Coal underground gasification device and method for simulating multi-dip-angle complex burial depth

Abstract

The invention discloses a coal underground gasification device and method for simulating multi-dip-angle complex burial depth, and belongs to the technical field of coal underground gasification equipment, the device is used for coal underground gasification similar physical experiments, the device comprises a pipeline assembly and a combustion furnace, the pipeline assembly comprises a gas supply pipeline and a tail gas pipeline, and the combustion furnace comprises a base platform. A hydraulic cylinder assembly is arranged above a base platform and supports a furnace body, the furnace body is provided with a cooling system and a pressurizing system, a gas inlet connector is arranged on the left side of the furnace body, a gas outlet connector is arranged on the right side of the furnace body, a gas supply pipeline is connected with the gas inlet connector, and a tail gas pipeline is connected with the gas outlet connector. And the combustion space area is detected through the handheld X-ray imaging detector. According to the coal underground gasification device and method for simulating the multi-dip-angle complex burial depth, the actual situation of coal seam occurrence can be simulated, coal underground gasification experimental data can be obtained through cooperation with a monitoring instrument, and guidance is provided for coal underground gasification production in the region where the coal underground gasification device is located.

Description

Technical Field

[0001] The present invention relates to the technical field of underground coal gasification equipment, and in particular to an underground coal gasification device and method for simulating multi-angle and complex burial depths. Background Art

[0002] my country's energy resources are characterized by being "rich in coal, lacking in oil, and having little natural gas." Coal resources account for approximately 94% of total fossil energy, so the effective development of coal resources plays a vital strategic role in my country. The development and utilization of underground coal gasification is an important path and means to achieve carbon peak and carbon neutrality goals. It is a realistic option for my country to optimize and adjust its energy structure, and is also a strategic requirement for the development of new energy and alternative energy. The amount of natural gas resources equivalent to gasified coal buried at a depth of 800 to 3000 meters in my country is (272 to 332)×10 12 m 3 , exceeding the sum of conventional natural gas and unconventional natural gas resources such as tight sandstone gas, shale gas, and coalbed methane, and has huge development potential.

[0003] In the practical production process of underground coal gasification, there are three main combustion chemical reactions:

[0004] C+O2→CO2 -393.5kJ / mol

[0005] C + CO2 → 2CO + 172.5 kJ / mol

[0006] C + H2O → CO + H2 + 131.28 kJ / mol

[0007] Controlling the stability of the reaction and the composition of the synthesis gas are the main challenges faced in underground coal gasification technology. Since underground coal gasification is an in-situ mining method without wells, its gasification process is "invisible". The stability of the underground coal gasification reaction and the composition of the synthesis gas can only be controlled by controlling the concentration, pressure and temperature of the gasifying agent introduced. Therefore, before underground coal gasification production, gasification pre-experiments must be carried out to obtain reasonable gasifying agent inlet concentration, pressure and temperature for specific coal seams. However, conducting underground coal gasification experiments in actual coal seams has high manpower, material and time costs. Existing methods for studying underground coal gasification mostly rely on computers to construct numerical simulation models. This method is limited by the rationality and accuracy of the construction of numerical simulation models, and has high requirements on the theoretical level and practical ability of the experimental personnel.

[0008] Currently available physical experiment devices for underground coal gasification have the following problems: 1. Existing physical experiment devices for underground coal gasification generally use stacked coal blocks to simulate coal seams. Even if coal powder or clay is used to smear between the coal blocks (such as patent CN113445975A), the discontinuous texture of the simulated coal seam will affect the simulation of coal seam combustion and collapse. 2. Underground coal seams generally have certain angles, some of which are even steeply inclined or ultra-thin coal seams. Although the furnace body of existing physical experiment devices for underground coal gasification can be angled, the combustion chamber inside the furnace is of a fixed size (such as patent CN104457252A). This makes it impossible to accurately simulate the impact of burial depth, coal seam thickness, or complex overlying strata on underground coal gasification experiments. Summary of the Invention

[0009] The purpose of the present invention is to provide an underground coal gasification device and method that simulates multiple inclination angles and complex burial depths. The method can accurately simulate the actual angle of coal seam occurrence, appropriately adjust the combustion chamber size of the furnace body, and provide pressure compensation through a hydraulic pressure pump when the coal seam is buried too deep and it is impossible to simulate all strata with similar physical materials. In conjunction with monitoring instruments, the method records various key gasification data of similar physical experiments of underground coal gasification, obtains key data such as the optimal composition ratio of the gasifying agent mixture and the optimal gas production composition, and provides theoretical guidance for underground coal gasification production in the area where the experimental coal seam is located.

[0010] To achieve the above-mentioned objectives, the present invention provides a coal underground gasification device that simulates multi-angle and complex burial depth, including a pipeline assembly and a combustion furnace, the pipeline assembly including an air supply pipeline and an exhaust gas pipeline, the combustion furnace including a base platform, a hydraulic cylinder assembly is arranged above the base platform, the hydraulic cylinder assembly is used to support the furnace body, a front-end cooling assembly is arranged at the front end of the furnace body, a top cooling assembly is arranged at the top of the furnace body, a bottom liquid cooling box and a sealed pressure pump assembly are arranged at the bottom of the furnace body, side cooling assemblies are arranged on both sides and the back of the furnace body, an air inlet connection port is arranged on the left side of the furnace body, and an air outlet connection port is arranged on the right side of the furnace body, the air supply pipeline is connected to the air inlet connection port, and the exhaust gas pipeline is connected to the air outlet connection port, and the combustion air zone inside the combustion furnace is detected by a handheld X-ray imaging detector.

