• 대한전기학회논문지
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• 제43권4호
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• pp.569-579
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• 1994

A 5.9kW phosphoric acid fuel cell(PAFC) power generation system that consists of a reformer, a stack, heat exchangers, an automatic data acquisition and control system was designed, fabricated and analyzed. This system which was firstly fabricated in Korea has been operated for 140 hours with an electricity generation of 684kWh. The PAFC generate electricity in the range of 38-52V and 50-160A and has a typical I-V characteristics of a fuel cell. Using the reformed fuel, the system performance is decreased in some degree due to CO content, compared to using the simulated fuel. At steady state operation condition, the total efficency of this system was 45.2%.

• 에너지공학
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• 제2권2호
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• pp.187-193
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• 1993

인산형 연료전시에서의 인산 전해질을 지지하기 위한 다공성 메트릭스의 제조는 결합제인 PTFE와 각종입자의 크기를 갖는 SiC분말 또는 whisker를 혼합 사용하여 제작하였다. 메트릭스로서 갖추어야 될 기본조건중에 bubble pressure와 인산 전해질의 함침량은 전지운영시 전극성능에 가장 큰 영향을 미칠것이라 보아 다공성 전극의 pore size보다 작은 pore size를 가지는 메트릭스를 제작하였다. 각종 SiC입자 크기와 PTFE함량에 따라 제작된 matrix의 bubble pressure와 함침량을 측정하였으며 porosimeter를 이용하여 측정된 메트릭스의 다공도와 비교하여 인산형 연료전지에 사용할 수 있는 최적의 메트릭스 조건을 결정하였다.

• 한국재료학회지
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• 제27권12호
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• pp.664-671
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• 2017

A composite material was prepared for the bipolar plates of phosphoric acid fuel cells(PAFC) by hot pressing a flake type natural graphite powder as a filler material and a fluorine resin as a binder. Average particle sizes of the powders were 610.3, 401.6, 99.5, and $37.7{\mu}m$. The density of the composite increased from 2.25 to $2.72g/cm^3$ as the graphite size increased from 37.7 to $610.3{\mu}m$. The anisotropy ratio of the composite increased from 1.8 to 490.9 as the graphite size increased. The flexural strength of the composite decreased from 15.60 to 8.94MPa as the graphite size increased. The porosity and the resistivity of the composite showed the same tendencies, and decreased as the graphite size increased. The lowest resistivity and porosity of the composite were $1.99{\times}10^{-3}{\Omega}cm$ and 2.02 %, respectively, when the graphite size was $401.6{\mu}m$. The flexural strength of the composite was 10.3MPa when the graphite size was $401.6{\mu}m$. The lowest resistance to electron mobility was well correlated with the composite with lowest porosity. It was possible the flaky large graphite particles survive after the hot pressing process.

• 한국세라믹학회지
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• 제34권12호
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• pp.1205-1212
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• 1997

The matrices which consisted of SiC whisker, PES(polyesterasulfone) as a binder, span 80(sorbitan monooleate) as a surfactant, TPP(triphenyl phosphate) as a plasticizer and dichloromethane as a solvent, have been prepared by the various methods such as tape casting, rolling, tape cast-coating and roll-coating method. The fuel cells of single stack type using these matrices are characterized by ac impedance spectroscopy and cyclic voltammetry technique. A fuel cell using a matrix prepared by the tape cast-coating method shows the best performance of 466.34 mA/$\textrm{cm}^2$ at 0.6V because it has the lowest polarization resistance at the interface between electrodes and a matrix due to the largest three phase contact region of gases, catalyst and electrolyte.

• 한국재료학회지
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• 제30권10호
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• pp.522-532
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• 2020

Conductive polymer composites with high electrical and mechanical properties are in demand for bipolar plates of phosphoric acid fuel cells (PAFC). In this study, composites based on natural graphite/fluorinated ethylene propylene (FEP) and different ratios of carbon black are mixed and hot formed into bars. The overall content of natural graphite is replaced by carbon black (0.2 wt% to 3.0 wt%). It is found that the addition of carbon black reduces electrical resistivity and density. The density of composite materials added with carbon black 3.0 wt% is 2.168 g/㎤, which is 0.017 g/㎤ less than that of non-additive composites. In-plane electrical resistivity is 7.68 μΩm and through-plane electrical resistivity is 27.66 μΩm. Compared with non-additive composites, in-plane electrical resistivity decreases by 95.7 % and through-plane decreases by 95.9 %. Also, the bending strength is about 30 % improved when carbon black is added at 2.0 wt% compared to non-additive cases. The decrease of electrical resistivity of composites is estimated to stem from the carbon black, which is a conductive material located between melted FEP and acts a path for electrons; the increasing mechanical properties are estimated to result from carbon black filling up pores in the composites.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1012-1015
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• 1996

