Energy and exergy analysis of the drying of corn grains

A mixed cabin solar dryer was designed and tested in Brazil in the spring equinox, for the drying of corn grains. The key advantage of the current design is its ability to work even in locations with no electricity because a photovoltaic module is used to power an electrical heater and fans. The analysis of the drying process was performed based on the first and second laws of thermodynamics. For average solar radi-ation and ambient temperature of 710 W/m(2) and 30 degrees C, respectively, the average thermal efficiency obtained was 21% and the exergy efficiency ranged between 10% and 66%, with an average value of 23%. It was observed that the corn grains reached the desired moisture content of 13% in 8.5 h, while a similar sample subjected to natural sun drying failed to reach this moisture content in 24 h. The PV module was also used to preheat the drying air, allowing an average increase in the airflow temperature of 14 degrees C, reaching a maximum of 27 degrees C. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

A mixed cabin solar dryer with a photovoltaic module for power was designed and tested in Brazil, achieving a faster drying time for corn grains compared to natural sun drying. The dryer also used the PV module to preheat drying air, improving overall efficiency.