A coal underground gasification pellet injection system and its control method

Abstract

This invention provides a coal underground gasification particle mixing and injection system and its control method, belonging to the field of coal underground gasification technology. The system includes: a gasifying agent delivery pipe for delivering the gasifying agent to the location of the coal seam to be gasified; a raw coal particle cutting material delivery pipe for delivering raw coal particle cutting material to the location of the coal seam to be gasified; a raw coal particle cutting material storage section for receiving and temporarily storing the raw coal particle cutting material delivered by the raw coal particle cutting material delivery pipe; a raw coal particle cutting material inlet section for sending the raw coal particle cutting material from the raw coal particle cutting material storage section to a mixing position; and a gas-solid mixing injection section for receiving the gasifying agent delivered by the gasifying agent delivery pipe and the raw coal particle cutting material from the raw coal particle cutting material inlet section, mixing the gasifying agent and raw coal particle cutting material to form a gas-solid mixture flow, and then injecting it into the coal seam to be gasified. This solution uses raw coal particle gas-solid mixing and injection to break and compact the coal seam, expand the gasification reaction area, and improve the efficiency of underground coal gasification.

Description

Technical Field

[0001] This invention relates to the field of underground coal gasification technology, specifically to an underground coal gasification particle mixing and injection system and its control method. Background Technology

[0002] Underground coal gasification (UCG) is a special coal development method that does not involve mining coal to the surface; instead, the coal undergoes pre-processing directly underground. Coal is ignited in situ within the strata through boreholes or tunnels, causing a series of thermal and chemical reactions that transform the solid coal into a gaseous state, which is then transported to the surface. Because the coal is subjected to in-situ stress and compression under these conditions, it is in a compacted state underground. Consequently, the gasifying agent in underground coal gasification can only oxidize and burn on the coal surface, resulting in relatively low efficiency. Summary of the Invention

[0003] The purpose of this invention is to provide a coal underground gasification particle mixing and injection system and its control method, so as to at least solve the problem that the gasifying agent is difficult to penetrate into the compacted coal seam and can only react on the surface of the coal seam in the existing coal underground gasification process, resulting in low gasification efficiency.

[0004] To achieve the above objectives, a first aspect of the present invention provides a coal underground gasification pellet mixing and injection system, the system comprising: a gasifying agent conveying pipe connected to a gasifying agent supply end for conveying the gasifying agent to the location of the coal seam to be gasified; a raw coal pellet cutting material conveying pipe connected to a raw coal pellet cutting material supply end for conveying raw coal pellet cutting material to the location of the coal seam to be gasified; and a raw coal pellet cutting material storage unit connected to the raw coal pellet cutting material conveying pipe for receiving and temporarily storing the raw coal pellets conveyed by the raw coal pellet cutting material conveying pipe. Particle cutting material; raw coal particle cutting material inlet, connected to the raw coal particle cutting material storage section, used to send the raw coal particle cutting material in the raw coal particle cutting material storage section into the mixing position; gas-solid mixing injection section, connected to the gasifying agent conveying pipe and the raw coal particle cutting material inlet respectively, used to receive the gasifying agent conveyed by the gasifying agent conveying pipe and the raw coal particle cutting material inlet, and mix the gasifying agent and the raw coal particle cutting material to form a gas-solid mixed flow before spraying it onto the coal bed to be gasified.

[0005] Optionally, the raw coal pellet cutting material supply end includes: a ground cutting preparation component, a coal inlet, a raw coal crusher, and an air pressurization device; the coal inlet is connected to the raw coal crusher so that the raw coal entering the coal inlet is crushed by the raw coal crusher to form raw coal pellet cutting material; the air pressurization device is connected to the raw coal pellet cutting material conveying pipe so that the raw coal pellet cutting material is sent into the raw coal pellet cutting material conveying pipe with the pressurized airflow.

[0006] Optionally, the raw coal pellet cutting material conveying pipe extends along the shaft to the location of the coal seam to be gasified; the raw coal pellet cutting material storage section is located at one end of the raw coal pellet cutting material conveying pipe near the coal seam to be gasified; the raw coal pellet cutting material storage section is also connected to a raw coal pellet cutting material return gas pipeline; the raw coal pellet cutting material return gas pipeline is connected to a gas circulation pump to guide the sample-carrying gas flow separated from the raw coal pellet cutting material storage section back to the raw coal pellet cutting material supply end.

