The level of personnel operation ability determines the expected effectiveness of large-scale complex equipment. Firstly, this paper constructs the personnel operational ability evaluation index system and analyzes th...The level of personnel operation ability determines the expected effectiveness of large-scale complex equipment. Firstly, this paper constructs the personnel operational ability evaluation index system and analyzes the data source of index. Secondly, the weight of index is determined and the fuzzy comprehensive evaluation model is proposed. Finally, results of instance analysis show that the evaluation model is feasible and effective.展开更多
Thick and ultra-thick coal seams are main coal seams for high production rate and high efficiency in Chinese coal mines, which accounts for 44 % of the total minable coal reserve. A fully mechanized top-coal caving mi...Thick and ultra-thick coal seams are main coal seams for high production rate and high efficiency in Chinese coal mines, which accounts for 44 % of the total minable coal reserve. A fully mechanized top-coal caving mining method is a main underground coal extraction method for ultra-thick coal seams. The coal extraction technologies for coal seams less than 14 m thick were extensively used in China. However, for coal seams with thickness greater than 14 m, there have been no reported cases in the world for underground mechanical extraction with safe performance, high efficiency and high coal recovery ratio. To deal with this case, China Coal Technology & Engineering Group, Datong Coal Mine Group, and other 15 organizations in China launched a fundamental and big project to develop coal mining technologies and equipment for coal seams with thicknesses greater than 14 m. After the completion of the project, a coal extraction method was developed for top-coal caving with a large mining height, as well as a ground control theory for ultra-thick coal seams. In addition, the mining technology for top-coal caving with a large mining height, the ground support technology for roadway in coal seams with a large cross-section, and the prevention and control technology for gas and fire hazards were developed and applied. Furthermore, a hydraulic support with a mining height of 5.2 m, a shearer with high reliability, and auxiliary equipment were developed and manufactured. Practical implication on the technologies and equipment developed was successfully completed at the No. 8105 coal face in the Tashan coal mine, Datong, China. The major achievements of the project are summarized as follows: 1. A top-coal caving method for ultra-thick coal seams is proposed with a cutting height of 5 m and a top-coal caving height of 15 m. A structural mechanical model of overlying strata called cantilever beam-articulated rock beam is established. Based on the model, the load resistance of the hydraulic support with a large mining height for top-coal caving method is determined. With the analysis, the movement characteristics of the top coal and above strata are evaluated during top-coal caving operation at the coal face with a large mining height. Furthermore, there is successful development of comprehensive technologies for preventing and controlling spalling of the coal wall, and the top-coal caving technology with high efficiency and high recovery at the top-coal caving face with a large mining height. This means that the technologies developed have overcome the difficulties in strata control, top-coal caving with high efficiency and high coal recovery, and enabled to achieve a production rate of more than 10 Mtpa at a single top-coal caving face with a large mining height in ultra-thick coal seams; 2. A hydraulic support with 5.2 m supporting height and anti-rockburst capacity, a shearer with high reliability, a scraper conveyor with a large power at the back of face, and a large load and long distance headgate belt conveyor have been successfully developed for a top-coal caving face with large mining height. The study has developed the key technologies for improving the reliability of equipment at the coal face and has overcome the challenges in equipping the top-coal caving face with a large mining height in ultra-thick coal seams; 3. The deformation characteristics of a large cross-section roadway in ultra-thick coal seams are discovered. Based on the findings above, a series of bolt materials with a high yielding strength of 500-830 MPa and a high extension ratio, and cable bolt material with a 1 × 19 structure, large tonnage and high extension ratio are developed. In addition, in order to achieve a safe roadway and a fast face advance, installation equipment for high pre-tension bolt is developed to solve the problems with the support of roadway in coal seams for top-coal caving operation with a large mining height; 4. The characteristics of gas distribution and uneven emission at top-coal caving face with large mining height in ultra-thick coal seams are evaluated. With the application of the technologies of gas drainage in the roof, the difficulties in gas control for high intensive top-coal caving mining operations, known as "low gas content, high gas emission", are solved. In addition, large flow-rate underground mobile equipment for making nitrogen are developed to solve the problems with fire prevention and safe mining at a top-coal caving face with large mining height and production rate of more than 10 Mtpa. A case study to apply the developed technologies has been conducted at the