A visualization system for underground coal plasma gasification

Abstract

The utility model discloses a kind of underground coal plasma gasification visual system, belong to coal underground gasification engineering technical field, comprising: with the injection pipe of gasification agent connection plasma torch;At least one set of camera system is fixedly arranged on the plasma torch, camera system includes camera and is covered in the perspective window of the light end of camera, the perspective window is provided with the positioning and ranging positioning scale line for;The video output end of the camera system is electrically connected with ground end equipment, for transmitting video signal to ground end equipment;The power supply end of the camera system is shared with plasma torch by power adapter and strong power supply, for power supply to camera system.The utility model provides a kind of underground visual system that can adjust position with coal seam gasification face movement, can directly present the advancing situation of underground coal seam gasification, significantly improves the observability, quantifiability and system reliability of underground plasma gasification process.

Description

Technical Field

[0001] This utility model belongs to the field of underground coal gasification engineering technology, and in particular relates to a visualization system for underground coal plasma gasification. Background Technology

[0002] Underground coal gasification is a process that involves injecting a gasifying agent into a coal seam to controllably burn coal buried deep underground. Through the thermal and chemical reactions of the coal, combustible gases are produced. This method offers advantages such as low investment, high efficiency, and environmental friendliness, and is of great significance for the efficient and comprehensive utilization of coal resources, especially deep coal resources. To increase the volume fraction of combustible gases in the gas produced by underground gasification, ion-activating the gasifying agent before its reaction with the coal seam is a very promising technological direction.

[0003] In underground coal plasma gasification, the plasma generator, or plasma torch, needs to be placed near the coal seam to be gasified so that the plasma gasifying agent can react with the coal as soon as possible, and the activated gasifying agent can be deactivated before it comes into contact with the coal seam. In this technology, supplying power to the underground equipment has become a necessity.

[0004] In underground coal gasification, especially shaftless underground coal gasification, the gasifying agent needs to be transported to the gasification face through boreholes. The operation of the gasification face, including the area and extent of combustion, the collapse of the roof of the combustion zone, and the distance between the gasification face and the gas injection terminal, is unknown. It can only be inferred from the composition of the coal gas, or by monitoring the changes in radon content in the ground soil to infer the approximate location of the underground combustion zone, or by simulating underground coal seam gasification in the laboratory and making analogies to real coal seam gasification based on the simulation.

[0005] In underground coal gasification, especially wellless underground coal gasification, the ability to observe the advancement of the coal seam gasification surface in real time is of great significance for timely adjustment of the injection end position, maintaining a relatively high content of combustible gas components in the produced coal gas, and preventing blockage of the underground gasification channel. Utility Model Content

[0006] The purpose of this invention is to provide an underground visualization system that can adjust its position as the coal seam gasification surface moves, thus intuitively presenting the progress of underground coal seam gasification.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A visualization system for underground coal plasma gasification includes:

[0009] A plasma torch connected to a vaporizing agent injection pipe;

[0010] At least one camera system is fixedly installed on the plasma torch. The camera system includes a camera and a viewing window covering the light-incident end of the camera. The viewing window is provided with positioning reticle lines for positioning and ranging.

[0011] The video output terminal of the camera system is electrically / signally connected to the ground terminal equipment for transmitting video signals to the ground terminal equipment;

[0012] The power supply terminal of the camera system shares a high-voltage power supply with the plasma torch via a power adapter, which is used to power the camera system.

[0013] Preferably, the viewing window is a double-layer viewing window with a vacuum sandwiched between the layers; this forms a highly efficient thermal insulation layer, significantly reducing the temperature of the inner surface of the viewing window and alleviating thermal shock stress.

[0014] Preferably, the viewing window is a double-layer viewing window, with a cooling gas inlet and a cooling gas outlet in the interlayer; this enables active gas cooling within the interlayer, continuously removing heat and isolating high-temperature crude gas, thereby reducing the window temperature.