[0011] Preferably, the top cooling assembly includes a top sliding cover plate, which is engaged with the furnace body slide groove provided on the furnace body through a sliding shaft, and the top sliding cover plate is connected to the top support arm of the furnace body by a pressure knob, and the pressure knob directly applies pressure to the top pressure knob base, and a support arm flange is provided at the root of the top support arm, and the support arm flange is fixed to the furnace body through a flange fixing bolt; a hydraulic pressure pump is horizontally arranged on the bottom surface of the top sliding cover plate, and a hydraulic pressure pump oil pipeline is provided inside the top sliding cover plate, one end of the hydraulic pressure pump oil pipeline is connected to the hydraulic pressure pump total liquid inlet above the top sliding cover plate, and the other end of the hydraulic pressure pump oil pipeline is connected to the hydraulic pressure pump The hydraulic booster pump oil pipeline is also provided with no less than one hydraulic booster pump inlet, the top sliding cover plate is provided with an O-ring sealing bag on the side and forms a seal with the inner wall of the furnace body, the front end protruding part of the top sliding cover plate is provided with a longitudinal bolt hole for connecting with the front end cooling assembly, the front end protruding part of the top sliding cover plate is also provided with an O-ring sealing bag pressurized oil inlet, an O-ring sealing bag pressurized oil outlet and a top cover plate transverse bolt hole for fixing with the sliding claw hook, a top liquid cooling box is provided above the top sliding cover plate, the upper surface of the top liquid cooling box is provided with a plane level, a top circulating coolant inlet and a top hydraulic pressurized liquid reserved port, and the side of the top liquid cooling box is provided with a top circulating coolant outlet.

[0012] Preferably, the side cooling assembly includes a side liquid cooling box, which is divided into liquid cooling boxes arranged on both sides and the back of the furnace body. The side liquid cooling box is connected to the bottom liquid cooling box through a liquid cooling box connecting pipe. The side liquid cooling box and the bottom liquid cooling box constitute a cooling system. The side liquid cooling box is provided with a side circulating coolant inlet, and the bottom liquid cooling box is provided with a circulating coolant outlet. A side level is provided in a position parallel to the air inlet connection port.

[0013] Preferably, the front-end cooling assembly includes a front-end sliding cover plate, which engages with the furnace body slide groove set at the front end of the furnace body, and a front liquid cooling box is set on the surface of the front-end sliding cover plate. The front liquid cooling box is provided with a front circulating coolant inlet, a front level and a front circulating coolant outlet. The front-end sliding cover plate is processed with a front-end cover plate transverse bolt hole for fixing with a sliding claw hook, and the sliding claw hook engages with the claw hook slide groove set on the back side of the furnace body slide groove.

[0014] Preferably, the sealing pressure pump assembly includes a sealing pressure pump oil pipeline, one end of the sealing pressure pump oil pipeline is connected to the sealing system pressurized liquid inlet arranged on the back of the furnace body, the other end of the sealing pressure pump oil pipeline is connected to the sealing pressure pump liquid inlet, the sealing pressure pump liquid inlet is connected to the sealing pressure pump, the sealing pressure pump is connected to the sealing pressure slider, the front end of the sealing pressure slider is provided with a sealing pressure slider slot, the rear end of the sealing pressure slider is provided with a sealing pressure pump force port, and the bottom cooling assembly includes a bottom liquid cooling box.

[0015] Preferably, an air inlet connection port reserved port is provided inside the side liquid cooling box corresponding to the air inlet connection port, and an air outlet connection port reserved port is provided corresponding to the air outlet connection port. A coolant outlet is also provided at the bottom of the side liquid cooling box, and a sealing system pressurized liquid reserved port is also provided at the bottom of the liquid cooling box on the back of the furnace body.

[0016] Preferably, the hydraulic cylinder assembly includes a supporting hydraulic cylinder, a supporting hydraulic rod is provided in the supporting hydraulic cylinder, the supporting hydraulic rod is connected to the furnace body and the base platform through a universal joint, a universal joint connection bearing is provided at the universal joint; a base platform support foot is provided under the base platform.

[0017] Preferably, the right section of the air supply pipeline is provided with three vertical pipelines, and the three vertical pipelines are, from right to left, a temperature sensor probe access port, an ignition control circuit access port and a gas composition sensor access port; the middle section of the air supply pipeline is provided with three monitoring meters, and the three monitoring meters are, from right to left, a furnace front pressure gauge, a furnace front temperature gauge and a furnace front flow meter. A rectifier is located on the left side of the three monitoring meters, and the rectifier is provided with a rectifier main valve and a rectifier sub-valve. The rectifier sub-valve is respectively connected to an oxygen cylinder, an inert gas cylinder, a steam generator and a blower, and the oxygen cylinder and the inert gas cylinder are provided with gas cylinder valves; the left section of the exhaust gas pipeline is provided with access pipelines for a post-furnace flow meter and a post-furnace pressure gauge from left to right, a gas chromatograph is provided on the right side of the post-furnace pressure gauge, and an exhaust gas treatment device is connected to the right side of the gas chromatograph.

[0018] The present invention also provides a method for simulating underground coal gasification with multiple inclination angles and complex burial depths, comprising the following steps:

[0019] S1. Prepare the coal seam, floor, roof, and other strata using similar physical principles. Simultaneously, open the furnace sealing system and cooling circulation system, adjust the coolant temperature to the same as the ambient temperature of the coal seam, and adjust the telescopic lengths of the four hydraulic rods supporting the furnace to ensure that the furnace inclination angle is the same as the coal seam inclination angle.

