Coal seam in-situ conversion thermal energy system and method

Abstract

A system and method for in-situ conversion of thermal energy in coal seams, in which the coordinates of a non-vertical channel extending a predetermined distance in the coal seam are used as the target point, and the channel vertically passes through the overburden and the upper edge of the coal seam from the surface, and gradually deflects from the coal seam to the target point until the non-vertical channel is penetrated; a conversion tube is arranged in the conversion channel, one end of the conversion tube is connected to a conversion tube driving device and an injection device on the surface, and the other end in the non-vertical channel is connected to a high-energy device, and the high-energy device generates high-temperature and highly active oxygen-containing component particles through the reaction medium provided by the injection tube to convert the coal seam into hot gas; one end of the recovery pipe is connected to the recovery device and the recovery pipe driving device on the surface, and the other end extending into the coal seam is open, and a comprehensive test device is arranged on the surface part of the recovery pipe to test the flow rate, composition and pressure parameters of the recovered hot gas. This system can efficiently convert underground coal seams directly into stable thermal products.

Description

Technical Field

[0001] The present invention relates to the technical field of coal seam gasification, and in particular to a system and method for in-situ conversion of thermal energy in coal seams. Background Art

[0002] The in-situ conversion technology of coal seams integrates well construction, coal mining and conversion, which can greatly shorten the heating link, thereby reducing carbon emissions and economic costs. Some studies have used the method of in-situ conversion of coal seams. After the coal is ignited in the coal seam after the well is built, oxygen-containing components are introduced, and the heat generated by burning the coal seam is discharged to the surface, or the heat energy is utilized after the sensible heat exchange of coal gas is carried out on the basis of in-situ gasification of the coal seam. The traditional method of in-situ combustion or gasification of coal seams is the spontaneous reaction of underground dense coal seams with oxidants or gasifiers, which is semi-natural force controlled, with low conversion efficiency and low production intensity; in addition, the underground coal seam environment is complex, and coal seam intercalation, underground water gushing and expansion of the reaction chamber all have a serious impact on the conversion reaction. The problem of flameout leading to suspension of production is often encountered, and it is necessary to re-ignite the coal seam to establish a fire zone. The coal seam ignition time takes 3 to 7 days, and the problem of stable heat supply is prominent.

[0003] Therefore, the current method of converting surface coal into thermal energy has the problems of large carbon emissions, high economic costs, and solid waste accumulation. The more advanced method of in-situ thermal energy conversion in coal seams has the problems of low conversion efficiency, low production intensity, and difficulty in stable heat supply. In view of the current problems of in-situ thermal energy conversion in coal seams, there is an urgent need for an efficient and stable in-situ thermal energy conversion system and method for coal seams to directly convert underground coal seams into stable thermal products.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0005] The purpose of the present invention is to provide a system and method for in-situ conversion of thermal energy in coal seams. In view of the problems of low conversion efficiency, low production intensity and difficulty in stable heat supply in the current in-situ conversion of thermal energy in coal seams, the present invention excites and dissociates the reaction medium mainly containing oxygen components to produce excited atoms or molecules, ground atoms or molecules, positive ions, negative ions and other active particles in the underground coal seams, and efficiently converts coal resources into high-grade thermal energy products on site. The system solves the problems of low conversion efficiency, low production intensity and difficulty in stable heat supply in the conventional in-situ conversion of thermal energy in coal seams. In order to achieve the above purpose, the present invention provides the following technical solutions:

[0006] A coal seam in-situ conversion thermal energy system of the present invention comprises:

[0007] A conversion channel, which vertically passes through the overburden and the upper edge of the coal seam from the surface and then gradually deflects to the horizontal direction to form a non-vertical channel in the coal seam, with the coordinates of the non-vertical channel extending a predetermined distance in the coal seam as the target point, and also vertically passes through the overburden and the upper edge of the coal seam from the surface, and gradually deflects from the coal seam to the target point until the non-vertical channel is penetrated;

[0008] A conversion component comprising,

[0009] A conversion tube is arranged in the conversion channel, one end of the conversion tube is connected to a conversion tube driving device and an injection device on the surface, and the other end in the non-vertical channel is connected to a high-energy device. A coaxial injection tube is arranged in the conversion tube, and a reaction medium injection tube, a cooling medium injection tube and a power cable are wrapped in the injection tube.

[0010] A conversion tube driving device is arranged on the surface to controllably move the conversion tube.

[0011] The injection device is connected to the conversion tube drive device and the injection tube to control the reaction medium injection amount and the cooling medium inlet loop flow rate. The injection device is provided with a plurality of reaction medium injection ports, cooling medium injection ports, power cables and corresponding valves and switches.

[0012] A high energy device that generates high temperature and highly reactive oxygen-containing component particles through a reaction medium provided through an injection pipe to convert the coal seam into hot gas;

[0013] A harvesting assembly comprising,

[0014] A recovery pipe driving device is provided on the ground to controllably move the recovery pipe.

[0015] A recovery device is arranged in the recovery pipe driving device and connected to the surface outlet of the recovery pipe. The recovery device is provided with a plurality of outlet valves for outputting hot gas.

[0016] The recovery pipe has one end connected to the recovery device and the recovery pipe driving device on the surface, and the other end extending into the coal seam is open.

[0017] The temperature measuring device is installed inside the recovery pipe to monitor the temperature distribution of the hot gas in the coal seam and the recovery pipe.

[0018] A comprehensive testing device is arranged on the surface of the recovery pipe to test the flow, composition and pressure parameters of the recovered hot gas.

[0019] In the coal seam in-situ conversion thermal energy system, the reaction medium includes air, pure oxygen, a mixture of oxygen and nitrogen with different volume fractions, oxygen and carbon dioxide with different volume fractions, oxygen and water with different volume fractions, oxygen and combustible gas with different volume fractions, and a combination of the above gases.

[0020] In the coal seam in-situ conversion thermal energy system, the high-energy device excites or dissociates the reaction medium to produce high-temperature and highly active oxygen-containing component particles, and the oxygen-containing component particles include excited state atoms or molecules, ground state atoms or molecules, positive ions, and negative ions.

[0021] In the coal seam in-situ conversion thermal energy system, the high-energy device includes a plasma generator or a high-energy burner.

[0022] In the coal seam in-situ conversion thermal energy system, the conversion tube driving device drives the conversion tube to perform forward and backward movements with a moving accuracy of 0.1m, and the recovery tube driving device drives the recovery tube to perform forward and backward movements with a moving accuracy of 0.1m.

[0023] In the coal seam in-situ conversion thermal energy system, the recovery pipe is coated with an insulation layer on the outside and an interlayer is arranged on the inside.

