Abstract: Disclosed is a characterization method of closed pores and connectivity of coal measure composite reservoirs, including collecting samples of coal seams and shales reservoirs, carrying out low-field NMR experiments and NMR freeze-thaw experiments on plunger samples and crushed samples with different particle sizes to obtain cumulative pore volume distribution and differential pore size distribution of the crushed samples, comparing crushed samples with plunger samples for optimal crushed particle sizes, and preliminarily determining a distribution range of closed pores; carrying out SAXS experiments on crushed samples to obtain size distribution and volume of total pores of 1-100 nanometers; calculating pore volume of total pores and closed pore volume in composite reservoirs by low-field NMR experiments results; carrying out non-steady overburden permeability experiments and variable factors on plunger samples of coal seams, shales and tight sandstone to characterize the connectivity under influence of pores

Abstract: The present disclosure discloses a low-energy-consumption grading and positioning method and system for a coal mine auxiliary transportation vehicle, which belongs to the technical field of mine tunnel transportation.

Abstract: A directional drilling-exploring-monitoring integrated method for guaranteeing safety of an underwater shield tunnel includes: drilling a small-diameter borehole below a water area, and establishing an initial geological model; reaming the small-diameter borehole into a large-diameter borehole, placing a parallel electrical method (PEM) power cable and a monitoring optical fiber cable into the large-diameter borehole, acquiring zero field data, primary field data and secondary field data through carbon rod measurement electrodes before tunnel excavation, and processing the data with an existing inversion method to form an inversion image, thereby obtaining a refined geological model of a stratum; starting the tunnel excavation, and respectively acquiring a disturbance condition of rock and soil and a sedimentation and deformation condition of rock and soil around the tunnel during the excavation, thereby implementing safety excavation of the tunnel; and continuously monitoring the tunnel and the surrounding r

Abstract: The present invention relates to a ground double-hole combined water inrush prevention method for overlying strata movement monitoring and bed separation water drainage. By arranging a rock strata movement monitoring borehole and a bed separation water drainage borehole, interior movement information of an overlying stratum and bed separation generation timing fed back by strata movement monitoring performed inside are monitored; work on the bed separation water drainage borehole is guided by monitoring changes in arranged monitoring points; and through combination of the movement monitoring borehole and the bed separation water drainage borehole, the utilization rate of the bed separation water drainage borehole is effectively increased.

Abstract: The present invention discloses a hoisting container pose control method of a double-rope winding type ultra-deep vertical shaft hoisting system. The method comprises the following steps of step 1, building a mathematical model of a double-rope winding type ultra-deep vertical shaft hoisting subsystem; step 2, building a position closed-loop mathematical model of an electrohydraulic servo subsystem; step 3, outputting a flatness characteristics of a nonlinear system; step 4, designing a pose leveling flatness controller of a double-rope winding type ultra-deep vertical shaft hoisting subsystem; and step 5, designing a position closed-loop flatness controller of the electrohydraulic servo subsystem.

Abstract: A method for constructing a dam inside a dump of an inner-dump strip mine includes: taking an upper surface connection line of a primary water-resisting layer as upper filling reference datum boundary of an artificial water-resisting layer; arranging a dam foundation pit and a trapezoidal abutment on a midline of the dam foundation pit; building and reinforcing a step-shaped retaining dam core wall on the artificial water-resisting layer; laying a foundation impervious layer, waterproof geotextile, and an earth blanket on one side, close to the primary aquifer, of the retaining dam core wall; strengthening advance of a dumping working face on one side, away from the primary aquifer, of the retaining dam core wall, and dumping overburden of a strip mine to form a support; filling a space between the earth blanket and the primary aquifer to form a blocker; and proceeding with construction and forming a continuous retaining dam.

Abstract: An intelligent reliability evaluation and service life prediction method for a kilometer deep well hoist brake, the method including: the establishment of a digital twin model for a hoist brake, data acquisition and synchronization, and reliability evaluation and service life prediction, wherein the digital twin model for the hoist brake can accurately reflect actual physical characteristics of the hoist brake, the data acquisition and synchronization can realize real-time mapping between a physical entity of the hoist brake and the digital twin model therefor, and furthermore, on the basis of the digital twin model for the hoist brake, the reliability evaluation and service life prediction are realized. Digital twin technology is combined with a reliability analysis method, so that real-time updating of reliability evaluation and service life prediction of the hoist brake are realized.

