Thermal Analysis of a Solar Light Trapping Particle Receiver using Computational Fluid Dynamics

Light-trapping particle receivers are a promising choice for 3rd-generation concentrating solar power (CSP) systems. Achieving thermal efficiencies exceeding 90% is imperative for the competitiveness of CSP systems compared to non-renewable fuels. It is equally critical to maintain peak panel temperatures below 900^oC to ensure material integrity. This study conducts a comprehensive analysis of light-trapping receiver panels at an integrated system level, aiming to understand the heat transfer physics associated with free convection and radiation from panel surfaces. ANSYS Fluent is employed as a Computational Fluid Dynamics (CFD) tool, for this purpose. The ANSYS CFD model incorporates incident solar flux on the receiver panels and the heat flux absorbed through falling particles behind these panels, enabling the prediction of the resulting temperature profiles. Subsequent to post-processing the flux integrals across the panel surfaces, the study characterizes thermal efficiency of receiver panels. Additionally, the research explores the sensitivity of thermal efficiency to key system parameters, including the particle heat transfer coefficient, particle inlet temperature, and flux intensity. To further enhance efficiency, a concept involving a protective heat shield is proposed and computationally tested to establish its viability. The study also generates 3D temperature profiles, which will assist in future thermo-mechanical analyses of these receiver panels.