• 한국신재생에너지학회:학술대회논문집
• /
• 2010.11a
• /
• pp.85.1-85.1
• /
• 2010

캐스케이드형 연료전지 시스템에 있어서 각 스택의 단에서 전기화학반응에 의해 생성된 물을 분리하여 적절하게 배출시켜주는 것은 스택의 성능 및 내구성 향상을 위해 매우 중요하다. 이를 위해 연료전지 스택 각 단의 상이한 조건에 맞는 기액분리기의 설계가 필요하다. 유량에 따른 기액분리기의 부피와 원활한 연료 가스와 생성수의 분리를 위한 내부구조 및 입구 속도 등의 변수들에 따라 기액분리기의 성능 뿐만 아니라 연료전지 시스템 전체의 성능에 영향을 준다. 그러나 기액분리기의 폐쇄적 구조 때문에 실험을 통해 내부의 거동 및 현상을 파악할 수 없어 앞서 언급한 변수들의 효과를 확인할 수 없는 문제점이 있다. 이에 CFD(Computational Fluid Dynamics, 전산유체역학)를 활용하여 각 조건에 따른 기액분리기 내부의 현상을 파악하고 이를 통해 기액분리기 설계를 최적화하였다.

• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.6 no.1
• /
• pp.65-71
• /
• 2010

The plugging rate of reheater tubes of Wolsung unit 1 nuclear power plant has been increased by corrosion and erosion since 1990. As the dimensions of the new first stage reheater bundle tubes which were supplied by Hanjung company to replace were different from old one, numerical calculations are carried out for flow and heat transfer in the reheater bundle tubes of the N.P.P. Numerical calculations consists of thermal performance, drain line pressure drop, flow change by pressure drop of line, stress analysis of finned tubes and analysis of flow induced vibration. Computational analysis using heat transfer research institute program is adopted to verify the results of the numerical calculations. It contains the evalution of performance in the system with view to location of the new reheater bundle and it shows the differences between the numerical calculation results and heat transfer research institute program output.

• Journal of the Korea Safety Management & Science
• /
• v.2 no.4
• /
• pp.177-186
• /
• 2000

The molten carbonate fuel cell has conspicuous features and high potential in being used as an energy converter of various fuels to electricity and heat. However, the MCFC which use strongly corrosive molten carbonate at $650^{\circ}C$ have many problem. Systematic investigation on corrosion behavior of Fe/20Cr/Ti has been done in (62+38)mol % (Li+K) $CO_3$ melt at 923K by using. steady state polarization and electrochemical impedance spectroscopy method. It found that the corrosion current of these Febased alloys decreased with increasing Ti content, and this attribute to the formation of $LiCrO_2$ layer at the surface.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.06a
• /
• pp.553-556
• /
• 2007

Hyundai${\cdot}$Kia Motors have developed PEMFC stack technologies for passenger car application in 1998. The developed 80kW class stack, which was installed Kia's Sportage FCV in 2005, has been modified for -10$^{\circ}C$ cold start-up and ensuring the stability and durability by using new technologies such as newly designed separator, manifold block, end plate, and so on. And also, the stack durability has been verified over 1,500hrs with the condition of combined vehicle driving mode. Hyundai${\cdot}$Kia Motors will keep continuing the stack R&D to reach the goal of FCV commercialization.

• 한국신재생에너지학회:학술대회논문집
• /
• 2006.11a
• /
• pp.481-484
• /
• 2006

본 연구에서는 소형 카트용 스택제작에 사용하기 위한 분리판에 관한 연구를 진행하였다. 분리판의 두께가 감소해야 스택의 부피를 줄이고 출력밀도를 높일 수 있기 때문에 분리판 두께 감소를 위한 채널의 깊이 최적화 실험을 진행하였다. 이를 위해 캐소드 채널 깊이에 따른 DMFC 성능의 변화를 관찰하기 위해 캐소드 채널의 깊이를 0.3mm에서부터 1.0mm로 변화시켰다. 채널깊이가 0.5mm일 때 가장 좋은 성능을 보였는데, 원인으로는 단면적 감소에 의한 선속도의 증가와 내부 압력증가를 들 수 있다. 채널깊이 변화에 따른 영향을 분석하기 위해 마노미터를 이용하여 차압을 측정하였고, 임피던스 분석법을 통해 전극의 저항을 측정하였다.

• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.10 no.1
• /
• pp.96-99
• /
• 2014

The aim of the study was to evaluate the water treatment of pressurized water reactor secondary side by the mixed amine of ammonia and ethanolamine, from the standpoint of corrosion control, as compared with all volatile treatment of ammonia. The pressurized water reactor systems have switched a secondary side pH control agent to minimize the corrosion in the moisture separator/reheater and feedwater heater systems and the transport of corrosion products into steam generator. As results of field test, pH was increased in the steam generator and the wet steam area of moisture separator/reheater and the concentration of Fe were decreased by more than 50% as compared with water treatment of ammonia.

• Electrical & Electronic Materials
• /
• v.9 no.8
• /
• pp.831-835
• /
• 1996

The molten carbonate fuel cell has conspicuous features and high potential in being used as an energy converter of various fuels to electricity and heat. However, the MCFC which use strongly corrosive molten carbonate at 650[.deg. C] have many problem. Systematic investigation on corrosion behavior of Fe-based Cr has been done in ($62{\times}38$)mol % (Li+K)$CO_3$ melt at 923K by using steady state polarization and electrochemical impedance spectroscopy method. It was found that the corrosion current of these Fe-based alloys decreased with increasing Cr content, and this was attributed to the formation of $LiCrO_2$ layer at the surface .

• Progress in Superconductivity and Cryogenics
• /
• v.17 no.3
• /
• pp.62-66
• /
• 2015

The cryostat is designed for the superconducting quadrupole magnets to be used in a heavy-ion accelerator facility. The main accelerator is superconducting linac, which can accelerate a $^{238}U$ beam to 200 MeV/u (Mega electron voltage per nucleon). The cryostat for the magnet employs an innovative design primarily driven by the requirement of the compactness, user-friendliness and reliability. Also, several ancillary requirements such as background field, space restriction due to the beam line and cryostat structure need technical attentions. The development of the cryostat for three quadrupole magnets in the in-flight fragmentation separator is presented in the paper. The concept of cryogenic design is reported and the amount of cryogenic load is estimated by a relevant analysis. The structure of the cryostat to endure the heavy iron yoke including three quadrupole magnets is presented. In addition, the design as well as the performance test of the support link for the cold mass is described.

• The KSFM Journal of Fluid Machinery
• /
• v.8 no.1 s.28
• /
• pp.30-36
• /
• 2005

A sludge treatment system for introducing the waste water mixture with paint sludge from the water bath of paint booth and for recycling cleaned water to paint booth after sludge separation is developed. Floated sludge is introduced from the water surface in the bath by using floating-skimmer, and is conveyed by pump to the centrifugal separator where sludge and cleaned water are separated. From the operation results of the present sludge treatment systems applied in actual paint booths, paint sludge can be separated automatically and effectively from water bath with its water content of $60-70\%$, and sludge-free clean water is returned to paint booth.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.193-193
• /
• 2010

Magnetic separation is expected to be applied for material refinement as an important supporting technology. In the superconducting magnetic separation, the cohesive force between particles is strong compared with that in the other magnetic separation. The use of high magnetic field by the superconducting magnet enhances the magnetic substance capture ability of the magnetic separation. Industrial raw materials was used for the superconducting magnetic separation. Cry-cooled, NB-Ti superconducting magnet with. 100 mm room temperature bore and 600 mm of height was used for magnetic separator.