区分
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乙
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氏 名
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| 論
文
題名 |
REAL TIME SYSTEM FOR CONTINUOUS
MONITORING, ANALYSIS AND FORECASTING OF CHOCK SHIELDS PERFORMANCE IN AN
INDIAN LONGWALL COAL MINE |
| (インドの長壁式石炭鉱山における自走枠の連続モニタリング、解析及び
予測のためのリアルタイムシステム) |
| Longwall mining method is
the most economic, effective and the safest one. So far, about 15
longwall units have been introduced into Indian underground coal mines.
However, the expected high performance has not been obtained due to the
aged equipment and the presence of hard-to-collapse roof strata. In
addition that, the Indian longwall coal mines do not have the latest
compatible indigenous technology to monitor the shield supports and
strata conditions for implementing maintenance of chock shields in real
time and to take precautionary measures during adverse strata
conditions. Therefore, the dissertation research is concentrated on developing an innovative system for monitoring, analysis and forecasting the chock shields performance to improve productivity and safety. An innovative real time (RT) system was developed with state-of-the-art technology. It acquired data continuously from underground sensors and displayed it on a real time monitor after the analysis. It has built-in warning modules in case of adverse behavior of the strata and supports. The RT display was updated automatically every minute with the latest information about strata and supports. The RT system is able to maintain data continuity and quality due to reliable wireless data transmissions. It recorded and forecasted successfully various strata and supports problems. Furthermore, it successfully forecasted the adverse strata behavior during longwall panel operation. Therefore, it has played a vital role in successful longwall operations. This is the first innovative RT system in India and was successfully implemented in one of the Indian longwall mines for improving safety and productivity. This dissertation describes and discusses the development and application of the innovative RT system in detail and consists of six chapters as follows: Chapter 1: This chapter describes the detailed discussion of an extensive literature review about longwall mining method considering the Indian longwall operations. The objectives of the dissertation research were finalized based on the literature review. The dissertation research objectives are to establish an RT monitoring system of chock shield performance and strata behavior in order to improve safety and productivity of longwall operations. Chapter 2: This chapter describes the Indian coal mining industry. Indian coal has lifespan of 200 years. Indian coal continues to play a dominant role in energy generation at present and in the future. Indian coal reserves are estimated to be around 214 billion tons up to depth of 1200 m as of Jan 1st, 2001. Opencast reserves are about 39 billion tons only, which is around 1/6th of the total coal reserves. Therefore, the life of opencast operations is very limited. The underground longwall method shall play an important role in the near future due to availability of superior grade coal at deeper level and limited life of opencast operations. Indian coal has low-sulphur and low-toxic trace elements that are the biggest positive factor. Hence it will be used in an eco-friendly manner. From the statistics of the Indian mine safety, roof and sidewall failures still remain the single major cause of accidents in coal mine in spite of various initiatives taken. Therefore, the reduction of mine disasters and the improving the mine safety are quite significant in underground mining. Chapter 3: This chapter describes the detailed information about the GDK 10A longwall mine where the dissertation research was performed. The topics include the location of longwall mine, coal measures formation, the details of experimental panel, location of goaf, preparation works of the panels, face operations, strata control observations, longwall equipment, condition monitoring, subsidence, ventilation, goaf water, techno-economics, crisis and justification of the dissertation research. Chapter 4: This chapter describes the development of an economically viable and intrinsically safe innovative RT (real time) system with the latest technology. The RT system is fully compatible with the underground environment. This was proven with extensive filed investigations. Furthermore, this chapter also describes the real time commissioning and associated systems in underground and on the surface. The proper commissioning of various systems will play an important role in getting better results. In the case of wireless systems, commissioning needs a line of sight for better transmission and reception. Therefore, the RT system and associated systems and various modules commissioned after extensive preliminary investigations. Chapter 5: This chapter describes the working conditions of powered supports, the detailed discussion of field data analysis, interpretation and forecasting. The discussion includes data analysis and interpretation of the first experimental longwall panel (No.11), data analysis and interpretation of the second experimental panel (No.4) and forecasting of the strata and the supports behavior. The support behaviors were grouped into six types as per S. S. Peng’s classification. The behavior in panel No.11 showed the poor performance (type E) due to the deteriorated roof strata conditions and the hydraulic leakage problems in the shield. On the contrary, in panel No.4, the chock shields showed the satisfied performance in mining cycles, mostly showing type A. Therefore, No.4 longwall operation was performed without any strata problems. The differential analysis is useful for effective warning of adverse behavior of chock shields and strata. The TWAP (time weighted average pressure) analysis showed the occurrence of periodic weighting clearly. Chapter 6: This chapter summarizes the dissertation research. The dissertation research outcome is playing a dominant role in Indian longwall operations at present and in the future. |
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