LIQUID NITROGEN DISTRIBUTION SYSTEM USED IN CRYOGENIC EQUIPMENT

Liquid nitrogen distribution system includes forced circulation and gravity fed self-circulation(natural circulation)system.This paper focus on the performance and characteristics of gravity fed self-circulation(natural circulation)system.Liquid nitrogen system of natural circulation is stable and reliable,with low system consumption of liquid nitrogen and higher efficiency.It will reduce working temperature,it does not use liquid nitrogen pump and reduce valves used in system.Before designing the natural circulation system,thermal and hydraulic analysis of system need to be conducted.In the natural circulation system design.System of analysis and prediction is very important,because the analysis and verification to ensure the evaporation rate is not exceeded 10%anywhere in system.It can significantly reduce design risk.Liquid nitrogen system of natural circulation has been applied in a variety of cryogenic equipment.