Temperature Profile and Mass Flow Rate Distributions in Regenerator of Gifford-McMahon Refrigerator Using Magnetic Regenerator Materials
Temperature Profile and Mass Flow Rate Distributions in Regenerator of Gifford-McMahon Refrigerator Using Magnetic Regenerator Materials
复制标题
使用磁性蓄热体材料的吉福德-麦克马洪冰箱蓄热体的温度分布和质量流量分布
DOI：
10.2221/jcsj.31.203
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
T. Hashimoto
中科院分区：
文献类型：
--
作者：
T. Kuriyama;Y. Ohtani;H. Nakagome;Masanori Yabuki;Hikaru Seshake;T. Hashimoto
两级GM制冷机通常用于许多低温系统中，例如低温泵和MRI。然而，常规GM制冷机的最低温度被限制在约10 K。最近，磁蓄冷材料，它具有更大的热容量低于10 K比传统的蓄冷材料的铅，使GM制冷机达到液氦的温度水平。在此温度范围内，GM制冷机中的氦气不能被视为理想气体。本研究旨在探讨一种以非理想氦气为工质之回热器。本文介绍了两级吉福德-麦克马洪（GM）制冷机回热器性能的实验研究结果。测量了再生器中的温度和压力，并根据这些数据计算了再生器中的质量流率。比较了理想气体操作和非理想气体操作时回热器内的温度分布、温度波动和质量流量。对于理想气体操作，温度分布是平滑的，并且在每个位置处的温度波动几乎相等。对于非理想气体操作，从热端到中间的蓄热室，观察到陡峭的温度梯度和大的温度波动，几乎覆盖了蓄热室的温差。从中间到冷端，温度梯度和温度波动都很小。理想气体操作的回热器中的质量流量从热端到冷端逐渐减小。对于非理想操作，质量流率增加。指出了理想气体操作再生器与非理想气体操作再生器的区别。
A two-stage GM cryocooler is commonly used in many cryogenic systems, such as a cryopump and an MRI. The lowest temperature for a conventional GM cryocooler, however, was limited to about 10K. Recently, magnetic regenerator materials, which have larger heat capacity below 10K than a conventional regenerator material of Pb, enable the GM refrigerator to achieve the liquid helium temperature level. In this temperature range, helium in the GM cryocooler cannot be regarded as an ideal gas. The purpose of this study is to investigate a regenerator, which is operated with non-ideal helium gas. The experimental results of the regenerator performance in a two-stage Gifford-McMahon (GM) cryocooler are described in this paper. Temperatures and pressure in the regenerator were measured and mass flow rate in the regenerator was calculated from these data. The temperature profile, temperature fluctuation and mass flow rate in the regenerator are compared between ideal gas operation and non-ideal gas operation. For ideal gas operation, the temperature profile was smooth and the temperature fluctuations at each positions are almost equal. For non-ideal gas operation, a steep temperature gradient and large temperature fluctuation, which almost covered the temperature difference of the regenerator were observed from the hot end to the middle of the regenerator. From the middle to the cold end, however, both the temperature gradient and the temperature fluctuation were very small. The mass flow rate in the regenerator for ideal gas operation decreased from the hot end to the cold end. For non-ideal operation, the mass flow rate increased. The difference between the regenerator for ideal gas operation and that for non-ideal gas operation was shown clearly.