Application of silver nanoparticles contained in ethanol as a working fluid in an oscillating heat pipe with a check valve (CLOHP/CV): a thermodynamic behaviour study

This research focused on the thermal behaviour of oscillating heat pipe with a check valve (CLOHP/CV). The CLOHP/CV was made from a copper capillary tube with an internal diameter of 2.03 mm, 40 turns, and 2 check valves. The CLOHP/CV had three sections: the evaporator and adiabatic condenser of a length of 50, 100, and 150 mm. The angles of inclinations were 90 degrees, 80 degrees, 60 degrees, 40 degrees, 20 degrees and 0 degrees at normal operating conditions. The two working fluids were an ethanol and silver nanoparticles concentration of 0.5 wt% contained in the ethanol (NE). The filling ratio was 50 % with respect to the total volume of the tube. The operating temperature (T-w) was 45, 65, 85, 105, 125 and 150 degrees C. The results of the study showed that the heat flux increased significantly when the operating temperature increased, and the heat flux increased when the Le decreased from 150 to 50 mm. Furthermore, the thermal behaviour of CLOHP/CV showed the highest heat flux of 2,012.63 W/m(2) at Le of 50, with an angle of inclination of 90 degrees and operating temperature of 150 degrees C with NE. The behaviour of 0.5 wt% of silver nanoparticles contained in the ethanol produced a good contact angle. The 0.5 wt% of silver nanoparticles decreased the wet ability, thus increasing the thermal behaviour. The optimum concentration for the addition of silver nanoparticles in the working fluid was 0.5 wt%.