小型室温磁制冷系统的改进及实验研究

基于先前报道的旋转内磁体式小型室温磁制冷系统,系统采用了新的双层同心嵌套式Halbach磁体组,开展了钆工质的制冷温跨与制冷量的实验研究。采用新的双层Halbach磁体组后,磁体组轴线处平均磁场强度由0.3?1.2 T提升至0.06?1.40T。在回热器两端绝热保温的工况下,采用新磁体组的系统在相似频率和利用系数下性能显著提升,并在1.25 Hz的运行频率下获得19.8K的制冷温跨。在系统引入高低温换热器的条件下,设定回热器高温端温度为27.5℃时,室温磁制冷机在7K制冷温跨下获得10W制冷量,工质比制冷量约47W·kg-1,并在1.7 K的制冷温跨下获得了50 W制冷量。

Experimental Researches on the Performance of a Rotary-type Magnetic Refrigerator With Modified Double-Halbach Permanent Magnet Arrays

A room-temperature rotary-type magnetic refrigerator based on previous experiences was designed and constructed with a modified double-Halbach permanent magnet arrays.The average magnetic field provided by the modified magnet system ranged from 0.06 T to 1.40 T in the center region of the inner bore.This was fairly superior to the average value of previous magnetic arrays,which ranged from 0.3 T to 1.2 T.A series of Gadolinium-experiments have been done to investigate the system performance including no-load temperature span and cooling power.The results show the refrigerator with modified magnetic field obtained the better cooling performance at similar operating frequencies and utilization factors,when both ends of regenerator were kept adiabatic without heat exchangers.And the maximum no-load temperature span of 19.8 K was achieved at 1.25 Hz.With the heat exchangers added(the hot end temperature kept at 27.5℃),10 W cooling power was obtained at 7 K temperature span,and the corresponding specific cooling power was about 47 W/kg.And the maximum cooling power of the measured is 50 W at 1.7 K temperature span.