Abstract: A visualization system and method for a multiphase fluids displacement seepage experiment with large viscosity difference in a complex pore structure. The visualization system includes: an injection pump assembly, a visualized complex pore model, a vacuum pressure pump and an image acquisition device; the system and method are printed by a 3D printing device to form the visualized complex pore model with at least two permeability, and displacement fluid mediums of different viscosities are injected into the visualized complex pore model through different injection pumps during an experiment, so that not only is the penetration of the same viscosity in the complex pore structure with different permeability observed, but also the displacement and plugging effect of different viscosities successively entering the complex pore structure with different permeability is realized.

Abstract: A device and method for detecting an angle of a shearer rocker arm based on optical fiber sensing. The device includes an optical system and a mechanical system. The optical system includes a broadband light source, a polarizer, collimating lenses, a gradient-rotation media plate, a polarization beam splitter, and a data processing module. The mechanical system includes a connecting base, connecting rods, a slider, a bracket, and a sensor housing. When the shearer operates, the rocker arm converts rotation angle information to linear displacement related to a gradient refractive index by using a connecting rod mechanism, and a position on the gradient-rotation media plate through which linearly polarized light produced by the optical system passes also changes. Due to an optical rotation effect, corresponding rotation angles of a plane of polarization that are formed after the light passing through the gradient-rotation media plate also vary.

Abstract: Provided is a fracturing relief method for stress concentration of remaining ore pillars in an overlying goaf, including first, performing directional fracturing on a roof to optimize the stress of the roof and reduce the source of force; secondly, performing pulse fracturing on a coal pillar to produce a crack network, weaken the stiffness of the coal pillar and reduce the bearing capacity of the coal pillar; and finally, performing pulse fracturing on a floor strata of the coal pillar to reduce the ability of transferring stress concentration thereof. A drilling machine is used for separately constructing fracturing drill holes in a roadway to a set depth at an interval in a direction oblique to the coal pillar in an upper goaf. The roof, the coal pillar and the floor can be fractured by an oblique fracturing hole in a sublevel retreating manner. The position of the directional fracturing of the roof is approximately 1 m above the middle of a main roof above the coal pillar.

Abstract: Disclosed is an interference protection device and method for a hydraulic support and a cutting part of a shearer. The device includes: a plurality of dust-proof cases evenly and fixedly provided on a surface of one side of a hauling part of the shearer that faces away from a coal wall, and a dust-proof housing fixed on the hydraulic support. A first ultrasonic transducer and a flash lamp are fixedly provided in each dust-proof case, and a second ultrasonic transducer, a receiver, and a data processing module are fixedly provided in the dust-proof housing. The data processing module is electrically connected to the second ultrasonic transducer and the receiver separately, the first ultrasonic transducers and the flash lamps are all electrically connected to an external single-chip microcomputer, and the data processing module is electrically connected to a hydraulic support control computer.

Abstract: A visualization system and method for a multiphase fluids displacement seepage experiment with large viscosity difference in a complex pore structure. The visualization system includes: an injection pump assembly, a visualized complex pore model, a vacuum pressure pump and an image acquisition device; the system and method are printed by a 3D printing device to form the visualized complex pore model with at least two permeability, and displacement fluid mediums of different viscosities are injected into the visualized complex pore model through different injection pumps during an experiment, so that not only is the penetration of the same viscosity in the complex pore structure with different permeability observed, but also the displacement and plugging effect of different viscosities successively entering the complex pore structure with different permeability is realized.

Abstract: A single-anchor centrally grouted full-length anchored steel wire bundle and a supporting method thereof are described herein. The steel wire bundle consists of parallel steel wires and a central pipe, wherein multiple strands of parallel steel wires are arranged around the central pipe, the central pipe is provided with a slurry output bracket which divides the parallel steel wires into a front part and a rear part, the front part is provided with large stirring jackets, and the rear part is provided with a threaded casing on its tail end. After the coal is cut by a tunneling machine and a roadway is formed, the steel wire bundle is anchored at the ends, and the roadway tunneling speed is increased; central grouting is carried out for the steel wire bundle so as to anchor the steel wire bundle in full length and ensure long-time stability of the roadway.

