脉管制冷机层叠丝网填充回热器导热特性数值分析及优化

Numerical analysis on thermal conductivity characteristics of mesh screen filled regenerator for pulse tube cryocooler and its optimization

回热器为回热式低温制冷装置的关键部件,其性能直接影响到整机性能。对层叠丝网回热器的轴向导热损失进行了理论分析和数学建模,采用单一及不同目数金属丝网混填了单级脉管回热器,基于80K,50Hz的工况下,理论分析了不同目数层叠丝网混合填充时,配比组合参数对回热器轴向导热损失的影响。结果显示:层叠丝网所引起的轴向导热损失为回热器轴向导热损失的主要形式。研究表明,恰当的混填形式可以提高回热器性能。在此基础上提出了层叠丝网回热器填充配比优化方法。

As one key device of the pulse tuber cryocooler, the regenerator plays an important role on the thermal perform- ance of the whole system. The theoretical analysis and mathematical modeling on the axial heat conduction losses of mesh screen filled regenerator were done, and the regenerator models filed with single type mesh stacked screen and mixed ones were selected, under the condition 80K, 50Hz. The filled length of the mesh screen, as the influence factor of the axial conduction losses, was theoretically analyzed. The results show that, the appropriate mixed ratio of different mesh screens filled in regenerator can reduce the axial thermal conduction losses and improve the performance of the whole system. Optimization methods of the ideal ratio of different filled mesh screen were also put forward.