可逆式(發電/產氫)固態氧化物燃料電池內部輸送現象探討以及電極關鍵設計參數分析

Investigation of transport phenomena inside unitized regenerative (power generation / hydrogen production) solid oxide fuel cell and analysis of electrode key design parameters

王辰博(Chen-Bo Wang)

指導教授 ： 蘇艾

元智大學/工程學院/機械工程學系/碩士(2012年)

摘要

本研究使用COMSOL Multiphysics對可逆式固態氧化物燃料電池(Unitized Regenerative Solid Oxide Fuel Cell，簡稱URSOFC)內部傳輸、極化現象和微結構參數對電池的影響進行研究分析。研究中使用數學式基礎架構(Equation-based) 方式建立燃料電池內部多重物理量的耦合計算，除了分析熱傳、質傳、化學反應、電流傳遞外，更考慮微結構參數對於電池內部物理量之影響。本論文分別改變操作溫度和微結構參數，研究URSOFC在兩種模式下之影響，並與實驗和文獻結果比較。研究結果發現氫氣極Porosity在SOFC模式下對電池呈現非線性影響，在不同操作溫度下有不同最佳參數值。氧氣極Porosity的變化，主要影響電極的有效導電度。氫氣極、氧氣極Tortuosity降低，能有效降低電極的歐姆極化和濃度極化影響，使電池性能提升。Anode function layer 的YSZ成份比增加，能使更多氧離子傳輸至電化學反應區進行反應，對於URSOFC操作在兩種模式下均能有效提升性能。

關鍵字

可逆式固態氧化物燃料電池 ； 產氫 ； 數值模擬

並列摘要

In this study, COMSOL Multiphysics was used to analyze the effect of internal transport phenomena, polarization and micro-structural parameters on unitized regenerative solid oxide fuel cell (URSOFC). Equation-based method was used to couple all multi-physics quantities within the fuel cell. In addition to analyze the heat transfer, mass transfer and chemical reaction, micro-structure related parameters which are able to affect cell performance was also investigated. In this study, URSOFC performance at different operation temperature and with different micro-structural design parameters were predicted based on the proposed computational model. Comparison of simulation results and experimental data indicates good agreement. Simulation results showed that the effect of hydrogen electrode porosity on cell performance under SOFC mode is nonlinear and different optimal parameter values is observed at different operating temperatures. The change of porosity on the oxygen electrode will mainly affect the electrode effective conductivity. The decrease in the tortuosity on the hydrogen and the oxygen electrode can effectively reduce both the ohmic polarization and concentration polarization to improve the cell performance. The increase of the YSZ composition in the Anode function layer resulted in more electrical chemical reactions on oxygen ion transport as well as effectively improving the performance under the two operation modes in URSOFC.

並列關鍵字

URSOFC ； Hydrogen Production ； Numerical Simulation

參考文獻

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