• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.82.1-82.1
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• 2010

Recently, Molten carbonate fuel cells(MCFCs) have been developing to get a good durability and economic feasibility for commercialization. To achieve these objectives, the cost of nickel based electrodes should be reduced. Regular anode thickness used in MCFCs is normally 0.7mm. Thus, in our study, the purpose was to reduce anode thickness up to 0.3 mm keeping MCFC performance on standard levels. In-situ sintering has been used, with 2 different fabrication methods (method A and B) and 2 different supports (support 1 and 2). Voltage losses at different temperature (600,620,640,$650^{\circ}C$) and after 1000 hours showed the higher performance that can be obtained using method B and support 2. After single cell test, an open-circuit voltage(OCV) of 1.075 V and a closed-circuit voltage(CCV) of 0.829V were obtained, at current density of $150mV/cm^2$. Also the voltage loss ratio at different cell temperature was lower in the case of method B and support 2. According to these results, the cost of anode fabrication can be reduced in the future, contributing for the economical feasibility of MCFCs.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.86.1-86.1
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• 2010

예비개질기(Pre-reformer)는 중대형 내부개질형 용융탄산염 연료전지(MCFC) 시스템에서 다양한 연료를 사용하기 위한 필수적인 화학반응기이다. 예비개질기는 스택 전단에 설치함으로서 스택 내부의 열균형을 유지하고, 다양한 원료를 연료로 이용할 수 있도록 하며, 황화물로부터 후단의 개질촉매 및 전극촉매를 보호하여 주개질 반응의 부담을 감소시켜 MCFC 시스템의 내구성 향상의 중요한 역할을 한다. 본 연구는 예비개질 반응기 설계에 CFD 모델링을 적용하기에 앞서 파일롯 반응기 내 농도/ 온도 구배를 측정하고자 하는 목적으로 수행되었다. 반응가스로는 천연가스 내 고차탄화수소(C2 이상) 중 상대적으로 높은 농도를 가진 에탄을 이용하였고, MCFC용 예비개질기의 운전특성을 고려하여 비교적 낮은 온도와 높은 수증기/탄소 비에서 단열반응기로 실험을 진행하였다. 향후 본 실험결과를 이용하여 CFD 모델링에 대한 검증을 수행할 예정이며, 하수처리장부생가스(ADG)/ 매립지 가스(LFG)용 MCFC 시스템을 위한 예비개질기 설계에도 적용을 하고자 한다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.10
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• pp.1361-1369
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• 2003

Design performance of hybrid power generation systems, comprised of a gas turbine and an atmospheric pressure molten carbonate fuel cell, has been analyzed. Two different configurations were analyzed and performances were compared. A reference calculation was performed for the design condition of a system under development and simulated results agreed well with the published data. Performances were analyzed in terms of main design parameters including turbine inlet temperature, operating temperature of the fuel cell and pressure ratio. Also examined were the effects of fuel utilization factor and heat exchanger effectiveness. It was found that the relationship between the turbine inlet temperature and the fuel cell temperature should be critically examined to evaluate achievable design performance. Considering current state of the art technologies, a system with the combustor located before the turbine could achieve higher efficiency and specific power than the other system with the combustor located after the turbine.

• Journal of Hydrogen and New Energy
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• v.17 no.4
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• pp.403-408
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• 2006

The plate reformer consisting of combustion chamber and reforming chamber for 25 kW MCFC stack has been operated and computational fluid dynamics was applied to estimate reactions and thermal fluid behavior in the reformer. The methane air 2-stage reaction was assumed in the combustion chamber, and three step steam reforming reactions were included in the calculation. Flow uniformity, reaction rate and species distribution, and temperature distribution were analyzed. In particular, temperature distribution was compared with the measurements to show good agreement in the combustion chamber, however, inappropriate agreement in the reformer chamber.

• Journal of Hydrogen and New Energy
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• v.21 no.4
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• pp.258-263
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• 2010

A numerical stack model has been developed to predict the temperature at a constant-load operation of molten carbonate fuel cell stacks. For the validity of the model, the simulated results with several boundary conditions were compared in the cell temperature data obtained from 75 kW class MCFC stack operation. It was shown that the simulated results with the existing boundary condition, which the stack outlet temperature was fixed at $650^{\circ}C$, didn't match well with the measured data. On the other hand, the stack model with the outlet temperature modified by the outlet manifold temperature measured from the stack under several electric loads was found to explain the measured cell temperature distribution well. The results show that the model can be used to predict the cell temperature distribution in the stacks by the measurement of the manifold outlet temperature.

