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12th Academic Conference of Geology Resource Management and Sustainable Development, GRMSD 2024

作者： Li, Wenjun Zhang, Zhuohua Su, Dongchuan Wu, Ge Tang, Qizhong Wu, Junjie College of Chemical Safety North China Institute of Science and Technology Hebei Sanhe065201 China Key Laboratory of Nuclear Reactor System Design Technology Nuclear Power Research and Design Institute of China Sichuan Chengdu610213 China

ISBN: (纸本)9798331314545

Underground in-situ pyrolysis of oil-rich coal can extract oil and gas resources in coal, which is an important measure for clean and low-carbon utilization of coal resources. The efficiency and energy consumption of underground in-situ pyrolysis of oil-rich coal depend on the heating equipment. The sodium heat pipe with large length-diameter ratio can complete the efficient long-distance heat transfer at high temperature, and has broad application prospects in the field of underground in-situ pyrolysis of oil-rich coal. Compared with the conventional high temperature heat pipe, the evaporation section of the sodium heat pipe with large length-diameter ratio is more likely to burn out during cold start-up, which leads to the failure of cold start-up. Therefore, for the sodium heat pipe with an aspect ratio of 115 (outer diameter D = 20 mm, axial length L = 2300 mm), the start-up characteristics of sodium heat pipes with three filling rates (5 %, 10 %, 15 %) under different heating powers were investigated. The results show that with the increase of the filling rate, the longer the start-up time of the sodium heat pipe with large length-diameter ratio, the more likely it is to produce temperature oscillation. Increasing the heating power can reduce the start-up time gap of the three liquid-filled sodium heat pipes, weaken the temperature oscillation phenomenon, and improve the temperature uniformity and steady-state operating temperature of the sodium heat pipe with large length-diameter ratio. In addition, the decrease of the filling rate of sodium with large length-diameter ratio and the increase of heating power can reduce the equivalent thermal resistance of sodium heat pipe with large length-diameter ratio, and improve the start-up characteristics and heat transfer effect of sodium heat pipe with large length-diameter ratio. When the heating power is 3.5 kW, the start-up time of sodium heat pipe with 5 % filling rate is as low as 450 s. © 2024 Proceedings of the

关键词： Coal deposits

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Electrolytic Failure Modeling of Aluminum Electrolytic Capacitor by Finite Element Method 2

Electrolytic Failure Modeling of Aluminum Electrolytic Capac...

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2nd IEEE International Power Electronics and Application Symposium, PEAS 2023

作者： Chen, Xinrui Yao, Ran Li, Hui Lai, Wei Min, Yuan Yang, Cheng Duan, Zeyu Chen, Siyu Chongqing University State Key Laboratory of Power Transmission Equipment Technology Chongqing China Nuclear Power Institute of China Science and Technology on Reactor System Design Technology Laboratory Chengdu China

ISBN: (纸本)9798350313765

The failure rate of aluminum electrolytic capacitor (AEC) is high in power electronic systems. Due to the complex structure of AEC, it is difficult to establish an actual model, so experiments are the common way to analyze the failure of AEC. Thus, this paper proposes a finite element method (FEM) for AEC considering electrolytic failure. Firstly, the mechanism of electrolytic failure and changes of characteristic parameters in the AEC are elucidated. Secondly, an equivalent finite element model is established to simulate and analyze the electrolytic failure of AEC. Finally, the effectiveness of the proposed AEC FEM method is verified through capacitor aging experiments. © 2023 IEEE.

关键词： aluminum electrolytic capacitor (AEC) electrolytic failure finite element method (FEM)

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Simulation Method for Multiscale Failure of Optocoupler Based on Aging of Solder Layer in Photovoltaic MOSFET 2

Simulation Method for Multiscale Failure of Optocoupler Base...

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2nd IEEE International Power Electronics and Application Symposium, PEAS 2023

作者： Chen, Xuan Yao, Ran Li, Hui Lai, Wei Min, Yuan Yang, Cheng Duan, Zeyu Chen, Siyu Xing, Zhen Chongqing University State Key Laboratory of Power Transmission Equipment Technology Chongqing China Nuclear Power Institute of China Science and Technology on Reactor System Design Technology Laboratory Chengdu China

ISBN: (纸本)9798350313765

This paper presents a simulation method for investigating the failure of optocoupler equipment (OCEP) in multi-physical fields. The method is based on the aging of the solder layer of the photosensitive field-effect tube (PFET) and aims to analyze the performance degradation of the PFET. Firstly, a comprehensive multi-physical field model of the OCEP is developed using the actual structure of the CT test OCEP, taking into account the conductivity of the chip. Next, an OCEP failure simulation method is proposed, which takes into account the shedding of the PFET solder layer caused by the failure mechanism of the OCEP. Finally, the simulation results demonstrate that the degree of solder layer shedding reaches 70%, resulting in the failure of the OCEP. © 2023 IEEE.

