研究温湿度变化对车用燃料电池输出性能(输出电压和功率)的影响可为高精度进气控制策略提供有效的依据.本工作提出了一个温湿度-电流(temperature and relative humidity-current,TRH-C)模型,该模型考虑了电池内部电化学反应、电渗迁移和加湿冷凝三部分水来源,揭示了电流随温湿度变化规律和由水活度表征的电渗迁移系数计算式.根据电池流道实物在计算软件COMSOL中建立网格,将TRH-C模型导入并应用有限体积法进行计算;搭建了燃料电池测试系统,在工作温度60 ℃和70℃、相对湿度分别为50％和100％条件下进行了实验并进行数据处理;并对通过TRH-C模型得到的极化曲线与实验数据进行比较,分析了电流密度和膜水含量分布云图.结果表明,TRH-C模型能预测燃料电池的性能,在工作温度为60 ℃、相对湿度为50％时,电压和功率密度的相对误差最大(电流密度为0.018A/cm2),分别为3.674％和3.696％.工作温度升高会导致膜水含量降低,但相对湿度增大会导致膜水含量升高.
Effect of temperature and humidity variations on the output performance of automotive fuel cells
This study aims to examine the impact of temperature and humidity on the output performance of automotive fuel cells.To this end,we propose a temperature and relative humidity-current(TRH-C)model.This model accounts for three sources of water:electrochemical reaction,electroosmotic migration,and humidification and condensation.It reveals the pattern of current variations with temperature and humidity and provides a calculation formula for the electroosmotic migration coefficient characterized by water activity.To implement our model,we established a grid in COMSOL and introduced the TRH-C model,which was then calculated using the finite volume method.We then built a fuel cell test system and conducted experiments at operating temperatures of 60 ℃ and 70 ℃,and relative humidity of 50％and 100％.We compared the polarization curve obtained from the TRH-C model with the experimental data and analyzed the cloud map of current density and film water content distribution.Our findings suggest that the TRH-C model can accurately predict fuel cell performance.However,we observed that when the operating temperature is 60 ℃ and the relative humidity is 50％,the relative errors of voltage and power density(with a current density of 0.018 A/cm2)are the largest,at 3.674％and 3.696％,respectively.We also found that an increase in operating temperature results in a decrease in membrane water content,while an increase in relative humidity leads to an increase in membrane water content.
temperature and relative humidityautomotive fuel cellcurrent density distributionwater content
万方数据
维普
