Sh型离心水泵轴封泄漏的改进

本文分析了Ｓｈ型水泵填料密封结构在使用中泄漏的原因，并提出了改进与延长轴封寿命的办法。     

高粘度匀浆泵轴封的研制

分析了进口高粘度匀浆泵轴封寿命短的原因。设计一种刃口型密封端面的机械密封,代替原泵轴封采用的橡胶油封。使用结果表明,采用该新型机械密封,轴封处密封效果良好,轴封寿命延长。     

蜂窝轴封泄漏特性研究

根据某型汽轮机迷宫轴封的泄漏特性进行了蜂窝轴封的改进设计,以及蜂窝轴封的泄漏特性和影响因素的研究。介绍了透平机械密封技术的研究进展。根据汽轮机迷宫轴封的结构特点,对高低齿迷宫密封的短齿部分改进设计成蜂窝结构,将传统的迷宫轴封设计成蜂窝轴封,并采用数值方法研究改进的蜂窝轴封泄漏特性。数值分析了传统迷宫轴封的泄漏特性。比较了不同间隙、不同芯格尺寸的蜂窝密封的泄漏特性,得出了最佳蜂窝密封尺寸。蜂窝轴封的最佳设计方案是径向间隙0.50mm,蜂窝芯格直径是2.75mm。     

无轴封主泵转动部件运行工况分析

根据系统设计和安全要求,第三代核电选用无轴封主泵,其转动部件与轴封型主泵的转动部件结构差异较大。鉴于转动部件运行工况直接影响主泵性能和寿命,根据相关试验和分析,归纳了影响三代核电无轴封主泵转动部件运行状况的重要因素并就其影响进行讨论。     

B6-3.43/0.981型背压汽轮机轴封漏汽的治理

对B6-3.43/0.981型背压式汽轮机轴封蒸汽泄漏的原因和造成的危害进行了分析,通过合理调整轴封间隙和改进轴封加热系统等措施,消除了轴封漏气现象,使机组获得了良好的运行效果.     

廉价的轴承轴封装置

<正> 图示的轴承轴封装置,可供给转子流量计轴承高于被测液体压力的润滑油,还可防止固体粉末等混入轴承。以往,轴承轴封装置有油封、机械油封。但前者效果不佳,后者则价格昂贵。本轴承轴封装置,克服了以往轴承轴封装置的缺点,具有价格低廉、轴封效果理想的优点。此外,能防止轴承的早期磨损,延长寿命和便于维修保养。     

浅谈轴封型核主泵轴封注入水系统

简单介绍了轴封型核主泵轴封注入水系统,该核主泵为立式、单级、单吸、高转动惯量和四轴承结构形式的轴封泵,轴封采用三级动压型密封加氮气能动停车密封组成。该结构形式主泵拥有大量的工程运行经验,其轴封注入水系统也在工程实践中得到不断完善改进,具有极高的可靠性。     

离心泵轴封的改进

对一种泵的轴封进行改进，新的轴封具有耐磨，可靠性高等特点。     

往复活塞式富气压缩机轴封泄漏原因分析

通过对往复压缩机轴封泄漏原因的分析，采取各种改进措施，有效延长轴封的使用周期。     

串联用末级泵轴封的改进

针对末级泵泄漏严重的问题，通过计算液体泄漏量，分析了轴封泄漏量与各相关参数之间的具体关系，从中找出了解决问题的途径，并对轴封进行了改进。改进后的轴封经实际应用，其效果稳定可靠，达到了预期目的。     

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.