Modelling of radiative and convective heat transfer in an open cavity volumetric receiver for a 50-MWth beam-down integrated receiver-storage concentrating solar thermal system

作者：Song Yang, Lifeng Li, Bo Wang, Yihan Zheng, Peter D. Lund, Jun Wang, Yulong Ding · 发表于：Renewable Energy · 年份：2025 · DOI：10.1016/j.renene.2025.122457 · 被引用次数：18 · 研究领域：Solar Thermal and Photovoltaic Systems、Phase Change Materials Research、solar cell performance optimization

This paper concerns solar-to-thermal energy conversion processes in an open cavity volumetric receiver for a 50-MW th integrated beam-down receiver-storage concentrating solar thermal system. A multiphysical model was developed in a COMSOL Multiphysics 6.1 environment. The model was validated against experimental and modelling data from the literature. The model incorporates specific solar irradiation profiles tailored to the beam-down optical system as the boundary condition, couples heat transfer with surface radiation and porous media radiation transport, and accounts for buoyancy effects on air convection within the cavity. The results reveal a significant reduction in the nonuniformity of net radiative heat flux distribution at cavity bottom, compared to the concentrated solar irradiation profile from the beam-down optics. The solar radiation is founded to absorb heat within the surface layer of the ceramic foam, with heat transfer in the porous media body dominated by volumetric convection. The buoyancy effects may cause air to escape from the cavity opening leading to non-negligible convective heat losses. The thermal performance is assessed by varying the concentration ratio, air flow rate, matrix thermal conductivity, and porosity of the ceramic foam. Under baseline conditions, the outlet air temperature could reach up to 1441 K, with solar-to-thermal and solar-to-exergy efficiencies of 39 % and 31 %, respectively. Heat losses are attributed to optical loss (33 %), c...