• Journal of Hydrogen and New Energy
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• v.28 no.1
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• pp.30-39
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• 2017

Interests in fuel cell based power generation systems are on the steady rise owing to various advantages such as high efficiency, ultra low emission, and potential to achieve a very high efficiency by a synergistic combination with conventional heat engines. In this study, the performance of a hybrid system which combined a molten carbonate fuel cell (MCFC) and an indirectly fired micro gas turbine adopting carbon dioxide capture technologies was predicted. Commercialized 2.5 MW class MCFC system was used as the based system so that the result of this study could reflect practicality. Three types of ambient pressure hybrid systems were devised: one adopting post-combustion capture and two adopting oxy-combustion capture. One of the oxy-combustion based system is configured as a semi-closed type, while the other is an open cycle type. The post-combustion based system exhibited higher net power output and efficiency than the oxy-combustion based systems. However, the semi-closed system using oxy-combustion has the advantage of capturing almost all carbon dioxide.

• New & Renewable Energy
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• v.4 no.1
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• pp.11-18
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• 2008

In-situ lithiated NiO has been manufactured as a conventional cathode material of molten carbonate fuel cell (MCFC), however this material has a weakness for commercialization of MCFC because NiO is spontaneously dissolved into the electrolyte under MCFC operating conditions, resulting in short circuit between cathode and anode. In this research, therefore, $Co(OH)_2$-coated Ni powder was prepared by precipitation method with controlling pH at low temperature and atmospheric pressure. Modified cathode was fabricated by a conventional tape casting method and sintered at 700$^{\circ}C$ in a $H_2/N_2$ atmosphere, Based on characterization result, Pore size distribution and porosity was suitable for the cathode of MCFC. According to the result of dissolution, Ni solubility of modified cathode was 33% lower than that of conventional cathode. In addition, modified electrode showed a good performance from the single cell operation.

• Journal of Energy Engineering
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• v.2 no.3
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• pp.293-299
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• 1993

In order to investigate the effect of Al addition on the electrochemical performance and structural stability of porous Ni anode for molten carbonate fuel cell, porous Ni anodes containing Al up to 10 wt% were fabricated by the tape casting technique. In this study half-cell performance of the anodes was evaluated by anodic polarization in the simulated MCFC anode condition(650$^{\circ}C$ , 80% H$_2$＋20% CO$_2$). At the anodic current of 150 ㎃/$\textrm{cm}^2$, the polarizations for H$_2$oxidation of the anode was about 100 ㎷. The sintering and creep resistance of Ni-Al anodes was higher than those of the pure Ni anode. It was considered that the increase of sintering and creep resistance was due to the formation of Al$_2$O$_3$ on the surface of Ni particles.

• Journal of Hydrogen and New Energy
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• v.29 no.1
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• pp.56-63
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• 2018

In this study, a $100cm^2$ cell frame for a molten carbonate fuel cell was designed using CFD analysis. Electrochemical reactions, gas flow, and the heat transfer in $100cm^2$ cell frame were modeled using COMSOL Multiphysics. Two design variables such as the height of the cell frame and the length of the gas input area were determined to obtain minimized temperature distribution and uniform gas distribution. With two design parameter such as height of the cell frame and the length of the gas flow channel, the temperature difference in the cell fame was decreased to $5^{\circ}C$ and the gas uniformity in the flow channel were achieved.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.11
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• pp.834-839
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• 2009

A three-dimensional computational fluid dynamics (CFD) analysis is performed to investigate flow characteristics in the anode channels and manifold of the internal reforming type molten carbonate fuel cell (MCFC). Considering the computational difficulties associated with the size and geometric complexity of the MCFC system, the polyhedral meshes that can reduce mesh connectivity problems at the intersection of the channel and the manifold are adopted and chemical reactions inside the MCFC system are not included. Through this study, the gas flow rate uniformity of the anode channels is mainly analyzed to provide basic insights into improved design parameters for anode flow channel design. Results indicate that the uniformity in flow-rate is in the range of ${\pm}$1% between the anode channels. Also, the mal-distributed inlet flow-rate conditions and the change in the size of the manifold depth have no significant effect on the flow-rate uniformity of the anode channels.