CFD Investigation of Particle Temperature in Fluidised Bed Solar Receivers

Abstract

This study investigates the influence of fluidised bed solar receiver geometries and fluidisation velocity on particle temperature distribution and bed performance, with a focus on evaluating the feasibility of using a square shape for fluidised bed solar receivers. The research compares cylindrical and square bed geometries under varying fluidisation velocities to assess their impact on temperature profiles, and overall receiver performance. The results indicate that increasing fluidisation velocity enhances particle mixing and raises mean particle temperatures across both geometries, with the cylindrical bed showing higher mean temperatures at higher velocity. However, the square bed maintains better temperature uniformity, especially at higher velocity, which is advantageous for minimising hot spots and ensuring stable operation. While increased velocities improve bed dynamics and facilitate rapid collection of intermittent solar power, they also require higher pumping power and can lead to greater heat loss. Despite these benefits, further investigation is needed on the square shape, particularly in exploring uneven fluidisation regimes to reduce higher temperatures at the corners. Overall, the findings suggest that square-shaped fluidised beds offer a promising and feasible design alternative for solar receivers, balancing temperature uniformity and operational efficiency.