Selection of a molten salt mixture for thermal storage in high temperature concentrated solar power systems
Young Kim, Seok Ho Yoon, Jun Seok Choi, Yundo Noh, Dong Ho Kim and Chan Ho Song
A set of mineral salts and their mixtures are investigated for their application as thermal storage media and heat transfer fluids at high temperature concentrated solar power systems. A thermal storage medium needs to have high heat capacity and thermal stability at its operating range to store the heat, and the inorganic salt is one of plausible candidates for such application. The salt may also directly transfer the heat to a heat sink in its molten state if the salt has a reasonably low melting point. In addition to the thermal properties, the cost of media is another crucial factor to be considered as it has significant influence on the economic feasibility of the whole thermal storage system. Candidate mineral salts derived from common anion and cation are evaluated based on their properties and costs. A eutectic mixture is suggested after following a screening and evaluation procedure. The selected salt mixture will be applied to a pilot thermal storage system. The results of this study will contribute to elevating the economics and thereby facilitating the commercialization of concentrated solar power systems.
Keywords: Molten salts, high temperature, thermal storage, sensible heat storage, heat transfer fluid