• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.206-209
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• 2004

Mechanical behavior of a fuel stack was studied using an orthotropic material model. The fuel stack is essentially composed of a bipolar plate (BP), a gasket, an end plate, a membrane electrolyte assembly (MEA), and a gas diffusion layer (GDL). Each component is fastened with a suitable pressure. It is important to maintain a suitable contact pressure distribution of BP, because it influences the power efficiency of the fuel cell stack. When it is exposed to high temperature, its behavior must be stable. Hence, we performed stress analysis at high temperature as well as at room temperature. At high temperature, the contact pressure distribution becomes poor. Many patents have shown that using an elastomer can overcome this phenomena. Its effect was also studied. By using an elastomer, we found a good contact pressure distribution at high temperature as well as at room temperature.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.180-184
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• 2005

An experimental study is performed to evaluate the performance and the efficiency by humidifying MEA and by making the double-tied catalyst layers in a fuel cell system which is taken into account the physical and thermal concept. An electrical output produced by PEFC(polymer Electrolyte Fuel Cell) is measured to assess the performance of the stack and the efficiency is also evaluated according to the different situation in which is placed with and without the humidification of MEA (Membrane Electrolyte Assembly). Subsequently, It is found that the measured values of stack voltage and current are influenced by the stack temperature, humidification, and the double-tied catalyst layers which gives more enhanced values to apply for electric units.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1991년도 추계학술대회 논문집
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• pp.160-164
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• 1991

The effect of various parameters, such as temperature, current density and operating valtage on the performance of phosphoric acid fuel cell stack was studied by using numerical analysis. The utilization ratio of reaction gas, inlet condition of reaction air and cooling air, inlet condition of cooling air flow latin were changed regularly, The results showed good agreements with the existing results and experimental ones.

• Journal of Advanced Marine Engineering and Technology
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• 제35권4호
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• pp.406-413
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• 2011

최근 선박에서 배출되는 온실가스를 저감하기 위한 기술로 연료전지가 주목 받고 있다. 본 연구에서는 메탄을 연료로 사용한 내부개질형 500kW급 고체산화물 연료전지의 선박 적용을 가정하여 연료전지 스택을 모델링하여 스택을 구성하는 셀의 수, 수소 변환율, 셀의 반응면적에 따른 출력 및 효율에 관한 특성을 평가하고, 공기와 메탄의 공급조건이 연료전지 스택의 성능에 미치는 영향 등에 관하여 검토하였다. 그 결과 셀의 수, 수소 변환율, 셀의 반응면적 및 공급 공기 유량이 증가할수록 스택의 출력 및 효율이 증가하였고, 메탄 공급 유량이 증가하면 출력은 증가하지만 효율은 감소하였다. 또한 Case 3의 경우에 전류가 976.4 A, 전압이 529.1 V에서 출력이 516.6 kW이고 이때의 연료전지 스택의 효율은 42.91%를 얻을 수있었다.

• 한국수소및신에너지학회논문집
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• 제27권1호
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• pp.42-48
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• 2016

This study presents an experiment investigation on natural convection heat transfer of air-cooling Proton exchange membrane fuel cells (PEMFCs) in a enclosure system for unmanned aerial vehicles (UAVs). Considered are replacing fuel cell stack with Aluminum block for heat generating inside a enclosure chamber. The volume ratio of fuel cell stack and chamber for simulation to the actual size of aerial vehicle is 1 to 15. The parameters considered for experimental study are the environmental temperature range from $25^{\circ}C$ to $-60^{\circ}C$ and the block heat input of 10 W, 20 W and 30 W. Effect of the thermal conductivity of the block and power level on heat transfer in the chamber are investigated. Experimental results illustrate the temperature rise at various locations inside the chamber as dependent upon heat input of fuel cell stack and environmental temperature. From the results, dimensionless correlation in natural convection was proposed with Nusselt number and Rayleigh number for designing air-cooling PEMFC powered high altitude long endurance (HALE) UAV.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1322-1324
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• 2002

