A coal underground gasification physical simulation device and method based on real rock mass

Abstract

This invention relates to the field of underground coal gasification simulation technology, and discloses a physical simulation device and method for underground coal gasification based on real rock mass. The device includes a rock mass with a coal chamber and a pressure loading chamber inside. The coal chamber is located above and connected to the pressure loading chamber. Multiple observation windows are provided on the rock mass, and these windows are connected to the coal chamber. The simulation components include a lifting mechanism and a furnace base. The lifting mechanism is located inside the pressure loading chamber, and a coal sample is placed on the furnace base. The lifting mechanism is used to lift the furnace base so that the coal sample extends into the coal chamber. The furnace base seals the coal chamber with a sealing element to form a furnace cavity. An experimental component is set on the furnace base for simulating the gasification of the coal sample within the furnace cavity. This invention enables physical simulation experiments of coal gasification under real rock mass, dynamically monitors the evolution of the gasification cavity, and provides physical experimental reference and basis for applications in medium-deep underground coal gasification projects.

Description

Technical Field

[0001] This invention relates to the technical field of underground coal gasification simulation devices, and in particular to a physical simulation device and method for underground coal gasification based on real rock masses. Background Technology

[0002] Underground coal gasification combines the advantages of fluidized bed mining and carbon emission reduction, which is of great significance for further releasing the potential of coal resources and optimizing the energy structure. A major challenge facing the commercialization of gasification projects is chamber stability. While a series of studies have been conducted on the stability and expansion characteristics of gasification chambers, most have explored the expansion characteristics through numerical simulations, with few physical simulations, and even fewer physical simulations of underground coal gasification based on real rock masses.

[0003] Conducting physical simulation experiments of underground coal gasification under realistic rock mass constraints can provide physical experimental references and basis for the application of underground coal gasification projects in medium and deep coal seams. However, existing physical simulation devices that consider the coal seam roof assume an extremely thin roof, which does not conform to real strata conditions. Furthermore, underground gasification physical simulation devices cannot achieve dynamic observation of cavity evolution, and the controlling factors, mechanisms, and control technologies for gasifier cavity expansion remain unclear. In addition, dynamic monitoring of cavity evolution during the gasification process under realistic roof rock mass constraints can not only study the impact of cavity expansion on roof rock mechanics and sealing properties, but also explore the controlling factors and technologies for cavity expansion.

[0004] Therefore, there is an urgent need for a physical simulation device and method for underground coal gasification based on real rock masses to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a physical simulation device and method for underground coal gasification based on real rock masses, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a physical simulation device for underground coal gasification based on real rock mass, comprising:

[0007] The rock mass has a coal seam chamber and a pressure loading chamber inside. The coal seam chamber is located above the pressure loading chamber and is connected to the pressure loading chamber. The rock mass is provided with multiple observation windows, which are connected to the coal seam chamber.

[0008] The simulation component includes a lifting mechanism and a furnace base. The lifting mechanism is located inside the pressure loading chamber. A coal sample is placed on the furnace base. The lifting mechanism is used to lift the furnace base so that the coal sample extends into the coal body chamber. The furnace base seals the coal body chamber with a sealing element to form a furnace cavity.

[0009] The test assembly, mounted on the furnace cavity substrate, is used to simulate the gasification of the coal sample within the furnace cavity.

[0010] According to the present invention, a physical simulation device for underground coal gasification based on real rock mass is provided. The lifting mechanism includes a base, which is located at the bottom of the pressure loading chamber. A section of several jacks is fixedly connected to the top of the base, and the other end of the jacks is fixedly connected to the bottom of the furnace chamber base.

[0011] According to the present invention, a physical simulation device for underground coal gasification based on real rock mass is provided. The test components include two ignition devices, several integrated devices, and several piston pressurization devices installed on the furnace chamber base.

[0012] Both the integrated device and the furnace cavity base are provided with several gasifying agent injection ports and several temperature / pressure measuring points.

[0013] The integrated device is equipped with a syngas outlet.

[0014] According to the present invention, a physical simulation device for underground coal gasification based on real rock mass is provided, wherein the integrated device is equipped with a fixed point for a three-dimensional laser scanning device.

[0015] According to the present invention, a physical simulation device for underground coal gasification based on real rock mass is provided, wherein the sealing element includes a first sealing ring and a sealing gasket fixedly connected to the furnace chamber substrate.

