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From laboratory to on-site operation:Reevaluation of empirically based electric water chiller models

Building Simulation 2022年第2期15卷 213-232页

作者： Bin Zhang Shijun You Sheng Wang Xiaoxiao Ding Chuang Wang Yan Gao School of Environmental Science and Engineering Tianjin UniversityTianjin 300072China State Key Laboratory of Air-Conditioning Equipment and System Energy Conservation Zhuhai 519070China Guangdong Key Laboratory of Refrigeration Equipment and Energy Conservation Technology Zhuhai 519070China Beijing Key Laboratory of Heating Gas SupplyVentilating and Air Conditioning EngineeringBeijing University of Civil Engineering and ArchitectureBeijing 100044China Beijing Advanced Innovation Center for Future Urban Design Beijing University of Civil Engineering and ArchitectureBeijing 100044China

Chiller model is a key factor to building energy simulation and chiller performance *** spread of new types of electric water chillers that have higher performance and wider operating range,new challenges have been faced by building energy simulation tools and their chiller *** work takes a new type of electric water chiller as a case study and reevaluates eight typical empirically based models for predicting the energy performance of electric water chiller to verify whether they are suitable for the new type of chiller,using both laboratory test data from chiller manufacturer and online monitoring data from on-site operation of a central cooling plant with chillers of the same *** prediction ability of the chiller models(including model prediction accuracy and generation ability)in laboratory test and on-site operation situations are *** results show that the existing models can well describe the chiller performance in the laboratory test situation but perform poorly in the on-site operation *** the best two models in the laboratory dataset,the overall prediction errors of DOE-2 and GN model increase more than 250%and 75%respectively in the field *** big discrepancy of model prediction accuracy in the two situations is mainly due to the differences of evaporator and condenser water flow rates between the laboratory and on-site operation datasets,which indicates the limitations of the empirical chiller models and implies further research in future in order to improve the suitability and reliability of chiller model.

关键词： electric water chiller performance model model validation model prediction ability variable water flow rates

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Study on irradiation damage of rpv steels based on coupling cluster dynamics and crystal plasticity finite element method

Study on irradiation damage of rpv steels based on coupling ...

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2020 International Conference on Nuclear Engineering, ICONE 2020, collocated with the ASME 2020 Power Conference

作者： Wang, Xiaotong Luo, Ying Dong, Yuanyuan Yao, Weihua Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China Nuclear Power Institute of China Chengdu China

ISBN: (纸本)9780791883785

Irradiation hardening is one of the most important aging effects of reactor pressure vessel (RPV) steel in long-term service. A number of studies have indicated that irradiation hardening is mainly caused by irradiation induced defects, such as dislocation loops and precipitates. In this paper, we have simulated the irradiation damage of low-copper reactor pressure vessel (RPV) steel. The generation of Mn-Ni-Si precipitates is simulated by the cluster dynamics model based on rate theory. On this basis, the crystal plasticity finite element method based on modified crystal plasticity model is used to simulate the effect of Mn-Ni-Si precipitates on the mechanical properties of RPV steels. The simulated results has been compared with the experimental results from the literature. By coupling the cluster dynamics and the crystal plastic finite element method, we suggest a multi-scale simulation method to simulate and predict irradiation damage of RPV steel. © 2020 American Society of Mechanical Engineers (ASME). All rights reserved.

关键词： Finite element method

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An Ontology-based Knowledge Modeling towards Eco-design for Additive Manufacturing 31

An Ontology-based Knowledge Modeling towards Eco-Design for ...

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31st CIRP Conference on Life Cycle Engineering, LCE 2024

作者： Wang, Yanan Peng, Tao Kim, Samyeon Xiong, Yi Tang, Yunlong Tang, Renzhong State Laboratory of Fluid Power Components and Mechatronic Systems School of Mechanical Engineering Zhejiang University Hangzhou310058 China Department of Mechanical Engineering Jeonju University Jeonju-si Jeollabuk-do55069 Korea Republic of School of System Design and Intelligent Manufacturing Southern University of Science and Technology Shenzhen518055 China Mechanical and Aerospace Engineering Department Monash University Melbourne3800 Australia Materials Science and Engineering Department Monash University Melbourne3800 Australia Zhejiang Province Key Laboratory of Advanced Manufacturing Technology School of Mechanical Engineering Zhejiang University Hangzhou310058 China