[0024] In the coal seam in-situ conversion thermal energy system, the interlayer is a hot gas annulus interlayer or a heating wire interlayer wrapped with a resistance heating wire.

[0025] In the coal seam in-situ conversion thermal energy system, the temperature measuring device includes a single multi-point temperature measuring thermocouple, and the temperature measuring range of the thermocouple is 50-1700°C.

[0026] In the coal seam in-situ conversion thermal energy system, the length of the thermocouple is consistent with that of the recovery pipe, the temperature measuring points are densely distributed at the end of the recovery pipe, and the temperature measuring points are sparse in the direction far from the end.

[0027] The conversion method of the coal seam in-situ conversion thermal energy system includes:

[0028] The non-vertical channel is formed in the coal seam after vertically passing through the overburden and the upper edge of the coal seam from the ground surface and then gradually deflecting to the horizontal direction. The coordinates of the non-vertical channel extending a predetermined distance in the coal seam are taken as the target point. The overburden and the upper edge of the coal seam are also vertically passed through from the ground surface, and the coal seam is gradually deflected to the target point until the non-vertical channel is penetrated to form a conversion channel.

[0029] The conversion tube extends from the surface into the coal seam in the conversion channel. One end of the conversion tube is connected to the conversion tube driving device and the injection device on the surface, and the other end is connected to the high-energy device on the surface and lowered to the coal seam. The injection tube is located in the conversion tube and is coaxial with the conversion tube. The injection tube wraps the reaction medium injection tube, the cooling medium injection tube and the power cable. The injection tube is connected to the conversion tube driving device, the injection device and the high-energy device respectively along the conversion tube. One end of the recovery tube is connected to the recovery device and the recovery tube driving device on the surface, and the other end extends into the coal seam. The recovery device is arranged in the recovery tube driving device and connected to the surface end outlet of the recovery tube.

[0030] The reaction medium is injected by the injection device, and the flow data of the comprehensive test device is used to feedback whether the conversion channel and the recovery pipe are unobstructed. After confirming that the conversion channel and the recovery pipe are unobstructed, the reaction medium and the cooling medium are injected by the injection device, and the high-energy device is started. The reaction medium flow and the power of the high-energy device are gradually adjusted to keep the load of the high-energy device between 10% and 50%. In addition to the injected inert gas, the volume fraction of CO2 in the outlet gas is greater than 10%, indicating that the coal seam conversion production has begun; during the conversion production process, when the temperature feedback of the temperature measuring device is 1000℃ and the flow feedback of the comprehensive test device is more than 1.1 times of the reaction medium injection flow, it indicates that the coal seam conversion production is normal and the distance between the recovery pipe and the high-energy device is normal;

[0031] During the conversion production process, if the feedback temperature of the temperature measuring device is lower than 1000℃ and the feedback flow rate of the comprehensive test device remains at least 1.1 times the injection flow rate of the reaction medium, move the recovery pipe toward the high-energy device until the feedback temperature of the temperature measuring device is 1000℃ and stop moving; when the feedback temperature of the temperature measuring device is 1000℃ but the feedback flow rate of the comprehensive test device continues to decrease, increase the injection flow rate of the reaction medium and the power of the high-energy device to increase the conversion reaction load to 60%~100%; the feedback temperature of the temperature measuring device and the feedback flow rate of the comprehensive test device both begin to decrease. After the temperature drops, keep the high-energy device started, withdraw the conversion tube 5 to 50 meters, and after the conversion tube is withdrawn, extend the recovery tube 5 to 50 meters to continue the coal seam conversion production; if the temperature feedback from the temperature measuring device continues to rise and exceeds 1000℃, but the flow feedback from the comprehensive test device is stable, withdraw the recovery tube until the gas temperature drops and stabilizes at 1000℃; if the temperature feedback from the temperature measuring device and the flow feedback from the comprehensive test device continue to rise, reduce the reaction medium injection flow and the power of the high-energy device until the gas temperature and the outlet gas flow are maintained in the normal range;

[0032] The production is adjusted in this way in a cycle. When the moving distance of the conversion tube drive device and the recovery tube drive device is close to the non-vertical channel distance, the power supply of the high-energy device is turned off, the injection of the reaction medium is stopped, the injection of the cooling medium is maintained, and the conversion tube and the recovery tube are withdrawn to the surface respectively.

[0033] In the above technical scheme, the present invention provides a coal seam in-situ conversion thermal energy system and method, which has the following beneficial effects: by exciting and dissociating the reaction medium mainly containing oxygen components by means including but not limited to plasma, high-energy burners, etc., excited atoms or molecules, ground atoms or molecules, positive ions, negative ions and other active particles are generated, and coal resources are efficiently converted into high-grade thermal energy products in situ in the underground coal seam, with high conversion efficiency, high production intensity, few by-products, and environmental friendliness. According to the technical characteristics of underground in-situ conversion of coal seams, a coal seam in-situ plasma conversion thermal energy control method is disclosed, which has strong operability and can ensure stable heat supply. The outer surface of the recovery pipe is coated with an insulation layer, and an interlayer is arranged inside. The interlayer includes but is not limited to passing hot gas or wrapping a resistance heating wire, etc., to prevent the heat loss of hot gas and maximize the heat recovery. The system solves the problems of low conversion efficiency, low production intensity and difficulty in stable heat supply in conventional coal seam in-situ conversion thermal energy methods, and can be used for the development and utilization of carbon-based energy such as coal, peat, oil sands, coal gangue, oil shale, and heavy oil layers. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0035] Figure 1 A schematic structural diagram of a coal seam in-situ thermal energy conversion system provided for one embodiment of the present invention.

[0036] Figure 2 A schematic cross-sectional diagram of a recovery pipe of a coal seam in-situ thermal energy conversion system provided in accordance with an embodiment of the present invention.

[0037] Figure 3 A process flow chart of a method for in-situ conversion of thermal energy in coal seams provided in accordance with one embodiment of the present invention.

[0038] Description of reference numerals:

[0039] 1. Coal seam; 2. Overburden; 3. Ground surface; 4. Conversion channel; 5. Conversion assembly; 6. Recovery assembly; 7. Conversion tube; 8. Injection tube; 9. High-energy device; 10. Conversion tube drive device; 11. Injection device; 12. Recovery tube; 13. Insulation layer; 14. Temperature measuring device; 15. Comprehensive testing device; 16. Recovery device; 17. Recovery tube drive device; 18. Interlayer. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0047] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0048] See also Figure 1-2 As shown, in one embodiment, a coal seam in-situ thermal energy conversion system of the present invention comprises:

[0049] The conversion channel 4, which vertically passes through the overburden 2 and the upper edge of the coal seam 1 from the ground surface 3, gradually deflects to the horizontal direction to form a non-vertical channel in the coal seam 1, with the coordinates of the non-vertical channel extending a predetermined distance in the coal seam 1 as the target point, also vertically passes through the overburden 2 and the upper edge of the coal seam 1 from the ground surface 3, and gradually deflects from the coal seam to the target point until the non-vertical channel is penetrated;

[0050] A conversion component 5, comprising,

[0051] The conversion tube 7 is arranged in the conversion channel 4. One end of the conversion tube 7 is connected to the conversion tube driving device and the injection device 11 on the ground surface 3, and the other end in the non-vertical channel is connected to the high-energy device 9. A coaxial injection pipe is arranged in the conversion tube 7. The injection pipe 8 encloses the reaction medium injection pipe, the cooling medium injection pipe and the power cable.