[0007] Optionally, the raw coal pellet cutting material storage section has an inlet end connected to the raw coal pellet cutting material conveying pipe, a return gas end connected to the raw coal pellet cutting material return gas pipe, and an outlet end connected to the raw coal pellet cutting material inlet section; the raw coal pellet cutting material storage section is used to reduce the flow rate of the raw coal pellet cutting material entering it, and to allow the raw coal pellet cutting material to remain in the raw coal pellet cutting material storage section and then be sent to the raw coal pellet cutting material inlet section through the outlet end.

[0008] Optionally, the raw coal pellet cutting material feeding section includes: a drive motor, a drive gear, a raw coal pellet cutting material conveyor belt, and a feeding control device; the drive motor is connected to the drive gear; the drive gear is engaged with the raw coal pellet cutting material conveyor belt; one end of the raw coal pellet cutting material conveyor belt is correspondingly arranged with the discharge end of the raw coal pellet cutting material storage section, and the other end is correspondingly arranged with the feeding control device, so as to send the raw coal pellet cutting material in the raw coal pellet cutting material storage section into the feeding control device.

[0009] Optionally, the gas-solid mixing injection section includes: a high-speed airflow compression section, a solid cutting material mixing port, and a raw coal particle cutting material mixing section; the high-speed airflow compression section is connected to the gasifying agent delivery pipe to receive and accelerate the gasifying agent delivered by the gasifying agent delivery pipe; the solid cutting material mixing port is connected to the sample injection control device and the raw coal particle cutting material mixing section respectively to introduce the raw coal particle cutting material fed by the sample injection control device into the raw coal particle cutting material mixing section, and to form a gas-solid mixed flow between the raw coal particle cutting material and the gasifying agent output by the high-speed airflow compression section in the raw coal particle cutting material mixing section.

[0010] Optionally, the gas-solid mixing injection section further includes a throat and a flow stabilizing chamber; the throat is located downstream of the raw coal particle cutting material mixing section and is connected to the raw coal particle cutting material mixing section; the flow stabilizing chamber is located downstream of the throat and is connected to the throat, so that the gas-solid mixture flows through the throat and enters the flow stabilizing chamber, and is sprayed from the flow stabilizing chamber onto the coal seam to be gasified.

[0011] Optionally, a high-temperature protective layer is provided on the outside of the gas-solid mixing injection section; the high-temperature protective layer covers at least the outside of the flow stabilizing cavity; a first connecting flange is provided at at least one connection position between the gasifying agent conveying pipe, the raw coal particle cutting material conveying pipe, the raw coal particle cutting material storage section and the gas-solid mixing injection section, so as to form a detachable sealed connection at the corresponding connection position through the first connecting flange.

[0012] A second aspect of the present invention provides a control method for a coal underground gasification pellet injection system. The method is applied to the aforementioned coal underground gasification pellet injection system. The method includes: acquiring raw coal pellet cutting material and conveying the raw coal pellet cutting material to the location of the coal seam to be gasified via a raw coal pellet cutting material conveying pipe; sending the raw coal pellet cutting material into a raw coal pellet cutting material storage section, temporarily storing the raw coal pellet cutting material in the raw coal pellet cutting material storage section, and transferring the sample-carrying gas flow generated during the conveying of the raw coal pellet cutting material from the storage section. The raw coal pellets are drawn out from the raw coal pellets storage section; the action of the raw coal pellets feeding section is controlled to send the raw coal pellets in the raw coal pellets storage section to the mixing position of the gas-solid mixing injection section; the gasifying agent is delivered to the gas-solid mixing injection section through the gasifying agent delivery pipe, so that the gasifying agent mixes with the raw coal pellets in the gas-solid mixing injection section to form a gas-solid mixed flow; the gas-solid mixed flow is sprayed from the gas-solid mixing injection section to the coal seam to be gasified, so that the raw coal pellets in the gas-solid mixed flow impact the coal seam to be gasified.

[0013] On the other hand, the present invention provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the above-described control method for a coal underground gasification particle mixing and injection system.

