开闭式反循环钻头的结构设计与工作原理

由于煤层松软和破碎的缘故,松软突出煤层瓦斯抽放孔易垮塌,将导致钻孔成孔率低,瓦斯抽放通道易堵塞,影响了瓦斯抽采效率。为解决这些问题,设计了开闭式反循环钻头,并对其结构特点和工作原理进行分析。这种钻头结合了全程筛管下放和反循环钻进2种工艺的优势。通过降低对孔壁的二次破坏,提高了钻孔成孔率和成孔深度;通过全孔段下放筛管,防止孔壁垮塌堵塞瓦斯通道,提高了瓦斯抽放孔的利用率。介绍了该新型钻头的结构设计、工作原理和应用情况。     

煤层气制LNG项目回流比对精馏塔理论板数和负荷的影响

利用PRO/II流程模拟软件,对煤层气液化制LNG装置精馏塔的模拟计算。利用简化法,计算最小回流比,分析回流比对理论板数和热负荷的影响。对回流比这一重要参数进行优化计算,从而选出最适宜回流比。     

Electrical and Acoustic Emissions in cement mortar beams subjected to mechanical loading up to fracture

The application of mechanical loading on cement-based materials generates weak electrical currents due to the formation and propagation of microfractures. This paper introduces the simultaneous recording of electrical signal emissions know as Pressure Stimulated Currents (PSCs) and Acoustic Emissions (AEs) detected in cement mortar beams of rectangular cross-section subjected to mechanical loading using the Three Point Bending tests. The rate of the applied load during the experiments was constant up to the fracture of the specimen. The characteristics of the AE and PSC were put in contrast in order to better understand the evolution of the microfracture processes up to fracture. Specifically, the recorded PSC and AE were studied in terms of their time series, cumulative energy along with AE rate and AE interevent times that may provide information about the upcoming specimen fracture. Moreover, non-extensive statistical physics modeling was attempted in terms of studying the Tsallis entropy. Specifically, the entropic index q was calculated and its dependence on the applied mechanical load was investigated.     

基于ABAQUS的双功能高压水表有限元分析

该文针对目前双功能高压水表在使用过程中出现的裂纹问题,提出了几种改进方案,同时利用Inventor进行三维建模,导入有限元分析软件ABAQUS进行分析,从而得到在不同改进方案下高压水表的应力、应变情况,为高压水表的进一步改进提供了很好的参考依据。     

Fracture toughness of Al2O3 fibers with an artificial notch introduced by a focused-ion-beam

The present work was carried out to estimate the fracture toughness of two types of Al₂O₃ fibers (85Al₂O₃–15SiO₂, Altex^® (Sumitomo Chemical Co., Ltd) and α-Al₂O_3, Almax^® (Mitsui Mining Co., Ltd)) and to elucidate the transition from the intrinsic defects-induced fracture to introduced notch-induced one. With an application of the focused-ion (Ga⁺)-beam micromachining method, a mode I type straight-fronted edge notch with a notch-tip radius around 25 nm was introduced in fiber specimen. The fracture toughness K_Ic was estimated for each fiber specimen based on the fracture mechanical approach in which the measured values of notch depth, fiber diameter, fracture strength and calculated correction factor were substituted. The fracture toughness values of the 85Al₂O₃–15SiO₂ and α-Al₂O₃ fibers were estimated to be 1.86 ± 0.24 and 2.05 ± 0.13 MPa m^1/2, respectively. The fracture toughness value was almost independent of the fiber diameter and notch depth in both fibers tested. From the obtained fracture toughness value and the measured fracture strength of the original fiber, the notch depth at the transition from intrinsic defects-induced fracture to notch-induced one, corresponding to the equivalent size of the intrinsic defects that determines the strength of the original fiber, were estimated to be 0.3 and 0.8 μm for 85Al₂O₃–15SiO₂ and α-Al₂O₃ fibers, respectively.     

轴心受压方钢管-钢骨混凝土组合长柱力学性能的非线性有限元分析

基于钢管-钢骨高强度混凝土轴压组合长柱轴压试验,利用大型有限元软件ANSYS建立三维有限元数值分析模型,并对建立的模型进行非线性有限元数值模拟,分析方钢管-钢骨高强度混凝土组合长柱在轴心压力作用下的力学性能。有限元计算出来的荷载-轴向应变曲线、极限承载力和延性系数与试验结果吻合较好,证明所建立三维有限元模型和分析结果是可靠有效的;在此基础上,利用有限元模拟对若干影响组合长柱受力性能的因素进行了分析。研究表明:组合长柱截面含骨率与混凝土轴心抗压强度对方钢管-高强度混凝土组合长柱的荷载-轴向应变曲线、极限承载力和延性系数有重要影响;随着方钢管厚宽比的增大,方钢管-高强度混凝土组合长柱的屈服承载力和极限承载力均有明显的增加。     

联动型ZYW-2000矿用全液压钻机重型泵站的研制

针对联动型ZYW-2000矿用全液压钻机泵站串泵工作时,小泵易损坏、维修不便等问题。提出了大小泵分开独立工作的设计理念,并改进大小泵的连接方式,研制出联动型ZYW-2000矿用全液压钻机重型泵站。     

基于大数据思维的瓦斯地质分析方法

初步建立全国范围的瓦斯地质相关信息的大数据库,包含10类信息表格,每类表格包括6-9种信息。以预测贵州省水城矿区大河边向斜全区域瓦斯含量为例,通过对瓦斯含量预测相关的所有可能数据,比如瓦斯含量、瓦斯压力、瓦斯涌出量、构造复杂程度、煤层透气性、甚至机电设备等相关性信息进行类比分析,选取最优化的模型,结果表明大数据思维为瓦斯地质分析方法提供新的可行性思路。     

联动型ZYW-2000煤矿用全液压钻机的研制

为了提高钻孔效率,降低工人劳动强度,研制了联动型煤矿用全液压钻机。详细阐述了联动型ZYW-2000煤矿用全液压钻机总体方案、主要结构和液压系统的设计,并介绍了钻机的试验及应用推广情况,试验结果表明各项技术指标达到了设计要求。     

ZZ2-8/100型矿用全液压钻装机的设计研究

根据煤矿小断面岩巷掘进的特点,介绍了矿用履带式全液压钻装机的主要工作结构和原理,通过结构设计与机构分析,验证了钻装机结构设计的可靠性,提高了煤矿生产率。