燃料电池膜系结构氧化还原性能研究

发布时间：2018-04-26 23:12

本文选题：阳极支撑氧化物燃料电池 + 微观形貌　；参考：《西北工业大学》2014年博士论文

【摘要】：燃料电池SOFC是一种在恒定工作温度下将储存在燃料中的化学能直接转化为电能的转化系统。和传统的热电转化系统相比，该系统是直接从化学能到电能转化过程，同时转化过程中气体污染物的排放量很低，接近于零排放，是一种高效清洁的能量转换系统。因此阳极支撑氧化物燃料电池工作过程中还原氧化过程的相关研究是一个亟待解决的重要科学和技术研究课题。基于此，论文在国家自然基金项目“长寿命能量转换多层膜系结构失效模式与表征方法研究”的资助下，研究了阳极支撑氧化物燃料电池的性能，对燃料电池的运行过程中的结构形貌变化，还原过程曲线，结构残余应力变化等进行了测试，深入探讨了阳极支撑固体氧化物燃料电池运行过程中变化规律。论文的主要工作如下：（1）论文首先测试了燃料电池阳极完全还原过程曲线，得到了不同还原时间和不同还原温度阳极层还原过程变化规律；并模拟分析了反应过程中热流场环境，实现了还原氧化反应过程中温度控制和流量控制，对燃料电池进行热力学描述，并设计了试验反应过程和还原氧化反应试验的操作流程。（2）论文研究发现了不同氧化还原时间与温度下阳极支撑氧化物燃料电池残余应力的变化规律，发现残余应力随还原程度增加而下降，，给出了曲线下降规律，分析了残余应力对电解质膜屈服强度等相关力学性能的影响，分析了发生塑性变形和开裂的原因。（3）论文研究了阳极支撑氧化物燃料电池半电池电解质层、界面层、阳极层在还原过程和还原再氧化过程的微观形貌，进行了结构表征，对比了反应前后微观形貌、能谱变化。（4）论文测试了阳极支撑氧化物燃料电池电解质层的热膨胀系数及应力应变，研究了半电池的还原及再氧化的热膨胀性能。论文研究对于燃料电池的运行和工艺改进具有理论意义和工程实用价值。
[Abstract]:Fuel cell SOFC is a conversion system that converts the chemical energy stored in the fuel into electric energy at a constant operating temperature. Compared with the traditional thermoelectric conversion system, this system is a kind of efficient and clean energy conversion system, which is a direct conversion process from chemical energy to electric energy. At the same time, the emission of gas pollutants in the conversion process is very low, close to zero emission. Therefore, the research on the reduction and oxidation process of anodic supported oxide fuel cells is an important scientific and technical research topic to be solved urgently. Based on this, the performance of anodic supported oxide fuel cell (OFC) is studied under the National Natural Fund project "study on failure modes and characterization methods of long Life Energy conversion Multilayer system". The changes of structure morphology, reduction curve and structural residual stress during the operation of the fuel cell were measured, and the variation law of the anode supported solid oxide fuel cell during the operation was discussed. The main work of the thesis is as follows: Firstly, the anodic complete reduction process curve of fuel cell is measured, and the variation law of anodic layer reduction process at different reduction time and temperature is obtained, and the heat flow field in the reaction process is simulated and analyzed. The temperature control and flow rate control in the process of reducing and redox reaction were realized, the thermodynamic description of fuel cell was carried out, and the experimental reaction process and the operation flow of reduction and oxidation reaction test were designed. 2) the variation of residual stress of anodic supported oxide fuel cell at different redox time and temperature is found. The residual stress decreases with the increase of reduction degree, and the curve decline rule is given. The influence of residual stress on the yield strength of electrolyte membrane was analyzed and the causes of plastic deformation and cracking were analyzed. In this paper, the microstructure of electrolyte layer, interface layer and anode layer of anode supported oxide fuel cell (OFC) during reduction and reoxidation were studied. The microstructure of the electrolyte layer and the energy spectrum before and after the reaction were compared. The thermal expansion coefficient and stress strain of anodic supported oxide fuel cell electrolyte layer were measured. The research in this paper has theoretical significance and practical value for fuel cell operation and process improvement.
【学位授予单位】：西北工业大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM911.4

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