[0016] According to the present invention, a physical simulation device for underground coal gasification based on real rock mass is provided. The piston pressurization device includes a groove formed on the furnace cavity base. A pressure-bearing shaft is slidably connected in the groove. An injection port is provided at the bottom end of the groove. Dimethyl silicone oil is injected into the groove through the injection port to drive the pressure-bearing shaft to move.

[0017] According to the present invention, a physical simulation device for underground coal gasification based on real rock mass is provided, wherein a second sealing ring is provided on the pressure-bearing shaft.

[0018] According to the present invention, a physical simulation device for underground coal gasification based on real rock mass is provided, wherein an infrared glass is installed inside the observation window, and external monitoring equipment monitors the coal sample in the coal chamber through the observation window.

[0019] According to the present invention, a physical simulation device for underground coal gasification based on real rock mass is provided, wherein several temperature / pressure measuring points are set on the upper part of the coal body.

[0020] A physical simulation method for underground coal gasification based on real rock masses includes the following steps:

[0021] The coal sample is transported to the coal body bin by lifting the furnace chamber base through the lifting mechanism, and the coal body bin is sealed to form a furnace chamber.

[0022] After sealing, the furnace cavity is evacuated.

[0023] After vacuum treatment, the gasification of coal samples in the furnace cavity was simulated using experimental components;

[0024] After vaporization is completed, a three-dimensional laser scanning device is installed on the test assembly to scan the spatial structural features of the vaporization chamber and obtain test data.

[0025] Compared with the prior art, the present invention has the following advantages and technical effects:

[0026] This invention provides a physical simulation device and method for underground coal gasification based on real rock mass. The rock mass is real; a coal chamber, a pressure loading chamber, and an observation window are excavated on the rock mass. External equipment is placed at the observation window for observation and recording. A coal sample is placed on the furnace chamber base. A lifting mechanism lifts the furnace chamber base and transports the coal sample into the coal chamber. The furnace chamber base then seals the coal chamber to form a furnace chamber. A set experimental assembly is used to conduct a gasification simulation experiment on the coal sample, thereby realizing a physical simulation experiment of gasification. This invention achieves a physical simulation experiment of coal gasification under real rock mass and can dynamically monitor the evolution of the gasification chamber under the constraint of a real roof rock mass, providing physical experimental reference and basis for the application of underground coal gasification projects in medium and deep coal formations. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the overall structure of underground coal gasification based on real rock mass according to the present invention;

[0029] Figure 2 This is a schematic diagram of the physical simulation structure of the gasifier of the present invention;

[0030] Figure 3 This is a schematic diagram of the furnace cavity substrate structure of the present invention;

[0031] Figure 4 This is a schematic diagram of the piston pressurization device of the present invention;

[0032] Figure 5 This is a schematic diagram of the gasification route control structure of the present invention;

[0033] The components are: 1. Rock mass; 2. Coal body chamber; 3. Observation window; 4. Pressure loading chamber; 5. Base; 6. Jack; 7. Furnace chamber base; 8. Coal sample; 9. Scattered speckle array; 10. Temperature / pressure measuring point; 11. Ignition device; 12. Gasifying agent injection port; 13. Integrated device; 14. First sealing ring; 15. Piston pressurization device; 16. Syngas outlet; 17. Fixing point of three-dimensional laser scanning device; 18. Sealing gasket; 19. Injection port; 20. Dimethyl silicone oil; 21. Pressure bearing shaft; 22. Second sealing ring. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Reference Figures 1-5 This invention provides a physical simulation device for underground coal gasification based on real rock masses, comprising:

[0037] Rock mass 1 has a coal body chamber 2 and a pressure loading chamber 4 inside. The coal body chamber 2 is located above the pressure loading chamber 4 and is connected to the pressure loading chamber 4. Multiple observation windows 3 are provided on the rock mass 1 and are connected to the coal body chamber 2.

[0038] The simulation component includes a lifting mechanism and a furnace base 7. The lifting mechanism is located inside the pressure loading chamber 4. A coal sample 8 is placed on the furnace base 7. The lifting mechanism is used to lift the furnace base 7 so that the coal sample 8 extends into the coal body chamber 2. The furnace base 7 seals the coal body chamber 2 through a sealing element to form a furnace cavity.

[0039] The test assembly, set on the furnace cavity base 7, is used to simulate the gasification of coal sample 8 inside the furnace cavity.

[0040] In one embodiment of the present invention, the rock mass 1 is a real rock mass. A coal bunker 2, a pressure loading chamber 4, and an observation window 3 are excavated on the rock mass 1. External equipment is placed at the observation window 3 for observation and recording. A coal sample 8 is placed on the furnace base 7. The furnace base 7 is lifted by a set lifting mechanism and the coal sample 8 is transported into the coal bunker 2. The coal bunker 2 is sealed by the furnace base 7 to form a furnace cavity. A gasification simulation test is conducted on the coal sample 8 by a set test component, thereby realizing a gasification physical simulation test.

