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.

Interactive mobile equipment safety task-training in surface mining

Improving the quality of equipment training for the Heavy Equipment Operators(HEO)is a critical task in improving safety and eliminating equipment-related injuries in mining.One of major responsibilities for the HEOs is proper machine inspection.Traditional miner safety training includes the use of hardcopy documents and video instructions.However,modern mobile and computer technology offers tremendous potential to improve the training process.In this study,we apply a 360-degree camera,opensource platform WordPress^(TM),and the software Unity3D in order to create materials and tools for the HEOs safety training to help trainees better understand the pre-shift safety machine inspection.The computer-based safety task training developed in this research is tested and implemented at a surface mine in the southern United States.

Environment Adaptability Evaluation for Buffering Airbag of Heavy Equipment During Airdrop Landing

Aimed at the difficulties in analyzing the buffer characteristics of airbag system by using thermodynamic or experimental method only,the finite element method was used to establish nonlinear models for heavy equipment and its airbag system.The models' efficiency and correctness were validated by using on-site experiment data in vehicle airdrop landing.The simulation results agree very well with the experiment results.Then,the environment adaptability of airbag system of heavy equipment under high-altitude condition was studied by using the models.Finally,some solutions were given to solve the overturn problem in the landing.

Jet formation in shock-heavy gas bubble interaction

The influences of the acoustic impedance and shock strength on the jet formation in shock-heavy gas bubble interaction are numerically studied in this work. The process of a shock interacting with a krypton or a SF6 bubble is studied by the numerical method VAS2D. As a validation, the experiments of a SF6 bubble accelerated by a planar shock were performed. The results indicate that, due to the mismatch of acoustic impedance, the way of jet formation in heavy gas bubble with different species is diversified under the same initial condition. With respect to the same bubble, the manner of jet formation is also distinctly different under different shock strengths. The disparities of the acoustic impedance result in different effects of shock focusing in the bubble, and different behaviors of shock wave inside and outside the bubble. The analyses of the wave pattern and the pressure variation indicate that the jet formation is closely associated with the pressure perturbation. Moreover, the analy- sis of the vorticity deposition, and comparisons of circulation and baroclinic torque show that the baroclinic vorticity also contributes to the jet formation. It is concluded that the pres- sure perturbation and baroclinic vorticity deposition are the two dominant factors for the jet formation in shock-heavy gas bubble interaction.

The design of intelligent monitoring and control system of the mechanical equipment base on “Internet plus”

each heavy machinery equipment for the end of the system, each end of the installation of a GSM data collector, complete the collection of the operating parameters of the equipment, the establishment of basic conditions for the exchange of things. According to the data server address the preset timing, collector through the GPRS network or Internet wireless network data transmission, data transmission acquisition collection to the cloud, the cloud to complete the function of data identification, error correction, classification, management and analysis of the data management system based on the transmitted data, so as to realize the management of large data.

渤海旅大27-2油田蒸汽吞吐先导试验注采工程

借鉴国内外蒸汽吞吐技术的开发经验,从地质-油藏工程方案、注采方案、地面(平台)方案几个方面进行研究,并结合现场实施情况进行综合分析。确定了油藏开发方案和注汽参数,研发了地面小型化、撬装化的蒸汽发生器及配套的海水淡化系统、高纯氮气系统,设计了油管注汽工艺、油套环空注高纯氮气工艺、伴注除氧剂的注汽工艺及井筒防腐措施;在海上首次采用了高温电潜泵(耐温250℃)进行热采稠油举升,并对高温井进行温度压力监测;首次在渤海旅大27-2油田进行了稠油先导性试验,取得了较好的试验效果,为下一步大规模开发渤海稠油油田提供了良好的依据和基础。

重型装备剖分-坎合技术的研究进展及其应用

介绍了一种在重型装备中应用的最新技术——剖分-坎合技术.剖分-坎合技术的应用可以很好地解决制造、运输难题,并能够降低加工成本,未来在工业中将有着广阔的应用前景.首先介绍了剖分-坎合的基本概念,然后利用弱边界原理、断裂力学原理、摩擦学等交叉学科的理论对其基本原理的最新研究进展进行了简要介绍,最后介绍了剖分-坎合结构在工程中的应用,并对该技术的进一步研究和应用提出了展望.

