不同相對溼度於中溫質子交換膜燃料電池的現象分析

The Phenomena Analysis of Medium Temperature PEMFC in Different Relative Humidity

石肇圻(Chao-CHI Shih)

指導教授 ： 翁芳柏

元智大學/工程學院/機械工程學系/碩士(2008年)

摘要

為避免CO毒化觸媒及減少水管理的問題，將燃料電池操作溫度提高大於100℃，而Nafion系列的質子交換膜，在此操作條件下會因乾膜而性能下掉，加入無機物磷酸鋯可提高膜材在高溫低溼下的含水率和機械強度，本文欲在中溫操作下分析電池內部的現象。用軟體分析以自製電池搭配自製磷酸鋯膜材所測得在中溫不同操作條件下的實驗數據，其分析結果顯示在0.3~0.7V之間，實驗所測得性能和模擬計算結果接近，在常壓於中溫低濕下，膜材在上游區的含水率較高，越往下游會由於水氣形成過熱氣而無法加濕膜材使得膜材在下游區的含水率較低，加入背壓可加強質傳反應而提升性能，較大的質量流率可提供較充足的燃料以及加強對流熱傳而提高膜導電度，反向流(counter flow)的方式讓膜材的導電度較均勻。

關鍵字

中溫 ； 含水率 ； 反向流

並列摘要

When fuel cell operated at medium temperatures can reduce CO poisoning and simplify heat rejection, but cause Nafion type membrane dried out to make membrane degradation. To add mineral can reinforce mechanical strength and hold out water content. The purpose of this study is to analyze the experimental data in the medium temperature tested by homemade cell with Zirconium phosphate .The analysis result shows that computing performance is quite similar to testing performance during cell voltage of 0.3V and 0.7V. At ambient pressure, low humidity and medium temperature, the membrane has higher water content in the upstream. Toward downstream the water forms superheated vapor and then can’t humidify membrane. To add backpressure can enhance catalyst reaction ability. The larger mass flow rate can provide more enough fuel and elevate convection heat transfer to increase membrane conductivity. The counter flow type can make the membrane conductivity more uniform.

並列關鍵字

medium temperature ； water content ； counter flow

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