Project Overview

Concentrated Solar Thermal, a renewable energy technology,  uses mirrors or collectors to concentrate sunlight and heat from the sun onto a reciever which generates steam and hence electricity in a plant. Tubular recievers are the industry standard in most CST plants however they struggle with heat transfer efficiency. Volumetric recievers present a better alternative as the highest temperature is contained in the bulk of the fluid and this increases the relative heat transfer efficiency but there isn't a lot of work and literature understanding the true behavior of these recievers. Understanding the thermofluid behavior of concentrated solar thermal (CST) receivers by investigating complex heat transfer interactions, e.g., radiation-induced natural convection and volumetric heating, involved in the absorption of solar energy by high-temperature molten salts is key to the decarbonization of industrial heat sector, representing 74% of total industrial energy demand. A 1D model and experimental setup using a high-flux solar simulator are being developed within an existing FES project to predict and validate temperature distribution inside the receiver using thermocouples. However, that project does not include any non-invasive flow visualization techniques like particle image velocimetry (PIV), which are needed to expand the study and capture lesser-known phenomena like radiation-induced gas bubble formation in salts causing flow instabilities. Recently, Lamenta et al. (2023) reported the first PIV setup for studying natural convection in molten salts, but they did not include solar radiation or volumetric heating effects, which are critical for CST and other molten salt systems like small modular reactors. This project aims to bridge that gap by conducting research on the thermofluid response of molten salts by investigating the integration of the reported PIV technique with the solar simulator facility to obtain high-resolution flow visualization data for developing accurate CST models that incorporate effects like bubble formation.