[0014] Through the above technical solution, the gasifying agent and raw coal pellet cutting material can be separately transported to the location of the coal seam to be gasified. They are temporarily stored and continuously fed underground through the raw coal pellet cutting material storage and injection sections. This allows the raw coal pellet cutting material to enter the gas-solid mixing injection section stably, instead of relying on a single long-distance direct injection. The gas-solid mixing injection section mixes the gasifying agent and raw coal pellet cutting material to form a gas-solid mixture flow, which is then sprayed onto the coal seam to be gasified. This causes the raw coal pellet cutting material, along with the gasifying agent, to impact the compacted coal seam surface, providing auxiliary crushing and cutting effects. This increases the exposed area of ​​the coal seam and the contact channels for the gasifying agent, improving the problem of the gasifying agent only reacting locally on the coal seam surface, and enhancing the sufficiency and efficiency of the underground coal gasification process.

[0015] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a system structure diagram of a coal underground gasification particle mixing and injection system provided in one embodiment of the present invention; Figure 2 This is a schematic diagram of the bottom hole device of the underground coal gasification particle mixing and injection system provided in one embodiment of the present invention. Figure 3 This is a flowchart of the steps of a control method for a coal underground gasification particle mixing and injection system provided in one embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures 1-Gasifying agent conveying pipe; 2-Raw coal pellet cutting material conveying pipe; 3-Raw coal pellet cutting material return gas pipe; 4-First connecting flange; 5-Raw coal pellet cutting material sample storage section; 6-Second connecting flange; 7-Drive motor; 8-Drive gear; 9-Raw coal pellet cutting material conveyor belt; 10-Sample feeding control device; 11-High-speed airflow compression section; 12-Solid cutting material mixing port; 13-Raw coal pellet cutting material mixing section; 14-Throat pipe; 15-Third connecting flange; 16-Flow stabilizing chamber; 17-High temperature protective layer; 18-Well shaft; 19-Air pressurization device; 20-Ground cutting preparation component; 21-Gas circulation pump; 22-Coal inlet; 23-Raw coal pulverizer. Detailed Implementation

[0018] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0019] Figure 1 This is a system structure diagram of a coal underground gasification particle mixing and injection system provided in one embodiment of the present invention. Figure 1 As shown, this invention provides a coal underground gasification pellet mixing and injection system. The system includes: a gasifying agent conveying pipe 1, connected to a gasifying agent supply end, for conveying the gasifying agent to the location of the coal seam to be gasified; a raw coal pellet cutting material conveying pipe 2, connected to a raw coal pellet cutting material supply end, for conveying raw coal pellet cutting material to the location of the coal seam to be gasified; and a raw coal pellet cutting material storage unit 5, connected to the raw coal pellet cutting material conveying pipe 2, for receiving and temporarily storing the raw coal pellet cutting material conveyed by the raw coal pellet cutting material conveying pipe 2. Material cutting; a raw coal particle cutting material feeding section, connected to the raw coal particle cutting material storage section 5, is used to send the raw coal particle cutting material in the raw coal particle cutting material storage section 5 into the mixing position; a gas-solid mixing injection section, connected to the gasifying agent conveying pipe 1 and the raw coal particle cutting material feeding section respectively, is used to receive the gasifying agent conveyed by the gasifying agent conveying pipe 1 and the raw coal particle cutting material fed into the raw coal particle cutting material feeding section, and mix the gasifying agent and the raw coal particle cutting material to form a gas-solid mixed flow before spraying it onto the coal layer to be gasified.

[0020] In this embodiment of the invention, the underground coal gasification particle mixing and injection system provided is arranged around the underground gas-solid mixing and injection requirements of the coal seam to be gasified. A gasifying agent delivery pipe 1 forms a gasifying agent supply channel, and a raw coal particle cutting material delivery pipe 2 forms a raw coal particle cutting material supply channel. Both deliver the gasifying agent and raw coal particle cutting material to the location of the coal seam to be gasified, respectively. A raw coal particle cutting material storage section 5 is located on the raw coal particle cutting material delivery path to temporarily store the raw coal particle cutting material entering the mine, preventing it from directly relying on long-distance transportation to reach the mixing position. The raw coal particle cutting material inlet section then delivers the raw coal particle cutting material from the storage section 5 into the gas-solid mixing injection section, causing the raw coal particle cutting material and gasifying agent to form a gas-solid mixed flow within the injection section. This gas-solid mixed flow is then sprayed onto the coal seam to be gasified, thereby providing auxiliary cutting and crushing effects on the compacted coal seam.

