两种工况下进气相对湿度对燃料电池性能影响的研究

Research for the inlet relative humidity effects on the performance of fuel cell with two working conditions

为研究进气相对湿度对燃料电池在不同工况(工作温度为70℃,进气相对湿度为40%和100%)下的影响,提出了进气加湿效率(Inlet Humidification Efficiency,IHE)模型。该模型将燃料电池总的水含量分为两部分:外部进气加湿携带的水和内部电化学反应生成的水,由此推导出进气加湿效率公式。建立几何模型并划分计算网格,将进气加湿效率模型导入计算流体动力学软件(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40%和100%的工况进行了试验。对IHE模型、Fluent模型和试验值进行比较分析,结果表明:当电池工作温度为70℃,电流密度为350 m A/cm2,进气相对湿度为100%时,IHE模型精确度比Fluent模型提高了37.4%;当进气相对湿度为40%时,进气加湿效率为34%。

In order to study the inlet relative humidity（RH） effects on the performance of proton exchange membrane fuel cell（PEMFC）（70 ℃ operating temperature, 40%RH and 100%RH）, an inlet humidification efficiency（IHE） model is proposed. The total water content of PEMFC in the IHE model is including two parts： the external water content of the humidified gas and the internal water content produced by electrochemical reaction. The calculation formula of inlet humidification efficiency is derived. The geometry model is established and the computational grids are partitioned. The IHE model is imported into the computational fluid dynamics software（Fluent）and calculated. The fuel cell experimental system is established and experiments had been done at the operating temperature of 70 ℃ and at 40% RH and 100% RH, respectively. The Fluent model,the IHE model and experimental are compared and analyzed. The results show that when the operating temperature is 70 ℃（100%RH and 350 m A/cm^2）, the accuracy of IHE model is improved by 37.4% compared with the Fluent model. When the RH of PEMFC is 40%, the inlet humidification efficiency is 34%.