What is the purpose of adding nitrogen to the mixed refrigerant?
Thread Content
The nitrogen concentration in the mixed refrigerant is 16%, the total pressure is 22 KG/CM², the temperature is -168 degrees, and the nitrogen partial pressure is 3.5 KG/CM². Under such conditions, liquefaction is impossible; no phase change occurs, and no cooling takes place. So what is the purpose then?
In mixed refrigerants, nitrogen contributes less to the cooling capacity, but it enables lower cooling temperatures； To reach the desired cooling temperature, nitrogen must be added. Furthermore, phase change is not necessarily required for cooling; a decrease in the pressure of a gaseous medium also absorbs heat.
I would like to ask how to calculate the partial pressure of a mixed refrigerant
Propane and isopentane are used for pre-cooling, ethylene for intermediate cooling, while methane and nitrogen are used for deep cooling; with more nitrogen, it’s Of course possible to lower the temperature in the cryogenic tank even further