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研究生： 李書鋒
Lee, Shu-Feng
論文名稱： 中低溫微型固態氧化物燃料電池堆系統多尺度模擬與設計
Multi-scale Simulation and Design of an Intermediate Temperature Micro Solid Oxide Fuel Cell Stack System
指導教授： 洪哲文
Hong, Che-Wun
口試委員:
學位類別： 博士
Doctor
系所名稱： 工學院 - 動力機械工程學系
Department of Power Mechanical Engineering
論文出版年： 2009
畢業學年度： 97
語文別： 英文
論文頁數： 98
中文關鍵詞： 多尺度模擬 、微固態氧化物燃料電池 、分子動態模擬
外文關鍵詞： multi-scale simulation, micro solid oxide fuel cell, molecular dynamics
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    • This thesis presents a multi-scale simulation technique for designing an intermediate-temperature planar-type micro solid oxide fuel cell (mSOFC) stack system. This multi-scale technique integrates the fundamentals of molecular dynamics (MD) and computational fluid dynamics (CFD). MD simulations are carried out to determine the optimal composition of a potential solid electrolyte that is capable of operation in the intermediate temperature region without sacrifice in performance. This thesis investigates the feasibility of two potential electrolytes, which are samarium-doped ceria (SDC) and gadolinium-doped ceria (GDC) respectively, compared with the traditional yittria-stablized zirconia (YSZ). The influences of the dopant concentrations and the operation temperatures on the ionic conductivity in the electrolyte were studied. Also the cell performance of an intermediate temperature mSOFC stack was studied using computational fluid dynamics technique are Butter-Volmer equations in the electrochemistry.
    In molecular dynamics, the transport mechanism of oxygen ions inside the solid oxide electrolyte is observed to be non-continuous hopping between oxygen vacancies. Simulation results show that there exists an optimal concentration for the SDC and GDC. Higher operation temperature promotes the oxygen ion move-ability in the electrolyte. The molecular dynamics simulation results were compared with published experimental results and showed reasonable agreements.
    A commercial computational fluid dynamics package plus a self-written computational electrochemistry code are integrated to design the fuel and air flow systems in a planar five-cell stack. Different SDC electrolyte compositions and operating temperatures from 673K to 1023K are investigated to identify the maximum ionic conductivity. The electrochemical performance simulation using an available 5-cell YSZ mSOFC stack shows good agreement with our experimental results. The same stack design is used to predict a new SDC mSOFC performance. Feasibility studies of this intermediate-temperature mSOFC stack are presented using this multi-scale technique. Furthermore, new manifold designs are studied to improve the stack system performance.

    本論文以多尺度模擬設計中低溫平板型微固態氧化物燃料電池堆系統，結合分子動態模擬(Molecular dynamics)與計算流體力學(Computational fluid dynamics)。分子動態模擬用來求出固態氧化物燃料電池電解質的最佳摻雜濃度，而且此固態電解質能夠在中低溫操作下仍具有良好離子傳導性能。本論文針對中低溫型固態電解質氧化釤-鈰固態電解質(samarium-doped ceria)與氧化釓-鈰固態電解質(gadolinium-doped ceria)比較傳統型釔安定化氧化鋯(yittria-stablized zirconia)固態電解質在中低溫下的性能表現。透過分子動態模擬探討摻雜濃度與操作溫度對於固態電解質中離子傳導率的影響，以及利用計算流體力學合併電化學反應方程式研究中低溫平板型微固態氧化物燃料電池堆性能。
    利用分子動態模擬，可以觀察氧離子在電解質內的傳遞現象，係藉由氧空洞的位置進行不連續性的動態傳遞，從分子動態模擬結果中得知，釤-鈰固態電解質與氧化釓-鈰固態電解質存在一最佳摻雜濃度。受到溫度影響，固態電解質內離子遷移性在較高溫時其傳導率越佳。最後，比對實驗結果證明分子動態模擬結果與實驗數據具有良好的匹配性。
