Influence of operating parameters on the energy consumption of a hybrid solar dryer: Application to the drying of gombo (Abelmoscus Esculentus)

Abstract

The present study aims to investigate the influence of temperature, drying air speed and product thickness on energy consumption during drying of okra slices. The experimental methodology consists of following the evolution over time of solar irradiation, of the temperature of the different elements of the collector, of the air at the inlet and outlet of the collector, of the electrical energy via a meter digital thus leading to the determination of energy consumption by equations found in the literature review. The results obtained are presented in the form of graphs and the analysis of the results revealed that the energy contribution provided by the solar collector increases from 1 to 9.8 kWh when the solar energy increases from 200 W/m2 to 850 W/ m2 and that this in electrical energy decreases from 6 to 1.3 kWh around 2 p.m. The energy consumption increases from 10.02 to 15.03 kWh when the air speed increases from 1 m/s to 2 m/s, an increase rate of 33.33%. In addition, increasing the air speed from 1 to 2 m/s increases the contribution of electrical energy from 54.89% to 60.80%, while that of solar energy decreases by 45.11% to 39.20%. It increases from 9.1 to 15.5 kWh when the thickness of the product increases from 10 to 20 mm; i.e. an increase rate of 58.71%. This increase in thickness from 10 to 20 mm increases the percentage of electrical energy contribution from 46.70% to 52.90%, on the other hand that of solar energy decreases from 53.30% to 47.10 %. Regarding the air temperature, the energy consumption increases from 7.82 to 14.95 kWh when the temperature increases from 40°C to 60°C, an increase of 47.69%. This increase in temperature from 40 to 60 °C increases the percentage of electrical energy input from 45.65% to 54.85%, while that of solar energy decreases from 54.35% to 45.15%.