A mechanism of heat transfer enhancement or deterioration of nanofluid flow boiling heat transfer

In present work, the heat transfer characteristics of SiC/H₂O and Graphite/H₂O nanofluids flow boiling are experimentally studied with the consideration of pressure, mass flux and heat flux. Compared with based fluid, both enhancement and deterioration of nanofluids boiling heat transfer are found. The flow boiling heat transfer capacities of 0.1vol.% SiC/H₂O nanofluid is changed from -24.7% to 30.6% compared with deionized water. Instead, it is changed from -29.4% to 13.3% for 0.1vol.% Graphite/H₂O nanofluid. In addition, a mechanism of this phenomenon from the point of view of the assistance and resistance. The assistance includes the improving of the thermal physical properties, the decreasing of surface tension and latent heat, the decreasing of contact angle, decreasing of the surface energy. Instead, the resistance is mainly the decreasing of the number of boiling site.