用于低温设备的液氮分配系统

液氮分配系统中包括强制循环系统和重力输送自循环（自然循环）系统，重点介绍重力输送自循环（自然循环）液氮系统的性能和特点，分析出自然循环液氮系统是稳定、可靠、低液氮消耗和较高效率的系统。分配系统降低了工作温度，可以不用液氮泵，减少了系统中的阀门。设计自然循环系统前，要进行系统的热和液压分析，在自然循环系统设计中，系统的分析和预测是非常重要的，因为通过分析和验证才能保证系统内任何地方蒸发率都不超过10％，这可以明显减少设计风险。自然循环液氮系统已在多种低温设备中得到应用。

LIQUID NITROGEN DISTRIBUTION SYSTEM USED IN CRYOGENIC EQUIPMENT

Liquid nitrogen distribution system includes forced circulation and gravity fed self-circulation （ natural circu- lation } 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.