Science

Your next fridge could keep cold more efficiently using magnets

Your next fridge could keep co...
A bottle of beer is cooled using the new magnetic refrigeration system developed by GE
A bottle of beer is cooled using the new magnetic refrigeration system developed by GE
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The prototype system that reduced the temperature of a water-based fluid flowing through it by 80° F (45° C)
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The prototype system that reduced the temperature of a water-based fluid flowing through it by 80° F (45° C)
Michael Benedict (left) and Venkat Venkatakrishnan using GE’s magnetic refrigeration system to chill a bottle of Coors Light
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Michael Benedict (left) and Venkat Venkatakrishnan using GE’s magnetic refrigeration system to chill a bottle of Coors Light
A bottle of beer is cooled using the new magnetic refrigeration system developed by GE
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A bottle of beer is cooled using the new magnetic refrigeration system developed by GE

The fridge is the most common of common household appliances. Despite improvements in efficiency over the years, they remain one of the biggest users of electricity in the home, relying on chemical refrigerant and a compressor to transfer heat from the inside to the outside of the fridge. GE researchers have now developed a new type of refrigeration technology using magnets that is more environmentally friendly and is predicted to be 20 to 30 percent more efficient that current technology ... and it could be in household fridges by the end of the decade.

Magnetic refrigeration is not a new idea. Ever since German physicist Emil Warburg observed in the 1880s that certain materials changed temperature when exposed to a changing magnetic field – known as the magnetocaloric effect – there have been efforts to create refrigerators based on the technique.

Such magnetic refrigeration systems were developed as far back as the 1930s, and researchers at the Los Alamos National Laboratory (LANL) in New Mexico successfully achieved a few degrees of refrigeration in the 1980s. However, the technology has failed to make it into household refrigerators as it relies on superconducting magnets that themselves need to be cooled to extremely low temperatures, making it not cost- or energy-efficient for household use.

GE teams in the US and Germany turned their collective efforts to the task a decade ago and built a cascade from special magnetic materials. Each step of the cascade lowered the temperature slightly but after five years of work they were only able to realize cooling of just 2° F with a prototype that Michael Benedict, design engineer at GE Appliances, describes as a "huge machine."

A breakthrough then came courtesy of the research team's materials scientists who developed a new type of nickel-manganese alloys for magnets that could function at room temperatures. By arranging these magnets in a series of 50 cooling stages, the team have managed to reduce the temperature of a water-based fluid flowing through them by 80° F with a device that is, according to Benedict, "about the size of a cart."

Michael Benedict (left) and Venkat Venkatakrishnan using GE’s magnetic refrigeration system to chill a bottle of Coors Light
Michael Benedict (left) and Venkat Venkatakrishnan using GE’s magnetic refrigeration system to chill a bottle of Coors Light

"Nobody in the world has done this type of multi-stage cooling,” said Venkat Venkatakrishnan, a leader of the research team. "We believe we are the first people who shrunk it enough so that it can be transported and shown. We were also the first to go below freezing with the stages."

The team has demonstrated the system for experts from the Department of Energy (DoE), White House staffers and the EPA and is now working to further refine the technology. They hope to achieve a 100° F drop in temperature at low power, with the ultimate goal of replacing current refrigerator technology, possibly before the end of the decade.

"We’ve spent the last 100 years to make the current refrigeration technology more efficient,” said Venkatakrishnan. "Now we are working on technology for the next 100 years."

The magnetocaloric refrigeration technology is explained in the following video.

Source: GE

16 comments
davem2
These new fridge magnets are also 35% more efficient at keeping your reminder notes and postcards stuck to door.
MG127
you should use Kelvin when you talk about temperature differences
Mel Tisdale
I wonder why they have used solid magnets that they have to oscillate in preference to coils fed with AC current, which, unlike the oscillating solid magnet components, will not wear out. If they can get it down in size to that shown at the end of the video, then all well and good. Failing that, there is no reason why something too big for the kitchen should not be located in the cellar and plumbed in to a kitchen fridge cabinet. Also, there are the obvious heat pump applications of domestic heating and cooling. If the kitchen unit is plumbed in, these could be combined with the fridge application into one unit that extracted waste heat from the sink and bathroom, etc. as well as from ground water in order to heat the house or in air conditioning mode, the domestic hot water tank.
Philip M. Fortman
I agree wilth Mel RE, the application of this technology to AC for a small home or apt where only a 20 F difference between I/O of air flow works to cool a dwelling. There is still the cost of moving a volumn of air through the system.
David Leithauser
MG127: 1 degree C = 1 degree K, so the temperature difference is the same in Kelvin and C.
myale
So if I understand this correctly we still need a heat transfer fluid, but it does not have to be one that changes phases under pressure and heat - as the magnets are replacing this step and doing the cooling. Sounds good.
ADVENTUREMUFFINffin
I see opportunities all over the place. In heating and cooling homes, in heating hot water. Why not standardize the fittings and make heat exchangers that can be used in ventilation ducts for heating and cooling, and for domestic hot water, as well as a refrigerator? Maybe even a stove? Think big guys, this is great work, and the opportunities abound if the energy savings and capacities can be realized! Congratulations. Time to cool a Champaign bottle!
donwine
There was no mention of the energy used, compared to a standard refrigerator. The same principal can be used with a propane flame, microwave or the standard compressor. It still takes energy to create heat. They are merely using the magnetic eddies to generate heat and alloys to cool down. I just loved the wash machine sound!
ralph.dratman
The GE presenter did a great job making the material easy to understand. I like his speech patterns and the mood and tone of his delivery.
Gadgeteer
Donwine, It's right there in the first paragraph. "...predicted to be 20 to 30 percent more efficient that current technology."