[0015] Preferably, the cooling gas inlet and cooling gas outlet are respectively connected to cooling gas pipelines, and the cooling gas pipelines are equipped with one-way valves that can be remotely controlled to open and close; this ensures unidirectional and controlled flow of cooling gas, preventing backflow and interlayer contamination; the ground-end equipment can remotely open and close the system to adjust the cooling and purging intensity as needed, improving system reliability and safety.

[0016] Preferably, the double-layer viewing window is a double-layer concentric spherical structure, with the height of the outer spherical layer being 1 / 4 to 1 / 2 of the sphere's radius, and the outer diameter of the outer spherical shell of the double-layer viewing window being 1 / 3 to 1 / 2 of the outer diameter of the plasma torch; each layer is 1 to 5 mm thick, and the interlayer thickness is 2 to 10 mm; the concentric spherical geometry has higher compressive strength and stress dispersion ability under internal pressure and thermal shock, a wider field of view, and is conducive to the self-cleaning of dirt by sliding off.

[0017] Preferably, the positioning reticle adopts a plane rectangular coordinate system, and the positioning reticle is arranged on a symmetrical plane containing the plasma torch axis and the center of the perspective window. The positive direction of the positioning reticle coordinate axis points away from the plasma torch. This provides a unified and clear geometric reference, which facilitates the establishment of a stable mapping between the image plane coordinates and the coal seam spatial coordinates, supports target point ranging and position reference, and reduces systematic errors caused by assembly deviations.

[0018] Preferably, at least one nozzle facing the viewing window is arranged around the viewing window on the plasma torch. The nozzle is connected to a high-pressure gas / liquid source on the ground or to a gasifying agent injection pipe through a spray pipe. An electrically controlled switch valve is installed on the spray pipe. By directionally spraying high-pressure gas / liquid or gasifying agent, tar / dust obstruction on the outer surface of the viewing window can be quickly removed. Remote electrical control allows for immediate cleaning when the image becomes blurry, improving visualization continuity and reducing downtime maintenance frequency. Reusing the gasifying agent pipeline simplifies downhole pipeline layout.

[0019] Preferably, the ground terminal equipment includes a video receiving module, a storage module, a display module, and a control module; realizing an integrated architecture for receiving video signals, long-term storage, real-time display, and centralized control, supporting online monitoring, historical tracing, and unified operation and maintenance control.

[0020] Preferably, the video receiving module receives video signals from the camera system; the storage module is electrically connected to the video receiving module and is used to store and manage the received video data; the display module is electrically connected to the storage module and is used to display the monitoring screen in real time; the control module is electrically connected to the video receiving module, the storage module, and the display module and is used to realize the operation management and remote control functions of the system.

[0021] Preferably, the control module is electrically / signally connected to the valves installed on the gasifying agent injection pipe, cooling gas pipe and injection pipe respectively; to realize remote linkage control of gas injection conditions, interlayer cooling / purging and viewing window cleaning, which facilitates real-time adjustment according to screen and condition feedback, and improves the system's safety, response speed and operational stability.

[0022] Compared with the prior art, the beneficial effects of this utility model are:

[0023] The "Visualization System for Underground Coal Plasma Gasification" proposed in this utility model can adjust its position as the coal seam gasification surface moves, and can intuitively present the progress of underground coal seam gasification. Focusing on four dimensions, namely "motion-guided in-situ visualization, steady-state imaging and anti-fouling, geometric quantification ranging, integrated power supply and remote linkage control", it significantly improves the observability, quantification and system reliability of the underground plasma gasification process, adapts to the long-term, stable and high-definition observation requirements of the entire ignition and operation cycle, and supports the optimization of operating conditions and safety assessment.

[0024] This invention fixes at least one camera system on the plasma torch body, which moves with the position of the plasma torch to achieve synchronous observation of each stage of ignition and operation. This avoids the problems of limited viewing angle and insufficient follow-up of traditional fixed monitoring, and ensures that continuous video evidence and situation information are obtained during the evolution of key states such as the expansion of the combustion zone and the collapse of the roof.

