本研究探討重組式燃料電池之系統熱平衡，設計重組裝置入口燃料(甲醇與水)蒸發之蒸發器(Evaporator)元件，蒸發甲醇與水提供足量的蒸氣燃料供重組器進行SRM( steam reforming of methanol)甲醇重組反應產氫。另外將重組器與磷酸燃料電池進行系統整合，減少重組式燃料電池啟動時間與維持系統熱平衡。
上述目標，蒸發器根據過去曾繁根教授實驗室與潘欽教授實驗室研究成果，設計五種排序結構之蒸發器，流道尾端2/5區域提供加熱場。分散結構有利流體側向分布，漸擴流道利於沸騰流動穩定，本研究用銅製作蒸發器進行沸騰熱傳研究，最佳蒸發器與重組器整合產氫。系統整合根據過去整合之成果，改善過去啟動時間過長的問題，使用絕熱封裝與高功率加熱縮短啟動時間。
研究結果前端分散結構後端水平漸擴結構蒸發器熱傳效率最佳，當流量為4.5ml/min時，有最佳熱傳效率91.41%，臨界熱通量達到147.95kW/m2，但在抗乾化能力上不如純漸擴結構蒸發器，在超過100W加熱功率下純漸擴結構有較好的臨界熱通量表現，其中又以水平漸擴結構蒸發器表現最佳臨界熱通量可達178.9 kW/m2，水平漸擴結構蒸發器與重組器進行重組反應產氫，甲醇轉換率在280℃可達到70.3%，氫氣產量達到443ml/min，與純蒸汽整合重組器相比，重組器在與燃料電池系統整合允許操作溫度240-260℃之間，最差情況下在260℃時，蒸發器可以達到純蒸氣88.1%的甲醇轉換率效能。系統快速啟動主要問題為加熱器功率不足，改用1000W加熱啟動時間縮短為10.8分鐘。
關鍵詞:重組式燃料電池、蒸發器、分散結構、水平漸擴結構、沸騰熱傳、抗乾化能力、甲醇轉換率、快速啟動

This study investigates the system thermal management of a reformed methanol fuel cell, designing evaporator components for evaporation of fuel (methanol and water) at the inlet of the reformation, providing sufficient evaporation of fuel for steam reforming of methanol (SRM) to produce hydrogen. In addition, the reformed device is systematically integrated with the phosphoric acid fuel cell to reduce the excessive startup time of the reformed fuel cell and maintain the system thermal balance.
According to the above objectives, five different structures of evaporator have been designed following previous researches, providing a local heating field for the two-fifths of the end area. The dispersed structure is beneficial to the lateral distribution of the fluid, and the diverging channel is beneficial to the stability of the flow boiling. In this study, the evaporator of different heat sink configurations of copper is used for boiling heat transfer research to find the best heat transfer effect of the evaporator and integrate with Swiss shape flow channel reformer that filled with 20 grams of copper and zinc catalyst for hydrogen production. For system integration experiment section, excessive start-up heating times for reformer fuel cells use adiabatic package with high power heaters to significantly reduce start-up time.
The results show that the heat transfer efficiency of dispersion combine horizontal diverging structure evaporator is the best. When the flow rate is 4.5ml/min, the optimal heat transfer efficiency is 91.41%, and the critical heat flux reaches 147.95kW/m2, however the ability to resist dry-out is not good as the purely diverging structure evaporator. When the heating power exceeds 100 W, the purely diverging structure has better critical heat flux performance, among them, the horizontally diverging structure evaporator has the best performance, reaching heat flux 178.9 kW/m2. Integrating the horizontal diverging structure evaporator and the reformer to do the reformation reaction, the highest methanol conversion rate can reach 70.3% at 280 °C, and the hydrogen production reaches 443 ml/min. Compared to the pure steam integrated reformer, the evaporator of reformer integrated with fuel cell can achieve 88.1% methanol conversion efficiency of the pure steam at operating temperature 260oC, which is the worst case among the operating temperature of 240~260oC.
In the system integration experiment, we found completely different results from the past. The main problem of the system quick start is the heater provides insufficient energy instead of the system heat loss. The start time is improved with a 1000W heater, and the start time is shortened from 158.25 minutes to 10.8 minutes.
Keywords: reformed methanol fuel cell, evaporator, dispersion structure, horizontal diverging structure, flow boiling, resist dry-out ability, methanol conversion rate, methanol conversion rate

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