U.S. Department of Energy

High Operating Temperature Liquid Metal Heat Transfer Fluids

UCLA logo University of California Berkeley logo Yale logo Four graphics in a grid that represent the sputtering technique being used in this project.

Combinatorial screening and high throughput characterization of materials will be used to identify, develop, and demonstrate metal alloys that meet the MURI HOT Fluids targets suitable for CSP applications. The University of California, Los Angeles, the University of California, Berkeley, and Yale University

The University of California, Los Angeles (UCLA), along with partners at the University of California, Berkeley, and Yale University, under the 2012 Multidisciplinary University Research Initiative (MURI): High Operating Temperature (HOT) Fluids funding opportunity, is investigating the use of metal alloys as a heat transfer fluid (HTF) in concentrating solar power (CSP) systems operating at temperatures in excess of 800°C. By allowing higher temperature operation, CSP systems can achieve greater efficiencies and thereby reduce the overall cost of electricity production.

Approach

The research team is working to identify a metal alloy with the following properties:

  • A freezing point below 100°C
  • Stable at temperatures greater than 800°C
  • Low corrosion of stainless steel and high-nickel content alloys
  • A heat capacity greater than 2 megajoules per meter cubed Kelvin (MJ/m3K)

If these and other project targets are met, this fluid has the potential to be used in both current and next-generation CSP technologies.

The UCLA-led project team is using a novel material synthesis system to rapidly screen metal alloys with the desired thermophysical properties. The search space is being defined through thermochemical modeling efforts, then being further refined by measurements taken with the rapid screening tools. The project team is using a combination of modeling and experimental tools, including high temperature corrosion flow loops, to verify that the metal alloys identified can meet all the needs of a CSP plant.

Innovation

The superior transport properties of liquid metals, including low vapor pressure, high thermal conductivity, and relatively low viscosity, make them a natural candidate for many thermal applications. The project team is using an advanced multi-target co-sputtering system to create massive compositional libraries in thin-film forms and employ high-throughput characterization methods to rapidly screen candidate liquid metals. These combinatorial experiments are being tightly integrated with thermochemical modeling to efficiently identify the most promising compositional spaces as well as to validate and improve material databases. A critical challenge in utilizing liquid metals at elevated temperatures is undesired reactions with structural materials. Systematic computational thermodynamics modeling and experimental tests are being conducted to develop effective corrosion mitigation strategies.

Publications, Patents, and Awards

At this time, this project does not have published articles, patents, or awards.

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Learn about other DOE competitive awards for concentrating solar power research that are in progress.