Study of the impact of using hybrid nanofluid and saline water preheating on the performance of both integrated solar still and photovoltaic panel using fractional modeling

A novel non-local model for studying the performance of solar still system integrated with a photovoltaic panel (PV) using hybrid nanofluid and preheating salty water is presented. The new model is simulated using two different fractional operators: Caputo–Fabrizio and Riemann–Liouville fractional derivatives. The performance of the solar still and photovoltaic panel by using hybrid nanofluid of aluminum oxide and copper oxide (Al2O3/CuO) and using 60%, 50%, and 40% of preheating salty water is also studied. The preheating salty water is implemented as a cooler for the solar cell panel by passing it on the front, back, and both front and back surfaces of the panel before entering the still basin. The obtained results from the two fractional models are compared with the results of a classical model and then compared to data obtained from a real experiment under a meteorological climate condition of Alexandria city, Egypt. The results reveal that the best agreement with the experimental data is obtained based on using Riemann–Liouville fractional derivative with an error of 3.59% unlike the percentage of error which reached 18.9% after using the classical derivative. The findings show that the highest value of the daily still productivity of 6.4099 kg/m2.day is achieved at 60% saline water preheating on the front surface of the PV panel. This value rises to 7.126 kg/m2.day after adding the hybrid nanoparticles (HN) achieving an increase of 10% compared with the system without HN. Moreover, the daily average power of the PV panel reaches 1106.84 W/m2 after using the HN, compared with 988.27 W/m2 without using HN. The maximum average daily energy and exergy efficiencies also occur at 60% of preheating water at the PV front surface with values of 54.61% and 15.3%, respectively, achieving an increase of nearly 10% after using the HN.