Key technologies and equipment for a fully mechanized top-coal caving operation with a large mining height at ultra-thick coal seams

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.

Trend Prediction Method Based on the Largest Lyapunov Exponent for Large Rotating Machine Equipments

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.

Study of large medical equipment allocation in Xuzhou

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.

Research of Personnel Operational Ability Evaluation of Large-scale Complex Equipment

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.

An Investigation into Large and Precise Instrument Management in Colleges and Universities

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.

Research on Effective Access for Strengthening and Improving the Management and Benefit use of Large Instruments

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.

基于精细化管理的大型医用设备全生命周期绩效评价体系的构建

目的构建大型医用设备全生命周期绩效评价体系,为大型医用设备的精细化管理提供参考。方法采用文献回顾和专家访谈建立原始指标池,经研究小组对初始指标整理讨论后编制专家函询问卷。采用德尔菲法对遴选的40名医用设备管理相关领域专家进行函询,构建大型医用设备全生命周期绩效评价体系,采用层次分析法确定指标权重。以青岛市某三级甲等医院某分院区健康体检中心CT设备为例,开展实证分析。结果构建了大型医用设备全生命周期绩效评价体系,包含4个一级指标、12个二级指标和117个三级指标。根据此评价体系,对青岛市某三级甲等医院某分院区健康体检中心CT设备展开评价,其采购配置阶段评分为47.1分,运行管理阶段评分为37.9分,根据评价标准该CT机综合评价结果为优秀。结论本研究的专家积极程度、权威程度和协调程度均符合标准,构建的大型医用设备全生命周期绩效评价体系具有较高的科学性和可靠性,可以为大型医用设备的精细化管理提供参考。

数据驱动儿童专科医院大型医疗设备运行评价体系建设

目的探索通过数据采集及分析评价儿童专科医院大型医疗设备运行水平的方法,提出大型医疗设备使用及配置建议。方法通过物联网终端采集设备运行数据,结合医院HIS、RIS、HRP等系统数据,建立儿童专科医院大型医疗设备评价指标体系,运用CRITIC法对单类、单台设备数据进行量化评价。结果医院大数据平台实现了对单台大型设备运行数据纵向分析并形成可视化图表,通过PC端及移动端展示。申康市级平台数据分析,实现对儿童专科医院大型设备运行水平的综合量化评价及使用配置建议。结论通过数据采集及分析,实现儿童专科医院大型设备运行评价体系建设,提升大型设备管理水平。

五措并举提升大型仪器设备共享成效的探索

大型仪器设备是高校提高教学科研水平和人才培养质量的重要条件,是反映学校的综合实力和办学水平的重要指标。随着高等教育的发展,高校大型仪器设备的类型和数量在不断增加,由此也带来了重复购置、利用率低等问题。通过加大大型仪器设备信息化共享、加强大型仪器设备人员队伍建设、建立健全大型仪器设备共享机制、探索大型仪器全成本核算管理、强化大型仪器设备制度集成创新,形成以内循环为主、区域化为辅的共享模式,全面提升大型仪器设备共享实效。

大型仪器设备分层化与特征化运行管理探索

随着高校和科研院所大型仪器设备数量及其功能复杂性的增加,运行管理模式需持续创新与优化,该文基于网络共享平台的运行管理模式和土壤与环境研究领域的测试特征,对大型仪器设备的运行管理模式进行了探索。根据大型仪器设备运行特点,该文将仪器划分为常规型、环节型、耗时型、高难型等4种类型,分别采用“专职人员”“专职人员培训-操作视频-送样人”“专职人员培训-送样人”“专职人员-送样人”等分层化模式进行运行管理,统计分析这些仪器的运行机时、操作故障、自然故障、维修情况、共享率、支撑成果等多个运行指标,结果均较为满意。该文提出的分层化与特色化大型仪器设备运行管理模式,可为大型仪器设备共享率与运行效率的提升提供参考。

大型仪器设备在本科实验教学中的应用研究与实践

大型仪器设备是激发学生学习兴趣、拓宽专业视野、培养创新思维的重要工具。分析了西南石油大学大型仪器设备的应用现状,以海洋油气工程专业为例,针对大型仪器设备在本科实验教学中的应用进行了研究与实践。将大型仪器设备分为精密设备、大型模型设备和大型操作设备,并介绍了各自的使用特点。为了充分发挥大型仪器设备的作用,利用信息技术,建设了线上学习资源,改革了教学模式,制订了实验项目教学方案。应用实践表明,教学改革实施后取得了良好的教学效果,大型仪器设备的使用率明显提高,学生主动思考和学习的自主性得到明显提升。

基于真实动态数据的大型医疗设备合理配置决策系统开发及应用

针对现阶段大型影像设备配置数量和功能缺少量化考核依据,本文研究并搭建实时监测与评价应用系统,详细介绍边缘计算架构工作过程及特性,并阐述了远程运维的必要性。搭建的系统对监控的7台CT设备从故障率、检查人数、检查时间间隔、设备使用年限四个维度进行详细说明与分析,量化评分并计算总评分及排名,为今后CT设备合理配置与采购决策提供必要的客观证据支持。

基于关键词的大型医用设备配置研究热点和趋势分析

为系统把握大型医用设备配置理论研究的演变及其未来发展趋势,对领域内文献关键词进行研究。借助CiteSpace工具生成可视化的研究领域知识图谱,基于关键词聚类、关键词突现分析,对现有研究方向进行总结,揭示研究动态和主要研究焦点。在此基础上,结合政策变化对大型医用设备配置研究未来发展趋势进行预测,为后续的相关研究提供参考。

