脉冲管制冷机在更高频率下运行能够大幅提高能量密度,有利于系统体积与质量的减小。据此本文开展了300Hz级超高频电驱动同轴脉冲管制冷机的研究。首先分析了直线压缩机与制冷机匹配特性,通过调节前腔体积,使得压缩机在280Hz附近谐振,并能够提供制冷机运行所需压比。实验中取得了最低无负荷冷头温度63.3K,在80K获得了1.0w的制冷量,消耗声功约为44w,以声功计算相对卡诺效率达到6.2%。实验中系统考察了整机性能随惯性管长度、运行频率和平均压力的变化趋势。
High frequency operation of pulse tube cooler driven by linear compressor could lead to a compacter system and a higher specific power. This article carried out the study of a coaxial pulse tube cryocooler driven by linear compressor. Firstly, the coupling characteristics between the compressor and cryocooler are analyzed. The resontant frequency was adjusted to 280 Hz by changing the front volume of the compressor, which was able to provide pressure ratio required. The cooler achieved a no-load cold-head temperature of 63.3 K and cooling power of 1.0 W at 77 K with an acoustic power consumption of about 44 W. Compared to the acoustic power, a relative Carnot emciency of 6.2% was acquired. The influence of different parameters such as inertance tube length, operating frequency and mean pressure were investigated experimentally.