink sleeve 300 and the pressure head 400 / pressure base 500, and providing structural support for complete gas collection.

[0033] In addition, the first gas collecting hole 410 of the pressure head 400 corresponds to the top area of ​​the heat shrink sleeve 300, and the second gas collecting hole 510 of the pressure base 500 corresponds to the bottom area of ​​the heat shrink sleeve 300. Both are synchronously connected to the gas detection device 700, which can form a dual-path gas collecting mode. This mode can simultaneously capture the gas released from the top and bottom when the rock breaks, avoiding the problem that a single gas collecting hole can only collect local gas.

[0034] Before conducting the experiment, the rock samples were processed, and the sealing gaskets of the pressure chamber 100 and the medium loading chamber 200 were checked. Aged components were replaced in advance, and the sealing performance of the pressure chamber 100 and the medium loading chamber 200 was tested to ensure no leakage. The TP coupling control system 830 was calibrated, the range of axial pressure and confining pressure was set, and data matching was performed with the sensors of the axial pressure loading system 810 / confining pressure loading system 820 to control the error range. The gas detection device 700 was also calibrated.

[0035] The sample is placed inside the heat-shrink sleeve 300 to form a closed sample loading space. The assembled heat-shrink sleeve 300 and sample are then placed into the medium loading chamber 200. The top end of the heat-shrink sleeve 300 is tightly connected to the pressure head 400, and the bottom end is tightly connected to the pressure base 500. It is essential to ensure that the first gas collecting port 410 of the pressure head 400 and the second gas collecting port 510 of the pressure base 500 are aligned with the internal space of the medium loading chamber 200 to form a smooth gas transmission channel. After all checks are completed, the medium loading chamber 200 and pressure chamber 100 are closed. Hydraulic oil is injected into the medium loading chamber 200 through the medium inlet / outlet 210 until the hydraulic oil fills the medium loading chamber 200 and wraps around the heat-shrink sleeve 300. Subsequently, a loading experiment is conducted. Throughout the loading process, the gas detection device 700 simultaneously collects gas through the first gas collecting port 410 and the second gas collecting port 510.

[0036] This application directly connects the heat-shrink sleeve 300 to the gas detection device 700 via the first gas collecting port 410 of the pressure head 400 and the second gas collecting port 510 of the pressure base 500. This allows for the rapid transmission of gas released during rock fracture to the gas detection device, accurately capturing key information at the moment of rock fracture. This reduces the clogging problems of traditional complex flow paths, ensures continuous monitoring, shortens transmission time, avoids changes in gas composition due to delays, and achieves synchronized detection. Furthermore, this application replaces traditional handheld detection with in-situ fixed detection, reducing operational errors and data jumps, improving the scientific rigor of the collected data, and meeting the requirements of rigorous analysis. Based on the synergy of multiple structures, this application's rock fracture gas collection system can completely capture gas parameters throughout the entire cycle from rock loading to fracture, and can reveal the law of rock stress fracture-gas release. This provides reliable data support for tunnel gas hazard risk assessment, early warning, and the formulation of prevention and control measures, thereby improving engineering safety.

[0037] In some embodiments, the pressure head 400 has a first working surface, the first end of the first air collecting hole 410 extends to the first working surface, and one or more first air collecting grooves 420 communicating with the first air collecting hole 410 are also provided on the first working surface of the pressure head 400. The pressure seat 500 has a second working surface, the first end of the second air collecting hole 510 extends to the second working surface, and one or more second air collecting grooves 520 communicating with the second air collecting hole 510 are also provided on the second working surface of the pressure seat 500.