[0041] Specifically, a speckle array 9 is prepared using high-temperature resistant white paint on the contact surface between the coal body and the observation window 3, which serves as the observation anchor point for digital image processing technology.

[0042] As an optional implementation, the lifting mechanism includes a base 5, which is located at the bottom of the pressure loading chamber 4. A section of several jacks 6 is fixedly connected to the top of the base 5, and the other end of the jacks 6 is fixedly connected to the bottom of the furnace cavity base 7.

[0043] In one embodiment of the present invention, the jack 6 is preferably a CNC hydraulic jack with a pressure control accuracy of ±0.01MPa, used to support and lift the furnace base and coal sample 8, and to apply pressure to seal the furnace base and surrounding rock.

[0044] As an optional implementation, the test assembly includes two ignition devices 11, several integrated devices 13, and several piston pressurization devices 15 mounted on the furnace base 7.

[0045] Both the integrated device 13 and the furnace base 7 are provided with several gasifying agent injection ports 12 and several temperature / pressure measuring points 10;

[0046] The integrated device 13 is equipped with a synthesis gas outlet 16.

[0047] In one embodiment of the present invention, a gasifying agent is injected through the gasifying agent injection port 12 using an external gasifying agent injection device. Different gasifying agent injection pressures can be set according to the experimental scheme. Note that the reservoir pressure after injection is the injection pressure, which cannot exceed half of the sealing pressure provided by the jack 6. After the gasifying agent is injected, it is ignited by the ignition device 11. At the same time, the syngas is collected through the syngas outlet 16 and connected to an external filtration and collection device. The harmlessly treated syngas is directly discharged.

[0048] Specifically, the number of piston pressurization devices 15 is preferably 9, the number of integrated devices 13 is preferably 6, the number of temperature / pressure measuring points 10 is preferably 64, the number of gasifying agent injection ports 12 is preferably 18, and the number of synthesis gas outlets 16 is preferably 2.

[0049] As an optional implementation, the integrated device 13 is provided with a three-dimensional laser scanning device fixing point 17.

[0050] In one embodiment of the present invention, after the simulation test is completed, the integrated device 13 is removed, and a three-dimensional laser scanner is assembled at the fixed point 17 of the three-dimensional laser scanning device to characterize the three-dimensional features of the gasification space.

[0051] As an optional implementation, the seal includes a first sealing ring 14 and a sealing gasket 18 fixedly connected to the furnace cavity base 7.

[0052] In one embodiment of the present invention, the first sealing ring 14 is preferably a high-temperature resistant sealing ring used for initial sealing in the early stage of vaporization, with a temperature resistance of 1000℃. The sealing effect is ensured by the first sealing ring 14. The sealing gasket 18 is preferably made of copper and is used for ultra-high temperature sealing. Under high temperature conditions, copper softens and, together with external stress, achieves double sealing, further ensuring the sealing effect.

[0053] As an optional implementation, the piston pressurizing device 15 includes a groove formed on the furnace cavity base 7, a pressure bearing shaft 21 slidably connected in the groove, and an injection port 19 provided at the bottom end of the groove. Dimethyl silicone oil 20 is injected into the groove through the injection port 19 to drive the pressure bearing shaft 21 to move.

[0054] In one embodiment of the present invention, a constant speed and constant pressure pump is connected to the injection port 19 to pump in dimethyl silicone oil 20, and the injection pressure is controlled by a numerical control system to simulate formation pressure.

[0055] As an optional implementation, a second sealing ring 22 is provided on the pressure-bearing shaft 21.

[0056] In one embodiment of the present invention, the second sealing ring 22 is preferably a high-temperature resistant sealing ring. The second sealing ring 22 ensures the airtightness of the pressure-bearing shaft 21 and prevents the leakage of dimethyl silicone oil 20.

[0057] As an optional implementation, an infrared glass is installed inside the observation window 3, and external monitoring equipment monitors the coal sample 8 inside the coal bunker 2 through the observation window 3.

[0058] In one embodiment of the present invention, the observation window 3 is a cuboid with dimensions of 40*10*40cm, and is fitted with high-temperature resistant infrared glass of corresponding size. An infrared thermal imager is equipped on the outside to monitor the surface temperature array of the coal body during the gasification process. The infrared thermal imager has a temperature measurement range of 0-1500℃ and an accuracy of ±0.5℃.