基于Z-number和改进DS证据理论的风险评估方法

针对任务风险难度量、评估信息不确定性强等问题,提出一种Z-number和改进DS证据理论的风险评估方法。利用Z-number方法描述评估指标,得到各风险等级的初始基本概率分配(basic probability assignment,BPA);基于信度熵和皮尔逊相关系数改进DS证据理论克服悖论问题进行信息融合,确定风险的最终等级;接着,基于信息融合结果引入Joussleme距离求解专家可信度。最后,以重装空投任务为例,验证本文所提风险评估方法的合理性,并对比分析不同改进DS证据理论方法得到的结果,验证所提方法的有效性和准确性。

基于熵权-理想点法的重型装备制造资源评价方法

针对复杂重型装备生产制造过程复杂性、生产指标值的动态性以及指标间具有耦合关系的特点,制造资源匹配结果在实际生产时效果存在偏差的问题。本文通过分析重型装备制造资源需求方和提供方的需求,构建了网络化制造模式下重型装备制造资源评价指标体系,结合评价分析和决策的方法,通过熵权法来确定评价指标的权重并结合理想点法构建重型装备制造资源评价模型。最后通过对给定的最优组合的实际生产指标数据,验证了该评价方法对复杂重型装备制造资源评价及决策的有效性和科学性。

基于LTE-R通信和400MHz数字通信的双模列尾技术研究

针对国能集团旗下铁路公司重载铁路列车跨线运行存在多种列尾通信制式的问题,在需求调研的基础上,提出基于LTE-R通信和400 MHz数字通信的双模列尾技术方案,并完成设备研制。功能和性能测试表明:该装置可有效提高通信的成功率,满足地方铁路列尾装置应用需求,保障重载铁路运输安全。

经济新常态下国有装备制造企业的涅槃重生--以山东重工集团为例

改革开放四十余年来,中国国有企业改革不断深化。当前,中国经济进入了新常态,深化国有企业改革进入关键时期。为了系统总结国有装备制造企业改革与发展中的成功经验与现存问题,以资国有装备制造企业涅槃重生进行借鉴,这里选取了山东重工集团进行个案研究:基于国有企业发展过程中的各个基础要素建立了"国有企业发展生态模型",用以对山东重工的文化、战略、财务、人力资源、创新五个内部要素以及政府调控和市场竞争两个外部要素进行分阶段纵向分析;在此基础上,归纳其发展中的经验与不足,并针对其现存问题提出了建设性意见。

Longitudinal dynamics and energy analysis for heavy haul trains

Whole trip longitudinal dynamics and energy analysis of heavy haul trains are required by operators and manufacturers to enable optimisation of train controls and rolling stock components. A new technology named train dynamics and energy analyser/train simulator （TDEAS） has been developed by the State Key Laboratory of Traction Power in China to perform detailed whole trip longitudinal train dynamics and energy analyses. Facilitated by a controller user interface and a graphic user interface, the TDEAS can also be used as a train driving simulator. This paper elaborates the modelling of three primary parts in the TDEAS, namely wagon connection systems, air brake systems and train energy components. TDEAS uses advanced wedge-spring draft gear models that can simulate a wider spectrum of friction draft gear behaviour. An effective and efficient air brake model that can simulate air brake systems in various train configurations has been integrated. In addition, TDEAS simulates the train energy on the basis of a detailed longitudinal train dynamics simulation, which enables a further perspective of the train energy composition and the overall energy consumption. To demonstrate the validity of the TDEAS, a case study was carried out on a 120-km-long Chinese railway. The results show that the employment of electric locomotives with regenerative braking could bring considerable energy benefits. Nearly 40 % of the locomotive energy usage could be collected from the dynamic brake system. Most of tractive energy was dissipated by propulsion resistance that accounted for 42.48 % of the total energy. Only a small amount of tractive energy was dissipated by curving resistance, air brake and draft gear systems.

