Hi all, I thought that these article archives would be of interest to some members. Great strides would be made in energy efficiency, an economical way to liquify hydrogen and environmental benefits could be some of the results if this technology is brought to market. Some of these sources are 5 years old so they have been working on these devices for several years.
regards http://www.external.ameslab.gov/news/release/2001rel/01magneticrefrig. htm Contacts: Karl Gschneidner, Jr., Metallurgy and Ceramics, (515) 294-7931 Kerry Gibson, Public Affairs, (515) 294-1405 MAGNETIC REFRIGERATOR SUCCESSFULLY TESTED Ames Laboratory developments push boundaries of new refrigeration technology Using materials developed at the U.S. Department of Energy's Ames Laboratory, researchers have successfully demonstrated the world's first room temperature, permanent-magnet, magnetic refrigerator. The refrigerator was developed by Milwaukee-based Astronautics Corporation of America as part of a cooperative research and development agreement with Ames Laboratory. Instead of ozone-depleting refrigerants and energy-consuming compressors found in conventional vapor-cycle refrigerators, this new style of refrigerator uses gadolinium metal that heats up when exposed to a magnetic field, then cools down when the magnetic field is removed. "We're witnessing history in the making," Ames Laboratory senior metallurgist Karl Gschneidner Jr. says of the revolutionary device. "Previous successful demonstration refrigerators used large superconducting magnets, but this is the first to use a permanent magnet and operate at room temperature." Initially tested in September at the Astronautics Corporation of America's Technology Center in Madison, Wis., the new refrigerator is undergoing further testing. The goal is to achieve larger temperature swings that will allow the technology to provide the cooling power required for specific markets, such as home refrigerators, air conditioning, electronics cooling, and fluid chilling. According to Gschneidner, who is also an Anson Marston Distinguished Professor of materials science and engineering at Iowa State University, the magnetic refrigerator employs a rotary design. It consists of a wheel that contains segments of gadolinium powder ö supplied by Ames Laboratory ö and a high-powered, rare earth permanent magnet. The wheel is arranged to pass through a gap in the magnet where the magnetic field is concentrated. As it passes through this field, the gadolinium in the wheel exhibits a large magnetocaloric effect ö it heats up. After the gadolinium enters the field, water is circulated to draw the heat out of the metal. As the material leaves the magnetic field, the material cools further as a result of the magnetocaloric effect. A second stream of water is then cooled by the gadolinium. This water is then circulated through the refrigerator's cooling coils. The overall result is a compact unit that runs virtually silent and nearly vibration free, without the use of ozone-depleting gases, a dramatic change from the vapor-compression-style refrigeration technology in use today. "The permanent magnets and the gadolinium don't require any energy inputs to make them work," Gschneidner said, "so the only energy it takes is the electricity for the motors to spin the wheel and drive the water pumps." Though the test further proves the technology works, two recent developments at Ames Laboratory could lead to even greater advances on the magnetic refrigeration frontier. Gschneidner and fellow Ames Laboratory researchers Sasha Pecharsky and Vitalij Pecharsky have developed a process for producing kilogram quantities of Gd5(Si2Ge2) alloy using commercial-grade gadolinium. Gd5(Si2Ge2) exhibits a giant magnetocaloric effect which offers the promise to outperform the gadolinium powders used in the current rotary refrigerator. When the alloy was first discovered in 1996, the process used high-purity gadolinium and resulted in small quantities (less than 50 grams). However, when lower-quality commercial-grade gadolinium was used, the magnetocaloric effect was only a fraction, due mainly to interstitial impurities, especially carbon. The new process overcomes the deleterious effect of these impurities, making it viable to use less expensive commercial-grade gadolinium to achieve roughly the same magnetocaloric effect as the original discovery. At the same time, Ames Lab researchers David Jiles and Seong-Jae Lee, along with Vitalij Pecharsky and Gschneidner, have designed a permanent magnet configuration capable of producing a stronger magnetic field. The new magnet can produce a magnetic field nearly twice as high as that produced by the magnet used in the initial refrigerator, an important advance since the output and efficiency of the refrigerator is generally proportional to the strength of the magnetic field. The group has filed patent applications on both the gadolinium alloy process and the permanent magnet. "These are important advances, but it will require additional testing to see how much they will enhance refrigeration capabilities," Gschneidner