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

Abstract

The invention relates to the technical field of coal underground gasification simulation, and discloses a coal underground gasification physical simulation device and method based on a real rock mass, the coal underground gasification physical simulation device comprises a rock mass, a coal body bin and a pressure loading bin are arranged in the rock mass, the coal body bin is located above the pressure loading bin and is communicated with the pressure loading bin, and a plurality of observation windows are arranged on the rock mass. The observation window is communicated with the coal bunker; the simulation assembly comprises a lifting mechanism and a furnace chamber base, the lifting mechanism is located in the pressure loading bin, a coal sample is placed on the furnace chamber base, the lifting mechanism is used for lifting the furnace chamber base to enable the coal sample to extend into the coal body bin, and the furnace chamber base seals the coal body bin through a sealing piece to form a furnace chamber; and the test assembly is arranged on the furnace chamber base and is used for carrying out gasification simulation on the coal sample in the furnace chamber. According to the invention, a coal gasification physical simulation test under a real rock mass is realized, cavity evolution in the gasification process is dynamically monitored, and physical experiment reference and basis are provided for application of medium-deep coal underground gasification engineering.

Description

Technical Field

[0001] The invention relates to the technical field of underground coal gasification simulation devices, and in particular to an underground coal gasification physical simulation device and method based on real rock mass. Background Art

[0002] Underground coal gasification has the advantages of fluidized coal mining and carbon emission reduction, which is of great significance to further release the potential of coal resources and optimize the energy structure. A major problem facing the commercialization of gasification engineering is chamber stability. In related technologies, a series of studies have been conducted on the stability and expansion characteristics of the gasification chamber. Most of them explore the expansion characteristics of the chamber through numerical simulation, and few physical simulations are used. Physical simulations of underground coal gasification based on real rock mass are even rarer.

[0003] Conducting physical simulation experiments of underground coal gasification under the constraints of real rock mass can provide physical experimental references and basis for the application of medium-deep underground coal gasification projects. However, the physical simulation device for considering the coal seam roof in the prior art considers the roof to be extremely thin, which does not meet the actual formation conditions. At the same time, the underground gasification physical simulation device cannot realize the dynamic observation of cavity evolution, and the control factors, mechanisms and control processes of the gasifier cavity expansion are still unclear. In addition, considering the dynamic monitoring of cavity evolution during the gasification process under the constraints of real roof rock mass, it is possible to not only study the impact of cavity expansion on roof rock mechanics, sealing properties, etc., but also explore the control factors and technologies of cavity expansion.

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

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

[0006] To achieve the above object, 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] A rock mass, wherein a coal body bin and a pressure loading bin are provided inside, wherein the coal body bin is located above the pressure loading bin and is communicated with the pressure loading bin, and a plurality of observation windows are provided on the rock mass, wherein the observation windows are communicated with the coal body bin;

[0008] The simulation component includes a lifting mechanism and a furnace chamber base, wherein the lifting mechanism is located in the pressure loading bin, a coal sample is placed on the furnace chamber base, the lifting mechanism is used to lift the furnace chamber base so that the coal sample extends into the coal body bin, and the furnace chamber base seals the coal body bin through a sealing member to form a furnace chamber;

[0009] The test assembly is arranged on the furnace chamber base and is used for simulating the gasification of the coal sample in the furnace chamber.

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

[0011] According to a physical simulation device for underground coal gasification based on real rock mass provided by the present invention, the test assembly includes two ignition devices, several integrated devices and several piston pressurizing devices installed on the furnace chamber base;

[0012] The integrated device and the furnace chamber base are both provided with a plurality of gasifying agent injection ports and a plurality of temperature / pressure measuring points;

[0013] The integrated device is provided with a synthesis gas outlet.

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

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

[0016] According to a physical simulation device for underground coal gasification based on real rock mass provided by the present invention, the piston pressurizing device includes a groove opened on the base of the furnace chamber, a pressure-bearing shaft is slidably connected in the groove, and 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 physical simulation device for underground coal gasification based on real rock mass provided by the present invention, a second sealing ring is arranged on the pressure-bearing shaft.

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

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

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

[0021] The furnace chamber base is lifted by a lifting mechanism to transport the coal sample into the coal body bin, and the coal body bin is sealed to form a furnace chamber;

[0022] After the sealing is completed, the furnace chamber is vacuumed;

[0023] After vacuum treatment, the coal sample in the furnace chamber is gasified by the test assembly;

[0024] After the gasification is completed, a three-dimensional laser scanning device is installed on the test assembly to scan the spatial structural characteristics of the gasification cavity to obtain test data.

