Flow Boiling Heat Transfer Enhancement from Carbon Nanotube-Enhanced Surfaces

Abstract

This paper presents an experimental study of flow boiling heat transfer from carbon nanotube (CNT) structures in a two-phase cooling facility. Multi-walled CNT (MWCNT) structures of dimensions 80 mm × 60 mm were applied to a horizontal flow boiling channel. Two CNT structures with different properties viz. NC-3100 and MERCSD were tested with a dielectric liquid FC-72. The height of the CNT structures was fixed at 37.5 μm and tests were conducted at coolant mass fluxes of 35, 50, and 65 kg/m2·s under saturated flow boiling conditions. The experimental results show that the CNT structures enhance the boiling heat transfer coefficients by up to 1.6 times compared to the smooth aluminum surface. The results also show that the CNT structures increase significantly the Critical Heat Flux (CHF) of the smooth aluminum surface from 66.7 W/cm2 to 100 W/cm2.