[0021] Preferably, the raw coal pellet cutting material supply end includes: a ground cutting preparation component 20, a coal inlet 22, a raw coal crusher 23, and an air pressurization device 19; the coal inlet 22 is connected to the raw coal crusher 23 so that the raw coal entering the coal inlet 22 is crushed by the raw coal crusher 23 to form raw coal pellet cutting material; the air pressurization device 19 is connected to the raw coal pellet cutting material conveying pipe 2 so as to send the raw coal pellet cutting material into the raw coal pellet cutting material conveying pipe 2 with the pressurized airflow.

[0022] Furthermore, the raw coal pellet cutting material conveying pipe 2 extends along the shaft 18 to the location of the coal seam to be gasified; the raw coal pellet cutting material storage section 5 is located at one end of the raw coal pellet cutting material conveying pipe 2 near the coal seam to be gasified; the raw coal pellet cutting material storage section 5 is also connected to the raw coal pellet cutting material return gas pipe 3; the raw coal pellet cutting material return gas pipe 3 is connected to the gas circulation pump 21 to guide the sample-carrying gas flow separated from the raw coal pellet cutting material storage section 5 back to the raw coal pellet cutting material supply end.

[0023] In this embodiment of the invention, the raw coal pellet cutting material supply end is arranged on the ground side, the ground cutting preparation component 20 serves as the preparation basis for the raw coal pellet cutting material, the coal inlet 22 is used to receive raw coal from the on-site raw coal source, after the coal inlet 22 is connected to the raw coal crusher 23, the raw coal entering the coal inlet 22 is sent into the raw coal crusher 23 for crushing, and the crushed raw coal forms raw coal pellet cutting material that can be transported with the airflow.

[0024] The particle size of the raw coal pellet cutting material can be selected according to the pipe diameter of the raw coal pellet cutting material conveying pipe 2, the depth of the shaft 18, and the impact requirements of the coal seam to be gasified. In specific implementation, a particle size of about 2 mm can be used, or it can be adjusted according to the on-site conveying resistance and mixing stability. The air pressurization device 19 is connected to the raw coal pellet cutting material conveying pipe 2. After the pressurized airflow output by the air pressurization device 19 enters the raw coal pellet cutting material conveying pipe 2, it carries the raw coal pellet cutting material into the shaft 18 and delivers it along the shaft 18 to the location of the coal seam to be gasified.

[0025] The raw coal pellet cutting material storage section 5 is located at the end of the raw coal pellet cutting material conveying pipe 2 near the coal seam to be gasified. After the raw coal pellet cutting material enters the raw coal pellet cutting material storage section 5, it is temporarily stored in the raw coal pellet cutting material storage section 5 due to changes in the flow space and a decrease in flow velocity. The raw coal pellet cutting material storage section 5 is connected to the raw coal pellet cutting material return gas pipe 3, which is in turn connected to the gas circulation pump 21. This allows the sample-carrying gas flow, after completing its carrying function, to be drawn out from the raw coal pellet cutting material storage section 5 and returned to the raw coal pellet cutting material supply end to participate in the subsequent conveying process. This forms a material supply path that connects surface sampling, underground sampling, and return gas circulation.

[0026] In another possible implementation, a particle buffer sorting chamber can be provided between the raw coal particle cutting material supply end and the raw coal particle cutting material conveying pipe 2. The particle buffer sorting chamber is located before the airflow output from the air pressurization device 19 enters the raw coal particle cutting material conveying pipe 2. The crushed raw coal particle cutting material first enters the particle buffer sorting chamber, where it spreads over a short distance by the inclined guide surface. This causes the excessively large raw coal particle cutting material to remain in the upstream area of ​​the inclined guide surface and be sent back to the raw coal crusher 23 through the return port. The raw coal particle cutting material that meets the conveying conditions then enters the raw coal particle cutting material conveying pipe 2 under the action of pressurized airflow.

[0027] Preferred, such as Figure 2 The raw coal pellet cutting material storage section 5 has an inlet end connected to the raw coal pellet cutting material conveying pipe 2, a return gas end connected to the raw coal pellet cutting material return gas pipe 3, and an outlet end connected to the raw coal pellet cutting material inlet section; the raw coal pellet cutting material storage section 5 is used to reduce the flow rate of the raw coal pellet cutting material entering it, and to allow the raw coal pellet cutting material to remain in the raw coal pellet cutting material storage section 5 and then be sent to the raw coal pellet cutting material inlet section through the outlet end.

