单拐曲轴参数化建模及模态分析

为了缩短L型往复压缩机产品的设计周期,节约设计成本,以Pro/E三维设计软件为基础,以炼化企业应用广泛的5L往复式压缩机曲轴为模型,进行L型压缩机曲轴三维参数化建模。根据压缩机热力学和动力学分析,对设计出的2.5L型往复式压缩机曲轴各危险截面进行静强度校核,并将其导入Workbench进行模态分析。分析结果表明,和曲轴的传统设计方法相比,该3D参数化设计结果可靠且极大减少了不同规格L型往复式压缩机曲轴的设计周期和设计成本,在实际压缩机设计生产中有很好的应用前景。     

以可靠性为核心的往复式压缩机维修方法浅析

往复式压缩机是容积式的压缩机,它能使一定容积的气体按照顺序吸进或排出一个封闭的空间,以提高静压力。往复式压缩机具有热效率高、造价低廉、设计成熟、应用范围广等优点,但也存在结构复杂、转速受限多、使用效率下降快以及噪声大等缺点。往复式压缩机的失效原理包括基于故障树的可靠性分析、关键零部件风险分析以及失效零件的机理分析,预防性维修的周期优化包括分布模型的确定、威布尔分布参数的确定以及可靠性结果的分析。     

往复式压缩机网状阀优化设计

基于往复式压缩机网状阀工作机理，介绍了往复式压缩机网状阀的优化设计方法，包括网状阀一些基本结构参数的合理选择、网状阔气流通道的优化设计、网状阀弹簧力的优化设计。     

涡旋压缩机参数化绘图

采用参数化技术进行相似产品的设计是提高设计效率的重要途径，本文针对涡旋压缩机的基本结构，阐述了涡旋压缩机的参数化设计过程和尺寸间的约束关系，并以动涡旋盘为例，分析了涡旋压缩机的零件尺寸与驱动尺寸间的关系，为涡旋压缩机的参数化设计奠定了基础     

大型高压往复式压缩机在石化领域的应用发展研究

针对国内外对活塞力≥1250kN的大型高压往复式压缩机产品的需求现状,结合多年来对国外发达国家关于大型高压往复式压缩机产品及技术的分析研究和应用研究,通过对大型往复式压缩机产品及技术在国内石化领域的应用状况分析,对在国内石化领域引进大型往复式压缩机产品、技术及国产化进行了分析论证,并在此基础上进行了归纳总结,为大型高压往复式压缩机产品及技术在国内石化领域有效使用及其国产化、设备采购、维护及管理工作等方面提供参考和借鉴。     

往复压缩机智能诊断专家系统的研究与应用

往复式压缩机是流程工业安全生产的关键机组,由于缺乏有效的安全监控和故障预知手段,往复式压缩机存在故障率高、安全事故频发的特点。为有效降低往复式压缩机故障停机时间并减少安全事故,在对压缩机运动部件结构、功能和故障机理分析的基础上,针对往复式压缩机振动激励源多和故障关联性强的特点,开发了基于多传感器信息融合和正向推理的往复式压缩机智能诊断专家系统,通过提取敏感特征参数并建立和故障类型相关的独立诊断规则,实现了自动故障诊断。建立的往复式压缩机智能诊断专家系统已应用于国内多家石油炼化企业。实践证明:往复式压缩机智能诊断专家系统在机组异常时能够自动报警并给出故障诊断结论,提高了设备预知维修水平,保证了往复式压缩机运行的安全性、可靠性。     

压缩机气缸可靠性分析与参数化设计方法

为提高气体压缩设备的设计水平,基于VC＋＋和Pro/E软件,开发了压缩机气缸的可靠性分析与参数化设计CAD系统.结果表明,结合可靠性理论与参数化技术的压缩机气缸CAD系统,有助于提高压力容器产品设计的可靠性与效率.     

往复式压缩机热力计算的程序研究

热力计算是往复式压缩机的基础，通过对传统计算方法的改进，编制了热力计算程序，成功简化了往复式压缩机的常规热力学计算、复算性计算和动力学计算过程，提高了计算参数的准确性和可靠性。     

涂装车间空气压缩机设计选型简介

本文根据汽车涂装车间压缩空气系统的需求,介绍了往复式压缩机与回转式压缩机基本特点,以及螺杆式空压机设计选型方法,以期为涂装车间压缩机设计选型提供参考。     

基于Workbench的往复式液压隔膜泵曲轴可靠性研究

曲轴是往复式液压隔膜泵动力端受力最复杂的零件,研究其可靠性对往复式液压隔膜安全工作具有非常重要的意义。通过Pro/E三维软件建立了隔膜泵的三维实体模型,运用有限元分析软件ANSYS Workbench对曲轴的应力和变形进行了校核。研究结果表明,该曲轴设计满足工作要求,可对大功率的三缸单作用往复式液压隔膜曲轴的结构分析和结构参数优化提供参考。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.