Performance enhancement analysis of The flat plate collectors: A comprehensive review

Enhancing thermal performance of flat plate collectors (FPCs) is an essential issue. This review includes the investigations conducted on the thermal performance enhancement of FPCs. The performance models and numerical and experimental works are collected in order to identify the methods for improving the thermal efficiency of FPCs. The effect of design parameters such as the thickness and coating of the glass cover, the thickness and material of the absorber plate, the air gap between the absorber plate and the glass cover, and the distance between risers and the insulation materials on the thermal performance of FPCs are discussed. Furthermore, the effects of nanofluids as working fluids and passive methods for heat transfer enhancement are investigated. The researches show that the use of turbulators in FPCs and nanofluids as working fluids are the most effective ways to improve heat transfer. Such a review provides a valuable tool to evaluate and compare various heat transfer enhancement methods, which lead to choosing the best option among them. Furthermore, the dynamic models are used to investigate the dynamic behavior of solar collectors when the variation of the external conditions during tests such as the intensity of solar irradiation is irrefutable.