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An early fault characteristics analysis method of reactor canned motor pump based on signal enhancement Hilbert transform and complete ensemble empirical mode decomposition with optimized adaptive noise

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Measurement 2025年 255卷

作者： Zhilong Liu Meng Li National Key Laboratory of Nuclear Reactor Technology Nuclear Power Institute of China Chengdu 610213 China School of Automation Engineering University of Electronic Science and Technology of China Chengdu 611730 China

The canned motor pump (CMP) is the key rotating equipment of nuclear reactors, which not only controls the flow of key medium in the primary circuit, but also is an important power equipment of the auxiliary system. In view of the difficulty in identifying the early fault characteristics of the reactor canned motor pump, a method based on complete ensemble empirical mode decomposition with optimized adaptive noise (CEEMDOAN) and signal enhancement Hilbert transform (SEHT) is proposed. Firstly, the vibration signal of the canned motor pump is modally decomposed by CEEMDOAN, and the target intrinsic mode function (TIMF) fraction is selected based on the selection criteria of the proposed TIMF and the standard deviation of white noise, so as to complete the noise reduction of the original vibration signal. Secondly, by improving the Hilbert transform (HT) using the designed function with enhanced frequency and amplitude, a SEHT method is proposed to process the TIMF component to analyze the early fault characteristics of the canned motor pump. Finally, simulation and experimental verification are carried out. The results have shown that the proposed method can effectively identify the early fault characteristics of the canned motor pump, which further improves the reliability of the canned motor pump operation, and has better performance than the existing methods.

关键词： Linear transformations

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Effects of Organosilane-modified PCE on the Fluidity and Hydration Properties of Cement-Fly Ash Composite Binder

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Journal of Wuhan University of technology(Materials science) 2020年第6期35卷 1081-1089页

作者： HE Yan LIU Shuhua JI Tao KONG Yaning SHUI Liangliang School of Civil Engineering Suzhou University of Science and TechnologySuzhou 215011China State Key Laboratory of Green Building Materials China Building Materials AcademyBeijing 100024China State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China Hubei Key Laboratory of Water System Science for Sponge City Construction Wuhan UniversityWuhan 430072China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China School of Architecture and Engineering Nanjing Institute of TechnologyNanjing 211167China China West Construction Academy of Building Materials Chengdu 610000China Shanghai Municipal Engineering Design Institute(Group)Co.Ltd. Shanghai 200092China

Effects of organosilane-modified PCE (OS-PCE) on the fluidity and the hydration properties of cement-fly ash (FA) composite binder were systematically *** experimental results show that OS-PCE possesses respectively 36.98% and 36.67% higher saturated adsorption amount on cement and FA,in comparison with ordinary PCE,and can contribute to higher fluidity of cement-FA composite *** addition of OS-PCE retards hydration process of cement-FA composite binder proportionally with the dosage of OS-PCE,but promotes the hydration kinetics of the composite *** reactivity enhancement is attributed to the well-dispersed FA by OS-PCE,which provides more nucleation sites for the reaction of heterogeneous C-S-H and enhances the contact with water to react with CH forming pozzolanic ***-distributed hydration products are exhibited in the hardened binder added with OS-PCE,with a large number of hydrated gels uniformly fill in the pores and gaps,which improves the compaction of the hardened structure.

关键词： cement fly ash organosilane-modified PCE fluidity hydration properties

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A combined reactivity control pattern on a floating nuclear power plant 27

A combined reactivity control pattern on a floating nuclear ...

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27th International Conference on Nuclear Engineering: Nuclear Power Saves the World!, ICONE 2019

作者： Zhou, Bingyan Song, Danrong Chen, Zhang Chai, Xiaoming Xiang, Hongzhi Hu, Yuying Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu Sichuan China