Owing to the unique technological merits of additive manufacturing (AM), design for AM, particularly eco-design for AM, has been gaining attention in improving the sustainable performance of AM-fabricated (AMed) parts. The main challenge in harvesting potential sustainability benefits is how to capture the impact of design on sustainable performance. Though several existing studies adopted quantitative evaluation on AM sustainability and investigated the relationships between design information and sustainability information of AMed part, the sustainability information is still unavailable in the design phase. This hardly guides eco-design for AM in practice. To support the increasing industrial applications of AM, this paper illustrates related knowledge, that is, material-process-structure-ecoProperty (MPSeP) relationships to connect design and sustainability information in eco-design for AM. An ontology-based method is proposed to model the MPSeP relationships of the AMed part in a structured way. An example of an AMed hydraulic valve body was used to demonstrate the MPSeP modeling process. It is discussed that how the constructed model effectively assists AM designers through providing eco-design recommendation, and enables design software tools to perform sustainability analysis towards eco-design for AM. © 2024 The Author(s).

关键词： 3D printing

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Burnup performance analysis for candidate materials of the LWR accident tolerant control rod 14

Burnup performance analysis for candidate materials of the L...

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14th International Nuclear Fuel Cycle Conference, GLOBAL 2019 and Light Water reactor Fuel Performance Conference, TOP FUEL 2019

作者： Liu, Yong Li, Mancang Yu, Yingrui Xiao, Peng Wang, Xingbo Zhang, Bin Wang, Dongyong Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China 328# Section 1 Changshun Avenue Chengdu China

The accident tolerant fuel (ATF) is considered to be one of the most advanced concepts to improve the safety of light water reactors (LWRs). The accident tolerant control rod (ATCR) is a significant aspect in the ATF concept. The melting temperature of traditional LWR control rod (CR) materials, such as silver-indium-cadmium (AIC) alloy, is too low to endure the high temperature under several accident conditions. Consequently, varieties of candidate materials for control rod have been proposed in the previous researches because of the outstanding characters of high-temperature behavior, as well as reactivity worth, stability in coolant water and so on. In this paper, the burnup performance of the sesquioxides of the rare-earth elements (RE2O3) and the hafnia (Hf) are analyzed and compared to the traditional AIC control rod. Two parameters are chosen to reveal the burnup performance of the candidate control rod materials, the initial control rod reactivity worth and the stability of the control rod reactivity worth along with the assembly burnup. The candidate-material control rods and the AIC control rod are placed in the ATF assembly with the same conditions, and the assembly is depleted to sufficient burnup. Numerical results indicate that Eu2O3, Dy2O3, Sm2O3 and Hf are excellent ATCR materials compared to AIC. The initial control rod reactivity worth of these materials is not less than that of AIC, and the burnup stability is outstanding, especially Eu2O3 and Dy2O3 Copyright © GLOBAL 2019 - International Nuclear Fuel Cycle Conference and TOP FUEL 2019 - Light Water reactor Fuel Performance *** rights reserved.

关键词： Hafnium oxides

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Super-Twisting Control for Re-entry Rigid-Elastic Coupled Hypersonic Vehicles

Super-Twisting Control for Re-entry Rigid-Elastic Coupled Hy...

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Chinese Automation Congress (CAC)

作者： Wentao Tang Junfang Fan Yi Ji Yafeng Li Xiaobin Xu Luyao Zang Beijing Key Laboratory of High Dynamic Navigation Technology Beijing Information Science and Technology University Beijing China School of Automation Beijing Information Science and Technology University Beijing China The System Design Institute of Mechan-ical-Electrical Engineering Beijing China

A super-twisting control strategy is proposed to tackle the complex problem of attitude stabilization control for rigid-elastic coupled hypersonic vehicles experiencing significant aerodynamic perturbations. Initially, the elastic modes are treated as uncertain factors, leading to the construction of a control-oriented dynamic model. To design the attitude subsystem, a combination of a super-twisting algorithm and a non-singular terminal sliding mode is proposed. A first-order differentiator is introduced to address the “derivative explosion” issue commonly found in traditional control methods, thus eliminating the need for intricate differential computations. Moreover, a switching control strategy is integrated into the nonlinear feedback control law design, ensuring robust velocity tracking. Simulation results validate that the proposed control method surpasses conventional methods in both tracking performance and robustness.