Distribution,fractionation,and contamination assessment of heavy metals in offshore surface sediments from western Xiamen Bay,China

Surface sediment samples were collected at 21 offshore sites in western Xiamen Bay, Southeast China. Total concentrations of Li, V, Cr, Co, Ni, Cu, Zn, St, Mn, Pb, Ba, Fe, and Ti were determined by inductively coupled plasma-optical emission spectrometry; Hg was determined by atomic fluorescence spectrometry. A modified BCR sequential extraction procedure was used to extract fractions of the above elements. Concentrations of Pb, Cr, and Hg at most sites met the primary standard criteria of Marine Sediment Quality except site S12 for Pb and S7 for Cr, while concentrations of Zn at 17 sites and Cu at seven sites exceeded the criteria. The mean concentration of Hg was three times higher than the background, with a possible source being the Jiulong River. Fe, Ti, Ba, Co, V, and Li dominated the residual phase, mainly from terrestrial input. Ni, Cr, Pb, and Hg in the non-residual phase varied largely between sites. Sr, Mn, Cu, and Zn were mainly in the non- residual fraction. Most sites showed considerable ecological risk; exceptions were site S7 （very high） and sites S10, S11, and S14 （moderate）. Cu showed moderate-to-high pollution and Pb exhibited no-to-low pollution, while other metals had a non-pollution status according to their ratios of secondary phase to primary phase （RSP）. Results of two assessment methods showed moderate pollution and a very high ecological risk for Cu, Zn, Ni, and Cr at site S7, which might be due to the local sewage treatment plant.

基于AHP-RS的重型装备网络化协同制造任务粒度评价体系研究

针对复杂重型装备网络化协同制造模式下任务分解完成后任务粒度的评价问题,提出一种基于AHP-RS的任务粒度评价方法。通过对复杂重型装备网络化协同制造模式下的项目流程进行分析,明确其任务粒度的合理评价需求,并面向该需求展开研究。基于任务粒度的影响因素,从绝对性指标和相对性指标两个角度出发建立评价指标体系。在此基础上,结合层次分析法(AHP)和粗糙集法(RS)分别计算了各相对性指标的主观及客观权重,并进行加权得到指标组合权重,完善了评价体系。最后以某125MN挤压机主工作缸研发设计项目为例,对任务粒度评价指标体系进行了验证,验证结果表明,评价结果同实际情况相符,能够为任务粒度评价提供一定参考。

Influence of Thermal Load on Mechanical Property of Cemented Carbide Material and Heavy Cemented Carbide Inserts Life

A large amount of cutting heat is produced during the heavy cutting process,and insert life is restricted by the effect of thermal load.The thermal load experiment of cemented carbide SCS,WF and YT15 is carried out,and the results show that the bending strength and fracture toughness of cemented carbide material decrease obviously under cyclic thermal load,while in the cooling process,the material mechanical property changes worse suddenly.The high-temperature mechanical property of SCS is the most stable,and that of YT15 is the worst.Further,a relation model among cutting temperature,cutting parameters and insert life is established.Finally,the measures to improve heavy cemented carbide inserts life are summarized from the aspects of cutting parameters selection,insert optimization design and TiCN,Al2O3,TiN complex insert coating.The research results are expected to provide support and reference for heavy cutting technology and insert technology.

