Experimental Characterization of a Latent Heat Storage Unit with Lithium Nitrate Inside Finned Cylinders for Assisting Solar Air Heating
Abstract
Thermal energy storage technologies represent a promising solution for reducing the mismatch between heat demand and solar heat supply. Medium temperature heat storage has huge potential for application in solar facilities for process heat. In this study, a small-scale latent heat storage unit is experimentally investigated. Lithium nitrate salt is selected as the storage material for its excellent properties. It is encapsulated inside vertical externally finned cylinders. Air is the heat transfer fluid. The thermal storage unit is integrated into an existing innovative prototype for direct solar heating of air. It can provide air up to 300 – 400 °C using a 79.2 m2 linear Fresnel collector field from the market. Results allow thermal characterization of the storage unit and underpin critical aspects for scaling up.