Exergoeconomic and enviroeconomic evaluation of double pass solar air heater with black coated porous wire mesh and galvanized iron packed bed.

Abstract

This study focused on developing a renewable energy-based thermal storage system using black porous wire mesh and galvanized iron (GI) packed bed, combined with multilayer porous insulation to reduce heat loss. The construction functioned as a Double Pass Solar Air Heater (DPSAH) utilizing solar energy to heat air. The system was optimized based on thermal, environmental and economic aspects, including energy, exergy, entropy, economic and environmental (5E) analyses. With three different air mass flow rates (0.021 kg/s, 0.028 kg/s, and 0.0323 kg/s), thermal assessment showed that a higher mass flow rate improved energy and exergy efficiency, whereas it reduced the temperature rise and entropy generation. The current design of the DPSAH system could mitigate CO₂ by more than 2 kg per hour with the environmental cost around 3¢/hr at higher mass flow rates. Technoeconomic analysis indicated an energy payback period of less than 2 years and an exergy payback period of over 30 years, where the two payback periods varied inversely with changes in mass flow rate. The results from experimental and theoretical comprehensive assessment processes indicated that the design showed improved performance compared to the conventional SAH systems using simple wire mesh.