检索结果-内蒙古大学图书馆

Wear Characteristics of the Nuclear Control Rod Drive Mechanism(CRDM)Movable Latch Serviced in High Temperature Water

引用

Chinese Journal of Mechanical Engineering 2022年第2期35卷 111-120页

作者： Tianda Yu Guozhong Fu Yanqing Yu Liting Zhu Maofu Liu Wei Li Qiang Deng Zhenbing Cai The State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqing 4000442China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610041China Tribology Research Institute Southwest Jiaotong UniversityChengdu 610031China Sichuan Huadu Nuclear Equipment Manufacturing Co. LtdDujiangyan 611830China

The current research of nuclear control rod drive mechanism(CRDM)movable latch only makes a simple measurement of wear *** wear volume and difference in various claw surfaces are ignored and the degradation mechanism of each claw surface is not *** this paper,a detailed degradation analysis was carried out on each claw surface of movable latch combined with wear result and worn *** indicate that the boundary of carbide is preferred for corrosion because carbide presents a nobler Volta potential compared to the metal matrix or boundary *** to the oscillation of drive shaft between the claw surfaces of movable latch,the dominant wear mechanism on the upper surface of claw(USC)and lower surface of claw(LSC)is plastic deformation caused by impact *** impact wear will cause the fragmentation of carbides because of the high hardness and low ductility of *** promotes the broken carbides to fall off from the metal *** generated fine carbides(abrasive particles)cause extra abrasive wear on USC when the movable brings the drive shaft upward or *** a result,USC has a higher wear volume than *** research proposes a method to evaluate the wear on the whole movable latches using a 3D full-size scanner.

关键词： CRDM Movable latch Degradation analysis Wear characteristics Carbide

来源：评论

学校读者我要写书评

暂无评论

CFD simulation of direct contact condensation phenomenon of vapor in subcooled water tank 23

CFD simulation of direct contact condensation phenomenon of ...

引用

23rd International Conference on Nuclear Engineering: Nuclear Power - Reliable Global Energy, ICONE 2015

作者： Ji, Yu Quan, Yan Zhang, Yining Zhang, Haochun Wang, Yahui Harbin Institute of Technology Harbin Heilongjiang China Science and Technology on Reactor System Design Technology Laboratory Chengdu Sichuan China

ISBN: (纸本)9784888982566

The direct contact condensation (DCC) is a significant phenomenon in nuclear reactor and its balance facilities, together with other chemical engineering systems. DCC occurs when the vapor is injected into the subcooled water, contacts and condenses on the interface directly. The DCC phenomenon accompanied with the heat transfer and mass transfer will result in the temperature and pressure fluctuations in the tank. This paper discusses the DCC in the subcooled water tank from the view of computation fluid dynamics. The numerical simulation was performed with the CFD software, Fluent, in which the direct contact condensation phenomenon was modeled with the Euler-Euler framework for two phases flow, and the evaporation & condensation model was adopted to simulate the mass transfer process. During the simulation process, the flow field and temperature field are derived. In addition, the shape and size of plume jet are also investigated. Copyright © 2015 by JSME.

关键词： Heat transfer

来源：评论

学校读者我要写书评

暂无评论

3-DOF decoupled magnetic platform for optical low-frequency vibration isolation

引用

International Journal of Mechanical sciences 2025年

作者： Wen-Hao Qi Tian-Yu Zhao Qiu-Hua Gao Jia-Jia Lu Long-Qi Cai Yang Li Ge Yan Wen-Ming Zhang State Key Laboratory of Mechanical System and Vibration School of Mechanical Engineering Shanghai Jiao Tong University 800 Dongchuan Road Shanghai 200240 China National Key Laboratory of Nuclear Reactor Technology Nuclear Power Institute of China Chengdu 610213 China

