Melting and solidification processes within the Trombe wall enhanced by a paraffin layer with nanoparticles

Abstract

This work focuses on the numerical simulation of a new Trombe wall design, incorporating a paraffin zone and fins. The simulations encompass both melting and solidification processes in the presence and absence of sunlight, comparing the performance with a classic Trombe wall. Time-dependent boundary conditions are applied to surfaces, while the paraffin is enhanced with nanoparticles for improved conduction. The Surface-to-Surface radiation model (S2S) and RNGKε for turbulent airflow are employed. Code verification for the classic Trombe wall and melting process demonstrated good agreement. Results revealed the temperature variations within the room and different layers, along with the distribution of liquid fraction. The liquid fraction increases and then decreases during each day, with the finless case displaying a higher value. The introduction of fins enhances the liquid fraction, and this difference amplifies over time. Incorporating a paraffin layer with a constant volume, increases temperature fluctuation by 8.06 %. However, the implementation of Y-shaped fins reduces temperature fluctuation by 28.97 % compared to the traditional unit, indicating a 29 % enhancement in thermal comfort with the proposed design.