CAJ | 학술논문

本文建立了直接甲醇燃料电池的两相、非等温模型.采用多孔介质中的经典多相流动模型来计算电池内与电化学反应相耦合的传质、传热问题;模型中考虑了水的汽化凝结过程和甲醇窜流对电池性能的影响.计算结果表明电池内温度分布不均匀,温度最高点出现在阴极催化层;阳极甲醇浓度分布不均匀是造成阳极催化层内局部反应速率不均匀分布的主要原因,而阴极催化层局部反应速率主要依赖于阴极过电势的分布;大的流场板开口比条件下电池整体均匀性较好,性能得到提高.
본문건립료직접갑순연료전지적량상、비등온모형.채용다공개질중적경전다상류동모형래계산전지내여전화학반응상우합적전질、전열문제;모형중고필료수적기화응결과정화갑순찬류대전지성능적영향.계산결과표명전지내온도분포불균균,온도최고점출현재음겁최화층;양겁갑순농도분포불균균시조성양겁최화층내국부반응속솔불균균분포적주요원인,이음겁최화층국부반응속솔주요의뢰우음겁과전세적분포;대적류장판개구비조건하전지정체균균성교호,성능득도제고.
A two-phase non-isothermal mass transport model is presented in this paper. The heat and mass transfer across the membrane electrode assembly (MEA), coupled with the electrochemical reactions in the catalyst layers (CLs), are calculated based on the classical two-phase flow model in the porous media. The effect of methanol crossover on the cell performance and the non-equilibrium evaporation/condensation of water are considered in this model. The modeling results show that the distribution of temperature in the MEA is not uniform, and the highest temperature appears in the cathode CL. The non-uniform distributed methanol concentration leads to the non-uniform distributed methanol oxidization reaction (MOR) rate while the oxygen reduction reaction (ORR) rate mainly depends on the distribution of the local overpotential in the cathode CL. The increase in the open ratio of the flow field plate results in more uniform distribution of physical fields in the fuel cell and the cell performance is also improved with a larger open ratio.