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: Disclosed are a measurement-while-drilling method and device for obtaining a coal seam gas parameter applicable to measurement of a coal seam gas/coal seam methane parameter while drilling and evaluation of gas drainage performance. The invention performs a measurement-while-drilling operation to obtain information about downhole gas and a coal seam, thereby realizing on-site measurement of a coal seam gas parameter while drilling. The measurement-while-drilling device for obtaining a coal seam gas parameter comprises a compartment (17), a pressure sensor (15), a temperature sensor (14), a flow sensor (4), an acoustic emission sensor (16), a monitoring and control module (11), a power module and a communication module. The device is installed between a drill bit (1) and a first drill pipe (20).

Abstract: The present invention discloses a drive system of a scraper conveyor and a control method. The drive system includes a nose sprocket, a tail sprocket, a nose sprocket drive mechanism, and a tail sprocket drive mechanism, where the nose sprocket drive mechanism is a hydraulic motor I, and the tail sprocket drive mechanism is a hydraulic motor II; and a hydraulic system that drives the hydraulic motor I and a hydraulic system that drives the hydraulic motor II include same hydraulic elements, and both include a three-position four-way solenoid directional valve, a two-position two-way solenoid directional valve, a two-position three-way solenoid directional valve, an accumulator, and an oil supplement valve group. The present invention is applicable to rapid starting and stopping of the scraper conveyor in a heavy load status while adjusting chain tension in real time, thereby resolving a power imbalance problem in a dual-drive system, and has a simple structure and a long service life.

Abstract: A mining machine applicable to fluidized mining and a mining method therefor are provided herein. A microwave transmitting mechanism, a liquid jet drill rod and a cutter-head are arranged at the head of a first excavation device of the mining machine. The ore body in front is first processed by the microwave transmitting mechanism and the liquid jet drill rod to reduce the strength of the ore body, which facilitates subsequent mining of the ore body, lowers the hardness requirements of the cutter-head, and reduces the wearing of the cutter-head. With this mining machine mining the ore body, the mined ores can be directly converted, under the ground, into resources in the easily transportable form, without transporting the ore to the surface for conversion, which saves the cost of transporting the ore to the surface.

Abstract: An experimental method and system for simulating the evolution of reservoir fracture stress field, the experimental method comprises the following steps: (S1) preparing horizontal well fracturing model (100); (S2) applying boundary loads and constraints to the horizontal well fracturing model (100); (S3) injecting fracturing fluid or fracturing gas into a fracturing wellbore (130) of the horizontal well fracturing model (100) after loading for fracturing; in a fracturing stage, a photoelastic fringe image of the horizontal well fracturing model (100) is obtained by an optical phase shift method; the fracturing stage comprises an initial state before fracturing fluid or fracturing gas is injected and an end state after fracturing is completed. The experimental method and system can effectively simulate the whole process of horizontal well fracturing, and accurately obtain the variation law of reservoir stress field and its influence on crack propagation during horizontal well fracturing.

Abstract: Disclosed are a wellbore inspection system and method for an ultra-deep vertical shaft. The wellbore inspection system includes a wire rope moving system, inspection robots, a visual image acquisition system, a wireless communication module, a central control system, and an image post-processing system of an upper computer. The wire rope moving system includes a surface wire rope guide rail, an underground wire rope guide rail, a surface wire rope moving device, an underground wire rope moving device, and a wire rope. The visual image acquisition system includes explosion-proof cameras. After image information acquired by the explosion-proof cameras is processed by a lower computer, the processed image is transmitted by a wireless image transmission module to the image post-processing system of the upper computer. The central control system is connected to the inspection robots and the wire rope moving system, and the inspection robots are connected to the central control system.

Abstract: A discrete element method for modelling fracture evolution of roadway surrounding rock is provided, which includes: taking rock cores from a coal seam in the field and recording RQD values, observing roadway deformation, and making a statistical analysis on distribution characteristics of fractures in the coal seam; testing mechanical parameters of coal-rock samples indoors, and calculating strength of a rock mass according to the RQD values; creating a numerical model by using a UDEC-Trigon module to adjust the parameters to match the strength of the rock mass, and correcting model parameters; and creating a numerical model of an engineering scale to adjust the parameters to match field deformation characteristics, and finally simulating fracture evolution of the roadway surrounding rock. The present invention provides accurate and basic mechanical parameters for discrete-element numerical simulation of roadway deformation, guaranteeing realistic and reliable simulation results.

Abstract: The present disclosure discloses an intelligent position sensing system based on spatial three-dimensional model image matching, which realizes three-dimensional precise positioning and target orientation positioning of closed spaces, such as a coal mine. The position sensing system includes a three-dimensional GIS server, a position matching server, a wireless camera, and a wireless access device. Position sensing is realized by comparing an image collected by the wireless camera with a two-dimensional image generated by rendering.

