SIMULATION OF AIR CHARACTERISTICS FOR PV HYBRID DRYING SYSTEM AND DRYING KINETICS OF STRAWBERRY FRUITS

Strawberry is an important fruit and could be dried to use throughout the year. A Photovoltaic (PV) hybrid solar dryer with water storage heat unit was conducted to can operate the drying for strawberry fruits continually at day and night using the stored heat. It is used to avoid the problems of sun drying as dust, pests, poor quality for dried products and long time for process. A COMSOL Multiphysics computer program was used the dimensions of the solar collector and the drying chamber, the measured inlet and outlet of the air characteristics to simulate the distribution of the air temperature, air velocity and pressure inside the solar collector and the drying chamber. It found that the air characteristics inside both of these parts were almost equivalent and it was in small scale difference. However, a theoretical approach based on mass transfer kinetics is used to model the change in moisture content of the food product. Moisture content of strawberry fruits was fitted to various thin-layer models. Based on the values of these statistical parameters obtained, the two-term model represented drying characteristics better than other models. The moisture diffusivity during solar drying process for strawberry fruits was ranged from 7.2×10^-9 to 9.5×10^-9 m^2/s. This paper presents an analytical approach for the solar drying of strawberry and the results are important for future validation studies using other products.