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Journal of Energy Chemistry 2024年第2期89卷 195-207,I0006页

作者： Zhuangzhuang Jia Yuanyuan Min Peng Qin Wenxin Mei Xiangdong Meng Kaiqiang Jin jinhua sun Qingsong Wang State Key Laboratory of Fire Science University of Science and Technology of ChinaHefei 230026AnhuiChina Gotion High-Tech Co. Ltd.Hefei 230012AnhuiChina

The safety valve is an important component to ensure the safe operation of lithium-ion batteries(LIBs).However,the effect of safety valve type on the thermal runaway(TR)and gas venting behavior of LIBs,as well as the TR hazard severity of LIBs,are not *** this paper,the TR and gas venting behavior of three 100 A h lithium iron phosphate(LFP)batteries with different safety valves are investigated under *** to previous studies,the main contribution of this work is in studying and evaluating the effect of gas venting behavior and TR hazard severity of LFP batteries with three safety valve *** significant results are obtained:(Ⅰ)the safety valve type dominates over gas venting pressure of battery during safety venting,the maximum gas venting pressure of LFP batteries with a round safety valve is 3320 Pa,which is one order of magnitude higher than other batteries with oval or cavity safety valve;(Ⅱ)the LFP battery with oval safety valve has the lowest TR hazard as shown by the TR hazard assessment model based on gray-fuzzy analytic hierarchy *** study reveals the effect of safety valve type on TR and gas venting,providing a clear direction for the safety valve design.

关键词： Lithium iron phosphate battery Safety valve Thermal runaway Gas venting behavior Thermal runaway hazard severity Gray-fuzzy analytic hierarchy process

Early warning method for thermal runaway of lithium-ion batteries under thermal abuse condition based on online electrochemical impedance monitoring

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Journal of Energy Chemistry 2024年第5期92卷 74-86页

作者： Yuxuan Li Lihua Jiang Ningjie Zhang Zesen Wei Wenxin Mei Qiangling Duan jinhua sun Qingsong Wang State Key Laboratory of Fire Science University of Science and Technology of ChinaAnhui 230026HefeiChin

Early warning of thermal runaway(TR)of lithium-ion batteries(LIBs)is a significant challenge in current application *** and effective TR early warning technology is urgently required considering the current fire safety situation of *** this work,we report an early warning method of TR with online electrochemical impedance spectroscopy(EIS)monitoring,which overcomes the shortcomings of warning methods based on traditional signals such as temperature,gas,and pressure with obvious delay and high *** in-situ data acquisition through accelerating rate calorimeter(ARC)-EIS test,the crucial features of TR were extracted using the RReliefF *** mechanisms corresponding to the features at specific frequencies were ***,a three-level warning strategy for single battery,series module,and parallel module was formulated,which can successfully send out an early warning signal ahead of the self-heating temperature of battery under thermal abuse *** technology can provide a reliable basis for the timely intervention of battery thermal management and fire protection systems and is expected to be applied to electric vehicles and energy storage devices to realize early warning and improve battery safety.

关键词： Online EIS measurement Lithium-ion batterysafety Multistage thermal runaway early warning Sensitivityanalysis

H9N2 influenza virus in China： a cause of concern

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Protein & Cell 2015年第1期6卷 18-25页

作者： Yipeng sun jinhua Liu Key Laboratory of Animal Epidemiology and Zoonosis Ministry of Agriculture College of Veterinary MedicineChina Agricultural University Beijing 100083 China

The recent human infection with avian influenza virus revealed that H9N2 influenza virus is the gene donor for H7N9 and H10N8 viruses infecting humans. The crucial role of H9N2 viruses at the animal-human interface might be due to the wide host range, adaptation in both poultry and mammalian, and extensive gene reassortment. As the most prevalent subtype of influenza viruses in chickens in China, H9N2 also causes a great economic loss for the poultry industry, even under the long-term vaccination programs. The history, epidemiology, bio- logical characteristics, and molecular determinants of H9N2 influenza virus are reviewed in this paper. The contribution of H9N2 genes, especially RNP genes, to the infection of humans needs to be investigated in the future.

