Influence of duct configurations on the performance of solar-assisted heat pump dryer for drying tobacco leaves

Abstract

nadequate storage facilities and preservation techniques lead to a decrease in the quality of agricultural products. Application of modern processing techniques has reduced post-harvest losses of agricultural crops. Drying was done to lower the moisture content for preservation. Tobacco drying requires massive amounts of wood, which has negative effects on the environment such as pollution, deforestation, and desertification. In the present study, a solar- assisted heat pump dryer (SAHPD) has been designed, fabricated and tested its performances as an alternative drying technology for tobacco leaves. The hot air generated from the solar collector and condenser unit of the heat pump was used as a source of heat in the drying chamber. In this study, we investigated thermal performance of three duct configurations of the SAHPD system (open, partially closed and completely closed) to establish the best configuration for drying tobacco leaves where did not conducted before. The average drying temperature was found to be 66, 64 and 60°C; the coefficient of performance of the heat pump was 3.4, 3.2 and 3.0; the heat energy contribution from the condenser was 98.7, 98.5 and 98.3%; and electrical energy consumption was 2.3, 2.8 and 2.6 kWh, for the open, partially and completely closed systems, respectively. Based on these results, the open system demonstrated the best performance. According to the study's findings, SAHPD has been shown to be an energy-efficient method of drying tobacco leaves and environmentally friendly as opposed to the conventional use of wood fuel, which results in environmental pollution, desertification, and deforestation. Future studies should focus on inclusive investigation of the life cycle and technoeconomic