[0038] like Figures 3 to 5 As shown, the first working surface of the pressure head 400 refers to the side of the pressure head 400 facing the pressure base 500, and the second working surface of the pressure base 500 refers to the side of the pressure base 500 facing the pressure head 400. The first gas collecting groove 420 of the first working surface of the pressure head 400 and the second gas collecting groove 520 of the second working surface of the pressure base 500 can form a planar gas collecting channel at the working surface. Compared with relying only on the first gas collecting hole 410 and the second gas collecting hole 510 for point gas collecting, the gas collecting groove has a larger gas collecting area, which can accurately capture the gas released when the sample inside the heat shrink sleeve 300 breaks, ensuring that the gas in the sample breaking area is collected without dead corners.

[0039] Furthermore, the first gas collecting groove 420 and the second gas collecting groove 520 can serve as temporary gas collection chambers. Gas released from rock fracturing first enters the first gas collecting groove 420 and the second gas collecting groove 520, and then flows rapidly through the grooves to the connected gas collecting holes, preventing gas from stagnating in the gap between the working face and the heat shrink sleeve 300. Preferably, multiple first gas collecting grooves 420 and multiple second gas collecting grooves 520 are provided, and multiple first gas collecting grooves 420 and multiple second gas collecting grooves 520 can respectively capture gas parameters at different positions on the first working face and the second working face.

[0040] Preferably, the first gas collecting groove 420 and the second gas collecting groove 520 have the same structure, both including annular grooves, connecting grooves, and collecting grooves. Multiple annular grooves are provided, coaxially arranged with their diameters decreasing radially along the working surface, forming concentric circles that cover most of the working surface from the edge to near the center. Several connecting grooves are also evenly spaced along the circumference of the working surface. Each connecting groove is radially spaced and penetrates all annular grooves, connecting annular grooves of different diameters to form a radial flow channel. The collecting groove is circular or funnel-shaped, located at the center of the working surface. The inner ends of all connecting grooves connect to the collecting groove, and the collecting groove is directly connected to the first gas collecting hole 410 and the second gas collecting hole 510, ultimately forming a complete gas collection path.

[0041] Multiple concentric annular grooves are arranged radially to capture gas from different radial regions of the working face. The outer annular grooves can collect gas released from micro-cracks at the edge of the sample, while the inner annular grooves collect gas released from cracks near the center of the sample. Combined with the connecting grooves that run through all the annular grooves, the gas collection coverage area of ​​the working face can be effectively improved, achieving no dead angles from the edge to the center, and ensuring that gas from the entire radial range of rock fractures can be captured.

[0042] In some embodiments, the rock fracture gas collection system further includes an air passage pad 600, which is attached to the first working surface of the pressure head 400 and / or the second working surface of the pressure seat 500. The air passage pad 600 is provided with a plurality of air passage holes 610, which communicate with the first gas collection groove 420 or the second gas collection groove 520.

[0043] During rock fracturing, tiny rock fragments are generated. These fragments can directly enter the gas collection tank with the gas, and the gas collection holes are prone to accumulating and clogging at the corners of the tank or narrow areas, leading to interruption of gas transmission and loss of monitoring data. The vent holes 610 of the gas perforation pad 600 can act as a filter barrier, preventing rock fragments from entering the gas collection tank and allowing only gas to pass through. At the same time, rock fragments on the surface of the pad can be removed along with the gas perforation pad 600 after the experiment, eliminating the need to disassemble and clean the gas collection tank. This avoids damage to the gas collection structure due to improper cleaning and ensures long-term unobstructed gas collection channels.

[0044] In addition, when using the air passage pad 600, the air passage holes 610 of the air passage pad 600 need to be precisely aligned with the gas collection groove. This can guide the dispersed gas directionally into the annular groove, and then quickly converge into the collection groove through the connecting groove. The directional guiding effect of the air passage holes 610 increases the number of paths for the gas to enter the gas collection groove. At the same time, the uniform distribution of the air passage holes 610 can avoid local airflow congestion caused by excessive gas inflow into the gas collection groove from a single area, ensuring that the gas flows evenly along the annular groove and the connecting groove. This, combined with the global distribution structure of the gas collection groove, realizes a highly efficient gas transmission mode of distributed collection and directional convergence, providing a stable airflow for subsequent accurate detection.

