电极孔径及温度对闭式氢氧燃料电池性能的影响机理研究
Effects of electrode pore size and temperature on the performances of closed hydrogen-oxygen fuel cells
叶清泉 1吴旭光 1陈丽园 1王万焕1
作者信息
- 1. 国网浙江省电力有限公司平阳县供电公司,浙江 温州 325400
- 折叠
摘要
针对燃料电池内部复杂的水传输机制和水管理策略的影响因素,研究多孔电极的孔径对水传输和水分布情况的影响.建立燃料电池等温模型,通过改变多孔电极的孔径,模拟燃料电池催化层在不同孔径下的水浓度和水分布规律.同时,考虑温度可能带来的影响,在研究过程中选取了燃料电池常见的运行温度,在每个温度值下都进行了模拟.结果表明,在设定的温度下,孔径对水浓度和水分布情况的影响规律是相似的.孔径较大时,电极内的水浓度较低.随着孔径减小,电极内的水浓度不断增大.同时,孔径越小,水浓度增大的速度越快.气体浓度的分布与变化情况正好与水浓度相反.水浓度越高的区域气体浓度越低.随着孔径减小,气体浓度不断上升.从模拟结果来看,当气体扩散层具有微米级孔隙结构时,电极内多余的水分可以较好地排出,同时在较高的温度下水管理更容易较好地实现.阴极流道出口和中部比较容易发生水淹,所以应该对这些区域加设除水装置或设计自除水结构.
Abstract
In view of the complex water transport mechanism and the influencing factors of water management strategy in fuel cells,the influence of pore size of porous electrode on water transport and distribution was studied in this paper.Firstly,a fuel cell isothermal model was established to simulate the water content and water distribution of the catalytic layer at different pore sizes by changing the pore size of the porous electrode.At the same time,in order to consider the possible influence of temperature,common operating temperatures of fuel cells were selected during the study,and simulations were carried out at each temperature value.The results show that the pore diameter has similar influence on the water concentration and distribution at the set temperature.When the pore diameter is larger,the water concentration in the electrode is lower,and the water content in the electrode increases with the decrease of the pore diameter.The distribution and change of gas concentration is exactly the opposite of that of water,the higher the concentration of water,the lower the concentration of gas,and the smaller the aperture,the higher the concentration of gas.It can be seen from the simulation results that when the gas diffusion layer has micrometer pore structure,the excess water in the electrode can be discharged better,and better water management can be achieved at higher temperatures.The outlet and the middle of the cathode flow path are more prone to flooding,so water removal devices should be installed in these areas or self-dewatering structures should be designed.
关键词
闭式氢氧燃料电池/多孔电极/孔径/质子交换膜/水传输机制/水浓度/水平衡/温度/气体流道/催化层/气体扩散层/氧气/氢气Key words
closed hydrogen and oxygen fuel cell/porous electrode/pore size/proton exchange membrane/water transport mechanism/water concentration/water balance/temperature/gas flow path/catalytic layer/gas diffusion layer/oxygen/hydrogen引用本文复制引用
出版年
2024
NETL
NSTL
万方数据