检索结果-南通市图书馆

Journal of Thermal Science 2020年第3期29卷 697-707页

作者： zhang zhuqian WANG Yulei BA Liming Institute of Thermal Engineering School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Beijing Key Laboratory of Flow and Heat Transfer of Phase Changing in Micro and Small Scale Beijing 100044China National Institute of Clean-and-Low-Carbon Energy Beijing 102211China

The temperature uniformity and component concentration distributions in solid oxide fuel cells during operating processes can influence the cell electrochemical and thermal characteristics.A three-dimensional thermal-fluid numerical model including electrochemical reactions and water-gas-shift(WGS)reaction for a single channel solid oxide fuel cell was developed to study the steady-state characteristics,which include distributions of the temperature(T),temperature gradient((35)T/(35)x),and fuel *** was shown that the maximum temperature(Tmax)changed with operating voltage and the maximum temperature gradient(((35)T/(35)x)max)occurred at the inlet of the channel of a solid oxide fuel cell by ***,the natural convection condition had a great influence on T and(35)T/(35)*** thermal stress generated by temperature differences was the key parameter and increasing the convection heat-transfer coefficient can greatly reduce the thermal *** addition,the results also showed that there were lower temperature gradients and lower current density at high working voltage;therefore,choosing the proper operating voltage can obtain better cell performance.

关键词： three-dimensional numerical simulation internal reforming reaction solid oxide fuel cell temperature gradient fuel utilization

A Study on the Transport Process in Gas Diffusion Layer of Proton Exchange Membrane Fuel Cells

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2011年第5期20卷 449-453页

作者： Zetao Tan Li Jia zhuqian zhang Department of Power Engineering Beijing Jiaotong University

Gas diffusion layer(GDL) plays a great important role in proton exchange membrane fuel cell(PEMFC).Water transport mechanism in GDL is still not *** the present study,an ex-situ transparent setup is built to visualize the transport phenomena and to measure the threshold pressure of water in GDL at different *** is found that the relationship between the breakthrough pressure and the temperature is nearly linear(*** pressure decreases linearly with the increase of temperature).To avoid the problems faced by the continuum models,the pore network model is developed to simulate the liquid water transport through the carbon paper.A uniform pressure boundary condition is used in simulation and the results are similar to the ones obtained in the *** reason is that the contact angle and surface tension coefficient of water in GDLs change accordingly with the change of temperature.

关键词： PEMFC gas diffusion layer pore network model water breakthrough temperature

Evaluating Breakthrough Pressure in Gas Diffusion Layers of Proton Exchange Membrane Fuel Cells

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2010年第5期19卷 459-464页

作者： Ma Yue Jia Li zhang zhuqian Wang Xia School of Mechanical and Electroriic Control Engineering Beijing Jiaotong University Beijing 100044 China Department of Mechanical Engineering Oakland University Rochester MI 48309 USA

This paper studied the breakthrough pressure for liquid water to penetrate the gas diffusion layer(GDL) of a proton exchange membrane fuel cell(PEMFC).An ex-situ testing was conducted on a transparent test cell to visualize the water droplet formation and detachment on the surface of different types of GDLs through a CCD *** breakthrough pressure,at which the liquid water penetrates the GDL and starts to form a droplet,was *** breakthrough pressure was found to be different for the GDLs with different porosities and *** equilibrium pressure,which is defined as the minimum pressure required maintaining a constant flow through the GDL,was also *** equilibrium pressure was found to be much lower than the breakthrough pressure for the same type of GDL.A pore network model was modified to further study the relationship between the breakthrough pressure and the GDL properties and *** breakthrough pressure increases for the thick GDL with smaller micro-pore size.

关键词： PEMFC Gas diffusion layer Visualization Network model

Thermal Modeling and Cooling Analysis of High-power Lithium Ion Cells

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2011年第6期20卷 570-575页

作者： zhuqian zhang Li Ji a Nan Zhao Lixin Yang School of Mechanical Electronic and Control Engineering Beijing Jiaotong UniversityNo.3 Shangyuancun Beijing 100044 China

The heat generation model and three-dimensional computational fluid dynamics model for lithium ion cells were established with boundary conditions *** order to provide a better insight about the behaviors of high-power lithium ion cells under realistic discharge conditions,the temperature difference of the cells and an active thermal management system with a pure air-cooling mode were analyzed and predicted with the factors affecting the unevenness of temperature field *** results show a significant effect of the cooling flow rate on the temperature rise of the cells for all discharge *** surface temperatures are relatively uniform at lower discharge rate that makes it easier to control the temperature of the *** temperatures are expected to rise significantly toward the end of discharge and they show non-uniformity at higher discharge *** air flow rate of active cooling is required at high discharge rate and high ambient temperature for practical pack thermal management system.

关键词： Lithium ion battery thermal management system air-cooling temperature rise

在线全文

学校读者我要写书评

暂无评论

质子交换膜燃料电池扩散层水传递可视化研究

中国电机工程学报 2011年第17期31卷 106-111页

作者：谭泽涛贾力张竹茜北京交通大学机械与电子控制工程学院北京市海淀区100044

质子交换膜燃料电池(polymer electrolyte fuel cell,PEFC)扩散层(gas diffusion layer,GDL)水管理对其性能十分关键,扩散层可视化研究对指导微观模型的建立,进而指导电池的设计意义重大。搭建了一个离线扩散层可视化研究实验台,通过对... 详细信息