[0020] S2. Open the valves of the oxygen cylinder and the inert gas cylinder, start the steam generator, rotate and open the main valve of the rectifier, and use a blower to blow the mixed gasifying agent into the gasification channel of the coal seam in the furnace for 20 minutes. At the same time, turn on the computer connected to the temperature sensor probe and the gas composition sensor to analyze the gas composition of the gasifying agent, and monitor the pressure gauge, temperature gauge, and flow meter in front of the furnace in real time. Based on the above data, adjust the rectifier valves in real time to ensure the stability of the ratio of the various components of the gasifying agent and the temperature and pressure of the gasifying agent;

[0021] S3. Turn on the gas chromatograph to monitor the gas composition to ensure that the gasifying agent has no composition change after passing through the coal layer of the furnace before starting the physical experiment similar to coal gasification;

[0022] S4. Use a handheld X-ray imaging detector attached to the outside of the liquid cooling box at the front of the furnace body and the outside of the liquid cooling box at the top to observe the collapse of the coal seam combustion zone in the subsequent gasification stage. Use the ignition control circuit to ignite the coal seam gasification channel near the gas inlet connection port. Simultaneously, start the tail gas treatment device. Record the data of each pressure gauge, temperature gauge, and flow meter every 15 minutes. Also record the data of the computer connected to the gas composition sensor and the gas chromatograph every 15 minutes. The experiment ends when the coal seam, roof, and other strata collapse due to excessive combustion zone, resulting in the shutdown of the furnace.

[0023] S5. Repeat steps S1, S2, S3, and S4, and conduct multiple gasification experiments by selecting different gasifying agent composition ratios by controlling the gas cylinder valve and the rectifier sub-valve, to obtain experimental data on the gasification experiment time, gasifying agent composition ratio, gasifying agent temperature, gasifying agent flow rate, gasifying agent pressure, and gas production composition ratio required for multiple groups of different coal seams to cause the coal seam, roof, and various strata to collapse and then shut down due to excessive combustion void area;

[0024] S6. After analyzing the experimental data, summarize the key data used to guide actual underground coal gasification production, including the optimal concentration ratio of each gasifying agent component, the optimal gasifying agent injection pressure, the optimal gasifying agent injection flow rate, and the optimal gas production composition.

[0025] Therefore, the present invention adopts the above-mentioned underground coal gasification device and method for simulating multiple inclination angles and complex burial depths, which has the following beneficial effects:

[0026] 1) By coordinating the universal joint with the supporting hydraulic cylinder and observing the inclination angle through the level meter, the furnace body can accurately simulate the occurrence angle of the real coal seam, which has universal applicability.

[0027] 2) When the coal seam is deposited at a great depth and the overlying roof and strata above the coal seam cannot all be stacked with similar physical materials, the hydraulic pressure pump at the bottom of the top sliding cover can be used for pressure compensation.

[0028] 3) By combining handheld X-ray imaging detectors, gas chromatographs, temperature sensors, etc., key data such as the composition of generated gas and the collapse of the combustion zone during underground coal gasification can be collected, and key data such as the optimal gas inlet velocity, temperature, pressure, concentration, and gas production composition can be analyzed.

[0029] 4) Considering the influence of factors such as the discontinuity of coal seam texture on the gasification process and the collapse of the combustion zone by using coal block stacking, a single large block of coal is cut into a rectangular block and placed directly inside the experimental furnace body, and then filled with other similar physical materials to simulate the coal seam roof, floor, overlying rock layer, stratum, etc., so that the underground coal gasification experiment is closer to the actual underground coal gasification production process.

[0030] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the front structure of a combustion furnace in an embodiment of an underground coal gasification device and method simulating multiple inclination angles and complex burial depths according to the present invention;

[0032] Figure 2 This is a schematic diagram of the back structure of a combustion furnace in an embodiment of an underground coal gasification device and method simulating multiple inclination angles and complex burial depths according to the present invention;

[0033] Figure 3 This is a schematic diagram of the structure of the sliding cover plate at the top of the combustion furnace of an embodiment of an underground coal gasification device and method simulating multiple inclination angles and complex burial depths according to the present invention;

[0034] Figure 4 This is a schematic diagram of the oil pipeline structure of the hydraulic pressure pump in the sliding cover plate at the top of the combustion furnace of an embodiment of the present invention's simulated multi-angle and complex buried depth underground coal gasification device and method;

[0035] Figure 5 This is a schematic structural diagram of a liquid cooling box on top of a combustion furnace according to an embodiment of an underground coal gasification device and method simulating multiple inclination angles and complex burial depths of the present invention;

[0036] Figure 6 This is a schematic structural diagram of the side liquid cooling box and the bottom liquid cooling box in the direction of the gas outlet connection port of the combustion furnace according to an embodiment of the present invention, which simulates an underground coal gasification device and method with multiple inclination angles and complex burial depths;

[0037] Figure 7 This is a schematic structural diagram of the side liquid cooling box and the bottom liquid cooling box in the direction of the gas inlet connection port of the combustion furnace in an embodiment of an underground coal gasification device and method simulating multiple inclination angles and complex burial depths according to the present invention;

[0038] Figure 8This is a schematic diagram of the front three-dimensional structure of the combustion chamber of a combustion furnace body of an embodiment of a simulated multi-angle and complex buried depth underground coal gasification device and method of the present invention;

[0039] Figure 9 This is a schematic diagram of the front structure of the combustion chamber of a combustion furnace body of an embodiment of a simulated multi-angle and complex buried depth underground coal gasification device and method of the present invention;

[0040] Figure 10 This is a schematic diagram of the oil pipeline structure of the sealing pressure pump at the bottom of the combustion furnace body of an embodiment of an underground coal gasification device and method simulating multiple inclination angles and complex burial depths of the present invention;

[0041] Figure 11 This is a schematic diagram of the structure of the sliding claw hook of the combustion furnace of an embodiment of an underground coal gasification device and method simulating multiple inclination angles and complex burial depths according to the present invention;

