Joint changing device, coal underground gasification simulation device and use method

Abstract

The invention provides a joint changing device, a coal underground gasification simulation device and a use method of the coal underground gasification simulation device, and the joint changing device comprises an outer frame seat, a frame plate, an external pressure surrounding assembly and a hole plugging grouting assembly; the outer frame base is arranged on the outer side wall of the combustion chamber, a telescopic adjusting rod is arranged on the outer frame base, and the frame plate is arranged at the telescopic end of the telescopic adjusting rod; the external pressure surrounding assembly is annularly arranged on the inner side wall of the combustion chamber, the extrusion end of the external pressure surrounding assembly is sleeved with an annular filter screen, and one side of the external pressure surrounding assembly is fixedly connected with the frame plate through a fixing support; the hole blocking and grouting assemblies are evenly distributed on the frame plate, and the discharging ends of the hole blocking and grouting assemblies are located in the combustion chamber. According to the joint changing device, main body adjustment can be conducted on a coal sample in the combustion chamber preferentially through the external pressure surrounding assembly and the hole blocking and grouting assembly, so that the coal sample can restore geological coal to the maximum extent, coal changes under different ground pressures can be simulated, and the accuracy of coal underground gas simulation test results is improved.

Description

Technical Field

[0001] The present invention relates to coal gasification simulation equipment, and in particular to a variable seam device, an underground coal gasification simulation device and a method for using the underground coal gasification simulation device. Background Art

[0002] The main principle of underground coal gasification is to create appropriate process conditions underground to enable controlled combustion of coal, and to generate combustible gases such as hydrogen, carbon monoxide and methane through coal pyrolysis and a series of chemical reactions between coal, oxygen and water vapor. It is a basic method for exploring the theory of thermal physics and chemistry, which can objectively reveal the gasification laws and control mechanisms, and form the core technology for improving gasification rate and gasification efficiency.

[0003] Conventional underground coal gasification simulations often utilize large-scale coal gasification and combustion chambers. However, due to the difficulty in controlling coal sample fractures, it is difficult to simulate the changing underground stress environment, resulting in significant deviations in the results. Therefore, developing a device capable of simulating the changing underground stress environment is a pressing technical challenge for those skilled in the art. Summary of the Invention

[0004] In response to the above problems, the present invention proposes a variable joint device to solve the technical problem that the large-scale coal gasification and combustion chamber experimental equipment in the existing technology cannot simulate coal samples under the changing underground stress environment, resulting in large deviations in the coal underground gas experimental simulation results.

[0005] A variable joint device includes an external frame, a frame plate, an external pressure surrounding component and a hole plugging and grouting component;

[0006] The outer frame is fixedly arranged on the outer side wall of one end of the combustion chamber, the outer frame is provided with a telescopic adjustment rod, and the frame plate is arranged at the telescopic end of the telescopic adjustment rod;

[0007] The external pressure enclosure assembly is annularly arranged on the inner side wall of the combustion chamber, and an annular filter is sleeved on the extrusion end of the external pressure enclosure assembly. The annular filter is coaxially arranged with the external pressure enclosure assembly, and one side of the external pressure enclosure assembly is connected and fixed to the frame plate through a fixing bracket;

[0008] The hole-plugging grouting components are evenly distributed on the frame plate, the discharge end of the hole-plugging grouting components is located inside the combustion chamber, and the input end of the hole-plugging grouting components is connected to the output end of the injection pump.

[0009] In order to better realize the present invention, further optimization is made in the above structure. A guide rod is slidably provided on the external frame seat, and the sliding direction of the guide rod is parallel to the sliding direction of the external pressure enclosure assembly. The end of the guide rod close to the combustion chamber is connected and fixed to the frame plate.

[0010] In order to better realize the present invention, further optimization is made in the above structure, wherein the external pressure surrounding assembly includes an outer ring frame, an inner ring body and a pressure body;

[0011] The outer ring frame is slidably sleeved on the outside of the annular filter screen, and a reduction gear seat is provided on the outer ring frame;

[0012] The inner ring body is coaxially rotatable and arranged in the outer ring frame, and a plurality of inner telescopic struts are circumferentially distributed on the inner ring body, and the telescopic ends of the inner telescopic struts are hinged to the outer ring frame; the reduction gear seat is meshed with the inner ring body through gear meshing.

[0013] The pressing body is hinged to one end of the inner telescopic support rod away from the outer ring frame, and the pressing body is in close contact with the outer side wall of the annular filter.

[0014] In order to better realize the present invention, further optimization is made in the above structure, the hole plugging grouting assembly includes a sealing shaft tube, a ring sleeve body and an external injection delivery head;

[0015] The sealing shaft tube is rotatably mounted on the frame plate via an injection tube. The circumferential side wall of the sealing shaft tube is provided with an annular groove, and the groove is provided with a through hole A communicating with the interior of the sealing shaft tube. The end of the injection tube away from the sealing shaft tube is communicated with the injection pump via an external tube.