关键词： Influenza Poultry H9N2 Evolution,Virulence Antigenic drift

Thermal stability of LiPF_6/EC+DMC+EMC electrolyte for lithium ion batteries

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Rare Metals 2006年第z1期25卷 94-99页

作者： WANG Qingsong sun jinhua CHEN Chunhua State Key Laboratory of Fire Science University of Science and Technology of China Hefei 230026 China State Key Laboratory of Fire Science University of Science and Technology of China Hefei 230026 China Department of Materials Science & Engineering University of Science and Technology of China Hefei 230026 China

The thermal stability of lithium-ion battery electrolyte could substantially affect the safety of lithium-ion battery. In order to disclose the thermal stability of 1.0 mol·L-1 LiPF6/ethylene carbonate (EC)+dimethyl carbonate (DMC)+ethylmethyl carbonate (EMC) electrolyte, a micro calorimeter C80 micro calorimeter was used in this paper. The electrolyte samples were heated in argon atmosphere, and the heat flow and pressure performances were detected. It is found that LiPF6 influences the thermal behavior remarkably, with more heat generation and lower onset temperature. LiPF6/EC shows an exothermic peak at 212 ℃ with a heat of reaction -355.4 J·g-1. DMC based LiPF6 solution shows two endothermic peak temperatures at 68.5 and 187 ℃ in argon filled vessel at elevated temperature. EMC based LiPF6 solution shows two endothermic peak temperatures at 191 and 258 ℃ in argon filled vessel. 1.0 mol·L-1 LiPF6/EC+DMC+ EMC electrolyte shows an endothermic and exothermic process one after the other at elevated temperature. By comparing with the thermal behavior of single solvent based LiPF6 solution, it can be speculated that LiPF6 may react with EC, DMC and EMC separately in 1.0 mol·L-1 LiPF6/EC+DMC+EMC electrolyte, but the exothermic peak is lower than that of 1.0 mol·L-1 LiPF6/EC solution. Furthermore, The 1.0 mol·L-1 LiPF6/EC+DMC+EMC electrolyte decomposition reaction order was calculated based on the pressure data, its value is n=1.83, and the pressure rate constants kp=6.49×10-2 kPa·-0.83·min-1.

关键词： lithium ion battery electrolyte thermal stability C80 micro calorimeter

主动电磁轴承支承的高速电动机总成热平衡分析

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轴承 2024年第7期 28-35页

作者：王鹏鹏孙进华李栋杰张钢上海大学机电工程与自动化学院上海200444

以一台由主动电磁轴承支承的某型卧式离心鼓风机为研究对象,对其电动机总成的电磁场进行仿真,得到电动机和主动电磁轴承的损耗分布,根据该鼓风机的三维模型提取空气域,分析不同风冷散热方式下冷却空气在其内部的流动情况,再运用Fluent... 详细信息

以一台由主动电磁轴承支承的某型卧式离心鼓风机为研究对象,对其电动机总成的电磁场进行仿真,得到电动机和主动电磁轴承的损耗分布,根据该鼓风机的三维模型提取空气域,分析不同风冷散热方式下冷却空气在其内部的流动情况,再运用Fluent对电动机总成温度场进行仿真,将得到的温度场仿真结果与试验结果进行对比,结果表明:电动机、径向主动电磁轴承、轴向主动电磁轴承的铜损耗率最高分别为768180,124590,281700 W/m^(3);双口直接通风加水冷散热和单口混合通风加水冷散热的仿真结果与试验结果的最大误差分别为4.15%和5.48%,单口混合通风加水冷的散热效果更好,验证了单向磁-热耦合温度场分析方法的合理性。

关键词：滑动轴承磁力轴承电动机温度场能量损耗散热有限元分析

维普期刊数据库博看期刊

Self-organized criticality judgment and extreme statistics analysis of major urban fires