飞机大尺寸组件外形数字化组合测量方法研究

现代飞机装配制造过程中,面对一些大尺寸组件的外形测量任务,单独使用手持三维激光扫描仪测量存在数据融合困难、累积误差较大等问题,因此,提出一种基于手持三维激光扫描仪与摄影测量系统的组合测量方法。利用摄影测量系统建立全局测量坐标系,通过相同视觉标志点匹配来获取局部视角测量坐标系与全局坐标系的变换关系,完成手持三维激光扫描仪局部扫描数据自动拼接。通过将测量数据模型与设计原型进行对比,获得大尺寸组件外形质量分析报告。在保证测量效率的条件下,组合测量方法可以提高型面测量精度。以某机前框组件外形精度的测量分析为例,测量精度可达23.6μm,证明了该方案的有效性和可行性。

实验技术队伍先进技术集群建设

实验技术队伍作为高校学科建设、创新型人才培养以及科学研究的重要力量,是高校加快推进高水平内涵式发展的重要支撑。该文详述了某高校实验技术队伍先进技术集群建设案例,先进技术集群建设突破了传统实验技术队伍的组织边界,是贯彻新发展理念、构建新发展格局的实践,创造了有利于实验技术队伍专业能力提升的良好学术生态圈,为实验技术队伍技术交流和协同创新提供平台,为建设世界一流实验技术体系提供技术保障和引领,以期为建设新时代高水平的实验技术队伍提供参考。

浅谈中国未来大型水电装备技术挑战与创新

我国水电资源丰富、开发程度处于中等水平,远不及欧洲发达国家。“双碳”战略下,水电作为清洁能源,以其高调节性、高稳定性将在以新能源为主的新型电力系统中发挥“压舱石”作用。资源特点和经济性决定未来水电开发将朝向更高水头(高转速)、更大容量趋势发展,机组将具备高海拔环境运行、超高水头、超大容量的特点。开发难度极高,技术挑战前所未有,亟待攻克。该文从多个角度分析阐述特殊工况下我国水电装备开发面临的问题和技术挑战,探讨关键技术发展趋势以及创新技术应用潜力,为未来水电装备的技术创新和突破提供参考方向。

大型仪器设备在本科实验教学中的应用实践

大型仪器设备在培养本科生的实践能力、应用能力和创新能力等方面发挥着重要的作用。基于西安工程大学环境与化学工程学院分析测试中心仪器设备共享平台,结合学院课程实际情况,以具体的实验课程案例为例,阐述大型仪器设备在本科实验教学中的应用实践,同时对大型仪器设备在为本科实验教学服务过程中存在的问题提出了一些建议。

大型钻探设备支承底盘焊接工艺优化研究

大型支承底盘作为大型钻探设备的支承平台,通常由大量钢板通过焊接装配而成,焊接残余应力和残余变形会对底盘的强度和刚度产生一定的影响。本文运用有限元分析方法,选取高斯移动热源,针对大型支承底盘中具有代表性的T形焊接接头建立了有限元模型,分别采用4种不同的焊接顺序和焊接速度,分析了其对焊接应力和变形的影响,得到了优化的焊接顺序和焊接速度。在此基础上,对底盘的整体焊接方案做出优化,对比分析了优化前后的焊接应力和变形,结果表明:优化后残余应力减少了约7%,最大变形减少了约26%。研究成果可为焊接工艺的制定提供参考。

基于真实世界数据的大型影像设备资源配置模型的构建与分析

目的构建基于真实世界数据(Real World Data,RWD)的计算机断层扫描(Computed Tomography,CT)、磁共振成像(Magnetic Resonance Imaging,MRI)设备的资源配置模型,以优化公立医院大型影像设备的配置问题。方法选取我院2018年1月至2023年12月医学影像科CT、MRI设备作为研究对象,使用年投资收益率指标分级评价设备的经济效益,然后采用Pearson相关系数法分析医院门诊人次、出院人次、CT/MRI设备检查量与时间的相关性,最后构建基于数据拟合与回归分析的配置预测模型并进行分析评价。结果CT和MRI设备检查量与住院人次的Pearson相关系数r分别为0.557和0.851(P<0.01),住院人次、CT和MRI设备检查量与月份的r分别为0.415、0.559和0.731(P<0.01),相关性强。通过数据拟合与回归分析得到三次配置拟合模型更符合我院实际情况,在未来3年内至少需要增配1台CT和2台MRI设备以顺应医院高速发展需求。结论构建基于RWD的CT、MRI设备的资源配置模型,有效地优化了大型影像设备的配置规划,为公立医院配置大型影像设备提供决策依据。

运用波士顿矩阵构建医院贵重设备综合评价体系——以大型彩超为例

目的构建一套完整的贵重医疗设备的综合评价体系,使医院贵重医疗设备管理有据可依。方法采用文献分析和专家问卷调查构建贵重医疗设备的综合评价指标体系,选取我院超声科12台采购金额超过100万的在用彩超设备,利用医院数据系统采集2023年的使用数据,基于综合评价指标体系对其使用数据进行评价,利用波士顿矩阵对其2023年的综合运营状况进行分析。结果12台贵重彩超设备中,明星设备为2台LOGIQ E9以及ACUSON SEQUOIA;金牛设备为ALOKA ARIETTA 850、LOGIQ E20、RS80A;瘦狗设备为EPIQ CVX、EPIQ 5、VIVID E95、APLIO I900、APLIO 400、MYLAB TWICE;没有问题设备,此结果与现实情况相符。结论基于波士顿矩阵的贵重医疗设备的综合评价体系能清晰地反映医院贵重设备的综合效益,给医院上层决定是否需要添置新设备、选择合适的机器型号、是否需要报废等增加数据支持,避免重复购置和闲置等资源浪费现象。