[0045] In some embodiments, the first end of the heat shrink sleeve 300 is fitted over the outside of the pressure head 400 and fixed by the first clamping ring 310; The second end of the heat shrink sleeve 300 is fitted onto the outside of the pressure seat 500 and fixed by the second hoop 320.

[0046] like Figures 1 to 2 As shown, the top end of the heat shrink sleeve 300 is fitted along the outer wall of the pressure head 400, with the fitted area corresponding to the outer periphery of the pressure head 400 near the first working surface. The fitted length is controlled at 5-10 mm to ensure a tight fit between the inner wall of the heat shrink sleeve 300 and the outer periphery of the pressure head 400 without gaps. Then, the first clamping ring 310 is fitted onto the outer side of the fitted section of the heat shrink sleeve 300, and a pre-tightening force is applied evenly in the circumferential direction to press the heat shrink sleeve 300 onto the outer wall of the pressure head 400. Similarly, the bottom end of the heat shrink sleeve 300 can be fitted along the outer wall of the pressure seat 500, and the second clamping ring 320 is used to press the heat shrink sleeve 300 onto the outer wall of the pressure seat 500.

[0047] The circumferential fastening effect of the first hoop 310 and the second hoop 320 can firmly fix the heat shrink sleeve 300 on the pressure head 400 and the pressure seat 500. Even under axial pressure loading or confining pressure fluctuation, the elastic preload of the first hoop 310 and the second hoop 320 can compensate for the small shape of the heat shrink sleeve 300, always maintain a sealed state, and ensure that the collected gas enters the subsequent detection device in full.

[0048] Furthermore, due to the thinness of the heat shrink sleeve 300, direct contact with the metal edge of the pressure head 400 or pressure base 500 can easily cause edge damage due to loading friction, resulting in tiny debris mixing into the collected gas, interfering with gas component detection, and leading to concentration detection deviations. The wrapping fixation of the clamp ring can prevent tearing of the heat shrink sleeve 300 edge due to stress concentration, ensuring the structural integrity of the heat shrink sleeve 300, preventing material debris from contaminating the collected gas, and further improving the accuracy of gas detection data.

[0049] In some embodiments, a first sealing ring 330 is provided between the heat shrink sleeve 300 and the first clamping ring 310, and a second sealing ring 340 is provided between the heat shrink sleeve 300 and the second clamping ring 320.

[0050] Preferably, fluororubber sealing rings can be used. Fluororubber sealing rings have a wide temperature range, are resistant to oil, acids, alkalis, and most corrosive gases, and can be used in experimental scenarios with certain temperature fluctuations or contact with trace amounts of corrosive gases. Of course, when the experimental temperature requirements are not extreme and hydraulic oil is used as the confining pressure medium, nitrile rubber sealing rings can be used. Nitrile rubber sealing rings have good oil resistance and can balance sealing performance with cost-effectiveness.

[0051] like Figures 1 to 2 As shown, after the sealing ring is compressed by the pre-tightening force of the hoop, it can elastically fill the gap, forming a mechanical fixation by the hoop and a double protection of elastic sealing by the sealing ring. The deformation of both the fluororubber and nitrile rubber sealing rings can reach over 25%, completely sealing the gap, reducing the gas escape rate, further improving the integrity of gas collection, and ensuring that even trace amounts of gas are fully retained. The contact between the sealing ring and the heat shrink sleeve 300 is flexible, with no metal-to-metal friction wear, further ensuring the sealing integrity of the heat shrink sleeve 300 and preventing gas leakage due to damage to the heat shrink sleeve 300.

[0052] In some embodiments, the medium loading chamber 200 includes a base 220, on which an air passage 221 is provided, and the outlet of the air passage 221 is connected and communicates with the gas detection device 700. The first air collecting port 410 and the second air collecting port 510 are connected and communicated through a pipeline; The pressure seat 500 is set on the base 220, and the second air collection hole 510 is connected and communicates with the air inlet of the air passage 221.

