Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
EXPERIMENTAL RESULTS FOR THE HEAT TRANSFER COEFFICIENT DURING FLOW BOILING OF DI-WATER IN A STAINLESS STEEL TUBE COATED WITH SIO2 NANOPARTICLES (15 NM AND 80 NM)
Submission Author:
Tiago Augusto Moreira , SP
Co-Authors:
Francisco Julio do Nascimento, Gherhardt Ribatski
Presenter: Tiago Augusto Moreira
doi://10.26678/ABCM.ENCIT2016.CIT2016-0048
Abstract
The present paper reports experimental results for the heat transfer coefficient during flow boiling of DI-water in a stainless steel (AISI-304) tube with internal diameter of 1.1 mm. The internal surface of the channel was coated through a boiling process using nanofluids composed of DI-water and SiO2. Nanofluids were prepared using two sizes of spherical SiO2 nanoparticles, corresponding to diameters of 15 nm and 80 nm. Tubes were nanocoated using nanofluids with volumetric concentrations of 0.001, 0.01 and 0.1% for each nanoparticle size. Flow boiling results were also obtained for DI-water in a surface without coating. For nanoparticles with diameter of 15 nm, the experimental data reveal that the nanocoating causes a reduction of the heat transfer coefficient. It was also observed that the heat transfer coefficient reduction is intensified by increasing the volumetric concentration of nanoparticles used for the deposition process. On other hand, for nanoparticles of 80 nm, the heat transfer coefficient was almost unaffected by the SiO2 nanocoating.
Keywords
Heat transfer coefficient, Flow boiling, Coated surface, nanoparticles, Nanofluids, microchannels
