Study on the Fractal Characteristics and Seepage Properties of Channels Filled by Coal Particles

• Published in: Environmental science and pollution research international Vol. 30; no. 53; pp. 113917 - 113931
• Main Authors: Yang, He, Liu, Zhen, Yu, Zehan, Li, Raorao, Wang, Shuangyue
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-11-2023; Springer Nature B.V
• Subjects: Accumulation; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Channels; Coal; Computer graphics; Computer Simulation; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Fractal geometry; Fractal models; Fractals; Fracture permeability; Fractures; Injection; Particle size; Permeability; Porosity; Powder; Powders; Research Article; Seepage; Velocity; Waste Water Technology; Water; Water injection; Water Management; Water Pollution Control; Coal seam water injection; Fractal theory; Permeability model; Particle migration and accumulation; Computer graphics
• ISSN: 1614-7499; 0944-1344; 1614-7499
• DOI: 10.1007/s11356-023-30222-3

Studying the seepage process in fracture channels (where coal particles are deposited) is of great significance for improving the performance of both on-site coal seam water injection and dust reduction technology. Through a self-developed simulation experiment of water-borne coal particle migration and accumulation and computer graphics, we investigated the influencing factors of particle accumulation in water injection and their influence law on seepage, discussed the interaction relationship between the fractal structure of coal and the characteristics of accumulated coal particles, and established a new fractal model of fracture permeability based on different particle accumulation states. The results show that the seepage velocity and the particle size jointly affect the migration and accumulation process of water-borne coal particles. When the coal particle size is constant and the seepage velocity increases, then the output of the coal powder increases, the deposition decreases, and the structure fractal dimension
D
3
of fractures decreases. At the same seepage velocity, with the increase of the coal particle size, the output of coal powder decreases, the deposition increases, and the structure fractal dimension
D
3
of fractures increases. In addition, the amount of coal powder produced in the intermittent water injection process is smaller than that produced in the continuous water injection process, more easily leading to accumulation. The variation law of the theoretical permeability with porosity remains consistent for different particle accumulation states: with the increase of porosity, the structure fractal dimension
D
3
of fractures decreases, while the theoretical permeability increases. The above research results can provide a theoretical basis for reducing the seepage damage of coal under the particle blocking effect.