[0025] This invention employs a double-layer perspective window structure. The interlayer can be a vacuum or equipped with cooling gas inlets and outlets and one-way valves, forming a highly efficient thermal isolation and active cooling channel. This significantly reduces the inner surface temperature, mitigates thermal shock, and isolates the imaging surface from tar / dust contamination in high-temperature crude coal gas, significantly improving image clarity and continuity, and extending continuous observation time. The double-layer concentric spherical geometry further enhances compressive strength and stress dispersion capabilities, expands the field of view, and facilitates self-cleaning by dirt sliding off. This allows the window to maintain high structural and imaging stability even under thermo-pressure coupling conditions. The given dimensional range achieves an engineering balance between strength, thermal insulation, and manufacturing feasibility.

[0026] This invention features nozzles arranged around the viewing window on a plasma torch, pointing towards the viewing window. These nozzles are connected to a high-pressure gas / liquid source on the ground or reused with a gasifying agent injection pipe. The electrical control valve can be remotely started and stopped. When the image becomes blurry, the tar / dust obstruction on the outer surface of the viewing window can be quickly cleared, improving visualization continuity and reducing downtime for maintenance. Reusing the gasifying agent pipeline can also reduce the number of downhole pipelines and boreholes, simplifying the layout.

[0027] This invention features positioning reticles on the viewing window, employing a Cartesian coordinate system arranged on a symmetrical plane containing the plasma torch axis and the center of the viewing window. The positive coordinates point away from the plasma torch, establishing a unified geometric reference and facilitating stable mapping between image plane coordinates and coal seam spatial coordinates. Based on the reticles and a monocular camera, combined with baseline methods or backward similar triangulation, target point distance measurement and temporal cross-section reconstruction of the gasification face can be completed without adding independent ranging hardware. This further forms the three-dimensional morphology of the combustion air zone, providing data support for online quantitative analysis and operational optimization of the gasification process.

[0028] The low-voltage end of this camera system is electrically connected to the plasma torch circuit via a power adapter, enabling integrated power supply for the main and auxiliary equipment. This reduces the number of independent power supply channels and cable connection points underground, simplifies deployment, reduces potential failure points, and improves system reliability. The ground-end equipment is modularized into video receiving, storage, display, and control modules, enabling closed-loop management of acquisition, storage, display, and control. It can remotely control the jet cleaning, interlayer cooling / purging, and gas injection valves, improving response speed and operational stability.

[0029] This utility model features an interlayer cooling gas channel with inlet and outlet and is equipped with a remotely controllable one-way valve to ensure unidirectional and controlled flow of cooling gas, preventing backflow and interlayer contamination. Combined with ground-end opening and closing control, the cooling and purging intensity can be adjusted as needed, taking into account both imaging stability and system safety. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a preferred embodiment of the present invention;

[0031] Figure 2This is a structural schematic diagram from another angle in a preferred embodiment of the present invention;

[0032] Figure 3 This is a cross-sectional view along the plane of symmetry shared by the plasma torch and the viewing window in the preferred embodiment of this utility model;

[0033] Figure 4 This is a schematic diagram of the outer spherical surface of the double-layer perspective window in a preferred embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the electrical connections of a preferred embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the baseline method for ranging in a preferred embodiment of the present invention;

[0036] Figure 7 This is a schematic diagram of the principle of the backward similar triangulation method for distance measurement in a preferred embodiment of this utility model.

[0037] In the diagram: 1. Camera; 2. Viewing window; 21. Outer shell of the viewing window; 22. Inner shell of the viewing window; 23. Interlayer; 3. Nozzle; 4. Positioning reticle; 5. Cooling gas inlet; 6. Cooling gas outlet. Detailed Implementation

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0039] Underground coal gasification involves injecting a gasifying agent into the coal seam, causing the coal to undergo in-situ heating and chemical reactions to generate combustible gases. To increase the content of combustible components, using plasma to activate the gasifying agent before it reacts with the coal seam is an important approach. This route requires lowering the plasma torch near the coal seam and achieving reliable power supply and control underground.

