- 學位論文
壓電可變式流道質子交換膜燃料電池之數值模擬分析
Numerical Analysis of Piezoelectric Device with Proton Exchange Membrane Fuel Cells
摘要
近年來由於石油價格的飆漲與排放過多的二氧化碳造成全球暖化的問題被各界所重視，因此尋找乾淨環保的替代能源為各界努力的目標。而燃料電池正符合上述需求，所以成為各界所關注的替代能源之一。本研究是利用CFD-RC套裝軟建立一三維與暫態之模型體來模擬壓電可變式流道質子交換膜燃料電池，並探討不同的操作參數條件下其電池之效能與陰極腔體內部之流場分析。論文中分別探討陰極壓電頻率、入口氣體溫度、電池操作溫度、入口氣體濕度、電池反應面積與陰極腔體肋條對於壓電可變式質子交換膜燃料電池之影響。其中陰極腔體肋條的有無對於電池的效能影響最大，因為陰極腔體中的肋條可以有助於電化學反應，減少電子在腔體中游離的阻力，在膜電極組中所產生的電子可以藉由最近的肋條傳遞到集電板上被收集，陰極腔體中加肋之條件下可以使電池所產生的平均電流密度為0.547A/cm2，較陰極腔體中無肋條件下電池所產生的平均電流密度0.379A/cm2高出約44%的電流密度，並且肋條為固體之故，其導熱效果較氣體的導熱效果好，因此陰極腔體中加肋的條件下陰極腔體內的溫度分佈會較陰極腔體中無肋的條件下均勻。本研究最佳操作條件為陰極腔體加肋、入口氣體相對濕度100%、入口溫度與電池操作溫度為323K與壓電頻率為64Hz，其電池產生的電流密度為0.595 A/cm2。
並列摘要
The increasing oil price and greenhouse issue have been paid much attention; therefore, studying a new and clean energy has been global target. Previous studies indicated piezoelectric device with proton exchange membrane fuel cell, PZT-PEMFC, the actuating micro-diaphragm with piezoelectric effects as one of the flow channels, could be successfully operated. In this study, we discuss the performance of PZT-PEMFC with different operating conditions, which includes frequency of piezoelectric device, inlet gas and cell temperatures, humidity of inlet gas, reaction area of PZT-PEMFC, and rib design in cathode chamber. Rib design in cathode chamber is the most obvious factor on the performance of PZT-PEMFC. In addition, the current density of PZT-PEMFC with rib may increase 44% than non-rib design. The reason is that the rib can reduce electron resistance and increase chemical reaction. Moreover, temperature distribution is more uniform in cathode chamber in adding rib condition. The optimal condition is 0.547A/cm2 at cathode chamber with rib, relative humidity of inlet gas 100%, vibration frequency of piezoelectric device 64Hz, and inlet gas and cell temperatures 323K.