New design of a PEFC cathode separator of for water management

2017 International Conference on New Energy and Future Energy System

Sugiura, K.^1 ; Takahashi, N.^1 ; Kamimura, T.^1

Department of Technological Systems, Mechanical Engineering Course, Osaka Prefecture University, College of Technology, Neyagawa Osaka

5728572, Japan^1

关键词: Cathode separator;    Cell performance;    Electric energies;    High temperature membranes;    Low humidity conditions;    Management issues;    Polymer electrolyte fuel cells;    System efficiency;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/93/1/012017/pdf
DOI  :  10.1088/1755-1315/93/1/012017

来源: IOP

【 摘 要 】

Generally, polymer electrolyte fuel cells (PEFCs) need humidifiers to prevent the drying of the membrane, but this use of humidifiers creates water management issues, such as the flooding/plugging phenomena and decreased system efficiency because of an increase in the electric energy needed for auxiliary equipment. Although most researchers have developed high-temperature membranes that do not need humidifiers, a lot of time is necessary for the development of these membranes, and these membranes drive up costs. Therefore, we propose a new cathode separator design that can recycle water generated by power generation in the same cell and a stack structure that can redistribute water collected in the cathode outlet manifold to drying cells. Because the new cathode separator has a bypass channel from the gas outlet to the gas inlet to transport excess water, a dry part in the gas inlet is supplied with excess water in the gas outlet through the bypass channel even if the PEFC is operated under dry conditions. Excess water in the PEFC stack can be transported from the cell with excess water to the drying cell through the cathode outlet manifold with a porous wall. Therefore, we confirm the influence of the plugging phenomenon in the cathode gas outlet manifold on the cell performance of each cell in the stack. As a result, the cell performance of the new cathode separator design is better than that of the standard separator under the low humidity conditions. We confirm that the plugging phenomenon in the cathode outlet manifold affects the cell performance of each cell in the stack.