Surface effects of ribbon heaters on critical heat flux in nanofluid pool boiling
Abbreviated Journal Title
Int. Commun. Heat Mass Transf.
Critical heat flux; Nanofluid; Pool boiling; Deposition; Concentration; NANO-FLUIDS; CHF; WATER; THIN; Thermodynamics; Mechanics
This paper deals with a study of enhanced critical heat flux (CHF) and burnout heat flux (BHF) in pool boiling of water with suspended silica nanoparticles using Nichrome wires and ribbons. Previously the current authors and other researchers have reported three-digit percentage increase in critical heat flux in silica nanofluids. This study investigates the effect of various heater surface dimensions, cross-sectional shapes as well as surface modifications on pool boiling heat transfer characteristics of water and water-based nanofluids. Our data suggest that the CHF and BHF decrease as heater surface area increases. For concentrations from 0.1 vol% to 2 vol%, the deposition of the particles on the wire allows high heat transfer through inter-agglomerate pores, resulting in a nearly 3-fold increase in burnout heat flux at very low concentrations. The nanoparticle deposition plays a major role through variation in porosity. The CHF enhancement is non-monotonic with respect to concentration. As the concentration is increased, the CHF and BHF decrease prior to increasing again at higher concentrations. Results show a maximum of 270% CHF enhancement for ribbon-type heaters. The surface morphology of the heater was investigated using SEM and EDS analyses, and it was inferred that the 2 vol% concentration deposition coating had higher porosity and rate of deposition compared with 0.2 vol% case. (C) 2012 Elsevier Ltd. All rights reserved.
International Communications in Heat and Mass Transfer
"Surface effects of ribbon heaters on critical heat flux in nanofluid pool boiling" (2013). Faculty Bibliography 2010s. 4802.