HEAT TRANSFER ENHANCEMENT IN HEAT PIPES AND THERMOSYPHONS USING NANOTECHNOLOGIES (NANO-COATING, NANO LIQUIDS AND NANO COMPOSITES AS THE HP ENVELOPE)
A new trend in the heat pipes and thermosyphons successful application is related with nanotechnologies.Nano liquids, nano coatings and nano composites invention open a new niche in the heat pipe and thermosyphon design and use.The aim of this work is to present a short review of some experimental results in the field of heat pipes and thermosyphons tests, using nano liquids and nano coating on the heat loaded zones.Nano fluids are considered as the vacant working liquids for the transparent flat mini heat exchangers heated by laser beam, or solar radiation.The combination of nano fluid and small channels constitutes an innovating method providing effectiveness, compactness and low thermal resistance.Thin porous nano coating in coaxial mini channels, or mini grooves of the heat pipe evaporator plays a role of additional centers for stable vapor generation, which do not require high superheating of the surface to obtain the heat transfer enhancement.The porous nano coating (thickness 25-100 μm) on the surface of mini grooves allows reducing its thermal resistance (2-3 times) and increasing the working fluid capillary pressure and permeability at the same time.Polymer composites reinforced by nano wires and nano particles are considered as promising alternative to metals.The new design of loop polymer based thermosyphon was suggested, designed and tested.The thermosyphon envelope consists of polyamide composite with nano carbon filaments and nano diamond particles to increase its effective thermal conductivity up to 11 W/m 0C, which is more than 40 times higher to compare with pure polymer thermal conductivity.It was found that a fiat grooved evaporator thermal resistance Rev of polymer thermosyphon is the same order of merit as a classical aluminum smooth grooved heat pipe evaporator.In certain applications polymers composites reinforced by carbon nano wires and nano particles can successfully replace the metal envelope of heat pipes and thermosypons.
L.L.Vasiliev L.L.Vasiliev.JR.
Luikov Heat and Mass Transfer Institute, National Academy of Sciences of Belarus,15, P.Brovka Str., 220072, Minsk, Belarus
国际会议
The 11th International Heat Pipe Symposium(第十一届国际热管研讨会)
北京
英文
37-47
2013-06-09（万方平台首次上网日期，不代表论文的发表时间）