A refrigerant R141b-based nanofluid was made by hydroxylated carbon nano-tube particles in 0.01%

0.03%

0.05%

0.07% and 0.10% mass fractions. An experimental study was carried out to investigate the nucleate boiling heat transfer characteristics of nanofluid on a smooth copper surface at pressure of 90.3 kPa. The surface roughness was made by sandpaper of grade 5000#. The result illustrates that the boiling heat transfer is enhanced by increasing nanoparticles. The improvement is related to the coefficient of thermal conductivity

deposition of nanoparticles and their disturbances to flow. The heat transfer coefficient increases with nanoparticle mass added except in later boiling period. The coefficient of thermal conductivity of 0.10% nanofluid is 1.18 times that of pure fluid R141b. The heat transfer coefficient is increased by 168% for 0.05% mass fraction at the heat flux of 87.4 kW·m-2. The boiling process of 0.03% mass fraction was recorded by the high-speed CCD.