Microbial reactor for simulating in-situ coal seam stress and experimental method
By designing a microbial reactor that simulates the stress of in situ coal seam, using high-temperature and high-pressure stainless steel cavity walls and precise control system, the problem that existing reactors cannot simulate the stress environment of the coal seam is solved, a more accurate and stable experimental environment is achieved, and the progress of coalbed methane research and mining technology has been promoted.
Patent Information
- Application Number
- CN202411967402.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-04-25
AI Technical Summary
Existing microbial reactors cannot effectively simulate the complex stress environment that coal seams are subject to underground, and cannot apply and control the ground stress conditions, affecting the growth and metabolism of microorganisms.
A microbial reactor that simulates the stress of in situ coal seams is designed, using high-temperature and high-pressure stainless steel cavity walls, equipped with a lower pressure head and an upper pressure head, which can simulate a high-pressure environment in the laboratory, and accurately regulate the temperature and pressure through a temperature-controlled electrical heating sleeve and a water pressure sensor.
The reactor can perform microbial metabolism experiments under the simulated real coal seam stress environment, which improves the accuracy and reliability of the experiment and helps reveal the impact of stress on the pore structure and microbial activities of the coal seam.
Smart Images
Figure CN119875792A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of coal bed gas exploitation, in particular to a microbial reactor for simulating in-situ coal bed stress and an experimental method. Background Art
[0002] One of the major technical challenges facing my country's coal mining is to develop new mining methods that can effectively recover legacy coal resources and explore new mining methods for non-economically recoverable and deep coal resources under existing mining technology conditions. Existing research results have shown that in-situ bacterial communities or composite microorganisms cultivated by artificial directional domestication can gradually degrade coal into methane. Therefore, microorganisms can be used to convert coal into coalbed methane in situ for mining. The technical principle of microbial gasification of coal is to inject nutrient solution and microorganisms into coal seams, and use in-situ anaerobic fermentation to convert coal into coalbed methane, a new technology for mining. Microbial in-situ gasification of coal has broad application prospects in unmined legacy coal and in-situ coal seams.
[0003] In the laboratory, serum bottles are currently the main containers used to simulate microbial reactions in coal seams. They are widely used in anaerobic microbial experiments because of their high transparency, low cost, and ability to create a sealed anaerobic environment. However, the actual stress environment in coal seams also includes high pressure, and serum bottles are designed for experiments under normal pressure conditions. They cannot withstand high pressure or simulate the in-situ stress state of coal seams. In addition, serum bottles are fragile and difficult to withstand changes in pressure and temperature for a long time, and their ability to simulate complex environments is limited.
[0004] In order to more accurately simulate the in-situ stress environment in coal seams, it is necessary to develop a new type of microbial reactor that can simultaneously simulate the high-pressure environment in the laboratory, accurately control variables such as temperature and pressure, achieve an environment close to the actual coal seam, and ensure that anaerobic bacteria can metabolize normally to produce methane under high-pressure conditions. Summary of the invention
[0005] The purpose of the present invention is to solve the problem that the existing microbial reactor cannot effectively simulate the complex stress environment that coal seams are subjected to underground. Coal seams are subjected to ground stress underground. These stresses will affect the pore structure of coal, the adsorption and transmission process of gas, and thus have an important impact on the growth and metabolism of microorganisms. However, due to its structural limitations, the microbial reactor cannot apply and control these stress conditions. Therefore, this patent proposes a microbial reactor and experimental method for simulating in-situ coal seam stress, aiming to solve the bottleneck of insufficient pressure resistance of existing laboratory equipment, provide a more accurate and stable experimental environment, and promote the advancement of coalbed methane research and mining technology.
