• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.822-828
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• 2013

Since the operating temperature of Solid Oxide Fuel Cell (SOFC) is high, the heat management of the gases supplied to fuel cell system is important. In this paper, the temperature characteristic of the gases supplied to the anode and the cathode of the fuel cell is studied in case of utilizing the waste heat contained in the ship exhaust gas as a heat source to heat up the fuel, gas and water supplied to a 500kW SOFC system for a ship power. For the fuel cell system proposed in this paper, the temperature of gases supplied to the anode and the cathode was the highest temperature at 963K when the exhaust gas of the fuel cell was utilized as the heat source for gases supplied to fuel cell system instead of utilizing the ship exhaust gas. In addition, the engine power did not effect on the temperature of gases supplied to the fuel cell stack.

• Architectural research
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• v.21 no.1
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• pp.21-29
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• 2019

Recent years in Korea, some new developed buildings are only using electricity as power for heating, cooling, bathing and even cooking which means except electricity, there is no natural gas or other kinds of energy used in such kind of building. In vehicle industry area, scientists already invented electric vehicle as an environment friendly vehicle; after that, in architecture design and construction field, buildings only using electricity appeared; the curiosity of the environment impact of energy consumption by such kind of building lead me to do this research. In general, electricity is known as a clean energy resource reasoned by it is noncombustible energy resource; however, although there is no environmental pollution by using electricity, electricity generation procedure in power plant may cause huge amount of environment pollution; especially, electricity generation from combusting coal in power plant could emit enormous air pollutants to the air. In this research, the yearly amount of air pollution by energy using under traditional way in research target building that is using natural gas for heating, bathing and cooking and electricity for lighting, equipment and cooling is compared with yearly amount of air pollution by only using electricity as power in the building; result shows that building that only uses electricity emits much more air pollutants than uses electricity and natural gas together in the building. According to the amount of air pollutants comparison result between two different energy application types in the building, residential SOFC (Solid oxide fuel cell) is simulated to apply in this building for decreasing environment pollution of the building; furthermore, high load factor could lead high efficiency of SOFC, in the scenario of simulating applying SOFC in the building, SOFC is shared by two or three households in spring and autumn to increase efficiency of the SOFC. In sum, this research is trying to demonstrate electricity is a conditioned environment friendly energy resource; in the meanwhile, SOFC is simulated efficiently applying in the building only using electricity as power to decrease the large amount of air pollutants by energy using in the building. Energy consumption of the building is analyzed by calibrated commercial software Design Builder; the calibrated mathematical model of SOFC is referred from other researcher's study.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2144-2148
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• 2008

Kerosene-driven solid oxide fuel cell (SOFC) system with reformer, desulfurizer and after-burner was mainly developed for this study. Originally the system was developed for 1kW class SOFC system for residential power generation (RPG) application. As a preliminary study of 1kW class SOFC system operation, a short stack was applied to the system. The short stack consists of 7 cells of $10cm{\times}10cm$ area and was operated at $720^{\circ}C$. The effect of anode inlet gas composition to stack performance was investigated. Firstly, I-V characteristics of SOFC with different fuel of kerosene and hydrogen were studied. Secondly $CH_4$ internal reforming was performed at various anode inlet gas compositions of $H_2$, $CH_4$ and $H_2O$. Through these experiments the effects of each anode inlet gas component to stack performance were analyzed and the significant operating parameters were iscussed.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.311-314
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• 2009

Recently by the development of the electronic engineering technology various mobile devices are developed. But their operation time need to be extended although capacity of the batteries are limited. We focused our attention to the portable SOFC system. Because SOFC has the high efficiency and a lot of strongness in comparison with other kinds of fuel cells, We evaluated hydrogen fed SOFC 50W system theoretically and got the results about the operating condition range from the comparison of the power efficiency, exhaust gas temperature, required heat for maintaining the operation temperature and operation time.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.51-54
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• 2008

This study aims to devise and analyze a power generation system combining the solid oxide fuel cell and oxy-fuel combustion technology. The fuel cell operates at an elevated pressure, a constituting a SOFC/gas turbine hybrid system. Oxygen is extracted from the high pressure cathode exit gas using ion transport membrane technology and supplied to the oxy-fuel power system. The entire system generates much more power than the fuel cell only system due to increased fuel cell voltage and power addition from oxy-fuel system. More than one third of the power comes out of the oxy-fuel system. The system efficiency is also higher than that of the fuel cell only system. Recovering most of the generated carbon dioxide is major advantage of the system.

