The magnetocaloric effect and its applications crc press book. Magnetic refrigeration is a cooling technology based on the magnetocaloric effect. When a suitable material is placed in a magnetic field, a small increase in temperature will occur in this material. Can you model the magnetocaloric effect that occurs in a material using comsol. Example of adiabatic temperature change due to the magnetocaloric effect. This technique can be used to attain extremely low temperatures, as well as the ranges used in common refrigerators. Gadolinium is an example of a second order material that. We have created a video tutorial for those of you who are new to the comsol multiphysics simulation software and need an introduction on how to use it. Magnetocaloric materials and the optimization of cooling. The video tutorial featured in this blog post shows you how to set up and run a simulation using comsol multiphysics. There are several materials, like paramagnetic salts or magnetic garnets see table 1, which are used for ad cooling in the same temperature range, but the advantage of ybpt 2 sn is that it is a good metal and it can easily be cast into rods, making preparation of cooling pills quite simple, in contrast to salts or garnets.
Can you model the magnetocaloric effect that occurs in a. The model includes the effect of a nonlinear bh curve in the core and. This is a pdf file of an unedited manuscript that has been accepted for publication. The principle of mr obeys the magnetocaloric effect mce, which is based on the effect caused by a magnetic field on the materials that bear the property of varying the magnetic entropy, as well as its temperature, when varying the magnetic field. Inverse magnetocaloric effect in ferromagnetic nimnsn. Oct 23, 2015 magnetocaloric materials are used in adiabatic demagnetization refrigerators to reach extremely low temperature without using helium. The magnetocaloric effect and its applications presents a complete overview of theoretical and experimental research results surrounding the magnetocaloric effect, and a comprehensive discussion of current and potential applications of the phenomenon. In this tutorial, we will solve one physical problem using a numerical toolbox called comsol multiphysics femlab. The model includes the effect of a nonlinear bh curve in the core and shows how to connect the transformer model to the external circuits using electric circuit interface. Large magnetocaloric effect and adiabatic demagnetization. Thermodynamics of the magnetocaloric effect caloricool. Review of magnetic properties and magnetocaloric effect in. This effect is particularly pronounced at temperatures and fields corresponding to magnetic phase transitions, and it is a. Search for tutorials and apps relevant to your area of expertise via the quick search feature.
This change in temperature may be of the order of 1c 2f, and is not to be confused with the much smaller hysteresis heating effect, which is irreversible. The thermodynamics of magnetic materials is discussed by introducing relevant free energy terms together with their microscopic origin leading to a discussion of the sources of entropy that can change in an applied magnetic field. This effect can be seen from either an adiabatic or an isothermal process. The best way to simulate the magnetocaloric effect is by changing the temperature abruptly, i. You can even use these entries as a starting point for your own. Advanced materials for magnetic cooling sigmaaldrich. This paper presents some aspects of the design of an innovative magnetocaloric system used for the construction of an efficient hvac unit for electric vehicles, which is an alternative to traditional hvac systems based on gas compression. Tutorial for running comsol files from comsol website. The reversible change of temperature accompanying the change of magnetization of a ferromagnetic or paramagnetic material. The magnetic refrigeration has several advantages compared to conventional techniques. The magnetocaloric project university of aveiro the. Can you model the magnetocaloric effect that occurs in a material.
The magnetocaloric effect describes the change in temperature of a magnetic material under adiabatic conditions through the application or removal of an external magnetic field. Today the nature of the effect is well explored and understood. An increase or decrease in the strength of an external magnetic field modifies the ordering of the magnetic moments of the atoms that form the material, thus altering magnetic entropy. Here, the authors report a large magnetocaloric effect in. Note that there is no need to include magnetism in the model. Magnetocaloric effect article about magnetocaloric effect. The magnetocaloric effect is commonly seen as a reversible heating and cooling of magnetic solids upon their exposure to a varying magnetic field. Masters thesis university of twente student theses. Comsol multiphysics is a generalpurpose simulation software for modeling designs, devices, and processes in all fields of engineering, manufacturing, and scientific research.
Magnetic air conditioners are based on a phenomenon known as the magnetocaloric effect. The equations of motion are averaged over volumes which are small compared to the computational domain but large compared to the size of the dispersed particlesbubblesdroplets. The physical properties of this compound are well studied see, for example. To access any comsol files, you need to have a comsol.