Optical instruments, such as atomic force microscopes (AFM), are susceptible to interference from external vibrations, which can diminish imaging clarity and hinder optimal performance. A three-degree-of-freedom (3-DOF) decoupled magnetic platform (DMP) is proposed for optical low-frequency vibration isolation. The specially developed platform attains vibration decoupling through an orthogonal structural design and utilizes six identical vibration isolation units that are specially configured to achieve low dynamic stiffness and significantly low-frequency vibration isolation performance in both horizontal and vertical directions simultaneously. Different from the traditional realization of positive and negative stiffness combination, the novel isolation unit is designed using the constant magnetic force, which is generated from the magnetic field distortion. This implementation is revealed through magnetic field analysis and verified via static calibration. The dynamic model is established by considering viscous damping and dry friction, and the Runge-Kutta Method is applied to calculate the vibration response. Theoretical analyses are conducted to guide the design of the DMP and predict dynamic responses under different structural parameters, damping settings, and excitation conditions. Experiments are implemented to demonstrate the vibration isolation performance of the prototype. The result reveals the different effects of viscous damping and dry friction and demonstrates that the developed DMP has a broad frequency decoupled vibration isolation capability. The magnetic platform achieved by reusing the newly designed quasi-zero stiffness (QZS) unit provides a new option for optical vibration isolation, with the advantages of a large stroke and strong vibration decoupling.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Analysis and Optimization of a Spatial Parallel Mechanism for a New 5-DOF Hybrid Serial-Parallel Manipulator

引用

Chinese Journal of Mechanical Engineering 2018年第3期31卷 60-68页

作者： Dong-Sheng Zhang Yun-Dou Xu Jian-Tao Yao Yong-Sheng Zhao Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of National Education Yanshan University

Hybrid manipulators have potentially application in machining industries and attract extensive attention from many researchers on the basis of high sti ness and high dexterity. Therefore,in order to expand the application prospects of hybrid manipulator,a novel 5?degree?of?freedom(DOF) hybrid serial?parallel manipulator(HSPM) is proposed. Firstly,the design plan of this manipulator is introduced. Secondly,the analysis of this manipulator is carried out in detail,including kinematics analysis,statics analysis,and workspace analysis. Especially,an amplitude equivalent method of disposing the over?constrained force/couple to the non?overconstrained force/couple is used in the statics analysis. Then,three performance indices are used to optimize the PM. Two of them have been widely used,and the third one is a new index which considers the characteristics of the actuated force. Based on the performance indices,the performance atlas is drawn and the optimal design of the PM is investigated. In order to satisfy the anticipant kinetic characteristics of the PM,the verification of the optimized physical dimension is done and the workspace based on the optimized physical dimension is carried out. This paper will lay good theoretical foundations for application of this novel HSPM and also can be applied to other hybrid manipulators.

关键词： Parallel mechanism Performance indices Optimal design Performance atlas

来源：评论

学校读者我要写书评

暂无评论

Optimization design of the reactor coolant pump flywheel comprised of multi-ring packing heavy metal alloy 9

Optimization design of the reactor coolant pump flywheel com...

引用

9th Global Conference on Materials science and Engineering, CMSE 2020

作者： Jiang, L. Wu, C.W. Shao, X.J. Zhang, Y. Yu, M.D. National Key Laboratory of Science and Technology on Reactor System Design Technology Nuclear Power Institute of China Chengdu610041 China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian116024 China

To improve energy storage performance of the multi-ring RCP flywheel comprised of inner hub, tungsten alloy ring and outer retainer, optimization design process for the radial thicknesses of components and interference fit assembly is demonstrated. Radial thicknesses of these components and magnitude of interference fit are set as design parameters to construct parametric analysis model. design of experiments (DOE) technique is adopted to generate design matrix for sensitive analysis. Subsequently, radial basis function (RBF) approximation is employed to search for the optimal design considering structural integrity requirement. Finally, a proper range of the magnitude of interference fit is obtained which can not only prevent neither slippage nor separation between the inner hub and tungsten alloy ring but also ensure the safety of structural strength. In addition, it is found that to ensure a high moment of inertia and energy density, a reasonable large radial thickness of tungsten alloy ring and a reasonable small radial thickness of outer retainer are required. © Published under licence by IOP Publishing Ltd.

关键词： Heavy metals

来源：评论

学校读者我要写书评

暂无评论

Investigation on the Influence of Entrained Air to Internal Flow of Centrifugal Pumps under Cavitation Condition

引用

International Journal of Fluid Machinery and systems 2022年第1期15卷 56-63页

作者： Fanjie, Deng Jianping, Yuan Song, Yang Biaobiao, Wang Qiaorui, Si Research Center of Fluid Machinery Engineering and Technology Jiangsu University Jiangsu Zhenjiang212013 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Sichuan Chengdu610000 China