[0042] Figure 12 This is a structural diagram of a sealing and pressurizing slider at the bottom of a combustion furnace according to an embodiment of an underground coal gasification device and method simulating multiple inclination angles and complex burial depths of the present invention;

[0043] Figure 13 This is a structural schematic diagram of a hydraulic cylinder assembly of a combustion furnace according to an embodiment of an underground coal gasification device and method simulating multiple inclination angles and complex burial depths;

[0044] Figure 14 This is a structural diagram of a combustion furnace base platform according to an embodiment of an underground coal gasification device and method simulating multiple inclination angles and complex burial depths according to the present invention;

[0045] Figure 15 It is a schematic diagram of the overall structure of an embodiment of an underground coal gasification device and method simulating multiple inclination angles and complex burial depths according to the present invention.

[0046] Reference numerals

[0047] 1. Base platform; 2. Support hydraulic cylinder; 3. Universal joint; 4. Sliding claw hook; 5. Air inlet; 6. Side level; 7. Side circulating coolant inlet; 8. Side liquid cooling box; 9. Top support arm; 10. Top liquid cooling box; 11. Pressurization knob; 12. Support arm fixing bolt; 13. Plane level; 14. Top circulating coolant inlet; 15. Top hydraulic pressurized liquid reserved port; 16. Top circulating coolant outlet; 17. O-ring seal bag pressurized oil inlet; 18. Top sliding cover; 19. O-ring seal bag pressurized oil outlet; 20. Front sliding Dynamic cover; 21, front liquid cooling box; 22, front circulating coolant inlet; 23, front level gauge; 24, front circulating coolant outlet; 25, bottom liquid cooling box; 26, universal joint connecting bearing; 27, base platform support foot; 28, liquid cooling box connecting pipe; 29, claw hook slide; 30, front end cover transverse bolt hole; 31, air outlet connection port; 32, support arm flange; 33, top pressure knob base; 34, flange fixing bolt; 35, sealing system pressurized liquid reserved port; 36, O-ring sealing bag; 37, top cover transverse bolt hole; 38, longitudinal bolt hole; 39, Hydraulic booster pump; 40, sliding shaft; 41, hydraulic booster pump oil pipeline; 42, hydraulic booster pump liquid inlet; 43, hydraulic booster pump total liquid inlet; 44, air outlet connection port reserved; 45, coolant outlet; 46, circulating coolant outlet; 47, air inlet connection port reserved; 48, furnace body slide; 49, sealing pressure slider; 50, sealing pressure pump; 51, sealing pressure pump liquid inlet; 52, sealing system pressure liquid inlet; 53, sealing pressure pump oil pipeline; 54, sealing pressure slider notch; 55, sealing pressure pump force port; 56, supporting hydraulic rod; 57, Oxygen cylinder; 58. Inert gas cylinder; 59. Steam generator; 60. Blower; 61. Air supply pipeline; 62. Pressure gauge in front of furnace; 63. Temperature gauge in front of furnace; 64. Flow meter in front of furnace; 65. Rectifier main valve; 66. Rectifier sub-valve; 67. Gas cylinder valve; 68. Rectifier; 69. Temperature sensor probe access port; 70. Ignition control circuit access port; 71. Gas composition sensor access port; 72. Pressure gauge behind furnace; 73. Flow meter behind furnace; 74. Handheld X-ray imaging detector; 75. Gas chromatograph; 76. Exhaust gas treatment device; 77. Exhaust gas pipeline. DETAILED DESCRIPTION

[0048] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0049] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "first", "second" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0050] Example 1

[0051] The present invention provides a coal underground gasification device that simulates multiple inclination angles and complex burial depths. The overall structure is as follows: Figure 15 As shown, it includes a pipeline assembly and a combustion furnace. The pipeline assembly includes an air supply pipe 61 and an exhaust pipe 77. The combustion furnace structure is as shown in FIG. Figure 1 、 2 As shown, it includes a base platform 1, a hydraulic cylinder assembly is arranged above the base platform 1, the hydraulic cylinder assembly is used to support the furnace body, a front cooling assembly is arranged at the front end of the furnace body, a top cooling assembly is arranged at the top of the furnace body, a bottom liquid cooling box 25 and a sealing pressure pump assembly are arranged at the bottom of the furnace body, side cooling assemblies are arranged on both sides and the back of the furnace body, an air inlet connection port 5 is arranged on the left side of the furnace body, an air outlet connection port 31 is arranged on the right side of the furnace body, an air supply pipe 61 is connected to the air inlet connection port 5, and an exhaust pipe 77 is connected to the air outlet connection port 31. The combustion air zone inside the combustion furnace is detected by a handheld X-ray imaging detector 74.

[0052] The top cooling assembly includes a top sliding cover plate 18, such as Figure 3-5 As shown, the top sliding cover plate 18 engages with the furnace body chute 48 provided on the furnace body via a sliding shaft 40. The top sliding cover plate 18 is connected to the furnace body's top support arm 9 via a pressure knob 11. The pressure knob 11 applies pressure directly to the top pressure knob base 33. Rotating the pressure knob 11 applies a vertical downward force to the top sliding cover plate 18, ensuring that the top sliding cover plate 18 does not collapse due to excessive pressure during the gasification experiment. A support arm fixing bolt 12 is provided in the middle of the top support arm 9, and a support arm flange 32 is provided at the base of the top support arm 9. The support arm flange 32 is secured to the furnace body via flange fixing bolts 34.

