Performance parameters evaluation and comparison of passive and active indirect type solar dryers supported by phase change material during drying ivy gourd

Experimental investigations were carried out by drying ivy gourd slices to evaluate the performance of passive and active indirect type solar dryers (PITSD and AITSD) supported with a thermal energy storage unit. The PITSD was restructured with central processing unit fans powered by photovoltaic solar panels to form the AITSD. Performance parameters and drying kinetics were evaluated from the data recorded during experiments. The average values of heat supplied, activation energy and specific energy consumption of PITSD and AITSD were 735.9 and 761.2 W, 38.95 and 36.35 kJ/mol, and 00.228 and 0.265 kWh/kg, respectively. Average collector and drying efficiencies were 66.7 and 69.87%, and 13.15 and 15.2% for PITSD and AITSD, respectively. The mean values of effective diffusivity, specific moisture extraction rate, heat and mass transfer coefficients of PITSD and AITSD were 8.06 x 10-9 and 10.00 x 10-9 m2/s, 78 and 4.380 kg/kWh, 0.0041 and 0.0055 m/s, and 4.7 and 6.28 W/m2 K, respectively. Moisture diffusivity, heat and mass transfer coefficients were negatively related in a logarithmic trend with moisture content. The AITSD performed well as compared to the PITSD. Uncertainty analysis was made to ascertain the reliability of the outcomes.

Automated summary

This study evaluated the performance of passive and active indirect type solar dryers for drying ivy gourd slices. The results showed that the active type had better drying efficiency and heat transfer performance compared to the passive type.