摘要
报道了基于微流体技术的燃料电池性能的数值预测.在这种微流体燃料电池中,液态燃料和氧化剂并行流入微通道,电池的内部电流是微通道内离子的横向输运形成的.模型考虑了流体动力、组分的对流和扩散以及发生在电极表面的电化学反应.通过给定一组工作电压,利用FLUENT软件预测对应的电流密度.计算结果表明,计算得到的电池的极化曲线与实验结果吻合较好.随着反应物体积流率的增加,两股流体的混合程度降低,浓度边界层厚度明显减小,电池性能逐渐增加.电池性能对阴极流体中氧气浓度的变化比较敏感,而阳极流体中甲酸浓度的变化对其影响较小.这一计算结果表明这种微流体燃料电池是阴极受限的,这与实验结果一致.
The performance of microfluidic-based fuel cells was predicted numerically by Fluent,where liquid fuel and liquid oxidant flow side by side in a channel at microscale and the current of electricity is achieved by electrochemical reactions at electrodes on channel walls.The obtained polarization curves were found to be in good agreement with experiments,and with the increase in the volumetric flow rate,the cell performance rises gradually.In our case,the cell performance is very sensitive to the content of oxygen in the cathode stream,while it is insensitive to the concentration of formic acid in the anode stream,confirming the cathode limited performance in microfluidic fuel cell as reported by others.
基金
Supported by National Natural Science Foundation of China(50876100)
