Numerical analysis of an active magnetic regenerator with parallel wire geometry based on a 1D AMR Model

The numerical geometrical configuration and cooling performances of parallel wire geometry have been investigated in one-dimensional active magnetic regenerator. Based on the actual regenerator, the wires in geometries were primarily arranged in square and triangular array, and worked in cross and parallel flow patterns. Regenerators containing wire bundles with three geometries were evaluated by varying utilization at fixed temperature spans between hot and cold reservoirs. The effects of geometrical parameters on heat transfer performance and friction factor of regenerator were firstly discussed here. Two materials, gadolinium and La(Fe,Mn,Si)₁₃H_y, have been used for simulating the cooling performance of wire geometry. The numerical results showed that the arrangement of wires did not have influence on the cooling power greatly and the wire geometry could provide a higher coefficient of performance in parallel flow. After optimization, the desirable parallel wire geometry had a porosity of 0.40 and wire diameter of 0.15 mm. When the frequency was 2 Hz and temperature span was 10 K, the maximum cooling power could reach 158.40 W and 100.3 W for Gd and La(Fe,Mn,Si)₁₃H_y wire geometries, whose coefficients of performance were as high as 13.46 and 14.96 respectively. Comparatively, the cooling powers of commonly used Gd and La(Fe,Mn,Si)₁₃H_y packed bed were one third lower than that of optimized wire geometry and the coefficients of performance were lower half.