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

[0026] The present invention provides a physical simulation device and method for underground coal gasification based on real rock mass. The rock mass is real rock mass. A coal body bin, a pressure loading bin 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. The furnace chamber base is lifted by a provided lifting mechanism and the coal sample is transported into the coal body bin. The coal body bin is sealed by the furnace chamber base to form a furnace chamber. A gasification simulation test is performed on the coal sample by a provided test assembly, thereby realizing a physical simulation test of gasification. The present invention realizes a physical simulation test of coal gasification under real rock mass, and can dynamically monitor the cavity evolution of the gasification process under the constraint of real roof rock mass, providing a physical experimental reference and basis for the application of medium-deep underground coal gasification engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor:

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

[0029] Figure 2 It 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 base structure of the present invention;

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

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

[0033] Among them: 1. rock mass; 2. coal body bin; 3. observation window; 4. pressure loading bin; 5. base; 6. jack; 7. furnace chamber base; 8. coal sample; 9. speckle array; 10. temperature / pressure measuring point; 11. ignition device; 12. gasification agent injection port; 13. integrated device; 14. first sealing ring; 15. piston pressurizing device; 16. synthesis gas outlet; 17. three-dimensional laser scanning device fixing point; 18. sealing gasket; 19. injection port; 20. dimethyl silicone oil; 21. pressure-bearing shaft; 22. second sealing ring. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Reference Figure 1-Figure 5 The present invention provides a physical simulation device for underground coal gasification based on real rock mass, comprising:

[0037] A rock mass 1 is provided with a coal body bin 2 and a pressure loading bin 4, wherein the coal body bin 2 is located above the pressure loading bin 4 and is connected to the pressure loading bin 4, and a plurality of observation windows 3 are provided on the rock mass 1, and the observation windows 3 are connected to the coal body bin 2;

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

[0039] The test assembly is arranged on the furnace chamber base 7 and is used for simulating the gasification of the coal sample 8 in the furnace chamber.

[0040] In one embodiment of the present invention, the rock mass 1 is a real rock mass, and a coal body bin 2, a pressure loading bin 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 chamber base 7, and the furnace chamber base 7 is lifted by a provided lifting mechanism and the coal sample 8 is transported into the coal body bin 2. The coal body bin 2 is sealed by the furnace chamber base 7 to form a furnace chamber, and a gasification simulation test is performed on the coal sample 8 by the provided test assembly, thereby realizing a gasification physical simulation test.

[0041] Specifically, the contact surface between the coal body and the observation window 3 is made of high temperature resistant white paint to prepare a speckle array 9, which is used as an observation anchor point for digital image processing technology.

[0042] As an optional embodiment, the lifting mechanism includes a base 5, which is located at the bottom end of the pressure loading chamber 4. A section of a plurality of jacks 6 is fixedly connected to the top of the base 5, and the other end of the jack 6 is fixedly connected to the bottom end of the furnace chamber 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 ±0.01 MPa, which is used to support and lift the furnace chamber base and the coal sample 8 and to apply pressure to seal the furnace chamber base and surrounding rock.

[0044] As an optional embodiment, the test assembly includes two ignition devices 11, a plurality of integrated devices 13 and a plurality of piston pressurizing devices 15 mounted on the furnace chamber base 7;

[0045] The integrated device 13 and the furnace chamber base 7 are both provided with a plurality of gasifying agent injection ports 12 and a plurality of temperature / pressure measuring points 10;

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

[0047] In one embodiment of the present invention, the gasifier is injected through the gasifier injection port 12 with the aid of an external gasifier injection device. Different gasifier injection pressures can be set according to the experimental plan. Note that after the injection is completed, the reservoir pressure is the injection pressure, and the pressure cannot exceed half of the sealing pressure provided by the jack 6. After the gasifier is injected, it is ignited by the ignition device 11, and the synthesis gas is collected through the synthesis gas outlet 16. The synthesis gas is connected to an external filtering treatment and collection device, and the synthesis gas after harmless treatment is directly discharged.

[0048] Specifically, the number of piston pressurizing 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, a three-dimensional laser scanning device fixing point 17 is provided on the integrated device 13 .