[0028] Furthermore, the raw coal pellet cutting material feeding section includes: a drive motor 7, a drive gear 8, a raw coal pellet cutting material conveyor belt 9, and a feeding control device 10; the drive motor 7 is connected to the drive gear 8; the drive gear 8 is engaged with the raw coal pellet cutting material conveyor belt 9; one end of the raw coal pellet cutting material conveyor belt 9 is correspondingly arranged with the discharge end of the raw coal pellet cutting material storage section 5, and the other end is correspondingly arranged with the feeding control device 10, so as to send the raw coal pellet cutting material in the raw coal pellet cutting material storage section 5 into the feeding control device 10.

[0029] In this embodiment of the invention, the raw coal pellet cutting material storage unit 5 is located underground near the coal seam to be gasified, and its interior forms a space for temporarily storing the raw coal pellet cutting material. The raw coal pellet cutting material storage unit 5 has a feed end, a return gas end, and a discharge end. The feed end is connected to the raw coal pellet cutting material conveying pipe 2 and is used to receive the raw coal pellet cutting material carried into the underground by pressurized airflow. The return gas end is connected to the raw coal pellet cutting material return gas pipe 3 and is used to extract the sample-carrying airflow after it has completed its carrying function. The discharge end is connected to the raw coal pellet cutting material feed end and is used to continue sending the retained raw coal pellet cutting material to the subsequent mixing location.

[0030] After the raw coal pellets enter the raw coal pellet sample storage section 5, the flow cross-section and flow direction change, and the carrying capacity of the sample-carrying airflow for the raw coal pellets decreases. Under the action of gravity and inertia, the raw coal pellets remain in the raw coal pellet sample storage section 5, while the airflow is discharged through the return gas end. This structure allows the long-distance pneumatic conveying process to be seamlessly connected with the subsequent quantitative sampling process, avoiding the raw coal pellets from directly entering the gas-solid mixing injection section with the high-speed airflow, which would cause sampling instability.

[0031] The raw coal pellet cutting material feeding section is located after the discharge end of the raw coal pellet cutting material storage section 5. The drive motor 7 outputs torque to the drive gear 8. The raw coal pellet cutting material storage section 5 and the drive motor 7 are connected by a second connecting flange 6. The drive gear 8 drives the raw coal pellet cutting material conveyor belt 9. One end of the raw coal pellet cutting material conveyor belt 9 corresponds to the discharge end of the raw coal pellet cutting material storage section 5 and is used to receive the raw coal pellet cutting material falling from the raw coal pellet cutting material storage section 5. The other end of the raw coal pellet cutting material conveyor belt 9 corresponds to the feeding control device 10 and is used to send the received raw coal pellet cutting material into the feeding control device 10. The feeding control device 10 then guides the raw coal pellet cutting material into the mixing position according to the mixing requirements of the gas-solid mixing injection section.

[0032] In specific implementation, the drive motor 7 can adopt a motor structure suitable for the underground sealed environment, and the raw coal particle cutting material conveyor belt 9 can adopt a wear-resistant conveyor belt or a ring conveyor belt with baffles. As long as the raw coal particle cutting material can be continuously or intermittently fed into the feeding control device 10 from the discharge end, it can be used as the implementation form of this embodiment.

[0033] In another possible implementation, an anti-bridging disturbance component is provided above the discharge end of the raw coal pellet cutting material storage section 5. This anti-bridging disturbance component is linked with the drive gear 8 or the raw coal pellet cutting material conveyor belt 9. When the raw coal pellet cutting material conveyor belt 9 is running, the anti-bridging disturbance component oscillates slightly or intermittently moves with the rotation of the drive gear 8, keeping the raw coal pellets near the discharge end loose and preventing the formation of a stable arch above the discharge end. The anti-bridging disturbance component can be a swing arm, an eccentric paddle, or a flexible scraper, with its end extending into a localized area of ​​the raw coal pellet cutting material storage section 5 near the discharge end, but without blocking the entry of the raw coal pellets into the raw coal pellet cutting material conveyor belt 9. Through this structure, the raw coal pellets temporarily stored in the raw coal pellet cutting material storage section 5 can fall more stably onto the raw coal pellet cutting material conveyor belt 9, reducing the possibility of the raw coal pellets entering the sample feeding section idling or intermittent feeding.

