燃料电池系统温度及空气化学计量比影响研究

Study on influence of temperature and air stoichiometry on fuel cell system

研究了电堆入口冷却液温度、空气化学计量比对于燃料电池系统发电性能的影响。结果表明:在中高功率(57%以上)条件下,燃料电池系统效率与冷却液温度相关,随温度上升而上升,66℃以上保持不变,优化冷却液温度可以提升1.0%的系统效率。但在低功率(14%以下)条件下,温度的影响不显著。提升空气化学计量比降低了燃料电池系统发电效率,相比最高效率下降了3.8%,但提高了单体电压一致性,显著影响最低单体电压及最大单体电压均低差值。可依据最大单体电压均低差值判断最优空气化学计量比。

The influence of the inlet coolant temperature and air stoichiometry on the performance of fuel cell system was studied.The results show that at medium and high load,the fuel cell system efficiency is relevant with the coolant temperature,increasing with the increasing temperature,but reaches the peak at 66℃.The optimum coolant temperature improves by 1.0%of the system efficiency.But the influence is little at low load.Increasing air stoichiometry reduces the fuel cell system efficiency by 3.8%compared to the maximum efficiency.However,high air stoichiometry improves the consistency in single cell voltages,influencing the minimum single cell voltage and mean/minimum difference of single cell voltage.The mean/minimum difference of single cell voltage can serve as the indicator for selecting the optimum air stoichiometry.