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DC-Side Decoupling Method of DC-link Capacitor Reduction for Single Phase PWM Rectifier

DC-Side Decoupling Method of DC-link Capacitor Reduction for...

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2020 IEEE Sustainable Power and Energy Conference, iSPEC 2020

作者： Wang, Jinxin Renyong, Peng Dai, Kailei Zhang, Zhiqiang Zhang, Ting Zhao, Junjie Chen, Qian Zhang, Jianjian Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China Nuclear Power Institute of China Chengdu China

ISBN: (纸本)9781728191645

The integrated charging system of Electric vehicle consists of a single-phase PWM rectifier and a Buck converter. When the single-phase PWM rectifier works with unit power factor, the dc-link voltage contains a large voltage harmonic of twice the grid frequency. Although the output voltage ripple can be controlled within the required range using the proper control of the Buck converter, the second-order harmonic on the dc-link capacitor is inevitable. This paper proposes a de-side decoupling method for the second-order harmonic problem of the dc-link voltage of the integrated charging system. A de-side decoupling half bridge is connected in parallel to absorb the ripple power of twice the grid frequency. This paper analyzes the operating principle of the de-side decoupling half bridge. Based on a theoretical analysis of the topology and the design procedure for controlling system, the proposed converter is designed and simulated. Finally, simulation results are given to verify the method. © 2020 IEEE.

关键词： Pulse width modulation

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Study on the thermal-mechanical performance of SiC composites cladding under multiple conditions

Study on the thermal-mechanical performance of SiC composite...

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2020 International Conference on Nuclear Engineering, ICONE 2020, collocated with the ASME 2020 Power Conference

作者： Yin, Chunyu Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China No.328 section 1 changshun avenue Chengdu China

ISBN: (纸本)9780791883761

SiC has become a candidate cladding material of Accident Tolerant Fuels (ATF) due to its excellent irradiation stability and corrosion resistance. However, because SiC is a ceramic material with low toughness, brittle failure is a significant concern. In order to improve the toughness, SiC fiber is required to manufacture multi-layer SiC composites. But the current performance model or analysis tool is not available for SiC composites cladding due to its obviously difference with Zr alloy cladding. On one side, Finite element method was used in this paper to analyze the performance of SiC composites cladding under operation conditions which include normal, transient conditions and LOCA conditions;on the other side, this paper gives the performance of the SiC composites with two layers under multiple operating conditions. The result showed that the temperature was stable and the maximum hoop stress was reached at about 70d under normal condition. The power ramp can increase the cladding temperature and has visible influence on the stress distribution. The hoop stress of the cladding reversed under LOCA condition. The tensile hoop stress on the outer surface significantly increased, which caused the obvious increase of failure probability of monolithic SiC, and the failure probability of SiC layer is significantly increased. The conclusion of the analysis has guiding significance for the theoretical design of SiC composites. Copyright © 2020 ASME.

关键词： Silicon carbide

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Joint Beamforming and Offloading design for Integrated Sensing, Communication and Computation system

arXiv

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arXiv 2024年

作者： Liu, Peng Fei, Zesong Wang, Xinyi Zhou, Yiqing Zhang, Yan Liu, Fan The School of Information and Electronics Beijing Institute of Technology Beijing100081 China The State Key Laboratory of Processors The Beijing Key Laboratory of Mobile Computing and Pervasive Device Institute of Computing Technology Chinese Academy of Sciences Beijing100190 China The School of System Design and Intelligent Manufacturing Southern University of Science and Technology Shenzhen518055 China

Mobile edge computing (MEC) is powerful to alleviate the heavy computing tasks in integrated sensing and communication (ISAC) systems. In this paper, we investigate joint beamforming and offloading design in a three-tier integrated sensing, communication and computation (ISCC) framework comprising one cloud server, multiple mobile edge servers, and multiple terminals. While executing sensing tasks, the user terminals can optionally offload sensing data to either MEC server or cloud servers. To minimize the execution latency, we jointly optimize the transmit beamforming matrices and offloading decision variables under the constraint of sensing performance. An alternating optimization algorithm based on multidimensional fractional programming is proposed to tackle the non-convex problem. Simulation results demonstrates the superiority of the proposed mechanism in terms of convergence and task execution latency reduction, compared with the state-of-the-art two-tier ISCC framework. Copyright © 2024, The Authors. All rights reserved.