[0016] The annular sleeve is a double-layered tube structure, the annular sleeve is sleeved and fixed on the groove, the inner side wall of the annular sleeve is provided with a through hole B connected to the through hole A, and the outer side wall of the annular sleeve is provided with a plurality of injection holes;

[0017] The external injection delivery head is arranged in the sealing shaft tube, and the external injection delivery head is arranged close to one end of the sealing shaft tube away from the injection tube.

[0018] At the same time, the present invention also provides an underground coal gasification simulation device, which includes a mixed water and gas input system, a separator, a combustion chamber and the above-mentioned seam-changing device;

[0019] The seam changing device is arranged on the combustion chamber, and an ignition device for igniting the coal sample is arranged in the combustion chamber;

[0020] The gas outlet end of the mixed water and gas input system is communicated with the gas inlet end of the combustion chamber, and the gas outlet end of the combustion chamber is communicated with the gas inlet end of the separator.

[0021] In order to better realize the present invention, further optimization is made in the above structure, wherein the mixed water and gas input system includes a gas injection system, a steam injection system and a mixed preheating system;

[0022] The gas outlet end of the gas injection system and the gas outlet end of the steam injection system are both connected to the gas inlet end of the mixing preheating system, and the gas outlet end of the mixing preheating system is connected to the gas inlet end of the combustion chamber.

[0023] In order to better implement the present invention, further optimization is made in the above structure, wherein the gas injection system includes a manifold, an exhaust pipe and three intake pipes;

[0024] The three air inlet pipes are respectively connected to the pure oxygen supply equipment, the oxygen-enriched air supply equipment and the air supply equipment;

[0025] The manifold is arranged in the mixed preheating system, the outlet ends of the three air inlet pipes are all connected to the manifold, the air inlet end of the exhaust pipe is connected to the air outlet end of the manifold, the air outlet end of the exhaust pipe extends to directly below the air outlet end of the steam injection system, and the height of the air outlet end of the exhaust pipe is greater than the height of the air inlet end of the exhaust pipe.

[0026] In order to better realize the present invention, further optimization is made in the above structure, and the mixing preheating system includes a mixing tank, a mixing bin, an upflow bin, a discharge fan and a side discharge pipe;

[0027] The mixing bin is arranged in the mixing tank;

[0028] The upper flow bin and the exhaust fan are both arranged in the mixing bin, and the upper flow bin and the exhaust fan are respectively arranged close to the upper and lower ends of the mixing bin;

[0029] The upper flow bin is an inverted conical structure, the small end of the upper flow bin is provided with an exhaust port, the exhaust port is provided with a centrifugal guide vane, and the gas outlet end of the steam generator is connected to the upper flow bin;

[0030] The air inlet end of the side discharge pipe is communicated with the mixing chamber, and the air inlet end of the side discharge pipe is located on the side of the exhaust fan, the air outlet end of the side discharge pipe is communicated with the mixing tank, and the height of the air outlet end of the side discharge pipe is greater than the height of the air inlet end of the side discharge pipe;

[0031] The manifold is arranged in the mixing tank, and the gas outlet end of the exhaust pipe passes through the wall of the mixing tank and extends to just below the exhaust port.

[0032] In order to better realize the present invention, the above structure is further optimized. The air inlet pipe is provided with a pressure regulating valve, a flow controller and a one-way valve connected in sequence; the air outlet end of the one-way valve is connected to the manifold.

[0033] In order to better implement the present invention, further optimization is made in the above structure, wherein the steam injection system includes a flow pump and a steam generator;

[0034] The liquid inlet of the flow pump is communicated with the water supply equipment, the liquid outlet of the flow pump is communicated with the liquid inlet of the steam generator, and the gas outlet of the steam generator is communicated with the mixed preheating system.

[0035] In order to better realize the present invention, the above structure is further optimized. The gas outlet end of the separator is externally connected to a cooling tower, and the gas outlet end of the cooling tower is provided with a gas sample analyzer.

[0036] In order to better realize the present invention, further optimization is made in the above structure. An air flow disk is provided inside the combustion chamber. The air flow disk is located at one end of the combustion chamber away from the variable seam device. An adjustment disk is rotatably provided inside the air flow disk. A plurality of air vents are provided on the air flow disk and the adjustment disk.

[0037] In order to better implement the present invention, further optimization is made in the above structure, and an adjustment bracket for adjusting the inclination angle of the combustion chamber is provided at the bottom of the combustion chamber.

[0038] In order to better realize the present invention, further optimization is made in the above structure, and an air supply pipe for adding catalyst is provided between the mixed water and gas input system and the combustion chamber.

