Fundamental study of evaporation heat transfer in porous media

The demand for better thermal management has been intensified over the years along with the rapid development of sophisticated electronic devices in order to prolong their life span and to prevent premature failure. One of the well-known thermal solutions is heat pipe, which has a wide range of applications in space and terrestrial. It applies the evaporative heat transfer in porous media. Therefore, an experimental study was carried out to investigate the effects of porosity on evaporation heat transfer in porous media. The porous media is created by metal balls with diameter 5mm, 10mm, and 20mm which placed randomly in a 100mm x 100mm metal container with a constant porous layer thickness of 20mm. The experiments were run at two different (100ºC and 120ºC) heat source temperature under atmospheric pressure. The results were obtained and analyzed under steady state condition. Based on the results obtained, it is found that the evaporation heat transfer in porous media can be enhanced by varying the porosity and pore sizes. The results were then compared with the evaporation from water only (without porous media). It showed that the evaporation heat transfer rate is better in porous media compared to with water only.