DMFC内部气液两相流动与电性能的短时落塔实验研究

利用国家微重力实验室落塔提供的短时微重力实验环境,对常重力和微重力条件下直接甲醇燃料电池(DMFC)内部的气液两相流动形态和相应电性能等的影响进行了实验研究,发现在微重力条件下,DMFC阳极流道内CO₂气泡速度很小,气泡尺寸随着时间的推移而不断长大,甚至堵塞流道;流道堵塞现象随电流增大而急剧强化.电性能曲线显示,在浓差极化区存在显著的重力效应,电性能的恶化随浓差极化程度的加强而增大. 

Experimental Study on Two-Phase Flow and Power Performance of DMFC Utilizing the Drop Tower Beijing

Utilizing the Drop Tower Beijing/NMLC,the characteristics of two-phase gas-liquid flow and power performance of a direct methanol fuel cell(DMFC)are studied experimentally in normal and microgravity conditions.It's found that CO_2 bubbles in anode channels of DMFC move much slowly in microgravity,and that their shapes change from ellipsoid to globosity and their sizes increase with time,even block the whole channel and then the flow pattern changes into slug flow gradually. Larger current density,more easily is it to block the channel.It's also shown in the power curves that there exists an evident influence of gravity in the regime of the concentration polarization.The diminution of the power performance of DMFC in microgravity increases with the degree of the concentration polarization.