Development of a Small Scale Flat Plate Solar Collector: for Drying of Fruits and Vegetables

Pakistan is facing an intense crisis in conventional energy resources. Utilization of unlimited solar energy will help in minimizing the dependency on conventional energy resources. The purpose of the study was to develop a high performance flat plate solar collector that would be used as a solar drier for various fruits and vegetables. A small scale flat plate solar collector (1.8 x 0.9 m) connected to a drying chamber was developed at the Department of Agricultural Mechanization, Faculty of Crop Production Sciences, Khyber Pakhtunkhwa Agricultural University Peshawar, Pakistan. Efficiency of collector was evaluated at seven air flow rates, one natural (0.57 kg.min-1) and six forced air flow rates (2.84, 5.68, 8.52, 11.37, 14.2 and 17.05kg.min-1) under three ambient temperatures of 20, 22 and 24oC. Results showed that flow rate significantly (P < 0.000) affected the efficiency of flat plate solar collector. Efficiency increased from 19.1 % at the natural flow rate to 56 % at a 17.05 kg.min-1. Efficiency also significantly (P < 0.000) increased from 53 to 55.1 % with an increase in ambient temperature from 22 to 24oC.