ISBN: (纸本)9784888983051

In this study, a new combined reactivity control pattern is presented to lower the power peaking factor on a floating nuclear power plant. In the pattern the whole cycle length is divided into several boron-adjusting periods. During one boron-adjusting period, the soluble boron concentration remains unchanged and the core reactivity change is controlled by control rods. Boron concentration would only be changed at the end of a boron-adjusting period. In the whole cycle the boron concentration would be changed for two to four times, which is acceptable for a floating nuclear power plant. To get an optimized solution, a model of the combined reactivity control pattern was established, which contained boron concentration and control rod pattern (CRP) as coupled variables. A particle swarm optimization with novel mutation operator (PSONM) was applied to optimize the solution. The model was practiced based on a small modular reactor ACP100 core. The solution was optimized separately for equal division of two, three, four and five boron-adjusting periods. The results show that the combined reactivity control pattern can get a lower power peak factor than the original rod-controlled-only pattern without shortening the cycle length. Therefore, the safety of the floating nuclear power plant can be improved. Copyright © 2018-2019 by JSME

关键词： Nuclear power plants

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Effect of gamma radiation on the sensing characteristics of FPs and FBGs 27

Effect of gamma radiation on the sensing characteristics of ...

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27th International Conference on Optical Fiber Sensors, OFS 2020

作者： Li, Zhuoyue Xiao, Yaqin Ran, Zengling Yang, Tingting He, Xiu Xiao, Yanbo Shen, Feng Rao, Yunjiang He, Zhengxi Zhu, Jialiang He, Peng Xu, Sijie Chu, Wangwei Zeng, Debiao Fiber Optics Research Center Key Laboratory of Optical Fiber Sensing & Communications Ministry of Education University of Electronic Science & Technology of China Sichuan Chengdu611731 China Center for Optical Fiber Sensing Zhejiang Laboratory Hangzhou310000 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China Chengdu Aircraft Industrial Group Co. Limited 610092 China

The sensing characteristics of Fabry-Perot interferometers (FPIs) and fiber Bragg gratings (FBGs) after irradiation were studied, in which pressure sensitivity of FPI was stable while temperature sensitivity curves of... 详细信息

ISBN: (纸本)9781557523075

关键词： Fiber Bragg gratings

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Stoichiometric effect on electrical and near-infrared photodetection properties of full-composition-range GaAs1−xSbx nanowires

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Nano Research 2021年第11期14卷 3961-3968页

作者： Jiamin Sun Mingming Han Meng Peng Lei Zhang Dong Liu Chengcheng Miao Jiafu Ye Zhiyong Pang Longbing He Hailu Wang Qing Li Peng Wang Lin Wang Xiaoshuang Chen Chongxin Shan Litao Sun Weida Hu Zai-xing Yang School of Physics and School of Microelectronics Shandong UniversityJinan250100China State Key Laboratory of Infrared Physics Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai200083China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan430074China SEU-FEI Nano-Pico Center Key Lab of MEMS of Ministry of EducationCollaborative Innovation Center for Micro/Nano FabricationDevice and SystemSoutheast UniversityNanjing210096China School of Physics and Photoelectric Engineering Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou310024China Henan Key Laboratory of Diamond Optoelectronic Materials and Devices School of Physics and EngineeringZhengzhou UniversityZhengzhou450001China

As one of the most important narrow bandgap ternary semiconductors, GaAs1−xSbx nanowires (NWs) have attracted extensive attention recently, due to the superior hole mobility and the tunable bandgap, which covers the whole near-infrared (NIR) region, for technological applications in next-generation high-performance electronics and NIR photodetection. However, it is still a challenge to the synthesis of high-quality GaAs1−xSbx NWs across the entire range of composition, resulting in the lack of correlation investigation among stoichiometry, microstructure, electronics, and NIR photodetection. Here, we demonstrate the success growth of high-quality GaAs1−xSbx NWs with full composition range by adopting a simple and low-cost surfactant-assisted solid source chemical vapor deposition method. All of the as-prepared NWs are uniform, smooth, and straight, without any phase segregation in all stoichiometric compositions. The lattice constants of each NW composition have been well correlated with the chemical stoichiometry and confirmed by high-resolution transmission electron microscopy, X-ray diffraction, and Raman spectrum. Moreover, with the increase of Sb concentration, the hole mobility of the as-fabricated field-effect-transistors and the responsivity and detectivity of the as-fabricated NIR photodetectors increase accordingly. All the results suggest a careful stoichiometric design is required for achieving optimal NW device performances.

关键词： GaAs1−xSbx nanowire stoichiometry effect full-composition-range field-effect hole mobility near-infrared photodetection

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Study on Acoustic-Induced Vibration (AIV) by reactor coolant pump at secondary support structure 48

Study on Acoustic-Induced Vibration (AIV) by reactor coolant...

