Method for creating explosion-proof gas environment in coal mines

Abstract

FIELD: coal mining.SUBSTANCE: method for creating an explosion-proof gas environment in coal mines. Two flat log-periodic antennas are rotated relative to each other by 90 degrees and form a triangular structure in the vertical plane. When antennas are connected in phase, radiation of a field with horizontal polarization is ensured, and when connected in antiphase, radiation of a field with vertical polarization is ensured. The working section of an underground mining with automated equipment located within it is isolated by means of an adjustable explosion-proof bulkhead equipped with a remote opening and closing mechanism. The concentration of methane in the atmosphere of the working part of the mine is brought to values exceeding 16 vol.%. In the working part of the mine, technological operations are carried out using automated equipment located there. The adjustable explosion-proof bulkhead is opened. The concentration of methane in the atmosphere of the working part of the mine is brought to a concentration of less than 1 vol.%, after which access is opened to personnel in the working part of the mine.EFFECT: elimination of the possibility of methane ignition, explosions of flammable gases and dust-gas mixtures with an increase in the overall level of safety of mining operations, an increase in the efficiency of coal mining and the conduct of mine workings using complex mechanized longwalls.8 cl, 10 dwg

Description

[0001] The technical solution relates to the field of mining industry, in particular to the technology of ensuring explosion safety in coal mine workings.

[0002] Experience in industrial-scale methane control using coal seam degassing technology spans over 70 years. More than 47 different degassing methods have been tested in coal mines for highly gas-bearing coal seams. Numerous measures have been developed to artificially enhance coal gas recovery (mechanical, hydraulic, pneumatic, explosive, plasma-pulse, etc.), and numerous unconventional methods for influencing seams (thermochemical, microbiological, physicochemical, etc.) have been created. Despite this, 80% of coal mines are potentially methane-explosive, and all currently used methods for combating dangerous methane concentrations, including ventilation, gas management, degassing, etc., cannot fully ensure safety in modern methane-rich, highly productive mines.

[0003] The depth of coal mining operations worldwide is steadily increasing. In Russia, this figure is increasing by an average of 16-17 meters per year. As mining depth increases, mining conditions become increasingly complex. Due to increasing geostatic pressure and the growing stress state of the rock mass within individual elementary blocks, cracks close, rock compaction occurs, rock porosity decreases, and the massif's block structure increases. In other words, all the key properties that directly influence mining technology parameters and significantly determine the quality and efficiency of degassing processes are changing.

[0004] As working depths continue to increase, mining conditions will objectively become increasingly difficult each year and will eventually deteriorate to the point where maintaining methane levels in workings within acceptable limits using current ventilation and degassing systems will be completely impossible. Excessive amounts of air required for ventilation will inevitably lead to exceeding permissible air flow rates within the workings. Degassing also has certain limitations in its effectiveness and, at a certain point, will not be able to capture methane to the required volumes. Furthermore, experience shows that localized layered methane accumulations in mine workings are possible even with normal ventilation.

[0005] Furthermore, the process of methane release from coal is highly unstable over time - at any moment, cases of sudden formation of an explosive concentration of methane-air mixture are possible, the causes of which are not always amenable to modern scientific analysis.

[0006] The production experience of the authors of the present invention in the field of gas-dynamic phenomena and preliminary reservoir degassing using the example of the extraction areas of Kuzbass mines from 2010 to the present fully confirms all of the above conclusions.

[0007] As a rule, coal mine management's desire to increase production leads to increased workloads at working faces and further stimulates methane emissions from the coal seams being mined. The main sources of ignition of the methane-air mixture currently include electrical equipment, frictional sparking, and underground fires.

[0008] In addition to the well-known causes of mine accidents listed above, it's also important to note those related to little-studied natural phenomena. In particular, deformation or brittle fracture of rock can be accompanied by mechanoelectric phenomena; sliding and friction surfaces in the earth's interior can generate an electrical discharge. Recent studies have also uncovered a phenomenon associated with the possibility of an uncontrolled electrical impulse occurring in a mine. This phenomenon is as follows: during mechanical loading or unloading of bolts used to secure workings from external forces (during rupture), a piezoelectric effect occurs, which can be the source of an electrical impulse sufficient to generate a spark, potentially igniting a methane-air mixture at an explosive concentration.

