Stiffness analysis of new spacer grid model for metal 3D additive manufacturing

Currently, the Republic of Korea operates a total of 28 nuclear power plants, including those under construction. Although every part of a nuclear power plant is important for safe operation, most attention is paid to the nuclear fuel assembly. The assembly is divided into fuel rods containing fuel assembly fuel and spacer grids. The spacer grid is an important component for core cooling by keeping the fuel rods protected and spaced apart. The spacer grid is produced from a strap bar, which is the base plate, and by spot welding eight edges of the strap bar. However, the spot welding machine has a large capacity and power supply such that the welding quality varies depending on the weld metal and surface conditions. As a result, the welding point may be defective. Therefore, this study aims to analytically verify the performance of a newly designed spacer grid for metal 3D AM as well as present analytical criteria for product development.

     

核电失效数据库的发展现状

受日本福岛核事故影响,我国的核电政策由积极发展改为谨慎前行,国家核安全监管部门对运行和在建核电厂开展了核安全检查,对核电站设备的安全可靠性提出了更高的要求.论文介绍了我国核电发展现状及规划、核电工程数据库的发展、核电失效案例库的发展、数据库中数据的分析及有效利用以及核电工程数据库存在的问题.     

Operation algorithm for a parallel hybrid electric vehicle with a relatively small electric motor

In this paper, operation algorithms for a parallel HEV equipped with a relatively small motor are investigated. For the HEV, the power assist and the equivalent fuel algorithms are proposed. In the power assist algorithm, an electric motor is used to assist the engine which provides the primary power source. In the equivalent fuel algorithm, the electric energy stored in the battery is considered to be an equivalent fuel, and an equivalent brake specific fuel consumption for the electric energy is proposed. From the equivalent fuel algorithm, distribution of the engine power and the motor power is determined to minimize the fuel consumption for a given battery state of charge (SOC) and a required vehicle power. It is found from the simulation results that the fuel economy and the final battery SOC depend on the motor discharge energy and it is the best way to charge the battery only by the regenerative braking, not by the engine to improve the overall fuel efficiency of the HEV with the relatively small motor.     

基于MATLAB的汽车整车性能分析的可视化研究

分析了影响汽车性能的因素,并利用MATLAB语言开发了仿真程序。以某一车型为例进行仿真,根据发动机的外特性、汽车的加速度曲线及时间图和汽车动力特性图,得到汽车整车的动力特性和燃油经济性等参数,与实际结果吻合较好。利用仿真不仅可以快速精确地获得汽车动力性和燃油经济性分析的相应数据和图形,而且将工程技术人员从繁杂的高强度劳动中解脱出来,使其有精力和时间投入到新的工作中。     

挤代加泵抽式能供系统燃料舱增压过程数学模型

根据液压流体力学和工程热力学的基本原理，针对某型热动力鱼雷能供系统，对鱼雷舷外海水通过雷体直接进入燃料舱增压挤代燃料的工作过程进行了分析，建立了燃料舱增压过程的数学模型，并对燃料舱增压过程进行了仿真研究。     

Drop strength of the fuel assembly in a nuclear power plant

The possible structural deformation of the fuel assembly in a nuclear power plant when dropped during transportation or other operations is considered. The consequences of such damage are studied.     

核电厂燃料抓取机桥架驱动机构自主化设计

以核电厂燃料抓取机为例,介绍了其桥架驱动机构的设计要求、结构布置,给出了设计计算过程。该部件的自主化设计方法能够推广用于核电厂其他设备的驱动机构设计,有益于提升我国核电厂装换料设备的自主化研发能力。     

基于VB语言的汽车燃油经济性分析的可视化研究

建立了汽车燃油经济性分析的数学模型,利用VisualBasic语言开发了仿真程序。以某一车型为例进行仿真,根据发动机的外特性、汽车的功率平衡和发动机的负荷特性,得到汽车整车的等速百公里油耗和六工况循环油耗等参数,与实际结果吻合较好。仿真结果不仅可以快速精确地获得汽车燃油经济性分析的相应数据和图形,而且使工程技术人员从繁杂的高强度劳动中解脱出来,使其有精力和时间投入到新的工作中。     

