GE researchers describe how they built their breakthrough magnetic refrigeration system. The technology, which is projected to be 20 percent more efficient than current refrigeration systems, could be inside your fridge by the end of the decade. It is using water based fluid to transfer heat, not chemical refrigerants. That significantly lowers any harm to the environment and makes the recycling of old refrigerators simpler. “This is a big deal,” says Venkat Venkatakrishnan, a leader of the research team. “We are on the cusp of the next refrigeration revolution.”
The new technology is taking advantage of a century-old discovery called the magnetocaloric effect. In the 1880s, German physicist Emil Warburg observed that certain metals would heat up near magnets and cool down when taken away.
Thomas Edison toyed with the concept of building a magnetocaloric heat pump, a device that takes thermal energy from a cold space like the refrigerator and moves it into a hotter environment, like the kitchen. But he could not find any practical materials for pulling it off.
GE materials scientists developed a new type of nickel-manganese alloys for magnets that could function at room temperatures. Design engineers arranged the magnets in a series of 50 cooling stages. Today they are capable of reducing temperature by 80 degrees. “We are focusing on magnetic refrigeration as a potential replacement for all the refrigeration technologies currently in use,” Benedict says.
The team is now working to achieve a 100-degree drop in temperature at low power. “We’ve spent the last 100 years to make the current refrigeration technology more efficient,” Venkatakrishnan says. “Now we are working on technology for the next 100 years.”
The most refreshing place on earth? Michael Benedict (left) and Venkat Venkatakrishnan used GE’s magnetic refrigeration system to chill a bottle of Coors Light.