Magnetic refrigeration: A comparison between MnAs and FeRh based alloys in the room temperature range

Abstract

This paper describes a two-dimensional (2D) multiphysics model of a parallel plate regenerator made of magnetocaloric material. The regenerator operates as a refrigerant for a magnetic refrigerator operating at room temperature on the strength of an Active Magnetic Regenerator (AMR) cycle. The model is able to simulate the thermofluidodynamic behavior of the magnetocaloric material and the magnetocaloric effect of the refrigerant. With this model direct (MnFeP0.45As0.55) and inverse (Fe49Rh51) magnetocaloric materials have been investigated. The tests were performed with fixed AMR cycle frequency (1.25 Hz), cold heat exchanger temperature (310 K), hot heat exchanger temperature (318 K), while secondary fluid flow rate was varied in the range 0.034÷0.057 kg/s. The secondary fluid used for simulations is liquid water. The results, generated for a magnetic induction which varies from 0 to 1.5 T, are presented in terms of temperature span, refrigeration power and coefficient of performance. Results clearly show that the best material from an efficiency's point of view is Fe49Rh51 which exhibits the highest values of ΔTspan, Qref and COP. Instead MnFeP0.45As0.55 shows, in this temperature range (centered around its Curie point), values of ΔTspan, Qref and COP too low for any kind of practical application.

The environmental impact of solid-state materials working in an active caloric refrigerator compared to a vapor compression cooler

“…In this paper a ∆TEWI analysis is presented, comparing numerically the environmental impact of a caloric refrigerator, operating with different caloric materials, with the one of a vapor compression cooler working with HFC134a. As a matter of fact, numerical modeling ensures good predictions of energetic results [25][26][27][28][29]. By means of a two-dimensional mathematical model the analysis is performed with the most performing magnetocaloric, electrocaloric, elastocaloric and barocaloric materials in order to provide a general framework of caloric cooling technique.…”