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Longwall shearer cutting force estimationReid, Anthony Walton Unknown Date (has links)
A methodology to monitor the real-time cutting forces generated by a longwall shearer is developed. Longwall shearers are the single productive element in an underground longwall coal mine, and are a major source of unscheduled system downtime. The cutting forces constitute the interaction between the longwall and the coal face. Knowledge of the forces can improve the reliability and productivity of longwall mines by providing a means of shearer condition monitoring. A Kalman filter based cutting force estimator is developed, and then tested using a comprehensive shearer simulation incorporating a dynamic representation of the cutterhead. Subsequently, prior work on autonomous shearer guidance with measured pick forces is extended by employing the estimated cutting forces to track changes to the shearer's horizon. This is validated by simulation. The force estimation methodology uses an extended Kalman filter to blend noisy measurement information with a nonlinear system model, the latter combining the dynamics of the shearer and its inputs. A detailed model is developed of the shearer rigid body dynamics, and of the measurements required for observability. The formulation avoids the use of sensors at the coal cutting interface. The methodology uses proven, practicable and reliable sensor technologies, making it suitable for longterm force monitoring. A comprehensive simulation of a longwall shearer is developed using the MATLAB(R) Simulink(R) and MSC.visualNastran 4DTM software environments. This incorporates dynamic representations of the major structures and inputs, including the interaction between the cutterhead and the coal face. The simulation is used to investigate the cutting forces in a number of different operational scenarios. This facilitates the construction of a basic dynamic model of the forces, and provides insight into the relationship between the cutting forces and the condition of the cutting interface. The cutting force estimator is tested using measurements from the shearer simulations. It is shown that the cutting force estimates track the fiducial forces well in each scenario. A number of modifications to the force models are also shown to improve the performance of the estimator. Sensitivity analyses are conducted to investigate the effect of tuned process noise covariance and model parameter errors on the estimates. The application to the problems of shearer condition monitoring and horizon tracking are considered. The first is demonstrated by detecting the effects of a worn pick and a seam hardness gradient on the force estimates, and the second by using the force estimates to track the motion of the cutterhead relative to an embedded stone band. The results show that it is possible, in principle, to estimate the cutting forces generated by a longwall shearer from indirect measurements using a Kalman filter methodology. Furthermore, the force estimates reveal changes to the cutting environment, and can track the vertical motion of the shearer as it operates. This thesis represents the first step in the development of a shearer cutting force estimator. The ultimate goal of the research is to improve the reliability and productivity of Australian longwall operations, using the estimated forces to monitor shearer condition. Autonomous horizon tracking with estimated forces can lead to further improvements to longwall productivity, and to the health and safety of mine personnel. A number of recommendations are made for future field validation, and development of an automated shearer condition monitoring system based on the cutting force estimates.
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Use BSC to improve the internal system of Longwangzhuang Coal Industry CompanyJi, Hui, Zheng, Tian January 2010 (has links)
<p>Nowadays Balanced Scorecard management system is widely used in Europe country. What’s the BSC? Balanced Scorecard Performance management is a new way for assessment of the sector team. Balanced Scorecard is a Performance Evaluation System also.</p><p>In the thesis, we want to check if the BSC could be used for a Chinese coal industry company. It was a good opportunity to see if the main principles of BSC depended on the culture, the place and the time, or if it was pretty much universal. So, we choose the Longwangzhuang coal Industry Company as our object to research and analysis. Longwangzhuang coal Industry Company created in 2003, located in Mianchi, Henan province. To begin with we provide a brief background on the Longwangzhuang coal industry company. We introduce the BSC and try to search and seek a suitable BSC management system which combined with the Chinese culture, special organization culture and structure. And we discussed the strategy and target with the CEO, analysed the company through information obtained from some documents and answers to questions we asked. Then we made a SWOT- analysis and form BSC four parts to recognise what the Company’s situation, what’s advantage and disadvantage of the company. After that we make detail BSC criterions, marks and analysis. There are six evaluations on internal process and four evaluations on innovation learning. Depends on these real evolutions we find out problem and give some advices to Longwangzhuang coal Industry Company. Sequentially, improve the internal system of this company.</p><p>After all, our conclusion is with the improved strategy and target that is possible to use BSC to improve the internal system in Longwangzhuang coal industry. As long as under the corporate culture, enterprise development and management of basic to development their own BSC. That BSC can be widely used in Chinese enterprises also.</p>
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The chemistry of the alkali-induced solubilisation of coalShoko, Lay. January 2005 (has links)
Thesis (M.Sc.)(Chemistry)--University of Pretoria, 2005. / Abstract in English. Includes bibliography. Available on the Internet via the World Wide Web.
