摘要
质子交换膜燃料电池膜内的水状态与工作性能密切相关。水的流进和流出管理不当,将出现水淹和干化现象。采用工作过程数学模拟的研究方法,可以深入了解燃料电池的湿度特性和水迁移特性。借助质量、动量和能量守恒及膜的特性关系式建立的数学模型,对电流、压力和水淹、干化的影响进行了研究。结果表明,有水从膜中流出时,膜中水的总量和膜的离子导电性下降,致使膜中的压降和欧姆热上升;在较大的电流密度作用下,膜中移动的质子数增多,携带水分子的能力也增大,从阳极带走的水分子增多,造成了阳极侧水浓度的下降;适当的压力梯度可以使燃料电池在运行过程中保持膜侧阳极的水化。研究证明,实际的湿度状态是各种因素的综合,电池的工作条件最终决定了它自身的水平衡状态。
Water flow in and out the membrane is closely related to proton exchange membrane fuel cells(PEMFC)performance. Through simulation of the fuel cell processes, its humid property and water transmission performance can be understood and predicted. This paper set up a numerical model and studied the influence of current, voltage, water logging and drying up. While water flows out the membrane the water mass in membrane will be reduced and the electric conductivity of ions there will be weakened. Then the pressure drop of the membrane together with a heat loss from electric resistance becomes lower. The mathematical simulation manifested that under a large electric flux the number of moving ions in the membrane will increase and so the ability to carry water molecules will become strong.
出处
《华北电力大学学报(自然科学版)》
CAS
北大核心
2004年第1期61-65,共5页
Journal of North China Electric Power University:Natural Science Edition