Department of Energy Awards Rollett $2.4 Million To 3D-Print Heat Exchangers

A team of researchers has received a $2.4 million grant from the U.S. Department of Energy's Advanced Research Projects Agency — Energy (ARPA-E) to create high temperature heat exchangers using new methods and techniques for 3D printing.

The project, led by Anthony Rollett, a Carnegie Mellon University professor of materials science and engineering, is one of 18 projects being supported by the Department of Energy for high-temperature materials and is part of the High Intensity Thermal Exchange through Materials and Manufacturing Processes program.

Professor Anthony Rollett, at left, and his team are seen in the 3D printing lab space. 

Rollett's lab at Carnegie Mellon is partnering with Vinod Narayanan's group at the University of California, Davis, on heat exchanger design and analysis. The team also includes the National Energy Technology Laboratory in Albany, Oregon; HEXCES; General Electric; Extrude Hone; and the Colorado School of Mines.

Heat exchangers are devices that transfer heat from one fluid to another without the fluids coming into contact. They are commonly used in engines of cars, ships and planes, and as heating and cooling systems, including air conditioners and refrigerators. The overall ARPA-E initiative is supporting the creation of critical heat exchangers for thermal energy use in applications such as electricity, nuclear reactors and transportation. The grant will bolster Rollett's research for three years and support Ph.D. students and help advance materials research and additive manufacturing. Through 3D printing, the exchangers will be able to have wider variations in their shapes, he said.

"The particular challenge is that we have to be able to print these heat exchangers because the only way to make them efficient enough, and in fact, modular enough, is through 3D printing," Rollett said.

Rollett is developing high temperature heat exchangers that pass strength requirements at 850 degrees Celsius. The exchangers must operate at these high temperatures and pressures because the working fluid will be supercritical carbon dioxide. In addition to maintaining strength, the exchangers must resist corrosion by the gas. Currently, the only choice of material is a nickel superalloy, the same material found inside gas turbine engines.

"This is a wonderful opportunity to demonstrate how 3D-printing helps in an advanced application." — Anthony Rollett

As part of the project, Rollett also will explore different alloys and materials that haven't been used before.

"We're trying to introduce alloys that can be 3D-printed that have significantly higher temperature capability compared to the standard ones that everybody knows about," he said. "This is a wonderful opportunity to demonstrate how 3D-printing helps in an advanced application."

The challenge is that there are many alloys, and each varies in composition, properties and how they are processed. Due to the large amounts of information about these materials, the project will use machine learning to whittle down the list of potential options.

"Instead of picking some alloy and saying, 'this looks as if it might do the job,' and then perhaps discovering that we can't print it, I'd rather try to put it into some systematic format and a database of some kind," Rollett said. "So if something doesn't work out, I can step back to the next candidate."

The grant signals a step in sustaining the development of 3D metals printing at Carnegie Mellon, especially in high-temperature materials. Overall, it also will contribute to acquiring new skills and help support the Department of Materials Science and Engineering's 3D metals printing facility.