[0052] A conversion tube driving device 10 is arranged on the ground surface 3 to controllably move the conversion tube 7,

[0053] The injection device 11 is connected to the conversion tube driving device 10 and the injection pipe 8 to control the injection amount of the reaction medium and the flow rate of the cooling medium inlet loop. The injection device 11 is provided with a plurality of reaction medium injection ports, cooling medium injection ports, power cables and corresponding valves and switches.

[0054] A high energy device 9, which generates high temperature and high activity oxygen-containing component particles through a reaction medium provided by an injection pipe 8 to convert the coal seam into hot gas;

[0055] A harvesting assembly 6, comprising:

[0056] The recovery pipe driving device 17 is arranged on the ground to controllably move the recovery pipe 12.

[0057] The recovery device 16 is arranged in the recovery pipe driving device 17 and connected to the surface outlet 3 of the recovery pipe 12. The recovery device 16 is provided with a plurality of outlet valves for outputting the hot gas.

[0058] The recovery pipe 12 has one end connected to the recovery device 16 and the recovery pipe driving device 17 at the surface 3, and the other end extending into the coal seam is open.

[0059] The temperature measuring device 14 is arranged inside the recovery pipe 12 to monitor the temperature distribution of the hot gas in the coal seam and the recovery pipe 12.

[0060] A comprehensive testing device 15 is arranged at the surface portion of the recovery pipe 12 to test the flow rate, composition and pressure parameters of the recovered hot gas.

[0061] In a preferred embodiment of the coal seam in-situ conversion thermal energy system, the reaction medium includes air, pure oxygen, a mixture of oxygen and nitrogen with different volume fractions, oxygen and carbon dioxide with different volume fractions, oxygen and water with different volume fractions, oxygen and combustible gas with different volume fractions, and a combination of the above gases.

[0062] In a preferred embodiment of the coal seam in-situ conversion thermal energy system, the high-energy device 9 excites or dissociates the reaction medium to produce high-temperature and highly active oxygen-containing component particles, and the oxygen-containing component particles include excited state atoms or molecules, ground state atoms or molecules, positive ions, and negative ions.

[0063] In a preferred embodiment of the coal seam in-situ thermal energy conversion system, the high-energy device 9 includes a plasma generator or a high-energy burner.

[0064] In a preferred embodiment of the coal seam in-situ conversion thermal energy system, the conversion tube driving device 10 drives the conversion tube 7 to perform forward and backward movements with a moving accuracy of 0.1 m, and the recovery tube driving device drives the recovery tube 12 to perform forward and backward movements with a moving accuracy of 0.1 m.

[0065] In a preferred embodiment of the coal seam in-situ thermal energy conversion system, the recovery pipe 12 is coated with an insulation layer 13 on the outside and an interlayer 18 is provided on the inside.

[0066] In a preferred embodiment of the coal seam in-situ thermal energy conversion system, the interlayer 18 is a hot gas annulus interlayer or a heating wire interlayer wrapped with a resistance heating wire.

[0067] In a preferred embodiment of the coal seam in-situ conversion thermal energy system, the temperature measuring device 14 includes a single multi-point temperature measuring thermocouple, and the temperature measuring range of the thermocouple is 50-1700°C.

[0068] In a preferred embodiment of the coal seam in-situ conversion thermal energy system, the length of the thermocouple is consistent with the recovery pipe 12, the temperature measuring points are densely distributed at the end of the recovery pipe 12, and the temperature measuring points are sparse in the direction far from the end.

[0069] A conversion method of a coal seam in-situ conversion thermal energy system comprises:

[0070] The ground surface 3 vertically passes through the overburden 2 and the upper edge of the coal seam 1, and then gradually deflects to the horizontal direction to form a non-vertical channel in the coal seam 1. The coordinates of the non-vertical channel extending a predetermined distance in the coal seam are taken as the target point. The ground surface 3 also vertically passes through the overburden 2 and the upper edge of the coal seam 1, and gradually deflects from the coal seam 1 to the target point until the non-vertical channel is penetrated to form a conversion channel 4.

[0071] The conversion tube 7 extends from the surface 3 into the coal seam in the conversion channel 4. One end of the conversion tube 7 is connected to the conversion tube driving device 10 and the injection device 11 on the surface 3, and the other end is connected to the high-energy device 9 on the surface 3 and lowered to the coal seam. The injection tube 8 is located in the conversion tube 7 and is coaxial with the conversion tube 7. The injection tube 8 wraps the reaction medium injection tube, the cooling medium injection tube and the power cable. The injection tube 8 is connected to the conversion tube driving device 10, the injection device 11 and the high-energy device 9 respectively along with the conversion tube 7. One end of the recovery tube 12 is connected to the recovery device 16 and the recovery tube driving device 17 on the surface 3, and the other end extends into the coal seam. The recovery device 16 is arranged in the recovery tube driving device and connected to the surface 3 end outlet of the recovery tube 12;

[0072] See also Figure 3 As shown, in one embodiment, a method for in-situ conversion of thermal energy in a coal seam of the present invention comprises:

[0073] The reaction medium is injected by the injection device 11, and the flow data of the comprehensive test device 15 is fed back to check whether the conversion channel 4 and the recovery pipe 12 are unobstructed. After confirming that the conversion channel 4 and the recovery pipe 12 are unobstructed, the reaction medium and the cooling medium are injected by the injection device 11, and the high-energy device 9 is started. The reaction medium flow and the power of the high-energy device 9 are gradually adjusted to keep the load of the high-energy device 9 between 10% and 50%, and the normal conversion production of the coal seam conversion begins. During the conversion production process, the temperature feedback from the temperature measuring device 14 is 1000°C, and the flow feedback from the comprehensive test device 15 is 1.1 times the injection flow of the reaction medium, indicating that the coal seam conversion production is normal, and the distance between the recovery pipe 12 and the high-energy device 9 is normal. Normal, if the feedback temperature of the temperature measuring device 14 is lower than 1000℃ and the feedback flow rate of the comprehensive test device 15 is maintained at more than 1.1 times of the reaction medium injection flow rate, move the recovery pipe 12 toward the high energy device 9 until the feedback temperature of the temperature measuring device 14 is around 1000℃, and stop moving. When the feedback temperature of the temperature measuring device 14 is at 1000℃, but the feedback flow rate of the comprehensive test device 15 continues to decrease, increase the reaction medium injection flow rate and the power of the high energy device 9 to increase the conversion reaction load to 60%~100%. After the feedback temperature of the temperature measuring device 14 and the feedback flow rate of the comprehensive test device 15 begin to decrease, keep the high energy device 9 started, and withdraw the conversion pipe 7. 5~50m, after the conversion tube 7 is withdrawn, the recovery tube 12 is extended forward and moved 5~50m to continue the coal seam conversion production, and the production is adjusted in this cycle. When the moving distance of the conversion tube driving device 10 and the recovery tube driving device 17 is close to the non-vertical channel distance, the power supply of the high-energy device 9 is turned off, the injection of the reaction medium is stopped, the injection of the cooling medium is maintained, and the conversion tube 7 and the recovery tube 12 are respectively withdrawn to the surface 3.

[0074] In one embodiment, by exciting and dissociating a reaction medium mainly composed of oxygen-containing components through methods including but not limited to plasma and high-energy burners, active particles such as excited atoms or molecules, ground-state atoms or molecules, positive ions and negative ions are generated, and coal resources are efficiently converted into high-grade thermal energy products on-site in underground coal seams. Based on the technical characteristics of underground in-situ conversion of coal seams, a method for regulating thermal energy of in-situ plasma conversion of coal seams is disclosed.

[0075] The underground coal in-situ efficient thermal energy conversion system comprises a conversion channel 4, a conversion component 5, and a harvesting component 6. After vertically passing through the overburden 2 and the upper edge of the coal seam from the ground surface 3, it gradually deflects to the horizontal direction to form a non-vertical channel in the coal seam, and the coordinates of the non-vertical channel extending a certain distance in the coal seam are taken as the target point, and the ground surface 3 also vertically passes through the overburden 2 and the upper edge of the coal seam, and gradually deflects from the coal seam to the target point until it penetrates, that is, a conversion channel 4 is formed.

[0076] The conversion assembly 5 includes a conversion tube 7, an injection tube 8, a high-energy device 9, a conversion tube drive device 10, and an injection device 11. The conversion tube 7 is in the conversion channel 4, extending from the surface 3 into the coal seam. One end of the conversion tube 7 is connected to the conversion tube drive device 10 and the injection device 11 on the surface 3, and the other end is connected to the high-energy device 9 on the surface 3 and lowered to the coal seam. The injection tube 8 is located in the conversion tube 7 and is coaxial with the conversion tube 7. The reaction medium injection tube, cooling medium injection tube and power supply cable required by the high-energy device 9 are wrapped in the injection tube 8. The injection tube 8 is connected to the conversion tube drive device 10 and the injection device 11, as well as the high-energy device 9 along with the conversion tube 7. The high-energy device 9 includes, but is not limited to, plasma, high-energy burners, etc., and uses air, pure oxygen, mixed gases of oxygen and nitrogen with different volume fractions, oxygen and carbon dioxide with different volume fractions, oxygen and water with different volume fractions, oxygen and combustible gases with different volume fractions, and combinations of the above gases as working media, which can produce high-temperature and highly active oxygen-containing component particles, and quickly and efficiently convert coal seams into high-temperature gases. The conversion tube drive device 10 is connected to one end of the conversion tube 7, and can be used to accurately move the conversion tube 7, including forward extension and backward movements, and the moving distance is accurate to 0.1m. The injection device 11 is connected to the conversion tube drive device 10 and communicated with the injection pipe 8 in the conversion tube 7. The injection device 11 is provided with multiple reaction medium injection ports, cooling medium injection ports, power cables, and corresponding valves, switches, etc. Each medium valve and each power switch is manually or automatically adjusted. The injection device 11 is used to accurately control the injection amount of the reaction medium, allocate the reaction medium injection components, control the cooling medium inlet circuit flow, and control the start, shutdown and power of the high-energy device 9.

[0077] The harvesting assembly 6 includes a harvesting pipe 12 , a temperature measuring device 14 , a comprehensive testing device 15 , a harvesting device 16 and a harvesting pipe driving device 17 . The recovery pipe 12 is located in the conversion channel 4, one end of the recovery pipe 12 is connected to the recovery device 16 and the recovery pipe driving device 17 on the surface 3, and the other end extends into the coal seam, and the end is open; the recovery pipe 12 is made of high-temperature resistant metal or non-metallic materials, etc., the outside of the recovery pipe 12 is covered with an insulation layer 13, and an interlayer 18 is arranged inside. The interlayer 18 includes but is not limited to passing hot gas or wrapping resistance heating wires, etc., to prevent the heat loss of the hot gas and maximize the heat recovery; a single multi-point temperature measuring thermocouple is inserted into the recovery pipe 12 as a temperature measuring device 14, the length of the thermocouple is consistent with that of the recovery pipe 12, the temperature measuring points are densely distributed at the end of the recovery pipe 12, and the temperature measuring points are sparse in the far end direction, the temperature measuring device 14 moves with the recovery pipe 12 in the coal seam, the temperature measuring device 14 is used to monitor the temperature distribution of the hot gas in the coal seam and the recovery pipe 12, the temperature measuring range is 50~1700℃, and the temperature measuring device 14 can be used to feedback the underground thermal energy conversion situation and provide a basis for the regulation of the conversion reaction. The comprehensive testing device 15 is arranged on the surface 3 part of the recovery pipe 12, and is used to test the parameters such as the flow rate, composition and pressure of the recovered hot gas. The comprehensive testing device 15 can be used to feedback the underground reaction situation and provide a basis for the regulation of the conversion reaction. The recovery device 16 is located in the recovery pipe driving device and is connected to the outlet at the surface 3 end of the recovery pipe 12. The recovery device 16 is provided with 1 to 3 outlet valves, which can be adjusted manually or automatically, and are used to stably output the hot gas to the heat energy utilization user. The recovery pipe driving device 17 is integrated with the recovery device 16 and is connected to one end of the surface 3 of the recovery pipe 12, and is used to accurately control the movement of the recovery pipe 12, including the forward extension and backward movement, and the moving distance is accurate to 0.1m.

[0078] In one embodiment, the conversion method comprises,

[0079] 1) Installation

[0080] After vertically passing through the overburden 2 and the upper edge of the coal seam 1 from the ground surface 3, it gradually deflects to the horizontal direction, forming a non-vertical channel in the coal seam 1. The coordinates of the non-vertical channel extending a certain distance in the coal seam 1 are taken as the target point. Similarly, the ground surface 3 vertically passes through the overburden 2 and the upper edge of the coal seam, and gradually deflects from the coal seam to the target point until it penetrates, thus forming a conversion channel 4.