said. "Progress (in this field) is measured in small steps and this is just another of those steps. However, we've come a long way since first announcing the giant magnetocaloric alloy five years ago." The research is funded by the DOE Office of Basic Energy Sciences' Laboratory Technology Research Program, Office of Computational Technology Research. Ames Laboratory is operated for the DOE by Iowa State University. The Lab conducts research into various areas of national concern, including energy resources, high-speed computer design, environmental cleanup and restoration, and the synthesis and study of new materials. For additional information about the Astronautics Corporation of America's rotary, room temperature, permanent magnet, prototype magnetic refrigerator please contact Robert Herman, 414-449-4248 or go to the company website at http://www.astronautics.com/PressRelease/Files/MagFrig.PDF http://www.external.ameslab.gov/news/release/crada.html Contacts: Karl Gschneidner Jr., Ames Laboratory, (515) 294-7931 Carl Zimm, Astronautics Corp. of America, (608) 221-9001 Susan Dieterle, Ames Lab Public Affairs, (515) 294-1405 Work begins on prototype magnetic-refrigeration unit Ames Laboratory, Astronautics Corp. of America collaborate on building rotary model AMES, Iowa -- Scientists at the U.S. Department of Energy's Ames Laboratory have received funding to begin building a prototype cooling unit based on magnetic-refrigeration technology. The researchers -- Karl Gschneidner Jr., Vitalij Pecharsky and David Jiles -- expect the prototype to demonstrate that magnetic refrigeration is a reliable source of cooling power, and is more energy-efficient and environmentally safe than the vapor-cycle systems now used in refrigerators and air conditioners. They will be working with scientist Carl Zimm of the Milwaukee-based Astronautics Corp. of America, the lab's industrial partner in the project. If successful, the prototype would be the first magnetic refrigerator capable of sustained operation and generating enough cooling power for commercial applications. Magnetic refrigeration is based on the magnetocaloric effect -- the ability of some materials to heat up when magnetized and cool when removed from the magnetic field. Using these materials as refrigerants would provide an environmentally friendly alternative to the volatile liquid chemicals, such as chlorofluorocarbons and hydrochlorofluorocarbons, used in traditional vapor-cycle cooling systems. Ames Laboratory and Astronautics have signed a Cooperative Research and Development Agreement to develop a rotary prototype magnetic-refrigeration unit. Under terms of the agreement, the Department of Energy will provide $750,000 in funding over the next three years toward the project. Astronautics, a leader in magnetic-refrigeration technology, will provide a matching amount through in-kind contributions of personnel, research, services and facilities. "Building the prototype is a crucial step in moving magnetic-refrigeration technology into the marketplace," said Gschneidner, a senior Ames Laboratory scientist and the project coordinator. In the rotary prototype, Gschneidner said the materials will move continuously through high and low magnetic fields on a rotating disc. Water or antifreeze will act as the heat-transfer fluid between the magnetic refrigerant and the heat exchangers. "The rotary magnetic-refrigeration unit shouldn't be any bigger than the compression system now used in most refrigerators and air conditioners," he said. The Ames Laboratory team will concentrate its efforts on optimizing the refrigerant materials, and developing a source for the magnetic field that is more convenient and cost-effective than superconducting magnets. Astronautics will design, build and test the rotary prototype. "When these pieces of the puzzle are properly put together, it will create a benchmark for all future developments of this new, emerging technology," said Pecharsky, a scientist at Ames Lab. Zimm, the principal Astronautics scientist involved in the project, said the company's main design goal for the rotary prototype is achieving a high operating frequency. "This will make the machine smaller, lighter and more economical," Zimm said. Ames Laboratory and Astronautics have collaborated on magnetic-refrigeration research for the past eight years. In 1996, they built a proof-of-principle model demonstrating that magnetic refrigeration was a reliable, competitive technology for refrigerators and air conditioners. The model operated for 18 months, achieving cooling power 30 times greater than previous magnetic refrigerators. Previous units were only capable of operating for no more than a few days. Gschneidner said initial findings indicate that magnetic refrigeration is about 20 percent more energy-efficient than traditional cooling systems. So, although magnetic refrigeration could initially cost more, Gschneidner said consumers would earn back the difference in energy savings within five years. Gschneidner said large-scale applications using magnetic refrigeration, such as commercial air conditioning and supermarket