直接甲醇燃料电池阳极三维两相流模拟

A Three-Dimensional Two-Phase Flow Model for the Anode of Direct Methanol Fuel Cell

目的研究直接甲醇燃料电池阳极电化学反应和传质特性对其性能的重要影响.方法建立一个直接甲醇燃料电池阳极三维两相流模型,分析电池阳极中甲醇和CO2的分布规律,以及电池温度和甲醇通入流速对电池阳极中甲醇质量浓度和CO2质量浓度分布的影响.结果分析结果表明沿着流道方向,甲醇质量浓度降低,而CO2质量浓度升高;流场脊下甲醇和CO2的质量浓度低于流道下甲醇和CO2的质量浓度;升高电池温度,电化学反应加快,甲醇质量浓度降低而CO2质量浓度升高;增大甲醇通入流速,CO2质量浓度升高.结论电池的电化学反应及流场结构决定了传质在电池中的质量浓度分布;电池的电化学反应速率受电池温度与甲醇通入流速的影响.研究结果对优化直接甲醇燃料电池操作参数,提高电池性能具有重要意义.

The paper aims to study the influence on the performance with electrochemical reaction and the mass transfer characteristics in the anode of direct methanol fuel cell. A three-dimensional two-phase flow model for the anode of direct methanol fuel cell is established to analyze the distribution of methanol and CO2 in the anode of fuel cell as well as the effect of fuel cell temperature and methanol inlet velocity on the distribution of methanol and CO2 concentration in anode. The results indicate that the methanol concentration decreases while the CO2 concentration elevated along the channel direction; the mass concentration of metha- nol and CO2 under the channel is lower than that under the flow ridge; if the fuel cell temperature increases, the electrochemical reaction would be accelerated and methanol concentration would decreased while CO2 concentration elevated;increase of the methanol access velocity would elevated the mass concentration of CO2. It is showed in this paper that the mass concentration distribution of transfer in the cell is determined by cell electrochemical reaction and flow field structure; the rate of cell electrochemical reaction is influenced by the cell temperature and inlet flow rate of methanol. The study has important significance on the optimization of direct methanol fuel cell operating parameters and the improvement of cell performance