Numerical investigations of a solar energy heat transfer performances with experimental validations in a water-based serpentine photovoltaic-thermal (PVT) collector

The Korea government announced an expansion of electricity generation ratio to 20% by 2030 from renewable energy. PVT (photovoltaic thermal) has a great potential to be used as a renewable and clean solar energy. In current article, in order to investigate and analysis solar heat transfer performance, numerical simulation of 3-D computational fluid dynamics (CFD) modeling was carried out using commercial code with ANSYS FLUENT 2019R3. The numerical simulation results were carefully validated with operating data. The thermal efficiencies of The numerical simulation results were in good agreement with operating data as error scale from 1.4 to 5.76%. After this careful verification, the CFD modeling was also carried out to investigations of solar thermal energy performances by pitch sizes (40, 60, 80, 100, and 120 mm) and water inlet positions. Specifically, significant parameters of a useful thermal energy ( Q u ), water outlet temperature, pressure drop, and Q u / ΔP (useful thermal energy ( ḿ ‧ C p‧ ΔT )/pressure drop ( ΔP )) were numerically derived with the pith sizes and the water inlet positions. Given the selected significant parameters and by considering Q u / ΔP , the optimal pitch size was found to be 80 mm, while it was shown that the optimal position for the water inlet was on the left side of the unit.