Enhancement of pool boiling heat transfer by laser texture-deposition on copper surface

Abstract

To improve the durability of pool boiling, laser texture-deposition technology was introduced to produce massive area of micro/nano structures on copper surface without any chemical treatment. The XPS analysis and the SEM images revealed that the two-tier micro/nano structure was formed on the micron protrusions, where villous cluster nano SiO2 layer was deposited on copper oxide nanoburrs. Subcooled pool boiling experiments indicated that villous cluster nano SiO2 structure delayed the oxidation of Cu, and thus enhanced the durability (capillary wicking/superhydrophilicity). Furthermore, the CHF and HTC of the laser texture-deposition surface reached 2805.8 kW/m2 and 111.8 kW/(m2·K). The CHF and HTC are 2.8 times and 2.1 times that of the original copper surface, respectively. Laser texture-deposition technology proves to be a promising green processing technology for the heat transfer of pool boiling.