Optimización de la eficiencia térmica en secadores solares de mediana capacidad, que utilicen materiales de cambio de fase (PCMs) y reflectores fotónicos: optimización de equipos térmicos y termodinámicos con enfoque mecatrónico.

Abstract

The research seeks to optimize thermal efficiency in solar dryers that use phase change materials (PCMs) and photonic reflectors for the sustainable dehydration of agricultural products in the inter-Andean region of Ecuador. In the first chapter the current situation of wheat and barley is exposed. Then, the typology of solar dryers and PCMs is exposed, and the incidence of photonic reflectors in the drying process is explained. In the second chapter, using the mathematical representation of the process in state space, the required power is related to the temperature in the drying chamber. In the third chapter the results of the simulations in MATLAB and sensitivity analysis are presented. 76 W is required to reach and maintain the drying chamber at a temperature of 56°C in 4 hours, and then an additional 40 W must be supplied for 2 hours for PCM melting. For the validation of the mathematical model, an experimental model is used which implements an electrical resistance that simulates the required solar energy; that during the cooling stage, the temperature of the ordinary solar dryer chamber without PCM rapidly drops from 56°C to 24°C in 15 minutes; while, the solar dryer with PCM decreases in 4 hours, therefore, implementing PCMs in the solar dryer optimizes the thermal efficiency of the dryer when solar energy is no longer available. Finally, the optimal values of the defined operational parameters are presented.