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Numerical simulation research on multiphase flow of aviation centrifugal pump based on OpenFOAM

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Chinese Journal of Aeronautics 2024年第4期37卷 256-275页

作者： Xianwei LIU Jiangfeng FU Junjie YANG Dewen YIN Zhenhua ZHOU Huacong LI College of power and Energy Northwestern Polytechnical UniversityXi’an 710072China Norinco Group Testing and research Institute Huayin 714200China AECC Xi’an Engine Control technology Co.Ltd. Xi’an 710077China AECC Guizhou Honglin Aero Engine Control technology Co.Ltd. Guiyang 550009China

This paper aims to tackle the calculation efficiency problem raised in the cavitation-flow simulation of the aviation centrifugal pump due to the fading-away interface resulting from the dissipation of numerics used in the phase-change control equation for unstructured-grid multiphase flow,and due to the limitation of flow time-step in whole flow regimes,the control equation of vapor–liquid two-phase flow considering cavitation mass transport is established firstly,modifying the momentum equation by introducing the surface tension,and adding the artificial convective flow to the phase equation to solve the numerical dissipation ***,in consideration of the local time step principle and based on the multi-dimensional general limiter algorithm with explicit solutions under the OpenFOAM platform,a solution method of steady-state VOF (Volume of Fluid) model considering cavitation two-phase change is constructed,and the feasibility of this method is verified by NACA hydrofoil and NASA flat plate ***,based on the platform developed,the cavitation performance of an aviation centrifugal pump inducer is *** research results show that the error of the calculated cavitation pressure distribution for NACA hydrofoil between the simulation test and the experimental-test is less than 5%,and the maximum error of calculated cavitation number at pump head dropping for NASA high-speed flat plate inducer between the simulation test and the experimental-test is 2.1%.The cavitation area observed in the simulation test is the same as that obtained in the high-speed photography *** on the OpenFOAM simulation method,the position of pump head dropping of the fuel centrifugal pump can be accurately *** error of the calculated cavitation number at pump head dropping between the simulation test and the experimental test is about 3.7%,showing high calculation accuracy.

关键词： Aero engine Fuel centrifugal pump Multiphase flow OpenFOAM Volume of fluid

Low-Frequency Stability Analysis of power Electronic Traction Transformer Based Train-Network System

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CSEE Journal of power and Energy Systems 2024年第4期10卷 1608-1617页

作者： Yi Hong Yang Li Zhikang Shuai Hanyu Yang College of Electrical and Information Engineering Hunan University and the Advanced Energy Technology Center of State Grid Shanghai Energy Interconnection Research Institute Co.Ltd.Shanghai 201203China College of Electrical and Information Engineering Hunan UniversityChangsha 410082China College of Electrical Engineering and Controal Science in Nanjing Tech University Nanjing 211816China

power electronic traction transformers(PETTs)will be increasingly applied to locomotives in the future for their small volume and light ***,similar to conventional trains,PETTs behave as constant power loads and may cause low-frequency oscillation(LFO)to the train-network *** solve this issue,a mathematical model of the PETT is firstly proposed and verified based on the extended describing function(EDF)method in this *** the proposed model,the LLC converter is simplified to an equivalent circuit consisting of a capacitor and a resistor in *** is further demonstrated that the model can apply to various LLC converters with different topologies and ***,when the parameter differences between cells are not obvious,the PETT can be simplified to a single-phase rectifier(i.e.,conventional train)by equivalent *** on the model of PETT,the system low-frequency stability and influential factors are analyzed by using the generalized Nyquist ***,the correctness and accuracy of theoretical analyses are validated by off-line and hardware-in-the-loop simulation results.

关键词： Extended describing function method impedance model low-frequency oscillation power electronic traction transformer train-network system

考虑电压-气压的电-气耦合综合能源系统静态稳定域分析方法（英文）

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Engineering 2024年第5期 132-145页

作者：穆云飞刘志彬郭向伟贾宏杰侯恺余晓丹骆柏锋栗海润 Key Laboratory of Smart grid of Ministry of Education Tianjin University State grid Tianjin Electric power Company china southern power grid Digital grid research Institute Co. Ltd.

