Enhancement of the performance heat transfer of a thermosyphon with fin and without fin heat exchangers using Cu-nanofluid as working fluids

Abstract

This research demonstrates the enhancement of a thermosyphon heat exchanger with fins and without fins using Cu-nanofluid as a working fluid. The heat pipe-type thermosyphon used in this study was made of steel. The steel tube had an outside diameter of 20 mm and a thickness of 1.25 mm. The lengths of the evaporator, adiabatic and condenser sections were 20, 10, and 20 cm, respectively. The thermosyphon heat exchanger had 13 tubes with Di-water and Cu-nanofluid as working fluids, and a filling ratio of 50% by total volume. The exchangers were installed with two fin sizes: 0.5 and 1.0 cm. The fins were a 16 piece/pipe. The evaporator section was heated by a heater, while the condenser section was cooled by fresh air. The hot air was controlled at three levels: 60, 70, and 80°C, and the fresh air velocities were adjusted at three levels: 0.5, 1.0, and 1.5 m/s. The test operation focused on the heat transfer rate and thermal effectiveness of the thermosyphon heat exchanger with a fin using Cu-nanofluid as a working fluid. It was found that the maximum value of heat transfer rate and thermal effectiveness occurred when the air velocity was 0.5 m/s, 1 cm of fin, temperature 80°C, and using Cu-nanofluid as the working fluid. It is indicated that the heat transfer rate and thermal effectiveness performance increased when compared with DI-water at all variables.