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Volume 31 (2011)
- Issue 123 Pages 133-
- Issue 122 Pages 91-
- Issue 121 Pages 1-
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Volume 31, Issue 123
Displaying 1-6 of 6 articles from this issue
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Makoto YAMAUCHI, Shumpei FUNATANI2011 Volume 31 Issue 123 Pages 133
Published: 2011
Released on J-STAGE: February 23, 2013
JOURNAL FREE ACCESSDownload PDF (194K) -
-Water Transport Properties and MEA Performance-Akihiko FUKUNAGA, Shuichi SUZUKI2011 Volume 31 Issue 123 Pages 134-138
Published: 2011
Released on J-STAGE: February 23, 2013
JOURNAL FREE ACCESSIn recent years, driven largely by the increased focus on environmental issues and effective use of energy resouses, fuel cell cogeneration systems for home use have become increasingly popular. Since 2008, such systems have been sold under the name ENE-FARM. At the heart of the system is a Polymer Electrolyte Fuel Cell (PEFC) which generates electricity though a chemical reaction between hydrogen(fuel) and oxygen in the air, in which water is produced as a by-product. Cell peformance is greatly dependent upon water transport between the anode and cathode. In this study, water transport was measured under various conditions by changing the operating cell conditions and the properties of Membrane Electrode Assembly (MEA). The results showed that cell performance was related to water transport. In continuous operation, uneven in-plane distribution of current was observed. Thus, to understand the properties of a PEFC, it is useful to visualize the water distribution in the MEA, which is closely linked to fuel cell performance.View full abstractDownload PDF (776K) -
Nobuyuki TAKENAKA2011 Volume 31 Issue 123 Pages 139-143
Published: 2011
Released on J-STAGE: February 23, 2013
JOURNAL FREE ACCESSIt is important to understand behavior of water which is generated by fuel cell operation to improve pelformance of the fuel cell. Neutron rays are transparent to most of metals and are attenuated by water. Therefore, neutron radiography is suitable to observe the water behavior in the fuel cell. The visualized and measurement results by using new neutron radiography techniques developed for the fuel cell researches were presented. Thmporal quantitative water thickness distributions in a JARI standard cell were measured. A network model was developed to simulate the gas flow velocity and the pressure distribution based on the measured results. Dynamic neutron CT was applied to 3-cell stack based on the JARI standard and the dynamic 3-D water behavior was observed every 15 seconds. The water distribution through plane in MEA and GDL in a small size fuel cell was measured by an imaging system using a bore-scope.View full abstractDownload PDF (821K) -
Shohji TSUSHIMA, Shuichiro HIRAI2011 Volume 31 Issue 123 Pages 144-148
Published: 2011
Released on J-STAGE: February 23, 2013
JOURNAL FREE ACCESSIn situ visualization of water in an operating polymer electrolyte fuel cell (PEFC) by magnetic resonance imaging (MRI) and soft X-ray radiography (SXRG) is presented. Concept and methodologies of these techniques in order to apply water visualization in PEFCs are described. MRI measurement of a hydrated polymer electrolyte membrane in a PEFC revealed a partial dehydration of the membrane due to electro-osmotic drag under insufficient humidification, while sufficient hydration of the membrane was confirmed under fully hunridified condition. SXRG was applied to visualize spatial and temporal variation of liquid water in both catalyst layers and gas diffusion layers. In-plane and through-plane visualization of water accunlUlation and discharge behaviors was explored and revealed inhomogeneous accumulation of liquid water in a porous electrode and local discharging process through a micro-scale crack in micro-porous layer.View full abstractDownload PDF (1224K) -
Junji INUKAI, Masahiro WATANABE2011 Volume 31 Issue 123 Pages 149-154
Published: 2011
Released on J-STAGE: February 23, 2013
JOURNAL FREE ACCESSNew visualization system was developed to understand the eleactions in running polymer electrolyte fuel cells in situ and in real time. Separate/simultaneous visualizations of oxygen partial pressure and water droplets were successfully carried out. The effects of the gas flow inside the gas diffusion layers were discussed.View full abstractDownload PDF (863K) -
Eiji EJIRI2011 Volume 31 Issue 123 Pages 155-160
Published: 2011
Released on J-STAGE: February 23, 2013
JOURNAL FREE ACCESSA fuel cell with a simple structure and capable of operating at nearly ambient temperature and pressure is suitable for small-sized generator sets for portable and outdoor use. In this study, detailed experimental analyses were conducted with a newly designed banded structure membrane fuel cell module consisting of 15-20 cells laid out in a plane in order to investigate the cause of a sudden power breakdown during long-term operation. Humidity near the anode and cathode GDL surface of a single cell was measured and temperature distribution over the cathode surface of the module was measured. The airflow near the cathode of a single cell was visualized with a particle image velocimetry system, in addition to the oxygen concentration with a novel visualization system, which used luminescent porphrin dye whose fluorescence intensity decreases with the increase of oxygen partial pressure.View full abstractDownload PDF (917K)
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