[0040] In particular, in wellless underground gasification, the gasifying agent is delivered to the gasification working face through boreholes. However, key state parameters such as the combustion area and its expansion range, the roof collapse in the combustion zone, and the distance between the working face and the gas injection end are difficult to obtain online and intuitively. Usually, they can only be indirectly inferred or compared by laboratory simulation through changes in gas composition or surface radon concentration. There is a lack of real-time, in-situ, and dynamic visual observation methods.

[0041] Therefore, this embodiment provides an underground visualization system that can synchronously adjust the observation position as the coal seam gasification surface advances and can directly quantify the gasification geometric parameters, so as to support the optimization of the gas injection end displacement, ensure the smooth flow of the gasification channel, and steadily increase the content of combustible components.

[0042] like Figures 1-7 As shown:

[0043] Please see Figure 1 and Figure 2 :

[0044] This embodiment provides a visualization system for underground coal plasma gasification, including:

[0045] A plasma torch connected to a vaporizing agent injection pipe;

[0046] At least one camera system is fixedly mounted on the plasma torch and moves along the gas injection direction with the plasma torch to achieve follow-up observation. The camera system includes a camera 1 and a viewing window 2 covering the light-incident end of the camera 1. The viewing window 2 is provided with positioning reticle lines 4 for positioning and ranging.

[0047] The video output terminal of the camera system is electrically / signally connected to the ground terminal equipment for transmitting video signals to the ground terminal equipment;

[0048] The camera system's power supply is shared with the plasma torch via a power adapter, providing power to the camera system. This achieves integrated power supply for the main and auxiliary equipment, reducing the need for independent power supply channels and laying complexity underground. It also reduces the number of cables and underground connection points, improving system reliability and deployment convenience, and facilitating unified remote monitoring and maintenance.

[0049] The plasma torch is mechanically connected to the gasifying agent injection pipe and electrically connected to the ground-based equipment, serving as the carrier for the gasifying agent plasma activation and visualization platform.

[0050] Furthermore, the optical axis of camera 1 is coaxial with the central axis of the viewing window 2; a safety gap is provided between the light-incident end of camera 1 and the inner surface of the viewing window 2 to ensure clear imaging and thermal isolation.

[0051] Specifically, to ensure clear imaging and thermal isolation, a safety gap is provided between the light-incident end of the camera and the inner surface of the viewing window. The value of this safety gap can be determined according to the following engineering principles:

[0052] Relationship with lens focusing capability: The safety gap shall not be less than the allowance required for the near-end working distance of the lens in the focusing state; in practical applications, it shall usually be at least a reasonable proportion of the near-end working distance, and allowance shall be reserved for assembly and thermal deformation.

[0053] Method for determining the safety gap when using a zoom lens: When using a zoom lens, the lower limit of the safety gap is determined based on the near-end focusing distance under the maximum focal length condition to ensure that a clear image can still be obtained when zooming to the telephoto end.

[0054] Tolerances and environmental margins: The safety clearance should include machining and assembly tolerances, imaging offset caused by the equivalent optical thickness of the viewing window, and structural thermal expansion and contraction margin caused by temperature changes; in practice, it is usually not less than 10 mm, and can be 10 to 30 mm in dust / tar pollution or high temperature impact environments, and can be appropriately relaxed if necessary.

[0055] Installation reference: The camera optical axis and the central axis of the viewing window are arranged coaxially to reduce image plane distortion and ranging error caused by eccentricity; the safety gap satisfies focusing while taking into account the flow field arrangement of air curtain / jet cleaning.

[0056] The above principles are used for selection and assembly guidance, and do not limit lens models or fixed values.

[0057] Camera 1 is preferably equipped with high temperature resistance, automatic / manual exposure, focus adjustment, and viewing angle adjustment capabilities to meet the shooting requirements of low-light and high-intensity flame dynamic scenes. Camera 1 is fixedly connected to the plasma torch housing, and its attitude and focus are adjusted by ground-based equipment. The output video stream is sent to the ground-based equipment to achieve real-time visualization of the ignition and operation process.

