相对湿度对PEMFC加载过程中动态响应的影响分析  

Analysis of the influences on dynamic response of relative humidity to PEMFC during loading

作　　者：刘永峰[1] 张璐 裴普成[2] 刘鑫桐 禹永帅 LIU Yongfeng;ZHANG Lu;PEI Pucheng;LIU Xintong;YU Yongshuai(Beijing Engineering Research Center of Monitoring for Construction Safety,Beijing University of Civil Engineering and Architecture,Beijing 100044,China;State Key Laboratory of Automotive Safety and Energy,Tsinghua University,Beijing 100084,China)

机构地区：[1]北京建筑大学,北京市建筑安全监测工程技术研究中心,北京100044 [2]清华大学,汽车安全与节能国家重点实验室,北京100084

出　　处：《汽车安全与节能学报》2023年第1期89-97,共9页Journal of Automotive Safety and Energy

基　　金：汽车安全与节能国家重点实验室开放基金课题(KFY2218);北京市建筑安全监测工程技术研究中心研究基金资助课题(BJC2020K005)。

摘　　要：为研究电流阶跃变化过程中相对湿度对质子交换膜燃料电池(PEMFC)动态性能的影响,提出动态传热(DHT)数值模型。该模型考虑了相对湿度和阶跃电流对输出电压的影响,揭示出电流阶跃变化条件下相对湿度对质子交换膜(PEM)内水含量和电流密度分布的响应规律。通过自定义函数(UDF)将DHT模型导入Fluent软件并应用有限体积法进行计算;对工作温度60℃、负载电流的加载幅值5 A、阴极相对湿度100%、阳极相对湿度50%和100%条件下的PEMFC动态响应性能进行了评价;并将通过DHT模型得到的极化曲线和输出电压响应结果与实验数据进行了比较。结果表明:当阴极相对湿度为100%,阳极相对湿度100%的输出电压及最大功率密度优于50%相对湿度;阳极相对湿度为100%时,DHT模型与实验所得极化曲线间误差为2.18%;电流密度的分布与PEM膜内水含量和阳极侧气体加湿程度有关,阳极侧相对湿度提高,跨膜的电流密度分布均匀性下降;当阳极侧相对湿度为50%、100%时,加载前后膜内水含量分布的极差值分别为2.9和3.1 kmol/m^(3)、3和4.2 kmol/m^(3)。A numerical model of dynamic heat transfer was proposed to analyze the influences of relative humidity on the dynamic performance of proton exchange membrane fuel cells(PEMFC), in which the effects of relative humidity and step current on the output voltage were considered, revealing the response law of relative humidity to the water content and current density distribution in the proton exchange membrane(PEM)under the condition of step current change. The dynamic heat transfer(DHT) model was imported into Fluent software through a custom function(UDF) and calculated by the finite volume method. The dynamic response performance of PEMFC was evaluated under the operating temperature of 60 ℃, load current loading amplitude of 5 A, cathode relative humidity of 100%, anode relative humidity of 50% and 100%, respectively. The polarization curves and output voltage responses by the DHT model were compared with the experimental data.The results show that the output voltage and maximum power density with anodic relative humidity of 100% are better than those obtained with anodic relative humidity of 50%. When the anode relative humidity is 100%, the error between the DHT model and the experiment is only 2.18%. The distribution of current density is related to the water content in PEM membrane and the humidity of gas at the anode side. With the increase of relative humidity on the anode side, the distribution uniformity of current density across the membrane decreases. When the relative humidity of anode side are 50% and 100%, the ranges of water content distribution in the membrane before and after loading are 2.9 and 3.1 kmol/m^(3), 3 and 4.2 kmol/m^(3), respectively.

关 键 词：质子交换膜燃料电池(PEMFC) 动态传热(DHT) 动态响应 相对湿度 电流密度分布 

分 类 号：U473.4[机械工程—车辆工程]