Effect of Heat Transfer in Circular Heat Pipe with Ethanol Methanol and Al2O3 as a Nanofluid: A Review

Abstract

Heat pipes work on the principle of evaporation and condensation and thus enhances large amount of heat. A variety of working fluid and wicks are used to make a heat pipe. In recent technology attempt is made to mix the nano-powder of oxides in the working fluid which produces nanofluid and leads to increase in thermal conductivity as well as overall heat transfer coefficient and decrease in thermal resistance of nanofluids.

Different types of nanofluids are used as working media in different types of heat pipe. Thermal efficiency of heat pipe changes with mass concentration of nanoparticle as well as working fluid, inclination angle, particle size of nanoparticle, shape of nanoparticle etc.

An experimental investigation of the performance of thermosyphons charged with ethanol and methanol along with Al₂O₃ has been carried out. The Al₂O₃ naoparticle are spherical in shape with 10% concentration by volume in working fluid.  The copper thermosyphon was 1000 mm long with an inner diameter of 26 mm. The evaporator length was 300 mm and the condenser length was 450 mm. With ethanol methanol as the working fluid corresponding to approximately 60% filled and overfilled evaporator section in order to ensure combined pool boiling and thin film evaporation/boiling conditions.

This review summarizes the use of Al₂O₃ nanoparticle in heat pipe having ethanol and methanol as working fluid and thus leading to increase in heat transfer rate along with minimum temperature difference.