Application of Enhanced Boiling Surface for Chip Cooling

• Main Authors: Chang Chann-Chaio, 張千喬
• Other Authors: 簡良翰
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/58917263311095451917

碩士 === 長庚大學 === 機械工程研究所 === 90 === ABSTRACT This experimental study investigated the effect of particle size and coating thickness of the porous surface on evaporator thermal resistance of the thermosyphon having a 16 mm diameter circular heating area. Copper particles having two kinds of size distributions were sintered on a copper plate. The two particle distributions are (1) 115 mm average diameter in the range of 50-to-500 mm, and (2) 247mm average diameter in the range of 180-to-350 mm. The particle coating thickness was either 0.5 or 1.0 mm for each distribution. Water was used as the working fluid, and it was tested at 60 or 70oC saturation temperature, which corresponds to sub-atmosphere saturation pressure. The heat flux varied between 30 and 550 kW/m2. The boiling surfaces were tested in vertical and horizontal orientation, and the experimental results showed negligible effect on the surface orientation. The best boiling surface in the present study is obtained by coating 1.0 mm thick having 247 mm average particle diameter. At 70oC this surface yielded less than 0.025 K/W evaporation thermal resistance at 93 W..