In the production of petrochemical and dangerous chemicals, the oil and gas medium had the characteristics of flammability and explosiveness, which was easy to cause safety accidents. In view of the emergency cutting in the case of planned maintenance and accident in flammable and explosive environment, the necessity of adopting cold cutting technology was pointed out. Based on the technical characteristics of abrasive water jet cutting, the adaptability of abrasive water jet cutting technology in flammable and explosive environment was analyzed. The application mode of abrasive water jet emergency cutting was discussed, and the advantages and disadvantages of its abrasive pre-mixing and post-mixing technology forms and application occasions were explained respectively, as well as the characteristics and methods of the explosion-proof mode and integrated mode of abrasive water jet cutting device in emergency cutting situations. The new development trend of jet cold cutting technology in the development of special cutting actuator, the technical breakthrough to improve the reliability of the device, and the development of new jet were proposed.

为改善松湖铁矿出矿贫化率高的问题,基于初选采场结构参数,采用编组立体放矿试验对初选参数进行了优选,回采效果工业试验结果表明:崩矿步距4 m进路的实践应用效果并不理想,崩矿步距3.2 m能达到较高的矿石回采目标,与排距为1.8,2.2m相比,其矿石总回采率提高了约11个百分点,说明优化结构参数与现场工业实验相结合具有推广有效性.

A new model is established to describe the relationship between permeability and stress according to the distribution characteristics of overlying rock permeability with the stress change under mining-induced condition.The permeability-stress mod el,through the fish language,is embedded into the FLAC3D software to simulate the change law between permeability and stress of the overlying strata.At the same time,the permeability change is used to determine the height of the pressure relief zone.Numeri cal results show that the permeability decreases with the increase of stress;the pressure releasing height increases with the increase of the mining distance,but the final value tends to a constant value;the protective layer can enhance the permeability of the coal layer,and can effectively improve the efficiency of gas drainage;after being protected by the protective layer,the permeability of the overlying strata in the mined area is about 3 times that of the overlying strata.

In order to investigate the effect on gas seepage in coal bedding,first,the seepage characteristics were analyzed,which of these two extremes of coal seam gas along the parallel and perpendicular to the bedding plane from the theory,by comparative analysis on the coefficient of permeability of coal seam gas,the coefficient of permeability of which the gas flow direction paralleled to the bedding plane is larger than that of vertical seam.Then,through testing of the raw coal in the laboratory and analysing on the experimental data,the curve is approximation smooth,which the gas paralleled to the bedding of the seepage velocity and stress strain,and the curve is rough between the gas seepage velocity perpendicular to the bedding plane and stress strain.The gas flow velocity of the vertical to bedding is greater than of the parallel to,but the coal gas seepage velocity of the parallel to bedding is larger than of the vertical to.This result is consistent with the theoretical analysis.

简要分析了某型保障装备所面临的复杂电磁环境,并分析了该保障装备在电磁环境下所受的影响,最后分析了从该保障装备的整体屏蔽机壳、控制系统、电缆线三个易受电磁干扰的部分提出了电磁防护措施,提高该保障装备的电磁防护能力.

本文分析了影响电源车战场抢修备件品种确定的各个因素.通过实例对运用模糊综合评判法就如何对战场抢修备件品种的选择进行了阐述,为装备保障部门确定战场抢修备件品种提供了理论依据.

There are lots of issues in the design for the traditional aero ground power supply equipment, such as the variety of species, too large volume and sole function.To solve these problems, this paper proposes a method for modular design in aero ground power supply equipment, and focuses on detail design processes.This paper designs generalized and modularized power supply equipment in order to realize miniaturization, multi-function and generalization for aero ground power supply equipment.

To acquire operating state data of ground power supply for aviation in plateau environment,this paper gave a design scheme of data acquisition system for plateau ground power supply of hardware and softwarc based on S3C2440.The system processes data with S3C2440 to control multi-channel analog switches and time division multiplex access to transmit data of multi-channel sensors of ground power supply into data acquisition card.Acquired data can be stored on portable storage device.To facilitate the interaction between user and system,it also provides many functions,such as report generation,archiving,print output,etc.System analysis software can make the details of the characteristic parameters be observed directly by reproducing the data of the experimental results,displaying the running curves and showing data tables.

This paper introduces the rectifier part and inverter part of three-phase 115/200V400Hz AC linear power supply system, designs the circuit of the system, simulates the linear power supply system, and draws the reasonable conclusion of the system design.

