The potential of arch-shaped fins for energy-charge enhancement in triplex-tube heat storage: Comparative analysis and optimization

Incorporating PCMs with thermal storage systems offer significant potential for improving the energy efficiency of diverse applications, including solar thermal power plants, air conditioning systems, and building heating and cooling systems. However, a key challenge in designing these systems is achieving efficient and rapid PCM melting during the charging process. This study aims to analyze and report on the potential of arch-shaped fins in enhancing the melting rate and overall performance of horizontal triplex-tube storage systems. The influences of fin base height and fin connecting angles were analyzed via simulations. The optimal arch-shaped fin design reduced melting time by 53 % and improved heat storage rate by 117 % compared to the no-fin case. Specifically, equal inner/outer fin base heights of 10 mm minimized melting time to 14.8 min and maximized heat storage to 477.2 W. Increasing the inner fin connecting angle from 0 degrees to 120 degrees decreased melting time by 15.2 % to 12.1 min and increased heat storage by 18.0 % to 591.3 W. Reducing the outer fin connecting angle from 240 degrees to 0 degrees reduced melting time by 10.8 % to 11.5 min and improved heat storage by 12.3 % to 591.3 W. These findings would have implications for advancing the design and optimization of heat storage systems, leading to improved performance and increased utilization of sustainable energy sources.