By establishing the numerical model in the vertical plane and the similar model in the horizontal plane of gas flow in goaf, the influence of high drainage roadway or drilling on the gas seepage field was analyzed, an...By establishing the numerical model in the vertical plane and the similar model in the horizontal plane of gas flow in goaf, the influence of high drainage roadway or drilling on the gas seepage field was analyzed, and the extraction mechanism was clarified. On this basis, the academic thought of directional long drilling group instead of high drainage roadway was put forward. And then using complex function theory, the permeation mechanical model of drilling group with circle distribution in the mining-induced fracture zone was established to explore the coupling relationship between the drilling quantity, extraction volume and the equivalent extraction rate of single drilling. Finally, combined with the concrete geological production conditions, the main parameters of directional long drilling group were determined. The distance between the drilling group center and the air-return roadway is 24 m, the height is 18 m, and the three drillings are in an approximate equilateral triangle distribution with a space of 8 m. The equivalent extraction square is 4.15 m2. It is shown that the effect of directional long drilling group is evident. The gas content in the upper comer is controlled below 0.95%, the content in the tail roadway is kept below the alarm value, and the content is over 50% in the drill, realizing the secure and effective extraction of coal and gas.展开更多
A series of sisal based activated carbon fibers were prepared with steam activation at temperature from 750℃ to 900℃. Their pore structures were characterized through their nitrogen adsorption isotherms at 77K using...A series of sisal based activated carbon fibers were prepared with steam activation at temperature from 750℃ to 900℃. Their pore structures were characterized through their nitrogen adsorption isotherms at 77K using different theories. The results showed that t-plot method and DR-plot method could suitably be used to characterize the mesopore structure and the multi-stage distribution of pore size of activated carbon fibers. It also showed that the pore size widens with the increase of activation temperature.展开更多
基金Project(50834005) supported by the National Natural Science Foundation of ChinaProject(2010QZ06) supported by the Fundamental Research Funds for the Central Universities of China
文摘By establishing the numerical model in the vertical plane and the similar model in the horizontal plane of gas flow in goaf, the influence of high drainage roadway or drilling on the gas seepage field was analyzed, and the extraction mechanism was clarified. On this basis, the academic thought of directional long drilling group instead of high drainage roadway was put forward. And then using complex function theory, the permeation mechanical model of drilling group with circle distribution in the mining-induced fracture zone was established to explore the coupling relationship between the drilling quantity, extraction volume and the equivalent extraction rate of single drilling. Finally, combined with the concrete geological production conditions, the main parameters of directional long drilling group were determined. The distance between the drilling group center and the air-return roadway is 24 m, the height is 18 m, and the three drillings are in an approximate equilateral triangle distribution with a space of 8 m. The equivalent extraction square is 4.15 m2. It is shown that the effect of directional long drilling group is evident. The gas content in the upper comer is controlled below 0.95%, the content in the tail roadway is kept below the alarm value, and the content is over 50% in the drill, realizing the secure and effective extraction of coal and gas.
基金Natural Science Foundation Committee of Chinese government (grant No. 50073029) and by Guangdong Provincial Natural Science Foundation (001276)
文摘A series of sisal based activated carbon fibers were prepared with steam activation at temperature from 750℃ to 900℃. Their pore structures were characterized through their nitrogen adsorption isotherms at 77K using different theories. The results showed that t-plot method and DR-plot method could suitably be used to characterize the mesopore structure and the multi-stage distribution of pore size of activated carbon fibers. It also showed that the pore size widens with the increase of activation temperature.
