Abstract
This paper used the X-ray three-dimensional (3D) microscope and acquired, through CT scanning, the 3D data of the long-frame coal sample from the Daliuta Coal Mine. Then, the 3D datacube reconstructed from the coal’s CT scanning data was visualized with the use of Avizo, an advanced visualization software (FEI, Hillsboro, OR, USA). By means of a gray-scale segmentation technique, the model of the coal’s micro-pore structure was extracted from the object region, and the precise characterization was then conducted. Finally, the numerical simulation on the water seepage characteristics in the coal micro-pores model under the pressure of 3 MPa was performed on the CFX platform. Results show that the seepage of low-pressure water exhibited preference to the channels with large pore radii, short paths, and short distance from the outlet. The seepage pressure of low-pressure water decreased gradually along the seepage direction, while the seepage velocity of low-pressure water decreased gradually along the direction from the pore center to the wall. Regarding the single-channel seepage behaviors, the seepage velocity and mass flow rate of water seepage in the X direction were the largest, followed by the values of the seepage in the Y direction, and the seepage velocity and mass flow rate of water seepage in the Z direction were the smallest. Compared with the results in single-channel seepage, the dual-channel seepage in the direction of (X + Y) and the multi-channel seepage in the direction of (X + Y + Z) exhibited significant increases in the overall seepage velocity. The present study extends the application of 3D CT scanning data and provides a new idea and approach for exploring the seepage rules in coal micro-pore structures.
Highlights
Water injection into coal seams is one of the most significant methods to prevent and deal with rock bursts, coal and gas outbursts, and coal dust
The effect to the effect of water pressure in Y direction, 92.36% of water flow that entered the coal sample in the direction would flow through the pressure outlet in due to the effect of of water pressure in Y direction, 92.36% of water flow that entered the coal sample in the X direction the X direction would flow through the pressure outlet in Y direction
The present study focused on the long-frame coal sample collected from the Daliuta Coal
Summary
Water injection into coal seams is one of the most significant methods to prevent and deal with rock bursts, coal and gas outbursts, and coal dust. By means of the micro-CT technique, Meng et al [8] conducted a quantitative study on the morphological characteristics of the pore structure of coking coals. Song et al [10] performed 3D scanning imaging on coal samples of different structures and precisely characterized their seepage pore properties. Perera et al [16] reviewed the effects of coal physical properties and permeability on carbon dioxide sequestration in a coal seam Despite all of these achievements, there is still a need for comprehensive and thorough understanding of the seepage laws of low-pressure water in coals at the micro-level. It is quite necessary to perform scanning and reconstruction on coals using high-precision micro-CT equipment, construct the coal’s micro-pore structure model and, investigate the seepage rules of pressurized water in coal’s micro-pore structure at the micro-level through simulations. The present study offers a new way towards a deeper understanding of coal’s real micro-pore structure and the seepage rules of pressurized water in coals
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