No. 8105 face, the Tashan coal mine in Datong, China. The case study demonstrates that the three units of equipment, i.e., the support, shearer and scraper conveyor, are rationally equipped. Average equipment usage at the coal face is 92.1%. The coal recovery ratio at the coal face is up to 88.9 %. In 2011, the coal production at the No. 8105 face reached 10.849 Mtpa, exceeding the target of 10 Mtpa for a topcoal caving operation with large mining height performed by Chinese-made mining equipment. The technologies and equipment developed provide a way for extracting ultra-thick coal seams. Currently, the technologies and equipment are used in 13 mining areas in China including Datong, Pingshuo, Shendong and Xinjiang. With the exploitation of coal resources in Western China, there is great potential for the application of the technologies and equipment developed.展开更多
In order to predict electromechanical equipments' nonlinear and non-stationary condition effectively, max Lyapunov exponent is introduced to the fault trend prediction of large rotating mechanical equipments based on...In order to predict electromechanical equipments' nonlinear and non-stationary condition effectively, max Lyapunov exponent is introduced to the fault trend prediction of large rotating mechanical equipments based on chaos theory. The predict method of chaos time series and two methods of proposing f and F are dis- cussed. The arithmetic of max prediction time of chaos time series is provided. Aiming at the key part of large rotating mechanical equipments-bearing, used this prediction method the simulation experiment is carried out. The result shows that this method has excellent performance for condition trend prediction.展开更多
Objective: To investigate the allocation and management of large medical equipment (LME) in Xuzhou, Jiangsu Province, China, in order to make the best use of LME to meet the medical needs of local people. Methods: The...Objective: To investigate the allocation and management of large medical equipment (LME) in Xuzhou, Jiangsu Province, China, in order to make the best use of LME to meet the medical needs of local people. Methods: The research collected data from all hospitals that have LME in Xuzhou using questionnaire; 38 (97.4%) hospitals returned the questionnaire. Results: In Xuzhou, there are a total of 71 pieces of LME, each serving 126 600 people in an area of 163 km2. Sixty-two percent of them are allocated in urban areas, with Gini coefficient at 0.52, indicating imbalance and biased allocation of LME. Conclusion: The al- location of LME in Xuzhou is out of control and unfairly allocated.展开更多
This paper studies how to manage large and precise equipment effectively in colleges and universities and proposes the necessity to establish experiment centers on the level of university and department. Finally, new ...This paper studies how to manage large and precise equipment effectively in colleges and universities and proposes the necessity to establish experiment centers on the level of university and department. Finally, new thought on paying more attention to the construction of technical management team and gathering necessary expenses, such as use expenses, maintenance expenses, function development expenses, etc. is given out.展开更多
The purchasement and development as well as the benefit of utilization for the large equipment in universities of China are analyzed in this paper, the paper in dicates that in utilization of large equipment the contr...The purchasement and development as well as the benefit of utilization for the large equipment in universities of China are analyzed in this paper, the paper in dicates that in utilization of large equipment the contradictions such as urgency and necessity for the purchasement and development of large equipment and serious waste in resources since inadequacy of annual utilization rate of large equipment are existed, it also raises that the key step of giving full play to the benefit of large equipment is to strengthen management and development after the equipment are purchased, the paper regards through stressing standardized management and maintenance、opening the laboratory、improving the functions of equipment、renovating technology、fully examining and scientifically deciding before purchasement, the investment benefit for the large equipment can be raised effectively.展开更多
以“采煤机、刮板输送机、液压支架”工作面三机,“转载机、破碎机、带式输送机”顺槽三机以及供电系统、供液系统、控制系统和通信系统为配套的大型采煤设施装备是煤炭工业平稳高效发展的重要支柱。本项目以满足特厚煤层超大采高综放...以“采煤机、刮板输送机、液压支架”工作面三机,“转载机、破碎机、带式输送机”顺槽三机以及供电系统、供液系统、控制系统和通信系统为配套的大型采煤设施装备是煤炭工业平稳高效发展的重要支柱。本项目以满足特厚煤层超大采高综放开采装备配套需求为目标,以高可靠性、长寿命、自动化、智能化技术为攻关重点,开发包含装机功率2×2000 kW前部输送机、装机功率3×1600 k W后部输送机及配套转载机、破碎机的超重型、超大运量,以及操作方式的自动化、智能化、形成了高可靠性综放工作面成套输送设备,并通过运输过程中发现的问题对转载机进行了相应的升级改造,确保了煤块流畅地卸载于顺槽转载机上,尽量减少回煤;创新性地开发了带式自移支撑装置,实现了装置的自行前移、支撑高度调整,有效减少了带式输送机中间架拆架次数。运输系统设备的升级改造满足产量15 Mt/a以上特厚煤层综放工作面开采需要。展开更多
基金supported by the Natural Science Foundation of China(71704184)Projects of the of the National Social Science Foundation of China(15GJ003-245)Science Foundation of Equipment Research(JJ20172A05095)
文摘The level of personnel operation ability determines the expected effectiveness of large-scale complex equipment. Firstly, this paper constructs the personnel operational ability evaluation index system and analyzes the data source of index. Secondly, the weight of index is determined and the fuzzy comprehensive evaluation model is proposed. Finally, results of instance analysis show that the evaluation model is feasible and effective.