[0006] In order to achieve the above object, the present invention adopts the following technical solutions:
[0007] A microbial reactor for simulating in-situ coal seam stress, comprising a high temperature and high pressure resistant stainless steel chamber wall, the upper and lower ends of the high temperature and high pressure resistant stainless steel chamber wall are open, a lower pressure head is movably installed at the upper end of the high temperature and high pressure resistant stainless steel chamber wall, and an upper pressure head is movably installed at the lower end, the lower pressure head and the upper pressure head are respectively sealed with the inner wall of the high temperature and high pressure resistant stainless steel chamber wall, and the high temperature and high pressure resistant stainless steel chamber wall between the lower pressure head and the upper pressure head is used to load the coal sample;
[0008] The down pressure head is built with a down pressure head inner tube connected to the high temperature and high pressure resistant stainless steel cavity wall cavity, and the down pressure head is also provided with an external water inlet pipe, which is connected to the down pressure head inner tube;
[0009] The upper pressure head is internally provided with an upper pressure head inner tube connected to the high temperature and high pressure resistant stainless steel cavity wall cavity, and the upper pressure head is also provided with an external water outlet pipe, which is connected to the upper pressure head inner tube;
[0010] A gas-liquid separator is installed on the water outlet pipe, and the gas-liquid separator is provided with a gas outlet and a liquid outlet.
[0011] As a further preferred solution, the outer surface of the high temperature and high pressure resistant stainless steel cavity wall is provided with a temperature-controlled electric heating jacket, and the heating temperature of the temperature-controlled electric heating jacket is 10-100°C.
[0012] As a further preferred solution, one end of the inner tube of the pressure head on the surface of the pressure head is a shower-type water outlet nozzle, and the other end of the inner tube of the pressure head is connected to the water inlet pipe.
[0013] As a further preferred solution, a sealing ring is respectively provided at the contact point between the lower pressure head and the upper pressure head and the inner wall of the high temperature and high pressure resistant stainless steel cavity wall.
[0014] As a further preferred solution, a water pressure sensor connected to the interior is provided on the high temperature and high pressure resistant stainless steel cavity wall, and a water pressure gauge is provided at the end of the water pressure sensor.
[0015] As a further preferred solution, the top of the upper pressure head is the upper platform of the testing machine, a pressure sensor is arranged on the top of the upper platform of the testing machine, and the bottom of the lower pressure head is the lower platform of the testing machine.
[0016] As a further preferred solution, the nutrient solution and the microbial liquid enter the high temperature and high pressure resistant stainless steel cavity wall through the water inlet pipe.
[0017] An experimental method for a microbial reactor simulating in-situ coal seam stress comprises the following steps:
[0018] Step 1: Put a sealing ring on the lower pressure head, and clamp the lower opening of the high-temperature and high-pressure stainless steel chamber wall with the lower pressure head. After placing the coal sample in the cavity of the high-temperature and high-pressure stainless steel chamber wall, fix another sealing ring on the upper pressure head to ensure that the sealing ring completely enters the cavity to ensure the airtightness of the entire system. Then, install the temperature-controlled electric heating jacket on the outer surface of the high-temperature and high-pressure stainless steel chamber wall, and assemble the water pressure gauge and water pressure sensor on the outer side of the chamber wall;
[0019] Step 2: Fix the microbial reactor on the lower platform of the test machine, connect the gas-liquid separation device to the outlet pipe, start the temperature-controlled electric heating jacket, set the reaction temperature to 35°C to simulate conditions suitable for microbial metabolism, adjust the rising speed of the lower platform of the test machine, observe the pressure sensor reading, and stop pressurizing when the set pressure is reached to ensure that the coal seam samples in the experiment are in a simulated in-situ stress environment;
[0020] Step three: Nutrient solution and microbial solution are injected regularly through the valve of the water inlet pipe to ensure continuous reaction between the coal sample and the microorganisms. During the reaction, the gas-liquid separation device is used to collect the generated gas and liquid regularly to monitor gas production, track nutrient consumption and detect by-products, help optimize experimental conditions and ensure accurate and reliable data. During the experiment, pressure sensors and water pressure sensors monitor internal stress and water pressure changes in real time, and synchronize the data to the computer system for recording and analysis.