[0081] The conversion tube 7 extends from the surface 3 into the coal seam in the conversion channel 4. One end of the conversion tube 7 is connected to the conversion tube driving device 10 and the injection device 11 on the surface 3, and the other end is connected to the high-energy device 9 on the surface 3 and lowered into the coal seam. The injection pipe 8 is located in the conversion tube 7 and is coaxial with the conversion tube 7. The injection pipe 8 contains the reaction medium injection pipe, the cooling medium injection pipe and the power cable required by the high-energy device 9. The injection pipe 8 is connected to the conversion tube driving device 10 and the injection device 11, as well as the high-energy device 9 along with the conversion tube 7.

[0082] The conversion tube driving device 10 is connected to one end of the conversion tube 7, and the injection device 11 is connected to the conversion tube driving device 10 and communicates with the injection pipe 8 in the conversion tube 7. The injection device 11 is provided with multiple reaction medium injection ports, cooling medium injection ports, power cables and corresponding valves, switches, etc.

[0083] The recovery pipe 12 is located in the conversion channel 4. One end of the recovery pipe 12 is connected to the recovery device 16 and the recovery pipe driving device 17 on the surface 3, and the other end extends into the coal seam. The comprehensive testing device 15 is arranged on the surface 3 part of the recovery pipe 12. The recovery device 16 is located in the recovery pipe driving device and is connected to the outlet of the surface 3 end of the recovery pipe 12. The recovery device 16 is provided with 1 to 3 outlet valves, which can be adjusted manually or automatically. The recovery pipe driving device 17 is integrated with the recovery device 16 and connected to one end of the recovery pipe 12 on the surface 3.

[0084] According to the construction and installation method, the conversion channel 4 is processed and all components are installed. The high-energy device 9 is debugged on the surface 3 to test the inflow and outflow of the reaction medium and the inflow and outflow of the cooling medium. The power is turned on to test the startup and the reaction medium flow and power adjustment to be normal. The high-energy device 9 is lowered to the conversion channel 4 through the conversion tube drive device 10 and extended to the coal seam until the horizontal distance of the vertical section on one side of the recovery pipe 12 is 5 to 50 meters. The recovery pipe 12 is lowered by the recovery pipe drive device 17 to the upper edge of the coal seam and lowered 0.5 to 2 meters.

[0085] 2) Initiation of conversion reaction

[0086] A certain flow rate of reaction medium is injected by the injection device 11, and the flow data of the comprehensive testing device 15 is fed back to check whether the conversion channel 4 and the recovery pipe 12 are unobstructed. After confirming that the conversion channel 4 and the recovery pipe 12 are unobstructed, the reaction medium and the cooling medium are injected by the injection device 11, and the power start switch of the high energy device 9 is turned on to start the high energy device 9.

[0087] The integrated test device 15 provides component feedback. When the gas at the outlet of the recovery pipe 12 is depleted of the injected inert gas (N 2 , CO2, etc.), the volume percentage of CO2 is higher than 10%, which means that the coal seam has started to convert. Gradually adjust the reaction medium flow rate and the power of the high energy device 9, keep the load of the high energy device 9 between 10% and 50%, and start the normal conversion production of the coal seam conversion.

[0088] 3) Main operations of the conversion process

[0089] according to Figure 3 The test data is fed back to identify the corresponding working conditions and operate the corresponding process control methods to enable the underground coal to efficiently and stably convert thermal energy in situ.

[0090] During the conversion production process, focus on the temperature feedback of the temperature measuring device 14 and the gas flow of the comprehensive testing device 15. When the feedback temperature of the temperature measuring device 14 is around 1000°C and the feedback flow of the comprehensive testing device 15 is more than 1.1 times the injection flow of the reaction medium, it indicates that the coal seam conversion production is normal and the distance between the recovery pipe 12 and the high-energy device 9 is normal.

[0091] During the production process, if the feedback temperature of the temperature measuring device 14 is lower than 1000°C, and the feedback flow rate of the comprehensive testing device 15 remains at least 1.1 times the injection flow rate of the reaction medium, it indicates that the recovery pipe 12 is too far away from the high energy device 9. The recovery pipe 12 is moved toward the high energy device 9 until the feedback temperature of the temperature measuring device 14 is around 1000°C, then the movement is stopped and normal coal seam conversion production is started;

[0092] For example, after a period of normal production, when the feedback temperature of the temperature measuring device 14 is still around 1000°C, but the feedback flow of the comprehensive testing device 15 continues to decrease, it indicates that the conversion reaction intensity of the coal seam decreases with the increase of the reaction cavity. At this time, it is necessary to increase the injection flow of the reaction medium and the power of the high-energy device 9 to increase the conversion reaction load to 60%~100%;

[0093] After a period of normal production, if the temperature feedback from the temperature measuring device 14 and the flow feedback from the comprehensive testing device 15 both begin to decrease, it indicates that the coal seam covered between the high-energy device 9 and the recovery pipe 12 has been converted. Keep the high-energy device 9 started, and move the conversion pipe 7 back 5 to 50 meters. After the conversion pipe 7 is withdrawn, correspondingly, move the recovery pipe 12 forward 5 to 50 meters to continue the coal seam conversion production;

[0094] If the feedback temperature of the temperature measuring device 14 is above 1000°C and continues to rise, while the feedback flow of the comprehensive testing device 15 remains basically stable, it indicates that the recovery pipe 12 is too close to the high-energy device 9. In order to protect the recovery assembly 6, the recovery pipe 12 is gradually withdrawn until the feedback temperature of the temperature measuring device 14 is stable at about 1000°C, and the coal seam conversion production continues;

[0095] If the feedback temperature of the temperature measuring device 14 and the feedback flow of the comprehensive testing device 15 continue to increase, it indicates that the reaction intensity in this section is too large. In order to maintain a stable supply of thermal energy products, the injection flow of the reaction medium and the power of the high-energy device 9 are gradually reduced until the feedback temperature of the temperature measuring device 14 stabilizes at around 1000°C and the feedback flow of the comprehensive testing device 15 remains in the normal range, and the coal seam conversion production continues.

[0096] 4) Production end operation

[0097] The production is adjusted in this way. According to the statistics of the moving distance of the conversion tube driving device 10 and the recovery tube driving device 17, when the horizontal moving distance of the two is close to the non-vertical section distance of the conversion channel 4, it indicates that the coal seam covered by the unit has been converted. Turn off the power supply of the high-energy device 9, stop the injection of the reaction medium, maintain the injection of the cooling medium, and withdraw the conversion tube 7 and the recovery tube 12 to the surface 3 respectively. Perform the production end operation. According to the above method, construction, installation and conversion production are carried out in another target coal seam block.

