Numerical simulation of a methanol reformer with micro-channel

• Main Authors: xianglun gao, 高祥倫
• Other Authors: 楊進丁
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/14900836190526773800

碩士 === 聖約翰科技大學 === 自動化及機電整合研究所 === 96 === To supply hydrogen fuel directly to proton exchange membrane fuel cell with a methanol reformer can solve the hydrogen storage problem. This is the motive of our study. We analyze the methanol-steam mixture reforming model in a 3-D reformer with micro-channel structure by using numerical simulation. The influences of parameters include reforming temperatures, inlet mixture velocities, carbon steam ratios, the depths of micro-channel and heat transfer boundary conditions. Those parameters are important to design a high efficiency reformer. The computation results are compared with other researcher’s publication.Both have the same trends. The computation results show increasing the reforming temperature always improve the chemical reaction rate and the methanol reforming rate.Increasing the mixture inlet velocity can force more methanols into the reformer and then improve the hydrogen production rate. However the residing time of methanol inside the reformer will decrease and some methanol just bypass the reformer. A large carbon stream ratio means more stream in the mixture. The methanol reforming rate will improve, but the hydrogen and production rate will. Decrease a reformer with deep micro-channel has no help to the methanol diffusion. This is the reason why the decreasing of methanol reforming rate in a reformer with deeper micro-channel. But this effect is limited. When the wall boundary conditions changed from isothermal to constant heat flux, the heat flux affects the reforming rate dramatically. This is an important factor for who wants to supply the heat flux to reformer by burning methanol. In order to get better reforming rate,it is necessary to accurately control the heat flux.