SOFC多尺度多場耦合和性能演化理論研究

林子敬

摘 要：針對本研究主攻一體化電池結構SOFC和使用以甲烷為代表的碳基燃料的科學技術目標，經過對目前理論與模擬研究現狀的系統全面考慮，我們在研究的前兩年著重開展了一些必需的基礎理論和模擬研究，以彌補現狀的不足。本報告側重介紹本課題在如下方面開展的創新性理論研究與所取得的成果：（1）獲得精度與Dusty-gas Model精度相當的物種流量解析表達式；（2）獲得能解釋實驗結果的Ni顆粒生長理論模型；給出三相線長度隨Ni顆粒生長變化的理論關系；（3）獲得能解釋實驗結果的多孔復合電極有效電導率理論模型；（4）建成微管SOFC多尺度多物理場耦合的二維模型；給出關鍵材料組分、微結構和工作參數對微管SOFC性能的影響，指明可具有合理力學性能的材料組分、微結構和工作參數。這些研究為后期的系統全面理論模擬研究奠定了良好基礎。

關鍵詞：多組分其他輸運 鎳顆粒生長 電導率 納米浸漬電極 微管SOFC 機械強度

Abstract：The overall objective of our 973 program is to conduct basic research on solid oxide fuel cells （SOFCs） with nano-composite electrode structures and using methane fuel as a representative of general fossil fuel. Based on this objective and considering the deficiency of the available theory and modeling technique， we carried out the corresponding theory and modeling activities to fill the gap. This report summaries some of our key findings on the following topics： （1） Obtaining analytical decoupled expressions for the fluxes of multi-component gas species with accuracy comparable to the coupled Dusty-Gas Model； （2） Developing a theoretical model for the Ni agglomeration that is capable of explaining the experimental data. Moreover， using this model to establish the relationship between the TPB length and the growth of Ni particles； （3） Developing models for the effective electrical conductivities of nano-composite electrode and explaining the experimental data； （4） Building multi-scale and multi-physics numerical 2D model for micro-tubular SOFC. Based on this numerical tool， conducting simulation study on the effects of key material composition， microstructure and operating parameters on the performance of micro-tubular SOFC. The simulation results are used to identify the material composition， microstructure and operating parameters with desirable mechanical properties. The above results provide a solid basis for a systematical and thorough theoretical and modeling study in the future activity of the program.

Key Words：Multi-component gas transport；Agglomeration of Ni particle；Electrical conductivity；Nano-particle infiltrated electrode；Micro-tubular SOFC；Mechanical strength

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