Research On Parameters Optimization Of The Gas Drainage Of The Mine With Low Permeability And High Concentrated Of Gas

How to increase the low air permeability high gas coal mine permeability is the more cutting-edge research in the field of the gas drainage technology now, and is also a global problem in gas drainage technology. Domestic and foreign scholars in this area have done a lot of active research and exploration, such as using deep-hole blasting, deep loosening blasting, hydraulic flushing, hydraulic fracturing, high-pressure abrasive cutting seam, three dimension cross holes, pressure-released zone drainage and pinnate drainage techniques to increase the permeability of coal seams and to enhance gas drainage rate of the low air permeability and high gas coal mine, and have made encouraging achievements. But among the many methods to increase gas permeability of low-permeability high gas coal mines, mostly are only from the way how to increase the coal seam permeability to make an study, and the gas drainage parameter optimization study about low air permeability high gas mine is relatively less.This paper which is based on these considerations, starts from the analysis of gas drainage way, and applies the Langmuir isotherm Theorem, Fick Theorem, Darcy's law and other related knowledge, which is on the basis of the characteristics of coal gas occurrence and the full understanding of gas movement law, to consider the coal seam gas adsorption, desorption, diffusion, seepage and so on, and constructs the gas flow equation around the hole drilling. Combining with the Shen-hua Wu-hai Energy Company Ping-gou coal mine site, this paper determines the gas pressure of different coal seam level and the coal seam permeability, and provides a theoretical basis for the different gas drainage methods. At the same time, by applying FLAC3D mining numerical simulation technique to simulate the distribution law of stress of the font of caol mining face, which are under the influence of pressure relief area and stress concentration area, using the limit equilibrium theory to construct the limit equilibrium equations for studying stress distribution status and the law of the front of mining working face pressure relief area with a limit equilibrium. The drilling drainage holes gas drainage radius is determined by using site negative pressure determining method, and thus to makes gas drainage parameters, which is in the pressure relief area gas drainage hole drilling, are optimized. This paper provides a scientific basis for the gas drainage boreholes design, the boreholes arrange pattern and provides scientific theoretical guidance for the gas drainage boreholes construction to avoid blind construction from studying the gas drainage parameters optimization of low air permeability and high gas mine. Thus it enhances the gas drainage rate and reduces the cost of gas drainage, and provides intellectual support and technical protection for the gas drainage, gas rational utilization and development and safety production of the low air permeability and high gas coal mine.