Coal underground gasification agent injection device

Abstract

The utility model provides a coal underground gasification agent injection device relates to coal underground gasification device field, including outer sleeve, shower nozzle, conveying pipeline and catalyst carrier, shower nozzle is connected in one end of outer sleeve, conveying pipeline is connected in the other end of outer sleeve, catalyst carrier is installed in the outer sleeve, is set up with multiple axial arrangement's catalytic passage in catalyst carrier, the aperture of catalytic passage gradually reduces along the direction of being close to shower nozzle. The utility model discloses a catalyst coating is fixed on the catalyst carrier with three -dimensional intercommunication porous structure and gradient aperture design, reduces gasification agent entrance airflow resistance, promotes the flow efficiency, and the contact area of gasification agent and catalyst is greatly expanded. Accelerate the reaction rate, make gasification reaction more thorough, and then effectively improve the gas production.

Description

Technical Field

[0001] This utility model relates to the field of underground coal gasification devices, and in particular to an underground coal gasification agent injection device. Background Technology

[0002] Underground coal gasification is a technology that converts underground coal into combustible gas through controlled combustion, offering advantages such as high safety and high resource utilization. The reaction efficiency between the gasifying agent (such as oxygen, steam, carbon dioxide, etc.) and coal is a key factor determining gasification performance, while the introduction of a catalyst can significantly reduce the activation energy of the reaction and increase the gas production rate. Traditional catalyst injection schemes typically employ powdered or granular catalysts, which are mixed with the gasifying agent and injected into the coal seam via separate pipelines. However, this approach has several drawbacks: the catalyst is easily carried away by the gas flow, resulting in low utilization and requiring frequent replenishment, thus increasing costs; powdered catalysts may clog coal seam pores, especially in low-permeability coal seams, leading to obstructed gasification channels; additional catalyst storage and transportation equipment is required, resulting in complex systems and high failure rates; and uneven mixing of the catalyst and gasifying agent within the coal seam leads to low activation efficiency and limited reaction rates. Utility Model Content

[0003] This utility model provides a coal underground gasification agent injection device to solve the problem of uneven mixing of catalyst and gasification agent in coal seams in the prior art.

[0004] This utility model provides a coal underground gasification agent injection device, including an outer casing, a nozzle, a delivery pipeline and a catalyst carrier; The nozzle is connected to one end of the outer sleeve, the delivery pipeline is connected to the other end of the outer sleeve, and the catalyst carrier is installed inside the outer sleeve. The catalyst carrier has multiple axially arranged catalytic channels, and the delivery pipeline is connected to the nozzle through the catalytic channels. The aperture of the catalytic channels decreases along the direction close to the nozzle, and the inner wall of the catalytic channels is loaded with a catalyst coating.

[0005] Furthermore, the nozzle has an injection channel that gradually narrows away from the outer sleeve.

[0006] Furthermore, it also includes a limiting ring, which is supported between the catalyst carrier and the outer sleeve.

[0007] Furthermore, the limiting ring is detachably connected between the catalyst carrier and the outer sleeve.

[0008] Furthermore, a first sealing gasket is provided between the limiting ring and the conveying pipeline.

[0009] Furthermore, a second sealing gasket is provided between the limiting ring and the nozzle.

[0010] Furthermore, the first sealing gasket and the second sealing gasket are configured as flexible graphite gaskets.

[0011] Furthermore, the gap between the outer sleeve and the limiting ring is less than 0.1 mm.

[0012] Furthermore, the catalyst support includes multiple carrier disks fixedly connected along the axial direction, and multiple catalytic through holes are formed on the carrier disks along the axial direction. The catalytic channel is formed between two adjacent carrier disks through the catalytic through holes arranged opposite to each other, and the diameter of the catalytic through holes decreases sequentially along the direction close to the nozzle.

[0013] The beneficial effects of this utility model are as follows: 1. By fixing the catalyst coating onto a catalyst carrier with a three-dimensional interconnected porous structure and gradient pore size design, the gas flow resistance at the gasifier inlet is reduced, the flow efficiency is improved, and the contact area between the gasifier and the catalyst is significantly increased. This accelerates the reaction rate, makes the gasification reaction more complete, and thus effectively increases coal gas production.