[0039] In addition, the present invention also provides a method for using the underground coal gasification simulation device, which is implemented by the above-mentioned underground coal gasification simulation device and includes the following steps:

[0040] S1: Using the mixed water and gas input system to mix and preheat air, oxygen-enriched air, pure oxygen and water vapor according to the required proportions, and then delivering the preheated mixed gas to the combustion chamber;

[0041] S2: The plugging and grouting components in the seam-changing device are used to fill the seams in the borehole of the coal sample, and the non-uniform gaps are filled with grouting slurry. Then, the external pressure enclosure component is used to apply radial external pressure to the coal sample to accurately simulate the deformation and permeability changes of the coal seam;

[0042] S3: igniting the coal sample in the combustion chamber using an ignition device;

[0043] S4: Record and measure the inlet pressure of the mixed water and gas input system, the inlet pressure of the combustion chamber, the outlet pressure of the combustion chamber, and the pressure inside the separator;

[0044] S5: Real-time collection of pressure, temperature, and flow parameters in the combustion chamber and calculation;

[0045] S6: Replace the coal sample and re-fill the seam, adjust the angle between the axis of the combustion chamber and the horizontal plane, and repeat steps S2-S5.

[0046] In summary, the present invention has at least the following technical effects:

[0047] The variable-seam device can use the external pressure enclosure component and the hole-plugging grouting component to preferentially adjust the main body of the coal sample in the combustion chamber. The adjustment content includes the coal sample cracks, internal temperature and pressure of the coal sample, so that the coal sample can maximize the restoration of the geological coal body, so as to simulate the changes of coal under different ground pressures, thereby improving the accuracy of the coal underground gas simulation test results.

[0048] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0050] Figure 1 A structural diagram of a variable seam device according to the present invention is shown;

[0051] Figure 2 It shows a structural schematic diagram of an external pressure surrounding component in a variable seam device of the present invention;

[0052] Figure 3 A schematic structural diagram of a hole plugging and grouting assembly in a seam-changing device according to the present invention is shown;

[0053] Figure 4 Shows a connection structure diagram of an underground coal gasification simulation device of the present invention;

[0054] Figure 5 A schematic structural diagram of a mixed water-gas input system in an underground coal gasification simulation device according to the present invention is shown;

[0055] Figure 6 A diagram showing the connection structure between the mixing preheating system and the combustion chamber in an underground coal gasification simulation device of the present invention is shown;

[0056] Figure 7 The internal structure diagram of the mixing preheating system in the underground coal gasification simulation device of the present invention is shown.

[0057] Markings in the figure:

[0058] 11. External frame; 111. Telescopic adjustment rod; 112. Guide rod; 12. Frame plate; 13. External pressure enclosure assembly; 131. External ring frame; 132. Inner ring body; 133. Shaft pressing body; 134. Inner telescopic support rod; 14. Hole plugging and grouting assembly; 141. Sealing shaft tube; 142. Ring sleeve body; 143. External injection delivery head; 15. Annular filter screen;

[0059] 2. Mixed water and gas input system; 21. Gas injection system; 211. Manifold; 212. Exhaust pipe; 213. Inlet pipe; 214. Pressure regulating valve; 215. Flow controller; 216. Check valve; 22. Steam injection system; 221. Flow pump; 222. Steam generator; 23. Mixed preheating system; 231. Mixing tank; 232. Mixing chamber; 233. Upflow chamber; 234. Exhaust fan; 235. Side exhaust pipe; 236. Centrifugal guide vane; 24. Air supply pipe;

[0060] 3. Separator;

[0061] 4. Combustion chamber; 41. Ignition device; 42. Airflow plate; 43. Adjustment plate; 44. Adjustment bracket;

[0062] 5. Cooling tower;

[0063] 6. Gas sample analyzer. DETAILED DESCRIPTION

[0064] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings 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 making creative efforts shall fall within the scope of protection of the present invention.

[0065] Example 1:

[0066] like Figures 1 to 3 As shown:

[0067] A variable seam device includes an external frame 11, a frame plate 12, an external pressure surrounding component 13 and a hole blocking component 14; wherein,

[0068] The outer frame 11 is fixedly mounted on the outer side wall of one end of the combustion chamber 4. A telescopic adjustment rod 111 is provided on the outer frame 11. The frame plate 12 is provided at the telescopic end of the telescopic adjustment rod 111 so as to drive the frame plate 12 to move toward or away from the combustion chamber 4.

[0069] The external pressure enclosure assembly 13 is annularly arranged on the inner side wall of the combustion chamber 4, and an annular filter 15 is sleeved on the extruded end of the external pressure enclosure assembly 13. The annular filter 15 is coaxially arranged with the external pressure enclosure assembly 13. One side of the external pressure enclosure assembly 13 is connected and fixed to the frame plate 12 via a fixing bracket, so that the external pressure enclosure assembly 13 can move together with the frame plate 12.

[0070] The hole plugging assembly 14 is evenly distributed on the frame plate 12 , the discharge end of the hole plugging assembly 14 is located inside the combustion chamber 4 , and the input end of the hole plugging assembly 14 is connected to the output end of the injection pump.

[0071] The variable seam device can utilize the external pressure enclosure component 13 and the hole plugging component 14 to preferentially adjust the main body of the coal sample in the combustion chamber 4. The adjustment content includes the coal sample cracks, the internal temperature and pressure of the coal sample, etc., so that the coal sample can maximize the restoration of the geological coal body, so as to simulate the changes of coal under different ground pressures, thereby improving the accuracy of the coal underground gas simulation test results.

