Lu J.-J.,China Coal Research Institute
Meitan Xuebao/Journal of the China Coal Society | Year: 2016
In order to realize 3D interpretation for water-containing or water-conductive structures in coal mine, further to prevent and reduce the occurrence of mine water hazards, a research on a 3D electrical resistivity inversion and imaging technology for coal mine was carried out. By using a whole space 3D resistivity inversion software to get inversion and imaging results for synthetic water-containing or water-conductive models, the inversion results for different survey systems, data sampling density, model parameters, and noise levels were compared and analyzed. A 3D inversion and imaging for a complex synthetic model was also conducted. Results show that a multi-tunnel perspective survey system achieves a higher inversion resolution. When transmitting electrode distance is larger than, and receiving electrode distance is smaller than anomaly size, high inversion resolution could be maintained under low data sampling density. Resistivity obtained by inversion is a combination of model's size, resistivity, depth, horizontal position, and background resistivity and so on. The influence of tunnel space is equal to about 2% random noise, and inversion results possess a good ability of noise resistance. According to inversion and imaging results, multi-bodies could be identified separately, and the 3D distribution range of the anomaly could also be determined. Although it is hard to precisely define the anomaly boundary, resistivity iso-surface could be used to extract the anomaly. ©, 2016, China Coal Society. All right reserved.
Liu Z.,Beijing University of Chemical Technology |
Shi S.,China Coal Research Institute |
Li Y.,Shanxi Institute of Coal CAS Chemistry
Chemical Engineering Science | Year: 2010
With fast increasing demand in liquid transportation fuels, limited and unevenly distributed petroleum resources, and volatile petroleum prices, coal liquefaction technologies have again received the world's attention since the beginning of this century. China has actively pursued R&D of coal liquefaction technologies in the past decade and is deploying the first and the largest direct coal liquefaction plant since WWII and the largest indirect coal liquefaction plants after Sasol, South Africa. This paper analyzes the historical developments of coal liquefaction technologies from science point of view, presents recent developments of the technologies in China, and identifies challenges of the technologies towards successful industrial application. © 2009 Elsevier Ltd. All rights reserved.
Liang Y.,China Coal Research Institute |
Zeng W.,Tianjin University
Journal of Hazardous Materials | Year: 2010
Through amending the SENKIN code of CHEMKIN III chemical kinetics package, a computational model of gas explosion in a constant volume bomb was built, and the detailed reaction mechanism (GRI-Mech 3.0) was adopted. The mole fraction profiles of reactants, some selected free radicals and catastrophic gases in the process of gas explosion were analyzed by this model. Furthermore, through the sensitivity analysis of the reaction mechanism of gas explosion, the dominant reactions that affect gas explosion and the formation of catastrophic gases were found out. At the same time, the inhibition mechanisms of water on gas explosion and the formation of catastrophic gases were analyzed. The results show that the induced explosion time is prolonged, and the mole fractions of reactant species such as CH4, O2 and catastrophic gases such as CO, CO2 and NO are decreased as water is added to the mixed gas. With the water fraction in the mixed gas increasing, the sensitivities of the dominant reactions contributing to CH4, CO2 are decreased and the sensitivity coefficients of CH4, CO and NO mole fractions are also decreased. The inhibition of gas explosion with water addition can be ascribed to the significant decrease of H, O and OH in the process of gas explosion due to the water presence. © 2009 Elsevier B.V. All rights reserved.
Zhang X.-J.,China Coal Research Institute
Meitan Xuebao/Journal of the China Coal Society | Year: 2011
The developing situation of hydrogenation technologies of coal tar from mid-low-temperature coal carbonization during last couple of decades was analyzed. All of them were classified into four categories depending upon their processing features. And the advantage and disadvantage of each category technology were discussed. As a result, the category of coal tar hydrocracking processing with suspending-bed reactor or slurry-bed reactor is considered to be the developing trend after comparing each technology, because it is better coal tar utility efficiency and higher products yields.
Bai G.-L.,China Coal Research Institute
Caikuang yu Anquan Gongcheng Xuebao/Journal of Mining and Safety Engineering | Year: 2010
Due to the importance studying the seepage law of overburden rocks, an equivalent permeability coefficient for overburden rock is deduced using the cubic law, in which the strain is considered as a parameter. Based on FLAC3D, an equivalent continuous medium numerical model in overburden rock is established considering the fluid-solid coupling effect and the program with FISH language is used to achieve the calculation of equivalent continuous medium numerical model. The results indicate that the increasing permeability zones in the overburden rock hshow a M-shaped distribution in the roof and W-shaped distribution in the floor in initial stages of coal seam mining. The conductive fracture formed when the two increasing permeability zone is intersected with the increasing permeability zone of the lower roof. The pore pressure changes periodically in the aquifer it will reach the maximum value when water burst takes place and then decreases rapidlly. So the equivalent permeability coefficient taking the strain as a parameter can describe the seepage law of the overburden rock stratum exactly.