Abstract
Compact power generation systems which consist of methanol reformer and Polymer Electrolyte Fuel Cell (PEFC) are greatly required as emergency power source. In this system, PEFC exhaust heat can be utilized for evaporating water/methanol solution before reforming. To use PEFC exhaust heat (about 80〜90 °C), a microchannel heat exchanger is suggested as an evaporator because of supplying heat more efficiently. However, phase change phenomena of water/methanol solution in a microchannel are not clarified. In this study, the double-pipe heat exchanger including the microchannel was developed. Then, phase change phenomena in the microchannel were visualized with varying concentration, flow rate and pressure.