Energy, exergy, and environmental (3E) analyses of reverse and cross-corrugated trapezoidal solar air collectors: An experimental study

Abstract Reported here is an experimental investigation of the thermal performances of two solar air collectors (SACs) with modified absorber plates, one reverse trapezoidal (type-I SAC) and the other cross-corrugated trapezoidal (type-II SAC). Tests are performed with air mass flow rates of 0.0039–0.0156 kg/s and tilt angles of 15°, 30°, and 45°, and the energy efficiency, exergy efficiency, temperature rise, sustainability index, and environmental impact factor are evaluated. The results indicate that because of its better heat transfer, the type-II SAC produces up to 7.72% more energy than does the type-I SAC. The energy efficiency increases with increasing tilt angle and is greatest at 45°. Furthermore, with a threefold increase in air mass flow rate, the energy and exergy efficiencies increase by as much as 100–105%. The maximum energy efficiency for the type-I and type-II SACs is found to be 30.3% and 39.4%, respectively. The sustainability index of the type-II SAC is 13.86% higher than that of the type-I SAC, whereas the environmental impact factor of the type-II SAC is almost 40.90% lower than that of the type-I SAC.