加壓型固態氧化物燃料電池性能與阻抗之定量量測與分析

Quantitative Measurements of Cell Performance and Electrochemical Impedance Spectra for Pressurized SOFC

張軒維(Hsuan-wei Chang)

指導教授 ： 施聖洋

國立中央大學/工學院/機械工程學系/碩士(2011年)

摘要

本論文實做一套高壓雙腔室固態氧化物燃料電池(solid oxide fuel cells, SOFC)之性能測試平台，並針對兩組除了流場板設計不同，其他組件與操作條件完全一樣的單電池堆，進行電池性能與電化學阻抗頻譜(electrochemical impedance spectra, EIS)的定量量測。測試平台之關鍵設備為一套雙腔室壓力容器，其內腔室為高壓可程式控制高溫爐，外腔室為加壓容器。單電池堆是由陽極支撐電池片、crofer-22-APU框架、集電層以及一對肋條流道之流場板層層堆疊而成。單電池堆組裝完成後，會以陶瓷基座包覆保護，並置入測試平台之內腔室，故可進行一系列的高溫高壓性能測試。為了能讓單電池堆安全且穩定地在加壓條件下操作，本研究亦建立一套標準的實驗流程。實驗結果顯示，增加SOFC操作壓力有助於提升電池性能，但壓力效應與電池性能的關係為非線性。當操作壓力(P)由1 atm增加至3 atm，功率密度約增加22%，但當P由1 atm增加至5 atm，功率密度則增加30%。此結果與EIS所量測的結果吻合，當P由1 atm增加至3 atm，電池極化阻抗可被明顯的抑制，但當P持續增加至5 atm，則其阻抗頻譜幾無變化。此外，本研究亦發現，在常壓條件下，單電池堆若採用本團隊過去所提出的加設導流條之優化流場板設計，其操作於0.6 V之功率密度可比未加導流條設計約高13%。當操作壓力增加至5 atm，兩者功率密度之差異則增加至16%，顯示在高壓條件下，流場均勻度效應仍是影響電池性能的重要因素。本論文所獲致之結果應有助於國內開發SOFC與氣渦輪機結合之複合式發電系統。

關鍵字

加壓型固態氧化物燃料電池，流場均勻度、功率密度、阻抗頻譜

並列摘要

This thesis presents the implementation of a high-pressure double-chamber solid oxide fuel cell (SOFC) testing platform for quantitatively measuring cell performance and electrochemical impedance spectra (EIS) of two sets of nearly identical single-cell stacks except using different flow distributors under pressurized conditions. The platform includes a high-pressure program-controlled tubular furnace, the inner chamber, which is resided in a relatively large pressurized chamber (the outer chamber). So the single-cell stack embedded in a ceramic housing and assembled by an anode-supported positive electrode-electrolyte-negative electrode, a crofer 22-APU supporting frame and two current collectors which are sandwiched by a pair of rib-channel flow distributors for both anode and cathode can be measured inside the inner chamber at high temperature and elevated pressure conditions. A standard procedure is also developed for the safety and stable operation of the single-cell stack under atmospheric and pressurized conditions. Experimental results show that the cell performance increases with increasing pressure (P) but the relationship between cell performance and P is not linear. There is an increase in performance of 22% from 1 to 3 atm and 30% from 1 to 5 atm. This is in good agreement with the EIS data which reveals that the polarization impedance is significantly decreased from 1 to 3 atm and then nearly keeps the same when P is further increased from 3 to 5 atm. Furthermore, it is found that by using small guide vanes around the feed header of commonly-used rib-channel flow distributors to improve effectively the degree of flow uniformity, the power density of the single-cell stack can be increased as compared to that without using guide vanes under exactly the same experimental conditions, and such increase about 13% at 1 atm can be further increased up to 16% as P increases to 5 atm. These results should be useful to provide the basic knowledge for the future development of the high-efficiency SOFC and gas turbine integrating power generation technology

並列關鍵字

Solid oxide fuel cells ； rib-channel interconnect

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