关键词： Beamforming

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Multiscale microstructure-based constitutive modeling of high-temperature creep rupture in post-irradiated ODS steels

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Journal of Materials Research and technology 2025年 36卷 8037-8047页

作者： Xiaobao Fu Zhenyu Zhao Zeyuan Yan Yuntao Zhong Dengke Chen Ruiqian Zhang Bin Liu Qihong Fang Jia Li State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle College of Mechanical and Vehicle Engineering Hunan University Changsha 410082 PR China State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 PR China Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of China Chengdu 610213 PR China Department of Engineering Mechanics School of Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 PR China

Oxide dispersion strengthened (ODS) steel exhibits the great potential as structural materials in nuclear energy production, owing to the complex interface between the oxide particles and the matrix to enhance the resistance of radiation damage. However, the impact of irradiation-induced defects on the thermal creep rate and resistance of ODS steel currently remains inadequately understood. The point defect concentration with the increasing time is predicted, and the coarsening of oxide particles is quantitatively evaluated during the creep using the Ostwald ripening theory. Considering the irradiation-induced microstructure, a modified thermal creep rate model is proposed, and the thermal creep rate and creep strain of irradiated ODS steel are predicted at different temperatures. The results show that the thermal creep rate reaches 3 × 10 −5 s −1 at the temperature of 500 °C and stress of 200 MPa, while the thermal creep strain does not exceed 3 % at the temperature of 800 °C. The average size and number density of the irradiated ODS steel are 8.34 nm and 2.72 × 10 18 m −3 . Meanwhile, the effect of the activation energy on the thermal creep life is predicted at different temperatures. The thermal creep life is maintained in the higher temperature range, even exceeding 10,000 h at 600 °C for irradiated ODS steels. High temperature causes the increased dislocation activity, and the coarsened oxide particles effectively hinder dislocation motion, thereby maintaining structural stability. This work aims to shed light on the influence of post-irradiation microstructure on the thermal creep performance of irradiated ODS steels, ultimately leading to the improved prediction of creep life.

关键词： Irradiation Oxide dispersion strengthening Point defect Thermal creep rate

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Effect of residual pore on the performance of UN kernel TRISO particle fuel 14

Effect of residual pore on the performance of UN kernel TRIS...

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14th International Nuclear Fuel Cycle Conference, GLOBAL 2019 and Light Water reactor Fuel Performance Conference, TOP FUEL 2019

作者： Liu, Shichao Chen, Ping Zhou, Yi Pang, Hua Xi, Yong Tang, Changbing Zhao, Yanli Qiu, Xi Guo, Zixuan Nuclear power institute of China Science and Technology on Reactor System Design Technology Laboratory Changshun Stress No.1 Chengdu Sichuan610200 China

The thermal-mechanical performance of uranium nitride (UN) tri-isotropic (TRISO) particle with residual pore used in Light Water reactor (LWR) was investigated. The effect of pore size and location on the performance of inner dense pyrolytic carbon (IPyC) layer, SiC layer and outer dense pyrolytic carbon (OPyC) layer was studied. The dimensional changes, fission gas release and internal pressure of the fuel particle layers were calculated. Residual pore size can affect the stress distribution of coated layers obviously. The residual pore especially the big ones may be the source of cracks on the SiC layer, which can break or loss the capacity of SiC layer. Residual pore location has little influence on the stress distribution of the coated layer. In order to maintain the fission retention capacity of TRISO particle, the big residual pore should be avoided during fabrication process. Copyright © GLOBAL 2019 - International Nuclear Fuel Cycle Conference and TOP FUEL 2019 - Light Water reactor Fuel Performance *** rights reserved.

关键词： Silicon carbide

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