• Journal of Electrochemical Science and Technology
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• v.11 no.2
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• pp.132-139
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• 2020

Solid oxide fuel cells (SOFCs) are among one of the promising technologies for efficient and clean energy. SOFCs offer several advantages over other types of fuel cells under relatively high temperatures (600℃ to 800℃). However, the thermal behavior of SOFC stacks at high operating temperatures is a serious issue in SOFC development because it can be associated with detrimental thermal stresses on the life span of the stacks. The thermal behavior of SOFC stacks can be influenced by operating or material properties. Therefore, this work aims to investigate the effects of the thermal conductivity of each component (anode, cathode, and electrolyte) on the thermal behavior of samarium-doped ceria-based SOFCs at intermediate temperatures. Computational fluid dynamics is used to simulate SOFC operation at 600℃. The temperature distributions and gradients of a single cell at 0.7 V under different thermal conductivity values are analyzed and discussed to determine their relationship. Simulations reveal that the influence of thermal conductivity is more remarkable for the anode and electrolyte than for the cathode. Increasing the thermal conductivity of the anode by 50% results in a 23% drop in the maximum thermal gradients. The results for the electrolyte are subtle, with a ~67% reduction in thermal conductivity that only results in an 8% reduction in the maximum temperature gradient. The effect of thermal conductivity on temperature gradient is important because it can be used to predict thermal stress generation.

• New & Renewable Energy
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• v.5 no.1
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• pp.11-17
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• 2009

To improve the performance of the anode-supported Solid Oxide Fuel Cell (SOFC) which can be operated at an intermediate temperature, the functional layer (FL) is introduced on a anode substrate. And the scandia-stabilized zirconia (ScSZ) and samaria-doped ceria (SDC) which have higher ionic conductivity and better chemical stability than yttria-stabilized zirconia (YSZ) are used as material for the anode FL with the Ni, The fabrication process of anode-supported single cell with the anode FL was established and the power density of those was evaluated. As a result, the sample with anode FL (Ni-YSZ) has higher power density than normal cell. The single cell which was composed of the FL (Ni-YSZ) and electrolyte (YSZ) showed about $550mW/cm^2$ of the maximum power density at $650^{\circ}C$ and $1430mW/cm^2$ at $750^{\circ}C$ respectively, In case of the single cell using the ScSZ and SDC as anode FL, the performance of samples decreased rapidly and those showed unstable voltage during long-term test. In case of using methane as a fuel, the cell performance with each FL decreased comparing with $H_2$ fuel. In the region of a high current density, there are large concentration polarizations.

• Journal of Electrochemical Science and Technology
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• v.11 no.2
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• pp.99-116
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• 2020

The article provides information on ceramic / nanostructured materials which are suitable for solid oxide fuel cells (SOFCs) working between 500 to 1000℃. However, low temperature solid oxide fuel cells LTSOFCs working at less than 600℃ are being developed now-a-days with suitable new materials and are globally explored as the "future energy conversion devices". The LTSOFCs device has emerged as a novel technology especially for stationary power generation, portable and transportation applications. Operating SOFC at low temperature (i.e. < 600℃) with higher efficiency is a bigger challenge for the scientific community since in low temperature regions, the efficiency might be less and the components might have exhibited lower catalytic activity which may result in poor cell performance. Employing new and novel nanoscale ceramic materials and composites may improve the SOFC performance at low temperature ranges is most focused now-a-days. This review article focuses on the overview of various ceramic and nanostructured materials and components applicable for SOFC devices reported by different researchers across the globe. More importance is given for the nanostructured materials and components developed for LTSOFC technology so far.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.723-732
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• 2022

Cracking ammonia inside solid oxide fuel cell (SOFC) stack is a compact and simple way. To prevent sharp temperature fluctuation and increase cell efficiency, the decomposition reaction should be spread on whole cell area. This leading to a question that, how does anode thickness affect the conversion rate of ammonia and the cell voltage? Since the 0D model of SOFC is useful for system level simulation, how accurate is it to use equilibrium solver for internal ammonia cracking reaction? The 1D model of ammonia fed SOFC was used to simulate the diffusion and reaction of ammonia inside the anode electrode, then the partial pressure of hydrogen and steam at triple phase boundary was used for cell voltage calculation. The result shows that, the ammonia conversion rate increases and reaches saturated value as anode thickness increase, and the saturated thickness is bigger for lower operating temperature. The similar cell voltage between 1D and 0D models can be reached with NH₃ conversion rate above 90%. The 0D model and 1D model of SOFC showed similar conversion rate at temperature over 750℃.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.7
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• pp.963-972
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• 2003

Performance characteristics of the planar-type solid oxide fuel cell (SOFC) are investigated by the analysis of flow fields coupled with heat and mass transfer phenomena in anode and cathode channels. For these purposes, performance analysis of the SOFC is conducted based on electrochemical reaction phenomena in electrodes and electrolyte coupled with flow fields in anode and cathode channels. In the present study, the isothermal model adopted in the previous paper prepared by the same authors is extended to the non-isothermal model by solving energy equation additionally with momentum and mass transfer equations using CFD technique. It is found that the difference between isothermal and non-isothermal models come from non-uniform temperature distribution along anode and cathode electrodes by solving energy equation in non-isothermal model. Non-uniform temperature distribution in non-isothermal model contributes to the increase of average temperature of the fuel cell and influences its performance characteristics.