文摘Thick and ultra-thick coal seams are main coal seams for high production rate and high efficiency in Chinese coal mines, which accounts for 44 % of the total minable coal reserve. A fully mechanized top-coal caving mining method is a main underground coal extraction method for ultra-thick coal seams. The coal extraction technologies for coal seams less than 14 m thick were extensively used in China. However, for coal seams with thickness greater than 14 m, there have been no reported cases in the world for underground mechanical extraction with safe performance, high efficiency and high coal recovery ratio. To deal with this case, China Coal Technology & Engineering Group, Datong Coal Mine Group, and other 15 organizations in China launched a fundamental and big project to develop coal mining technologies and equipment for coal seams with thicknesses greater than 14 m. After the completion of the project, a coal extraction method was developed for top-coal caving with a large mining height, as well as a ground control theory for ultra-thick coal seams. In addition, the mining technology for top-coal caving with a large mining height, the ground support technology for roadway in coal seams with a large cross-section, and the prevention and control technology for gas and fire hazards were developed and applied. Furthermore, a hydraulic support with a mining height of 5.2 m, a shearer with high reliability, and auxiliary equipment were developed and manufactured. Practical implication on the technologies and equipment developed was successfully completed at the No. 8105 coal face in the Tashan coal mine, Datong, China. The major achievements of the project are summarized as follows: 1. A top-coal caving method for ultra-thick coal seams is proposed with a cutting height of 5 m and a top-coal caving height of 15 m. A structural mechanical model of overlying strata called cantilever beam-articulated rock beam is established. Based on the model, the load resistance of the hydraulic support with a large mining height for top-coal caving method is determined. With the analysis, the movement characteristics of the top coal and above strata are evaluated during top-coal caving operation at the coal face with a large mining height. Furthermore, there is successful development of comprehensive technologies for preventing and controlling spalling of the coal wall, and the top-coal caving technology with high efficiency and high recovery at the top-coal caving face with a large mining height. This means that the technologies developed have overcome the difficulties in strata control, top-coal caving with high efficiency and high coal recovery, and enabled to achieve a production rate of more than 10 Mtpa at a single top-coal caving face with a large mining height in ultra-thick coal seams; 2. A hydraulic support with 5.2 m supporting height and anti-rockburst capacity, a shearer with high reliability, a scraper conveyor with a large power at the back of face, and a large load and long distance headgate belt conveyor have been successfully developed for a top-coal caving face with large mining height. The study has developed the key technologies for improving the reliability of equipment at the coal face and has overcome the challenges in equipping the top-coal caving face with a large mining height in ultra-thick coal seams; 3. The deformation characteristics of a large cross-section roadway in ultra-thick coal seams are discovered. Based on the findings above, a series of bolt materials with a high yielding strength of 500-830 MPa and a high extension ratio, and cable bolt material with a 1 × 19 structure, large tonnage and high extension ratio are developed. In addition, in order to achieve a safe roadway and a fast face advance, installation equipment for high pre-tension bolt is developed to solve the problems with the support of roadway in coal seams for top-coal caving operation with a large mining height; 4. The characteristics of gas distribution and uneven emission at top-coal caving face with large mining height in ultra-thick coal seams are evaluated. With the application of the technologies of gas drainage in the roof, the difficulties in gas control for high intensive top-coal caving mining operations, known as "low gas content, high gas emission", are solved. In addition, large flow-rate underground mobile equipment for making nitrogen are developed to solve the problems with fire prevention and safe mining at a top-coal caving face with large mining height and production rate of more than 10 Mtpa. A case study to apply the developed technologies has been conducted at the No. 8105 face, the Tashan coal mine in Datong, China. The case study demonstrates that the three units of equipment, i.e., the support, shearer and scraper conveyor, are rationally equipped. Average equipment usage at the coal face is 92.1%. The coal recovery ratio at the coal face is up to 88.9 %. In 2011, the coal production at the No. 8105 face reached 10.849 Mtpa, exceeding the target of 10 Mtpa for a topcoal caving operation with large mining height performed by Chinese-made mining equipment. The technologies and equipment developed provide a way for extracting ultra-thick coal seams. Currently, the technologies and equipment are used in 13 mining areas in China including Datong, Pingshuo, Shendong and Xinjiang. With the exploitation of coal resources in Western China, there is great potential for the application of the technologies and equipment developed.