Index termsmagnetic refrigeration, magnetocaloric effect, numerical models. Simulation of solidstate magnetocaloric refrigeration systems. Magnetic materials heat up when they are exposed to a magnetic field, then cool down when the field is removed. The effect of demagnetization on the magnetocaloric. Applications of the magnetocaloric effect, revised, small. Modeling of a magnetocaloric system for electric vehicles. Comsol lep tutorial for tank flow system two cstr in series. Magnetic refrigeration system with peltier elements as thermal diodes is modeled. Comsol lep tutorial for tank flow system two cstr in series step 1. Simulating the magnetocaloric effect comsol multiphysics.
To download the mphfiles, log in or create a comsol access account that is associated with a valid comsol license. The magnetocaloric effect and its applications condensed. If you can, could you please share the tutorials or advice me which module to use. For those of you who are not familiar with this effect.
If you can, could you please share the tutorials or advice me which module to. This is the transient model of a single phase ecore transformer using a multiturn coil domain. Such entropies account for measurable magnetocaloric effects. Multiphysics analysis of a magnetocaloric cooling system. Comsol multiphysics and its gui but would like to learn more about how to set up a certain model. Open chapter and click on comsol tab present in the bottom of the page step 2. Exploration of selected room temperature magneto caloric materials using comsol multiphysics. The refrigerator will be designed to use the magnetocaloric mce effect rather than a conventional vapor compression cycle and thus reduce greenhouse gas emissions by eliminating the use of highglobalwarmingpotential refrigerants. The magnetocaloric effect is the thermal response of a magnetic material when. Exploration of selected room temperature magneto caloric materials. Warburg1, is an exciting propriety of magnetic materials. The magnetocaloric effect mce manifests itself by an adiabatic temperature change in certain magnetic materials when the external magnetic field is changed brueck, 2005, gschneidner, pecharsky, 2008, tishin, spichkin, 2003.
Pdf the magnetocaloric effect and magnetic permeability in annealed and. Risser1 1national institute of applied science insa, strasbourg, france abstract introduction in automotive industry, regardless the type of engine we use, heating and airconditioning is. Magnetic refrigeration mr at room temperature is an emerging technology and shows real potential to enter conventional markets. Magnetocaloric refrigeratorfreezer department of energy. Although the magnetocaloric effect is only a few kelvin, larger temperature spans are usually created via regeneration by pumping a heat transfer fluid back and forth through porous magnetocaloric materials after each magnetization or demagnetization process. Magnetocaloric effect definition is a reversible change in the temperature of a thermally insulated magnetizable substance in a magnetic field of varying intensity with the temperature rising or falling according as the field intensity is increased or decreased. The magnetocaloric effect mce in paramagnetic materials has been widely used for attaining very low temperatures by applying a magnetic field.
Magnetocaloric heat pump system based on magnetocaloric effect mce is a promising alternative to vapor compression system. This model is made with the software program comsol multiphysics. Dear all, i am currently working on my bachelor project, which involves the numerical analysis of the magnetocaloric effect mce. Get an introduction to a 6part tutorial series on modeling em phenomena in cables using the comsol multiphysics software. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. We calculate the heat conduction in a simple heat sink aluminium cooling a high voltage copper cable. The magnetocaloric e ect is the change in temperature of a material as a result of the alignment of its magnetic spins that occurs on exposure to an external magnetic eld. Magnetocaloric materials are used in adiabatic demagnetization refrigerators to reach extremely low temperature without using helium. May 15, 2005 the magnetocaloric effect mce in paramagnetic materials has been widely used for attaining very low temperatures by applying a magnetic field isothermally and removing it adiabatically.
In addition to using multiphysics modeling for your own projects, you can also turn your models into simulation applications and. Magnetic refrigeration is based on the magnetocaloric effect which manifests itself. Simulation of solidstate magnetocaloric refrigeration. Magnetocaloric effect definition of magnetocaloric effect. This manuscript focuses on the physics and the properties of materials which are commonly used for magnetic refrigeration at cryogenic temperatures. If you still need help with comsol and have an onsubscription license, please visit our support. The behavior of both the extensive and intensive measures of the giant magnetocaloric effect in firstorder phase transition materials is different when compared to the conventional magnetocaloric effect in secondorder phase transition compounds, as can be easily seen in figure 5 when compared to figures 1 and 2. As a result, many new materials with large magnetocaloric effect have been discovered, and a much better understanding of this magnetothermal property has resulted. The application gallery features comsol multiphysics. The magnetocaloric effect magnetic air conditioners. The magnetocaloric e ect and magnetocaloric materials.
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