CAP1400蒸汽发生器关键制造技术

根据第三代非能动压水堆(CAP1400)水堆核电蒸汽发生器制造过程中积累的经验并结合其他压水堆型核电蒸汽发生器的制造经验,介绍了CAP1400蒸汽发生器的结构特点,并分别对制造过程中的一些关键制造技术,如管板一次侧镍基堆焊、管板深孔钻、内套筒的装配、管束穿管、液压胀管和水室封头焊接等进行详细的阐述,为后续压水堆型核电蒸汽发生器的制造提供经验参考。     

蒸汽发生器穿管及抗震条的装配和检测

介绍了欧洲第三代先进压水堆型(EPR)核电蒸汽发生器穿管及抗震条的装配和检测方法,对比了以往工艺方案的优缺点,对逐层穿管和安装抗震条的方法,通过工艺装备保证U形管和抗震条的间隙,以及抗震条的定位和测量等进行了详细的阐述,为后续ACP1000等压水堆型核电蒸汽发生器的制造和质量控制提供经验参考。     

蒸汽发生器管板一次侧大面积往焊新技术

压水堆核电厂一回路核岛主要设备蒸汽发生器管板一次侧表面为保证一定的耐蚀需大面积堆焊镍基合金,且要求较高的堆焊质量。管板堆焊是蒸汽发生器整个制造过程中首先要进行的部分,堆焊时间的长短直接影响着后面工序的进行。为了保证堆焊层质量,缩短堆焊时间,必须选择堆焊效率较高且堆焊质量稳定的工艺。     

核电蒸汽发生器管板液压胀接压痕问题的分析

液压胀接技术是核电蒸汽发生器管子和管板接头采用的关键制造工艺。介绍了液压胀接的原理,针对核电蒸汽发生器管板液压胀接后传热管内壁产生的压痕问题,进行了原因分析,并结合工程经验制订了改进措施,包括改进胀管器,改进胀接止环,对支撑圈使用控制,进行胀接过程控制。     

蒸汽发生器管板疲劳分析中若干影响因素的分析

蒸汽发生器是压水堆核电厂的关键核设备,研究核安全级设备的疲劳特性是保障核电安全的关键所在。蒸汽发生器的管板为排布有密集深孔的大型锻件,其制造难度高,生产周期长。在设备运行期间经历复杂而全面的载荷,针对蒸汽发生器管板,根据ASME BPV Code III-1-NB要求和规定,进行疲劳分析的多种对比计算。以考察管板组合体应力分布对瞬态条件、材料不连续、孔板应力修正方法和孔桥超差的敏感性,最终确定合理的分析方法,为今后蒸汽发生器结构应力分析提供方法参考,而且更重要的,为处理管板制造过程中经常发生的孔桥超差不符合项提供评定的数据依据和计算的方法。     

1000MW核电蒸汽发生器管子管板焊接

管子管板焊接是核电站一回路主设备蒸汽发生器制造过程中的关键工序,管子管板焊接质量直接影响着蒸汽发生器的使用寿命和制造进度。分别对二代改进型压水堆和三代压水堆1000MW蒸汽发生器管子管板焊接工艺进行介绍,比较了RCC-M规范和ASME规范对管子管板焊接要求的异同,针对焊接过程中出现的问题,分析了缺陷产生的根本原因,对焊接参数重新进行优化,同时加强了焊接过程控制,得到了质量稳定、焊缝形状和尺寸均满足设计要求的焊接接头。     

核电设备中的Inconel 690镍基合金热丝TIG堆焊技术

正1.概述第三代核电EPR堆型电功率约为1 600MW,每个机组由4个环路组成,每个环路有一台蒸汽发生器。蒸汽发生器型号为77/19TE,传热面积为7 960m2。蒸汽发生器是核电站一回路主设备之一,起着隔离一回路和二回路的作用。由于蒸汽发生器管板一回路侧长期接触带有放射性和腐蚀性的载热剂介质,其表面需堆焊一定厚度的镍基合金,以保证一定的耐蚀性。由于EPR管板直径大,厚度较厚,堆焊要求较高,工艺控制要求高,同时Inconel 690材料焊接性差,对氧化、DDC敏感,所以选择堆焊质量要求高的方式     

EPR蒸汽发生器最终环缝坡口机加工和总装技术研究

着重介绍了三代核电EPR项目核岛主设备蒸汽发生器(SG)的最终环缝坡口机加和蒸汽发生器总装技术,通过EPR项目最终环缝坡口机加和蒸汽发生器总装技术的实践和研究,总结出了更为合理、高效工艺路线,更好的实现产品的技术要求,降低制造成本,同时对后续更大型的核电主设备制造提供更好的技术支持。     

AP1000与CPR1000核电蒸发器吊装技术对比分析

AP1000是二环路的百万千瓦级压水堆三代核电堆型,采用非能动安全设施。与传统的三环路CPR1000压水堆核电技术相比,蒸汽发生器本体特征和核岛内的就位要求均有较大的改进性变化。根据AP1000及CPR1000蒸汽发生器SG自身吊装特点,并在实践的基础上,对两种堆型核电机组的蒸发器吊装技术进行对比、分析、总结,为后续中国核电蒸发器设计、施工提供经验。     

核电蒸汽发生器胀接接头质量事故分析及应对措施研究

全深度液压胀接技术是核电机组蒸汽发生器及其他换热器管子-管板接头普遍采用的制造工艺,具有液压胀接压力均匀、管壁减薄均匀、管子和管板的残余应力小、接头质量稳定等优点。液压胀管时需将300兆帕水介质封闭在胀管区域,一旦密封失效,将直接影响接头质量,胀接过程中易出现未胀合缝隙长度过大(欠胀)、过胀、肿胀、漏胀、重复胀接以及造成换热管划痕等质量问题。对国内外蒸汽发生器制造厂出现的典型胀接缺陷归类并进行原因分析,结合工程经验获得良好经验反馈及应对纠正措施,为核电蒸汽发生器管子管板接头胀接工序提供指导。     

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.     

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.