[0098] Example 1: (Air plasma efficiently converts lignite layer into thermal energy)

[0099] The embodiment of the present invention proposes a method for efficiently converting lignite into thermal energy using air plasma. The lignite seam resource is buried at a depth of about 1,150 meters, the average thickness of the coal seam is 7.5 meters, and the mining area is about 56 kilometers away from the urban area. The thermal energy utilization of this project is mainly used for heating residents in winter, and the production cycle is from October 1st of each year to May 1st of the following year. According to the heating demand and coal quality characteristics, a conversion unit is designed to cover a horizontal distance of 550 meters from the coal seam.

[0100] After vertically passing through the overburden layer 2 and the upper edge of the lignite layer from the ground surface 3, it gradually deflects to the horizontal direction, forming a non-vertical channel in the lignite layer. The coordinates of the non-vertical channel extending a certain distance in the lignite layer are taken as the target point. Similarly, the ground surface 3 vertically passes through the overburden layer 2 and the upper edge of the lignite layer, and gradually deflects from the lignite layer to the target point until it penetrates, thus forming a conversion channel 4 unit.

[0101] The conversion tube 7 extends from the ground surface 3 into the lignite layer in the conversion channel 4. One end of the conversion tube 7 is connected to the conversion tube driving device 10 and the injection device 11 on the ground surface 3, and the other end is connected to the high-energy device 9 on the ground surface 3 and lowered to the lignite layer. The injection pipe 8 is located in the conversion tube 7 and is coaxial with the conversion tube 7. The injection pipe 8 contains the air injection pipe, the cooling medium injection pipe and the power cable required by the plasma generator. The injection pipe 8 is connected to the conversion tube driving device 10 and the injection device 11, as well as the plasma generator along with the conversion tube 7.

[0102] The conversion tube driving device 10 is connected to one end of the conversion tube 7, and the injection device 11 is connected to the conversion tube driving device 10 and communicates with the injection pipe 8 in the conversion tube 7. The injection device 11 is provided with an air injection port, a cooling medium injection port, a power cable and corresponding valves, switches, etc.

[0103] The recovery pipe 12 is located in the conversion channel 4. One end of the recovery pipe 12 is connected to the recovery device 16 and the recovery pipe driving device 17 on the surface 3, and the other end extends into the lignite layer. The comprehensive testing device 15 is arranged on the surface 3 part of the recovery pipe 12. The recovery device 16 is located in the recovery pipe driving device and is connected to the outlet of the recovery pipe 12 on the surface 3. The recovery device 16 is provided with two outlet valves, which can be adjusted manually or automatically. The recovery pipe driving device 17 is integrated with the recovery device 16 and connected to one end of the recovery pipe 12 on the surface 3.

[0104] According to the construction and installation method, the conversion channel 4 is processed and all components are installed. The plasma generator is debugged on the surface 3, and the air medium in and out and the cooling medium in and out circulation are tested. The power is turned on to test the startup and air flow and power adjustment to be normal. The plasma generator is lowered to the conversion channel 4 through the conversion tube drive device 10, and extended to the lignite layer until the horizontal distance of the vertical section on one side of the collection tube 12 is 20m. The collection tube 12 is lowered to the upper edge of the lignite layer by the collection tube drive device 17 and lowered 1m.

[0105] 100 Nm is injected by the injection device 11 3 / h air, and the flow data of the comprehensive testing device 15 is fed back to see whether the conversion channel 4 and the collection pipe 12 are unobstructed. After confirming that the conversion channel 4 and the collection pipe 12 are unobstructed, the injection device 11 injects air and cooling medium, turns on the power start switch of the high energy device 9, and starts the high energy device 9.

[0106] According to the feedback from the comprehensive test device 15, when the volume percentage of CO2 in the gas at the outlet of the recovery pipe 12 is higher than 10% in addition to the injected N2, it indicates that the lignite layer has started to convert. Gradually adjust the air flow rate to 500 Nm 3 / h, the plasma generator power reaches about 1000 kW, the plasma generator load is maintained at about 50%, and the normal conversion production of the lignite seam conversion begins. During the production process, the temperature measurement device 14 feedback temperature is about 1000℃, and the comprehensive test device 15 feedback outlet gas flow rate is 730 Nm 3 / h, which is more than 1.4 times the injection flow rate of the reaction medium, indicating that the conversion production is normal and the distance between the recovery pipe 12 and the high-energy device 9 is normal.

[0107] After 6 days of normal production, the temperature measured by the temperature measuring device 14 was about 1020℃ and fluctuated within 5℃. However, the flow rate of the comprehensive testing device 15 continued to decrease, indicating that the conversion reaction intensity of the lignite layer decreased with the increase of the reaction cavity. At this time, the air flow rate needs to be increased to 900 Nm 3 / h, the plasma generator power reaches about 1700 kW, and the conversion reaction load increases to about 90%.

[0108] After 4 days of continuous production, the temperature feedback from the temperature measuring device 14 and the flow feedback from the comprehensive testing device 15 began to decrease, indicating that the lignite layer covered between the high-energy device 9 and the recovery pipe 12 had been completely converted. The high-energy device 9 was kept in the started state, and the conversion pipe 7 was withdrawn by 20 m. After the conversion pipe 7 was withdrawn, the recovery pipe 12 was extended by 20 m accordingly to continue the conversion production.

[0109] After 8 months of production adjustment, according to the statistics of the movement distance of the conversion tube drive device 10 and the recovery tube drive device 17, the horizontal movement distance is close to 500m, indicating that the lignite layer covering the unit has been completely converted. Turn off the plasma generator power supply, stop air injection, maintain cooling medium injection, and withdraw the conversion tube 7 and the recovery tube 12 to the surface 3 respectively. Perform the production end operation. The surface 3 and the withdrawn conversion assembly 5 and recovery assembly 6 are arranged for standby use.

[0110] Example 2: (High-energy burner using pure oxygen and natural gas as reaction medium converts long flame coal seam into thermal energy)

[0111] The embodiment of the present invention proposes a method for converting long flame coal seams into thermal energy using a high energy burner with pure oxygen and natural gas as reaction media. The long flame coal seam resources are buried at a depth of about 1260m, the coal seam thickness is 9m on average, and the mining area is about 125km away from the urban area. The thermal energy utilization of this project is mainly used for power generation, with long-term stable production. A conversion unit is designed to cover a horizontal distance of 1500m from the coal seam.

