EXPERIMENTAL STUDY OF THERMO-HYDRAULIC PERFORMANCE OF SWCNT NANOFLUIDS IN SINGLE-PHASE FLOW

ABDUL ORLANDO CARDENAS GOMEZ¹; ENIO PEDONE BANDARRA FILHO¹

¹ UFU

doi:10.20906/CPS/COB-2015-2314

Resumo

The present work deals on experimental study of thermal-hydraulic performance of single walled carbon nanotubes nanofluids dispersed in distilled water. The tests were performed in single-phase flow, fully developed turbulent regime, inside smooth and horizontal tubes with uniform heat flux applied on the surface. An experimental bench was modified to guarantee the nominal conditions imposed for the tests. The mass flow rate varied between 30 and 80 kg/s, related to Reynolds numbers between 4000 and 22000. The heat flux varied from 14 up to 22 kW/m2 and the inlet temperature was maintained constant in 25, 30 and 35°C. The physical properties of nanofluids such as thermal conductivity and viscosity were measured experimentally and its values used to evaluate the heat transfer coefficient. Pressure drop, friction factor and pumping power were also analyze. Effects such as nanoparticle shape, defined by the aspect ratio, and mass concentration of nanoparticles were evaluate as well. The heat transfer coefficient of SWCNT/water nanofluids increased, in average, 11.3%, in function of Reynolds number. In relation to the mass velocity, the heat transfer coefficient decreased 6.9%, in average, in comparison with the base fluid. Finally, the experimental results for pressure drop of nanofluids were, in average, 7.3%, greater than the base fluid.

Palavras-chave: Nanofluids; Single-walled carbon nanotube; Convective Heat transfer; Pressure drop; Performance evaluation