Abstract: Methods for specimen preparation and for characterization of internal three-dimensional deformation of specimen are provided. Firstly, a plurality of first digital particle models are generated, and a plurality of first volumetric images are generated based on central point positions of the speckle particles simulated by each first digital particle model of the plurality of first digital particle models. A simulated optimal particle radius value and a simulated optimal volume fraction value corresponding to speckle particles included in a target specimen are determined based on all the first volumetric images. Finally, the target specimen may be prepared based on the simulated optimal particle radius value and the simulated optimal volume fraction value corresponding to the speckle particles included in the target specimen.

Abstract: Disclosed are a testing system and method under fluid-solid coupling effects. A dynamic stress field during fluid flow, deformation of a porous rock framework, real-time evolution of the stress field and deformation of a fluid-solid interface under fluid-solid coupling effects can be obtained, on the basis of a collected photo-elastic stripe image and a surface deformation image. A stress field of a solid framework and fluid in porous rock, and a strain field of the solid framework and the fluid-solid interface under fluid-solid coupling effects can be visually and quantitatively displayed by means of a display device.

Abstract: A fluidized coal mining method for implementing CO2 underground storage, includes mining area division, tunneling mining, filling and supporting, roof and bottom plate sealing, and boundary surrounding rock sealing. A goaf formed by a mining device after tunneling and mining along a mining strip is filled and supported, and filling and supporting can form a high-strength supporting wall body, which not only provides an effective supporting effect for roof and bottom plate rocks, but also forms a filled and supported wall body; a space for underground storage of CO2 is formed between adjacent filled and supported wall bodies; at the same time, the mining device further seals the roof and a bottom plate of the goaf, and seals boundary surrounding rocks of a mine field, so that the entire mine field forms a whole closed space for the underground storage of CO2 after mining is completed.

Abstract: Disclosed are a testing system and method under fluid-solid coupling effects. A dynamic stress field during fluid flow, deformation of a porous rock framework, real-time evolution of the stress field and deformation of a fluid-solid interface under fluid-solid coupling effects can be obtained, on the basis of a collected photo-elastic stripe image and a surface deformation image. A stress field of a solid framework and fluid in porous rock, and a strain field of the solid framework and the fluid-solid interface under fluid-solid coupling effects can be visually and quantitatively displayed by means of a display device.

Abstract: Provided are a system and a method for monitoring bearing compression rate of a filler in a coal mine gob area. An ground information processing system, a vibration source control system, and a monitoring system are arranged on the ground according to a buried depth of the filler in the gob area. The vibration source control system generates vibration, and transmits a signal to the filler. The monitoring system on the ground receives different reflected waves according to different elasticities of the fillers under different compaction degrees. Final data is transmitted to the ground information processing system for data processing. The monitoring of the filler starts when the filler is filled in the gob area; the filler is gradually compacted. The filler is monitored until the thickness of the filler does not change. Finally, a bearing compression rate formula is utilized to calculate the bearing compression rate of the filler.

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: 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: 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: 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: 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: Provided are a system and a method for monitoring bearing compression rate of a filler in a coal mine gob area. An ground information processing system, a vibration source control system, and a monitoring system are arranged on the ground according to a buried depth of the filler in the gob area. The vibration source control system generates vibration, and transmits a signal to the filler. The monitoring system on the ground receives different reflected waves according to different elasticities of the fillers under different compaction degrees. Final data is transmitted to the ground information processing system for data processing. The monitoring of the filler starts when the filler is filled in the gob area; the filler is gradually compacted. The filler is monitored until the thickness of the filler does not change. Finally, a bearing compression rate formula is utilized to calculate the bearing compression rate of the filler.

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: 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: 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).