Performance Analysis of a Novel Cross-flow Solar Air Heater with Square Perforated Absorber Plate: An Experimental Study

Abstract

The current study introduces and analyzes a novel square cross-flow perforated solar air heater (SAH). Since the convection mechanism in SAHs is weak, numerous methods have been suggested to address this problem and improve thermal efficiency. Perforations and cross-flow configuration generate high turbulency and, consequently, high convection rate resulted. Hence these methods have been applied to enhance thermal efficiency. To achieve this goal, an experimental setup was fabricated and tested at outdoor conditions for two air mass flow rates (mair) of 0.015 kg/s and 0.03 kg/s while several sensors monitored the collector’s heat dynamics and ambient conditions. The obtained results illustrate that outlet temperature reaches the peak values of 38 oC and 34 oC, which is only 6 oC and 7 oC lower than the maximum absorber temperature. This crucial issue proves a high heat exchange rate in the fabricated SAH that causes the absorber temperature to approach the outlet temperature due to high turbulency. The strong convection mechanism in the fabricated SAH improves daily thermal efficiency, in which its value reaches nearly 78.6% for the mass flow rate of 0.03 kg/s. In conclusion, the square cross-flow perforated SAH is an economy, applicable, compact collector, ensuring high thermal efficiency.

Keywords

• cross-flow perforated solar air heaters
• perforations
• thermal efficiency
• transient dynamics