[0058] Specifically, the camera uses a zoom lens with a focal length of 6–12 mm and a horizontal field of view of 30°–80°; the lens uses a high-temperature resistant anti-reflective coating (operating temperature ≥200℃), and the front lens element has a replaceable structure for easy maintenance.

[0059] The plasma torch and camera module meet IP66 / IP67 standards; vibration resistance meets IEC 60068-2-6: 5 Hz~500Hz, 5 g; shock resistance meets IEC 60068-2-27: 30 g / 11 ms; and dustproof rating meets IEC 60529 requirements.

[0060] For further details, please refer to Figure 3 and Figure 4 The viewing window 2 is a double-layered viewing window. The interlayer 23 is either vacuum-sealed or equipped with a cooling gas inlet 5 and a cooling gas outlet 6, evenly distributed at the interface between the interlayer 23 and the plasma torch. These outlets are connected to cooling gas pipes, which are equipped with one-way valves that open and close under pressure differential, or remotely controlled one-way valves, to ensure unidirectional controlled flow of the cooling gas. The cooling gas can be a gas with good thermal insulation properties (CO2, He, Ar, propane, etc.), or a vaporizing agent can be used directly. The cooling gas pipes can be laid separately to a ground-based cold source, or connected to a vaporizing agent injection pipe or a plasma torch gas path channel.

[0061] The double-layer viewing window is preferably a double-layer concentric spherical structure, with the height h of the outer spherical surface being 1 / 4 to 1 / 2 of the sphere radius, in order to improve compressive strength and field of vision, and to facilitate the slippage and self-cleaning of dirt.

[0062] The outer diameter of the outer spherical shell is 1 / 2 to 1 / 3 of the outer diameter of the plasma torch; the thickness of each layer is 1 to 5 mm, preferably 2 mm; the thickness of the interlayer is 2 to 10 mm, preferably 4 to 8 mm, and even more preferably 5 mm.

[0063] The viewing window material should be high-temperature and high-pressure resistant glass, such as tempered glass, borosilicate glass, quartz glass, or ceramic glass.

[0064] The transition between the viewing window and the housing is rounded (R2~R3 mm), with a flexible seal and floating clamping structure. The recommended sealing material is expanded graphite / mica + metal pressure ring. The metal ring material is Inconel 625 or 316L to alleviate thermal stress and expansion mismatch.

[0065] The double-layer concentric spherical surface combined with the sandwich cooling / vacuum structure enhances the pressure resistance, thermal shock resistance and thermal insulation capabilities, reduces the inner surface temperature of the viewing window, inhibits tar / dust adhesion and expands the viewing field, significantly improves imaging stability and clarity, and extends the continuous observation time.

[0066] Specifically, the glass used for the viewing window can be made of one or more of the following materials:

[0067] Quartz glass: continuous operating temperature ≤1000 ℃, thermal shock limit ΔT≥200 K; high transmittance and low coefficient of thermal expansion, suitable for high temperature and temperature gradient environments.

[0068] Borosilicate glass: continuous operating temperature ≤500 ℃, thermal shock limit ΔT≥150 K, low cost, good processability, suitable for medium and high temperature and fully cooled scenarios.

[0069] Sapphire: Continuous operating temperature ≤1200 ℃, high strength, strong erosion resistance, and high cost, making it the preferred choice for high erosion and high pressure differential conditions.

[0070] A positioning reticle 4 is set on the perspective window 2. The positioning reticle 4 adopts a plane rectangular coordinate system and is arranged on a symmetrical plane containing the plasma torch axis and the center of the perspective window 2. The positive direction of its coordinate axis points away from the plasma torch. It is used to calibrate the relative position of the camera 1 and the plasma torch, the heading / pitch reference, and the distance measurement of the target point in the image, which facilitates the mapping between the image plane coordinates and the coal seam spatial coordinates. Without adding new independent ranging hardware, in-situ geometric quantization can be performed based on monocular imaging, laying the foundation for image plane calibration for the temporal three-dimensional reconstruction of the gasification surface and the combustion air zone.

