Effect of two different fins (longitudinal-tree like) and hybrid nano-particles ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si44.svg"> <mml:mrow> <mml:mi mathvariant="italic">Mo</mml:mi> <mml:msub> <mml:mi>S</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:mo linebreak="badbreak" linebreakstyle="after">-</mml:mo> <mml:mi>T</mml:mi> <mml:mi>i</mml:mi> <mml:msub> <mml:mi>O</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> ) on solidification process in triplex latent heat thermal energy storage system

To tackle global warming, a reliable storage system seems crucial due to unpredictability of renewable energy. As a result, storage units based on Phase Change Material (PCM) are found to be of great worth where latent heat transfer occurring in an almost isothermal condition lay the foundation for far more compact and easy-to-fabricate storage components. Despite their advantageous, one major drawback being weak thermal conductivity needs to be addressed. So, in this study a triplex-tube heat exchanger with tree-like and rectangular fins along with hybrid nanoparticles made of MoS2-TiO2 are put into perspective to dispose of this weakness and Galerkin Finite Element Method (GFEM) is applied using FlexPDE to analyze the solidification process and evaluate the influence of single and combined usage of fins and nanoparticles. Moreover, the credibility of this study and GFEM has been confirmed by an experimental work. The results unveiled that, while the combined usage of nanoparticles and tree-like fins gives the best result by lowering the solidification time by 78% compared to bare tube, tree-like fins claim the best performance taking 1700 s followed by rectangular fins with 3500 s if nanoparticles are out of reach.