A Comprehensive Review of Evacuated Tube Solar Collectors: Advances in Design, Simulation, and Applications

Abstract

Evacuated tube solar collectors (ETSCs) are one of the most efficient solar thermal technologies, and they are high performance systems of solar thermal energy over a variety of environmental conditions. It is a comprehensive overview of the recent advancements in the design of ETSC, simulation, and its application in practice. The contributions are: (1) the introduction of phase change materials (PCMs) to increase heat storage during lowirradiance conditions, (2) the use of new selective nano-coatings to reduce radiative losses and maximize absorption efficiency, and (3) hybrid designs by using ETSCs with parabolic trough collectors to achieve higher thermal outputs. Moreover, the latest simulation tools, including CFD analysis and energy-exergy analysis, are mentioned and explained in terms of the optimization of collector designs. Other uses of ETSC that are reviewed in this review include domestic water heating, industrial process heat, solar air heating, and desalination, as well as the sustainability issues and the cost-benefit issues. The article is an integrated source of information for the researchers and engineers who seek to come up with the next generation ETSC systems that have a high level of efficiency, durability, and low costs.