以合成气为燃料的SOFC多物理场传递过程数值分析

Numerical Analysis of Multi-Physics Transport Processes of Solid Oxide Fuel Cell Fueled by Syngas

固体氧化物燃料电池(SOFC)内存在复杂的多物理场传递过程,这些过程对电池的性能具有重要的影响.以某实际生产的SOFC为对象,建立了其三维模型,模型描述了以合成气为燃料时其内部发生的传质、传热、化学及电化学反应等多物理场过程.根据模拟结果,给出了两种合成气组分下电池内温度、气体组分、化学反应速率以及电流密度等参数的分布.结果显示:电池内温度分布很不均匀,且合成气中H_(2)初始含量对电池内温度分布具有重要影响,H_(2)含量越小,电池内最高温度越低,但局部区域温度梯度会变大;化学反应速率和电流密度分布也不规律,其大小都受到当地温度和气体成分分布的影响,且电流密度最大值处于肋片、流道和电极的交界处.

Inside a solid oxide fuel cell(SOFC),there exist complex multi-physics transfer processes,which have an important impact on the performance of the cell.A three-dimensional model of an actual SOFC fueled by syngas is established,which describes the multi-physics processes occurring in the multi-channel SOFC,such as mass transfer,heat transfer,and chemical and electrochemical reactions.According to the simulation results,the distributions of temperature,gas composition,chemical reaction rate and current density in the cell under two syngas components were given.The results show that the temperature distribution in the cell is very uneven,strongly affected by the initial content of H_(2) in the syngas.A smaller H_(2) content leads to a lower maximum temperature,but the value of the temperature gradient in some areas of the cell increases.The distributions of chemical reaction rate and current density are also irregular,and their sizes are affected by local temperature and gas com-position distribution.It is also predicted that the maximum current density is located at the interfaces between ribs,channels and electrodes.