| 摘要: | 本研究建立一套高溫固態氧化物燃料電池(solid oxide fuel cell, SOFC)性能測試平台，並針對不同棋盤狀流道設計之單電池堆，進行一系列的電流-電壓曲線量測與分析，以獲得不同流道設計對電池性能有何影響的結 果。SOFC單電池堆由一40 mm x 40 mm陽極支撐PEN (positive electrode- electrolyte-negative electrode)、加上集電層(陽極為鎳網而陰極為白金網)，以及自行利用陶瓷材料加工的不同棋盤狀流道板所組構而成。所探討的流道設計參數，包括三個不同格狀突出物寬度與流道寬度總和(Wpitch = 2 mm, 4 mm, 10 mm），以及三個不同流場板中格狀突出物寬度與流道寬度之比值(f = 0.33, 0.5, 0.66）。實驗結果顯示，當f = 0.5，並將電池操作溫度控制在850 oC時，電池堆的峰值功率密度值(Peak power density, PPD)會隨Wpitch之減小而增大。PPD值在Wpitch = 2 mm比在10 mm Wpitch提昇了約7.2 %，故採用越小的Wpitch，有助於使反應氣體均勻分佈於PEN表面。此外，當Wpitch固定時，則f值越小，PEN與反應物接觸的有效面積越大，因此PPD值在f = 0.33比f = 0.66可提升約2.4 %。最後本論文也將統合分析操作條件，如反應物質量流率以及操作溫度對電池性能的影響。 This thesis aims to establish a high-temperature solid oxide fuel cell (SOFC) performance testing platform, so that a series of current-voltage curve measurements and analysis for a single-cell stack using different designs of flow distributors can be performed. The SOFC single-cell stack consists of a 40 mm x 40 mm anode-support PEN (positive electrode-electrolyte-negative electrode), two collector layers (nickel meshes for the anode and platinum meshes for the cathode), and home-made pin-type flow distributors with various sizes. Two key geometrical parameters of the pin-type flow distributors, including three different pitch widths (Wpitch = Wpin + Wchannel = 2 mm, 4 mm, 10 mm) and three different values of the pin-width fractions (f = Wpin / Wpitch = 0.33, 0.5, 0.66), are discussed. Experimental results show that the stack performance, i.e., peak power density (PPD), increases with decreasing Wpitch when f fixed as 0.5, and the stack was operated at 850 oC. It is found that flow distribution in the flow distributors with Wpitch = 2 mm is more uniform than that of the case with Wpitch = 10 mm and thus a 7.2 % increase of the PPD can be obtained. Furthermore, the flow distributors with a smaller f can increase the contact area between the reactants and PEN so that the stack using the flow distributors with f = 0.33 can produce a PPD 2.4 % higher than that of the case with f = 0.66. Finally, the effects of the operator conditions, such as the flow rate of the reactants and the operating temperatures, on the stack performance are also discussed. |