[0072] It should be noted that during the grouting process of the plugging assembly 14, the cracks are filled in the coal body by grouting, and the telescopic end of the telescopic adjustment rod 111 drives the frame plate 12 from left to right (with Figure 1 The direction of the coal sample is taken as the standard), that is, the coal sample is adjusted from the deep position to the shallow position so that the coal sample can be fully filled internally;

[0073] In this embodiment, a plurality of boreholes are drilled in the coal sample, and each hole plugging assembly 14 is inserted into the borehole to continuously or intermittently grout the seams, and then the external pressure enveloping assembly 13 is used to provide an external radial extrusion force to simulate the changes in coal under ground pressure;

[0074] The main function of grouting is to fill the cracks in the coal sample to control the distribution of cracks in the coal body.

[0075] Optimized, a guide rod 112 is slidingly provided on the above-mentioned external frame seat 11, and the sliding direction of the guide rod 112 is parallel to the sliding direction of the external pressure enclosure assembly 13. The end of the guide rod 112 close to the combustion chamber 4 is connected and fixed to the frame plate 12 to limit the sliding direction of the frame plate 12 and the external pressure enclosure assembly 13, so that the movement of the frame plate 12 and the external pressure enclosure assembly 13 during the grouting process is more stable and smooth.

[0076] Optimized, the above-mentioned external pressure surrounding assembly 13 includes an outer ring frame 131, an inner ring body 132 and a pressure body 133, see Figure 2 ;in,

[0077] The outer ring frame 131 is slidably sleeved on the outside of the annular filter 15, and a reduction gear seat (not shown in the figure) is provided on the outer ring frame 131;

[0078] The inner ring body 132 is coaxially rotatably arranged in the outer ring frame 131, and a plurality of inner telescopic struts 134 are circumferentially distributed on the inner ring body 132. The telescopic ends of the inner telescopic struts 134 are hinged to the outer ring frame 131; the reduction gear seat is meshed with the inner ring body 132 through gear meshing.

[0079] The pressure body 133 is hinged at one end of the inner telescopic support rod 134 away from the outer ring frame 131, and the pressure body 133 is in close contact with the outer wall of the annular filter 15, that is, the inner ring body 132 can rotate so that each pressure body 133 can radially squeeze the coal sample through the inner telescopic support rod 134 to achieve central squeezing of the coal sample.

[0080] Optimized, the above-mentioned plugging assembly 14 includes a sealing shaft tube 141, a ring sleeve body 142 and an external injection head 143, see Figure 3 ;

[0081] The sealing shaft tube 141 is rotatably mounted on the frame plate 12 via the injection pipe. An annular groove is provided on the circumferential sidewall of the sealing shaft tube 141. The groove is provided with a through hole A that communicates with the interior of the sealing shaft tube 141. The end of the injection pipe away from the sealing shaft tube 141 is connected to the injection pump via an external pipe.

[0082] The annular sleeve 142 is a double-layered tube structure. The annular sleeve 142 is sleeved and fixed in the groove. The inner wall of the annular sleeve 142 is provided with a through hole B connected to the through hole A. The outer wall of the annular sleeve 142 is provided with multiple injection holes.

[0083] The external injection head 143 is arranged in the sealing shaft tube 141, and the external injection head 143 is arranged close to the end of the sealing shaft tube 141 away from the injection tube; during the grouting process, the slurry can be injected into the borehole through the external injection head 143. If the external injection head 143 is blocked, the slurry can enter the annular cavity of the annular sleeve body 142 through the through hole A and the through hole B in turn, and flow out from the multiple injection holes on the outer wall of the annular sleeve body 142 to the borehole in the coal sample to complete the filling of the slurry.

[0084] Example 2:

[0085] like Figures 1 to 7 As shown:

[0086] An underground coal gasification simulation device includes a mixed water and gas input system 2, a separator 3, a combustion chamber 4 and the joint device described in Example 1, see Figure 4 ;in,

[0087] The changing seam device is arranged on the combustion chamber 4. The combustion chamber 4 is provided with an ignition device 41 for igniting the coal sample. The ignition device 41 adopts an electric heating method. The ceramic column is subjected to instant high temperature by electric heating, so that the temperature of the ignition end of the ignition device 41 reaches 1800°C within 5 seconds, achieving the effect of instant high temperature ignition. The power of the ignition device 41 is 0.6KW. It uses heat-insulating refractory mud for heat insulation to improve the safety of the underground coal gasification simulator.

[0088] At the same time, an external circulating water jacket is provided on the side wall of the combustion chamber 4 to prevent high temperature, so as to further improve the safety of the underground coal gasification simulation device;

[0089] The air outlet of the mixed water and gas input system 2 is connected to the air inlet of the combustion chamber 4, and a mixed gas of oxygen, air and water vapor is input into the combustion chamber 4 through the mixed water and gas input system 2. The air outlet of the combustion chamber 4 is connected to the air inlet of the separator 3, and the separation of water and gas is completed through the separator 3.