[0009] Thus, as practice shows, despite modern scientific research and many years of experience in operating coal seam degassing technology, all currently used methods for combating hazardous methane concentrations, including ventilation, gas management, and others, cannot fully ensure explosion safety during mining operations in highly productive coal mines. Moreover, due to the shift of mining operations to deeper levels of deposits, under increasingly complex mining and geological conditions, the relevance of this problem is only increasing.

[0010] A known method for preventing gas-air mixture explosions is described in Russian Patent No. 2429349 (priority date: October 19, 2009). This method involves recording the concentration of the gas-air mixture and, when it approaches the maximum permissible explosive concentration, emitting an audible and visual signal. This method involves shutting off the gas supply to the gas pipeline after a 10-15 second delay and ventilating the room for a period of time dependent on the volume of the room being ventilated, the air exchange rate, and the capacity of the emergency ventilation fan.

[0011] The disadvantages of this method are the low reliability of explosion protection and the difficulty of implementation.

[0012] A method for preventing methane explosions in mines is known under Russian Federation Patent No. 2371583, priority dated November 30, 2007, which includes isolating mine workings in which methane is emitted from the influx of fresh air and increasing the concentration of methane by releasing it from the mined coal, the mined space and the surrounding rocks to values ​​​​exceeding the upper explosive limit of methane, characterized in that after isolating the mine workings, they are filled with an inert gas, reducing the oxygen concentration to explosion-proof values, and then increasing the concentration of methane due to the natural influx to values ​​​​exceeding the upper explosive limit of methane.

[0013] The disadvantages of this method include its potential for explosion during the process of sealing off mine workings and filling them with inert gas. Furthermore, these operations require additional specialized equipment and the direct involvement of personnel. Therefore, this method is susceptible to human error and is not safe enough.

[0014] The objective of the invention is to create the most effective method for ensuring an explosion-proof environment in the working areas of coal mines, characterized by potentially hazardous factors, including the risk of methane ignition, explosions of flammable gases and dust-gas mixtures.

[0015] The technical result of the invention consists in eliminating the possibility of methane ignition, explosions of flammable gases and dust-gas mixtures with an increase in the overall level of safety of mining operations, an increase in the efficiency of coal mining and the conduct of mine workings using complex mechanized faces.

[0016] The technical result is achieved by isolating the working section of an underground mine working with automated equipment located therein by means of an adjustable explosion-proof bulkhead equipped with a remote opening and closing mechanism; bringing the methane concentration in the working section of the working to values ​​exceeding 16% by volume; carrying out technological operations in the working section of the working by means of the automated equipment located therein; opening the adjustable explosion-proof bulkhead, bringing the methane concentration in the working face cavity to values ​​less than 1% by volume, after which personnel are allowed access to the working section of the working.

[0017] The following features of the technology can also contribute to achieving the technical result:

[0018] - the working part of the working with the automated equipment located in it is isolated by means of adjustable explosion-proof jumpers in the amount of 1 to 4, depending on the layout of the workings;

[0019] - explosion-proof jumpers are designed to contain shock waves from explosions of flammable gases and dust-gas mixtures with a front pressure of up to 2.8 MPa;

[0020] - control of automated equipment located in the working part of the workings is carried out by personnel located in a separate safe part of the underground workings;

[0021] - control of automated equipment located in the working part of the mine is carried out by personnel located on the daylight surface;

[0022] - automated equipment is controlled by a remote control system;

[0023] - automated equipment is controlled via a telematic control system;

[0024] - automated equipment is controlled by a robotic control system.

[0025] The essence of the technical solution is explained by the figures of the drawing, which schematically show possible variants of implementing the invention.

[0026] Fig. 1 - 4 show schematic diagrams with options for installing explosion-proof adjustable barriers in mine workings of mining sections of coal mines.