For developing a 100 kW MCFC power generation system, Several design parameters for a fuel cell stack and system analysis results by Cycle Tempo, a processing computer soft ware, were described. Approximately 170 cells are required to generate 100 kW at a current density of 125 mA/$cm^2$ with 6000 $cm^2$ cells. An overall heat balance was calculated to predict exit temperature. The 100 kW power is expected only under pressurized operation condition at 3 atm. Recycle of cathode gas by more than 50% is recommended to run the stack at 125 mA/$cm^2$ and 3 atm. Manifolds should be designed based on gas flow rates for the suggested operating condition. The fuel cell power generation system was designed conceptually with several choices of utilization of anode exhaust gas. Also system efficiency was calculated at various type of system and operation conditions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1300-1302
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• 2001

For developing a 100 kW MCFC power generation system. Several design parameters for a fuel cell stack and system analysis results by Cycle Tempo, a processing computer soft ware, were described. Approximately 170 cells are required to generate 100 kW at a current density of $125mA/cm^2$ with $6000cm^2$ cells. An overall heat balance was calculated to predict exit temperature. The 100 kW power is expected only under pressurized operation condition at 3 atm. Recycle of cathode gas by more than 50% is recommended to run the stack at $125mA/cm^2$ and 3 atm. Manifolds should be designed based on gas flow rates for the suggested operating condition. The fuel cell power generation system was designed conceptually with several choices of utilization of anode exhaust gas. Also system efficiency was calculated at various type of system and operation conditions.

• 설비공학논문집
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• 제6권2호
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• pp.120-129
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• 1994

A numerical investigation has been carried out for the electrochemical reaction, mass and heat transfer characteristics of the Molten Carbonate Fuel Cell(MCFC) stack. The effects of cooling air channel and water gas shift reaction were taken into account. The current density distribution of electrodes, the molecular fractions of reactant gasses and three dimensional temperature distribution can be calculated and shown by several lines of equivalent values. The results have been compared with the existing ones, and reasonable agreement has been obtained. To examine the influence of changing parameters, such as the composition of reactant gases, the target average current density, the utilization of reactant gases, the cooling air inlet temperature and flow rates, the computer simulation has been done. The analysis method and computer program developed in this study will be greatly helpful to design and verify the optimum operating condition of MCFC stack.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.248-251
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• 2008

The objective of this study is to select fuel/air feeders for reliable operation of BOP(Balance of Plant) system for a DMFC (direct methanol fuel cell). A 42-cell 50W DMFC stack is considered for performance comparison of selected fuel pumps and air blowers. The present stack has two serpentine anode channels with depth of 1.2 mm and rib of 1 mm and one serpentine cathode channel with depth of 1.5 mm and rib of 1 mm. The pressure drop through the stack is estimated in advance by utilizing the pre-existing loss coefficients data for various flow configurations. Then the operating points of feeders are determined at the balance point of the flow impedance curves for the channels in the DMFC stack and the selected pump and blower performance curves. After estimating the operating flow rates in the anode and cathode channels, the flow measurement with the selected feeders is performed for the comparison with the estimated flow rates. The measured results show that the discrepancy between the estimation and the measurement for the cathode is about 26%, about 3% for the anode

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.100-103
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• 1997

Korea Electric Power Corporation (KEPCO) started a fuel cell project to develop alternative sources of electric power because of the rapid increase in power demand and global environmental problems. For the development of a molten carbonate fuel cell (MCFC), KEPCO started the project in 1993 to develop a 2 kW MCFC system and finished it at the end of 1996. In this project, $ASPEN^+$ was utilized to design the 2 kW MCFC generation system. Based on this simulation, a power generation system was designed and installed for operation and a long term test of internally manifolded 2 kW class MCFC stack. This stack has 20 cells with an effective electrode area of $1000\;cm^2$. It was run at 0.84 V and $150\;mA/cm^2$ and was operated for more than 3,250 hours continuously. This paper describes the system configuration and its control and measurement units. An analysis of the stack performance, the effect of gas utilization ratio, and the stack performance requirements are also discussed.