Consistent coupled optical and thermal analysis of volumetric solar receivers with honeycomb absorbers. (January 2020)

• Record Type: Journal Article
• Authors: Ali, Mahmoud; Rady, Mohamed; Attia, Mohamed A.A.; Ewais, Emad M.M.
• Is Part Of: Renewable energy. Volume 145(2020)
• Page Start: 1849
• Page End: 1861
• Publication Date: 2020-01
• Subjects: Concentrated solar power -- Volumetric solar receiver -- Absorptivity -- Porous ceramics -- Monte Carlo ray tracing -- CFD; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2019.07.082
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: In concentrating solar power plants with central towers, successful design of volumetric solar receivers requires proper understanding of the interaction between optical, heat transfer, and fluid flow phenomena occurring at the microscopic scale of receiver structure material and their effect on the overall solar-to-thermal efficiency. In the present article, coupled, 3D, optical, heat transfer and fluid flow numerical models have been developed for the analysis and design of honeycomb volumetric receiver modules. The optical model considers the absorptivity and micro dimensions of honeycomb absorber structure and employs a Monte Carlo ray tracing technique to calculate and analyze the absorbed solar heat flux distribution. This, in turn, is employed as a volumetric heat source term at the solid surface for consistent heat transfer and fluid flow modeling using a realistic solution domain and proper boundary conditions. The validated models have been employed to investigate the effects of different types of absorber materials, material absorptivity, and air flow rate on the performance of the solar receiver. It has been shown that positive volumetric effect and high solar-to-thermal efficiency can be obtained by controlling the absorbed radiation heat flux distribution within the honeycomb receiver using surface coating of the absorber material. Highlights: Optical, CFD models for the analysis and design of volumetric solar receivers. Effects of absorber material and air flow rate on the performance are analyzed. A novel honeycomb receiver made of Alumina has been introduced. Coated Alumina honeycomb absorbers show a favorable receiver performance.