The Ames Laboratory, a national laboratory with the US Department of Energy’s Office of Science and operated by Iowa State University, works to solve our world’s pressing issues with innovative energy materials, solutions, and technologies. While the laboratory spent a lot of time in 2017 focusing on its metal 3D printing powder technology and 3D printed chemically active catalytic objects, now researchers are taking a closer look at magnetocaloric cooling.
Scientists have been working to develop new technologies, such as solid-state systems with up to 30% more energy efficiency, to replace gas compression refrigeration technology that’s 100 years old. The magnetocaloric effect is a phenomenon in which a suitable material goes through a temperature change caused by exposure to a changing magnetic field.Researchers at Ames Laboratory designed and built an advanced model system, with the help of 3D printing technology, that can successfully achieve refrigeration-level cooling using very small quantities of magnetocaloric materials.
The system is called CaloriSMART, or Small Modular Advanced Research-scale Test-station, and is a research thrust of CaloriCool – The Caloric Materials Consortium.
“Despite predictions we would fail because of anticipated inefficiencies and losses, we always believed it would work, but we were pleasantly surprised by just how well it worked,” said CaloriCool project director and Ames Laboratory scientist Vitalij Pecharsky. “It’s a remarkable system and it performs exceptionally well. Magnetic refrigeration near room temperature has been broadly researched for 20 years, but this is one of the best systems that has been developed.”
“But the main reason we conceived and built CaloriSMART is to accelerate design and development of caloric materials so they can be moved into the manufacturing space at least two to three times faster compared to the 20 or so years it typically takes today.”
Caloric cooling is a different way of looking at refrigeration technology, and is the science behind CaloriCool, which is sponsored by the DOE’s Office of Energy Efficiency and Renewable Energy through its Advanced Manufacturing Office. The research collaboration is led by the Ames Laboratory and was established as part of the Energy Materials Network.
The CaloriSMART system, which took about five months to build, was specifically developed to enable rapid evaluation of materials in regenerators (regenerative heat exchangers) without having to invest a lot of manufacturing or time.
Pecharsky, also an Anston Marston Distinguished Professor in the university’s Department of Materials Science and Engineering, credits project scientist Julie Slaughter and her team for the system’s design, which includes a custom 3D printed manifold that holds gadolinium samples and circulates the actual fluid that, according to the laboratory, “harnesses the system’s cooling power.”
“We only need 2-5 cubic centimeters of sample material – in most cases about 15-25 grams. We are setting the benchmark with gadolinium and we know there are other materials that will perform even better. And our system should be scalable (for commercial cooling) in the future,” Slaughter explained.
Gadolinium is a malleable and ductile rare earth metal, found in nature only in oxidized form. The first test of the CaloriSMART system administered a sample of three cubic centimeters of gadolinium to sequential magnetic fields, which caused it to switch back and forth between cooling down and heating up. During these cycles, the system used well-timed pumps to circulate water, which allowed it to demonstrate a sustained cooling power of 10 watts and a 15°C gradient between the hot and cold ends.
Customized neodymium-iron-boron magnets are also included in the CaloriSMART system, and are able to send a concentrated 1.4 Tesla magnetic field right to its circulating, precision in-line pumping system, and to the sample itself.
Now that CaloriSmart has achieved successful magnetocaloric testing, the research team plans to upgrade the system with electrocaloric materials, which reversibly heat up and cool down when subjected to a changing electric field, as well as elastocaloric materials, which behave in a similar fashion but when cyclic tension or compression is administered. The CaloriSmart system will even be able to operate in an innovative combined-field mode, which allows for the simultaneous use of a combination of techniques.
“There are a handful of places studying elastocaloric and electrocaloric materials, but nobody has all three in one place and our system now gives us that capability,” said Pecharsky.
3D printing technology has the ability to achieve unique, custom shapes at a faster rate of time, which is why we’ve often seen 3D printed manifolds put to work before in cars, vintage fire engines, and even ventilators. Now, we can add a magnetocaloric cooling system to the list.
Discuss this and other 3D topics at 3DPrintBoard.com or share your thoughts below.[Source/Images: Ames Laboratory]