[0034] Preferably, the gas-solid mixing injection section includes: a high-speed airflow compression section 11, a solid cutting material mixing port 12, and a raw coal particle cutting material mixing section 13; the high-speed airflow compression section 11 is connected to the gasifying agent conveying pipe 1 to receive and accelerate the gasifying agent conveyed by the gasifying agent conveying pipe 1; the solid cutting material mixing port 12 is connected to the sample injection control device 10 and the raw coal particle cutting material mixing section 13 respectively to introduce the raw coal particle cutting material fed by the sample injection control device 10 into the raw coal particle cutting material mixing section 13, and to form a gas-solid mixed flow between the raw coal particle cutting material and the gasifying agent output by the high-speed airflow compression section 11 in the raw coal particle cutting material mixing section 13.

[0035] Furthermore, the gas-solid mixing injection section also includes a throat 14 and a flow stabilizing chamber 16; the throat 14 is located downstream of the raw coal particle cutting material mixing section 13 and communicates with the raw coal particle cutting material mixing section 13; the flow stabilizing chamber 16 is located downstream of the throat 14 and communicates with the throat 14, so that the gas-solid mixture flows through the throat 14 and enters the flow stabilizing chamber 16, and is sprayed from the flow stabilizing chamber 16 onto the coal seam to be gasified.

[0036] Preferably, a high-temperature protective layer 17 is provided on the outside of the gas-solid mixing injection section; the high-temperature protective layer 17 covers at least the outside of the flow stabilizing cavity 16; at least one connection position between the gasifying agent conveying pipe 1, the raw coal particle cutting material conveying pipe 2, the raw coal particle cutting material storage section 5 and the gas-solid mixing injection section is provided with a first connecting flange 4, so as to form a detachable sealed connection at the corresponding connection position through the first connecting flange 4.

[0037] In this embodiment of the invention, the gas-solid mixing injection section is located near the coal seam to be gasified, and is used to complete the underground mixing and injection of the gasifying agent and the raw coal particle cutting material. The high-speed airflow compression section 11 is connected to the gasifying agent delivery pipe 1. After the gasifying agent enters the high-speed airflow compression section 11 from the gasifying agent delivery pipe 1, a high-velocity airflow is formed and output within the high-speed airflow compression section 11. The high-speed airflow compression section 11 can adopt a constricted flow channel, a nozzle flow channel, or an acceleration structure with a local diameter reduction section. As long as the gasifying agent can form a sufficient flow velocity before entering the raw coal particle cutting material mixing section 13, it is a possible structural form in this embodiment.

[0038] The solid cutting material mixing port 12 is located on the side or upstream of the raw coal particle cutting material mixing section 13, and is connected to the sampling control device 10 and the raw coal particle cutting material mixing section 13, respectively. After the raw coal particle cutting material sent by the sampling control device 10 enters the raw coal particle cutting material mixing section 13 through the solid cutting material mixing port 12, it encounters the gasifying agent output by the high-speed airflow compression section 11 and is carried by the gasifying agent to form a gas-solid mixed flow with impact capability.

[0039] Downstream of the raw coal pellet cutting material mixing section 13 is a connecting throat 14. The throat 14 is used to constrain the flow cross-section of the gas-solid mixture, allowing the raw coal pellet cutting material to continue moving along a predetermined injection direction under the carrying of the gasifying agent. A flow stabilizing chamber 16 is provided downstream of the throat 14, and the two are connected by a third connecting flange 15. The flow stabilizing chamber 16 is connected to the throat 14. After the gas-solid mixture enters the flow stabilizing chamber 16 through the throat 14, the flow direction and local pressure are further regulated, and then it is injected from the flow stabilizing chamber 16 toward the coal seam to be gasified. The flow stabilizing chamber 16 is not limited to a single cavity shape. It can be set as a cylindrical, gradually expanding, or cavity structure with injection ports at the end, depending on the underground installation space. The key is to ensure that the gas-solid mixture output from the throat 14 has a relatively stable flow path before being injected.

[0040] Considering the high-temperature environment near the coal seam to be gasified, a high-temperature protective layer 17 is installed on the outside of the gas-solid mixing injection section. The high-temperature protective layer 17 covers at least the outside of the flow stabilizing cavity 16 to reduce the impact of external high temperature on the flow stabilizing cavity 16 and its internal gas-solid mixing flow channel. A first connecting flange 4 can be installed at the connection position between the gasifying agent delivery pipe 1, the raw coal particle cutting material delivery pipe 2, the raw coal particle cutting material storage section 5, and the gas-solid mixing injection section, forming a detachable sealed connection. This connection method facilitates underground assembly, segmented installation, and subsequent maintenance, and also facilitates the replacement of corresponding pipe sections or mixing components according to different coal seam thicknesses, shaft 18 layouts, and injection angles.