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Use BSC to improve the internal system of Longwangzhuang Coal Industry CompanyJi, Hui, Zheng, Tian January 2010 (has links)
Nowadays Balanced Scorecard management system is widely used in Europe country. What’s the BSC? Balanced Scorecard Performance management is a new way for assessment of the sector team. Balanced Scorecard is a Performance Evaluation System also. In the thesis, we want to check if the BSC could be used for a Chinese coal industry company. It was a good opportunity to see if the main principles of BSC depended on the culture, the place and the time, or if it was pretty much universal. So, we choose the Longwangzhuang coal Industry Company as our object to research and analysis. Longwangzhuang coal Industry Company created in 2003, located in Mianchi, Henan province. To begin with we provide a brief background on the Longwangzhuang coal industry company. We introduce the BSC and try to search and seek a suitable BSC management system which combined with the Chinese culture, special organization culture and structure. And we discussed the strategy and target with the CEO, analysed the company through information obtained from some documents and answers to questions we asked. Then we made a SWOT- analysis and form BSC four parts to recognise what the Company’s situation, what’s advantage and disadvantage of the company. After that we make detail BSC criterions, marks and analysis. There are six evaluations on internal process and four evaluations on innovation learning. Depends on these real evolutions we find out problem and give some advices to Longwangzhuang coal Industry Company. Sequentially, improve the internal system of this company. After all, our conclusion is with the improved strategy and target that is possible to use BSC to improve the internal system in Longwangzhuang coal industry. As long as under the corporate culture, enterprise development and management of basic to development their own BSC. That BSC can be widely used in Chinese enterprises also.
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Development of a Low NOx Burner System for Coal Fired Power Plants Using Coal and Biomass BlendsGomez, Patsky O. 16 January 2010 (has links)
The low NOx burner (LNB) is the most cost effective technology used in coal-fired power plants to reduce NOx. Conventional (unstaged) burners use primary air for transporting particles and swirling secondary air to create recirculation of hot gases. LNB uses staged air (dividing total air into primary, secondary and tertiary air) to control fuel bound nitrogen from mixing early and oxidizing to NOx; it can also limit thermal NOx by reducing peak flame temperatures. Previous research at Texas A&M University (TAMU) demonstrated that cofiring coal with feedlot biomass (FB) in conventional burners produced lower or similar levels of NOx but increased CO. The present research deals with i) construction of a small scale 29.31 kW (100,000 BTU/hr) LNB facility, ii) evaluation of firing Wyoming (WYO) coal as the base case coal and cofiring WYO and dairy biomass (DB) blends, and iii) evaluating the effects of staging on NOx and CO.
Ultimate and Proximate analysis revealed that WYO and low ash, partially composted, dairy biomass (LA-PC-DB-SepS) had the following heat values and empirical formulas: CH0.6992N0.0122O0.1822S0.00217 and CH_1.2554N_0.0470O_0.3965S_0.00457. The WYO contained 3.10 kg of Ash/GJ, 15.66 kg of VM/GJ, 0.36 kg of N/GJ, and 6.21 kg of O/GJ while LA-PC-DB-SepS contained 11.57 kg of Ash/GJ, 36.50 kg of VM/GJ, 1.50 kg of N/GJ, and 14.48 kg of O/GJ.
The construction of a LNB nozzle capable of providing primary, swirled secondary and swirled tertiary air for staging was completed. The reactor provides a maximum residence time of 1.8 seconds under hot flow conditions. WYO and DB were blended on a mass basis for the following blends: 95:5, 90:10, 85:15, and 80:20. Results from firing pure WYO showed that air staging caused a slight decrease of NOx in lean regions (equivalence ratio, greater than or equal to 1.0) but an increase of CO in rich regions (=1.2). For unstaged combustion, cofiring resulted in most fuel blends showing similar NOx emissions to WYO. Staged cofiring resulted in a 12% NOx increase in rich regions while producing similar to slightly lower amounts of NOx in lean regions. One conclusion is that there exists a strong inverse relationship between NOx and CO emissions.
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A history of Jewish life in the central Appalachian coalfields, 1870s to 1970sWeiner, Deborah R. January 1900 (has links)
Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains v, 499 p. Includes abstract. Includes bibliographical references (p. 484-499).
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The effect of solvents and processing conditions on the solvent extraction of coalBhole, Manish R. January 1900 (has links)
Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains xiii, 122 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 100-103).
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Labor disturbances in Pennsylvania, 1850-1880 ...Coleman, James Walter, January 1936 (has links)
Thesis (Ph. D.)--Catholic University of America, 1936. / Published also without thesis note, under title: The Molly Maguire riots. "The sources": p. 177-180.
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Pitch production using solvent extraction of coal suitability as carbon anode precursor /Ali Pour, Mehdi Mohammad. January 2009 (has links)
Thesis (M. Sc.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on Dec. 14, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Chemical Engineering, Department of Chemical and Materials Engineering, University of Alberta." Includes bibliographical references.
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Social and economic implications of strip mining in Harrison County /Hill, Jack K. January 1965 (has links)
Thesis (M.S.)--Ohio State University, 1965. / Available online via OhioLINK's ETD Center
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