闭式燃料电池中的液滴脱离时间研究

Study on remove time of droplet in a dead-ended proton membrane fuel cell

燃料电池中电化学反应过程生成的液态水经过多孔电极爬升到扩散层表面,并在外力的作用下实现脱离。通过建立闭式燃料电池多孔电极中液态水提升行为的Lucas-Washburn方程,研究液态水在电极内部的提升时间,同时根据液滴的长大与脱离规律,研究不同的电流密度下液滴的自脱离时间,结果表明:相对于液滴的长大行为,液态水在电极中的传输时间可忽略不计,液滴的自脱离时间主要与电流密度有关,电流密度越大,液滴生长速率越快,所需的脱离时间越短。

Liquid water generated in the electrochemical reaction climbs up to the gas diffusion layer surface through the porous electrode and then is removed out of the fuel cell by the external force. The Lucas-Washburn equation of liquid water climbing behavior in the dead-ended proton exchange membrane fuel cell（PEMFC） was established,and based on the equation the climbing time of liquid water in the porous electrode was studied. Meanwhile, the self-remove time of droplets under different current densities was studied according to the droplet growing up and remove mechanism. The result shows that compared with the growing up time of the droplet, the transfer time of the liquid water in the electrode can be neglected. Self-remove time of the droplet is mainly associated with the current density, the growth rate of droplet becomes faster and the self-remove time is shorter with the increase of current density.