In an integrated electricity-gas system(IEGS), load fluctuations affect not only the voltage in the power system but also the gas pressure in the natural gas system. The static voltage stability region(SVSR)method is a tool for analyzing the overall static voltage stability in a power system. However, in an IEGS, the SVSR boundary may be overly optimistic because the gas pressure may collapse before the voltage collapses. Thus, the SVSR method cannot be directly applied to an IEGS. In this paper, the concept of the SVSR is extended to the IEGS-static stability region(SSR) while considering voltage and gas ***, criteria for static gas pressure stability in a natural gas system are proposed, based on the static voltage stability criteria in a power system. Then, the IEGS-SSR is defined as a set of active power injections that satisfies multi-energy flow(MEF) equations and static voltage and gas pressure stability constraints in the active power injection space of natural gas-fired generator units(NGUs). To determine the IEGSSSR, a continuation MEF(CMEF) method is employed to trace the boundary point in one specific NGU scheduling direction. A multidimensional hyperplane sampling method is also proposed to sample the NGU scheduling directions evenly. The obtained boundary points are further used to form the IEGSSSR in three-dimensional(3D) space via a Delaunay triangulation hypersurface fitting method. Finally,the numerical results of typical case studies are presented to demonstrate that the proposed method can effectively form the IEGS-SSR, providing a tool for IEGS online monitoring and dispatching.

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Low-Carbon Dispatch of an Integrated Energy System Considering Confidence Intervals for Renewable Energy Generation

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Energy Engineering 2024年第2期121卷 461-482页

作者： Yan Shi Wenjie Li Gongbo Fan Luxi Zhang Fengjiu Yang power Supply Service Supervision and Support center East Inner Mongolia Electric Power Co.Ltd.Tongliao028000China School of Electrical and Electronic Engineering North China Electric Power UniversityBeijing102206China

Addressing the insufficiency in down-regulation leeway within integrated energy systems stemming from the erratic and volatile nature of wind and solar renewable energy generation,this study focuses on formulating a coordinated strategy involving the carbon capture unit of the integrated energy system and the resources on the load storage side.A scheduling model is devised that takes into account the confidence interval associated with renewable energy generation,with the overarching goal of optimizing the system for low-carbon *** begin with,an in-depth analysis is conducted on the temporal energy-shifting attributes and the low-carbon modulation mechanisms exhibited by the source-side carbon capture power plant within the context of integrated and adaptable operational *** from this analysis,a model is devised to represent the adjustable resources on the charge-storage side,predicated on the principles of electro-thermal coupling within the energy ***,the dissimilarities in the confidence intervals of renewable energy generation are considered,leading to the proposition of a flexible upper threshold for the confidence *** on this,a low-carbon dispatch model is established for the integrated energy system,factoring in the margin allowed by the adjustable *** the final phase,a simulation is performed on a regional electric heating integrated energy *** simulation seeks to assess the impact of source-load-storage coordination on the system’s low-carbon operation across various scenarios of reduction margin *** findings underscore that the proactive scheduling model incorporating confidence interval considerations for reduction margin reserves effectively mitigates the uncertainties tied to renewable energy *** harmonized orchestration of source,load,and storage elements,it expands the utilization scope for renewable energy,safeguards the economic efficiency of system operati

关键词： Integrated energy system carbon capture power plant confidence interval optimized scheduling

Editorial:The development of eco-friendly insulating gases and SF6-free equipment for‘net-zero’

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High Voltage 2024年第1期9卷 1-1页

作者： Song Xiao Yi Li Ju Tang Xiaoxing Zhang State Key Laboratory of power grid Environmental Protection School of Electrical Engineering and AutomationWuhan UniversityWuhanHubeiChina Hubei Engineering research center for Safety Monitoring of New Energy and power grid Equipment School of Electrical and Electronic EngineeringHubei University of TechnologyWuhanHubeiChina

Developing low-carbon gas insulated transmission and distribution equipment is essential to achieve the‘carbon peak,carbon neutralisation’or‘net-zero’in the power *** have carried out various research on the eco-friendly insulating gas(such as C4F7N,C5F10O)and next-generation SF6-free equipment to gradually reduce the utilisation of strong greenhouse gas SF6.