雷达液位计在乏燃料水池监测中的应用

尽管工业领域已使用的液位计的类型较多,但根据已运行核电站乏燃料水池的特殊情况,能适用于的液位测量类型很少。本文详细介绍了非接触式液位计尤其是雷达液位计的测量原理,通过研究相关技术,提出适用的改进及安装措施,保证雷达液位计在环境工况下的可靠性应用,以推动雷达液位测量仪表在核电站特殊场所中的使用。     

Intelligent vehicle electrical power supply system with central coordinated protection

The current research of vehicle electrical power supply system mainly focuses on electric vehicles (EV) and hybrid electric vehicles (HEV). The vehicle electrical power supply system used in traditional fuel vehicles is rather simple and imperfect;electrical/electronic devices (EEDs) applied in vehicles are usually directly connected with the vehicle’s battery. With increasing numbers of EEDs being applied in traditional fuel vehicles, vehicle electrical power supply systems should be optimized and improved so that they can work more safely and more effectively. In this paper, a new vehicle electrical power supply system for traditional fuel vehicles, which accounts for all electrical/electronic devices and complex work conditions, is proposed based on a smart electrical/electronic device (SEED) system. Working as an independent intelligent electrical power supply network, the proposed system is isolated from the electrical control module and communication network, and access to the vehicle system is made through a bus interface. This results in a clean controller power supply with no electromagnetic interference. A new practical battery state of charge (SoC) estimation method is also proposed to achieve more accurate SoC estimation for lead-acid batteries in traditional fuel vehicles so that the intelligent power system can monitor the status of the battery for an over-current state in each power channel. Optimized protection methods are also used to ensure power supply safety. Experiments and tests on a traditional fuel vehicle are performed, and the results reveal that the battery SoC is calculated quickly and sufficiently accurately for battery over-discharge protection. Over-current protection is achieved, and the entire vehicle’s power utilization is optimized. For traditional fuel vehicles, the proposed vehicle electrical power supply system is comprehensive and has a unified system architecture, enhancing system reliability and security.     

21世纪初中国重大工程建设中的若干机械强度问题

就与结构安全性可靠性有关的近期重大建设工程和近二十年来国内外发生的由于结构强度和振动问题引发的重大事故进行综述。提出重大建设工程中的若干机械强度与振动问题。这些工程项目是喷气式民航飞机、长寿命高可靠性通信卫星、100万千瓦核电站、提速铁路、磁悬浮铁路、西气东输工程和巨型水电站。最后讨论应予考虑的几个问题。     

核电厂DCS系统相关的人因陷阱识别与优化措施

本文以田湾核电厂5号机组调试过程为依据,从人机接口设计方面分析调试期间数字化仪控系统(DCS)存在的典型人因失误陷阱,其中包括现场控制站间通讯信号检索问题、DCS系统信号传递问题、现场控制站工程版本问题、工艺系统流程图画面问题,并提出相应的优化措施。经过整个调试过程的跟踪验证,这些优化措施在避免此类人因陷阱方面起到了很好的效果,可供其他核电厂DCS系统调试参考。     

地面及飞行通用的燃气轮机最佳循环参数简化解及其应用

本文系统地推导出对地面及飞行燃气轮机通用的、各最佳循环参数的定比热循环参数的定比热简化解,包括前所未见的较繁的耗油率最佳压比的解,与压气机及涡轮定等熵效率或定多变效率的两种变比热准确作比较。从而看出：简化解可初估性能随压比变化的趋势及各最佳压比,可作准确解的起步,也可初估各最佳压比及其性能受部件参数及飞行条件影响的趋势;此外,简化解简捷地探求新循环的作用,也值得注意。     

核燃料组件自适应柔性检测装置及其误差补偿方法

定期对核燃料组件变形状态及其表面氧化膜厚度开展高精度检测已成为保障核电站安全运营的重要举措。针对现有核燃料组件检测装置普遍存在的被动自适应性能欠佳、接触与测量柔性不足、检测精度与效率亟待提升等突出问题,通过设计引入基于变异虎克铰的自适应对中机构、融合接触力动态反馈的主/被动柔性检测单元和基于串并混联的高精度检测机构,创新研制出一款集变形与膜厚高精度检测功能于一体的核燃料组件被动自适应柔性检测装置。在此基础上,通过深入分析装置变形与膜厚检测机理,基于构建的串并混联闭环检测回路,融合制定的概率化传感误差协同补偿策略,提出了一种基于参数动态整合的测量误差补偿方法。样机测试实验结果表明研制装置能够自适应对中各向异性随机变形下的核燃料组件,满足检测过程中的柔性接触与柔性测量要求,配合提出的测量误差补偿方法,可实现核燃料组件变形及氧化膜厚度的高精度检测,有效提升了核燃料组件的检测精度、检测效率与检测安全。     

