http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
고분자전해질 연료전지의 물 배출 성능 향상을 위한 촉매층 공급 대류 촉진 사행성 유동장 설계
최갑승,배병철,박기원,김형만,Choi, Kap-Seung,Bae, Byeong-Cheol,Park, Ki-Won,Kim, Hyung-Man 한국전기화학회 2012 한국전기화학회지 Vol.15 No.2
고분자전해질 연료전지의 성능은 매우 복잡한 물리 현상들에 의해 변화하게 된다. 반응면적이 25 $cm^2$인 5-pass, 4-turn 사행성 유동유로의 립 부분에 보조유동유로를 가지는 형상에 대하여 물관리 측면에서의 연료전지 성능을 수치해석을 통해 비교하였다. 보조유동유로를 추가함에 따라 촉매층 공급 대류의 유동 방향이 변경되어 유로 내부의 물 배출 특성을 향상시키는 결과를 나타내었다. 또한 입구에서의 공급기체를 보조유동유로로 분산시킴에 따라 입구에서의 전류 밀도는 낮아지며 보조유동유로로 이동하는 공급기체들은 주 유동유로의 내에서의 체류시간보다 길어져서 전체적인 전류밀도 분포가 균일해지는 것을 확인하였다. Proton exchange membrane fuel cell performance is changed by the complicated physical phenomenon. In this study, water discharge performance of proton exchange membrane fuel cell were performed numerically to compare serpentine channel flow fields of 5-pass 4-turn serpentine and 25 $cm^2$ reaction surface between with and without sub-channel at the rib. Through the supplement of sub channel flow field, it is shown from the results that water removal characteristic inside channel improves because the flow direction of under-rib convection is changed into the sub channel. Reacting gases supplied from entrance disperse into sub channel flow field and electrochemical reaction occurs uniformly over the reaction surface. The results obtained that total current density distributions become uniform because residence time of reacting gases traveling to sub-channel flow field is longer than to main channel.
최갑승,곽철호,김상은,노수인,최익수,Choi, Kab-Seung,Kwak, Cheol-Ho,Kim, Sang-Eun,Roh, Su-In,Choi, Ik-Su 대한족부족관절학회 2004 대한족부족관절학회지 Vol.8 No.2
Purpose: To compare clinical characteristics of ganglions in hand & Foot. Materials and Methods: Seventeen cases of ganglions located in foot and fifty-five cases in hand. Excised from Mar.1988 to Apr.2003, were included in the study. The clinical characteristics and recurrence ratio were evaluated Results: The mean size of 2.2 cm in hand and 2.5 cm in foot. The most common area of ganglions are dorsum of foot and wrist. The cosmetic problem of palpable mass is the primary chief complaint of ganglions on hand and the pain is that of foot. The recurrence was found in 5 cases in hand and 4 cases in foot. The recurrence was related to incomplete excision of ganglion in foot and the large size of ganglion and incomplete excision of ganglion in hand. Conclusion: recurrence ratio in the cases of foot is higher than that of hand. The ganglions in foot and hand need to treated by meticulous surgical excision to prevent the recurrence.
대형 디젤 엔진의 연소실 평균 표면온도 측정에 관한 연구
최갑승(Kap-seung Choi),김창호(Chang-ho Kim),이동제(Dong-je Lee),김형만(Hyung-man Kim),이동호(Dong-ho Lee) 한국자동차공학회 2003 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
In the recent development of internal combustion engine. considerable increase in speed and power has been accomplished. This achievement, however, brought up various problems due to the excessive engine parts temperature which becomes a crucial factor in engine durability.<br/> In this paper, temperature measurement of diesel engine parts was investigated experimentally and theoretical analysis was indicated on appendix. The adapter is designed to pull out the thermocouple. The thermocouple is welded on the surface of the cylinder cover to measure the surface average temperature. and drawn out through the safety valve hole. Ceramic Bond was used for prevent the affect of high temperature combustion gas. The cylinder cover temperature of experimental engine and low-speed engine(K90MC) is measured by means of surface welding method. The results. Average temperature range is indicated that experimental engine of cylinder cover, cylinder liner is respectively 215 ~ 335℃ , 85 ~93℃ and low-speed engine(K90MC) of cylinder cover. cylinder liner is respectively 291 ~ 378℃, 137 ~ 158℃ .<br/> This study inspected surface welding method by measuring cylinder cover, piston crown temperature of experimental engine. Then apply to low-speed engine(K90MC), developed temperature measuring method without damaged engine.<br/>
Under-rib convection의 유동 방향을 고려한 PEM fuel cell 분리판 형상 설계
최갑승(Kap-Seung Choi),신기수(Gisoo Shin),장상훈(Sanghoon Jang),김형만(Hyung-Man Kim) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5
PEMFC performance is changed by the very complicated physical phenomenon. In this study, numerical analyses on performance for Fuel Cell in the aspects of water management were performed to compare Serpentine channel flow fields of 5pass 4turn Serpentine and 25㎠ reaction surface between with and without sub channel at rib. PEMFC operating conditions were the same and the inlet flow velocity was controlled by stoichiometric numbers of 1.5 at anode and 2.0 at cathode. Through the supplement of sub channel flow field, it is shown from the results that water removal characteristic inside channel improves because the flow direction of under-rib convection is changed into the sub channel. Reacting gases supplied from entrance disperse into sub channel flow field and electrochemical reaction occurs uniformly over the reaction surface. Therefore, it was also known that total current density distributions become uniform because retention time of reacting gases traveling to sub channel flow field is longer than to main channel.