高频微型非金属脉冲管制冷机轴向导热损失的计算分析

针对所开发的高频微型同轴非金属脉冲管制冷机进行了轴向导热损失的计算与分析,并与相同几何尺寸的金属脉冲管制冷机进行了比较。仅从降低轴向导热损失的角度讲,使用低导热率的非金属材料制作制冷机部件对制冷性能有较大的积极作用。对于2台实验样机而言,通过蓄冷器和脉冲管内的气体的轴向导热损失已经超出通过各自管壁的轴向导热而成为最大的导热损失项,但通过蓄冷填料的轴向导热损失却成为三项损失中一个可以忽略的小量,这是非金属脉冲管制冷机区别于相同几何尺寸的常规金属脉冲管制冷机的显著特点。

ANALYSIS AND CALCULATION OF AXIAL HEAT CONDUCTION LOSSES OF HIGH FREQUENCY MINIATURE CO-AXIAL NONMETALLIC PULSE TUBE CRYOCOOLERS

The axial heat conduction losses through the high frequency miniature co-axial nonmetallic pulse tube cryocoolers(PTCs)was analyzed and calculated.It compares with those through conventional metallic PTCs.The usage of nonmetallic materials with low heat conductivity is beneficial to a better performance provided that only the axial heat conduction losses are considered.For each of the two sample PTCs,the axial heat conduction loss through the gas in each tube exceeds that through the tube wall and thus becomes the biggest one,while that through regenerator matrix becomes neglectable.The characteristics mentioned above are remarkably different from those of conventional metallic PTCs with the same geometrical dimensions.