[0059] Specifically, high-temperature resistant sealant and high-temperature resistant nano-cement are used to seal the observation window.

[0060] As an optional implementation, several temperature / pressure measuring points 10 are provided on the upper part of the coal bunker 2.

[0061] In one embodiment of the present invention, measurements are performed using several temperature sensors and pressure sensors. The temperature sensors have a measurement range of 0-1500℃ and an accuracy of ±0.5℃, while the pressure sensors have a range of 0-25MPa and an accuracy of ±0.5MPa.

[0062] A physical simulation method for underground coal gasification based on real rock masses includes the following steps:

[0063] The coal sample 8 is transported into the coal body 2 by lifting the furnace cavity base 7 through the lifting mechanism, and the coal body 2 is sealed to form a furnace cavity.

[0064] After sealing, the furnace cavity is evacuated.

[0065] After vacuum treatment, the gasification of coal sample 8 in the furnace cavity was simulated using experimental components;

[0066] After vaporization is completed, a three-dimensional laser scanning device is installed on the test assembly to scan the spatial structural features of the vaporization chamber and obtain test data.

[0067] This invention provides a physical simulation method for dynamic evolution observation of underground coal gasification cavities based on real rock masses. When using this method:

[0068] In the rock mass 1 section, where the structure is simple and there are no obvious cracks, a cave of appropriate size and an observation window 3 are constructed. At the same time, high-temperature resistant infrared glass is installed and sealed with high-temperature resistant sealant and high-temperature resistant nano cement.

[0069] Grind the inner and outer walls of coal bunker 2, apply a thin layer of nano high-temperature resistant cement, and then grind until smooth and flat, which is beneficial for sealing.

[0070] The raw coal was processed into four cube samples, each 50cm long, 50cm wide, and 50cm high and wide. The surfaces were polished smooth. Corresponding sensor probe holes were drilled according to the temperature and pressure measuring points on the furnace base 7.

[0071] The samples were placed sequentially on the furnace base 7 and assembled into a 100*100*50cm rectangular coal sample. At the same time, a high-temperature / pressure sensor was installed and adjusted accordingly to ensure that it could accurately reflect the temperature of each part of the coal body.

[0072] Control the jack 6 to slowly lift the furnace base 7 and the sample. The lifting speed is ≤10cm / min. When the furnace base 7 is about to contact the rock mass, the lifting speed is reduced to 10mm / min. The lifting is stopped at any time by monitoring the relative distance between the furnace base 7 and the lower part of the coal bunker 2.

[0073] Perform an airtightness check on the entire experimental system. Once the airtightness is confirmed, perform a vacuum process to remove any residual gas from the experimental system. The vacuum process should last for at least 2 hours.

[0074] After vacuum treatment, pressure loading is applied to simulate formation pressure. Dimethyl silicone oil 20 is pumped into piston pressurization device 15 simultaneously through an external constant speed and constant pressure pump. The pumping program is set to constant pressure mode, and the pumping pressure is the target formation pressure. The valve is closed after the target pressure is reached.

[0075] The experimental system records temperature and pressure data from various measurement points using a data logging system.

[0076] Using an external gasifying agent injection device, gasifying agent is injected through gasifying agent injection port 12. Different gasifying agent injection pressures can be set according to the experimental plan. Note that the reservoir pressure after injection is completed is the injection pressure, which cannot exceed half of the sealing pressure provided by jack 6.

[0077] After the vaporizing agent is injected, it is ignited by the ignition device 11. At the same time, real-time data and photos are recorded through the observation window by an external infrared thermal imager and a high-precision industrial camera for subsequent temperature and stress-strain analysis.

[0078] Ignition is completed by detecting the temperature near the ignition point. Once completed, the ignition device 11 is turned off. At the same time, the syngas is extracted and collected through the syngas outlet. The syngas is then connected to an external filtration and collection device. The syngas is discharged directly after being treated to be harmless.

[0079] During the gasification process, gas samples need to be taken at certain time intervals to analyze the composition and calorific value of the collected syngas.

[0080] During the gasification process, the expansion of the gasification chamber needs to be observed in real time through the observation window. When the height of the chamber reaches a certain limit, the gasifying agent injection port 12 on the furnace base 7 should be closed, and the same gasifying agent injection port 12 on the integrated device 13 should be opened to start injecting the same gasifying agent to guide the gasification path (gasification chamber expansion route). During this period, different gasifying agents can also be injected or the injection rate can be adjusted according to the experimental plan to explore their effects on the composition and yield of syngas. Subsequently, the opening and closing of the gasifying agent injection port should be controlled sequentially according to the experimental plan.

