Experimental study of the effect of single walled carbon nanotube/water nanofluid on the performance of a two-phase closed thermosyphon

Abstract

Thermosyphons are one of the most efficient heat exchanger apparatus that are used extensively in different industries. One of the most common uses of this device is energy recovery, which is essential due to the energy crisis. Several parameters, such as geometric dimensions, type of working fluid and type of the body, affect the efficiency of a thermosyphon. In this work, the effect of type and concentration of single-walled carbon nanotube nanofluid (SWCNT/water) on the efficiency of heat transfer in a two-phase closed thermosyphon (TPCT) was investigated. For this purpose, a system with a two- -phase closed thermosyphon was initially constructed. Then SWCNT/water nanofluids at 0.2, 0.5 and 1 % weight concentration were used as the working fluid in the thermosyphon system. The results of the current experiments showed that the addition of a nanofluid at any weight concentration and an increase in input power increases the performance of the system. In addition, the heat resistance of the TPCT was reduced when the level of SWCNT and input power increased. Hence, for the prepared nanofluid samples, the minimum thermal resistance was obtained at 1 wt. % SWCNT and 120 W. Moreover, the Nusselt number increased with increasing input power and decreased with increasing concentration. In all experiments, all the prepared nanofluid samples had a significantly better thermal performance in comparison with pure water.