    利用多尺度模擬，進行中低溫平板型微固態氧化物燃料電池堆性能研究，由計算流體力學合併電化學反應方程式針對不同固態電解質與進氣岐管設計進行電池性能差異研究。在873K中低溫平板型微固態氧化物燃料電池堆系統使用氧化釤-鈰固態電解質能獲得較高的性能，相較於傳統型釔安定化氧化鋯固態電解質在中低溫操作環境下電池性能表現較差。為了改善中低溫平板型微固態氧化物燃料電池堆系統性能，利用新設計的進氣岐管來改善氣體利用率，由電池性能模擬結果顯示，此新型進氣岐管設計確實能夠獲得較高的電池性能。

    TABLE OF CONTENT Abstract I Table of Content V List of figures VII List of Tables XI Chapter 1 Introduction 1 1.1 Background 1 1.2 Introduction to SOFC 3 1.3 Motivation 6 1.4 Literature Survey 7 1.4.1 Fabrication and experiments of SOFC electrolytes 8 1.4.2 MD Simulation of SOFC electrolytes 9 1.4.3 CFD Simulation of SOFCs………………………….. 10 Chapter 2 Molecular Dynamics Simulation of the Ceria Based Electrolytes 12 2.1 Atomistic Model…………………………………………………………….12 2.2 Interaction Potential Function 17 2.3 Simulation Process and Numerical Scheme 20 2.4 Summary of the Molecular Dynamics Simulation 23 Chapter 3 Computational Fluid Dynamics of an Intermediate Temperature Planar Micro Solid Oxide Fuel Cell Stack 25 3.1 Computational Fluid Dynamics Model………… 25 3.1.1 Assumptions of the Computational Fluid Dynamics Model 25 3.1.2 Governing Equations in the Computational Fluid Dynamics Model 27 3.2 Experimental Description of Planar Micro Solid Oxide Fuel Cell Stack….. 36 Chapter 4 Results and Discussions 40 4.1 Simulation Results of SDC 40 4.1.1 Monitoring Equilibrium-SDC 40 4.1.2 Ionic Transport Process-SDC 44 4.1.3 Mean Square Displacement and Ionic Conductivity-SDC 48 4.1.4 Molecular Structure-SDC 55 4.2 Simulation Results of GDC 58 4.2.1 Monitoring Equilibrium-GDC 58 4.2.2 Mean Square Displacement and Ionic Conductivity-GDC 64 4.2.3 Molecular Structure-GDC 70 4.3 CFD Simulation Results of Solid Oxide Fuel Cell Stack 73 4.3.1 Grid Convergence of CFD Model 73 4.3.2 Performance Simulation of Solid Oxide Fuel Cell Stack 76 Chapter 5 Conclusions 91 References……………..……………………………………………………..…....94

    1. Williams, K. R., 1966, An Introduction To Fuel Cells, Elsevier Publishing Company, Chap 1.
    2. USDOE, 2004, Fuel Cell Handbook7th edition.
    3. Mouritsen, O.G., 1984, Computer Studies of Phase Transitions and Critical Phenomena, Springer-Verlag, Berlin..
    4. Singhal S. C. and Kendall K., 2003, High Temperature SOFCs: Fundamentals, Design and Applications, Elsevier.
    5. Tianshu Z., Hing P., Huang H, Kilner J., 2002, “Ionic Conductivity in the CeO2–Gd2O3 system (0.05 Gd/Ce 0.4) Prepared by Oxalate Coprecipitation,” Solid State Ionics, Vol.148, pp. 567-573.
    6. Peng, C., Zhang, Y., Cheng, Z. W., Cheng, X., Meng, J., 2002, “Nitrate–Citrate Combustion Synthesis and Properties of Ce1-xSmxO2-x/2 Solid Solutions,” Journal of Materials Science: Materials in Electronics, Vol.13, pp.757-762.
    7. Perez-Coll D., Nunez P., Frade J. R., Abrantes J. C. C., 2003, “Conductivity of CGO and CSO Ceramics Otained from Freeze-Dried Precursors,” Electrochimica Acta, Vol.48, pp.1551-1557.
    8. Herle, J. V., Horita, T., Kawada, T., Sakai, N., Yokokawa, H., and Dokiya, M., 1996, “Low Temperature Fabrication of (Y,Gd,Sm)-Doped Ceria Electrolyte,” Solid State Ionics, Vol.86-88 (2), p.p. 1255-1258.
    9. Mogensen, M., Sammes, N. M., and Tompsett, G. A., 2000, “Physical, Chemical and Electrochemical Properties of Pure and Doped Ceria,” Solid State Ionics, Vol.129 (1-4), p.p. 63-94.
