19-01-2015, 04:23 AM
sir,
iwant to present seminar on mag refri., please send me its theory in pdf [/align]
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magnetic refrigeration seminar
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sir,
iwant to present seminar on mag refri., please send me its theory in pdf [/align]
25-03-2017, 03:41 PM
Magnetic cooling is a cooling technology based on the magnetocaloric effect. This technique can be used to achieve extremely low temperatures, as well as the ranges used in common refrigerators. Compared to traditional gas compression refrigeration, magnetic refrigeration is safer, quieter, more compact, has greater cooling efficiency and is more environmentally friendly because it does not use harmful and harmful ozone gases. The effect was first observed by a French physicist P. Weiss and the Swiss physicist A. Piccard in 1917. The fundamental principle was suggested by P. Debye (1926) and W. Giauque (1927). The first functional magnetic refrigerators were built by several groups from 1933.
Work materials
The magnetocaloric effect (ECM) is an intrinsic property of a magnetic solid. This thermal response of a solid to the application or removal of magnetic fields is maximized when the solid is near its magnetic ordering temperature. Therefore, the materials considered for magnetic refrigeration devices must be magnetic materials with a magnetic phase transition temperature close to the temperature region of interest. For refrigerators that can be used in the home, this temperature is the ambient temperature. The temperature change can be further increased when the order parameter of the phase transition changes strongly within the temperature range of interest. The magnitudes of magnetic entropy and adiabatic temperature changes depend strongly on the magnetic ordering process. The magnitude is generally small in antiferromagnets, ferrimagnets and spin glass systems, but may be much larger for ferromagnets that undergo a magnetic phase transition. The first-order phase transitions are characterized by a discontinuity in the magnetization changes with temperature, resulting in latent heat. The second-order phase transitions do not have this latent heat associated with the phase transition.
25-03-2017, 03:41 PM
Magnetic cooling is a cooling technology based on the magnetocaloric effect. This technique can be used to achieve extremely low temperatures, as well as the ranges used in common refrigerators. Compared to traditional gas compression refrigeration, magnetic refrigeration is safer, quieter, more compact, has greater cooling efficiency and is more environmentally friendly because it does not use harmful and harmful ozone gases. The effect was first observed by a French physicist P. Weiss and the Swiss physicist A. Piccard in 1917. The fundamental principle was suggested by P. Debye (1926) and W. Giauque (1927). The first functional magnetic refrigerators were built by several groups from 1933.
Work materials
The magnetocaloric effect (ECM) is an intrinsic property of a magnetic solid. This thermal response of a solid to the application or removal of magnetic fields is maximized when the solid is near its magnetic ordering temperature. Therefore, the materials considered for magnetic refrigeration devices must be magnetic materials with a magnetic phase transition temperature close to the temperature region of interest. For refrigerators that can be used in the home, this temperature is the ambient temperature. The temperature change can be further increased when the order parameter of the phase transition changes strongly within the temperature range of interest. The magnitudes of magnetic entropy and adiabatic temperature changes depend strongly on the magnetic ordering process. The magnitude is generally small in antiferromagnets, ferrimagnets and spin glass systems, but may be much larger for ferromagnets that undergo a magnetic phase transition. The first-order phase transitions are characterized by a discontinuity in the magnetization changes with temperature, resulting in latent heat. The second-order phase transitions do not have this latent heat associated with the phase transition.
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