[0053] A hydraulic pressure pump 39 is arranged horizontally on the bottom surface of the top sliding cover 18, and a hydraulic pressure pump oil pipeline 41 is provided inside the top sliding cover 18. One end of the hydraulic pressure pump oil pipeline 41 is connected to the hydraulic pressure pump total liquid inlet 43 above the top sliding cover 18, and the other end of the hydraulic pressure pump oil pipeline 41 is connected to the hydraulic pressure pump 39. The hydraulic pressure pump oil pipeline 41 is also provided with no less than one hydraulic pressure pump liquid inlet 42. An O-shaped sealing bag 36 is provided on the side of the top sliding cover 18 and forms a seal with the inner wall of the furnace body. The front end protruding part of the top sliding cover 18 is provided with The longitudinal bolt hole 38 is used to connect with the front sliding cover plate 20 in the front cooling assembly. The front protruding part of the top sliding cover plate 18 is also provided with an O-ring sealing bag pressurized oil inlet 17, an O-ring sealing bag pressurized oil outlet 19 and a top cover plate transverse bolt hole 37 for fixing with the sliding claw hook 4. A top liquid cooling box 10 is provided above the top sliding cover plate 18. The upper surface of the top liquid cooling box 10 is provided with a plane level 13, a top circulating coolant inlet 14 and a top hydraulic pressurized liquid reserved port 15. The side of the top liquid cooling box 10 is provided with a top circulating coolant outlet 16.

[0054] like Figure 6 、 7 As shown, the side cooling assembly includes a side liquid cooling box 8, which is arranged on both sides and the back of the furnace body. The side liquid cooling box 8 and the bottom liquid cooling box 25 are connected through a liquid cooling box connecting pipe 28 to form a cooling system. The side liquid cooling box 8 is provided with a side circulating coolant inlet 7, and the bottom liquid cooling box 25 is provided with a circulating coolant outlet 46. A side level 6 is provided in a position parallel to the air inlet connection port 5.

[0055] like Figure 8 、 9 As shown, the front-end cooling assembly includes a front sliding cover plate 20, which engages with the furnace body chute 48 provided at the front end of the furnace body. A front liquid cooling box 21 is provided on the surface of the front sliding cover plate 20. The front liquid cooling box 21 is provided with a front circulating coolant inlet 22, a front level gauge 23, and a front circulating coolant outlet 24. Transverse bolt holes 30 for securing the sliding claw hook 4 are machined at both ends of the front sliding cover plate 20. The sliding claw hook 4 is fixed to the transverse bolt holes 30 of the front cover plate by bolts. The sliding claw hook 4 engages with the claw hook chute 29 provided on the back of the furnace body chute 48, and the sliding claw hook 4 can slide up and down freely in the claw hook chute 29. The top liquid cooling box 10 and its accessories, the front liquid cooling box 21 and its accessories each constitute a cooling system, and the side liquid cooling box 8 and the bottom liquid cooling box 25 constitute a cooling system. The entire furnace body is provided with three cooling systems.

[0056] like Figure 10-12As shown, the sealing pressure pump assembly includes a sealing pressure pump oil pipeline 53, one end of the sealing pressure pump oil pipeline 53 is connected to the sealing system pressurized liquid inlet 52 set on the back of the furnace body, and the other end of the sealing pressure pump oil pipeline 53 is connected to the sealing pressure pump liquid inlet 51, the sealing pressure pump liquid inlet 51 is connected to the sealing pressure pump 50, and the sealing pressure pump 50 is connected to the sealing pressure slider 49. The front end of the sealing pressure slider 49 is provided with a sealing pressure slider groove 54 for pressing and engaging with the sliding shaft 40, and the rear end of the sealing pressure slider 49 is provided with a sealing pressure pump force port 55.

[0057] An air inlet connection port reserved port 47 is provided inside the side liquid cooling box 8 corresponding to the air inlet connection port 5, and an air outlet connection port reserved port 44 is provided corresponding to the air outlet connection port 31. A coolant outlet 45 is also provided at the bottom of the side liquid cooling box 8, and a sealing system pressurized liquid reserved port 35 is also provided at the bottom of the liquid cooling box on the back of the furnace body.

[0058] like Figure 13 、 14 As shown, the hydraulic cylinder assembly includes a supporting hydraulic cylinder 2, which contains a supporting hydraulic rod 56. The supporting hydraulic rod 56 is connected to the furnace body and the base platform 1 through a universal joint 3. A universal joint connecting bearing 26 is provided at the universal joint 3; a base platform supporting foot 27 is provided under the base platform 1.

[0059] The right section of the air supply pipe 61 is provided with three vertical pipelines, which are, from right to left, a temperature sensor probe access port 69, an ignition control circuit access port 70 and a gas composition sensor access port 71; the middle section of the air supply pipe 61 is provided with three monitoring meters, which are, from right to left, a furnace front pressure gauge 62, a furnace front temperature gauge 63 and a furnace front flow meter 64. On the left side of the three monitoring meters is a rectifier 68, which is provided with a rectifier main valve 65 and a rectifier sub-valve 66. The rectifier sub-valve 66 is respectively connected to the oxygen cylinder 57, the inert gas cylinder 58, the steam generator 59 and the blower 60, and the oxygen cylinder 57 and the inert gas cylinder 58 are provided with a gas cylinder valve 67; the left section of the exhaust gas pipe 77 is provided with access pipelines for the furnace rear flow meter 73 and the furnace rear pressure gauge 72 from left to right, a gas chromatograph 75 is provided on the right side of the furnace rear pressure gauge 72, and an exhaust gas treatment device 76 is connected to the right side of the gas chromatograph 75.

