Integration of the beam-down technology into SOLATOM's linear Fresnel solar field: Design and experimental results

Abstract

The beam-down linear Fresnel solar field (BDLFR) is a concentrating solar technology that can irradiate linearly a heat flux on a ground receiver. This technology is developed for thermally processing high-density materials up to temperatures of 150–300 °C, such as asphalt aggregates. Here, the linear beam-down technology has been scaled-up and tested. SOLATOM's commercial linear Fresnel reflector has been re-adapted to a BDLFR. This demonstrator loop is located in Universitat Politècnica de València (39.47° N, 0.37° W) and consists of ten linear mirrors 50 cm wide, curved along the transversal axis, and oriented clockwise 18° from the East-West axis. Different beam-down configurations were studied for the design conditions, and once the design was established, it was built using ten flat 15 cm wide mirrors and coupled to a SOLATOM XL module. The modified solar field was tested on day 269 and the obtained heat flux was measured, achieving a peak of 4100 W/m2 for a direct irradiance of 640 W/m2, in two adjacent normal distributions due to misalignments and errors in the installation of beam-down. This was contrasted with Monte Carlo ray-tracing simulations, and with proper mirror alignment it is expected to achieve 7750 W/m2 under similar conditions.