Study On The Law Of Adsorption And Seepage Of Methane In Coal Effected By Electric Field Combination

As the gas is one of the main factors of disasters happened in China's coal mine and the coal and gas outburst has been greatly imperiling the safety of China's coal mine,the gas pre extraction,as a kind of prevention measures for regional outburst,can effectively eliminate the outburst hazard in mining face.In China,the geological conditions of coal fields are complicated,the permeability of most coal seams is poor,and the gas is difficult to extract from coal seams,therefore,the improvement of gas extraction to high gas and low permeability coal seam has become the key to safe and efficient production of coal mines those are of high gas and happening outburst easily.It is necessary to study efficient permeability enhancement of low permeability coal seams.In this paper,the characteristics of adsorption and permeability of gas in coal seams under different combinations of electric field are studied through experimental test and data analysis.The main work and achievements in the research are as follows:(1)An experiment equipment for adsorption and permeability of gas in coal seams applied different combinations of electric field established,and the characteristics of isothermal adsorption of different adsorbate in coal under different pulse electric field adsorption tested-analyzing the relationship between the adsorption characteristics of different adsorbate in coal body and the intensity and frequency of electric field applied,it was brought to light that the difference of isothermal adsorption between gas(methane)and carbon dioxide adsorpted in coal under pulse electric field.Under the same pulsed electric field,the isothermal adsorption of gas in coal is affected by electric field,which has even greater effect on gas than carbon dioxide.(2)The isothermal adsorption characteristics of gas(methane)in coal under different electric field combinations were tested and analyzed.It is found that the combination of electric field reduces the amount of gas adsorpted in coal,and the decrease of gas adsorption under the combination of electric field is more obvious than that of a single alternating electric field.(3)That testing and analyzing the change law of permeability of coal under the combination of electric field,and the comparison the influence between the combination of electric field and the single alternating electric field on the coal permeability,is aim to explore the effect of different electric field on permeability of coal.The permeability order of coal effected by alternating electric field and combination of electric field is as follows: YangZhuang coal > QiPanJing coal > Yuan Zhuang coal,besides,the improvement of permeability of coal combination of electric field is superior to that effected by the single alternating electric field.