Numerical analysis of integrated photovoltaic thermal systems utilizing nanoparticles with phase change material and fin attachments

In this study, a three-dimensional photovoltaic thermal /phase change material (PVT/PCM) model is numerically assessed to evaluate the impact of using a variable number of rectangular fins on the system's efficiency. Specifically, PVT/PCM assemblies with 5, 10, 15, and 20 fins, alongside vane heights of 0.15, 0.4, 0.65, and 0.9 (expressed as the ratio h/H), were examined using a 6 % MWCNT nanofluid coolant. A novel aspect of this research is the investigation of the cooling process's response to flow conditions ranging from laminar to turbulent. The charging and solidification processes of PCM are modeled using a method that combines enthalpy and porosity considerations. Furthermore, a pressure-dependent finite volume method with a transient solver has been employed to perform the computational fluid dynamics (CFD) analysis of the relevant equations. The numerical results show that the utilization of rectangular fins in the PCM region reduces both the average photovoltaic temperature and the coolant outlet temperature while at the same time increasing the melting fraction of the PCM. Specifically, a fin with an h/H ratio of 0.9 outperforms the 0.65 h/H configuration by 8.8 %, the 0.4 h/H setup by 32.4 %, and significantly surpasses the 0.15 h/H arrangement by 70.2 %. In terms of electrical efficiency, the PVT/PCM system achieves its peak at a blade-to-channel height ratio (h/H) of 0.9 and a blade count (N) of 5, corresponding to a Reynolds number of 5000, with a peak efficiency recorded at 13.524 %.