Thermal performance enhancement of solar collectors through optimization of outlet temperature

Abstract

Solar thermal collectors play a pivotal role in harnessing solar energy for heating applications, yet achieving consistent outlet temperatures remains a critical challenge for efficiency and practicality. This study addresses the optimization of solar collectors to maintain a constant outlet temperature of 50 degrees C, a key requirement for residential and industrial applications. A simplified model based on energy equations was developed, coupled with computational fluid dynamics analysis, to derive design-ready formulas for collector size and fluid mass flow rate. The research integrates numerical modeling and predictive frameworks, bridging gaps between theoretical and experimental approaches prevalent in prior studies. Key findings reveal an optimal collector length range of 0.537-0.539 m, with mass flow rates scaling proportionally to solar intensity (peaking at 1.049 kg/h at 1000 W/m2). The Nusselt number reached 124.46 under high radiation, confirming enhanced convective heat transfer, outperforming conventional designs by 12%. The novelty of this work lies in its dual theoretical-practical approach, offering actionable insights for industrial design while advancing scalable solar thermal solutions. These results not only provide a robust tool for solar collector optimization but also contribute to global sustainable energy goals by improving the efficiency and applicability of solar thermal systems.