• 한국연소학회지
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• 제19권3호
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• pp.44-52
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• 2014

Solid oxide fuel cell(SOFC) makes electric power using hydrogen or reformed from methane and emits high temperature products that contain flammable species like hydrogen, carbon monoxide and methane which varies with operation condition. SOFC/gas turbine integrated system which uses thermal and chemical energy of the discharges is more efficient than SOFC itself. Burning character of the SOFC products will affect the efficiency and stability of the system. Experiments were conducted to know the characteristics of the flame for two typical composition of SOFC products, i.e. start-up and steady state composition. When coflowing air temperature was higher than $600^{\circ}C$, auto-ignitin occurred for both fuels. Though start-up fuel has higher contents of hydrogen, it makes longer flame than steady state composition. It was inferred that the amount of oxidizer necessary to burn makes this phenomenon. Steady state composition fuel was unstable since it contains lots of water. Nozzle that had 6 holes, distance between each hole was 16.7 times of hole diameter, improved the stability of the flame.

• Journal of Advanced Marine Engineering and Technology
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• 제39권7호
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• pp.765-772
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• 2015

본 연구는 SOFC/GT(Solid Oxide Fuel Cell/Gas Turbine)시스템의 SOFC 스택으로 공급되는 공기, 메탄 및 물의 유량변화에 따른 SOFC/GT시스템의 온도, 스택 출력 및 시스템 효율의 특성에 관하여 조사하였다. 이 때 SOFC 스택의 애노드 및 캐소드로 공급되는 가스 온도는 외부 열원의 추가 없이 시스템에서 배출되는 배기가스를 활용하여 일정하게 유지하였다. 그 결과 본 연구의 범위 내에서 외부 열원의 추가 없이 SOFC/GT시스템의 배기가스를 활용하여 SOFC 스택으로 공급되는 애노드 및 캐소드 가스 공급온도를 1000(K)로 일정하게 유지하는 것이 가능하였다. 시스템 효율은 공급 공기 유량은 많을수록, 공급 메탄 유량은 적을수록 높아짐을 알 수 있었고, 터빈으로 공급되는 배기 가스의 유량이 시스템 효율에 큰 영향을 미침을 알 수 있었다. 또한, SOFC/GT시스템의 운전 조건에 따라서 SOFC 스택 효율은 51~57%, 시스템 효율은 57~73%의 값을 얻을 수 있었다.

• 대한기계학회논문집B
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• 제31권1호
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• pp.62-67
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• 2007

Optimization of cathode properties for intermediate temperature-operating SOFC (IT-SOFC) is carried out by using composite-type electrode structure in this study. Composite cathode may lower cathode overpotential by enhancing mixed ionic-electronic conductivity. In this study, particularly, LSM/YSZ, LSF/YSZ, LSCF/CGO, and PSC/CGO were selected as cathode materials. LSM/YSZ composite cathode showed the best performance of about 0.9${\Omega}cm^2$ at $700^{\circ}C$. It is inferred that the resistance is mainly affected by the reactivity between cathode and electrolyte which can cause the formation of resistive phases. Area specific resistance (ASR) characteristics were not changed significantly with decreasing sintering temperature of cathode, because reaction sites were increased even with worse adhesion of cathode on electrolytes.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.703-707
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• 2001

A performance analysis of a SOFC/MGT hybrid system has been carried out for concept design. Thermo-dynamic models for each component being able to describe electrochemical characteristics and heat and mate-rial balance are proposed. Estimated is the power capacity of a SOFC suitable for the hybrid operation with a 5kW class MGT. Effects of current density and operating pressure are also investigated. Electric efficiency showed weak dependence on operating pressure and current density. It is desirable that the SOFC operates at high current density in manufacturing cost's point of view though operating with high current density slightly decreases the electric efficiency find specific power.

• Journal of Mechanical Science and Technology
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• 제20권3호
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• pp.391-398
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• 2006

This work involves a method for modeling the flow distribution in the stack of a solid oxide fuel cell. Towards this end, a three dimensional modeling of the flow through a Solid Oxide Fuel Cell (SOFC) stack was carried out using the CFD analysis. This paper examines the efficacy of using cold flow analysis to describe the flow through a SOFC stack. It brings out the relative importance of temperature effect and the mass transfer effect on the SOFC manifold design. Another feature of this study is to utilize statistical tools to ascertain the extent of uniform flow through a stack. The results showed that the cold flow analysis of flow through SOFC might not lead to correct manifold designs. The results of the numerical calculations also indicated that the mass transfer across membrane was essential to correctly describe the cathode flow, while only temperature effects were sufficient to describe the anode flow in a SOFC.

