Performance investigation of an innovative solar heating unit for a powered self-sustained solar dryer

Abstract

Drying food is an efficient way to prevent crop decay. However, drying techniques are known to be intensive processes in which the energy required is usually met by fossil fuels, the main sources of greenhouse gas emissions. Thus, the development of a solar-powered sustainable drying system is not only crucial for zero CO2 emissions, but also for improved energy efficiency. This study performs a comparative analysis of four solar collectors used as heating units in an indirect forced convection solar dryer. The collectors evaluated were a flat solar collector, two solar air collectors with latent thermal storage (CaCl26H2O and paraffin), and a novel heating unit combining the latter two collectors. This study conducted a comprehensive 4E analysis, evaluating the performance of the collectors through energetic, exergetic, economic, and environmental assessments. The results showed that the pioneering heating unit caused a 30 °C increase in nocturnal temperature compared to other collectors. It demonstrated an annual energy consumption of 640 kWh/year and an energy payback period of 2.5 years. The environmental analysis revealed a significant CO2 reduction of 39 tons. Overall, the proposed heating unit allows a more sustainable and cost-effective drying process while reducing greenhouse gas emissions and promoting energy conservation.