[0071] Furthermore, at least one nozzle 3, preferably three equidistantly distributed, is arranged around the viewing window 2 on the plasma torch, facing the viewing window 2. These nozzles are used to spray high-pressure gas or liquid to remove tar / dust and other obstructions adhering to the outer surface of the viewing window 2. The nozzles 3 are connected to a high-pressure gas / liquid source on the ground via a spray pipe, and are opened and closed by a ground valve; or they are connected to a vaporizing agent injection pipe, on which an electrically controlled switch valve is installed. The switch valve is connected to ground-end equipment and is remotely opened when contamination of the viewing window 2 is detected, spraying vaporizing agent for rapid cleaning, and then closed after clarity is restored. The combination of rapid decontamination and anti-contamination via the spray pipe improves the continuity and clarity of visualization, reduces the frequency of downtime maintenance, and reduces the need for independent pipelines and orifices when reused with the vaporizing agent pipeline, simplifying downhole layout.

[0072] Specifically, solid or hollow cone nozzles (spray angle 30°–60°) are used for gas injection; CO2, N2, or a gasifying agent are used as the gas medium; the working pressure is 0.2–0.6 MPa, and the single nozzle flow rate is 20–60 NL / min; it is used for rapid decontamination and reinforcement of anti-fouling air curtains.

[0073] Liquid cleaning uses fan-shaped nozzles (spray angle 40°~80°); the liquid medium is clean water or cleaning solution containing surfactants; the working pressure is 0.5~1.5 MPa, and the single nozzle flow rate is 0.1~0.5 L / min; it is used for intermittent cleaning in heavily tar-contaminated scenarios.

[0074] The response time of the solenoid valve / pneumatic valve is ≤100 ms, and the temperature resistance is ≥150 ℃; it can be linked with the ground-based equipment to spray as needed and is interlocked with the image clarity index.

[0075] When the injection pipe is connected to the vaporizing agent injection pipe, the injection branch should be equipped with a one-way valve, a flame arrester, a 0.1 MPa-level fusible plug, and a 10 µm filter to prevent backfire and particulate blockage; the branch start-up and shutdown should be interlocked with the main gas line to prevent misoperation and back pressure backflow.

[0076] Furthermore, the ground-based equipment includes a video receiving module, a storage module, a display module, and a control module, wherein:

[0077] The video receiving module receives video signals from the camera system; the storage module is electrically connected to the video receiving module and is used to store and manage the received video data; the display module is electrically connected to the storage module and is used to display the monitoring screen in real time; the control module is electrically connected to the video receiving module, the storage module and the display module and is used to realize the operation management and remote control functions of the system.

[0078] The control module is also electrically / signally connected to the signal and power interfaces of camera 1, the vaporizing agent injection pipe, the cooling gas pipe, and the one-way valve installed on the injection pipe, etc., to realize remote start and stop of camera 1 attitude and focus adjustment, spray cleaning and cooling gas on / off control, and to centrally monitor and maintain the system operation.

[0079] Please see Figure 5 The visualization system for underground coal plasma gasification adopts an integrated power supply and video management solution. Data from multiple front-end cameras 1 is aggregated to a video recorder and used for display. The power supply is uniformly provided by a low-voltage power supply adapted to the power adapter of the plasma torch circuit, meeting the system requirements for centralized ground reception, storage, and display. Specifically:

[0080] A high-voltage power supply provides the main power for the plasma torch, while simultaneously converting it to low-voltage power for the camera system via a power adapter. The camera system consists of three cameras (two dome-type and one bullet-type), fixedly mounted on the plasma torch body. The ground-based equipment comprises four core modules: a video receiving module implemented by a switch, responsible for aggregating the network signals from each camera to form a multi-channel video stream Ethernet transmission channel; a storage module corresponding to a video recorder, connected to the switch via a network cable, used for receiving and locally storing video data; a display module, a monitor connected to the back of the video recorder, providing a visual representation of the monitoring footage; and a control module (not shown in the diagram), responsible for system operation and management. This structural design optimizes the signal transmission path, improves system deployment efficiency and operational reliability, and provides comprehensive visual monitoring capabilities for the underground coal plasma gasification process.

