An Experimental Study of Carbon Nanotube Coatings for Pool Boiling Heat Transfer Enhancement
Nucleate pool boiling heat transfer performance of silicon surfaces with different CNT coated areas were experimentally investigated with FC-72 as the coolant in a water-cooled thermosyphon system. The experimental results revealed that the heat transfer enhancement and CHF increased with increasing CNT coated area. At 90% CNT coating area, approximately 1.5 times enhancement in both pool boiling heat transfer and CHF were recorded as compared to a bare silicon surface. Based on visual observations of bubble nucleation between the low (5 W/cm2) and intermediate (16 W/cm2) heat flux regimes where most of the bubbles were seen departing from the edges of the CNT coating, the interlaced patterned CNT coating was developed to increase the CNT coating perimeter for further heat transfer enhancement. Subsequent experiments with the interlaced patterned CNT coating recorded a further 15% heat transfer enhancement as compared to the surface with 90% CNT coated area.