[0050] In one embodiment of the present invention, after the simulation test is completed, the integrated device 13 is disassembled, and a three-dimensional laser scanner is assembled through the set three-dimensional laser scanning device fixing points 17 to characterize the three-dimensional characteristics of the gasification space.

[0051] As an optional implementation, the sealing member includes a first sealing ring 14 and a sealing gasket 18 fixedly connected to the furnace chamber 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 gasification, with a temperature resistance of 1000°C. The sealing effect is ensured by the setting of the first sealing ring 14. The sealing gasket 18 is preferably made of copper and used for ultra-high temperature sealing. Under high temperature conditions, copper becomes soft and double sealing is achieved with external stress to further ensure the sealing effect.

[0053] As an optional embodiment, the piston pressurizing device 15 includes a groove opened on the furnace chamber base 7, in which a pressure-bearing shaft 21 is slidably connected, and an injection port 19 is 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, the injection port 19 is externally connected to a constant speed and constant pressure pump, into which dimethyl silicone oil 20 is pumped, and the injection pressure is controlled by a numerical control system to simulate the 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 is provided to ensure the airtightness of the pressure bearing shaft 21 and prevent the dimethyl silicone oil 20 from leaking.

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

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

[0059] Specifically, the observation window is sealed using high temperature resistant sealant and high temperature resistant nano cement.

[0060] As an optional implementation, a plurality of temperature / pressure measuring points 10 are provided on the upper portion of the coal bin 2 .

[0061] In one embodiment of the present invention, the measurement is performed by a plurality of temperature sensors and pressure sensors, the temperature sensor has a measurement range of 0-1500°C and an accuracy of ±0.5°C, and the pressure sensor has a measurement range of 0-25MPa and an accuracy of ±0.5MPa;

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

[0063] The furnace chamber base 7 is lifted by the lifting mechanism to transport the coal sample 8 into the coal body bin 2, and the coal body bin 2 is sealed to form a furnace chamber;

[0064] After the sealing is completed, the furnace chamber is vacuumed;

[0065] After the vacuum treatment, the coal sample 8 in the furnace chamber is subjected to gasification simulation by the test assembly;

[0066] After the gasification is completed, a three-dimensional laser scanning device is installed on the test assembly to scan the spatial structural characteristics of the gasification cavity to obtain test data.

[0067] The present invention provides a physical simulation method for observing the dynamic evolution of an underground coal gasification cavity based on a real rock mass. When used:

[0068] A cave of corresponding size and an observation window 3 are constructed at a place where the rock mass 1 has a simple cross-section structure and no obvious cracks, and high-temperature resistant infrared glass is installed, and high-temperature resistant sealant and high-temperature resistant nano-cement are used for sealing;

[0069] Grind the inner and outer walls of the coal body bin 2, apply a thin layer of nano-high temperature resistant cement, and then grind them until they are smooth and flat, which is conducive to sealing;

[0070] The raw coal is processed into 4 cube samples with a length of 50 cm, a width of 50 cm, and a height of 50 cm. The surface is polished to be smooth and flat. The corresponding sensor holes are drilled according to the positions of the temperature and pressure measuring points on the furnace chamber base 7.

[0071] Place the samples on the furnace chamber base 7 in order and assemble them into 100*100*50cm rectangular coal samples. Install high temperature resistant temperature / pressure sensors and make corresponding adjustments to ensure that they can accurately reflect the temperature of each part of the coal body.

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

[0073] Check the air tightness of the entire experimental system. When the airtightness is intact, perform vacuum treatment to extract the residual gas in the experimental system. The vacuum treatment time should be ≥ 2 hours;

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

[0075] Record the temperature and pressure measurement point data of the experimental system through the data recording system;

[0076] The gasifying agent is injected through the gasifying agent injection port 12 by means of 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 the injection is completed is the injection pressure, which cannot exceed half of the sealing pressure provided by the jack 6;

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

[0078] By detecting the temperature near the ignition point, it is determined whether the ignition is completed. After completion, the ignition device 11 is turned off, and the syngas is extracted and collected through the syngas outlet, and the syngas is connected to an external filtering treatment and collection device, and the syngas after harmless treatment is directly discharged;

[0079] During the gasification process, gas sampling needs to be carried out at certain time intervals, and the collected syngas composition and calorific value need to be analyzed;