关键词： multi-physics modeling optocoupler solder layer failure

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Improving the ductility of laser directed energy deposited borated stainless steel by increasing laser power

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Journal of Manufacturing Processes 2025年 145卷 494-507页

作者： Huang, Sheng Li, Qingyu Zhang, Xiaoyu Cui, Bin Li, Dichen Zhang, Anfeng Miao, Kai State Key Laboratory for Manufacturing Systems Engineering School of Mechanical Engineering Xi'an Jiaotong University Xi'an710049 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China Department of Mechanical and Electrical Engineering Yuncheng University Yuncheng044000 China Co. Ltd. Chengdu610091 China

Borated stainless steels (BSSs) are extensively applied in the nuclear energy industry due to boron's excellent thermal neutron absorption capacity, but large and brittle borides formed during casting result in a low ductility. Here, a BSS was produced by laser directed energy deposition, and an investigation was conducted to analyze the impact of laser power on both the microstructure and mechanical properties of the deposited material. Fibrous borides with relatively low volume fraction in the overlapping zone resulted in higher ductility, while lamellar borides with relatively large volume fraction in the non-overlapping zone led to higher strength. As the laser power increased from 180 W to 330 W, the size of fibrous and lamellar eutectic borides and austenite increased significantly, the width of the soft overlapping zone increased by 2.27 times, and the elongation increased by 2.03 times, although yield strength and ultimate tensile strength decreased by 46.3 % and 31.7 %, respectively. As a result, these findings confirmed the feasibility of significantly improving the ductility of the as-deposited BSS by increasing the laser power. The work here provides a way to tailoring the mechanical properties of BSS produced by laser additive manufacturing. © 2025 The Society of Manufacturing Engineers

关键词： Ductility

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Improving the ductility and toughness of nano-TiC/AZ61 composite by optimizing bimodal grain microstructure via extrusion speed

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Journal of Magnesium and Alloys 2024年第8期12卷 3264-3280页

作者： Lingling Fan Mingyang Zhou Wulve Lao Yuwenxi Zhang Hajo Dieringa Ying Zeng Yuanding Huang Gaofeng Quan Key Laboratory of Advanced Technologies of Materials Ministry of EducationChengdu 610031China School of Materials Science and Engineering Southwest Jiaotong UniversityChengdu 610031China Institute of Material and Process Design Helmholtz-Zentrum HereonGeesthacht 21502Germany Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China Institute of Metallic Biomaterials Helmholtz-Zentrum HereonGeesthacht 21502Germany

In this study,the nano-TiC/AZ61 composites with different heterogeneous bimodal grain(HBG)structures and uniform structure are obtained by regulating the extrusion *** effect of HBG structure on the mechanical properties of the composites is *** increasing ductility and toughening mechanism of HBG magnesium matrix composites are carefully *** the extrusion speed increases from 0.75 mm/s to 2.5 mm/s or 3.5 mm/s,the microstructure transforms from uniform to HBG *** with Uniform-0.75 mm/s composite,Heterogeneous-3.5 mm/s composite achieves a 116.7%increase in ductility in the plastic deformation stage and almost no reduction in ultimate tensile *** is mainly because the lower plastic deformation inhomogeneity and higher strain hardening due to hetero-deformation induced(HDI)***,Heterogeneous-3.5 mm/s composite achieves a 108.3%increase in toughness compared with the Uniform-0.75 mm/s *** is mainly because coarse grain(CG)bands can capture and blunt cracks,thereby increasing the energy dissipation for crack propagation and improving *** addition,the CG band of the Heterogeneous-3.5 mm/s composite with larger grain size and lower dislocation density is more conducive to obtaining higher strain hardening and superior blunting crack ***,the increased ductility and toughness of the Heterogeneous-3.5 mm/s composite is more significant than that Heterogeneous-2.5 mm/s composite.

关键词： Nano-TiC/AZ61 composite Extrusion speed Heterogeneous bimodal grain structure Increasing ductility mechanism Toughening mechanism

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Direct Contact Condensation Characteristics of Steam Injection into Cold-Water Pipe Under Rolling Condition 23rd

Direct Contact Condensation Characteristics of Steam Injecti...