关键词： SF6 carbon free

Lithium polysulfide solvation and speciation in the aprotic lithium-sulfur batteries

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Particuology 2024年第6期89卷 238-245页

作者： Jinhao Zhang Qingshan Fu Peng Li Ruibo Linghu Xiaozhong Fan Haibin Lin Juncao Bian Songbai Han Gengzhi Sun Long Kong Frontiers Science center for Flexible Electronics and Xi’an Institute of Flexible Electronics Northwestern Polytechnical UniversityXi’an710129China china Automotive Innovation Corporation Nanjing211100China Academy for Advanced Interdisciplinary Studies Southern University of Science and TechnologyShenzhen518055China Institute of Advanced Materials Nanjing Tech UniversityNanjing211816China

Fingerprinting sulfur speciation in aprotic electrolytes is a key to understand fundamental chemistry and design well-performing lithium–sulfur(Li–S)*** polysulfide(LiPS)dissolution and deposition in ether-based electrolytes during redox reactions have been probed and established by spectroscopy and ***,detailed LiPS structure and solvation properties influenced by conventional and newly developed electrolytes remain elusive,which exert fundamental challenges and practical difficulties in decoupling battery performance from electrolyte *** perspective aims to provide timely information to uncover underlying mechanisms that rein in sulfur speciation by considering the charge density of LiPSs and the coordination strength of solvents/*** discussion starts with unlocking the baseline electrolyte formulation to investigate its role in LiPS formation and *** that,the term coordination strength is used instead of donor number and dielectric constant to describe interactions between solvents and LiPSs and to reveal LiPS structure *** work is expected to encourage the discovery of new electrolyte working mechanisms to develop energy-dense and power-intensive Li–S batteries.

关键词： Sulfur speciation Redox kinetics Coordination strength Solvation chemistry Lithium-sulfur batteries

Surface encapsulation of layered oxide cathode material with NiTiO_(3) for enhanced cycling stability of Na-ion batteries

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Chinese Physics B 2024年第8期33卷 551-558页

作者：胡紫霖唐彬林挺张楚牛耀申刘渊高立克谢飞容晓晖陆雅翔胡勇胜 Key Laboratory for Renewable Energy Beijing Key Laboratory for New Energy Materials and DevicesBeijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing 100190China College of Materials Science and Optoelectronic technology University of Chinese Academy of SciencesBeijing 100049China Huairou Division Institute of PhysicsChinese Academy of SciencesBeijing 101400China Yangtze River Delta Physics research center Co.Ltd Liyang 213300China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100049China Guangxi power grid Co.Ltd. Nanning 530023China

In Na-ion batteries,O3-type layered oxide cathode materials encounter challenges such as particle cracking,oxygen loss,electrolyte side reactions,and multi-phase transitions during the charge/discharge *** study focuses on surface coating with NiTiO_(3) achieved via secondary heat treatment using a coating precursor and the surface *** in-situ x-ray diffraction(XRD)and differential electrochemical mass spectrometry(DEMS),along with crystal structure characterizations of post-cycling materials,it was determined that the NiTiO_(3) coating layer facilitates the formation of a stable lattice structure,effectively inhibiting lattice oxygen loss and reducing side reaction with the *** enhancement in cycling stability was evidenced by a capacity retention of approximately 74%over 300 cycles at 1 C,marking a significant 30%improvement over the initial ***,notable advancements in rate performance were *** results indicate that a stable and robust surface structure substantially enhances the overall stability of the bulk phase,presenting a novel approach for designing layered oxide cathodes with higher energy density.

