臺灣博碩士論文加值系統

平板式固態氧化物燃料電池(SOFC)是由連接板、正電極-電解質-負電極(PEN)、Frame(框架)、玻璃陶瓷、多孔性鎳網所組成。在穩態操作下，由於溫度很高，SOFC會因為溫度梯度及組件間熱膨脹係數的差異而產生熱應力。當SOFC的熱應力很高時，可能會導致SOFC組件發生氣體洩漏或者破裂的情況，降低SOFC的效能。所以在設計SOFC時，對SOFC穩態操作情況進行熱應力分析是必要的。
本文使用ANSYS作為分析軟體，套用以發展中平板式SOFC設計為基礎建構出的3D模型來作熱應力分析，並且探討不同拘束條件、不同通入氣體方式及熱膨脹係數差異對熱應力的影響。模擬結果顯示，在穩態操作下，連接板及Frame可能已經發生塑性變形，PEN及玻璃陶瓷則還在強度安全範圍內。底面三種不同的拘束條件對於SOFC熱應力的影響並不大。兩種不同的氣體通入方式中，Co-flow產生之熱應力比Counter-flow小，對SOFC結構上較為安全。當忽略熱膨脹係數時，熱應力分佈完全被溫度分佈所影響著。

Planar solid oxide fuel cell is composed of the interconnect, positive electrode-electrolyte-negative electrode (PEN), frame, glass-ceramic, and porous nickel. At steady-state operation, the temperature is high and the thermal stresses in planar SOFC are caused by the temperature gradients and mismatch of coefficient of thermal expansion (CTE) between all cell components. When the thermal stresses in a fuel cell are sufficiently high, gas leakage or failure may occur in the SOFC components. This will reduce the SOFC efficiency. A steady-state thermal stress analysis of SOFC is necessary for the design of SOFC.
Commercial FEA code ANSYS is utilized to analyze the thermal stress distribution in planar SOFC under steady-state condition in this study. A 3-D model based on a developing planar SOFC design would be constructed in the current study to perform a thermal stress analysis for planar SOFC. We discuss the influence on thermal stress due to different constraint, different flow-path configurations, and the mismatch of CTE. Modeling results indicated that interconnect and frame might have plastic deformations under steady-state operation, but PEN and glass-ceramic were still in the range of strength security. Three different constraint at bottom interconnect of SOFC would not cause significant changes in the thermal stress distribution. The thermal stresses owing to co-flow are smaller than counter-flow, and co-flow is more safe for SOFC structure. Thermal stress distribution is fully influnced by temperature distribution when we ignore the mismatch of CTE.

中文摘要..............................i
Abstract.............................ii
誌謝................................iii
目錄.................................iv
圖目錄..............................vii
表目錄................................x
符號說明.............................xi
第一章、緒論..........................1
1-1 前言..............................1
1-2 研究動機與目的....................4
1-3 論文架構與內容....................6
第二章、理論基礎......................7
2-1 固態氧化物燃料電池(SOFC)的組成....7
2-1-1 陽極............................7
2-1-2 陰極............................8
2-1-3 電解質..........................8
2-1-4 連接板..........................9
2-1-5 密封材料.......................10
2-2熱應力............................12
2-3 降伏準則.........................12
2-3-1 延性材料之降伏準則.............13
2-3-2 脆性材料之降伏準則.............16
2-3-3 本文的破壞準則.................16
2-4 收斂分析準則.....................18
第三章、ANSYS分析....................20
3-1 基本假設.........................20
3-2 分析流程.........................21
3-3 建立SOFC的實體模型...............22
3-4 在ANSYS中讀入SOFC的實體模型......24
3-5 選擇元素、輸入材料性質...........25
3-6 設定接觸面.......................28
3-7 產生有限元素模型.................31
3-8 讀入溫度分佈圖...................33
3-9 設定對稱及拘束邊界條件...........35
3-10 求解............................37
3-11 輸出結果........................38
第四章、ANSYS分析結果與討論..........39
4-1 收斂測試的分析結果...............39
4-2 不同拘束條件的分析結果...........43
4-3 不同之通入氣體方式的分析結果.....51
4-4 熱膨脹係數的效應.................56
第五章、結論與未來展望...............58
5-1 結論.............................58
5-2 未來展望.........................59
參考文獻.............................60