基于改进NSGA-Ⅱ算法的双运输机重装空投研究

为了提高空降部队突击突防能力,对双运输机重装空投编队多目标规划问题进行研究。首先,基于分离法分析重装空投货台运动过程,通过欧拉迭代思想构建货台动力学模型。然后,考虑到前机尾涡对后机影响,构建了双运输机编队空间位置模型。为确定双机编队位置关系的最优解,采用改进后的NSGA-II算法,引入支配强度、优化精英策略、种群等级交叉系数以及高斯变异算子,同时基于方差表示拥挤度,计算出最终结果。仿真实验数据表明,优化后的算法不仅能够提升双运输机编队飞行安全性,而且使得空投点更加密集、空投精度更高。

矿山装备关键旋转件轴-径组合式磁性液体密封结构设计及性能

针对传统机械密封运行阻力大、寿命短和轴向式磁性液体密封适用性差等问题,结合矿山装备旋转部件的高转速、重载荷工况特点,提出一种新型轴-径组合式磁性液体密封结构。对密封结构中关键部件的尺寸参数进行优化;用ANSYS软件对轴-径组合式与单一轴向式密封结构进行磁场特性仿真,并将2种密封结构的密封性能进行对比。结果表明:新型轴-径组合式磁性液体密封的结构设计合理,可有效避免因离心力造成的高速旋转轴密封失效问题,且相比于单一轴向式磁性液体密封结构其耐压能力提高了52.7%,验证轴-径组合式密封结构的可靠性。

Safety modeling and simulation of multi-factor coupling heavy-equipment airdrop

Heavy-equipment airdrop is a highly risky procedure that has a complicated system due to the secluded and complex nature of factors＇ coupling. As a result, it is difficult to study the modeling and safety simulation of this system. The dynamic model of the heavy-equipment airdrop is based on the Lagrange analytical mechanics, which has all the degrees of freedom and can accurately pinpoint the real-time coordinates and attitude of the carrier with its cargo. Unfavorable conditions accounted in the factors＇ models, including aircraft malfunctions and adverse environments, are established from a man-machine-environment perspective. Subsequently, a virtual simulation system for the safety research of the multi-factor coupling heavy-equipment airdrop is developed through MATLAB/Simulink, C language and Flightgear software. To verify the veracity of the theory, the verification model is built based on dynamic software ADAMS. Finally, the emulation is put to the test with the input of realistic accident variables to ascertain its feasibility and validity of this method.

A parametric study of the hydrodynamic roughness produced by a wall coating layer of heavy oil

In water-lubricated pipeline transportation of heavy oil and bitumen, a thin oil film typically coats the pipe wall. A detailed study of the hydrodynamic effects of this fouling layer is critical to the design and operation of oil-water pipelines, as it can increase the pipeline pressure loss （and pumping power requirements） by 15 times or more. In this study, a parametric investigation of the hydrodynamic effects caused by the wall coating of viscous oil was conducted. A custom-built rectangular flow cell was used. A validated CFD-based procedure was used to determine the hydrodynamic roughness from the measured pressure losses. A similar procedure was followed for a set of pipe loop tests. The effects of the thickness of the oil coating layer, the oil viscosity, and water flow rate on the hydrodynamic roughness were evaluated. Oil viscosities from 3 to 21300 Pa s were tested. The results show that the equivalent hydrodynamic roughness produced by a wall coating layer of viscous oil is dependent on the coating thickness but essentially independent of oil viscosity. A new correlation was developed using these data to predict the hydrodynamic roughness for flow conditions in which a viscous oil coating is produced on the pipe wall.

国产2(1/4)Cr-1 Mo特厚钢板的开发和应用

长期以来,加氢装置中的加氢反应器等核心设备使用的主体材料——21/4Cr-1Mo厚钢板一直依赖进口,价格高,交货周期长,经常成为制约项目建设的瓶颈。为此,舞阳钢铁有限责任公司与中石化合作开发了国产21/4Cr-1Mo厚钢板。介绍21/4Cr-1Mo厚钢板国产化开发的目标,总结开发的重点和难点,阐述国产21/4Cr-1Mo特厚钢板的性能和应用情况,对下一步的工作提出了建议。