Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Magnetic nanoparticles could aid heat dissipation: Particles suspended in cooling water could prevent hotspots in nuclear plant cooling systems and electronics

Abstract:
Cooling systems generally rely on water pumped through pipes to remove unwanted heat. Now, researchers at MIT and in Australia have found a way of enhancing heat transfer in such systems by using magnetic fields, a method that could prevent hotspots that can lead to system failures. The system could also be applied to cooling everything from electronic devices to advanced fusion reactors, they say.

Magnetic nanoparticles could aid heat dissipation: Particles suspended in cooling water could prevent hotspots in nuclear plant cooling systems and electronics

Cambridge, MA | Posted on November 20th, 2013

The system, which relies on a slurry of tiny particles of magnetite, a form of iron oxide, is described in the International Journal of Heat and Mass Transfer, in a paper co-authored by MIT researchers Jacopo Buongiorno and Lin-Wen Hu, and four others.

Hu, associate director of MIT's Nuclear Reactor Laboratory, says the new results are the culmination of several years of research on nanofluids — nanoparticles dissolved in water. The new work involved experiments where the magnetite nanofluid flowed through tubes and was manipulated by magnets placed on the outside of the tubes.

The magnets, Hu says, "attract the particles closer to the heated surface" of the tube, greatly enhancing the transfer of heat from the fluid, through the walls of the tube, and into the outside air. Without the magnets in place, the fluid behaves just like water, with no change in its cooling properties. But with the magnets, the heat transfer coefficient is higher, she says — in the best case, about 300 percent better than with plain water. "We were very surprised" by the magnitude of the improvement, Hu says.

Conventional methods to increase heat transfer in cooling systems employ features such as fins and grooves on the surfaces of the pipes, increasing their surface area. That provides some improvement in heat transfer, Hu says, but not nearly as much as the magnetic particles. Also, fabrication of these features can be expensive.

The explanation for the improvement in the new system, Hu says, is that the magnetic field tends to cause the particles to clump together — possibly forming a chainlike structure on the side of the tube closest to the magnet, disrupting the flow there, and increasing the local temperature gradient.

While the idea has been suggested before, it had never been proved in action, Hu says. "This is the first work we know of that demonstrates this experimentally," she says.

Such a system would be impractical for application to an entire cooling system, she says, but could be useful in any system where hotspots appear on the surface of cooling pipes. One way to deal with that would be to put in a magnetic fluid, and magnets outside the pipe next to the hotspot, to enhance heat transfer at that spot.

"It's a neat way to enhance heat transfer," says Buongiorno, an associate professor of nuclear science and engineering at MIT. "You can imagine magnets put at strategic locations," and if those are electromagnets that can be switched on and off, "when you want to turn the cooling up, you turn up the magnets, and get a very localized cooling there."

While heat transfer can be enhanced in other ways, such as by simply pumping the cooling fluid through the system faster, such methods use more energy and increase the pressure drop in the system, which may not be desirable in some situations.

There could be numerous applications for such a system, Buongiorno says: "You can think of other systems that require not necessarily systemwide cooling, but localized cooling." For example, microchips and other electronic systems may have areas that are subject to strong heating. New devices such as "lab on a chip" microsystems could also benefit from such selective cooling, he says.

Going forward, Buongiorno says, this approach might even be useful for fusion reactors, where there can be "localized hotspots where the heat flux is much higher than the average."

But these applications remain well in the future, the researchers say. "This is a basic study at the point," Buongiorno says. "It just shows this effect happens."

The team also included Thomas McKrell, a research scientist in MIT's Department of Nuclear Science and Engineering, and Elham Doroodchi, Behdad Moghtaderi, and Reza Azizian of the University of Newcastle in Australia. The work was supported by the University of Newcastle, Granite Power Ltd., the Australian Research Council, and King Saud University in Saudi Arabia.


