Future refrigerators will create cold with magnets
The refrigerator is the most common of household appliances. Despite improvements in efficiency over the years, they remain one of the largest consumers of electricity in the home, due to the work on chemical refrigerants and compressors to transfer heat from the inside to the outside of the refrigerator. GE researchers have developed a new type of cooling technology with magnets, which is a more environmentally friendly technology, and is projected to be 30 percent more efficient than current technologies.
Such a development could be revolutionary in the use in domestic refrigerators by the end of the decade.
Magnetic cooling is not really a new idea. Back in 1880, the German physicist Emil Warburg noticed that certain materials change temperature when exposed to a changing magnetic field.This phenomenon was called the magnetocaloric effect and there were attempts to create refrigerators based on this technology.
Such magnetic cooling systems were developed in the 1930s. Researchers at the Los Alamos National Laboratory in New Mexico (USA) successfully implemented several degrees of cooling in the 1980s. However, the technology could not be applied in domestic refrigerators, since superconducting magnets were used, which themselves should be cooled to very low temperatures, which made this technology economically or energy-saving unprofitable.
GE teams in the USA and Germany turned their collective efforts to solve a problem ten years ago and built a cascade of special magnetic materials. Each stage of the cascade lowered the temperature slightly.
The breakthrough came when scientists from a research group of materials developed a new type of nickel-manganese alloy for magnets that can function at room temperature. By arranging these magnets in a series of 50 cooling stages, the team managed to reduce the temperature of the water-based fluid flowing through them at 26.6 ° C.
“Nobody in the world has done this type of multi-stage cooling,” said the head of the research team, Venkat Venkatrishnan. “We believe that we are the first researchers who reduced it so much that a similar refrigerator can be transported. We were also the first to achieve liquid cooling below zero degrees. ”
The team has demonstrated a system for experts from the US Department of Energy, the White House staff and the EPA and is now working on further improving the technology. They hope to achieve a low-temperature reduction of 38 ° C, with the ultimate goal of replacing refrigerators working on modern refrigerant technology until the end of the decade.