[0081] Working principle:

[0082] Initialization and calibration:

[0083] The plasma torch and camera module are lowered as a whole to the gasification face near the coal seam. Cooling gas is turned on and the opening and closing status of the inlet / outlet check valves and the direction of airflow are checked to confirm that the interlayer cooling or vacuum status meets the standards. The video system is turned on, the image geometry is calibrated, and the initial mapping relationship between the image plane coordinates and the spatial coordinates is established.

[0084] Operation and Cleaning:

[0085] The system captures images in real time during ignition and operation. When a decrease in image clarity or blockage of the viewing window is detected, the system controls the opening of the injection pipe via ground-based equipment to spray high-pressure gas / liquid or vaporizing agent to clean the window until the image becomes clear again, at which point the system closes the pipe. The entire video is transmitted back and stored in the ground system for subsequent analysis.

[0086] By using camera imaging and the positioning reticle on the perspective window, the reticle corresponding to a point in the vaporization zone or combustion air zone in front of the camera can be obtained. Combined with other known information, ranging is performed using the baseline method or the backward similar triangulation method described below. Then, the data is processed in batches by computer to perform three-dimensional reconstruction of the vaporization zone or combustion air zone. Baseline method:

[0087] Please see Figure 6 Based on paraxial imaging at small angles and the relationship between similar triangles, the target distance is calculated using known geometric references and image plane readings.

[0088] Symbol definitions in the diagram (letters are illustrative symbols, not part numbers):

[0089] C: Camera optical center position;

[0090] P: The point to be measured;

[0091] R: A reference object with known actual size / position;

[0092] D: The actual lateral distance between the reference object R and the point P to be measured in the plane perpendicular to the optical axis (e.g., the actual distance in the X-axis or Y-axis direction).

[0093] d: The projection of the reference object R onto the same direction as the positioning reticle (the absolute value is taken as the length converted from reticle scale / pixel).

[0094] a: The geometric distance from the optical center of the camera to the plane containing the reticle;

[0095] L: The actual distance from the camera to the point P to be measured.

[0096] During the test, align the point P to be tested with the origin of the division. Then, from similar triangles, we can obtain:

[0097]

[0098] Utilizing this principle, the system can measure spatial distances using only a monocular camera and positioning reticles on a viewing window, without adding independent ranging hardware. This provides real-time geometric data support for the gasification process and lays the foundation for subsequent 3D reconstruction. This design not only simplifies the hardware configuration but also improves the system's reliability under high-temperature and high-pressure environments, enabling staff to safely monitor and quantitatively analyze the underground gasification process in real time.

[0099] Retreat similar triangle method:

[0100] Please see Figure 7 The camera is moved back a known distance m from position 1 along the optical axis to position 2. The distance to the point to be measured is obtained using the relationship of similar triangles.

[0101] Symbol definitions in the diagram (letters are illustrative symbols, not part numbers):

[0102] C1: The optical center of the camera at position 1;

[0103] C2: The optical center of the camera at position 2;

[0104] P: The point to be measured;

[0105] R: A reference object with known actual size / position;

[0106] a: The geometric distance from the optical center of the camera to the plane containing the reticle;

[0107] m: The distance the camera moves back from position 1 to position 2 along the optical axis;

[0108] x: When the camera is at position 1, the projection of the reference object R in the same direction as the positioning reticle (the absolute value is taken as the length converted from the reticle scale / pixel).

[0109] y: When the camera is at position 2, the projection of the reference object R in the same direction as the positioning reticle (the absolute value is taken as the length converted from the reticle scale / pixel).

[0110] L: When the camera is in position 1, the actual distance from the camera to the point P to be measured;

[0111] n: The actual lateral distance between the reference object R and the point P to be measured in the plane perpendicular to the optical axis (e.g., the actual distance in the X-axis or Y-axis direction).

