Numerical simulation of influencing factors on active magnetic regenerator with liquid hydrogen temperature range

Cryogenic and refrigeration technologies in the liquid hydrogen temperature range are critical refrigeration techniques in the fields of energy power, infrared detection, and scientific research. Due to its potential for high efficiency in the liquid hydrogen temperature range, magnetic refrigeration technology is expected to become one of the key refrigeration technologies in this temperature range. This study constructs a two-dimensional transient active magnetic regenerator simulation model in the liquid hydrogen temperature range based on the multiphysics simulation software COMSOL Multiphysics. For an AMR in liquid hydrogen temperature range magnetic refrigeration, this study analyzes the impact of particle diameter and timing between magnetic field and fluid flow on refrigeration performance, and assesses its cooling capacity from 20K to 30K using actual magnetocaloric materials. The refrigeration performance of the active magnetic regenerator filled with actual magnetocaloric materials in the temperature range of 20K to 30K is evaluated. The results indicate that the sensitivity of AMR refrigeration performance to particle diameter is greater than its sensitivity to the timing ratio as the specific surface area of the AMR decreases sharply by approximately to 1/8 when the particle diameter increases from 0.05 mm to 0.40 mm. This study provides theoretical guidance for understanding the performance characteristics of multi-stage magnetic refrigeration systems in the liquid hydrogen temperature range, as well as for the optimized design and performance evaluation of prototype.