Saturated pool boiling heat transfer from highly conductive graphite foams
- 31 October 2011
- journal article
- Published by Elsevier BV in Applied Thermal Engineering
- Vol. 31 (14-15), 2685-2693
- https://doi.org/10.1016/j.applthermaleng.2011.04.038
Abstract
This paper presents an investigation of heat transfer enhancement using highly conductive graphite foam as porous insert in a pool boiling evaporator. Graphite foams of different bulk thermal conductivities and pore sizes were investigated with phase change coolants FC-72 and HFE-7000 and compared with a copper block in a designed thermosyphon. The heater wall temperature, superheat and thermal resistances were obtained to evaluate the boiling performance. Associated with the analysis of various boiling regimes, nondimensional parameters including the Capillary, Grashof and Bond numbers were used to analyze the bubble formation from the porous insert. The experimental results show that the boiling thermal resistances of the system with a graphite foam insert are about 2 and 3 times lower than those of the copper block immersed in FC-72 and HFE-7000, respectively. The nondimensional analysis showed that the bubbles from the small pore diameter graphite foam have to overcome a large surface tension force before departure, although the foam possesses high thermal conductivity. This implies that a balanced relation between thermal conductivity and pore diameter could maximize the enhancement on pool boiling heat transfer. The current thermosyphon with a porous insert can allow a heat flux of 112 W/cm2 to be removed with a maximum heater temperature of 90 °C.Keywords
This publication has 18 references indexed in Scilit:
- Numerical and experimental study of forced convection in graphite foams of different configurationsApplied Thermal Engineering, 2010
- Performance of different structured surfaces in nucleate pool boilingApplied Thermal Engineering, 2009
- Study of Highly Conductive Graphite Foams in Thermal Management ApplicationsAdvanced Engineering Materials, 2008
- Forced Convection Heat Transfer and Hydraulic Losses in Graphitic FoamJournal of Heat Transfer, 2006
- New pool boiling data for water with copper-foam metal at sub-atmospheric pressures: Experiments and correlationApplied Thermal Engineering, 2006
- Characterization of Porous Carbon Foam as a Material for Compact RecuperatorsJournal of Engineering for Gas Turbines and Power, 2006
- Experimental study on CPU cooling system of closed-loop two-phase thermosyphonHeat Transfer, 2005
- Carbon foams for thermal managementCarbon, 2003
- Design and performance evaluation of a compact thermosyphonIEEE Transactions on Components and Packaging Technologies, 2002
- Optimization of Enhanced Surfaces for High Flux Chip Cooling by Pool BoilingJournal of Electronic Packaging, 1993