氨燃料固体氧化物燃料电池低温化性能分析

Low Temperature Performance Analysis of Ammonia Fuel Solid Oxide Fuel Cell

在氨燃料固体氧化物燃料电池(solid oxide fuel cell,SOFC)低温化发展趋势下,降低工作温度将会提高电池寿命,但随之带来的化学及电化学反应速率降低和电解质欧姆损失增加等问题,这会直接影响电池的输出性能。该文基于COMSOL仿真平台,构建SOFC的多物理模型仿真模型,对SOFC内部化学及电化学反应、质量传递、能量传递和温度场分布进行耦合求解,着重量化分析工作温度和电解质厚度参数对氨燃料SOFC输出性能的敏感性影响。结果表明:降低工作温度至700℃可以显著降低电池内部热应力,尤其入口和出口侧降幅达14.37%。增加阳极厚度和氨气浓度导致功率密度下降48.76%。采用10μm电解质厚度和氧化钆参杂氧化铈(gadolinia-doped ceria,GDC)材料可以提高电池平均功率密度至785.87 W/m^(2),增幅达77.25%。因此,降低温度可以有效降低电池内部的热应力及分布差异,可提高电池的寿命,但阳极氨气平均浓度增加56.57%,镍基氮化作用随之增强可能会对电池稳定性造成不利影响,可采用减小电解质厚度和换用电解质材料两种方法对电池的输出性能进行提升。

In the trend towards the low-temperature development of ammonia-fueled solid oxide fuel cells(SOFC),reducing the operational temperature would extend the cell lifespan but introduce challenges such as decreased chemical and electrochemical reaction rates,and increase electrolyte ohmic losses,directly affecting cell performance.Using the COMSOL simulation platform,this study constructs a multi-physics simulation model for SOFC,coupling the internal chemical and electrochemical reactions,mass and energy transfer,and temperature distribution.The analysis quantifies the sensitivity of the ammonia-fueled SOFC's performance to operational temperature and electrolyte thickness.Results reveal that lowering the operational temperature to 700℃ significantly reduces internal thermal stress by 14.37%,notably at the inlet and outlet.Increasing anode thickness and ammonia concentration leads to a 48.76% decline in power density.Employing a 10μm electrolyte thickness and gadolinia-doped ceria(GDC)material raises the average power density to 785.87 W/m^(2),a 77.25%increase.Thus,temperature reduction effectively mitigates internal thermal stress and differences in distribution,enhancing cell lifespan.However,the rise in average ammonia concentration and heightened nickel nitride effects might negatively impact cell stability.Methods such as reducing electrolyte thickness and switching electrolyte materials could enhance cell performance.