[0090] Preferably, the combustion chamber 4 is divided into 10 groups of areas, and the 10 groups of areas are arranged along the length direction of the combustion chamber 4, see Figure 4 , so as to better measure the temperature of the coal sample in the combustion chamber 4, thereby obtaining more accurate temperature information (temperature information at different positions of the coal sample).

[0091] Optimally, the mixed water and gas input system 2 comprises a gas injection system 21, a steam injection system 22 and a mixed preheating system 23, see Figure 5 ;in,

[0092] The gas outlet of the gas injection system 21 and the gas outlet of the steam injection system 22 are both connected to the gas inlet of the mixing and preheating system 23, so that oxygen, air, oxygen-enriched air (oxygen content greater than 21% and less than 100%) and water vapor can be mixed and preheated in the mixing and preheating system 23;

[0093] The gas outlet of the mixing and preheating system 23 is connected to the gas inlet of the combustion chamber 4, so that the mixed and preheated mixed gas can directly enter the combustion chamber 4 and undergo relevant chemical reactions with the burning coal sample.

[0094] Preferably, the combustion chamber 4 is provided with an airflow disk 42, which is located at one end of the combustion chamber 4 away from the slit device. An adjusting disk 43 is rotatably provided in the airflow disk 42, and the airflow disk 42 is provided with a driving device for driving the adjusting disk 43 to rotate. A plurality of vents are provided on both the airflow disk 42 and the adjusting disk 43.

[0095] By rotating the regulating disk 43 through the driving device, the connection and stagger between the vent holes on the air flow disk 42 and the vent holes on the regulating disk 43 can be controlled to achieve control of the intake amount of the mixed gas.

[0096] Optimally, the gas injection system 21 includes a manifold 211, an exhaust pipe 212 and three intake pipes 213. Figure 5 ;in,

[0097] The three air inlet pipes 213 are respectively connected to the pure oxygen supply equipment, the oxygen-enriched air supply equipment and the air supply equipment;

[0098] The manifold 211 is arranged in the mixing preheating system 23, and the outlet ends of the three air inlet pipes 213 are all connected to the manifold 211, and the air inlet end of the exhaust pipe 212 is connected to the air outlet end of the manifold 211. The air outlet end of the exhaust pipe 212 extends to directly below the air outlet end of the steam injection system 22, and the height of the air outlet end of the exhaust pipe 212 is greater than the height of the air inlet end of the exhaust pipe 212, so that oxygen, air and oxygen-enriched air can be fully mixed with water vapor.

[0099] Preferably, the air inlet pipe 213 is provided with a pressure regulating valve 214, a flow controller 215 and a one-way valve 216 which are connected in sequence. The inlet pressure of the pressure regulating valve 214 is 20 MPa, the outlet pressure of the pressure regulating valve 214 is 0-10 MPa (adjustable), the working pressure of the flow controller 215 is 10 MPa, and the flow control range is 3 m 3 / h; the outlet end of the one-way valve 216 is connected to the manifold 211.

[0100] Optimized, the above-mentioned mixing preheating system 23 includes a mixing tank 231, a mixing chamber 232, an upper flow chamber 233, an exhaust fan 234 and a side exhaust pipe 235, see Figure 7 ;in,

[0101] The mixing chamber 232 is provided in the mixing tank 231;

[0102] The upper flow chamber 233 and the exhaust fan 234 are both disposed in the mixing chamber 232, and the upper flow chamber 233 and the exhaust fan 234 are disposed near the upper and lower ends of the mixing chamber 232, respectively.

[0103] The upper flow bin 233 is an inverted conical structure, that is, the large end of the upper flow bin 233 faces upward and the small end of the upper flow bin 233 faces downward. The small end of the upper flow bin 233 is provided with an exhaust port, and the exhaust port is provided with a centrifugal guide vane 236. The gas outlet end of the steam generator 222 is connected to the upper flow bin 233;

[0104] The air inlet end of the side exhaust pipe 235 is connected to the mixing chamber 232 and is located on the side of the exhaust fan 234. The air outlet end of the side exhaust pipe 235 is connected to the mixing tank 231. The height of the air outlet end of the side exhaust pipe 235 is greater than the height of the air inlet end of the side exhaust pipe 235.

[0105] The centrifugal guide vane 236 has a similar function to the exhaust fan 234 , and both are used to generate negative pressure inside the cavity to better deliver the water vapor into the mixing chamber 232 and the mixed gas into the mixing tank 231 ;

[0106] The manifold 211 is disposed in the mixing tank 231 , and the outlet end of the exhaust pipe 212 passes through the wall of the mixing chamber 232 and extends to just below the exhaust port to improve the mixing effect of oxygen, air, oxygen-enriched air and water vapor.