Written by: David L. Chandler, MIT News Office

####

For more information, please click here

Contacts:
Sarah McDonnell
MIT News Office

phone: 617-253-8923

Copyright © Massachusetts Institute of Technology

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Paper: "Effect of magnetic field on laminar convective heat transfer of magnetite nanofluids":

Jacopo Buongiorno:

Department of Nuclear Science and Engineering:

ARCHIVE: "Lin-Wen Hu: Advancing MIT’s educational mission":

ARCHIVE: "Finding the keys to boiling heat transfer":

Related News Press

News and information

Nanofiltration Membrane Market 2015 - Global Industry Survey, Analysis, Size, Share, Outlook and Forecast to 2020 July 31st, 2015

Nanozirconia Market 2015 - Global Industry Survey, Analysis, Size, Share, Outlook and Forecast to 2020 July 31st, 2015

Self-Healing Nano Anti-rust Coatings Market 2015 - Global Industry Survey, Analysis, Size, Share, Outlook and Forecast to 2020 July 31st, 2015

Nano Spray Instrument Market 2015 - Global Industry Survey, Analysis, Size, Share, Outlook and Forecast to 2020 July 31st, 2015

Chip Technology

This could replace your silicon computer chips: A new semiconductor material made from black phosphorus may be a candidate to replace silicon in future tech July 30th, 2015

March 2016; 6th Int'l Conference on Nanostructures in Iran July 29th, 2015

Meet the high-performance single-molecule diode: Major milestone in molecular electronics scored by Berkeley Lab and Columbia University team July 29th, 2015

Short wavelength plasmons observed in nanotubes: Berkeley Lab researchers create Ludinger liquid plasmons in metallic SWNTs July 28th, 2015

Discoveries

Heating and cooling with light leads to ultrafast DNA diagnostics July 31st, 2015

Theoretical Physicists at Freie Universität Berlin Develop New Insights into Interface between Classical and Quantum Worlds July 31st, 2015

Sol-gel capacitor dielectric offers record-high energy storage July 30th, 2015

Controlling Dynamic Behavior of Carbon Nanosheets in Structures Made Possible July 30th, 2015

Announcements

Nano Spray Instrument Market 2015 - Global Industry Survey, Analysis, Size, Share, Outlook and Forecast to 2020 July 31st, 2015

Nanocellulose Market 2015 - Global Industry Survey, Analysis, Size, Share, Outlook and Forecast to 2020 July 31st, 2015

Heating and cooling with light leads to ultrafast DNA diagnostics July 31st, 2015

Theoretical Physicists at Freie Universität Berlin Develop New Insights into Interface between Classical and Quantum Worlds July 31st, 2015

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Nano Spray Instrument Market 2015 - Global Industry Survey, Analysis, Size, Share, Outlook and Forecast to 2020 July 31st, 2015

Nanocellulose Market 2015 - Global Industry Survey, Analysis, Size, Share, Outlook and Forecast to 2020 July 31st, 2015

Heating and cooling with light leads to ultrafast DNA diagnostics July 31st, 2015

Theoretical Physicists at Freie Universität Berlin Develop New Insights into Interface between Classical and Quantum Worlds July 31st, 2015

Energy

Springer and Tsinghua University Press present the second Nano Research Award: Paul Alivisatos of the University of California Berkeley receives the honor for outstanding contributions in nanoscience July 30th, 2015

Controlling Dynamic Behavior of Carbon Nanosheets in Structures Made Possible July 30th, 2015

March 2016; 6th Int'l Conference on Nanostructures in Iran July 29th, 2015

Reshaping the solar spectrum to turn light to electricity: UC Riverside researchers find a way to use the infrared region of the sun's spectrum to make solar cells more efficient July 27th, 2015

Safety-Nanoparticles/Risk management

March 2016; 6th Int'l Conference on Nanostructures in Iran July 29th, 2015

Environmentally friendly lignin nanoparticle 'greens' silver nanobullet to battle bacteria July 13th, 2015

NIST ‘How-To’ Website Documents Procedures for Nano-EHS Research and Testing July 1st, 2015

Proposed TSCA Nanomaterial Rule ‘Premature’, Says Former EPA Toxicologist July 1st, 2015

Research partnerships

Newly-Developed Polymers Control Size of Nanoparticles during Production Process July 30th, 2015

Meet the high-performance single-molecule diode: Major milestone in molecular electronics scored by Berkeley Lab and Columbia University team July 29th, 2015

Spintronics: Molecules stabilizing magnetism: Organic molecules fixing the magnetic orientation of a cobalt surface/ building block for a compact and low-cost storage technology/ publication in Nature Materials July 25th, 2015

Stretching the limits on conducting wires July 25th, 2015

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project