关键词： Na-ion battery layered oxides high voltage surface coating

Electricity-Heat-Based Integrated Demand Response Considering Double Auction Energy Market with Multi-Energy Storage for Interconnected Areas

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CSEE Journal of power and Energy Systems 2024年第4期10卷 1688-1700页

作者： Dan Wang Deyu Huang Qing'e Hu Hongjie Jia Bo Liu Yang Lei Key Laboratory of Smart grid of Ministry of Education Tianjin UniversityTianjin 300072China Key Laboratory of Smart Energy&Information technology of Tianjin Municipality Tianjin 30072China

With development of integrated energy systems and energy markets,transactive energy has received increasing attention from society and academia,and realization of energy distribution and integrated demand response through market transactions has become a current research *** on optimized operation of a distributed energy station as a regional energy supply center is of great significance for improving flexibility and reliability of the *** on retail-side energy trading market,this study first establishes a framework of combined electric and heating energy markets and analyses a double auction market mechanism model of interconnected distributed energy *** study establishes a mechanism model of energy market participants,and establishes the electric heating combined market-clearing model to maximize global surplus considering multi-energy ***,in the case study,a typical user energy consumption scenario in winter is selected,showing market-clearing results and demand response effects on a typical *** of transmission line constraints,energy supply equipment capacity,and other factors on clearing results and global surplus are compared and analyzed,verifying the effects of the proposed method on improving global surplus,enhancing interests of market participants and realizing coordination and optimal allocation of both supply and demand resources through energy complementarity between regions.

关键词： Double auction energy market integrated energy system interconnected energy stations multi-energy storage

Nb_(3)Sn六极复合超导磁体测试全过程的实时分布式应变检测:从组装到励磁

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Acta Mechanica Sinica 2024年第4期40卷 78-88页

作者：王省哲杨韬略关明智辛灿杰吴北民吴魏孙良亭赵红卫周又和 Key Laboratory of Mechanics on Western Disaster and Environment Ministry of EducationCollege of Civil Engineering and MechanicsLanzhou UniversityLanzhou730000China china southern power grid technology Co. Ltd.Guangzhou510080China Institute of Modern Physics Chinese Academy of SciencesLanzhou730000China Advanced Energy science and technology Guangdong Laboratory Huizhou516000China

六极Nb_(3)Sn超导磁体系统是第四代电子回旋共振离子源(FECR)中的核心部件.这些超导磁体处于高磁场、超低温以及高应力的极端运行环境,由此关联的磁体应力/应变特征和行为的精确表征对于确保系统可靠性和最优功能实现极具重要意义.传统... 详细信息

六极Nb_(3)Sn超导磁体系统是第四代电子回旋共振离子源(FECR)中的核心部件.这些超导磁体处于高磁场、超低温以及高应力的极端运行环境,由此关联的磁体应力/应变特征和行为的精确表征对于确保系统可靠性和最优功能实现极具重要意义.传统的单点应变测量技术仅能实现局部小区域的测量,并且存在显著的电磁干扰等,这些局限性严重影响了测量精度和可靠性,使得大型复杂超导磁体极端多场下的力学测量面临着诸多挑战.本文建立了低温极端多场下的光纤测量新技术,可实现六极复合超导磁体的实时、分布式应变测量.该测量系统基于光频域反射技术(OFDR)和高空间分辨率分布式光纤技术,首次实现了超导磁体系统的组装、冷却、励磁及失超全过程中应变状态的实时监测.相关结果有效揭示了超导磁体在整个运行过程中的全局应变特性,如磁体内部全局应变状态的非对称分布现象等.本文研究对于超导磁体研制中的实时和全局力学性能监测和评估提供了有效途径.

关键词：超导磁体励磁应变状态失超力学测量分布式光纤电磁干扰应变特性