Helium refrigerator uses a helium compressor to acquire high-pressure helium gases. Part of the high-pressure helium gases produces cold upon expansion in the turbo expander while the remaining high-pressure helium gases are cooled down stage by stage in the multi-stage heat exchangers. Finally, liquefied helium is acquired via a Joule Thomson throttling valve.

The liquefied helium is used to provide 4.5K constant-temperature cooling for user equipment and the evaporated helium gas returns back into the cold box of the refrigeration device for recycling purpose and such a refrigeration device is called helium refrigerator。

4.5K Helium Refrigerator

Specifications of  4.5K Helium Refrigerators

20K Helium Refrigerator

20K helium refrigerator adopts helium reverse turbine-Brayton cycle to realize the 20K Cooling. In a 20K helium refrigerator, the helium gas below 20K is used to provide cooling  for the user's equipment, and after cooling it returns to the cold box for the purpose of recovering the sensible heat and recycling. 

Main equipment of 20K helium refrigerator includes compressor, oil removal system, 20K cold box, control system, helium buffer tank, etc. The 20K cold box is a vacuum insulated cold box which contains the multi-stage heat exchangers, turbine expanders, internal adsorbers, cryogenic valves and measuring elements.

10kW@20K Helium Refrigerator