摘要
本文藉由數值方法模擬質子交換膜燃料電池中質量、熱量、液態水和電流的分佈。使用的套裝軟體為ESI-CFDRC公司所發展的CFD-ACE+程式，該程式採用有限體積法(finite volume method)將微分方程離散化，計算氣體在多孔材質中的傳輸現象，電化學的反應，液態水的流通和水凝結與蒸發的潛熱，流體的壓力變化與速度分佈。
本文在數值程式的模擬中，以單電池為主體，建立一個三維燃料電池的模組，藉由參數測試與結果分析，以討論輸入參數的正確性與靈敏度。在文中討論過去的文獻所模擬的熱傳導係數與實際的材料比較上為一個過高的輸入；降低了熱傳導係數之後得到一個不合理的溫度場，歸咎於模擬中的質子熱焓性質參數輸入錯誤的關係；更改過後則可得到一個比較合理的溫度場。將等溫的邊界條件改成對一穩定環境有熱對流的邊界條件，還有免除壓力差之後的電池分析。其中氣體的質量會因為壓力差而少量的穿過多孔材質的現象，可以在改變壓力後發現影響程度。
模擬液態水的凝結，與氣體質量分析和溫度場的分佈有著相當大的關連，雖然大多都可用物理觀念解釋，但是也有少部分無法釐清的模擬結果出現，如果要驗證模擬出的熱水流分佈正確性，必須依靠真正的實驗來加以證明。

關鍵字：質子交換膜燃料電池、數值模擬、熱水流分析

Abstract

The report summarizes the results of the numerical simulations of proton exchange membrane fuel cell (PEMFC) by computational fluid dynamic (CFD) software. The code employed is CFD-ACE+ developed by ESI-CFDRC Company. The purpose of the study is to assess the capabilities of CFD-ACE+ code in the simulations of PEMFC.
The phenomena involved in the water and heat management of PEMFC are very complicated. The phenomena involved include the flow of multi-component and multi-phase fluid in an open channel and through porous media, the electrochemical reactions at catalyst layers, the evaporation and condensation of water, conduction and convection heat transfer.
A three-dimension single cell PEMFC model is built and the input values of the physical and chemical parameters of PEMFC are collected from the literatures surveyed. The measured polarization curves of a PEMFC can be reproduced by the present simulations. The PEMFC simulation results of CFD-ACE+ are examined and discussed in detail to check the consistency of the simulated results.
Sensitivity studies are performed. The parameters considered in the sensitivity studies are the direction of flow (co-flow and counter flow), the thermal conductivities of membrane-electrode assembly (MEA), the coefficient of the proton in the JANNAF method which calculates the enthalpy of the mix gases, the thermal boundary condition of fuel cell outer surface (constant temperature and convective).
The result of the simulations demonstrated that CFD-ACE+ has the capabilities to simulate the hydrodynamic phenomena of PEMFC. However, the code does not provide enough output about liquid water flow in the channel and its distribution in the fuel cell.

Key words: PEMFC, PEFC, CFDs, heat and water analytic.

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