Distinctive Features of the Use of Nanofluids To Enhance Boiling Heat Transfer

The authors have analyzed the results of investigations of nucleate and fi lm regimes of boiling of nanofluids. In the nucleate regime of boiling of nanofluids, the increase in the critical heat flux compared to a pure fluid is observed; here, there can be both an increase and a decrease in the heat-transfer coefficient. The increase in the critical heat flux during the boiling of a nanofluid is linked to the formation of a deposited nanoparticle layer on a heated surface, which contributes to the change in the microcharacteristics of the process of boiling and to the decrease in the wetting angle of the surface. Results of theoretical investigation of the fi lm boiling of a nanofluid on a vertical heated surface have been presented. It has been shown that the greatest infl uence on the processes of heat and mass transfer in a vapor film is exerted by the superheating of the wall, the relation of the temperature and Brownian diffusions, and the concentration of nanoparticles in the fluid.