A computational analysis on the operational behaviour of open-cathode polymer electrolyte membrane fuel cells

摘要

In the present work, a comprehensive, three-dimensional computational fuel cell model is developed, validated, and utilized to study the operational and hygrothermal behaviour of an open-cathode (air cooled) polymer electrolyte membrane fuel cell at various ambient conditions compared to conventional liquid cooled cells and a hypothetical isothermal case. The spatial distributions of relative humidity, temperature, and membrane water content are analysed during operation of the cell and the strong hygrothermal characteristic of the open-cathode fuel cell system is established. The high temperature and relative humidity gradients inside the cell are found to limit the cell performance for open-cathode cells unlike the other operational cases. Moderate self-heating followed by membrane drying is found to be the key factor limiting the net cell performance while in operation at moderate-to-high current densities and high air flow rates. The open-cathode fuel cell is also found to perform better at high temperature and high relative humidity ambient conditions; however, in contrast to liquid cooled cells, the performance is restricted by inefficient thermal and water management. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.