A new generation of solid particle and other high-performance receiver designs for concentrating solar thermal (CST) central tower systems

This chapter reviews new solar thermal receiver designs to achieve higher temperatures for higher-efficiency power cycles and high-temperature thermochemical processes. Direct particle receivers include free-falling, obstructed-flow, centrifugal, and fluidized designs that irradiate the particles directly. Advantages include the potential for high efficiencies due to direct irradiance of the heat transfer media. Challenges include reducing particle and heat losses through the open aperture. Indirect particle receivers include gravity-driven flow in enclosures and fluidized flow in tubes. Advantages include complete containment of the particles, while challenges include increasing heat transfer between the irradiated surfaces and particles. Other novel receiver designs include features and geometries that trap radiation and minimize thermal emittance by reducing localized view factors in the hottest regions and creating a volumetric heating effect. Finally, the use of air curtains and active airflow have the potential to reduce convective heat losses from cavity receivers.