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EAST装置是"九五"国家重大科学工程项目之一,做为世界上第一个全超导托卡马克装置,其纵场和极向场线圈全部由超导磁体组成,进行安全,准确,有效的失超保护是装置安全运行的首要环节。如何在全超导托卡马克装置这样复杂的电磁环境进行失超检测在世界上也无先例可寻。EAST上失超检测系统经过几十轮单饼超导线圈实验及两轮装置正式放电实验后逐步建立和完善起来,并已通过工程验收达到装置实验运行要求。主要介绍了EAST超导装置失超检测系统的基本结构和检测原理,同时还简述失超检测技术的发展并给出了实验结果。 相似文献
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高温气冷堆示范工程反应堆保护系统故障树模型的建立和分析 总被引:4,自引:4,他引:0
数字化保护系统正逐步取代模拟系统,应用于新建和升级的核电厂中,数字化保护系统的可靠性分析已成为仪控领域的热点研究课题。本工作以高温气冷堆示范工程(HTR-PM)的反应堆保护系统为研究对象,研究数字化保护系统故障树模型的建立和分析方法,主要研究内容包括:故障树顶事件的选取;基于失效模式与影响分析(FMEA)的故障树搭建方法,重点研究保护系统冗余通道的“2/4”表决逻辑以及通道旁通的处理方法;对故障树模型进行定性分析,并根据故障树的最小割集讨论保护系统的薄弱环节。该研究对于分析数字化保护系统的可靠性并改进系统设计具有重要意义。 相似文献
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杨睿琬 《核电子学与探测技术》2023,(5):1096-1100
可靠性预计作为电路可靠性分析的一种手段,在核电厂保护系统改造中,针对元器件停产、再选型具有很好的辅助作用。在电路可靠性分析中,可靠性预计主要是对每一种部件进行失效模式和影响分析(FMEA)评估,建立失效模型,计算失效率。故障树作为可靠性预计的一种分析方法,能直观体现卡件的单点故障。通过故障树法特有的树状结构图列出卡件的失效率计算式,从而得出电路改造前后卡件的平均无故障工作时间(MTBF)并将结果进行对比,该对比结果能作为核电厂保护系统电路改造可靠性分析的一项重要指标。 相似文献
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《核安全》2021,(4)
用动态故障树弥补传统故障树对系统时序失效行为建模能力的不足,改进和完善现有核电厂系统可靠性和概率风险评价方法,已成为核电厂概率安全研究的一种发展趋势。近30年来,动态故障树的建模理论和分析技术已日趋成熟,并初步形成了以蒙特卡洛(MC)数值模拟、马尔科夫链模型以及组合法三类主要分析方法。本文将从动态故障树的分析方法、在核能系统可靠性评价中的应用、未来的发展趋势三个方面进行阐述,着重分析动态故障树分析方法的特点,提出了核电厂时序失效行为与特性以及未来动态故障树在核能系统中的发展方向,为动态故障树方法在核能系统可靠性和概率风险分析中的应用提供理论依据和实践指导。 相似文献
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Zhigang ZHU Qiyona ZHANG Yuntao SONG Ming ZHUANG Zhiwei ZHOU Anyi CHENG Ping ZHU 《等离子体科学和技术》2017,19(5):55603
Since 2006,the superconducting toroidal field (TF) coils of the Experimental Advanced Superconducting Tokomak (EAST) have been successfully cooled by supercritical helium at a temperature of 4.5 K and a pressure of 4 bara in eleven experiments.To obtain higher operating currents and magnetic fields it is necessary to lower the operating temperature of the TF coils.The EAST sub-cooling helium cryogenic system,with a warm oil ring pump (ORP),was tested twice in cool-down experiments,which made the TF coils operate at 3.8 K.However,the long term operational stability of the sub-cooling system cannot be guaranteed because of the ORP's poor mechanical and control performance.In this paper,the present status of the EAST subcooling helium cryogenic system is described,and then several cooling methods below 4.2 K and their merits are presented and analyzed.Finally,an upgrading method with a cold compressor for an EAST sub-cooling helium cryogenic system is proposed.The new process flow and thermodynamic calculation of the sub-cooling helium system,and the main parameters of the cold compressor,are also presented in detail.This work will provide a reference for the future upgrading of the sub-cooling helium system for higher operation parameters of the EAST device. 相似文献
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A large scale helium cryogenic system is one of the key components for the EAST tokamak device for the cooling of PF and TF coils, structures, thermal shields, buslines, current leads and cryopumps. Since the cooling scheme of the EAST cryogenic system is fairly complicated, a reliable and flexible control system is required for cryogenic system. The cryogenic control system is based on DeltaV DCS which is the process control software developed by Emerson Company. The EAST cryogenic system has been in operation for four years and has been proved to be safe, stable and energy saving by the past 7 experiments. This paper describes the redundant control network, hardware configuration, software structure, auxiliary system and the new development in the future. 相似文献
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The EAST superconducting tokamak,an advanced steady-state plasma physics experimental device,has been built at the Institute of Plasma Physics,Chinese Academy of Sciences.All the toroidal field magnets and poloidal field magnets,made of NbTi/Cu cable-in-conduit conductor,are cooled with forced flow supercritical helium at 3.8 K.The cryogenic system of EAST consists of a 2 kW/4 K helium refrigerator and a helium distribution system for the cooling of coils,structures,thermal shields,bus-lines,etc.The high-speed turbo-expander is an important refrigerating component of the EAST cryogenic system.In the turbo-expander,the axial supporting technology is critical for the smooth operation of the rotor bearing system.In this paper,hydrostatic thrust bearings are designed based on the axial load of the turbo-expander.Thereafter,a computational fluid dynamics-based numerical model of the aerostatic thrust bearing is set up to evaluate the bearing performance.Tilting effect on the pressure distribution and bearing load is analyzed for the thrust bearing.Bearing load and stiffness are compared with different static supply pressures.The net force from the thrust bearings can be calculated for different combinations of bearing clearance and supply pressure. 相似文献
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The experimental advanced superconducting tokamak (EAST) is being constructed at the Institute of Plasma Physics of Chinese Academy of Sciences (CASIPP). The EAST project, approved by the Chinese government as a national mega project of science research is a fully superconducting tokamak. The most key component for EAST is the superconducting magnet coils (SMCs), which consists of 16 toroidal field coils (TFCs) and 14 poloidal field coils (PFCs). In 2003, three prototypes, one TFC and two PFCs, were successfully completed and passed a series of cryogenic tests. Batch production, needed for the SMCs has begun at CASIPP since 2002. Up to now, all 58 CIC conductors with a total length of 32 km, 12 TFCs out of 16 and 10 PFCs out of 14 have been fabricated. This paper emphasizes on the various technology issues that must be faced and solved for four R&D lines of SMCs after transforming to batch production. Quality control methods in process are also described. 相似文献