[0027] Fig. 5 - 10 show schematic diagrams with options for installing explosion-proof adjustable barriers in mine workings in the development (preparatory) sections of coal mines.

[0028] The drawing shows the following positions:

[0029] 1 - explosion-proof adjustable jumper in the “Open” operating mode;

[0030] 2 - explosion-proof adjustable jumper in the “Closed” operating mode;

[0031] 3 - insulating jumper;

[0032] 4 - a comprehensive mechanized face of a mining site with equipment including sections of mechanized support, a face conveyor, a mining combine, etc.;

[0033] 5 - conveyor for transporting rock mass from the face;

[0034] 6 - scraper loader for transporting rock mass from the face to the conveyor;

[0035] 7 - direction of movement of the complex mechanized face;

[0036] 8 - direction of movement of the fresh air stream in the “Open” mode of operation of explosion-proof adjustable jumpers;

[0037] 9 - direction of movement of the exhaust air stream when the explosion-proof adjustable jumpers are in the “Open” mode;

[0038] 10 - direction of movement of rock mass from the face;

[0039] 11 - exhaust space;

[0040] 12 - underground mining;

[0041] 13 - sensor for monitoring the gas state of the atmosphere in mine workings;

[0042] 14 - explosion-localizing water or shale barrier, automatic explosion suppression-explosion localization system;

[0043] 15 - complex mechanized tunneling (preparatory) face;

[0044] 16 - ventilation pipe for supplying fresh air to the mining face;

[0045] 17 - local ventilation fan for supplying fresh air to the mining face;

[0046] 18 - ventilation jumper regulating the direction of air movement.

[0047] The presented figures of the drawing and the description of providing an explosion-proof gas environment in sections of underground mine workings do not limit the scope of the claimed technical solution - other options for the execution and use of the proposed invention are possible within the scope of its formula.

[0048] The proposed invention provides the possibility of coal mining using inert gas environments in combination with mining operations without the constant presence of people in work areas using advanced digital, automated and / or robotic technologies that enable remote work of production personnel - automated unmanned coal mining.

[0049] The essence of the proposed method for creating an explosion-proof gas environment in coal mines is that coal mining processes associated with methane release, which pose hazards to miners, are carried out in a space isolated from the general mine atmosphere and filled with an explosion-proof (inert) gas mixture. The work is performed using remotely controlled, automated, or robotic equipment, while maintenance personnel remain in separate, safe, well-ventilated sections of the mine workings or on the surface.

[0050] The installation of explosion-proof adjustable bulkheads (1, 2) is necessary to regulate the amount of air supplied to working areas of mines where there is a high risk of methane ignition, flammable gas explosions, and dust-gas mixtures. These include active mining and tunneling areas of coal mines.

[0051] Installation of explosion-proof adjustable jumpers (1, 2) and mining equipment in underground mine workings is carried out under normal existing conditions of coal mines in accordance with the current requirements of industrial safety standards and regulations.

[0052] After installation of bulkheads (1, 2, 3) and mining equipment, before the start of mining or tunneling operations, explosion-resistant adjustable bulkheads (1, 2) are closed, completely isolating sections of the mine workings and gradually filling them with methane or inert gas mixtures due to natural release from the coal massif and / or rock to levels exceeding 16% by volume. This ensures controlled gasification of working sections of the mine workings.

[0053] A methane (CH4) concentration in air greater than 16% by volume (without oxygen) is the natural upper limit of flammability and explosiveness, completely eliminating the risk of ignition or explosion. Methane is completely self-extinguishing.

[0054] Start-up of equipment in an isolated space is carried out with complete inertization of the working environment to methane concentrations above 16% by volume that are safe for equipment operation.

[0055] To perform auxiliary work and equipment maintenance in isolated sections of mine workings, according to standard measures for the coal industry, in accordance with the current requirements of the norms and rules in the field of industrial safety, explosion-proof adjustable jumpers (1, 2) are gradually (smoothly) opened and controlled degassing (ventilation) of the workings is carried out until an acceptable safe concentration of 0.0 to 1.0% by volume is reached, at which methane is also not subject to combustion or explosion, after which the mine personnel can safely perform any work in the degassed mine workings.

