Dynamic corrosion testing of metals in solar salt for concentrated solar power

ABSTRACT: Potassium nitrate and sodium nitrate in mixing proportion of KNO3-NaNO3 40-60 wt% (also called solar salt) has been successfully used for over a decade as heat storage medium for concentrated solar power parabolic-trough collector plants at temperatures up to 400 degrees C. At temperatures of 560 degrees C, reached in state-of-the-art solar tower systems, corrosion of metallic components in contact with solar salt can become an issue and has caused leaks and plant shut-downs in recently built tower projects. While the corrosion rates of several materials have been determined for different temperatures in static molten salt immersion experiments, there is a lack of corrosion data for dynamic in-service conditions. In this work, a dynamic corrosion test has been conducted on 19 different material types including protective coatings, mimicking flow-rate, temperature gradient and draining of inservice operation of a receiver in a concentrated solar power tower. The measured corrosion rates are presented and compared to static corrosion tests reported in literature.

Keywords

Materials Corrosion Molten salt Coatings Thermal energy storage Concentrated solar power Durability test

URI

http://hdl.handle.net/10400.9/3670

Citation

Sutter, Florian... [et.al.] - Dynamic corrosion testing of metals in solar salt for concentrated solar power. In: Solar Energy Materials and Solar Cells, 2021, Vol. 232, article nº 111331