Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

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

Organic solar cells reach record efficiency, benchmark for commercialization April 23rd, 2018

Remote-control shoots laser at nano-gold to turn on cancer-killing immune cells April 20th, 2018

New qubit now works without breaks: A universal design for superconducting qubits has been created April 19th, 2018

Observing biological nanotransporters: Chemistry April 19th, 2018

Chip Technology

New qubit now works without breaks: A universal design for superconducting qubits has been created April 19th, 2018

Salt boosts creation of 2-D materials: Rice University scientists show how salt lowers reaction temperatures to make novel materials April 18th, 2018

When superconductivity disappears in the core of a quantum tube: By replacing the electrons with ultra-cold atoms, a group of physicists has created a perfectly clean material, unveiling new states of matter at the quantum level April 16th, 2018

Nanometrics to Announce First Quarter Financial Results on May 1, 2018 April 10th, 2018

Discoveries

Organic solar cells reach record efficiency, benchmark for commercialization April 23rd, 2018

Remote-control shoots laser at nano-gold to turn on cancer-killing immune cells April 20th, 2018

New qubit now works without breaks: A universal design for superconducting qubits has been created April 19th, 2018

Observing biological nanotransporters: Chemistry April 19th, 2018

Announcements

Organic solar cells reach record efficiency, benchmark for commercialization April 23rd, 2018

Remote-control shoots laser at nano-gold to turn on cancer-killing immune cells April 20th, 2018

New qubit now works without breaks: A universal design for superconducting qubits has been created April 19th, 2018

Observing biological nanotransporters: Chemistry April 19th, 2018

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

Organic solar cells reach record efficiency, benchmark for commercialization April 23rd, 2018

Remote-control shoots laser at nano-gold to turn on cancer-killing immune cells April 20th, 2018

New qubit now works without breaks: A universal design for superconducting qubits has been created April 19th, 2018

Observing biological nanotransporters: Chemistry April 19th, 2018

Energy

Organic solar cells reach record efficiency, benchmark for commercialization April 23rd, 2018

Psst! A whispering gallery for light boosts solar cells April 14th, 2018

High efficiency solar power conversion allowed by a novel composite material: A composite thin film developed at INRS improves significantly solar cells' power conversion efficiency April 10th, 2018

Light 'relaxes' crystal to boost solar cell efficiency: Rice, Los Alamos discovery advances case for perovskite-based solar cells April 6th, 2018

Safety-Nanoparticles/Risk management

NIOSH Releases New Nanotechnology Workplace Design Recommendations March 13th, 2018

How harmful are nano-copper and anti-fungal combinations in the waterways? October 27th, 2017

Do titanium dioxide particles from orthopedic implants disrupt bone repair? September 16th, 2017

Tests show no nanotubes released during utilisation of nanoaugmented materials June 9th, 2017

Research partnerships

New qubit now works without breaks: A universal design for superconducting qubits has been created April 19th, 2018

Salt boosts creation of 2-D materials: Rice University scientists show how salt lowers reaction temperatures to make novel materials April 18th, 2018

Psst! A whispering gallery for light boosts solar cells April 14th, 2018

Artificial intelligence accelerates discovery of metallic glass: Machine learning algorithms pinpoint new materials 200 times faster than previously possible April 13th, 2018

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



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project