Experimental performance and economic viability of evacuated tube solar collector assisted greenhouse dryer for sustainable development

A walk-in type solar greenhouse dryer supplemented with solar air heating system has been developed with an objective of sustainable development. One of its novel features is the use of an evacuated tube solar air heating system with the greenhouse dryer to achieve required drying temperature for different products in north India plains. This dryer was tested in laboratory in both batch and semi-continuous mode for turmeric (Curcuma longa). The open sun drying was used as control. The thermal efficiency of the dryer for batch and semi-continuous drying obtained are 18.5% and 22.5% respectively. Drying time in comparison to open sun drying has been found to be 55% approximately. The quality of dried turmeric obtained using this dryer is superior to open sun drying in terms of polishing loss, curcumic content, volatile oil content and colour. Its energy payback period and cost payback period were estimated as 2.95 and 1.10 years, respectively, which is very low as compared to its life of 20 years. In the entire lifetime, the CO2 mitigation was found to be 209.21 tons, which proves its suitability. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The walk-in solar greenhouse dryer, integrated with a solar air heating system, has been shown to have low energy payback period and cost payback period during turmeric drying processes. The efficiency of the dryer is high, and the quality of dried turmeric is superior to open sun drying.