[0014] 2. The tapered nozzle channel design improves the gasifying agent injection velocity and coal seam contact coverage. Combined with precise airflow guidance and a uniform flow design, it avoids localized accumulation or obstructed flow of the gasifying agent within the coal seam. Simultaneously, the multiple sealing structures and micro-gap design provide double protection, preventing gasifying agent leakage and ensuring that all gasifying agent flows through the catalyst carrier for pre-activation. This improves gasifying agent utilization and ensures the uniformity of the gasification reaction, further optimizing overall gasification performance. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the internal structure of an embodiment of the present utility model.

[0016] Figure 2 This is a schematic diagram of the overall structure of an embodiment of the present utility model.

[0017] Figure 3 This is a schematic diagram showing the structural relationship between the catalyst support and the limiting ring located at one end of the delivery pipeline.

[0018] Figure 4 This is a schematic diagram showing the structural relationship between the catalyst support and the limiting ring located at one end of the nozzle.

[0019] Figure label: 1. Nozzle; 11. Injection channel; 2. Delivery pipeline; 3. Catalyst carrier; 31. Carrier disc; 32. Catalytic through hole; 4. Outer sleeve; 5. Limiting ring; 51. Half ring; 6. Connecting bolt; 7. Fixing bolt. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0021] The terms "first" and "second" in the specification and claims of this utility model may explicitly or implicitly include one or more of the features. In the description of this utility model, unless otherwise stated, "multiple" means two or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0022] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0023] The following is combined Figures 1-4 This invention describes an underground coal gasification agent injection device, comprising an outer casing 4, a nozzle 1, a delivery pipeline 2, and a catalyst carrier 3. The nozzle 1 is connected to one end of the outer casing 4, the delivery pipeline 2 is connected to the other end of the outer casing 4, and the catalyst carrier 3 is installed inside the outer casing 4. The catalyst carrier 3 has multiple axially arranged catalytic channels. The delivery pipeline 2 is connected to the nozzle 1 through these catalytic channels. The aperture of the catalytic channels decreases towards the nozzle 1, and the inner wall of the catalytic channels is coated with a catalyst coating.

[0024] Specifically, the catalyst carrier 3 is made of high-temperature resistant composite ceramic material, featuring a three-dimensional interconnected porous structure and a gradient pore size structure. The end connected to the delivery pipeline 2 has a large pore size, while the end connected to the nozzle 1 has a small pore size. The interconnected pores form catalytic through-holes 32, with a catalyst coating loaded on the inner wall of each pore. The outer sleeve 4 is made of 316L stainless steel, with a wall thickness of 8mm. Both ends of the outer sleeve 4 are connected to the nozzle 1 and the delivery pipeline 2, respectively, and the catalyst carrier 3 is fixedly installed inside the outer sleeve 4.

[0025] When using the gasifying agent injection device, the gasifying agent enters from the delivery pipeline 2, comes into contact with the catalyst coating through the catalytic channel, and is then sprayed out by the nozzle 1 to participate in the gasification reaction. Fixing the catalyst coating to the inner wall of the catalytic channel on the catalyst carrier 3 replaces traditional powder or granular catalysts, effectively preventing catalyst loss due to gas flow, extending catalyst lifespan, reducing frequent replenishment needs, and lowering operating costs. The gradient pore size structure of the catalytic channel within the catalyst carrier 3 reduces the gas flow resistance at the gasifying agent inlet, improves flow efficiency, and expands the contact area between the gasifying agent and the catalyst coating, achieving pre-activation of the gasifying agent, significantly reducing the reaction activation energy, accelerating the reaction rate, and increasing coal gas production.

[0026] Furthermore, an injection channel 11 is provided inside the nozzle 1, and the injection channel 11 gradually contracts in the direction away from the outer sleeve 4.

[0027] Specifically, such as Figure 1 As shown, the injection channel 11 is designed with a tapered structure, which can increase the injection velocity of the gasifying agent and improve the contact efficiency between the gasifying agent and the coal seam. The inner diameter of the injection channel 11 at the end near the outer casing 4 is matched with the inner diameter of the outer casing 4, while the inner diameter at the end away from the outer casing 4 is designed according to the gasifying agent injection velocity requirements, ensuring that the gasifying agent velocity increases smoothly as it flows through, and avoiding airflow turbulence.

[0028] Furthermore, it also includes a limiting ring 5, which is supported between the catalyst carrier 3 and the outer sleeve 4.

