摘要
提出了一种使用竖直细小传热管内高速空气 -过冷水环状两相流用于质子交换膜型燃料电池高效冷却的方法 .理论模拟结果表明 ,在细小管内壁上过冷水形成非常薄的液膜 ,壁面热流密度可以分为液膜吸热、液膜蒸发和湿蒸汽吸热 ,各种因素影响这 3部分热量的耦合匹配 ,使得管内两相流的传热传质特性十分复杂 .在管内的前段部分 ,液膜升温吸收大部分壁面热量 ,而在大部分区域内 ,对流蒸发耦合换热是支配性的传热方式 ,即使在十分高的热流密度条件下 ,壁温也能够稳定地保持在质子交换膜型燃料电池运行温度以下 .探讨了各种流动条件、加热管几何尺寸。
A new concept was proposed for highly effective cooling of polymer electrolyte membrane fuel cell(FEMFC) using the annular two-phase flow of high-velocity air and subcooled water in a small vertical tube. A numerical simulation study based on the two phase flow boundary layer model was performed to investigate the heat and mass transfer characteristics of the annular two-phase flow of high-velocity air and subcooled water through a small vertical heated tube with uniform wall heat flux. Numerical calculation simulated the coupling heat transfer of evaporation and convection in the tube and the effects of various flow parameters, the wall heat flux and geometrical sizes of the heated tube on the heat and mass transfre charactristics. The simulation results show that the annular two-phase flow of air and subcooled water in a small vertical tube can provide quite high heat transfer ability by the evaporation of the water film, while wall temperatures can lie in a low range. This cooling method is suitable for high effective cooling of PEMFC.
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
2004年第7期1152-1155,共4页
Journal of Shanghai Jiaotong University
基金
国家自然科学基金资助项目 ( 5 0 3 760 2 9)
关键词
环状两相流
强化换热
蒸发
annular two-phase flow
enhanced heat transfer
evaporation