[0056] After completing all necessary auxiliary operations at production sites, personnel are taken out to workings with a fresh air stream or to the daylight surface (to a safe place), then explosion-proof adjustable bulkheads are closed, controlled gasification of the work area is carried out again, the work cycle for conducting workings or coal mining at the sites is repeated.

[0057] The claimed method for creating an explosion-proof gas environment in coal mines is based on remote control of the operating modes of explosion-proof adjustable bulkheads (1, 2) and monitoring their "Open-Closed" states. Electric, hydraulic, combined, or other mechanisms can be used as opening and closing mechanisms for the explosion-proof adjustable bulkheads. The opening and closing mechanisms of the bulkheads (1, 2) are controlled remotely from known-safe locations in mine workings with a fresh air stream or from the surface.

[0058] Monitoring of the gas state of the atmosphere in mine workings is carried out continuously and continuously using control sensors (13) located in mine workings in all operating modes of explosion-proof adjustable jumpers (1, 2).

[0059] The defining aspect of the invention is that its implementation is only possible in the production areas of mines using technologies associated with the use of units of various designs for conducting mine workings and coal mining without the direct presence of a person in the operating faces, with remote control of equipment for coal mining or conducting mine workings, the introduction of complex-mechanized (automated) faces, robotic technology.

[0060] When implementing the proposed invention, equipment of various levels of automation can be used (in particular, in a comprehensively mechanized development (preparatory) face (15). In this case, 5 levels of equipment automation can be distinguished, as described below.

[0061] Level 1 – Remote control within line of sight. This level of automation involves the most significant human involvement in process operations and involves the operator, at a safe distance, working within line of sight of the object being controlled via remote control.

[0062] Level 2 - Telematic Control (TC). Equipment is controlled using video cameras and manipulators, as well as other means of transmitting control signals to the equipment and monitors. With these devices, the operator determines the current location of the equipment and monitors it. Compared to line-of-sight remote control, TC removes the operator to a significantly greater distance.

[0063] Level 3 - Semi-Automatic Control (SA). This level of automation is similar to telematics control in that operator control is still required, but to a lesser extent. Some functions are automated, and the equipment itself is typically controlled from the surface, eliminating the need for the operator to descend into the underground mine.

[0064] Level 4 - Fully Automated Control (Robotization). Fully automated control can involve the autonomous operation of one or more pieces of equipment, with the operator merely monitoring the process. Robotic components control all critical equipment functions without the need for operator intervention. Fully autonomous mining systems offer the highest productivity compared to other types of automation, as software controls one or more mining machines, allowing operators to perform monitoring and troubleshooting functions. The advantages of robotization include: significantly improved personnel safety, single operator control of one or more pieces of equipment, reduced risk of damage, increased equipment lifespan, and significantly increased equipment utilization and productivity.

[0065] Level 5 - interconnected industrial enterprises with a unified digital control system, including through artificial intelligence (in particular, technological solutions of the “Connected mine” class for fully automatic, “unmanned” control of underground treatment equipment).

[0066] The choice of a specific level of automation is determined based on the complexity of the mining and geological conditions of the enterprise, as well as other factors that determine the possible depth of automation of technological processes - such as the qualifications and number of personnel, the features of the equipment used, the required productivity, etc.

[0067] The choice of the most optimal options for the placement and operation of explosion-resistant adjustable bulkheads (1, 2), as well as their number, parameters, materials, design, necessity and composition of special structural elements for their reinforcement - is determined in each individual case individually in accordance with the specific mining and technological conditions of coal mines and depends on the maximum possible volumes of accumulations of explosive methane mixtures (gas content of coal seams, length of mine workings, cross-sections of mine workings, length of working face, volume of mined space), directions of air movement through mine workings, locations of installation of bulkheads, etc.

