Analysis of Ceramic Material Behaviour Under Highly Concentrated Solar Radiation

Abstract

This paper analyzes the results of receiver component tests for a 20 MWe Gascooled Solar Tower (GAST). Three groups of specimens were tested: Insulation materials for inner cavity wall, ceramic boards for aperture and protective materials to be used like a passive quick closing device to shield aperture and door in emergency cases.

Items of investigation were: Time of survival under different solar flux levels, thermal shock resistance, solar reflectivity, solar transmission and temperature gradient. Types of materials tested included refractory board of alumina fiber, alumina-silicon carbide and zirconia, boron-nitrite and other insulation materials. Optical properties of materials under highly concentrated solar radiation were measured at MAN (West Germany) using a xenon arc-lamp solar simulator.

Solar tests were carried out on Lajet concentrator at ASINEL Test Facility for the last three years. Microstructural transformations (devitrifications, melting, etc.) of tested samples have been followed by XRD, SEM and EDX techniques and related to their behaviour and optical, thermal and mechanical properties.