[0021] Beneficial Effects
[0022] The microbial reactor for simulating in-situ coal seam stress provided by the present invention uses a microbial conversion unit to provide a closed and stable reaction environment for coal samples and microorganisms, ensuring the efficient conduct of microbial metabolic processes and coalbed methane generation. The pressure control and monitoring unit can accurately apply and monitor axial stress in real time, simulate the stress state of the real coal seam, and reveal the influence of stress on the pore structure and microbial activity of the coal seam. The temperature control unit supports flexible temperature adjustment between 10°C and 100°C, and can simulate a gradient change environment to optimize the growth conditions of microorganisms. The water flow diffusion unit realizes isobaric injection of the entire cross section of the cavity, providing support for studying water transmission under stress conditions. The gas-liquid separation unit is used to efficiently separate and monitor the gas and liquid in the metabolites online, ensuring the accuracy and integrity of the experimental data. The device has the advantages of simple structure, wide coverage, simple operation, and strong controllability. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 A schematic diagram of the structure of a microbial reactor for simulating in-situ coal seam stress provided by the present invention;
[0024] Figure 2 for Figure 1 The enlarged schematic diagram at A in the middle;
[0025] Figure 3 Schematic diagram of the testing machine's test status. DETAILED DESCRIPTION
[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.
[0027] The present invention proposes a microbial reactor for simulating in-situ coal seam stress, which solves the above defects in the prior art. The device has a simple structure, a wide range of applications and strong controllability.
[0028] The present invention is composed of a microbial transformation unit, a pressure control and monitoring unit, a water flow diffusion unit, a temperature control unit and a gas-liquid separation unit;
[0029] like Figure 1 and 2 The microbial transformation unit is used for the reaction and metabolic cycle between the coal sample and the microorganisms. The microbial transformation unit includes an upper pressure head 2, a high-temperature and high-pressure stainless steel cavity wall 1, two sets of sealing rings 4 and a lower pressure head 3 which are connected in series from top to bottom. The outer surface of the upper pressure head 2 is provided with a water outlet pipe 6, the outer surface of the lower pressure head 3 is provided with a water inlet pipe 5, and the cavity of the high-temperature and high-pressure stainless steel cavity wall 1 is used to load the coal sample.
[0030] The high temperature and high pressure resistant stainless steel chamber wall 1 is made of stainless steel material and has good high pressure resistance, high temperature resistance and corrosion resistance. The upper and lower pressure heads are installed at both ends of the chamber wall through sealing rings to ensure the airtightness of the reaction environment; the structure with a smaller diameter of the upper half of the lower pressure head makes it impossible for the high temperature and high pressure resistant stainless steel chamber wall to move downward after clamping, and only the upper pressure head moves downward to apply pressure to the bioreactor, and the upper and lower platforms of the testing machine are adjusted by the electro-hydraulic servo universal testing machine to achieve accurate pressurization of the coal seam sample and simulate the axial stress of the coal seam.
[0031] like Figure 3 The pressure control and monitoring unit is used to provide and monitor the internal pressure of the reactor and simulate the in-situ stress environment. The pressure control and monitoring unit is arranged on the outer surface of the high temperature and high pressure resistant stainless steel cavity wall 1, and is equipped with a water pressure sensor 10 and a water pressure gauge 11 which can monitor the water pressure changes in the reaction cavity in real time. The water pressure gauge 11 monitors the water pressure changes in the cavity in real time. The difference between the pressure applied by the testing machine and the water pressure in the cavity is the actual pressure on the coal sample.
[0032] The water flow diffusion unit is a shower-type water outlet nozzle 12, which is equipped at the top of the down-pressure head. Through the uniformly distributed water flow injection, the uniform velocity injection of the entire section of the cavity is realized, simulating the water penetration process under different stress conditions, which is helpful to study the influence of stress on the water transmission of coal seams and the water utilization of microorganisms.
[0033] The temperature control unit is used to adjust the ambient temperature through the temperature-control electric heating sleeve to ensure that the microorganisms grow under suitable conditions. The temperature control unit is arranged on the outer surface of the high-temperature and high-pressure resistant stainless steel cavity wall 1, and is equipped with a temperature-control electric heating sleeve 13. The temperature-control electric heating sleeve 13 can be heated to 10-100°C, and the temperature-control electric heating sleeve 13 is connected to a power supply.
