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 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 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: 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: 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.

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: The present invention proposes a method for rapidly dehazing an underground pipeline image based on dark channel prior (DCP). The method includes: preprocessing a hazy underground pipeline image to obtain a dark channel image corresponding to the hazy image; average-filtering the obtained dark channel image to estimate an image transmittance; compensating an offset value for an average filtering result to obtain a rough estimate of the transmittance; using a pixel value of the original image and an average-filtered image to estimate a global atmospheric light value; and using a physical restoration model to restore a dehazed image. The method of the present invention realizes the timeliness of the algorithm while ensuring the dehazing effect, and is suitable for scientific fields such as video monitoring of underground pipeline environment and identification of underground pipeline defects.

Abstract: A bidirectional variable cross-section water-pressure bearer cycle test system for a coal mine water inrush model test, comprising a water-pressure loading portion and a water-pressure bearer portion, wherein the water-pressure loading portion has a water supply tank, a loading water pump, a water piezometer, a water control valve, a water inlet pipe, a water discharge pipe, etc., through the loaded water pressure to control the cyclic loading of the water pressure. The water-pressure bearer portion has a variable cross-section water-pressure bearer assembly and a airtight main frame variable water-level water-pressure bearer assembly.

Abstract: An experiment system and transparent experiment method for replicating fluid displacement in a pore structure of a natural rock mass are provided. The natural pore structure is extracted and a digital porous model corresponding to the natural rock mass is reconstructed with the image processing method. Based on the digital porous model, a three-dimensional pore structure model with a transparent and visible internal structure is printed by a 3D printing device, such that the pore space inside the three-dimensional pore structure model is visible. In this way, the whole fluid flow during the displacement-seepage process within the natural rock mass can be replicated and visually observed from the outside when performing the displacement-seepage experiment. Further, temperature, flow rate, and pressure can be accurately controlled, to replicate various experiment conditions, so as to perform quantitative analysis on distribution features of a seepage field and a fluid speed field.

Abstract: A mine field layout method suitable for fluidized mining of coal resources is provided. A main shaft and an air shaft are provided in the mine field, the bottom of the main shaft is located in the shallow horizontal coal seam zone, and the bottom of the air shaft is located in the deep horizontal coal seam zone. The horizontal main roadways are arranged at two boundaries along the strike of the coal seam, and inclined main roadways are arranged at two boundaries along the dip direction of the coal seam. Connecting roadways are located inside the mine field and are in communication with the horizontal main roadways. In the coal mining stage, the coal resources can be converted into the fluidized energy product and/or electricity by an unmanned automatic mining machine.

Abstract: A mine field layout method suitable for fluidized mining of coal resources is provided. A main shaft and an air shaft are provided in the mine field, the bottom of the main shaft is located in the shallow horizontal coal seam zone, and the bottom of the air shaft is located in the deep horizontal coal seam zone. The horizontal main roadways are arranged at two boundaries along the strike of the coal seam, and inclined main roadways are arranged at two boundaries along the dip direction of the coal seam. Connecting roadways are located inside the mine field and are in communication with the horizontal main roadways. In the coal mining stage, the coal resources can be converted into the fluidized energy product and/or electricity by an unmanned automatic mining machine.

Abstract: The present invention proposes a method for rapidly dehazing an underground pipeline image based on dark channel prior (DCP). The method includes: preprocessing a hazy underground pipeline image to obtain a dark channel image corresponding to the hazy image; average-filtering the obtained dark channel image to estimate an image transmittance; compensating an offset value for an average filtering result to obtain a rough estimate of the transmittance; using a pixel value of the original image and an average-filtered image to estimate a global atmospheric light value; and using a physical restoration model to restore a dehazed image. The method of the present invention realizes the timeliness of the algorithm while ensuring the dehazing effect, and is suitable for scientific fields such as video monitoring of underground pipeline environment and identification of underground pipeline defects.