[0068] To increase the efficiency of explosion-proof adjustable barriers (1, 2) in extreme situations, as auxiliary explosion-proof engineering devices for reducing the energy of the shock wave front from the explosion of dust-gas-air mixtures and thermal impulses, explosion-localizing water or shale barriers, standard for the coal industry, automatic explosion suppression-localization systems, special parachute-type barriers, widening devices in the walls of mine workings (periodic increase in the cross-section at a certain interval) or other safety systems can be used in the used mine workings.

[0069] The claimed method ensures the formation of an inert, explosion-proof gas environment in certain underground coal mine sections with a high risk of methane ignition, flammable gas explosions, and dust-gas mixtures. These sections are equipped with automated, remotely controlled, and monitored underground mining faces, while maintaining partial ventilation in the main workings. These sections, isolated from fresh air by adjustable barriers (1, 2), may include separate working or tunneling faces.

[0070] The claimed method for creating an explosion-proof gas environment for use in individual production areas of coal mines will effectively solve the problem of high methane levels in existing production areas under current conditions and in planned coal mines, which will significantly increase the level of safety by eliminating the likelihood of combustion, flashes and explosions of methane and methane mixtures in underground conditions.

[0071] The proposed invention also allows:

[0072] - eliminate the need for all types of preliminary (concomitant) degassing of coal seams and isolated methane removal;

[0073] - to make maximum use of the technical capabilities of existing high-performance coal mining and tunneling equipment, which is held back by the “gas barrier”, as well as to further increase the production capacity of enterprises;

[0074] - reduce the total required amount of air supplied for ventilation of mine workings, sections of preparatory mine workings in tunneling and light;

[0075] - reduce the volume and time required to prepare sites for resuming mining operations; improve the efficiency of construction and installation work and mining equipment, eliminating the need for heavy-duty combines, local ventilation fans, etc.

[0076] - eliminate the need to build powerful main ventilation and gas control fans, and the costs of servicing infrastructure facilities on the surface of mines;

[0077] - reduce energy costs;

[0078] - contribute to a significant reduction in greenhouse gas emissions into the atmosphere;

[0079] - reduce the number of production, industrial and auxiliary personnel;

[0080] - reduce the level of costs for employee insurance;

[0081] - implement coal-methane co-production technologies that ensure a high degree of methane recovery with significant volumes of high-concentration gas produced.

Claims

1. A method for creating an explosion-proof gas environment in coal mines, wherein: the working section of an underground mine working with automated equipment located therein is isolated by means of an adjustable explosion-proof bulkhead equipped with a remote opening and closing mechanism; the methane concentration in the atmosphere of the working section of the working is brought to values ​​exceeding 16% by volume; technological operations are carried out in the working section of the working by means of the automated equipment located therein; the adjustable explosion-proof bulkhead is opened, the methane concentration in the atmosphere of the working section of the working is brought to concentration values ​​of less than 1% by volume, after which access to the working section of the working is opened for personnel.

2. A method for creating an explosion-proof gas environment in coal mines according to paragraph 1, characterized in that the working part of the working with automated equipment located therein is isolated by means of adjustable explosion-proof jumpers in a quantity of 1 to 4, depending on the layout of the workings.

3. A method for creating an explosion-proof gas environment in coal mines according to paragraph 1 or 2, characterized in that the explosion-proof bulkheads are designed with the ability to contain shock waves from explosions of flammable gases and dust-gas mixtures with a pressure at the front of up to 2.8 MPa.

4. A method for creating an explosion-proof gas environment in coal mines according to paragraphs 1-3, characterized in that the control of automated equipment located in the working part of the working is carried out by personnel located in a separate safe part of the underground workings.

5. A method for creating an explosion-proof gas environment in coal mines according to paragraphs 1-3, characterized in that the automated equipment located in the working part of the working is controlled by personnel located on the daylight surface.

6. A method for creating an explosion-proof gas environment in coal mines according to paragraphs 1-5, characterized in that the automated equipment is controlled by a remote control system.

7. A method for creating an explosion-proof gas environment in coal mines according to paragraphs 1-5, characterized in that the automated equipment is controlled by a telematic control system.

8. A method for creating an explosion-proof gas environment in coal mines according to paragraphs 1-5, characterized in that the automated equipment is controlled by a robotic control system.

Images