[0060] When using the underground coal gasification device simulating multiple inclination angles and complex burial depths described in this embodiment, the steps are as follows:

[0061] S1. The original intention of the design of this invention is to simulate the coal seam with similar physical materials after cutting large pieces of coal. The bottom surface size of the furnace combustion chamber is designed to be 400mm×500mm. Due to the existence of the front sliding cover 20 and the top sliding cover 18, the height of the furnace combustion chamber is designed to be adjustable in the range of 400mm~800mm. The large pieces of coal sampled on site are cut and prepared into a coal seam shape of 400mm×500mm×10mm, and the rock mechanical properties of the roof, floor and various formations in the coal seam storage environment are extracted. According to the mechanical property data, the material similarity physical principle is used to use materials such as sand, calcium carbonate, gypsum, water and other materials to mix in a certain proportion to prepare the roof, floor and various formations. The plane size is 400mm×500mm, and the height is determined according to the actual proportion of the longitudinal layer thickness occupied by each formation.

[0062] S2. Slide the top sliding cover 18, determine the longitudinal height of the furnace combustion chamber in proportion to the actual buried depth of the coal seam, and slide and adjust the front sliding cover 20 to match this height. At this time, slide the sliding claw hook 4 into the claw hook slot 29 (the number of sliding claw hooks 4 is not less than 5 on each side in principle) and dock with the transverse bolt hole 30 of the front cover and use bolts to fix it to form a seal. The bottom plate, coal seam, top plate, and each layer made of similar physical materials are arranged in the combustion chamber from bottom to top, and the coal seam is connected to the air inlet connection port 5 and the air outlet connection port 5. 31 is flush, and a gasification channel is drilled in the coal seam through the air inlet connection port 5 using a long drill bit. This channel runs through the coal seam from the air inlet connection port 5 to the air outlet connection port 31. At this time, the top sliding cover plate 18 is placed on the furnace body and flush with the front sliding cover plate 20. Two sliding claw hooks 4 are used on both sides of the top sliding cover plate 18. The transverse bolt holes 37 of the top cover plate are fixed to the sliding claw hooks 4 by bolts to form a seal. The longitudinal bolt hole 38 in the middle of the protruding part of the front end of the sliding top sliding cover plate 18 is fixed to the front sliding cover plate 20 by bolts to form a seal.

[0063] S3. The pressurized oil is passed into the pressurized oil inlet 17 of the O-ring sealing bag, and the pressurized oil outlet 19 of the O-ring sealing bag is temporarily in a closed state. At this time, the O-ring sealing bag 36 expands due to pressure, so that the top sliding cover plate 18 forms a seal with the inner wall of the furnace body; the pressurized oil is passed into the pressurized liquid inlet 52 of the sealing system at the bottom, and the sealing pressure pump 50 pushes the sealing pressure slider 49 forward to form a seal with the front sliding cover plate 20.

[0064] S4. Screw the three pressurizing knobs 11 into the top support arm 9 and contact the top sliding cover plate 18 so that the top sliding cover plate 18 will not collapse due to excessive pressure during the gasification experiment.

[0065] S5. If the depth of the simulated coal seam is relatively small, it is sufficient to ensure that the bottom plane of the hydraulic pressure pump 39 on the bottom surface of the top sliding cover plate 18 is in contact with the uppermost stratum, and the hydraulic pressure pump 39 does not need to apply pressure to it; if the depth of the simulated coal seam is relatively large and it is impossible to make similar physical materials of all strata, the pressurized oil is introduced into the total liquid inlet 43 of the hydraulic pressure pump, and pressure is given to the hydraulic pressure pump 39 to make it pressurize the uppermost stratum, thereby replacing the pressure of some strata that cannot be simulated on the coal seam.

[0066] S6. When the telescopic lengths of the four supporting hydraulic rods 56 are different, the experimental furnace body will tilt at an angle. According to the actual collected coal seam inclination angle data, adjust the telescopic lengths of the four supporting hydraulic rods 56 and observe the pointer information of the three spirit levels at all times. After repeated operation, the furnace body inclination angle is consistent with the actual coal seam inclination angle.

[0067] S7. Use a heating (cooling) device to preheat (precool) the coolant to the same temperature as the coal seam environment, and then inject it into all liquid cooling boxes through the coolant inlet. All liquid cooling box outlets are connected to the heating (cooling) device, and the cycle is repeated to ensure that the external environment temperature of the experimental furnace remains unchanged.

[0068] S8. Open the cylinder valves 67 of the oxygen cylinder 57 and the inert gas cylinder 58, start the steam generator 59, rotate and open the rectifier main valve 65, and use the blower 60 to blow the mixed gasifying agent into the gasification channel of the coal seam in the furnace body for 20 minutes. At the same time, turn on the computer connected to the temperature sensor probe and the gas composition sensor to analyze the gas composition of the gasifying agent, and observe the furnace pressure gauge 62, furnace temperature gauge 63, and furnace flow meter 64 in real time. According to the above data, adjust the rectifier sub-valve 66 in real time to ensure the stability of the proportion of each component of the gasifying agent and the temperature and pressure of the gasifying agent.

[0069] S9. Turn on the gas chromatograph 75 to monitor the gas composition to ensure that the gasifying agent has no composition change after passing through the coal layer of the furnace before starting the coal gasification similarity physical experiment.

[0070] S10. Use a handheld X-ray imaging detector 74 to attach to the outside of the liquid cooling box 21 at the front of the furnace body and the outside of the top liquid cooling box 10 to observe the collapse of the coal seam combustion zone in the subsequent gasification stage. Use the ignition control circuit to ignite the coal seam gasification channel near the air inlet connection port 5. At the same time, turn on the exhaust gas treatment device 76. Record the data of each pressure gauge, temperature gauge, and flow meter every 15 minutes. Also record the computer data connected to the gas composition sensor and the data of the gas chromatograph 75 every 15 minutes. The experiment ends when the coal seam, roof, and various strata collapse due to the excessive combustion zone, and the furnace is shut down.

