Experimental results from a high heat flux solar furnace with a molten metal-cooled receiver SOMMER

Abstract

Abstract Liquid metals are promising candidates for highly efficient thermal receivers in concentrating solar power plants due to their excellent thermal conductivity. In the SOMMER (SOlar furnace with a Molten MEtal-cooled Receiver) facility at the Karlsruhe Institute of Technology (KIT), the cooling of a 10-kW thermal receiver by a lead–bismuth eutectic flow has been successfully demonstrated at high heat flux conditions in a solar furnace without any receiver damage. The experimental results show that peak heat fluxes of up to 4\xa0MW/m2 can be achieved in the SOMMER facility and efficiently cooled with a liquid metal flow. In this study, the experimentally determined heat flux densities in the focal point of the solar furnace and the power input by the receiver are presented. In addition, the estimation of the thermal losses of the receiver are described and the results are discussed. The test results from three different shutter blinds positions as well as three different inlet temperatures (200\xa0°C, 250\xa0°C, 300\xa0°C) and different mass flows are presented. During the measurement campaign in the summer of 2019 the Direct Normal Irradiance (DNI) values ranged from 670\xa0W/m2 to 960\xa0W/m2. Under these conditions maximum wall temperatures of 670\xa0°C were measured. All in all, the results prove the excellent cooling ability of liquid metals under high heat flux conditions of up to 4\xa0MW/m2.