Environmental and economic analysis of novel hybrid active greenhouse solar dryer with evacuated tube solar collector

Abstract

The novel hybrid active greenhouse solar dryer is developed in which a heat exchanger is kept inside the dryer that also acts as a drying bed. The hot water from the evacuated tube solar collectors is supplied to the copper tubes of the heat exchanger that transfers its heat to the room air as well as to the crop surface in contact with it. The experiment is performed on the developed dryer for three crops to test its economic viability and environment suitability. The three high moisture crops selected for the analysis are tomato, bottle gourd and ginger. The maximum temperature inside the dryer is 46.9 °C when the ambient temperature is 31 °C. The developed dryer reduces the drying time of tomato, bottle gourd and ginger by 47.36%, 61.90% and 34.09% respectively as compared to the conventional dryer. The developed dryer with evacuated tube collector mitigates 88.12, 50.49 and 135.04 tonnes of CO2 in its life time while the conventional dryer without collector mitigates 49.58, 26.57 and 41.22 tonnes of CO2 in its lifetime for tomato, ginger and bottle gourd respectively. Energy payback time of tomato, ginger and bottle gourd is 0.69, 1.79 and 2.87 years less than the conventional dryer.