Development of a Smart Dual-Energy Crop Dryer with Heat Recovery Integration: Zero-Load Thermal Dynamics Test Validation
DOI:
https://doi.org/10.63746/njtd.v22i5.3818Keywords:
Hybrid solar dryer, heat-up time, thermal efficiency, photovoltaic energy, energy analysisAbstract
Innovative drying strategies are essential to the advancement of sustainable postharvest processing. This work presents the development and zero-load thermal characterization test of a smart dual-energy crop dryer integrated with a heat recovery unit. To improve thermal stability and energy efficiency, the dryer incorporates an Arduino-based control unit, solar and electric heating, and heat recovery. According to test data, the solar collector maintained a 38 to 45% thermal gain over ambient conditions and a 40.9% temperature increase in the drying air while reaching temperatures of up to 65°C. It exhibited a remarkable thermal efficiency of 80.76%. The dryer adaptively consumed 74.1% electric and 25.9% solar energy, guaranteeing a steady heat supply during variable solar radiation. A heat-up time of 6.2 to 12 minutes was recorded, with the best performance occurring between 55 °C and 60°C and 1.5 m/s and 2.0 m/s of air velocity. The dryer’s heat-up behaviours were successfully predicted by a fitted quadratic model (R² = 0.9585). The exhaust heat recovery system reduced energy loss and improved the moisture extraction effectiveness by providing low-humidity preheated air. These results demonstrate the dryer's fast response time, energy flexibility, and appropriateness for off-grid crop drying.
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