[1]K. P. Recknagle, R. E. Williford, L. A. Chick, D. R. Rector, and M. A. Khaleel, “Three-dimensional thermo-fluid electrochemical modeling of planar SOFC stacks” , Journal of Power Sources, Vol. 113, pp. 109-114, 2003.
[2]C. S. Montross, H. Yokokawa, and M. Dokiya, “Thermal stresses in planar solid oxide fuel cells due to thermal expansion differences” , British Ceramic Transactions, Vol. 101, pp.85-93 , 2002.
[3]A. Selimovic, M. Kemm, T. Torisson, and M. Assadi, “Steady state and transient theraml stress analysis in planar solid oxide fuel cells” , Journal of Power Sources, Vol. 145, pp. 463-469, 2005.
[4]衣寶廉，燃料電池-原理與應用，五南圖書出版股份有限公司，台北市，2005年3月。
[5]H. Yokokawa, N. Sakai, T. Horita, and K. Yamaji, “Recent developments in solid oxide fuel cell materials” , Fuel Cells, Vol. 1, pp. 117-131, 2001.
[6]R. M. Ormerod, “Solid oxide fuel cells” , Chemical Society Reviews, Vol. 32, pp.17-28, 2003.
[7]J. W. Fergus, “Sealants for solid oxide fuel cells” , Journal of Power Sources, Vol. 147, pp. 46-57, 2005.
[8]Richard B.Hetnarski, “Thermal stress I ” ,Elsevier Science Publishers B.V.,1986.
[9]徐秉業、劉信聲著，應用彈塑性力學，凡異出版社，新竹市，1997。
[10]Beer & Johnston，材料力學，沈勇全等共譯，高立圖書有限公司，台北市，1990。
[11]陳宗廷，「平板式固態氧化物燃料電池堆熱應力分析」，國立中央大學，碩士論文，民國95年。
[12]K. S. Weil, J. E. Deibler, J. S. Hardy, D. S. Kim, G.-G. Xia, L. A. Chick, and C. A.Coyle, “Rupture testing as a tool for developing planar solid fuel cell seals” ,Journal of Material Engineering and Performance, Vol. 13, pp. 316-326, 2004.

[13]J. Malzbender, R. W. Steinbrech, and L. Singhesier, “Failure probability of solid oxide fuel cells” , Proceedings of the 29th International Conference on Advanced Ceramics and Composites, pp. 293-298 ,Cocoa Beach, Florida, 2005, January 23-28.
[14]B. N. Nguyen, B. J. Koeppel, S. Ahzi, M. A. Khallel, and P. Singh, “Crack growth in solid oxide fuel cell materials: From discrete to continuum damage modeling” , Journal of the American Ceramic Society, Vol. 89, pp. 1358-2368, 2006.
[15]江烈光，“SOFC連接板熱傳及熱應力分析”，核能研究所工作報告，2006年7月5日。
[16]王栢村，電腦輔助工程分析之實務與應用，全華科技圖書股份有限公司，台北市，2003。
[17]康淵、陳信吉編著，ANSYS入門《修訂三版》，全華科技圖書股份有限公司，台北市，2006年5月。
[18]N. P. Bansal and E. A. Gamble, “Crystallization kinetics of a solid oxide fuel cell seal glass by differential thermal analysis” , Journal of Power Sources, Vol. 147, pp. 107-155,2005.
[19]W. Koster, “The temperature dependence of the elasticity modulus of pure metals” Zeitschrift fur Metallkunde, Vol. 39, pp. 1-9, 1948 (in German).
[20]Y. P. Chyou, T. D. Chung, J. S. Chen, and R. F. Shie, “Integrated thermal engineering analyses with heat transfer at periphery of planar solid oxide fuel cell ” , Journal of Power Sources, Vol. 139, pp. 126-140, 2005.