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48th International Congress and Exhibition on Noise Control Engineering, INTER-NOISE 2019 MADRID

作者： Huang, Xuan Cai, Fengchun Wu, Wanjun Qi, Huanhuan Feng, Zhipeng Liu, Shuai Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu Sichuan China

ISBN: (纸本)9788487985317

The reactor coolant pump is the core equipment of nuclear power stations. During the operation of reactor coolant pump, acoustic pulsations are generated due to nonuniform flow within the reactor coolant pump and pass through the main pipe and coolant to the structure in the reactor. The acoustic pulsations can cause the vibration of the structure in the reactor, which is regarded as one of the main reasons of fatigue failure of the structure. In this paper, the finite element model of secondary support structure will be built and verified by test, then the pressure pulsations relation between the reactor coolant pump outlet and the secondary structure will be investigated, the pressure pulsation caused by the reactor coolant was calculated. Finally, the acoustic-induced vibration response of secondary support structure caused by the reactor coolant pump were obtained by harmonic analysis and high circle fatigue analysis will be done on the basis of the results. This study is helpful to understand the acoustic-induced vibration of the reactor coolant pump and to improve the hydraulic design of the reactor coolant pump. © INTER-NOISE 2019 MADRID - 48th International Congress and Exhibition on Noise Control Engineering. All Rights Reserved.

关键词： Harmonic analysis

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Detecting bulk carbon ferromagnetism in graphene multi-edge structure

arXiv

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arXiv 2023年

作者： Wang, Chao Jian, Nan Yin, Meijie Zhang, Xi Yang, Zhi Mo, Xiuhao Kikkawa, Takashi Daimon, Shunsuke Saitoh, Eiji Li, Qian Yan, Wensheng Hou, Dazhi Yang, Lei Diao, Dongfeng Institute of Nanosurface Science and Engineering Shenzhen University Shenzhen518060 China Electron Microscopy Center of Shenzhen University Shenzhen518060 China National Key Laboratory of Radio Frequency Heterogeneous Integration Shenzhen University Shenzhen518060 China Department of Applied Physics The University of Tokyo Tokyo113-8656 Japan Tokyo152-8550 Japan Institute for AI and Beyond The University of Tokyo Tokyo113-8656 Japan WPI Advanced Institute for Materials Research Tohoku University Sendai980-8577 Japan National Synchrotron Radiation Laboratory School of Nuclear Science and Technology University of Science and Technology of China Anhui Hefei230029 China Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China Hefei230026 China Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi’an Jiaotong University Xi’an710049 China

The emergence of bulk carbon ferromagnetism is long-expected over years. At nanoscale, carbon ferromagnetism was detected in graphene nanoribbon segments1–3, graphene triangulene dimers4,5, and other graphene-like molecules6–8 by analyzing their magnetic edge states via scanning tunneling microscopy(STM)9, and its origin can be explained by local redistribution of electron wave function3,5,8. Recently, there are experimental efforts on discovering orbital ferromagnetism in twisted bilayer graphene10,11, which is still limited in STM region. In larger scale, carbon ferromagnetism can be created by deliberately producing defects in graphite12–14, and detected by macroscopic technical magnetization. Meanwhile, it becomes crucial to determine that the detected magnetization is originated from carbon rather than from magnetic impurities. One solution to eliminate this uncertainty is X-ray magnetic circular dichroism (XMCD). A contrast of dichroism at π* absorption energy was observed in the scanning x-ray microscope image of proton-irradiated graphite15. Nonetheless, a reproducible, full section of XMCD spectrum across C-1s absorption energy has not appeared yet, which should be decisive for assuring the indisputable existence of bulk carbon ferromagnetism. Besides, the lack of direct observation on the atomic structure of the ferromagnetic carbon leaves the structural origin of its ferromagnetism still in mist. In this work, for detecting bulk carbon ferromagnetism, we managed to grow all-carbon film consisting of vertically aligned graphene multi-edge (VGME), which wove into a three-dimensional hyperfine-porous network. Magnetization (M-H) curves and XMCD spectra co-confirmed bulk carbon ferromagnetism of VGME at room temperature, with the average unit magnetic momentum of ~0.0006 μB/atom. The influence of magnetic impurities on magnetization was excluded by both absorption spectra and inductively coupled plasma mass spectrometry measurements. The spin transfer behavio

关键词： Ferromagnetism

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Research on periodic test scheme of safety digital control system for nuclear power plant 27

Research on periodic test scheme of safety digital control s...