[0080] During the gasification process, the expansion of the gasification chamber needs to be observed in real time through the observation window. When the chamber height reaches a certain limit, the gasification agent injection port 12 on the furnace chamber base 7 should be closed, and the gasification agent injection port 12 on the integrated device 13 should be opened to start injecting the same gasification agent to guide the gasification path (gasification chamber expansion route). During this period, different gasification agents can also be injected or the injection speed can be adjusted according to the experimental arrangement to explore its effect on the composition and yield of the synthesis gas. The gasification agent injection port switch is subsequently controlled in sequence according to the experimental plan;

[0081] In the later stage of gasification, the injection of gasifying agent is gradually reduced until the gasification reaction is terminated;

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

[0083] After the gasification cavity structure feature scanning is completed, the gasification experimental target is replaced to the other side and the steps are repeated;

[0084] Organize experimental data and perform processing and analysis.

[0085] The present invention controls the combustion process of the coal body by controlling the switches of different synthesis gas injection ports, thereby controlling the shape and size of the gasification cavity, and analyzing the effective influence range of the temperature thermal effect in the gasification process by monitoring the temperature and pressure data. At the same time, the synthesis gas at different times is collected to analyze its composition, yield and calorific value, and to explore the optimal gasification control process.

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

[0087] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined 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: A rock mass (1) is provided with a coal body bin (2) and a pressure loading bin (4) inside, the coal body bin (2) is located above the pressure loading bin (4) and is connected to the pressure loading bin (4), and a plurality of observation windows (3) are provided on the rock mass (1), and the observation windows (3) are connected to the coal body bin (2); A simulation component, comprising a lifting mechanism and a furnace chamber base (7), wherein the lifting mechanism is located in the pressure loading chamber (4), a coal sample (8) is placed on the furnace chamber base (7), the lifting mechanism is used to lift the furnace chamber base (7) so that the coal sample (8) extends into the coal body chamber (2), and the furnace chamber base (7) seals the coal body chamber (2) through a sealing member to form a furnace chamber; The test assembly is arranged on the furnace chamber base (7) and is used to simulate the gasification of the coal sample (8) in the furnace chamber.

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

3. The physical simulation device for underground coal gasification based on real rock mass according to claim 1, characterized in that: The test assembly comprises two ignition devices (11), a plurality of integrated devices (13) and a plurality of piston pressurizing devices (15) mounted on the furnace chamber base (7); The integrated device (13) and the furnace chamber base (7) are both provided with a plurality of gasifying agent injection ports (12) and a plurality of temperature / pressure measuring points (10); The integrated device (13) is provided with a synthesis gas outlet (16).

4. The physical simulation device for underground coal gasification based on real rock mass according to claim 3 is characterized by: A three-dimensional laser scanning device fixing point (17) is provided on the integrated device (13).

5. The physical simulation device for underground coal gasification based on real rock mass according to claim 1 is characterized by: The sealing member comprises a first sealing ring (14) fixedly connected to the furnace chamber base (7) and a sealing gasket (18).

6. The physical simulation device for underground coal gasification based on real rock mass according to claim 3 is characterized by: The piston pressurizing device (15) comprises a groove formed on the furnace chamber base (7), a pressure-bearing shaft (21) being slidably connected in the groove, an injection port (19) being provided at the bottom end of the groove, and dimethyl silicone oil (20) being injected into the groove through the injection port (19) to drive the pressure-bearing shaft (21) to move.

7. The physical simulation device for underground coal gasification based on real rock mass according to claim 6, characterized in that: A second sealing ring (22) is provided on the pressure-bearing shaft (21).

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

9. The physical simulation device for underground coal gasification based on real rock mass according to claim 1, characterized in that: A plurality of temperature / pressure measuring points (10) are arranged on the upper part of the coal body bin (2).

10. A method for simulating underground coal gasification based on real rock mass, applicable to the device for simulating underground coal gasification based on real rock mass as claimed in claim 1, characterized in that: The following steps are involved: The furnace chamber base (7) is lifted by a lifting mechanism to transport the coal sample (8) into the coal body bin (2), and the coal body bin (2) is sealed to form a furnace chamber; After the sealing is completed, the furnace chamber is vacuumed; After the vacuum treatment, the coal sample (8) in the furnace chamber is subjected to gasification simulation by the test assembly; After the gasification is completed, a three-dimensional laser scanning device is installed on the test assembly to scan the spatial structural characteristics of the gasification cavity to obtain test data.

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