关于静态法流量计检测标准装置的研究

本文中的静态法流量计检测标准装置由液体流量标准装置和标准量器组成,此装置可以进行静态容积法和标准表法的流量计检定。容积法是由精度0.05%标准量器对被检流量计进行检定。标准表法采用精度等级较高的流量计作为标准表,标准流量计的量程范围能够覆盖所有被检流量计的流量点,根据被检流量计不同精度选择不同的检定方法。此装置为不同精度的速度式流量计、容积式流量计、质量流量计等的检定提供实验条件,也为研究新型流量计检定方法提供实验基础。     

用相似理论分析涡轮流量计与旋涡流量计的流量系数

一、前言蜗轮流量计与旋蜗流量计的流量系数随被测介质的物理性质而变化,因而出厂前用水在标准设备上对流量系数标定后,使用单位不得不根据被测介质的物理性质重新标定。这项工作需要标准设备,技术性强,工作繁重,许多用户宁愿降低仪表的使用精度,也不标定流量系数。为了免于重新标定又不降低使用精度,本文用相似论推导出其流量系数表达式,结论是:流量系数仅是雷诺数的函数。使用这一结论建立出流量系数与雷诺数的关系图(表),可供用户选取准确的流量系数,而不必重新标定,从而保证了仪器原有的测量精度。二、涡轮流量计流量系数分析     

智能小流量靶式流量计的研制

小流量、高黏度的介质流量的测量是测量中的难点。靶式流量计测量高黏度介质流量有其独特的优点,但传统的靶式流量计存在机械结构复杂、灵敏度低、小流量时流量系数变化等缺点。介绍了靶式流量传感器的工作原理,对小流量流动流量系数的变化提出了修正方法并研制了智能型小流量测量的靶式流量计。实验结果表明:设计的流量计对高黏度、小流量测量具有较高精度。     

XSG—361型数字流量显示仪

开封仪表厂和北京自动化所合作,研制成功了 XSG-361型数字流量显示仪。该仪表由中大规模专用电路Ⅰ040、Ⅰ041组装而成,与流量变送器配套组成流量计,可积算容积流量的总量;指示容积流量的瞬时值及实现系数器自校。其主要技术性能:积算容     

相似理论与流量系数

0 前言 本文根据相似理论对孔板流量计、浮子流量计、旋涡流量计的流量系数进行了分析推论,这种分析方法也适于分析类似工作原理的其它流量计的流量系数。     

三段流量系数修正算法在涡街流量计非线性修正中的应用

通过对涡街(Vortex)流量计原理和大量试验数据的分析,针对流量计存在的流量系数非线性问题,采用三段流量系数修正算法,将流量函数线性化,使流量系数为一常数.实验表明,该方法减小了指示值与实际流量值之间的误差,将测量的范围比由1:8扩大到1:18,提高了测量精度.     

日本流量仪表的发展动向

详细介绍了日本流量仪表包括差压流量计、电磁流量计、容积式流量计、面积式流量汁、旋涡流量计、超声波流量计及质量流量计的发展动向。     

流量检测仪表 第一讲 流量测量的一般概念

在工业自动化仪表中,流量检测仪表以其种类繁多、影响因素复杂而著称。为普及流量检测仪表知识,为沟通用户和制造厂之间的信息,我们特请本刊编委邵朋诚高级工程师撰写《流量检测仪表专题讲座》。该讲座重点介绍国内普遍使用和即将推广使用的流量检测仪表,计划分12讲: 1.流量测量的一般概念;2.流量测量仪表的分类与选用;3.节流式流量测量装置;4.容积式流量计;5.涡轮流量计;6.电磁流量计;7.漩涡流量计;8.浮子(转子)流量计;9.插入式(分流式)流量测量方法;10.超声波流量计;11.质量流量计;12.流量测量仪表的发展动态。     

简易翻斗式自记流量计的制作及其应用

翻斗式自记流量计从工作原理的角度看,属于容积式流量计的一种,但从应用范围看,又与目前各种形式的容积式流量计均有所不同.目前传统的容积式流量计主要应用于有压管道情况,而翻斗式自记流量计主要应用于各种无压、低水头、小流量的地表和地下径流的监测.针对水文科学中有关无压、低水头、小流量的地表和地下径流的监测手段较为落后的局面,在分析翻斗式自记流量计基本构成、工作原理的基础上,对其制作工艺、误差及主要应用情况进行了阐述,旨在能够提高我国水文监测的水平.     

基于容积法的翻斗式自记流量计的制作工艺及应用

翻斗式自记流量计从工作原理的角度看,属于容积式流量计的一种,但从应用范围看,又与目前各种形式的容积式流量计均有所不同。目前传统的容积式流量计主要应用于有压管道情况,而翻斗式自记流量计主要应用于各种无压、低水头、小流量的地表和地下径流的监测。本文针对水文科学中有关无压、低水头、小流量的地表和地下径流的监测手段较为落后的局面,在分析翻斗式自记流量计基本构成、工作原理及可应用领域的基础上,重点对其制作工艺和应注意的问题进行了详细介绍与说明,旨意能够起到抛砖引玉的作用,提高我国水文监测的水平。     

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.