Abstract: The present invention discloses a hard rock roadway and tunnel boring machine with actively rotating hobs, including a rack provided with a crawler track unit. The rack is provided with a hydraulic power unit and a high-pressure abrasive jet generation system connected therewith. A transmission box is fixedly arranged at one of ends of the rack. The transmission box is provided with two input shafts and one output shaft. The input shafts are connected with planetary reduction mechanisms. Input ends of the planetary reduction mechanisms are connected with cantilever disc driving motors. A cantilever disc is fixed to the output shaft. Four cantilevers are hinged to the cantilever disc. Cantilever driving motors are further arranged on the cantilever disc. Actively rotating hob devices are arranged at ends of the cantilevers away from the cantilever disc. The transmission box is further provided with rotary sealing devices.

Abstract: A device and method for testing the working performance of an anchor rod cable by simulating stratum fracture and separation on the basis of electromagnetic action, applicable to the technical field of testing working performance of anchor rod cables by simulating a tunnel field. The device comprises a top base (1) and a bottom base (2); a plurality of hydraulic vertical columns (3) are provided between the top base (1) and the bottom base (2); the plurality of hydraulic vertical columns (3) are provided thereon with clamping devices, and an electromagnetic block (9) is disposed between two groups of drawing block-shaped clamp holders (4).

Abstract: The present invention provides an inversion calculation method of coal-bed gas parameters of fast test while-drilling. The technical solution is that an inversion calculation method of coal-bed gas parameters of fast test while-drilling includes: during drilling in a coal bed, testing a gas flow and a gas concentration of an orifice in real time while-drilling, calculating drilling gas discharge amounts of the orifice, inversely calculating a coal-bed gas pressure at a drill bit based on borehole and coal-bed permeability parameters, and calculating a coal-bed gas content according to a gas content and gas pressure relational expression. The present invention has the beneficial effects that the present invention does not occupy the drilling and drill rod replacement time, is accurate, convenient, real-time and fast, and can test and calculate the coal-bed gas parameters of each section along the whole borehole length.

Abstract: Provided is a fracturing relief method for stress concentration of remaining ore pillars in an overlying goaf, including first, performing directional fracturing on a roof to optimize the stress of the roof and reduce the source of force; secondly, performing pulse fracturing on a coal pillar to produce a crack network, weaken the stiffness of the coal pillar and reduce the bearing capacity of the coal pillar; and finally, performing pulse fracturing on a floor strata of the coal pillar to reduce the ability of transferring stress concentration thereof. A drilling machine is used for separately constructing fracturing drill holes in a roadway to a set depth at an interval in a direction oblique to the coal pillar in an upper goaf. The roof, the coal pillar and the floor can be fractured by an oblique fracturing hole in a sublevel retreating manner. The position of the directional fracturing of the roof is approximately 1 m above the middle of a main roof above the coal pillar.

Abstract: The present invention discloses a vehicle-mounted large-flow fire-fighting foam fluid mixing system, including a supply kit, a mixing kit, a control kit, and a pipeline kit. The supply kit includes an auxiliary gas supply device, a fire pump, an integrated foam pump, a fire pump main motor, and a coupling. The mixing kit includes a fire monitor interface, a foam generating device, and a fluid mixing device. The control kit includes a foam mixing proportion single-chip microcomputer control system, an alarm module, a power module, an auxiliary air compressor switch module, a frequency converter, and a central control display screen. The pipeline kit includes an air drainage tube, a fire hose, a foam liquid pipe, and a pipeline valve. For the problems of flow fluctuation and low foam foaming efficiency, the present invention optimizes the design and adopts a new control policy, thereby implementing precise mixing under the large-flow condition.

Abstract: An automatic coal mining machine and a fluidized coal mining method are provided. A first excavation cabin is configured to cut coal seam to obtain raw coal and to be transported to a first coal preparation cabin for separating coal blocks from gangue. Then, the obtained coal blocks are transported to a first fluidized conversion reaction cabin. The first fluidized conversion reaction cabin converts the energy form of the coal block into liquid, gas or electric energy, which is transported to a first energy storage cabin for storing. Coal mining and conversion are carried out in underground coal mines, so it is not necessary to raise coal blocks to the ground for washing and conversion, thereby reducing the transportation cost of coal, improving the utilization degree of coal, and avoiding the pollution of the ground environment caused by waste in the mining and conversion process.