Energy, exergy, environment and techno-economic analysis of parabolic trough collector: A comprehensive review

Inexhaustible energy sources are the focus of the energy industry for meeting the increased need for energy and reducing carbon emissions. Among various alternatives, harnessing solar energy has become a promising choice around the world. Parabolic trough collectors (PTCs) are an effective way to transform radiant energy into thermal energy, as well as electricity. However, these collectors can be improved by refining their design and tweaking the parameters related to thermal behavior. This may be done either by enhancing the surface area or improving the heat transfer coefficient of the heat carrying medium. These kinds of improvements could be achieved by making the use of nanofluids and by using inserts or fins within the collector tube. The current study provides an extensive review of PTCs from the points of view of their design, along with their thermal characteristics. Different types of nanofluids as the working liquid are investigated and discussed to achieve better PTC performance. Inserts within the collector tube and various design approaches, including fins, twisted tubes, U-shaped tubes, coiled wire inserts, and porous twisted tape inserts, are reviewed and discussed in detail. Finally, based on this review, challenges of PTC applications are described and future research recommendations are proposed.