RECENT IMPROVEMENTS OF THE OPTICAL AND THERMAL PERFORMANCE OF THE PARABOLIC TROUGH SOLAR COLLECTOR SYSTEMS

Parabolic trough solar collectors (PTSCs) are commonly used for applications that reach a temperature of up to 500 °C.  Recently, improving the efficiency of PTSCs has been the focus of research because PTSCs have advantages, such as cost and size reduction and improved optical and thermal performance.  This study summarizes relevant published research on the preparation, properties and experimental behavior of the optical and thermal properties of PTSCs. Analyzing of the thermal modeling method presents a steady and transient heat transfer analysis.  Optical efficiency depends on material properties, such as mirror reflectance, glass cover transmittance, receiver absorption–emission, intercept factor, geometry factor and incidence angle. Also analyzed and discussed are the models used in computational fluid dynamics to study the physical properties of PTSCs. Lastly, studies on PTSC performance and enhancement, including novel designs, enhancement of passive heat transfer and laden flows of nanoparticles inside the absorber tube, are presented and examined separately. Nanofluids have illustrated their advantages and ability to increase heat transfer rates. Moreover, other works that aimed to enhance the optical and thermal efficiency of PTSCs are evaluated.