[0112] After vertically passing through the overburden 2 and the upper edge of the long flame coal seam from the ground surface 3, it gradually deflects to the horizontal direction, forming a non-vertical channel in the long flame coal seam. The coordinates of the non-vertical channel extending a certain distance in the long flame coal seam are used as the target point. Similarly, it vertically passes through the overburden 2 and the upper edge of the long flame coal seam from the ground surface 3, and gradually deflects from the long flame coal seam to the target point until it penetrates, thus forming a conversion channel 4 unit.

[0113] The conversion tube 7 extends from the ground surface 3 into the long flame coal seam in the conversion channel 4. One end of the conversion tube 7 is connected to the conversion tube driving device 10 and the injection device 11 on the ground surface 3, and the other end is connected to the high energy burner on the ground surface 3, and is lowered to the long flame coal seam. The injection pipe 8 is located in the conversion tube 7 and is coaxial with the conversion tube 7. The injection pipe 8 contains the pure oxygen injection pipe, natural gas injection pipe, cooling medium injection pipe and power cable required by the high energy burner. The injection pipe 8 is connected to the conversion tube driving device 10 and the injection device 11, as well as the high energy burner along with the conversion tube 7.

[0114] The conversion tube driving device 10 is connected to one end of the conversion tube 7, and the injection device 11 is connected to the conversion tube driving device 10 and communicated with the injection pipe 8 in the conversion tube 7. The injection device 11 is provided with a pure oxygen injection port, a natural gas injection port, a cooling medium injection port, a power cable and corresponding valves, switches, etc.

[0115] The recovery pipe 12 is located in the conversion channel 4. One end of the recovery pipe 12 is connected to the recovery device 16 and the recovery pipe driving device 17 on the ground surface 3, and the other end extends into the long flame coal seam. The comprehensive testing device 15 is arranged on the ground surface 3 part of the recovery pipe 12. The recovery device 16 is located in the recovery pipe driving device and is connected to the outlet of the ground surface 3 end of the recovery pipe 12. The recovery device 16 is provided with 3 outlet valves, 1 open and 2 standby, and the valves can be adjusted manually or automatically. The recovery pipe driving device 17 is integrated with the recovery device 16 and connected to one end of the ground surface 3 of the recovery pipe 12.

[0116] According to the construction and installation method, the conversion channel 4 is processed and all components are installed. The high-energy burner is debugged on the surface 3, and the reaction medium in and out and the cooling medium in and out circulation are tested. The power is turned on to test the startup and reaction medium flow and power adjustment to be normal. The high-energy burner is lowered to the conversion channel 4 through the conversion tube drive device 10, and extended to the long flame coal seam until the horizontal distance of the vertical section on one side of the recovery pipe 12 is 30m. The recovery pipe 12 is lowered by the recovery pipe drive device 17 to the upper edge of the long flame coal seam and lowered 2m.

[0117] Before starting, inject 100 Nm 3 / h nitrogen, and the flow data of the comprehensive testing device 15 is fed back to see whether the conversion channel 4 and the recovery pipe 12 are unobstructed. After confirming that the conversion channel 4 and the recovery pipe 12 are unobstructed, the injection device 11 injects the reaction medium and the cooling medium. The reaction medium is oxygen and natural gas. The injection volume ratio of oxygen and natural gas is 3:1, and the injection natural gas flow rate is 50 Nm 3 / h, oxygen flow rate 150 Nm 3 / h. Turn on the high energy burner start switch to start the high energy burner.

[0118] According to the feedback from the comprehensive test device 15, when the volume percentage of the remaining CO2 in the gas at the outlet of the recovery pipe 12 is higher than 10% except for the CO2 produced by the combustion of the injected natural gas, it indicates that the long flame coal seam has started the conversion reaction. Gradually adjust the natural gas flow rate to 100 Nm 3 / h, oxygen flow rate 300 Nm 3 / h, keeping the high energy burner load at about 50%, and starting the long flame coal seam conversion normal conversion production. During the production process, the temperature measurement device 14 feedback temperature is about 1000℃, and the comprehensive test device 15 feedback outlet gas flow rate is 580 Nm 3 / h, which is about 1.5 times of the reaction medium injection flow rate, indicating that the conversion production is normal and the distance between the recovery pipe 12 and the high-energy burner is normal.

[0119] After 9 days of normal production, the temperature measured by the temperature measuring device 14 was around 990°C and fluctuated within 5°C. However, the flow rate of the comprehensive testing device 15 continued to decrease, indicating that the conversion reaction intensity of the long flame coal seam decreased with the increase of the reaction cavity. At this time, the natural gas flow rate needed to be increased to 200 Nm 3 / h, oxygen flow rate 600 Nm 3 / h, the conversion reaction load is increased to about 100%.

[0120] After production was maintained for 12 hours, the feedback temperature from the temperature measuring device 14 was above 1000°C and continued to rise, while the feedback flow from the comprehensive testing device 15 remained basically stable, indicating that the recovery pipe 12 was too close to the high-energy device 9. In order to protect the recovery component 6, the recovery pipe 12 was gradually withdrawn until the feedback temperature from the temperature measuring device 14 stabilized at around 1000°C, and the coal seam conversion production continued.

[0121] After 20 days of continuous production, the temperature feedback from the temperature measuring device 14 and the flow feedback from the comprehensive testing device 15 began to decrease, indicating that the long flame coal seam covered between the high energy burner and the recovery pipe 12 was completely converted. The high energy burner was kept started, and the conversion pipe 7 was withdrawn by 30m. After the conversion pipe 7 was withdrawn, the recovery pipe 12 was extended by 30m accordingly to continue the conversion production.

[0122] After 49 months of such cycle adjustment, according to the statistics of the movement distance of the conversion tube drive device 10 and the recovery tube drive device 17, the horizontal movement distance is close to 1500m, indicating that the lignite layer covering the unit has been completely converted. Turn off the power supply of the high-energy burner, stop the injection of oxygen and natural gas, maintain the injection of cooling medium, and withdraw the conversion tube 7 and the recovery tube 12 to the surface 3 respectively. Perform the production end operation. The surface 3 and the withdrawn conversion assembly 5 and recovery assembly 6 are arranged for standby use.

[0123] Finally, it should be noted that the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of the present application.