[0081] In the later stages of gasification, gradually reduce the injection of gasifying agent until the gasification reaction terminates;

[0082] After the gasification process is terminated and the temperature returns to normal, the integrated device 13 is removed in sequence, the gasification ash is collected for subsequent testing, and after sampling, a three-dimensional laser scanning device is installed to scan the spatial structural features of the gasification chamber.

[0083] After the structural features of the vaporization cavity are scanned, the vaporization experimental target is moved to the other side, and the steps are repeated.

[0084] Organize, process, and analyze the experimental data.

[0085] This invention controls the combustion process of coal by controlling the opening and closing of different syngas injection ports, thereby controlling the shape and size of the gasification cavity. Furthermore, it analyzes the effective range of temperature and thermal effects during the gasification process by monitoring temperature and pressure data, and collects syngas at different times to analyze its composition, yield, and calorific value, in order to explore the optimal gasification control process.

[0086] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0087] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A physical simulation device for underground coal gasification based on real rock mass, characterized in that, include: The rock mass (1) has a coal chamber (2) and a pressure loading chamber (4) inside. The coal chamber (2) is located above the pressure loading chamber (4) and is connected to the pressure loading chamber (4). The rock mass (1) is provided with multiple observation windows (3) and the observation windows (3) are connected to the coal chamber (2). The simulation component includes a lifting mechanism and a furnace base (7). The lifting mechanism is located inside the pressure loading chamber (4). A coal sample (8) is placed on the furnace base (7). The lifting mechanism is used to lift the furnace base (7) so that the coal sample (8) extends into the coal body chamber (2). The furnace base (7) seals the coal body chamber (2) with a sealing element to form a furnace cavity. The test assembly is set on the furnace cavity base (7) and is used to simulate the gasification of the coal sample (8) in the furnace cavity; The test assembly includes two ignition devices (11), several integrated devices (13), and several piston pressurization devices (15) installed on the furnace cavity base (7); several gasifying agent injection ports (12) and several temperature and pressure measuring points (10) are provided on the integrated devices (13) and the furnace cavity base (7); a synthesis gas outlet (16) is provided on the integrated devices (13); the piston pressurization device (15) includes a groove opened on the furnace cavity base (7), a pressure bearing shaft (21) is slidably connected in the groove, and an injection port (19) is provided at the bottom of the groove. Dimethyl silicone oil (20) is injected into the groove through the injection port (19) to drive the pressure bearing shaft (21) to move.

2. The physical simulation device for underground coal gasification based on real rock mass according to claim 1, characterized in that: The lifting mechanism includes a base (5), which is located at the bottom of the pressure loading chamber (4). A number of jacks (6) are fixedly connected to one end of the top of the base (5), and the other end of the jacks (6) is fixedly connected to the bottom of the furnace base (7).

3. The physical simulation device for underground coal gasification based on real rock mass according to claim 1, characterized in that: The integrated device (13) is provided with a three-dimensional laser scanning device fixing point (17).

4. The physical simulation device for underground coal gasification based on real rock mass according to claim 1, characterized in that: The sealing element includes a first sealing ring (14) and a sealing gasket (18) fixedly connected to the furnace cavity base (7).

5. The physical simulation device for underground coal gasification based on real rock mass according to claim 1, characterized in that: A second sealing ring (22) is provided on the pressure-bearing shaft (21).

6. The physical simulation device for underground coal gasification based on real rock mass according to claim 1, characterized in that: An infrared glass is installed inside the observation window (3), and external monitoring equipment monitors the coal sample (8) inside the coal body bunker (2) through the observation window (3).

7. The physical simulation device for underground coal gasification based on real rock mass according to claim 1, characterized in that: Several temperature and pressure measuring points (10) are set on the upper part of the coal body silo (2).

8. A physical simulation method for underground coal gasification based on real rock mass, applicable to the physical simulation device for underground coal gasification based on real rock mass as described in claim 1, characterized in that, Includes the following steps: The coal sample (8) is transported into the coal body bin (2) by lifting the furnace cavity base (7) through the lifting mechanism, and the coal body bin (2) is sealed to form a furnace cavity; After sealing, the furnace cavity is evacuated. After vacuum treatment, the coal sample (8) in the furnace cavity was simulated for gasification using experimental components; After vaporization is completed, a three-dimensional laser scanning device is installed on the test assembly to scan the spatial structural features of the vaporization chamber and obtain test data.

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