refrigeration systems, could be available within five to 10 years. Within 10-15 years, the technology could be available in home refrigerators and air conditioners. Ames Laboratory is operated for the Department of Energy by Iowa State University. The Lab conducts research into various areas of national concern, including energy resources, high-speed computer design, environmental cleanup and restoration, and the synthesis and study of new materials. other related links http://www.external.ameslab.gov/news/Inquiry/fall97/bigchill.html Define the perfect fuel and it would most likely be one that burns cleanly, poses no harm to the environment and, above all, is renewable or in limitless supply. Liquid hydrogen could prove to be close to a perfect fuel, but first scientists and engineers must jump a few technological hurdles. One of the biggest hurdles, an efficient method of liquefying hydrogen, has been eliminated by recent developments at Ames Laboratory. Scientists have developed a highly efficient magnetocaloric material that makes magnetic refrigeration technology efficient enough to cheaply produce liquid hydrogen, very likely one of the first major commercial uses of magnetic refrigerators. Conventional production methods for liquid hydrogen begin by using liquid nitrogen to lower hydrogen gas to minus 196 degrees Celsius (320.8 degrees Fahrenheit). A gas-compression system, similar to the one in your refrigerator at home, is then used to further reduce the temperature to minus 253 C (423.4 F). One drawback to this method, however, is that the inefficiency of the gas-compression cycle cannot economically produce less than five tons of liquefied gas a day. This limits the production sources of liquid hydrogen to large plants that are few and far between. Karl Gschneidner Jr. hopes that this is where magnetic refrigeration could eventually fill in. Gschneidner is a senior metallurgist at Ames Lab and an Anson Marston distinguished professor of materials science and engineering at Iowa State University. Early this decade, Gschneidner, Ames Lab Associate Scientist Vitalij Pecharsky and fellow researchers began developing intermetallic compounds specifically for application in magnetic refrigerators. Their latest discovery is a new class of alloys with significantly more cooling power than the best existing materials. The new materials are based on gadolinium, an element with two to three times the magnetocaloric effect of a typical ferromagnetic iron and a popular choice for low-temperature ranges. "This is a tremendous breakthrough," says Gschneidner. "I think it's going to put magnetic refrigeration in the market." Magnetic refrigeration technology takes advantage of the magnetocaloric effect, the remarkable ability of a magnetic material to heat up in the presence of a magnetic field and cool when the field is removed. Magnetocaloric materials store heat energy in the way the atoms vibrate and in the way in which electrons spin within each atom. More heat energy increases the vibrations and also makes the spins more random. In other word, when the party heats up, things get a little crazy. Scientists refer to this "craziness" as entropy, which is a measure of thermodynamic disorder. When a strong magnetic field is applied to the coolant material, the magnetic moments of its atoms become aligned, making the system more ordered. The more ordered material has a lower entropy and compensates for the loss by heating up. But when the strong magnetic field is removed, the party is forced to cool down. The magnetic moments return to their random directions, entropy increases and the material cools. Typically, the temperature of a material can drop by about 10 to 15 degrees C (52 to 59 F), depending on the magnetic field strength. The temperature at which most of the change in magnetic entropy occurs is known as the material's ordering temperature or its Curie point. This is the point where the material changes from being ferromagnetic to paramagnetic, and the farther away from this point the weaker the magnetocaloric effect. The useful portion of the magnetocaloric effect usually spans about 25 degrees C (77 F) on either side of the material's Curie temperature. Therefore, in order to span a wide temperature range, a refrigerator must contain several different coolants arranged according to their differing ordering temperatures. Gschneidner and Pecharsky found that they could tune the operating temperature (gradually lower the Curie point) of a gadolinium silicide compound (Gd5Si4) by substituting germanium (Ge) for silicon. This resulted in a new compound, Gd5Si2Ge2, which has a magnetocaloric effect about twice as large as gadolinium alone. Additional work has revealed that Gd5Si2Ge2 is one of a family of compounds that exhibits a giant magnetocaloric effect and whose ordering temperature can be tuned from 30 Kelvin (-405.4 F) to near room temperature (290 K or 62.6 F) by adjusting the ratio of silicon to germanium. "There are very few systems that will give you that temperature span," says Gschneidner. "It's unheard of." That is music to the ears