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27th International Conference on Nuclear Engineering: Nuclear Power Saves the World!, ICONE 2019

作者： Xie, Weibo Wu, Zhiqiang Zeng, Shan Li, Yutong Hu, Qingren Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu Sichuan China

ISBN: (纸本)9784888983051

The main trend in the development of the local power plant control system is to adopt digital safety DCS system with rather strong ability of self-diagnosis. Apart from the self-diagnosis, it is also necessary to carry out periodic test in certain frequency to check the potential fault within a system and to certify the completeness and effectiveness of reactor protection function. Regarding nowadays in-service or in-building power plant, there are some deficiency in the automation and simplication of the periodic test method, which still can be improved. Based on the research on the overall optimization of nuclear power plant safety DCS periodic test, an integrated and comprehensive periodic test method was put forward. This method, not only achieved a high degree of automation, supporting T2 online test, which increasing the system reliability, in order to save the cost of human and material during window phase in the overhaul life. Copyright © 2018-2019 by JSME

关键词： Nuclear power plants

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Numerical methods research and fracture failure analysis for critical crack size 27

Numerical methods research and fracture failure analysis for...

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27th International Conference on Nuclear Engineering: Nuclear Power Saves the World!, ICONE 2019

作者： Shi, Kaikai Yuan, Yanli Chen, Jianguo Bai, Xiaoming Zheng, Liangang Lu, Xifeng Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu Sichuan China

ISBN: (纸本)9784888983051

Safety analysis of fracture mechanics is an important part of structural integrity assessment and critical crack size is one ofmain concerns for fracture failure. From the perspective of mathematics, the calculation of critical crack size is the solving and analysis for nonlinear equation f(x)=0. About the solution of nonlinear equation, there are the bisection method, the false position method, the simple iteration method, the newton method and the secant method. For the complexity of load imposed on nuclear power equipment, there may be the multi-value phenomenon of critical crack size in analyzing fracture failure problems. Considering that the corresponding mechanical states of the shallow crack and the deep crack are different when the fracture failure occurs, the crack toughness factor needs to be considered in the fracture failure analysis of shallow cracks. Connecting the bottom head of nuclear power plant main equipment, the pipeline large break transient of accident condition and the welding research council bulletin 175, the algorithm and the convergence of multi-value phenomenon of critical size are studied. Using the crack toughness factor, the fracture failure critical crack size is deeply analyzed and discussed. The algorithm and fracture failure theory in the present study can provide the technical support for the prolonging operation life projects of nuclear power plant main equipment in future. Copyright © 2018-2019 by JSME

关键词： Numerical methods

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The defect analysis technology study of reactor pressure vessel main bolt 27

The defect analysis technology study of reactor pressure ves...

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27th International Conference on Nuclear Engineering: Nuclear Power Saves the World!, ICONE 2019

作者： Zheng, Liangang Zhang, Rui Huang, Qian Bai, Xiaoming Yuan, Feng Lu, Xifeng Yuan, Yanli Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu Sichuan China

ISBN: (纸本)9784888983051

The existence of non conformances and defects are inescapable during the manufacture and in service of reactor pressure vessel (RPV). After being analyzed, most of the defects have no influence on the capability and safety of the structure if the analysis results satisfy criteria. The defects including main bolts defects, the non conformances of cladding thickness and structure dimension, structure scratch, material inclusion and so on. The typical and serious defects is main bolts defects, including thread defect, stress relaxation of bolt and the extreme case of bolt break. The results of stress, fatigue and seal performance of reactor pressure vessel will be changed considering these defects. Based on the mechanics theory and numerical simulation technique, a kind of stress, fatigue and seal performance analysis method about the defects effects is studied in this paper. The influence to the reactor pressure vessel induced by several kinds of bolt break accident is analyzed using this analysis method. Copyright © 2019 by JSME

关键词： Fatigue of materials

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