Corrosion aspects of molten nitrate salt-based nanofluids for thermal energy storage applications. (1st September 2019)

• Record Type: Journal Article
• Authors: Nithiyanantham, Udayashankar; Grosu, Yaroslav; González-Fernández, Luis; Zaki, Abdelali; Igartua, Josu Mirena; Faik, Abdessamad
• Is Part Of: Solar energy. Volume 189(2019)
• Page Start: 219
• Page End: 227
• Publication Date: 2019-09-01
• Subjects: Corrosion -- Molten salts -- Nanofluids -- Thermal energy storage; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2019.07.050
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: Nanoparticles doping has complex effect on the corrosion of molten nitrate salt. Incorporation of nanoparticles (NP) reduces the corrosion rates. Air trapped inside the interparticle porosity increases the corrosion rates. The overall corrosion effect of NP (positive or negative) depends on temperature. Abstract: Efficient energy storage is a bottleneck for nearly every renewable energy technology. Thermal energy storage (TES) is widely considered as a relatively simple and reliable method, particularly for concentrated solar power (CSP) plants. Currently, considerable scientific effort is focused on the development of new molten salt-based nanofluids as storage materials with enhanced thermophysical properties and lower cost for TES purpose. However, an understanding of the effect of nanoparticles on the corrosivity of such nanofluids is practically absent. In the present work, using nanofluids based on eutectic mixture of NaNO3 -KNO3 we demonstrate that nanoparticles doping has complex effects on the corrosion rates of carbon steel. In particular, if the negative effect of microbubbles of air trapped between the nanoparticles is not predominant, one can obtain reduced corrosion rates due to the incorporation of the nanoparticles into the oxidation layer. The obtained results are important both for expanding the very limited knowledge on the corrosion aspects of molten salts-based nanofluids, as well as for comprehensive evaluation of the feasibility of such nanofluids for TES applications.