[0041] Figure 3 This is a flowchart of a method for controlling a coal underground gasification particle mixing and injection system according to one embodiment of the present invention. Figure 3 As shown, this invention provides a control method for a coal underground gasification particle mixing and injection system, the method comprising: Step S10: Obtain raw coal pellet cutting material and transport the raw coal pellet cutting material to the location of the coal seam to be gasified through the raw coal pellet cutting material conveying pipe 2.

[0042] Step S20: The raw coal pellet cutting material is fed into the raw coal pellet cutting material storage section 5, so that the raw coal pellet cutting material is temporarily stored in the raw coal pellet cutting material storage section 5, and the sample-carrying airflow formed during the transportation of the raw coal pellet cutting material is drawn out from the raw coal pellet cutting material storage section 5.

[0043] Step S30: Control the operation of the raw coal particle cutting material feeding section to send the raw coal particle cutting material in the raw coal particle cutting material storage section 5 into the mixing position of the gas-solid mixing spray section.

[0044] Step S40: Gasifying agent is supplied to the gas-solid mixing injection section through the gasifying agent delivery pipe 1, so that the gasifying agent is mixed with the raw coal particle cutting material in the gas-solid mixing injection section to form a gas-solid mixed flow.

[0045] Step S50: The gas-solid mixture is sprayed from the gas-solid mixture injection section onto the coal seam to be gasified, so that the raw coal particles in the gas-solid mixture impact the coal seam to be gasified.

[0046] The present invention also provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the above-described control method for a coal underground gasification particle mixing and injection system.

[0047] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0048] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details described above. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe the various possible combinations.

[0049] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the embodiments of the present invention, they should also be regarded as the content disclosed by the embodiments of the present invention.

Claims

1. A coal underground gasification pellet mixing and injection system, characterized in that, The system includes: The gasifying agent conveying pipe is connected to the gasifying agent supply end and is used to convey the gasifying agent to the location of the coal seam to be gasified. The raw coal pellet cutting material conveying pipe is connected to the raw coal pellet cutting material supply end and is used to convey the raw coal pellet cutting material to the location of the coal seam to be gasified. The raw coal pellet cutting material storage section is connected to the raw coal pellet cutting material conveying pipe and is used to receive and temporarily store the raw coal pellet cutting material conveyed by the raw coal pellet cutting material conveying pipe. The raw coal pellet cutting material inlet is connected to the raw coal pellet cutting material storage section and is used to send the raw coal pellet cutting material in the raw coal pellet cutting material storage section into the mixing position. The gas-solid mixing injection section is connected to the gasifying agent conveying pipe and the raw coal particle cutting material injection section, respectively. It is used to receive the gasifying agent conveyed by the gasifying agent conveying pipe and the raw coal particle cutting material fed in by the raw coal particle cutting material injection section, and mix the gasifying agent and the raw coal particle cutting material to form a gas-solid mixed flow before spraying it onto the coal layer to be gasified.

2. The coal underground gasification particle mixing and injection system according to claim 1, characterized in that, The raw coal pellet cutting feed supply end includes: Ground cutting preparation components, coal inlet, raw coal crusher, and air pressurization device; The coal inlet is connected to the raw coal crusher so that the raw coal entering the coal inlet is crushed by the raw coal crusher to form raw coal granular cutting material. The air pressurization device is connected to the raw coal particle cutting material conveying pipe to send the raw coal particle cutting material into the raw coal particle cutting material conveying pipe with the pressurized airflow.

3. The coal underground gasification particle mixing and injection system according to claim 2, characterized in that, The raw coal pellet cutting material conveying pipe extends along the wellbore to the location of the coal seam to be gasified. The raw coal pellet cutting material storage section is located at one end of the raw coal pellet cutting material conveying pipe near the coal seam to be gasified. The raw coal pellet cutting material storage section is also connected to the raw coal pellet cutting material return gas pipeline. The raw coal pellet cutting material return gas pipeline is connected to a gas circulation pump to guide the sample-carrying gas flow separated from the raw coal pellet cutting material storage section back to the raw coal pellet cutting material supply end.

