• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.31 no.5
• /
• pp.473-481
• /
• 2007

Compared to other types of fuel cells, SOFC has advantages like a wide output range and the direct use of hydrocarbon fuel without the process of external reforming. Particularly because the direct use of fuel without reforming reaction is closely linked to overall system efficiency, it is a very attractive advantage. We tried the operation with methane. However, although methane has a small number of carbons compared to other hydrocarbon fuels, our experiment found the deposition of carbon on the surface of the SOFC electrode. To overcome the problem, we tried the operation through activating internal reforming. The reason that internal reforming was possible was that SOFC runs at high temperature compared to other fuel cells and its electrode is made of Ni, which functions as a catalyst favorable for steam reforming.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.31 no.2 s.257
• /
• pp.125-131
• /
• 2007

This paper presents guideline for a practical design of the hybrid system combining a pressurized solid oxide fuel cell and a gas turbine. Design of the hybrid system based on a virtually designed gas turbine was simulated using models for off-design operation of the gas turbine. Two system configurations, with different method for supplying reforming steam, are considered and their design characteristics are compared. A higher design cell temperature provides better system performance. However, there exists a maximum allowable design cell temperature because the operating point of the compressor approaches the surge point with increasing fuel cell temperature. Increased pressure loss at the fuel cell moves the compressor operating point toward the surge point and reduces system performance.

• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.2015-2020
• /
• 2007

Diesel is an excellent candidate fuel for fuel cell applications due to its high hydrogen density and well-established infrastructure. But, it is hard to guarantee desirable performance of diesel reformer because diesel reforming has several problems such as sulfur poisoning of catalyst and carbon deposition. We have been focusing on diesel autothermal reforming(ATR) for substantial period. It is reported that ATR of diesel has several technical advantages such as relatively high efficiency and fuel conversion compared to steam reforming(SR) and partial oxidation(POX). In this paper, we investigate characteristics of diesel reforming under various ratios of reactants(oxygen to carbon ratio, steam to carbon ratio) for improvement of reforming performances(high reforming efficiency, high fuel conversion, low carbon deposition). We also exhibit calculated heat balance of autothermal reformer at each condition to help thermal management of SOFC system.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.41 no.2
• /
• pp.109-115
• /
• 2017

Using the computational fluid dynamics (CFD) technique, we performed a numerical simulation in anodesupported solid oxide fuel cell (SOFC). The effect of gas channel/rib width on the cell performance and temperature uniformity was investigated in planar type SOFC. The open source CFD toolbox, OpenFOAM, was used as a numerical analysis tool. As a result, the effect of gas channel/rib width on the cell performance and temperature uniformity was not significant if the oxygen depletion is not occurring. On the other hand, the usage of a wide rib and operation at high current density may lead to performance degradation due to oxygen depletion.

• Current Industrial and Technological Trends in Aerospace
• /
• v.7 no.2
• /
• pp.95-105
• /
• 2009

Fuel cells are applied to the propulsion system of aircraft based on environmental-friendly characteristics with low noise and zero emission of CO2, currently many kinds of UAV and small manned aircraft equipped with fuel cells are being developed. Fuel cells for aircraft typically classified into PEMFC(Proton Exchange Membrane Fuel Cell) type and SOFC(Solid Oxide Fuel Cell) type and the system is developed to adapt missions and operational conditions of aircraft. For UAV, various types of aircraft mostly based on PEM fuel cell technology are investigated for military or commercial uses, and the stability and endurance of system will be improved. For small manned aircraft, many researches are carried out to substitute the propulsion system by fuel cell, also some developments for the higher performance of APU of large commercial aircraft to apply fuel cells are in progress. In the future, a fuel cell aircraft will be expected to improve the reliability and efficiency with higher power density.

• 한국전기화학회:학술대회논문집
• /
• 2002.04a
• /
• pp.47-47
• /
• 2002

• 한국전기화학회:학술대회논문집
• /
• 2003.07a
• /
• pp.133-138
• /
• 2003

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2011.06a
• /
• pp.987-988
• /
• 2011

• 한국연소학회:학술대회논문집
• /
• 2006.10a
• /
• pp.260-265
• /
• 2006

An experimental study on the catalytic reformer adopted in the auxiliary power unit system of solid oxide fuel cell was conducted. A 3-fluid nozzle, by which liquid fuel such as diesel, water and air are sprayed and uniformed mixed, was designed and used in this study. An electrically heated monolith inserted in the reformer was used for the vaporization of fuel and water in the transient state of reformer. The reformer uses the partial oxidizing reaction at the catalyst and the supply of water prevents the flame combustion in the spraying zone and lessens the deactivation of catalyst. The result showed that the reforming of liquid fuel can be started by the electrically heated monolith and the 3-fluid nozzle can give the uniform mixing of fuel, water and air. It was also found that the reformer fueled by n-hexadecane can make the reformate, at best, containing $H_2$ at 15.5% and CO at 11.5% that are used as fuel in the solid oxide fuel cell.

• Korean Journal of Materials Research
• /
• v.17 no.6
• /
• pp.313-317
• /
• 2007

In-situ micro-channeled multi tubular solid oxide fuel cell(SOFC) was fabricated using multi-pass extrusion process with out side diameter of 2.7 mm and active length of 5 mm that contained 61 individual cells. Cell materials used in this work were NiO-YSZ (50 : 50 vol.%), 8 mol% yttria-stabilized zirconia(8YSZ), $La_{0.8}Sr_{0.2}MnO_3(LSM)$ as anode, electrolyte, and cathode, respectively. The arrangement of each electrode and electrolyte layer in green bodies showed uniformity and integrity after extrusion and sintering. The XRD analysis confirmed that no reaction phases appeared and the microstructure of the electrolyte was fairly dense (relative density > 96%) after sintering.