Numerical investigation of the process of melting and solidification within a parabolic trough solar collector using nanoparticles and fins

Abstract

This study investigates the integration of heat storage and solar concentrating systems utilizing phase-change material (PCM) in a triplex tube parabolic trough solar collector (TTPTSC). The simulated system contains a middle region filled with PCM (RT82), with Syltherm 800 flowing via the inner and outer tubes. The finite volume technique was used to simulate this laminar flow with variable heat flux on the outer wall. This numerical study aims to assess the impacts of adding Alumina and Single-Walled Carbon Nano Tube (SWCNT) nanoparticles at volume fractions of 0 and 0.025, as well as the effects of fin installation, geometry, rim angles (φR), and other relevant parameters on these processes. The addition of nanomaterials in different cases led to significant reductions in melting times, ranging from 7.39% to 8.1%, compared to cases without nanoparticles. In addition, the fins in various cases improved the melting performance compared to the simple case. The melting time reductions ranged from 26.2% to 30.14%, demonstrating how fins can improve heat transfer and accelerate the melting process. The case with seven longitudinal outer fins and a rim angle of 60 had the shortest melting time among the studied configurations.