[0053] Specifically, such as Figures 1 to 2 As shown, the pressure base 500 is fixed to the top surface of the base 220, and the bottom end of the second gas collecting hole 510 is connected to the air inlet of the air passage 221, forming a gas transmission path. Simultaneously, the outlet of the first gas collecting hole 410 of the pressure head 400 and the second gas collecting hole 510 of the pressure base 500 are sealed together via an oil-resistant and pressure-resistant connecting pipe, allowing the gas collected in the first gas collecting hole 410 to be directionally transported to the second gas collecting hole 510 through this connecting pipe. Finally, all the gas collected in the first and second gas collecting holes 410 converges at the second gas collecting hole 510 and is then transmitted together through the air passage 221 of the base 220 to the gas detection device 700.

[0054] In some embodiments, the gas detection device 700 includes: Gas chromatograph 710; A first gas path 720, one end of which is connected to and communicates with a gas chromatograph 710, and the other end of which is connected to and communicates with the outlet of a gas passage 221. A gas pressure gauge 721 and a gas flow meter 722 are connected in series on the first gas path 720; and The second gas path 730 has one end connected to and communicates with the gas chromatograph 710, and the other end connected to and communicates with the outlet of the gas passage 221. A miniature vacuum pump 731 is installed on the second gas path 730.

[0055] like Figures 1 to 2 As shown, when the pressure of the gas released from rock fracturing is high, the gas can flow naturally into the gas chromatograph 710 through the first gas path 720. At this time, the pressure in the flow path is recorded in real time by the gas pressure gauge 721, and the flow rate is monitored by the gas flow meter 722. When the pressure of the gas released from rock fracturing is low or the flow rate is very small, the miniature gas pump 731 of the second gas can actively extract the gas, overcome the problem of slow gas flow under low pressure, and ensure that the trace amount of gas will not be retained in the flow path and will be completely delivered to the gas chromatograph 710 for detection.

[0056] The dual-gas-path setup of the first gas path 720 and the second gas path 730 solves the limitations of traditional single-gas-path systems, which are prone to overload under high pressure and cannot detect low pressure. It can cover the gas release state throughout the entire cycle of rock fracture in the sample and improves the adaptability of detection.

[0057] Preferably, a first three-way solenoid valve 740 can be installed at the outlet of the gas passage 221. The three ports of the first three-way solenoid valve 740 can be respectively sealed to the outlet of the gas passage 221, the input end of the first gas path 720, and the input end of the second gas path 730 through sealing joints. The first three-way solenoid valve 740 can serve as a front-end distribution hub, selectively guiding the rock fracture gas collected in the gas passage 221 to the first gas path 720 or the second gas path 730 according to parameters such as gas release pressure and flow rate. It can also achieve preliminary diversion of the two gas paths in specific scenarios.

[0058] A second three-way solenoid valve 750 can also be installed at the gas inlet port of the gas chromatograph 710. The three ports of the second three-way solenoid valve 750 can be respectively sealed and connected to the output end of the first gas path 720, the output end of the second gas path 730, and the gas inlet of the gas chromatograph 710 through sealing connectors. The second three-way solenoid valve 750 can serve as a back-end distribution hub to receive and aggregate gases from a single or dual gas path, and then stably deliver them to the gas chromatograph 710.

[0059] When there is a specific analytical need for a particular gas, the gas chromatograph 710 can be replaced with a mass spectrometer.

[0060] In some embodiments, the gas detection device 700 further includes a gas phase data acquisition instrument 760, which is connected to a gas pressure gauge 721 and a gas chromatograph 710, respectively.

