不同进气相对湿度下PEMFC进气加湿效率分析

Analysis of inlet humidification efficiency of PEMFC under different inlet relative humidity

为研究不同进气相对湿度下PEMFC的加湿效率,提出了进气加湿效率(IHE)模型。该模型认为燃料电池中的水由两部分组成,并推导出进气加湿效率计算公式。建立几何模型并划分计算网格,将IHE模型导入Fluent中进行计算。建立燃料电池测试系统,对工作温度为70℃,进气相对湿度分别为55%和85%的工况进行了实验。并比较分析了Fluent模型、IHE模型和实验值,结果表明:工作温度为70℃,进气相对湿度为55%,电流密度为350 mA/cm2时,IHE模型精确度比Fluent模型提高15%;在进气相对湿度为55%时,电池进气加湿效率达到52%。

In order to study the humidification efficiency of PEMFC under the different relative humidity (RH), the inlet humidification efficiency (IHE) model was proposed. Two parts of water contents were considered in the IHE model. The computational formula of inlet humidification efficiency was derived. The geometric model was established and the computational meshes were partitioned. The IHE model was imported into the Fluent. The fuel cell test system was established and the experiments were conducted at the operating temperature of 70 ℃ and at 55%RH and 85% RH, respectively. The Fluent model, IHE model and experimental values were compared and analyzed. The results show that when the operating temperature is 70 ℃(55%RH and 350 mA/cm^2), the accuracy of the IHE model increases by 15% compared with the Fluent model. When the operating temperature is 70 ℃(55%RH),the inlet humidification efficiency is 52%.