Comparison between the experimental researches of before and after improvements on hybrid magnetic refrigerator

The experimental prototype was improved based on hybrid magnetic refrigeration system in room temperature by rotating permanent magnets. Experimental tests were carried out to measure the cooling performance of this hybrid prototype. Improvement 1) Using regular gadolinium sheets instead of irregular gadolinium chips as regenerative matrix; 2) Laying out the electric motor from inside to outside; 3) Adding a thermal buffer tube between the cold heat exchanger and expansion chamber. The influence of operating frequency of oscillating gas on the cooling performance was investigated. Comparison was made between the experimental researches of before and after improvements on hybrid magnetic refrigerator with the experimental results. The experimental results show that after improving the system, the cooling performance of hybrid magnetic refrigerator was better than that before improvement under same experiment conditions. The lowest no load cooling temperature of -16.5°C and cooling power of 58 W over temperature span of 12.5 K were obtained.