Energy, exergy, economic and environmental (4E) assessments of a tea withering trough coupled with a solar air heater having an absorber plate with Al-can protrusions
Anindita Sharma, Partha Pratim Dutta
Abstract
Green tea leaves are dried partially at low temperatures (withered) after harvest. The present study evaluated the energy, exergy, economic and environmental aspects of a solar energy based laboratory-scaled tea withering trough. The trough was coupled with a solar air heater having an absorber plate protruded with waste Al-cans. The temperature within the trough was maintained around 35 °C. The airflow rates considered were 0.03, 0.04 and 0.05 kg/s. The maximum thermal efficiencies computed for the SAH for these mass flow rates were 52.58% at solar radiation of 747 W/m2, 63.65% at 760 W/m2 and 59.25% at 753 W/m2. The exergy efficiencies of the SAH and the withering trough were obtained within (1.41–3.56)%, (1.59–4.51)%, (1.33–4.24)%, and (32.36–72.69)%, (50.59–91.16)%, (37.50–85.62)% respectively. The economic and energy payback periods of the withering trough were computed as 0.90 and 1.26 years. The carbon credit earned was estimated within (145.25–581)$ for a lifetime of 20 years.