Experimental Study On The Effect Of Coal Gas Release By Continuous Impacting

Gas is not only significant harm to efficient mining of coal, and also is a great contribution to greenhouse gases, apparently contrary to the country’s efforts to control the amount of greenhouse gases if we emission into the atmosphere directly. while gas is a clean energy, improve gas drainage effectively, adjust China "lack of oil, less gas, rich in coal," the unique energy constitution, has a very important significance. With coal mining depth increased year by year, the deep coal seam gas high adsorption, low permeability gas drainage implementation becomes more difficult. so this dissertation experimental study carried out by continuous impacting in coal gas release characteristics of adsorption of rich gas, desorption theory, methods to improve the permeability of the coal-related research.In this paper, The current study on coal gas adsorption, desorption theory and research progress of various methods to improve the permeability of coal, relying on the National Natural Science Foundation of China "Study on desorption and degassing of gas in coal seams under sonic waves" (Fund Code:40972105) and "coal and gas outburst mechanism of infiltration instability" (Fund Code:41272171), Huainan mining area of low permeability, coal and gas outburst in coal as the research object, using experimental and theoretical derivation method of combining studied Under continuous impact and vibration effects to enhance coal gas release mechanism and field experiment, the contents of this thesis, and made the main conclusions are as follows:(1) Riching gas like natural coal the effect of the adsorption equilibrium, the impact of effective stress and permeability with continuous impact. The results show: the adsorbed gas will be part of the adsorbed gas will be desorbed into free gas, and the effective stress will reduce, gas permeability will be significantly strengthened with continuous impact;(2) When impact energy is small, study the effect of continous impacts frequency. Experimental results show that the relatively small single hammering energy (3J) did not significantly improve the efficiency of coal gas released, only the energy and the corresponding frequency (at least 20 times/min) continuous impact in order to effectively improve coal gas releasing effectively.(3) The results showed that certain continuous impact method and corresponding frequency energy can improve the efficiency of coal gas release up to 300%, the effect of continuous impact to improve the rate of release of methane gas in it more obvious in the late time, the impact on accelerating coal tiny cracks and matrix, the small, micro methane gas release more effectively.(4) A certain energy (3 J) continuous impact method can improve the efficiency of the release of gas in the coal, with the extension of the continuous time of impact, and gas flow rate can not be maintained in an initial peak velocity, and later will be gradually reduced, but the flow decrease ratio after steady flow before continuous impact is still improved.(5)With a continuous impact time, the actual gas extraction rate increased more than 95%, the decay time is about 3h. Designed continuous impact equipment, according to the site containing gas and coal seam characteristics of the design of the appropriate drilling layout, and conducted on-site coal continuous impact experiment, on-line monitoring data show that the continous impact on time in a row the flow rate is increased about 35%, the concentration increased about 45%.Through theoretical analysis and experimental study, the paper discuss the gas occurrence of coal by continuous impact, effective stress of coal, the coal gas release rate and achieved a new understanding, in order to improve gas drainage drilling efficiency, ensure safe production and reduce greenhouse gas emissions, and provide a new idea for providing clean energy. Figure [46], table [17], reference [223]...