This study focuses on the optimal operation and control strategy of the fuel cell process. The control objective of the Phosphoric Acid Fuel Cell (PAFC) is established and dynamic modeling equations of the entire fuel cell process are formulated as discrete-time type. On-line optimal control of the MIMO system employs the direct decomposition-coordination method. The objective function is modified as the tracking form to enhance the response capability to the load change. The weight factor matrices Q,R, which are design parameters, are readjusted. This control system is compared with LQI method and the results show that the suggested method is better than the traditional method in pressure difference control.

• 에너지공학
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• 제2권1호
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• pp.75-82
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• 1993

상용 모사기인 ASPEN PLUS를 이용하여 천연가스를 사용하는 50 ㎾ 인산형 연료전지시스템의 정상상태 전산모사를 실시하였다. 연료전지 본체의 모사를 위하여 USER 블럭과 FORTRAN 블럭을 작성하였다. 여러가지 조업조건에 따른 수소의 수율 변화를 살펴봄으로써 개질기의 효율을 최대로 하는 조업범위를 찾았고, 실제 경우와 근사한 결과를 얻었다. 이로부터 향후 실용화될 국내의 연료전지시스템에 대한 기본 자료와 최적조건을 제시할 수 있다. 기존의 발전효율을 얻기 위하여는 수소이용률이 50%, 이상으로 유지되어야 하며, 고온으로 조작되는 개질기와 연료전지 본체에서 발생되는 고온의 열을 효율적으로 회수하여 이용함으로써 공정의 에너지효율을 높일 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1707-1709
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• 1996

For the improvement of the performance and life time of phosphoric acid fuel cell, the management of electrolyte in the electrocatalyst layer and electrolyte matrix in the cell structure is very important. Porous bipolar pinto structure, that is known as an advanced type, is generally used for the storage of electrolyte in the cell. In this paper, the single cell was made of the electrode by coating directly electrocatalyst layer on porous bipolar plate. The single cell showed $186\;mA/cm^2$ at 0.6V. This performance is similar to the performance of the conventional nonporous plate single cell. The technology of porous plate single cell could be directly used to the fabrication of stack in order to improve the performance and life time of phosphoric acid fuel cell.

• 에너지공학
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• 제2권2호
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• pp.200-207
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• 1993

본 논문은 5.9kW급 인산형 연료전지 발전시스템의 운전에 필요한 메탄올 연료개질기의 설계와 이의 운전 특성에 관한 것이다. 연료개질장치는 메탄올을 연소용 및 개질용연료로 사용하며, 개 질 반응 촉매는 CuO-ZnO계를 사용하고, 개질 반응기는 단일 환형 반응기 형태로 설계하였다. 개질 장치의 일산화탄소 생성 특성은 전체적으로 이론적인 평형값에는 도달하지 못하였으나, 반응온도가 증가할수록 농도가 증가하였으며, 개질 연료의 물/메탄올 몰비가 증가하면 감소하였다. 정격운전에서 촉매반응기의 축방향 온도분포는 이론적인 값과 잘 일치하였으며, 운전 개시후 50분 훈에 정상 운전이 가능하였다. 개질 시스템의 효율은 정격운전에서는 72.3%, 1/4 부하에서는 77%로 부하가 증가할수록 효율은 감소하였다. 개질기를 연료전지 본체와 연계운전시 개질기에 개질용 메탄올 및 연소용 메탄올의 공급유량이 각각 88.1 mol/h, 50.0mol/h 인 경우 정격전압인 37.6V의 전안에서 안정적인 5.5 kWh의 전력을 생산 할 수 있었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1998년도 한국재료학회 춘계학술발표강연 및 논문개요집
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• pp.87-87
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• 1998