变浓度精馏型自复叠制冷系统实验研究

Experimental Studies on an Variable Compositions Auto-Cascade Refrigerator Operating With a Rectifying Column

本文在传统自复叠制冷系统基础上，提出了一种变浓度精馏型自复叠制冷系统，并搭建了实验装置，进行了两组不同开机模式下的系统开机对比实验验证。实验结果表明，启用变浓度模块可使系统开机过程的排气温度下降10-30℃，排气压力下降0．4—1．1MPa，输入功率下降40％左右，避免了润滑油的碳化，保证了压缩机的正常平稳开机，并最后实现了-175℃的制冷温度。通过变浓度模块，可以使系统更自由地调节其参与实际循环的制冷剂的流量与成分，而且这种调节是可逆的。制冷温度越低，变浓度模块的效果越明显，变浓度运行方法特别适用于制冷温度低于-150℃以下的自复叠制冷系统。

This paper proposed a variable compositions auto-cascade refrigerator operating with a rectifying column based on the traditional auto-cascade refrigerator. An experimental rig was set up and experimental comparisons verifications have been conducted in two starting up modes. The experimental results show that the discharge temperature, discharge pressure and input power of the compressor is reduced by 10-30℃, 0.4-1.1 MPa and about 40% respectively when the variable composition regulation modules are used. It avoids the risk of lubricating oil carbonization and insures the normal start-up of the compressor to reach a low cold box temperature of -175℃. The compositions and flowrates of the refrigerants in the system can be regulated easily and reversibly by using variable composition regulation modules. The lower the refrigeration temperature is, the more obvious the benefit of the regulation is. It is especially suitable for the auto-cascade refrigeration system whose refrigeration temperature is below -150℃.