of Carl Zimm. Zimm is chief scientist at Astronautics Corporation of America in Madison, WI. He and his colleagues have been working with the researchers at Ames Lab and other Department of Energy research facilities since the early 1990s to develop magnetic refrigeration technology to the point where it can compete with conventional gas-cycle systems, and in some cases make them obsolete. "There are many places in the United States that produce smaller amounts of hydrogen as a byproduct of some other industrial process," says Zimm. "An efficient liquefaction system could turn those amounts into fuel instead of having them go to waste." Earlier this year, Astronautics unveiled an active magnetic refrigerator with unprecedented efficiency. Zimm and other researchers nationwide see more than just the liquefaction of hydrogen and other gases on the horizon for magnetic refrigeration technology. Although the history of development for gas-compression cycle refrigerators has given it a head start, the efficiency of the new coolants makes magnetic refrigeration truly competitive with conventional gas-compression technology for the first time. Large-scale applications, says Zimm, could soon be developed. Examples include supermarket-sized refrigerators and freezers, air conditioning for large buildings, industrial chemical processing, and waste separation and treatment. Also, the new coolants may eliminate the need for the superconducting magnets associated with earlier cryocoolers. This opens the way for small-scale applications of this technology, such as car and home air conditioners. Another factor helping to heat up the development of magnetic refrigeration technology is the recent ban on chlorofluorocarbons (CFCs) and other environmentally harmful substances. Magnetic refrigeration doesn't use CFCs and, in the case of the Astronautics model, water is used as the heat transfer fluid. Only antifreeze is added to allow the Astronautics unit to reach temperatures below 273 K, the freezing point of water, and down to about 225 K (-54.4 F). Below that, helium gas is used as the heat transfer fluid. Despite all its promise, magnetic refrigeration technology still has hurdles to overcome if it is to ever give conventional vapor-based technology a run for the money. For example, when it comes to a small temperature span, such as the range of temperature in cooling a home or car, the old standard still leads the race. Only for large temperature spans, such as those associated with liquefying gases, do small increases in efficiency make a big money-saving difference. Continuing research into even more efficient coolant materials could narrow the gap, says Gschneidner. "The new knowledge will allow us to improve existing materials and point the way to new and better ones, which will ensure the success of magnetic refrigeration as a viable energy-saving and environmentally safe technology in the next century," Gschneidner says. "The limitations of magnetic refrigeration are only in the minds of scientists and engineers." For more information: Karl Gschneidner Jr., 515-294-7931 [EMAIL PROTECTED] Carl Zimm, 608-221-9001 [EMAIL PROTECTED] Current research funded by: DOE Advanced Energy Projects Program http://www.iprt.iastate.edu/releases/magneticrefrig.html Contacts: Karl Gschneidner, Center for Rare Earths and Magnetics, 515-294-7931 Susan Dieterle, IPRT Public Affairs, 515-294-1405 Cars May Be First to Benefit from Magnetic Refrigeration Grant allows researchers to study feasibility of new automobile air-conditioner system Ames, Iowa÷Magnetic-refrigeration research at Iowa State University will take its first step from the laboratory toward the world of automobile air conditioning with the help of a grant from the U.S. Department of Energy (DOE). ISU's Center for Rare Earths and Magnetics received a one-year, $150,000 grant from DOE's Cooperative Automotive Research for Advanced Technologies (CARAT) Program to explore the feasibility of using magnetic refrigeration in automobile air-conditioner systems. The CARAT Program funds research and development work geared toward producing cars and light trucks that are extremely fuel-efficient, have low emissions and are "fuel flexible." Magnetic refrigeration is based on the magnetocaloric effect÷the ability of some metals to heat up when magnetized and cool down when removed from the magnetic field. Using these metals as the refrigerant material would provide an environmentally friendly alternative to the volatile liquid chemicals, like chlorofluorocarbons and hydrochlorofluorocarbons, used in traditional vapor-cycle cooling systems. Karl Gschneidner Jr., an Anson Marston distinguished professor of materials science and engineering at ISU, says an automobile air-conditioner system based on magnetic refrigeration would run on the electrical power generated by the alternator, thereby reducing the load on the powertrain and making the car more fuel efficient. The technology ideally lends itself to use in electric cars, Gschneidner says, adding that the cooling process also could be reversed in order to heat the vehicle. "I