POOL BOILING HEAT TRANSFER ENHANCEMENT BY y-Al₂O₃/FC-72 NANOFLUIDS ON A SMOOTH SURFACE

The influence of y-Al2O3/FC-72 nanofluids on pooling boiling heat transfer with a smooth surface was experimentally investigated. The fluorocarbon surfactant FSO-100 was also used in the experiment. In order to distinguish the effects of surfactant, four groups of contrast tests were designed as follows: base fluids (FC-72), base fluids with nanoparticles (y-Al2O3+FC-72), base fluids with surfactant (FC-72+FSO-100) and nanofluids with surfactant (Y-A12O3/FC-72+FSO-100). The results of nanofluids with surfactant showed that the heat transfer performance is enhanced compared with base fluid, but will weaken with the increase of particle concentration. In general, nanofluids can enhance the boiling heat transfer to some extent, and the enhancement is affected by the adjunction of surfactant and the sedimentation of nano-particules. Nanofluids prepared with only nanoparticles were not stable due to nonuniform distribution of the particles. The adjunction of surfactant (without nanoparticules) will lead to a significant deterioration in both heat transfer coefficient and CHF (Critical Heat Flux), but it can keep nanofluids stable and homogeneous to some degree for heat transfer enhancement.