| Abstract: | 因地球資源的逐漸減少與環境污染的日益嚴重，於是尋找與積極的開發替代能源便開始受到各界的重視。其中具有高效率、低污染、低噪音的燃料電池便頗受各界矚目，而直接甲醇燃料電池(DMFC)具有系統結構簡單、體積能量單位密度高、操作溫度低及易攜帶等特性被評估為極具潛力應用於3C產業的替代電源之一
本論文第一部分藉由數值模擬軟體來針對DMFC之陰陽極進行模擬與分析。陽極部分探討了甲醇溶液的均勻性並利用流道內部壓力梯度來設計立體式流道，進而增進排除電池反應所產生的二氧化碳。陰極部份則探討空氣分布均勻性與水蒸氣排放的順暢性進行分析。最後藉由可視化實驗驗證流道設計對於氣泡排出性的改善狀況。第二部份將藉由實驗量測來針對DMFC陰陽極環境參數對於單電池，平面電池堆與PCB平面電池組效能的影響。陽極部分探討了DMFC在不同的甲醇溶液溫度、流量、濃度等環境參數對於DMFC效能的影響。陰極部分探討了在特定的環境下，陰極空氣流量、空氣流速對電池效能的影響。本論文最後則探討單電池、平面電池堆、與電池組的比較。
除了尋找較佳的陰陽極環境條件外，本論文的最終目的更要進一步探討環境參數在單電池映射至PCB平面電池組間的特性關係，提供DMFC在未來設計與系統操作的參考
As the earth resources gradually decrease and environmental pollution is getting serious, hunting and development on new resources of energy become important among country and research institution. Fuel cell is one of the most prominent new technologies because of its high efficiency, low pollution and low noise characterizations. The direct methanol fuel cell has been considered as full potentially applied to 3C industry as a substitute power source because it has the advantages of simple structure, high volume energy density, low operating temperature, and easier carried out.
The first part of this paper is applying CFD technique to make the analysis and design on a DMFC anode and cathode flow boards. In anode design, the uniformity of fuel supplement is important as well as making inner pressure gradient to help drive carbon dioxide moving out. In cathode flow design, the air flow uniformity and smoothness of air driven out are discussed. Finally, the present algorithm will be verified via visualization experiments. The second part of this paper points out the environmental parametric effects on the single, planer, and PCB-based fuel cell DMFCs by experimental studies. In anode side, the effects on the DMFC performance under different conditions of MEOH solution temperature, flow rate and concentration have been addressed. In cathode side, the effects of airflow rate and velocity on DMFC performance at same specific conditions are also investigated. At the end of this paper, the comparison among single, planer fuel, and PCB-based DMFCs is included.
In addition to looking for a better operating condition of a DMFC, the ultimate purpose of the paper will discuss the characterizations of mapping relationships from single, planer to PCB-based DMFC. The results could be a useful reference for further DMFC design and system operation in the future. |