[0034] The gas-liquid separation unit is used to separate the gas and liquid generated by the reaction to improve the collection efficiency of the metabolic products. The gas-liquid separation unit includes a gas-liquid separator 14 externally connected to the water outlet pipe 6, and a gas outlet 15 and a liquid outlet 16 that can realize gas-liquid separation of the reaction products.
[0035] An upper testing machine platform 7 is arranged at the top of the upper pressure head 2 , a pressure sensor 8 is arranged at the top of the upper testing machine platform 7 , and a lower testing machine platform 9 is arranged at the bottom of the lower pressure head 3 .
[0036] The present invention is a microbial reactor for simulating in-situ coal seam stress, which accurately reproduces the real stress environment of the coal seam by applying axial pressure on the reactor. The key advantages of this reactor are: first, it can dynamically adjust the pressure to simulate the axial stress state of the underground coal seam; second, the reactor uses a high-pressure resistant alloy, which can withstand the high-pressure conditions of the simulated coal seam stress environment, so that the experimental results are closer to the generation and transmission laws of coal seam gas; finally, it can accurately control the temperature, pressure and liquid environment, so that the growth and metabolic conditions of microorganisms match the actual geological environment, thereby improving the reliability and accuracy of the experiment.
[0037] The experimental method of the microbial reactor for simulating in-situ coal seam stress comprises the following steps:
[0038] First, put a set of sealing rings 4 on the upper half of the lower pressure head 3, and clamp the lower opening of the high temperature and high pressure stainless steel chamber wall 1 with the lower pressure head 3. After placing the coal sample in the chamber wall 1, fix another set of sealing rings 4 on the upper pressure head 2 to ensure that the sealing rings completely enter the chamber to ensure the airtightness of the entire system. Next, install the temperature-controlled electric heating jacket 13 on the outer surface of the chamber wall 1, and assemble the water pressure gauge 11 and the water pressure sensor 10 on the outer side of the chamber wall 1;
[0039] Fix the microbial reactor on the lower platform 9 of the testing machine and connect the gas-liquid separation device 14 to ensure that the gas outlet 15 and the liquid outlet 16 are correctly connected to the reaction system. Start the temperature-controlled electric heating jacket 13 and set the reaction temperature to 35°C to simulate conditions suitable for microbial metabolism. Adjust the rising speed of the lower platform 9 of the testing machine through a hydraulic pump (not shown in the figure), observe the pressure sensor reading, and stop pressurizing when the set pressure is reached to ensure that the coal seam samples in the experiment are in a simulated in-situ stress environment;
[0040] Nutrient solution and microbial liquid are regularly injected through the water inlet pipe 5 to ensure continuous reaction between the coal sample and the microorganisms. During the reaction process, the gas-liquid separation device 14 is used to regularly collect the generated gas and liquid for monitoring gas production, tracking nutrient consumption and detecting by-products. It helps optimize experimental conditions, improve reaction efficiency and ensure accurate and reliable data. During the experiment, the pressure sensor 8 and the water pressure sensor 10 monitor the internal stress and water pressure changes in real time, and synchronize the data to the computer system for recording and analysis.
[0041] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.
Claims
1. A microbial reactor for simulating in-situ coal seam stress, comprising a high temperature and high pressure resistant stainless steel chamber wall (1), characterized in that: The upper and lower ends of the high temperature and high pressure resistant stainless steel chamber wall (1) are open, a lower pressure head (2) is movably mounted at the upper end of the high temperature and high pressure resistant stainless steel chamber wall (1), and an upper pressure head (3) is movably mounted at the lower end, the lower pressure head (2) and the upper pressure head (3) are respectively sealed with the inner wall of the high temperature and high pressure resistant stainless steel chamber wall (1), and the cavity of the high temperature and high pressure resistant stainless steel chamber wall (1) between the lower pressure head (2) and the upper pressure head (3) is used to load the coal sample; The pressure head (3) is internally provided with a pressure head inner tube connected to the cavity of the high temperature and high pressure resistant stainless steel cavity wall (1); the pressure head (3) is also provided with an external water inlet pipe (5), and the water inlet pipe (5) is connected to the pressure head inner tube; The upper pressure head (3) is internally provided with an upper pressure head inner tube connected to the cavity of the high temperature and high pressure resistant stainless steel cavity wall (1); the upper pressure head (3) is also provided with an external water outlet pipe (6), and the water outlet pipe (6) is connected to the upper pressure head inner tube; A gas-liquid separator (14) is installed on the water outlet pipe (6), and the gas-liquid separator (14) is provided with a gas outlet (15) and a liquid outlet (16).