Abstract: A rock burst hazard prediction method based on vibration wave energy attenuation characteristics of a mine earthquake cluster is provided. The rock burst hazard prediction method comprehensively considers the static load and dynamic load effects of the vibration waves of the mine earthquake cluster based on vibration wave energy attenuation characteristics of the mine earthquake cluster. The static load strength index and the dynamic load strength index involved in the method have clear physical meanings. A comprehensive prediction index calculation model proposed based on the dynamic and static load superposition principle of rock burst occurrence is clear, and the method has a firm theoretical support as well as strong universality and operability. Meanwhile, the updating and adjustment of weights are rapid and the objective judgment and prediction of the final comprehensive prediction results are efficient, and the high-energy mine earthquake and impact behavior area can be effectively predicted.

Abstract: A multi-dimensional space load and fire test system for a tunnel structure, which includes a multi-point loading self-balancing reaction force system having a rigid platform, two furnace body side-sealing apparatuses (22) and a model assembly and transport apparatus (23) for transporting and situating a tunnel model are on a track on the rigid platform (9), the two furnace body side-sealing apparatuses (22) are respectively used for sealing two end openings of the tunnel model, a tower-type combustion vehicle can be placed within an inner cavity of the tunnel model, a plurality of sets of evenly distributed self-adaptive loading apparatuses (3) used for exerting loading forces on an outer wall of the tunnel model are connected between two reaction force frames (1) of the multi-point loading self-balancing reaction force system.

Abstract: The present disclosure relates to a technical field of coal mining, in particular to a surrounding rock stability control method adapted for a coal mining area main roadway. The method comprises the following steps: reinforcing support on a roof and two sides of the mining area main roadway on a basis of an original support form; digging a safety roadway along a stop line of a present working face required by coal mine design, and supporting the safety roadway, wherein a protective coal pillar is formed between the safety roadway and the mining area main roadway; performing slitting blasting on the roof in the safety roadway, wherein blast holes are arranged on a roadway corner line on one side of the present working face to form a pre-splitting slit; and performing stoping at a next working face after completing coal mining at the present working face when stoping at the present working face advances to the safety roadway.

Abstract: A method for constructing a dam inside a dump of an inner-dump strip mine includes: taking an upper surface connection line of a primary water-resisting layer as upper filling reference datum boundary of an artificial water-resisting layer; arranging a dam foundation pit and a trapezoidal abutment on a midline of the dam foundation pit; building and reinforcing a step-shaped retaining dam core wall on the artificial water-resisting layer; laying a foundation impervious layer, waterproof geotextile, and an earth blanket on one side, close to the primary aquifer, of the retaining dam core wall; strengthening advance of a dumping working face on one side, away from the primary aquifer, of the retaining dam core wall, and dumping overburden of a strip mine to form a support; filling a space between the earth blanket and the primary aquifer to form a blocker; and proceeding with construction and forming a continuous retaining dam.

Abstract: The present disclosure relates to the field of mineral processing and separation, and in particular, to an underground coal hypergravity field separation system and a separation process. The separation system includes a grading hydrocyclone group, hypergravity field separators, feeding pumps, and conveying pumps. Coal collected underground is graded through a grading hydrocyclone first, then is fed into the hypergravity field separators for separation, and finally, is conveyed to a next link for dehydration through the conveying pumps. The separation system of the present disclosure has less supporting equipment, small floor area, and no complex pipeline, and is suitable for a downhole operation. In addition, the hypergravity field separators can provide a high-strength centrifugal acceleration, which can realize rapid separation of coal gangue particles in a radial direction and a tangential direction, and realize effective separation of fine coal gangue particles.

Abstract: A frictional force monitoring system for middle troughs of a scraper conveyor, comprising a scraper conveyor system and a sensing detection system. The scraper conveyor system consists of a machine body, middle troughs, thrust lugs, scrapers, a double chain, a sprocket, a speed reducer, an electric motor and a frequency converter. The sensing monitoring system consists of force receiving modules, a three-dimensional force sensor, and a pre-embedded temperature sensor. The frictional force monitoring system is able to monitor impact loads, frictional forces, friction coefficients, temperature, etc. between an annular chain, coal bulk, and middle troughs of the scraper conveyor under complex and severe operating conditions, and to provide the technical means for the design, safety early-warning and health evaluation of the scraper conveyor, and can provide a data basis for studying friction wear and fatigue breaking mechanism of middle troughs of a scraper machine.

