论文总字数：32629字

摘 要

燃料电池是现在最引人注目的新型能源装置之一，被公认为21世纪最有前途的清洁能源，它为解决不断加剧的生态环境问题和能源危机问题提供了新途径。质子交换膜燃料电池（Proton exchange membrane fuel cell, PEMFC）是一种将燃料和氧化剂之间的化学能通过电极反应直接转化成电能的装置，并且有发电效率高、污染小、操作性能良好、等优点。在汽车动力源、可移动电源和固定电站等方面有广阔的应用前景。

运行寿命及稳定性不理想是造成燃料电池不能大规模应用的原因之一。而外部操作条件不当会加速电池内部关键材料的衰减，它的好坏直接影响到燃料电池的性能。操作温度是影响燃料电池性能的关键因素之一，高的温度可以提高膜的质子电导率，提高氧气还原、氢气氧化的电极动力学。然而，过高的温度会使膜电极组件（Membrane Electrode Assembly, MEA）产生变形，增大各接触面的接触压力，破坏催化剂。因此，研究温度对燃料电池膜电极组件的影响对燃料电池的发展和应用都有重要意义。

本课题以三通道蛇形流场PEM燃料电池为研究对象，采用有限元方法研究温度对燃料电池性能影响，本文的主要内容和结论如下：

（1）考虑PEM燃料电池中各部件间的接触装配关系和接触属性，利用ABAQUS有限元软件建立了包括燃料电池端板、电流收集器、双极板、弹性体垫片、膜电极组件和螺栓等在内燃料电池完整的三维有限元模型。有限元分析结果表明，工作温度对PEM燃料电池膜电极组件的位移、应力有显著影响。

（2）有限元分析结果表明，随着燃料电池温度的升高，质子交换膜与GDL的应力及位移均增大。

（3）有限元分析结果表明，质子交换膜四角及边缘的位移相对较大，其中间的位移相对较小，整体存在不均匀性。

（4）有限元分析结果表明，GDL在膨胀作用下被压入流道内的部分，该区域的应力较小但位移较大，而GDL与双极板上流场的脊发生接触的部分应力较大但位移较小。

关键词：PEM燃料电池 膜电极组件 温度 应力 位移

ABSTRACT

Fuel cells are one of the most compelling new energy devices now , and it is recognized as most promising clean energy in the 21st century , it provides a new way to solve the growing environmental problem and the problem of energy crisis. Proton exchange membrane fuel cell ( PEMFC) is a kind of equipments which directly converts chemical energy between the fuel and oxidizer through the electrode reaction into the electrical energy , it has been received great attention with high power generation efficiency , less pollution , good operating performance , etc. It can be widely applied in automobile power source, in mobile power supply and fixed station and so on.

Operating life and stability of fuel cells causes that the fuel cell can not be applied widely. The external operating conditions will accelerate the decay of the key material inside the battery , which has a direct impact on fuel cell performance .Operating temperature is one of the key factors that affects fuel cell performance , high temperatures can increase the proton conductivity of the membrane, improve electrode kinetics of oxygen reduction and hydrogen oxidation. However , the high temperature will make MEA deformed , increase the contact pressure of the contact surface , damage the catalyst. Therefore, it is significant to understand the temperature of fuel cell which influences on the fuel cell performance in theory and in practical applications.

In this paper, the PEM fuel cell with three-channel serpentine flow field was selected to be representative, the effect of the temperature on the the performance of the fuel cell was studied using finite element method under the various assembly forces.The main work and conclusions are summarized as follows:

( 1 ) Considering the contact relationship and contact behavior between components of the PEM fuel cell, using the ABAQUS finite element software , a complete three-dimensional finite element model of the PEM fuel cell was established including end plate, current collector, bipolar plate, gasket, membrane electrode assembly(MEA), and bolt. The FEM analysis shows that the temperature have a significant impact on displacement and stress of MEA in PEM fuel cells.

( 2 ) The FEM analysis results show that with increasing temperature of the fuel cell ,stress and displacement of proton exchange membrane and GDL are increased .
( 3 ) The FEM analysis results show that displacement in the corners and edges of the proton exchange membrane is larger than displacement in middle part of the proton exchange membrane .The displacement has no uniformity.

( 4 ) The FEM analysis results show that the part of GDL which is pressed into the channel in the expansion effect has smaller stress and higher displacement,the part of GDL which is contacted with the backbone has higher stress and smaller displacement.

KEYWORDS: PEM proton exchange membrane fuel cell; Membrane Electrode Assembly; temperature; stress; displacement

目 录

摘 要 I

ABSTRACT II

第一章 绪 论 1

1.1 引言 1

1.1.1 课题背景 1

1.1.2 本课题研究目的及工程应用价值 2

1.2 燃料电池发展 2

1.3 PEM燃料电池研究现状 3

1.3.1 PEM燃料电池典型结构 4

1.3.2 双极板 5

1.3.3 质子交换膜 6

1.3.4 气体扩散层 7

1.3.5 膜电极组件（MEA） 7

1.3.6 催化剂 8

1.3.7 温度对PEMFC膜电极组件应力及位移的影响 9

1.4 本文的主要研究内容 10

1.4.1 数值模拟与有限元分析方法 10

1.4.2 膜电极组件在不同温度下的数值模拟 10

第二章 数值模拟与有限元分析方法 11

2.1 引言 11

2.2 有限元方法的基本思想 12

2.3 数值模拟的理论基础 12

2.3.1 牛顿迭代法 12

2.3.2 温度应力方程及求解方法 14

2.3.3 ABAQUS有限元软件 14

2.4 本章小结 17

第三章 膜电极组件在不同温度下的数值模拟 18

3.1 引言 18

3.2 MEA有限元分析 18

3.2.1 几何参数及有限元模型 18

3.2.2 网格划分 19

3.2.3 材料属性参数定义 20

3.2.4 定义各部件间相互作用 21

3.2.5 载荷施加及边界条件设置 21

3.3 结果与分析 22

3.3.1 质子交换膜数值模拟结果与分析 22

3.3.2 气体扩散层数值模拟结果与分析 24

3.4 本章小结 26

第四章 结论与展望 28

4.1 结论 28

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