Concentrated solar powered agricultural products dryer: Energy, exergoeconomic and exergo-environmental analyses

초록

Only energy-efficient and sustainable drying processes can ensure a long-term and safe storage of agricultural products. Therefore, in this study, a multi-conical solar concentrating system is proposed for drying of various agricultural products. This paper focuses on multiple aspects of performance including energy, exergo-economic and exergo-environmental performance analyses. Copper oxide/water nanofluid was used as a heat transfer medium and the drying characteristics of green pumpkin and carrot slices were studied as samples application. It was found that the proposed multi-conical solar dryer showed a significant improvement in the thermal per-formance, and the drying time which takes to reach the set drying temperature was reduced by 40% related to the conventional solar dryers. In addition, the inside temperature of the dryer was well maintained at the set temperature for 10 h. Using multi-conical solar dryer, the average values of exergy efficiency and exergy loss were found to be 38.08% and 0.61 kW, respectively. In context of economic and environmental analyses, the energy payback time and CO2 mitigation for the expected lifetime of CuO nanofluid based solar dryer were 4.38 years and 13.41 tons, respectively, and with water as a heating medium these values were found to be 7.65 years and 10.39 tons, respectively. The performed assessments revealed that the nanofluid powered multi-conical solar drying system is highly efficient for drying of agricultural products at an industrial scale.

키워드