针对三相负载不平衡的波形畸变和输出电压不对称等问题,应用三相组合式逆变拓扑原理进行了逆变电路设计,满足了不平衡负载对逆变器的要求,提升了逆变电路的可靠性.通过仿真验证,证明了电路设计的合理性和有效性.

针对多电飞机需要270V直流的外部电源保障,介绍了270V直流直线供电系统的整流部分和DC/DC部分;设计了270V直线供电系统的具体电路,仿真了270V直线供电系统电路;通过对仿真结果的分析,得出了270V直流直线供电系统设计合理的结论.

Based on Mohr-Coulomb Criterion of rock failure and for the purpose of studying the overburden rock failure law of the inclined coal seam in deep mining, in this paper, simulation analysis was made on the stress, displacement and failure of surrounding rock in the whole mining process with the working face advance by using FLAC3D numerical software, which preliminarily revealed that the failure feature and movement rule of the overburden strata were influenced by the stress redistribution induced by step excavation. A numerical model of the coal-rock mass permeability ratio coefficient was established according to the empirical relationship between the permeability and mining-induced stress variation in mining and by using the FISH programming language. The coefficient change after mining was calculated by using this model and it was then the characterization of the pressure relief range of the coal seam during mining. All of these provided a strong guarantee for surrounding rock control and gas treatment in deep mining of the inclined coal seam.

To counter the problem that the pattern of gas-relieving drainage holes can't meet the needs of gas drainage in air-return way in the working face of the protective seam in Songzao Mine,improvement was carried out for the pattern of the gas-relieving drainage holes at the drilling site,the two-way fan-shaped hole pattern was changed into one-way forward-inclined hole pattern along the cutting direction of the face. The improvement of the gas drainage hole pattern raised the gas drainage volume at the drilling site and reduced the gas overrun phenomenon,so it has good practicability.

文章分析了大舍煤矿松软煤层水力排渣钻孔施工发生问题的原因,提出了风力排渣加螺旋钻杆施工的途径,并在井下进行了实验,成功解决了问题.可为类似的煤层钻孔施工起到借鉴作用.

利用电液伺服岩石力学试验系统,进行了煤样全应力应变渗透试验,分析了应力应变对煤样渗透特性的影响。试验结果表明,垂直应力σ1(即轴向压力p1)对渗透系数的影响最大,其对煤体透气性的变化起着决定性作用。

根据国内最新的涌水量预测方法,利用现有生产水平涌水量的参考资料,结合大量现场实测数据,对石壕煤矿东翼Ⅱ区煤层-200m标高水平开采生产能力提高到180万t/a时的涌水量进行了预测,可为类似矿井涌水量预测提供参考。

A series of triaxial compression tests on sandstone from Chongqing has been performed,aiming to relate the orientation of shear bands with respect to the minimum principal axial direction to confining pressure.Comparison of experimental and theoretical results reveals that the orientation of the shear fault decreases with confining pressure,and the predictions of the orientation based on Mohr criterion agrees well with measurements.

对高应力软岩的基本概念及形成条件进行了讨论,在掌握高应力软岩巷道的变形特征和支护原理的基础上,并以芙蓉矿区白皎煤矿井下高应力软岩巷道支护为对象,对3种不同的支护方式进行了研究与实践,结果表明预留刚隙柔层支护方式为最佳的适合高应力软岩条件下的巷道支护方式。

分析了新兴煤矿北翼采区的涌水来源、特点,全面、规范地开展了涌水量的测定,对矿井涌水量进行客观的预测,提出矿井水灾治理总体技术方案,并有针对性的对K13煤层涌水区域进行了局部钻孔抽水设计。对其他类似涌水矿井进行水治理具有参考意义。

With the increasing depth of coal mining,underground roadways will be a higher environment of geo-stress,especially in the areas where there have happened intense activities of geological structure.Researching of scientific supporting fashions of soft rock roadways in high geo-stress environment is the key of ensuring coal mining deeply in coal mine.Basic concept of high geo-stress soft rock and its forming conditions have been discussed based on mastery of deformation characters and supporting principle of high geo-stress soft rock roadways,three different supporting fashions have also been researched and executed with taking high geo-stress soft rock roadways′ supporting of Baijiao Coal Mine in Furong Mining Area as objects.The results indicate that rigid gap flexible layer supporting fashion is the best one which can fit high geo-stress soft rock conditions.