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23rd Pacific Basin Nuclear Conference, PBNC 2022

作者： Wang, Zhiwei He, Yanping Duan, Zhongdi Huang, Chao Liu, Shiwen State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Shanghai China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China

ISBN: (纸本)9789819910229

Direct contact condensation (DCC) is widely occurred in nuclear power systems and leads to undesired phenomena such as condensation-induced water hammer. For ocean nuclear power ships, DCC is inevitable in the passive heat removal system and influenced by sea conditions. In this paper, the characteristics of DCC under rolling conditions are analyzed. The numerical model of DCC is established based on computational fluid dynamics approach. The VOF model, SST k–ω turbulence model and the additional inertia force model are incorporated to describe the liquid-gas two-phase flow under the rolling motion. The condensation model based on surface renewal theory (SRT) is used to simulate steam-water DCC phenomenon. The simulation results are compared with the experimental data and show reasonable agreement. The effects of rolling motion on DCC for steam injection into a horizontal pipe filled with cold water are numerically investigated. The results show that the additional inertial forces and the average condensation rate increase with the increase of the rolling angle and frequency. The reverse flow of the seawater induced by rolling motion leads to the accumulation of the steam at the lower part of the pipe, resulting in a large pressure pulse. With the increase of rolling angle and frequency, the pressure pulse induced by DCC increases. © 2023, The Author(s).

关键词： Condensation

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Effects of Inlet Conditions on the Two-Phase Flow Water Hammer Transients in Elastic Tube 23rd

Effects of Inlet Conditions on the Two-Phase Flow Water Hamm...

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23rd Pacific Basin Nuclear Conference, PBNC 2022

作者： Zhao, Zixiang Duan, Zhongdi Xue, Hongxiang Yuan, Yuchao Liu, Shiwen State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Shanghai China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China

ISBN: (纸本)9789819910229

Two-phase flow water hammer events occur in the pipelines of the nuclear power systems and lead to transient and violent pressure shock to tube structures. For the sake of operation safety, the occurrence and severity of the two-phase water hammer should be carefully assessed. This paper presents a parameter analysis of the inlet conditions on the two-phase flow water hammer transients, with considering the elastic effect of the tube walls. A numerical model is established for the vapor-liquid two-phase flow based on the two-fluid six-equation modelling approach, with incorporating correlations and criterions for two-phase flow regime, interfacial interactions and heat transfer. The governing equations are transformed to matrix form expressed by characteristic variables, and solved using the splitting operator method and the total variation diminishing scheme. The accuracy of the model is verified against the experimental data in open literature. Then, the model is applied to investigate the effect of inlet velocity and inlet water temperature on the two-phase flow water hammer transients. The simulation results show that the increase of inlet velocity increases the pressure peak values and brings forward the onset of water hammer, and the increase of inlet temperature decreases the pressure shock. A comparison of the water hammer results between the elastic tube and rigid tube is further presented, and the effect of the elastic modulus on the water hammer is analyzed. The results also show that the pressure peak is largely affected by the tube diameter. © 2023, The Author(s).

关键词： Condensation

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NUMERICAL INVESTIGATION ON DIRECT CONTACT CONDENSATION CHARACTERISTICS OF STEAM INJECTION INTO COLD-WATER PIPE UNDER HEAVING CONDITION 30

NUMERICAL INVESTIGATION ON DIRECT CONTACT CONDENSATION CHARA...

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30th International Conference on Nuclear Engineering, ICONE 2023

作者： Wang, Zhiwei He, Yanping Duan, Zhongdi Huang, Chao Liu, Shiwen State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Shanghai200240 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China

ISBN: (纸本)9784888982566

Direct contact condensation (DCC) is widely appeared in the nuclear power plants and will lead to serious temperature and pressure fluctuations. For ocean nuclear power plants, the DCC is inevitably affected by the sea conditions, such as rolling, heaving motion. In this study, the integration of volume of fluid model (VOF) and condensation model is adopted to simulate the DCC characteristics under heave conditions. The interfacial heat and mass transfer are calculated by user-defined functions (UDF). The additional inertial force method is used to describe the heave motion. First, the DCC numerical model under heave motion is validated by the experimental data, which coincides well with the experiment results. Then, the characteristics of DCC under different heave parameters are numerically studied. The results show that the average condensation rate increases with an increase in heave amplitude, decreases with an increase in heave period. This is mainly because the heave motion will cause the liquid phase to impact the upper pipe wall, and increasing the contact area of vapor and subcooled water. The pressure oscillations induced by DCC are more complicated under heaving conditions. With heave period continuing to change, the formation mechanisms of the pressure peak are different. When the heave period is relatively small, the pressure peak is mainly induced by the acceleration of water phase under high frequency heaving motion. With an increase in the heave period, the heaving motion accelerated the formation of isolated steam bubble, and caused the condensation induced water hammer (CIWH) events, which in turn induced the pressure peak. In addition, the pressure peak is proportional to the heave amplitude. In summary, the direct contact condensation characteristics are more sensitive to the heave period under heaving conditions. These qualitative conclusions may serve as a reference for direct contact condensation simulations under heaving conditions. © 2023 by