基金Sponsored by Key Funding Project for Science and Technology under the Beijing Municipal Education Commission(KZ200910772001)
文摘In order to predict electromechanical equipments' nonlinear and non-stationary condition effectively, max Lyapunov exponent is introduced to the fault trend prediction of large rotating mechanical equipments based on chaos theory. The predict method of chaos time series and two methods of proposing f and F are dis- cussed. The arithmetic of max prediction time of chaos time series is provided. Aiming at the key part of large rotating mechanical equipments-bearing, used this prediction method the simulation experiment is carried out. The result shows that this method has excellent performance for condition trend prediction.
文摘Objective: To investigate the allocation and management of large medical equipment (LME) in Xuzhou, Jiangsu Province, China, in order to make the best use of LME to meet the medical needs of local people. Methods: The research collected data from all hospitals that have LME in Xuzhou using questionnaire; 38 (97.4%) hospitals returned the questionnaire. Results: In Xuzhou, there are a total of 71 pieces of LME, each serving 126 600 people in an area of 163 km2. Sixty-two percent of them are allocated in urban areas, with Gini coefficient at 0.52, indicating imbalance and biased allocation of LME. Conclusion: The al- location of LME in Xuzhou is out of control and unfairly allocated.
文摘This paper studies how to manage large and precise equipment effectively in colleges and universities and proposes the necessity to establish experiment centers on the level of university and department. Finally, new thought on paying more attention to the construction of technical management team and gathering necessary expenses, such as use expenses, maintenance expenses, function development expenses, etc. is given out.
文摘The purchasement and development as well as the benefit of utilization for the large equipment in universities of China are analyzed in this paper, the paper in dicates that in utilization of large equipment the contradictions such as urgency and necessity for the purchasement and development of large equipment and serious waste in resources since inadequacy of annual utilization rate of large equipment are existed, it also raises that the key step of giving full play to the benefit of large equipment is to strengthen management and development after the equipment are purchased, the paper regards through stressing standardized management and maintenance、opening the laboratory、improving the functions of equipment、renovating technology、fully examining and scientifically deciding before purchasement, the investment benefit for the large equipment can be raised effectively.
文摘以“采煤机、刮板输送机、液压支架”工作面三机,“转载机、破碎机、带式输送机”顺槽三机以及供电系统、供液系统、控制系统和通信系统为配套的大型采煤设施装备是煤炭工业平稳高效发展的重要支柱。本项目以满足特厚煤层超大采高综放开采装备配套需求为目标,以高可靠性、长寿命、自动化、智能化技术为攻关重点,开发包含装机功率2×2000 kW前部输送机、装机功率3×1600 k W后部输送机及配套转载机、破碎机的超重型、超大运量,以及操作方式的自动化、智能化、形成了高可靠性综放工作面成套输送设备,并通过运输过程中发现的问题对转载机进行了相应的升级改造,确保了煤块流畅地卸载于顺槽转载机上,尽量减少回煤;创新性地开发了带式自移支撑装置,实现了装置的自行前移、支撑高度调整,有效减少了带式输送机中间架拆架次数。运输系统设备的升级改造满足产量15 Mt/a以上特厚煤层综放工作面开采需要。