• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2834-2838
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• 2008

An free breathing proton exchange membrane fuel cell (PEMFC) was developed. This paper presents a study of the several effect on the performance of a fuel cell such as air flow rate, opening ratio, and cathode structures. Especially, an air flow rate is critical condition to improve the fuel cell performance. In this paper, we developed a synthetic jet micro air blower to supply high stoichiometric air. The synthetic jet actuation is usually generated by a traditional PZT-driven actuator, which consists of a small cylindrical cavity, orifices and PZT diaphragms. In comparison with free convection fuel cells, the forced-convection fuel cell which equipped synthetic jet micro air blower brings higher performance and stability for long term test. Also, power consumption of the synthetic jet micro air blower is under 0.3W. The results show that the maximum power density was $188mW/cm^2$ at $400mA/cm^2$. The maximum power density was higher 40% than power density of free convection fuel cell.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.2
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• pp.231-238
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• 2006

The performance of free-breathing polymer electrolyte membrane fuel cell (PEMFC) was studied experimentally and the effect of cathode separator structure on the cell performance was investigated. Cathode separators were used for the cell with $18cm^2$ active area. In channel type, the contact resistance is low, and the nature convection. which is strongly affected by the cross-sectional shape of cathode separator channel, is dominant in a cell performance. The maximum power density with $18cm^2$ active area is $105mW/cm^2$ using the 10mm depth and 2mm width channel. A computational analysis was optimum structure of free-breathing channel type PEMFC for robotic application.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.2
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• pp.225-230
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• 2006

This study investigates drying condition when a small fan is added to a operating the free-breathing proton exchange membrane fuel cells (PEMFCs) with dry $H_2$ and Air. Polarization tests were conducted on PEMFCs at cell temperatures between 30 and $50^{\circ}C$ under dry operation. In the results, the cell performance strongly depended on the cell temperature and the cathode gas stoichiometric flow rates. The cell performance increases as cell temperature decreases from 50 to $30^{\circ}C$. In the domain where the stoichiometry of air is quite large, reduction of the concentration overpotential compensated the increased internal resistance due to drying. The maximum performance was obtained at the small air flow rate beyond which flooding occurs. This indicates that the fan should be operated in the stoichiometry domain with a well designed cell structure to avoid flooding.