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Zhao H.-Z.,China University of Mining and Technology | Zhang R.-X.,China University of Mining and Technology | Liu X.-Q.,China Coal Pingshuo Group Co. | Zhen X.,China University of Mining and Technology | Zhen X.,China Coal Research Institute
Meitan Xuebao/Journal of the China Coal Society | Year: 2014

According to the sharp dropping coal seam and peaking stripping ratio caused by complicated geological conditions, which can not be solved by regulating the stripping and mining with traditional advance stripping method, a method of double pits dynamic regulating mode based on the basic principles of surface mine was put forward, and then, double pit-leaping mining mode and it's applicable conditions and key factors were detailed analyzed. The coal seam of Antaibao Surface Coal Mine in China changes from flat seam to sharp dropping seam during the mining area of Luzigou anticline. Combining with the surface mine problems that occurred during the anticline mining area, this paper took Antaibao Surface Coal Mine as a case study. The results show that the stripping ratio is balanced and the production keeps stability, moreover, the economic benefit is improved with double pits dynamic regulating mode in sharp dropping seam surface mine.

Yang M.,XJ Electrical Co. | Sun Z.-J.,China Coal Pingshuo Group Co. | Li N.,XJ Electrical Co. | Liu W.-P.,XJ Electrical Co. | Liu J.,XJ Electrical Co.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2013

Firing pulse is one of the key technologies of HVDC valves control as well as the research emphasis of domestic control and protection platform. This paper briefly introduces the generating principle of firing pulse used for valve control in HVDC transmission system, based on which the resolution about phase integrator and PLL tracking controller and their functions during the process of the firing pulse generation are analyzed. At last, the significance of equidistance pulses in 6 pulses system is analyzed, as well as how to minimize the equidistance error. This paper gives corresponding testing methods based on the design. Combining theory with practice, this paper describes the generation principle of firing pulse and the realization method, which provides a strong support for realizing home-made production for HVDC control and protection system.

Chen X.,LIAONING Technical University | Chen X.,Key Laboratory of Mine Thermodynamic Disasters and Control of Ministry of Education | Ge S.,LIAONING Technical University | Ge S.,Key Laboratory of Mine Thermodynamic Disasters and Control of Ministry of Education | And 4 more authors.
Chinese Journal of Environmental Engineering | Year: 2014

For the high concentration of dust source, it needs to arrange multi-nozzle for co-inhibition which usually accompanied by interference phenomenon. The mutual collision and re-breaking of droplets plays an important role in the process of removaling dust. Meanwhile, the number and location of nozzles affect the whole effect of atomization remarkably. In order to comprehend the series of dynamic events in the process of droplet movement, the UDF method on the basis of collision model, breakup model and evaporation model were used to make numerical simulation for spray field. The simulation results show that the increase of nozzle numbers can appropriately improve the uniformity of particle diameter distribution, then to improve dust removal efficiency. With the increase of atomizing pressure, the initial kinetic energy of droplets increased, which had a good dust removal effect for the respirable dust of less than 5 μm.

Ge S.,LIAONING Technical University | Ge S.,Motive | Gao Z.,LIAONING Technical University | Gao Z.,Motive | And 4 more authors.
Chinese Journal of Environmental Engineering | Year: 2016

The down-to-hole (DTH) drill is the most frequently utilized drill in open-pit mines, where drilling dust is one of the main dust sources. The Pingshuo Anjialing Open-pit Mine, an area where dust pollution is very serious, was chosen as the experimental spot. In order to obtain the optimal drilling-dust-removal scheme, numerical simulation was combined with field measurements. Eulerian and DPM methods were used for developing a gas-solid two-phase flow model to study the drilling-dust-diffusion rule and dust-removal efficiency. Based on particle tracking technology, a cyclonic bag, two-stage dust removal mechanism was quantitatively analyzed by comparison with a cyclonic one-stage dust-removal system. The results show that the total drilling-dust-removal efficiency was up to 99.7% and that the respirable-dust-removal efficiency was up to 94.7%, after the two-stage dust removal scheme was applied. The total dust-removal efficiency of the two-stage dust-removal scheme increased by 47%, and the respirable-dust-removal efficiency increased by 56%, compared to the one-stage dust-removal system. Ultimately, the dust concentration met the national standard. © 2016, Science Press. All right reserved.

Zhao Q.F.,North China Institute of Science and Technology | Wang Y.H.,North China Institute of Science and Technology | Liu Y.D.,North China Institute of Science and Technology | Li H.T.,North China Institute of Science and Technology | And 2 more authors.
Progress in Mine Safety Science and Engineering II - Proceedings of the 2nd International Symposium of Mine Safety Science and Engineering | Year: 2014

In order to control the severe floor heave of large cross section mining roadway in No. 1 Coal Mine of China Coal Ping-shuo Group Co., ltd, the various controlling measures are simulated by numerical simulation software FLAC, such as floor bolting, pressure-relief groove and floor drilling, and the stress distribution and displacement characteristics of the roadway floor are analyzed in the condition of different measures. Additionally the combinatorial controlling measure of reinforcement method (floor bolting) and pressure relief method (pressure-relief groove) is put forward. The engineering test results show that the maximum displacement and the maximum rate of floor heave are within the controllable range. Thus the combinatorial controlling technique can effectively control the floor heave and keep the surrounding rock stable. © 2014 Taylor & Francis Group.

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