[0061] like Figure 1 As shown, the gas phase data acquisition instrument 760 is simultaneously connected to the gas pressure gauge 721 and the gas chromatograph 710, which can bind the two sets of data in real time through a unified timestamp. Combined with the TP coupling loading system, the time-series data obtained in the experiment are deeply fused and collaboratively analyzed. The integrated key parameters cover mechanical response indicators such as stress-strain, confining pressure, and oil bath temperature, as well as gas release characteristic indicators such as the concentration of each component gas, gas pressure, and instantaneous gas release rate. Based on the above data, a curve of gas release rate versus time can be constructed and superimposed on the rock stress-strain curve to form a mechanical-gas coupled response map. Simultaneously, it can analyze the total release of specific gases and their proportion in the total gas at different deformation stages, and determine the gas source based on characteristic gas ratios such as CO2 / CH4, CO2 / CO, and CO / H2. It analyzes the influence of important geochemical indicators such as organic matter pyrolysis, carbonate rock decomposition, magma degassing, and inclusion fracture, and performs rock gas source tracing to analyze the deep-seated causes of rock gas inrush in tunnels.

[0062] Furthermore, by combining regional chemical behavior characteristics, the release mechanisms of various gases are analyzed: for example, the pyrolysis of organic matter mainly releases hydrocarbon gases, primarily CH4, and may be accompanied by heavier hydrocarbons such as C2H6; the decomposition of carbonate rocks significantly releases CO2 under high-temperature conditions; magma degassing processes are often accompanied by the release of gases such as CO, H2, and SO2; and the fracturing of mineral inclusions may release various gaseous components sealed within them. A correspondence between gas genesis and geological processes is established, enabling the inference from experimental phenomena to geological source rocks. For example, if rocks mainly release CH4 during high-temperature, high-pressure fracturing, accompanied by a small amount of C2H6, and have a high dryness coefficient, it indicates that the hydrocarbon gases originate from the pyrolysis of organic matter. If CO2 is the main component and its release is significant at high temperatures, it indicates the combined effects of the thermal decomposition of carbonate minerals, mantle-derived geological processes, and inclusion fracturing. By systematically comparing the experimental gas release characteristics with the components and release patterns of gas outbursts in the field, the source rock type of tunnel gas outbursts and the geological conditions for gas generation and enrichment can be effectively verified, thus providing a quantitative and traceable scientific basis for the analysis of the formation mechanism of tunnel rock mass gas outbursts and the determination of gas sources.

[0063] In some embodiments, the gas chromatograph 710 is connected to a carrier gas cylinder 711, a hydrogen generator 712, and an air generator 713.

[0064] like Figure 1 As shown, the carrier gas cylinder 711 can use argon or helium as the carrier gas in the gas passage. The hydrogen generator 712 and the air generator 713 continuously produce hydrogen, oxygen and nitrogen as the carrier gas for the gas chromatograph 710. At the same time, oxygen can be used as a combustion accelerant and hydrogen can be used as fuel to detect flammable hydrocarbon gases, such as methane.

[0065] In some embodiments, the rock fracture gas collection system further includes a heating rod 230 and a thermometer 240, both of which are disposed within the medium loading chamber 200.

[0066] Heating rod 230 can be set at the bottom of medium loading chamber 200 to regulate the oil temperature of hydraulic oil in medium loading chamber 200 by electric heating. Temperature sensor 240 is set at intervals with heating rod 230 and is directly inserted into hydraulic oil to collect the internal temperature of medium loading chamber 200 in real time. Both are linked with TP coupling control system 830 to form a closed-loop temperature control system of heating-monitoring-feedback.

[0067] The heating rod 230 provides an adjustable temperature range within a certain range. Combined with the precise monitoring of the temperature sensor 240, it can provide real-time feedback on temperature deviations and trigger the start and stop of the heating rod 230. This accurately reproduces the ground temperature environment at different burial depths and better matches the actual field measurement data.

