Reheating issue of cold box refrigerant

Thread Content

The system I have here uses a mixed refrigerant for cooling (methane, ethylene, propane, isopentane, liquid nitrogen). During the production process, the liquid phase is pre-cooled to a temperature of -20°C, while the gas phase is cooled to around -115°C after deep cooling! But the temperature after the gas and liquid phases combine is only 15°C! The temperature of the materials and refrigerant entering the cold box is around 30°C! What methods are there to keep the temperature after mixing above 20°C? In my opinion, the reasons why the temperature doesn’t rise are as follows: 1. The circulation volume of the gaseous refrigerant is too high, which prevents the temperature in the pre-cooling stage from dropping; 2. There is an issue with the refrigerant mixture – I believe there are too many light components in the liquid phase (mainly propane, with less isopentane)