October 1, 2017.
Concentrating solar power (CSP) systems focus light energy from the sun to generate heat. Heat transfer fluids (HTF) act as thermal energy storage in CSP systems. The HTF flows through the system in a containment material; molten salts have served as HTFs in CSP systems. As the molten salts move through the system, the containment material is subject to corrosion_Üîlessening the lifetime of the system. To create affordable CSP, various compositions of molten salts and containment materials have been tested. Via linear sweep voltammetry (LSV), the corrosion rate of Inconel-625 was studied. A NaKMg-Cl molten salt composition_Üî24.5-20.5-55 %wt NaCl-KCl-MgCl2_Üîwas utilized during experimentation. An extensive purification process was used to remove water from the salt prior to LSV; water in a MgCl2-based CSP system leads to the formation of HCl, increasing the corrosion rate of the containment material in use. Due to time constraints, the results of the study have not been collected. LSV test results are currently being extrapolated to calculate the corrosion rate of Inconel-625 in 24.5-20.5-55.0 wt% NaCl-KCl-MgCl2.
National Renewable Energy Laboratory (NREL)
This material is based upon work supported by the National Science Foundation through the Robert Noyce Teacher Scholarship Program under Grant # 1418852. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. The research was also made possible by the California State University STEM Teacher and Researcher Program, in partnership with Chevron (www.chevron.com), the National Marine Sanctuary Foundation (www.marinesanctuary.org) and National Renewable Energy Laboratory.