Testing an external sodium receiver up to heat fluxes of 2.5 MW/m 2: Results and conclusions from the IEA-SSPS high flux experiment conducted at the central receiver system of the Plataforma Solar de Almeria (Spain)

Abstract

During the IEA-SSPS High Flux Experiment conducted at the sodium-cooled central receiver system of the Plataforma Solar de Almeria (Spain), an increase of the 1.4 MW/m 2 design heat flux to a maximum of 2.5 MW/m 2 was accomplished by focusing all available heliostats on the Advanced Sodium Receiver's central panel. Receiver efficiency was measured in various independent tests from 0.8 MW to 3.5 MW with sodium inlet and outlet temperatures being 200 400 , 270 530 , and 280 560 °C. The incoming flux distribution was measured with a radiometer bar and the receiver surface temperature distribution was recorded with an infrared camera system. These data were used to verify two different thermodynamic models. Receiver efficiency did not drop when operating the receiver under high peak and power levels but was found to even rise slightly over its design value of 90%. The experiment showed that current design upper flux, power and temperature limits have not yet been reached and that there is a promising potential for increasing annual thermal output.