    10. Barsoukov E., Macdonald J. R., 2005, Impedance Spectroscopy Theory, Experiment, and Applications, 2nd Edition, John Wileys & Sons.
    11. Balazs G. B., Glass R. S., 1995, “AC Impedance Studies of Rare Earth Oxide Doped Ceria,” Solid State Ionics, Vol.76, pp. 155-162.
    12. Yamashita K., Ramanujachary K. V., Greenblatt M., 1995, “Hydrothermal Synthesis and Low Temperature Conduction Properties of Substituted Ceria Ceramics,” Solid State Ionics, Vol.81, pp. 53-60.
    13. Toshiyuki Mori, et al, 2003, “Influence of Nano-Structural Feature on Electrolytic Properties in Y2O3 Doped CeO2 System,” Science and Technology of Advanced Materials, Vol.4, pp.213-220.
    14. Minh N.Q., 1993, “Ceramic Fuel Cells,” Journal of the American Ceramic Society, Vol.76, pp. 563–588.
    15. Kudo T. and Obayashi H., 1975, “Oxygen Ion Conduction of the Fluorite-Type Ce1-xLnxO2-x2/ (Ln=Lanthanoid element),” Journal of the Electrochemical Society, Vol.122, pp. 142–147.
    16. Leach A. R., 2003, Molecular Modelling Principles and Applications, 2nd Edition, Prentice Hall.
    17. Yamamura Y., Kawasaki S., Sakai H., 1999, “Molecular Dynamics Analysis of Ionic Conduction Mechanism in Mttria-Stabilized Zirconia,” Solid State Ionics, Vol. 126(1), pp. 181-189.
    18. Tojo T., Kawaji H., Atake T., 1999, “Molecular Dynamics Study on Lattice Vibration and Heat Capacity of Yttria-Stabilized Zirconia,” Solid State Ionics, Vol. 118(3-4), pp. 349-353.
    19. Perumal T. P., Sridhar V., Murthy K. P. N., Easwarakumar K. S., Ramasamy S., 2002, “Molecular Dynamics Simulations of Oxygen Ion Diffusion in Yttria-Stabilized Zirconia,” Physica A , Vol. 309(1-2), pp. 35-44.
    20. Fisher, C. A. J., and Matsubara, H., 1999, “The Influence of Grain Boundary Misorientation on Ionic Conductivity in YSZ,” Journal of the European Ceramic Society, Vol.19, pp. 703-707.
    21. Cheng C. H., Chang Y. W., Hong C. W., 2005, ”Multi-Scale Parametric Studies on the Transport Phenomenon of a Solid Oxide Fuel Cell,” Journal of Fuel Cell Science and Technology, Vol.2, pp. 219-225.
    22. Cheng C. H., Lee S. F., Hong C. W., 2007, “Ionic Dynamics of an Intermediate-Temperature Yttria-Doped-Ceria Electrolyte,” Journal of The Electrochemical Society, Vol.154, E158-163.
    23. Recknagle, K. P., Williford, R. E., Chick, L. A., Rector, D. R. and Khaleel, M. A., 2003, “Three-Dimensional Thermo-Fluid Electrochemical Modeling of Planar SOFC Stacks,” J. Power Sources, Vol.113 (1), p.p. 109-114.
    24. Achenbach, E., 1994, “Three-Dimensional and Time-Dependent Simulation of a Planar Solid Oxide Fuel Cell Stack,” J. Power Sources, Vol.49 (1-3), p.p. 333-348.
    25. Larrain, D., Van herle, J., Maréchal, F. and Favrat, D., 2003, “Thermal Modeling of a Small Anode Support Solid Oxide Fuel Cell,” J. Power Sources, Vol. 118 (1-2), p.p. 367-374.
    26. Kakac, S., Pramuanjaroenkij, A. and Zhou, X. Y., 2007, “A Review of Numerical Modeling of Solid Oxide Fuel Cells,” Int. J. Hydrogen Energy, Vol. 32 (7), p.p. 761-786.
    27. Aguiar, P., Chadwick, D. and Kershenbaum, L., 2002, “Modelling of an Indirect Internal Reforming Solid Oxide Fuel Cell,” Journal of Chemical Engineering Science. Vol. 57, p.p. 1665-1677.
