Document type
Conference papers
Document subtype
Abstract
Title
Nanosalts (Molten Salts Nanofluids) – Challenges to Experimental Measurements of Thermophysical Properties
Participants in the publication
Carlos Nieto de Castro (Author)
Dep. Química e Bioquímica
CQE
Maria José Lourenço (Author)
Fernando José Santos (Author)
Manuel Matos Lopes (Author)
Valentim Nunes (Author)
Summary
Nanofluids, stable dispersions of nanomaterials in base fluids have proved to be excellent alternatives to current heat transfer fluids, in many applications in chemistry and chemical engineering. IoNanofluids, when the base fluid is an ionic liquid (low temperature molten salt), also followed the same impact, with the special advantage of flexibility, negligible vapour pressure target oriented fluids. However its application to heat transfer fluids for high temperature applications, like CSPs, concentrated solar power plants, where a high temperature material, is necessary for heat transfer and storage is highly limited by thermal degradation and/or decomposition.\nMolten salt storage systems offer the possibility to supply electrical production at constant conditions and became an interesting option as storage material because it has high energy density per specific volume and very high thermal inertia due to its high heat capacity and low thermal conductivity (E. Gonzalez-Roubaud, et al., 2017). CSP plants are a priority in EU because they have reduced the cost of electricity production, and substantial improvement in efficiency and reduction of costs in all CSP components is necessary to achieve the proposed LCOE target of 10 c€/kWh for 2030. Nanosalts (Molten Salts Nanofluids) are a flagship issue in the CSPs, as they can improve the thermal properties of molten salts as nanoparticles enhance the heat transfer and storage capabilities of High Temperature Nanofluids. Increments of up to 50% in the specific heat and 40% in the thermal conductivity have been reported.\nHowever producing nanosalts is not trivial, and most of the methods so far developed produce the dispersions at room temperature, evaporate the solvent to complete dryness (solid phase) and then fill the measuring cell in solid state, melt the sample and measure properties. Monitoring the molten nanosalt during the measurements to assure the stability off the nanofluid is therefore a very challenging task. \nIt is the purpose of this paper to discuss this problem and several experimental difficulties encountered in the accurate measurement of thermophysical properties of nanosalts.
Editor(s)
Catherine Bessada, Pierre Camelot, Michel Cassir
Date of Publication
2019-05-19
Institution
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Event
11th International Symposium on Molten Salts Chemistry and Technology, 19-23 May, 2019
Publication Identifiers
Address
Orleans, France
Organizers
Catherine Bessada, , Pierre Camelot, Michel Cassir
Publisher
Université d'Orleans