4. The coal underground gasification particle mixing and injection system according to claim 3, characterized in that, The raw coal pellet cutting material storage section has an inlet end connected to the raw coal pellet cutting material conveying pipe, a return gas end connected to the raw coal pellet cutting material return gas pipe, and an outlet end connected to the raw coal pellet cutting material inlet section. The raw coal particle cutting material storage section is used to reduce the flow rate of the raw coal particle cutting material entering it, and to allow the raw coal particle cutting material to remain in the raw coal particle cutting material storage section and then be sent to the raw coal particle cutting material feeding section through the discharge end.

5. The coal underground gasification particle mixing and injection system according to claim 4, characterized in that, The raw coal pellet cutting feed inlet includes: Drive motor, drive gear, raw coal pellet cutting conveyor belt and feeding control device; The drive motor is connected to the drive gear transmission; The drive gear is engaged with the raw coal pellet cutting conveyor belt. One end of the raw coal pellet cutting material conveyor belt is set to correspond to the discharge end of the raw coal pellet cutting material storage section, and the other end is set to correspond to the sampling control device, so as to send the raw coal pellet cutting material in the raw coal pellet cutting material storage section into the sampling control device.

6. The coal underground gasification particle mixing and injection system according to claim 5, characterized in that, The gas-solid mixing injection unit includes: High-speed airflow compression section, solid cutting material mixing port and raw coal particle cutting material mixing section; The high-speed airflow compression section is connected to the vaporizing agent delivery pipe to receive and accelerate the vaporizing agent delivered by the vaporizing agent delivery pipe; The solid cutting material mixing port is connected to the sampling control device and the raw coal particle cutting material mixing section, respectively, so as to introduce the raw coal particle cutting material fed by the sampling control device into the raw coal particle cutting material mixing section, and to form a gas-solid mixture flow between the raw coal particle cutting material and the gasifying agent output by the high-speed airflow compression section in the raw coal particle cutting material mixing section.

7. The underground coal gasification particle mixing and injection system according to claim 6, characterized in that, The gas-solid mixing injection section also includes a throat and a flow stabilizing chamber; The throat is located downstream of the raw coal particle cutting material mixing section and is connected to the raw coal particle cutting material mixing section; The flow stabilizing chamber is located downstream of the throat and communicates with the throat so that the gas-solid mixture flows through the throat and enters the flow stabilizing chamber, and is then sprayed from the flow stabilizing chamber onto the coal seam to be gasified.

8. The underground coal gasification particle mixing and injection system according to claim 7, characterized in that, The gas-solid mixing injection section is provided with a high-temperature protective layer on its exterior. The high-temperature protective layer covers at least the outer side of the flow stabilizing cavity; At least one connection position between the gasifying agent conveying pipe, the raw coal particle cutting material conveying pipe, the raw coal particle cutting material storage section, and the gas-solid mixing injection section is provided with a first connecting flange to form a detachable sealed connection at the corresponding connection position through the first connecting flange.

9. A control method for a coal underground gasification pellet mixing and injection system, characterized in that, The method is applied to the coal underground gasification particle mixing and injection system according to any one of claims 1-8, and the method includes: Obtain raw coal pellet cutting material and transport the raw coal pellet cutting material to the location of the coal seam to be gasified through the raw coal pellet cutting material conveying pipe. The raw coal pellet cutting material is fed into the raw coal pellet cutting material storage section, where the raw coal pellet cutting material is temporarily stored, and the sample-carrying airflow formed during the conveying of the raw coal pellet cutting material is drawn out from the raw coal pellet cutting material storage section. Control the operation of the raw coal particle cutting material feeding section to send the raw coal particle cutting material in the raw coal particle cutting material storage section to the mixing position of the gas-solid mixing spray section; A gasifying agent is supplied to the gas-solid mixing injection section through a gasifying agent delivery pipe, so that the gasifying agent mixes with the raw coal particle cutting material in the gas-solid mixing injection section to form a gas-solid mixed flow. The gas-solid mixture is sprayed from the gas-solid mixture jet section onto the coal seam to be gasified, so that the raw coal particles in the gas-solid mixture impact the coal seam to be gasified.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to perform the control method for the coal underground gasification particle mixing and injection system as described in claim 9.

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