The introduction of air is often used in engineering to delay the occurrence of cavitation. A steady simulation on a single-stage and single-suction centrifugal pump was used to study the influence of the air on the internal flow under cavitation condition at 1% inlet void fraction. Steady simulation based on SST k-ω turbulence model and Rayleigh-Plesset cavitation model included in Ansys CFX 17.0 were processed to obtain vapor volume fraction, gas volume fraction and the turbulent energy of the impeller under the condition of natural cavitation and cavitation with entrained air. A homogeneous two-phase flow model was adopted to describe the air-water mixed flow. The experimental cavitation performance curve provides boundary condition support for the numerical simulation. In conclusion, it shows that the head of the pump keeps steady after 1% air entrained like natural cavitation. Then it goes worse when the cavitation number decreases but with lower NPSHr which means cavitation performance is improved by 1% air entrained. It indicated that the entrained air changes the distribution of the vapor in the passage of the impeller. However, the descent of the pressure over a certain value will also do harm to the internal flow of the model pump whether it is ventilati ng or not. The internal flow of the pump will be seriously damaged and even be blocked completely due to more and more vapor generated causing a dramatic decline of the head. © 2022, Turbomachinery Society of Japan. All rights reserved.

关键词： Cavitation

来源：评论

学校读者我要写书评

暂无评论

Structural design and strength analysis of multi-ring packed flywheel with heavy metal alloy segments 2

Structural design and strength analysis of multi-ring packed...

引用

2nd International Conference on Numerical Modelling in Engineering, NME 2019

作者： Jiang, L. Zhang, W. Wu, C.W. Zhang, L.P. Zhang, Y.X. Liu, Z.Y. National Key Laboratory of Science and Technology on Reactor System Design Technology Nuclear Power Institute of China Chengdu610041 China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian116024 China

Flywheel, as a kinetic energy storage and conversion device, has promising applications due to its high efficiency, no pollution and long lifetime. In particular, with a three-layer structure packed with heavy metal alloy middle layer, a flywheel can achieve both a large rotational inertia and a high energy density. To guarantee structural strength safety of this type of multi-ring packed flywheel operating at high temperature, structural and thermal stress analysis for a flywheel with a tungsten alloy layer sandwiched between two stainless steel layers is carried out using finite element method (FEM). Based on plane stress assumption, flywheel stress characteristic along radius under assembly force, centrifugal force and thermal loading is demonstrated. The results show that, the rise of temperature causes inconsistent thermal expansion between neighbouring layers and results in a large thermal stress. Particularly, a high circumferential tensile stress occurs in the middle layer. It is also found that, the segments of the middle tungsten alloy layer can efficiently relieve the inconsistent thermal expansion and lower the thermal stress. Moreover, the number of segments significantly influences the efficiency of thermal stress releasing and the reserved gap between adjacent segments significantly improves the contact pressure between inner hub and tungsten alloy layer. This work may provide reference for structural design of the multi-ring packed flywheels under thermal loading. © Published under licence by IOP Publishing Ltd.

关键词： Kinetics

来源：评论

学校读者我要写书评

暂无评论

A novel approach for radionuclide diffusion in the enclosed environment of a marine nuclear reactor during a severe accident

引用

Nuclear science and Techniques 2022年第2期33卷 53-65页

作者： Fang Zhao Shu-Liang Zou Shou-Long Xu Xuan Wang Jun-Long Wang De-Wen Tang School of Resource Environment and Safety Engineering University of South ChinaHengyang 421001China Hunan Provincial Key Laboratory of Emergency Safety Technology and Equipment for Nuclear Facilities Hengyang 421001China Shanghai Nuclear Engineering Research and Design Institute Co.LTD Shanghai 200000China Science and Technology On Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China

A severe accident in a marine nuclear reactor leads to radionuclide leakage,which causes hidden dangers to workers and has adverse effects of environmental *** is necessary to propose a novel approach to radionuclide diffusion in a confined environment after a severe accident in a marine nuclear ***,this study proposes a new method for the severe accident analysis program MELCOR coupled with computational fluid dynamics scSTREAM to study radioactive diffusion in severe *** radionuclide release fraction and temperature calculated by MELCOR were combined with the scSTREAM calculations to study the radionuclide diffusion behavior and the phenomenon of radionuclide diffusion in different space environments of the reactor under the conditions of varying wind velocities of the ventilation system and diffusion *** results show that the wind velocity of the ventilation system is very small or zero,and the turbulent diffusion of radionuclides is not obvious and diffuses slowly in the form of condensation sedimentation and gravity *** the wind speed of the ventilation system increases,the flow of radionuclides meets the wall and forms eddy currents,affecting the time variation of radionuclides diffusing into chamber *** wind velocity of the ventilation system and the diffusion speed has opposite effects on the time variation trend of radionuclide diffusion into the four chambers.