关键词： Nuclear power plants

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Enhanced thermal isolation in porous thermal barrier coatings by the formation of pore guided thermal-shock cracks

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Science China(Technological Sciences) 2023年第4期66卷 1007-1017页

作者： ZHEN Yu WU KaiJin LIU MengQi ZHENG SongLin HE LingHui YU Yin NI Yong CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsCAS Center for Excellence in Complex System MechanicsUniversity of Science and Technology of ChinaHefei 230026China National Key Laboratory of Shock Wave and Detonation Physics China Academy of Engineering PhysicsInstitute of Fluid PhysicsMianyang 621900China

Pore structure design is an effective strategy to tailor the thermal isolation capability of thermal barrier coatings(TBCs).Pursuing optimal porosity is crucial to balance the requirements of thermal isolation and mechanical reliability since the pore structure shields thermal heat transfer but increases mechanical *** this work,we investigate how thermal heat transfer couples with fracture propagation in porous TBCs by the using thermo-mechanical coupling phase field model for *** simulated results show that cracks induced by thermal shock favor deflection that is sometimes perpendicular to the direction of heat *** thermal conductivity degradation by the transverse cracks significantly impedes thermal heat transfer,leads to enhanced reduction of the effective thermal conductivity of TBCs,decreases the average thermal stress of the substrate,and thus decreases the risk of the crack penetrating into the *** numerical results demonstrate that the phase field method fully considering the thermo-mechanical interaction between cracks and pores can be a useful tool to improve the thermal isolation of porous TBCs under extreme thermal shock loadings through pore structure design.

关键词： phasefield TBCs porosity thermal shock cracks

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reactor Containment Passive Safety Analysis: Steam Condensation in Presence of Non-condensable Gas Scaled Experiment and Modeling

Reactor Containment Passive Safety Analysis: Steam Condensat...

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2024 Pacific Basin Nuclear Conference, PBNC 2024

作者： Bhowmik, Palash K. Schlegel, Joshua P. Sabharwall, Piyush Division of Reactor System Design and Analysis Idaho National Laboratory Idaho FallsID United States Department of Nuclear Engineering and Radiation Science Missouri University of Science and Technology RollaMO United States

ISBN: (纸本)9798331307653

This study presents steam condensation scaled experiments and semi-empirical models in presence of nitrogen (N)—a noncondensable gas (NCG), simulating air in the reactor containment—to support water-cooled small modular reactors (SMRs) passive containment cooling system (PCCS) design and analysis. Previous experimental studies on PCCS are focused on fixed and smaller tube (mostly 2-in.) geometries and specific test condition variations, bringing challenges with geometric scaling and mismatching with SMR prototypic design. To address these challenges, this study presents steam condensation test dataset obtained from three scaled test sections of 1-, 2-, and 4-in.-diameter steam condensers with an annular/ jacket cooling of 2-, 3-, and 6 in.-diameter tubes, respectively. Test data were collected for steam ranges from 58 to 63 kg/hr., and NCG flow of to 13.3 kg/hr. Annular cooling water flow was varied to obtain required testing conditions of saturated steam 4.4 inlet and fully condensed outlet. Axial temperature test data of bulk cooling water, steam and condensate were collected by thermocouples for three test sections and various steam-NCG mixing/testing conditions. A standard data reduction method was adopted—utilizing iterative and nodalized mass and heat transfer calculation—to estimate axial local heat fluxes, heat transfer coefficients (HTCs), condensation rates, film thickness, and Nusselt number. Based on the obtained dataset semi-empirical model results—a ratio of experimental and Nusselt’s theoretical HTC are presented. Such results and findings are supportive of developing scaled-up testing facility, to model validations and accelerate next generation of reactors development and deployment. © 2024 Pacific Basin Nuclear Conference, PBNC 2024. All rights reserved.

关键词： Thermocouples

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