PEMFC直条流场水分布可视化研究

采用大面积(120cm2)透明质子交换膜燃料电池(PEMFC),研究了阴极直条流场内液态水的传递行为,通过测量不同位置流道进、出口压降,分析了流场内不均匀水分布。本方法可实时、在线、直接观察流道内液滴出现、积累及排出过程,得到实际工况下的实时液态水分布,将非常有助于流场设计和电池操作条件优化。结果表明,液态排水是一间歇过程,只有当液滴达到临界体积才会随反应气体排出。稳定运行状态下,液态水在流场内呈不均匀分布,主要集中于流场中下部区域,其他区域几乎没有液态水。

Visualization of the water distribution in straight flow-field in transparent PEMFC

Liquid water transportation in straight flow-field was study experimentally through a transparent H2/air PEM single cell with active area of 120 cm2. Pressure-drop between the inlet and outlet of different channels were monitored and recorded to analyze the uneven water distribution in the flow-field. This method was capable of watching the water droplet buildup, accumulation and removal in the channel on-line directly, and giving real-time liquid water distribution under the practical conditions, which was of great helpful to the flow-field design and operation style optimization. Results showed that liquid water removal was intermittent and droplet discharged only when it reached the critical size. Under the steady state, liquid water distribution was not uniform, which was almost in middle and bottom of the flow-field, and few in other place.