• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1993.05a
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• pp.96-100
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• 1993

상용 모사기인 ASPEN PLUS를 이용하여 메탄올을 원료로 한 고체 고분자 전해질 연료전지 발전 시스템의 정상상태 전산 모사를 실시하여 최적의 설계를 시도하였다. 연료전지 본체의 모사를 위하여 USER block과 FORTRAN block을 작성하였으며, 다른 공정은 ASPEN PLUS에서 제공되는 모델을 사용하였다. 모사 결과, 실제 경우와 근사한 값을 얻었으며, 이를 근거로 하여 조업조건에 따른 출력의 변화를 살펴봄으로써 효율을 최대로 하는 각 단위공정의 최적 조업조건을 찾아내었다. 이로부터 향후 실용화될 국내의 고체 고분자 전해질 연료전지 발전 시스템에 대한 기본 자료를 제시할 수 있으며, 개발되는 공정은 고온으로 조작되는 개질기의 열을 효율적으로 회수하여 이용함으로써 공정의 에너지 효율을 높이도록 하여야 한다.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.585-589
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• 2007

Gas hydrate is a special kind of inclusion compound that can be formed by capturing gas molecules to water lattice in high pressure and low temperature conditions. When referred to standard conditions, $1m^3$ solid hydrates contain up to $172Nm^3$ of methane gas, depending on the pressure and temperature of production, Such large volumes make natural gas hydrates can be used to store and transport natural gas. In this study, three-phase equilibrium conditions for forming methane hydrate were theoretically obtained in aqueous single electrolyte solution containing 3wt% Nacl. The results show that Nacl acts as a inhibitor, but help gases such as ethan, propane, i-butane, and n-butane reduce the hydrate formation pressure at the same temperature.

• Journal of the Korean Ceramic Society
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• v.42 no.2 s.273
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• pp.77-80
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• 2005

A series of proton conductive composite membranes based on poly(vinyl alcohol) and phosphosilicate gels powders were successfully prepared. The proton conductivity of these composite was attributed to the phosphosilicate gel, which derived from tetraethoxysilane and phosphoric acid by sol-gel process at a molar ratio of P/Si = 1.5. The proton conductivity increased with increasing both the content of phosphosilicate gel and relative humidity. Temperature dependence of conductivity showed a Vogel-Tamman-Fulcher type behavior, indicating that proton was transferred through a liquidlike phase formed in micropores of phosphosilicate gel. The high conductivity of 0.065 S/cm with a membrane containing 60 wt$\%$ of the gel was obtained at $60^{\circ}C$ at $90\%$ relative humidity.

• The Korean Journal of Ceramics
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• v.4 no.3
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• pp.204-206
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• 1998

The Gibbs free energy of formation of $BaThO_3$ from elemental oxides has been measured at temperatures between 853 and 903 K using a $CaF_2$ solid electrolyte galvanic cell. The galvanic cell consisted of Pt, $O_2, CaO+CaF_2 \parallel CaF_2 \parallelBaThO_3+ThO_2+BaF_2, O_2$, Pt EMF gave the standard Gibbs free energy for the reaction $CaF_2+BaThO_3=CaO+BaF_2+ThO_3$ as $\DeltaG^o$,/TEX>=124111.031-117.597 T(J/mol).

• Journal of the Korean Ceramic Society
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• v.22 no.5
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• pp.23-28
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• 1985

A model for degradation of $eta$-$Al_2O_3$ is derived from sress generated by Poiseuille pressure capillary effect and effulent flux in charging process of Na-S Battery. Critical current density for degradation increase with increasing the crack length and crack tip radius. radius 10-7cm and crack length 10-5cm Dependence of crack growth velocity on crack lengh is seperated two regions that is for a large crack length it is predominated by Poiseuille pressure and effulent fluex but in the case of small crack length it is controlled by capillary effect.

