Energy and exergy analysis of microchannel central solar receivers for pressurised fluids. (25th January 2023)

• Record Type: Journal Article
• Authors: D'Souza, D.; Montes, M.J.; Romero, M.; González-Aguilar, J.
• Is Part Of: Applied thermal engineering. Volume 219(2022)Part B
• Publication Date: 2023-01-25
• Subjects: Microchannel -- Pressurised fluids -- Solar receiver -- Solar thermal power -- Energy efficiency -- Exergy efficiency; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2022.119638
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Compact heat exchanger structures analysed for microchannel solar receiver. Versatile thermo-fluid model developed for analysis of different receivers. Optimisation of geometric configuration of each structure has been performed. Optimisation maximises exergy efficiency, factoring heat & pressure losses. Comparison of structures show perforated and rectangular outperform others. Abstract: Within the new generation of advanced central solar receivers, microchannel pressurised gas receivers are emerging as reliable and efficient alternatives to operate at high temperatures and pressures. This paper presents an optimisation and comparative analysis of different compact plate-fin type structures, constituting the receiver's absorber panels, classified according to the type of fin arrangement inside: plain rectangular, plain triangular, wavy, offset strip, perforated, and louvred fin. A versatile thermo-fluid receiver model is implemented, allowing simple variation of characteristic geometric parameters of each structure. Exergy efficiency is chosen as the optimisation function, as it considers both heat and pressure losses. The framework of the analysis is set by the receiver's boundary conditions, operating at the design point conditions of a solar thermal power plant. For each compact structure, the optimal configuration is determined, providing interesting findings that have not been reported in the state-of-the-art to date. Although all geometries show good thermal performance, the perforated and plain rectangular configurations demonstrate the best exergy efficiencies of 59.21% and 58.80%, respectively, favouring taller and narrower channels. This analysis methodology could be seamlessly extrapolated to other gases and working conditions, owing to the thermo-fluid model's versatility, to reveal the optimal configuration for each case.