Identification and novel adaptive fuzzy control of nonlinear system for PEMFC stack

PEMFC is a clean energy with high efficiency.Itis a high-tech subject,which has rapidly developed inmany countries.In the last decade,great progress onPEMFC modeling has been achieved by many research-ers.Many kinds of mathematical models have been es-tab…     

基于改进型RBF神经网络的PEMFC电特性建模

常规能源短缺的今天,开发利用新型清洁、绿色能源已成为各国科学家共同追求的目标。质子膜燃料电池（PEMFC）以其高功率密度,启动迅速,无污染等优点成为21世纪首选清洁能源系统。但其原理涉及热力学、电化学、流体力学、传质学等理论,形成一个非线性复杂系统,难以建立数学模型。因此,采用一种动态白适应网络即最近邻聚类径向基函数神经网络,它能够动态调节网络的规模和参数,具有较强的逼近能力以及自学习能力。并利用测试数据作为训练样本,在氢气流速给定的条件下,以空气（或氧气）压力和冷却水流速作为模型的输入量,电池的电压为输出量,建立了在工作温度为60℃和80℃时的PEMFC电特性模型。表明该方法具有简单、可行、精度高等优点。并为PEMFC控制系统的设计和电池性能的优化提供了基本依据。     

PEMFC用小型稳压变换器及其监控系统

设计了质子交换膜燃料电池(PEMFC)用稳压变换器及其监控系统.采用Boost、Buck串联拓扑结构为稳压DC/DC 变换器的主电路,对其工作原理进行了分析.介绍了监控系统的监控对象及其参数设定,研制出了样机.试验结果表明,该样机各项技术指标均达到使用要求,工作稳定可靠.     

胶体法制备PEMFC催化剂的评述

胶体法可有效地控制催化剂颗粒的粒径,是制备高Pt负载量催化剂的有效方法.对近几年胶体法制备质子交换膜燃料电池(PEMFC)催化剂的状况进行了评述.按稳定胶体的机理,胶体法可分为无保护剂法和有保护剂法.     

石墨/酚醛树脂复合板与碳纸间接触电阻

应用模压工艺制备了质子交换膜燃料电池（PEMFC）用石墨/酚醛树脂（PF）复合板.通过四电极法测量了复合板与碳纸间的接触电阻.考察了接触压力、PF树脂含量及模压工艺条件对接触电阻的影响.结果表明,接触压力和PF树脂含量是对接触电阻有较大程度影响的两个重要因素.接触压力的增大导致接触电阻迅速减小,而随着PF树脂含量的增加,接触电阻有着非常快的增加趋势.模压压力对接触电阻已有一定程度的影响,但其影响幅度不如接触压力和树脂含量那么大.随着模压压力的增大,接触电阻的增加趋势比较缓慢.模压时间和模压温度对接触电阻基本没有影响.     

全氟磺酸树脂/PVDF共混膜的研究

为了降低质子交换膜的成本,选用聚偏氟乙烯和全氟磺酸树脂为原料,采用溶液-浇铸法制备了全氟磺酸树脂/聚偏氟乙烯的共混膜.通过XPS测试发现共混膜在制备过程中不同接触面元素含量不同;这些不同的元素含量对共混膜的发电性能产生了一定程度的影响.在相同条件下,O2通往空气成膜一方时的发电性能比通往玻璃一方的发电性能要好.     

Comparison of multi-inlet and serpentine channel design on water production of PEMFCs

Two flow field designs, a new multi-inlet design and a conventional serpentine design, for a PEMFC together with relative humidity (RH) and porosity of the gas diffusion layer (GDL) are studied in relation to net water production using a 3-dimensional computational fluid dynamics simulation. The results show that (1) with increasing GDL porosity, discharged water in the serpentine design slightly increases, because accumulated water decreases, whereas discharged water in the multi-inlet design decreases due to a reduction of generated water; (2) although fuel cell power performance improves as RH increases, net water production decreases in both designs, because more water is accumulated; and (3) comparatively higher power and net water production are observed with the multi-inlet design, owing to uniform distributions of reactant gas and water. It is determined that, for net water production without compromising power production, input water should be decreased and, for higher cell performance, flow field design like multi-inlet design should be developed.     

Swelling effect of a polymer electrolyte membrane on the development of a semi-empirical cell voltage model

We developed a new cell voltage model which depends on the current density response of the proton exchange membrane fuel cell (PEMFC). The proposed model focuses on the conductivity of a PEMFC fuel cell. The model for conductivity of a polymer electrolyte membrane, Nafion, uses the thermodynamic function to represent water activity. We observed membrane conductivity by monitoring the chemical potential of the swelling of the hydrogel. The swelling equilibrium of the ionized hydrogel is governed by the free energy of mixing, the free energy of elasticity, and the concentration of counterions with fixed charges on the gel network. A cell voltage equation with reasonable boundary conditions, including the swelling effect, which plays a major role in determining the cell voltage of a PEMFC, was newly developed.     

聚合物电解质膜燃料电池气体扩散层上新型双层微孔层的制备和性能

聚合物电解质膜燃料电池（PEMFC）的微孔层对电池性能有重要影响。首次使用多壁碳纳米管（MWCNTs）在碳纸上先制备1层微孔层,再用碳黑（CB）在其上制备第2层微孔层,形成双层微孔层。从不同尺度上观察了微孔层（MPL）的形貌和结构,测量了气体扩散层（GDL）垂直向电阻,并测试了电池性能。结果表明,双层微孔层的平整程度与单独使用碳黑制备的微孔层相似,比单独使用MWCNTs制备的微孔层更加平整;双层微孔层的GDL垂直向的电阻比单层微孔层的GDL更小;使用双层微孔层制备的膜电极比相同碳载量下的单层微孔层制备的膜电极性能更好。     

空气自然对流式质子交换膜燃料电池的三维建模和实验分析

在空气自然对流式燃料电池内部,速度、温度、组分浓度及电流分布特性有着极强的耦合作用.氧气质量传输限制引起的浓度过电位是这种燃料电池的主要性能损失.从自然对流、传热传质的角度,建立了三维数学模型.利用三维流体动力学软件和用户建立的子程序,对自然对流下Navier-Stokes 方程,能量方程,电化学动力学方程以及组分、水的传输方程进行了数值求解.通过分析数值计算的结果,结合自然对流的特性,设计了实验系统.对温度分布和电池性能进行了测试.对空气湿度对电池性能的影响进行了分析.数值计算结果与实验结果很好地吻合.模型的建立,对于认识空气自然对流式质子交换膜燃料电池内部的耦合传输现象有极大的意义,可以作为质子交换膜燃料电池的计算机辅助优化设计工具.