2014-Sustainable Industrial Processing Summit
SIPS 2014 Volume 6: Rare Earths & Ionic Liquids
| Editors: | Kongoli F |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2014 |
| Pages: | 432 pages |
| ISBN: | 978-1-987820-08-9 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Thermophysical properties of candidate molten salts for solar thermal storage applications
Robert Campbell1;1NETZSCH INSTRUMENTS NORTH AMERICA, LLC, Burlington, United States;
Type of Paper: Regular
Id Paper: 134
Topic: 11
Abstract:
Concentrating solar power (CSP) plants offer the key advantage of reliable and dispatchable power generation through the use of thermal energy storage (TES). CSP parabolic trough plants use organic heat transfer fluids (HTF) to generate turbine steam at 393°C. Power towers use molten salts to generate steam at 565°C. This higher steam temperature increases the power generation efficiency of the power plant. The current binary nitrate salt mixture of sodium and potassium nitrate (NaNO3/KNO3) has a maximum operating temperature of about 580°C and an average heat capacity of 1.5 J/g.K. Next-generation CSP plants will require advances in HTF and TES systems to generate higher temperatures in the range from 500° to 800°C so they can provide thermal energy to advanced power cycles such as supercritical carbon dioxide (CO2) and improve the thermodynamic efficiency of the power plant. We selected several candidate molten salt systems that operate at these higher temperatures using thermodynamic databases. The selection criteria were heat capacity, heat of fusion, melting temperature, thermal stability, and cost. These thermal properties as well as the thermal conductivity of the candidate molten salts were evaluated and reported. Measurement methods include differential scanning calorimetry, laser flash diffusivity and thermogravimetry.