    28. Haynes, C., 2002, “Simulating Process Settings for Unslaved SOFC Response to Increase in Load Demand,” J. Power Sources, Vol.109 (2), p.p. 365-376.
    29. Lin, P. H. and Hong, C. W., 2006, “On the Start-up Transient Simulation of a Turbo Fuel Cell System,” J. Power Sources, Vol. 160 (2), p.p. 1230-1241.
    30. Yakabe, H., Ogiwara, T., Hishinuma, M. and Tasuda, I., 2001, “3-D Model Calculation for Planar SOFC,” Journal of Power Sources. Vol. 102, p.p. 144-154.
    31. Haile, J. M., 1997, Molecular Dynamics Simulation: Elementary Methods, Wiley Press, New York.
    32. Yahiro, H., Eguchi, Y., Eguchi K., and Arai, H., 1988,”Oxygen Ion Conductivity of the Ceria-Samarium Oxide System with Fluorite Structure,” Journal of Applied Electrochemistry. Vol. 18, p.p. 527-531.
    33. Lewis, G. V., and Catlow, C. R. A.,1985, “Potential Models for Ionic Oxides,” J. Phys. C: Solid State Phys., Vol.18 (6) p.p. 1149-1161.
    34. Minervini, L., Grimes, R. W., Sickafus, K. E., and Randall, C., 2000, “Disorder in Pyrochlore Oxides”, Journal of American Ceramic Society, Vol.83, p.p. 1873-1885.
    35. Allen, M., P., and Tildesley, D., J., 1987, Computer Simulation of Liquids, Oxford Science Publication.
    36. Gear C. W., 1971, Numerical Initial Value Problems in Ordinary Differential Equations, Chap.9, Englewood Cliffs, NJ.
    37. Verlet, L., 1967, “Computer ‘experiments’ on Classical Fluids. I. Thermodynamical Properties of Lennard-Jones Molecules,” Phys. Rev., Vol.159 (1) p.p. 98-103.
    38. Bathe K. J., 2005, Theory and Modeling Guide Volume III: ADINA CFD & FSI”, ADINA R&D, Inc.
    39. Matsui, T., Inaba, M., Mineshige A., and ogumi, Z., 2005, “Electrochemical Properties of Ceria-Based Oxides for Use in Intermediate-Temperature SOFCs,” Solid State Ionics, Vol.176, pp. 647-654.
    40. Zha, S. W., Xia, C. R., and Meng, G. Y., 2001”Calculation of the e.m.f. of Solid Oxide Fuel Cells” Journal of Applied Electrochemistry, Vol. 31, p.p. 93-98.
    41. Lisbona, P., Corradetti, A., Bove, R., and Lunghi, P., 2007“Analysis of a Solid Oxide Fuel Cell System for Combined Heat and Power Applications under Non-nominal Conditions ,” Electrochimica Acta, Vol. 53, pp. 1920-1930.
    42. Costamagna, P., Honegger, K., 1998“Modeling of Solid Oxide Heat Exchanger Integrated Stacks and Simulation at High Fuel Utilization,” Journal of Electrochemical Society, Vol. 145, pp. 3995-4007.
    43. Chan, S. H., Khor, K. A., and Xia, Z. T., 2001 “A Complete Polarization Model of a Solid Oxide Fuel Cell and its Sensitivity to the Change of Cell Component Thickness,” Journal of Power Sources, Vol. 93, pp. 130-140.
    44. Janardhanan, V. M., Deutschmann, O., 2006 “CFD Analysis of a Solid Oxide Fuel Cell with Internal Reforming : Coupled Interactions of Transport, Heterogeneous Catalysis and Electrochemical Processes,” Journal of Power Sources, Vol.162, pp. 1192-1202.
    45. Damm, D. L., Fedorov, A. G., 2006 ” Reduced-Order Transient Thermal Modeling for SOFC Heating and Cooling,“ Journal of Power Sources, Vol.159, pp. 956-967.
    46. Ferguson, J.R., Fiard, J.M.,and Herbin, R., 1996“ Three-dimensional numerical simulation for various geometries of solid oxide fuel cells,” Journal of Power Sources, Vol.58, pp. 109-122.

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