[0124] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A coal seam in-situ thermal energy conversion system, characterized in that: These include, A conversion channel, which vertically passes through the overburden and the upper edge of the coal seam from the surface and then gradually deflects to the horizontal direction to form a non-vertical channel in the coal seam, with the coordinates of the non-vertical channel extending a predetermined distance in the coal seam as the target point, and also vertically passes through the overburden and the upper edge of the coal seam from the surface, and gradually deflects from the coal seam to the target point until the non-vertical channel is penetrated; A conversion component comprising, A conversion tube is arranged in the conversion channel, one end of the conversion tube is connected to a conversion tube driving device and an injection device on the surface, and the other end in the non-vertical channel is connected to a high-energy device. A coaxial injection tube is arranged in the conversion tube, and a reaction medium injection tube, a cooling medium injection tube and a power cable are wrapped in the injection tube. A conversion tube driving device is arranged on the surface to controllably move the conversion tube. The injection device is connected to the conversion tube drive device and the injection tube to control the reaction medium injection amount and the cooling medium inlet loop flow rate. The injection device is provided with a plurality of reaction medium injection ports, cooling medium injection ports, power cables and corresponding valves and switches. A high energy device that generates high temperature and highly reactive oxygen-containing component particles through a reaction medium provided through an injection pipe to convert the coal seam into hot gas; A harvesting assembly comprising, A recovery pipe driving device is provided on the ground to controllably move the recovery pipe. A recovery device is arranged in the recovery pipe driving device and connected to the surface outlet of the recovery pipe. The recovery device is provided with a plurality of outlet valves for outputting hot gas. The recovery pipe has one end connected to the recovery device and the recovery pipe driving device on the surface, and the other end extending into the coal seam is open. The temperature measuring device is installed inside the recovery pipe to monitor the temperature distribution of the hot gas in the coal seam and the recovery pipe. A comprehensive testing device is arranged on the surface of the recovery pipe to test the flow rate, composition and pressure parameters of the recovered hot gas; the reaction medium includes air, pure oxygen, a mixture of oxygen and nitrogen with different volume fractions, oxygen and carbon dioxide with different volume fractions, oxygen and water with different volume fractions, oxygen and combustible gas with different volume fractions, and a combination of the above gases; The high-energy device excites or dissociates the reaction medium to generate high-temperature and high-activity oxygen-containing component particles, which include excited-state atoms or molecules, ground-state atoms or molecules, positive ions, and negative ions.

2. The coal seam in-situ conversion thermal energy system according to claim 1, characterized in that: The high energy device includes a plasma generator or a high energy burner.

3. The coal seam in-situ conversion thermal energy system according to claim 1, characterized in that: The conversion tube driving device drives the conversion tube to perform the forward extension and backward movement with a moving accuracy of 0.1 m, and the recovery tube driving device drives the recovery tube to perform the forward extension and backward movement with a moving accuracy of 0.1 m.

4. The coal seam in-situ conversion thermal energy system according to claim 1, characterized in that: The recovery pipe is coated with a heat-insulating layer on the outside and an interlayer is arranged on the inside.

5. The coal seam in-situ thermal energy conversion system according to claim 4, characterized in that: The interlayer is a hot gas annulus interlayer or a heating wire interlayer wrapping a resistance heating wire.

6. The coal seam in-situ thermal energy conversion system according to claim 1, characterized in that: The temperature measuring device includes a single multi-point temperature measuring thermocouple, and the temperature measuring range of the thermocouple is 50~1700℃.

7. A coal seam in-situ thermal energy conversion system according to claim 6, characterized in that: The length of the thermocouple is consistent with that of the recovery pipe. The temperature measuring points are densely distributed at the end of the recovery pipe and sparsely distributed at the far end.

8. A method for converting coal seam in-situ thermal energy using a system for converting coal seam in-situ thermal energy according to any one of claims 1 to 7, characterized in that: These include, The non-vertical channel is formed in the coal seam after vertically passing through the overburden and the upper edge of the coal seam from the ground surface and then gradually deflecting to the horizontal direction. The coordinates of the non-vertical channel extending a predetermined distance in the coal seam are taken as the target point. The overburden and the upper edge of the coal seam are also vertically passed through from the ground surface, and the coal seam is gradually deflected to the target point until the non-vertical channel is penetrated to form a conversion channel. The conversion tube extends from the surface into the coal seam in the conversion channel. One end of the conversion tube is connected to the conversion tube driving device and the injection device on the surface, and the other end is connected to the high-energy device on the surface and lowered to the coal seam. The injection tube is located in the conversion tube and is coaxial with the conversion tube. The injection tube wraps the reaction medium injection tube, the cooling medium injection tube and the power cable. The injection tube is connected to the conversion tube driving device, the injection device and the high-energy device respectively along the conversion tube. One end of the recovery tube is connected to the recovery device and the recovery tube driving device on the surface, and the other end extends into the coal seam. The recovery device is arranged in the recovery tube driving device and connected to the surface end outlet of the recovery tube. The reaction medium is injected by the injection device, and the flow data of the comprehensive test device is used to feedback whether the conversion channel and the recovery pipe are unobstructed. After confirming that the conversion channel and the recovery pipe are unobstructed, the reaction medium and the cooling medium are injected by the injection device, and the high-energy device is started. The reaction medium flow and the power of the high-energy device are gradually adjusted to keep the load of the high-energy device between 10% and 50%. In addition to the injected inert gas, the volume fraction of CO2 in the outlet gas is greater than 10%, indicating that the coal seam conversion production has begun; during the conversion production process, when the temperature feedback of the temperature measuring device is 1000℃ and the flow feedback of the comprehensive test device is more than 1.1 times of the reaction medium injection flow, it indicates that the coal seam conversion production is normal and the distance between the recovery pipe and the high-energy device is normal; During the conversion production process, if the feedback temperature of the temperature measuring device is lower than 1000℃ and the feedback flow rate of the comprehensive test device remains at least 1.1 times the injection flow rate of the reaction medium, move the recovery pipe toward the high-energy device until the feedback temperature of the temperature measuring device is 1000℃ and stop moving; when the feedback temperature of the temperature measuring device is 1000℃ but the feedback flow rate of the comprehensive test device continues to decrease, increase the injection flow rate of the reaction medium and the power of the high-energy device to increase the conversion reaction load to 60%~100%; the feedback temperature of the temperature measuring device and the feedback flow rate of the comprehensive test device both begin to decrease. After the temperature drops, keep the high-energy device started, withdraw the conversion tube 5 to 50 meters, and after the conversion tube is withdrawn, extend the recovery tube 5 to 50 meters to continue the coal seam conversion production; if the temperature feedback from the temperature measuring device continues to rise and exceeds 1000℃, but the flow feedback from the comprehensive test device is stable, withdraw the recovery tube until the gas temperature drops and stabilizes at 1000℃; if the temperature feedback from the temperature measuring device and the flow feedback from the comprehensive test device continue to rise, reduce the reaction medium injection flow and the power of the high-energy device until the gas temperature and the outlet gas flow are maintained in the normal range; The production is adjusted in this way in a cycle. When the moving distance of the conversion tube drive device and the recovery tube drive device is close to the non-vertical channel distance, the power supply of the high-energy device is turned off, the injection of the reaction medium is stopped, the injection of the cooling medium is maintained, and the conversion tube and the recovery tube are withdrawn to the surface respectively.

Images