• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.12
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• pp.1188-1193
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• 2007

This study focuses on the corrosion problems of STS316(stainless steel 316) tube for the cooling system of PEMFC (Proton Exchange Membrane Fuel Cell) operation. Deionized water which is highly corrosive is used especially for cooling agent of PEMFC to eliminate electrical conductivity, The tensile stress analysis was performed to check the change of mechanical strength of cooling line and pH of the water was monitored for the observation of extent of corrosion at simulated PEMFC operating condition. When STS316 tube was exposed to deionized water for 500 hours, substantial cracks were found on the surface and the pH of water was decreased from 6.8 to 5.8. For prevention of corrosion problems, the STS316 was coated by three kinds of fluororesin such as PTFE, FEP and ETFE. Among the coating materials, PTFE was the most protective in corrosive environment and was maintained the mechanical strength. To lower the cost, the same experimental analyses were carried out for iron tubes and the result will be discussed in detail.

• Journal of Hydrogen and New Energy
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• v.21 no.4
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• pp.307-312
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• 2010

Poly (ether sulfone)s with Bisphenol-TP and Bisphenol-AF were prepared with Bisphenol-TP <4,4-dihydroxy tetraphenyl methane>, 4-Fluorophenyl sulfone, and Bisphenol-AF <4,4-(hexafluoroisopropylidene) diphenol> using Potassium carbonate in Sulfolane at $210^{\circ}C$. Sulfonated PBTP-AF were obtained by reaction of Chlorosulfuric acid with copolymers. A series of copolymers were studied by $^1H$-NMR spectroscopy, Differential Scanning Calorimeter (DSC), and Thermo Gravimetric Analysis (TGA). Sorption experiments were conducted to observe the interaction of polymers with water and methanol.

• Journal of Hydrogen and New Energy
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• v.20 no.3
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• pp.216-223
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• 2009

The relation between temperature and hydrogen desorption on variation in output was investigated for the metal hydride canister. For this study, an AB$_5$ type alloy were chosen as a hydrogen storage material in the metal hydride canister. And application to the single proton exchange membrane fuel cell was evaluated. As the results, the hydrogen desorption was linearly increased as the temperature was risen. In addition, metal hydride canister heating was able to correspond the variation of load as power request in the PEMFC system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.235-239
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• 2005

We analyzed the thermal and mechanical behaviors of micro reformer for the purpose of design verifications and modification of micro channels. The reformer designed for hydrogen generation from methanol is essential to PEM(Proton Exchange Membrane) type fuel cell. For the mobile applications, the size and the simplicity would be the most critical issues. We utilized silicon process for micro reformer to obtain the thickness thinner than 2 mm thick. We have used commercial simulation software, IDEAS, to analyze the thermal and mechanical characteristics of micro reformer structure. The heat generation rates of heaters, heat transfer rates, and fluid temperatures are derived from thermal equilibrium relation and these values were used for thermal boundary conditions. We also analyzed the thermal stresses, thermal deformations to examine the possibility of failure.

• Corrosion Science and Technology
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• v.9 no.3
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• pp.129-136
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• 2010

The corrosion behaviors of 316L stainless steel were investigated in simulated anodic and cathodic environments for proton exchange membrane fuel cell (PEMFC) by using electrochemical measurement techniques. Interfacial contact resistance(ICR) between the stainless steel and gas diffusion layer(GDL) was also measured. The possibility of 316L was evaluated as a substitute material for the graphite bipolar plate of PEMFC. The value of ICR decreased with an increase in compaction stress(20 N/$cm^2$~220 N/$cm^2$) showing the higher values than the required value in PEMFC condition. Although 316L was spontaneously passivated in simulated cathodic environment, its passive state was unstable in simulated anodic environment. Potentiostatic and electrochemical impedance spectroscopy (EIS) measurement results showed that the corrosion resistance in cathodic condition was higher and more stable than that in anodic condition. Field emission scanning electron microscopy (FE-SEM), and inductively coupled plasma(ICP) were used to analyze the surface morphology and the metal ion concentration in electrolytes.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.356-359
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• 2006

