Improved the thermal performance of a closed two-phase thermosyphone using graphene acetone as nano-fluid for photovoltaic cooling application

Two phase thermosyphon (TPTS) is a passive device to transfer heat energy by evaporation of the working fluid filled in it. This device is used in a various engineering applications such as a photovolatic cooling. The thermal performance of (TPTS) charged with graphen acetone (G.A) nanofluid is analyzed and compared with that of acetone as base working fluid. The concentration of G.A is varied with (0.05%, 0.1%, 0.15% and 0.2%) for each filling charge ratio of (5%, 10%, 15% and 20%). The (TPTS) charged with G.A and A is evaluated for different input heat flux load of (100, 400, 700, 1000 and 1300 w∕m^2 ) the impacted input power, filling charge ratio and G.A concentration on the performance of the (TPTS) are investigated. The thermal resistance of (TPTS) and the overall heat transfer coefficient were determined at different input power, filling charge and G.A concentration. At input load power of 1300w∕m^2 . The thermal resistance of (TPTS) charged with G.A (at 15% filling charge ratio) is reduced by (7.2%), (26.1), (33.4%) and (42.8%) respectively for (0.05%, 0.1%, 0.15% and 0.2%) concentration in comparisons with pure acetone. The thermal performance of (TPTS) charged with G.A increases in comparison to pure acetone. Further and due to increasing the concentration of G.A, the overall heat transfer coefficient has been increased at the highest input heat flux load. The improvement of the overall heat transfer coefficient of (TPTS) charged with G.A reached 17.5% compared to pure acetone.