Design of high-temperature atmospheric and pressurised gas-phase solar receivers: A comprehensive review on numerical modelling and performance parameters

摘要

Gas-phase solar receivers can operate over a wider temperature range than receivers which use conventional liquid heat transfer media. However, due to their relatively poor heat transfer performance, gas-phase receivers require substantially more heat transfer area and/or higher flow rates to extract the same amount of heat which leads to more complicated designs (e.g. a porous-media absorber with small feature/pore size) and decreased reliability (e.g. internal temperature gradients and higher thermal stresses). Detailed numerical modelling techniques can help elucidate the fundamental heat and mass transfer mechanisms/interactions in such to help mitigate these risks and to create innovative, high-performance, designs. To collate the research efforts towards gas-phase receiver modelling, this paper systematically reviews-and critically compares-the latest numerical studies of various high-temperature gas-phase receiver designs. It was found that, from a numerical point of view, gas-phase receivers can be categorised by whether they contain a porous medium or not. This categorisation is crucial, because it dictates the numerical techniques needed to capture the underlying phenomena. It was also found that no standardised performance metrics are reported for gas-phase receivers. This study suggests that a holistic figure of merit, such as the one developed by Lenert et al. (2012), be adopted in this field to merge all performance criteria for comparative evaluation. Overall, the present review is expected to serve as a guide for the development/enhancement of receiver designs based on linking best practices in simulation/ modelling with the key features and limitations of gas-phase receivers.