Abstract: The present disclosure relates to a technical field of coal mining, particularly to a method of no-pillar mining with gob-entry retaining adapted for fully-mechanized top coal caving in a thick coal seam, which comprises the following steps: reinforcing support on a roof and two sides of a roadway; performing roof slitting blasting to form a pre-splitting slit; erecting a temporary support device and a gangue retaining device in the roadway along the retained entry; performing no caving within a range of a preset distance at an end of the working face near the retained entry side; and removing the temporary support device in the roadway after entry forming stabilizes, and closing the goaf to complete entry retaining.

Abstract: Disclosed is a device and method for distributed detection of straightness of a working face of a scraper conveyor based on optical fiber sensing. The device includes a broadband light source, a first optical fiber circulator array, a second optical fiber circulator array, a collimator array, a reflecting film array, a third optical fiber circulator array, and an optical path analyzer. During transmission of light emitted from the broadband light source, the light with different wavelengths is separated via several optical gratings etched on a single-mode optical fiber (SMF), and reaches reflecting films adhered to the working face of the scraper conveyor through first optical fiber circulators, second optical fiber circulators, and collimators. The light with the different wavelengths is then reflected back from the reflecting films, enters the SMF through third optical fiber circulators, and finally enters the optical path analyzer.

Abstract: Disclosed is a permanent magnet direct-drive slurry pump based on gas film drag reduction, which includes a permanent magnet motor, a main shaft, an impeller, and a valve block. The permanent magnet motor includes a housing, a stator core, stator windings, a rotor core, and a permanent magnet. The rotor core and the impeller share the main shaft, and an airflow channel is provided inside the main shaft. The impeller includes a front cover plate, a back cover plate, and blades. The blades are modularly manufactured, and blade gas jet holes and hemispherical pits are provided on the pressure surface. The airflow channel in the main shaft is communicated with the blade gas-jet holes. The valve block is disposed at the tail end of the main shaft so as to control gas exhaust and prevent liquid from entering the shaft. The present invention has such advantages as a small size, high efficiency, and strong wear resistance.

Abstract: The present invention provides an experimental platform for simulating a coal rock disaster of a coal mine extraction, including a base device, a coal simulation device, an immediate roof simulation device, a hydraulic support and a removable impact device. The coal simulation device is fixedly disposed on the base device; the hydraulic support is fixed on the base device and is located at one side of the coal simulation device; the immediate roof simulation device is disposed above the coal simulation device and the hydraulic support; the removable impact device is disposed above the immediate roof simulation device; the immediate roof simulation device is a rectangular frame; the rectangular frame is configured to pave a bulk simulation material and an immediate roof simulation material sequentially from the bottom up; and the removable impact device can impact the immediate roof simulation material and the bulk simulation material.

Abstract: Disclosed is a permanent magnet direct-drive slurry pump based on gas film drag reduction, which includes a permanent magnet motor, a main shaft, an impeller, and a valve block. The permanent magnet motor includes a housing, a stator core, stator windings, a rotor core, and a permanent magnet. The rotor core and the impeller share the main shaft, and an airflow channel is provided inside the main shaft. The impeller includes a front cover plate, a back cover plate, and blades. The blades are modularly manufactured, and blade gas jet holes and hemispherical pits are provided on the pressure surface. The airflow channel in the main shaft is communicated with the blade gas-jet holes. The valve block is disposed at the tail end of the main shaft so as to control gas exhaust and prevent liquid from entering the shaft. The present invention has such advantages as a small size, high efficiency, and strong wear resistance.

Abstract: Disclosed is a device and method for distributed detection of straightness of a working face of a scraper conveyor based on optical fiber sensing. The device includes a broadband light source, a first optical fiber circulator array, a second optical fiber circulator array, a collimator array, a reflecting film array, a third optical fiber circulator array, and an optical path analyzer. During transmission of light emitted from the broadband light source, the light with different wavelengths is separated via several optical gratings etched on a single-mode optical fiber (SMF), and reaches reflecting films adhered to the working face of the scraper conveyor through first optical fiber circulators, second optical fiber circulators, and collimators. The light with the different wavelengths is then reflected back from the reflecting films, enters the SMF through third optical fiber circulators, and finally enters the optical path analyzer.

Abstract: An intelligent detection and recognition system and method for a coal-rock interface of a mine are provided. The intelligent detection and recognition system mainly includes an intelligent lifting support fastened to the top of a shearer, a non-contact radar antenna disposed at the top of the intelligent lifting support, and an operating terminal with which the radar antenna wirelessly conducts information transmission. In an operating state, a radiation direction of the radar antenna is perpendicular to the surface of a to-be-detected coal seam, and the operating terminal is configured to acquire radar data of the to-be-detected coal seam collected by the radar antenna, and draw and display a coal-rock horizon occurrence curve according to the radar data.