고분자전해질 연료전지의 MEA를 CCM (Catalyst Coated Membrane) CCS(Catalyst Coated Substrate) 형태로 각각 제조하고 백금담지 비율이 서로 다른 백금 담지촉매를 각각 적응하여 MEA를 CCM형태로 제조하여 단위전지 성능평가를 수행하였다 백금담지 비율이 다른 촉매를 적용한 CCM형태 MEA의 표면을 SEM (scanning electron microscopy)으로 분석하였으며, 단위전지 성능평가를 수행하는 동시에 EIS (Electrochemical Impedance Spectroscopy)를 통하여 MEA의 저항을 분석하였다. 고분자전해질 연료전지의 성능은 MEA의 제조방법과 백금담지 촉매의 백금담지비율에 따라 크게 변함을 확인 할 수 있었다.

• KEPCO Journal on Electric Power and Energy
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• v.3 no.2
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• pp.141-146
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• 2017

In this work, a simulation study on net 500 MW class of Poly-Generation was conducted for the retrofit of an aged natural gas combined cycle. An entrained gasifier which has a capacity of maximum $260,000Nm^3/h$, 50 MW class of a Polymer Electrolyte Membrane Fuel Cell, and H-class Gas Turbine were selected as key processes. After unit design for those employed processes was set up and combined, the simulation was carried out with Gate-Cycle software (Ver. 6.0) for two cases. The selected cases are a retrofit type (Poly-Gen 1) and a new type (Poly-Gen 2). It was found that the efficiency of the retrofit case is 2.7% lower than that of the new case.

• Journal of Hydrogen and New Energy
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• v.15 no.3
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• pp.220-227
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• 2004

The purpose of this paper is, based on the theoretical background of the principle of gas purification and absorption, and the absorbing ability of metals, to syudy the efficiency of gas purification of inorganic gases using Zr alloys, so as to contribute to the IT industry. To produce and distribute gas with high purity and ultra-high purity, different types of gas purifier are currently being used: distillation type, getter type, catalyst type, absorption at low-temperature type, and membrane separation equipment. From the different purification methods mentioned above, the getter type gas purifier is capable of not only high performance and capacity but also P.O.U(Point Of Use) method. The key of the getter type gas purifier is its efficiency of gas purification, which is the subject chosen for this study.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.247-250
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• 2009

This study considers the feasibility of using the low cost assembled separator. The graphite plate has been widely used as the separator in the field of PEMFCs(Polymer electrolyte membrane fuel cell) industry because of its excellent material properties such as good corrosion resistance, good electrical conductance and so on. However, there are some problems for the commercialization due to its poor cost effectiveness for the large volume manufacturing and lack of mechanical strength. From this respect, this study has focused on the manufacturing technology in order to reduce the price for the commercialization of separator. This study also shows that the assembled separator of the suggested structure, which is composed of grafoil and PC(PolyCarbonate) materials, could be manufactured at low cost enough for the mass production. The flow fields produced by cutting foils and the base plates of the separators were simply made by mechanical work.

• Journal of the Korean Electrochemical Society
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• v.17 no.3
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• pp.201-208
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• 2014

A Pt catalyst ($Pt/G_xC_y$) supported on the hybrid supporting materials composed of graphene oxide (GO) and carbon black (C) was fabricated using polyol method to improve the durability of electrocatalysts. The electrochemical performances measured by cyclic voltammograms using three-electrode system revealed that the properly designed $Pt/G_xC_y$ catalyst exhibited higher durability than that of Pt/C catalyst without sacrificing an electrocatalytic acivity. In the oxygen reduction reaction (ORR) performed in acid solution with the rotating disk electrode, the $Pt/G_xC_y$ catalyst showed greater mass and area-specific activity than those of Pt/C catalyst.