质子交换膜燃料电池(polymer electrolyte fuel cell,PEFC)扩散层(gas diffusion layer,GDL)水管理对其性能十分关键,扩散层可视化研究对指导微观模型的建立,进而指导电池的设计意义重大。搭建了一个离线扩散层可视化研究实验台,通过对不同碳纸进行液态水穿透实验,观测了液态水突破现象,并得到碳纸突破压力随温度近似呈线性变化且成反比。同时通过分析碳纸中传递过程,建立了一种微观模型,通过MATLAB编程计算突破压力大小,并与实验值进行了对比,得到比较一致的结果。

关键词：质子交换膜燃料电池扩散层水传递温度影响

在线全文

学校读者我要写书评

暂无评论

静电旋风分离器气相流场的数值模拟

应用力学学报 2006年第1期23卷 44-47页

作者：张吉光张竹茜沈恒根青岛理工大学青岛266033 北京科技大学北京100083 东华大学上海200051

对一内部安装电晕极的切向进口旋风分离器,以三维贴体坐标为基础,应用Bradshaw的修正k-ε湍流模型,用非交错的SIMPLE算法对静电旋风分离器的气相流场进行求解,计算结果与实验结果进行了对比。分析了电晕极的不同安装位置对旋风分离器流... 详细信息

对一内部安装电晕极的切向进口旋风分离器,以三维贴体坐标为基础,应用Bradshaw的修正k-ε湍流模型,用非交错的SIMPLE算法对静电旋风分离器的气相流场进行求解,计算结果与实验结果进行了对比。分析了电晕极的不同安装位置对旋风分离器流场的影响。从流场的角度来看,电晕极安装在筒体与排气管之间并靠近排气管的位置有利于提高静电旋风分离器的分离效率。

关键词：静电旋风分离器湍流模型数值模拟流场

圆柱形锂离子动力电池放电过程电化学与传热特性研究

在线全文

学校读者我要写书评

暂无评论

中国电机工程学报 2013年第32期33卷 54-61+5页

作者：徐蒙张竹茜贾力杨立新北京交通大学机械与电子控制工程学院

锂离子动力电池放电过程中的内部产热对电池性能和安全运行有重要影响。该文通过对磷酸铁锂动力电池建立一个涉及质量守恒、电荷守恒和能量守恒,并伴有电化学反应过程的电化学-热耦合模型,研究电池恒流放电过程的温度场和生热速率,并通... 详细信息

锂离子动力电池放电过程中的内部产热对电池性能和安全运行有重要影响。该文通过对磷酸铁锂动力电池建立一个涉及质量守恒、电荷守恒和能量守恒,并伴有电化学反应过程的电化学-热耦合模型,研究电池恒流放电过程的温度场和生热速率,并通过实验验证了模型的合理性。结果表明,低倍率放电时,可逆生热速率在总生热速率中所占份额较大;而高倍率放电时,欧姆热生热速率占绝对优势。大电流放电时,产热速率高,有必要使用电池热管理系统。

关键词：电动汽车锂离子动力电池电化学热耦合模型热特性

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

应用于质子交换膜燃料电池的数值优化方法

北京交通大学学报 2010年第3期34卷 67-70页

作者：张竹茜贾力张欣欣北京交通大学机械与电子控制工程学院北京100044 北京科技大学机械工程学院北京100083

将具有全局搜索能力的遗传算法应用于质子交换膜燃料电池(PEMFC)扩散电极的性能优化,通过对PEMFC单体建立二维稳态数值计算模型,在ISIGHT-FD软件平台上利用径向基函数(RBF)神经网络拟和模型,在相应的设计空间内生成RBF拟和曲面,调用多... 详细信息

将具有全局搜索能力的遗传算法应用于质子交换膜燃料电池(PEMFC)扩散电极的性能优化,通过对PEMFC单体建立二维稳态数值计算模型,在ISIGHT-FD软件平台上利用径向基函数(RBF)神经网络拟和模型,在相应的设计空间内生成RBF拟和曲面,调用多岛遗传算法(MIGA)对RBF拟和进行遗传搜索,得到了阴极扩散层厚度、孔隙率和渗透率的最优值,通过优化前后的氧气浓度和输出性能比较,表明这些参数可改善气体扩散层的传质性能.

关键词：燃料电池数值模型优化遗传算法

圆柱形锂离子动力电池放电过程电化学与传热特性研究

在线全文

学校读者我要写书评

暂无评论

中国电机工程学报 2013年第32期33卷 I0009-I0009页

作者： XU Meng zhang zhuqian JIA Li YANG Lixin Beijing Jiaotong University

Preparation of silver nanoparticles through the reduction of straw-extracted lignin and its antibacterial hydrogel

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 504-514页

作者： Lou zhang Shuo Li Fu Tang Jingkai zhang Yuetong Kang Hean zhang Lidong Li State Key Laboratory for Advanced Metals and Materials School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

Silver nanoparticles(Ag NPs)have attracted attention in the field of biomaterials due to their excellent antibacterial ***,the reducing and stabilizing agents used for the chemical reduction of Ag NPs are usually toxic and may cause water *** this work,Ag NPs(31.2 nm in diameter)were prepared using the extract of straw,an agricultural waste,as the reducing and stabilizing *** analysis revealed that the straw extract contained lignin,the structure of which possesses phenolic hydroxyl and methoxy groups that facilitate the reduction of silver salts into Ag *** surfaces of Ag NPs were negatively charged due to the encapsulation of a thin layer of lignin molecules that prevented their *** the prepared Ag NPs were added to the precursor solution of acrylamide,free radical polymerization was triggered without the need for extra heating or light irradiation,resulting in the rapid formation of an Ag NP-polyacrylamide composite *** inhibition zone test proved that the composite hydrogel possessed excellent antibacterial ability due to the presence of Ag *** prepared hydrogel may have potential applications in the fabrication of biomedical materials,such as antibacterial dressings.

关键词： silver nanoparticles hydrogel straw extraction antibacterial