ECOLOGICAL MAGNETIC REFRIGERATORS
Journal Title: Proceedings of Electrotechnical Institute Prace Instytutu Elektrotechniki - Year 2013, Vol 60, Issue 261
Abstract
The magnetocaloric effect (MCE) is a thermodynamic process in which the temperature changes of a paramagnetic material are the effect of an external magnetic field changing in cycles. The refrigeration occurs in two stages: the first one is the isothermal magnetizing of the material, during which the intensity of the magnetic field rises from [i]H[/i][sub]0[/sub] to [i]H[/i][sub]3[/sub] (Fig. 1 process 1-2); during the magnetizing the dipoles of the paramagnetic material become arranged parallely to the intensity of the external magnetic field and the entropy of the material decreases from [i]S[/i][sub]1[/sub] to [i]S[sub][/sub][/i][sub]2[/sub]. As a result of magnetizing, heat is transferred to the surroundings in a quantity proportional to the work executed by the magnetic field. The second stage is the adiabatic demagnetization of the paramagnetic material to the value of the field intensity of [i]H[/i][sub]0[/sub], during which there occures a decrease in temperature of the material from [i]T[/i][sub]p[/sub] to [i]T[/i][sub]12[/sub] (Fig. 2 process 2-3).<br/><br/>
Authors and Affiliations
Renata Sulima
Keywords
Related Articles
- EP ID EP68391
- DOI -
- Views 122
- Downloads 0
SYSTEM ROZRUCHU SILNIKÓW SPALINOWYCH Z WYKORZYSTANIEM SUPERKONDENSATORÓW
Artykuł przedstawia system rozruchu silników spalinowych, pozwalający na zmniejszenie kosztów eksploatacji pojazdów ciężarowych oraz znacznie ułatwiający ich rozruch. Rozwiązanie to może być szczególnie przydatne w warun...
WPŁYW NARAŻEŃ ŚRODOWISKOWYCH NA NAPIĘCIE VOLTY PRZETWORNIKA E-U
Jednym z czynników ograniczających czułość i stabilność mierników pól elektrycznych, takich jak młynek polowy, są szumy w układzie przetwarzania wynikające z niestabilnego kontaktu występującego pomiędzy obracającą się p...
MESOPIC CONTRAST SENSITIVITY AS AN ADDITIONAL PARAMETER FOR EVALUATION OF VISUAL FATIGUE CAUSED BY DISCOMFORT GLARE EXPOSURE
The article presents method and results of mesopic contrast sensitivity measurements after exposure to discomfort glare subjects of different age. Mesopic contrast sensitivity in conditions of glare and no glare are stan...
LASER-INDUCED BREAKDOWN SPECTROSCOPY FOR PAINTING LAYERS RESEARCH ON THE DOOR OF THE KING’S CHINESE ROOM AT THE WILANOW PALACE MUSEUM
Results of the research of the European lacquerware layers deposited on the door of the King’s Chinese Room at the Wilanów Palace Museum are presented. Laser-Induced Breakdown Spectroscopy and the optical microscopy were...
LEDs OPTICAL RADIATION HAZARD
In the paper, on the basis of literature reports and own researches of the optical radiation of LEDs, the photobiological risks were estimated. The evaluation was made on the basis of standard PN-EN 62471 “Photobiologica...