低压配电BZT系统在东深供水工程泵站的应用

阐述要确保供水系统正常供水,如何提高站用电的可靠性是关键之一。本文介绍第四期改造后的东深供水工程泵站自投产以来,低压配电BZT系统运行可靠,可供重要负荷运行参考。     

大型混流泵液压调节机构故障分析及处理

介绍了东深供水工程旗岭和金湖泵站大型混流泵液压调节机构运行中出现的故障分析及处理情况。     

节能型自由侧翻式拍门在泵站改造中的应用

介绍了节能型自由侧翻式拍门的特点和工作原理,以及在东深供水工程上埔泵站拍门改造中的应用.     

东深工程两种大型泵结构与调节机构比较

介绍东深供水改造工程莲湖和旗岭泵站液压全调节抽芯式混流泵及叶片调节机构的特点及应用。     

风电机组齿轮箱油液监测典型案例分析

作为风电机组传动链中的核心部件,齿轮箱对整机的安全、高效运行起着至关重要的作用,而油液监测技术的引入,则为风电齿轮箱的状态监测和故障预警提供了一项有效的技术手段。通过对风电场润滑管理各环节中典型案例的分析,介绍油液监测技术在新油验收、油品更换、机组出质保验收、设备运行状态跟踪、油品按质换油方面的重要作用。     

大型立式抽芯式混流泵的故障原因分析

本文介绍了大型立式抽芯式混流泵在东深供水工程中的运行情况,重点分析了运行中出现的故障原因,并提出处理措施,为同类型水泵的运行管理提供参考。     

文丘里管流量计在东深工程供水计量中的应用

本文简要比较了几种常用流量计的性能,分析了东深工程沿线供水计量中选用文丘里流量计的原因及应用特点,介绍了文丘里管流量计水实流标定系统组成、标定过程和有关数据的处理。     

基于目标电耗的城镇供水泵机组节能技术的研究及应用

针对供水输送系统由于水泵选型不当、工况调节不合理、能耗评估困难等原因造成运行效率低、能耗浪费严重的问题,以某城镇供水泵站为研究对象,通过分析供水系统设备安装情况和生产周期内泵的运行工况,以能耗系数为评估指标,建立一套通过检测管网关键运行工况点,绘制泵的实际运行外特性曲线,来分析泵机组能耗原因,比较改造前后系统总KE—Q方程,得出系统节能空间的方法。实际改造方案以"大小泵阶梯搭配"和"同型号泵+一泵变频"两方案进行节能空间与改造投资成本分析,确定"大小泵阶梯搭配"组合运行为最佳改造方案。改造后测试结果表明,供水泵机组月节电12850 kW·h,系统节电率19.58%,为其它城镇供水泵站节能改造提供借鉴。     

泵站运行管理的问题和规范化管理浅谈

泵站作为我国水利工程的重要部分,承担着供水、抗旱、除涝、防汛等多项任务。由于在泵站运行管理中存在一些问题,导致泵站的功能作用无法得到充分发挥,需准确了解泵站运行管理中的问题,对其进行规范化管理,为泵站提供更加稳定的运行环境。鉴于此,本文针对泵站运行管理中存在的问题进行深入分析,并根据实际情况提出一些具体的管理方法。     

能耗最小法确定泵站经济运行方案

根据供水泵站的运行情况，给出了利用能耗最小法确定机组间最优流量分配、机组优化组合的数学模型及求解方法。     

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.