• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1700-1702
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• 1996

Solid oxide fuel cell(SOFC) is an electrochemical energy device which converts the free energy of fuel gas directly to electric energy. SOFC has several diratinct advantages over other types of fuel cells: no use of noble metals, no requirement of a reformer, no problem of liquid electrolyte management, and no problem of corrosion by liquid electrolyte. In this study, we have investigated the cell components and the single cell of the planar SOFC fabricated by composite plate process, in which green films of electrolyte, anode and cathode were co-fired. The planar SOFCs were tested and the cell performance characteristics wag evaluated by using electrochemical methods.

• 설비공학논문집
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• 제16권7호
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• pp.615-622
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• 2004

Recently, the hybrid system combining fuel cell and gas turbine has drawn much attention owing to its high efficiency and ultra low emission. It is now on the verge of world wide development and various system configurations have been proposed. A national project funded by Korean government has also been initiated to develop a pressurized hybrid system. This work aims at presenting design performance analysis for various possible system configurations as an initial step for the system development. Study focuses are given to major design options including the power ratio between gas turbine and fuel cell, reforming method (internal or external), reforming heat source (reforming burner, cathode hot air, fuel cell heat release) and steam supply method for reformer (anode gas recirculation, external steam generator). A wide variation in performance among different configurations has been predicted.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.373-380
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• 2001

Solid Oxide Fuel Cells (SOFCs) have received considerable attention because of the advantages of high effiiciency, low pollution, cogeneration application and excellent integration with simplified reformer In this paper, we reported development of anode-tubular SOFC by wet process. For making tubular cell, Ni-cermet YSZ anode tube was fabricated using extrusion process, and YSZ electrolyte layer and LSM-YSZ composite, LSM, LSCF cathode layer were coated onto the anode supported tube using slurry dipping process and sintered by co-firing process. By using this tubular cell, we fabricated single cell consisted of the various cathode layers and 4 cell stack with an effective area of $75 cm^2$ per single cell, and evaluated their performance characteristics.

• 전기화학회지
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• 제8권2호
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• pp.88-93
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• 2005

고체산화물 연료전지의 작동온도를 낮추고 셀의 출력 밀도를 향상시키기 위해 연료극 지지체식 셀을 제조하고 공기극의 구조를 개선시켜 그 특성을 조사 분석하였다. 셀 제조는 습식법에 의해 이루어졌으며, 제조된 연료극 지지체상에 전해질을 코팅하고 최종적으로 공기극을 코팅하였다. 제조된 셀은 $8mol\%\;V_2O_3$로 안정화된 $ZrO_2(YSZ)$ 전해질 층 및 Ni/YSZ 연료극 지지체로 이루어졌으며, 공기극은 $(La_{0.85}Sr_{0.15})_{0.9}MnO_{3-x}(LSM),\;LSM/YSZ(LY)$ 복합체, $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3{LSCF)$를 두층 또는 3층으로 두께를 변화시키면서 코팅하였다 임피던스로 전기화학적 특성을 조사하였으며, $3\%$수분을 함유한 수소와 공기로 $800^{\circ}C$ 이하에서 단전지의 성능을 평가하였다 작동온도 $800^{\circ}C$에서, $LY\;9{\mu}m/LSM\;9{\mu}m/LSCF\;17{\mu}m$의 다층이 코팅된 전지가 $590mW/cm^2$로 가장 좋은 성능을 나타냈으며, $0.244{\Omega}cm^2$로 가장 작은 분극저항을 가졌다. 측정된 임피던스 결과, 공기극의 분극저항이 3층 코팅된 셀의 경우 가장 작게 나타났음을 확인하였으며, 이것은 LY복합전극에 의한 전극 계면 저항 감소뿐 만 아니라 LSCF에 의한 공기극의 산소환원 반응의 전하이동 저항이 감소하였기 때문인 것으로 해석된다.

• 한국재료학회지
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• 제12권9호
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• pp.691-695
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• 2002

A low temperature anode-supported tubular solid oxide fuel cell was developed. The anode-supported tube was fabricated using extrusion process. Then the electrolyte layer and the cathode layer were coated onto the anode tube by slurry dipping process, subsequently. The anode tube and electrolyte were co-fired at $140^{\circ}C$, and the cathode was sintered at $1200^{\circ}C$. The thickness and gas permeability of the electrolyte depended on the number of coating and the slurry concentration. Anode-supported tube was satisfied with SOFC requirements, related to electrical conductivity, pore structure, and gas diffusion limitations. At operating temperature of $800^{\circ}C$, open circuit voltage of the cell with gastight and dense electrolyte layer was 1.1 V and the cell showed a good performance of 450 mW/$\textrm{cm}^2$.