[0029] Furthermore, the limiting ring 5 is detachably connected between the catalyst carrier 3 and the outer sleeve 4.

[0030] Specifically, such as Figure 1 , Figure 2As shown, two limiting rings 5 ​​are provided. The inner diameter of the limiting ring 5 is slightly larger than the outer diameter of the outer sleeve 4, and the outer diameter of the limiting ring 5 is slightly smaller than the inner diameter of the nozzle 1 and the inner diameter of the delivery pipeline 2. The outer sleeve 4, nozzle 1, delivery pipeline 2, limiting rings 5, and catalyst carrier 3 are fixedly connected by fixing bolts 7. Two M8 through-threaded holes are symmetrically opened on each limiting ring 5. The side walls of the nozzle 1, outer sleeve 4, and delivery pipeline 2 are respectively provided with connecting through holes for the fixing bolts 7 to pass through. The fixing bolts 7 are screwed into the through-threaded holes to fix the limiting rings 5, thus fixing the nozzle 1, outer sleeve 4, and delivery pipeline 2. Simultaneously, the fixing bolts 7 press against the outer wall of the catalyst carrier 3, and the limiting rings 5 ​​position the catalyst carrier 3, preventing displacement due to airflow impact or temperature changes.

[0031] In some alternative embodiments, such as Figure 1 , Figure 2 As shown, the limiting ring 5 is configured as two symmetrical half-rings 51, which are fixed together by connecting bolts 6. During installation, the two half-rings 51 are attached to the outer sides of both ends of the catalyst carrier 3, and the two half-rings 51 are installed by connecting bolts 6, so that the two half-rings 51 hug the catalyst carrier 3, thereby achieving a fixed connection between the catalyst carrier 3 and the limiting ring 5.

[0032] Furthermore, a first sealing gasket is provided between the limiting ring 5 and the conveying pipeline 2.

[0033] Furthermore, a second sealing gasket is provided between the limiting ring 5 and the nozzle 1.

[0034] Furthermore, the first and second sealing gaskets are configured as flexible graphite gaskets.

[0035] Specifically, such as Figure 1 As shown, the first sealing gasket is a 0.5mm thick flexible graphite gasket, laid at the joint surface between the limiting ring 5 and the conveying pipeline 2. The second sealing gasket is also a 0.5mm thick flexible graphite gasket, laid at the joint surface between the limiting ring 5 and the nozzle 1. The flexible graphite gasket has high temperature resistance, corrosion resistance, and good sealing performance, adapting to the high-temperature environment of underground coal gasification, resisting the erosion of gasifying agents and reaction products. Simultaneously, its elasticity and toughness compensate for minor deformations at the joint surface, ensuring the airtightness of the device during long-term operation and reducing the frequency of gasket maintenance and replacement.

[0036] Furthermore, the gap between the outer sleeve 4 and the limiting ring 5 is less than 0.1 mm.

[0037] In one specific embodiment, the outer sleeve 4 is made of 316L stainless steel tubing, with both end faces machined by CNC lathe, the flatness of both end faces being ≤0.02mm. The inner wall of the outer sleeve 4 is honed, with a surface roughness Ra ≤0.8μm. The limiting ring 5 is machined from 316L stainless steel bar stock, and the inner diameter of the limiting ring 5 is precision processed to ensure that the fitting clearance with the outer diameter of the outer sleeve 4 is ≤0.1mm. This clearance design can limit the radial relative displacement between the outer sleeve 4 and the limiting ring 5, ensure the coaxiality of the device, reduce the leakage channels of the gasifying agent, and further improve the airtightness with the sealing gasket, ensuring that all the gasifying agent flows through the catalytic through-hole 32 of the catalyst carrier 3.

[0038] Furthermore, the catalyst carrier 3 includes multiple carrier disks 31 fixedly connected along the axial direction. Multiple catalytic through holes 32 are opened on the carrier disks 31 along the axial direction. Adjacent carrier disks 31 form a catalytic channel through the catalytic through holes 32 arranged opposite to each other. The aperture of the catalytic through holes 32 decreases sequentially along the direction close to the nozzle 1.