• 한국가스학회지
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• 제28권1호
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• pp.1-10
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• 2024

본 연구에서는 농업 분야 에너지 자립 시스템 기술도입의 일환으로 농산부산물 기반 SOFC 열병합발전 시스템의 공정 모사 모델을 구축하고 열교환망 최적화를 진행하였다. 0.3 ton/d급 농산부산물 반탄화 연료 가스화기 실험 결과를 기반 농산부산물 SOFC 열병합발전 시스템 모델을 구축하여 4~20 kW급 SOFC 발전 용량별 열교환망 최적화를 진행하였다. 현재 시스템상에서 8 kW급 농산부산물 기반 SOFC 열병합발전 시스템이 최적으로 도출되었으며, 본 연구 결과를 기반으로 추후 상용 설비 설계 시 기초자료로 활용이 가능할 것으로 판단된다.

• 한국전기전자재료학회논문지
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• 제25권3호
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• pp.241-246
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• 2012

A layered planer SOFC module was designed from planar-type SOFC. It was prepared by multi-layered ceramic technology. To form the cathode and the anode in the layered structure, reliable channels should be made on the both side of electrolyte perpendicularly. However, monolithic SOFC using multi-layered ceramic technology hasn't been studied another group, and the warpage of electrolyte in the channel, also, hasn't been studied, when electrode is printed on the electrolyte. In this study, the channels are prepared with electrode printing, and their warpage are evaluated. In the case of YSZ without electrode, the warpages are nothing in the limit of measurement using optical microscope. The warpage of 'YSZ-NiO printed' increases than that of 'NiO printed', and also, the case of 'double electrode printed' is similar to 'YSZ-NiO printed'. It is thought that, in the printed electrolyte, the warpage is related to the difference of the sintering behavior of each material.

• Journal of Advanced Marine Engineering and Technology
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• 제36권1호
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• pp.40-50
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• 2012

폐열의 활용은 연료전지시스템의 효율의 제고에 중요하다. SOFC/GT/ST 하이브리드시스템은 연료전지시스템 폐열의 전력화에 가스터빈 및 증기터빈을 활용하는 방식이다. 본 논문은 SOFC/GT/ST 하이브리드시스템에 대한 스택의 작동온도와 전류밀도, 가스터빈의 압력비가 시스템의 성능에 미치는 영향 등을 시뮬레이션을 통하여 검토한 것이다. 그 결과로 SOFC/GT/ST 하이브리드시스템은 단독 SOFC시스템과 비교하여 효율의 급격한 변화를 완화시키며 또한 효율을 크게 제고시키고 있음을 확인하였다.

• 한국전기전자재료학회논문지
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• 제25권7호
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• pp.552-557
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• 2012

In this study, we have coated the inner surface of YSZ channel using LSM powder ink through depressurization process for making the cathode of a stacked planar-type SOFC module. To coat the surface of YSZ channel uniformly, we tried to find the optimum manufacturing condition for LSM ink. We used four different dispersants (BYK series) and two different solvents (ethanol and DMF) to make the LSM ink. It was revealed that the ink made with the ethanol solvent and the BYK-111 dispersant has the lowest viscosity, relatively low contact angle and most excellent dispersibility. After depressurizing a chamber filled with LSM ink and sintered YSZ channel, we have found that the YSZ channel was uniformly coated with LSM cathode. The LSM ink with 25 vol% BYK-111 showed the most uniform coating.

• 청정기술
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• 제16권4호
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• pp.297-303
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• 2010

본 연구에서는 유체유동해석프로그램인 Fluent를 이용하여 연료극 지지채식 관형 고체산화물 연료전지(SOFC)에서의 연결재 구조에 따른 성능 변화를 고찰하였다. 실험적 사실과 부합되는 이론적 결과를 확보하기 위해서는 전기적으로 전극과 하나로 되어있는 연결재의 구조가 전지 성능에 어떠한 영향을 미치는지 살피는 것이 중요하다. 두께가 작은 연결재가 단전지 성능을 우수하게 하는 것으로 보아 옴(ohmic) 저항에 직결되는 연결재의 두께가 전지 성능에 있어 주요 변수임을 확인하였다. 일정 두께로 고정된 조건 하에 연결재 폭을 변화시킨 경우, 전지 성능은 상대적으로 큰 차이를 보이지 않았다. 이는 본 연구에서 고려한 SOFC의 관형 구조 특성상 연결재의 폭으로는 원주 방향으로 흘러가는 전류 경로를 효과적으로 단축시킬 수 없기 때문으로 사료된다.