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Chinese Science Bulletin 2011年第6期56卷 567-572页

作者： WANG JingHong XIE Shu sun jinhua State Key Laboratory of Fire Science University of Science and Technology of China Hefei 230026 China USTC-CityU Joint Advanced Research Centre Suzhou 215123 China Anhui General Fire Brigade Hefei 230026 China

The spatial (economic loss) and temporal characteristics of urban fires were analyzed employing relevant statistical methods. A fractal structure in terms of the power-law relation between fire frequency and economic loss was found on a spatial scale, and an exponential relation between frequency and time interval was found on a temporal scale. Thus, urban fire does not meet the rigorous criteria of self-organized criticality. In addition, based on the spatial power-law distribution characteristics, a correlation model of the frequency and scale of loss due to urban fire was established using the extremum statistical method. This model was then applied to the case analysis of Hefei and the probability of major fire incidents in the future was predicted.

关键词：自组织临界性城市火灾统计分析统计方法时空特征经济损失时间尺度相关模型

A reduced state SISO iterative decoding algorithm for serially concatenated continuous phase modulation

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Science in China(Series F) 2007年第4期50卷 539-550页

作者： sun jinhua LI JianDong JIN LiJun State Key Laboratory of Integrated Service Networks Xidian University Xi'an 710071 China

In this paper, serially concatenated continuous phase modulation （SCCPM） system is analyzed and a reduced state soft input soft output （SlSO） a posteriori probability algorithm is proposed. Based on the reduced state sequence detection （RSSD）, it has the more general form compared with other reduced state SISO algorithms. The proposed algorithm can greatly reduce the state number, thus leads to the computation complexity reduction. It also minimizes the degradation in Euclidean distance with decision feedback in the reduced state trellis. Analysis and simulation results show that the performance degradation is little with proper reduction scheme.

关键词： concatenated codes continuous phase modulation (CPM) soft input soft output (SISO) Euclidean distance

Experimental and LES investigation of flame propagation in a hydrogen/air mixture in a combustion vessel

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Chinese Science Bulletin 2014年第20期59卷 2496-2504页

作者： Huahua Xiao Zhanli Mao Weiguang An jinhua sun State Key Laboratory of Fire Science University of Science and Technology of China Department of Fire Protection Chinese People’s Armed Police Force Academy

This work presents an experimental and numerical investigation of premixed flame propagation in a hydrogen/air mixture in a closed combustion *** the experiment,high-speed schlieren video photography and pressure sensor are used to examine the flame dynamics and pressure *** the numerical study,a large eddy simulation(LES)based on a RNG sub-grid approach and a LES combustion model is applied to reproduce experimental *** effects of four physical phenomena on the burning velocity are considered in the combustion model,and the impact of grid type on the combustion dynamics is examined in the LES *** flame experiences four stages both in experiment and LES calculations with structured and unstructured grids,i.e.,spherical flame,finger-shaped flame,flame with its skirt in contact with the sidewalls,and tulip-shaped *** flame speed and pressure in the vessel develop with periodical oscillations in both the experiment and LES simulations due to the interaction of flame front with pressure *** numerical simulations compare well with the detailed experimental measurements,especially in term of the flame shape and position,pressure build-up,and periodical oscillation *** LES combustion model is successfully validated against the bench-scale *** is put into evidence that mesh type has an impact to a certain extent on the numerical combustion dynamics,and the LES calculation on structured grid canpredict the flame dynamics and pressure rise more accurately than that on unstructured grid with the same mesh *** flame shape is more asymmetrical in the LES on an unstructured grid than that on a structured grid,and both the flame speed and the pressure rise at the later flame stage are underestimated in the LES on the unstructured grid.