[0068] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0069] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0070] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A rock fracture gas collection system, characterized in that, include: Pressure chamber (100); A medium loading chamber (200) is disposed within the pressure chamber (100), and the medium loading chamber (200) is provided with a medium inlet / outlet (210). A heat shrink sleeve (300) is disposed inside the medium loading chamber (200), and a sample loading space is formed inside the heat shrink sleeve (300); A pressure head (400) is disposed in the medium loading chamber (200) and connected to the first end of the heat shrink sleeve (300). The pressure head (400) is provided with a first gas collecting hole (410) communicating with the medium loading chamber (200). Pressure seat (500), the pressure seat (500) is disposed in the medium loading chamber (200) and connected to the second end of the heat shrink sleeve (300), the pressure seat (500) is provided with a second air collection hole (510) communicating with the medium loading chamber (200). as well as A gas detection device (700) is connected to the first gas collecting hole (410) and the second gas collecting hole (510), respectively.

2. The rock fracture gas collection system according to claim 1, characterized in that, The pressure head (400) has a first working surface, and the first end of the first gas collecting hole (410) extends to the first working surface. The first working surface of the pressure head (400) is also provided with one or more first gas collecting grooves (420) that communicate with the first gas collecting hole (410). The pressure seat (500) has a second working surface, and the first end of the second gas collecting hole (510) extends to the second working surface. The second working surface of the pressure seat (500) is also provided with one or more second gas collecting grooves (520) that communicate with the second gas collecting hole (510).

3. The rock fracture gas collection system according to claim 2, characterized in that, The rock fracture gas collection system further includes an air passage pad (600), which is attached to the first working surface of the pressure head (400) and / or the second working surface of the pressure base (500). The air passage pad (600) is provided with a plurality of air passage holes (610), which are connected to the first gas collection groove (420) or the second gas collection groove (520).

4. The rock fracture gas collection system according to claim 1, characterized in that, The first end of the heat shrink sleeve (300) is fitted onto the outside of the pressure head (400) and fixed by the first hoop (310); The second end of the heat shrink sleeve (300) is fitted onto the outside of the pressure seat (500) and fixed by the second hoop (320).

5. The rock fracture gas collection system according to claim 4, characterized in that, A first sealing ring (330) is provided between the heat shrink sleeve (300) and the first hoop (310), and a second sealing ring (340) is provided between the heat shrink sleeve (300) and the second hoop (320).

6. The rock fracture gas collection system according to claim 1, characterized in that, The medium loading chamber (200) includes a base (220), on which an air passage (221) is provided, and the outlet of the air passage (221) is connected to and communicates with the gas detection device (700); The first gas collecting hole (410) and the second gas collecting hole (510) are connected and communicated through a pipeline; The pressure seat (500) is disposed on the base (220), and the second air collection hole (510) is connected and communicates with the air inlet of the air passage (221).

7. The rock fracture gas collection system according to claim 6, characterized in that, The gas detection device (700) includes: Gas chromatograph (710); A first gas path (720) is connected at one end to the gas chromatograph (710) and at the other end to the outlet of the gas passage (221). A gas pressure gauge (721) and a gas flow meter (722) are connected in series on the first gas path (720). The second gas path (730) is connected to the gas chromatograph (710) at one end and to the outlet of the gas passage (221) at the other end. A micro pump (731) is provided on the second gas path (730).

8. The rock fracture gas collection system according to claim 7, characterized in that, The gas detection device (700) also includes a gas phase data acquisition instrument (760), which is connected to the gas pressure gauge (721) and the gas chromatograph (710) respectively.

9. The rock fracture gas collection system according to claim 7, characterized in that, The gas chromatograph (710) is connected to a carrier gas cylinder (711), a hydrogen generator (712), and an air generator (713).

10. The rock fracture gas collection system according to claim 1, characterized in that, The rock fracture gas collection system also includes a heating rod (230) and a thermometer (240), both of which are located inside the medium loading chamber (200).

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