Abstract: A transparent constraint apparatus for the normal deformation of a planar model, including rigid transparent retainer plates, a planar model, and magnetic force components. The magnetic force components are provided at edge positions of the rigid transparent retainer plates; the normal direction of the planar model is parallel to the normal direction of the two rigid transparent retainer plates, and said two retainer plates are symmetrically arranged relative to the plane of symmetry of the planar model; the magnetic force components are symmetrically arranged relative to the plane of symmetry of the planar model, mutually symmetrical magnetic force components producing mutually attractive magnetic force. The transparent constraint apparatus solves the problem of constraining the normal deformation of a planar model under planar-strain conditions during testing.

Abstract: The present invention discloses an I-shaped water-retaining dam for an underground reservoir in a coal mine. The I-shaped water-retaining dam is located between coal pillar dams to isolate an underground reservoir from a corresponding coal roadway. The I-shaped water-retaining dam includes an upper flange plate, a web plate, and a lower flange plate from top to bottom, where a vertical face of a dam body is of an I shape; the upper flange plate extends into a roadway roof; two ends of the web plate are embedded into the coal pillar dams; and the lower flange plate extends into a floor. The I-shaped water-retaining dam is located in an underground coal roadway, and bears complex surrounding rock stress. The present invention effectively overcomes water seepage of a weak part at an upper part of a conventional I-shaped water-retaining dam.

Abstract: A method for measuring the dynamic stress field evolution law of a complex heterogeneous structure, comprising: preparing a transparent photosensitive resin model of a complex heterogeneous structure by means of three-dimensional (3D) printing technology to serve as a test piece (S101); placing the test piece in a light path of a circularly polarized light dark field, performing continuous stress loading on the test piece, and recording images (S102); acquiring a plurality of continuously changing full-field stress fringe grayscale images according to videos generated by the image recording (S103); then acquiring grayscale value change sequences of pixel points at each position in the images (S104); and finally, calculating full-field fringe orders under continuous loading conditions according to the relation between the grayscale values and the fringe orders so as to calculate full-field stress values under the continuous loading conditions (S105).

Abstract: A method for measuring a stress field evolution during a CO2 fracturing process is provided, which is adopted to not only transparently display the spatial distribution and propagation morphology of internal fracturing fracture of a three-dimensional physical models, but also obtain internal three-dimensional stress phase diagram in a fracture propagation process by integration of a CT scanning, a digital reconstruction, a 3D printing, a CO2 fracturing experiment, a stress freezing and a photoelastic measurement techniques, thereby realizing transparent display and quantitative characterization of the three-dimensional stress field and its evolution law of a solid matter in the CO2 fracturing process.

Abstract: A method for measuring the dynamic stress field evolution law of a complex heterogeneous structure, comprising: preparing a transparent photosensitive resin model of a complex heterogeneous structure by means of three-dimensional (3D) printing technology to serve as a test piece (S101); placing the test piece in a light path of a circularly polarized light dark field, performing continuous stress loading on the test piece, and recording images (S102); acquiring a plurality of continuously changing full-field stress fringe grayscale images according to videos generated by the image recording (S103); then acquiring grayscale value change sequences of pixel points at each position in the images (S104); and finally, calculating full-field fringe orders under continuous loading conditions according to the relation between the grayscale values and the fringe orders so as to calculate full-field stress values under the continuous loading conditions (S105).

Abstract: A method for measuring a stress field evolution during a CO2 fracturing process is provided, which is adopted to not only transparently display the spatial distribution and propagation morphology of internal fracturing fracture of a three-dimensional physical models, but also obtain internal three-dimensional stress phase diagram in a fracture propagation process by integration of a CT scanning, a digital reconstruction, a 3D printing, a CO2 fracturing experiment, a stress freezing and a photoelastic measurement techniques, thereby realizing transparent display and quantitative characterization of the three-dimensional stress field and its evolution law of a solid matter in the CO2 fracturing process.

Abstract: A device for stress-freezing experiments during fracturing process according to the present application, in which heating and cooling treatment on a specimen under corresponding temperature control according to a preset temperature gradient and a photosensitive curve is performed by a temperature control system, to realize stress-freezing of the specimen; a pressure is applied to a specimen by a true triaxial servo loading system; and corresponding fracturing experiments are performed to the specimen by a fracturing liquid pumping system having an output end arranged in a thermo-controlled oven.