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

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 degrees, 30 degrees, and 45 degrees, 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 degrees. 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.

Automated summary

Experimental investigation on two solar air collectors (SACs) with modified absorber plates shows that the cross-corrugated trapezoidal SAC produces up to 7.72% more energy than the reverse trapezoidal SAC. Energy efficiency increases with tilt angle and a threefold increase in air mass flow rate leads to 100-105% increase in energy and exergy efficiencies. Overall, the environmental impact factor of the type-II SAC is significantly lower than that of the type-I SAC.