Experimental performance investigation of a novel movable greenhouse solar dryer for drying potato slices in the arid climate of India

Abstract

In the present study, the drying of 5 kg potato slices in a small-size movable greenhouse solar dryer is performed experimentally to determine its performance. The study was carried out at Ajmer, India, in May 2022, and the results demonstrated that the dryer could heat the air to a maximum temperature of 59.5°C with a daily average air temperature of 56.2°C under the no-load test for an average ambient temperature and a solar intensity of 39.8°C and 676 W/m2. Under load, the moisture content of potato slices was reduced to 6.3%, 21.1% and 55.9% from an initial moisture content of 85% (w.b.) in the greenhouse solar dryer, open sun and under shade, respectively, in 5 h. However, for complete drying up to 6.3% moisture content, open sun drying and shade drying took 6 and 9.5 h, respectively. Maximum exergy inflow and outflow of 13.2 W and 9.2 W and maximum exergy efficiency of 69.6% were attained during the drying. The payback period for the developed greenhouse solar dryer was 0.35 years for an expected life of 10 years. Also, the efficiency of the developed greenhouse dryer under load was 26.9%.