Slag as Inventory Material for a Thermal Energy Storage (TES): Material investigation and thermo-mechanical consideration

Kurzfassung

Concentrating solar tower power systems with thermal energy storage using air as heat transfer fluid have a particularly promising potential for a high solar-to-electric efficiency at relatively low levelized electricity costs. Slag as inventory for the thermal energy storage can lower the costs further, but has new uncertainties. The present work diminishes them while looking at material and thermos-mechanical aspects. Hydrations tests in oven are performed as well as thermo-mechanical investigations in packed beds made of slag pebbles. In the latter, a simplified approach based on discrete element method is developed which allows calculating very quickly conservative estimates of the forces and stresses in the bed and the container wall. The results of the various storage concepts show that these aspects are to be investigated further in detail.