核电站核岛气密门技术研究

大亚湾核电站和岭澳一期核电站使用的特种门都是从法国进口,研究核电站核岛特种门技术并使其产品国产化具有非常重要意义。从岭澳二期核电站起,通过我公司对核电站特种门的研发,已成功应用于岭澳二期核电站,并将在后续的红沿河、宁德、阳江等核电项目工程中实施应用,为中国核电发展做出贡献。     

“华龙一号”安全级DCS工程硬件设计标准化研究

核电厂安全级DCS供货活动中,工程硬件设计、机柜结构设计、机柜集成通常为串行工作关系,工程设计是否标准统一,对后续的机柜结构设计、机柜集成等环节带来一系列的影响。而华龙一号堆型作为后续建设的主要堆型,为了提高设计效率和质量,本文提出一种安全级DCS工程硬件设计标准化的方法,分别从机柜功能标准化、设备选型标准化、机柜布局标准化、设备命名标准化及图纸输出标准化等不同维度进行标准化设计。该方法优化了设计流程及设计方法,不仅可以提升各环节效率,缩短项目工期,还可以提高安全级DCS的质量,保证核电及公众的安全。     

Critical velocity of fluidelastic vibration in a nuclear fuel bundle

In the core of the nuclear power plant of PWR, several cases of fuel failure by unknown causes have been experienced for various fuel types. From the common features of the failure pattern, failure lead time, flow conditions, and flow induced vibration characteristics in nuclear fuel bundles, it is deduced that the fretting wear failure of the fuel rod at the spacer grid position is due to the fluidelastic vibration. In the past, fluidelastic vibration was simulated by quasi-static semi-analytical model, so called the static model, which could not account for the interaction between the rods within a bundle. To overcome this defect and to provide for more flexibilities applicable to the fuel bundle, Tanaka’s unsteady model was modified to accomodate the geometrical differences and governing parameter changes during the operations such as the number of rods, pitch to diameter ratio (P/D), spring force, damping coefficient, etc. The critical velocity was calculated by solving the governing equations with the MATLAB code. A comparison between the estimated critical velocity and the test result shows a good agreement. Finally, the level of decrease of the critical velocity due to the reduction in the spring force and reduced damping coefficient due to the radiation exposure is also estimated.     

Structural analysis for the determination of design variables of spent nuclear fuel disposal canister

This paper presents the results of a structural analysis to determine design variables such as the inner basket array type, and thicknesses of the outer shell, and the lid and bottom of a spent nuclear fuel disposal canister. The canister construction type introduced here is a solid structure with a cast iron insert and a corrosion resistant overpack, which is designed for the spent nuclear fuel disposal in a deep repository in the crystalline bedrock, entailing an evenly distributed load of hydrostatic pressure from the ground water and high swelling pressure from the bentonite buffer. Hence, the canister must be designed to withstand these high pressure loads. Many design variables may affect the structural strength of the canister. In this study, among those variables, the array type of inner baskets and thicknesses of outer shell and lid and bottom are attempted to be determined through a linear structural analysis. Canister types studied here are one for the pressurized water reactor (PWR) fuel and another for the Canadian deuterium and uranium reactor (CANDU) fuel.     

基于摄影测量的乏燃料组件池边检查系统设计

乏燃料组件池边检查是核电站燃料组件必不可少的重要检测项目。针对国内外池边检查技术发展现状的不足,设计了一套基于摄影测量的乏燃料组件池边检查系统,结合接触式与非接触式测量方法,能够快速对组件的整体尺寸及变形进行检测,并能实现对燃料棒长度、直径、棒间隙与氧化膜厚度的检测。针对关键检测元件CCD相机在辐射环境下寿命短的问题,设计了一种耐辐射相机防护装置,通过一次反射减少进入相机的辐射剂量,可用普通CCD相机代替昂贵的耐辐射相机。详细介绍了燃料组件长度、燃料棒与上下管座间隙、格架宽度、组件弯曲及扭曲的视觉测量实现方法,具有理论和实际的可行性,以及重要的应用价值。