Numerical analysis of thermal management in a photovoltaic solar system with porous heat storage, parabolic reflector and self-cleaning coating

This work aims to enhance the performance of concentrated photovoltaic-thermal (CPVT) solar systems by integrating a phase change material (PCM) layer to improve solar energy saving and utilization. A parabolic reflector focuses solar irradiation onto the CPVT system, while the discrete ordinates (DO) method is employed to analyze the heat flux distribution on the panel. To mitigate the negative impact of dust deposition on the glass surface, the nanoparticle-based self-cleaning coating is applied. The PCM layer is further optimized using porous foam to increase thermal storage capacity, and fins are added to improve overall system efficiency. Simulations indicated that neglecting buoyancy force effects is a reasonable assumption. Incorporating porous foam and fins in the storage system significantly enhances electrical performance, resulting in a 2.94 % improvement in electrical efficiency (eta el) at higher flow rates (Q), exceeding the PCM-only configuration by 2.66 %. The highest electrical efficiency achieved is 13.35 % with the PCM-Foam-Fins configuration. Additionally, the liquid fraction (LF) decreases significantly with increasing flow rates, showing reductions of 40.74 % without fins and 35.77 % with fins. Coating the glass cover with SiO2 nanoparticles improves LF, particularly at lower flow rates.