EXPERIMENTAL INVESTIGATION ON REFRIGERATION PERFORMANCE OF A RECIPROCATING ACTIVE MAGNETIC REGENERATOR OF ROOM TEMPERATURE MAGNETIC REFRIGERATION

摘要

Room temperature magnetic refrigeration has been proven to be a feasible refrigerating technology and has a prosperous application potential. In this research the magnetocaloric effect of the metal gadolinium is measured and the metal is prepared from an ingot to granular state by a method of hydriding-ball milling-dehydriding. The other compound, Gd{sub}5Si{sub}2Ge{sub}2 alloy, is also prepared in grains by a mechanical comminuting and its magnetocaloric property is obtained. An experimental system of room temperature magnetic refrigeration is established, and three kinds of magnetic refrigerants (MR I: 0.3mm mean diameter gadolinium particle, MR II: 0.55 mm mean diameter gadolinium particle and MR III: 0.3□0.75 mm Gd{sub}5Si{sub}2Ge{sub}2 alloy particle) are employed in an AMR. Performance experiments of the AMR system under various temperature ranges, temperature spans, flow rates, and flow period conditions are investigated. The results indicate that AMR adopting MR I, II, III can generate a maximal refrigeration capacity of 18.7 W, 17.8 W, and 10.3 W, respectively under a 3 K temperature span. With the increase of the temperature span, the capacity decreases. MR I and MR II have an equivalent refrigeration ability higher than the MR III.