期刊刊名：科技學刊－科技類 　 卷期：16卷2期

篇名出版日期：2007年5月1日

作者：Chung-Hsing Chao,趙中興

語言：English

關鍵字：local thermal non-equilibrium, fuel cells, porous electrodes, transport phenomena,局部非熱平衡,燃料電池,多孔電極,輸送現象

被點閱次數：0次

閱讀時間：0sec

摘要：
Developing heat transfer and fluid flow in a porous medium that simulates the po-rous electrode of fuel cells using a non-isothermal model have been studied numeri-cally. The computational domain consists of a porous electrode and a parallel, gas-flow channel. A reacting layer in the porous electrode acts as a source of the trans-port parameter such as heat, species, and current. The porous electrode consists of a catalyst layer and a diffusion layer. The heat transfer in the catalyst layer is coupled with species transports via a macroscopic electrochemical model. In the diffusion layer, the energy equations based on the non-isothermal model are derived to resolve the temperature difference between the solid phase and the fluid phase. The maxi-mum wall temperature occurs at the downstream end of the module, while the mini-mum wall temperatures are located at the module inlet. Results show that the diffu-sion layer of porous electrode becomes non-isothermal as the Stanton number around unity. The porous electrode is in a local thermal equilibrium when St >1. Finally, the effect of local thermal non-equilibrium on the thermal-mass transports in the porous electrode is investigated.

　　　　　[全文下載]