[0107] Optimally, the steam injection system 22 includes a flow pump 221 and a steam generator 222; wherein,

[0108] The liquid inlet of the flow pump 221 is connected to the water supply equipment, the liquid outlet of the flow pump 221 is connected to the liquid inlet of the steam generator 222 , and the gas outlet of the steam generator 222 is connected to the mixing preheating system 23 .

[0109] It should be noted that the working pressure of the flow pump 221 is 20 MPa, and the flow control range is 0-60 ml / min;

[0110] The above-mentioned steam generator 222 consists of a high-temperature furnace circulation pipe and a temperature control system. The circulation pipe connects the heating surface of the high-temperature furnace and the evaporation chamber of the steam generator 222, and is used to guide the working medium (usually water) inside the steam generator 222 into the high-temperature furnace for heating. The temperature control system is used to monitor and adjust the temperature of the steam generator 222. The working pressure of the steam generator 222 is 20 MPa, and the temperature control range is 80°C-200°C.

[0111] Optimally, the gas outlet end of the above-mentioned separator 3 is connected to a cooling tower 5, and a gas sample analyzer 6 is provided at the gas outlet end of the cooling tower 5. The temperature of the exhaust gas can be lowered by the cooling tower 5, and the exhaust gas is introduced into the gas sample analyzer 6 for analysis to determine whether the exhaust gas can be directly discharged into the atmosphere.

[0112] Optimally, the bottom of the combustion chamber 4 is provided with an adjustment bracket 44 for adjusting the inclination angle of the combustion chamber 4;

[0113] By adjusting the bracket 44, the angle between the axis of the combustion chamber 4 and the horizontal plane can be adjusted, thereby simulating the influence of different coal seam inclinations on gasification (compared with horizontal coal seams, the larger the inclination, the more likely it is that the coal body at the top of the gasification channel (i.e., the fracture channel in the coal sample) expands under high temperature, and after breaking, it is continuously filled in the gasification channel due to its own weight, thereby increasing the development of fractures in the coal body. Although part of the coal body may partially block the gasification channel, the impact is not significant, thereby expanding the permeability of the gasifying agent, increasing the reaction contact area, and promoting gasification).

[0114] Optimally, an air supply pipe 24 for adding catalyst is provided between the mixed water and gas input system 2 and the combustion chamber 4, see Figure 6 ;in,

[0115] By selecting the main flow gas (water vapor) and the subsequent mixed gas (pure oxygen, oxygen-enriched air, and air), the composition of the mixed gas can be precisely controlled while achieving a better mixing effect;

[0116] The main flow gas will drive the subsequent mixed gas during the flow process, making the mixing between the gases more uniform;

[0117] The flow rate of the main flow gas can be controlled by adjusting the flow pump 221 to control the overall gas flow speed and volume. At the same time, the flow rate of the subsequent mixed gas can also be adjusted (both are adjusted and controlled by the pressure regulating valve 214) to achieve the desired adjustment of gas flow characteristics, such as flow rate and flow direction, so as to simulate the effects of different gasifying agents and ratios on the synthesis gas yield and composition (the O2 supply determines the oxidation zone temperature and gasification intensity; the H2O supply determines the gasification rate; the O2 / H2O ratio affects the gasification chamber temperature distribution and gasification chamber morphology evolution, ultimately determining the gas production and component concentration; according to the calculation of the gasification gas component balance, it is believed that the oxygen-water ratio of 1:3-5 has the highest calorific value of the raw coal gas).

[0118] The air supply pipe 24 can transport catalysts (oxide catalysts, such as iron oxide, zinc oxide, etc., which participate in redox reactions during the gasification process; sulfide catalysts: such as iron sulfide, sodium sulfide, etc., which participate in sulfidation reactions during gasification), so as to simulate the gasification effects of adding different catalysts (the influence of catalyst concentration on the catalytic gasification effect of coal samples; the influence of catalyst type on the catalytic gasification of coal samples; the influence of coal type on the catalytic gasification effect of catalyst).

[0119] Example 3:

[0120] like Figures 1 to 7 As shown:

[0121] A method for using an underground coal gasification simulation device, the method being implemented by the underground coal gasification simulation device of Example 2, the method comprising the following steps:

[0122] S1: Using the mixed water gas input system 2, air, oxygen-enriched air, pure oxygen, and water vapor are mixed and preheated in the required ratio (1:3-5), and the preheated mixed gas is delivered to the combustion chamber 4. The ratio of air, oxygen-enriched air, pure oxygen, and water vapor can be adjusted by the flow controller 215. The temperature control range of the mixed water gas input system 2 is room temperature-200°C, and the heating power is 4KW.

