中文摘要：

对有效面积为9cm^2的直接甲醇燃料电池（DMFC）进行了可视化实验研究，观察了阳极流道内两相流动的情况．研究了平行流道内CO2气泡的生长特性以及不同甲醇浓度、甲醇进料温度、甲醇流量及阴阳极压差下CO2的流动及其对电池性能的影响。研究表明：CO2气泡在扩散层表面与流道侧壁面的角区出现．此后又多在碳布纤维束之间的交叉空隙中优先生成．之后经历聚合、长大、形成不连续气弹．两相流周期性地重复出现；甲醇流量的增加加快了CO2气泡的排出速度，甲醇传质增强，电池性能提高；甲醇温度升高降低了CO2的溶解度，CO2气泡体积变大，但甲醇传质的增强和催化反应速度的加快使得电池性能提高；甲醇浓度增大，电池性能提高．但浓度过高导致电池性能急剧下降：阴阳极压差增大使得大的CO2气弹增多．但催化剂表面氧气浓度的提高和甲醇渗透减弱提高了电池性能。

英文摘要：

A 9 cm^2 transparent DMFC was developed to visualize the bubbles flow in the anode channels. Parameter studies including flow rate, concentration, temperature of methanol solution, and the pressure difference between the anode and the cathode of the DMFC were performed to assess the effects of the bubbles flow in the anode channels on the performance of tested transparent DMFC. The results show that CO2 bubbles nucleate at the corner of the GDL and the side wall firstly and form large bubble slugs through growth and coalescence in the channel. And the pores on the across of the carbon cloth fibers are favored for the emergence of CO2 bubbles. Increasing flow rate of the methanol solution accelerates the removal velocity of the discrete CO2 bubbles which enhances mass transfer of methanol hence improves the performance of the tested DMFC. Hoisting the temperature of methanol solution may reduce the solubility of CO2 in methanol solution and enlarge the volume of CO2 bubbles in the channels whereas the performance of DMFC is improved by the enhancement of mass transfer of methanol and acceleration of the catalysis velocity due to high temperature. High methanol concentration results in high performance of DMFC while it toboggans by excessive concentration. More bubbles and bigger gas slugs appear in the channels with increasing pressure difference between the anode and the cathode, but the performance may be improved by high oxygen concentration on the catalyst surface and low methanol crossover due to high pressure on the cathode.