[0039] Specifically, such as Figure 1 As shown, the diameter of the catalytic through-holes 32 on each carrier disk 31 is set according to the installation position. For example... Figure 3 , Figure 4 As shown, the catalytic through-holes 32 on the carrier disk 31 closest to the delivery pipeline 2 have the largest pore size, and the pore size of subsequent adjacent carrier disks 31 decreases sequentially, with the carrier disk 31 closest to the nozzle 1 having the smallest pore size. The catalytic through-holes 32 between the two carrier disks 31 are interconnected, thus forming a continuous gradient pore size catalytic channel. When the gasifying agent flows through, it passes through the catalytic through-holes 32 with gradually decreasing pore size, making full contact with the catalyst coating on each carrier disk 31, achieving pre-activation and improving catalytic efficiency.

[0040] In some specific embodiments, each carrier disk 31 is made of 80-mesh SiC powder with a purity ≥99%, 100-mesh Si3N4 powder with a purity ≥98%, or other high-temperature resistant materials. The inner wall of the catalytic through-hole 32 of each carrier disk 31 is loaded with Fe2O3-NiO / CeO2 or other composite metal oxide catalyst coating. Multiple carrier disks 31 are fixedly connected along the axial direction to form a complete catalyst carrier 3, which is installed in the outer sleeve 4.

[0041] After all components are installed, close the nozzle 1 outlet and introduce 0.8MPa compressed air into the delivery pipeline 2, maintaining the pressure for 3 minutes. Apply soapy water to all mating surfaces, including the mating surface between nozzle 1 and limit ring 5, the mating surface between limit ring 5 and outer sleeve 4, the mating surface between outer sleeve 4 and delivery pipeline 2, and threaded connections. Observe for air bubbles. If no air bubbles are generated, the airtightness is qualified. If a leak is found, fine-tune the torque of the corresponding fixing bolt 7 until the leak is eliminated. After the airtightness test is successful, conduct a gasifying agent flow test. Connect the gasifying agent supply system and introduce N2 as a simulated gasifying agent into the delivery pipeline 2, controlling the flow rate at 50m³ / h. Monitor the gas flow stability using a flow meter to ensure that the airflow uniformity is ≥90%.

[0042] In actual operation, the gasifying agent is fed into the pipeline by the gasifying agent supply system. The gasifying agent comes into contact with the composite catalytic coating of the catalyst carrier 3 to preactivate the catalyst. Finally, it is sprayed out through the gasifying agent nozzle 1 to participate in the gasification reaction, thereby improving gasification efficiency and increasing coal gas production.

[0043] Where there is no conflict, the above embodiments and features described herein can be combined with each other.

[0044] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A coal underground gasification agent injection device, characterized in that: This includes the outer casing, nozzle, delivery pipeline, and catalyst carrier; The nozzle is connected to one end of the outer sleeve, the delivery pipeline is connected to the other end of the outer sleeve, and the catalyst carrier is installed inside the outer sleeve. The catalyst carrier has multiple axially arranged catalytic channels, and the delivery pipeline is connected to the nozzle through the catalytic channels. The aperture of the catalytic channels gradually decreases along the direction close to the nozzle, and the inner wall of the catalytic channels is loaded with a catalyst coating.

2. The underground coal gasification agent injection device according to claim 1, characterized in that: The nozzle has an injection channel that gradually narrows away from the outer sleeve.

3. The underground coal gasification agent injection device according to claim 1, characterized in that: It also includes a limiting ring, which is supported between the catalyst carrier and the outer sleeve.

4. The underground coal gasification agent injection device according to claim 3, characterized in that: The limiting ring is detachably connected between the catalyst carrier and the outer sleeve.

5. The underground coal gasification agent injection device according to claim 3, characterized in that: A first sealing gasket is provided between the limiting ring and the delivery pipeline.

6. The underground coal gasification agent injection device according to claim 5, characterized in that: A second sealing gasket is provided between the limiting ring and the nozzle.

7. The underground coal gasification agent injection device according to claim 6, characterized in that: The first sealing gasket and the second sealing gasket are configured as flexible graphite gaskets.

8. The underground coal gasification agent injection device according to claim 3, characterized in that: The gap between the outer sleeve and the limiting ring is less than 0.1 mm.

9. The underground coal gasification agent injection device according to any one of claims 1-8, characterized in that: The catalyst support includes multiple carrier disks fixedly connected along the axial direction. Multiple catalytic through holes are formed on the carrier disks along the axial direction. The catalytic channel is formed between two adjacent carrier disks through the catalytic through holes arranged opposite to each other. The diameter of the catalytic through holes decreases sequentially along the direction closer to the nozzle.

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