http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
왕학민(Hak-Min Wang),김대영(Dae-Young Kim),최인재(In-Jea Choi),최갑승(Kap-Seung Choi),김형만(Hyung-Man Kim) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.10
Fuel cell is a electrochemical device that combines hydrogen fuel and oxygen from the air to produce electricity, heat and water. Recently, the interest on development of fuel cell is growing rapidly because it is considered to be a novel form of power source to solve not only the environment problem but also natural resource exhaustion problem. In this paper, hydrogen gas flow in micro-channel was numerically analyzed about various channel shapes to improve the efficiency of micro fuel cell. Flow characteristics with the same boundary condition were simulated in six different shapes of micro-channels which have been already developed and newly designed as well. The result of analysis shows that flow characteristics such as velocity, uniformity, and flow rate, depend highly upon the channel shape itself. That means it is expectable to increase the efficiency of micro fuel cell through optimal configuration of channel shape for hydrogen gas flow. Finally, actual micro flow channels were fabricated using SU-8 and the performance of PEM fuel cell was also carried out with these micro prototypes.
소형 고분자 전해질 연료전지의 성능향상을 위한 채널 형상의 개선 및 제작
김대영(Dae-Young Kim),왕학민(Hak-Min Wang),최갑승(Kap-Seung Choi),박상기(Sang-Ki Park),김민철(Min-Chol Kim),김형만(Hyung-Man Kim) 한국자동차공학회 2007 한국자동차공학회 지부 학술대회 논문집 Vol.- No.-
Recently, the interest on the development of fuel cell is growing rapidly . because, it is considered to be a novel form of power source to solve not only the environment problem but also drain natural resource problem. In this paper, hydrogen gas flow in micro-channel was numerically analyzed concerning about various channel shapes to estimate the efficiency of micro fuel cell. Each flow characteristic with the same boundary condition was simulated in each different shape (6-types) of micro-channels which have been already developed and newly designed as well. The result of analysis shows that characteristics of flow such as velocity, uniformity, and flow rate, depend highly upon the channel shape itself. That means it is expectable to increase the efficiency of micro fuel cell through optimal configuration of channel shape for hydrogen gas flow. Finally, actual micro flow channels were fabricated using SU-8 and the performance of PEM fuel cell was also carried out by these micro prototypes.
강일환(Il-Hwan Kang),김형만(Hyung-Man Kim),왕학민(Hak-Min Wang),최갑승(Kap-Seung Choi) 한국자동차공학회 2005 한국자동차공학회 지부 학술대회 논문집 Vol.- No.-
As fuel cells approach commercialization, hydrogen production becomes a critical step in the overall energy conversion pathway. Reforming is a process that produces a hydrogen-rich gas from hydrocarbon fuels. Hydrogen production via autothermal reforming (ATR) is particularly attractive for applications that demand a quick stan-up and response time in a compact size. However. further research is required to optimize the performance of autothermal reformers and accurate models of reactor performance must be developed and validated. The design includes the requirement of accommodating a wide range of experimental set ups. Factors considered in the design of the reformer are capability to use multiple fuels. ability to vary stoichiometry. precise temperature and pressure control, implementation of enhancement methods, capability to implement variable catalyst positions and catalyst arrangement, ability to monitor and change reactant mixing, and proper implementation of data acquisition. A model of the system was first developed in order to calculate flowrates, heating, space velocity, and other important parameters needed to select the hardware that comprises the reformer. Predicted performance will be compared to actual data once the reformer construction is completed. This comparison will quantity the accuracy of the model and should point to areas where further model development is required. The end result will be a research tool that allows engineers to optimize hydrogen production via autothermal reformation.
나선형 홈이 있는 브레이크 디스크의 열탄성불안정성에 대한 수치해석
정해일(Hae-Il Jung),최갑승(Kap-Seoung Choi),강일환(Il-Hwan Kang),왕학민(Hak-Min Wang),김형만(Hyung-Man Kim) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.5
The brake disc is the thermoelastic instability by the frictional heating during braking. In the present paper, the helical grooved vent brake disc is proved the thermoelastic instability by numerical analysis. The FEM analysis had been practiced for the comparisons of the thermoelastic instability and thermal deformation between the helical grooved vent brake disc and the conventional one.