化工学报
化工學報
화공학보
JOURNAL OF CHEMICAL INDUSY AND ENGINEERING (CHINA)
2014年
5期
1893-1899
,共7页
燃料电池%自增湿%质子交换膜%水传递%数值分析
燃料電池%自增濕%質子交換膜%水傳遞%數值分析
연료전지%자증습%질자교환막%수전체%수치분석
fuel cell%self-humidification%proton exchange membrane%water transport%numerical analysis
增湿及水管理系统使得燃料电池系统结构复杂，质子交换膜燃料电池（proton exchange membrane fuel cell, PEMFC）自增湿操作在实用化方面逐渐引起研究者的兴趣。提高PEMFC自增湿性能的关键在于对生成水的有效管理，保证质子交换膜的良好水合。实践证实采用自增湿膜电极组件是一个有效途径。本文建立催化层中增加保水层的水传递平衡模型预测膜中水的分布，考察自增湿操作的可行性和稳定性。数值分析表明：只有低于50μm （如Nafion112）的薄膜能满足电池自增湿膜水合的要求。保证膜水合性能和电池操作稳定性的电池温度为60℃，操作压力为0.15 MPa，阴极气体过量系数可以增大到1.8。在上述操作条件下，电池自增湿性能与饱和增湿有可比性，与饱和增湿最佳条件有差距。因此 PEMFC 自增湿性能在综合考虑降低成本和费用，简化结构和操作时具有可行性，但不能替代增湿操作。
增濕及水管理繫統使得燃料電池繫統結構複雜，質子交換膜燃料電池（proton exchange membrane fuel cell, PEMFC）自增濕操作在實用化方麵逐漸引起研究者的興趣。提高PEMFC自增濕性能的關鍵在于對生成水的有效管理，保證質子交換膜的良好水閤。實踐證實採用自增濕膜電極組件是一箇有效途徑。本文建立催化層中增加保水層的水傳遞平衡模型預測膜中水的分佈，攷察自增濕操作的可行性和穩定性。數值分析錶明：隻有低于50μm （如Nafion112）的薄膜能滿足電池自增濕膜水閤的要求。保證膜水閤性能和電池操作穩定性的電池溫度為60℃，操作壓力為0.15 MPa，陰極氣體過量繫數可以增大到1.8。在上述操作條件下，電池自增濕性能與飽和增濕有可比性，與飽和增濕最佳條件有差距。因此 PEMFC 自增濕性能在綜閤攷慮降低成本和費用，簡化結構和操作時具有可行性，但不能替代增濕操作。
증습급수관리계통사득연료전지계통결구복잡，질자교환막연료전지（proton exchange membrane fuel cell, PEMFC）자증습조작재실용화방면축점인기연구자적흥취。제고PEMFC자증습성능적관건재우대생성수적유효관리，보증질자교환막적량호수합。실천증실채용자증습막전겁조건시일개유효도경。본문건립최화층중증가보수층적수전체평형모형예측막중수적분포，고찰자증습조작적가행성화은정성。수치분석표명：지유저우50μm （여Nafion112）적박막능만족전지자증습막수합적요구。보증막수합성능화전지조작은정성적전지온도위60℃，조작압력위0.15 MPa，음겁기체과량계수가이증대도1.8。재상술조작조건하，전지자증습성능여포화증습유가비성，여포화증습최가조건유차거。인차 PEMFC 자증습성능재종합고필강저성본화비용，간화결구화조작시구유가행성，단불능체대증습조작。
External humidification for fuel and oxidant gases of PEMFC makes the system complicated, it is of practical interest to operate PEMFCs through self-humidification. The key to improve PEMFC performance of self-humidification operation is to maintain the polymer electrolyte membrane adequately hydrated. Thus, self-humidifying membrane electrode assembly (MEA) is an effective way. In this paper, a mathematical model of water transport balance was developed to predict water content distribution in proton exchange membrane, and further study the feasibility and stability of self-humidification operation. Numerical analysis illustrated that the membrane was thin enough to satisfy the demand of hydration. In order to maintain the membrane hydrated well and achieve good performance of PEMFC, cell temperature and operating pressure were set 60℃ and 0.15 MPa, air stoichiometry was increased to 1.8. Based on these conditions, the performance of PEMFC showed a little difference between self-humidification and full-humidification. But there was a large gap compared to optimized full-humidification. It was applicable for self-humidificaiton to simplify the structure and reduce the cost, mass and complexities of PEMFC. But full humidification cannot be replaced completely.
