Subcooled Pool Boiling Experiments on Horizontal Heaters Coated With Carbon Nanotubes
Open Access
- 30 April 2009
- journal article
- Published by ASME International in Journal of Heat Transfer
- Vol. 131 (7), 071501
- https://doi.org/10.1115/1.3000595
Abstract
Pool boiling experiments were conducted with three horizontal, flat, silicon surfaces, two of which were coated with vertically aligned multiwalled carbon nanotubes (MWCNTs). The two wafers were coated with MWCNT of two different thicknesses: 9 μm (Type-A) and 25 μm (Type-B). Experiments were conducted for the nucleate boiling and film boiling regimes for saturated and subcooled conditions with liquid subcooling of 0–30°C using a dielectric fluorocarbon liquid (PF-5060) as test fluid. The pool boiling heat flux data obtained from the bare silicon test surface were used as a base line for all heat transfer comparisons. Type-B MWCNT coatings enhanced the critical heat flux (CHF) in saturated nucleate boiling by 58%. The heat flux at the Leidenfrost point was enhanced by a maximum of ∼150% (i.e., 2.5 times) at 10°C subcooling. Type-A MWCNT enhanced the CHF in nucleate boiling by as much as 62%. Both Type-A MWCNT and bare silicon test surfaces showed similar heat transfer rates (within the bounds of experimental uncertainty) in film boiling. The Leidenfrost points on the boiling curve for Type-A MWCNT occurred at higher wall superheats. The percentage enhancements in the value of heat flux at the CHF condition decreased with an increase in liquid subcooling. However the enhancement in heat flux at the Leidenfrost points for the nanotube coated surfaces increased with liquid subcooling. Significantly higher bubble nucleation rates were observed for both nanotube coated surfaces.Keywords
This publication has 20 references indexed in Scilit:
- Liquid-Vapor Phase-Change PhenomenaPublished by Informa UK Limited ,2018
- Effects of carbon nanotube arrays on nucleate pool boilingInternational Journal of Heat and Mass Transfer, 2007
- Enhanced Pool Boiling Using Carbon Nanotube Arrays on a Silicon SurfacePublished by ASME International ,2005
- Effects of Varying Geometrical Parameters on Boiling From Microfabricated Enhanced StructuresJournal of Heat Transfer, 2003
- Graphite Foam Thermosyphon Evaporator Performance: Parametric Investigation of the Effects of Working Fluid, Liquid Level, and Chamber PressurePublished by ASME International ,2002
- Unusually High Thermal Conductivity of Carbon NanotubesPhysical Review Letters, 2000
- Combined effects of sub-cooling and operating pressure on the performance of a two-chamber thermosyphonIEEE Transactions on Components and Packaging Technologies, 2000
- BOILING HEAT TRANSFERAnnual Review of Fluid Mechanics, 1998
- Optimization of Enhanced Surfaces for High Flux Chip Cooling by Pool BoilingJournal of Electronic Packaging, 1993
- Helical microtubules of graphitic carbonNature, 1991