Energy and exergy analysis of a trapezoidal absorber plate‐based solar air collector

Abstract

Abstract This study presents energy and exergy characteristics of solar air collectors (SACs) having two different absorber plates, namely flat (Model‐I) and trapezoidal (Model‐II) plates. Experiments were conducted at different tilt angles of 15º, 30º, and 45º and varying mass flow rates (MFR) from 0.0039 kg/s to 0.0156 kg/s in an open environment. Results indicated that with an increment in MFR, the outlet temperature decreases while the heat extraction rate improves. Quantitatively, increasing MFR threefold improves thermal efficiency by 60% and reduces exergy efficiency by 39%. Furthermore, its efficiency increased by 38%–66% when the inclination angle is increased from 15º to 45º. The energy and exergy efficiencies of Model‐II were increased by 8.5% and 8.4%, respectively, more than that of Model‐I. Results indicated that the trapezoidal plate‐based collector offers better heat extraction characteristics and performs better in terms of energy, exergy, effective efficiency, and temperature rise than its flat counterpart.

Keywords

• effective efficiency
• exergy efficiency
• pressure drop
• solar collector
• trapezoidal absorber