think this is the only answer for heating and cooling an electric vehicle," he says, adding that the challenge will be to devise an air-conditioner that is lightweight, inexpensive and highly efficient. The project will make use of a new class of magnetic-refrigeration materials discovered by Gschneidner and Vitalij Pecharsky, an ISU associate professor of materials science and engineering. They found that alloys made of gadolinium, silicon and germanium are two to 10 times more effective in their cooling power than other prototype magnetic-refrigeration materials. The CARAT Program grant enables Gschneidner and Pecharsky to being their first practical, real-world application of magnetic refrigeration. The benefits of the research won't be limited to automobiles, Gschneidner says. "If we're successful in developing this air-conditioning technology for automobiles, we would be able to use it in homes as well," he notes, adding that they also envision magnetic refrigeration being used in commercial and home refrigerators in the future. The CARAT Program provides funding in three phases. If the ISU researchers succeed this year with the first part of the project, which involves proving the feasibility of the concept, they could apply for a second phase to move the technology from laboratory scale to near-production scale. The third phase of the funding would involve vehicle-stage validation. In all, the CARAT Program this year awarded more than $3.7 million in phase-one cooperative agreements to 26 small businesses and universities for the development of automotive components and subsystems that will contribute to cleaner, more efficient cars and light trucks. "CARAT will channel the creativity and resourcefulness of the small business and academic communities to resolve the technology barriers which are keeping promising automotive technologies from becoming a reality," said Dan Reicher, DOE Assistant Secretary for Energy Efficiency and Renewable Energy. The Center for Rare Earths and Magnetics is a member of the Institute for Physical Research and Technology, a consortium of research, technology-development, technology-transfer and technical-assistance centers at ISU. http://www.psfc.mit.edu/technology_engineering/mr.html Magnetic refrigeration has been used chiefly as a cooling method to obtain temperatures below 1 K. During the past ten years, however, the technology has been developed also for refrigeration applications at temperatures above 1 K. The former type of magnetic refrigerator utilizes an adiabatic one-shot process to approach zero Kelvin as a purely scientific goal. For application at temperatures higher than 1 K, a continuously cycling magnetic refrigerator with reasonable refrigeration capacity is employed. This latter type of refrigerator can be utilized in actual engineering applications, such as cooling sensitive electronics and optical devices on board spacecraft. Two important research topics are required to support any successful magnetic refrigerator development program: magnetothermodynamic analysis, and low-loss superconducting magnet development. The former is usually done by computer simulation, in parallel with the overall conceptual design. One calculates the real thermodynamic properties of the magnetic refrigerant and performs cycle analysis. The latter topic is the more practical task, relying largely on empirical knowledge. The development of a pulsed superconducting magnet was one of the PSFC's important R&D areas, and intensive work has been performed to characterize proper superconducting wire for various types of magnet. A Nb3Sn low loss ac superconducting magnet is an excellent choice for magnetic refrigeration. The operation of such a magnet at temperatures higher than 4.2 K using, a cryocooler, will also increase the overall thermodynamic efficiency of a magnetic refrigeration system. http://en.wikipedia.org/wiki/Magnetic_refrigeration Magnetic refrigeration >From Wikipedia, the free encyclopedia. Magnetic refrigeration is a cooling technology presently (2003) being developed by a partnership of the United States Department of Energy's Ames Laboratory and Astronautics Corp. of America. A proof-of-principle model was successfully demonstrated in 1996. The technology uses the magnetocaloric effect, which is the tendency of certain materials, such as the metallic element gadolinium, to heat up when placed in a magnetic field and to cool down when removed from the field. http://www.ameslab.gov/News/release/crada.html. http://en.wikipedia.org/wiki/Gadolinium http://htslab.sharif.edu/kianzad/archive/magneticrefrigerator/mag- ref.htm Aternate Energy Resource Network resources-news sources updated through out the day http://www.alternate-energy.net Weekly News Alerts http://www.alternate-energy.net/newsalerts04-12.html Alternative Energy System Calculators http://www.alternate-energy.net/calcsyst04.html ------------------------ Yahoo! Groups Sponsor ---------------------~--> Buy Ink Cartridges or Refill Kits for your HP, Epson, Canon or Lexmark Printer at MyInks.com. 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