Modeling of thermoelectric module integrated with sinusoidal U-pipes solar system using hybrid nanomaterial and novel fin designs

In the current study, an evacuated solar collector with sinusoidal U-pipes filled with paraffin was investigated for energy saving. To generate electricity in addition to storing thermal energy, thermoelectric generator (TEG) was integrated into the unit. The paraffin was enhanced with hybrid nanoparticles composed of silver (Ag) and titanium dioxide (TiO₂) to improve thermal conductivity. Additionally, innovative fin shapes were employed to accelerate the melting process, and various fin arrangements were tested. A numerical technique was utilized to model the process, and the outputs showed good agreement with previous study, confirming the accuracy of the simulations. The study aimed to identify the optimal geometry for the solar energy system. The best-performing configuration included two sinusoidal U-pipes and four inclined fins, in contrast to the base case, which featured circular U-pipes without fins. For the optimal geometry, the liquid fraction (LF) and paraffin temperature (T_PCM) increased by 47.38 % and 1.16 %, respectively, over time. At 45 min, with all enhancements applied, LF and T_PCM improvements reached 52.21 % and 2.63 %, respectively. The integration of the TEG module allowed the system to produce electricity while storing thermal energy, although the efficiency of the TEG decreased by about 3.5 % due to the modifications. The modified solar system achieved an electrical output of 7.15 kW. By integrating sinusoidal U-pipes, hybrid nanoparticles, and novel fin designs, the study significantly improves thermal energy storage and electricity generation.