High-Flux Solar Absorber Concept for Central Receiver Power Plants

For cylindrical receivers with a capacity of about 400 MW/t, an aim-at-the-belt focusing strategy can produce average fluxes the order of 0.5 MW/m² with peaks as high as 2 MW/m². An absorber concept is described which uses liquid sodium coolant and a three-header configuration to efficiently capture this solar power. The mechanical design of this absorber is discussed and thermal performance estimates are presented showing the solar-capture efficiency over a range of solar intensities. The sodium-flow characteristics and some potential flow-control problems are also described. A thermal-stress analysis is presented which shows that a limiting factor on the flux capability may be tube-wall creep/fatigue failure and not the heat-transfer capability of sodium.