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《Fusion Engineering and Design》2014,89(5):595-599
EAST cryogenic system is one of the critical sub-systems of the EAST tokamak device. It is a large scale helium cryoplant, which adopts distributed control system to realize monitoring and control of the cryogenic process and devices. However, the maintenance and management of most field devices are still in the corrective maintenance or traditional preventive maintenance stage. Under maintained or over maintained problems widely exist, which could cause devices fault and increase operation costs. Therefore, a device management platform is proposed for a safe and steady operation as well as fault diagnosis and predictive maintenance of EAST cryogenic system.This paper presents the function design and architecture design of the cryogenic device management platform. This platform is developed based on DeltaV DCS and acquires monitoring data through OPC protocol. It consists of three pillars, namely device information management, device condition management, and device performance monitoring. The development and implementation of every pillar are illustrated in detail in this paper. Test results and discussions are presented in the end. 相似文献
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CHENXian-Zhong WUSong-Tao 《核技术(英文版)》2005,16(2):126-128
EAST is a full superconducting tokamak with an elongated plasma cross-section. It consists of superconducting poloidal field (PF) magnet system, toroidal field (TF) magnet system, vacuum vessel with inner parts, thermal shields and cryostat vessel. The mission of the project is to widely investigate both physics and technologies of advanced tokamak operations, especially the mechanism of power and particle handling for steady-state operations. The cryogenic component is mainly composed of superconducting TF and superconducting PF coils that ensure the ability of sustaining magnetic field for plasma confinement, control and shaping in steady-state. This report describes the process of the structure design of cryogenic component support for EAST. 相似文献
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Liang LIAO 《等离子体科学和技术》2022,24(3):35106
An external resonant magnetic perturbation (RMP) field, which is an effective method to mitigate or suppress the edge localized mode (ELM), has been planned to be applied on the ELM control issue in ITER. A new set of magnetic perturbation coils, named as high m coils, has been developed for the EAST tokamak. The magnetic perturbation field of the high m coils is localized in the midplane of the low field side, with the spectral characteristic of high m and wide n, where m and n are the poloidal and toroidal mode numbers, respectively. The high m coils generate a strong localized perturbation field. Edge magnetic topology under the application of high m coils should have either a small or no stochastic region. With the combination of the high m coils and the current RMP coils in the EAST, flexible working scenarios of the magnetic perturbation field are available, which is beneficial for ELM control exploration on EAST. Numerical simulations have been carried out to characterize the high m coil system, including the magnetic spectrum and magnetic topology, which shows a great flexibility of magnetic perturbation variation as a tool to investigate the interaction between ELM and external magnetic perturbation. 相似文献
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The magnetic field configurations of poloidal field (PF) and toloidal field (TF) are the base of tokamak plasma operation. They are determined by the parameters such as positions and structures of PF and TF coils. Parameters of TF and PF coils of a new fully superconducting tokamak with non-circular cross-section EAST will change when the coils are cooled down from the ambient temperature to 4 K. Because of the cryogenic and refrigerator system, these parameters cannot be measured directly. Using magnetic probes signals, we measured and reconstructed magnetic field configuration of TF and PF coils. Parameters such as the positions of PF coils, the profile of the toloidal field in radial direction, the ripple and error field of toloidal field are obtained from the measurements. 相似文献
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The toroidal field (TF) magnet system of EAST (HT-7U), which consists of 16 superconducting coils enclosed in steel cases, has been manufactured to generate the magnetic field of 3.5 T at the plasma center to maintain plasma in a tokamak configuration with a current up to 1 MA. The TF coils have an approximately D-shape geometry of 2.6 m wide and 4.0 m high, and operate at a maximum field of 5.8 T. The conductor used in the TF coil is NbTi/Cu cable-in conduit (CIC) conductor, and its operating current is 14.3 kA.In March 2006, the first cooling down of the EAST device has been carried out successfully. The total of TF magnet system has been cooled down from room temperature to 4.5 K, and the TF system has been energized up to 8.2 kA with 5 A/s ramp rate. In September 2006, full performances of the TF magnet system have been reached, and the device of EAST has delivered its first plasma. In addition, the TF magnet system has been routinely operated with a current maintained constant on a whole day basis, for a preliminary program of more than 500 shots.In this paper, the main parts of the design, developmental tests, and the fabrication and assembly of TF coils are described in detail. 相似文献