Performance analysis of stand-alone solar photovoltaic thermal dryer for drying of green chili in hot-humid weather conditions of North-East India

摘要

In the present study, an innovative stand-alone solar photovoltaic thermal (PVT) dryer has been designed and tested in hot-humid weather conditions of North-East India for drying green chili. The electrical output of the hybrid PVT solar dryer has been utilized to operate the blower for the dryer making the system self-sustained. A comparative analysis of the drying phenomena under the open sun and in the PVT based dryer is performed. Mathematical modeling is also done to investigate the drying kinetics of green chili for both drying conditions. Results indicate that the moisture content of 0.030 (d.b.) in the solar dryer and 0.035 (d.b.) in the open sun has been reduced for a span of 21 and 37 hr, respectively. Hybrid PVT solar dryer has achieved an average thermal efficiency of 31.37% and an average specific moisture extraction rate of 0.228 kg/kWh. The overall energy consumption for drying green chili is calculated to be 4.90 kWh/kg. Also, the overall thermal efficiency of 64.16%, thermal efficiency of 30.15%, and average electrical efficiency of 12.92% are secured. The results demonstrate the improved performance of the present PVT dryer for green chili drying in comparison to some of the conventional direct/indirect solar dryers.Practical Applications The present PVT solar dryer system can be utilized for drying the products using thermal energy produced by PVT air collector as well as generating electrical power in the decentralized off-grid areas. Solar drying is not adequately popular in the North-Eastern part of India due to the unavailability of solar drying systems for farmers. The agricultural products can be dried in the farming areas by installing this system. This PVT solar dryer provides a solution to the farmers for drying at zero energy cost and can be used as a source of income generation. This PVT solar drying system can be used to increase the storage life and reduce the spoilage and deterioration of agricultural commodities. Energy efficient solar drying process, high-quality products, and faster drying rate compared to traditional drying method can be achieved with the help of using this system.