Transportation of gases and technologies providing it are the most important issues of the world economy and technological development. The most widely used pipeline transportation and transportation of gases in a liquefied state. When moving over long distances (more than 2.5 thousand km), the transportation of liquefied gases is often more economical.
In existing working technologies, the gas itself is the working medium for gas liquefaction technologies. At the same time, up to a quarter of the original volume of gas is lost in the process of liquefaction: that is, it takes a whole ton to liquefy three tons of gas. In other words, in the process of gas liquefaction, very large losses of valuable raw materials occur.
V. A. Kotelnikov RAS, under the guidance of a young scientist – senior researcher of the Laboratory of Physics of Magnetic Phenomena Alexei Mashirov, is working on the creation of original methods for cooling and liquefying gases based on the use of solid materials and strong magnetic fields within the framework of the Russian Science Foundation project.
In the laboratory of the IRE RAS, as in many laboratories around the world, a promising technology of solid-state magnetic cooling based on the magnetocaloric effect is being investigated. The essence of this effect is that with a sharp change in the external magnetic field, the temperature of the magnetic material decreases, which can be used as a cooling element. Compounds of rare earth metals, such as dysprosium and gadolinium, have the greatest magnetocaloric effect.
Senior Research Fellow IRE them. V. A. Kotelnikova RAS Svetlana Vyacheslavovna von Gratovsky said: “Why is solid-state cooling promising? If a solid-state working body is used for cooling, then during the cooling process the solid body does not evaporate anywhere, but remains for further use in the limit for an infinite number of cycles. At the same time, there is no irretrievable loss of almost 25% of valuable gas raw materials.”
“Another advantage of solid-state refrigeration, compared to gas or gas-liquid refrigeration, is that solids have a higher heat capacity and exhibit a higher reversibility of energy conversion processes than gases. It is expected that solid-state magnetic cooling will be able to replace traditional gas expansion cooling methods in the future,” she explained.
“To evaluate the effectiveness of gas cooling and liquefaction technologies, there is a special “gold standard” – the process efficiency coefficient, a kind of analogue of the efficiency factor, which was discovered two hundred years ago by the French scientist Sadi Carnot. The higher the efficiency factor of the process, the higher the “energy perfection” of the technology being created. A group led by Mashirov is busy searching for such processes, materials and creating prototypes of cryogenic refrigerators based on them, the parameters of which would be the closest to a device that provides energy perfection,” explained Svetlana Vyacheslavovna.
To create economical sources of strong magnetic fields for solid-state refrigerators, scientists led by Alexei Mashirov decided to use two classes of new solid-state materials in one device at once, to combine two breakthrough technologies at once.
Along with magnetic materials with a magnetocaloric effect, there is another breakthrough technology based on another class of unique materials, based on another rare earth metal – yttrium. Some materials based on it – high-temperature superconductors – have an amazing ability to lose electrical resistance when cooled below the boiling point of liquid nitrogen – 192 ° C. At temperatures below this, superconductivity occurs in them.
The production of wires and cables from such high-temperature superconductors has been mastered by the domestic industry. The work of the IRE RAS proposes to combine two new promising technologies at once: the technology of high-temperature superconductors, which makes it possible to generate superstrong magnetic fields (up to hundreds of thousands of oersteds) with low power consumption, and the phenomenon of magnetic cooling based on rare-earth magnetic alloys.
During the project, the researchers created and tested a prototype of a magnetocaloric cryogenic refrigerator operating using solid-state magnetic cooling technology in strong magnetic fields up to 100,000 oersteds. The new technology is not inferior to foreign prototypes in terms of energy parameters. Researchers continue their work in the direction of searching for original design solutions and selection of materials, the so-called thermal interfaces, necessary to increase the cooling capacity of a promising solid-state magnetic cryogenic refrigerator.
Von Gratowski also noted: “So far, no one in the world has achieved“ energy perfection ”. History gives a very great hope that the Russian group from the IRE RAS will reach it. The Russian group is one of the few in the world that has taken the path of evaluating its results precisely from the point of view of “energetic perfection”, introduced by Sadi Karno, named after the Persian Sufi poet Saadi Shirazi. And it was in Iran that more than two and a half millennia ago, badgirs were created – the most ancient air conditioners-coolers that are more efficient than modern ones.
In addition to saving houses from heat, badgirs were also used to cool underground channels and water storages. Their efficiency was so great that the water in the underground storages was cooled almost to the freezing point – it was not just cold, but icy in the heart of the desert.
Badgirs are the efficient nature-like green energy-heat machines of the ancient world. Inside, the badgirs are divided into several parts by partitions made of unbaked brick or wood. With their hybrid technology, cooling cascading, durability, environmental friendliness, and many other things, bagdirs resemble technologies developed at IRE RAS.