2. A microbial reactor for simulating in-situ coal seam stress according to claim 1, characterized in that: The outer surface of the high temperature and high pressure resistant stainless steel cavity wall (1) is provided with a temperature-controlled electric heating sleeve (13), and the heating temperature of the temperature-controlled electric heating sleeve (13) is 10-100°C.
3. A microbial reactor for simulating in-situ coal seam stress according to claim 2, characterized in that: One end of the inner tube of the pressure head is a shower-type water outlet nozzle (12) on the surface of the pressure head (2), and the other end of the inner tube of the pressure head is connected to the water inlet pipe (5).
4. A microbial reactor for simulating in-situ coal seam stress according to claim 3, characterized in that: A sealing ring (4) is provided at each of the contact points between the lower pressure head (2) and the upper pressure head (3) and the inner wall of the high temperature and high pressure resistant stainless steel cavity wall (1).
5. A microbial reactor for simulating in-situ coal seam stress according to claim 4, characterized in that: The high temperature and high pressure resistant stainless steel cavity wall (1) is provided with a water pressure sensor (10) connected to the interior, and a water pressure gauge (11) is provided at the end of the water pressure sensor (10).
6. The microbial reactor for simulating in-situ coal seam stress according to claim 1, characterized in that: The top of the upper pressure head (2) is the upper platform (7) of the testing machine, a pressure sensor (8) is arranged on the top of the upper platform (7) of the testing machine, and the bottom of the lower pressure head (3) is the lower platform (9) of the testing machine.
7. The microbial reactor for simulating in-situ coal seam stress according to claim 1, characterized in that: The nutrient solution and the microbial liquid enter the high temperature and high pressure resistant stainless steel cavity wall (1) through the water inlet pipe (5).
8. The experimental method of a microbial reactor for simulating in-situ coal seam stress according to claim 5, characterized in that: The following steps are involved: Step 1: Put a sealing ring (4) on the lower pressure head (3), and clamp the lower opening of the high-temperature and high-pressure stainless steel chamber wall (1) with the lower pressure head (3). After placing the coal sample in the cavity of the high-temperature and high-pressure stainless steel chamber wall (1), fix another sealing ring (4) on the upper pressure head (2) to ensure that the sealing ring completely enters the cavity to ensure the airtightness of the entire system. Then, install the temperature-controlled electric heating sleeve (13) on the outer surface of the high-temperature and high-pressure stainless steel chamber wall (1), and assemble the water pressure gauge (11) and the water pressure sensor (10) on the outer side of the chamber wall (1); Step 2: Fix the microbial reactor on the lower platform (9) of the test machine, connect the gas-liquid separation device (14) to the outlet pipe (6), start the temperature-controlled electric heating jacket (13), set the reaction temperature to 35°C to simulate conditions suitable for microbial metabolism, adjust the rising speed of the lower platform (9) of the test machine, observe the reading of the pressure sensor (8), and stop pressurizing when the set pressure is reached to ensure that the coal seam sample in the experiment is in a simulated in-situ stress environment; Step 3: Nutrient solution and microbial liquid are injected regularly through the valve of the water inlet pipe (5) to ensure continuous reaction between the coal sample and the microorganisms. During the reaction, the gas-liquid separation device (14) is used to regularly collect the generated gas and liquid to monitor gas production, track nutrient consumption and detect by-products, help optimize experimental conditions and ensure accurate and reliable data. During the experiment, the pressure sensor (8) and the water pressure sensor (10) monitor the internal stress and water pressure changes in real time, and synchronize the data to the computer system for recording and analysis.