关键词： Radionuclide diffusion MELCOR coupled with scSTREAM Severe accident Marine nuclear reactor

来源：评论

学校读者我要写书评

暂无评论

Curvature-property coupling governed heat transfer deterioration in supercritical helically coiled tubes: Mechanistic insights and mitigation strategies via structural parametrization

引用

International Journal of Thermal sciences 2025年 215卷

作者： Chang, Fucheng Xin, Jiaxing Wu, Xiaoyi Li, Liwei Li, Huixiong Zhu, Yanlin National Key Lab of Aerospace Power System and Plasma Technology School of Mechanical Engineering Xi'an Jiaotong University Xi'an 710049 China China Special Equipment Testing and Research Institute Beijing 100029 China State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'an 710049 China Shanghai Nuclear Engineering Research & Design Institute Co. Ltd Shanghai 200233 China

The unique thermo-hydrodynamic coupling phenomena in the helically coiled tube (HCT) handling supercritical fluids present both opportunities and challenges for next-generation compact heat exchangers. While the pronounced thermophysical property variations near pseudo-critical temperatures (T_pc) and curvature-induced secondary flows synergistically enhance heat transfer coefficient (HTC), their nonlinear coupling mechanisms may unexpectedly provoke severe heat transfer deterioration (HTD). Through systematic numerical investigations, this study reveals that circumferential wall temperature inhomogeneity (CWTI) exhibits an inverted N-shaped evolution, providing valuable insights for thermal homogenization design near T_pc. The secondary flow Reynolds number (Se), quantifying secondary flow intensity, shows a monotonic increase with decreasing coil diameter (D_c) or inner diameter (D_i), reaching saturation in high-enthalpy regions. Notably, CWTI demonstrates non-monotonic behavior, achieving minimum values near T_pc before manifesting distinct rebound characteristics near T_pc conditions. Parametric analysis establishes that: (1) Elevating heat flux (q) increases Se, reducing D_c boosts it by 50.3 %, and decreasing D_i raises it by 60.0 %. (2) HTD predominantly initiates at the outer wall under high-q conditions, with D_c reduction achieving HTD suppression and 26.9 % enhancement in the local HTC;(3) Reducing the D_i results in a reduction of maximum CWTI by 22.5 %–28.6 %, suggesting that structural parametrization effectively mitigates wall temperature non-uniformity, thus suppressing the HTD. While centered on supercritical water, the dimensionless scaling relationships demonstrate extendibility to other media, with the curvature-property coupling mechanism both elucidating fundamental interactions and guiding robust heat exchanger design. © 2025 Elsevier Masson SA

关键词： Heat transfer deterioration Helically coiled tube Structural parametrization Supercritical fluid Thermo-hydrodynamic coupling

来源：评论

学校读者我要写书评

暂无评论

PREDICTION OF CRITICAL HEAT FLUX BASED ON RANDOM FOREST ALGORITHM 29

PREDICTION OF CRITICAL HEAT FLUX BASED ON RANDOM FOREST ALGO...

引用

2022 29th International Conference on Nuclear Engineering, ICONE 2022

作者： Sun, Zhuo Han, Mingyang Yuan, Peng Gong, Lei Chen, Di Yuan, Guanghui Zhang, Shuang Nuclear Power Institute of China Chengdu China Science and Technology on Reactor System Design Technology Laboratory Chengdu China

ISBN: (纸本)9780791886410

The accurate prediction of critical heat flux(CHF) is of great significance to the safe operation of the reactor. At present, most of the traditional methods for predicting CHF are based on relational fitting in mathematical form, which are not accurate enough and may can not taking full advantage of experimental data. Therefore, a prediction model based on random forest algorithm (RF) is proposed, the model is based on CHF 2006 look-up table, and the accuracy and smoothness of the model have been verified when predicting CHF. In this paper, the variation trend of CHF predicted value and actual value with pressure, mass flow rate and thermodynamic quality is given. It has been verified that the error of this method is acceptable, the predicted value is in good agreement with the experimental value, and conforms to the corresponding physical laws, which can provide a reference for the development of high-precision CHF prediction models or CHF-related experiments. Copyright © 2022 by ASME.

关键词： Heat flux

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：