[0112] During the test, when the camera moved backward, based on the proportional relationship between corresponding sides of similar triangles, we have:

[0113]

[0114]

[0115] Summarized as follows:

[0116] (where x>y, a>0)

[0117] Using the above relationship, without knowing the actual lateral length D, the distance to the target point can be calculated simply by recording the retracement readings before and after axial retraction and the retraction distance m.

[0118] In underground coal plasma gasification applications, this ranging method can be used when the camera can move along the axis of the plasma torch. By observing from two different locations, the spatial position of the internal structure of the gasification chamber can be accurately calculated, providing more accurate spatial data for monitoring the gasification process. Compared to fixed-position monocular ranging, this method can provide higher precision measurement results, especially for distant targets.

[0119] The above-described ranging and reconstruction algorithms are optional methods for achieving visualization and are used to illustrate the working principle of this utility model. They do not constitute a limitation on the scope of protection.

[0120] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A visualization system for underground coal plasma gasification, characterized in that, include: A plasma torch connected to a vaporizing agent injection pipe; At least one camera system is fixedly installed on the plasma torch. The camera system includes a camera (1) and a viewing window (2) covering the light-incident end of the camera (1). The viewing window (2) is provided with positioning reticle (4) for positioning and distance measurement. The video output terminal of the camera system is electrically / signally connected to the ground terminal equipment for transmitting video signals to the ground terminal equipment; The power supply terminal of the camera system shares a high-voltage power supply with the plasma torch via a power adapter, which is used to power the camera system.

2. The visualization system for underground coal plasma gasification according to claim 1, characterized in that, The viewing window (2) is a double-layer viewing window, with the interlayer (23) being a vacuum.

3. The visualization system for underground coal plasma gasification according to claim 1, characterized in that, The viewing window (2) is a double-layer viewing window, with a cooling air inlet (5) and a cooling air outlet (6) in the interlayer (23).

4. The visualization system for underground coal plasma gasification according to claim 3, characterized in that, The cooling gas inlet (5) and cooling gas outlet (6) are respectively connected to the cooling gas pipeline, and the cooling gas pipeline is equipped with a one-way valve that can be remotely controlled to open and close.

5. The visualization system for underground coal plasma gasification according to claim 2 or 3, characterized in that, The double-layer perspective window is a double-layer concentric spherical structure. The height of the outer spherical surface is 1 / 4 to 1 / 2 of the radius of the sphere, and the outer diameter of the outer spherical shell of the double-layer perspective window is 1 / 3 to 1 / 2 of the outer diameter of the plasma torch. The thickness of each layer is 1 to 5 mm, and the thickness of the interlayer (23) is 2 to 10 mm.

6. The visualization system for underground coal plasma gasification according to claim 1, characterized in that, The positioning reticle (4) adopts a plane rectangular coordinate system. The positioning reticle (4) is arranged on a symmetrical plane containing the plasma torch axis and the center of the perspective window (2). The positive direction of the coordinate axis of the positioning reticle (4) points away from the plasma torch.

7. The visualization system for underground coal plasma gasification according to claim 1, characterized in that, At least one nozzle (3) facing the viewing window (2) is arranged around the plasma torch. The nozzle (3) is connected to the high-pressure gas / liquid source on the ground or to the gasifying agent injection pipe through the injection pipe. An electrically controlled switch valve is installed on the injection pipe.

8. The visualization system for underground coal plasma gasification according to claim 1, characterized in that, The ground-based equipment includes a video receiving module, a storage module, a display module, and a control module.

9. The visualization system for underground coal plasma gasification according to claim 8, characterized in that, The video receiving module receives video signals from the camera system; the storage module is electrically connected to the video receiving module and is used to store and manage the received video data; the display module is electrically connected to the storage module and is used to display the monitoring screen in real time; the control module is electrically connected to the video receiving module, the storage module and the display module and is used to realize the operation management and remote control functions of the system.

10. The visualization system for underground coal plasma gasification according to claim 8 or 9, characterized in that, The control module is electrically / signally connected to the valves installed on the vaporizing agent injection pipe, cooling gas pipe, and injection pipe, respectively.

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