[0123] S2: The plugging assembly 14 in the seam changing device is used to fill the seam in the borehole of the coal sample, and the non-uniform gaps are filled with a filling slurry. Then, the external pressure enveloping assembly 13 is used to apply radial external pressure to the coal sample to accurately simulate the deformation and permeability changes of the coal seam;

[0124] S3: Ignite the coal sample in the combustion chamber 4 using the ignition device 41; wherein, the combustion chamber 4 uses electric heating to instantly heat the ceramic column to 1800°C in 5 seconds, achieving the effect of instant high-temperature ignition. The combustion chamber 4 is divided into 10 groups for temperature measurement, including the temperature measurement of the mixing preheating system 23, the temperature measurement of the separator 3, and the temperature measurement of the cooling tower 5;

[0125] S4: Record and measure the inlet pressure of the mixed water and gas input system 2, the inlet pressure of the combustion chamber 4, the outlet pressure of the combustion chamber 4, the pressure inside the separator 3, and the pressure inside the cooling tower 5 to ensure that the underground coal gasification simulation device is always in normal operation;

[0126] S5: Real-time collection of pressure, temperature, and flow rate parameters in the combustion chamber 4 and calculation;

[0127] S6: Carry out multiple tests, replace the coal sample and re-fill the seam, and use the adjustment bracket 44 to adjust the angle between the axis of the combustion chamber 4 and the horizontal plane, and repeat the above steps S2-S5.

[0128] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A variable seam device, characterized in that: It comprises an external frame (11), a frame plate (12), an external pressure surrounding component (13) and a hole plugging and grouting component (14); The outer frame seat (11) is fixedly arranged on the outer side wall of one end of the combustion chamber (4); a telescopic adjustment rod (111) is arranged on the outer frame seat (11); and the frame plate (12) is arranged at the telescopic end of the telescopic adjustment rod (111); The external pressure enclosure component (13) is arranged in an annular manner on the inner wall of the combustion chamber (4), and an annular filter (15) is sleeved on the extrusion end of the external pressure enclosure component (13), and the annular filter (15) is coaxially arranged with the external pressure enclosure component (13), and one side of the external pressure enclosure component (13) is connected and fixed to the frame plate (12) through a fixing bracket; The hole-plugging grouting components (14) are evenly distributed on the frame plate (12), the discharge end of the hole-plugging grouting components (14) is located inside the combustion chamber (4), and the input end of the hole-plugging grouting components (14) is connected to the output end of the injection pump.

2. The variable seam device according to claim 1, characterized in that: A guide rod (112) is slidably provided on the outer frame seat (11), the sliding direction of the guide rod (112) being parallel to the sliding direction of the external pressure enclosure assembly (13), and one end of the guide rod (112) close to the combustion chamber (4) is connected and fixed to the frame plate (12).

3. The variable seam device according to claim 2, characterized in that: The external pressure enclosure assembly (13) comprises an outer ring frame (131), an inner ring body (132) and a shaft pressing body (133); The outer ring frame (131) is slidably sleeved on the outside of the annular filter (15), and a reduction gear seat is provided on the outer ring frame (131); The inner ring body (132) is coaxially rotatably arranged in the outer ring frame (131), and a plurality of inner telescopic struts (134) are circumferentially distributed on the inner ring body (132), and the telescopic ends of the inner telescopic struts (134) are hinged to the outer ring frame (131); the reduction gear seat is meshed with the inner ring body (132) through gear meshing. The pressing body (133) is hinged to one end of the inner telescopic support rod (134) away from the outer ring frame (131), and the pressing body (133) is in close contact with the outer side wall of the annular filter (15).

4. The variable seam device according to claim 3, characterized in that: The hole plugging and grouting assembly (14) comprises a sealing shaft tube (141), a sleeve body (142) and an external injection delivery head (143); The sealing shaft tube (141) is rotatably arranged on the frame plate (12) through an injection pipe, a circular groove is provided on the circumferential side wall of the sealing shaft tube (141), a through hole A communicating with the interior of the sealing shaft tube (141) is provided on the groove, and one end of the injection pipe away from the sealing shaft tube (141) is communicated with the injection pump through an external pipe; The annular sleeve (142) is a double-layered tube structure, the annular sleeve (142) is sleeved and fixed on the groove, the inner side wall of the annular sleeve (142) is provided with a through hole B communicating with the through hole A, and the outer side wall of the annular sleeve (142) is provided with a plurality of injection holes; The external injection delivery head (143) is arranged in the sealing shaft tube (141), and the external injection delivery head (143) is arranged close to one end of the sealing shaft tube (141) away from the injection tube.

5. An underground coal gasification simulation device, characterized in that: It comprises a mixed water-gas input system (2), a separator (3), a combustion chamber (4) and a slot-changing device according to any one of claims 1 to 4; The seam-changing device is arranged on the combustion chamber (4), and an ignition device (41) for igniting the coal sample is arranged in the combustion chamber (4); The gas outlet end of the mixed water gas input system (2) is communicated with the gas inlet end of the combustion chamber (4), and the gas outlet end of the combustion chamber (4) is communicated with the gas inlet end of the separator (3).

6. The underground coal gasification simulation device according to claim 5, characterized in that: The mixed water and gas input system (2) includes a gas injection system (21), a steam injection system (22) and a mixed preheating system (23); The gas outlet end of the gas injection system (21) and the gas outlet end of the steam injection system (22) are both connected to the gas inlet end of the mixing preheating system (23), and the gas outlet end of the mixing preheating system (23) is connected to the gas inlet end of the combustion chamber (4).

