Numerical study of a photovoltaic thermal (PV/T) system using mono and hybrid nanofluid

摘要

Photovoltaic thermal systems (PV/T) are system that simultaneously turn solar energy into electricity and thermal energy. Through the working fluids (water, ethylene glycol) used in the solar collector, PV/T systems aiming to reduce solar cell temperature come to the fore with increase in electrical efficiency. In recent years, the use of mono nanofluid with superior to heat transfer properties comparison conventional fluids as working fluid in photovoltaic thermal systems has become widespread. The main purpose of this study is to investigate the improvements in the use of hybrid and mono nanofluid on the performance of sheet and tubes based PV/T systems compared to water. In numerical analysis, different velocity inlet (0.02-0.08 m/s) of base fluid, CuO + Fe/water and CuO/water (50:50) are investigated via ANSYS Fluent 18.2 software. The three dimensional geometry used includes serpentine channel, absorber plate and solar cells to examine heat transfer mechanisms via conduction and convection. The results indicate that increase in inlet fluid velocity positively affects the thermal efficiency, but also increases pressure drop. However, there is no significant effect in terms of electrical efficiency. The increase after 0.06 m/s velocity gradually decrease and a more stable value is reached. The maximum increase of electrical and thermal efficiency for (phi = 2%) hybrid nanofluid is 2.14% and 5.4% comparison to water. While this value for mono nanofluid is 1.32% and 3.33%. Using hybrid nanofluid, the pressure drop was 214.78 Pa. As a consequence of the study, it is determined that the using hybrid nanofluid improves the PV/T system performance.