关键词：火焰传播实验测量空气混合物燃烧器 Les 非结构化网格燃烧动力学数值模拟

Transition-metal redox evolution and its effect on thermal stability of LiNixCoyMnzO_(2) based on synchrotron soft X-ray absorption spectroscopy

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Journal of Energy Chemistry 2021年第8期30卷 446-454,I0010页

作者： Chen Liang Wenhua Zhang Zesen Wei Zhaoyu Wang Qingsong Wang jinhua sun State Key Laboratory of Fire Science University of Science and Technology of ChinaHefei 230026China National Synchrontron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China

Based on the synchrotron soft X-ray absorption spectroscopy experiments,the fundamental electronic structures of layered Li NixCoyMnzO_(2)(NCM)are investigated systematically and the data of transitionmetal(TM)L-and O K-edges spectra are *** of Ni ions under different oxidation states is evaluated according to linear combination *** is found that the ratio of Ni^(4+)expands with the increase of Ni since it dominates in charge compensation during charging,and that the existence of Ni^(3+)is nearly negligible in delithiated *** valence state of Co also strongly depends on Ni content,the perceptible position shift of Co L_(3)-edge absorption peak towards higher energy in Ni-rich material agrees well with the small voltage plateau at around 4.2 *** stability of Mn is verified as no obvious spectral change with the Mn L-edge is ***,as Ni content rises,the O 2p holes near the Femi level increases with higher oxidation state of Ni,indicating the enhanced hybridization of O 2p-TM 3 *** NCMs with higher Ni content are prior to lose electron existing in highly hybridized Ni3 dO 2 p bands upon heating,which accounts for the pronounced O_(2)release in phase transitions and the deterioration in thermal *** detailed observation of the electronic structure evolution is one of the key ingredients to improving the electrochemical and thermal performance of NCM.

关键词： Lithium ion battery safety Cathode material Soft X-ray absorption spectroscopy Thermal stability

Inhibiting effect of Al(OH)_3 and Mg(OH)_2 dust on the explosions of methane-air mixtures in closed vessel

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Science China(Technological Sciences) 2012年第5期55卷 1371-1375页

作者： WANG QiuHong WEN Hu WANG QingSong sun jinhua State Key Laboratory of Fire Seience University of Science and Technology of ChinaHeJei 230026China School of Energy Engineering Xi'an University of Science and TechnologyXi'an 710054China

The inhibiting effect of AI（OH）3 and Mg（OH）2 dust on explosion of methane-air mixtures was investigated by means of explosion parameter tests in a 20-liter closed vessel. The influences of varying methane concentration and dust concentration on explosion parameters were characterized based on the experimental data to determine the maximum explosion pressure, maximum rate of pressure rise, lower explosion limits and upper explosion limits. The inhibiting mechanisms of these kinds of dust were analyzed as well. The investigations indicate that AI（OH）3 and Mg（OH）2 dust can be used as inhibitors to prevent meth- ane explosion, however, their inhibiting effects are less than those of inert gas such as N2 and CO2 in that their dust can weaken the methane explosion but cannot totally eliminate it. The tests show that all of the explosion parameters with dust additives are strongly dependent on methane/air ratio and dust concentration, and AI（OH）3 dust has better performance than Mg（OH）2 dust in inhibiting methane explosion. The average percentage decreases of maximum explosion pressure and maximum rate of pressure rise with AI（OH）3 dust are 11.08% and 66.15%, respectively. Experiments also showed that there is a special phe- nomenon when methane explosion is inhibited by AI（OH）3 and Mg（OH）2 dust, in which is that during the process of explosion the maximum explosion pressure value first decreases then increases as dust concentration increases. The best dust concentrations to inhibit the explosion are 250 g/m3 with methane/air ratio at 9.5%, and 200 g/m3 with methane/air ratio at 7%. It is suggested that water vapor produced by the thermal decomposition of metal hydroxides makes the particles of descending dust combine, resulting in a decrease of the real dust concentration in the vessel. Water vapor also is the major cause of another phenomenon that the LEL curve and the UEL curve never meet with the increase of gas concentration.

关键词： explosion inhibition explosion pressure explosion limits dust metal hydroxides