[0071] S11. Repeat steps S1, S2, S3, and S4, and conduct multiple gasification experiments by selecting different gasifier composition ratios through controlling the gas cylinder valve 67 and the rectifier sub-valve 66, and obtain experimental data on the gasification experiment time, gasifier composition ratio, gasifier temperature, gasifier flow rate, gasifier pressure, and gas production composition ratio required for multiple groups of different coal seams to be shut down due to the collapse of coal seams, roofs, and various strata caused by excessive combustion void areas.

[0072] S12. After analyzing the experimental data, summarize the key data used to guide actual underground coal gasification production, including the optimal concentration ratio of each gasifying agent component, the optimal gasifying agent injection pressure, the optimal gasifying agent injection flow rate, and the optimal gas production composition.

[0073] Therefore, the present invention adopts the above-mentioned coal underground gasification device and method for simulating multiple inclination angles and complex burial depths. Through the cooperation of the supporting hydraulic cylinder, the universal joint, and the level, the actual angle of the coal seam can be accurately simulated. Due to the existence of the top sliding cover plate and the front sliding cover plate, the combustion chamber of the furnace body can be adjusted in size, and the hydraulic pressure pump on the bottom surface of the top sliding cover plate can provide pressure compensation when the coal seam is buried too deep and it is impossible to simulate all strata with similar physical materials. This invention is compatible with other instruments (pressure gauge, temperature gauge, flow meter, computer, temperature sensor) The device can be used in conjunction with a gas chromatograph (e.g., a head, a gas composition sensor, a handheld X-ray imaging detector, and a gas chromatograph) to capture or record various key gasification data of similar physical experiments in underground coal gasification, such as gasifier temperature, gasifier pressure, gasifier flow rate, gasifier concentration, gas production composition, gas production concentration, shape and size of the coal seam combustion zone, etc., so as to analyze the experimental data and determine the optimal gasifier mixture composition ratio and optimal gas production composition when the combustion zone collapses and does not cause the furnace to stop, thereby providing theoretical guidance for underground coal gasification production in the area where the experimental coal seam is located.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An underground coal gasification device simulating multiple inclination angles and complex burial depths, characterized by: It includes a pipeline assembly and a combustion furnace, the pipeline assembly includes an air supply pipeline and an exhaust gas pipeline, the combustion furnace includes a base platform, a hydraulic cylinder assembly is arranged above the base platform, the hydraulic cylinder assembly is used to support the furnace body, a front end cooling assembly is arranged at the front end of the furnace body, a top end cooling assembly is arranged at the top of the furnace body, a bottom liquid cooling box and a sealed pressure pump assembly are arranged at the bottom of the furnace body, side cooling assemblies are arranged on both sides and the back of the furnace body, an air inlet connection port is arranged on the left side of the furnace body, an air outlet connection port is arranged on the right side of the furnace body, the air supply pipeline is connected to the air inlet connection port, the exhaust gas pipeline is connected to the air outlet connection port, and the combustion air zone inside the combustion furnace is detected by a handheld X-ray imaging detector.

2. The underground coal gasification device for simulating multiple-angle and complex burial depths according to claim 1, characterized in that: The top cooling assembly includes a top sliding cover plate, which is engaged with the furnace body slide groove provided on the furnace body through a sliding shaft, and the top sliding cover plate is connected to the top support arm of the furnace body by a pressure knob, and the pressure knob directly applies pressure to the top pressure knob base, and the root of the top support arm is provided with a support arm flange, and the support arm flange is fixed to the furnace body by a flange fixing bolt; a hydraulic pressure pump is horizontally arranged on the bottom surface of the top sliding cover plate, and a hydraulic pressure pump oil pipeline is provided inside the top sliding cover plate, one end of the hydraulic pressure pump oil pipeline is connected to the hydraulic pressure pump total liquid inlet above the top sliding cover plate, and the other end of the hydraulic pressure pump oil pipeline is connected to the hydraulic pressure pump. The hydraulic booster pump oil pipeline is also provided with at least one hydraulic booster pump inlet, the top sliding cover plate is provided with an O-ring sealing bag on the side and forms a seal with the inner wall of the furnace body, the front end protruding part of the top sliding cover plate is provided with a longitudinal bolt hole for connecting with the front end cooling assembly, the front end protruding part of the top sliding cover plate is also provided with an O-ring sealing bag pressurized oil inlet, an O-ring sealing bag pressurized oil outlet and a top cover plate transverse bolt hole for fixing with the sliding claw hook, a top liquid cooling box is provided above the top sliding cover plate, the upper surface of the top liquid cooling box is provided with a plane level, a top circulating coolant inlet and a top hydraulic pressurized liquid reserved port, and the side of the top liquid cooling box is provided with a top circulating coolant outlet.

3. The underground coal gasification device for simulating multiple-angle and complex burial depths according to claim 1, characterized in that: The side cooling assembly includes a side liquid cooling box, which is divided into liquid cooling boxes arranged on both sides and the back of the furnace body. The side liquid cooling box is connected to the bottom liquid cooling box through a liquid cooling box connecting pipe. The side liquid cooling box and the bottom liquid cooling box constitute a cooling system. The side liquid cooling box is provided with a side circulating coolant inlet, and the bottom liquid cooling box is provided with a circulating coolant outlet. A side level is provided in a position parallel to the air inlet connection port.