• 한국재료학회지
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• 제23권3호
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• pp.206-210
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• 2013

In the segmented-in-series solid-oxide fuel cells (SIS-SOFCs), fabrication techniques which use decalcomania paper have many advantages, i.e., an increased active area of the electrode; better interfacial adhesion property between the anode, electrolyte and cathode; and improved layer thickness uniformity. In this work, a cell-stack was fabricated on porous ceramic flattened tube supports using decalcomania paper, which consists of an anode, electrolyte, and a cathode. The anode layer was $40{\mu}m$ thick, and was porous. The electrolyte layers exhibited a uniform thickness of about $20{\mu}m$ with a dense structure. Interfacial adhesion was improved due to the dense structure. The cathode layers was $30{\mu}m$ thick with porous structure, good adhesion to the electrolyte. The ohmic resistance levels at 800, 750 and $700^{\circ}C$ were measured, showing values of 1.49, 1.58 and $1.65{\Omega}{\cdot}cm^2$, respectively. The polarization resistances at 800, 750 and $700^{\circ}C$ were measured to be 1.63, 2.61 and $4.17cm^2$, respectively. These lower resistance values originated from the excellent interfacial adhesion between the anode, electrolyte and cathode. In a two-cell-stack SOFC, open-circuit voltages(OCVs) of 1.915, 1.942 and 1.957 V and maximum power densities(MPD) of 289.9, 276.1 and $220.4mW/cm^2$ were measured at 800, 750 and $700^{\circ}C$, respectively. The proposed fabrication technique using decalcomania paper was shown to be feasible for the easy fabrication of segmented-in-series flattened tube SOFCs.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.361-364
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• 2009

KEPRI has studied planar type SOFC stacks using anode-supported single cells and kW class co-generation systems for residential power generation. A 1kW class SOFC system consisted of a hot box part, a cold BOP part and a water reservoir. A hot box part contains a SOFC stack made up of 48 cells with $10{\times}10cm^2$ area and ferritic stainless steel interconnectors, a fuel reformer, a catalytic combustor and heat exchangers. Thermal management and insulation system were especially designed for self-sustainable operation. A cold BOP part was composed of blowers, pumps, a water trap and system control units. When a 1kW class SOFC system was operated at $750^{\circ}C$ with hydrogen, the stack power was 1.2kW at 30 A and 1.6kW at 50A. Turning off an electric furnace, the SOFC system was operated using hydrogen and city gas without any external heat source. Under self-sustainable operation conditions, the stack power was about 1.3kW with hydrogen and 1.2kW with city gas respectively. The system also recuperated heat of about 1.1kW by making hot water. Recently KEPRI developed stacks using $15{\times}15cm^2$ cells and tested them. KEPRI will develop a 5 kW class CHP system using $15{\times}15cm^2$ stacks by 2010.

• 한국수소및신에너지학회논문집
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• 제20권5호
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• pp.384-389
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• 2009

KEPRI (Korea Electric Power Research Institute) has studied planar type solid oxide fuel cell (SOFC) stacks using anode-supported cells and kW class co-generation systems for residential power generation. In this work, a 1 kW SOFC system consisted of a hot box part, a cold BOP (balance of plant) part, and a hot water reservoir. The hot box part contained a SOFC stack made up of 48 cells, a fuel reformer, a catalytic combustor, and heat exchangers. Thermal management and insulation system were especially designed for self-sustainable operation in that system. A cold BOP part was composed of blowers, pumps, a water trap, and system control units. When the 1 kW SOFC stack was tested using hydrogen at $750^{\circ}C$, the stack power was about $1.2\;kW_e$ at 30 A and $1.6\;kW_e$ at 50 A. Turning off an electric furnace, the SOFC system was operated using hydrogen and city gas without any external heat source. Under self-sustainable operation conditions, the stack power was about $1.3\;kW_e$ with hydrogen and $1.2\;kW_e$ with city gas respectively. The system also recuperated heat of about $1.1\;kW_{th}$ by making hot water.

• 한국수소및신에너지학회논문집
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• 제27권1호
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• pp.49-62
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• 2016

In this study, a solid oxide fuel cell (SOFC) system model including balance of plant (BOP) for building electric power generation is developed to study the effect of operating conditions on the system efficiency and power output. SOFC system modeled in this study consists of three heat-exchangers, an external reformer, burner, and two blowers. A detailed computational cell model including internal reforming reaction is developed for a planer SOFC stack which is operated at intermediate temperature (IT). The BOP models including an external reformer, heat-exchangers, a burner, blowers, pipes are developed to predict the gas temperature, pressure drops and flow rate at every component in the system. The SOFC stack model and BOP models are integrate to estimate the effect of operating parameters on the performance of the system. In this study, the design of experiment (DOE) is used to compare the effects of fuel flow rate, air flow rate, air temperature, current density, and recycle ratio of anode off gas on the system efficiency and power output.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.793-794
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• 2012