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

• Autor(a) principal: Sutter, Florian
• Data de Publicação: 2021
• Outros Autores: Oskay, Ceyhun, Galetz, Mathias Christian, Cunha Diamantino, Teresa, Pedrosa, Fátima, Figueira, Isabel, Glumm, Stefan, Bonk, Alexander, Aguero, Alina, Rodríguez, Sergio, Reche-Navarro, Tomas Jesus, Caron, Simon
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.9/3670
• topic: Materials; Corrosion; Molten salt; Coatings; Thermal energy storage; Concentrated solar power; Durability test

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.