Sensitivity study of multi-layer active magnetic regenerators using first order magnetocaloric material La(Fe,Mn,Si)₁₃H_y

Abstract

We present simulation results of multi-layer active magnetic regenerators using the solid-state refrigerant La(Fe,Mn,Si) 13 H y. This material presents a large, however quite sharp, isothermal entropy change that requires a careful choice of number of layers and working temperature for multi-layer regenerators. The impact of the number of layers and the sensitivity to the working temperature as well as the temperature span are quantified using a one dimensional numerical model. A study of the sensitivity of variation in Curie temperature through a uniform and normal distribution is also presented. The results show that the nominal cooling power is very sensitive to the Curie temperature variation in the multi-layer regenerators. A standard deviation of the Curie temperature variation for a normal distribution less than 0.6 K is suggested in order to achieve sufficient performance of a 15layer regenerator with Curie temperature spacing of 2 K. V

Study of geometries of active magnetic regenerators for room temperature magnetocaloric refrigeration

“…To study the AMRs using different geometries, a 1D transient numerical model developed at the Technical University of Denmark [46,47] is used. The energy equations for the heat transfer liquid and solid refrigerant [25] can be expressed as:…”

The La(Fe,Mn,Si)13Hz magnetic phase transition under pressure

“…This addresses one of the major bottlenecks to the uptake of the technology: the need to reduce expensive rare‐earth element based permanent magnets. (iii) Resolving issues of working temperature in magnetic refrigerators: literature has shown that the cooling power of a magnetic regenerator may decrease by about 90% if T C of the material is just a few kelvins from the absolute working temperature , which can vary significantly during 1 day. Therefore, controlling T C is of extreme relevance for application and the application of pressure to fine tune performance maxima would lead to an extension of the working fridge temperature range.…”

Study of the Microstructure, Mechanical, and Magnetic Properties of LaFe11.6Si1.4Hy/Bi Magnetocaloric Composites

“…It is of great importance to examine materials with a large MCE that may work at different temperature ranges, especially for around room temperature [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26]. Early studies indicated that high-purity Gd shows considerable MCE near room temperature, with nice mechanical properties [11,12].…”

“…One of the most promising room temperature magnetic refrigerants is La(Fe x Si 1−x ) 13 hydride [11]. However, the inherent brittleness and hydrogen cracking of the 1:13 phase during the hydrogenation break the hydrides into powder, which is not in conformity with the requirements of shape for use in magnetocaloric regenerators [9,10,16]. Lyubina et al obtained porous La(Fe,Si) 13 materials by hot pressed (HP) La-Fe-Si particles which exhibited better mechanical properties and lower hysteresis compared with bulk materials [10].…”