小流量高压比组装式离心压缩机的研制

通过理论分析和数值模拟研究方法,对组装式离心压缩机级条件下的内部流动和流动机理进行研究,通过对流动结构的分析,进行了离心式压缩机通流部件的设计。论文研究对离心式压缩机性能的提升和设计具有很好的理论和工程应用参考价值。同时对组装式离心压缩机转子进行了临界转速分析,并对整机的装置结构进行了规划。研究的对象是SVK16-5S组装式离心压缩机结构为五段、五级,每级由叶轮、扩压器和蜗壳等组成。其中前四级采用高效后弯的三元半开叶轮,第五级叶轮为闭式叶轮。     

高压轴流压缩机的加减级设计及模化设计

结合两个实例的模化设计计算，详细讨论了在具有性能好、压比高多级的轴流压缩机作为样机，并掌握和详细计算其气动参数各级分布的前提下，采用加减级设计及模化设计开发新型轴流压缩机，具有周期短、设计结果可靠，叶片尺寸和产品部件便于系列化、工艺简化和方便质量管理等优点。     

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     

新型轴流压缩机的开发研究

综合分析了国内外几种典型的轴流压缩机的特点，初步研究了轴流级＋斜流级＋离心级复合式压缩机的设计。这种新型压缩机拓宽了轴流压缩机的应用范围，机体尺寸缩小，耗功减少，产品制造成本降低。     

组装式离心压缩机的特点及发展趋势

介绍了组装式离心压缩机的主要结构特点，根据这些特点分析了组装式离心压缩机所具有的技术优势。论述了这种压缩机设计、制造中的关键技术。预测了我国组装式离心压缩机的发展趋势。     

往复式压缩机可靠性参数化设计方法研究

为快速响应市场需求,以大型往复式压缩机关键零部件的设计选型问题为研究对象,基于可靠性理论和计算机三维建模技术,开发设计了往复式压缩机关键部件参数化设计平台,可以快速、准确得出设计所需的各项技术参数和各种分析曲线,快速构造产品模型,实现数字化设计和装配,并以实例研究分析了参数化选型设计对压缩机局部结构优化的作用,验证了优化后结构的合理性。对此类机械产品借助可靠性分析、参数化设计可提高设计质量和效率,从而提高产品的市场竞争力具有现实意义。     

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。     

单轴压缩机推力轴承在组装式压缩机中的应用

介绍了单轴压缩机推力轴承形式应用在组装式压缩机中的结构特点,通过分析SVK1-1H产品,解决了原结构高速转子工作转速超二阶临界转速,转子挠性大的问题,提高了机组的运行稳定性。     

整体齿轮组装式离心压缩机设计

介绍了组装式离心压缩机的市场和发展现状,论述了SVK12—4H组装式离心压缩机所具有的技术优势、结构特点及压缩机的设计、制造中的关键技术,从现场运转的结果证明重要技术和各项措施的应用有效,研制成功。     

串列叶栅后焊接排气蜗壳改进设计

对组装式离心压缩机某模型级的实验装置进行了数值模拟。通过对模型级原结构及流场的分析,进行了多种焊接型式排气蜗壳方案的改进设计,并通过对比分析,得到比较理想的焊接排气蜗壳设计方案,实现级效率提高约4%。     

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.     

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....     

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。     

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.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.