• Journal of Electrochemical Science and Technology
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• v.11 no.1
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• pp.41-49
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• 2020

In this study poly(carbazole) films deposited on stainless steel have been investigated as electrode material for supercapacitor applications. Poly(carbazole) films were electrodeposited using cyclic voltammetry in presence of lithium, sodium and tetrabutylammonium perchlorate salts. Poly(carbazole) films doped with perchlorate anions having different counter cations were characterized by SEM, ATR-FTIR and solid state conductivity measurements. Capacitive behaviours of PCz coated steel electrodes were tested by cyclic voltammetry, charge-discharge analysis and electrochemical impedance spectroscopy. It was found that counter cation of the dopant is significantly effective on the capacitive performance on the obtained PCz films and the PCz film synthesized from lithium perchlorate has the better capacitive performance than the poly(carbazole)s synthesized from sodium perchlorate and tetrabutylammonium perchlorate salts.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.956-961
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• 2000

This paper describes the design of a small size Alkali Metal Thermal to Electric Converter (AMTEC) which employs a capillary structure for recirculating sodium working fluid. The cycle is based on the simple and small capillary type ${\beta}"$ -alumina and wick tube element. The proposed cell consists of the 37 conversion elements with capillary tube of $50{\mu}m$ in diameter and the sealed cylindrical vessel of 22mm in outer diameter. Results on the cycle analysis of sodium flow and heat transfer in the cell showed that the expected power output was 4.65W and the conversion efficiency was 19% for the source temperature of 900K.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.2
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• pp.116-121
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• 2006

This paper presents an effective modeling and simulation scheme of solar-powered hydrogen production system (PV-SPE: Photovoltaic Solid Polymer Electrolyte). Existing Hydrogen production technologies can produce vast amounts of hydrogen from hydrocarbons but emit large amounts of carbon dioxide (CO2) into the atmosphere. Advanced hydrogen production methods need development. Renewable technologies such as solar and wind need further development for hydrogen production to be more cost-competitive from other resources. In this paper, authors have focused on a renewable technology to move one step further toward commercial readiness of solar-powered hydrogen production system. Software (PSCAD/EMTDC) based model of PV-SPE system is studied for an effective simulation of hydrogen production system. Using the simulation results, an actual PV-SPE system is implemented to verify the simulation results by comparing them with actual values obtained from the data acquisition system.

• Journal of Sensor Science and Technology
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• v.11 no.4
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• pp.218-223
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• 2002

NASICON sensors that the NASICON electrolytes with various CaO amounts were sintered at low temperature($900^{\circ}C$), were fabricated to improve $CO_2$ sensitivity and stability in sensing behaviors. The manufactured device was shown good sensing characteristics and stability of output electromotive force at $250^{\circ}C$, comparatively low operating temperature.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.103.1-103.1
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• 2011

고체 산화물 연료전지(SOFC)는 크게 음극(anode), 양극(cathode), 전해질(electrolyte)로 구성되 있으며 연결자를 통해 직렬 또는 병렬로 연결된 형태로 발전장치 등에 활용되고 있다. 이중 연료의 산화반응을 담당하고 있는 연료전지의 음극으로 지금까지 Cobalt, Platinum, Palladium 등의 전이금속 또는 귀금속들이 사용되었지만 현재는 Nickel 또는 Nickel을 함유한 물질들 특히, Ni-YSZ 복합체가 주로 사용되고 있다. Ni-YSZ 복합체는 가격과 성능 등 여러가지 면에서 SOFC의 음극으로 사용하기에 가장 적합한 물질인데 특히 전지의 지지체 역할과 동시에 전극으로서의 역할도 병행해야하는 음극 지지형 SOFC의 경우 Ni-YSZ 복합체의 효용성을 더욱 커지게 된다. 본 연구에서는 SOFC의 음극물질로 가장 널리 쓰이고 있는 Ni-YSZ 복합체를 core shell 형태로 만들어 전도 path를 효율적으로 하고 그 특성을 최적화하기 위한 미세구조 및 소결 거동, 전기적 특성을 평가하였다.