Investigation on Solar Drying Characteristics of Ginger (Zingiber officinale) in a Reflector Attached Solar Air Heater and Thermal Energy Storage System using Nano Materials

By changing its design and materials, a solar dryer can help to lower consumption and drying time. The dryer was run with a reflector attached zigzag solar air heater thermally coated with 2% MWCNT, 2% CuO, and 96% black paint with a reflector. To check the microstructure and morphology analysis of the nano powders and coated surface XRD, SEM, EDAX and Elemental mapping has also been conducted. In this paper the feasibility of the cabinet dryer with rotating trays was investigated to dry ginger slices in case of attaching a energy storage device. The moisture content of the ginger slices were successfully reduced from 90 – 12% within the time frame of 7 hr 15 min. The different drying characteristics and quality parameters were evaluated and then compared in case of zigzag with coated surface and reflector, with coated surface and with reflector respectively. The results show that using a reflector it increases the air heater's outlet temperature by 10-12%, and using a coated surface increases the temperature by another 8–10%. The average thermal and exergy efficiency of an air heater was found to be 70.2 and 4.4 %, respectively. The average overall thermal efficiency of carbon nanotubes + copper oxide-paraffin wax energy storage unit was 31.19%, with 11.9 % as the average overall exergy efficiency. The energy storage increases the drying time near about 3 hr during off sunshine hours.