7. The underground coal gasification simulation device according to claim 6, characterized in that: The gas injection system (21) includes a manifold (211), an exhaust pipe (212) and three intake pipes (213); The three air inlet pipes (213) are respectively connected to the pure oxygen supply equipment, the oxygen-enriched air supply equipment and the air supply equipment; The manifold (211) is arranged in the mixed preheating system (23); the outlet ends of the three air inlet pipes (213) are all connected to the manifold (211); the air inlet end of the exhaust pipe (212) is connected to the outlet end of the manifold (211); the outlet end of the exhaust pipe (212) extends to directly below the outlet end of the steam injection system (22); and the height of the outlet end of the exhaust pipe (212) is greater than the height of the air inlet end of the exhaust pipe (212).

8. The underground coal gasification simulation device according to claim 7, characterized in that: The mixing and preheating system (23) includes a mixing tank (231), a mixing chamber (232), an upper flow chamber (233), an exhaust fan (234) and a side exhaust pipe (235); The mixing bin (232) is arranged in the mixing tank (231); The upper flow chamber (233) and the exhaust fan (234) are both arranged in the mixing chamber (232), and the upper flow chamber (233) and the exhaust fan (234) are respectively arranged near the upper and lower ends of the mixing chamber (232); The upper flow bin (233) is an inverted conical structure, the small end of the upper flow bin (233) is provided with an exhaust port, the exhaust port is provided with a centrifugal guide vane (236), and the gas outlet end of the steam generator (222) is in communication with the upper flow bin (233); The air inlet end of the side discharge pipe (235) is in communication with the mixing chamber (232), and the air inlet end of the side discharge pipe (235) is located on the side of the exhaust fan (234). The air outlet end of the side discharge pipe (235) is in communication with the mixing tank (231), and the height of the air outlet end of the side discharge pipe (235) is greater than the height of the air inlet end of the side discharge pipe (235). The manifold (211) is arranged in the mixing tank (231), and the gas outlet end of the exhaust pipe (212) passes through the wall of the mixing tank (232) and extends to just below the exhaust port.

9. The underground coal gasification simulation device according to claim 7, characterized in that: The air inlet pipe (213) is provided with a pressure regulating valve (214), a flow controller (215) and a one-way valve (216) which are connected in sequence; the air outlet end of the one-way valve (216) is communicated with the manifold (211).

10. The underground coal gasification simulation device according to claim 6, characterized in that: The steam injection system (22) includes a flow pump (221) and a steam generator (222); The liquid inlet of the flow pump (221) is connected to the water supply equipment, the liquid outlet of the flow pump (221) is connected to the liquid inlet of the steam generator (222), and the gas outlet of the steam generator (222) is connected to the mixed preheating system (23).

11. The underground coal gasification simulation device according to any one of claims 5 to 10, characterized in that: The gas outlet end of the separator (3) is externally connected to a cooling tower (5), and the gas outlet end of the cooling tower (5) is provided with a gas sample analyzer (6).

12. The underground coal gasification simulation device according to claim 11, characterized in that: An airflow disk (42) is provided inside the combustion chamber (1). The airflow disk (42) is located at one end of the combustion chamber (1) away from the variable seam device. An adjustment disk (43) is rotatably provided inside the airflow disk (42). Both the airflow disk (42) and the adjustment disk (43) are provided with a plurality of ventilation holes.

13. The underground coal gasification simulation device according to claim 12, characterized in that: An adjustment bracket (44) for adjusting the inclination angle of the combustion chamber (4) is provided at the bottom of the combustion chamber (4).

14. The underground coal gasification simulation device according to claim 13, characterized in that: An air supply pipe (24) for adding catalyst is provided between the mixed water and gas input system (2) and the combustion chamber (4).

15. A method for using an underground coal gasification simulation device, characterized in that: The method is implemented by the underground coal gasification simulation device according to any one of claims 5 to 14, and the method comprises the following steps: S1: using the mixed water and gas input system (2) to mix and preheat air, oxygen-enriched air, pure oxygen and water vapor according to the required proportions, and then delivering the mixed and preheated gas to the combustion chamber (4); S2: The plugging grouting component (14) in the seam changing device is used to fill the seam in the borehole of the coal sample, and the non-uniform seam is filled with the seam filling slurry. Then, the external pressure enveloping component (13) is used to apply radial external pressure to the coal sample to accurately simulate the deformation and permeability change of the coal seam; S3: Ignite the coal sample in the combustion chamber (4) using the ignition device (41); S4: Record and measure the inlet pressure of the mixed water and gas input system (2), the inlet pressure of the combustion chamber (4), the outlet pressure of the combustion chamber (4), and the pressure inside the separator (3); S5: Real-time collection of pressure, temperature, and flow rate parameters in the combustion chamber (4) and calculation; S6: Replace the coal sample and re-fill the seam, adjust the angle between the axis of the combustion chamber (4) and the horizontal plane, and repeat the steps S2-S5.

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