Experimental performance evaluation of a solar powered evaporative cooling system for preservation of agricultural produce in tropical region

Abstract

Lack of suitable power supplies and storage facilities are major contributors to post-harvest loss of fruits and vegetables in low- and middle-income nations. The problem of food security can be greatly alleviated by solar-powered cooling systems that store agricultural produce in a decentralized manner. In addition to decreasing food loss and waste, this approach promotes green economic growth by lowering greenhouse gas emissions. In view of this, a direct active solar-powered evaporative cooling system is developed and its performance was assessed. In this investigation, the temperature and humidity within the evaporative cooling system were recorded using a Floureon RC-4HC data logger. The data logger was configured to capture data every half an hour for six to seven hours. The wet and dry bulb temperatures of the surrounding area were recorded using a combination wet bulb and dry bulb hygrometer. To determine the relative humidity values, a psychometric chart was utilized in conjunction with the hygrometer data. To measure the air velocity entering the evaporative cooling system, a digital anemometer was employed. Readings were taken consecutively over four days with varying pad thicknesses (from 20mm to 80mm) under no load conditions and for eight days under load conditions. Results of the study shows that the temperature of the cooling chamber reduced to 25&oC with a drop range from 3 to 10&oC and the highest relative humidity of 88.2% was recorded inside the cooling chamber while relative humidity of 66.5% was recorded for the surroundings. The cooling efficiency of the cooling chamber was found to vary from 61.4 to 87.5% under no load conditions and 47.06 to 91.1% under load conditions. Moreover, the rate of evaporation, cooling capacity and saturation efficiency vary respectively from 0.00116