Exergy and sustainability analysis of a solar heat collector with wavy delta winglets as turbulent promoters: A numerical analysis
Rajesh Maithani, Anil Kumar, Masood Ashraf Ali, Naveen Kumar Gupta, Sachin Sharma, Tabish Alam, Sayed M. Eldin, Javed Khan Bhutto, Dan Dobrotă, Florin CIOFU
Abstract
This numerical study aims to determine the exergy analysis for a modified solar heat collector (SHC) having wavy delta winglets as turbulent promoters. These winglets disrupt the viscous layer to improve the heat transfer rate from the heat-absorbing surface to the fluid medium in the rectangular channel. The analysis considers following parameters: the relative longitudinal pitch (P/H), number of waves (ϕ), and flow angle of attack (α0) and flow Reynolds number range of 4000–18000. The maximum exergy efficiency of 29.18% is achieved with a longitudinal pitch of 5, an angle of attack of 60°, and a relative number of waves of 5. To evaluate the system's feasibility and sustainability, the study uses a Sustainability Index (SI), which reflects the system's Waste Energy Ratio (WER) and Improvement Potential (IP). This assessment helps identify opportunities for improvement in the thermal system.