Experimental characterization of a gravity-driven particle-flow solar receiver for high-temperature applications
Year: 2026
Type: article
Abstract: A gravity-driven particle-flow solar receiver operating at temperatures exceeding 1000 ∘ C is experimentally investigated. The receiver consists of a vertical silicon carbide tube enclosed by a solar cavity, in which ceramic particles of diameter O ( 100 μ m ) fall by gravity against an airflow. The hydrodynamics of the system are first investigated under ambient conditions in a transparent twin via high-speed backlighting and particle image velocimetry, to extract instantaneous velocity and concentration profiles of the particle phase. The thermal performance at high temperatures under concentrated radiation (up to 5000suns) is experimentally evaluated using a high-flux solar simulator to mimic heat transfer conditions in solar towers. Steady-state flow rates and particle outlet temperatures are measured, and thermal efficiencies, as well as the wall-to-particles heat transfer coefficients, are determined. Airflows comparable to the particle fall speed lead to significant deceleration of the particle phase, with the higher airflow rates resulting in dynamic particle clusters and core–annulus–like concentration patterns. Overall, the upward airflow increases the thermal performance, leading to thermal efficiencies between 39 and 51%, with the corresponding particle outlet temperatures being 736 ∘ C and 304 ∘ C , respectively. Heat transfer coefficients in excess of 1000 W m −2 K −1 are obtained. The present study demonstrates the benefits of the counter-current airflow extending the particle residence time in the irradiated region, and of the high temperature and thermal performance attainable with ceramic tube receivers.
Source: Solar Energy
Institution: ETH Zurich
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,900
Award: G2624337035
OpenAlex ID: W7153592991