介绍一种测温方法

在热处理生产中,温度是保证产品热处理质量的关键参数。目前,对炉温的监测大多仍采用图1方式进行,即将测温元件插入加热炉有效工作区内,通过导线与指示调节仪表联接形成一套测温计量装置。每次开炉前,由专职仪表人员用标准测温元件、直流电位差计进行炉前校温,符合要求后正式投入使用。生产过程中仪表自动记录加热温度曲线,以便实施追踪管理。测温元件、指示调节仪表、直流电位差计等计     

可倾瓦轴承温度监测方法研究

可倾瓦轴承是高参数旋转机械的关键零部件之一,轴承瓦块温度超标可能诱发机组间断停机或失效,有必要对瓦温实时监测并给出补救措施。通过对可倾瓦轴承瓦块温度、油膜压力及最小油膜厚度等的分布规律研究,提出一种多点关联测温方法。该方法由特征点协同测温和特殊点独立测温2种方案构成。针对某机组可倾瓦轴承,利用上述测温方法获得试验轴承温度实时测试数据。试验结果表明,轴承主承载瓦温度随转速升高而升高,最高瓦温出现在近出油边;副承载瓦温度随转速变化趋势与主承载瓦一致;瓦块温度在撤掉顶轴油前后有明显突变,说明瓦块温度与静压、动压效应关系密切。试验验证了该测温方法的可行性,为滑动轴承温度超标防治提供了技术手段。     

滚动轴承内圈温度无线监测技术

温度是反映滚动轴承运行状态的重要指标之一,高速运行中轴承旋转套圈的温度远高于静止套圈温度,实现轴承旋转套圈（通常为内圈）的实时温升监测对保证运行安全尤为重要。基于电气和机械设计技术的协同,提出一种滚动轴承内圈温度无线监测方案,将测试系统嵌入轴承锁紧螺母中,利用锁紧螺母与轴承接触配合实现对轴承内圈温度采集。设计研究集成温度测试、无线数据传输及无线电能供给电路。重点实现电能无线供给以满足轴承旋转套圈温度持续监测的电能需求。最后通过对32008圆锥滚子轴承温度采集,验证该方案的可行性。该方法在保障轴承完整性的条件下能实现轴承旋转套圈温度的监测,为轴承状态监测和热特性试验研究提供了新的技术手段,解决了实际工况下轴承旋转套圈测温难题。     

齿轮箱的温度监控

随着对齿轮箱运行要求的提高,对于轴承、润滑油和驱动电动机的温度监测与控制,日益为人们所重视。现代测量技术和微机技术的发展,给我们提供了各种各样的温度监测元件和控制手段。但根据被监控对象的实际情况,合理地选用监测元件和控制方案,则是设计人员面临的课题。     

非接触式红外测温技术在点检系统中的应用

红外测温技术的发展有助于对运动目标和微小目标实施快速、准确、无损的测温。根据机械设备在运行过程中出现的热效应现象，监测人员在日常的巡视过程中可通过数采器中的红外测温装置收集设备的温度信息后，上传至点检系统进行分析，以提高对设备的在线检测、诊断的技术水平，确保设备的安全、高效运行。     

提高铂热电阻温度测量精度的方法及其在水电站的应用

铂热电阻是_低温测量中应用最为广泛的一种工业测温元件.介绍了铂热电阻测量温度的原理和提高测量精度的方法,以及铂热电阻三线制接法在水电站机组温度监测系统中的应用.     

基于涡流传感器的柴油机主轴承磨损检测装置设计

为了能够实时监测柴油机主轴承磨损的情况,提出了通过涡流传感器eddy NCDT300在一定范围内测量活塞上下运动距离是否有波动和温度传感器PT100测量轴瓦温度相结合的方案。设计的柴油机主轴承磨损监测装置以STM32单片机为核心芯片。涡流传感器实时监测活塞运动位置,并通过信号的处理电路和A/D转化芯片AD7606将数据传输到处理器。与此同时,温度传感器PT100检测柴油机轴瓦温度。测试和记录了柴油机在运行时活塞实时位置和不同负载下轴瓦实时温度。测试结果表明,设计的装置能够稳定、准确检测柴油机主轴承磨损的情况,性价比高。     

基于无源无线传感技术的电力电缆测温装置

温度是电缆运行状态的关键参数,对电缆温度进行实时监测可有效防止事故发生,保障电力系统安全稳定运行。采用超高频RFID温度传感芯片研制一种基于无源无线传感技术的电力电缆测温装置,装置由基底、天线、RFID无源测温模块、固定基板及加固模块构成,将装置嵌入电力电缆内部来实现电缆测温。该装置的标签天线在920 MHz工作频率下在金属表面可表现其优良性能,并且具有低剖面、小尺寸、低成本的优势。该电缆测温装置能够长期、安全、有效监测电力电缆的温度变化,避免因电力电缆温度过高引发的安全隐患,为电力系统的安全运行提供技术保障。     

干式变压器的测温元件选用和正确放置方式

分析了在干式变压器中采用机械式温包进行温度测量和控制的种种弊端,探讨干式变压器测温元件应采用的布置方式,指出在干式变压器中选用温包式机械测温装置的不合理性。     

基于核主元分析和支持向量机的火电厂炉膛温度的研究

以华能嘉祥电厂330 MW机组为例,根据火电厂的工艺流程分析选取辅助变量以及利用LSSVM建立炉膛温度软测量模型等问题,与上海新华、山东鲁能DCS充分结合,建立炉温软测量系统。现场实测数据表明,该系统在不增加装置设备投资成本的前提下,运用该软监测效果良好,不仅避免了在测温元件损坏时对生产的影响,还为屏式过热器入口温度的预测及受热面的安全性提供了条件,为后续的燃烧优化工作奠定基础。     

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.     

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....     

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.