4. The underground coal gasification device for simulating multiple-angle and complex burial depths according to claim 1, characterized in that: The front-end cooling assembly includes a front-end sliding cover plate, which engages with the furnace body slide groove set at the front end of the furnace body, and a front liquid cooling box is set on the surface of the front-end sliding cover plate. The front liquid cooling box is provided with a front circulating coolant inlet, a front level and a front circulating coolant outlet. The front-end sliding cover plate is processed with a front-end cover plate transverse bolt hole for fixing with a sliding claw hook, and the sliding claw hook engages with the claw hook slide groove set on the back side of the furnace body slide groove.

5. The underground coal gasification device for simulating multiple-angle and complex burial depths according to claim 1 is characterized by: The sealing pressure pump assembly includes a sealing pressure pump oil pipeline, one end of the sealing pressure pump oil pipeline is connected to the sealing system pressurized liquid inlet arranged on the back of the furnace body, the other end of the sealing pressure pump oil pipeline is connected to the sealing pressure pump liquid inlet, the sealing pressure pump liquid inlet is connected to the sealing pressure pump, the sealing pressure pump is connected to the sealing pressure slider, the front end of the sealing pressure slider is provided with a sealing pressure slider notch, and the rear end of the sealing pressure slider is provided with a sealing pressure pump force port.

6. The underground coal gasification device for simulating multiple-angle and complex burial depths according to claim 3, characterized in that: An air inlet connection port reserved opening is provided inside the side liquid cooling box corresponding to the air inlet connection port, and an air outlet connection port reserved opening is provided corresponding to the air outlet connection port. A coolant outlet is also provided at the bottom of the side liquid cooling box, and a sealing system pressurized liquid reserved opening is also provided at the bottom of the liquid cooling box on the back of the furnace body.

7. The underground coal gasification device for simulating multiple-angle and complex burial depths according to claim 1, characterized in that: The hydraulic cylinder assembly includes a supporting hydraulic cylinder, a supporting hydraulic rod is arranged in the supporting hydraulic cylinder, the supporting hydraulic rod is connected to the furnace body and the base platform through a universal joint, a universal joint connection bearing is arranged at the universal joint; a base platform support foot is arranged under the base platform.

8. The underground coal gasification device for simulating multiple-angle and complex burial depths according to claim 1, characterized in that: The right section of the air supply pipeline is provided with three vertical pipelines, and the three vertical pipelines are, from right to left, a temperature sensor probe access port, an ignition control circuit access port and a gas composition sensor access port; the middle section of the air supply pipeline is provided with three monitoring meters, and the three monitoring meters are, from right to left, a furnace front pressure gauge, a furnace front temperature gauge and a furnace front flow meter. The left side of the three monitoring meters is a rectifier, and the rectifier is provided with a rectifier main valve and a rectifier sub-valve. The rectifier sub-valve is respectively connected to an oxygen cylinder, an inert gas cylinder, a steam generator and a blower, and the oxygen cylinder and the inert gas cylinder are provided with gas cylinder valves; the left section of the exhaust gas pipeline is provided with access pipelines for a post-furnace flow meter and a post-furnace pressure gauge from left to right, a gas chromatograph is provided on the right side of the post-furnace pressure gauge, and an exhaust gas treatment device is connected to the right side of the gas chromatograph.

9. A method for simulating underground coal gasification with multiple inclination angles and complex burial depths, characterized in that: The following steps are involved: S1. Prepare the coal seam, floor, roof, and other strata using similar physical principles. Simultaneously, open the furnace sealing system and cooling circulation system, adjust the coolant temperature to the same as the ambient temperature of the coal seam, and adjust the telescopic lengths of the four hydraulic rods supporting the furnace to ensure that the furnace inclination angle is the same as the coal seam inclination angle. S2. Open the valves of the oxygen cylinder and the inert gas cylinder, start the steam generator, rotate and open the main valve of the rectifier, and use a blower to blow the mixed gasifying agent into the gasification channel of the coal seam in the furnace for 20 minutes. At the same time, turn on the computer connected to the temperature sensor probe and the gas composition sensor to analyze the gas composition of the gasifying agent, and monitor the pressure gauge, temperature gauge, and flow meter in front of the furnace in real time. Based on the above data, adjust the rectifier valves in real time to ensure the stability of the ratio of the various components of the gasifying agent and the temperature and pressure of the gasifying agent; S3. Turn on the gas chromatograph to monitor the gas composition to ensure that the gasifying agent has no composition change after passing through the coal layer of the furnace before starting the physical experiment similar to coal gasification; S4. Use a handheld X-ray imaging detector attached to the outside of the liquid cooling box at the front of the furnace body and the outside of the liquid cooling box at the top to observe the collapse of the coal seam combustion zone in the subsequent gasification stage. Use the ignition control circuit to ignite the coal seam gasification channel near the gas inlet connection port. Simultaneously, start the tail gas treatment device. Record the data of each pressure gauge, temperature gauge, and flow meter every 15 minutes. Also record the data of the computer connected to the gas composition sensor and the gas chromatograph every 15 minutes. The experiment ends when the coal seam, roof, and other strata collapse due to excessive combustion zone, resulting in the shutdown of the furnace. S5. Repeat steps S1, S2, S3, and S4, and conduct multiple gasification experiments by selecting different gasifying agent composition ratios by controlling the gas cylinder valve and the rectifier sub-valve, to obtain experimental data on the gasification experiment time, gasifying agent composition ratio, gasifying agent temperature, gasifying agent flow rate, gasifying agent pressure, and gas production composition ratio required for multiple groups of different coal seams to cause the coal seam, roof, and various strata to collapse and then shut down due to excessive combustion void area; S6. After analyzing the experimental data, summarize the key data used to guide actual underground coal gasification production, including the optimal concentration ratio of each gasifying agent component, the optimal gasifying agent injection pressure, the optimal gasifying agent injection flow rate, and the optimal gas production composition.

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